The use of pneumatic impact lithotripsy and a retrieval pouch to create a closed system for removal of cystic calculi in standing male horses

Multiple techniques exist for removal of cystic calculi in the male horse, some of which use a perineal urethrotomy (PU) to facilitate access to the urinary bladder for removal of small uroliths in the standing, sedated horse. These techniques have limited efficacy in the removal of uroliths that have a diameter larger than the PU site, typically 4-5 cm. Pneumatic lithotripsy as reported in this article provides a novel way to fragment these larger uroliths while containing the fragments and protecting the urethra and urinary bladder. Ten geldings and one stallion underwent a lithotripsy procedure to remove one (n = 10) or several (n = 1) uroliths ranging in diameter from 4 to 9 cm. A PU was performed and a laparoscopic retrieval bag was inserted into the urinary bladder through the PU site. The urolith was manipulated into the bag using blind transrectal manipulation or endoscopic guidance and the opening of the bag was exteriorised out of the PU site. A pneumatic lithotrite was used to fragment the stone. When the urolith was adequately fragmented, the fragments were removed by the use of sponge forceps and by flushing the fragments from the bag with obstetrical lube. This was continued until the bag could smoothly be withdrawn from the urinary bladder. All uroliths were successfully removed. The PU sites healed without complication and none of the horses had recurrence of presenting clinical signs. This article also discusses the difference between two types of laparoscopic retrieval bags. Pneumatic impact lithotripsy in combination with a retrieval pouch offers a safe alternative to other methods for removal of cystic calculi in the horse.