Outcome in cats with benign ureteral obstructions treated by means of ureteral stenting versus ureterotomy

Abstract

OBJECTIVE To evaluate the outcome for cats with benign ureteral obstructions treated by means of ureteral stenting and to compare the outcome for these cats with outcome for a historical cohort of cats treated by means of ureterotomy only. DESIGN Prospective study with historical cohort. ANIMALS 62 client-owned cats with benign ureteral obstructions, including 26 cats treated with ureteral stenting and 36 cats previously treated with ureterotomy. PROCEDURES Data were recorded prospectively (ureteral stent cases) or collected retrospectively from the medical records (ureterotomy cases), and results were compared. RESULTS Cats treated with ureteral stents had significantly greater decreases in BUN and serum creatinine concentrations 1 day after surgery and at hospital discharge, compared with values for cats that underwent ureterotomy. Six cats in the ureteral stent group developed abdominal effusion after surgery, and cats in this group were significantly more likely to develop abdominal effusion when a ureterotomy was performed than when it was not. Cats that developed abdominal effusion after surgery were significantly less likely to survive to hospital discharge. Cats that underwent ureteral stenting were significantly more likely to have resolution of azotemia prior to hospital discharge than were cats that underwent ureterotomy alone. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that cats with benign ureteral obstructions treated with ureteral stenting were more likely to have resolution of azotemia prior to hospital discharge, compared with cats undergoing ureterotomy alone. Results of ureteral stenting were encouraging, but further investigation is warranted.

Feline ureteral obstructions Part 2: surgical management

“…Ureteroscopy is not possible in cats due to small ureteral size. In cats, ureteral stents have been described for the management of ureterolithiasis, dried solidified blood stones, ureteral strictures, intraluminal bypass to facilitate healing after ureteral surgery or trauma, and neoplasia (Berent 2011, Zaid et al 2011, Berent et al 2012, Nicoli et al 2012, Horowitz et al 2013, Kulendra et al 2014, Manassero et al 2014, Steinhaus et al 2015, Culp et al 2016. Both temporary and long-term use are described for veterinary patients, which is in contrast to most uses in humans.…”

“…The vast majority of cats require laparotomy for ureteral stent placement, which can be performed in both a retrograde or anterograde fashion, though anterograde surgical placement is preferred (Berent et al 2012, Culp et al 2016, Wormser et al ). Ureterotomy to facilitate stone removal and aid in wire and stent passage may be necessary, regardless of whether an anterograde or retrograde approach is used (Berent et al 2012, Kulendra et al 2014, Culp et al 2016. In both approaches, dilation with the tapered end of the provided 0·034ʺ pusher/dilator of any normal diameter ureter is often needed to facilitate stent placement.…”

“…In both approaches, dilation with the tapered end of the provided 0·034ʺ pusher/dilator of any normal diameter ureter is often needed to facilitate stent placement. This is due to the fact that even the smallest available stents for cats, which are 2+ French in diameter (less than 1 mm outer diameter, 3 French = 1 mm), are still more than twice the diameter of the normal internal diameter of the feline ureter (0·4 mm) (Kochin et al 1993, Roberts et al 2011, Berent et al 2012, Culp et al 2016, Infiniti medical Vet-Stent Ureter feline ureteral stent). Patience and gentle tissue handling are essential for feline ureteral stent placement.…”

“…Surgical management techniques have been traditional in the management of ureteral obstructions in cats. Described techniques include single or multiple ureterotolithotomies (ureterotomy/ureterotomies), ureteral resection and anastomosis, ureteral reimplantation (ureteroneocystostomy), and ureteronephrectomy (Kochin et al 1993, Hardie & Kyles 2004, Kyles et al 2005a, 2005b, Adin & Scansen 2011, Roberts et al 2011, Culp et al 2016. When a ureteral reimplantation is performed, if there is concern for tension on the ureter upon retraction of the bladder, a renal descensus, which involves dissection of the kidney from its retroperitoneal attachments for increased caudal mobility, and cystopexy are techniques for tension relief described in conjunction with ureteral surgery (Kyles et al 2005a).…”

“…Complications of ureteral surgery include oedema and inflammation causing re-obstruction, stricture, recurrence of obstructive calculi, including migration of nephroliths, persistence of azotaemia and urine leakage. Urine leakage is the most common complication -reported in up to 16% of patients (Kochin et al 1993, Hardie & Kyles 2004, Kyles et al 2005a, 2005b, Adin & Scansen 2011, Roberts et al 2011, Culp et al 2016. Major postoperative complication rates in cats are reported to be as high as 31% and mortality rates for cats undergoing ureteral surgery are reported to be as high as 21% (Kyles et al 2005b, Adin & Scansen 2011, Roberts et al 2011.…”