Active nerve management for above the knee amputation: A comparison of through the wound versus posterior approach.

Targeted muscle reinnervation (TMR) and regenerative peripheral nerve interface (RPNI) are used to prevent or treat neuromas in amputees. TMR for above-the-knee amputation (AKA) is most commonly performed through a posterior incision rather than the stump wound because recipient motor nerves are primarily located in the proximal third of the thigh. When preventative TMR is performed with concurrent AKA, a posterior approach requires intraoperative repositioning and an additional incision. The purpose of this study was to evaluate feasibility of TMR and operative times for nerve management performed through the wound compared to a posterior approach in AKA patients to guide surgical decision-making. Patients who underwent AKA with TMR between 2018-2023 were reviewed. Patients were divided into two groups: TMR performed through the wound (Group I) and TMR performed through a posterior approach (Group II). If a nerve was unable to undergo coaptation for TMR due to the lack of suitable donor motor nerves, RPNI was performed. Eighteen patients underwent AKA with nerve management were included from Group I (8 patients) and Group II (10 patients). TMR coaptations performed on distinct nerves was 1.5 ± 0.5 in Group I compared to 2.6 ± 0.5 in Group II (p = 0.001). Operative time for Group I was 200.7 ± 33.4 min compared to 326.5 ± 37.1 min in Group II (p = 0.001). TMR performed through the wound following AKA requires less operative time than a posterior approach. However, since recipient motor nerves are not consistently found near the stump, RPNI may be required with TMR whereas the posterior approach allows for more TMR coaptations.

Surgical Management of Sirenomelia: A Case Study.

Background: Sirenomelia is a rare congenital condition characterized by fusion of the lower limbs. Patients with sirenomelia generally do not survive long after birth because the condition is associated with multisystem organ dysfunction due to developmental anomalies. Considering the low incidence and few cases surviving the neonatal period, there is minimal understanding regarding the surgical management of sirenomelia. We present a unique case of an infant born with type 1 sirenomelia, absence of external genitalia, presence of a cloaca, absence of the bladder, and presence of an imperforate and vestigial anus, who not only survived the birth process, but, at the age of 11 months, was determined to be a candidate for surgical separation of the lower extremities. Methods: This case was approached much like a dorsal rectangular flap syndactyly release. Large Z-plasty flaps were designed and raised, and the soft tissue within the skin bridge was meticulously dissected to preserve anatomy and to provide adequate skin flaps without perineal skin grafting. A quadrangular flap was designed to reconstruct the perineum and produce a neo-vulva using de-epithelialization. Results: Successful lower extremity separation was achieved. There were no major postoperative complications. The patient progressed with lower extremity function, and eventually achieved independent ambulation. Conclusions: Management of sirenomelia is incredibly challenging, and data to guide surgical management are limited. This report details our approach to a successful lower extremity separation, repair, and neo-vulvar reconstruction in a case of type I sirenomelia.

Contralateral C7 nerve transfer for severe pediatric brachial plexus injuries: donor site morbidity.

BACKGROUND: Pediatric brachial plexus injuries (BPI) can have a devastating impact on upper extremity function. With localized lesions, nerve grafting and transfers are well-described. However, reconstruction of pan-plexus (C5-T1) injuries (PPI) requires donor nerves outside of the brachial plexus. The cross C7 (CC7) nerve transfer extended with sural nerve grafts to the contralateral recipient nerve offers the advantage of supplying robust donor axons. Though controversial in the West, CC7 transfer is routine in many Asian centers. We present a case series of pediatric patients who underwent CC7 transfer for BPI. Our objective was to catalog donor site morbidity incurred by transferring the C7 nerve root. METHODS: This retrospective study was approved by the Institutional Review Board of our university. INCLUSION CRITERIA: patients under 18 years old that underwent CC7 nerve transfer for BPI at our health system between 2021 and 2022. A chart review was completed to collect demographic and outcomes data. RESULTS: Three patients underwent a complete CC7 transfer between 2021 and 2022 for BPI reconstruction. All patients underwent concomitant additional nerve transfers. Post-operative donor site sensory deficits were minimal and transient in all but one patient, who reported mild but persistent paresthesia of the donor side hand with movement of recipient side digits; however, no patients suffered donor site motor deficits (Table 1). CONCLUSIONS: We conclude that CC7 nerve transfer is a safe surgical option to provide additional donor motor axons for PPI in pediatric patients.

Outcomes after Anterior Interosseous Nerve to Ulnar Motor Nerve Transfer.

Background Ulnar nerve lesions proximal to the elbow can result in loss of intrinsic muscle function of the hand. The anterior interosseous nerve (AIN) to deep motor branch of the ulnar nerve (DBUN) transfer has been demonstrated to provide intrinsic muscle reinnervation, thereby preventing clawing and improving pinch and grip strength. The purpose of this study was to evaluate the efficacy of the AIN to DBUN transfer in restoring intrinsic muscle function for patients with traumatic ulnar nerve lesions. Methods We performed a prospective, multi-institutional study of outcomes following AIN to DBUN transfer for high ulnar nerve injuries. Twelve patients were identified, nine of which were enrolled in the study. The mean time from injury to surgery was 15 weeks. Results At final follow-up (mean postoperative follow-up 18 months + 15.5), clawing was observed in all nine patients with metacarpophalangeal joint hyperextension of the ring finger averaging 8.9 degrees (+ 10.8) and small finger averaging 14.6 degrees (+ 12.5). Grip strength of the affected hand was 27% of the unaffected extremity. Pinch strength of the affected hand was 29% of the unaffected extremity. None of our patients experienced claw prevention after either end-to-end ( n = 4) or end-to-side ( n = 5) AIN to DBUN transfer. Conclusion We conclude that, in traumatic high ulnar nerve injuries, the AIN to DBUN transfer does not provide adequate intrinsic muscle reinnervation to prevent clawing and normalize grip and pinch strength.

Supraclavicular Approach to the Brachial Plexus.

The brachial plexus consists of an intricate array of nerves originating from the C5-T1 ventral rami of the spinal cord. Their course is complex and can be substantially distorted after injury. Thus, dissection of the brachial plexus can be difficult. Here, we present a practical approach to the supraclavicular dissection of the brachial plexus, with emphasis on relevant anatomy and surgical landmarks. Methods: This anatomical review was prepared using intraoperative surgical imaging. In addition, illustrations are used to display the images in schematic form. We present a stepwise surgical approach to the supraclavicular dissection of the brachial plexus. We highlight the differences between pre- and postganglionic nerve root injuries, and also relevant anatomical variants of the brachial plexus. Results: Eleven steps are recommended to facilitate the supraclavicular approach to the brachial plexus. Conclusion: The supraclavicular dissection of the brachial plexus is reliable with consistent landmarks and can be carried out in a stepwise fashion.

Minimally-Invasive Corneal Neurotization (MICN): 10 Year Update in Technique and Lessons Learned Including Novel Donor Transfer of the Great Auricular Nerve.

VIDEO PLUS SUBMISSION SUMMARY: Corneal anesthesia, caused by lack of corneal innervation, is a rare but devastating condition that can lead to neurotrophic keratopathy 1, corneal ulceration, scarring, and blindness. Minimally-Invasive Corneal Neurotization (MICN) enables transfer of regional donor sensory nerves to the cornea to provide sensation and ocular protection. Here, we provide an update on technical advances and modifications that have arisen over ten years that have refined the surgery. We provide intraoperative step by step videos of corneal neurotization, noting its critical steps, pitfalls, and caveats. This video submission will focus on the novel technique of utilizing the greater auricular nerve with a sural nerve graft extension as the donor nerve for the procedure. The steps and considerations depicted will allow surgeons to carry out corneal neurotization efficiently, safely, and effectively.

A functional screening of the kinome identifies the Polo-like kinase 4 as a potential therapeutic target for malignant rhabdoid tumors, and possibly, other embryonal tumors of the brain.

PURPOSE: Malignant rhabdoid tumors (MRTs) are deadly embryonal tumors of the infancy. With poor survival and modest response to available therapies, more effective and less toxic treatments are needed. We hypothesized that a systematic screening of the kinome will reveal kinases that drive rhabdoid tumors and can be targeted by specific inhibitors. METHODS: We individually mutated 160 kinases in a well-characterized rhabdoid tumor cell line (MON) using lentiviral clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9). The kinase that most significantly impaired cell growth was further validated. Its expression was evaluated by microarray gene expression (GE) within 111 pediatric tumors, and functional assays were performed. A small molecule inhibitor was tested in multiple rhabdoid tumor cell lines and its toxicity evaluated in zebrafish larvae. RESULTS: The Polo-like kinase 4 (PLK4) was identified as the kinase that resulted in higher impairment of cell proliferation when mutated by CRISPR/Cas9. PLK4 CRISPR-mutated rhabdoid cells demonstrated significant decrease in proliferation, viability, and survival. GE showed upregulation of PLK4 in rhabdoid tumors and other embryonal tumors of the brain. The PLK4 inhibitor CFI-400945 showed cytotoxic effects on rhabdoid tumor cell lines while sparing non-neoplastic human fibroblasts and developing zebrafish larvae. CONCLUSIONS: Our findings indicate that rhabdoid tumor cell proliferation is highly dependent on PLK4 and suggest that targeting PLK4 with small-molecule inhibitors may hold a novel strategy for the treatment of MRT and possibly other embryonal tumors of the brain. This is the first time that PLK4 has been described as a potential target for both brain and pediatric tumors.