J Reconstr Microsurg 2006; 22 - A016
DOI: 10.1055/s-2006-949686

Treatment of Upper and Lower Extremity Neuromas by End-to-Side Neurorrhaphy

Oskar C Aszmann 1, Juan Carlos Zambrano 1, Veith Moser 1, Manfred Frey 1
  • 1Universidad Javeriana and Division of Plastic and Reconstructive Surgery, Medical University of Vienna, Austria

The successful treatment of painful neuroma remains a difficult goal to obtain. In this report, the authors reviewed the experimental evidence for neuroma prevention by inserting the proximal end of a nerve through an end-to-side neurorrhaphy into an adjacent mixed nerve to provide a pathway and target for axons deprived of their end organ. They also presented their first clinical series of patients with a follow-up of 28 months.

In the experimental study, a total of 20 250 g Sprague-Dawley rats were used. The right saphenous nerve was transected and implanted end-to-side into the tibial nerve. After 12 weeks, the corresponding sensory neurons were identified by retrograde labeling and histomorphometric analysis of the proximal and distal tibial nerve. The clinical series of patients included 11 upper and three lower extremity sensory nerves that were treated in the manner already described. Follow-up included detailed sensory status and motor function, overall clinical evaluation, and pain score at a mean of 28 months post surgery.

The results of the retrograde labeling of the corresponding sensory neuron pool validated that sensory neurons penetrate the perineurial sheath and axons regenerate along the tibial Schwanan cell tubes toward their targets. In this first clinical series, of a total of 15 different sensory nerves, only one had recurrent symptoms. All others had a definite improvement of symptoms. None of the “borrowed” nerves had a measurable or subjective loss or decrease of function.

Both experimental and clinical data suggest that axons of a severed peripheral nerve that are provided with a pathway and target through an end-to-side coaptation will either be pruned or will establish some type of end organ contact so that a neuroma can be prevented. The clinical series suggests that new axons will not lead to disturbing sensations such as paresthesia or dysesthesia in the newly-found environment, but will remain silent co-dwellers.