Faculty Bibliography

OBJECTIVE: Determine long-term loss of mandible height with use of stress-shielding reconstruction plates for free fibula flap mandible reconstruction. DESIGN: Retrospective single-blinded medical record review. SUBJECTS: Seventy patients who had fibula free flap mandible reconstructions performed for 10 years. Patients who underwent radiotherapy were excluded. METHODS: Review of 70 fibula free flap mandible reconstructions performed for the last 10 years in a city hospital revealed 7 patients (10%) who had resections for benign odontogenic diseases. All had a three-dimensional cast model made, on which the reconstruction plate was bent to the desired shape preoperatively. Free fibula height on panoramic x-ray images taken preoperatively and at 2 and 12 months postoperatively. RESULTS: Seven (10%) patients met criteria for the study. Bone height was maintained at 2 months postoperatively, but at 12 months, there was a statistically significant loss of fibular bone height averaging 20% in the anterior, body, and ramus areas (P < 0.05). Despite this, all patients were considered eligible for dental rehabilitation, and 4 of 7 patients have had osseointegrated implants placed. CONCLUSIONS: As opposed to miniplates, increased resorption may have been due to the stress-shielding phenomenon unique to a reconstruction plates. However, this did not seem to affect the ability to place osseointegrated implants.

BACKGROUND: The study of human autologous fat grafting has been primarily anecdotal. In this study, the authors aim to develop a murine model that recapitulates human fat grafting to study the fate of injected fat and the cell populations contained within. METHODS: The authors' method of fat harvesting and refinement has been described previously. The authors injected nude and tie2/lacZ mice with 2 ml of human lipoaspirate placed on the dorsal surface in a multipass, fan-like pattern. Fatty tissue was injected in small volumes of approximately 1/30 ml per withdrawal. The dorsal skin and associated fat was excised at various time points. Sections were stained with hematoxylin and eosin and cytochrome c oxidase IV. Transgenic tie2/lacZ samples were stained with X-galactosidase. At the 8-week time point, volumetric analysis was performed. RESULTS: Volumetric analysis at the 8-week time point showed 82 percent persistence of the original volume. Gross analysis showed it to be healthy, nonfibrotic, and vascularized. Hematoxylin and eosin analysis showed minimal inflammatory or capsular reaction, with viable adipocytes. Fat grafted areas were vascularized with multiple blood vessels. Cytochrome c oxidase IV human-specific stain and beta-galactosidase expression revealed these vessels to be of human origin. CONCLUSIONS: The authors have developed a murine model with which to study the fate of injected lipoaspirate. There is a high level of persistence of the grafted human fat, with minimal inflammatory reaction. The fat is viable and vascularized, demonstrating human-derived vessels in a mouse model. This model provides a platform for studying the populations of progenitor cells known to reside in lipoaspirate

Free transverse rectus abdominis myocutaneous and deep inferior epigastric perforator flaps represent increasingly popular options for breast reconstruction. Although several retrospective, small-scale studies comparing these flap, have been published, most have failed to find a significant difference in flap complication rates or donor-site morbidity. We systematically reviewed the Current literature, and Subsequently pooled and analyze(] data from included studies. Included studies reported flap complications and/or donor site morbidities for both flap types. Eight studies met the inclusionary, criteria. For flap complications, there was a statistically significant difference between deep interior epigastric perforator and free transverse rectus abdominis myocutaneouS flaps in fat necrosis rates (25.5 +/- 0.49 vs. 11.3%, +/- 0.41%. P < 0.001) and total necrosis rates (4.15 +/- 0.08 vs. 1.59% +/- 0.08%, P = 0.044). Partial necrosis rates were not statistically Significant (3.54 +/- 0.07 vs. 1.60% +/- 0.07%, P = 0.057). For donor-site morbidity. there was no statistically significant difference in abdominal bulge (8.07 +/- 0.23 vs. 11.25% +/- 0.29%, P = 0.28). Multicenter. prospective studies are needed to further investigate differences between these flap options

Large, traumatic wounds around the proximal third of the lower extremity may have disrupted local vasculature, potentially obviating local pedicled options. However, free-tissue transfer to this area is technically challenging given the resulting paucity of recipient options and the depth of principal blood vessels. We present an anatomic and radiographic study of the proximally based peroneal vascular bundle as a recipient option in the proximal leg. Optimal approach was prone, through an incision over the fibula with dissection between lateral and posterior compartments. Magnetic resonance angiography demonstrated consistent vascular anatomy between patients. A proximally based peroneal vascular bundle protected by a cuff of flexor hallucis longus was used as a recipient vessel in free flap reconstruction of an open knee wound. The bundle itself does not require coverage by virtue of its own local muscle cuff. Caveats for its use include the need for adequate leg inflow and foot outflow.

Large acquired intracranial defects can result from trauma or surgery. When reoperation is required because of infection or tumor recurrence, management of the intracranial dead space can be challenging. By providing well-vascularized bulky tissue, intracranial microvascular free flaps offer potential solutions to these life-threatening complications. A multi-institutional retrospective chart and radiographic review was performed of all patients who underwent microvascular free-flap surgery for salvage treatment of postoperative intracranial infections between 1998 and 2006. A total of six patients were identified with large intracranial defects and postoperative intracranial infections. Four patients had parenchymal resections for tumor or seizure and two patients had posttraumatic encephalomalacia. All patients underwent operative debridement and intracranial free-flap reconstruction using the latissimus dorsi muscle ( N = 2), rectus abdominis muscle ( N = 2), or omentum ( N = 2). All patients had titanium ( N = 4) or Medpor ( N = 2) cranioplasties. We concluded that surgery or trauma can result in significant intracranial dead space. Treatment of postoperative intracranial infection can be challenging. Vascularized free tissue transfer not only fills the void, but also provides a delivery system for immune cells, antibodies, and systemically administered antibiotics. The early use of this technique when intracranial dead space and infection coexist is beneficial

The success of lower extremity microsurgical reconstructions may be compromised postoperatively secondary to several factors, including thrombosis, infection, bleeding, and edema. To address edema, surgeons may use protocols for gradually dangling and/or wrapping the affected extremity. Such protocols vary widely among surgeons and are typically based on training and/or prior experience. To that end, we distributed surveys to five plastic surgeons who are experienced in microvascular lower extremity reconstruction at five different institutions. The surveys inquired about postoperative management protocols for lower extremity free flaps with regard to positioning, compression, initiation and progression of postoperative mobilization, nonweightbearing and weightbearing ambulation, assessment of flap viability, and flap success rate. These protocols were then evaluated for similarities to create a consensus of postoperative management guidelines. Progressive periods of leg dependency and compression therapy emerged as important elements. Although the consensus protocol developed in this study is considered safe by each participant, we do not intend for these recommendations to serve as a standard of care, nor do we suggest that any one particular protocol leads to improved outcomes. However, these recommendations may serve as a guide for less experienced surgeons or those without a protocol in place

BACKGROUND: Impaired diabetic wound healing is due, in part, to defects in mesenchymal progenitor cell tracking. Theoretically, these defects may be overcome by administering purified progenitor cells directly to the diabetic wound. The authors hypothesize that these progenitor cells will differentiate into endothelial cells, increase wound vascularity, and improve wound healing. METHODS: Lineage-negative progenitor cells were isolated from wild-type murine bone marrow by magnetic cell sorting, suspended in a collagen matrix, and applied topically to full-thickness excisional dorsal cutaneous wounds in diabetic mice. Application of lineage-positive hematopoietic cells or acellular collagen matrix served as comparative controls (n = 16 for each group; n = 48 total). Time to closure and percentage closure were calculated by morphometry. Wounds were harvested at 7, 14, 21, and 28 days and then processed, sectioned, stained (lectin/DiI and CD31), and vascularity was quantified. RESULTS:: Wounds treated with lineage-negative cells demonstrated a significantly decreased time to closure (14 days) compared with lineage-positive (21 days, p = 0.013) and collagen controls (28 days, p = 0.004), and a significant improvement in percentage closure at 14 days compared with the lineage-positive group (p < 0.01) and the collagen control (p < 0.01). Fluorescently tagged lineage-negative cells remained viable in the wound for 28 days, whereas lineage-positive cells were not present after 7 days. Lineage-negative, but not lineage-positive, cells differentiated into endothelial cells. Vascular density and vessel cross-sectional area were significantly higher in lineage-negative wounds. CONCLUSION: Topical progenitor-cell therapy successfully accelerates diabetic wound closure and improves wound vascularity