Current concepts in end-to-side neurorrhaphy

In peripheral nerve injury,end-to-side neurorrhaphy involves coaptation of the distal stump of a transected nerve to the trunk of an adjacent donor nerve.It has been proposed as an alternative technique when the proximal stump of an injured nerve is unavailable or the nerve gap is too long to be bridged by a nerve graft.Experimental and clinical data suggests that end-to-side neurorrhaphy can provide satisfactory functional recovery for the recipient nerve,without any deterioration of the donor nerve function.The most accepted mechanism of nerve regeneration following end-to-side neurorrhaphy is collateral sprouting.The source of the regenerating axons traveling in the epineurium of the donor nerve is thought to be the proximal Ranvier’s nodes at the site of end-to-side neurorrhaphy,however,histologic evidence is still lacking.Partial neurotomy of the donor nerve may enhance regeneration of motor neurons through end-to-side neurorrhaphy and reinnervation of motor targets.

The reasons for end-to-side coaptation:how does lateral axon sprouting work?

Nerve fibers are attracted by sutureless end-to-side nerve coaptation into the recipient nerve. Opening a window in the epineurium enhances axon attraction and myeliuation. The authors analyze the features of nerve repair by end-to-side coaptation. They highlight the known mechanisms of axon sprouting and different hypotheses of start up signals （presence or absence of an epineurial window, role of Schwann cells, signaling from the distal trunk）. The clinical literature is also presented and differences between experimental and clinical applications are pointed out. The authors propose their point of view and perspectives deriving from recent experimental and clinical experiences.

Axonal regeneration from the spinal cord to peripheral nerve induced by end-to-side neurorrhaphy Evidence from acetylcholinesterase staining and Fluorogold retrograde tracing

BACKGROUND： In recent years, surgeons have advocated root or trunk repair of avulsed nerve roots for overall recovery. However, donor nerves pose a major problem, because they do not contain adequate numbers of axons. Moreover, the procedures lead to nerve deficits in the donor nerve following transplantation. OBJECTIVE： To observe whether axonal regeneration occurs by end-to-side neurorrhaphy in the peripheral nerve and spinal cord. DESIGN, TIME AND SETTING： A neuroanatomical, randomized, controlled, animal study was performed at Functional Anatomy Lab in Nagoya University School of Medicine from May 2002 to July 2003. MATERIALS： Fluorogold was purchased from Fluorochrome, LLC, USA. BX50 light microscope and fluorescent microscope were purchased from Olympus, Japan. METHODS： A total of 21 rats were randomly divided into three groups, and the posterior avulsion injury model （C6-8） of the brachial plexus was performed. In the ventral root graft group, the avulsed C7 ventral roots were reanastomosed to the small anterior lateral aspect window of the spinal cord via nerve grafts. In the dorsal root graft group, the C7 dorsal roots were reanastomosed at the small pia mater window of the posterior lateral aspect of the spinal cord via nerve grafts. In the control group, the avulsed nerve roots were not repaired. MAIN OUTCOME MEASURES： The nerve grafts were collected from the ventral and dorsal root graft groups, and the C7 proximal nerve end was collected from the control group. Acetylcholinesterase staining was performed on the tissue. Fluorogold retrograde tracing technique was applied to determine the origin of the regenerating axons. RESULTS： Results showed that acetylcholine-positive axons existed in nerve grafts of the ventral and dorsal root graft groups. However, axons were not found in the avulsed nerve roots of the control group. Fluorogold retrograde tracing confirmed the presence of fluorogold-containing neurons in the ventral and dorsal horn of the ventral and dorsal root graft groups. Fluorogold-positive neurons were not observed in the control group. CONCLUSION： End-to-side neurorrhaphy induced axonal regeneration from the spinal cord to the peripheral nervous system.

Study on functions of regenerated axons in end-to-side neurorrhaphy

Objective: To probe the possibility of functional sensory endings regeneration after end-to-side neurorrhaphy. Methods: Fifteen New Zealand rabbits were used in this study. The left greater auricular nerve served as the donor nerve. A nerve ed taken from the right ear served as the receptive nerve which anastomosed to the donor nerve by means of end-to-side method and the other end implanted into the denervated skin flap. Normal skin and denervated skin flap without nerve implantation served as control groups, 5 animals in each group. The single nerve fibre recording technique was used to investigate the number, distribution and types of regenerated discharging nerve fibers 4 mouths after operation. Results: The inductive discharges of nerve fibres wave observed in all types of regenerated sensory nerves, the total discharging fibers was about 58% of that in normal skin. Few discharging fibers were observed in denervated skin flap without nerve implantation. Conclusion: End-to-side neurorrhaphy can regenerate functional axons.

End-to-side neurorrhaphy repairs peripheral nerve injury：sensory nerve induces motor nerve regeneration

End-to-side neurorrhaphy is an option in the treatment of the long segment defects of a nerve.It involves suturing the distal stump of the disconnected nerve（recipient nerve） to the side of the intimate adjacent nerve（donor nerve）.However,the motor-sensory specificity after end-to-side neurorrhaphy remains unclear.This study sought to evaluate whether cutaneous sensory nerve regeneration induces motor nerves after end-to-side neurorrhaphy.Thirty rats were randomized into three groups：（1） end-to-side neurorrhaphy using the ulnar nerve（mixed sensory and motor） as the donor nerve and the cutaneous antebrachii medialis nerve as the recipient nerve;（2） the sham group：ulnar nerve and cutaneous antebrachii medialis nerve were just exposed;and（3） the transected nerve group：cutaneous antebrachii medialis nerve was transected and the stumps were turned over and tied.At 5 months,acetylcholinesterase staining results showed that 34% ± 16% of the myelinated axons were stained in the end-to-side group,and none of the myelinated axons were stained in either the sham or transected nerve groups.Retrograde fluorescent tracing of spinal motor neurons and dorsal root ganglion showed the proportion of motor neurons from the cutaneous antebrachii medialis nerve of the end-to-side group was 21% ± 5%.In contrast,no motor neurons from the cutaneous antebrachii medialis nerve of the sham group and transected nerve group were found in the spinal cord segment.These results confirmed that motor neuron regeneration occurred after cutaneous nerve end-to-side neurorrhaphy.

Resting-state brain network remodeling after different nerve reconstruction surgeries:a functional magnetic resonance imaging study in brachial plexus injury rats

Distinct brain remodeling has been found after different nerve reconstruction strategies,including motor representation of the affected limb.However,differences among reconstruction strategies at the brain network level have not been elucidated.This study aimed to explore intranetwork changes related to altered peripheral neural pathways after different nerve reconstruction surgeries,including nerve repair,endto-end nerve transfer,and end-to-side nerve transfer.Sprague–Dawley rats underwent complete left brachial plexus transection and were divided into four equal groups of eight:no nerve repair,grafted nerve repair,phrenic nerve end-to-end transfer,and end-to-side transfer with a graft sutured to the anterior upper trunk.Resting-state brain functional magnetic resonance imaging was obtained 7 months after surgery.The independent component analysis algorithm was utilized to identify group-level network components of interest and extract resting-state functional connectivity values of each voxel within the component.Alterations in intra-network resting-state functional connectivity were compared among the groups.Target muscle reinnervation was assessed by behavioral observation(elbow flexion)and electromyography.The results showed that alterations in the sensorimotor and interoception networks were mostly related to changes in the peripheral neural pathway.Nerve repair was related to enhanced connectivity within the sensorimotor network,while end-to-side nerve transfer might be more beneficial for restoring control over the affected limb by the original motor representation.The thalamic-cortical pathway was enhanced within the interoception network after nerve repair and end-to-end nerve transfer.Brain areas related to cognition and emotion were enhanced after end-to-side nerve transfer.Our study revealed important brain networks related to different nerve reconstructions.These networks may be potential targets for enhancing motor recovery.

周围神经端侧吻合后靶肌肉及其运动终板的形态学研究

[目的]研究周围神经端侧吻合后靶肌肉及其运动终板的形态,为端侧吻合的应用提供进一步的形态学依据。[方法]W istar大白鼠26只,随机分实验组和对照组,每组13只,实验组右侧腓总神经切断后,近端反转结扎,远端与胫神经外膜开窗处行端侧吻合,对照组右侧腓总神经切断后,两端均反转结扎,两组动物左侧作正常对照,不作处理。术后3个月,行双侧腓总神经、胫前肌组织学检查,胫前肌湿重测定,运动终板检查。[结果]实验侧胫前肌结构清晰,肌纤维较粗大,运动终板面积大,结构清晰,着色深,接近正常侧。实验侧与对照侧的胫前肌肌湿重比、肌纤维截面积比、运动终板的面积比和着色比具有极显著性差异(P<0.01)。[结论]神经端侧吻合能保护靶肌肉及其运动终板。

Use of Muscle Feeding Arteries as Recipient Vessels for Soft Tissue Reconstruction in Lower Extremities

Summary:Microsurgical free tissue transfer is still playing an important role in lower extremity reconstruction.Finding a suitable recipient artery for anastomosis is critical in the microsurgical procedure,especially in an extensive wound,or in a complex trauma combined with vascular injury.From April 2014 to March 2018,we retrospectively reviewed patients with traumatic/posttraumatic,oncologic,and electrical wounds in the lower extremity.Those treated with muscle feeding artery as recipient vessels were included.The latissimus dorsi(LD)muscle free flap,anterior lateral thigh(ALT)perforator free flap,and deep inferior epigastric perforator(DIEP)free flap were raised.The muscle feeding arteries to vastus lateral muscle and to medial head of gastrocnemius muscle,concomitant veins,and great saphenous vein were used as recipient vessels.Injuries included in the study were caused by tumour in 2 cases,car accident in 3 cases,crushing in 3 cases,burns in one case,and electrical injury in one case.The wound size varied from 14 cm x 6 cm to 30 cm x 20 cm.LD,ALT,and DIEP free flaps were used in 6,3,and 4 patients,respectively.The muscle feeding arteries to medial head of gastrocnemius muscle,to sartorius muscle,and to vastus lateral muscle were used as recipient arteries in 4,5,and one patient,respectively.Concomitant and great saphenous veins were used as recipient veins in 10 and 4 patients,respectively.Using the muscle feeding artery is feasible to avoid injury to the main artery and facilitate dissection and anastomoses,particularly when the wound is located proximal to the mid-third of the lower leg.

Candy cane syndrome:A systematic review

BACKGROUND Candy cane syndrome(CCS)is a condition that occurs following gastrectomy or gastric bypass.CCS remains underrecognized,yet its prevalence is likely to rise due to the obesity epidemic and increased use of bariatric surgery.No previous literature review on this subject has been published.AIM To collate the current knowledge on CCS.METHODS A literature search was conducted with PubMed and Google Scholar for studies from May 2007,until March 2023.The bibliographies of the retrieved articles were manually searched for additional relevant articles.RESULTS Twenty-one articles were identified(135 patients).Abdominal pain,nausea/vomiting,and reflux were the most reported symptoms.Upper gastrointestinal(GI)series and endoscopy were performed for diagnosis.Surgical resection of the blind limb was performed in 13 studies with resolution of symptoms in 73%-100%.In surgical series,9 complications were reported with no mortality.One study reported the surgical construction of a jejunal pouch with clinical success.Six studies described endoscopic approaches with 100%clinical success and no complications.In one case report,endoscopic dilation did not improve the patient’s symptoms.CONCLUSION CCS remains underrecognized due to lack of knowledge about this condition.The growth of the obesity epidemic worldwide and the increase in bariatric surgery are likely to increase its prevalence.CCS can be prevented if an elongated blind loop is avoided or if a jejunal pouch is constructed after total gastrectomy.Diagnosis should be based on symptoms,endoscopy,and upper GI series.Blind loop resection is curative but complex and associated with significant complications.Endoscopic management using different approaches to divert flow is effective and should be further explored.

A novel method for reconstruction in laparoscopic pancreaticoduodenectomy:an experience of 13 cases

Laparoscopic pancreaticoduodenectomy(LPD)is a challenging operation to general surgeon.Up to date,only about 135 cases have been reported,16 cases in China,119 cases outside China.The reconstruction of alimentary system is a key procedure to ensure success of the whole surgery.It is worth investigating the methods of reconstruc-tion in LPD.A retrospective study is made to investigate the methods of reconstruction in LPD.We analyze 13 cases of LPD performed in our center.Child’s or modified Child’s method was used to make the reconstruction in our practice.We tried three methods to make the anastomosis of pancre-aticojejunostomy,including end-to-end dunking binding pancreaticojejunostomy in two cases,end-to-end dunking pancreaticojejunostomy using interrupted suture in two cases,and duct-to-jejunal end-to-side embedding pancreaticojeju-nostomy in nine cases.The clinical data was collected and analyzed.Three of four patients,who underwent end-to-end pancreaticojejunostomy,had a little pancreatic leakage,especially in the first case.None of other nine patients,who underwent duct-to-jejunal end-to-side embedding pancreati-cojejunostomy,was detected to have pancreatic leakage,and the operating time of these nine cases was less than other four cases.Duct-to-jejunal end-to-side embedding pancreaticoje-junostomy is a safe and efficient method of reconstruction in LPD.