Hand-assisted laparoscopic cystotomy for cystic calculus removal in male horses (3 cases)

A technique for hand-assisted laparoscopic removal of cystic calculi in male horses is described. Three cystic calculi ranging from 5 to 10 cm in diameter were removed successfully using bilateral para-inguinal laparoscopic portals assisted by a human hand within the abdomen, effectively sealing the midline incision. Long-term follow-up information obtained from referring veterinarians and owners indicated that the patients returned to their previous activity level and had no recurrence of clinical signs in the following 6 to 12 months.Key clinical message:Hand-assisted recumbent laparoscopy is a satisfactory surgical technique for removal of cystic calculi in horses which cannot be operated on standing or whose body condition would make the parainguinal approach difficult.     

Use of laparoscopic-assisted cystoscopy for removal of urinary calculi in dogs

Urinary calculi were removed by means of laparoscopic-assisted cystoscopy in 3 dogs. Two small abdominal incisions were made--1 for a laparoscope and 1 for placement of a Babcock forceps to aid in grasping and lifting the urinary bladder to the abdominal wall. A cystoscope and instruments for calculi removal were passed through a small cystotomy. Biopsy of the urinary bladder or other abdominal organs could also be performed by use of this technique. Laparoscopic-assisted cystoscopy was minimally invasive and provided clear images of the mucosal surface of the urinary bladder and proximal portion of the urethra for easy retrieval of urinary calculi. An imaging procedure should be performed to ensure complete removal of calculi.     

CALCIUM OXALATE URETEROLITH IN A CAT

A 4-year-old cat was presented for polyuria and polydipsia. Unilateral hydronephorosis and hydroureter was diagnosed on ultrasound examination of the abdomen, and right ureteral calculi were seen in survey abdominal radiographs. Intravenous urography confirmed hydronephrosis and indicated poor renal funttion in the right kidney. Surgical removal of the ureteral calculus improved right renal function. Analysis of the calculus indicated composition of calcium oxalate, an uncommon calculus in cats.     

Endoscopic-assisted disruption of urinary calculi using a holmium:YAG laser in standing horses

OBJECTIVE: To describe a technique for endoscope-assisted disruption and removal of urinary calculi using a holmium:YAG laser in sedated, standing horses. STUDY DESIGN: Retrospective study. ANIMALS: Six horses with urinary calculi. METHODS: A holmium:YAG laser was used to disrupt naturally occurring urinary calculi in horses (4 geldings, 1 stallion, 1 mare). Ischial urethrotomy was performed in male horses to provide a portal for the endoscope and laser fiber. Calculus fragments were removed by a combination of lavage, transendoscopic basket snare removal, forceps, and digital manipulation. Ischial urethrotomies healed by second intention. Follow-up was obtained by recheck examination and telephone interview of owners. RESULTS: No major operative or postoperative complications occurred. Two calculi (1 stallion and 1 mare) were fragmented by a combination of laser ablation and manual disruption with a lithotrite. Postoperative dysuria occurred in the mare, but resolved after 1 month. Mean (+/- SD) follow-up was 306 +/- 149 days; no other complications were reported. CONCLUSIONS: Calcium carbonate urinary calculi (up to 15 cm in diameter) in horses can be effectively fragmented with a holmium:YAG laser. It is not known if this technique would be completely effective for larger calculi or extremely dense calculi. CLINICAL RELEVANCE: Calculus disruption by an endoscopically assisted holmium:YAG laser offers a minimally invasive method that can be performed in standing horses and that minimizes patient risk.     

Dissolution of a struvite nephrolith in a dog.

A large radiodense calculus in the left renal pelvis of a 22-month-old, male Great Dane disappeared one month following surgical removal of two struvite (magnesium ammonium phosphate) calculi from the right renal pelvis. The dog's urine likely became undersaturated with struvite for a sufficient period to permit dissolution of the renal calculus. Several factors may have contributed to the decrease in urine struvite concentration, including eradication of a urease-producing Proteus sp from the urinary tract and induction of polydipsia and compensatory polyuria by oral administration of sodium chloride.     

Diagnosis and surgical management of ureteral calculi in dogs: 16 cases (1990-2003)

AIMS: To examine the clinical signs, laboratory and radiographic findings, surgical technique, ureterolith composition, and post-operative outcomes in dogs managed surgically for ureterolithiasis to determine whether surgical removal of ureteroliths in dogs resulted in a positive clinical outcome. METHODS: The medical record database of a university veterinary hospital in Pennsylvania, USA, was searched for dogs that underwent surgery to remove obstructive ureteral calculi between 1990 and 2003. Records were reviewed for signalment, clinical history and examination findings, radiographic and laboratory test results, surgical technique, and ureterolith analysis. Follow-up information was obtained from telephone interviews with owners or referring veterinarians, or by reviewing the medical record of subsequent hospital visits. RESULTS: Sixteen dogs were included in this study; ten were neutered females, two intact females and four castrated males. Abdominal radiography revealed ureteral calculi in 14/16 dogs, renal calculi in 8/16, cystic calculi in 8/16, urethral calculi in 1/16, renomegaly in 6/16 and renal mineralisation in 5/16. Ureterolith type included struvite in six dogs, calcium oxalate in five, calcium phosphate in one, and a mix of struvite, calcium phosphate and calcium oxalate in another. Compared to dogs with non-struvite ureteroliths, those with struvite ureteroliths had a higher pre-operative white blood cell (WBC) count (25.6, SD 7 vs 17.6, SD 6 x 103 cells/mul; p=0.046), and were more likely to have a purulent discharge from the ureteral incision noted at the time of surgery (p=0.015). Following discharge, 14/16 dogs were re-evaluated. Median survival time was 904 days (range 2-1,876). Two dogs required additional surgery on the urinary tract. Four dogs died or were euthanised because of azotaemia and clinical signs related to the urinary system or non-specific signs of illness (vomiting, lethargy) at 8, 90, 333 and 904 days post-operatively. CONCLUSIONS: Surgical management of ureteroliths was successful and resulted in good long-term survival in the majority of dogs examined in this small study population. Similar proportions of calcium oxalate and struvite ureteroliths were identified. CLINICAL RELEVANCE: The use of the ureteral surgery may increase as the frequency of diagnosis of ureteroliths in dogs increases.     

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.     

Glucosuria associated with renal calculi in Asian small-clawed otters

Urine from one female and 2 male Asian small-clawed otters (Aonyx cinerea) with bilateral renal calculi, one female with unilateral calculi, and one nonaffected male were evaluated for abnormal urinary crystalloid excretion. One otter with bilateral renal calculi had cystic calculi composed of calcium oxalate monohydrate and dihydrate. The 2 affected males were littermates, as were the 2 affected females, but the 2 litters were from different parents. At the time of the study, the otters did not have clinical signs of disease. Hematologic and serum biochemical, electrolyte, and enzyme values were normal. The urinary excretion of calcium, oxalate, uric acid, phosphate, citrate, and amino acids in otters with renal calculi was similar to that of the nonaffected otter. The 4 otters with renal calculi had glucosuria but the nonaffected otter did not have glucosuria. The glucosuria, in the absence of hyperglycemia, suggested a renal tubular transport defect for glucose. Other renal abnormalities were not found.     

Renal Calculi in Dogs and Cats: Prevalence, Mineral Type, Breed, Age, and Gender Interrelationships (1981–1993)

Three hundred seventeen specimens of urinary calculi of renal origin from 214 female dogs and 103 male dogs, and 71 specimens of urinary calculi of renal origin from 38 female cats and 33 male cats were submitted for mineral analysis between July 1, 1981, and December 31, 1993. Among dogs, 45 breeds were affected with renal calculi. Thirty-three breeds and a crossbred group were represented among females, but 8 breeds and the crossbred group accounted for 81% of the total. Among male dogs, 30 breeds and a crossbred group were represented, but 7 breeds and the crossbred group accounted for 69% of the total. Among cats, 10 breeds and a crossbred group were represented. Dogs and cats with renal calculi were older than those of 2 comparison population groups. More than one-half of the renal calculi in both dogs and cats were from the 1st known episode of urolithiasis. The risk of formation of renal calculi was found to be higher for cats than for dogs, when compared to other stone-forming cats and dogs (approximately 4.95 per 100 stone-forming cats and 2.88 per 100 stone-forming dogs). Among dogs, breeds at highest risk of developing renal calculi were Miniature Schnauzers, Shih Tzus, Lhasa Apsos, Yorkshire Terriers, and female Pugs. Also at high risk were male Dalmatians and male Basset Hounds. Among small dogs, females generally were at higher risk of developing renal calculi than were males. Regardless of size, terrier breed males generally were at higher risk of developing renal calculi. Breeds of dogs at low risk for development of renal calculi included crossbreds, German Shepherd Dogs, Labrador Retrievers, Golden Retrievers, and female Dachshunds. When only 1 kidney was involved, the risk of left renal calculus was greatest for both dogs and cats, but bilateral renal involvement was relatively common in both species (19% and 9%, respectively). Among dogs, specimens composed of 1 mineral substance (eg, struvite) occurred more often in males (58.3%) than in females (37.9%). Female dogs formed renal calculi containing struvite or oxalate more often than did males; males formed calculi containing urate more often than did females. Calculi containing oxalate, apatite, or some combination of these minerals predominated among cats; only 1 specimen from 38 female cats and only 4 specimens from 33 male cats contained neither oxalate nor apatite. Crossbred cats were significantly less likely to have renal calculi than were other breeds. A single renal calculus specimen was identified in several uncommon breeds including Tonkinese and Birman cats, and Affenpinscher, Clumber Spaniel, English Shepherd, and Field Spaniel dogs. No significant differences were observed between male and female dogs or between male and female cats with regard to mineral type of the specimen and the presence of urinary tract infection.     

Renal and ureteral surgery in dogs

Renal and ureteral surgeries are performed commonly in veterinary medicine. Potential surgeries include nephrectomy, nephrotomy, pyelolithotomy, neoureterostomy, and ureteral anastomosis. The most common reason for surgery is the removal of urinary calculi. Before performing surgery, consideration of the patient's renal function is important to obtain optimal results. Maintaining normal urine production in the perioperative and postoperative period is important in most cases. The surgical procedures listed previously are reviewed individually, including postoperative care.     

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.     

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.     

Sonography of the kidney

Sonographic scanning techniques of the kidney are presented. Normal nephrosonographic anatomy is given as a basis for comparison with the sonographic appearance of various renal lesions. The sonographic appearance of renal calculi, hydronephrosis, renal parenchymal and cystic disease, and renal neoplasia is described.     

Management and outcome of cats with ureteral calculi: 153 cases (1984-2002)

OBJECTIVE: To determine outcome of medical and surgical treatment in cats with ureteral calculi. DESIGN: Retrospective study. ANIMALS: 153 cats. PROCEDURE: Medical records were reviewed. Owners and referring veterinarians were contacted for follow-up information. RESULTS: All cats were initially treated medically before a decision was made to perform surgery. Medical treatment included parenteral administration of fluids and diuretics to promote urine production and passage of the ureteral calculus and supportive treatment for renal failure. Ureteral calculi in the proximal portion of the ureter were typically removed by ureterotomy, whereas ureteral calculi in the distal portion of the ureter were more likely to be removed by partial ureterectomy and ureteroneocystostomy. Ureterotomy could be performed without placement of a nephrostomy tube for postoperative urine diversion. Postoperative complication rate and perioperative mortality rate were 31% and 18%, respectively. The most common postoperative complications were urine leakage and persistent ureteral obstruction after surgery. Chronic renal failure was common at the time of diagnosis and continued after treatment, with serum creatinine concentration remaining greater than the upper reference limit in approximately half the cats. Twelve-month survival rates after medical and surgical treatment were 66% and 91%, respectively, with a number of cats dying of causes related to urinary tract disorders, including ureteral calculus recurrence and worsening of chronic renal failure. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that medical and surgical management of ureteral calculi in cats are associated with high morbidity and mortality rates. Treatment can stabilize renal function, although many surviving cats will continue to have impaired renal function.     

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.     

Renal calculi in wild Eurasian otters (Lutra lutra) in England

Macroscopic renal calculi were seen in 50 of 492 (10.2 per cent) wild Eurasian otters found dead in England from 1988 to 2007. Forty-eight adults and two subadults were affected. Calculi were present in 15.7 per cent (31 of 197) of adult males and 12.7 per cent (17 of 134) of adult females. There was an increase in prevalence in the study population over time; no calculi were found in 73 otters examined between 1988 and 1996, but in most subsequent years they were observed with increased frequency. Calculi occurred in both kidneys but were more common in the right kidney. They varied greatly in shape and size; larger calculi were mostly seen in the calyces while the smallest ones were commonly found in the renal medulla. Calculi from 45 cases were examined by x-ray diffraction analysis; in 43 (96 per cent), they were composed solely of ammonium acid urate. Affected otters had heavier adrenal glands relative to their body size than unaffected otters (P<0.001). There was no significant association between body condition index and the presence of calculi (P>0.05). Many otters had fresh bite wounds consistent with intraspecific aggression. The proportion bitten increased over time and this coincided with the increased prevalence of renal calculi.     

Clinical, clinicopathologic, radiographic, and ultrasonographic abnormalities in cats with ureteral calculi: 163 cases (1984-2002)

OBJECTIVE: To determine clinical, clinicopathologic, radiographic, and ultrasonographic abnormalities in cats with ureteral calculi. DESIGN: Retrospective study. ANIMALS: 163 client-owned cats. PROCEDURE: Medical records were reviewed, and information on signalment, history, clinical signs, and results of clinicopathologic testing and diagnostic imaging was obtained. RESULTS: The number of cats in which ureterolithiasis was diagnosed each year increased progressively during the study period. Clinical signs tended to be non-specific and included inappetence, vomiting, lethargy, and weight loss. A combination of survey radiography and abdominal ultrasonography revealed ureteral calculi in 66 of 73 (90%) cats in which the diagnosis was confirmed at surgery or necropsy. Ultrasonography revealed that ureteral calculi were causing ureteral obstruction in 143 of 155 (92%) cats. One hundred thirty-four of 162 (83%) cats had azotemia, 84 of 156 (54%) had hyperphosphatemia, and 22 of 152 (14%) had hypercalcemia. Urinary tract infection was documented in 10 of 119 (8%). Fifty-eight of 76 (76%) cats with unilateral ureterolithiasis had azotemia and 33 (43%) had hyperphosphatemia, indicating impairment of renal function in the contralateral kidney or prerenal azotemia. Ultrasonographic imaging of the contralateral kidney in cats with unilateral ureteral calculi suggested that preexisting renal parenchymal disease was common in cats with ureterolithiasis. Ninety-one of 93 (98%) ureteral calculi contained calcium oxalate. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that abdominal imaging should be performed in all cats with chronic nonspecific signs or with acute or chronic renal failure to rule out ureterolithiasis. Preexisting renal disease may be common in cats with ureteral calculi.     

Parotid Duct Sialolithiasis in Horses

Parotid duct sialolithiasis was diagnosed in four adult mixed-breed mares. Successful surgical removal of the calculi was performed using a percutaneous approach. The salivary calculi were found to contain barley grains in the center, surrounded with mineral layers composed mainly of calcium carbonate and calcium oxalate.     

Urolithiasis in 68 Horses

Medical records of 68 horses with urolithiasis were examined. Calculi were in the bladder in 47 horses, urethra in 11 horses, kidneys in 15 horses, and ureter in two horses. They occurred at several sites in six horses. Common clinical signs included hematuria, altered micturition (pollakiuria, dysuria, urinary incontinence), and tenesmus. Weight loss, possibly attributable to chronic renal failure and colic, was associated more commonly with renal and ureteral calculi. Weight loss also occurred in 13% of horses with cystic calculi only. In male horses, most cystic calculi were removed by perineal (ischial) urethrotomy under epidural anesthesia. Although there were few surgical complications with urethrotomy, seven of 15 horses with follow-up suffered recurrent urolithiasis.