Feline ureteral obstructions Part 2: surgical management

Surgical repositioning with omentalisation of an exposed subcutaneous ureteral bypass shunting port in a cat

Case summary

A 9-year-old, spayed, female domestic shorthair cat presented with an open wound approximately 1 cm in size with exposure of the left subcutaneous ureteral bypass (SUB) shunting port that was placed approximately 11 months before presentation. Primary closures were attempted twice before local wound management with omentalisation and repositioning of the port. The exposed port was lavaged topically with a polyhexanide and propylbetaine wound irrigation solution before omentalisation and repositioning, resulting in successful retention of the implant. Five months after revision and omentalisation, there was complete coverage and healing of the wound.

Relevance and novel information

Adequate topical treatment, repositioning and omentalisation could be a successful treatment option for the uncommon complication of SUB shunting port extrusion secondary to resistant local infection originating from the urinary tract.

Recasting the gold standard - part I of II: delineating healthcare options across a continuum of care

AIM

This is the first part of a two-part series on spectrum of care that encourages practitioners to embrace a non-binary approach to healthcare delivery. When care is not framed as all-or-none, either/or or best versus lesser, the provider and client can agree to diagnostic and/or treatment plans that individualize the practice of veterinary medicine. Care is tailored to the patient along a continuum of acceptable options. Care may also be intentionally incremental, with plans to reassess the patient and revise case management as needed.

RELEVANCE

Acknowledgment and ultimately acceptance that patient care journeys can be distinct, yet equitably appropriate, offers providers the flexibility to adapt case management competently and confidently to the patient based upon contextualized circumstances including client needs, wants and expectations for healthcare outcomes. Thinking outside the box to recast the historic gold standard with a continuum of care strategically offers feline practitioners a means by which they can overcome barriers to healthcare delivery.

SERIES OUTLINE

This first article introduces spectrum of care as an appropriate approach to case management and broadens its definition beyond cost of care. Part II explores communication strategies that enhance veterinary professionals' delivery of spectrum of care through open exchange of relationship-centered dialogue.

Factors Affecting the Outcome of Medical Treatment in Cats with Obstructive Ureteral Stones Treated with Tamsulosin: 70 Cases (2018-2022)

Simple Summary

Other than surgical approaches the treatment options for feline ureterolithiasis are limited compared to those of human medicine. After various studies on ureteral muscle relaxation drugs, tamsulosin has been used as a treatment for distal ureteral stones in human medicine. However, the available clinical veterinary data on the efficacy of drugs that relax the ureter are limited. Thus, this study aimed to investigate the factors affecting the outcome of tamsulosin treatment for feline ureterolithiasis. With tamsulosin treatment, the ureteric stone passage was confirmed in 22 out of 70 cats, with a success rate of 31.43%. Negative factors with statistical significance for stone passage in this study were high baseline creatinine levels, female sex, proximal location of stones, and large diameter stones. The results of this study suggest that tamsulosin can be considered for the treatment of ureterolithiasis in cats with small distal ureteral stones. In addition, this study serves as an important reference for determining whether medical treatment of feline ureteral obstruction using tamsulosin can be attempted.

Abstract

The incidence of diseases associated with feline ureteral obstruction is increasing; however, non-surgical treatment options are limited. This study evaluated the outcome of medical treatment in cats with obstructive ureteral stones treated with tamsulosin and identified potential factors predicting spontaneous stone passage. We retrospectively reviewed 70 client-owned cats treated at the Western Referral Animal Medical Center, Seoul, Korea, from 2018 to 2022. All the cats had obstructive ureterolithiasis and were treated using tamsulosin. The baseline characteristics of the cats, stone diameter and location, and stone passage outcomes were analyzed. Stone passage occurred in 22 cats; the remaining 48 cats showed no change in stone locations. Sex, creatinine, and diameter and location of stones were potential risk factors associated with successful stone passage, but age, weight, and side of the stone were not. No serious adverse events related to tamsulosin treatment were observed. This is the first study to identify the risk factors predictive of the spontaneous stone passage of cats with obstructive ureterolithiasis after tamsulosin treatment. Tamsulosin could be an alternative treatment for ureteral obstruction in male cats with smaller distal ureteral stones and low baseline serum creatinine levels. These findings could help develop guidelines for treating feline ureterolithiasis.

Multicenter retrospective evaluation of transmural migration of subcutaneous ureteral bypass devices within the digestive tract in catsone

BACKGROUND

Placement of a subcutaneous ureteral bypass (SUB) device is an effective method to relieve all causes of ureteral obstruction in cats. Complications involving migration within the gastrointestinal tract have been seldomly described.

OBJECTIVES

To characterize transmural migration of SUB devices within the digestive tract in cats.

ANIMALS

Eleven migrated SUB catheters identified in 8 cats between 2017 and 2021.

METHODS

Retrospective review of medical records of cats with a SUB device in which migration into the gastrointestinal tract was identified.

RESULTS

The median time from SUB device placement to implant migration was 928 days (201-2298 days). Seven cats had obstruction of the SUB device and a positive urine culture at diagnosis. The migration was identified by ultrasound in 6/11, pre-operative contrast radiography in 2/2, and only at time of surgery in 3 SUB devices. All cats underwent surgical correction. Four nephrostomy and 7 cystotomy catheters migrated. Migration occurred into the duodenum (3/11), jejunum (7/11), and colon (1/11). SUB devices were removed in 7 cats and replaced in 2 cats, with 1 cat diagnosed with 2 migration events. Gastrointestinal resection and anastomosis were performed in 7/8 cats and an enterotomy in 2 cats. Six cats survived to discharge. The median follow-up time after migration diagnosis was 365 days (range, 0-1114 days) and 2 cats are still alive.

CONCLUSIONS AND CLINICAL IMPORTANCE

Although a rare complication, migration of SUB device should be considered in cats with SUB device obstruction and a positive urine culture.

Feline ureteral obstruction: a case-control study of risk factors (2016-2019)

OBJECTIVES

Ureteral obstruction (UO) in cats causes acute kidney injury and typically requires surgical intervention. Information is required about potentially modifiable risk factors to inform prevention strategies.

METHODS

A case-control study was performed to assess risk factors associated with feline UO. Cases were defined as cats with either of the following: (1) ureteral obstruction (ureteroliths: 13/18; unknown: 5/18) confirmed with pyelography; or (2) a creatinine concentration >140 µmol/l with both UO (ureteroliths: 6/10; blood clots: 3/10; pyonephrosis: 1/10) and pyelectasia ⩾5 mm on abdominal ultra sonography. Controls were defined as cats without evidence of UO on history, physical examination and abdominal ultrasound. Age, sex, breed (domestic shorthair/longhair), diet (predominantly dry, mixed or predominantly moist food), housing (indoors or mixed) and plasma total calcium were evaluated for their association with UO using multivariable logistic regression. A receiver operator characteristic (ROC) curve was created to evaluate the predictive ability of the final model.

RESULTS

In total, 168 cats (28 cases, 140 controls) were included. Age, sex, breed, housing and total calcium were not significantly associated with UO; however, diet was. Compared with cats eating a predominantly moist food diet, cats fed a predominantly dry food diet were 15.9 times more likely to develop a UO (95% confidence interval 2.9-295; P = 0.009). There was no difference in the association between diet and UO in cats fed a mixed diet vs cats fed a predominantly moist food diet (P = 0.25). The area under the ROC curve was 72%.

CONCLUSIONS AND RELEVANCE

Changes in diet formulation could provide a simple and economical method to reduce the risk of UO.

Case Report: Imaging Features and Successful Management of Ureteral Stenosis in a Kitten With Bilateral Atypical Papillary Transitional Mucosal Hyperplasia

A 3-month-old cat weighing 2.62 kg was brought to the VIP Animal Medical Center with vomiting, diarrhea, anorexia, and depression. Laboratory findings confirmed azotemia with elevated blood urea nitrogen (BUN) (168.9 mg/dl) and creatinine (5.9 mg/dl) and symmetric dimethylarginine (SDMA) (86 μg/dl). Abdominal radiography revealed bilateral renomegaly. Ultrasonography revealed bilateral hydronephrosis and left partial and right complete ureteral obstructions with bilateral focal irregular and circumferential thickenings at ureters. Reduction of bilateral renal function was confirmed through excretory urography on computed tomography. The cat underwent subcutaneous ureteral bypass surgery on the left kidney, right nephrectomy, and bilateral ureterectomy. Histopathology of bilateral ureteral irregular and circumferential thickening revealed bilateral atypical papillary transitional mucosal hyperplasia. Three days after surgery, the left hydronephrosis resolved, and azotemia was almost resolved. This is the first report of successful management of ureteral stenosis with congenital papillary transitional mucosal hyperplasia in a kitten using multimodality imaging.

Complications and survival after subcutaneous ureteral bypass device placement in 24 cats: a retrospective study (2016-2019)

OBJECTIVES

The aim of this study was to document survival, complications and risk factors for the development of complications and mortality prior to discharge after placement of a subcutaneous ureteral bypass (SUB) device in cats.

METHODS

The medical records of cats with SUB placement between January 2016 and August 2019 were retrospectively analysed. The development of complications (overall, intraoperative, perioperative, short- and long-term complications) and risk factors for mortality prior to discharge were statistically assessed with univariate binary logistic regression. All variables with a P value ⩽0.10 in the univariate analysis were assessed in a multivariate model. Variables were significant if P <0.05.

RESULTS

Twenty-four cats were included; 12 (50.0%) received a unilateral SUB, 11 (45.8%) a bilateral nephrostomy tube with single cystostomy catheter and the remaining cat (4.2%) two unilateral SUBs. Nearly 80% of the cats developed complications, ranging from mild to fatal, including (partial) SUB obstruction (33.3% of complications), lower urinary tract infection (20.8%), pyelonephritis (20.8%) and sterile cystitis (12.5%). Five cats (20.8%) died prior to discharge. Six cats (25.0%) underwent revision surgery. The overall median survival time (MST) was 274 days (range 1-311 days). Complications were most common in the long-term period (14/16 cats), followed by the short-term (9/18 cats), perioperative (10/23 cats) and intraoperative (4/24 cats) periods. Older cats had an increased risk for developing perioperative complications (P = 0.045) and were less likely to survive to discharge (P = 0.033). An increased haematocrit at presentation was a risk factor for the occurrence of short-term complications (P = 0.03).

CONCLUSIONS AND RELEVANCE

Although complications similar to those previously described were observed, the complication rate was higher and the MST shorter than previously reported in cats undergoing SUB placement. Despite good short-term survival, the development of complications may necessitate regular and intensive control visits. Owners that consider SUB placement should be informed that follow-up can be strenuous and expensive.

Risk factors and clinical relevance of positive urine cultures in cats with subcutaneous ureteral bypass

Background

The objective of the study was to report the incidence and risk factors associated with positive urine bacterial cultures as well as long-term outcome in cats with subcutaneous ureteral bypass (SUB) devices.

Results

Medical records of cats that underwent SUB device placement were retrospectively reviewed. Signalment of the cat, laterality of the ureteral obstruction, surgery, anesthesia and hospitalization duration, bacterial culture results and follow-up data were retrieved.

Thirty-two cats met the inclusion criteria. Four cats (12.5%) had a positive intraoperative culture, with two of them being treated successfully. Ten cats out of 28 (35.7%) were documented with a positive urine culture during follow-up period, with a median time between discharge and identification of the first positive urine culture of 159 days (range 8–703 days). Bacteriuria resolved in 60% of cats (6/10). Escherichia coli was the most common organism, isolated in 4 out of 10 postoperative urine cultures. Overall, subclinical bacteriura was documented for 6 of 32 (18.8%) cats and 5 of 32 (15.6%) cats displayed clinicals signs suggestive of persistent UTI. One cat had subclinical bacteriuria. Three cats died during the follow-up period.

There was a significant difference between negative and positive urine bacterial culture groups in median hospitalization duration (5 days versus 6 days, P = 0.022) and in median body condition score (5/9 versus 4/9, P = 0.03). Cats with a longer hospital stay and with a lower body condition score were more likely to have a positive urine culture during follow-up period.

Conclusions

SUB device placement surgery is associated with complications such as chronic bacteriuria. Bacteriuria in our study resolved with appropriate antibiotic treatment in more than half of cats. Risk factors identified for positive urine culture were a longer hospitalization duration and a decreased body condition score.

Renal pelvic rupture, intrapelvic haematoma and retroperitoneal haemorrhage associated with obstructive ureterolithiasis in a cat

A neutered female cat presented with a 9-day history of hyporexia and depression. The referring veterinarian had identified moderate non-regenerative anaemia, haematuria and suspected unilateral obstructive ureterolithiasis. Subsequent ultrasonography revealed moderate distension of the left renal pelvis with echogenic material, ureteral distension and ureterolithiasis. A partial ureteral obstruction was suspected. After 4 days of medical management, there was further distension of the renal pelvis with well-delineated echogenic material and an accumulation of perinephric fluid. A left nephroureterectomy was performed. Renal pelvic rupture with intrapelvic haematoma and retroperitoneal haemorrhage was confirmed by histopathology. Eighteen months following surgery, the cat remained clinically well with normal renal values.

Postoperative outcomes of 12 cats with ureteral obstruction treated with ureteroneocystostomy

OBJECTIVE

To report complications and long-term outcomes of cats with benign ureteral obstruction treated with ureteroneocystostomy and to determine the effects of double pigtail catheter (DPT) placement on postoperative outcomes.

STUDY DESIGN

Retrospective study.

ANIMALS

Twelve client-owned cats with ureteral urolithiasis treated with ureteroneocystostomy.

METHODS

Records were reviewed for signalment, location of the obstruction, diagnostic tests, surgical technique, perioperative complications, long-term measurements of kidney function, and survival. Cats were divided into two groups; in one group, a DPT was placed at the time of ureteroneocystostomy, and, in the other group, a DPT was not placed at the time of ureteroneocystostomy (NDPT).

RESULTS

A DPT was placed in six of 12 cats. The NDPT group included four cats with temporary catheters and two cats with no catheter. Median creatinine concentration decreased from 10.4 mg/dL (range, 1.6-20.3) to 2.2 mg/dL (range, 1.1-3.6) at the time of discharge (P = .015) in all cats. Two cats in the NDPT group required revision surgery for uroabdomen. Eleven cats were discharged from the hospital. Long-term complications (hematuria, pollakiuria, urinary tract infections) were more common in the DPT group (P = .047). Seven cats were alive a median of 329 days (range, 8-1772) after surgery. Median creatinine concentration was 2.0 mg/dL (range, 0.6-6.4) at a median of 157 days (range, 43-1772) after surgery.

CONCLUSION

Ureteroneocystostomy resulted in acceptable long-term outcomes in 11 of 12 cats. The placement of a DPT did not influence the long-term outcome in this small population.

CLINICAL SIGNIFICANCE

Ureteroneocystostomy with or without intraoperative placement of a DPT should be considered to relieve benign ureteral obstructions in cats.