Evolution of Robotic-Assisted Sympathetic Trunk Reconstruction: Technical Innovation and Clinical Experience.

Rat sciatic nerves were used in a comparative study of vascularized and free (nonvascularized) nerve grafts transplanted into silicone tubes. A total of 39 sciatic nerves were used, 21 as vascularized nerve grafts and 18 as free nerve grafts. The rats were killed at intervals from the first to the 24th postoperative weeks, and biopsied sciatic nerves were processed for morphometric studies using a fiber caliber analyzer. There was a significant increase in the number of large myelinated axons (more than 5 mu) in the vascularized nerve graft models over those in the free nerve graft models at the distal ankle region. Furthermore, the diameters of myelinated axons in the vascularized nerve graft were larger than those in the free nerve graft at all specimen sites during all postoperative weeks. We suggest that the preservation of the vascular system in vascularized nerve grafts would decrease the likelihood of fibrosis and result in better regeneration of axons.

The use of vascularized nerve graft models has been limited because of the complexity of the operation. The authors sought to develop a simple and effective rabbit model for facial nerve repair and evaluated its advantages over conventional nerve grafts. Rabbits were divided into three groups consisting of six rabbits each. The central auricular nerve and its nutrient vessels were used as a vascularized graft. Rabbits were grafted with a vascularized facial nerve graft (vascularized nerve graft group), with a free nerve graft (free nerve graft group), or with a vascularized nerve graft and a free nerve graft on each side of the face (vascularized nerve graft/free nerve graft group). Four months after surgery, facial performance and electrophysiologic monitoring were evaluated. The rabbits were then killed to prepare the nerve specimens for histologic, immunohistochemical, and transmission electron microscope study. At 4 months after the facial nerve repair, the functional recovery of the facial nerve was observed and analyzed. The side grafted with vascularized nerve graft was superior to the side grafted with free nerve graft. Regenerated nerve fibers were observed in all groups, and rabbits grafted with vascularized nerve grafts had more regenerated axons than those that underwent free nerve grafting, although the regenerated nerves were not as good as the natural nerves. This study demonstrates that it is feasible to establish a vascularized nerve graft model in rabbits. The model offers the obvious advantages of operability and reliability. The vascularized nerve graft is demonstrated to have a superior value for facial nerve repair.

BackgroundPost-sympathectomy complications affect thousands globally, yet reconstruction remains limited by donor site morbidity and inability to address extensive nerve defects. Extended sympathectomy procedures of the past created defects exceeding 10 cm—beyond the reach of conventional free nerve grafts. This study presents the first robotic technique for harvesting vascularized intercostal nerve grafts within the same operative field, potentially revolutionizing sympathetic trunk reconstruction.MethodsThis retrospective technical innovation study enrolled patients undergoing robot-assisted sympathetic trunk reconstruction from December 2023 to June 2025. Eight patients received either vascularized intercostal nerve grafts (n = 4) or propensity score-matched free intercostal nerve grafts (n = 4), with one additional patient receiving dual vascularized grafts for bilateral T1-T10 defects. Primary outcomes included technical feasibility, Visual Analog Scale symptom scores, and safety parameters.ResultsAll vascularized procedures achieved 100% technical success with zero vascular complications. The vascularized group demonstrated remarkable improvements within 6 months: temperature regulation (9.0 vs. 3.75, P = 0.01), chest compensatory sweating (9.25 vs. 4.25, P = 0.04), back compensatory sweating (9.5 vs. 6.25, P < 0.01), and psychological symptom with loss of interest (4.25 vs. 1, P = 0.01) - outcomes typically requiring more than 6 months with conventional grafts. The dual-graft patient achieved complete reconstruction of previously “unreconstructable” bilateral defects spanning 9 intercostal levels, with 3-points improvement across all symptom domains.ConclusionsRobotic vascularized intercostal nerve grafting represents a paradigm shift in sympathetic reconstruction, eliminating donor site morbidity while accelerating recovery and enabling treatment of previously impossible extensive defects. This innovation may establish new standards for complex nerve reconstruction globally.

Twenty-five patients with severe brachial plexus lesions (having a rather poor prognosis in general), were subjected to a variety of split nerve graft procedures, with 22 achieving useful functional recovery. Thirty-eight nerves were reconstructed, with 32 of them achieving useful recovery. Results in these patients were no better nor worse than those obtained with other types of nerve grafts (e.g., free cutaneous nerve grafts, vascularized nerve grafts, etc.). The technique of splitting the nerve for the use of split fascicle groups as free nerve grafts is nevertheless recommended as an alternative to the application of the ulnar nerve as a vascularized nerve graft. The plexiform arrangement of the fascicles within the ulnar nerve apparently does not preclude the possibility of harvesting sufficiently long nerve grafts.

Endoscopic thoracic sympathectomy (ETS) is widely used to treat primary hyperhidrosis; however, compensatory sweating (CS) has emerged as a significant complication. Various surgical approaches for managing CS have evolved over the past 4 decades, yet their development and outcomes remain poorly documented. This study aims to examine the historical evolution and advances in techniques for reconstruction of the thoracic sympathetic trunk. A review was conducted using PubMed, Embase, and the Cochrane library, focusing on currently published studies related to the reversal surgery of thoracic sympathectomy. Eligible studies included animal model and clinical studies, and a comprehensive comparison was conducted among different surgical techniques, clinical results, and complications. Twenty-three studies (3 experimental models and 20 clinical reports; 192 cases) demonstrated three distinct eras: open thoracotomy (1980-2003), video-assisted thoracoscopic surgery (2003-2015), and robotic-assisted reconstruction (2016-present). Different techniques showed varying success rates: unclipping (0-89%), direct reconstruction with nerve grafting (36.8-100%), and intercostal nerve bypass (0-93.4%). Among the documented cases, the reported CS improvement rates were highest for direct sympathetic trunk reconstruction with free nerve grafting. Complications were generally mild, including temporary chest wall neuralgia (2.6%), bleeding (1%), and Horner syndrome/temporary blepharoptosis (1.5%). This first comprehensive review demonstrates that sympathetic trunk reconstruction has evolved from an experimental procedure to a viable option for severe CS. Although robotic assistance has enhanced surgical precision, successful outcomes depend primarily on fundamental microsurgical principles, particularly precise nerve coaptation and the proper identification of healthy nerve stumps.

The aim of this review is to present and compare the various animal models of vascularized nerve grafts described in the literature as well as to summarize preclinical evidence for superior functional results compared to non-vascularized free nerve grafts. We also will present the state of the art on prefabricated vascularized nerve grafts. A systematic literature review on vascularized nerve graft models was conducted via the retrieval with the PubMed database on March 30, 2019. Data on the animal, nerve, and vascularization model, the recipient bed, the evaluation time points and methods, and the results of the study results were extracted and analyzed from selected articles. The rat sciatic nerve was the most popular model for vascularized nerve grafts, followed by the rabbit; however, rabbit models allow for longer nerve grafts, which are suitable for translational evaluation, and produced more cautious results on the superiority of vascularized nerve grafts. Compared to free nerve grafts, vascularized nerve grafts have better early but similar long-term results, especially in an avascular bed. There are few studies on avascular receiving beds and prefabricated nerve grafts. The clinical translation potential of available animal models is limited, and current experimental knowledge cannot fully support that the differences between vascularized nerve grafts and free nerve grafts yield a clinical advantage that justifies the complexity of the procedure.

Experimental study of vascularized nerve grafts: Multifactorial analyses of axonal regeneration of nerves transplanted into an acute burn wound

Vascularized nerve grafts (VNGs) have been proposed as a superior alternative to free nerve grafts (FNGs) for complex nerve defects. A greater regenerative potential has been suggested by clinical and experimental studies, but conclusive evidence is still lacking. In this experimental study, 10 adult male Wistar rats received a non-vascularized orthotopic sciatic nerve graft on their right side, and a vascularized orthotopic sciatic nerve graft nerve on their left side. Functional outcome following nerve regeneration was evaluated through electrodiagnostic studies, target muscles weight and histomorphology, and data of VNGs and FNGs were compared. The results of this study showed a significant difference in the motor unit number of Gastrocnemius Medialis (GM) estimated by MUNE in the VNG side compared to the FNG side. No other significant differences in axonal regeneration and muscle reinnervation were evident at either electrodiagnostic, histomorphology studies or muscle weight. This experimental model showed slight differences in nerve regeneration between VNGs and FNGs, but cannot support a high clinical advantage for VNGs. The results of this study show that VNGs are not strongly superior to FNGs in the rat model, even in avascular beds. Clinical advantages of VNGs are likely to be limited to extensive and thick nerve defects and can only be assessed on experimental model with bigger animals. Also, we showed that the MUNE technique provided a reliable and reproducible evaluation of functional outcomes in the rat sciatic nerve and defined a reproducible protocol for functional evaluation of muscle reinnervation.

A comparative study of nerve regeneration was performed on vascularized nerve graft (VNG) and free nerve graft (FNG) in Fischer strain rats. A segment of the sciatic nerve with vascular pedicle of the femoral artery and vein was harvested from syngeneic donor rat for the VNG group and the sciatic nerve in the same length without vascular pedicle was harvested for the FNG group. They were transplanted to a nerve defect in the sciatic nerve of syngeneic recipient rats. At 2, 4, 6, 8, 12, 16, and 24 weeks after operation, the sciatic nerves were biopsied and processed for evaluation of choline acetyltransferase (CAT) activity, histological studies, and measurement of wet weight of the muscle innervated by the sciatic nerve. Electrophysiological evaluation of the grafted nerve was also performed before sacrifice. The average CAT activity in the distal to the distal suture site was 383 cpm in VNG and 361 cpm in FNG at 2 weeks; 6,189 cpm in VNG and 2,264 cpm in FNG at 4 weeks; and 11,299 cpm in VNG and 9,424 cpm in FNG at 6 weeks postoperatively. The value of the VNG group was statistically higher than that of the FNG group at 4 weeks postoperatively. Electrophysiological and histological findings also suggested that nerve regeneration in the VNG group was superior to that in the FNG group during the same period. However, there was no significant difference between the two groups after 6 weeks postoperatively in any of the evaluations. The CAT measurement was useful in the experiments, because it was highly sensitive and reproducible.

Thoracic sympathectomy to treat palmar hyperhidrosis (PH) has widely been performed. Many patients regret the surgery due to compensatory hyperhidrosis (CH), gustatory hyperhidrosis, arrhythmia, hypertension, gastrointestinal disturbances, and emotional distress. Robotic applications in microsurgery are very limited. We report the technique and long-term patient-reported outcomes of bilateral robot-assisted microsurgical sympathetic trunk reconstruction with a sural nerve graft in an interdisciplinary setting. A 59-year-old female suffered from severe adverse effects after endoscopic thoracic sympathectomy (ETS) for PH 25 years ago. She reported CH over the whole trunk, gustatory hyperhidrosis, excessive dry hands, and emotional distress. An interdisciplinary surgical team performed a bilateral sympathetic trunk reversal reconstruction with an interpositional sural nerve graft per side by a da Vinci® Robot. The nerve graft was microsurgically coapted using 9-0 sutures end-to-end to the sympathetic trunk stumps and side-to-end to the intercostal nerves T2-T4. At 24, 33 and 42 months, palmar dryness and emotional distress were strongly reduced. A highly specialized interdisciplinary setting may provide a precise, safe, and efficient treatment for ETS sequelae. A clinical study is initiated to validate this new therapy.

The aim of this study was to compare postoperative elbow flexion outcomes in patients receiving functioning free muscle transplantation (FFMT) innervated by either intercostal nerve (ICN) or spinal accessory nerve (SAN) grafts. A comprehensive systematic review on FFMT for brachial plexus reconstruction was conducted utilizing Medline/PubMed database. Analysis was designed to compare functional outcomes between (1) nerve graft type (ICN vs. SAN) and (2) different free muscle graft types to biceps tendon (gracilis vs. rectus femoris vs. latissimus dorsi). A total of 312 FFMTs innervated by ICNs (169) or the SAN (143) are featured in 10 case series. The mean patient age was 28 years. Patients had a mean injury to surgery time of 31.5 months and an average follow-up time of 39.1 months with 18 patients lost to follow-up. Muscles utilized included the gracilis (275), rectus femoris (28), and latissimus dorsi (8). After excluding those lost to follow-up or failures due to vascular compromise, the mean success rates of FFMTs innervated by ICNs and SAN were 64.1 and 65.4%, respectively. This analysis did not identify any difference in outcomes between FFMTs via ICN grafts and those innervated by SAN grafts in restoring elbow flexion in traumatic brachial plexus injury patients.

Prosthetic nerve grafts: A resorbable tube as an alternative to autogenous nerve grafting

Comparison of different methods of repair of long peripheral nerve defects: an experimental study

Voice Quality after Recurrent Laryngeal Nerve Resection and Primary Reconstruction

Adult brachial plexus injury remains a dilemma to a reconstructive microsurgeon, especially when attempting to reconstruct cases of total root avulsion. Different degrees and different levels of injury require different strategies of reconstruction. The purpose of this article is to illustrate the author's reconstructive strategy in correlation with the injury level of classification. Nerve transfer, functioning free muscle transplantation, and other palliative surgery are reconstructive options for level 1 injuries. Neurolysis, nerve repair, nerve grafts (free nerve graft or vascularized ulnar nerve graft), nerve transfer if associated with level 1 lesion in other spinal nerves, and palliative reconstruction are chosen options for level 2, 3, and 4 lesions. A clavicle osteotomy is often required in level 3 lesions. Nerve grafts are frequently applied in level 4 lesions, which result in less aberrant reinnervation and a better prognosis.