ABSTRACT
BACKGROUND: Outcomes after peripheral nerve injuries are poor despite current nerve repair techniques. Currently, there is no conclusive evidence that mammalian axons are capable of spontaneous fusion after transection. Notably, certain invertebrate species are able to auto-fuse after transection. Although mammalian axonal auto-fusion has not been observed experimentally, no mammalian study to date has demonstrated regenerating axolemmal membranes contacting intact distal segment axolemmal membranes to determine whether mammalian peripheral nerve axons have the intrinsic mechanisms necessary to auto-fuse after transection. OBJECTIVE: This study aims to assess fusion competence between regenerating axons and intact distal segment axons by enhancing axon regeneration, delaying Wallerian degeneration, limiting the immune response, and preventing myelin obstruction. METHODS: This study will use a rat sciatic nerve model to evaluate the effects of a novel peripheral nerve repair protocol on behavioral, electrophysiologic, and morphologic parameters. This protocol consists of a variety of preoperative, intraoperative, and postoperative interventions. Fusion will be assessed with electrophysiological conduction of action potentials across the repaired transection site. Axon-axon contact will be assessed with transmission electron microscopy. Behavioral recovery will be analyzed with the sciatic functional index. A total of 36 rats will be used for this study. The experimental group will use 24 rats and the negative control group will use 12 rats. For both the experimental and negative control groups, there will be both a behavior group and another group that will undergo electrophysiological and morphological analysis. The primary end point will be the presence or absence of action potentials across the lesion site. Secondary end points will include behavioral recovery with the sciatic functional index and morphological analysis of axon-axon contact between regenerating axons and intact distal segment axons. RESULTS: The author is in the process of grant funding and institutional review board approval as of March 2020. The final follow-up will be completed by December 2021. CONCLUSIONS: In this study, the efficacy of the proposed novel peripheral nerve repair protocol will be evaluated using behavioral and electrophysiologic parameters. The author believes this study will provide information regarding whether spontaneous axon fusion is possible in mammals under the proper conditions. This information could potentially be translated to clinical trials if successful to improve outcomes after peripheral nerve injury. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/18706.
ABSTRACT
BACKGROUND: Microsurgical free flaps require careful monitoring to detect early signs of compromise. At many hospitals, nursing staff provides the majority of postoperative monitoring of free flap patients and it lies within their responsibility to alert physicians of a failing free flap. The aim of this study is to identify knowledge gaps in the monitoring of microvascular free tissue transfer in both novice and experienced nurses and to provide appropriate education to address these gaps. METHODS: This was a pre- and postintervention study. An initial pilot survey was administered to identify knowledge deficiencies. A nursing educational session on free flap physiology and monitoring was then designed to address these deficiencies. An 18-question multiple choice quiz was administered before and after the educational session. Pre- and post-test scores were compared based on nursing experience. At 6 months, the participating nurses completed a survey rating their confidence with free flap patient care as a result of the educational session. RESULTS: A total of 72 nurses completed the in-service training course and quiz. The average quiz score increased from 61.9 to 89.3% after the in-service (p < 0.001). There was no correlation between precurriculum test scores and nursing experience as referenced by total number of years in the profession (r s = -0.038, p = 0.754). The follow-up survey showed that prior to the course 38% of respondents reported little or no confidence caring for free flap patients, decreasing to 6% after the course (p < 0.05). CONCLUSION: Based on the results of this study, nursing knowledge of capillary refill, venous congestion, and basic microsurgical free flap physiology is inadequate. With implementation of a teaching in-service curriculum highlighting these key areas of deficiencies, nurses improved both their understanding and confidence levels, regardless of their level of experience.
