Hand-Sewn Versus Stapled Small Bowel Anastomoses in Patients With Secondary Mesenteric Ischemia.

INTRODUCTION: Although stapled anastomoses have been widely evaluated in the context of the elective surgery, few reports compared manual with stapled anastomoses in patients undergoing emergency surgery. The aim of this study is to compare the outcome of hand-sewn end-to-end anastomoses with stapled side-to-side and stapled end-to-side anastomoses in patients undergoing small bowel resection for acute mesenteric ischemia secondary to intestinal obstruction. METHODS: From January 2015 to June 2021 all the hemodynamically stable patients undergoing emergency surgery with small bowel resection for intestinal obstruction were enrolled in this study. According to surgical technique in performing anastomosis, the patients were divided into three groups: group 1: hand-sewn end-to-end anastomosis, group 2: stapled end-to-side anastomosis, and group 3: stapled side-to-side anastomosis. RESULTS: Although the anastomosis failure rate was higher in group 3, it was not significantly different between the three groups (P = 0.78: chi-square test). Likewise, no significant differences in the median hospital stay were found between the patients' groups (P = 0.87: Kruskal-Wallis test). The median operating time was similar in patients undergoing stapled anastomoses and was significantly higher in patients undergoing hand-sewn anastomoses (P = 0.0009: Kruskal-Wallis test). CONCLUSIONS: In patients undergoing emergency small bowel resection for complicated intestinal obstruction, a similar outcome in terms of dehiscence rate and hospital stay can be achieved performing stapled or hand-sewn anastomoses, even if restoring the intestinal continuity with stapled technique is associated with lower operating time.

Distal end side-to-side anastomosis of sequential coronary bypass for size mismatched saphenous vein grafts and coronary arteries.

INTRODUCTION: The distal end anastomosis is critical to the entire sequential grafts in coronary artery bypass grafting (CABG), but caliber mismatch diminishes the quality of the anastomosis. We aimed to introduce a modified distal end side-to-side (deSTS) anastomosis to handle the size mismatch and compared with classic distal end end-to-side (deETS) anastomosis. METHODS: From January 2014 to December 2018, 185 patients who underwent off-pump CABG with size mismatched sequential vein grafts (≥3.5 mm) and target coronaries (1.0-1.5 mm) at the distal end anastomoses were included. We retrospectively reviewed the data of the patients, perioperative and follow-up outcomes were analyzed. RESULTS: The deSTS group (n = 67) showed higher anastomotic flow (19.8 ± 8.0 vs 14.9±6.8 mL/min; p < 0.001) and lower pulsatility index (2.7 ± 0.8 vs 3.2 ± 1.0; p = 0.001) than the deETS group (n = 118). Higher incidence of in-hospital myocardial infarction (MI) was found in the deETS group but without significant difference (9.0% vs. 15.3%; p = 0.220). Kaplan-Meier analysis illustrated a relatively lower MI and major adverse cardiovascular and cerebrovascular events (MACCE) incidence in the deSTS group, and the deSTS group was associated with a reduction in long-term death, MI and MACCE in the adjusted Cox regression model. In addition, relatively higher graft patency was found in the deSTS group. CONCLUSIONS: The deSTS anastomosis showed superiority in solving size mismatch in sequential CABG, including better intraoperative flow dynamics, ideal long-term graft patency and reduced the incidence of perioperative and follow-up adverse events especially in MI.

End-to-Side vs. Free Graft Nerve Reconstruction-Experimental Study on Rats.

The long history of regeneration nerve research indicates many clinical problems with surgical reconstruction to be resolved. One of the promising surgical techniques in specific clinical conditions is end-to-side neurorrhaphy (ETS), described and then repeated with different efficiency in the 1990s of the twentieth century. There are no reliable data on the quality of recipient nerve regeneration, possible donor nerve damage, and epineural window technique necessary to be performed. This research attempts to evaluate the possible regeneration after end-to-side neurorrhaphy, its quality, potential donor nerve damage, and the influence of epineural windows on regeneration efficiency. Forty-five female Wistar rats were divided into three equal groups, and various surgical technics were applied: A-ETS without epineural window, B-ETS with epineural window, and C-free graft reconstruction. The right peroneal nerve was operated on, and the tibial nerve was selected as a donor. After 24 weeks, the regeneration was evaluated by (1) footprint analysis every two weeks with PFI (peroneal nerve function index), TFI (tibial nerve function index), and SFI (sciatic nerve function index) calculations; (2) the amplitude and latency measurements of motor evoked potentials parameters recorded on both sides of the peroneal and tibial nerves when electroneurography with direct sciatic nerve electrical stimulation and indirect magnetic stimulation were applied; (3) histomorphometry with digital conversion of a transverse semithin nerve section, with axon count, fibers diameter, and calculation of axon area with a semiautomated method were performed. There was no statistically significant difference between the groups investigated in all the parameters. The functional indexes stabilized after eight weeks (PFI) and six weeks (TFI and SFI) and were positively time related. The lower amplitude of tibial nerve potential in groups A and B was proven compared to the non-operated side. Neurophysiological parameters of the peroneal nerve did not differ significantly. Histomorphometry revealed significantly lower diameter and area of axons in operated peroneal nerves compared to non-operated nerves. The axon count was at a normal level in every group. Tibial nerve parameters did not differ from non-operated values. Regeneration of the peroneal nerve after ETS was ascertained to be at the same level as in the case of free graft reconstruction. Peroneal nerves after ETS and free graft reconstruction were ascertained to have a lower diameter and area than non-operated ones. The technique of an epineural window does not influence the regeneration result of the peroneal nerve. The tibial nerve motor evoked potentials were characterized by lower amplitudes in ETS groups, which could indicate axonal impairment.

Targeting Chondroitin Sulphate Synthase 1 (Chsy1) Promotes Axon Growth Following Neurorrhaphy by Suppressing Versican Accumulation.

Versican is a chondroitin sulfate proteoglycan (CSPG), which deposits in perineurium as a physical barrier and prevents the growth of axons out of the fascial boundary. Several studies have indicated that the chondroitin sulfate (CS) chains on versican have several possible functions beyond the physical barrier, including the ability to stabilize versican core protein in the extracellular matrix. As chondroitin sulfate synthase 1 (Chsy1) is a crucial enzyme for CS elongation, we hypothesized that in vivo knockdown of Chsy1 at peripheral nerve lesion site may decrease CS and versican accumulation, and result in accelerating neurite regeneration. In the present study, end-to-side neurorrhaphy (ESN) in Wistar rats was used as an in vivo model of peripheral nerve injury to evaluate nerve regeneration after surgical intervention. The distribution and expression of versican and Chsy1 in regenerating axons after ESN was studied using confocal microscopy and western blotting. Chsy1 was silenced at the nerve lesion (surgical) site using in vivo siRNA transfection. The results indicated that Chsy1 was successfully silenced in nerve tissue, and its downregulation was associated with functional recovery of compound muscle action potential. Silencing of Chsy1 also decreased the accumulation of versican core protein, suggesting that transient treating of Chsy1-siRNA may be an alternative and an effective strategy to promote injured peripheral nerve regeneration.

End-to-side circular stapled versus side-to-side linear stapled intrathoracic esophagogastric anastomosis following minimally invasive Ivor-Lewis esophagectomy: comparison of short-term outcomes.

PURPOSE: The search for the optimal procedure for creation of a safe gastroesophageal intrathoracic anastomosis with a lower risk of leakage in totally minimally invasive Ivor-Lewis esophagectomy (TMIIL) is ongoing. In the present study, we compared the outcomes of end-to-side (with circular stapler [CS]) and side-to-side (with linear stapler [LS]) techniques for intrathoracic anastomosis during TMIIL performed in 2 European high-volume centers for upper gastrointestinal surgery. A propensity score method was used to compare the CS and LS groups. METHODS: We retrospectively evaluated patients with lower esophageal cancer or Siewert type 1 or 2 esophagogastric junction carcinoma who underwent a planned TMIIL esophagectomy, performed from January 2017 to September 2020. The anastomosis was created by a semi-mechanical technique using a LS in one center and by a mechanical technique using a CS in the other center. General features, operative techniques, pathology data, and short-term outcomes were analyzed. Statistical evaluations were performed on the whole cohort, stratifying the analyses by risk strata factors identified with the propensity scores, and on a subgroup of patients matched by propensity score. The primary endpoint of the study was the rate of anastomotic leakage in the two groups. Secondary endpoints included rates of anastomotic stricture and overall postoperative complications. RESULTS: Considering the whole population, 256 patients were included; of those, 220 received the anastomosis with a circular stapler (CS group), and 36 received the anastomosis with a linear stapler (LS group). No significant differences by group in terms of sex, age, American Society of Anesthesiologists physical status classification, and type of neoplasm were showed. The rate of anastomotic leakage did not differ in the two groups (9.6% CS vs. 5.6% LS, p = 0.438), as well as the rate of anastomotic stricture in the 3-month follow-up (0.9% CS vs. 2.8% LS, p = 0.367). The rate of chyle leakage and of pulmonary, cardiac, and infective complications was not significantly different in the groups. After propensity score matching, 72 patients were included in the analysis. The 2 obtained propensity score matched groups did not differ for any of the clinical and pathologic variables considered for the analysis, resulting in well-balanced cohorts. The results obtained on the whole population were confirmed in the matched groups. CONCLUSIONS: The results of our study suggest that both techniques for esophagogastric anastomosis during TMIIL are feasible, safe, and effective, with comparable rates of postoperative anastomotic leakage and stricture.

Side-to-side versus end-to-side ileocolic anastomosis in right-sided colectomies: A cohort control study.

Aims: The three main types of anastomotic configurations following colorectal resection are Side-to-Side Anastomosis (S-S), End-to-Side Anastomosis (E-S) and End-to-End Anastomosis (E-E). This study aims to present results from a local cohort supplemented by a systematic review with meta-analysis of existing literature to compare the post-operative outcomes between E-S and S-S. Methods: A cohort study of patients who underwent right colectomy with E-S or S-S anastomosis, was conducted at the National University Hospital Singapore. Electronic databases Embase and Medline were systematically searched from inception to 21 August 2020, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. Studies were included if they compared post-operative outcomes between E-S and S-S. Results: In the cohort study, 40 underwent E-S and 154 underwent S-S. Both post-operative ileus (12.5% vs. 29.2%, P = 0.041) and length of hospital stay (9.35 days vs. 14.04 days, P = 0.024) favoured E-S, but anastomotic bleed favoured S-S (15.0% vs. 3.2%, P = 0.004). Five studies were included in the meta-analysis with 860 E-S and 1126 S-S patients. Similarly, post-operative ileus (odds ratio [OR] =0.302; 95% confidence interval [CI]: 0.122-0.747; P = 0.010) and length of hospital stay (mean differences = ‒1.54 days; CI: ‒3.00 to ‒0.076 days; P = 0.039) favoured E-S. Additional sensitivity analysis including only stapled anastomosis showed a lower rate of anastomotic leak in E-S patients (OR = 0.185; 95% CI: 0.054-0.627; P = 0.007). Conclusions: This is the first systematic review to show that the E-S technique produces superior post-operative outcomes after right colectomy compared to S-S. However, the choice of anastomosis was largely surgeon dependent, but surgeon factors were not reported.

Syndecan-3 contributes to the regulation of the microenvironment at the node of Ranvier following end-to­side neurorrhaphy: sodium image analysis.

Syndecan-3 (SDC3) and Syndecan-4 (SDC4) are distributed throughout the nervous system (NS) and are favourable factors in motor neuron development. They are also essential for regulation of neurite outgrowth in the CNS. However, their roles in the reconstruction of the nodes of Ranvier after peripheral nerve injury (PNI) are still unclear. Present study used an in vivo model of end-to-side neurorrhaphy (ESN) for 1-3 months. The recovery of neuromuscular function was evaluated by grooming test. Expression and co-localization of SDC3, SDC4, and Nav1.6 channel (Nav1.6) at regenerating axons were detected by proximity ligation assay and confocal microscopy after ESN. Time-of-flight secondary ion mass spectrometry was used for imaging ions distribution on tissue. Our data showed that the re-clustering of sodium and Nav1.6 at nodal regions of the regenerating nerve corresponded to the distribution of SDC3 after ESN. Furthermore, the re-establishment of sodium and Nav1.6 correlated with the recovery of muscle power 3 months after ESN. This study suggested syndecans may involve in stabilizing Nav1.6 and further modulate the distribution of sodium at nodal regions after remyelination. The efficiency of sodium re-clustering was improved by the assistance of anionic syndecan, resulting in a better functional repair of PNI.

Comparison of one-year patency rates of end-to-side and side-to-side anastomosis technique in proximal forearm region radial-cephalic fistulas.

OBJECTIVES: In this study, the effects of anastomosis techniques on the results of patients with autogenous radial-cephalic proximal forearm fistula were investigated. METHODS: Patients who underwent radial-cephalic proximal forearm fistula surgery (arteriovenous fistula) between April 2015 and August 2017 at the Department of Cardiovascular Surgery of Ordu University were compared retrospectively in terms of the results of anastomosis techniques. The study included 131 patients who had arteriovenous fistulas created by side-to-side and end-to-side anastomosis technique. RESULTS: There was no significant difference in demographic data, comorbidities, radial artery, and cephalic vein diameters in patients undergoing radial-cephalic proximal forearm fistula surgery. However, it was observed that fistula maturation was earlier in the group with end-to-side anastomosis technique, and the one-year patency rates were higher in the group with side-to-side anastomosis technique. CONCLUSION: In Arteriovenous fistulas created in the proximal forearm region, the one-year patency rate of the side-to-side anastomosis technique was higher, while the maturation of the end-to-side technique observed earlier.

End-to-side versus side-to-side anastomosis with distal vein ligation for arteriovenous fistula creation.

INTRODUCTION: There is lack of compelling evidence about the best technique to carry out the anastomosis between the artery and the vein: end to side or side to side. This issue was addressed by very few randomized controlled studies. This topic has recently re-emerged with the advent of the endovascular fistula creation using the side-to-side technique.Objectives: To compare the results of both surgical techniques for the creation of arteriovenous anastomosis. METHODS: This is a randomized controlled prospective study. All renal failure patients, 18 years and older, referred to our institution requiring creation of a new arm arteriovenous fistulas, including distal radio-cephalic, ulno-basilic, proximal brachio-cephalic or brachio-basilic configurations were included. RESULTS: Between February 2018 and October 2018, 378 patients underwent creation of permanent haemodialysis access. A total of 100 patients were randomized equally into the end-to-side and side-to-side groups. Follow-up for the study purpose continued until May 2019 (mean = 9 months, range 1-12). Patients' age ranged from 19 to 68 years. Sevety-seven arteriovenous fistulas were created at the elbow (37 brachio-basilic and 40 brachio-cephalic). Radio-cephalic fistulae were 23, created at wrist and in the forearm. Primary technical success was 97%, and 35 (70%) and 17 (34%) cases achieved functionally maturation in the end-to-side and side-to-side groups, respectively (P = 0.0001). Primary and secondary patency rates at 12 months were 76% end to side versus 78% STS (P = 0.381) and 84% end to side versus 86% STS (P = 0.225), respectively. CONCLUSION: End-to-side technique should be used in all instances of arteriovenous fistulas creation.

Combining reverse end-to-side neurorrhaphy with rapamycin treatment on chronically denervated muscle in rats.

This preliminary research determines whether a combination of reverse end-to-side neurorrhaphy and rapamycin treatment achieves a better functional outcome than a single application after prolonged peripheral nerve injury. We found that the tibial nerve function of the reverse end-to-side + rapamycin group recovered better, with a higher tibial function index value, higher amplitude recovery rate, and shorter latency delay rate (P < 0.05). The reverse end-to-side + rapamycin group better protected the gastrocnemius muscle with more forceful contractility, tetanic tension, and a higher myofibril cross-sectional area (P < 0.05). Combining reverse end-to-side neurorrhaphy with rapamycin treatment is a practical approach to promoting the recovery of chronically denervated muscle atrophy after peripheral nerve injury.

Large-to-Small End-to-Side Venous Anastomosis in Free Flap Transfer.

BACKGROUND: Vessel size discrepancy is one of the major risk factors for anastomotic failure in free flap transfer. The situation becomes challenging for reconstructive microsurgeons when the recipient vein is much smaller than the flap vein. We investigated the feasibility of large-to-small end-to-side venous anastomosis for such cases. MATERIALS AND METHODS: The subjects were 16 consecutive patients who underwent a free flap transfer for oncologic defects with a large-to-small end-to-side venous anastomosis. The larger flap vein was anastomosed to the side slit of the smaller recipient vein under an operating microscope. Surgical details and postoperative outcome were investigated retrospectively. RESULTS: An anterolateral thigh flap was used in five patients, a superficial inferior epigastric artery flap in four, a thoracodorsal artery perforator flap in three, and a latissimus dorsi musculocutaneous flap and a fibular osteocutaneous flap in two patients each. The internal mammary vein and the anterior tibial vein were most frequently used as a recipient vein (four patients each), followed by the deep inferior epigastric vein (three patients). The extent of vessel size discrepancy ranged from 1.3- to 3.3-fold, and the mean discrepancy was 1.9-fold. No anastomotic failure occurred postoperatively, and the flap survived in all patients. CONCLUSIONS: Large-to-small end-to-side venous anastomosis can be a versatile option when only a small vein is available as a recipient vein. Internal mammary, deep inferior epigastric, and anterior tibial veins are good candidates for this technique.

Assessment of axonal sprouting and motor performance after hypoglossal-facial end-to-side nerve repair: experimental study in rats.

Hypoglossal-facial nerve anastomosis (HFA) aims to reanimate denervated mimic muscles with hypoglossal axons when the transected facial nerve is not accessible. The aim of this study was to evaluate the recovery of HFA using a "Y" tube in two variants: (1) the proximal stump of the hypoglossal nerve was entubulated to the "Y" tube (classic "Y" tube HFA) and (2) the "Y" tube was sutured to an epineurial window of a slightly damaged hypoglossal nerve (end-to-side "Y" tube HFA). A total of 48 adult female rats were divided into four groups: intact controls (group 1), sham operated (group 2), classic "Y" tube HFA (group 3) and end-to-side "Y" tube HFA (group 4). The abdominal aorta with both common iliac arteries of isogeneic male rats served as the Y-tube conduit. Animals from group 4 recovered better than those from group 3: the degree of collateral axonal branching (3 ± 1%) was significantly lower than that determined in group 3 (13 ± 1%). The mean deviation of the tongue from the midline was significantly smaller in group 4 (6 ± 4°) than that measured in animals from group 3 (41 ± 6°). In the determination of vibrissal motor function in group 3 and group 4, a decrease in amplitude was found to be - 66% and - 92%, respectively. No differences in the reinnervation pattern of the target muscles were detected. As a result, these surgical models were not determined to be able to improve vibrissal movements. It was concluded that performance of end-to-side "Y" tube HFA diminishes collateral axonal branching at the lesion site, which in turn, promotes better recovery of tongue- and vibrissal-motor performance.

Comparison of end-to-side hand-sewn and side-to-side stapled cervical esophagogastric anastomosis in patients with lower thoracic esophageal cancer undergoing transhiatal esophagectomy: an Iranian retrospective cohort study.

BACKGROUND: Controversies in terms of efficacy and postoperative advantages surround stapled esophagogastric anastomosis compared with the hand-sewn technique as a treatment for patients with esophageal cancer. The purpose of this study was to compare the clinical outcomes of hand-sewn end-to-side esophago-gastrostomy and side-to-side stapled cervical esophagogastric anastomosis after esophagectomy for the aforementioned patients. METHODS: This retrospective cohort study involved examining the medical records of 433 patients who underwent transhiatal esophagectomy for esophageal cancer from March 2010 to March 2016. All the patients were operated using end-to-side hand-sewn esophago-gastrostomy and side-to-side stapled cervical esophagogastric anastomosis. 409 of the patients received a year's worth of follow-up evaluations. All the cases were revisited in 2 weeks as well as in four, eight, and 12 months after surgery. The patients were assessed in terms of postoperative outcomes, including reflux symptoms, anastomotic leakage and stricture, and the need for anastomotic dilatation. RESULTS: Hand-sewn anastomosis was carried out in 271 (62.5%) patients, whereas stapled anastomosis was performed in 162 (37.4%) patients. The mean operative times were 214.46 ± 84.33 min and 250.55 ± 43.31 min for the stapled and hand-sewn anastomosis groups, respectively (P = 0.028). The two groups showed no significant differences with respect to stays in intensive care units and hospitals. Postoperatively, 38 (14.67%) cases of anastomotic leakage were detected in the hand-sewn anastomosis group, with incidence being significantly higher than that in the stapled anastomosis group (8 cases or 5.33%; P = 0.002). Anastomotic stricture occurred less frequently in the patients who underwent stapled anastomosis (P = 0.004). Within the one-year follow-up period, the patients treated via hand-sewn anastomosis more frequently required anastomotic dilatation (P = 0.02). CONCLUSION: Side-to-side stapled cervical esophagogastric anastomosis may reduce operation times and decrease the rates of anastomotic leakage, anastomotic stricture, and anastomotic dilatation in patients with lower thoracic esophageal cancer undergoing transhiatal esophagectomy.

Anastomotic bleeding following ileocolic end-to-side anastomosis using a circular stapler: incidence and risk factors.

PURPOSE: To identify the incidence of and risk factors for postoperative bleeding after ileocolic end-to-side anastomosis using a circular stapler. METHODS: We analyzed, retrospectively, the risk factors for postoperative anastomotic bleeding in patients who underwent right-sided colectomy with end-to-side anastomosis done using a circular stapler during colon tumor surgery at our institute between January 2015 and March 2019. RESULTS: Anastomotic bleeding developed in 10 (3.6%) of the total 279 patients. Univariate analysis revealed that age ≥ 80 years (8.8% vs. 1.9%; P = 0.008) and Eastern Cooperative Oncology Group performance status (ECOG PS) ≥ 1 (12.5% vs. 2.8%; P = 0.014) were significant risk factors for anastomotic bleeding. Postoperative anticoagulation therapy was not a risk factor for anastomotic bleeding. Multivariate analysis revealed that only age ≥ 80 years was an independent risk factor (odds ratio 4.12, 95% confidence interval 1.02-16.68, P = 0.047). Six of the ten patients with anastomotic bleeding were treated conservatively, three were treated by colonoscopic clipping, and one required surgery. CONCLUSION: End-to-side anastomosis is safe and feasible, but must be performed carefully in the elderly, who are at higher risk of anastomotic bleeding.

Comparison Between Supercharged Ulnar Nerve Repair by Anterior Interosseous Nerve Transfer and Isolated Ulnar Nerve Repair in Proximal Ulnar Nerve Injuries.

PURPOSE: To compare combined ulnar nerve repair with supercharged end-to-side anterior interosseous nerve to ulnar motor nerve transfer (UR+SETS) with conventional isolated ulnar repair techniques in proximal ulnar nerve transection, with respect to intrinsic muscle power recovery and claw hand deformity correction. METHODS: We conducted a comparative matched-paired series prospectively on 21 patients with proximal ulnar nerve transection injury. Eleven patients were managed by UR+SETS and 10 by isolated ulnar repair. The outcome was reported at 3, 6, 12, and 18 months using the score of Birch and Raji and Brand's criteria. RESULTS: A total of 21 patients with acute proximal ulnar nerve transection injury had completed 18 months' follow-up. We observed better results in the UR+SETS group regarding the return of intrinsic function and reduction of deformity with earlier improvement in the score of Birch and Raji and Brand's criteria. CONCLUSIONS: In the short term, UR+SETS transfer appears to result in better intrinsic muscle reinnervation and clawing deformity correction after proximal ulnar nerve transection injury. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

Absence of the Pronator Quadratus Muscle Precluding Distal Nerve Transfer.

The branch of the anterior interosseous nerve to the pronator quadratus (PQ) is increasingly used as a donor nerve for end-to-end and reverse end-to-side nerve transfers. The anatomy of the PQ (and its nerve branch) is generally considered reliable in the absence of prior trauma. In this report, we describe a patient with an absent PQ despite intact clinical examination of other muscles supplied by the anterior interosseous nerve. The absence of the PQ precluded the use of its nerve as a donor nerve for transfer.

Effect of Reverse End-to-Side (Supercharging) Neurotization in Long Processed Acellular Nerve Allograft in a Rat Model.

PURPOSE: Processed acellular nerve allograft (PNA) has been suggested as a convenient tool for overcoming short and medium nerve defects. Although the clinical implications are unclear, animal data suggest that PNA becomes less effective at longer lengths. Although reverse or supercharging end-to-side nerve transfer may improve the neurotrophic potential in chronically denervated nerve tissue, the application of this strategy to long acellular nerve allograft has not been previously investigated. We hypothesized that supercharging acellular nerve allograft would increase its effective length. METHODS: Sprague-Dawley and Thy1-green fluorescent protein Sprague-Dawley rats underwent transection of the tibial nerve, followed by immediate repair with 20-, 40-, or 60-mm acellular nerve allografts processed identically to commercially available human acellular nerve allograft (AxoGen, Inc., Alachua, FL) or isograft. Half of the allograft group was supercharged with a reverse end-to-side transfer from the ipsilateral peroneal nerve. At 10 weeks, the reconstructed nerve in the Thy1-green fluorescent rat groups were exposed and examined under a fluorescence-enabled microscope. At 20 weeks, the remaining rats underwent motor testing and tissue harvest for morphological examination. RESULTS: In comparison with a nonenhanced allograft, supercharging had a statistically significant positive impact on the reinnervated muscle normalized force generation and distal axon counts for all graft sizes. Muscles in the supercharged group were heavier than those in the allograft group for the 40-mm-length grafts and G-ratio measurements were higher in the supercharged allograft group for 60-mm-length grafts only. CONCLUSIONS: This study supports that hypothesis that supercharging nerve transfer improves axon regeneration within PNA. CLINICAL RELEVANCE: When an appropriate donor nerve is available, supercharging nerve transfer may improve nerve regeneration in PNA across long nerve defects.

Current concepts in peripheral nerve surgery.

The injuries of the peripheral nerves are relatively frequent. Some of them may lead to defects which cannot be repaired with direct end-to-end repair without tension. These injuries may cause function loss to the patient, and they consist a challenge for the treating microsurgeon. Autologous nerve grafts remain the gold standard for bridging the peripheral nerve defects. Nevertheless, there are selected cases where alternative types of nerve reconstruction can be performed in order to cover the peripheral nerve defects. In all these types of reconstruction, the basic principles of microsurgery are necessary and the surgeon should be aware of them in order to achieve a successful reconstruction. The purpose of the present review was to present the most current data concerning the surgical options available for bridging such defects.

Morphofunctional evaluation of end-to-side neurorrhaphy through video system magnification.

BACKGROUND: The surgical microscope is an essential tool for microsurgery. Nonetheless, several promising alternatives are being developed, including endoscopes and laparoscopes with video systems. However, these alternatives have only been used for arterial anastomoses so far. The aim of this study was to evaluate the use of a low-cost video-assisted magnification system in end-to-side neurorrhaphy in rats. MATERIALS AND METHODS: Forty rats were randomly divided into four matched groups: (1) normality (sciatic nerve was exposed but was kept intact); (2) denervation (fibular nerve was sectioned, and the proximal and distal stumps were sutured-transection without repair); (3) microscope; and (4) video system (fibular nerve was sectioned; the proximal stump was buried inside the adjacent musculature, and the distal stump was sutured to the tibial nerve). Microsurgical procedures were performed with guidance from a microscope or video system. We analyzed weight, nerve caliber, number of stitches, times required to perform the neurorrhaphy, muscle mass, peroneal functional indices, latency and amplitude, and numbers of axons. RESULTS: There were no significant differences in weight, nerve caliber, number of stitches, muscle mass, peroneal functional indices, or latency between microscope and video system groups. Neurorrhaphy took longer using the video system (P < 0.05). The amplitude was higher in the microscope group than in the video group. CONCLUSIONS: It is possible to perform an end-to-side neurorrhaphy in rats through video system magnification. The success rate is satisfactory and comparable with that of procedures performed under surgical microscopes.