Abdominal Wall and Spine

A 2-year-old boy with a history of omphalocele presents for correction of a 5-cm abdominal bulge with a 3-cm widened scar over the bulge. Which of the following is the most appropriate next step in management of the bulge? A) Anterior component separation B) Interposition acellular dermal matrix placement C) Interposition prosthetic mesh placement D) Tensor fascia lata flap E) Tissue expander placement

A For most patients with omphaloceles less than 5 cm in diameter, a single operation involving a traditional anterior component separation from costal margin to iliac crest is sufficient to reduce the omphalocele and reapproximate the rectus diastasis. Extended component separations are typically only needed when the omphalocele is large and accompanied by a diaphragmatic hernia. Once the abdominal wall defect extends past 5 cm in diameter, a staged procedure involving the placement of tissue expanders and subsequent flap advancement must be considered. Autologous tissue options, such as the tensor fascia lata flap, may be needed for larger defects that can not be managed with component separation. While prosthetic or biologic mesh placement is used to correct large abdominal wall defects, it is typically used only after autologous options have failed or are not available.

A 64-year-old man is brought to the emergency department after collapsing at home. Examination shows a ruptured abdominal aortic aneurysm and hemodynamic instability. The patient is taken to the operating room to undergo open repair of the aneurysm. Postoperatively, urine output decreases despite aggressive fluid resuscitation, and urinary bladder pressure is greater than 30 mmHg. Increased peak airway pressures are noted. Which of the following is the physiologic effect of increased intra-abdominal pressure in this patient? A) Direct organ compression leads to decreased systemic afterload B) Elevation of the diaphragm leads to decreased preload C) Elevation of the diaphragm leads to increased flow in the inferior vena cava D) Vascular compression leads to increased flow in the inferior vena cava E) Vascular compression leads to decreased renal vascular resistance

Abdominal compartment syndrome (ACS) may develop rapidly after an increase in intra-abdominal pressure. Chronic causes of elevated intra-abdominal pressure (such as central obesity or large abdominal tumors) may be compensated for, but acute elevations as a result of trauma, bleeding, burn, or abdominal surgery may lead to life-threatening failure of multiple organ systems. Three mechanisms present in ACS lead to multiple organ failure: vascular compression, elevation of the diaphragm, and direct organ compression. These three forces and their interactions create a constellation of physiologic effects that lead to the circulatory collapse at the center of ACS. Vascular compression results in decreased flow to the inferior vena cava and an increase in renal vascular resistance. Diaphragmatic elevation results in decreased flow to the inferior vena cava and an increase in intrathoracic pressure and decreased cardiac pre-load. Direct organ compression leads to an increase in systemic afterload. Left untreated, these forces eventually lead to renal failure, respiratory failure, intracranial hypertension, and intestinal and hepatic ischemia.

A 25-year-old man is scheduled to undergo soft-tissue coverage and nerve grafting using a seventh intercostal space nerve graft after he sustained a gunshot wound just above the left clavicle. On preoperative examination, he had difficulty abducting the shoulder, and injury to the brachial plexus was suspected. Between which of the following structures is the thoracic intercostal nerve located? A) External intercostal and pectoralis major muscles B) Innermost intercostal and internal intercostal muscles C) Internal and external intercostal muscles D) Parietal pleura and transverse thoracis muscle E) Transverse thoracis innermost intercostal muscles

Although not commonly used, the thoracic intercostal nerves can provide graft material up to 12 cm in length. Harvest of the intercostal nerve has minimal donor site numbness and can be harvested through an open or endoscopic approach. The intrinsic chest muscles include (from superficial to deep) the external intercostal, internal intercostal, innermost intercostal, and transverse thoracis muscles. The external intercostal muscle is most active during inspiration. It functions to stiffen the chest wall during descent of the diaphragm to prevent paradoxical collapse of the chest. The other more internal intercostal muscles are weaker and are more involved in expiration. The intercostal nerve emerges from the spinal cord and immediately splits into a dorsal ramus (that innervates the back) and ventral ramus. The ventral ramus runs between the internal and innermost internal intercostal muscles before crossing over the internal thoracic vessels and penetrating through the intercostal muscles to supply the anterior chest skin.

A 27-year-old woman is evaluated for a recurrent abdominal desmoid tumor. CT scan shows a mass that occupies the full-thickness right musculofascial abdominal wall, involving the rectus abdominis muscle and oblique muscles, including lateral to the semilunar line. Resection is performed. Photographs of the defect are shown. Which of the following is the most appropriate management? A) Bilateral component separation, primary skin closure with incisional topical negative pressure wound therapy, adjuvant chemotherapy B) Left component separation, bridging wide intraperitoneal underlay biologic mesh, primary closure skin C) Pedicled right anterolateral thigh flap with rectus femoris, no mesh D) Placement of a bridging inlay of biologic mesh with primary split-thickness skin grafting and negative pressure wound therapy E) Placement of a bridging inlay of uncoated heavyweight polypropylene mesh with adjuvant radiation therapy

B The lesion in this patient is a recurrent desmoid tumor, also known as aggressive fibromatosis. It is a benign tumor, usually found in younger patients between 10 and 40 years of age, and is locally aggressive. It is often associated with pregnancy and previous surgery and can frequently recur. Management is en bloc, full-thickness, wide local excision (usually with frozen section confirmation of negative margins). An aggressive full-thickness abdominal wall resection is standard of care, making reconstruction more challenging. The more durable and functional reconstruction entails complete restoration of the abdominal wall, especially musculofascial components, in a primary reapproximation. However, depending on the size of the tumor and resultant defect, this may not be possible. Basic principles, after obtaining proper margins after resection of the tumor, would then be reduction in defect size to the maximal extent possible and wide bridging underlay of mesh with at least 4- to 5-cm margins in all directions. Bridging inlay, whereby a mesh is simply sewn to the margins of the defect, has clearly been shown to be inferior in terms of recurrence rates. Mesh choice can be either synthetic or biologic, although if significant contamination exists, if soft-tissue coverage is tenuous, or if one desires to decrease the amount of adhesion formation when placing mesh directly against the bowel, one should consider placement of biologic mesh, accepting the fact that there is a higher incidence of postoperative bulges using these materials, by and large. In this case, only a left component separation is possible, given that the tumor has invaded the right rectus muscle and obliques, precluding their use for myofascial advancement. There is no role for chemotherapy or radiation therapy in the treatment of these tumors. Coverage with a right anterolateral thigh flap, with or without rectus femoris, can reconstruct the soft-tissue defect, but avoiding the use of mesh in a defect over 4 cm has a significantly higher chance of a recurrent hernia and would not be standard of care. Primary skin grafting on top of a nonvascularized thick piece of acellular dermal matrix will not "take," even with use of negative pressure wound therapy.

A 55-year-old man comes to the office because of the ventral hernia shown. History includes a sigmoid colectomy for diverticular disease using a midline incision 7 years ago. Postoperatively, an incisional hernia developed. He underwent mesh repair, which was unsuccessful. Physical examination shows a 28 (horizontal at the level of the umbilicus) × 25-cm (vertical) palpable fascial defect. Which of the following is the most appropriate method of reconstruction of the abdominal wall? A ) Component separation technique only B ) Component separation technique with mesh repair C ) Mesh repair only D ) Tissue expansion and component separation technique with mesh repair E ) Use of a pedicled tensor fascia lata flap

Component separation is a well-described technique for repairing midline abdominal wall hernias. Originally described by Ramirez et al. in 1990, the technique involves incising the external oblique fascia lateral to the rectus muscle. The external oblique is elevated off of the internal oblique muscle in a loose areolar plane that is largely avascular, except for the intercostal branches to the external oblique muscles that are located far posteriorly. The posterior rectus sheath can be incised longitudinally to provide an additional 1 to 2-cm mobilization if needed. The attachments of the internal oblique to the rectus muscle are preserved, as are the intercostal neurovascular bundles that supply the rectus muscle. Hence, the rectus muscle is kept innervated and functional. Under ideal conditions, mobilization of the rectus-internal oblique muscle flap on both sides allows for closure of defects at the epigastrium, mid abdomen, and low abdomen of 10, 20, and 6 cm, respectively. A component separation repair alone would be insufficient because the defect described is 28 cm wide. There would still be a persistent defect in the fascia. Therefore, component separation with supplemental mesh would be required to adequately close this defect. Component separation mobilizes functional muscle medially to help restore abdominal wall integrity and minimizes the amount of bridging that would be repaired with mesh. A mesh repair alone would close the fascial defect but would do nothing to restore the functionality of the abdominal wall. Large defects repaired with mesh can be associated with hernia recurrence and long-term bulging. Tissue expansion can be useful in situations where skin coverage may be lacking. Tissue expansion is unnecessary in the patient described because skin coverage is not an issue. Free flap reconstruction, such as with a tensor fascia lata flap, has been described for abdominal wall defects and can provide vascularized fascia. There are even case reports of innervated free flap reconstructions. However, failure to maintain sufficient muscular tone in the long term leads to eventual attenuation of the fascia and abdominal wall bulging.

The plastic surgeon is called to the neonatal unit to evaluate a newborn with a myelomeningocele. There is an intact 4 × 4-cm sac at the lumbosacral area with minimal fluid oozing from the area. Early operative repair is indicated for which of the following reasons? A) To decrease the need for cerebrospinal fluid shunt placement B) To decrease the need for folic acid supplementation C) To improve motor function return D) To prevent bacterial meningitis E) To prevent cerebrospinal fluid leakage

D The major indication to repair a myelomeningocele defect in the early postnatal period is to prevent infection and bacterial meningitis. Great care is taken to keep the sac sterile and hydrated. Further cardiac, orthopedic, and urologic workup is often necessary, as well as evaluation for hydrocephalus. Although improvement in the return of motor function with early repair has not been shown, neurogenic bladder prognosis is improved. Leakage of cerebrospinal fluid is commonly observed regardless of timing of closure. Although folic acid supplementation has been shown to decrease the neural tube defects and myelomeningocele formation, postnatal supplementation has not been shown to be effective. Approaches to surgical therapy for the treatment of these defects have seen a shift toward prenatal, fetal reconstructive surgery. A recent study by Adzick et al. in the New England Journal of Medicine examined the use of prenatal surgery versus postnatal surgery. In this randomized trial, the authors found a decreased need for cerebrospinal fluid shunt placement and improved motor function outcomes.

A 56-year-old man is evaluated for a ventral hernia after undergoing midline laparotomy for diverticulitis. BMI is 38 kg/m2. Physical examination shows midline fascial defect measuring 20 × 15 cm; there is no evidence of infection and skin coverage is stable. Repair with rectus advancement and polypropylene mesh is planned. Placement of mesh between which of the following planes is most likely to decrease this patient's risk of hernia recurrence? A) Anterior rectus sheath and rectus muscle B) Internal and external oblique muscles C) Medial edges of rectus muscle D) Rectus muscle and posterior sheath E) Skin and anterior rectus sheath

D Although recurrence rates are generally very high for large ventral hernias, placement of mesh in the retrorectal position appears to have the most decreased rate of recurrence compared with other methods. Placement above the plane of the rectus muscle requires division of vascular perforators that traverse the rectus muscle and perfuse the overlying skin flaps. These perforating branches of the epigastric circulation are most dense in the periumbilical zone. Preservation of the perforators has been shown to be beneficial in a number of case series reports. Placement of mesh between the oblique muscles in this case would not provide support for the midline hernia because these muscles are more lateral. Hernia recurrence rates are generally more increased in the presence of infection, with large defects when the rectus muscles cannot be advanced back together in the midline, in obese patients, and in patients with multiple medical comorbidities. Patients with several risk factors can expect recurrence rates in the range of 20 to 40%, whereas patients with few risk factors have recurrence about 5% of the time.

An 83-year-old woman comes to the office for repair of a deep sternal wound infection after undergoing open single-vessel coronary artery bypass grafting using the left inferior mammary artery. Medical history includes cancer of the left breast for which she underwent wide excision with oncoplastic reconstruction followed by adjuvant radiation therapy to the breast and axilla. She does not smoke cigarettes. The patient's infection resolves with aggressive debridement and culture-guided antibiotics. A photograph is shown (midline sternal defect around 6x5 cm). Which of the following is the most appropriate reconstructive option? A) Left pectoralis turnover flap coverage with skin graft resurfacing B) Left vertical rectus abdominis musculocutaneous flap coverage C) Right latissimus dorsi musculocutaneous flap coverage D) Right pectoralis advancement flap with skin readvancement closure E) Right vertical rectus abdominis musculocutaneous flap coverage

E Deep sternal wound infections represent life-threatening infections whose most frequent etiology in contemporary cases is surgical site infection following open heart surgery, with a reported incidence of 0.2 to 3% of patients undergoing median sternotomy. Risk factors in adults include diabetes mellitus, obesity, peripheral arterial disease, tobacco use, reoperation, and other surgical complications such as prolonged operative time and postoperative bleeding. Published mortality rates range from 8.1 to 14.8%. Once a diagnosis is made, initial treatment in cases of deep infection typically involve a combination of antimicrobial therapy and staged surgical debridement followed by delayed closure. Sternotomy wounds can be complex problems because of their proximity to heart and lungs and exposure of these vital organs following debridement. Principles of reconstruction once a healthy wound bed has been obtained include durable coverage of vital structures with obliteration of dead space with a view to retaining or restoring optimal form and function. In the case scenario described, a right superiorly based rectus abdominis myocutaneous flap provides the most reliable, well vascularized and non-irradiated option for regional soft tissue reconstruction of the composite chest wall defect (shown). A left vertical rectus abdominis myocutaneous flap is suboptimal in the setting of a relatively compromised superior epigastric vascular pedicle in the setting of known sacrifice of its parent left internal mammary artery (IMA). Latissimus and pectoralis flaps in any form are less reliable in their ability to fully cover inferior third sternectomy defects. While a turnover pectoralis flap can reach the inferior sternum, a left pectoralis turnover flap is furthermore less reliable in the setting of known sacrifice of its inferior segmental internal mammary perforators in the setting of known IMA sacrifice. Skin re-advancement in the setting of prior radiation and distorted perfusion from prior reduction mammoplasty also invites further unnecessary risk.

A 56-year-old woman who has type 2 diabetes mellitus is scheduled to undergo removal of prosthetic mesh that became infected after ventral hernia repair. Weight is 311 lb (141 kg); BMI is 53 kg/m2. Reconstruction with component separation technique and onlay grafting of reinforcing mesh is planned. Compared with polytetrafluoroethylene, acellular dermal matrix is preferable for this patient because of its ability to undergo which of the following processes? A ) Contraction B ) Encapsulation C ) Imbibition D ) Inosculation E ) Revascularization

Implant infection is a common clinical complication of abdominal hernia repair. Use of biologic mesh in contaminated cases has gained widespread acceptance. The ability of acellular dermal matrix (ADM) to revascularize is most likely the key to its successful application in contaminated scenarios. Revascularization subsequently helps clear bacteria. Contraction is a normal part of wound healing mediated by myofibroblasts, which are not present in polytetrafluoroethylene (PTFE) or ADM. Encapsulation is a foreign body reaction, whereby the organism forms a sterile scar around an alloplastic material. Imbibition is the process by which autogenous grafts perform initial metabolic exchange through diffusion. Inosculation is the first stage of neoangiogenesis, whereby immature vasculature between graft and recipient bed begin to organize in preparation for ingrowth. Neither process occurs in PTFE or ADM, as there is no existing vasculature in either product.

A 60-year-old man undergoes sigmoid resection and colostomy for management of ruptured diverticulitis. The patient has smoked one pack of cigarettes daily for the past 35 years. BMI is 36 kg/m2. After colostomy reversal, he has an abdominal wound infection and fascial dehiscence. Reconstruction with a bridging human acellular dermal matrix is planned. Compared with traditional polypropylene mesh repair, which of the following complications is more likely with the planned approach? A) Abdominal bulge B) Fistula C) Hematoma D) Infection E) Skin necrosis

The correct response is Option A. Acellular dermal matrices (ADM) have been advocated for the past decade as an important adjunct in the complex field of abdominal wall reconstruction. Many studies have verified the use and general safety of ADM in abdominal wall reconstruction, but conclusive evidence of its advantages over other techniques is still lacking. What can be inferred is its advantage over prosthetic mesh in contaminated fields. Polypropylene mesh would be contraindicated in the infected wound in this example. After adequate debridement and appropriate antibiotics in an optimized patient, ADM can be used for hernia repair or reconstruction along with component separation. Postoperative infections can be as common as 40%, but conservative management measures often suffice, rather than reoperation and graft explantation, which are required with prosthetic mesh. One recognized drawback in the stretchable nature of dermal matrix grafts is that they can often stretch under tension to 50% or more of their initial dimensions. Postoperative bulging without true herniation is common. Strategies for prevention include suturing the graft under maximal stretch and use of porcine dermal grafts rather than human grafts. Hernia recurrence in the complex abdominal wall reconstruction remains a common event, regardless of technique. Although some studies assert a strong advantage with ADM, others report a similar or increased recurrence rate. As successful operative techniques become more standardized, perhaps more uniform success will be demonstrated in future studies. Skin necrosis and hematoma are common surgical complications that should not vary between choice of graft material. Fistula rates are decreased with ADM versus prosthetic mesh reconstruction.

The blood supply to the mid-abdomen originates primarily from which of the following arcade regions? A ) Deep epigastric B ) Deep internal mammary C ) Mid epigastric D ) Superficial epigastric E ) Superficial internal mammary

The correct response is Option A. Blood is supplied to the abdominal wall both by direct cutaneous vessels and musculocutaneous vessels. Haddad demonstrated the exact locations of these vessels using arteriography. Huger later classified the vascular supply into simple zones for use in abdominal lipectomy. This classification can be applied to abdominal reconstruction. The mid-abdomen is supplied primarily by the deep epigastric arcade. The superior epigastric artery arises from the internal thoracic artery and descends with the posterior rectus sheath. The deep inferior epigastric artery arises from the external iliac artery and ascends with the posterior rectus sheath. Each of these vessels supplies branches to the rectus muscle and overlying skin. The lower abdomen is supplied by branches of the epigastric arcade and the external iliac artery. The superficial epigastric and superficial external pudendal arteries originate from the femoral artery running superficial to the fascia to supply the overlying skin. The inferior epigastric artery on the posterior rectus sheath supplies the underlying muscle in this zone. The deep circumflex iliac artery supplies the muscles in the area of the anterior iliac spine. The flanks and lateral abdomen are supplied by the intercostal, subcostal, and lumbar arteries. These vessels arise from the aorta and give off perforators to the back and flank. They travel circumferentially on the transversus abdominis, perforating the oblique muscles and supplying the overlying skin.

An otherwise healthy 47-year-old man comes to the office because of the recurrent ventral hernia shown. He does not smoke cigarettes. Physical examination shows "Swiss cheese-type" defects, which are confirmed by CT scan. He desires reconstruction. Which of the following is the most appropriate surgical treatment? A) Component separation with mesh placement B) Laparoscopic hernia repair with mesh placement C) Open hernia reduction with bridging mesh placement D) Open reduction with free tensor fascia lata flap E) Total autologous component separation

The correct response is Option A. Given the size and history of the defect, the patient described has a significant chance of recurrence of his hernia. To optimize the chances of a functional recovery that is durable and has the lowest chance of recurrence, the component separation technique with mesh reinforcement (synthetic or biologic) is indicated. The component separation technique, originally described by Ramirez et al. in 1990, allows for recruitment of the rectus complex towards the midline to facilitate primary reapproximation (in the best-case scenario) or at least decrease the size of the residual defect. Studies have shown that reinforcement of hernia repairs with mesh decreases recurrence rates by 50 to 75%, even in secondary repairs. It is not clear, however, whether the mesh should be placed as an overlay or underlay. Nonetheless, mesh reinforcement leads to lower recurrence rates, especially if combined with component separation. Specifically, component separation allows for reduction of the hernia defect size after hernia reduction, and leads to lower recurrence rates versus hernia reduction and bridging mesh repair alone. Laparoscopic repair is a useful technique in hernia repairs. However, the complex, large "Swiss cheese-type" defect described lends itself more to open repair in terms of facilitation of reduction, optimization of safety (avoidance of unrecognized bowel injury), and decrease in operative time. A tensor fascia lata flap, originally described for large hernia repairs because it allows transfer of fascia to the abdomen, does not demonstrate superior results compared to available meshes. It also incurs donor site morbidity versus the mesh reinforcement techniques.

A 70-year-old man is evaluated because of chest wall incision drainage associated with leukocytosis, high fever, and blood cultures positive for Staphylococcus aureus 14 days after undergoing quintuple coronary artery bypass grafting using both internal mammary arteries. History includes type 2 diabetes mellitus, hypertension, hypercholesterolemia, and chronic obstructive pulmonary disease. He has smoked one pack of cigarettes daily for the past 40 years. BMI is 32 kg/m2. In addition to broad-spectrum antibiotic therapy, which of the following is the most appropriate initial management of this condition? A) Debridement and negative pressure wound therapy B) Debridement and reconstruction with a pectoralis turnover flap C) Debridement and reconstruction with sternal plating D) Debridement with primary rewiring and wound irrigation

The correct response is Option A. Post-sternotomy mediastinitis is a severe complication, with an incidence ranging between 0.2 and 8%. Risk factors include advanced age, diabetes mellitus, morbid obesity, reoperation for bleeding, and use of bilateral internal mammary arteries. Deep sternal wound infections are more serious and have a higher mortality rate than superficial or sterile sternal wounds. The most common organisms are Staphylococcus aureus and Staphylococcus epidermidis, but mixed gram-positive and gram-negative infections are not uncommon. Broad-spectrum antibiotic therapy to include coverage of MRSA infection and Pseudomonas should be instituted. Nevertheless, debridement is the mainstay of therapy. Adequate sternal and soft-tissue debridement is vital and can be combined with immediate sternal closure with delayed primary wound closure versus delayed closure of the entire wound with or without flaps to aid in obliterating any dead space. Many studies have demonstrated that the use of negative pressure wound therapy for wound coverage as a bridging method to final wound closure decreases the morbidity of these patients and is associated with decreased recurrent infection and treatment failure rates compared with conventional therapy, specifically primary rewiring or plating, especially for those at high risk. Flap closure at the time of sternal debridement can be performed; however, if bilateral internal mammary arteries are used for the bypass, a pectoralis turnover flap is not an option because of loss of the internal mammary artery for the pectoralis major. Options would include coverage with the pectoralis transposition flap based on the thoracoacromial artery, an omental flap, or a rectus abdominis flap based on the intercostal artery.

A 25-year-old man returns to the operating room for closure of the abdomen 2 weeks after undergoing small-bowel resection. The abdomen was left open after the resection and treated with abdominal negative pressure wound therapy. The bowel wall edema has improved, and the fascia and rectus muscles are 30 cm apart at the level of the umbilicus. There is no evidence of contamination. Abdominal wound closure is planned. There is adequate skin for primary closure. Which of the following methods is most appropriate for fascial closure? A) Acellular dermal matrix and negative pressure wound therapy B) Component separation and acellular dermal matrix interposition C) Skin grafting and negative pressure wound therapy D) Subcutaneous tissue expansion, staged closure of skin flaps E) Submuscular tissue expansion, staged closure of fascial flaps

The correct response is Option B. Abdominal wall reconstruction after severe trauma involves evaluation of the skin and fascia. First, the surgeon needs to determine if there is sufficient skin and subcutaneous tissue for primary closure. If there is insufficient skin, then tissue expanders, local tissue rearrangement, or distant flaps need to be considered. Second, if there is insufficient fascia, then component separation with primary fascial closure and mesh onlay or a mesh interposition are options for fascial closure. Since the fascial defect is 30 cm, it is unlikely that primary fascial closure can be achieved with component separation alone. An interposition of acellular dermal matrix is appropriate to bridge the fascial gap if primary fascial closure cannot be achieved.

The dominant vascular supply of the rectus abdominis muscle originates from which of the following vessels? A) Common femoral B) External iliac C) Internal iliac D) Internal mammary E) Superficial femoral

The correct response is Option B. Component separation for closure of large abdominal wall defects was first described by Ramirez in 1990. The purpose of the surgery is to achieve abdominal wall closure with well-vascularized, innervated muscle flaps. The primary vascular supply to the rectus muscles are the deep inferior epigastric artery and vein, which arise from the external iliac vessels. The internal mammary vessels give rise to the superior epigastric arteries and veins, which is a secondary, nondominant vascular supply of the rectus muscles. The femoral vessels give rise to the superficial inferior epigastric artery and vein, which perfuse the skin and subcutaneous fat of the inferior lateral abdomen.

A 55-year-old man who underwent abdominal surgery 10 years ago undergoes lysis of adhesions for treatment of ongoing intermittent bowel obstruction symptoms. He does not smoke cigarettes and has a history of hypertension and diabetes mellitus. A single enterotomy is made and repaired primarily. During abdominal wall closure after the intra-abdominal procedure, the fascial edges cannot be approximated without marked tension with a relaxed defect diameter maximum of 7 cm. Which of the following is the best method of repair? A) Bioprosthetic mesh bridging B) Component separation and bioprosthetic mesh underlay C) Component separation and synthetic mesh underlay D) Component separation with no mesh E) Synthetic mesh bridging

The correct response is Option B. Given the size of the defect, the patient's comorbidities, and bowel violation, the best method to optimize results is a component separation with a bioprosthetic mesh underlay. The use of bridging mesh without approximation of the fascia is not recommended due to a high recurrence rate. Instead the Ventral Hernia Working Group (VHWG) recommends reapproximation of the rectus muscle at the midline whenever possible without undue tension. This can be done by using the component separation technique originally described by Ramirez. The procedure calls for a release of the external oblique aponeurosis 1 cm lateral to the linea semilunaris, which allows for medialization of the rectus abdominis and underlying lateral musculature for primary approximation. Given the enterotomy, a bioprosthetic mesh would be recommended as opposed to a synthetic mesh, because it is likely more resistant to infection and does not necessarily need removal in a contaminated wound. It is the VHWG's preferred method to place mesh in an underlay manner, because intra-abdominal pressure pushes the mesh against the native abdominal wall instead of away from it. It also adds another layer of tissue over the prostatic material and would be preferred with a bioprosthetic because of decreased risk for bowel adhesions. Additionally, lower rates of hernia recurrence have been shown in patients who underwent component separation with mesh as opposed to those without.

A 45-year-old woman comes to the office seeking consultation for an abdominoplasty. Physical examination shows diastasis recti and excess skin and fat in the infraumbilical region. Abdominoplasty with undermining of the upper abdominal flap and plication of the diastasis is planned. Decrease in overall sensation in which of the following areas is most likely after more than 3 years postoperatively? A) Epigastric B) Infraumbilical C) Lateral abdominal D) Subxiphoid E) Suprapubic

The correct response is Option B. The area below the umbilicus and above the incision is most likely to have decreased sensation in the long term (after more than 3 years). This is true for superficial touch, superficial pain, temperature (hot and cold), and vibration. The area above the umbilicus recovers sensation to touch, pain, and vibration within 3 years; sensation to hot and cold temperatures recovers beyond 3 years. The suprapubic area has decreased sensation to temperature; however, touch, pain, and vibration recover in the short term. The areas below the xiphoid, at the lateral abdomen, as well as all other areas on the abdomen, have decreased sensation to pressure, although the infraumbilical region had the greatest change. The anterior nerve branches of the 6th to 12th intercostal nerves travel in a plane between the transversus abdominis and internal oblique muscles. They enter the internal oblique fascia, divide into two branches, and enter the posterior rectus sheath. One branch ascends 3 cm from the lateral edge of the rectus muscle to supply sensation to the skin over the lateral half of the rectus muscle. The other branch travels between the rectus and the posterior sheath before penetrating the linea alba and supplying sensation to the medial half of the rectus muscle. These nerves are divided during undermining from the abdominoplasty.

A 1-day-old female newborn is evaluated because of repair of a lumbar myelomeningocele. After dural repair, physical examination shows the spinal cord at the base of the wound with a 4 × 4-cm soft-tissue and skin defect. Which of the following is most appropriate to reconstruct the wound? A) Gluteal muscle flap and skin advancement flap B) Paraspinous musculofascial flap and skin advancement flap C) Skin advancement flap only D) Split-thickness skin grafting

The correct response is Option B. The most appropriate method to reconstruct the wound is a local musculofascial flap and skin advancement flap. The major principle of myelomeningocele repair is to obtain a well-vascularized layer of soft-tissue coverage between the dural and skin repairs. The fascia overlying the paraspinous muscles can be turned over as flaps, followed by paraspinous muscle advancement flaps to cover the underlying dural repair. This vascularized soft-tissue layer will minimize the risk of cerebrospinal fluid contact with cutaneous bacteria and subsequent meningitis if either the dural repair or skin repair breaks down. A split-thickness skin graft over the dura would not adequately protect the spinal cord. Closing the skin directly over the dural repair using skin advancement flaps would place the child at risk for meningitis in the event of a cerebrospinal fluid leak or if wound breakdown occurred along the incision line of the widely undermined skin flaps. The use of a regional gluteal or latissimus muscle flap to cover the dural repair is unnecessary because local tissue (paraspinous muscles and fascia) is available. Harvesting the gluteal or latissimus muscles also may cause significant donor site morbidity in a child already at risk for ambulatory problems from a neurologic deficit.

To maintain innervated muscle flaps during abdominal component separation, which of the following is the most appropriate plane of dissection? A) Below subcutaneous fat pad, above fascia B) Below fascia, above external oblique C) Below external oblique, above internal oblique D) Below internal oblique, above transversalis E) Below transversalis, above peritoneum

The correct response is Option C. Component separation for closure of large abdominal wall defects was first described by Ramirez in 1990. The purpose of the surgery is to achieve abdominal wall closure with well-vascularized, innervated muscle flaps. The muscles of the abdominal wall are innervated by the intercostal nerves from T7-L4. The plane below the external oblique and above the internal oblique is an avascular plane that will allow for medial advancement of the rectus muscle flaps while protecting the intercostal nerves that run under the internal oblique.

A 4-year-old boy is scheduled to undergo abdominal wall repair using a component separation technique. He underwent living donor liver transplantation during infancy, at which time the graft was noted to be too large for size. A midline incisional hernia was intentionally made to facilitate organ function after transplantation. Current physical examination shows ventral herniation with marked loss of domain. During abdominal wall repair by component separation, parallel aponeurotomy is most likely to be performed immediately lateral to which of the following anatomical structures? A ) Arcuate line of Douglas B ) Inguinal ligament C ) Linea semilunaris D ) Midline E ) Tendinous inscription

The correct response is Option C. Separation of components of the abdominal wall is fast becoming a first-choice procedure for large ventral defects. The procedure involves medial advancement of the rectus abdominis muscle flap after division of the aponeurosis or fascia of the external oblique muscle layer. Properly identifying the correct fascia to incise is a critical step in the procedure, and it relies on knowledge of the abdominal wall anatomy. The rectus abdominis muscles are separated by the midline linea alba, and each rectus muscle is medial to the layered triad of muscles—the external oblique, internal oblique, and transversus. Division of external oblique fascia is properly performed lateral to the linea semilunaris, which represents the lateral border of the rectus sheath, which is formed by the contributions of the external oblique, internal oblique, and transversus layers as the envelope of the rectus abdominis muscle. Above the arcuate line, the later layers split around the rectus muscle at the level of the internal oblique, forming both the anterior and posterior rectus sheaths; however, below the arcuate line, all layers travel anteriorly, forming the anterior sheath but no distinct posterior rectus sheath. The inguinal ligament exists between the anterior superior iliac spine and the pubic symphysis and should not be divided in component separation. Transverse tendinous inscriptions interrupt the rectus sheath, and division of the anterior rectus sheath or the inscriptions is not part of the classic component separation.

A 40-year-old man undergoes ventral hernia repair with biologic mesh and fascial closure at the midline. A bilateral component separation technique with incision of the external oblique fascia and muscle lateral to the linea semilunaris and dissection in the plane between the external and internal oblique muscles, and separation of the rectus muscle off of the posterior rectus fascia is performed. At which of the following levels can the least amount of advancement of the medial fascial edges be expected? A) Midway between the umbilicus and pubis B) Midway between the umbilicus and subcostal margin C) Subcostal margin D) Suprapubic E) Umbilicus

The correct response is Option C. The component separation technique can be used to achieve medial transposition of the rectus muscle and overlying anterior fascia. The surgery involves division of the external oblique fascia and muscle lateral and parallel to the linea semilunaris. The plane deep to the external oblique muscle, which is relatively avascular, is then dissected laterally. The rectus muscle is also separated off of the posterior rectus sheath (using access from the medial laparotomy or hernia incision). This allows for medial advancement of the rectus muscle, overlying anterior rectus sheath, internal oblique muscle, and transversus muscle as a unit. The segmental neurovascular bundles course deep to the internal oblique muscle and penetrate into the rectus muscle 10 to 25 mm medial to its lateral margin. The component separation technique, when performed in the scenario described, can give unilateral advancement toward the midline approximately 10 cm at the level of the umbilicus, which equates to a bilateral advancement of 20 cm. The least amount of advancement is in the subxiphoid and subcostal regions, often making more cranially located defects more difficult to close. Since it was originally reported in 1990, several modifications and variations of this technique have been described in the literature. These include perforator-preserving and/or endoscopic techniques to methods that describe additional maneuvers to increase mobilization or improve durability with the addition of biologic or prosthetic meshes.

A 65-year-old man is evaluated for a large mass in a previously irradiated area of the posterolateral chest. Preoperatively obtained ventilation-perfusion scans and pulmonary function testing are within normal limits. A full-thickness chest wall resection to include three ribs and at least 10 cm of each rib is planned. The soft-tissue defect is anticipated to be 20 cm in diameter. Which of the following factors in this patient is most likely to necessitate a rigid chest wall reconstruction? A) Posterolateral position of the defect B) Previous chest wall radiation therapy C) Total area of the chest wall defect D) Total number of ribs resected

The correct response is Option C. The most likely factor to indicate rigid chest wall reconstruction in this very large anticipated chest wall defect is the total area of the bony chest wall that is resected. Generally, reconstruction of the lateral bony chest wall seems necessary if four or more consecutive ribs are resected or if the diameter of the total defect is larger than 5 cm. Historically, protection of a flail segment of chest wall was based on the pendelluft principle, a phenomenon in which there is airflow back and forth between the lungs, resulting in underventilated segments of lung. This out-of-phase movement of the airway gas between the intact and flail-chest-side lungs was long believed to be the major contributor to respiratory dysfunction in patients with flail chest but has failed to be proven and appears to be a flawed hypothesis. In patients who have had radiation therapy, larger defects may be tolerated without rigid chest wall stabilization owing to fibrosis. As many as five ribs may be resected in patients who have undergone radiation therapy before reconstruction is considered because increased fibrosis produces chest wall stiffness. Anterior and posterior defects are typically better tolerated than lateral defects.

A 45-year-old man undergoes abdominal reconstruction with a component separation technique. After release of the external oblique muscle bilaterally, which of the following best explains the preservation of flexion of the trunk? A ) Preservation of the nerves between the anterior rectus fascia and pyramidalis muscle B ) Preservation of the nerves between the external oblique and internal oblique muscles C ) Preservation of the nerves between the internal oblique and transversalis muscles D ) Preservation of the nerves between the transversus abdominis and the peritoneum

The correct response is Option C. The rectus muscle is the primary flexor of the pelvis. Its segmental nerve supply enters the rectus sheath laterally in a plane between the internal oblique and transversalis muscles. Separation of components is a versatile and powerful technique for autologous abdominal wall reconstruction. Along with the ability to close large midline ventral defects primarily, the rectus muscle remains innervated because only the aponeurosis of the external oblique is released. If correctly performed, the internal oblique layer will shield the underlying nerve supply to the rectus and result in a functional abdominal wall repair.

In bilateral component separation for abdominal wall reconstruction, which of the following points is most likely to be the area of greatest advancement? A) Arcuate line B) Ligament of Treitz C) Suprapubic D) Umbilicus E) Xyphoid

The correct response is Option D. Component separation for abdominal wall reconstruction involves release of the fascia lateral to the rectus abdominus muscles, just lateral to the semilunar line, dissecting the external oblique off the internal oblique muscles. This creates innervated musculofascial flaps that can be advanced medially for closure of ventral hernias. If the posterior rectus sheath is also dissected free, further advancements can be gained. Per rectus muscle, approximately 4 cm can be gained at the epigastric and suprapubic areas; 10 cm can be advanced at the waist. Therefore, the most advancement can be gained at the umbilicus, which is in the area of the waist. The xyphoid and ligament of Treitz are in the epigastric area, while the arcuate line is in the suprapubic area.

A 1-day-old female newborn is evaluated because of a 4 × 4-cm defect after undergoing dural repair of a lumbar myelomeningocele. Which of the following is the most appropriate next step in management? A) Negative pressure wound therapy B) Split-thickness skin grafting C) Coverage with a skin advancement flap D) Coverage with a local musculofascial flap E) Coverage with a free flap

The correct response is Option D. The most appropriate next step in management is coverage with a local musculofascial flap. The major principle of myelomeningocele repair is to obtain a well-vascularized layer of soft-tissue coverage between the dural repair and skin repairs. The fascia overlying the paraspinous muscles can be turned over as flaps followed by paraspinous muscle advancement flaps to cover the underlying dural repair. This vascularized soft-tissue layer will minimize the risk of contact of cerebrospinal fluid with cutaneous bacteria and subsequent meningitis if either the dural repair or skin repair breaks down. Vacuum-assisted wound therapy over a dural repair would increase the risk of cerebrospinal fluid leak, dural injury, and breakdown of the repair. A split-thickness skin graft over the dura would not adequately protect the spinal cord. Closing the skin directly over the dural repair would place the patient at risk for meningitis in the event of a cerebrospinal fluid leak, or if wound breakdown occurred along the incision line of the widely undermined skin flaps. The use of a free flap to cover the dural repair is unnecessary because local tissue (paraspinous muscles and fascia) is available. Harvesting the gluteal muscle(s) may cause significant donor site morbidity in a child already at risk for ambulatory problems from a neurologic deficit.

A 65-year-old man who underwent three-vessel coronary artery bypass grafting (CABG) five weeks ago comes to the office because he has a draining lesion near the sternotomy incision. The CABG procedure included harvest of the patient €™s left internal mammary artery. Temperature is 38.7EC (101.7EF). Physical examination shows a 3-mm papule at the manubrium of the healed sternotomy incision. CT scan of the chest shows a sinus tract leading to the internal sternal plate. In addition to removal of sternal wires and debridement of the wound, which of the following is the most appropriate management? (A) Continuous irrigation (B) Negative-pressure wound therapy (C) Omental flap (D) Pectoralis major muscle flaps (E) Rectus abdominis muscle flaps

The correct response is Option D. The most effective treatment of the sternal wound infection described is initial debridement to healthy bleeding tissue and bone, removal of all foreign bodies, and immediate closure with bilateral pectoralis major muscle flaps. Post €'sternotomy wounds are classified according to the duration of time that has elapsed between the sternotomy and the clinical onset of the infection. Type I infections occur within the first week after sternotomy and have no bony involvement. Type II infections occur during the second to fourth weeks after sternotomy. Bony involvement is frequent, but chostochondritis is rare. Type III infections occur months to years after sternotomy and typically involve chronic draining sinus tracts. Osteomyelitis, chostochondritis, and retained foreign bodies are all common. The patient described had a Type III infection with a deep sinus tract as confirmed by CT scan. Although delayed closure had previously been considered the treatment of choice for Type III sternotomy wounds, more recent data suggest that a single-stage approach with bilateral pectoralis major muscle flaps results in quicker recovery, improved cosmesis, and decreased morbidity and mortality compared with staged approaches. Given the chronicity of the wound, all foreign bodies, including retained suture material and wires, should be removed. Pectoralis major turnover flaps provide additional bulk and might therefore be considered preferable. However, the left internal mammary artery has been harvested in this patient, compromising the blood supply to the left pectoralis major turnover flap.

Which of the following is the most appropriate term for the amount of air that is inspired and expired with a single breath during normal resting respiration? A) Dead-space volume B) Functional capacity C) Residual volume D) Tidal volume E) Vital capacity

The correct response is Option D. Tidal volume (VT) is the volume of air that is moved into or out of the lungs during quiet breathing. Tidal volume can be measured directly through spirometry or estimated based on a patient's ideal body mass. It is a key parameter in mechanical ventilation to allow adequate ventilation without causing barotrauma to the lungs. Vital capacity (VC) is the volume of air expired after deepest inspiration. Functional capacity is a physiologic description of an individual's ability to complete activities of daily living. It can be estimated through exercise treadmill testing and reported in metabolic equivalents (METs). Residual volume (RV) is the volume of air remaining in the lungs after maximal exhalation. Dead-space volume is the volume of air inhaled that does not take part in gas exchange. This volume can include both gas that remains in conducting airways (e.g., trachea, bronchi) during respiration and gas that reaches nonfunctional alveoli (e.g., nonperfused lung parenchyma following pulmonary embolism).

A 66-year-old man with a history of adenocarcinoma of the lung undergoes a left pneumonectomy using a posterolateral thoracotomy incision. Postoperatively, he receives radiation therapy. The patient subsequently develops a nonhealing ulcer of the chest wall measuring 5 × 6 cm in the region of the nipple-areola complex. Which of the following is the most appropriate option for reconstruction? A) Negative pressure wound therapy B) Pedicled intercostal muscle flap and a split-thickness skin graft C) Pedicled latissimus dorsi musculocutaneous flap D) Pedicled vertical rectus abdominis musculocutaneous flap E) Split-thickness skin graft only

The correct response is Option D. Tissue injury from radiation results in irreversible damage that limits the ability of wounds to heal with skin grafts or by secondary intention, such as using negative pressure wound therapy. Tissues within the field of radiation are also generally affected, which would limit use of an intercostal muscle flap. Although a latissimus dorsi musculocutaneous flap would provide an adequate amount of tissue from outside of the field of radiation, it would be unreliable in the setting of prior posterolateral thoracotomy, unless there is documentation that the latissimus was spared. A vertical rectus abdominis musculocutaneous flap would provide sufficient tissue from outside of the field of radiation and would not have been affected by the patient's prior surgery.

Which of the following best describes the benefit of using acellular human dermal matrix compared with alloplastic mesh in complex abdominal wall reconstruction? (A) Adhesion potential (B) Cost effectiveness (C) Definitive scar formation (D) Rapid absorption (E) Resistance to infection

The correct response is Option E. Acellular human dermal matrix, which is commercially available as AlloDerm or FlexHD, has emerged as a versatile material for abdominal wall reconstruction. Because of retained vascular channels, this material revascularizes rapidly and resists infection. In addition, the matrix serves as a soft-tissue scaffold, retaining its original strength and becoming incorporated with minimal scar or adhesion formation. These materials are more expensive than alloplastic mesh, although a formal cost analysis has not yet been published.

A 55-year-old woman with recurrent rectal cancer comes to the office for preoperative consultation for pelvic exenteration, which will include total vaginal resection and reconstruction with a vertical rectus musculocutaneous flap. Which of the following long-term complications is most likely in this patient? A) Abdominal hernia B) Pelvic abscess C) Rectovaginal fistula D) Small-bowel obstruction E) Vaginal stenosis

The correct response is Option E. Reconstruction of the vagina after oncologic resection can be challenging for plastic surgeons, as restoration of form and function must be considered. Restoration of form is often achievable by a variety of procedures, including the vertical rectus musculocutaneous flap, gracilis musculocutaneous flap, pudendal artery fasciocutaneous flap, skin grafting, and interpositional colonic grafts. Restoration of functional outcome, however, is controversial. Return of sexual activity across multiple studies shows wide variability from 31 to 100% (53.8% pooled data). A recent survey study found that 50% of responders were sexually active and were able to achieve orgasm after reconstruction. However, a majority of responders reported wishing that they had been given more information on the procedure before surgery. The most common long-term complication from total reconstruction of the vagina is stenosis with rates reported from 18 to 22%. This requires regular use of obturators for dilatation and this should be clearly discussed with patients preoperatively. Abdominal hernia, rectovaginal fistula, pelvic abscess, and small-bowel obstruction are less common complications.

An 18-year-old woman comes to the office because of a small area of titanium extruding through the skin overlying the sacrum 12 months after undergoing a successful posterior spinal fusion and an autologous bone graft for myelodysplasia and lumbosacral kyphotic deformity. Physical examination shows a midline scar with a 2 × 2-cm wound at the level of the fourth lumbar vertebra with a visible screw. Which of the following is the most appropriate next step in management? A) Bilateral skin advancement flaps B) Free rectus abdominis muscle flap C) Gluteus maximus muscle flap D) Negative pressure wound therapy and skin graft E) Removal of the hardware

The correct response is Option E. The most appropriate next step in management of the exposed titanium is removal of the hardware. The titanium rod or one of the screws likely loosened and subsequently migrated to extrude through the skin. The vertebral column is adequately fused 1 year following the procedure. The orthopedics team should be consulted regarding removal of the hardware. Once the hardware is removed, the wound is easily repaired using delayed primary closure or by allowing it to heal secondarily. Although local skin flaps, skin grafts, regional muscle transfer, and free flaps will provide vascularized soft-tissue coverage over the exposed hardware, these options ultimately will fail. The exposed hardware is much stronger than any soft-tissue coverage and will extrude through a flap, especially when the patient is supine. Definitive management requires eliminating the cause of the problem, which is malpositioned hardware, and not inadequate soft-tissue coverage.

A 45-year-old man is scheduled to undergo abdominal wall reconstruction to repair a central defect resulting from abdominal compartment syndrome. Removal of a temporary colostomy placed two years ago and an autologous repair using a component separation technique are planned. Which of the following techniques is LEAST likely to preserve innervation of the rectus muscles in this patient? A ) Endoscopic release of the external oblique aponeurosis B ) Laparoscopic division of the transversalis muscle C ) Periumbilical perforator sparing components release D ) Use of an anterior sheath fascial turnover flap E ) Use of a rectus muscle medial turnover flap

The correct response is Option E. The original description of component separation technique of the abdominal wall by Ramirez includes the following maneuvers: elevation of the skin and subcutaneous fat off of the sheath and oblique fascia, division of the external oblique aponeurosis with elevation of the external oblique laterally, and selective scoring of the posterior rectus sheath. Important modifications to this technique, which can provide up to 10 cm of advancement per side, include preservation of the periumbilical perforators, endoscopic release of the external oblique, laparoscopic release of the transversalis only, and anterior sheath fascial flap to provide additional midline reach. Harvesting the rectus muscle as a turnover flap will provide additional vascularized tissue medially, but this maneuver divides the intercostal nerves that travel between the internal oblique and transversalis muscle, providing motor supply to the rectus. The denervated muscle loses its previous advantage as an innervated, functional flap.

A 46-year-old woman undergoes breast reconstruction with a pedicled transverse rectus abdominis musculocutaneous (TRAM) flap. Weight is 185 lb (84 kg); BMI is 32 kg/m2. The donor site is reconstructed with mesh. Six months postoperatively, the patient develops a bulge at the donor site. Which of the following best represents the deepest layer of the anterior rectus sheath when it is harvested caudal to the arcuate line? A) External oblique aponeurosis B) Internal oblique aponeurosis C) Rectus abdominis fascia D) Transversalis fascia E) Transversus abdominis aponeurosis

The correct response is Option E. The rectus sheath is the semifibrous compartment that encompasses the rectus abdominis muscle and consists of an anterior and posterior sheath created by the aponeurotic extensions of the external oblique, internal oblique, and transversus abdominis muscles. Proximal to the arcuate line, which is located approximately at the level of the anterior superior iliac spine, the anterior rectus sheath comprises the aponeuroses of the external oblique and the anterior leaf of the internal oblique. The internal oblique has two leaves, the deeper of which contributes to the posterior rectus sheath along with the transversus abdominis and transversalis fascia. At the level of the arcuate line, the posterior leaf of the internal oblique aponeurosis and the transversus abdominis aponeurosis travel superficially to the rectus abdominis, making the posterior sheath very weak. When the anterior rectus sheath is defective at this level, the likelihood for bulging or hernia is high. The level of the arcuate line is not always clear from topographical landmarks, which can make the planning of a transverse rectus abdominis musculocutaneous (TRAM) flap more difficult and increase the risk for a hernia complication.

A 29-year-old woman comes to the office because of a firm, mildly tender, well-circumscribed mass of the abdomen. A photograph is shown. The mass has been slowly increasing in size for the past 6 months. CT scan shows a mass that occupies the left musculofascial abdominal wall, including the rectus, external, and internal oblique muscles, and penetrates through the anterior rectus sheath. Which of the following is the most appropriate management? A) Neoadjuvant chemotherapy B) Radiation therapy C) Wide local excision, bilateral component separation, adjuvant chemotherapy D) Wide local excision, mesh placement, radiation therapy E) Wide local excision, right component separation, mesh reinforcement

The lesion in this patient is a desmoid tumor, also known as aggressive fibromatosis. It is a benign tumor, usually found in younger patients between 10 and 40 years old, and is locally aggressive. It is oftentimes associated with pregnancy and prior surgery, and can frequently recur. Treatment is en bloc full-thickness wide local excision (usually with frozen section confirmation of negative margins). As aggressive full-thickness abdominal wall resection is standard of care, reconstruction is more challenging. If midline fascia can be reapproximated, it should be, as primary fascial closure is associated with the lowest hernia recurrence rates. Reinforcement with mesh has been prospectively demonstrated to reduce recurrence rates even further, especially in defects over 4 cm. If midline fascial reapproximation is not possible, reduction in the size of the defect is crucial to decrease recurrence rates. This is done by component separation. However, in this case, only a right component separation is possible, given that the tumor has invaded the left rectus muscle and obliques, precluding their use for myofascial advancement. If the obliques had been spared, a component separation could still have been attempted even if there were violation of the rectus. The most durable reconstruction would be achieved if midline fascial reapproximation were possible with mesh reinforcement. Second best would be reduction in the size of the defect with a right component separation and placement of mesh as a bridging underlay. There is no role for neoadjuvant chemotherapy or radiation therapy in the treatment of these tumors.

A 62-year-old woman presents with a new-onset draining sinus of the left thoracic cage with associated indurated skin. Medical history includes bilateral breast cancer that was managed with bilateral radical mastectomy with radiation therapy 27 years ago. On CT scan, the image (shown) is consistent with osteoradionecrosis. Resection of affected skin, soft tissue, and thoracic cage produces a 35 × 20-cm soft-tissue defect and a skeletal defect spanning five ribs. A photograph of the defect is shown. The thoracic cage is fibrotic and noncompliant because of previous radiation. Which of the following approaches is most appropriate for reconstruction?

The most appropriate option for this patient is a left latissimus dorsi muscle flap with skin graft over acellular dermal matrix, given the alternatives listed. Basic principles of thoracic reconstruction include: debridement of devitalized tissue, removal of foreign bodies, establishment of healthy wound bed, restoration of stability/structure (generally reconstruction of skeleton if more than four ribs or a greater than 5-cm-diameter defect is involved), restoration of normal respiratory mechanics, protection of vital structures/organs, obliteration of dead space, provision of durable coverage, and delivery of an aesthetic result. However, if a patient has been previously irradiated, and therefore loses compliance of the thoracic cage because of radiation-induced fibrosis, skeletal reconstruction may not be mandatory if there is no paradoxical motion of the thoracic cage upon respirations and there is preservation of respiratory efficiency. Such is the case with this patient. A left rectus turnover flap would not be a good option for two reasons: 1) as can be seen in the image, the left internal mammary artery has been harvested, thereby compromising the superior epigastric vessel on which this flap would be based, and 2) it is insufficient to provide enough soft-tissue coverage of a defect this size. Furthermore, as indicated above, methyl methacrylate would not be mandatory in this patient. A right pectoralis turnover flap is insufficient to cover a defect this size. A free omental flap can be used to reconstruct this defect (as can a pedicled omental flap), but again, thoracic skeletal reconstruction would not be mandatory in this previously irradiated patient; furthermore, even if it were, titanium mesh and reconstruction plates would not be utilized. A reverse abdominoplasty flap (Ryan procedure) would not be able to cover a defect this size.

A 59-year-old man with hypertension, peripheral vascular disease, and coronary artery disease has sternal osteomyelitis after coronary artery bypass grafting with saphenous vein and left internal mammary artery grafts. Reconstruction with bilateral pectoralis advancement flaps is performed, but the flaps do not survive. Debridement is performed, and a defect remains. A photograph is shown. Which of the following is the most appropriate reconstruction? A ) Adjacent tissue transfer and coverage with bilateral skin advancement flaps B ) Coverage with left rectus abdominis turnover flap and skin grafting C ) Coverage with left superior epigastric artery perforator fasciocutaneous flap D ) Coverage with omental flap and skin grafting E ) Coverage with right latissimus myocutaneous flap

The most appropriate option in the patient described is an omental flap with skin grafting. The defect encompasses the entirety of the sternum, from the sternal notch to the xiphoid. The first-line muscle flaps for this defect would usually be bilateral pectoralis muscle flaps (that do not include a left pectoralis turnover flap option due to the lack of a left internal mammary artery (IMA) used for the coronary graft). However, this option has already been used. An omental flap has an axial blood supply that is not compromised (the gastroepiploic) and the ability to completely span the defect and obliterate the dead space; the skin graft provides the skin coverage needed to complete the reconstruction. Hence, it is the optimal choice in this patient. An adjacent tissue transfer of random skin flaps bilaterally would not obliterate the dead space and would not provide robust axial blood supply to the necessary area, with the tenuous coverage existing along the sternal midline, exactly where the most vital blood supply would be necessary. A left rectus abdominis turnover flap would not be an appropriate option for two reasons: 1) the left IMA has been harvested, thereby compromising the superior epigastric vessel on which this flap would be based; and 2) it would not reach the upper portion of the defect. A left superior epigastric artery perforator fasciocutaneous flap would not be an appropriate option for two reasons: 1) the pedicle is compromised from the left IMA harvest; and 2) muscle flaps have been proven to be optimal for sternal defects more than fasciocutaneous flaps. A right latissimus muscle flap may be a viable choice to get full coverage of the defect with dead space obliteration. However, the option indicates this is a myocutaneous flap, which would not allow for sufficient skin to be harvested to reconstruct the size of this defect.

A 41-year-old man is being evaluated prior to ventral hernia repair. History includes a traumatic abdominal injury with exposed bowel 4 years ago treated with negative pressure dressings and skin grafting. A separation of components technique will be used. The connection between which of the following layers will most likely remain intact during this procedure? A ) Bowel and fascial edge B ) External oblique and internal oblique C ) External oblique and subcutaneous layer D ) Internal oblique and transversus abdominis E ) Rectus muscle and posterior rectus sheath

The principle of component separation is that the layers of the abdominal wall are able to be mobilized to a greater degree when they are separated from one another. In a ventral hernia repair, the bowel is freed from the fascial edges. Large skin flaps are developed that expose the abdominal fascia. The external oblique layer is separated from the internal oblique layer just lateral to the rectus sheath. Incising the posterior rectus sheath can add 1 to 2 cm of additional mobilization if necessary. The internal oblique muscle is usually not separated from the transversus abdominis muscle because it contains the intercostal nerves and blood vessels. This makes dissection difficult, bloody, and heightens the risk of denervating the rectus abdominis muscle.