Faculty Bibliography

BACKGROUND: Microvascular free flap anastomoses performed for lower extremity reconstruction are traditionally proximal to the zone of injury. The authors assessed the feasibility and outcomes of microvascular free flaps with anastomoses performed distal to the zone of injury. METHODS: The authors retrospectively reviewed all microvascular free flaps performed at their institution over the past 10 years for lower extremity reconstruction and compared this group with their previously published experience (January of 1979 through August of 1995). Between September of 1995 and May of 2005, 119 flap procedures were performed for lower extremity reconstruction. Twenty-eight flaps (24 percent) were anastomosed distal to the zone of injury and 87 (76 percent) were anastomosed proximally. There were insufficient data on the location of the anastomosis for four free flaps (all successful). RESULTS: Twenty-seven of 28 distal microvascular free flaps were successful (96 percent); two (7 percent) required emergent postoperative reexploration of the anastomosis. Of the 87 proximal flaps, 79 (91 percent) were successful and eight (9 percent) failed. There was no statistically significant difference in the success rate of microvascular free flaps between the proximal and distal anastomosis groups (p = 0.30, Fisher's exact test). Combined with the data from the authors' previous series (January of 1979 to August of 1995), there were 63 free flaps with anastomosis performed distal to the zone of injury; 61 (97 percent) were successful. CONCLUSION: The authors' extensive 25-year experience with lower extremity reconstruction demonstrates that in appropriately selected patients, free tissue transfer to recipient vessels distal to the zone of injury is reliable and in certain cases preferable

The ability to affect gene expression via topical therapy has profound therapeutic implications for conditions characterized by open wounds including cutaneous neoplasms, thermal injury, skin disorders and dysfunctional wound healing. Specifically targeting local gene expression avoids systemic toxicity and simplifies treatment. We have developed a new method of topical matrix-based short interfering RNA application to precisely and effectively silence local gene expression in nondelimited wounds

BACKGROUND: Gustilo IIIB fractures involve high-energy tibial fractures for which there is inadequate soft tissue coverage. In addition to orthopedic fixation, these injuries require soft tissue reconstruction, often in the form of a microvascular free flap. Although the majority of orthopedic literature favorably compares intramedullary rod fixation to external fixation in open tibial fractures, these studies have not focused on the role of either method of fixation in relation to the soft tissue reconstruction. METHODS: Because we had noted numerous complications after providing free-flap coverage over intramedullary rodded fractures, we sought to investigate whether there were differences in outcomes between free flap-covered lower-extremity fractures which were fixated by external fixation versus intramedullary rods. A retrospective chart review was performed on all patients in our institution who had lower-extremity free flaps for coverage of Gustilo IIIB fractures from 1995-2005 in relation to the type of bony fixation. RESULTS: Of the 38 patients studied, 18 underwent external fixation of the tibial fracture, and 20 had intramedullary rodding. Overall flap survival was 95%, with 1 failure in each group. However, the intramedullary rod group had higher incidences of wound infection, osteomyelitis, and bony nonunion (25%, 25%, and 40%, respectively) than the external fixation group (6%, 11%, 17%, respectively). CONCLUSIONS: For Gustilo IIIB fractures that require free-flap coverage, the added bony and soft tissue manipulation required for intramedullary rodding may disrupt the surrounding blood supply and lead to higher rates of complications that threaten the overall success of the reconstruction. Plastic and orthopedic surgeons should discuss the optimal method of bony fixation for complex tibial fractures when a free flap will likely be needed for soft tissue coverage. This integrated team approach may help minimize complications

BACKGROUND: Lower-extremity reconstruction with microvascular free flap coverage is often the only option for limb salvage. Flap failure rates, however, continue to have higher complication rates than those to other anatomic sites; a significant number of flaps that fail result in amputation. This study retrospectively analyzed patients treated at a single institution who underwent attempted lower-extremity limb salvage with microsurgical techniques over a 25-year period. Of particular interest are the outcome data for patients who had initial free flap failure. PATIENTS AND METHODS: A prospectively maintained database was used to identify patients who satisfy criteria. Every patient who was treated with a microvascular free flap to their lower extremities was identified and included in this analysis. All records were reviewed from 1980 through 2004. Patients who had free flaps to the lower extremity fail after the initial operation were identified and selected for further analysis. RESULTS: Five hundred eighty-eight patients who underwent microsurgical reconstruction of lower extremity wounds had a failure rate of 8.5%. Trauma patients (83%) had a failure rate of 9%. On subset analysis, the failure rate for trauma patients decreased from 11% (1980-1992) to 3.7% (1993-2004). Of patients who had a failed free flap, 18% went on to limb amputation; the remainder was salvaged with secondary free flaps, local flaps, or skin grafting. CONCLUSION: This single institutional experience spanning 25 years represents the longest continual series of lower-extremity free flaps reported in the literature. The improved success rate seen in the second half of the study period is attributed to a more critical selection of free-flap candidates, improved understanding of the physiology surrounding acute trauma and a more sophisticated multidisciplinary team organization

Successful nonextremity replantations, particularly of the facial anatomy and testicles, are rare procedures, and only a handful of cases have been reported. This article reviews the current literature in nonextremity replantations and representative cases performed at the authors' institution. Certain underlying themes and problems are consistently encountered in the surgical management of these cases. These are identified and reviewed. Although the replantation of these body parts remains technically challenging, all efforts should be made, when indicated, to repair these injuries microsurgically, because it currently offers the best reconstructive solution for these patients

Calreticulin (CRT), an intracellular chaperone protein crucial for the proper folding and transport of proteins through the endoplasmic reticulum, has more recent acclaim as a critical regulator of extracellular functions, particularly in mediating cellular migration and as a requirement for phagocytosis of apoptotic cells. Consistent with these functions, we show that the topical application of CRT has profound effects on the process of wound healing by causing a dose-dependent increase in epithelial migration and granulation tissue formation in both murine and porcine normal and impaired animal models of skin injury. These effects of CRTare substantiated, in vitro, as we show that CRT strongly induces cell migration/wound closure of human keratinocytes and fibroblasts, using a wound/scratch plate assay, and stimulates cellular proliferation of human keratinocytes, fibroblasts, and vascular endothelial cells, providing mechanistic insight into how CRT functions in repair. Similarly, in both animal models, the histology of the wounds show marked proliferation of basal keratinocytes and dermal fibroblasts, dense cellularity of the dermis with notably increased numbers of macrophages and well-organized collagen fibril deposition. Thus, CRT profoundly affects the wound healing process by recruiting cells essential for repair into the wound, stimulating cell growth, and increasing extracellular matrix production