What You Need to Know About Bladder Surgery
Find out the latest on urinary medicine and surgery.
Two bladder stones still present after cystotomy in a pug.
Dr. Phil Zeltzman
Just in case you’re not quite up to speed on reading journals, I’m here to help. Here are summaries of six important recent articles related to urinary medicine and surgery.
Closing the Bladder
Cystotomy incisions are often closed with an inverting double-layer suture pattern to ensure a tight seal. Surgeons at the University of Florida (Thieman et al*) compared the inverting double-layer closure to a single-layer technique. They performed cystotomies on more than 140 patients (120 dogs and 24 cats) for a variety of indications (stones, ectopic ureters, tumors, rupture). About half the patients received an inverting double-layer suture pattern. The other half got a single-layer closing technique, either simple continuous (80 percent) or simple interrupted (20 percent). Various absorbable suture materials are used.
One patient in each group has a uroabdomen following leakage through the incision. Reintervention fixes the leak in both. The authors conclude that there is no need for a double-layer suture pattern to close the bladder. A single-layer appositional technique is recommended.
Benefits include shorter surgery and anesthesia times, less tissue trauma and less suture material left in the patient—along with the financial benefits. Another major benefit is that less suturing should mean less chance of placing suture material inside the bladder lumen, and therefore a lower recurrence rate of bladder stones.
Conclusion: Use a single-layer appositional technique to close cystotomy incisions.
Don’t Forget Bladder Stones
A team from Virginia Tech looked into the frequency of incomplete bladder stone removal. Out of 128 dogs, completeness of stone removal could only be assessed in 44 or one third of dogs (nine of the 44, or 20 percent, had failure). Only 15 percent of patients had appropriate postop imaging. So the actual number of failures may be higher in reality.
Of the dogs who had post-op X-rays, eight of 19 (42 percent) of those with appropriate postop imaging had stones left behind.
Conclusion: These results “emphasize the importance of performing postoperative imaging to verify the completeness of urolith removal.” Post-op X-rays are typically considered standard of care and should not be an option.
When to Give IV Antibiotics
A culture is often taken during a cystotomy. Some colleagues are concerned that giving an IV antibiotic prior to harvesting the culture may negatively alter the results. Board-certified surgeon Nicole Buote* put this concern to the test.
More than 40 dogs underwent a cystotomy. Importantly, none had received an oral antibiotic before the study. Half received an injection of cefazolin (22 mg/kg) at the time of induction of anesthesia; the other half got it after the culture was secured.
Culture samples contained a urine swab, a piece of bladder mucosa and a crushed bladder stone. No significant difference was noticed between the two protocols, whichever criteria are studied.
Conclusion: As in all modern surgery protocols, antibiotics should be given at the time of induction, or about 30 minutes before skin incision.
How to Flush the Prepuce
A study out of the University of Florida (Neilhaus et al*) recently targeted the methods behind preputial flushing before surgical procedures. The prepuce should be flushed before a cystotomy so that the urethra can be catheterized intraoperatively in a sterile fashion. But which antiseptic technique should we choose?
The authors designed a beautifully simple study to settle this debate. They compared the efficacy of chlorhexidine, povidone-iodine, and saline (as a control) by performing a culture before and after the flushing procedure. Solutions of 0.05 percent chlorhexidine and 1 percent povidone were used. The hair from the tip of the prepuce was shaved before scrubbing the area with a gloved hand with a standard chlorhexidine scrub for two minutes. The culture was taken with a sterile saline-moistened swab in the area of the bulbis glandis.
The flushing procedure was performed by inserting a sterile 12 ml curved-tip syringe into the prepuce, infusing enough solution to mildly inflate the tissue, then manually agitating the area before allowing the solution to be released.
This procedure was repeated six times over two minutes before the same culture protocol was followed to obtain the second sample.
Amazingly, cultures showed no significant difference between sterile saline and povidone-iodine flushes.
The chlorhexidine flush, however, provided a significant decrease in the number of positive cultures after flushing.
Conclusion: A two-minute flush with 0.05 percent chlorhexidine is recommended for pre-surgical preparation of the prepuce.
Treating Bladder Infections
Colleagues (Westropp et al*) from The University of Ohio compared 14 days of amoxicillin-clavulanic acid at a dose of 13.75-25 mg/kg PO BID to three days of enrofloxacin dosed at 18-20 mg/kg PO SID to treat urinary tract infections in 68 dogs. Results showed no significant difference between the therapies when cultures were taken at 0, 10 and 21 days. The microbiologic cure rate was 77 percent and 81 percent for three days of enrofloxacin and 14 days of amoxicillin-clavulanic acid respectively.
Conclusion: Consider short-term, high doses of enrofloxacin for simple UTIs.
Which Antispasmodic to Use in Cats
Antispasmodic drugs like phenoxybenzamine and prazosin are sometimes used in the medical management of urethral obstruction in male cats. The authors of a study (Hetrick et al*) compared the recurrence of urinary obstruction in cats treated with either drug.
The study included 192 cats that were evaluated for re-obstruction at 24 hours and 30 days post catheterization. At 24 hours, 7 percent of cats treated with prazosin had re-obstructed compared to 18 percent of cats treated with phenoxybenzamine.
At 30 days, the cats treated with prazosin had a 22 percent re-obstruction rate compared to 39 percent of cats treated with phenoxybenzamine. In addition, re-obstruction rate at 24 hours was significantly lower when a 3.5 F versus a 5 F urinary catheter was used.
Conclusion: Prefer prazosin for your “blocked kitty” protocol.
Katie Kegerise, a certified veterinary technician in Reading, Pa., contributed to this article.
1. KM Thieman-Mankin et al. “Comparison of short-term complication rates between dogs and cats undergoing appositional single-layer or inverting double-layer cystotomy closure: 144 cases (1993-2010).” JAVMA 2012, Vol 240, N 1, p. 65-68.
2. DC Grant et al. “Frequency of incomplete urolith removal, complications, and diagnostic imaging following cystotomy for removal of uroliths from the lower urinary tract in dogs: 128 cases (1994-2006).” JAVMA 2010, Vol 236, N 7, p. 763-766.
3. N Buote et al. “The effect of preoperative antimicrobial administration on culture results in dogs undergoing cystotomy.” JAVMA 2012, Vol. 241, N 9, p. 1185-1189.
4. SA Neihaus et al. “Presurgical Antiseptic Efficacy of Chlorhexidine Diacetate and Providone-Iodine in the Canine Preputial Cavity.” JAAHA 2011, Vol. 47, N. 6, p. 406-412.
5. JL Westropp et al. “Evaluation of the efficacy and safety of high dose short duration enrofloxacin treatment regimen for uncomplicated urinary tract infections in dogs.” JVIM 2012, Vol 26, N 3, p. 506-512.
6. PF Hetrick et al. “Initial treatment factors associated with feline urethral obstruction recurrence rate: 192 cases (2004–2010).” JAVMA 2013, Vol. 243, No. 4, pages 512-519.