Prophylactic Regenerative Peripheral Nerve Interface (RPNI) Surgery in Pediatric Lower Limb Amputation Patients.

OBJECTIVE: To evaluate the prophylactic effect of Regenerative Peripheral Nerve Interface (RPNI) surgery on pediatric post-amputation pain. SUMMARY OF BACKGROUND DATA: Chronic post-amputation pain is a debilitating and refractory sequela of limb amputation affecting up to 83% of pediatric patients with limb loss, resulting in disability and decreased quality of life. We postulate that prophylactic RPNI surgery performed during amputation may decrease the incidence of symptomatic neuroma and development of phantom limb pain, as well as limit analgesic use among pediatric patients with limb loss. METHODS: Retrospective chart review was performed on pediatric patients between the ages of 8 and 21 years who underwent major lower limb amputation with and without RPNI surgery. Documented neuroma and phantom limb pain scores as well as analgesic use was recorded. Narcotic use was converted to milligrams morphine equivalents per day (MME/day) while overall analgesic use was converted to Medication Quantification Scale version III (MQSIII) scores. Analysis was performed using Stata. RESULTS: Forty-four pediatric patients were identified; 25 RPNI patients and 19 controls. Seventy-nine percent of control patients developed chronic post-amputation pain versus 21% of RPNI patients (P<0.001). Among the patients who developed post-amputation pain, 20% of controls developed clinical neuroma pain, compared to 0% of RPNI patients (P<0.001). Additionally, RPNI patients demonstrated a significant decrease in pain score (P=0.007) and narcotic usage (P<0.01), compared to controls. Overall analgesic use did not vary significantly between groups. CONCLUSIONS: Prophylactic RPNI surgery shows promise for pediatric patients undergoing major lower limb amputation by preventing both symptomatic neuromas and possibly the development of phantom limb pain.

Gender Affirming Mastectomy Improves Quality of Life in Transmasculine Patients: A Single-center Prospective Study.

OBJECTIVE: To determine the impact of gender-affirming mastectomy on depression, anxiety, and body image. BACKGROUND: There are many cross-sectional and ad-hoc studies demonstrating the benefits of gender-affirming surgery. There are few prospective investigations of patient-reported outcomes in gender-affirming surgery using validated instruments. METHODS: In this prospective study, patients presenting to the University of Michigan for gender-affirming Mastectomy were surveyed preoperatively and 6-months postoperatively. Primary outcomes were patient-reported measurements of anxiety measured by General Anxiety Disorder-7, depression measured by Patient Health Questionnaire-9, body image measured by BODY-Q and Body Image Quality of Life Index, psychosocial and sexual functioning measured by BREAST-Q, and satisfaction with decision measured by BREAST-Q. Linear regression analysis was used to control for presence of complication and existing history of mental health conditions. RESULTS: A total of 70 patients completed the study. The average age of participants was 26.7. The mean Patient Health Questionnaire-9 score pre-operatively was 7.8 and postoperatively was 5.4 ( P =0.001). The mean preoperative and postoperative General Anxiety Disorder-7 scores were 7.6 and 4.6, respectively ( P <0.001). There were significant improvements in both psychosocial (35 to 79.2, P <0.001) and sexual (33.9 to 67.2, P< 0.001) functioning related to chest appearance as measured by the BREAST-Q and global psychosocial functioning (-15.6 to +32, P <0.001) as measured by the Body Image Quality of Life Index. Satisfaction with chest contour (14.3 to 93.8, P <0.001) and nipple appearance (29.3 to 85.9, P <0.001) measured by the BODY-Q significantly improved. Patients had a mean satisfaction with outcome score of 93.1. CONCLUSIONS: Patients undergoing gender-affirming mastectomy in this single-center prospective study reported significant improvements in anxiety, depression, body image, psychosocial, and sexual functioning after this procedure. Patients were extremely satisfied with the decision to undergo this operation.

Ultrasound appearance of regenerative peripheral nerve interface with clinical correlation.

OBJECTIVE: To describe the ultrasound (US) appearance of regenerative peripheral nerve interfaces (RPNIs) in humans, and correlate clinically and with histologic findings from rat RPNI. MATERIALS AND METHODS: Patients (≥ 18 years) who had undergone RPNI surgery within our institution between the dates of 3/2018 and 9/2019 were reviewed. A total of 21 patients (15 male, 6 female, age 21-82 years) with technically adequate US studies of RPNIs were reviewed. Clinical notes were reviewed for the presence of persistent pain after RPNI surgery. Histologic specimens of RPNIs in a rat model from prior studies were compared with the US findings noted in this study. RESULTS: There was a variable appearance to the RPNIs including focal changes involving the distal nerve, nerve-muscle graft junction, and area of the distal sutures. The muscle grafts varied in thickness with accompanying variable echogenic changes. No interval change was noted on follow-up US studies. Diffuse hypoechoic swelling with loss of the fascicular structure of the nerve within the RPNI and focal hypoechoic changes at the nerve-muscle graft junction were associated with clinical outcomes. US findings corresponded to histologic findings in the rat RPNI. CONCLUSION: Ultrasound imaging can demonstrate various morphologic changes involving the nerve, muscle, and interface between these two biological components of RPNIs. These changes correspond to expected degenerative and regenerative processes following nerve resection and muscle reinnervation and should not be misconstrued as pathologic in all cases. N5 and N1 morphologic type changes of the RPNI were found to be associated with symptoms.

Where Have All the Rhinoplasties Gone? A Call to Action for Academic Plastic Surgeons to Focus on Increasing Rhinoplasty Procedures Before It Is Too Late.

BACKGROUND: The armamentarium of a plastic surgeon is vast, consisting of an array of surgical procedures from head to toe. Unfortunately, plastic surgeons have been losing portions of their operative domain to other surgical subspecialties for years. The number of subspecialties invading our niche is bothersome, but more concerning is the fact that losing the reins of these core procedures results in less surgical exposure and competency for plastic surgery residents.Lately, in academic institutions, otolaryngologists seem to be performing most rhinoplasty procedures, resulting in fewer surgeries performed by plastic surgeons. Trainees must perform 10 rhinoplasties to fulfill graduation requirements but, more importantly, residents should graduate feeling competent and confident performing rhinoplasties. The aims of this study are to determine the number of rhinoplasties being performed at academic centers each year and to evaluate the trend with regard to which specialties are performing these procedures. METHODS: Three academic institutions with plastic surgery and otolaryngology residency programs searched medical records for rhinoplasty Current Procedural Terminology codes from January 1, 2009, to December 31, 2019. The total numbers of rhinoplasties performed each year, by each specialty, were tallied. RESULTS: Growth rate in rhinoplasty volume among participating institutions ranged from 27% to 149%. At these institutions, plastic surgeons performed less than one third of all rhinoplasties. In 2009, 10% of rhinoplasties were performed by plastic surgeons at institution 1, 22% at institution 2, and 18% at institution 3. In 2019, the volume of rhinoplasties performed by plastic surgeons was 5%, 12%, and 27%, respectively. The 3 ENT departments had statistically significant increasing trends in rhinoplasty volume. Institutions 1 and 2's plastic surgery departments showed that negative volume trends, however, were not statistically significant. Institution 3's plastic surgery department has had an increasing trend, which was statistically significant. CONCLUSIONS: Otolaryngology is performing most rhinoplasties at several academic institutions. This is concerning for the education of plastic surgery trainees. Academic plastic surgeons must focus on increasing the number of rhinoplasties performed to adequately train residents this core procedure. If rhinoplasties are not made a priority now, this surgery may become a historic operation instead of a vital skill in plastic surgeons' armamentarium.

Chronic Exertional Compartment Syndrome Requiring Bilateral Fasciotomy: An Atypical Complication of Familial Stiff Skin Syndrome in a Father and Son.

ABSTRACT: Stiff skin syndrome (SSS) is a rare cutaneous disorder characterized by cutaneous fibrosis resulting in the early onset of thickened and indurated skin, joint mobility restrictions, and contractures. We describe a father and son with familial SSS who presented with bilateral exertional pain and a confirmed diagnosis of chronic exertional compartment syndrome on 4-compartment pressure testing. Patients experienced restored functionality with bilateral 4-compartment fasciotomy. Chronic exertional compartment syndrome should be considered in the differential diagnosis of patients with SSS and chronic pain of the lower limbs.

Sensory nerve regeneration and reinnervation in muscle following peripheral nerve injury.

Sensory afferent fibers are an important component of motor nerves and compose the majority of axons in many nerves traditionally thought of as "pure" motor nerves. These sensory afferent fibers innervate special sensory end organs in muscle, including muscle spindles that respond to changes in muscle length and Golgi tendons that detect muscle tension. Both play a major role in proprioception, sensorimotor extremity control feedback, and force regulation. After peripheral nerve injury, there is histological and electrophysiological evidence that sensory afferents can reinnervate muscle, including muscle that was not the nerve's original target. Reinnervation can occur after different nerve injury and muscle models, including muscle graft, crush, and transection injuries, and occurs in a nonspecific manner, allowing for cross-innervation to occur. Evidence of cross-innervation includes the following: muscle spindle and Golgi tendon afferent-receptor mismatch, vagal sensory fiber reinnervation of muscle, and cutaneous afferent reinnervation of muscle spindle or Golgi tendons. There are several notable clinical applications of sensory reinnervation and cross-reinnervation of muscle, including restoration of optimal motor control after peripheral nerve repair, flap sensation, sensory protection of denervated muscle, neuroma treatment and prevention, and facilitation of prosthetic sensorimotor control. This review focuses on sensory nerve regeneration and reinnervation in muscle, and the clinical applications of this phenomena. Understanding the physiology and limitations of sensory nerve regeneration and reinnervation in muscle may ultimately facilitate improvement of its clinical applications.

"Decreasing Postamputation Pain with the Regenerative Peripheral Nerve Interface (RPNI)".

Over 185,000 limb amputations are performed in the United States annually, many of which are due to the sequelae of peripheral vascular disease. Symptomatic neuromas remain a significant source of postamputation morbidity and contribute to both phantom limb (PLP) and residual limb pain (RLP). While many interventions have been proposed for the treatment of symptomatic neuromas, conventional methods lead to a high incidence of neuroma recurrence. Furthermore, these existing methods do not facilitate an ability to properly interface with myoelectric prosthetic devices. The Regenerative Peripheral Nerve Interface (RPNI) was developed to overcome these limitations. The RPNI consists of an autologous free muscle graft secured around the end of a transected nerve. The muscle graft provides regenerating axons with end organs to reinnervate, thereby preventing neuroma formation. We have shown that this simple, reproducible, and safe surgical technique successfully treats and prevents neuroma formation in major limb amputations. In this paper, we describe RPNI surgery in the setting of major limb amputation and highlight the promising results of RPNIs in our animal and clinical studies.

Surgically Implanted Electrodes Enable Real-Time Finger and Grasp Pattern Recognition for Prosthetic Hands.

Currently available prosthetic hands are capable of actuating anywhere from five to 30 degrees of freedom (DOF). However, grasp control of these devices remains unintuitive and cumbersome. To address this issue, we propose directly extracting finger commands from the neuromuscular system. Two persons with transradial amputations had bipolar electrodes implanted into regenerative peripheral nerve interfaces (RPNIs) and residual innervated muscles. The implanted electrodes recorded local electromyography with large signal amplitudes. In a series of single-day experiments, participants used a high speed movement classifier to control a virtual prosthetic hand in real-time. Both participants transitioned between 10 pseudo-randomly cued individual finger and wrist postures with an average success rate of 94.7% and trial latency of 255 ms. When the set was reduced to five grasp postures, metrics improved to 100% success and 135 ms trial latency. Performance remained stable across untrained static arm positions while supporting the weight of the prosthesis. Participants also used the high speed classifier to switch between robotic prosthetic grips and complete a functional performance assessment. These results demonstrate that pattern recognition systems can use intramuscular electrodes and RPNIs for fast and accurate prosthetic grasp control.

Reinventing Extremity Amputation in the Era of Functional Limb Restoration.

BACKGROUND: Recent progress in biomechatronics and vascularized composite allotransplantation have occurred in the absence of congruent advancements in the surgical approaches generally utilized for limb amputation. Consideration of these advances, as well as of both novel and time-honored reconstructive surgical techniques, argues for a fundamental reframing of the way in which amputation procedures should be performed. METHODS: We review sentinel developments in external prosthetic limb technology and limb transplantation, in addition to standard and emerging reconstructive surgical techniques relevant to limb modification, and then propose a new paradigm for limb amputation. RESULTS: An approach to limb amputation based on the availability of native tissues is proposed, with the intent of maximizing limb function, limiting neuropathic pain, restoring limb perception/proprioception and mitigating limb atrophy. CONCLUSIONS: We propose a reinvention of the manner in which limb amputations are performed, framed in the context of time-tested reconstructive techniques, as well as novel, state-of-the-art surgical procedures. Implementation of the proposed techniques in the acute setting has the potential to elevate advanced limb replacement strategies to a clinical solution that perhaps exceeds what is possible through traditional surgical approaches to limb salvage. We therefore argue that amputation, performed with the intent of optimizing the residuum for interaction with either a bionic or a transplanted limb, should be viewed not as a surgical failure, but as an alternative form of limb reconstruction.

Regenerative peripheral nerve interface free muscle graft mass and function.

BACKGROUND: Regenerative peripheral nerve interfaces (RPNIs) transduce neural signals to provide high-fidelity control of neuroprosthetic devices. Traditionally, rat RPNIs are constructed with ~150 mg of free skeletal muscle grafts. It is unknown whether larger free muscle grafts allow RPNIs to transduce greater signal. METHODS: RPNIs were constructed by securing skeletal muscle grafts of various masses (150, 300, 600, or 1200 mg) to the divided peroneal nerve. In the control group, the peroneal nerve was transected without repair. Endpoint assessments were conducted 3 mo postoperatively. RESULTS: Compound muscle action potentials (CMAPs), maximum tetanic isometric force, and specific muscle force were significantly higher for both the 150 and 300 mg RPNI groups compared to the 600 and 1200 mg RPNIs. Larger RPNI muscle groups contained central areas lacking regenerated muscle fibers. CONCLUSIONS: Electrical signaling and tissue viability are optimal in smaller as opposed to larger RPNI constructs in a rat model.

Developing Strategies for Targeted Improvement of Perioperative Education for Postbariatric Surgery Body-Contouring Patients.

BACKGROUND: The quality of perioperative patient education impacts surgical outcomes, patient experiences, and resources needed to address patient concerns and unplanned visits. We examined patient inquiries and education materials to assess the quality of perioperative education and identify areas of targeted improvement for postbariatric surgery body-contouring procedures. METHODS: We examined 100 consecutive postbariatric procedures at an academic center. Themes of patient-generated calls, e-mails, and electronic medical record portal messages during the perioperative period were identified via qualitative analysis. Understandability and actionability of perioperative educational resources were assessed using the Patient Education Materials Assessment Tool (PEMAT). RESULTS: Among 212 communications identified, 167 (79%) were postoperative. Common themes were concerns regarding the surgical site (38%), medications (10%), and activity restrictions (10%). One hundred thirty inquiries were resolved through patient re-education (57%), but 36 (16%) required in-person evaluation including 4 unplanned emergency department visits and 3 readmissions for surgical-site concerns. The PEMAT scores for institutional materials were fair for understandability (69%) and actionability (60%). American Society of Plastic Surgeons materials were more understandable (84%) but less actionable (40%). CONCLUSIONS: Patient queries can be leveraged as a source of qualitative data to identify gaps in perioperative education. High-yield topics, such as education regarding the surgical site and medications, can be targeted for quality improvement through better communication and potentially reduce the number of unnecessary visits. Using the PEMAT, we also identified how directly the education materials can be revised. Improving perioperative education can promote mutual understanding between patients and surgeons, better outcomes, and efficient resource utilization.

Stem-cell-based therapies to enhance peripheral nerve regeneration.

Peripheral nerve injury remains a major cause of morbidity in trauma patients. Despite advances in microsurgical techniques and improved understanding of nerve regeneration, obtaining satisfactory outcomes after peripheral nerve injury remains a difficult clinical problem. There is a growing body of evidence in preclinical animal studies demonstrating the supportive role of stem cells in peripheral nerve regeneration after injury. The characteristics of both mesoderm-derived and ectoderm-derived stem cell types and their role in peripheral nerve regeneration are discussed, specifically focusing on the presentation of both foundational laboratory studies and translational applications. The current state of clinical translation is presented, with an emphasis on both ethical considerations of using stems cells in humans and current governmental regulatory policies. Current advancements in cell-based therapies represent a promising future with regard to supporting nerve regeneration and achieving significant functional recovery after debilitating nerve injuries.

The future of upper extremity rehabilitation robotics: research and practice.

The loss of upper limb motor function can have a devastating effect on people's lives. To restore upper limb control and functionality, researchers and clinicians have developed interfaces to interact directly with the human body's motor system. In this invited review, we aim to provide details on the peripheral nerve interfaces and brain-machine interfaces that have been developed in the past 30 years for upper extremity control, and we highlight the challenges that still remain to transition the technology into the clinical market. The findings show that peripheral nerve interfaces and brain-machine interfaces have many similar characteristics that enable them to be concurrently developed. Decoding neural information from both interfaces may lead to novel physiological models that may one day fully restore upper limb motor function for a growing patient population.

Short-wave infrared light imaging measures tissue moisture and distinguishes superficial from deep burns.

Existing clinical approaches and tools to measure burn tissue destruction are limited resulting in misdiagnosis of injury depth in over 40% of cases. Thus, our objective in this study was to characterize the ability of short-wave infrared (SWIR) imaging to detect moisture levels as a surrogate for tissue viability with resolution to differentiate between burns of various depths. To accomplish our aim, we constructed an imaging system consisting of a broad-band Tungsten light source; 1,200-, 1,650-, 1,940-, and 2,250-nm wavelength filters; and a specialized SWIR camera. We initially used agar slabs to provide a baseline spectrum for SWIR light imaging and demonstrated the differential absorbance at the multiple wavelengths, with 1,940 nm being the highest absorbed wavelength. These spectral bands were then demonstrated to detect levels of moisture in inorganic and in vivo mice models. The multiwavelength SWIR imaging approach was used to diagnose depth of burns using an in vivo porcine burn model. Healthy and injured skin regions were imaged 72 hours after short (20 seconds) and long (60 seconds) burn application, and biopsies were extracted from those regions for histologic analysis. Burn depth analysis based on collagen coagulation histology confirmed the formation of superficial and deep burns. SWIR multispectral reflectance imaging showed enhanced intensity levels in long burned regions, which correlated with histology and distinguished between superficial and deep burns. This SWIR imaging method represents a novel, real-time method to objectively distinguishing superficial from deep burns.

Characterizing the Circulating Cell Populations in Traumatic Heterotopic Ossification.

Heterotopic ossification (HO) occurs secondary to trauma, causing pain and functional limitations. Identification of the cells that contribute to HO is critical to the development of therapies. Given that innate immune cells and mesenchymal stem cells are known contributors to HO, we sought to define the contribution of these populations to HO and to identify what, if any, contribution circulating populations have to HO. A shared circulation was obtained using a parabiosis model, established between an enhanced green fluorescent protein-positive/luciferase+ donor and a same-strain nonreporter recipient mouse. The nonreporter mouse received Achilles tendon transection and dorsal burn injury to induce HO formation. Bioluminescence imaging and immunostaining were performed to define the circulatory contribution of immune and mesenchymal cell populations. Histologic analysis showed circulating cells present throughout each stage of the developing HO anlagen. Circulating cells were present at the injury site during the inflammatory phase and proliferative period, with diminished contribution in mature HO. Immunostaining demonstrated that most early circulatory cells were from the innate immune system; only a small population of mesenchymal cells were present in the HO. We demonstrate the time course of the participation of circulatory cells in trauma-induced HO and identify populations of circulating cells present in different stages of HO. These findings further elucidate the relative contribution of local and systemic cell populations to HO.

Stimulated grip strength measurement: Validation of a novel method for functional assessment.

BACKGROUND: Reliable measurement of functional recovery is critical in translational peripheral nerve regeneration research. Behavioral functional assessments such as volitional grip strength testing (vGST) are limited by inherent behavioral variability. Isometric tetanic force testing (ITFT) is highly reliable but precludes serial measurements. Combining elements of vGST and ITFT, stimulated grip strength testing (sGST) involves percutaneous median nerve stimulation to elicit maximal tetanic contraction of digital flexors, thereby allowing for consistent measurement of maximal grip strength. METHODS: We measured side-to-side equivalence of force using sGST, vGST, and ITFT to determine relative reliability and repeatability. We also performed weekly force measurements following median nerve repair. RESULTS: sGST demonstrated greater reliability and inter-trial repeatability than vGST and similar reliability to ITFT, with the added benefit of serial measurements. CONCLUSIONS: sGST is a valid method for assessing functional recovery that addresses the limitations of the currently available modalities used in translational peripheral nerve regeneration research.

Current Trends in Breast Augmentation: Analysis of 2011-2015 Maintenance of Certification (MOC) Tracer Data.

BACKGROUND: Breast augmentation is the most common aesthetic surgery performed in the United States. Despite its popularity, there is no consensus on many aspects of the procedure. OBJECTIVES: The authors assessed current trends and changes in breast augmentation from January 1, 2011 to December 31, 2015. METHODS: A retrospective cross-sectional study of 11,756 women who underwent breast augmentation based on the American Board of Plastic Surgery (ABPS) Maintenance of Certification Tracer Database was performed. RESULTS: There were clearly dominant trends in how ABPS-certified plastic surgeons performed breast augmentations. Most surgeries were performed in freestanding outpatient (47.3%) or office operating room (33.7%). The inframammary fold incision was most popular (75.1%), followed by periareolar (17.8%) and transaxillary approaches (4.1%). Implants were more commonly placed in a submuscular pocket (30.6%) compared with dual plane (26.7%) or subglandular (6.7%). Silicone implants (66.8%) were favored over saline (25.1%), with a statistically significant increase in silicone prostheses from 2011 to 2015. Data were "not applicable" or "other" in the remainder of cases. Administration of both preoperative antibiotics (3.8% in 2011, 98.7% in 2015, P < 0.05) and deep venous thromboembolism (DVT) prophylaxis (3.8% in 2011, 90.6% in 2015, P < 0.05) dramatically increased during the study period. Overall adverse events (7.4%) and reoperation rates (2.2%) were low. CONCLUSIONS: Changes in standard of care for breast augmentation are reflected by the evolving practice patterns of plastic surgeons. This is best evidenced by the dramatic increase in use of antibiotic and DVT prophylaxis from 2011 to 2015.

Regenerative peripheral nerve interfaces for real-time, proportional control of a Neuroprosthetic hand.

INTRODUCTION: Regenerative peripheral nerve interfaces (RPNIs) are biological constructs which amplify neural signals and have shown long-term stability in rat models. Real-time control of a neuroprosthesis in rat models has not yet been demonstrated. The purpose of this study was to: a) design and validate a system for translating electromyography (EMG) signals from an RPNI in a rat model into real-time control of a neuroprosthetic hand, and; b) use the system to demonstrate RPNI proportional neuroprosthesis control. METHODS: Animals were randomly assigned to three experimental groups: (1) Control; (2) Denervated, and; (3) RPNI. In the RPNI group, the extensor digitorum longus (EDL) muscle was dissected free, denervated, transferred to the lateral thigh and neurotized with the residual end of the transected common peroneal nerve. Rats received tactile stimuli to the hind-limb via monofilaments, and electrodes were used to record EMG. Signals were filtered, rectified and integrated using a moving sample window. Processed EMG signals (iEMG) from RPNIs were validated against Control and Denervated group outputs. RESULTS: Voluntary reflexive rat movements produced signaling that activated the prosthesis in both the Control and RPNI groups, but produced no activation in the Denervated group. Signal-to-Noise ratio between hind-limb movement and resting iEMG was 3.55 for Controls and 3.81 for RPNIs. Both Control and RPNI groups exhibited a logarithmic iEMG increase with increased monofilament pressure, allowing graded prosthetic hand speed control (R2 = 0.758 and R2 = 0.802, respectively). CONCLUSION: EMG signals were successfully acquired from RPNIs and translated into real-time neuroprosthetic control. Signal contamination from muscles adjacent to the RPNI was minimal. RPNI constructs provided reliable proportional prosthetic hand control.

Simplifying Arterial Coupling in Microsurgery-A Preclinical Assessment of an Everter Device to Aid with Arterial Anastomosis.

BACKGROUND: A novel arterial everter device was engineered to simplify microvascular coupling of arteries by reliably securing the stiff, muscular wall of arteries over coupler pins. We compare microvascular coupling with the everter device to manual suturing for arterial anastomoses in a live large animal model. MATERIALS AND METHODS: In this preliminary study, bilateral external femoral arteries of five male swine were exposed and sharply divided. Arteries were anastomosed using either interrupted sutures (n = 5) or the everter device and Synovis Coupler (n = 5). The efficiency in engaging coupler pins, the time taken to perform the anastomosis, and vessel patency immediately post-op and at 1-week postanastomosis were evaluated. Vessel wall injury and luminal stenosis were compared between groups using histomorphometric analyses. RESULTS: On an average, 80% of coupler pins engaged the vessel walls after a single pass of the everter. The average time to perform the anastomosis was significantly less when using the everter/coupler compared with manual suturing (6:35 minutes versus 25:09 minutes, p < 0.001). Immediately post-op, 100% patency was observed in both groups. At 1 week post-op, four of five (80%) of coupled arteries and all five (100%) of hand-sewn arteries were patent. The degree of arterial wall injury, neointimal formation, and luminal stenosis for patent arteries were similar between groups. CONCLUSIONS: Successful arterial anastomoses using the everter device with the Synovis Coupler was easier and significantly more efficient when compared with a standard hand-sewn technique. Both techniques had acceptable patency rates and similar effects on the vessel wall and intima.