Head and Neck Microsurgeon Practice Patterns and Perceptions Regarding Venous Thromboembolism Prophylaxis

BACKGROUND: Patients undergoing head and neck (H&N) microvascular reconstruction comprise a population at high risk for venous thromboembolism (VTE). Free flap and VTE thromboprophylaxis may coincide but tend to vary from surgeon to surgeon. This study identifies VTE prophylaxis patterns and perceptions among H&N microsurgeons in the United States. METHODS: An online survey on VTE prophylaxis practice patterns and perceptions was emailed to 172 H&N microsurgeons in the United States using an anonymous link. RESULTS: There were 74 respondents (43% response rate). These surgeons completed residencies in otolaryngology (59%), plastic surgery (31%), and oral maxillofacial surgery (7%). Most underwent fellowship training (95%) and have practiced at an academic center (97%) for at least 6 years (58%), performing an average of 42 ± 31 H&N free flap cases per year (range = 1-190). Most adhered to general VTE prophylaxis guidelines (69%) while 11% did not and 20% were unsure. Nearly all surgeons (99%) would provide prophylactic anticoagulation, mostly in the form of subcutaneous heparin (51%) or enoxaparin (44%); 64% additionally used aspirin, while 4% used aspirin alone. The majority of surgeons (68%) reported having postoperative VTE complications, with six surgeons (8%) reporting patient deaths due to pulmonary embolism. A third of the surgeons have encountered VTE prophylaxis-related adverse bleeding events, but most still believe that chemoprophylaxis is important for VTE prevention (92%). While 35% of surgeons were satisfied with their current practice, most would find it helpful to have official prophylactic anticoagulation guidelines specific to H&N free flap cases. CONCLUSION: The majority of microsurgeons experienced postoperative VTE complications after H&N free flap reconstruction despite the routine use of prophylactic anticoagulation. Though bleeding events are a concern, most surgeons believe chemoprophylaxis is important for VTE prevention and would welcome official guidelines specific to this high-risk population

Standard Fixed Enoxaparin Dosing for Venous Thromboembolism Prophylaxis Leads to Low Peak Anti-Factor Xa Levels in Both Head and Neck and Breast Free Flap Patients

INTRODUCTION: Venous thromboembolism (VTE) is a serious complication, particularly in cancer patients undergoing free flap reconstruction. Subcutaneous enoxaparin is the conventional prophylaxis for VTE prevention, and serum anti-factor Xa (afXa) levels are being increasingly used to monitor enoxaparin activity. In this study, free flap patients receiving standard enoxaparin prophylaxis were prospectively followed to investigate postoperative afXa levels and 90-day VTE and bleeding-related complications. METHODS: Patients undergoing free tissue transfer during an 8-month period were identified and prospectively followed. Patients received standard fixed enoxaparin dosing at 30 mg twice daily in head and neck (H&N) and 40 mg daily in breast reconstructions. Target peak prophylactic afXa range was 0.2 to 0.5 IU/mL. The primary outcome was the occurrence of 90-day postoperative VTE- and bleeding-related events. Independent predictors of afXa level and VTE incidence were analyzed for patients that met the inclusion criteria. RESULTS: Seventy-eight patients were prospectively followed. Four (5.1%) were diagnosed with VTE, and six (7.7%) experienced bleeding-related complications. The mean afXa levels in both VTE patients and bleeding patients were subprophylactic (0.13 ± 0.09 and 0.11 ± 0.07 IU/mL, respectively). Forty-six patients (21 breast, 25 H&N) had valid postoperative peak steady-state afXa levels. Among these, 15 (33%) patients achieved the target prophylactic range: 5 (33%) H&N and 10 (67%) breast patients. The mean afXa level for H&N patients was significantly lower than for breast patients (p = 0.0021). Patient total body weight was the sole negative predictor of afXa level (R (2) = 0.47, p \u3c 0.0001). CONCLUSION: Standard fixed enoxaparin dosing for postoperative VTE prophylaxis does not achieve target afXa levels for the majority of our free flap patients. H&N patients appear to be a particularly high-risk group that may require a more personalized and aggressive approach. Total body weight is the sole negative predictor of afXa level, supporting a role for weight-based enoxaparin dosing

Regenerative peripheral nerve interface free muscle graft mass and function

BackgroundRegenerative peripheral nerve interfaces (RPNIs) transduce neural signals to provide high‐fidelity control of neuroprosthetic devices. Traditionally, rat RPNIs are constructed with ~150 mg of free skeletal muscle grafts. It is unknown whether larger free muscle grafts allow RPNIs to transduce greater signal.MethodsRPNIs were constructed by securing skeletal muscle grafts of various masses (150, 300, 600, or 1200 mg) to the divided peroneal nerve. In the control group, the peroneal nerve was transected without repair. Endpoint assessments were conducted 3 mo postoperatively.ResultsCompound muscle action potentials (CMAPs), maximum tetanic isometric force, and specific muscle force were significantly higher for both the 150 and 300 mg RPNI groups compared to the 600 and 1200 mg RPNIs. Larger RPNI muscle groups contained central areas lacking regenerated muscle fibers.ConclusionsElectrical signaling and tissue viability are optimal in smaller as opposed to larger RPNI constructs in a rat model.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/166376/1/mus27138.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/166376/2/mus27138_am.pd