Faculty Bibliography

BACKGROUND: The purpose of this study was to investigate whether lymphatic reconstitution and regeneration occurs after clinical facial transplantation using indocyanine green lymphography and immunohistochemical markers. METHODS: Allograft skin biopsies at multiple posttransplant time points were stained with Lyve1 lymphatic antibody and other endothelial antibodies. Staining intensity was interpreted on a scale of none, mild, moderate, and strong by 2 investigators and consolidated by a third party for final interpretation. Standardized real-time lymphography was performed at various posttransplant time points to evaluate lymphatic reconstitution and regeneration. RESULTS: Forty-two biopsies were evaluated at 15 different time points from posttransplant days 7 to 420. Strong Lyve1 staining was observed in 52.4%, moderate staining in 14.3%, and weak staining in 33.3% of biopsies. Strong staining was present on days 7, 10, 44, 79, 269, 402, and 420. Three lymphographic studies were conducted at 8.5, 30, and 35 months posttransplant. Initial drainage via distinct lymphatic channels with abrupt dermal splash and lymphostasis was observed at 8.5-month posttransplant. At 30- and 35-month posttransplant, communication of multiple lymphatic channels between donor tissue and recipient tissue was evident with distinct drainage into native recipient cervical lymph nodes. This correlated with ongoing clinical resolution of facial edema and was unaffected by 3 episodes of acute rejection. CONCLUSIONS: These findings support ongoing lymphatic reconstitution between the donor facial allograft and recipient native tissue. Donor lymphatic regeneration begins after facial transplantation and continues long term. This mechanism may be responsible for the temporal and spatial process of lymphatic reconstitution with recipient lymphatic channels.

BACKGROUND: Wide variations in fat graft survival have been reported. The authors hypothesize that treating the adipose tissue on Telfa gauze creates a processed lipoaspirate with a more functional adipokine profile that improves fat graft survival. METHODS: Suction-assisted lipoaspirate was harvested from humans and was either processed by centrifugation, rolled on Telfa gauze, or left unprocessed. Progenitor cell populations were quantified and characterized by flow cytometry. Glycerol-3-phosphate dehydrogenase assay was used to measure the functional adipocytes. The lipoaspirates were grafted into (n = 45) wild-type mice and harvested to assess fat graft persistence. Vascular endothelial growth factor and platelet-derived growth factor-BB secretions were measured by enzyme-linked immunosorbent assay technique. RESULTS: Centrifuged lipoaspirate had a greater number of progenitor cells per gram of tissue than Telfa-processed and unprocessed lipoaspirate. However, Telfa-processed lipoaspirate had a greater number of functional adipocytes (0.104 U/ml) than centrifuged (0.080 U/ml) and unprocessed lipoaspirate (0.083 U/ml) on glycerol-3-phosphate dehydrogenase assay (p < 0.05). After 10 weeks of grafting, it had greater fat graft persistence (70.9 +/- 6.2 percent) than centrifuged (56.7 +/- 5.5 percent) and unprocessed lipoaspirate (42.2 +/- 2.7 percent) (p < 0.05). It also maintained a greater secretion of vascular endothelial growth factor and platelet-derived growth factor-BB at weeks 1 and 2 than centrifuged and unprocessed lipoaspirate. Furthermore, CD31 staining demonstrated an increase in vascular density of the Telfa-processed lipoaspirate at week 2 compared with the centrifuged lipoaspirate (37 +/- 1 percent and 14 +/- 4 percent per high-power field; p < 0.05). CONCLUSIONS: Lipoaspirate processing technique has a significant impact on fat graft survival rate. Increasing the number of functional adipocytes by processing the fat on Telfa gauze may augment the secretion of angiogenic and mitogenic adipokines within the graft, thereby improving its survivability. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

BACKGROUND: Open tibia fractures are commonly stratified by the Gustilo classification, an orthopedic grading system that does not incorporate the presence of arterial injury when limb perfusion is intact. In the authors' experience, however, the presence of arterial injury appears to negatively impact microsurgical outcomes. METHODS: In a retrospective review of 806 lower extremity reconstructions between 1979 and 2016, 361 soft-tissue flaps performed for Gustilo type IIIB/C coverage met inclusion criteria. Patient demographics, flap characteristics, and outcomes were analyzed. RESULTS: Most patients suffered type IIIB [n = 332 (91.9 percent)] injuries; 29 (8.0 percent) had type IIIC injuries. Preoperative angiography [n = 243 (67.3 percent)] demonstrated arterial injury in 126 (51.8 percent); 27 arterial injuries were identified intraoperatively; and the overall incidence was 153 of 361 (42.4 percent). Complications occurred in 143 flaps (39.6 percent) and included 37 partial losses (10.2 percent) and 31 total losses (8.6 percent). Injured recipient arteries [n = 62 (17.2 percent)] had more complications (p = 0.004); specifically, increased take-backs (p = 0.009). Decreasing vessel runoff increased the risk of complications (p = 0.025), take-backs (p = 0.007), and total flap failures (p = 0.024) accordingly. Specifically, among grade IIIB injuries, controlling for age, sex, time since injury, and vein number, single-vessel runoff was associated with higher rates of complications (relative risk, 3.07; p = 0.012), take-backs (relative risk, 3.43; p = 0.013), and total flap failures (relative risk, 4.80; p = 0.010) compared with three-vessel runoff. CONCLUSIONS: Arterial injury was common among Gustilo type IIIB patients and correlated with increased reconstructive complications. Nonischemic arterial injury appears to negatively impact reconstructive outcomes and should be accounted for when considering free tissue transfer for lower extremity salvage. The authors propose a 3-2-1 modification of the Gustilo type IIIB classification to incorporate degree of arterial injury, as it appears to add prognostic value and certainly influences the reconstructive plan. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, IV.

PURPOSE/OBJECTIVE:Consolidation is a standard part of most post-distraction protocols. This study aims to determine whether the deliberate omission of a consolidation period following mandibular distraction (MD) in neonates with Pierre Robin sequence (PRS) affected the airway outcomes and complication rates. PATIENTS AND METHODS/METHODS:A retrospective chart review of 28 neonates with PRS who underwent MD for severe airway obstruction between 2009 and 2014 was performed. Neonates were split into 2 cohorts: those with a very short or no consolidation (no consolidation group, n = 18) and those with a traditional consolidation period (consolidation group, n = 10). RESULTS:Mean consolidation length was 25 days in the conventional consolidation group and 1.5 days in the no consolidation group (P < 0.01). Postoperatively, both groups showed equivalent improvements in their obstructive index as measured by polysomnography. Compared with the patients who underwent convention consolidation, patients in the "no consolidation" group did not require a greater number of repeat distraction, supplemental oxygen, or tracheostomy. Nor was there any significant difference in the number of complications between the 2 groups. CONCLUSION/CONCLUSIONS:In neonates with PRS treated with MD for severe airway obstruction, the omission of a consolidation period does not appear to significantly affect the complication rate or resolution of airway obstruction.

BACKGROUND: Left ventricular assist devices (LVADs) have become useful adjuncts in the treatment of patients with end-stage heart failure. LVAD implantation is associated with a unique set of problems; one such problem is device infection. We report our experience with flap salvage of infected and/or exposed LVAD hardware. METHODS: Between 2011 and 2016, 49 patients underwent LVAD implantation at our institution. Patients were then categorized by infectious status: systemic infection not directly involving the LVAD device, hardware infection responsive to antibiotics, and exposure of LVAD hardware or device infection refractory to antibiotics requiring debridement and flap coverage. RESULTS: Approximately 50% of device-related infections resolved with either oral or intravenous antibiotics while the other 50% necessitated debridement and coverage with healthy tissue. In total, 12 patients (24%) developed a device-related infection ranging from superficial driveline cellulitis to purulent pocket infections. Seven patients (14%) required extensive debridement and/or flap coverage. CONCLUSION: Early debridement and coverage of exposed hardware are crucial to successfully treating these LVAD infections.

OBJECTIVE:Driveline infection is a common complication of durable left ventricular assist device support. The majority involve the driveline exit site and can be treated with antibiotics and local wound care. Less frequently, these infections extend into deeper tissues and surgical debridement is necessary. Few studies have described the surgical strategy for treatment of deep driveline infection or have reported long-term outcomes. With a growing population of patients being implanted as destination therapy, there is an obvious need to evaluate and optimize treatment for complex driveline infections. METHODS:Outcomes of patients undergoing durable left ventricular assist device implantation at a single center between 2011 and 2017 were reviewed retrospectively. Data including occurrence of driveline infection, pathogen, time to driveline infection, and treatment strategy were abstracted from the electronic medical record. RESULTS:Driveline infection occurred in 10 (16.4%) of 61 patients at a median of 362 days (Q1 = 99, Q3 = 694) after primary left ventricular assist device implantation. Three (30.0%) of 10 driveline infections were categorized as deep and did not resolve with intravenous antibiotic therapy. In these cases, a multistage approach that included initial debridement and exteriorization of the infected driveline, followed by delayed surgical relocation of the driveline in a clean vascularized soft tissue bed, was used. Long-term device salvage was achieved in all cases. CONCLUSIONS:An aggressive surgical strategy, including debridement and formal relocation of the driveline exit site, can result in long-term device salvage after deep driveline infection. This approach is a less invasive alternative to device exchange for refractory driveline infections.

OBJECTIVE: Examine oral complications 6 months after modern radiation therapy (RT) for head and neck cancer (HNC). METHODS: Prospective multi-center cohort study of HNC patients receiving Intensity-Modulated Radiation Therapy (IMRT) or more advanced RT. Stimulated whole salivary flow, maximal mouth opening, oral mucositis, oral pain, oral health-related quality of life (OH-QOL), and oral hygiene practices, were measured in 372 subjects pre-RT and 216 at 6 months from start of RT. RESULTS: Mean stimulated whole salivary flow declined from 1.09 ml/min to 0.47 ml/min at 6 months (p < 0.0001). Mean maximal mouth opening reduced from 45.58 mm to 42.53 mm at 6 months (p < 0.0001). 8.1% of subjects had some oral mucositis at 6 months, including 3.8% with oral ulceration. Mean overall pain score was unchanged. OH-QOL was reduced at 6 months, with changes related to dry mouth, sticky saliva, swallowing solid foods, and sense of taste (p