Tiam Mana Saffari

39 THE ROLE OF VASCULARIZATION IN NERVE REGENERATION 2 portion of the axons had recovered 45 . Although this result was encouraging, technical difficulties were recognized and the procedure was suggested to be only performed in young patients, based on a case report and opinion of the authors. In the 1980’s, several experimental and clinical studies investigated the effectiveness of adding vascularization to a nerve graft 37,38,46-50 . Some of these studies demonstrated superior results of VNGs compared to NVNGs, while others suggested that the sensory- and motor functional recovery after VNGs were not significantly enhanced. The risk of thrombosis of the anastomosis in a VNG with subsequent necrosis of the nerve graft was considered by some authors as concerning and they advised against use of VNGs 51 . Conclusive findings on the superiority of VNGs in a clinical setting remain lacking due to multiple confounders, different duration of outcomes and the studies being mostly case reports or small case series 52-57 . There is no clear consensus on the clinical indications for VNGs. The application of VNGs should be considered in the following cases: large length of nerve gap of more than 6-7 cm, large diameter of the injured nerve, scarred recipient bed that could not support a NVNG and substantial pre-operative delay of more than 24 months 16,38,46,47,57,58 . It is imperative to understand that this recommendation is based on case reports, small case series and the anecdote of expert opinions. Doi and colleagues compared 27 cases of free vascularized sural nerve grafts in the upper extremity to 22 non-vascularized sural nerve grafts. These grafts were used to repair axillary, median, ulnar, radial and digital nerves, with a mean nerve gap of 6.0 cm in the VNG group versus 4.7 cm in the NVNGs. Two years postoperatively, the VNGs performed better in terms of rate of axonal regeneration, rate of EMG return and motor- and sensory outcome 59 . Significant changes were found evaluating (i) the abductor pollicis brevis muscle (M2.5, S3 and M1, S2.3) for the median nerve, (ii) the abductor digiti minimi muscle (M3.3, S3 and M2, S2) for the ulnar nerve and (iii) extensor digiti communis muscle (M3.5 and M1) for the radial nerve, comparing the successful VNGs to conventional grafts using the Medical Research Council (MRC) scale, respectively. The authors concluded that VNGs are technically difficult and equally good to conventional grafts. The variability in use e.g. different motor nerves, mixed motor and sensory nerves, or sensory nerves, and difficulties in consistent measures of outcome, combined with the small numbers, make a definite conclusion