The Use of Pneumatic Impact Lithotripsy in a Laparoscopic Retrieval Pouch for Removal of Large Cystoliths in Two Female Horses

Two mares, aged 15 and 21 years, were examined because of urinary incontinence, intermittent hematuria, and urine scalding. On admission of both horses, physical parameters were within normal limits and urine scalding of the skin at the ventral perineum was noted. Transrectal palpation and cystoscopy revealed a large type I cystolith (>10 cm) with associated hyperemia and focal ulceration of the bladder mucosa. In horse 1, hemogram, serum biochemical analysis, and renal ultrasound were not performed because of owner finances. In horse 2, results from hematological and serum biochemical analysis were unremarkable and renal ultrasonography did not reveal any abnormalities. Pneumatic impact lithotripsy in a laparoscopic retrieval pouch was performed under cystoscopic guidance after caudal epidural anesthesia, with the horses standing and under sedation. A laparoscopic retrieval device was passed alongside a flexible endoscope into the urinary bladder and the cystolith was manipulated into the pouch. A customized single stainless-steel rod scaler attached to an air compressor was used for fragmentation of the cystolith contained within the retrieval pouch. Lithotripsy time was 42 minutes for horse 1 and 31 minutes for horse 2. Both horses were released from hospital the day of surgery. Both horses were continent and voided normal streams of urine for the duration of the follow-up periods of 27 and 19 months for horse 1 and horse 2, respectively. Pneumatic impact lithotripsy in a laparoscopic retrieval pouch provided a time-efficient and minimally invasive surgical treatment option for removal of large cystoliths in mares.     

Use of laser lithotripsy for fragmentation of uroliths in dogs: 73 cases (2005-2006)

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.     

Holmium:YAG Laser Lithotripsy for Urolithiasis in Horses

Background: Laser lithotripsy has been used as an alternative to surgical removal of uroliths.
Objective: To describe the procedure and efficacy of laser lithotripsy for removal of lower urinary tract uroliths in horses. Additionally, the ultrastructure and the differences in mineralogy and microstructure from 1 successful and 1 unsuccessful laser lithotripsy case are described.
Animals: Six client-owned horses with 7 episodes of naturally occurring urocystoliths, urethroliths, or both.
Methods: Retrospective study of all horses treated between 2006 and 2008 by laser lithotripsy. All horses were sedated followed by laser lithotripsy. Quantitative urolith analysis was performed in all cases. Ultrastructure and microstructure analyses were performed on uroliths from 2 horses.
Results: Procedural success was achieved in 5 of 7 laser lithotripsy procedures. No complications occurred as a result of laser lithotripsy. One horse developed uroabdomen likely as a result of manual lithotrite disruption of the bladder after failure of laser lithotripsy. There were differences in microstructure between 1 urolith that was successfully fragmented by laser lithotripsy and 1 urolith that was resistant to laser fragmentation.
Conclusions and Clinical Importance: Laser lithotripsy is an effective procedure for removal of some urocystoliths, urethroliths, or both in horses.     

Failure of holmium:yttrium-aluminum-garnet laser lithotripsy in two horses with calculi in the urinary bladder

Holmium:yttrium-aluminum-garnet (Ho:YAG) laser lithotripsy was attempted in a mare and a gelding with calculi in the urinary bladder. The procedure was unsuccessful in producing adequate fragmentation of the calculi. In the gelding, pulsed dye laser lithotripsy was subsequently used to fragment the urolith. Manual removal of the urolith via the urethra was performed in the mare.     

Cystic calculus in a mare due to a misplaced uterine glass marble

A 9-year-old Quarter Horse mare was referred for evaluation of continuous oestrus, polyuria and suspected pyometra after a glass marble was placed in the uterus by the owner. Palpation per rectum and transrectal ultrasonography confirmed the presence of a spherical object, but it was not possible to discern whether it was located within the lumen of the uterus or urinary bladder. Thus, an endoscopic examination of both uterus and bladder was carried out and a spherical, spiculated surface urolith was found on the floor of the bladder. The cystic urolith with suspected marble core was removed using a 12-mm specimen retrieval bag with endoscopic guidance. Follow-up with the owner one month after discharge revealed that the mare had not shown any signs of discomfort while urinating nor signs of oestrus.     

Pararectal Cystotomy for Urolith Removal in Nine Horses

Objective: To report outcome of horses after standing pararectal cystotomy for removal of uroliths. Study Design: Case series. Animals: Horses (n=9) with cystic calculi. Methods: Medical records (December 1998–May 2007) of horses with cystic calculi that had standing pararectal cystotomy were reviewed. Signalment; urolith number, size, and type; surgical technique; sedation and analgesia protocols; intra‐ and postoperative complications and outcome were analyzed. Results: Uroliths (mean diameter, 6.37 cm; median, 6 cm; range, 3–10 cm) were removed intact without need for fragmentation. Eight (89%) horses had no complications and 1 horse (11%) developed persistent drainage from the perineal incision and incisional healing was prolonged. The complications resolved after wound revision, and although cystoscopy showed absence of uroliths, the clinical signs associated with cystitis recurred. Conclusions: Cystic calculi can be removed safely in standing horses using a pararectal approach. The procedure was well tolerated and no serious complications were encountered. Clinical Relevance: Pararectal cystotomy allows removal of cystic calculi in standing sedated horses. The technique may offer an economic advantage over approaches that require general anesthesia.     

Parainguinal laparocystotomy for urolith removal in geldings

OBJECTIVE: To describe parainguinal laparocystotomy for urolith removal and to report outcome. STUDY DESIGN: Prospective clinical study. ANIMALS: Ten geldings with uroliths. METHODS: Signalment, number, size, type of uroliths, surgical technique, and complications were recorded. Long-term follow-up was obtained by telephone interviews with the client and/or examination by the referring veterinarian. RESULTS: Cystic calculi, 3-9 cm in diameter, were removed by parainguinal laparocystotomy. Mean surgical time was 59 minutes (range, 40-100 minutes). With this approach, ligation of the pudendal or superficial epigastric vessels was not needed. Serous incisional drainage resolved without treatment in 3 horses and 2 horses developed moderate-to-severe incisional swelling. On long-term follow-up (mean, 52 months; range, 11-82 months) for 9 horses, owners reported no recurrence of clinical signs associated with cystic calculi. CONCLUSIONS: Parainguinal laparotomy represents a satisfactory alternative approach to the apex of the bladder for urolith removal. CLINICAL RELEVANCE: Parainguinal laparocystotomy avoids the pudendal and superficial epigastric blood vessels that are encountered when performing median or paramedian laparocystotomy in geldings. This approach minimizes dead space by avoiding the reflection of the prepuce in paramedian or median approaches.     

Laparoscopic-assisted cystotomy for urolith removal in geldings

OBJECTIVE: To describe a technique for laparoscopic-assisted removal of cystic calculi in geldings and report outcome. STUDY DESIGN: Clinical report. ANIMALS: Four geldings with cystic calculi. METHODS: Laparoscopic-assisted cystotomy and urolith retrieval was performed in 4 anesthetized geldings positioned in dorsal recumbency. With a laparoscope portal located at the umbilicus, the abdomen was insufflated and then the surgical table was tilted (30 degrees head-down position) before an instrumental portal was created parallel and 2-3 cm medial to the left external inguinal ring. Laparoscopic grasping forceps were inserted to grasp the cranial aspect of the bladder and elevate it to the ventral abdominal wall. With the instrumental portal as mid-point, the parainguinal skin incision was longitudinally extended cranial and caudal (approximately 8-10 cm) to accommodate the size of the urolith. The apex of the bladder was exteriorized and sharply incised, the urolith extracted, and after cystotomy closure, the bladder was repositioned. The mini-laparotomy and trocar incisions were closed in layers. RESULTS: There were no intra- or post-operative complications. All horses had minor incisional swelling for 3-4 days. No signs of abdominal or incisional pain were observed. Hematuria and slight stranguria occurred until the 3rd or 4th day. Surgical time (skin incision to skin closure) was 35-40 minutes. On long-term follow-up (up to 12 months) no recurrence of clinical signs associated with cystic calculi occurred. CONCLUSION: Uroliths (6-8 cm diameter) can be removed by laparoscopic-assisted cystotomy in geldings. CLINICAL RELEVANCE: Laparoscopic-assisted cystotomy combines the advantages of the parainguinal laparocystotomy with laparoscopic technique for removal of cystic calculi while avoiding their disadvantages.     

Cystic calculi in two horses

The use of real-time ultrasound for examination of the bladder was a useful diagnostic aid in 2 cases of cystic calculi. The ultrasound procedure revealed that a firm mass palpated per rectum in the bladder of one horse was a calculus. In the other horse, ultrasound revealed additional small uroliths. To remove the uroliths in both horses, laparocystidotomy via a ventral paramedian approach was chosen because it provided the best access to the bladder lumen. The calculi were analyzed by qualitative chemical analysis and quantitative crystallography. Results differed between analysis methods. Crystallography revealed that the mineral composition of both calculi was pure calcium carbonate. Chemical analysis erroneously indicated that the calculi contained phosphate, magnesium, and oxalate.     

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.     

Evaluation of trends in urolith composition in cats: 5,230 cases (1985-2004)

OBJECTIVE: To determine trends in urolith composition in cats. DESIGN: Retrospective case series. SAMPLE POPULATION: 5,230 uroliths. PROCEDURES: The laboratory database for the Gerald V. Ling Urinary Stone Analysis Laboratory was searched for all urolith submissions from cats from 1985 through 2004. Submission forms were reviewed, and each cat's age, sex, breed, and stone location were recorded. RESULTS: Minerals identified included struvite, calcium oxalate, urates, dried solidified blood, apatite, brushite, cystine, silica, potassium magnesium pyrophosphate, xanthine, and newberyite. During the past 20 years, the ratio of calcium oxalate stones to struvite stones increased significantly. When only the last 3 years of the study period were included, the percentage of struvite stones (44%) was higher than the percentage of calcium oxa-late stones (40%). The most common location for both types of uroliths was the bladder. The number of calcium oxalate-containing calculi in the upper portion of the urinary tract increased significantly during the study period. The number of apatite uroliths declined significantly and that of dried solidified blood stones increased significantly, compared with all other stone types. No significant difference in the number of urate stones was detected. CONCLUSIONS AND CLINICAL RELEVANCE: The increasing proportion of calcium oxalate uroliths was in accordance with findings from other studies and could be a result of alterations in cats' diets. However, the decreased percentage of calcium oxalate calculi and increased percentage of struvite calculi observed in the last 3 years may portend a change in the frequency of this type of urolith.     

Comparison of three techniques for the diagnosis of urinary tract infections in dogs with urolithiasis

OBJECTIVES: To identify an appropriate sampling technique(s) to accurately detect the bacteria causing urinary tract infections in dogs with urolithiasis. METHODS: Twenty-one dogs with urolithiasis were included in the study. Three types of samples were taken from each dog. Urine was collected by cystocentesis, and a urinary bladder mucosal biopsy and urolith were retrieved during cystotomy. The samples were then cultured on blood agar and MacConkey's agar to identify the bacteria associated with urinary tract infections. RESULTS: Bacterial urinary tract infection was found in 16 cases (76.19 per cent). The most prevalent bacteria found to cause urinary tract infection were Escherichia coli (n=7), followed by coagulase-positive Staphylococcus species (n=4), Klebsiella pneumoniae (n=2), Pseudomonas aeruginosa (n=2) and Proteus mirabilis (n=1). In the case of a positive urine culture, the same bacteria were also cultured from the urinary bladder mucosal biopsy alone or from both the urinary bladder mucosal biopsy and urolith. However, in the case of a negative urine culture, bacteria were found to be present in the urinary bladder mucosal biopsy or urolith cultures in 23.81 per cent of dogs. The uroliths that gave positive culture results were either infection-induced uroliths composed of struvite and calcium carbonate phosphate, ammonium acid urate only or metabolic uroliths composed of calcium oxalate and calcium phosphate, or calcium phosphate only. All the uroliths that gave negative culture results were metabolic uroliths composed of calcium oxalate and/or calcium phosphate, and uric acid and calcium phosphate. CLINICAL SIGNIFICANCE: When the culture from the urine obtained by cystocentesis is negative, cultures of urinary bladder mucosal biopsy and urolith are recommended in dogs with urolithiasis in order to accurately assess the microbiological status of the urinary tract.     

Removal of cystic calculi using a transinguinal laparoscopic‐assisted technique in two stallions

A 12‐year‐old donkey and a 6‐year‐old Connemara pony, both sexually intact males, were admitted for surgical removal of urinary calculi. Both underwent a laparoscopic‐assisted cystotomy technique to exteriorise the bladder and remove uroliths via the inguinal canal after hemi‐castration. Both surgeries were successful and no complications occurred. This modified technique, which is minimally invasive, may be a safe and efficient way to remove bladder stones from adult stallions.     

Holmium: YAG laser lithotripsy for urolithiasis in dogs

BACKGROUND: Laser lithotripsy has been used as an alternative to surgical removal of uroliths in a number of species. OBJECTIVES: To determine the effectiveness of laser lithotripsy for removing urocystoliths, urethroliths, or both in dogs, and to determine the influence of dog (chronological order of lithotripsy, endoscope type, sex, body weight) and urolith (total urolith and urocystolith number, presence or absence of urethroliths, largest urolith dimension, and urolith composition) factors on outcome. ANIMALS: Twenty-five client-owned dogs with urocystoliths, urethroliths, or both were included. Male dogs were required to weigh > or =6.8 kg. METHODS: A single-arm prospective clinical trial. Laser lithotripsy was performed under general anesthesia. Main outcomes included procedure success and lithotripsy time. Predictors of procedure success and lithotripsy time were selected using logistic and linear regression modeling, respectively. RESULTS: The procedure was successful in 21 of 25 dogs. The procedure was successful more often and in less time in female spayed than in male neutered dogs. Sex was identified as a predictor of success. Univariable analysis showed that sex, endoscope type, and chronological order in which the dog received lithotripsy were significantly associated with lithotripsy time. Stepwise linear regression modeling identified sex, body weight, >10 uroliths, and largest urolith dimension as predictors of lithotripsy time. CONCLUSIONS AND CLINICAL IMPORTANCE: Laser lithotripsy is an effective procedure for the removal of urocystoliths, urethroliths, or both with rare important adverse effects and some limitations in male dogs.     

Ectopic Bone as a Nidus for Calcium Oxalate Urocystolithiasis in a Cat

A 7‐year‐old female spayed domestic shorthair cat was referred to the urology service for nonsurgical urocystolith removal. A urolith was attached to the urothelium by ectopic bone. Interventional removal without surgery was successful. Follow‐up evaluation 3 years after urolith removal revealed recurrent uroliths, bladder wall mineralization, and marked renal mineralization. This case illustrates the metaplastic potential of the urothelium and that ectopic bone should be included among the pathological factors that promote lithogenesis.     

Laser lithotripsy of a urethral calculus via ischial urethrotomy in a steer

A steer examined because of obstructive urolithiasis and urethral rupture underwent laser lithotripsy, using a chromium-thulium-holmium:yttrium-aluminum-garnet (Ho:YAG) laser inserted through an ischial urethrotomy. Procedures were performed with caudal epidural anesthesia. Six months after surgery, the urethra was patent with no clinical evidence of urethral stricture or fistula. Ischial urethrotomy provided rapid access to the bladder for catheterization and to the obstructive urolith for lithotripsy. Laser lithotripsy was a rapid and effective means of urolith removal in this steer.     

Cystinuria in the dog: clinical studies during 14 years of medical treatment

The purpose of this study was to summarize 14 years of clinical experience with medical treatment of 88 cystinuric dogs. Of special interest was evaluation of recurrence rate of cystine uroliths and adverse effects during long-term tiopronin treatment. Twenty-six different breeds were recognized, and the most common breeds were Dachshunds, Tibetan Spaniels, and Basset Hounds. In 76 of 88 treated dogs (86%), re-formation of cystine uroliths was prevented. Recurrence rate of cystine uroliths changed from 7 months before to 18 months during tiopronin treatment. On 28 occasions, bladder stones were found, and in about 60% of the dogs, the uroliths dissolved. Quantitative measurement of the urinary excretion of cystine showed a significantly (P < .03) higher excretion of cystine in dogs with recurrent urolith formation than in dogs with only 1 urolith episode. Another finding was a significant (P = .02) decrease in urinary cystine excretion in older (>5 years) than in younger (<5 years) dogs. Adverse effects were found in 11 dogs, and the most severe signs were aggressiveness and myopathy. All signs disappeared when tiopronin treatment was stopped. In conclusion, this study emphasizes the importance of an individual strategy for lifelong treatment of cystinuria. In addition to increasing water intake, chemical modification of the cysteine molecule into a more soluble form by means of tiopronin is useful. In dogs with re-formed cystine uroliths, dissolution may be induced by increasing the tiopronin dosage to 40 mg/kg body weight per day. In dogs with a low urolith recurrence rate and low urinary cystine excretion, the tiopronin dosage may be decreased or treatment discontinued.     

Modified parainguinal approach for cystic calculus removal in five equids

This report describes a modification of the parainguinal approach for removal of cystic calculi: a ventral midline laparotomy‐guided parainguinal laparocystotomy. The ventral midline approach to the abdomen is rapid and routinely used by equine surgeons. With an arm introduced to the abdomen via the ventral midline, the surgeon is able to select the ideal parainguinal laparotomy incision location that allows bladder exteriorisation with the minimum amount of tension. Because the surgeon's hand is introduced via the ventral midline incision, the parainguinal incision can be sized to just allow exteriorisation of the urinary bladder and urolith, increasing extra‐abdominal bladder security during cystotomy while reducing incision size in the parainguinal region. Finally, an assistant's hand via the ventral midline incision can maintain bladder stability within the parainguinal incision during cystotomy closure.     

Feline urethral plugs and bladder uroliths: a review of 5484 submissions 1998-2003

The results of 5484 submissions from cats to the Canadian Veterinary Urolith Centre between February 1998 and February 2003 are presented. Of the submissions, 618 were urethral plugs and 4866 were bladder uroliths. The majority of the urethral plugs were from male domestic shorthair and longhair cats. Approximately 50% of the urolith submissions were oxalate, 44% were struvite. Oxalate uroliths were the most common mineral type in males and in Himalayan, Persian, and Siamese cats. Struvite uroliths were the most common mineral type in domestic shorthair and longhair cats. Females outnumbered males by 1.4:1 in struvite urolith submissions. A review of risk factors for urethral plugs and bladder uroliths is presented.     

Characterization of the urogenital microbiome in Miniature Schnauzers with and without calcium oxalate urolithiasis

BackgroundCalcium oxalate (CaOx) uroliths are common in dogs. Humans with CaOx urolithiasis exhibit alterations of the urinary and urogenital microbiomes that might mediate urolith formation. Detection of urogenital microbes associated with CaOx in dogs could inform disease pathophysiology.ObjectiveTo identify compositional differences in the urogenital microbiome of Miniature Schnauzers with and without CaOx uroliths.AnimalsNineteen midstream, voided urine samples from Miniature Schnauzers with (n = 9) and without (n = 10) a history of CaOx urolithiasis.MethodsAnalytical cross‐sectional study. Microbial DNA was extracted from previously frozen urine samples and sequenced for the bacterial 16S rRNA V3‐V4 hypervariable regions. Diversity and composition of microbial populations were compared between urolith formers and controls.ResultsAlpha and beta diversity measures were similar between groups. Five individual bacterial taxa differed in abundance (indicator values >0.5 and P < .05): Acinetobacter, 2 Geobacillus variants, and Hydrogenophaga were overrepresented in the urine of urolith formers, and Sphingopyxis was overrepresented in controls. Two distinct subtypes of urine microbial composition were observed based on beta diversity measures, independent of urolith status, and other clinical variables.Conclusions and Clinical ImportanceAlthough we did not detect a difference in the overall urogenital microbial composition between groups, observed differences in individual bacterial taxa might be clinically relevant. For example, Acinetobacter was overrepresented in urolith formers and is associated with CaOx urolithiasis in humans. Two unique clusters of the microbiome were identified, independent of urolith status, which may represent distinct urotypes present in Miniature Schnauzers.