A Multicenter Matched Cohort Study of Processed Nerve Allograft and Conduit in Digital Nerve Reconstruction.

PURPOSE: Biomaterials used to restore digital nerve continuity after injury associated with a defect may influence ultimate outcomes. An evaluation of matched cohorts undergoing digital nerve gap reconstruction was conducted to compare processed nerve allograft (PNA) and conduits. Based on scientific evidence and historical controls, we hypothesized that outcomes of PNA would be better than for conduit reconstruction. METHODS: We identified matched cohorts based on patient characteristics, medical history, mechanism of injury, and time to repair for digital nerve injuries with gaps up to 25 mm. Data were stratified into 2 gap length groups: short gaps of 14 mm or less and long gaps of 15 to 25 mm. Meaningful sensory recovery was defined as a Medical Research Council scale of S3 or greater. Comparisons of meaningful recovery were made by repair method between and across the gap length groups. RESULTS: Eight institutions contributed matched data sets for 110 subjects with 162 injuries. Outcomes data were available in 113 PNA and 49 conduit repairs. Meaningful recovery was reported in 61% of the conduit group, compared with 88% in the PNA group. In the group with a 14-mm or less gap, conduit and PNA outcomes were 67% and 92% meaningful recovery, respectively. In the 15- to 25-mm gap length group, conduit and PNA outcomes were 45% and 85% meaningful recovery, respectively. There were no reported adverse events in either treatment group. CONCLUSIONS: Outcomes of digital nerve reconstruction in this study using PNA were consistent and significantly better than those of conduits across all groups. As gap lengths increased, the proportion of patients in the conduit group with meaningful recovery decreased. This study supports the use of PNA for nerve gap reconstruction in digital nerve reconstructions up to 25 mm. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

Peripheral nerve repair throughout the body with processed nerve allografts: Results from a large multicenter study.

BACKGROUND: Peripheral nerve damage resulting in pain, loss of sensation, or motor function may necessitate a reconstruction with a bridging material. The RANGER® Registry was designed to evaluate outcomes following nerve repair with processed nerve allograft (Avance® Nerve Graft; Axogen; Alachua, FL). Here we report on the results from the largest peripheral nerve registry to-date. METHODS: This multicenter IRB-approved registry study collected data from patients repaired with processed nerve allograft (PNA). Sites followed their own standard of care for patient treatment and follow-up. Data were assessed for meaningful recovery, defined as ≥S3/M3 to remain consistent with previously published results, and comparisons were made to reference literature. RESULTS: The study included 385 subjects and 624 nerve repairs. Overall, 82% meaningful recovery (MR) was achieved across sensory, mixed, and motor nerve repairs up to gaps of 70 mm. No related adverse events were reported. There were no significant differences in MR across the nerve type, age, time-to-repair, and smoking status subgroups in the upper extremity (p > .05). Significant differences were noted by the mechanism of injury subgroups between complex injures (74%) as compared to lacerations (85%) or neuroma resections (94%) (p = .03) and by gap length between the <15 mm and 50-70 mm gap subgroups, 91 and 69% MR, respectively (p = .01). Results were comparable to historical literature for nerve autograft and exceed that of conduit. CONCLUSIONS: These findings provide clinical evidence to support the continued use of PNA up to 70 mm in sensory, mixed and motor nerve repair throughout the body and across a broad patient population.

Use of Processed Nerve Allografts to Repair Nerve Injuries Greater Than 25 mm in the Hand.

Processed nerve allografts (PNAs) have been demonstrated to have improved clinical results compared with hollow conduits for reconstruction of digital nerve gaps less than 25 mm; however, the use of PNAs for longer gaps warrants further clinical investigation. Long nerve gaps have been traditionally hard to study because of low incidence. The advent of the RANGER registry, a large, institutional review board-approved, active database for PNA (Avance Nerve Graft; AxoGen, Inc, Alachua, FL) has allowed evaluation of lower incidence subsets. The RANGER database was queried for digital nerve repairs of 25 mm or greater. Demographics, injury, treatment, and functional outcomes were recorded on standardized forms. Patients younger than 18 and those lacking quantitative follow-up data were excluded. Recovery was graded according to the Medical Research Council Classification for sensory function, with meaningful recovery defined as S3 or greater level. Fifty digital nerve injuries in 28 subjects were included. There were 22 male and 6 female subjects, and the mean age was 45. Three patients gave a previous history of diabetes, and there were 6 active smokers. The most commonly reported mechanisms of injury were saw injuries (n = 13), crushing injuries (n = 9), resection of neuroma (n = 9), amputation/avulsions (n = 8), sharp lacerations (n = 7), and blast/gunshots (n = 4). The average gap length was 35 ± 8 mm (range, 25-50 mm). Recovery to the S3 or greater level was reported in 86% of repairs. Static 2-point discrimination (s2PD) and Semmes-Weinstein monofilament (SWF) were the most common completed assessments. Mean s2PD in 24 repairs reporting 2PD data was 9 ± 4 mm. For the 38 repairs with SWF data, protective sensation was reported in 33 repairs, deep pressure in 2, and no recovery in 3. These data compared favorably with historical data for nerve autograft repairs, with reported levels of meaningful recovery of 60% to 88%. There were no reported adverse effects. Processed nerve allograft can be used to reconstruct long gap nerve defects in the hand with consistently high rates of meaningful recovery. Results for PNA repairs of digital nerve injuries with gaps longer than 25 mm compare favorably with historical reports for nerve autograft repair but without donor site morbidity.

Processed nerve allografts for peripheral nerve reconstruction: a multicenter study of utilization and outcomes in sensory, mixed, and motor nerve reconstructions.

PURPOSE: As alternatives to autograft become more conventional, clinical outcomes data on their effectiveness in restoring meaningful function is essential. In this study we report on the outcomes from a multicenter study on processed nerve allografts (Avance® Nerve Graft, AxoGen, Inc). PATIENTS AND METHODS: Twelve sites with 25 surgeons contributed data from 132 individual nerve injuries. Data was analyzed to determine the safety and efficacy of the nerve allograft. Sufficient data for efficacy analysis were reported in 76 injuries (49 sensory, 18 mixed, and 9 motor nerves). The mean age was 41 ± 17 (18-86) years. The mean graft length was 22 ± 11 (5-50) mm. Subgroup analysis was performed to determine the relationship to factors known to influence outcomes of nerve repair such as nerve type, gap length, patient age, time to repair, age of injury, and mechanism of injury. RESULTS: Meaningful recovery was reported in 87% of the repairs reporting quantitative data. Subgroup analysis demonstrated consistency, showing no significant differences with regard to recovery outcomes between the groups (P > 0.05 Fisher's Exact Test). No graft related adverse experiences were reported and a 5% revision rate was observed. CONCLUSION: Processed nerve allografts performed well and were found to be safe and effective in sensory, mixed and motor nerve defects between 5 and 50 mm. The outcomes for safety and meaningful recovery observed in this study compare favorably to those reported in the literature for nerve autograft and are higher than those reported for nerve conduits.

Recovery of Motor Function after Mixed and Motor Nerve Repair with Processed Nerve Allograft.

BACKGROUND: Severe trauma often results in the transection of major peripheral nerves. The RANGER Registry is an ongoing observational study on the use and outcomes of processed nerve allografts (PNAs; Avance Nerve Graft, AxoGen, Inc., Alachua, Fla.). Here, we report on motor recovery outcomes for nerve injuries repaired acutely or in a delayed fashion with PNA and comparisons to historical controls in the literature. METHODS: The RANGER database was queried for mixed and motor nerve injuries in the upper extremities, head, and neck area having completed greater than 1 year of follow-up. All subjects with sufficient assessments to evaluate functional outcomes were included. Meaningful recovery was defined as ≥M3 on the Medical Research Council scale. Demographics, outcomes, and covariate analysis were performed to further characterize this subgroup. RESULTS: The subgroup included 20 subjects with 22 nerve repairs. The mean ± SD (minimum-maximum) age was 38 ± 19 (16-77) years. The median repair time was 9 (0-133) days. The mean graft length was 33 ± 17 (10-70) mm with a mean follow-up of 779 ± 480 (371-2,423) days. Meaningful motor recovery was observed in 73%. Subgroup analysis showed no differences between gap lengths or mechanism of injury. There were no related adverse events. CONCLUSIONS: PNAs were safe and provided functional motor recovery in mixed and motor nerve repairs. Outcomes compare favorably to historical controls for nerve autograft and exceed those for hollow tube conduit. PNA may be considered as an option when reconstructing major peripheral nerve injuries.

Vascular Reconstruction in a Neonate after Iatrogenic Injury during Cardiac Catheterization.

As technology and interventional techniques continue to evolve, both the volume and complexity of cardiac catheterizations will increase, leading to a rise in the number of complications. One of the most morbid complications of cardiac catheterization is vascular injury. We report the case of a 31-day-old, 3.0-kg infant with hypoplastic left heart syndrome who experienced a left common iliac artery disruption during cardiac catheterization resulting in a retroperitoneal hemorrhage. The extent of the vascular injury combined with the vessel caliber posed a technically challenging surgical scenario. Ultimately, the vascular supply to the left lower extremity was reconstructed by the plastic surgery team with a reverse autologous vein graft. To our knowledge, this multidisciplinary approach with the involvement of plastic surgery represents a unique case.

Outcomes of arterial vascular extremity trauma in pediatric patients.

BACKGROUND: Vascular trauma in children, although rare, carries significant risk for repair. Here we report outcomes from a single trauma center for children with extremity vascular trauma, proximal to the digits. METHODS: Retrospective chart review of patients less than age 18years with an acute, non-iatrogenic traumatic arterial vascular injury of the upper and/or lower extremity between January 2008 and December 2013. Abstracted patient demographics, injury characteristics, surgical management, and disposition were summarized and compared with nonparametric methods. RESULTS: 23 children comprised the study cohort: median age of 8years (IQR: 4.6-12), 61% (n=14) males, 100% survival. Penetrating injuries were the predominate mechanism (n=17, 74%). The median time to presentation was 154min (IQR: 65-330). Acute operations for revascularization included a primary repair (n=15, 65%) or reversed vein graft (n=7, 30%). Fasciotomies were done for 3 (13%) patients. Three amputations were done for failed revascularization. Upper extremity vascular injury (n=15, 65%) was more common. The rate of associated extremity fracture was similar between upper (21%) and lower (33%) extremities (p=0.643). Eight (35%) patients required additional surgery most commonly for debridement, washouts and dressing changes. Three patients' hospital stays were complicated by infection. Impaired function was the most common short- and long-term complication (60%, 75%). CONCLUSION: Pediatric vascular injuries are commonly associated with penetrating injuries and male gender and occurred more frequently in the upper extremities. Overall patency rates after repair were 87%. Fasciotomies were done in 13% of patients, and the overall surgical amputation rate was 13%. There was no mortality in this cohort; however, multiple operations are commonly required, including the return to OR for washouts, debridements and dressing changes. The most common short- and long-term complication was impaired function. Overall good results are achievable in pediatric vascular trauma treated with revascularization.

Outcomes of digital artery revascularization in pediatric trauma.

BACKGROUND: Digit amputation is rare in pediatric trauma but can lead to functional morbidity. The true incidence of digital arterial injury is lacking in the literature, and revascularization techniques are not well-described. METHODS: Retrospective review of a pediatric trauma registry identified patients with a digital artery injury between July 2008 and December 2013. Isolated vein injuries and arterial injuries proximal to the digits were excluded. Descriptive statistics were used. RESULTS: Twenty-five subjects met inclusion. Most were male (n=16; 64%) and the median age was 6.8 (IQR: 2.8, 11.1) years. The most common blunt (n=12) trauma was struck/crushed by object (n=4; 33%) and the most common penetrating (n=13) trauma was because of glass (n=9; 69%). All subjects were managed operatively. Initial operations for arterial repair were primary arterial repair (15; 20%), vein graft (7; 28%), thrombectomy (1; 4%), and amputation (1; 4%). Twelve patients (48%) had reported complications at initial follow-up, but only two (8%) had long-term (>24weeks) sequelae. CONCLUSION: Digital artery injury is rare among pediatric traumas. Functional outcomes after digital artery revascularization are favorable. Primary repair can successfully manage these injuries and vein grafting appears to be a suitable alternative when primary repair is not feasible.

Factors in Free Fasciocutaneous Flap Complications: A Logistic Regression Analysis.

BACKGROUND: Free tissue transfer using fasciocutaneous flaps has increased in frequency over the past decade. Predictive analyses are lacking for fasciocutaneous free flaps in terms of complication rates for reconstruction. This study therefore was designed to identify key variables that drive complications in fasciocutaneous free flap surgery. METHODS: A retroactive chart review of 91 patients undergoing 91 fasciocutaneous flaps was performed. Twelve variables were identified and tracked through clinic and hospital charts (i.e., surgeon experience, hospital, age, flap type, traumatic wound, smoking, large fasciocutaneous flap, type of anastomosis, recipient vessel choice, sex, anatomical region of wound, and flap debulking). A logistic regression model was used to determine the presence of complications associated with the prescribed predictors. RESULTS: The model revealed that smoking, age, anatomical area of wound, flap size, flap type, and presence of a traumatic wound impacted complications. The model was found to be a good fit (Hosmer-Lemeshow, p = 0.135). Factors impacting complications with fasciocutaneous flaps included anatomical area (62.3 percent increase in complications; p = 0.047), surgeon experience (27 percent reduction in complications; p = 0.007), and reconstruction of a trauma activation patient (80 percent reduction in complications; p = 0.025). CONCLUSION: The implications of these findings can be used to contain cost and minimize poor outcomes within the health care system.