Outcomes of Biodegradable Temporizing Matrix for Soft Tissue Reconstruction of the Hand and Extremities.

Background: NovoSorb biodegradable temporizing matrix (BTM) is a novel, bilayer, synthetic skin substitute made of biodegradable polyurethane foam covered with a sealing membrane. BTM has demonstrated excellent outcomes in burn literature; however, few studies have been published for hand and extremity soft tissue reconstruction. Methods: All patients who underwent extremity reconstruction with BTM from 2018 to 2023 were reviewed. Demographics, presentations, and clinical outcomes were recorded. Results: A total of 86 cases from 54 patients (53.7% pediatric; age range: 0-81 years) were included. Common indications included trauma (36%), infection (18.6%), and malignancy (11.6%). BTM was placed over exposed tendon (38.4%), bone (19%), joints (12.8%), nerves (8.1%), and/or blood vessels (7%). BTM served as temporary wound coverage in 26 cases. Complications included hematoma (8.1%), infection (4.7%), and spontaneous delamination (4.7%). Wound closure was successfully obtained without flap use in 93.3%. Poor BTM take was associated with peripheral vascular disease, hypertension, immunosuppression, and BTM hematoma and infection (<0.05). Conclusion: This study contributes to the growing body of evidence favoring BTM use in challenging reconstructive cases. Although prospective comparative studies are forthcoming, BTM likely has broad applications in reconstructive surgery.

Expanding Indications of the Medial Femoral Condyle Free Flap: Systematic Review in Head and Neck Reconstruction.

The medial femoral condyle free flap serves as an attractive reconstructive option for small- to intermediate-sized bony defects. It is commonly applied in the extremities with limited reports in the head and neck. Methods: A systematic review of the literature was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results: Seventeen articles met inclusion criteria, yielding 166 cases for analysis, with a majority of the cohort from a single study (n = 107; 64.4%). However, all included studies represented novel reconstructive sites and surgical indications. Flap components were described in 157 cases; periosteum was used only in four cases (2.5%), whereas all others are composed of cortical bone combined with periosteum, cancellous bone, and/or cartilage (97.5%). Additionally, a skin island was used in 43 cases (25.9%). Flap measurements were reported in 51 cases, averaging 4.5 ± 2.7 cm in length. Seven cases listed skin island dimensions, averaging 20.2 ± 12.8 cm2. The descending genicular artery was the primary pedicle employed (n = 162; 97.6%), while the superior medial genicular was used in the descending genicular artery's absence (n = 4; 2.4%). Descending genicular artery pedicle length from 15 reporting cases averaged 6.4 ± 1.2 cm. Successful reconstructions totaled 160 cases (96.4%). Recipient complications were seen in 16 cases (9.6%) with six constituting flap failures (3.6%). Donor site complications were minimal (n = 6; 3.6%); however, this included one major complication of femoral shaft fracture. Conclusion: The medial femoral condyle free flap is an effective reconstructive option for the head and neck due to its versatile nature, low complication profile at both recipient and donor site, ease of harvest, and two-team approach.

The epithelial Na+ channel UNC-8 promotes an endocytic mechanism that recycles presynaptic components to new boutons in remodeling neurons.

Circuit refinement involves the formation of new presynaptic boutons as others are dismantled. Nascent presynaptic sites can incorporate material from recently eliminated synapses, but the recycling mechanisms remain elusive. In early-stage C. elegans larvae, the presynaptic boutons of GABAergic DD neurons are removed and new outputs established at alternative sites. Here, we show that developmentally regulated expression of the epithelial Na+ channel (ENaC) UNC-8 in remodeling DD neurons promotes a Ca2+ and actin-dependent mechanism, involving activity-dependent bulk endocytosis (ADBE), that recycles presynaptic material for reassembly at nascent DD synapses. ADBE normally functions in highly active neurons to accelerate local recycling of synaptic vesicles. In contrast, we find that an ADBE-like mechanism results in the distal recycling of synaptic material from old to new synapses. Thus, our findings suggest that a native mechanism (ADBE) can be repurposed to dismantle presynaptic terminals for reassembly at new, distant locations.

Reconstruction of a Near-total Scalp Avulsion with NovoSorb Biodegradable Temporizing Matrix: Pediatric Case Report.

Traumatic dog bites of the face and head are common among the pediatric population, although injuries resulting in total or subtotal scalp avulsions are rare and life-threatening. Standard treatment in these cases includes attempts at replantation or free tissue transfer; however, these procedures may not always be possible. An alternative treatment option involves the use of dermal substitutes, such as Integra (Integra LifeScience Corporation), with subsequent skin grafting. More recently, an alternative skin substitute called NovoSorb Biodegradable Temporizing Matrix (BTM) (PolyNovo North America LLC) has displayed favorable reconstructive outcomes in recent burn literature. NovoSorb BTM is a novel, fully synthetic bilayer scaffold made of biodegradable polyurethane matrix covered with a sealing membrane. In this report, the authors describe a 3-year-old boy who presented emergently with a severe dog bite avulsion to the subpericranial level of approximately 80% of his scalp, which was not replantable. The surgical plan involved a staged reconstruction using Integra and later skin grafting. Purulent infection ensued and required removal of Integra less than 2 weeks from application. Upon clearing of the infection, the wound was successfully closed with BTM and subsequent skin grafting. With proper wound management and over 6 months of follow-up, the patient experienced excellent healing of the graft with stable calvarial coverage and an acceptable aesthetic outcome. He will undergo tissue expansion of the remaining hair-bearing scalp in the future.