History of Microsurgery: The Legacy of Harry J. Buncke, MD.

A historical review of the history of Microsurgery including the important influence and contributions of Harry J. Buncke MD considered by many to be the "Father of Microsurgery". An chronological list of Historic Replants and "Free Flap" and microvascular transplants is included. Those who lived through the age of the birth of this new surgical specialty were fortunate.

Narrative review of the history of microsurgery in urological practice.

The clinical need for magnified visualization during surgery spurred the evolution of microscope and microsuture technology. Innovative surgeons across various surgical specialties recognized the importance of utilizing and advancing these technologies. Operative microscopy allows human dexterity to perform beyond direct visual limitations. Microsurgery started in otolaryngology and ophthalmology, became popular in reconstruction and transplantation, and was then adopted in urology. Microsurgery in urology involves renal and penile revascularization, penile transplantation and free flap phalloplasty, testicular autotransplantation, reproductive tract reconstruction of the vas deferens and epididymis, varicocele repair, and sperm retrieval. By examining the peer reviewed and lay literature, this review discusses the history of microsurgery and its subsequent development as a subspecialty in urology.

Evidence-Based Approach to Timing of Nerve Surgery: A Review.

ABSTRACT: Events causing acute stress to the health care system, such as the COVID-19 pandemic, place clinical decisions under increased scrutiny. The priority and timing of surgical procedures are critically evaluated under these conditions, yet the optimal timing of procedures is a key consideration in any clinical setting. There is currently no single article consolidating a large body of current evidence on timing of nerve surgery. MEDLINE and EMBASE databases were systematically reviewed for clinical data on nerve repair and reconstruction to define the current understanding of timing and other factors affecting outcomes. Special attention was given to sensory, mixed/motor, nerve compression syndromes, and nerve pain. The data presented in this review may assist surgeons in making sound, evidence-based clinical decisions regarding timing of nerve surgery.

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.

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.

Digit Tip Injuries: Current Treatment and Future Regenerative Paradigms.

Over the past several decades there has been a profound increase in the understanding of tissue regeneration, driven largely by the observance of the tremendous regenerative capacity in lower order life forms, such as hydra and urodeles. However, it is known that humans and other mammals retain the ability to regenerate the distal phalanges of the digits after amputation. Despite the increased knowledge base on model organisms regarding regenerative paradigms, there is a lack of application of regenerative medicine techniques in clinical practice in regard to digit tip injury. Here, we review the current understanding of digit tip regeneration and discuss gaps that remain in translating regenerative medicine into clinical treatment of digit amputation.

Fluoroquinolone-Associated Tendinopathy of the Hand and Wrist: A Systematic Review and Case Report.

BACKGROUND: Fluoroquinolone use has been known to be associated with tendinopathy and tendon rupture for over 30 years. Hand and wrist involvement has been reported rarely, yet without early recognition and withdrawal of the fluoroquinolone, there is potential for significant morbidity. METHODS: We searched Medline using a comprehensive search strategy for fluoroquinolones and tendinopathy of the hand and wrist, and provide a case report of a possible levofloxacin-related tendon rupture in a patient with a previous mutilating hand injury. RESULTS: We located 10 previously reported cases of fluoroquinolone-associated tendinopathy in the hand or wrist ranging from 1983 to 2015. Unlike Achilles tendinopathy, women were no more likely than men to have tendon rupture affecting the hands or wrists. Our patient was a 59-year-old man with prior tendon repair but otherwise noncontributory medical history who experienced spontaneous tendon rupture on an extended course of levofloxacin and required extensive pulley and boutonnière repair. CONCLUSIONS: Given the extensive damage that may be caused to weakened tissue, clinicians should maintain a high index of suspicion of tendinopathy in patients taking fluoroquinolones who have had previous tendon repairs, particularly in the setting of unexplained changes in recovery trajectory.

Microsurgical ear replantation-is venous repair necessary?-A systematic review.

BACKGROUND: A common postoperative observation after microsurgical ear replantation has been venous congestion necessitating alternate modes of decongestion, frequently in conjunction with blood transfusion. A comprehensive literature search was performed to assess the relationship between mode of vascular reconstruction and postoperative outcome as well as postoperative transfusion requirement after microsurgical ear replantation. METHODS: The search was limited to cases of microsurgical ear replantation following complete amputation. Only articles published in English and indexed in PubMed were included. RESULTS: The initial search retrieved 285 articles, which was narrowed down to 40 articles reporting on 60 cases that matched the aforementioned criteria. Reconstruction of the arterial and venous limb (Group 1) was performed in 63.3% of patients and artery-only anastomosis (Group 2) was performed in 31.7%. Among measurable outcomes, only the duration of surgery was significantly different between groups (2.6 hours longer in Group 1 than Group 2; P = 0.0042). CONCLUSION: In light of contemporary data demonstrating successful artery-only ear replantation, replantation should not be abandoned when unable to establish venous outflow microsurgically. © 2015 Wiley Periodicals, Inc. Microsurgery 36:345-350, 2016.

Outcomes of short-gap sensory nerve injuries reconstructed with processed nerve allografts from a multicenter registry study.

BACKGROUND: Short-gap digital nerve injuries are a common surgical problem, but the optimal treatment modality is unknown. A multicenter database was queried and analyzed to determine the outcomes of nerve gap reconstructions between 5 and 15 mm with processed nerve allograft. METHODS: The current RANGER registry is designed to continuously monitor and compile injury, repair, safety, and outcomes data. Centers followed their own standard of care for treatment and follow-up. The database was queried for digital nerve injuries with a gap between 5 and 15 mm reporting sufficient follow-up data to complete outcomes analysis. Available quantitative outcome measures were reviewed and reported. Meaningful recovery was defined by the Medical Research Council Classification (MRCC) scale at S3-S4 for sensory function. RESULTS: Sufficient follow-up data were available for 24 subjects (37 repairs) in the prescribed gap range. Mean age was 43 years (range, 23-81). Mean gap was 11 ± 3 (5-15) mm. Time to repair was 13 ± 42 (0-215) days. There were 25 lacerations, 8 avulsion/amputations, 2 gunshots, 1 crush injury, and 1 injury of unknown mechanism. Meaningful recovery, defined as S3-S4 on the MRCC scales, was reported in 92% of repairs. Sensory recovery of S3+ or S4 was observed in 84% of repairs. Static 2PD was 7.1 ± 2.9 mm (n = 19). Return to light touch was observed in 23 out of 32 repairs reporting Semmes-Weinstein monofilament outcomes (SWMF). There were no reported nerve adverse events. CONCLUSION: Sensory outcomes for processed nerve allografts were equivalent to historical controls for nerve autograft and exceed those of conduit. Processed nerve allografts provide an effective solution for short-gap digital nerve reconstructions.

Long-term results and costs of muscle flap coverage with Ilizarov bone transport in lower limb salvage.

OBJECTIVES: To determine long-term outcomes and costs of Ilizarov bone transport and flap coverage for lower limb salvage. DESIGN: Case series with retrospective review of outcomes with at least 6-year follow-up. SETTING: Academic tertiary care medical center. PATIENTS: Thirty-four consecutive patients with traumatic lower extremity wounds and tibial defects who were recommended amputation but instead underwent complex limb salvage from 1993 to 2005. INTERVENTION: Flap reconstruction and Ilizarov bone transport. MAIN OUTCOME MEASUREMENTS: Outcomes assessed were flap complications, infection, union, malunion, need for chronic narcotics, ambulation status, employment status, and need for reoperations. A cost analysis was performed comparing this treatment modality to amputation. RESULTS: Thirty-four patients (mean age: 40 years) were included with 14 acute Gustilo IIIB/C defects and 20 chronic tibial defects (nonunion with osteomyelitis). Thirty-five muscle flaps were performed with 1 flap loss (2.9%). The mean tibial bone defect was 8.7 cm, mean duration of bone transport was 10.8 months, and mean follow-up was 11 years. Primary nonunion rate at the docking site was 8.8% and malunion rate was 5.9%. All patients achieved final union with no cases of recurrent osteomyelitis. No patients underwent future amputations, 29% required reoperations, 97% were ambulating without assistance, 85% were working full time, and only 5.9% required chronic narcotics. Mean lifetime cost per patient per year after limb salvage was significantly less than the published cost for amputation. CONCLUSIONS: The long-term results and costs of bone transport and flap coverage strongly support complex limb salvage in this patient population.

Functional outcome following nerve repair in the upper extremity using processed nerve allograft.

PURPOSE: Reconstruction of peripheral nerve discontinuities with processed nerve allograft has become increasingly relevant. The RANGER Study registry was initiated in 2007 to study the use of processed nerve allografts in contemporary clinical practice. We undertook this study to analyze outcomes for upper extremity nerve repairs contained in the registry database. METHODS: We identified an upper extremity-specific population within the RANGER Study registry database consisting of 71 nerves repaired with processed nerve allograft. This group was composed of 56 subjects with a mean age of 40 ± 17 years (range, 18-86 y). We analyzed data to determine the safety and efficacy of processed nerve allograft. Quantitative data were available on 51 subjects with 35 sensory, 13 mixed, and 3 motor nerves. The mean gap length was 23 ± 12 mm (range, 5-50 mm). We performed an analysis to evaluate response-to-treatment and to examine sensory and motor recovery according to the international standards for motor and sensory nerve recovery. RESULTS: There were no reported implant complications, tissue rejections, or adverse experiences related to the use of the processed nerve allografts. Overall recovery, S3 or M4 and above, was achieved in 86% of the procedures. Subgroup analysis demonstrated meaningful levels of recovery in sensory, mixed, and motor nerve repairs with graft lengths between 5 and 50 mm. The study also found meaningful levels of recovery in 89% of digital nerve repairs, 75% of median nerve repairs, and 67% of ulnar nerve repairs. CONCLUSIONS: Our data suggest that processed nerve allografts offer a safe and effective method of reconstructing peripheral nerve gaps from 5 to 50 mm in length. These outcomes compare favorably with those reported in the literature for nerve autograft, and exceed those reported for tube conduits.

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.

Subdivision of the sural nerve: step towards individual facial reanimation.

Long term facial paralysis is a serious affliction and upsetting for the patient. Dynamic facial reanimation has become the treatment of choice. Various techniques that use different donor muscles have been developed since the first functional muscle transplant for facial paralysis more than 30 years ago. The concept of using a single muscle was refined into the use of dividable muscle slips such as serratus muscle or separate muscular subunits to avoid the resulting mass movements. Because the results are still not satisfactory, efforts were put into also dividing the donor nerve transplant into corresponding subunits to create a continuous line of individual action. Twenty human cadaveric sural nerves were successfully dissected into three completely separate subunits, transecting the interfascicular bridges. This anatomical study gives the potential to allow an independent triple innervation of three separate serratus anterior muscle slips, so decreasing further the mass movement after facial reanimation.

From simple interrupted to complex spiral: a systematic review of various suture techniques for microvascular anastomoses.

Accomplishing successful microvascular anastomoses is undoubtedly one of the most critical steps in performing free tissue transfer. However, the ideal technique has often been a subject of debate. Therefore, our objective was to review the current literature in an attempt to find objective evidence supporting the superiority of one particular technique. A PubMed and OVID on-line search was performed in November 2007 using the following keywords: microvascular anastomoses, microsurgical anastomosis, continuous suture, interrupted suture, mattress suture, and sleeve anastomosis. Our literature review found no difference in short- and/or long-term patency rates between the six main published techniques, which includes continuous suture, interrupted suture, locking continuous, continuous horizontal, horizontal interrupted with eversion, and sleeve anastomoses. These findings were consistent for each technique as long as the microsurgeon maintained standard microsurgical principles and practice, including suture line eversion, minimized tension, and direct intima-to-intima contact. Current literature supports no overall statistical difference in short- and/or long-term patency rates between any of the various techniques. The choice to perform one suture technique over another ultimately depends on the plastic surgeon's preference and microsurgical experience. To date, there are no human randomized, controlled clinical trials comparing the efficacy and clinical outcomes of each of the various suture techniques, and therefore one's comfort and familiarity should dictate his or her microsurgical technique. However, "exposure to many and mastery of one" simply provides the plastic surgery resident, fellow, or staff the technical flexibility needed for less-complicated surgical planning when performing free tissue transfer.

Refining outcomes in dorsal hand coverage: consideration of aesthetics and donor-site morbidity.

BACKGROUND: With high success rates, flap survival should no longer be the sole criterion in judging success in dorsal hand and wrist reconstruction. The authors sought to determine the best flap for dorsal hand coverage in terms of aesthetic appearance, donor-site morbidity, and minimization of revision surgery. METHODS: A retrospective review of all free flaps for dorsal hand and wrist coverage from 2002 to 2008 was performed. Flaps were divided into four groups: muscle, fasciocutaneous, fascial, and venous flaps. Outcomes assessed included need for debulking, blinded grading of aesthetic outcomes, and flap and donor-site complications. RESULTS: A total of 125 flaps were performed with no flap losses. There was no difference in partial loss or infection among the different flap groups. There was a significant range in the need for future debulking procedures, with debulking required in 67 percent of fasciocutaneous, 32 percent of muscle, 5.8 percent of fascial, and 0 percent of venous flaps. There was a significant difference in aesthetic outcomes: venous flaps had the best overall aesthetic outcomes; fascia and muscle flaps scored equally in terms of overall aesthetics, color, and contour match; and fasciocutaneous flaps had significantly worse aesthetic, contour, and color match results compared with all other flap types. Fasciocutaneous flaps had greater donor-site morbidity in terms of need for skin grafting and wound breakdown. CONCLUSION: The aesthetic outcome of dorsal hand reconstruction is dependent on flap choice, with statistically significant differences in revision surgeries and aesthetics among flap types.

Simultaneous double second toe transplantation for reconstruction of multiple digit loss in traumatic hand injuries.

The objective of this study is to review a single institution's 10-year experience of simultaneous double second toe transplantations for reconstruction of traumatic hand injuries. Eleven cases of traumatic hand injuries treated with simultaneous double second toe transplantation for digital reconstruction were retrospectively reviewed. All patients sustained traumatic injury resulting in multiple digit loss not amenable to replantation. A simultaneous three-team approach was performed in all cases. The average operating time was 9 hours (range 7 to 15 hours). The mean time to reconstruction was 5.7 months following injury (range 2 to 15 months). Mean hospital stay was 8 days (range 6 to 11 days). Complications included microvascular thrombosis in two toes, loss of one transplanted toe, hematoma, and wound infection. Twenty-one toes survived; secondary surgery was performed in ten patients. Average moving 2-point discrimination was 8 mm in each digit at 7-month follow-up. Mean grip and pinch strength approached 67% of the contralateral hand. Mean time to return to work after finger reconstruction was 10 months. Simultaneous double second toe transplantation is a useful and efficient option for multidigit reconstruction. A three-team approach allows for single-stage reconstruction resulting in decreased operative time, decreased hospital stay, and good functional outcomes when compared with alternative techniques.

A recommended protocol for the immediate postoperative care of lower extremity free-flap reconstructions.

The success of lower extremity microsurgical reconstructions may be compromised postoperatively secondary to several factors, including thrombosis, infection, bleeding, and edema. To address edema, surgeons may use protocols for gradually dangling and/or wrapping the affected extremity. Such protocols vary widely among surgeons and are typically based on training and/or prior experience. To that end, we distributed surveys to five plastic surgeons who are experienced in microvascular lower extremity reconstruction at five different institutions. The surveys inquired about postoperative management protocols for lower extremity free flaps with regard to positioning, compression, initiation and progression of postoperative mobilization, nonweightbearing and weightbearing ambulation, assessment of flap viability, and flap success rate. These protocols were then evaluated for similarities to create a consensus of postoperative management guidelines. Progressive periods of leg dependency and compression therapy emerged as important elements. Although the consensus protocol developed in this study is considered safe by each participant, we do not intend for these recommendations to serve as a standard of care, nor do we suggest that any one particular protocol leads to improved outcomes. However, these recommendations may serve as a guide for less experienced surgeons or those without a protocol in place.