Surgical treatment of 4 horses for cryptorchidism caused by failure of regression of the cranial suspensory ligament of the testis.

Objective: To report surgical management of 4 horses with cryptorchidism caused by failure of regression of the cranial suspensory ligament (CSL).
Study Design: Retrospective case series.
Animals: Cryptorchid horses (n = 4).
Methods: Horses with unilateral or bilateral cryptorchidism caused by failure of regression of the CSL were treated by removing the retained testes through a standing laparoscopic approach (2), flank laparotomy (1), or paramedian celiotomy (1). After identification of the retained testis attached to the caudal pole of the kidney by the CSL, the vascular pedicle and ductus deferens were ligated and removed.
Results: Two horses had bilateral cryptorchidism and 2 horses had unilateral cryptorchidism. Standing laparoscopic cryptorchidectomy was performed successfully in 2 horses and in 2, the retained testes were removed using a flank or paramedian celiotomy. All testes were located in the dorsal aspect of the abdomen just caudal to the kidney and had a well-developed CSL. All horses recovered successfully from surgery.
Conclusions: Failure of regression of the CSL is an uncommon cause of cryptorchidism in horses; however, affected horses can be treated using surgical approaches that facilitate exploration of the dorsocaudal aspect of the abdomen.
(© Copyright 2014 by The American College of Veterinary Surgeons.)