ObjectiveTo explore the feasibility of transposition of the proximal motor branches from tibial nerve (TN) as direct donors to suture the deep peroneal nerve (DPN) so as to provide a basis for surgical treatment of high fibular nerve injury. MethodsNineteen lower limb specimens were selected from 3 donors who experienced high-level amputation (2 left limbs and 1 right limb) and 8 fresh frozen cadavers (8 left limbs and 8 right limbs). The length and diameter of the three motor branches from TN (soleus, medial gastrocnemius, and lateral gastrocnemius) and the distance from the initial points to the branch point of the common peroneal nerve (CPN), as well as the length and diameter of the noninvasive separated bundles of DPN, then the feasibility of tensionless suturing between the donor nerves and the DPN bundle was evaluated. At last, part of the nerve tissue was cut out for HE and Acetylcholine esterase staining observation and the nerve fiber count. ResultsGross anatomic observation indicated the average distance from the initial points of the three donor nerves to the branch point of the CPN was (71.44±2.76) (medial gastrocnemius), (75.66±3.20) (lateral gastrocnemius), and (67.50±3.22) mm (soleus), respectively. The three donor nerves and the DPN bundles had a mean length of (31.09±2.01), (38.44±2.38), (59.18±2.72), and (66.44±2.85) mm and a mean diameter of (1.72±0.08), (1.88±0.08), (2.10±0.10), and (2.14±0.12) mm, respectively. The histological observation showed the above-mentioned four nerve bundles respectively had motor fiber number of 2 032±58, 2 186±24, 3 102±85, and 3 512±112. Soleus nerve had similar diameter and number of motor fibers to DPN bundles (P>0.05), but the diameter and number of motor fibers of the medial and lateral gastrocnemius were significantly less than those of DPN bundles (P<0.05). ConclusionAll of the three motor branches from TN at popliteal fossa can be used as direct donors to suture the DPN for treating high CPN injuries. The nerve to the soleus muscle should be the first choice.
ObjectiveTo investigate the effect of electrospun chitosan/polylactic acid (ch/PLA) nerve conduit for repairing peripheral nerve defect in rats. MethodsNerve conducts loaded with ch/PLA was made by the way of electrospun. The mechanical property, hydrophility, biocompatibility were tested, and the scanning electron microscope was used to observe the ultrastructure. The same experiments were also performed on pure PLA nerve conducts as a comparison. Then, 54 Sprague Dawley rats were divided into 3 groups randomly, 18 rats in each group. Firstly, the 10 mm defects in the right sciatic nerves were made in the rats and were respectively repaired with ch/PLA (group A), autografts (group B), and no implant (group C). At 4, 8, and 12 weeks after operation, general observations, sciatic functional index (SFI), electrophysiological evaluation, wet weight of gastrocnemius and soleus muscles, histological examination, immunohistological analysis, and transmission electron microscopy were performed to evaluate the effects. ResultsCompared with pure PLA nerve conducts, the addition of chitosan could improve the mechanical property, hydrophility, biocompatibility, and ultrastructure of the nerve conducts. At 4 weeks postoperatively, the regenerated nerve bridged the nerve defect in group A. The SFI improved gradually in both group A and group B, showing no significant difference (P>0.05). Compound muscle action potentials and nerve conduction velocity could be detected in both group A and group B at 8 and 12 weeks after operation, and significant improvements were shown in both groups (P<0.05). The wet weight and myocyte cross section of gastrocnemius and soleus muscles showed no significant difference between group A and group B (P>0.05), but there was significant difference when compared with group C (P<0.05) at 12 weeks postoperatively. Immunohistological analysis revealed that S-100 positive Schwann cells migrated in both group A and group B, and axon also regenerated by immunohistological staining for growth associated protein 43 and neurofilaments 160. Transmission electron microscopy showed no significant difference in the diameter of nerve fiber between group A and group B (P>0.05), but the thickness of myelin sheath in group A was significantly larger than that in group B (P<0.05). ConclusionThe electrospun ch/PLA nerve conduits can effectively promote the peripheral nerve regeneration, and may promise an alternative to nerve autograft for repairing peripheral nerve defect.
ObjectiveTo evaluate the long-term effects on the lower limb function after S1 nerve root transection as dynamic source. MethodsBetween January 2007 and December 2011, 47 patients with atonic bladder dysfunction underwent S1 nerve root transposition to reconstrut the bladder function. There were 43 males and 4 females, with an average age of 40.7 years (range, 22-66 years). The locations were LS1 in 33 cases, LS2 in 5 cases, LS3 in 2 cases, TS12, LS1 in 3 cases, LS1, LS2 in 1 case, LS1, LS3 in 1 case, LS1, LS4 in 1 case, and LS2, LS3 in 1 case. The anastomosis of the SS2 or SS3 nerve root to S1 nerve root was performed from 4 to 24 months (mean, 8 months) after spinal cord injury. The strength of ankle plantar flexion was grade 4 in 5 cases and grade 5 in 42 cases before operation. ResultsThe strength of ankle plantar flexion had no obvious decrease (grade 4 or 5) in 31 cases, reduced 0.5 grade in 16 cases at 2 days after operation. All the patients were followed up 3-8 years (mean, 5.1 years). At 2 weeks after operation, the nerve electrophysiological examination showed neurogenic damage at operated side in most patients, including reduced amplitude tibial nerve in 19 cases, for common peroneal nerve in 13 cases, and for tibial nerve and common peroneal nerve in 9 cases. Except the velocity of common peroneal nerve (t=-1.881, P=0.093), the other electric physiological indexes showed significant differences between at pre- and post-operation (P<0.05). The muscle strength basically recovered to preoperative level (grade 4 or 5) during follow-up, and there was no impairment of lower limb function. ConclusionS1 transection has no significant effects on lower limb function, so S1 nerve can be used as dynamic nerve for nerve function reconstruction.
ObjectiveTo study the long-term prevention effect of self-developed chitosan electrospun membrane on cerebrospinal fluid leakage. MethodsTwenty-five healthy adult New Zealand rabbits were selected to prepare the bilateral dural defect (0.8 cm×0.8 cm in size) via midline incision of head.Defect of the right was repaired with chitosan electrospun membrane as the experimental group; defect of the left was not repaired as the control group.At 2-16 weeks after operation,one rabbit was sacrificed for the general observation of inflammatory response surrounding bone window and absorption of chitosan electrospun membrane; at 3 and 6 weeks after operation,5 rabbits were sacrificed for sampling to observe histological change and collagen expression by HE and Masson staining,and to measure the expressions of epidermal growth factor receptor (EGFR) and basic fibroblast growth factor (bFGF) by immunohistochemical staining. ResultsNo inflammatory reaction of swelling,exudation,and sppuration appeared in the skin and subcutaneous tissue after operation in 2 groups.There was no adhesion around the chitosan electrospun membrane,and new fiber membrane formed under the chitosan electrospun membrane in the experimental group; no cerebrospinal fluid leakage happened; the chitosan electrospun membrane was gradually degraded with time,and was completely absorbed at 16 weeks.There was uneven scar around the dural detect in control group.Histological observation showed less inflammatory cell infiltration in the experimental group,showing significant difference in the number of inflammatory cells compared with control group at 3,6 weeks (P<0.05); capillary,granulation tissue and collagen fiber massively proliferated; collagen fiber arranged in line,and there was a clear borderline between chitosan electrospun membrane and adjacent collagen fiber.The immunohistochemical staining showed that there were high expressions of bFGF and EGFR in the experimental group,and low expressions of bFGF and EGFR in the control group. ConclusionChitosan electrospun membrane for dural defect of rabbit can effectively reconstruct the dura,and it has exact long-term prevention effect on cerebrospinal fluid leakage.
ObjectiveTo investigate the regularity of myelin degeneration and regeneration and the difference of axonal density between tibial nerve and common peroneal nerve after sciatic nerve injury repair in rhesue monkey. MethodsNine adult rhesue monkeys (male or female, weighing 3.5-4.5 kg) were selected to establish the model of rat sciatic nerve transaction injury. The tibial nerve and common peroneal nerve of 5 mm in length were harvested at 5 mm from injury site as controls in 3 monkeys; the distal tibial nerve and common peroneal nerve were repaired with 9-0 suture immediately in the other 6 monkeys. And the gross observation and neural electrophysiological examination were performed at 3 and 8 weeks after repair respectively. Then, distal tibial nerve and common peroneal nerve at anastomotic site were harvested to observe the myelin sheath changes, and to calculate the number of axon counts and axonal density by staining with Luxol Fast Blue. ResultsAtrophy of the lower limb muscle and various degrees of plantar ulcer were observed. Gross observation showed nerve enlargement at anastomosis site, the peripheral connective tissue hyperplasia, and obvious adhesion. The compound muscle action potential (CMAP) of tibial nerve and common peroneal nerve could not be detected at 3 weeks; the CMAP amplitude of common peroneal nerve was less than that of the tibial nerve at 8 weeks. Different degrees of axonal degeneration was shown in the tibial nerve and common peroneal nerve, especially in the common peroneal nerve. The average axonal density of common peroneal nerve was lower than that of tibial nerve at 3 weeks (13.2% vs. 44.5%) and at 8 weeks (10.3% vs. 35.3%) after repair. ConclusionThe regeneration of tibial nerve is better and faster than that of common peroneal nerve, and gastrocnemius muscle CMAP recovers quicker, and amplitude is higher, which is the reason of better recovery of tibial nerve.