OBJECTIVE To determine outcomes of subcutaneous ureteral bypass (SUB) device placement for treatment of benign ureteral obstruction in cats.
DESIGN Retrospective case series.
ANIMALS 134 cats with SUB devices placed in 174 obstructed ureters during 144 hospitalizations.
PROCEDURES Medical records of cats that underwent SUB device placement for treatment of benign ureteral obstruction between 2009 and 2015 were reviewed. The SUB device was placed by use of fluoroscopic and surgical methods. Signalment, history, diagnostic imaging results, postprocedural results, duration of hospitalization, complications, and short- and long-term outcomes were recorded.
RESULTS Ureteral obstructions were caused by ureterolithiasis (114/174 [65.5%]), stricture (28/174 [16.1%]), both ureterolithiasis and stricture (29/174 [16.7%]), or pyonephrosis (1/174 [0.6%]); in 2 (1.1%) cats, the cause was not recorded. Fifty-two of the 134 (39%) cats had bilateral ureteral obstruction. At admission, 127 (95%) cats were azotemic. Median serum creatinine concentrations at admission and 3 months after SUB device placement were 6.6 and 2.6 mg/dL, respectively. Median renal pelvis diameters before and after the procedure were 9.2 and 1.5 mm, respectively. Postsurgical complications included device occlusion with blood clots (14/172 [8.1%]), device leakage (6/172 [3.5%]), and kinking of the device tubing (8/174 [4.6%]). Cats survived to hospital discharge after 135 of the 144 (94%) hospital admissions. The most common long-term complication was catheter mineralization (40/165 [24.2%]), which was documented a median of 463 days after device placement. A high postoperative serum ionized calcium concentration was significantly associated with SUB device occlusion.
CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that SUB device placement may be a viable option for treatment of cats with benign ureteral obstruction.
Objective—To evaluate the technical, short-term, and long-term outcomes in cats with benign ureteral obstructions treated by means of double-pigtail ureteral stent placement.
Design—Retrospective case series.
Animals—69 cats (79 ureters).
Procedures—The diagnosis of benign ureteral obstruction was made via abdominal ultrasonography, radiography, and ureteropyelography. Ureteral stent placement was attempted endoscopically, surgically, or both, with fluoroscopic guidance. The medical records were reviewed for pre-, intra-, and postoperative data; complications; and outcome.
Results—69 cats (79 ureters) had stent placement attempted for various causes: ureterolithiasis (56/79 [71%]), stricture (10/79 [13%]), both ureterolithiasis and stricture (12/79 [15%]), or a purulent plug (1/79 [1%]). Stent placement was successful in 75 of 79 ureters (95%). Median number of stones per ureter was 4 (range, 0 to > 50), and 67 of 79 (85%) had concurrent nephrolithiasis. Preoperative azotemia was present in 95% (66/69) of cats (median creatinine concentration, 5.3 mg/dL [range, 1.1 to 25.8 mg/dL]), and 71% (49/69) remained azotemic (median, 2.1 mg/dL [range, 1.0 to 11.8 mg/dL]) after successful surgery. Procedure-related, postoperative (< 7 days), short-term (7 to 30 days), and long-term (> 30 days) complications occurred in 8.7% (6/69; 7/79 ureters), 9.1% (6/66), 9.8% (6/61), and 33% (20/60) of cats, respectively; most of these complications were minor and associated with intermittent dysuria or the need for ureteral stent exchange. The perioperative mortality rate was 7.5% (5/69), and no deaths were procedure related. The median survival time was 498 days (range, 2 to > 1,278 days). For patients with a renal cause of death, median survival time was > 1,262 days, with only 14 of 66 cats (21%) dying of chronic kidney disease. Nineteen (27%) cats needed a stent exchange (stricture in-growth [n = 10], migration , ureteritis , dysuria , pyelonephritis , or reflux ). No patient died of the procedure or recurrent ureteral obstruction.
Conclusions and Clinical Relevance—Results of the present study indicated that ureteral stenting is an effective treatment for benign ureteral obstructions in cats regardless of obstructive location, cause, or stone number. The perioperative morbidity and mortality rates were lower than those reported with traditional ureteral surgery. The short- and long-term complications were typically minor but may necessitate stent exchange or use of an alternative device, particularly with ureteral strictures. The prognosis for feline ureteral obstructions after ureteral stenting could be considered good when the procedure is performed by trained specialists.
Objective—To describe the technical aspects and clinical outcome of endoscopic- and fluoroscopic-guided ureteropelvic lavage and ureteral stent placement for treatment of obstructive pyonephrosis in dogs.
Procedures—All patients with obstructive pyonephrosis were treated with a ureteral stent. Medical records were reviewed for history, clinical signs, pre- and postprocedural clinical and imaging data, and short- and long-term outcomes.
Results—13 dogs (14 ureters) had unilateral or bilateral ureteral obstructions and pyonephrosis due to ureterolithiasis (n = 13) or a suspected ureteral stricture (1). Eleven dogs had positive results of bacteriologic culture of urine obtained from the bladder, renal pelvis, or both. Ten were thrombocytopenic, and 8 were azotemic. Stents were placed fluoroscopically with endoscopic (n = 11) or surgical (3) assistance. Median hospitalization time was 48 hours (range, 6 to 260 hours). Median follow-up time was 480 days (range, 2 to 1,460 days). Intraoperative complications occurred in 2 patients (stent occlusion from shearing of a guide wire, and wire penetration of the ureter at the location of a stone). Short-term complications included a bladder hematoma (n = 1) and transient dysuria (1). Long-term complications included stent encrustation (n = 1), stent migration (1), and tissue proliferation at the ureterovesicular junction (5), which had no clinical implications. Recurrent urinary tract infections were documented in 7 dogs.
Conclusions and Clinical Relevance—Ureteral stenting was a successful renal-sparing treatment for obstructive pyonephrosis in dogs and could often be performed in a minimally invasive manner. There were few major complications. This technique may be considered as an effective treatment option for this condition in dogs.
A 5-year-old 11.5-kg (25.3-lb) castrated male Boston Terrier (dog 1), an 8-year-old 27.8-kg (61.2-lb) castrated male Boxer (dog 2), and a 10.5-year-old 15.9-kg (35.0-lb) spayed female Pembroke Welsh Corgi (dog 3) were evaluated because of severe, gross hematuria and suspected idiopathic renal hematuria.
All 3 dogs had hematuria, anemia, blood clots in their urinary bladders, and unremarkable findings on coagulation and mucosal bleeding time assessments. With cystourethroscopy, lower urinary tract hemorrhage originating from a small lesion in the urinary bladder (n = 2) or urethra (1) and normal-appearing yellow urine jetting from both ureterovesicular junctions were visualized in each dog.
TREATMENT AND OUTCOME
Cystoscopically guided surgical resection of a hemorrhagic lesion of the urinary bladder was performed on dog 1, and histologic evaluation of the resected tissue confirmed urinary bladder telangiectasia. Dogs 2 and 3 each underwent cystourethroscopically guided laser ablation of a hemorrhagic lesion (presumptively diagnosed as hemangioma, angioma, or telangiectasia) in the urinary bladder (dog 2) or urethra (dog 3). The longest follow-up duration was 7 years, and none of the 3 dogs had subsequent recurrence of gross hematuria.
Findings suggested that cystourethroscopy should be considered part of the diagnostic plan for hematuria in dogs before pursuing major surgical treatment or when results of conventional diagnostic procedures do not indicate the underlying cause. In addition, histologic results for dog 1 indicated urinary bladder telangiectasia, previously an unreported cause of severe, chronic lower urinary tract hematuria in dogs.
Objective—To describe the procedure and clinical usefulness of locking-loop pigtail nephrostomy catheter (PNC) placement in dogs and cats.
Design—Retrospective case series.
Animals—16 cats (18 kidneys) and 4 dogs (4 kidneys) that underwent PNC placement.
Procedures—Medical records of patients that underwent PNC placement were reviewed. The PNCs were placed percutaneously with ultrasonographic and fluoroscopic guidance or via a ventral midline laparotomy with fluoroscopic guidance. Either a modified Seldinger technique or a 1-stab trocar introduction technique was used for PNC placement. Preoperative renal pelvic size, postoperative renal pelvic decompression, catheter patency, serum biochemical changes, and results of microbial culture of urine samples were reviewed. Length of time the catheter was in place, reason and method for catheter removal, complications, and clinical outcomes were noted.
Results—Reasons for PNC placement were ureterolithiasis (15 kidneys), ureteral stricture (3), malignant obstruction (2), and percutaneous nephrolithotomy (2). Seven of 22 catheters were placed percutaneously, and 15 were placed via a ventral midline laparotomy. Catheters were either size 5F (n = 17) or 6F (5). The PNCs remained indwelling for a median of 7 days (range, 1 to 28 days). Catheter-associated complications included urine leakage (n = 1) and accidental dislodgement by the patient at home (1). All catheters performed successfully by providing temporary urine diversion and drainage for successful renal pelvis decompression.
Conclusions and Clinical Relevance—Placement of locking-loop PNCs was safe, effective, and well tolerated in dogs and cats for temporary urine diversion to achieve renal pelvis decompression.
Objective—To describe use of transurethral cystoscope–guided laser lithotripsy for fragmentation of cystic and urethral uroliths and determine procedure duration and short-term and long-term outcome in dogs.
Design—Retrospective case series.
Animals—73 dogs with naturally occurring uroliths in the urinary bladder, urethra, or both.
Procedures—Transurethral cystoscope–guided laser lithotripsy was performed in all dogs, and medical records were reviewed for short-term and long-term outcome and complications.
Results—Laser lithotripsy resulted in complete fragmentation of all uroliths in all 28 female dogs and a majority of male dogs (39/45 [86.7%]). Dogs with urethroliths had shorter median laser time than dogs with cystic uroliths. Basket extraction and voiding urohydro-propulsion were successful for removal of the urolith fragments following laser lithotripsy. Complications related to cystoscope-guided laser lithotripsy occurred in 5 of 28 (17.9%) female dogs and 6 of 45 (13.3%) male dogs.
Conclusions and Clinical Relevance—Transurethral cystoscope–guided laser lithotripsy was successful in female dogs and most male dogs for fragmentation of cystic and urethral uroliths. Short-term complications were most commonly related to urethral swelling and resolved with placement of an indwelling urinary catheter. There were no long-term complications.
Case Description—A 5-year-old 8.6-kg (18.9-lb) spayed female Pug was evaluated because of chronic hematuria and recurrent urinary tract infections.
Clinical Findings—Excretory urography, ultrasonography, and excretory CT urography were performed. Results indicated that the dog had bilateral hydronephrosis and hydroureter and suspected proximal ureteral stenosis. Retrograde ureteropyelography confirmed the presence of stenosis at the ureteropelvic junction of each ureter, along with a large amount of endoluminal ureteral debris. Clinical findings suggested that the dog had a congenital bilateral anomaly of the upper urinary tract.
Treatment and Outcome—The dog was anesthetized, and 2 double-pigtail ureteral stents were placed cystoscopically with fluoroscopic guidance for immediate relief of the ureteropelvic junction obstructions. Each stent extended from the left or right renal pelvis to the urinary bladder. The procedures and the patient's recovery from anesthesia were uncomplicated. Continuing improvements in severity of hydronephrosis, hydroureter, and dysuria were evident during routine follow-up examinations at 2, 4, 12, 16, and 45 weeks after stent placement. Over the subsequent 12 months, all clinical signs remained resolved other than a urinary tract infection that was successfully treated with antimicrobials.
Clinical Relevance—Ureteral stenosis should be considered as a differential diagnosis for hydronephrosis in dogs, particularly when urinary tract calculi or neoplasia is not present. Chronic hematuria and recurrent urinary tract infections can be associated with this condition. Placement of ureteral stents may be a successful treatment option for ameliorization of congenital ureteral obstructions.
To describe techniques and outcomes for dogs and cats undergoing endoscopic nephrolithotomy (ENL) for the removal of complicated nephroliths.
11 dogs and 1 cat (n = 16 renal units) with complicated nephroliths that underwent ENL via a surgically assisted ENL approach (12 renal units) or a percutaneous nephrolithotomy approach (4 renal units) between December 2005 and June 2017.
Data were obtained from the medical records regarding preoperative, operative, and postoperative findings. Follow-up information on complications and outcomes was also collected.
Indications for nephrolith removal included massive calculi displacing parenchyma (n = 7), recurrent urinary tract infections (5), and ureteral outflow obstruction (4). Median nephrolith diameter was 2.5 cm (range, 0.5 to 5.7 cm). Nephrolith composition differed among patients; calcium oxalate was the most common type (n = 7 [including 2 mixed nephroliths containing ≥ 60% calcium oxalate]). Following ENL (median duration, 180 minutes), 15 of 16 renal units were completely nephrolith free. Procedure-related complications included renal puncture-associated hemorrhage requiring a blood transfusion (n = 1), renal capsule tear (1), and ureteral puncture (1); all were managed without adverse consequence. Five of 12 patients remained alive at the final follow-up (median, 557 days after ENL), and none died from the procedure.
CONCLUSIONS AND CLINICAL RELEVANCE
ENL as performed was safe and effective in removing complicated nephroliths in a renal-sparing manner for the patients in this study. This procedure requires technical training and could be considered for the treatment of complicated nephrolithiasis in dogs and possibly cats.
Objective—To describe the use of sclerotherapy for the renal-sparing treatment of idiopathic renal hematuria (IRH) in dogs and report clinical outcomes.
Design—Retrospective case series.
Animals—6 dogs (8 renal pelvises) with IRH.
Procedures—Medical records of dogs that underwent sclerotherapy were reviewed. Each ureterovesicular junction was identified cystoscopically to determine the side of bleeding, and a retrograde ureteropyelogram was performed with endoscopic and fluoroscopic guidance. A ureteropelvic junction balloon was used for ureteral occlusion, and pelvis filling volumes were recorded. A povidone iodine mixture, followed by a sterile silver nitrate solution, was infused into the renal pelvis. A double-pigtail ureteral stent was placed after the procedure. Information on preprocedure and postprocedure biochemical changes, imaging parameters, and clinical outcomes was obtained.
Results—6 dogs (5 males and 1 female) had sclerotherapy for unilateral (4) or bilateral (2) bleeding. Five were right-sided and 3 were left-sided. The median age and weight of dogs were 3 years and 42.4 kg (93.28 lb), respectively. Median procedure time was 150 minutes. One dog that did not have a ureteral stent placed following the procedure developed short-term signs of renal pain and pyelectasis. Cessation of macroscopic hematuria occurred in 4 of 6 dogs (median, 6 hours). Two additional dogs improved moderately. Median follow-up time was 8 months (range, 3.5 to 20.5 months).
Conclusions and Clinical Relevance—Topical sclerotherapy for IRH was safe and effective. Local sclerotherapy for IRH in dogs could be considered a valuable and minimally invasive renal-sparing treatment over ureteronephrectomy.