An anatomical study of external carotid artery vascular territories in face and midface flaps for transplantation.

BACKGROUND: The technical success of facial composite tissue allotransplantation demands full understanding of superficial and deep perfusion for reliable microvascular transfer. Candidates with composite midface defects require an appreciation of the circulatory patterns to design a composite midface allotransplant. METHODS: External carotid vascular territories were evaluated in 10 cadavers to determine the reliability of facial soft-tissue flaps based on a single vascular pedicle. The right common carotid artery was injected with red latex and the left was injected with blue latex. Dual perfusion was confirmed by purple, following two-color mixing. Vascular pedicles included the superficial temporal, transverse facial, and facial arteries. In five additional cadavers, the midface segment was isolated by Le Fort III osteotomy after two-color latex injection with inclusion of the internal maxillary vascular pedicle. Cadavers were imaged with three-dimensional computed tomographic reconstructions following latex injection to confirm perfusion patterns. RESULTS: In soft-tissue facial flaps, unilateral carotid dominance was seen in the nasal dorsum and tip, confirming reliable supply by a single external carotid artery. In midface flaps, bilateral perfusion was seen in the maxilla. Ipsilateral perfusion was observed at the zygomaticomaxillary complex without any contralateral contribution. CONCLUSIONS: Dual soft-tissue perfusion was confirmed in most specimens at the nasal, central face, and maxilla. The inclusion of the maxilla in the design of a facial composite allotransplant demands bilateral vascular pedicles based on the internal maxillary arteries. The authors highlight a procurement strategy for design of such flaps.

A diagnostic predictor model for indeterminate or suspicious thyroid FNA samples.

BACKGROUND: The management of patients with thyroid fine-needle aspiration (FNA) specimens that are neither benign nor malignant still remains problematic. Efforts to improve their management have focused on identifying risk factors that predict malignancy. This study seeks to identify clinical and tumor characteristics that predict thyroid malignancy among patients with indeterminate or suspicious FNA and to develop a diagnostic predictor model. METHODS: The records of 639 patients with an indeterminate or suspicious thyroid FNA between January 1995 and April 2005 were reviewed. Patient and tumor characteristics were evaluated for their potential to predict malignancy in the final surgical histopathology. A diagnostic predictor model was designed based on statistically significant predictors. Patients seen between April 2005 and April 2007 were used to validate the model. RESULTS: Patient age, nodule size, and FNA cytopathology were identified as risk factors. Patients at extremes of age were at increased risk. Patients 50 years of age had the lowest risk of malignancy. For patients less than age 50, the risk increased 3% for each year decrease in age (p = 0.001). After 50, the risk increased 3.4% for each year increase in age (p = 0.016). Nodules 2.5 cm had the lowest likelihood of malignancy. For smaller nodules, the risk increased 53% per cm decrease in size (p < 0.001). For larger nodules, the risk increased 39% per cm increase (p < 0.001). Patients with FNA cytology suspicious for papillary thyroid carcinoma had the greatest risk of malignancy (p < 0.001). CONCLUSIONS: A predictor model was created using the variables age, nodule size, and FNA cytology to predict thyroid malignancy.

Dural repair with grafts using the gastrointestinal anastomosis stapler.

Repair of large dural defects requires patch duraplasty with grafts. The ideal dural repair is watertight, inert, and resistant to adhesions. When a sizable defect requires multiple grafts, the grafts can be hand sewn to form one large sheet. This method can add significant time to the operative course. In addition, the risk of cerebrospinal fluid leakage is high with multiple hand-sewn seams. To reduce operating time and decrease the risk of cerebrospinal fluid leakage, we have used the 80-mm gastrointestinal anastomosis stapler with 3.8-mm titanium staples to create large sheets of graft material for dural repair. In 3 patients requiring repair of large dural defects, this method has produced seams that were atraumatic and watertight.

A heterotopic primate model for facial composite tissue transplantation.

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.

Efficacy of a percutaneous A1 pulley release technique with identification of anatomic differences between genders.

BACKGROUND: This cadaver study investigates the efficacy and safety of the Biomet knife and technique for percutaneous A1 pulley release. We also evaluate the anatomic relationship between specific palmar surface landmarks and relevant underlying structures and identify differences between genders. METHODS: Eighty percutaneous A1 pulley releases, excluding the thumb, were performed on 20 fresh human cadaver hands (10 male, 10 female). RESULTS: Complete release was obtained in 60 of 80 fingers. Success rates for each surgeon improved markedly as the study progressed. There were no significant differences between males and females regarding the distance between a standardized incision site and the proximal edge of the A1 pulley. CONCLUSIONS: A learning curve exists for percutaneous A1 pulley release using the Biomet knife and technique. The extended distal palmar crease is a reasonable incision site for percutaneous release of the index, middle, and ring A1 pulleys in both men and women as the A1 pulley begins just distal to this surface landmark.

Sustained antibody-dependent cell-mediated cytotoxicity (ADCC) in SIV-infected macaques correlates with delayed progression to AIDS.

Although several in vitro lines of evidence support the potential power of antibody-dependent cell-mediated cytotoxicity (ADCC) in controlling HIV infection, the role of ADCC in the pathogenesis of HIV infection in vivo remains uncertain. There are few studies to date that longitudinally determine the plasma ADCC activity in HIV-infected subjects. We sought to establish an SIV/macaque model to perform such a longitudinal study. In the rhesus macaque cohort studied here, three of five macaques (designated Group 1) maintained higher plasma ADCC activity for at least 1 year after inoculation with SIV/17E-Br. The ADCC activity of the two remaining macaques (Group 2) fell 12 weeks after inoculation. There were also differences in longitudinal measurements of anti-SIV envelope IgG titers and CD4 counts. Group 1 macaques maintained higher antienvelope IgG titers and higher CD4(+) T cell numbers as late as 60 weeks postinoculation, while Group 2 macaques had significantly lower titers at 1 year postinoculation and lower CD4(+) T cell counts by 30 weeks postinoculation. Our study shows a correlation between humoral response, ADCC activity, and disease progression (as measured by CD4(+) T cell counts). In these animals, ADCC activity is associated with delayed progression to AIDS. Further studies are underway to determine if ADCC is a protective immune response in SIV infection or if ADCC is a marker of intact cellular and humoral immune responses.