Tissue-engineered grafts exploit axon-facilitated axon regeneration and pathway protection to enable recovery after 5-cm nerve defects in pigs.

Functional restoration following major peripheral nerve injury (PNI) is challenging, given slow axon growth rates and eventual regenerative pathway degradation in the absence of axons. We are developing tissue-engineered nerve grafts (TENGs) to simultaneously "bridge" missing nerve segments and "babysit" regenerative capacity by providing living axons to guide host axons and maintain the distal pathway. TENGs were biofabricated using porcine neurons and "stretch-grown" axon tracts. TENG neurons survived and elicited axon-facilitated axon regeneration to accelerate regrowth across both short (1 cm) and long (5 cm) segmental nerve defects in pigs. TENG axons also closely interacted with host Schwann cells to maintain proregenerative capacity. TENGs drove regeneration across 5-cm defects in both motor and mixed motor-sensory nerves, resulting in dense axon regeneration and electrophysiological recovery at levels similar to autograft repairs. This approach of accelerating axon regeneration while maintaining the pathway for long-distance regeneration may achieve recovery after currently unrepairable PNIs.

Cleft Lip and Palate Research in Low- and Middle-income Countries: A Scientometric Analysis.

Cleft lip and palate (CLP) comprise over 90% of the world's congenital anomalies and cause significant disability worldwide, while disproportionally burdening low- and middle-income countries (LMICs). Research can help inform strategies that reduce disparities in accessing CLP care. We performed a scientometric analysis of CLP research in LMICs to identify influential contributors and themes. METHODS: The authors searched seven citation databases accessed via Web of Science, from inception to March 2, 2021. Social network analysis was done using VOSviewer. The Kruskal-Wallis test and linear regression were used. RESULTS: In total, 1561 articles authored by 6414 researchers affiliated with 2113 organizations in 119 countries were included. Most authors (n = 6387, 99.6%) had published two or more articles. The USA (454 articles), Brazil (211 articles), China (175 articles), and India (127 articles) published the most. The most prolific institutions were the University of Sao Paulo (94 articles), the University of Pittsburgh (57 articles), and the University of Iowa (55 articles). Marazita ML (33 articles), Shi B (27 articles), and Murray JC (22 articles) had the highest number of publications. An estimated 510 articles (32.7%) were focused on epidemiology, 240 (15.4%) on management, and 54 (3.5%) on global plastic surgery for CLP. CONCLUSIONS: LMICs are disproportionally burdened by CLP, but research is limited and often produced by high-income countries. This study elucidates partnership and health system strengthening opportunities to improve LMIC research capacity and ultimately informs the management and outcomes for patients with CLP.

A Porcine Model of Peripheral Nerve Injury Enabling Ultra-Long Regenerative Distances: Surgical Approach, Recovery Kinetics, and Clinical Relevance.

BACKGROUND: Millions of Americans experience residual deficits from traumatic peripheral nerve injury (PNI). Despite advancements in surgical technique, repair typically results in poor functional outcomes due to prolonged periods of denervation resulting from long regenerative distances coupled with slow rates of axonal regeneration. Novel surgical solutions require valid preclinical models that adequately replicate the key challenges of clinical PNI. OBJECTIVE: To develop a preclinical model of PNI in swine that addresses 2 challenging, clinically relevant PNI scenarios: long segmental defects (≥5 cm) and ultra-long regenerative distances (20-27 cm). Thus, we aim to demonstrate that a porcine model of major PNI is suitable as a potential framework to evaluate novel regenerative strategies prior to clinical deployment. METHODS: A 5-cm-long common peroneal nerve or deep peroneal nerve injury was repaired using a saphenous nerve or sural nerve autograft, respectively. Histological and electrophysiological assessments were performed at 9 to 12 mo post repair to evaluate nerve regeneration and functional recovery. Relevant anatomy, surgical approach, and functional/histological outcomes were characterized for both repair techniques. RESULTS: Axons regenerated across the repair zone and were identified in the distal stump. Electrophysiological recordings confirmed these findings and suggested regenerating axons reinnervated target muscles. CONCLUSION: The models presented herein provide opportunities to investigate peripheral nerve regeneration using different nerves tailored for specific mechanisms of interest, such as nerve modality (motor, sensory, and mixed fiber composition), injury length (short/long gap), and total regenerative distance (proximal/distal injury).

Polypoid Endometriosis Presenting as a Renal Cortical Tumor.

A 41-year-old female patient presented with left-sided flank pain and gross hematuria temporally unrelated to her menstrual cycle. Abdominal computed tomography scan showed a large left-sided solid, enhancing kidney mass radiographically consistent with renal cell carcinoma. Following surgical resection, histopathological examination revealed polypoid endometriosis. Polypoid endometriosis is rare and mimics a neoplasm clinically, radiographically, and on gross examination. Patients with polypoid endometriosis often present with symptoms related to mass effect rather than classic endometriosis hallmark symptoms such as dyspareunia, dysmenorrhea, and cyclic abdominal pain. Treatment includes surgical resection.