Bengang Qin

Functioning free gracilis transfer to reconstruct elbow flexion and quality of life in global brachial plexus injured patients

In the study, the functional recovery and relative comprehensive quality of life of cases of global brachial plexus treated with free functioning muscle transfers were investigated. Patients who received functioning gracilis muscle transfer between August 1999 and October 2014 to reconstruct elbow flexion, wrist and fingers extension were recruited. The mean age of the patients was 26.36 (range, 16–42) years. The mean period of time from gracilis transfer to the last follow-up was 54.5 months (range, 12–185 months). Muscle power, active range of motion of the elbow flexion, wrist extension, and total active fingers extension were recorded. SDS, SAS and DASH questionnaires were given to estimate patients’ quality of life. 35.71% reported good elbow flexion and 50.00% reported excellent elbow flexion. The average ROM of the elbow flexion was 106.5° (range, 0–142°) and was 17.00° (range, 0–72°) for wrist extension. The average DASH score was 51.14 (range, 17.5–90.8). The prevalence of anxiety and depression were 42.86% and 45.24%. Thrombosis and bowstringing were the most common short and long-term complications. Based on these findings, free gracilis transfer using accessory nerve as donor nerve is a satisfactory treatment to reconstruct the elbow flexion and wrist extension in global-brachial-plexus-injured patients.

Development of a novel experimental rat model for brachial plexus avulsion injury.

Brachial plexus injuries (BPI) are devastating events that frequently result in severe functional impairment of the upper extremity, and yet, present surgical reconstruction provides limited results. An animal model is an important tool to study peripheral nerve repair and regeneration. Here, a passive traction apparatus that allowed a multidirectional force exerted on a fixed forelimb was designed to produce a BPI rat model in a noninvasive manner. Behavioral and histological analyses were carried out to assess the suitability of the model. Using the apparatus, a reproducible upper BPI model was established with the forelimb abducted 30° and a test weight of 2 kg. Avulsion of the nerve roots resulted in almost a total loss of forelimb function and the average Terzis score was decreased significantly compared with the sham group. No obvious recovery of shoulder and elbow movements was noted during the test period. In addition, nerve roots avulsion injury led to severe retrograde degeneration of motoneurons in the C5-C7 spinal cord segments. Nissl staining results showed that motoneurons decreased significantly in number and appeared to have irregular morphologies. These results indicated that a novel noninvasive rat model for BPI that simulates the mechanism of a human lesion could be produced using our passive traction apparatus, and it is expected to produce reliable preclinical evidence in the assessment of new therapeutic strategies for this lesion.

Diagnostic Value and Surgical Implications of the 3D DW-SSFP MRI On the Management of Patients with Brachial Plexus Injuries

Three-dimensional diffusion-weighted steady-state free precession (3D DW-SSFP) of high-resolution magnetic resonance has emerged as a promising method to visualize the peripheral nerves. In this study, the application value of 3D DW-SSFP brachial plexus imaging in the diagnosis of brachial plexus injury (BPI) was investigated. 33 patients with BPI were prospectively examined using 3D DW-SSFP MR neurography (MRN) of brachial plexus. Results of 3D DW-SSFP MRN were compared with intraoperative findings and measurements of electromyogram (EMG) or somatosensory evoked potentials (SEP) for each injured nerve root. 3D DW-SSFP MRN of brachial plexus has enabled good visualization of the small components of the brachial plexus. The postganglionic section of the brachial plexus was clearly visible in 26 patients, while the preganglionic section of the brachial plexus was clearly visible in 22 patients. Pseudomeningoceles were commonly observed in 23 patients. Others finding of MRN of brachial plexus included spinal cord offset (in 16 patients) and spinal cord deformation (in 6 patients). As for the 3D DW-SSFP MRN diagnosis of preganglionic BPI, the sensitivity, the specificity and the accuracy were respectively 96.8%, 90.29%, and 94.18%. 3D DW-SSFP MRN of brachial plexus improve visualization of brachial plexus and benefit to determine the extent of injury.

Vascularized proximal fibular epiphyseal transfer for Bayne and Klug type III radial longitudinal deficiency in children.

Background: Treatment of Bayne and Klug type III radial longitudinal deficiency with fibular epiphyseal transplantation in children has had limited success to date. The purpose of this investigation was to review the authors’ results of microvascular epiphyseal transplantation for radial longitudinal deficiency. Methods: Between 2007 and 2009, four children with a mean age of 4.3 years (range, 3.3 to 5.8 years) who had a type III radial longitudinal deficiency underwent microsurgical reconstruction of the distal radius with vascularized proximal fibular transplantation, including the physis, partial superior tibiofibular joint, and a variable length of the diaphysis. All of the grafts were supplied by the inferior lateral genicular artery. In all patients, the range of motion of the digits, wrist, forearm, and elbow; the length of the forearm; and the deviation of the wrist were evaluated. Results: The mean duration of follow-up was 42 months (range, 24 to 65 months). All four transfers survived and united with the host bone within 3 months postoperatively. An average correction of 28 degrees in the hand-forearm angle was obtained. Forearm length was 67.9 percent that of the normal side on average at the final follow-up. The overall range of wrist motion was approximately 55 percent that of the contralateral extremity. No major complications were observed. Conclusions: Vascularized proximal fibular epiphyseal transfer, based on the inferior lateral genicular artery, is a technically feasible method for treatment of type III radial longitudinal deficiency, which maintains hand-forearm alignment, provides excellent function, and minimizes the length discrepancy between the distal radius and ulna. Clinical question/level of evidence: Therapeutic, IV.

Penile erectile dysfunction after brachial plexus root avulsion injury in rats

Our previous studies have demonstrated that some male patients suffering from brachial plexus injury, particularly brachial plexus root avulsion, show erectile dysfunction to varying degrees. However, the underlying mechanism remains poorly understood. In this study, we evaluated the erectile function after establishing brachial plexus root avulsion models with or without spinal cord injury in rats. After these models were established, we administered apomorphine (via a subcutaneous injection in the neck) to observe changes in erectile function. Rats subjected to simple brachial plexus root avulsion or those subjected to brachial plexus root avulsion combined with spinal cord injury had significantly fewer erections than those subjected to the sham operation. Expression of neuronal nitric oxide synthase did not change in brachial plexus root avulsion rats. However, neuronal nitric oxide synthase expression was significantly decreased in brachial plexus root avulsion + spinal cord injury rats. These findings suggest that a decrease in neuronal nitric oxide synthase expression in the penis may play a role in erectile dysfunction caused by the combination of brachial plexus root avulsion and spinal cord injury.

Diagnostic accuracy of three sensory tests for diagnosis of sensory disturbances.

BACKGROUND Clinical diagnosis of sensory disturbances is extremely challenging, partly because the utility of sensory tests is questionable. Transection of C7 nerve root provides an objective assessment model to determine the diagnostic accuracy of sensory tests. The purpose of this study was to investigate the diagnostic accuracy of Semmes-Weinstein Monofilaments (SWM; Sammons Preston, Bolingbrook, IL), static two-point discrimination (s2PD), and current perception threshold (CPT) tests in patients with contralateral C7 nerve root transfer. METHODS The contralateral index finger of patients was tested preoperatively and 6 weeks postoperatively, including the Revised Short-Form McGill Pain Questionnaire (SF-MPQ-2), SWM, s2PD, and CPT tests. The SF-MPQ-2 was used as a gold standard for sensory disturbances. RESULTS A total of 38 patients were included in the study. The likelihood probability ratio of SWM and CPT tests generated small shifts in probability, whereas the s2PD test did not show any capacity to detect sensory disturbances. The areas under the curves (AUC) for SWM and CPT tests were 0.724 and 0.697, respectively. Based on different positive test standards, the AUCs for s2PD (≥ 6 mm) and s2PD (≥ 7 mm) tests were 0.632 and 0.658, respectively. When CPT and SWM tests were combined as a measure, the AUC increased to 0.763. CONCLUSION The SWM and CPT tests show a small capacity to detect sensory disturbances, whereas the s2PD test does not show any diagnostic capacity. To better understand sensory disturbances, a comprehensive testing protocol including valid measures of physical impairment and symptom-specific measurement tools should be adopted.

Donor-side morbidity after contralateral C-7 nerve transfer: results at a minimum of 6 months after surgery

OBJECT Donor-side morbidity associated with contralateral C-7 (CC7) nerve transfer remains controversial. The purpose of this study was to evaluate functional deficits in the donor limb resulting from prespinal route CC7 nerve transfer. METHODS A total of 63 patients were included. Forty-one patients had undergone CC7 nerve transfer surgery at least 6 months previously and were assigned to one of 2 groups based on the duration of postoperative follow-up. Group 1 (n = 21) consisted of patients who had undergone surgery between 6 months and 2 years previously, and Group 2 (n = 20) consisted of patients who had undergone surgery more than 2 years previously. An additional 22 patients who underwent CC7 nerve transfer surgery later than those in Groups 1 and 2 were included as a control group (Group 3). Results of preoperative testing in these patients and postoperative testing in Groups 1 and 2 were compared. Testing included subjective assessments and objective examinations. An additional 3 patients had undergone surgery more than 6 months previously but had severe motor weakness and were therefore evaluated separately; these 3 patients were not included in any of the study groups. RESULTS The revised Short-Form McGill Pain Questionnaire (SF-MPQ-2) was the only subjective test that showed a significant difference between Group 3 and the other 2 groups, while no significant differences were found in objective sensory, motor, or dexterity outcomes. The interval from injury to surgery for patients with a normal SF-MPQ-2 score in Groups 1 and 2 was significantly less than for those with abnormal SF-MFQ-2 scores (2.4 ± 1.1 months vs 4.6 ± 2.9 months, p = 0.002). The 3 patients with obvious motor weakness showed a tendency to gradually recover. CONCLUSIONS Although some patients suffered from long-term sensory disturbances, resection of the C-7 nerve had little effect on the function of the donor limb. Shortening preoperative delay time can improve sensory recovery of the donor limb.

Flow-through anastomosis using a T-shaped vascular pedicle for gracilis functioning free muscle transplantation in brachial plexus injury

OBJECTIVE: In gracilis functioning free muscle transplantation, the limited caliber of the dominant vascular pedicle increases the complexity of the anastomosis and the risk of vascular compromise. The purpose of this study was to characterize the results of using a T-shaped vascular pedicle for flow-through anastomosis in gracilis functioning free muscle transplantation for brachial plexus injury. METHODS: The outcomes of patients with brachial plexus injury who received gracilis functioning free muscle transplantation with either conventional end-to-end anastomosis or flow-through anastomosis from 2005 to 2013 were retrospectively compared. In the flow-through group, the pedicle comprised a segment of the profunda femoris and the nutrient artery of the gracilis. The recipient artery was interposed by the T-shaped pedicle. RESULTS: A total of 46 patients received flow-through anastomosis, and 25 patients received conventional end-to-end anastomosis. The surgical time was similar between the groups. The diameter of the arterial anastomosis in the flow-through group was significantly larger than that in the end-to-end group (3.87 mm vs. 2.06 mm, respectively, p<0.001), and there were significantly fewer cases of vascular compromise in the flow-through group (2 [4.35%] vs. 6 [24%], respectively, p=0.019). All flaps in the flow-through group survived, whereas 2 in the end-to-end group failed. Minimal donor-site morbidity was noted in both groups. CONCLUSIONS: Flow-through anastomosis in gracilis functioning free muscle transplantation for brachial plexus injury can decrease the complexity of anastomosis, reduce the risk of flap loss, and allow for more variation in muscle placement.

The upper brachial plexus defect model in rhesus monkeys: a cadaveric feasibility study.

To establish a model for nerve grafts and determine the anatomic characteristics of the brachial plexus in rhesus monkeys. Ten specimens of the brachial plexus were obtained from five rhesus monkey cadavers. Anatomic dissection of the brachial plexus was systemically performed. The length of each root, trunk, and each division was measured using a Vernier caliper proximodistally. The anatomic distributions of the suprascapular, axillary, and musculocutaneous nerve were documented. The brachial plexus of rhesus monkeys included the spinal nerves or roots of C5, C6, C7, C8, and T1 (80%, 8/10), with a small contribution from the C4 root (20%, 2/10) occasionally. The upper trunk was not measurable because of their irregular structures. The lower trunk had a mean length of 1.62 (range, 0.96–2.1 mm) and a mean diameter of 2.29 (range, 1.9–2.94 mm). For the upper trunk, the C5 and C6 roots either divided into two very short divisions or sent out very long divisions before they joined together. For the middle trunk, the C7 root had a straight course after leaving the foramen and blended imperceptibly into the middle trunk before dividing into the anterior and posterior divisions. The lower trunk was noted in almost all the specimens (80%, 8/10), which was formed by C8 and T1. The brachial plexus in rhesus monkeys varies from that of humans, and defects can be made at the level of C5 and C6 roots and the C7 root should also be cut off and ligated.

A novel rat model of brachial plexus injury with nerve root stumps

BACKGROUND The C5-C6 nerve roots are usually spared from avulsion after brachial plexus injury (BPI) and thus can be used as donors for nerve grafting. To date, there are no appropriate animal models to evaluate spared nerve root stumps. Hence, the aim of this study was to establish and evaluate a rat model with spared nerve root stumps in BPI. NEW METHOD In rupture group, the proximal parts of C5-T1 nerve roots were held with the surrounding muscles and the distal parts were pulled by a sudden force after the brachial plexus was fully exposed, and the results were compared with those of sham group. To validate the model, the lengths of C5-T1 spared nerve root stumps were measured and the histologies of the shortest one and the corresponding spinal cord were evaluated. RESULTS C5 nerve root stump was found to be the shortest. Histology findings demonstrated that the nerve fibers became more irregular and the continuity decreased; numbers and diameters of myelinated axons and thickness of myelin sheaths significantly decreased over time. The survival of motoneurons was reduced, and the death of motoneurons may be related to the apoptotic process. COMPARISON WITH EXISTING METHOD(S) Our model could successfully create BPI model with nerve root stumps by traction, which could simulate injury mechanisms. While other models involve root avulsion or rupturing by distal nerve transection. CONCLUSIONS This model would be suitable for evaluating nerve root stumps and testing new therapeutic strategies for neuroprotection through nerve root stumps in the future.