Re: Comparison of vasovasostomy with conventional microsurgical suture and fibrin adhesive in rats.

We read with great interest the paper by Wilson F. Busato Junior and colleagues (1). In this elegant study two techniques of vasovasostomy have been tested in a laboratory setting. One group of rats underwent “conventional” one-layer anastomosis on the left vas deferent, after transection on the right side; another group was evaluated for a simplified anastomosis performed with one anchor point plus fibrin glue, and the last group served as control after a sham operation. The authors concluded that the two techniques are similar (p > 0.05) and the operative time is the only relevant difference. As a first point to debate we would emphasize that the results of this study cannot be considered out of an experimental concern. This is because the anastomosis was performed using perfect stumps of deferens and they were immediately reattached after cutting. Thus, it does not reproduce the real clinical condition in which a scar tissue can be found at the cut ends. Another issue refers to the way of apposing the divided ends of the vasa. The authors applied a direct end-to-end anastomosis in both procedures. However, in a clinical context, it might be helpful a modified approach based on preparing the vas ends. As reported by Fox, the convoluted portion of the vas is always thinner and more difficult to suture than the straight part. Therefore, in all cases in which the stumps are of different size, it is advantageous to transect obliquely the deferent in order to augment the diameter of its lumen (2). This technique has shown ensuing paternity in one third of patients either after primary or revised vasovasostomy. Finally, the authors suggest that the fibrinsupplied vasovasostomy since requires less operative time may became a simplified procedure suitable also for a general urologist. Nevertheless the microsurgical vasovasostomy performed at microscope is widely considered improved over other methods using less magnification (3). Thus, in our opinion the vasovasostomy should preferably address to urologists trained in microsurgery (clinical or experimental) or practiced in dedicated centers. In any case, we congratulate the authors for a well drawn study dealing with appropriate number of animals according to modern ethical rules (4).