Faculty Bibliography

The purpose of this study was to develop a nonhuman primate model for heterotopic composite tissue facial transplantation in which to study the natural history of facial transplantation and evaluate immunosuppressive regimens.A composite oromandibular facial segment transplant based on the common carotid artery was evaluated. Flaps from 7 cynomolgus monkeys were transplanted to the groins of 7 recipients at the superficial femoral artery and vein. The immunosuppressive regimen consisted of thymoglobulin, rapamycin, and tacrolimus. Allograft survival ranged from 6 to 129 days. Histology performed in the long-term survivor at the time of necropsy revealed extensive inflammation and necrosis of the allograft skin; however, muscle and bone elements were viable, with minimal inflammation. This heterotopic facial transplantation model avoids the potential morbidity of mandibular resection and orthotopic facial transplantation. Our work also concurs with the work of other groups who found that the skin component is the most antigenic.

Repair of large complex abdominal hernias with significant loss of domain requires component separation in combination with either a synthetic or biologic interpositional material. We previously described an algorithm for complex abdominal hernia repair, which incorporates Alloderm as an interpositional material and selective use of prolene mesh as an overlay. We now report recurrent laxity in a series of patients who were repaired with interpositional Alloderm alone without prolene mesh overlay. We reviewed all patients who underwent repair of massive ventral hernias and identified 7 patients who presented with abdominal wall laxity following component separation with interpositional Alloderm alone. All patients developed laxity within 12 months and required a secondary procedure. At the time of re-exploration, severe attenuation in the Alloderm was noted. The segment was excised, the edges closed primarily, and prolene mesh was placed as an onlay. Although Alloderm has been reported to be an effective biologic material for abdominal hernia reconstruction, we have noted significant laxity requiring secondary intervention.

BACKGROUND: Posttraumatic, high-energy defects of the midface can be challenging to reconstruct because they involve extensive composite tissue loss and result in significant permanent functional and cosmetic deformity. These injuries require replacement of the bony framework, external soft tissue, and intraoral mucosa. Local skin flaps and nonvascularized bone grafts have been used for reconstruction, but bony resorption and the associated soft-tissue collapse limit long-term viability. The authors present a classification of maxillary defects following high-energy trauma and a treatment algorithm using vascularized bone flaps. METHODS: Fourteen patients with significant maxillary loss from high-energy trauma underwent reconstruction with composite vascularized bone flaps. Eight patients had fibula flaps and six had iliac crest flaps. There were five women and nine men, with a mean age of 36.3 years (range, 21 to 48 years) and a mean follow-up of 18 months (range, 5 to 54 months). RESULTS: Thirteen of the 14 flaps survived. Nine patients had additional procedures. Nine patients had oronasal fistulas and eight were dependent on gastrostomy tubes preoperatively. All patients were able to feed orally without nasal regurgitation postoperatively. All patients achieved stable restoration of the midfacial architecture. CONCLUSIONS: The classification scheme presented centers on the missing maxillary subunits. The reconstructive algorithm is based on the type of defect, tissue requirement, and donor tissues necessary to restore facial projection and prosthodontic rehabilitation. Iliac crest and fibula bone free flaps are ideal for restoring a variety of traumatic maxillary defects. The authors advocate early reconstructive intervention using vascularized bone flaps to achieve superior functional and cosmetic outcomes.

The long-term projection of nipple reconstruction is a challenge. Fifty-eight consecutive female patients underwent 58 nipple reconstructions with modified top hat flap with cartilage graft following breast reconstruction in 54 autologous tissues and 4 implants, respectively. The average neonipple size was 11.5 mm initially and 8.5 mm at a mean follow-up of 44.9 months (range, 24-65 months), with a mean decrease in projection of 26.1%. Thirty-three patients achieved an excellent result, 20 patients a good result, 3 patients a fair result, and 2 patients a poor result, respectively. The complication rate was 12.1% (7 of 58 cases), and there was no statistically significant difference between the immediate and delayed groups; the revision rate was 8.6% (5 of 58 cases). The modified top hat flap with banked costal cartilage graft provides a sustainable solution to the gradual loss of nipple projection, with few complications.

We present the case of an 18-year-old girl with McCune Albright Syndrome (MAS) and a near total mandibular defect reconstructed with a free fibula flap. There are three reports of mandibular reconstruction in a patient with MAS using the free fibula flap; however this case is unique for two reasons. One, the continuity defect in our patient was much larger than previously reported, representing nearly the entire length of the mandible (21 cm) and required the entire harvestable length of the fibula. Two, the progression of the patient's disease limited options for reconstruction and dictated the use of a fibula with small dysplastic changes.

BACKGROUND: Recent clinical trials involving patients with acute coronary syndromes have demonstrated significant reduction in the progression of coronary artery thrombosis using a regimen of aspirin, heparin, and the glycoprotein IIb/IIIa inhibitor tirofiban. Acute coronary syndromes and free tissue transfer are similar pathophysiologically in that they both involve endothelial injury, thrombosis, and ischemia. In this study, the authors investigate tirofiban, combined with aspirin and heparin, for the prevention of microsurgical anastomotic thrombosis in a thrombogenic rat model. METHODS: Using a randomized, controlled, double-blind experimental design, 80 thrombogenic anastomoses were performed on rat femoral arteries (n = 40) and veins (n = 40). Preoperatively, each rat received one of four treatment regimens: aspirin and heparin (regimen 1), aspirin and heparin plus tirofiban (regimen 2), tirofiban alone (regimen 3), or isotonic saline (control) (regimen 4). Vessels were assessed for patency at 5, 15, 30, and 120 minutes after reperfusion and then harvested for microscopic analysis. RESULTS: At 120 minutes after reperfusion, regimen 1 had an arterial and venous patency rate of 80 percent and 70 percent, respectively, whereas the vessel patency rate for regimen 2 was 100 percent. The difference between regimens 1 and 2 was not statistically significant. Regimens 3 and 4 had vessel patency rates of 40 percent or less. The aspirin/heparin and aspirin/heparin/tirofiban groups both demonstrated significantly improved vessel patency and significantly less thrombotic occlusion compared with controls. CONCLUSIONS: Combination therapy with aspirin, heparin, and tirofiban significantly increases arterial and venous patency and decreases anastomotic thrombus formation in thrombogenic anastomoses in rats. The role of glycoprotein IIb/IIIa inhibitors in microsurgery warrants further investigation.

BACKGROUND: Large, complex, posttraumatic and recurrent abdominal hernias present a reconstructive challenge. Multiple techniques have been described to restore the integrity of the abdominal wall, although the indications and applications can be difficult to navigate. The authors propose an algorithm that facilitates the assessment and treatment of secondary large ventral defects. METHODS: The algorithm described involves a systematic approach to abdominal wall reconstruction and was applied to 23 consecutive patients at the R Adams Cowley Shock Trauma Center. Data collected from the chart review included age, body mass index, mechanism of injury, placement of skin graft and use of resorbable mesh before definitive reconstruction, size of defect, number of tissue expanders placed, length of follow-up, and complications. RESULTS: There were six female patients and 17 male patients, with an average age of 36 years. The average follow-up was 7 months. Seventeen patients had posttraumatic laparotomies, five patients had aggressive abdominal wall debridement following necrotizing fasciitis, and one patient developed a large abdominal wall hernia following complications from gastric bypass surgery. All patients underwent delayed abdominal wall reconstruction, with an average time to initial reconstruction of 19.5 months. Sixteen patients had no postoperative complications. Seven patients had complications, including one with an enterocutaneous fistula, one with a partial small bowel obstruction, two with seromas, one with a superficial wound infection, and two with recurrent abdominal wall laxity. CONCLUSIONS: The reconstructive ladder for large, complex abdominal hernias is poorly defined. The proposed algorithm provides a systematic staged approach that incorporates available techniques used for delayed reconstruction of the abdominal wall.