Cystotomy for Urolith Removal Evaluated

This study investigated the effectiveness of routine surgical cystotomy in the complete removal of uroliths (urocystoliths, ureteroliths, or both) in the lower urinary tract (bladder and urethra). The authors evaluated records of dogs that underwent cystotomy from 1994 to 2006. Only surgeries that included urethral catheterization or retrograde urohydropropulsion (or both) were included, although only 19 dogs had appropriate postoperative imaging to determine whether all bladder and urethral stones were removed. Among the 19 dogs with appropriate postoperative imaging, 8 (42%) cystotomies resulted in failure to remove all uroliths. In 25 dogs, cystotomy was determined to be successful because the number of uroliths recovered matched the number observed via preoperative imaging; in 10 of these dogs, postoperative imaging confirmed complete stone removal. Follow-up procedures to remove remaining bladder stones were performed in 8 dogs. These procedures included cystoscopic basket retrieval, fluoroscopic basket retrieval, urethrotomy, and ureterolith removal by crushing via digital transrectal palpation and milking of urolith out of the urethra. Overall, recorded complications included seroma formation, cutaneous suture reaction, excessive cutaneous incision swelling, and cutaneous incision dehiscence. The authors concluded that surgeons failed to completely remove bladder or urethral stones via cystotomy using hydropulsion in 20% of the dogs in which effectiveness could be assessed and in 42% of the dogs in which postoperative imaging was used to determine removal. The proportion of dogs in this study with a failed cystotomy was higher than the 14% reported in another study but is similar to the rate in other reports. Appropriate postoperative imaging, especially double contrast cystography, is especially important in determining surgical success.

Commentary: This study was unique in that it documents the effectiveness of surgical cystotomy. However, it was unclear how the disproportionately low number of patient data reported over this 12-year period could accurately reflect general practice. Clinical relapse of symptoms related to bladder and urethral stones after surgery are—anecdotally, at least—often surgeon-dependent. Also, the surgical technique was not described in the evaluated cases. The relatively high incidence of surgical failure in this study (8 of 19 dogs that underwent imaging after surgery) is actually quite scary, and the reasons for this high rate should be further investigated.

Frequency of incomplete urolith removal, complications, and diagnostic imaging following cystotomy for the removal of uroliths from the lower urinary tract in dogs: 128 cases (1994-2006). Grant DC, Harper TAM, Werre SR. JAVMA 236:763-766, 2010.