Comparison of ultrasonographic and radiographic measurements of bladder dimensions and volume determinations

The purpose of this study was to compare the linear dimensions of the bladder measured by ultrasonographic and radiographic methods and the accuracy of these methods for evaluation of bladder volume. Forty dogs were included in this study. Each dog was placed in right lateral recumbency and a plain lateral caudal abdominal radiograph was made. The bladder length and depth were measured in centimetres from the radiograph, taking into account magnification errors. Immediately after radiography was completed, ultrasonographic measurements of bladder length and depth on longitudinal section were measured in centimetres. The bladder was then emptied by catheterisation and the actual urine volume measured. 'Best subsets' analysis indicated that radiographic and ultrasonographic bladder lengths were the best predictors of actual bladder volume. Formulae were derived from radiographic and ultrasonographic bladder dimensions for estimating bladder volume. The formula using radiographic measurements was found to be a better predictor of actual bladder volume than the formula derived from ultrasonographic measurements, since it had higher F and lower error mean square values.     

Postpartum partial cystectomy through the vagina in a mare with everted partially necrotic bladder.

The bladder of a 750-kg Clydesdale mare had everted through the urethra into the vagina immediately after parturition. The bladder was reinverted into the peritoneal cavity by an attending veterinarian, but 4 days later, the bladder was everted again in the vagina. The mare was able to void urine through both ureters, which could be seen in the mucosal surface of the bladder. The everted bladder had become edematous and could not be reinverted through the urethra. A considerable portion of the fundus was necrotic. The mare was administered xylazine epidurally to induce perineal analgesia, and the necrotic portion of the bladder was resected and healthy bladder tissue was opposed with a double layer of simple continuous sutures. The urethral sphincter was longitudinally incised through the vaginal mucosa to allow reinversion of the bladder through the urethra. A purse-string suture inserted in the urethral opening decreased the urethral diameter and prevented recurrence of the condition. An inflated Foley catheter was maintained in the bladder for 5 days. The mare recovered normal urination after the catheter was removed.     

ESTIMATION OF BLADDER VOLUME USING ULTRASONOGRAPHIC DETERMINATION OF CROSS-SECTIONAL AREAS AND LINEAR MEASUREMENTS

The purpose of this study was to determine if ultrasonographic measurement of multiple cross-sectional areas combined with linear dimensions of the bladder could be used as a method of estimating bladder volume in the dog, and, if so, to compare the accuracy of this estimation with that described previously using linear measurements alone. Fifty-two live dogs undergoing investigation for urological disease and 37 fresh canine cadavers were used for bladder volume determination. Maximal length, depth, width, and area were measured from the maximal longitudinal and transverse sonograms in each living animal. In cadavers, the cross-sectional area of the longitudinal section of the bladder was measured at one centimeter intervals, and the measurements were summed. Based on sequential partial regression analysis, the cross-sectional area of the longitudinal section of the bladder and length were the best predictors of actual bladder volume in living animals. However, based on the cadaver experiment, the best predictor of actual bladder volume was summed parasagittal area alone, and, in cadavers, this was a much better predictor of actual bladder volume than the combination of the cross-sectional area of the longitudinal section of the bladder and length. The formula derived in living dogs using the corss-sectional area of the longitudinal section of the bladder and length gave a less accurate estimation of bladder volume than a previously published formula where only linear measurements were used.     

USE OF CONE‐BEAM COMPUTED TOMOGRAPHY TO CHARACTERIZE DAILY URINARY BLADDER VARIATIONS DURING FRACTIONATED RADIOTHERAPY FOR CANINE BLADDER CANCER

Urinary bladder cancer is difficult to treat accurately with fractionated radiation therapy (RT) due to daily positional changes of the bladder and surrounding soft‐tissue structures. We quantified the daily motion experienced by the canine bladder with patients in dorsal vs. sternal vs. lateral recumbency. We also described the dose distribution for three different planning target volume expansions (5, 10, and 15 mm) for each of the three positions to ensure adequate bladder dose and minimize irradiation of nearby healthy tissues. Analysis was based on data from retrospective daily cone‐beam computed tomography (CT) (CBCT) images obtained for positioning of canine patients undergoing routine RT. Organs of interest were contoured on each CBCT data set and the images, along with the contours, were registered to the original planning CT. All measurements were made relative to the planning CT and dosimetric data for the organs of interest was determined using a dose volume histogram generated from sample parallel‐opposed beam configuration. There was a wide range in bladder position throughout treatment. The least amount of bladder variation and the lowest rectal dose was with dogs in lateral recumbency. It was also determined that a margin of 10 mm would allow for sufficient dose to be delivered to the bladder while minimizing rectal dose.     

CONTRAST CYSTOGRAPHY IN THE GOAT (Capra hircus)

Contrast cystography was performed by four different methods in 24 normal adult goats. Methods included pneumocystography, positive-contrast cystography, and double-and triple-contrast cystography. Sodium iothalamate and air were used as positive- and negative-contrast media. Amputation of urethral process in male goats was necessary for retrograde catheterization and complete evacuation of the bladder. Placement of the catheter tip beyond the neck of the bladder was not possible in male goats. Positive- and negative-contrast cystography were satisfactory for demonstration of the shape, size, and location of the bladder, while double- and triple-contrast cystography were better for visualization of bladder wall. Double-contrast cystography with pneu-moperitoneum was superior to double-contrast cystography alone for evaluation of the mucosal surface of the bladder. Complications were not encountered during or after cystography. Vesi-coureteral reflux was seen in 29% of the goats.     

THE USE OF COMPUTED TOMOGRAPHY FOR ASSESSMENT OF THE SWIM BLADDER IN KOI CARP (CYPRINUS CARPIO)

Seven normal koi (Cyprinus carpio) and seven koi with negative buoyancy were examined using computed tomography (CT) to assess the swim bladder. The volume of the swim bladder was calculated in all animals. In the healthy koi there was a statistical correlation (r=0.996) between body mass and swim bladder volume with volume (ml) being related to body mass according to the formula 4.9+0.054 × BM (g). In all koi with buoyancy problems, the gas volume of the swim bladder was reduced. Additionally, fluid was found within the swim bladder in three of the abnormal koi. CT proved to be a quick noninvasive technique for the examination of the swim bladder in koi.     

Evaluation of associations between lifetime exposure to drinking water disinfection by-products and bladder cancer in dogs

OBJECTIVE: To assess the risk of bladder cancer in dogs from exposure to drinking water disinfection by-products and determine whether dogs could serve as sentinels for human bladder cancer associated with such exposures. DESIGN: Case-control study. ANIMALS: 100 dogs with cancer of the urinary bladder and 100 control dogs. PROCEDURES: Case and control dogs were frequency-matched by age (within 2 years) and sex. Owners of dogs enrolled provided verbal informed consent and were interviewed by telephone. The telephone questionnaire included a complete residence history for each dog. Each dog's total exposure history to trihalomethanes was reconstructed from its residence history and corresponding drinking water utility company data. RESULTS: No association was detected between increasing years of exposure to chlorinated drinking water and risk of bladder cancer. Dogs with bladder cancer were exposed to higher total trihalomethanes concentrations than control dogs; however, the difference was not significant. CONCLUSIONS AND CLINICAL RELEVANCE: Although humans and their dogs live in the same household, the activity patterns of dogs may lead to lower exposures to household tap water. Thus, although exposure to disinfection by-products in tap water may be a risk factor for human bladder cancer, this may not be true for canine bladder cancer at the concentrations at which dogs are exposed.     

Cystosonographic measurements of canine bladder tumours

The purpose of this study was to evaluate the variability of cystosonographic bladder tumor measurements with both operator and bladder volume changes. Ten dogs with bladder tumors were included. In each dog, three operators determined tumor dimensions for three different bladder volumes. Intraclass correlation coefficient was used to assess operator reliability. Response Evaluation Criteria in Solid Tumors (RECIST) and greater than or equal to 50% differences in tumor measurements were used as guidelines. Poor to fair correlations between operators were found for the different tumor dimensions (r_I = 0.4 – 0.7). The percent differences in tumor dimensions with operator and bladder volume changes were significant enough to misclassify the tumors into the categories of partial response (PR) or progressive disease (PD). These results suggest that cystosonographic measurements of bladder tumors are affected by both changes in operator and bladder volume, and the discrepancies are significant enough to change response classification.     

Estimation of the volume of the gall bladder of 32 dogs from linear ultrasonographic measurements

The maximum length and depth of the longitudinal section, and the maximum width and depth of the transverse section of the gall bladders of 32 dog cadavers were measured ultrasonographically; the contents of the gall bladder were then aspirated and its actual volume measured. The volume of the gall bladder was estimated from the ultrasonographic measurements by using formulae suggested for assessment of the volumes of the urinary bladder in human beings and the gall bladder of dogs, and these formulae were compared with a formula derived from the measurements made in this study. In 21 of the dogs, the measurements were repeated twice so that their reproducibility could be evaluated. All the formulae gave good estimations of the volume of the dogs' gall bladders, but the formula for the human urinary bladder volume was better than the other two. The actual volume of the gall bladder was related to the dogs' bodyweight. There were no significant differences between the repeated measurements of the maximum length and depth of the longitudinal section or the width of the transverse section of the gall bladder, but there were significant variations in the depth of the transverse section.     

Failure to gulp surface air induces swim bladder adenomas in Japanese medaka (Oryzias latipes)

In order to elucidate the effects of swim bladder inflation failure on swim bladder carcinogenesis, we investigated the sequential histopathological changes of swim bladders at 13, 24, 35, and 53 days post-hatch (dph) in medakas with an uninflated swim bladder, which was experimentally induced by denying access to the air–water interface between 0 and 6 dph. The reactive oxygen species (ROS) levels were measured at 24 dph. An uninflated swim bladder was induced in 47.3% of the fish denied access to the air–water interface (the denied group). The total incidence of swim bladder adenoma was 54.1% in the denied group; however, these tumors were observed in all fish with an uninflated swim bladder. In fact, these tumors were observed from 13 dph and onwards. The TBARS levels of the juveniles showed a 2.6-fold increase in fish with an uninflated swim bladder in the denied group compared to that in the control group. It is speculated that swim bladder inflation failure has some effects on the gas gland to produce ROS, leading to DNA damage in the gas glandular epithelium, which develops into swim bladder adenomas. Consequently, it is concluded that denying access to the air-water interface between 0 and 6 dph in medaka is an easy method of inducing swim bladder tumors in a short-term period, and is a useful method for producing tumor-bearing fish.     

Colonic seromuscular augmentation cystoplasty following subtotal cystectomy for treatment of bladder necrosis caused by bladder torsion in a dog

CASE DESCRIPTION: A 5-year-old Labrador Retriever was evaluated because of a 3-day history of lethargy, anorexia, vomiting, stranguria, and anuria after routine ovariohysterectomy. CLINICAL FINDINGS: On initial examination, signs of abdominal pain and enlargement of the urinary bladder were detected. Clinicopathologic abnormalities included leukocytosis, azotemia, and hyperkalemia. Radiography and surgical exploration of the abdomen revealed urinary bladder torsion at the level of the trigone; histologically, there was necrosis of 90% of the organ. TREATMENT AND OUTCOME: After excision of the necrotic wall of the urinary bladder (approx 0.5 cm cranial to the ureteral orifices), the remaining bladder stump was closed with a colonic seromuscular patch. Eleven weeks later, cystoscopy revealed an intramural ureteral stricture, for which treatment included a mucosal apposition neoureterocystostomy. Thirteen months after the first surgery, the dog developed pyelonephritis, which was successfully treated. By 3 months after subtotal cystectomy, the dog's urinary bladder was almost normal in size. Frequency of urination decreased from 3 to 4 urinations/h immediately after surgery to once every 3 hours after 2 months; approximately 4 months after the subtotal cystectomy, urination frequency was considered close to normal. CLINICAL RELEVANCE: Urinary bladder torsion is a surgical emergency in dogs. Ischemia of the urinary bladder wall may result from strangulation of the arterial and venous blood supply and from overdistension. Subtotal resection of the urinary bladder, preserving only the trigone area and the ureteral openings, and colonic seromuscular augmentation can be used to successfully treat urinary bladder torsion in dogs.     

Use of an Endoscopic Suturing Device for Laparoscopic Resection of the Apex of the Bladder and Umbilical Structures in Normal Neonatal Calves

OBJECTIVE: To develop a laparoscopic technique using an endoscopic suturing device for the resection of the apex of the bladder and the umbilical structures in large-animal neonates. Study Design-Experimental study. Animals or Sample Population-Seven healthy male Holstein calves. METHODS: A laparoscopic technique for resection of the apex of the bladder was developed on 2 calf cadavers, then evaluated on 5 anesthetized calves. The calves were positioned in dorsal recumbency, and 4 ventral abdominal portals were used. The umbilical vessels were double-ligated using an endoscopic suturing device and subsequently transected. The apex of the bladder was transected between a row of laparoscopic clips applied near the apex and atraumatic laparoscopic forceps applied distally; then, the edges were apposed using an endoscopic suturing device. The dissected umbilical remnants were removed from the abdomen through a small incision centered at the umbilicus. One month later, the calves were euthanatized and a second-look laparoscopy performed; then, bladders were collected for gross and histologic examination. RESULTS: No major complications occurred during or after surgery. The endoscopic suturing device permitted both effective ligation of the umbilical vessels and closure of the bladder. During second-look laparoscopy, healing of the peritoneal surface of the bladder and umbilical vessels was assessed to be excellent in 4 calves. A focal adhesion of omentum to the bladder suture line was observed in 1 calf. Focal adhesions of the omentum to the umbilical incision site occurred in 2 calves. The bladder mucosa was completely healed at the surgical sites. CONCLUSION AND CLINICAL RELEVANCE: Resection of the apex of the bladder and umbilical vessels in calves can be accomplished laparoscopically using an endoscopic suturing device.     

EFFECTS OF BLADDER DISTENTION ON CANINE AND FELINE RETROGRADE URETHROGRAPHY

Retrograde urethrography with viscous contrast medium was performed in male and female dogs and cats before and after bladder distention. The viscosity of commercially prepared contrast medium was increased by addition of an aqueous lubricant. The diameter of the proximal urethra of female dogs (regions 1 and 2) was larger during urethrography (p<0.05) following bladder distention. The diameter of regions 1 and 2 of the proximal uretha of female cats in lateral recumbency was larger during urethrography (p<0.05) following bladder distention. The diameter of the distal urethra of female dogs and cats was not significantly different before or after bladder distention. The diameter of the prostatic urethra of male dogs was larger (p<0.003) following bladder distention. The diameter of the membranous and penile urethra of male dogs was not significantly different before or after urinary bladder distention. Similarly, the diameter of the urethral lumen in male cats was not significantly different before or after bladder distention. The increased viscosity of the contrast medium due to the aqueous lubricant failed to distend all areas of the male and female canine and feline urethra maximally during urethrography when the bladder was not distended. On the basis of the results of this study, the authors recommend urinary bladder distention with a lubricant-free positive contrast medium to generate intravesical hydrostatic pressure sufficient to induce urethral distention. The degree of bladder distention should be determined by digital palpation.     

Ventrocaudal cystorrhaphy without urethral sphincterotomy in two broodmares

Two broodmares were diagnosed with rupture of the urinary bladder. One mare revealed abnormalities post partum and the other associated with ante partum uterine torsion. The clinical symptoms included mild abdominal pain, anorexia, decreased urinary volume and increased peritoneal fluid. In one mare, based on the creatinine level of the peritoneal fluid and serum biochemical abnormalities, uroperitoneum was diagnosed. In the other mare, the bladder rupture was found during the celiotomy for surgical repair of uterine torsion that was diagnosed upon rectal examination. Surgery was performed without a urethral sphincterotomy. The vaginal floor was incised in a standing position and the bladder was diverted into the vagina in order to suture the tears located in the ventrocaudal aspect of the bladder. Both mares survived after treatment for uraemia. Bladder rupture, although uncommon, may affect peripartum mares. Approach to the ruptured bladder without urethral sphincterotomy in a standing position should be considered as a choice for surgical repair.     

A technique for resection of invasive tumors involving the trigone area of the bladder in dogs: preliminary results in two dogs

Objective— To describe a surgical technique for resection of the entire bladder neck, including the trigone and proximal urethra in dogs with invasive tumors causing life-threatening urinary tract obstruction.
Study Design— Clinical case reports.
Animals— Dogs (n=2) with bladder tumors.
Methods— Circumferential excision of the bladder neck and proximal urethra with preservation of the neurovascular pedicles was performed to remove a rhabdomyosarcoma (dog 1) and a transitional cell carcinoma (dog 2) involving the trigone and bladder neck that were causing urinary tract obstruction. Reconstruction of the bladder and proximal urethra included bilateral ureteroneocystostomy. Adjuvant chemotherapy was administered postoperatively to both dogs.
Results— Postoperatively, dogs 1 and 2 were continent after 7 and 17 days, respectively, and regained normal urinary function after resolution of a transient pollakiuria. Dog 1 had no evidence of local or regional recurrence; however, a large solitary pulmonary metastatic lesion was diagnosed 8 months later. The dog was euthanatized despite a lack of clinical signs. Dog 2 had at least 1 metastatic lesion in the abdominal wall 6 months later and was euthanatized at 580 days because of renal failure.
Conclusion— En-bloc removal of the bladder neck and proximal urethra with preservation of the dorsal vascular and nervous pedicles, although a technically challenging procedure, can be performed without associated urinary incontinence or bladder wall necrosis.
Clinical Relevance— In dogs with invasive bladder tumors causing life-threatening urinary tract obstruction, resection of the bladder neck and proximal urethra should be considered as a promising surgical alternative to urinary diversion.     

Standing laparoscopic repair of a ruptured urinary bladder in a mature draught horse

Rupture of the urinary bladder, although relatively common in foals, is an infrequent occurrence in adult stallions. Standing laparoscopic repair of a ruptured urinary bladder offers significant advantages over other treatment options, and to date, there are no reports describing this technique in treating adult stallions. This case study details the treatment of a mature draught horse for uroperitoneum secondary to a ruptured urinary bladder. Standing laparoscopic repair of the ruptured bladder was performed. No major post operative complications developed, and the horse has not had any recurrence of problems with the urinary bladder. Successful standing laparoscopic repair in this horse demonstrated the method's viability, which offers superior intraoperative visualisation and access to the bladder, while eliminating the risks of general anaesthesia.     

RADIOGRAPHIC AND ULTRASONOGRAPHIC FINDINGS OF EMPHYSEMATOUS CYSTITIS IN FOUR NONDIABETIC FEMALE DOGS

The urinary bladder of four dogs with emphysematous cystitis was assessed radiographically. Ultrasonography was also performed using a 7.5-MHz microconvex probe in dorsal recumbency and in a standing position. Ultrasonographically there were bright echoes and reverberations typical of gas in all dogs. This was entrapped in the bladder wall as it appeared in the same location in recumbent and standing positions. Bladder size was reduced and bladder content was echogenic in all dogs. In only one out of the four dogs was a gas stripe seen in the bladder on radiographs. Proteus mirabilis was isolated from the urine of all patients. Diabetes was ruled out on the basis of urine and blood analysis. A small amount of gas can be difficult to detect on radiographs. Ultrasonography appears to be a more sensitive technique for detection of gas within the bladder at an early stage of emphysematous cystitis. Prevalence of emphysematous cystitis may be underestimated if only radiographs are made.     

Treatment with a combined cystopexy-colopexy for dysuria and rectal prolapse after bilateral perineal herniorrhaphy in a dog

A 9-year-old castrated male Yorkshire Terrier was evaluated for dysuria and rectal prolapse 2 weeks after bilateral perineal herniorrhaphy. Dysuria was secondary to caudal displacement of the bladder, rather than retroflexion of the bladder. Dysuria and rectal prolapse were associated with disruption of supporting ligaments of the urinary bladder and colon, which may have been caused by tenesmus. Combined cystopexy and colopexy were used successfully to treat the dysuria and rectal prolapse.