Use of Flow-through Free Flaps in Head and Neck Reconstruction.

Background: Reconstructive obstacles in composite head and neck defects are compounded in reoperated, traumatized, irradiated, and vessel-depleted surgical fields. In cases that require multiple free flaps, recipient vessel accessibility and inset logistics become challenging. Strategic flow-through flap configurations mitigate these issues by supplying arterial inflow and venous outflow to a second flap in a contiguous fashion. This approach (1) permits the use of a singular native recipient vessel, (2) increases the reach of the vascular pedicle, avoiding the need for arteriovenous grafting, and (3) allows for a greater three-dimensional flexibility in configuring soft tissue and bony flap inset. Methods: To demonstrate this technique, we conducted a retrospective review of all head and neck reconstruction patients presenting to us from March 2019 to April 2021. Results: We present seven oncological and two traumatic patients (N = 9) who received flow-through free flaps for head and neck reconstruction. The most common flap used as the flow-through flap was the anterolateral thigh flap (N = 7), followed by the fibula flap (N = 2). Mean follow-up time was 507 days. No flap failures occurred. Conclusion: In head and neck reconstruction, the use of the flow-through principle enables uninterrupted vascular flow for two distinct free flaps in single-stage reconstruction for patients with vessel-depleted, irradiated, and/or reoperated fields. We demonstrate that flow-through flaps in the head and neck may be used successfully for a variety of cases and flaps.

ALT Free Flap Coverage after Carotid Endarterectomy in the Setting of Severe Radiation Changes.

Carotid endarterectomy with patch angioplasty is commonly performed for severe atherosclerotic disease to reduce stroke risk. After neck radiation, loss of tissue planes; reactive fibrosis of skin; contraction; and rarely, necrosis of skin may occur, leading to severe wound complications and possible exposure of carotid artery reconstruction. Historically, local myocutaneous flaps have been performed to provide soft tissue coverage; however, these procedures may be associated with increased donor site morbidity and can be affected by radiation changes. This report describes the novel use of a fasciocutaneous free flap for durable vascularized soft tissue, and the associated secondary benefit of improved suppleness and range of motion. Additionally, the distant location of the donor site allows for an efficient two-team approach. Here, we describe a patient with severe carotid artery disease with a history of multiple surgical procedures and radiation, which was successfully treated with a carotid endarterectomy and bovine patch angioplasty by vascular surgery and immediate free anterolateral thigh flap coverage by our team.

Autologous Mandible Reconstruction in a Hypercoagulable Patient following Multiple Failed Free Flaps.

Coagulopathies affect 3% of free flap patients and are among the leading causes of free flap failure. This report describes the case of a head and neck cancer patient that experienced two remote free flap failures before successful autologous mandibular reconstruction. Following identification of an unrecognized thrombophilic state, a focused anticoagulation strategy was executed, including an intraoperative heparin drip, stringent postoperative maintenance of Factor Xa levels between 0.3 and 0.5 IU per mL, and transition to an outpatient enoxaparin regimen of 1 mg per kg twice daily for 1.5 months following surgery. Here, we demonstrate that free tissue transfer following multiple previous failed attempts in the setting of hypercoagulability remains a viable reconstructive option with close interdisciplinary collaboration, close clinical monitoring, and patient-specific antithrombotic protocols.

Experimental Model of Zygomatic and Mandibular Defects to Support the Development of Custom Three-Dimensional--Printed Bone Scaffolds.

INTRODUCTION: Autologous reconstruction of segmental craniomaxillofacial bone defects is limited by insufficient graft material, donor site morbidity, and need for microsurgery. Reconstruction is challenging due to the complex three-dimensional (3D) structure of craniofacial skeleton. Customized 3D-printed patient-specific biologic scaffolds hold promise for reconstruction of the craniofacial skeleton without donor site morbidity. The authors report a porcine craniofacial defect model suitable for further evaluation of custom 3D-printed engineered bone scaffolds. METHODS: The authors created a 6 cm critical load-bearing defect in the left mandibular angle and a 1.5 cm noncritical, nonload bearing defect in the contralateral right zygomatic arch in 4 Yucatan minipigs. Defects were plated with patient-specific titanium hardware based on preoperative CT scans. Serial CT imaging was done immediately postoperatively, and at 3 and 6 months. Animals were clinically assessed for masticatory function, ambulation, and growth. At the 6-month study endpoint, animals were euthanized, and bony regeneration was evaluated through histological staining and micro-CT scanning compared to contralateral controls. RESULTS: All 4 animals reached study endpoint. Two mandibular plates fractured, but did not preclude study completion due to loss of masticatory function. One zygoma plate loosened while the site of another underwent heterotopic ossification. Gross examination of site defects revealed heterotopic ossification, confirmed by histological and micro-CT evaluation. Biomechanical testing was unavailable due to insufficient bony repair. CONCLUSIONS: The presented porcine zygoma and mandibular defect models are incapable of repair in the absence of bone scaffolds. Based on the authors' results, this model is appropriate for further study of custom 3D-printed engineered bone scaffolds.

Current Trends in Pediatric Spine Deformity Surgery: Multimodal Pain Management and Rapid Recovery.

STUDY DESIGN: Narrative review. OBJECTIVES: The purpose of this article is to perform a review of the literature assessing the efficacy of opioid alternatives, multimodal pain regimens, and rapid recovery in pediatric spine surgery. METHODS: A literature search utilizing PubMed database was performed. Relevant studies from all the evidence levels have been included. Recommendations to decrease postoperative pain and expedite recovery after posterior spinal fusion in adolescent idiopathic scoliosis patients have been provided based on results of studies with the highest level of evidence. RESULTS: Refining perioperative pain management to lessen opioid consumption with multimodal regimens may be useful to decrease recovery time, pain, and complications. Nonsteroidal anti-inflammatory drugs, acetaminophen, gabapentin, neuraxial blockades, and local anesthesia alone offer benefits for postoperative pain management, but their combination in multimodal regimens and rapid recovery pathways may contribute to faster recovery time, improved pain levels, and lower reduction in total opioid consumption. CONCLUSION: A rapid recovery pathway using the multimodal approach for pediatric scoliosis correction may offer superior postoperative pain management and faster recovery than traditional opioid only pain protocols.

Ultrasound Imaging of the Superficial Fascial System Can Predict the Subcutaneous Strength of Abdominal Tissue Using Mean Gray Value Quantification.

BACKGROUND: This study is the first to correlate sonographic findings of subcutaneous tissue to structural and biomechanical properties. METHODS: Precisely sized tissue specimens (59 samples) were collected from five abdominoplasty procedures. A Philips Lumify L12-4 linear array probe, connected to an Android tablet, was used to obtain ultrasound images of the superficial fascial system. A no. 1 Vicryl suture on a CTX needle placed though a needle guide within a three-dimensionally printed template ensured equal bites of subcutaneous tissue across specimens. Suture pull-out strength was measured until failure at a displacement rate of 2.12 mm/second using an Admet MTEST Quattro. Mean gray value for the superficial fascial system in associated ultrasonographic images was quantified by CellProfiler. RESULTS: Superficial fascial system visualization can be accomplished using high-resolution portable ultrasound. Comparing multiple specimens' imaging, interpatient and intrapatient variability of superficial fascial system quantity and structural characteristics are apparent. The superficial fascial system is highly abundant in some patients, but has limited presence in others. Individual-specimen mean gray value and whole-patient mean gray value positively correlated with tissue tensile strength (p = 0.006) and patient-average tissue tensile strength (p = 0.036), respectively. Whole-patient mean gray value accounted for 98.5 percent of the variance seen in patient-average tensile strength, making it a strong predictor for tensile strength. CONCLUSIONS: Portable ultrasound and image-processing technology can visualize, quantify, and predict subcutaneous tissue strength of the superficial fascial system. The superficial fascial system quantity correlates with suture tensile strength. Clinically, preoperative superficial fascial system quantification may aid in outcome predictions, manage patient expectations, and potentially lower complication rates. CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, V.

Preoperative Evaluation of the Superficial Fascial System Can Predict Wound Complications in Body Contouring Surgery.

BACKGROUND: The demand for body contouring surgery continues to rise. The inclusion of the superficial fascial system (SFS) during closure of such procedures has been shown to improve outcomes; however, currently reported wound complication rates remain high. The authors assess whether decreased quantities of SFS are associated with wound complications in these patients. METHODS: A retrospective study of patients undergoing body contouring surgery was performed. Preoperatively, ultrasound images were obtained of the SFS. Using Cellprofiler, the mean gray values (MGVs) of the SFS were calculated to quantify this structure. Chart review was performed to identify postoperative wound complications. RESULTS: Thirty-six patients were included: 30 abdominoplasties, 3 bilateral medial thigh lifts, and 3 bilateral brachioplasties. The overall wound complication rate was 22.5%. There were no significant differences in body mass index, age, smoking status, weight of resected specimen, or diabetes when comparing the complication and noncomplication groups. However, the MGV was significantly greater in the noncomplication group compared with the complication group (0.135 ± 0.008 vs 0.099 ± 0.005, respectively, P = 0.03). The average MGV for the entire cohort was 0.127. Patients with an MGV of greater than 0.127 had a wound complication rate of 0% compared with that of 39% for patients with an MGV of 0.127 or less (P = 0.005). CONCLUSIONS: Poor quantities of SFS identified by ultrasound were associated with increased wound complications in patients undergoing body contouring surgery. Furthermore, patients with better than average SFS seem to be protected from such complications.

Effect of dietary salt intake on epithelial Na+ channels (ENaC) in vasopressin magnocellular neurosecretory neurons in the rat supraoptic nucleus.

KEY POINTS: A growing body of evidence suggests that epithelial Na+ channels (ENaCs) in the brain play a significant role in the regulation of blood pressure; however, the brain structures that mediate the effect are not well understood. Because vasopressin (VP) neurons play a pivotal role in coordinating neuroendocrine and autonomic responses to maintain cardiovascular homeostasis, a basic understanding of the regulation and activity of ENaC in VP neurons is of great interest. We show that high dietary salt intake caused an increase in the expression and activity of ENaC which resulted in the steady state depolarization of VP neurons. The results help us understand one of the mechanisms underlying how dietary salt intake affects the activity of VP neurons via ENaC activity. ABSTRACT: All three epithelial Na+ channel (ENaC) subunits (α, ß and γ) are located in vasopressin (VP) magnocellular neurons in the hypothalamic supraoptic (SON) and paraventricular nuclei. Our previous study demonstrated that ENaC mediates a Na+ leak current that affects the steady state membrane potential in VP neurons. In the present study, we evaluated the effect of dietary salt intake on ENaC regulation and activity in VP neurons. High dietary salt intake for 7 days caused an increase in expression of ß- and γENaC subunits in the SON and the translocation of αENaC immunoreactivity towards the plasma membrane. Patch clamp experiments on hypothalamic slices showed that the mean amplitude of the putative ENaC currents was significantly greater in VP neurons from animals that were fed a high salt diet compared with controls. The enhanced ENaC current contributed to the more depolarized basal membrane potential observed in VP neurons in the high salt diet group. These findings indicate that high dietary NaCl intake enhances the expression and activity of ENaCs, which augments synaptic drive by depolarizing the basal membrane potential close to the action potential threshold during hormonal demand. However, ENaCs appear to have only a minor role in the regulation of the firing activity of VP neurons in the absence of synaptic inputs as neither the mean intraburst frequency, burst duration, nor interspike interval variability of phasic bursting activity was affected. Moreover, ENaC activity did not affect the initiation, sustention, or termination of the phasic bursting generated in an intrinsic manner without synaptic inputs.

Validation of an integrated pedal desk and electronic behavior tracking platform.

BACKGROUND: This study tested the validity of revolutions per minute (RPM) measurements from the Pennington Pedal Desk™. Forty-four participants (73 % female; 39 ± 11.4 years-old; BMI 25.8 ± 5.5 kg/m(2) [mean ± SD]) completed a standardized trial consisting of guided computer tasks while using a pedal desk for approximately 20 min. Measures of RPM were concurrently collected by the pedal desk and the Garmin Vector power meter. After establishing the validity of RPM measurements with the Garmin Vector, we performed equivalence tests, quantified mean absolute percent error (MAPE), and constructed Bland-Altman plots to assess agreement between RPM measures from the pedal desk and the Garmin Vector (criterion) at the minute-by-minute and trial level (i.e., over the approximate 20 min trial period). RESULTS: The average (mean ± SD) duration of the pedal desk trial was 20.5 ± 2.5 min. Measures of RPM (mean ± SE) at the minute-by-minute (Garmin Vector: 54.8 ± 0.4 RPM; pedal desk: 55.8 ± 0.4 RPM) and trial level (Garmin Vector: 55.0 ± 1.7 RPM; pedal desk: 56.0 ± 1.7 RPM) were deemed equivalent. MAPE values for RPM measured by the pedal desk were small (minute-by-minute: 2.1 ± 0.1 %; trial: 1.8 ± 0.1 %) and no systematic relationships in error variance were evident by Bland-Altman plots. CONCLUSION: The Pennington Pedal Desk™ provides a valid count of RPM, providing an accurate metric to promote usage.