Pseudomembranous cystitis in cats with presumed or confirmed mineralization: A retrospective study of 26 cases (2016-2021)

BACKGROUND

Pseudomembranous cystitis (PMC) in cats is a recognized disease, but concurrent mineralization is reported rarely and its outcome is poorly described.

HYPOTHESIS AND OBJECTIVES

Describe a population of cats with PMC and the prevalence of concurrent mineralization.

ANIMALS

Twenty-six cats with PMC.

METHODS

Medical records were retrospectively reviewed (January 2016 to December 2021). Cats with an ultrasound diagnosis of PMC were included. Clinicopathologic results, imaging, treatment, and outcome were reviewed.

RESULTS

All cats were male and 21 (80%) were diagnosed with urethral obstruction (UO). Five cats (23.8%) had positive urine culture (Staphylococcus felis, 3/5; Proteus mirabilis, 2/5) with a median urine pH of 8 (range, 6-9). All cats had ultrasonographic changes suggestive of mineralization. On ultrasound examination, 10 cats (38.5%) had pseudomembranes with acoustic shadowing suggestive of mineralization, 15 (57.7%) had changes indicative of ulceration, and 8 (31%) had changes compatible with of a urachal anomaly. Twenty-two cats received medical treatment, 4 underwent surgery (3 percutaneous cystolithotomy, 1 cystotomy). Twenty cats (77%) survived to discharge. Follow-up ultrasound examination indicated resolution of PMC in 6/7 cats, 4 had persistent hyperechoic bladder lining. Five of 12 cats with follow-up had a relapse of lower urinary tract signs.

CONCLUSIONS AND CLINICAL IMPORTANCE

Pseudomembranous cystitis was diagnosed mainly in male cats with UO and imaging findings suggestive of mineralization were present in all cases. Frequent negative urine culture suggests a different etiology than encrusting cystitis related to urease-positive bacteria. Good outcomes can be achieved with medical management.

Retrospective comparison of modified percutaneous cystolithotomy (PCCLm) and traditional open cystotomy (OC) in dogs: 218 cases (2010-2019)

OBJECTIVE

To compare short- and long-term clinical variables between dogs undergoing a modified percutaneous cystolithotomy (PCCLm) and open cystotomy (OC) and evaluate for risk factors associated with complications and outcomes within the groups.

STUDY DESIGN

Retrospective study.

ANIMALS

A total of 218 dogs.

METHODS

Records were reviewed for dogs that underwent PCCLm or OC between January 2010 and December 2019. Signalment; history and diagnostic findings; procedural, anesthetic, and hospitalized care data; complications; urolith recurrence; and follow-up were recorded. Logistic regression analysis was used to evaluate effects of clinical variables on outcomes within PCCLm and OC groups and to identify significant categorical variables between PCCLm and OC groups. Two sample t-tests were used to identify significant numerical variables between PCCLm and OC groups.

RESULTS

A total of 60.1% (131/218) of dogs underwent the PCCLm procedure and 39.9% (87/218) of dogs underwent the OC procedure. Anesthesia time (p < .001) was significantly longer in the OC group. No significant difference in incomplete urolith removal was noted between groups. Although surgical site infection and inflammation rates were not significantly different between OC and PCCLm groups, incisional infections were significantly associated with complications occurring during PCCLm (p = .027). Significantly reduced postoperative lower urinary tract signs (p = .022) were noted in the PCCLm group.

CONCLUSION

The PCCLm may result in reduced lower urinary tract signs postoperatively compared to OC, but other clear advantages of the PCCLm were not identified in this study.

CLINICAL SIGNIFICANCE

PCCLm procedures are an effective alternative to OC for urolith removal in dogs.

Retrospective comparison of open vs minimally invasive cystotomy in 28 cats using a composite outcome score

OBJECTIVES

The aim of this study was to compare the outcomes of cats undergoing open cystotomy with those undergoing minimally invasive surgery (MIS) for removal of cystic calculi by use of a composite outcome score.

METHODS

Twenty-eight cats were retrospectively enrolled and divided into two groups: open cystotomy (n = 14) and MIS (n = 14). The primary outcome measure was a composite outcome score, including three variables: pain scores ⩾2 at either 6 or 12 h postoperatively; failure to remove all stones as determined by postoperative radiographs; and postoperative complications requiring a visit to the hospital separate from the planned suture removal appointment. Other data collected included signalment, history, other procedures performed during anesthesia, willingness to eat the day after surgery and the financial cost of the procedures.

RESULTS

There was no significant difference in age, weight, sex or breed between the two groups. The risk of experiencing the composite outcome was 3/14 (21.4%) in the MIS group and 10/14 (71%) in the open procedure group (P = 0.02). The cats in the open surgery group had 8.3 times greater odds of developing the composite outcome than cats in the MIS group (odds ratio 8.3, 95% confidence interval 1.3-74.4; P = 0.02). In the MIS group, 10/14 cats were eating the day after surgery vs 3/14 in the open procedure group (P = 0.02). The procedural cost was higher in the MIS group, with a median cost of US$945 (interquartile range [IQR] US$872-1021) vs US$623 (IQR US$595-679) in the open group (P <0.01).

CONCLUSIONS AND RELEVANCE

In this study the composite outcome score provided evidence to support the use of MIS techniques in cats with cystic calculi. The composite outcome score should be considered in future veterinary studies as a promising method of assessing clinically relevant outcomes.

Bladder wall adhesion causing a vesicular septum in a dog following surgical cystotomy

CASE DESCRIPTION

An 8-year-old spayed female Yorkshire Terrier-Poodle dog was evaluated for persistent pollakiuria and stranguria following routine cystotomy for calcium oxalate cystoliths.

CLINICAL FINDINGS

The dog presented for a cystotomy with intermittent hematuria. Postoperative radiographs revealed no remaining cystoliths. Urine, cystolith, and bladder mucosal aerobic cultures were negative. Pollakiuria, stranguria, and hematuria developed immediately after surgery and persisted despite antibiotics. Ultrasound revealed suspected fibrous adhesions within the urinary bladder lumen connecting the dorsal and ventral bladder wall creating a septum. This was confirmed cystoscopically 4 weeks after surgery.

TREATMENT AND OUTCOME

Cystoscopic-guided laser ablation was performed to incise abnormal tissue connecting the ventral and dorsal bladder wall using a holmium:yttrium-aluminum-garnet laser. Three weeks later, ultrasound revealed adhesion resolution though mild pollakiuria and stranguria persisted. Oxybutynin was prescribed and clinical signs resolved. At 27 months after ablation, hematuria occurred with recurrent cystoliths. These cystoliths were removed by percutaneous cystolithotomy, documenting a cystoscopically normal bladder wall. The patient had normal urination for 55.5 months after ablation, with normal bladder wall thickness on ultrasound repeated at 27 and 36 months after ablation.

CLINICAL RELEVANCE

To the authors' knowledge, an adhesion creating a septum between the dorsal and ventral bladder wall has not been previously reported as a complication after cystotomy in any species and should be considered as a cause of persistent lower urinary signs after surgery. Ultrasound identified the lesion in this dog. Because bladder abnormalities can develop quickly after surgery, ultrasound might be considered if urine testing is not supportive of infection. Cystoscopic-guided laser ablation was a successful minimally invasive treatment in this case.

Comparison of percutaneous cystolithotomy and open cystotomy for removal of urethral and bladder uroliths in dogs: Retrospective study of 81 cases (2014-2018)

OBJECTIVE

Compare percutaneous cystolithotomy (PCCL) and open cystotomy (OC) for removal of bladder and urethral uroliths.

DESIGN

Retrospective study.

ANIMALS

Client-owned dogs and cats that underwent PCCL (n = 41) or OC (n = 40) between January 1, 2014 and February 28, 2018 at a referral center.

METHODS

Medical records of dogs and cats that underwent a PCCL or an OC were reviewed. History, signalment, physical examination, diagnostic tests, length of the procedure and anesthesia, complications, and duration of hospitalization were recorded.

RESULTS

A total 17 cats (PCCL = 10; OC = 7) and 64 dogs (PCCL = 31; OC = 33) were included. There was no significant difference, regardless of species, in the mean surgical time (45 min [24-160 min] and 48.5 min [15-122 min] with P = .54 in dogs, P = .65 in cats) nor mean duration of anesthesia (90 min [50-120 min] and 98 min [54-223 min] with P = .87 in dogs, P = .08 in cats) in the PCCL and OC groups respectively. Number of uroliths did not affect duration of surgery in either group. Complete urolith removal was achieved in 98% of dogs and cats in both groups. The median hospitalization time was significantly shorter in the PCCL group for dogs (11.3 hours [range 4 to 51.3] in the PCCL vs 56.6 hours [range 7.3 to 96] in the OC group; P < .001) but did not differ for cats (24.5 hours [range 8.3 to 30] in the PCCL vs 56.6 hours [range 10.1 to 193.2] in the OC group; P = .08).

CONCLUSION AND CLINICAL RELEVANCE

Bladder urolith removal by PCCL procedure is no longer than OC. Further studies are needed to compare the pain related to procedure between PCCL and OC.

Radiographic features of suspected suture-associated cystic calculi in dogs

This retrospective case series describes the radiographic features of suspected suture-associated cystic calculi in six dogs with a history of at least one or multiple prior cystotomies. One of the dogs presented twice. Suspected suture-associated cystic calculi were multifocal, short, predominantly linear mineral opacities localized in the center of the urinary bladder on abdominal radiographs. One patient (n = 1) presented with multifocal round, pin point, and linear radiopaque calculi. The calculi were all calcium oxalate in composition. On gross examination, the calculi had a hollow center. Six cystotomies used monofilament absorbable suture material (polydioxanone [n = 4] or poliglecaprone 25 [n = 1]) in prior cystotomies. Suture material in two of the cases was unknown. Suspected suture-associated cystic calculi are a rare occurrence in veterinary medicine but should be considered in dogs that have a history of prior cystotomy, hollow core on gross analysis, and radiographic evidence of mineral opaque, predominantly linear, cystic calculi.

Removal of lower urinary tract stones by percutaneous cystolithotomy: 68 cases (2012-2017)

OBJECTIVE

To describe the use and outcome of percutaneous cystolithotomy (PCCL) for removal of urethral and bladder stones in dogs and cats.

STUDY DESIGN

Retrospective case series.

ANIMALS

Sixty-eight client-owned dogs and cats.

METHODS

Records were reviewed and analyzed for dogs and cats that underwent PCCL between January 2012 and December 2017. Signalment, clinical presentation, laboratory and imaging data, procedure time, use of lithotripsy, biopsy, perioperative and immediate postoperative complications, hospitalization times, stone composition, and urine culture results were recorded. Owners were contacted by phone or email 3 weeks after the procedure. Follow-up communications with the owner and referring veterinarian were also recorded.

RESULTS

Seventy percutaneous cystolithotomies were performed in 59 dogs and nine cats. The median duration of the procedure was 95 minutes (45-420), and lithotripsy was required in 3% (2/70) of PCCL. Complications during the procedure were reported in one case. In eighty-three percent of procedures (58/70), animals were discharged within 24 hours postoperative. Twenty-four percent (16/68) of animals had minor complications (lower urinary tract signs), and one dog had a major complication (surgical wound dehiscence) during the 3 weeks after the operation. Long-term follow-up revealed stone recurrence in 21% of cases followed more than a year after the procedure (7/33).

CONCLUSION

Percutaneous cystolithotomy allowed removal of bladder and urethral stones with rapid postoperative recovery and few major perioperative or short-term postoperative complications.

CLINICAL SIGNIFICANCE

Percutaneous cystolithotomy provides an attractive minimally invasive surgical alternative for removal of lower urinary tract stones in small animals.

Outcome of ureteral stent placement for treatment of benign ureteral obstruction in dogs: 44 cases (2010-2013)

OBJECTIVE To describe the technique and short- and long-term outcomes for dogs undergoing double-pigtail ureteral stent placement for treatment of benign ureteral obstruction. DESIGN Retrospective case series. ANIMALS 44 dogs (57 ureters). PROCEDURES Medical records of dogs that underwent ureteral stenting for treatment of benign ureteral obstruction between 2010 and 2013 were reviewed. Signal-ment, history, pertinent diagnostic imaging results, endourologic and post-procedural details, duration of hospitalization, complications, and outcome (short term, 7 to 30 days; long term, > 30 days) were recorded. Ureteral stent placement was performed endoscopically, surgically, or both, with fluoroscopic guidance. RESULTS 57 ureters (44 dogs) underwent stenting because of obstructive ureterolithiasis (n = 48 [84%]), stricture (5 [9%]), or both (4 [7%]). Endoscopic or surgical techniques were successful for stent placement in 45 of 55 and 12 of 12 ureters (34/42 and 10/10 dogs), respectively. Median hospitalization time was 1 day. Median creatinine concentration was 2 mg/dL prior to stenting and 1.3 mg/dL 3 months after the procedure. Urinary tract infections were present in 26 of 44 (59%) dogs prior to stenting and in 11 of 43 dogs (26%) after stenting. One of the 44 (2%) dogs died after undergoing stenting, but the cause of death was not related to the procedure. Median follow-up time was 1,158 days (range, 3 to > 1,555 days), with 30 of 44 dogs alive at the time of last follow-up. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that ureteral stenting may be a viable option for first-line treatment of dogs with benign ureteral obstruction. However, patients should be monitored for urinary tract infection following stenting.

Endoscopic laser-ablation for the treatment of orthotopic and ectopic ureteroceles in dogs: 13 cases (2008-2017)

BACKGROUND

Ureteroceles are a rare condition in dogs in which conventional treatments can result in substantial morbidity. Cystoscopic and fluoroscopic-guided laser ablation (CLA) of ureteroceles can successfully relieve obstruction.

OBJECTIVES

To describe the technique and outcomes of attempting CLA for treatment of ureteroceles in dogs.

ANIMALS

Thirteen client-owned dogs that underwent CLA for treatment of ureteroceles.

METHODS

Retrospective multicentered study. Medical records were reviewed in all dogs that underwent CLA for ureterocele(s). A laser was used to extend the opening of the ureteral orifice (UO) unless surgical conversion was necessary. Data collected included signalment, clinicopathologic data, imaging, procedural findings, complications, and short- and long-term outcome.

RESULTS

Thirteen dogs with 13 ureteroceles associated with 14 UOs resulting in ureteral obstruction were included. One ureterocele extended bilaterally. Treatment was initiated via retrograde cystoscopy (7 females), percutaneous perineal urethrocystoscopy (4 males), or percutaneous antegrade cystoscopy (2 males). Surgical conversion was necessary in 2 males. Ten of 14 (71%) UOs associated with the ureteroceles were ectopic. Thirteen of 14 had stenotic or imperforate UOs. No postoperative complications were noted. Preoperative incontinence or pollakiuria was present in 9 of 13 and 3 of 13 dogs and resolved in 8 of 9 and 3 of 3 dogs, respectively. Follow-up imaging showed resolution of all ureteroceles and improved ureteral/renal pelvic dilatation. Median follow-up time was 27 months (range, 3-96 months).

CONCLUSIONS AND CLINICAL IMPORTANCE

Cystoscopic-guided laser ablation was effective for the treatment of ureteroceles(s) in 11 of 13 dogs.

Interventional Therapies of the Urinary Tract

Minimally invasive interventional therapies are the new standard of care in veterinary medicine. In comparison with standard surgical procedures, they are associated with minimal tissue injury, leading to shorter, smoother recovery and decreasing the perioperative morbidity and mortality. A thorough understanding of the therapeutic options available is essential to properly educate and inform clients. Proper equipment, technical expertise, and experience are essential prerequisites to many of these procedures.

Minimally Invasive Management of Uroliths in Cats and Dogs

Urolithiasis commonly affects cats and dogs. The American College of Veterinary Internal Medicine established guidelines for the treatment of uroliths that reflect modern techniques prioritizing minimally invasive procedures with an emphasis on prevention strategies to limit morbidity and mortality. Extracorporeal shockwave lithotripsy and endoscopic nephrolithotomy constitute some of the minimally invasive treatment modalities available for upper urinary tract uroliths. Cystoscopic-guided basket retrieval, cystoscopic-guided laser lithotripsy, and percutaneous cystolithotomy are minimally invasive options for the management of lower urinary tract uroliths. Following stone removal, prevention strategies are essential to help reduce morbidity and mortality associated with stone recurrence.

ACVIM Small Animal Consensus Recommendations on the Treatment and Prevention of Uroliths in Dogs and Cats

In an age of advancing endoscopic and lithotripsy technologies, the management of urolithiasis poses a unique opportunity to advance compassionate veterinary care, not only for patients with urolithiasis but for those with other urinary diseases as well. The following are consensus-derived, research and experience-supported, patient-centered recommendations for the treatment and prevention of uroliths in dogs and cats utilizing contemporary strategies. Ultimately, we hope that these recommendations will serve as a foundation for ongoing and future clinical research and inspiration for innovative problem solving.

Cystoscopy in dogs and cats

Cystoscopy has become an important and widely available component of the diagnostic evaluation of diseases of the lower urinary tract in dogs and cats. In addition, a large number of cystoscopic guided procedures have been described that can be used to treat disease processes that were previously treatable only with invasive surgical procedures. This article reviews the indications and contraindications for cystoscopy, cystoscopy equipment and techniques for male and female dogs and cats, potential complications associated with cystoscopy, and management options for these complications.

Advances in Urinary Tract Endoscopy

The use of endoscopy in veterinary medicine has become the mainstay of diagnosis and treatment in the subspecialty of small animal urology over the past decade. This subspecialty is termed endourology. With the common incidence of urinary tract obstructions, stones disease, renal disease, and urothelial malignancies, combined with the recognized invasiveness and morbidity associated with traditional surgical techniques, the use of endoscopic-assisted alternatives using interventional endoscopic techniques has become appealing to both owners and clinicians. This article provides a brief overview of some of the most common urologic procedures being performed in veterinary medicine.

Double pigtail ureteral stenting and renal pelvic lavage for renal-sparing treatment of obstructive pyonephrosis in dogs: 13 cases (2008-2012)

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.

DESIGN

Retrospective case series.

ANIMALS

13 client-owned dogs (14 obstructed ureters).

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.

Interventional urology: endourology in small animal veterinary medicine

The use of novel image-guided techniques in veterinary medicine has become more widespread, especially in urologic diseases. With the common incidence of urinary tract obstructions, stones disease, renal disease, and urothelial malignancies, combined with the recognized invasiveness and morbidity associated with traditional surgical techniques, the use of minimally invasive alternatives using interventional radiology and interventional endoscopy techniques has become incredibly appealing to owners and clinicians. This article provides a brief overview of some of the most common procedures done in endourology in veterinary medicine to date, providing as much evidence-based medicine as possible when comparing with traditional surgical alternatives.

Current concepts in minimally invasive surgery of the abdomen

Minimally invasive surgery of the abdomen constitutes an increasingly common and developed set of surgical options in small animal veterinary patients. In addition to established procedures, such as laparoscopic gonadectomy and biopsies, more advanced procedures, such as adrenalectomy, cholecystectomy, cisterna chyli ablation, and lymph node extirpation, are described. Some laparoscopic procedures have been reported using different techniques or approaches, reflecting the field's progression beyond its infancy. Advances in equipment and experience among an ever-growing group of veterinary surgeons are expected to result in progressively more widespread adoption of minimally invasive procedures.

Evaluation of costs and time required for laparoscopic-assisted versus open cystotomy for urinary cystolith removal in dogs: 43 cases (2009-2012)

OBJECTIVE

To compare required time and costs of surgery and hospitalization as well as prevalence of incomplete urinary cystolith removal associated with laparoscopic-assisted cystotomy versus open cystotomy in dogs.

DESIGN

Retrospective case series.

ANIMALS

20 dogs with urolithiasis treated by laparoscopic-assisted cystotomy and 23 dogs treated by open cystotomy.

PROCEDURES

Medical records were reviewed. Surgery cost, hospitalization cost, total cost, surgery time, days in hospital, incomplete cystolith removal, and number of doses of analgesic administered IV after surgery were compared between the laparoscopic-assisted cystotomy and open cystotomy groups. Results-Surgery cost and total cost were significantly higher in the laparoscopic-assisted cystotomy group. Hospitalization cost, days in hospital, and prevalence of incomplete cystolith removal did not differ significantly between groups. Number of doses of analgesic was significantly lower in the laparoscopic-assisted cystotomy group.

CONCLUSIONS AND CLINICAL RELEVANCE

Laparoscopic-assisted cystotomy was more time-consuming and expensive but associated with fewer postoperative doses of injectable analgesics, compared with open cystotomy. Laparoscopic-assisted cystotomy is an acceptable, more expensive, and minimally invasive alternative to open cystotomy for the removal of urinary cystoliths in dogs.

Cystourethroscopy in the cat: What do you need? When do you need it? How do you do it?

PRACTICAL RELEVANCE

Diagnostic and therapeutic cystourethroscopy has become very popular in the diagnosis and treatment of canine lower and upper urinary tract disease in the past 5-7 years. As expertise is expanding, the use of similar techniques in feline patients is growing.

OUTLINE

This is a brief overview of the indications, equipment needed and procedure for performing cystourethroscopy in feline patients. The principal focus is normal feline lower urinary tract anatomy. Some examples of abnormalities that might be seen are also provided, and therapeutic cystourethroscopy is touched upon.

New techniques on the horizon

Practical relevance:

Interventional radiology and interventional endoscopy (IR/IE) uses contemporary imaging modalities, such as fluoroscopy and endoscopy, to perform diagnostic and therapeutic procedures in various body parts. The majority of IR/IE procedures currently undertaken in veterinary medicine pertain to the urinary tract, and this subspecialty has been termed ‘endourology’. This technology treats diseases of the renal pelvis, ureter(s), bladder and urethra. In human medicine, endourology has overtaken traditional open urologic surgery in the past 20–30 years, and in veterinary medicine similar progress is occurring.

Aim:

This article presents a brief overview of some of the more common IR/IE procedures currently being performed for the treatment of urinary tract disease in veterinary patients. These techniques include percutaneous nephrolithotomy for lithotripsy of problematic nephrolithiasis, mesenchymal stem cell therapy for chronic kidney disease, sclerotherapy for the treatment of idiopathic renal hematuria, various diversion techniques for ureteral obstructions, laser lithotripsy for lower urinary tract stone disease, percutaneous cystolithotomy for removal of bladder stones, hydraulic occluder placement for refractory urinary incontinence, percutaneous cystostomy tube placement for bladder diversion, urethral stenting for benign and malignant urethral obstructions, and antegrade urethral catheterization for treatment of urethral tears.

Evidence base:

The majority of the data presented in this article is solely the experience of the author, and some of this has only been published and/or presented in abstract form or small case series. For information on traditional surgical approaches to these ailments readers are encouraged to evaluate other sources.