Can inhibin-B predict the outcome of microsurgical epididymal sperm aspiration in patients with suspected primary obstructive azoospermia?

M. Smit¹, G. R. Dohle¹, M. F. Wildhagen², R. F .A. Weber<sup>1

1</sup>Andrology unit of the department of Urology, 3000 CA Rotterdam, the Netherlands
² Department of Urology and Gynecology, 3000 CA Rotterdam, the Netherlands

DOI: 10.1111/j.1745-7262.2006.00209.x

Abstract
Aim: Obstructive azoospermia (OA) can be treated with microsurgical epididymal sperm aspiration (MESA) to be used for intracytoplasmic sperm injection. Primary idiopathic OA is suspected in patients with azoospermia, normal testicular volume and normal endocrine analysis without a history of vasectomy or congenital bilateral absence of the vas deferens. The aim of the present study was to evaluate whether inhibin-B can predict the outcome of a MESA procedure in patients with suspected primary OA and if inhibin-B can replace testicular biopsy in the diagnostic work-up of these patients. Methods: In retrospect, inhibin-B levels and testicular biopsy scores were related to the outcome of MESA in 43 patients with suspected primary OA. MESA was considered to be successful when epididymal sperm could be identified. Results: Spermatozoa were present in the epididymal aspirate in 28 out of 43 patients (65 %). Inhibin-B values were not significantly different in patients with successful or unsuccessful MESA. The modified Johnsen score, however, was significantly lower in patients with unsuccessful MESA (P = 0.003). Conclusion: Inhibin-B cannot replace testicular biopsy as a diagnostic tool in the work-up of patients with suspected primary OA. Testicular biopsy is useful in identifying patients with spermatogenic arrest, who might have normal inhibin-B values. A rete testis obstruction or epididymal malfunctioning was found in 15 % of patients with suspected primary OA, reflected by unsuccessful MESA despite normal inhibin-B levels and normal testicular histology.

Keywords: Inhibin B; male infertility; microsurgical epididymal sperm aspiration; primary obstructive azoospermia

Correspondence to: Dr G. R. Dohle, Department of Urology, Erasmus MC, PO Box 2040, 3000 CA Rotterdam, the Netherlands.
Tel: +31-10-4633-132, Fax: +31-10-4635-838
E-mail: g.r.dohle@erasmusmc.nl
Received 2005-12-31 Accepted 2006-06-16