Community-wide feasibility of the Lower Extremity Amputation Protocol amongst vascular amputees.

BACKGROUND: The Lower Extremity Amputation Protocol (LEAP) is a multidisciplinary enhanced recovery after surgery pathway for vascular amputees. The objective of this study was to examine feasibility and outcomes of community-wide implementation of LEAP. METHODS: LEAP was implemented at three safety net hospitals for patients with peripheral artery disease or diabetes requiring major lower extremity amputation. Patients who underwent LEAP (LEAP) were matched 1:1 with retrospective controls (NOLEAP) on hospital location, need for initial guillotine amputation, and final amputation type (above- vs below-knee). Primary endpoint was postoperative hospital length of stay (PO-LOS). RESULTS: A total of 126 amputees (63 LEAP and 63 NOLEAP) were included with no difference between baseline demographics and co-morbidities between the groups. After matching, both groups had the same prevalence of amputation level (76% below-knee vs 24% above-knee). LEAP patients had shorter duration of postamputation bed rest (P = .003) and were more likely to receive limb protectors (100% vs 40%; P ≤ .001), prosthetic counseling (100% vs 14%; P ≤ .001), perioperative nerve blocks (75% vs 25%; P ≤ .001), and postoperative gabapentin (79% vs 50%; P ≤ .001). Compared with NOLEAP, LEAP patients were more likely to be discharged to an acute rehabilitation facility (70% vs 44%; P = .009) and less likely to be discharged to a skilled nursing facility (14% vs 35%; P = .009). The median PO-LOS for the overall cohort was 4 days. LEAP patients had a shorter median PO-LOS (3 [interquartile range, 2-5] vs 5 [interquartile range, 4-9] days; P < .001). On multivariable logistic regression, LEAP decreased the odds of a PO-LOS of ≥4 days by 77% (odds ratio, 0.23; 95% confidence interval, 0.09-0.63). Overall, LEAP patients were significantly less likely to have phantom limb pain (5% vs 21%; P = .02) and were more likely to receive a prosthesis (81% vs 40%; P ≤ .001). In a multivariable Cox proportional hazards model, LEAP was associated with an 84% reduction in time to receipt of prosthesis (hazard ratio, 0.16; 95% confidence interval, 0.085-0.303; P < .001). CONCLUSIONS: Community wide implementation of LEAP significantly improved outcomes for vascular amputees demonstrating that utilization of core ERAS principles in vascular patients leads to decreased PO-LOS and improved pain control. LEAP also affords this socioeconomically disadvantaged population a greater opportunity to receive a prosthesis and return to the community as a functional ambulator.

Closing the Gap Between Mammalian and Invertebrate Peripheral Nerve Injury: Protocol for a Novel Nerve Repair.

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.