General Surgery

6 P's of an acutely ischaemic limb

pain, pallor, pulseless, paresthesia, paralysis, and poikilothermia (inability to regulate temperature) Paresthesia = changes in sensation tend to be lost early on. A paralysed limb represents an irreversible process of ischemia.

Cardiopulmonary bypass

"Heart-lung machine" Venous blood is pumped out into a oxygenator - bypassing cardiac chambers - into aorta Supplies circulation appropriate to physiologic needs Lung function = blood gas exchange, maintenance of acid-base balance, thermal exchange Allows induced cardiac arrest (cardioplegia) with maintained circulation to the rest of the body "Open heart" surgery = directing ALL venous return from the body to the pump and return to the arterial circulation with isolation of the heart from the circulation. Used for valve, congenital or other intra-cardiac surgery. NOT coronary surgery. Complications - Trauma to cardiac structures - Air embolism - Circulating blood element trauma (RBCs, platelets) - SIRS - Cerebral, pulmonary, renal and vascular damage

Microvascular complications of T2DM - What 3 factors predispose people to diabetic foot disease? - What complication is most common in diabetic smokers? - What arteries are most affected?

- Occlusive arterial disease, neuropathy, and increased risk of infection - Co-existent arterial disease with calcification of the tibial arteries - Infrapopliteal arteries are most affected with relative sparing of the intrinsic foot and digital vessels Autonomic neuropathy = shunting blood from capillary beds = relative tissue ischemia Neuropathy Retinopathy Nephropathy Micro-angiopathy = infra-popliteal vessels most severely affected

Ruptures AAA - 4 locations of rupture and their presentations? - Who is AAA more likely to rupture in? - Classic presenting triad? - What is permissive hypotension? - Risk of ruptus

- Rupture into extra/intraperitoneal = back pain, hypotension, collapse - Rupture into GI tract (aortoenteric fistula) = GI bleeding and collapse - Rupture into IVC or left renal vein (aortocaval fistula) = High output cardiac failure, and leg swelling - Rupture into ureter (aortouteric fistula) = presents with haematuria and shock - More likely to rupture in women than men - smokers - COPD - HTN - Rapid expansion rate - Pain - Hypotension/collapse - Tender pulsatile mass - Permissive hypotension is BP to maintain coronary and cerebral blood flow Saccular aneurysms more likely to rupture (compared to fusiform) - Laplace's law dictates that as diameter of aneurysm increases, so to does the risk of rupture Risk of rupture in next 12 months <5cm generally don't rupture (1%) 5-5.9cm 1-11% 6-6.9cm 10-22% >7cm 30-33%

Mx of acute perianal pain = thrombosed external haemorrhoid - Epidemiology of haemorrhoids

- haemorrhoids are common. 1/4 of the population are affected by symptoms at some point in their life - Aetiology = straining leads to elongation of submucosal vessels and stretching of submucosal attachments - Internal haemorrhoids = visceral sensation, covered by mucosa, arise above dentate line - External haemorrhoids = somatic sensation, arise below dentate line (painful), covered by skin - Categorisation of haemorrhoids = - 1st degree = bleed > rubber band ligation - 2nd degree = prolapse but reduce spontaneously > banding or excise a single pedicle - 3rd degree = prolapse and require manual reduction > treat with staple

Perioperative anticoagulants - Indications for anticoagulation: risk, reduction - 4 Anticoagulants mechanism of action: what are these measured by? What can they be reversed by? - When to stop anticoagulants before surgery?

1. Atrial Fibrillation: ® 3.5% risk per year in non-anticoagulated patient. ® Anticoagulation reduces risk by 68%. 2. Cardiac valve replacements: prevention of stroke/systemic embolism or valve thrombosis. ® 4% risk per year in non-anticoagulated patient. ® Anticoagulation reduces risk by 75%. ® Risk greater with mitral valve than aortic valve. 3. DVT/PE: anticoagulation can be temporary or lifelong, depending on preceding - indication - Warfarin inhibits Vit K-dependent clotting factors = II, VII, IX and X, and anticoagulant proteins C and S). Reversal by Vit K (takes >6 hours) or Prothrombin Complex Concentrate (immediate). - Unfractionated heparin - activates antithrombin (which inactivates thrombin [IIa] and Xa). Can be reversed by protamine, need monitoring APTT and for heparin-induced thrombocytopenia. - Enoxaparin & Dalteparin (LMWH): binds to antithrombin and creates a conformational change which accelerates its inhibitor of factor Xa in conversion of prothrombin to thrombin. - New oral anticoagulants (NOACs) = Direct thrombin inhibitor (dabigatran) prevent thrombin cleaving fibrinogen to fibrin. Direct factor Xa inhibitors (rivaroXaban) prevent Xa cleaving prothrombin to thrombin. Stopping anticoagulation prior to elective surgery Warfarin = 5 days Dabigatran = 24-96 hrs Rivaroxaban = 24-72 hrs

Triple assessment of a breast lump

1. CLINICAL Pt history and clinical breast exam 2. RADIOLOGICAL imaging - MMG +/- USS 3. PATHOLOGICAL non-excision biopsy: FNA or core biopsy ANY postitive = +ve ALL negative = -ve

Empiric Therapy 1. Definition 2. When not to use empirical therapy (instances of colonisation rather than Abx) 3. When to use empirical therapy UTI Pyelonephritis Intra-abdominal infections Skin infection w/ pus 4. Features of empiric therapy 5. What triple therapy is used for peritonitis?

1. use of antibiotics before the aetiology of the infection is known 2. a) URTIs b) blood cultures with coagulase -ve staph c) Urine cultures with numerous epithelial cells d) urine cultures from IDCs e) sputum cultures from patients with tracheostomy f) wound cultures g) infection control; - rectal swabs for VRE - nose swabs for MRSA h) Not usually in chronic infection 3. a) Fevers in neutropaenic patients b) Surgical wound infection c) pneumonia Trimethoprim Ampicillin and gentamicin (E.coli) Ticarcillin/Clavulanate Clindamycin or Cotrimoxazole (Staph. Aureus) 4. Broad, local epidemiology, patient specific microbial profile (antibiotic use, prior resistance, allergies, renal function) Peritonitis triple antibiotic therapy: 1. Ampicillin - covers enterococcus 2. Gentamicin - covers E. coli 3. Metronidazole - covers anaerobes.

Rule of 2's for Meckel's

2 feet proximal from ileocecal valve 2cm wide 2% of population

Assess depth and % burn surface areas - What is the 2 week rule? - 5 thicknesses of burns? - 5 parameters of thickness?

2 week rule = unhealed burn should be grafted to prevent hypertrophic scar.

Presentation of rectal prolapse

3 types: - Full-thickness - Mucosal - Internal (internal intussusception) Can prolapse after bowel motion and need to be manually replaced. Concentric folds differentiate from haemorrhoid 50% caused by chronic straining with defecation and constipation = pregnancy, surgery, COPD, BPH, pelvic floor disfunction, parasitic infections, neuro disorders, pertussis

Risk factors for colorectal cancer

3rd most common cancer, and 3rd most common cause of cancer mortality. Age is strongest risk factor (>60 yo) Family history Prior hx of colorectal cancer Long hx of IBD Genetic: FAP, polyposis syndromes, HNPCC Obesity Smoking Low fibre diet Sedentary lifestyle Adenoma - carcinoma sequence

Indications for adjuvant chemo in breast cancer

AIM = reduce micrometastases, prevent recurrence, improve survival ADJUVANT CHEMO Begin 4-6 weeks post surgery. Only in <75 yo, medically fit. Postoperative chemo is guided by pt clinical status and tumour characteristics: - Pt should receive if they did not receive neoadjuvant therapy - Pt who did receive neoadjuvant therapy and have hormone receptor + - Pt treated with neoadjuvant endocrine therapy who undergo surgery should continue adjuvant endocrine therapy

Indications for endocrine therapy in breast cancer

AIM = reduce micrometastases, prevent recurrence, improve survival ENDOCRINE THERAPY Oestrogen stimulates breast cancer cell growth in ER+ Postmenopausal = >60, oophorectomy, amenorrhea for 12 months + estradiol in range, amenorrhea on tamoxifen and FSH/estradiol are in range - Aromatase inhibitor (AI) ~ which inhibits oestrogen synthesis within the breast cancer. Prescribed for 5-10 years. - Tamoxifen ~ (NSAID with oestrogen antagonist in breast tissue) - partial oestrogen agonist effect. Prescribed for 5 years. Premenopausal - High risk features = ovarian suppression + exemestane - Not at high risk = tamoxifen for 5 years Ovarian suppression/ablation = oophorectomy, pelvic radiation

Indications for radiotherapy in breast cancer

AIM = reduce micrometastases, prevent recurrence, improve survival RADIOTHERAPY 45-50 Gy in 25 fractions ~ 5 days per week for 5 weeks Primary field = breast or chest wall ~ depends on surgical approach - BCT = usually whole breast radiation therapy (WBRT) - Masectomy = less evidence for WBRT, but still a role. Regional field = axilla +/- supra/infraclavicular, internal mammary regions ~ depends on no. of nodes. 3+ nodes = definitely regional RT Radiation therapy boost to the tumour bed = intends to decrease recurrence Accelerated partial breast irradiation (APBI) = limited, focused RT - less evidence. SE = sun burning, fatigue, rare/long term = radiation-induced angiosarcoma Contraindications: previous RT, scleroderma, pregnancy, can't abduct shoulder

Clinical manifestations of AAA - What is the definition of AAA - What is the common sight? - Who is affected by AAA? - Who is AAA rare in? - How do the majority of AAA present? - How regularly are AAA palpable? - What 5 signs and symptoms of symptomatic AAA?

Abdominal aorta >3cm 80% infrarenal aorta (less collagen in this area) Male:female 4:1 More in white males Rare <50 years 5-10% elderly males have a AAA ?Recent decline in overal incidence 80% asymptomatic 75% of AAA >5cm are palpable Incidental finding Symptomatic Presentation Enlarging aneurysms can be tender Erosion into adjacent structures = pain Compression of adjacent structures: ureter, duodenum, nerves Embolisation Thrombosis Clinical Exam. - Check BP and all pulses - Palpate aorta: Tenderness usually = imminent rupture - Size aneurysm - Palpate for aneurysms elsewhere Rupture - Intraperitoneal = "classic triad" pain (abdo, flank, black - can radiate), hypotension and collapse - Aortoenteric = GI bleeding and collapse - Aorticaval fistula ~ into IVC or renal vein = cardiac failure, leg swelling - Aortoureteric fistula = haematuria and shock

Cushing's tumour vs Conn's syndrome vs phaeochromocytoma - What is the Adrenal incidentaloma? - What percentage are functional? - A tumour in each location would produce what syndrome? - How are non-functional tumours generally treated? - How are functional tumours generally treated? - What is a andrenocortical carcinoma? - How often are these tumours functional? - How does these usually present? - What is Cushing's syndrome? - How often is there a malignant cause? - 6 signs and symptoms of the disease? - What percentage have an adrenal cause? - What test can be done to diagnose this syndrome? - What is Conn's syndrome? - How often is this benign? - What will potassium and renal function appear as? - What are the 6 signs and symptoms? - What are the two major causative tumours? - How often are sex hormone secreting tumours malignant? - What do these tumours lead to systemically? - What test can be done to identify this abnormality? - What is a phaeochromocytoma? - What cells make up this tumour? - What 3 catecholamines are released by this tumour? - What is the patients BP usually found at? - When can this tumour present? - 6 signs and symptoms at presentation? - What percentage of HTN patients have a phaechromocytoma? - What percentage of cases are asymptomatic? - What percentage are malignant? - what percentage are bilateral? - What might a malignant tumour invade? - What 3 genetic links does this tumour have? - What blockades are required prior to surgery? - Stepwise approach to testing?

Adrenocortical Adenoma Functional tumours = secreting hormones (15%) = adrenalectomy Glomerulosa = Conn's syndrome (Aldosterone) Fasuculata = Cushing's (Cortisol) Reticularis = virilisation or feminization (sex steroids) - Non-functional tumours are generally require no intervention - Functional tumours generally require andrenalectomy Adrenocortical carcinoma (rare, highly aggressive) often functional (60%-70%). Associated with Lynch and Li Fraumeni - Often present late with varicocele/flank mass/metastases Conn's = aldosterone secreting tumour - HTN, headaches and hypokalaemia - 70% adrenal adenoma, 30% adrenal micronodular hyperplasia - Low K+ with normal renal function Cushing's = cortisol secreting tumour - Weight gain, 'moon-like' faces, buffalo hump, thin skin, striae, muscle wasting - 10% adrenal tumour, 65% ACTH producing pituitary adenoma, 25% paraneoplastic ACTH - Dexamethasone suppression test - Sex hormone secreting tumours malignant 50% of the time - Virilisation and Feminisation - Serum DHEA test Phaeo - Chromaffin cells of medulla - Adrenaline, noradrenaline, and dopamine - Usually hypertensive - Episodic palpitations, headaches, sweating, tremors, anxiety, and weight loss - 0.5% of HTN patients have a phaeochromocytome - 1/3 of phaeochromocytoma are asymptomatic - Majority benign, 10% malignant - Majority unilateral, 10% bilateral - Malignant tumours can grow along the renal/adrenal vein and invade the IVC - Associated with MENIIa/Neurofibromatosis type 1/Von Hippel Lindau Syndrome MIBG scan = concentrates in adrenal if + - Suppress prior to surgery = alpha blockade - 2 weeks prior with liberal salt and water until nasal stuffiness (phenoxybenzamine), beta blockade for HR Similar to paragangliomas (tumour of sympathetic NS) - Metanephrines > 24hr catecholamines > MIBG scan > CT/MRI

Explain the cryptoglandular theory of perianal abscess development - Where are anal crypts found? - How do they develop sepsis? - 4 potential spaces for anal abscess? - List types of fistula in order of incidence? - What disease states may lead to fistula?

Anal crypt gland extend to dentate line. When they're blocked/infected they develop sepsis, which spreads between/through/above sphincters. Potential spaces = Supralevator, interspincteric, perianal, submucosal, ischioanal Types of fistulae: ITSE interspincteric (70%), transsphincteric (23%), suprasphincteric (5%), extraspincteric (5%) - Crohn's - HIV - Haematological conditions - Malignancy Mx - Fistulotomy - Fistulectomy - Flaps (low incontinence rate) - LIFT - Fibrin glue (low incontinence rate)

Salmon-Goodsall rule

Anterior-opening fistulas tend to follow a simple, direct course - while posterior-opening fistulas may follow a devious curving path with some being even horse-shoe shaped before opening in the posterior midline

Perioperative antiplatelets - 2 indications for antiplatelet use? - 2 antiplatelets? Their uses? and their MOA? - Reversal agents? - When to stop before surgery? - How long should stent surgery be deferred?

Antiplatelets = IHD, ACS, Cardiac stents - Aspirin. primarily given as a preventer of cardiovascular and cerebrovascular accidents Blocks COX = blocks thromboxane A2 (platelet aggregation stimulator) forming from AA - Clopidogrel: given as a replacement for aspirin or as a combination antiplatelet with aspirin inhibits PSY12 (ADP receptor on platelet membrane) Stopped 7-10 days prior to surgery. No reversal agents (transfusion). - bare metal stent = 6 weeks - 3 months - DES = 12 months (after 12 months surgery can be performed with continuation of aspirin)

Benign nipple discharge

Benign "galactorrhea" = nonpathologic nipple discharge unrelated to pregnancy or breast feeding. *Usually* bilateral and white/clear. Most often caused by hyperprolactinaemia, secondary to: - drugs (cause lactotroph stimulation or inhibit dopamine) - endocrine tumours (pituitary adenoma) - endocrine anomalies - other medical conditions - neurogenic stimulation (chronic breast stimulation, post thoracotomy syndrome) Often milky discharge from multiple ducts after massage.

Pathogen directed antibiotic therapy - 3 questions to ask yourself in considering resistance? - Two ways of killing bacteria = a) Concentration dependent b) Time dependent

Best guess antibiotic profile; -What antibiotics has the patient used in the past? -What has the patient been resistant to previously? -Likely resistance in geographical area? Concentration dependent - Maximal killing at maximal concentrations - Upper limit is capped by limit that will cause toxicity Time dependent - Do not get better at higher concentrations - Very important to have long time at MIC = minimal inhibitory concentration - Give ABx every 6hrs to keep blood levels at MIC

Anatomy of breast including blood supply and lymphatic drainage - Boundaries of breast - Define retromammary space and what it contains - What are the Ligaments of Cooper? - 3 tissue types - 4 branches of blood supply - 3 sites of lymphatic drainage - 3 levels of lymph nodes - 4 nerves

Between subcut tissue and superficial pectoral fascia. Between breast and pec major is retromammary space (which contains thin layer of loose areolar tissue with lymphatics and small vessels) Suspensory ligaments of Cooper provide structural support 3 tissue types - Glandular epithelium (surrounded by myoepithelium and basement membrane) - Fibrous stroma and supporting structures - Fat Terminal lobules > terminal ductules/acini > arborising tree of branching ducts > subareolar ducts > lactiferous sinuses (10-15) > nipple Blood supply = internal thoracic (2nd and 3rd intercostal spaces), lateral thoracic, perforating branches from intercostal arteries, pectoral branches of thoracoacromial artery Lymphatic drainage = axillary, internal thoracic (medial breast) and supraclavicular LNs. 3 levels of LNs I. Lateral to pec minor II. Posterior to pec minor III. Medial to pec minor Nerves - Long thoracic = winged scapula deformity - Thoracodorsal - Medial pectoral - Brachial cutaneous nerves (sensory intercostal brachial)

What is meant by the term "field change"

Biological process in which large areas of cells at a tissue surface are affected by carcinogenic alteration. Urothelium undergoes widespread change due to exposure to a carcinogen - making it more sensitive to malignant transformation. Therefore multiple tumours arise more easily.

Pathological features of DCIS - Where do most tumours arise from? - What is DCIS characterised by? - Where is it confined to? - What does this mean for spread of disease? - What is the hallmark on mammography and pathology? - What are the four types of DCIS? - What is the treatment for DCIS? - What is the prognostic tool used for DCIS? - Risk of invasive cancer on recurrence? - Four types of invasive ductal carcinomas?

Breast cancers can be invasive or non-invasive (in situ) and ductal or lobular. Most tumours arise from the terminal ductules, with mixed features of ductal and lobular components. Special types of invasive cancers include medullary, tubular, mucoid and inflammatory cancer. Ductal Carcinoma in Situ (DCIS) is pre-invasive breast cancer characterised by proliferation of malignant breast epithelium confined to the duct basement membrane (therefore cannot access lymphatics and blood vessels). - Calcium deposited within the ducts gives risk to the hallmark microcalcifications on mammography. Types = solid, comedo, papillary, micropapillary - Wide local excision with clear margins - Van Nuys Prognostic Index (Size, Margin, Pathology) - Wide local excision - WLE + Radiotherapy - Mastectomy - 50% Invasive ductal carcinoma refers to cancer which has invaded the basement membrane of the duct and invaded the surrounding tissue. Special types exist, including medullary, tubular, mucoid and inflammatory cancer.

Indications for masectomy

Breast conservation is contradicted or unsuccessful - Multicentric dx with 2+ primaries in separate quadrants - Diffuse malignant microcalcifications - Hx of radiation that included portion of affected breast, which + more radition would result in excessive total radiation to chest wall - Pregnancy - Persistent positive resection margins after reasonable attempts at reexcision - Relatively large tumour Patient choice Prophylaxis - Hereditary breast and ovarian syndrome (BRCA1 and BRCA2)

Workup and interventions for CAD

CAD presentation: angina, MI, HF, AF Indications for intervention: failed medical control, likelihood of catastrophic event (infarction), mechanical complications of infarction (rupture) Three systems of arteries = LAD, circumflex, right coronary Classification as single/double/triple dx applies to how many systems, NOT how many grafts Gold standard diagnosis = coronary angiogram Interventions: Lytic therapy Intra-coronary stenting and endovascular procedures = atherectomy Coronary bypass (CABG): conduits = internal mammary artery, saphenous or cephalic vein, radial artery, other e.g. gastro-epiploic

Adrenocortical insufficiency

Chronic = Addison's disease AI destruction Acute = crisis produced by inadequate glucocorticoid during acute stress/Rapid withdrawal of gluccocorticoid therapy/Waterhouse-Friderichsen syndrome

How to perform and interpret ABI? - Where to measure? - How to calculate? - Normal range? - Range indicative of PAD? - Range >1.2? - Symptoms of ABI <0.3?

Compared to the arm, lower blood pressure in the leg is an indication of blocked arteries due to peripheral artery disease (PAD). The ABI is calculated by dividing the systolic blood pressure at the ankle (highest pressure in DP or PT) by the systolic blood pressure in the arm (brachial pressure). Pt must be supine. You need a doppler and a BP cuff (usually a bigger one for the ankle, as the arteries are deeper and covered with muscle). Between 0.9 and 1.2 is considered normal (free from significant PAD), while a lesser than 0.9 indicates arterial disease. A value of 1.3 or greater is also considered abnormal, and suggests calcification of the walls of the arteries and incompressible vessels, reflecting severe peripheral vascular disease. <0.3 rest pain and tissue loss

Indications and types of cardiac pacemakers

Components Pulse generator and lead(s) - Awareness of interference with diathermy - Cannot have MI Bradycardia - Single chamber (VVI) - Dual chamber (DDD) = lead in atrium and ventricle. Can control atrio-ventrical synchrony. No use in AF. Tachycardia (AICD) - Cardioverter - VT - Defibrillator - VF Heart failure (triple chamber) Cardiac resynchronisation therapy (CRT) - lead in RV, LV and coronary sinus. Synchronise ventricular contractions.

Embryology of midgut

Connection to yolk sac (vitelline duct). Gut tube extends out into vitelline duct. Top part shifts to right and curls into small intestine (which then goes out of vitelline duct over the top of the bottom part. Bottom part buds off appendix and travels down to RLQ = colon. Midgut is supplied by superior mesenteric artery. Hindgut is supplied by inferior mesenteric artery.

Initial fluid mx for burns patient

Considerations 1. Increased cap permeability (histamine, serotonin, PGs, bradykinin, thromboxanes, angiotensin) 2. increased cap perfusion pressure 3. increased interstitial colloid oncotic pressure 4. decrease intravascular colloid oncotic pressure 5. loss of skin as a barrier to external fluid loss 6. decrease in function of Na/K pump with influx of sodium and water into the cell 3ml/kg/%

Pathological features and clinical presentation of Crohn's disease

Crohn's: Chronic transmural inflammatory process. Mouth to anus. Typically ileal, ileo-colonic, colonic. Associated perianal disease 4-80% prevalence. Fissures common (painless), no increase in resting anal sphincter. Skin tags are a results of lymphoedema. Cavitating ulcers are rare. Abscess and fistula are common (require drainage, control of proctitis, surgery). Increased with proctitis. Ano-rectal stricture. Extraintestinal manifestations Granulomas on histology. Presentation depends on segment of gut. >50% perianal. 30-50% small and large bowel. Investigations = CT, colonoscopy. Fat stranding. Tx = steroids, Abs, thiopurines, cyclosporin A, biologics (infliximab, adalimumab). Surgery = acute abdomen, perforation. ?obstruction ?fistula ?haemorrage. Ileocolic resection Proctocolectomy and ileostomy.

Different types of IV fluids and how to document a fluid order

Crystalloids = Hartmann's, normal saline, 4% dextose + 1/5 saline, 5% dextrose Colloids = Human ~ albumex 4 (40g albumin + saline), albumex 20 (200g albumin + saline); synthetic ~ gelofusine (gelatin + saline), volvulen (hydroxyethyl starch + saline) Crystalloids most oftenly prescribed. Saline induces a mild metabolic acidosis. Kidneys should compensate. K (20mmol) can be administered (generally not needed in first 2 days). Need 40-60mmol/day. 20-40mmol per 1L crystalloid. Dextrose tends to cause fluid overload and hyponatremia Albumex only used for albumin replacement (<20) Gelofusine / Volvulen = intended to maintain intravascular volume (e.g. in acute stress, sepsis, bleeding). Should be avoided outside of OT/ICU setting.

Radiological features of DCIS

DCIS is associated with microcalcification on mammography. Calcification deposited within ducts gives rise to DCIS - MMG = mass, spiculation, distortion, microcalcification - USS = mass, solid, hypoechoic, infiltration of surrounding tissues, microcalcification

Mx of acute perianal pain = anal fissure - Definition: extension, locations - Aetiology - Symptoms - Treatment - principal aim - Conservative management: medications, diet, healing rate, recurrence rate - Surgical Management: what procedure to use and when to use? what is the aim of the procedure and what does it involve? What post operative care is required and what is the complication rate? - 4 causes of secondary fissure?

Definition: An anal fissure is a linear tear or superficial ulcer of the anal canal, extending from just below the dentate line to the anal margin. It usually occurs in the midline posteriorly, or sometimes anteriorly in females, particularly after a pregnancy. Aetiology: Although the precise aetiology is unknown, it is usually related to constipation and trauma to the anal canal from a hard stool. Hypertonia of the internal anal sphincter with an associated raised anal resting pressure is common. Symptoms: The cardinal symptoms are severe anal pain during and immediately after defecation and anal outlet bleeding. The pain is so intense that the patient is afraid of and consequently avoids opening the bowels. The pain has been attributed to spasm of the internal sphincter. Treatment: The principal aim is to relax the internal sphincter, thereby relieving pain (which is due to spasm of that sphincter). Conservative = Conservative treatment includes the application of topical anaesthetic and hydrocortisone ointment, and a high-fibre diet to increase stool bulk (so that the stool itself dilates the sphincter). The complete healing rate is about 50% after 4 weeks of treatment. ***Recurrence rate is high, at about 25%. Glycerine trinitrate paste (0.2%) is effective in up to 50% of patients by relaxing the internal sphincter; however, the recurrence rate is high. ***It may also cause severe headache. More recent examples of chemical sphincterotomy include the use of calcium channel blockers and botulinum toxin. Surgical Management: Lateral internal anal sphincterotomy is the procedure of choice for chronic anal fissure or an acute fissure that remains severely symptomatic after a prolonged course of non-operative measures. V to Y flap repair in pregnant women (low pressure fissure) The aim of surgery is to break the vicious cycle of internal sphincter spasm. The distal internal sphincter, up to but not above the dentate line, is divided under anaesthesia. This procedure offers almost immediate relief of pain. The large sentinel skin tag and hypertrophied anal papilla are excised. After sphincterotomy, the patient should be put on a high-fibre diet. The recurrence rate is less than 3%. Some minor impairment of control of flatus occurs in up to 10% of patients but major faecal soiling is rare. In this regard, sphincterotomy performed through the base of the fissure is best avoided. Can be secondary to Crohn's, SCC, infection, trauma. Primary fissures associated with sphincter spasm and increased resting tone. Mx: analgesia, stool softener, GTN ointment, diltiazen ointment, botox Surgery: lateral internal sphincterotomy (historical), V to Y flab repair.

Aetiology and pathogenesis of arterial aneurysm - What are the main aetiologies for aneurysm? - What are the main risk factors for AAA (8)?

Degenerative - Atherosclerosis - 60% in the abdominal aorta - Most commonly infra-renal - 40% in the thoracic aorta Connective tissue diseases - Marfan's - Ehler's Danlos (collagen) Post-dissection Fibromuscular dysplasia Vasculitis Infection (mycotic: SBE, syphilis) Trauma Post-surgical false aneurysms Polycystic kidney disease Post-stenotic (coarctation, entrapments) Anomalous vessels (Right SCA, persistent sciatic) High-flow states (AVMs, fistulae, pregnancy) Congenital (tuberous sclerosis) Risk factors of AAA - Old - Male - Smoking - COPD - HTN - Hypercholesterolaemia - Atherosclerosis - Negative association with DM Exact pathogenesis ?? Genetic / foetal origin Anatomic Haemodynamics Systemic arteriomegaly Inflammation Proteolysis Apoptosis Angiogenesis Oxidative stress Infection Autoimmunity

Gynaecomastia

Hypertrophy of breast tissue in men Physiological - neonatal - puberty - senescence Decreased androgens - Klinefelter's - Bilateral cryptochordism - Hyperprolactinaemia - Renal failure Increased oestrogens - Testicular tumours - Lung cancer - Thyrotoxicosis - Adrenal/liver disease Drugs ETOH, marijuana, anabolic steroids, heroin, antiandrogens, spironolactone, TCA's, ranitidine, omeprazole Examine chest wall and testicles MMG / USS +/- FNA aFP, bHCG, prolactin, testosterone 80% of pubertal gynaecomastic will settle Medical tx = tamoxifen / danazol Surgical tx = subcutaneous mastectomy

Hypokalaemia - limits - Causes - How to correct?

Hypokalaemia K <3.5mmol/l Abnormal losses: GIT, renal (diabetic ketoacidosis), drugs (diuretics), Conn's syndrome Correct slowly! 20-40mmol per 1L of crystalloids

Open, endovascular and non-operative options for aneurysm treatment - What is EVAR? - How common is EVAR? - What are difficulties posed to EVAR procedure? - What is the mortality rate? - What role does surveillance play and how often should these be checked? - What is the most common type of endoleak? - Benefits of open repair? - What is hardman criteria?

EVAR is insertion of an aortic graft via a catheter through the femoral artery - More common - Requires more than 2.5cm of normal aorta below the renal arteries to ensure graft is able to be fixed in place - Tortuous/calcified/narrow arteries pose difficulties - EVAR has a lower mortality rate than open repair Standard treatment is surveillance 3-3.9cm USS every 2 years 4-4.5cm USS every year 4.5-5cm USS every 6 mo >5cm USS every 3 mo (CT with contrast = CTA, including chest) Repair 5-5.5cm in males, 5cm in females 2/3 die at time of AAA rupture 25-50% of those who reach hospital die in hospital Overall survival of 1/6 Elective repair 1-5% - Rupture 85% Open: graft (Dacron tube). 5-10 day hospital stay. - Less graft related repair - Equivalent quality of life and mortality at 1 year - Appropriate for thoracoabdominal aneurysms Endoleak = most commonly from branch vessel of the mesenteric or lumbar arteries that continue to flow into the aneurysmal sac and may cause rupture Endovascular: through femoral arteries, grafts are feeded through. Risk of endoleak (blood continues to flow out of sack into aneurysm) - can occur at attachment site (type I), branch vessel (type II - COMMON), disarticulation (tube III), or porosity of graft (type IV) Non-repair: Not suitable for those meeting Hardman criteria = age >76 years, ECG ischaemia, ALOC, Hb <90, creatinine >0.19mmol/L (score 3-5 = 100% mortality)

Paget's disease of the nipple

Eczematous, scaling, tichy nipple change Usually seen in older women Often associated with underlying ductal adenocarcinoma ~ represents intradermal carcinomatous spread Underlying mass may not be palpable Histologically has large clear Paget's cells in the epidermis Differentiate from eczema ~ confirm with biopsy Standard tx is mastectomy, though excision of the nipple areolar complex + breast RT Because of risk of underlying invasive cancer - SNB +/- axillary dissection is recommended

Escharotomy for circumferential burns

Eschar = thick, leathery, full thickness burn due (coagulative necrosis) Indications - Limb feels tight - Nearly or fully circumferential full thickness burn Usually prophylactic ~ before compartment sydnrome 5 P's occur late Only extends to subcutaneous fat

Spectrum of fibroepithelial lesions (fibroadenoma and Phyllodes tumour) - How common is fibroadenoma? - What age do they present? - How do they present? - How does fibroadenoma appear on USS? - What Mx of Fibroadenoma exists? - What categorisation exists for phyllodes tumour? - When do these tumours present? - How do these tumours present? - How do they spread? and how often? - How are these treated? - How common is recurrence?

Fibroadenoma is most common lesion of breast. Freq multiple and bilateral. Develop from intralobular stroma. Firm but highly mobile. Seen 15-35 years. USS = hypoechocia, ovoid, wider-than-tall, well defined. - If <25 lump be left alone - If older, consider FNAC or removal Phyllodes tumour Can be benign (80%), boderline or malignant. Leaf-like histology 2.5% of fibroepithelial lesions. Arise from intralobular stroma Seen 40-50 years. Grow rapidly, causing distortion, cutaneous venous engorgement and may ulcerate. Mets <5% but up to 25% if malignant = haematogenous spread ~ often in lungs Excision with a margin.

What is the embryology of the foregut?

Foregut tube gives off respiratory, hepatic, ventral pancreas and dorsal pancreatic buds. Attached to dorsal and ventral mesogastrium (greater and lesser omentum) Shimmy's to the left (dorsal = behind stomach; ventral = top of stomach) Spleen develops in dorsal mesogastrium Liver develops in ventral mesogastrium = and grows massively to obliterate peritoneum at the back of adbo = this creates the lesser sac behind the stomach Lesser omentum (connecting liver and stomach) ends at the foregut Greater omentum continues to grow over the transverse colon, and joins with transverse mesocolon

External signs of trauma that may indicate splenic injury and investigations required - What concomitant injuries are seen in the chest? - What concomitant injuries are seen in the abdomen? - What investigations may be conducted?

Generalised abdo pain = intraperitoneal blood LUQ or hypogastric pain Left shoulder tenderness (subdiaphragmatic nerve root irritation) Abdominal distention Signs of shock = hypotension, tachy, SOB, restlessness, anxiety, pallor, decreased cap refill, decreased pulse pressure Often due to blow to L lower ribs Concomitant chest injuries: fractured ribs, pneumothorax, lung contusions, diaphragm rupture Concomitant abdo injuries: left kidney laceration, bowel rupture Investigations FAST (focussed assessment with sonography for trauma) scan = four areas for free fluid = Morison's pouch (hepatorenal recess), perisplenic space, pericardium and pelvis Interventional radiology Exploratory laparotomy CT

Electrical and hydrofluoric acid burns

HF doesn't cause coagulative necrosis (unlike other acids) - causes liquefactive necrosis. Fluoride ions penetrate and form insoluble salts with Ca and Mg = hypocalcaemia, hypomagnasaemia, arrhythmias and death Debride blisters and irrigate for 30 min Neutralise fluoride with calcium gluconate with DMSO in lubricant jelly Hexafluorine solution a newer option May require ICU and calcium/magnesium replacement Electrical burns Low voltage <1000V (car batteries). = local entrance/exit wound. High voltage >1000V (AC: power lines/transformers, DC: lightning) - rarely only flashover - full thickness entrance/exit wounds - extensive deep tissue damage - arrhythmias - rhabdo - comparment syndrome = fasciotomy Severity proportional to voltage, current and duration Haemochromogenuria (haem in urine) = increased fluids

Complications of Meckel's - What percentage of cases contain heterotopic epithelium? - Who are usually symptomatic? - Where might the epithelium be from? - Where do gastric ulcer symptoms occur? - What are the 5 major complications? - Where are symptoms of peptic ulcer normally felt?

In 20% of cases, the mucosa contains heterotopic epithelium of gastric, colonic or pancreatic origin. Symptomatic cases are usually males. Bleeding peptic ulceration adjacent to ectopic gastric epithelium is found. This usually occurs in young patients. Small bowel obstruction due to intussusception may occur. The apex of intussusception is usually the in- flamed heterotopic tissue at the mouth of the diverticulum. - Obstruction of the small bowel may also be caused by the presence of a band between the apex of the diverticulum and the umbilicus, causing kinking or volvulus. Meckel's diverticulitis is usually due to lodgement of enteroliths or a sharp foreign body in the diverticulum, or narrowing of the mouth of the diverticulum. - The clinical features are similar to appendicitis. Perforation may occur, causing generalised peritonitis. Gastric heterotopia may cause peptic ulcer-like symptoms, with meal-related pain around the umbilicus because of its mid-gut location.

Differences in burns dressings - Flamazine should not be used in which 6 clinical settings? - When is flamazine good to use? - Acticoat is reliant on what 2 factors? - How does Mepilex Ag work? - What needs to be applied to Mepilex Ag?

Initial = gladwrap. Flamazine/melolin if transfer time >6 hours Flamazine NOT in infants, pregnancy, lactation, sulfur allergy, G6-PD deficiency, face (can cause keratitis) GOOD perineal/buttock burns, immediate transfers Acticoat Reliant on patient compliance vital to keep moist. Mepilex Ag Foam secretes silver. Most comfortable and easiest. Needs overlying compression to keep applied to wound

Management of urothelial tumours

Investigations - Urine cytology - CT IVP (Upper tract) - Flexible cystoscopy (Lower tract) - Mets = LFTs, CT, bone scan - Histology T1 = subepithelial Ta = urothelium Tis = carcinoma in situ T2 = muscle T3 = perivesical fat T4 = beyond bladder Non muscle invasive bladder cancer: - Transurethral resection of bladder tumour (TURBT) - Low grade = intravesical chemo (mitomycin C) - High grade / CIS disease = intravesical BCG immunotherapy Muscle invasive bladder cancer - Radical cystectomy - Radiotherapy F/U Serveillance flexible cystoscopies Urine cytology

Local and systemic response to minor and major burns

Jackson's burn wound model - Zone of coagulation (central) - Zone of stasis - Zone of hyperaemia Want zone of stasis to recover. General = SIRS Seen in >20% TBSA ~ proportional to burn depth Resp = bronchoconstriction (ARDS) Metabolic = basal metabolic rate increased x3 (due to catabolic hormones - adrenaline, cortisol and glucagon. Temp set-point raised. Need to keep pt warn and close wound. Severe catabolic state). Immune = reduced CVS = reduced motility; increased cap permeability; peripheral and splanchnic vasoconstriction Skin regeneration Epidermal keratinocytes replenished from appendages = hair sheath cells, bulge stem cells, basaloid cells of sebacious glands.

Venous drainage of left and right adrenal glands

L = renal vein R = IVC Arterial = aorta, renals and inferior phrenics

Macrovascular complications of T2DM

Large vessel atherosclerosis = CAD, CVD, PVD Glycosolation of vascular BM and HDL, dyslipidaemia

Should you continue/stop antithrombotic agents perioperatively?

Low risk of bleeding in operation = continue warfarin if INR in range. Intermediate risk of bleeding in operation = assess thrombotic risk: - Low: stop warfarin 4-5 days prior to surgery. Use prophylactic dose of LMWH. Restart warfarin on day of procedure. - Med: stop warfarin 4-5 days prior to surgery. Use prophylactic dose of LMWH 2 days before surgery - stop before surgery. Restart warfarin on day of procedure. Restart LMWH once haemostasis is adequate. - High: stop warfarin 4-5 days prior to surgery. Use treatment dose of LMWH 2 days before surgery - stop 24hrs before surgery. Restart warfarin on evening of day of procedure. Restart LMWH when haemostasis is adequate. High risk of bleeding in operation Stop warfarin 4-5 days prior to surgery. Use treatment dose of LMWH 2 days before surgery - stop 24hrs before surgery. Start IV unfractionated heparin on day before surgery - stop 6 hours before surgery. Restart warfarin on evening of day of procedure. Restart unfractionated heparin when haemostasis is adequate.

Antibiotic prophylaxis - When is best to give Abx? - Which Abx is used and why? - When do we use vancomycin? - What should be used in GI surgery? - What other 2 uses do prophylactic abx have?

Lowest infection rate = Abs 60min before incision 1st gen cephalosporins e.g. cephazolin 1g - Less allergy than penicillins - Strep and staph Vancomycin - Known MRSA - Re-do procedure - Hypersensitive to penicillins/cephalosporins GI tract surgery Need anaerobe coverage Cephazolin + metronidazole OR Cefoxitin (2nd gen cephalosporin) 1. In patients with ascites to prevent spontaneous bacterial peritonitis 2. In immunocompromised patients to prevent: • Pneumocystis carinii pneumonia • Cytomegalovirus • Fungal infections

Breast screening

Majority of breast cancers are asymptomatic and clinically impalpable BreastScreen targets women 50-75, but accepts women from 40 yo = screened every 2 years MMG with MLO and CC views read by 2 independent clinicians Any suspicious microcalcification or lesion is subject to further MMG and USS +/- biopsy

Types of burns in paeds vs adult

Males:Female 2:1 Children = scalds more common. 13-24 months most common age. Adults = flames more common. 20-29 years most common age. Contact burns least common. Paeds: scald (55%), contact (21%), flame (11%), friction (9%) > chemical, radiation, electrical, other Adult: flame (46%), scald (28%), contact (13%), chemical (6%), > friction, radiation, electrical, other Place of injury most is commonly home for both paeds and adult. Children = residence of friend > place of recreation > street Adults = trade and service area > street > place of recreation Most burns 0-9% TBSA

Tx for DCIS

Masectomy or BCT

Heart valve replacements

Mechanical valve substitutes Disadvantages = life-long anticoagulation (risk of thrombosis), may be obstructive or cause haemolysis, noisy Benefits = durable, low incidence of mechanical failure Types: Starr-Edwards (Ball-in-Cage) ~ older type. Tilting disc (most common) = Bjork-Shiley or St.Jude bi-leaflet Bio-prosthetic valve substitutes Heterografts = porcine/bovine Homografts Less thrombogenic Less durable (8-10 years)

Access to the chest

Median sternotomy = mostly RV. Risk of mal-union (sternum not uniting), infection (superficial, osteomyelitis, mediastinitis), keloid Thoracotomy = less risky than sternotomy! Right thoracotomy = used in women for "cosmetic purposes" can hide scar under breast. Used for Mitral valve surgery, ASD closure, tricuspid valve surgery. Left thoracotomy = used for PDA (patent ductus arteriolus) and shunts, aortic coarctation, closed mitral valvotomy Videoscopic = coronary artery surgery, mitral valve and simple congenital cardiac repairs Clam-shell - bilateral thoracotomy = used for emergency surgery for life-threatening chest trauma; heart-lung or bilateral lung transplant; cosmetic benefit in cardiac surgery for young females

Aortic vs mitral valvular heart disease - risk factors and presentation

Mitral = repair Regurgitation (second most common) ~ disease of leaflets, anulus or subvalvar mechanism (papillary muscles or chordae) Techniques - Leaflet resection - Ring anuloplasty - Artificial cords for ruptured chordae Common aetiologies: mitral valve prolapse, RHD, IE, annular calcification, cardiomyopathy and IHD. Presentation: SOB, fatigue, orthopnoea, pulmonary oedema Aortic stenosis (most common) Diagnosis by doppler or echo Most commonly degenerative (atherosclerosis) Triad of symptoms = chest pain, heart failure, syncope

Fibrocystic change Breast Cysts (a part of fibrocystic change) - Epidemiology - Morphology - USS appearance - What are the cysts lined by? - Asymptomatic Cysts - Large and painful cysts - Blood stained fluid - If palpable mass persists - Presentation to; -The Clinician - The Radiologist - The Pathologist - Who does this typically affect? - What is the likely pathogenic modality? - What is the most common presentation? - Aetiology - Diagnostic Imaging/Testing

Most common benign breast disorder 50% women clinically, 90% histologically - Very common 7% of women - 1/3 of women aged 35-50 years - Fluid filled ovoid/round structure - Anechoic on USS with post. enhancement - Lined by either flattened atrophic epithelium or metaplastic apocrine cells - Apocrine cysts are more likely to return - Asymptomatic Cysts = observe - Large and painful cysts = complete aspiration - Blood stained fluid = request cytology - If palpable mass persists = further investigation - To the Clinician: "Lumpy and bumpy" - To the Radiologist: "Dense breasts with cysts" - To the Pathologist: "Benign histologic findings" - Premenopausal women aged 20-50 years - Hormonal Imbalan - Breast Pain and Tender Nodularities - formed by dilating and unfolding of lobules - Cannot be differentiated from solid mass on MMG - Requires USS and FNA - Greenish-brown fluid Generally affects premenopausal women 20-50 years ? caused by hormonal imbalance Most commonly presents as breast pain, tender nodularities Breast cysts 7% of women Can occur with breast cysts - formed by dilation and unfolding of lobules. USS needed to distinguish from solid mass. FNA = green-brown fluid. Projections into middle of cyst may indicated intracystic papilloma or malignancy. Asymptomatic = observe Large and painful = aspiration Bloodstained fluid = cytology Palpable mass persists = further investigations

Mx of acute perianal pain = perianal abscess - What percentage develop a fistula? - What are the two main aetiologies? - What is management?

Perianal abscess 20-30% develop fistuale Painful peri-anal lumb Progresses rapidly (in DM and immunocompromised) Caused by infecter intersphincteric anal crypt gland or peri-anal sweat gland. Mx = drainage and f/u

How does sensory and motor neuropathy combine to produce ulceration and ultimately Charcot foot? - What is Charcot's foot? - What is LOPS - What is primary problem in diabetic foot? - What is the pattern of neuropathy?

Motor neuropathy results in paralysis and atrophy of the lumbrical muscles of the foot, which produces clawing of the toes with neuropathic ulceration forming under the metatarsal heads (maximum area of load bearing) The predominant problem in diabetic foot is the loss of protective sensation associated with diabetic neuropathy (LOPS). - Leads to structural foot abnormalities, collapse of arch, fracture of small bones - Combination is a set up for ulceration with poor healing and an inability to recognise damage to foot. - Neuropathy typically begins in the toes then moves proximally à very quickly migrates to weight bearing surfaces. Loss of protective sensation (LOPS) is predominant aetiology

What constitutes the foregut? What is the blood supply of abdominal foregut structures?

Mouth Oesophagus Stomach 1st part of duodenum Blood supply from coeliac trunk

Explain why sigmoid diverticular disease develops and associated complications

Mucosal/submucosal herniations at point of weakness 40% people >60 yo Sigmoid colon has the highest intraluminal pressures - and is the most commonly affected Stranding of mesentery = secondary to inflammation

Technique of examination for aneurysms and their complications

Need to feel deeply and firmly through relaxed abdomen Sometimes in left lateral

What is the relationship between foregut structures and epigastric pain?

Nerves run along arteries (from the coeliac trunk) into abdominal structures. Greater splanchnic nerve (coeliac ganglion) runs into abdo structures. Therefore pain in one of these areas generalises to the whole coeliac ganglion = generalised epigastric pain.

What is the relationship between midgut and hindgut structures and periumbilical and hypogastric pain? - What nerves supply each area? - What ganglions do they arise from? - What are the structures of the midgut? - What are the structures of the hindgut?

Nerves run along arteries into abdominal structures. Sympathetic lesser/least splanchnic nerves (superior mesenteric ganglion) runs into midgut abdo structures. - From duodenum to proximal 2/3 of transverse colon - Supplied by the superior mesenteric artery Lumbar splanchnic nerves (inferior mesenteric ganglion) run into hindgut. - From distal 1/3 of transverse colon to anus - Supplied by inferior mesenteric artery

Spectrum of breast lesions

Papillomas = polyp of epithelium lined lactiferous ducts. Within 5cm of nipple. 30-50 yo. Present with nipple discharge, palpable mass, incidental finding. Pseudoangiomatous stromal hyperplasia (PASH) = benign stromal proliferation that simulates a vascular lesion. Rarely symptomatic Lipomas Present in 5th decade Adenomas - Tubular = glands with little stroma - Lactating = occur in pregnancy or lactation. Often multiple. Regress once lactation ceases. - Nipple = non-discrete palpable growth of papilla of nipple. Erosion of nipple with blood discharge. Lactiferous ductal hyperplasia. Hamartomas Benign palpable masses Adipose, glandular, fibrous and smooth muscle tissue Rare. Usually >35 yo MMG = well circumscribed with thin radiopaque pseudocapsule zone surrounding both soft tissue and lipomatous elements 2-5cm

Diagnosis and treatment of DVT in surgical patients - What are the two types of DVT? - Which one has a higher risk of PE? - Describe Virchow's triad? - Diagnosis: Hx, Examination, and Investigations - What is the general treatment? - When in LMWH used?

Permanent disability death after arterial thromboembolism = 70%; after venous thromboembolism = 4-10%, after post-op bleed = 1-6% 2 categories of DVT: - Distal = deep calf veins - Proximal = popliteal, femoral or iliac veins. More commonly associated with PE. Prevention - Early mobilisation and hydration Mechanical prophylaxis (can't use in PVD) - Graduated compression stockings - Sequential compression devices - Venous foot pumps Pharmacological prophylaxis - Unfractionated heparin - LMWH Diagnosis: - History - Exam: Homan's sign (discomfort behind the knee with dorsiflexion of foot) - Investigations: Duplex USS, D-Dimer, thrombophilia screen Treatment - At least 3 months of anticoagulation (Dabigatrin, Rivaroxaban) - LMWH (overlapped with warfarin initially, and solely throughout entirety of treatment in presence of malignancy) Virchow's Triad - Blood stasis - Endothelial injury - Hypercoagulabilitya 2 categories of risk for DVT - Inherited thrombophilia - Acquired disorders 5 forms of VTE prophylaxis - LMWH - UFH - Compression Stockings - Sequential Compression Devices - Venous foot pumps

Diagnosis and treatment of PE - presenting symptoms of PE? - 5 signs on examination? - Investigation of choice and cautions? - 3 steps of treatment?

Presentations: Asymptomatic to shock or sudden death Common = SOB Pleuritic chest pain Cough Symptoms of DVT Rare = haemoptysis Examination Common = tachypnoea, signs of DVT, tachycardia, decreased BS, jugular vein distention, fever Uncommon = circular collapse (RV failure) Investigation CT pulmonary angiogram (CTPA) - caution in renal failure V/Q scan D-dimer ECG Duplex USS of legs Treatment Stabilisation = O2, IV fluids, vasopressors Empiric anticoagulation Long term anticoagulation (as for DVT)

Management of colon vs rectal cancer

Principles: - Lymphovascular resection - Tension free, well perfused anastamosis - Restore continuity where possible Rectal cancer Rectum is different - outer layer is made of longitudinal muscle. Contains 3 folds ~ valves of Houston. - High local recurrence rates historically >25%. - Positive LN distal to tumour (but within mesorectal package) - ULAR easier than low anterior resection - Cover anastomosis with ileostomy - Colonic J pouch reconstruction - Sphincter saving Colonic stents = useful in metastatic disease. Chemo is better, so people are outliving their stents. Chemo 5FU > New agents (oxaliplatin, irinotecan) > avastin / cetuximab

Benign breast proliferations

Proliferative breast disease with atypia - Atypical ductal hyperplasia (ADH) - Atypical lobular hyperplasia (ALH) Increased risk of breast cancer Proliferative lesions without atypia - Sclerosing adnosis - Radial scars / complex sclerosing lesions - Intraductal papillomas - Florid ductal epithelial hyperplasia

What is the difference between colonic pseudo-obstruction (Ogilvie's sydnrome) and left sided mechanical large bowel obstruction?

Pseudo-obstruction = clinical picture of mechanical obstruction, in the absence of any demonstrable evidence of an obstruction. Acute or chronic. Acute colonic psuedo-obstruction (ACPO = Ogilvie syndrome) the colon may be massively dilated. Causes are multifactorial - commonly trauma, serious infection or cardiac disease. Other conditions = recent surgery, spinal cord injury, old age, neuro disorder, hypothyroidism, electrolyte imbalance, resp disorder, renal insufficiency, meds, severe constipation. Suggested etiology is increased sympathetic tone = reduced motility. Tx = in the absence of perforation, conservative mx (bowel rest, hydration, mx underlying dx) for first 24 hrs. Could then try colonoscopic decompression. Otherwise surgical intervention. Mechanical bowel obstruction = evidence of obstruction. E.g. ileus, volvulus, intussusception, malignancy, stricture, diverticular disease Treatment = volume resus, Abs, NGT, surgical consultation

Management of diabetic foot

Refer to multidisciplinary clinic Optimise glycaemic control Drin, debride as necessary Culture and treat infection Offloading - redistribute pressure = total contact cast, cast walkers, wedge sandals Assess perfusion and revascularise if necessary

Physiology of visceral vs somatic vs referred pain

Referred = peripheral afferent nerve fibres from many internal organs enter the spinal cord through through nerve roots that also carry nociceptive fibres from other locations Visceral = due to stretching of fibres innervating the walls of hollow or solid organs = mucosa is usually first to be disrupted in infection/trauma, so firstly feel visceral pain Somatic = caused by irritation of parietal peritoneum fibres = serosa

Mastitis

Relacted to LACTATION Etiology - Stasis of milk flow - Cracked nipple Usually staph Continue breast feeding! Early Abs (flucloxacillin) If abscess = serial aspiration Incision and drainage risk of fistual - but if necrotic overlying skin, or pt does not tolerate aspiration NON-lactation Periareolar - periductal mastitis - associated with smoking - altered flora due to toxins - plugging of ducts with debris - rarely a manifestation of comedo-necrosis in DCIS - staph / strep / anaerobes Peripheral - older women - associated with DM, trauma, RA, steroids Think about inflammatory breast cancer...

Pathogenesis of a Meckel's diverticulum

Remnant of midgut that extends into the yolk sac "vitelline duct" (usually resolves at 7 weeks gestation) "True" diverticulum (as it involves all layers of the intestine)

Right hemicolectomy vs left hemicolectomy vs high and low anterior resection of the rectum vs abdominoperineal resection vs Hartmann's

Right hemicolectomy = taking branches ileocolic vessels and their draining lymph nodes, anastamosing terminal ileum to the transverse colon Left hemicolectomy = (splenic flexure carcinoma) - boundary of mid and hind-gut - need to take vessels and LNs of the left colic and left branch of middle colic. Subtotal colectomy = attach ileum to sigmoid High anterior resection = attach descending colon to the rectum Low anterior resection = 5cm distal clearance on an upper rectal carcinoma Ultra-low anterior resection (ULAR) = for mid/low rectal carcinoma - entire mesorectal package. Abdominoperineal resection = tumour involving sphincter or pelvic floor. Anus is removed and a permanent end colostomy is made Hartmann's (perforated sigmoid diverticulitis or perforated cancer) = sigmoid is resected, rectum is stapled off, colostomy created.

Presentaion of pt with cancer of right colon, left colon, rectum, anus

Right-sided = more likely to bleed and cause diarrhoea Left-sided = usually detected later and may present as LBO Colorectal symptoms: PR bleeding (60% in rectal cancer) Fe deficiency anaemia Change in bowel habit LBO (more likely colon cancer) Perforation Metastatic disease (12-20% have metastatic dx at presentation) Screening (Immunochemical FOBT offerred at age 50,55,65,70,72,74) Abdominal pain Anal cancer = SCC. Linked to HPV. Anal squamocolumnar junction precancerous lesions: AIN. Presents with anal/pelvic pain, PR bleeding, sensation of rectal mass, prolapse, incontinence, obstructive constipation (obstipation).

Risk factors for DVT

Risk factors: Inherited thrombophilia (Factor V leiden, prothrombin gene, protein S/C deficiency, antithrombin deficiency). Acquired disorders: - Malignancy - Surgery (especially ortho) - Trauma - Pregnancy/post partum - OCP / HRT - Immobilisation - Obesity - Smoking - CCF - Presence of central venous line - Antiphospholipid antibody syndrome - Myeloproliferative disorders - Inflammatory bowel disease - Nephrotic syndrome - Increasing age - Previous VTE

11 Indications for splenectomy

Rupture (most common indication) - Trauma - Iatrogenic (traction or laparoscopic trochar injury) - Pathological (malaria, EBV, CMV) Haematopoetic dx - Refractory ITP (immune thrombocytopaenic purpura) - Hereditary spherocytosis Malignancy - Lymphoma - Isolated mets - Distal pancreatectomy - Colon cancer invasion (splenic flexure) Infective - Abscess - Hydatid cyst

Sentinel node biopsy (SNB) and axillary lymph node dissection

SNB identifies the first draining LN with blue dye or lymphoscintigraphy - then closely assessed by pathology Formal axillary dissection is reserved for when there is obvious malignant involvement of the LNs (palpable, visible on US or +ve SNB) SE = seroma, shoulder stiffness, parasthesia, lymphoedema

Nottingham Score

Scoring system to assess the grade of breast cancers. Based on 3 histological findings: Mitotic activity Differentiation / tubule formation Nuclear pleomorphisms

Pathologic nipple discharge

Secretory production of fluids other than milk can be due to pathological process = usually unilateral and localised to a single duct, persistent and spontaneous. Clear/yellow (serous) or bloody. From a solitary duct. - Papilloma (52-57%) = papillary tumour growing from lining of breast duct - Malignancy is found in 5-15% of cases of pathologic nipple discharge (most commonly DCIS) D

Describe the factors to consider when prescribing fluids to a surgical patient

Signs of hydration: HR, BP, skin turgor, mucous membranes, urine output % dehydration - Mild <5% (2.5L lost) = concentrated urine - Moderate 5-8% (4L lost) = tachycardia - Severe >8% (6L lost) = hypotensive Ongoing losses Upper GI = vomiting, NGT Lower GI = diarrhoea, stoma, fistula 3rd space = ileus, ascites, pleural effusions, retroperitoneal oedema and other soft tissue oedema, surgical drains Skin = severe burns Pt factors - Level of activity - Titrate up/down according to: age, CVS reserve, renal disease, surgical condition (bowel resection, inguinal hernia) - Problems with excessive fluid: dependent oedema, pulmonary oedema, urinary retention, prolonged ICU stay, increased anastomotic leakage 1-2L/day is adequate for majority of patients Post-surgery - Increase in ADH - Urine output of 100ml every 4 hours is acceptable - Ileus expected to last ~5 days - Maintenance IV fluids is all that's necessary - Diuresis = bowel function recovery! No need to replace via IV fluids.

Mx for complications of diverticulitis

Simple diverticulitis: IV antibiotics. Image guided-drainage if needed. Perforation: emergency surgery ~ Hartmann's procedure = resection of sigmoid (including diverticular disease) and production of an end colostomy. Abscess formation: CT guided percutaneous drainage for abscess >4cm in diameter. Otherwise surgery. Stricture: if it's causing an obstruction = surgery. Bleeding: should be self-limiting. Massive haemorrhage will require surgery.

True vs false aneurysm

True = permanent localised dilation of ALL layers of artery that exceeds normal diameter by 50% False = haematoma contained by adventitia or peri-adventitia

Prophylactic treatments post-splenectomy - What organisms are a risk of infection post splenectomy? - How are these risk treated? - How long after splenectomy is OPSI considered a risk? - Which type of splenectomy is correlated to OPSI?

Splenectomy leads lack of bacterial phagocytosis and Ig production - Capsules made of polysaccharides permit bacteria to evade phagocytosis by macrophages (as only proteins are recognised by macrophages). So humoral immunity in forms of opsonin proteins are needed against capsules. Triple vaccination (Encapsulated organisms: N meningiditis, Haemophilus influenzae and Strep pneumoniae) Antibiotic prophylaxis (penicillin) 0.5% of trauma related splenectomies 20% of haematological related splenectomies Annual flu vax

First aid for burns

Stop, drop and roll Remove clothing containing heat or contaminated 20 min cool (clean) running water within 1st 3 hours - avoid hypothermia Chemical burn first aid - protective equipment - remove clothing - protect surrounding skin (soft white paraffin) - 30 min water in first 2 hours - diphoterine solution - bitumen = irrigate until hard and cool, soften with paraffin and remove with forcepts - Metallic lithium, sodium, potassium or magnesium = avoid water. cover with liquid paraffin and remove with forceps - Phosphorus = copious irrigation, debride visible particles, apply copper sulphate Treatment Epidermal = moisturise Superficial-dermal and mid-dermal = dressing. Fluids and nutrition. Deep-dermal and full-thickness = debridement and split skin graft. Dressing and support.

Treatment for rectal prolapse

Surgery = abdominal or perineal Abdominal procedures have lower recurrence but higher morbidity Abdominal surgical procedures: - Anterior resection of redundant colon (sigmoid) and left colon anatomosed to rectum - Marlex procedure = mesh is fixed to presacral fascia. Rectum is placed on tension and material wrapped around the rectum (except anterior wall - to prevent circumferential obstruction). - Suture rectopexy: rectum is fixed to presacral fascia with suture material rather than mesh - Resection rectopexy: combination of anterior resection and Marlex = after resection, the lateral ligaments are sutured to presacral fascia. Perineal surgical procedures - Anal encirclement = band around anus - no longer performed unless palliative - Delorme mucosal sleeve resection: resection made through mucosa near dentate line = mucosa is stripped from rectum to apex of prolapse. Denuded prolapsed muscle is then pleated with a suture and reefed up like an accordion, and edges of mucosa sutured together. - Altemeier perineal rectosigmoidectomy: full thickness circumferential incision made 1-2cm from dentate line. Bowel is transected and sewn to distal anal canal - then anastomise. - Perineal stapled prolapse resection: resecting prolapse

Staging of colorectal cancer

T1 = through submucosa T2 = into muscularis propria T3 = through muscularis propria T4 = other organs N1 = 1-3 nodes N2 = >3 M0 = none M1 = mets Dukes staging I: does not breach muscularis propria (T1 or T2) II: through full thickness muscularis propria (T3) III: positive lymph nodes IV: distant mets Mets = liver, lungs

Principles of informed consent

The nature of the potential risks: more common and more serious risks. The nature of the proposed procedure The patient's desire for information (e.g. asking questions) The temperament and health of the patient: (e.g. anxious patients) The general surrounding circumstances (e.g. elective vs required; healthy vs chronic illness pt)

Indications for breast conserving treatment (BCT) for breast ca - 5 pre-requisites for BCT - Palpable vs. impalpable lesion - Margins - When to we revert to mastectomy? - Recurrence rate - Why use radiotherapy? - Side effects of radiotherapy?

This involves complete local excision of the primary breast tumour with a rim of macroscopically normal breast tissue on all sides. The overlying skin may be included, if necessary. The incision must be carefully planned and the specimen oriented. Breast conservation surgery is routinely followed by radiotherapy. This reduced the local recurrence rate to between 1 and 2% per year compared with 0.5% per year following a total mastectomy. Breast conservation and radiotherapy has now become the standard procedure for patients with breast cancer and is performed on greater than 70% of all patients. Many trials have now confirmed that breast conservation is as safe as total mastectomy with regard to overall survival, and the cosmetic and psycholgical result is far superior. Breast Surgery conservation is however time-consuming and expensive, and radiotherapy is not easily available for all patients. Breast conserving surgery is appropriate when: • It is preferred by the patient • The tumour size is small relative to the breast size (<3-4cm) • Disease is confined to a single breast quadrant • The patient is able to attend for radiotherapy (at a major metropolitan centre typically for 6 weeks) • There are no contraindications to radiotherapy. *Lymph node involvement is NOT a contraindication for BCT - BCT has a slightly higher local recurrence rate compared to total mastectomy but overall survival is equal For a palpable lesion: - aim to excise 1cm normal tissue around the lesion. - Typically remove a disc of breast tissue down onto the pectoral muscle and preserve both the muscle and the overlying skin. For impalpable lesion: - use a hook wire to localise the lesion. - Wire the site on the morning of the operation using US or mammography. - Aim for a 1cm margin around the site. - Perform mammography on the specimen to ensure excision of the lesion and gauge margins of excision. Surgical margins in breast conserving surgery is at least 1mm, ideally 5mm. - Deep and superficial margins can be closer (near pectoral fascia and skin). - If there are close or involved margins, further excision(s) will be needed. - Mastectomy is generally indicated after 2 attempts at wide local excision with involved margins. Without radiotherapy, there are unacceptably high rates of local recurrence, except for very small favourable cancers which are usually <1cm. Absolute contraindications to radiotherapy include: • Previous breast radiotherapy • Scleroderma • Pregnancy • Unable to abduct shoulder. Relative contraindications to radiotherapy include: • Unable to attend follow-up • Severe CVS or respiratory illness. Dose of radiotherapy: 45-50 Gy in 25 fractions +/- tumour bed boost. Treatment is delivered 5 days per week for 5 weeks. Sun burning and fatigue are normal side effects of radiotherapy during the last 2 weeks of treatment and for 2 weeks after treatment. Radiation induced angiosarcoma is a rare long term complication of radiotherapy. Angiosarcoma is an aggressive sarcomatous change which occurs in radiation field, initially presents like a bruise - need to treat with mastectomy (however recurrence is almost inevitable).

Physiology of fluid and electrolyte distribution and fluid losses in the body - How total body water? L? % of body weight? - How is it distributed between plasma, interstitial, and intracellular? - Daily water/Na/K requirements? - Daily water loss urine/faecal/resp./skin?

Total body water 42L = 60% body weight 3L plasma, 14L interstitial, 25L intracellular Daily water requirements = 30-35mL/kg Daily Na requirement = 2mmol/kg Daily K requirement = 1mmol/kg Daily urine output = 0.5-1ml/kg/hr Insensible losses - Faecal = 100ml - Resp = 400ml - Skin = 500ml

Pathological features and clinical presentation of Ulcerative colitis

UC: Confined to large intesine Mucosal inflammation from ano-rectal junction 30% come to surgery = acute colitis; refractory disease; malignancy; haemorrhage Sigmoidoscopy = confluent ulcers, muco-pus, erythema AXR = "thumbprinting" odema of folds Treatment = hydrocortisone Surgery = total colectomy and end ileostomy with closed or open mucous fistula. J-pouch reconstruction = ileum attached to rectum. Ileal pouch anal anastomosis (IPAA) = 6 BM/ day; defer defecation; continence; pouchitis; female fertility 30% reduction; 90% retain pouch.

Outline the risk factors for urothelial carcinoma of the renal tract

Urothelial = bladder = transitional cell carcinoma Men 1 in 43 Women 1 in 143 Peak 65 yo 90% bladder cancers are urothelial ca (others = SCC, adenocarcinoma, small cell, mets) Risk Cigarette smoking Chemical exposure to aromatic amines (aniline dyes ~ textile industry; tyre/rubber, petroleum, painters, hair dressers) Phenacetin (compound analgesic) Radiation Cyclophosphamide Piogliazone Commonly presents with painless macroscopic haematuria > frequency, urgency, dysuria

Mx plan for 1st, 2nd and 3rd degree haemorrhoids

Vascular cushions 1st degree = bleed = rubber band 2nd degree = prolapse but reduce spontaneously = band or excise with single pedicle 3rd degree = prolapse and require manual reduction = staple Internal (above dentate line = covered with mucosa = VISCERAL sensation) or external (below dentate line = covered with skin = SOMATIC sensation) Fibre supplements Rubber band ligation = well tolerated Infection sclerotherapy = less common Open haemorrhoidectomy = rarely ever employed Stapled haemorrhoidectomy = effective for circumferential haemorrhoids

Why does the pain of appendicitis begin in the epigastrium and shift to the right iliac fossa?

Visceral pain starts first - with irritation of mucosa (mid-gut = referred to epigastrium) Somatic pain = peritoneal irritation = right iliac fossa

Pathology and mx of caecal volvulus and sigmoid volvulus - What is a volvulus? - List sites for volvulus by frequency? - Who does volvulus occur in and why does it occur? - What is the principle of treatment? - What is the radiological findings for sigmoid and caecal volvulus? - How often is treatment successful? - What is the risk of treatment? - How may you prevent early recurrence? - How often does recurrence take? - What happens to mesentery in caecal volvulus? - What else predisposes someone to volvulus? - Surgeries for Sigmoid volvulus? - Surgeries for caecal volvulus?

Volvulus: abnormal twisting or rotation of the intestine on its mesentery, leading to ischaemia and subsequent risk of perforation. ® Sigmoid colon is the most common site for volvulus to occur, the caecum is a possible site, and the transverse colon is an infrequent site. ® Volvulus is 20 times more common in those >60 years, where In Western countries sigmoid volvulus is essentially a condition of the elderly and frail, often with a long history of constipation and laxatives. ® Must decompress or operate to avoid perforation. Sigmoid volvulus = see gas bubble in RUQ. Caecal volvulus = see gas bubble in LUQ. Treatment of sigmoid volvulus involves attempted endoscopic decompression with rigid sigmoidscope/colonoscope. ® Decompression can be achieved in most instances. ® The instrument being passed through the spiral lumen at the level of the volvulus may perforate the colon, particularly if there is an area of ischaemia. ® If decompression is successfully achieved it may be useful to pass a long flatus tube through the lumen of a rigid sigmoidscope to splint the sigmoid colon in the hope of preventing early recurrence. Recurrence occurs in approximately half of patients Caecal volvulus is due to congenital incomplete dorsal mesenteric fixation of the caecum or ascending colon associated with an abnormally elongated mesentery distal to this area of absent mesentery. Appendicitis with formation of adhesions also predisposes to volvulus. Surgery Sigmoid = anterior resection > Hartmann's Caecal = right hemicoloectomy > caecopexy (caecum sewed down)