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.

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.

Computed tomographic assessment of retrograde urohydropropulsion in male dogs and prediction of stone composition using Hounsfield unit in dogs and cats

Background

Persistent uroliths after a cystotomy in dogs are a common cause of surgical failure.

Objectives

This study examined the following: the success rate of retrograde urohydropropulsion in male dogs using non-enhanced computed tomography (CT), whether the CT mean beam attenuation values in Hounsfield Units (mHU) measured in vivo could predict the urolithiasis composition and whether the selected reconstruction kernel may influence the measured mHU.

Methods

All dogs and cats that presented with lower urinary tract uroliths and had a non-enhanced CT preceding surgery were included. In male dogs, CT was performed after retrograde urohydropropulsion to detect the remaining urethral calculi. The percentage and location of persistent calculi were recorded. The images were reconstructed using three kernels, from smooth to ultrasharp, and the calculi mHU were measured.

Results

Sixty-five patients were included in the study. The success rate of retrograde urohydropropulsion in the 45 male dogs was 55.6% and 86.7% at the first and second attempts, respectively. The predominant components of the calculi were cystine (20), struvite (15), calcium oxalate (8), and urate (7). The convolution kernel influenced the mHU values (p < 0.05). The difference in mHU regarding the calculus composition was better assessed using the smoother kernel. A mHU greater than 1,000 HU was predictive of calcium oxalate calculi.

Conclusions

Non-enhanced CT is useful for controlling the success of retrograde urohydropropulsion. The mHU could allow a prediction of the calculus composition, particularly for calcium oxalate, which may help determine the therapeutic strategy.

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.

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.

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.

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.

Laparoscopic-Assisted Surgical Procedures

Laparoscopic-assisted procedures allow a balance between the improved patient recoveries often associated with smaller incisions and the need for appropriate visualization of visceral organs/identification of lesions. The organ systems of small animal veterinary patients that are highly amenable to laparoscopic-assisted procedures include the urinary bladder, the gastrointestinal tract, and the reproductive tracts. Laparoscopic-assisted procedures are especially beneficial in the approach to luminal organs, allowing the organ incision to be exteriorized through the body wall, protecting the peritoneal cavity from contamination from luminal contents. Procedure-specific morbidities and patient selection should be considered when choosing between assisted laparoscopic and open approaches.

Urethrotomy of the glans penis in three male dogs with urolithiasis

Three intact male dogs with stranguria and haematuria caused by uroliths in the penile urethra underwent urethrotomy using a novel surgical approach directly over the caudal part of the os penis because conservative procedures to resolve the obstructions had failed. Haemorrhage was minimal, and the incisions healed rapidly by second intention. Complications did not occur during the 6-month follow-up period. Urethrotomy directly over the os penis is straightforward, associated with few complications and holds promise for the removal of urinary calculi in the penile urethra.

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.

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.

Comparison of short-term complication rates between dogs and cats undergoing appositional single-layer or inverting double-layer cystotomy closure: 144 cases (1993-2010)

OBJECTIVE

To compare short-term complication rates in dogs and cats undergoing cystotomy closure by use of an inverting double-layer pattern (group I) versus cystotomy closure by use of an appositional single-layer pattern (group A).

DESIGN

Retrospective case series.

ANIMALS

144 client-owned dogs and cats that underwent cystotomy between 1993 and 2010.

PROCEDURES

Information on signalment, reason for cystotomy, method of cystotomy closure, complications that developed during hospitalization, and duration of hospitalization were obtained from the medical record. The effect of closure technique on short-term complication rate and duration of hospitalization was examined.

RESULTS

2 of the 144 animals developed dehiscence and uroabdomen following cystotomy closure: 1 from group A and 1 from group I. Of group A animals, 29 of 79 (37%) developed minor complications such as hematuria and dysuria. Of group I animals, 33 of 65 (50%) developed the same complications. Group A and group I animals did not differ significantly with regard to prevalence of minor or major complications. The mean duration of hospitalization was 4.1 days and did not differ significantly between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

An appositional single-layer suture pattern for cystotomy closure was a safe and effective procedure with minimal risk of urine leakage and a short-term complication rate of 37%. The appositional single-layer suture pattern for cystotomy closure may be recommended for clinical use because the inverting double-layer suture pattern offered no clear advantage.

Complications of lower urinary tract surgery in small animals

Surgical procedures of the lower urinary tract are commonly performed in small animal practice. Cystotomy for removal of uroliths and urethrostomy diverting urine outflow due to urethral obstruction are the most commonly performed surgical procedures of the bladder and urethra respectively. Surgical procedures of the lower urinary tract are typically associated with few complications, including leakage of urine, loss of luminal diameter (stricture or stenosis), urine outflow obstruction, tissue devitalization, denervation, urinary incontinence, urinary tract infection, and death. Complications can result from inappropriate or inadequate diagnosis, localization, and surgical planning; failure to respect regional anatomy, and other causes.