Protective distal side-to-side neurorrhaphy in proximal nerve injury-an experimental study with rats.

BACKGROUND: Side-to-side neurorrhaphy may protect the denervated end organ and preserve the initial connection with proximal stump. We examined the effect of protective side-to-side anastomosis on nerve and end organ regeneration in proximal nerve injury model. METHODS: The left common peroneal nerve of 24 Sprague Dawley rats was proximally transected. In groups B and C, side-to-side neurorrhaphy was performed distally between the peroneal and tibial nerves without (group B) and with (group C) partial donor nerve axotomy inside the epineural window. Group A served as an unprotected control. After 26 weeks, the proximal transection was repaired with end-to-end neurorrhaphy on all animals. Regeneration was followed during 12 weeks with the walk track analysis. Morphometric studies and wet muscle mass calculations were conducted at the end of the follow-up period. RESULTS: The results of the walk track analysis were significantly better in groups B and C compared to group A. Groups B and C showed significantly higher wet mass ratios of the tibialis anterior and extensor digitorum longus muscle compared to group A. Group C showed significantly higher morphometric values compared to group A. Group B reached higher values of the fibre count, fibre density, and percentage of the fibre area compared to group A. CONCLUSIONS: Protective distal side-to-side neurorrhaphy reduced muscle atrophy and had an improving effect on the morphometric studies and walk track analysis. Distal side-to-side neurorrhaphy does not prevent the regenerating axons to grow from the proximal stump to achieve distal nerve stump.

Results of spinal accessory nerve to suprascapular nerve transfers in children with brachial plexus birth injury.

Shoulder external rotation after brachial plexus birth injury can be restored by transfer of the spinal accessory nerve to the suprascapular nerve, or more distally to its infraspinatus branch. We studied the outcome of these nerve transfers in 52 patients with a minimum postoperative follow-up of 12 months (mean 7.3 years). The median postoperative improvement in shoulder external rotation was 120° (interquartile range [IQR] 45-135) after anterior and 110° (IQR 83-120) after dorsal spinal accessory nerve transfer to the suprascapular nerve main trunk, and 110° (IQR 80-125) after transfer to the infraspinatus branch. Patients operated after 20 months obtained external rotation ≥90° less frequently. The results of this study suggest that a decision about distal nerve transfer for shoulder external rotation is recommended at 1.5 years of age.Level of evidence: III.

Indications, anaesthesia and postoperative protocol for replantation and revascularization in the hand in Nordic countries.

In this survey, we compared the current postoperative practices in the largest replantation units of four Nordic countries. The topics included were indication for surgery, anaesthesia, postoperative monitoring, use of antibiotics, anticoagulation and postoperative intravenous fluids, change of dressings, duration of bed rest and hospital stay, hand therapy and follow-up after discharge. Although there were many similarities between the units in the postoperative protocols, we found a large variety of practices. There is no robust evidence to assess or support or reject most of the strategies in postoperative care. The differences in practice warrant prospective studies in order to establish an evidence-based postoperative protocol for replantation surgery.

Effect of Axonal Trauma on Nerve Regeneration in Side-to-side Neurorrhaphy: An Experimental Study.

BACKGROUND: Side-to-side (STS) neurorrhaphy can be performed distally to ensure timely end-organ innervation. It leaves the distal end of the injured nerve intact for further reconstruction. Despite encouraging clinical results, only few experimental studies have been published to enhance the regeneration results of the procedure. We examined the influence of different size epineural windows and degree of axonal injury of STS repair on nerve regeneration and donor nerve morbidity. METHODS: Three clinically relevant repair techniques of the transected common peroneal nerve (CPN) were compared. Group A: 10-mm long epineural STS windows; group B: 2-mm long windows and partial axotomy to the donor tibial nerve; and group C: 2-mm long windows with axotomies to both nerves. Regeneration was followed by the walk track analysis, nerve morphometry, histology, and wet muscle mass calculations. RESULTS: The results of the walk track analysis were significantly better in groups B and C compared with group A. The nerve fiber count, total fiber area, fiber density, and percentage of the fiber area values of CPN of the group C were significantly higher when compared with group A. The wet mass ratio of the CPN-innervated anterior tibial muscle was significantly higher in group C compared with group A. The wet mass ratio of the tibial nerve-innervated gastrocnemial muscle was higher in group A compared with the other groups. CONCLUSIONS: All three variations of the STS repair technique showed nerve regeneration. Deliberate donor nerve axotomy enhanced nerve regeneration. A larger epineural window did not compensate the effect of axonal trauma on nerve regeneration.

Comparison of Peripheral Nerve Regeneration with Side-to-side, End-to-side, and End-to-end Repairs: An Experimental Study.

BACKGROUND: The present study was conducted to find out a tool to enable improved functional recovery with proximal nerve injury. In this experimental study, nerve regeneration was compared between side-to-side (STS), end-to-side (ETS), and end-to-end repairs. METHODS: The walk track analysis was used as an outcome of functional recovery. Nerve regeneration was studied with morphometry and histology 6 or 26 weeks postoperatively. RESULTS: All 3 repair techniques showed regeneration of the nerve. From 12 weeks onward, the functional results of the 3 intervention groups were significantly better compared with the unrepaired control group. End-to-end repair was significantly better when compared with the STS and ETS groups. At 26 weeks, the functional and morphometric results and histologic findings did not differ between the STS and ETS groups. The functional results correlated with the morphometric findings in all groups. CONCLUSIONS: STS neurorrhaphy showed nerve regeneration, and the end results did not differ from clinically widely used ETS repair. Further studies are warranted to optimize the neurorrhaphy technique and examine possible applications of STS repair in peripheral nerve surgery.