Indicaciones para Cistotomia

In the United States, cystic calculi occur relatively frequently in dogs and less commonly in cats. The most common calculi isolated are struvite, calcium oxalate, urate, silicate, and cystine. Since 2002 calcium oxalate stones have become the most commonly isolated stone in the United States. Treatment options for cystic calculi will depend on the severity of obstruction. Clinical signs may include hematuria, pollakiuria, stranguria, abdominal pain, signs of postrenal azotemia, and urinary tract infection. If the stones are very small it may be possible to expel them via voiding urohydropropulsion. If the stones are of a known composition, such as struvite stones, medical dissolution may be possible in some circumstances. However, most often these patients will present on an emergency basis and require surgical removal of the calculi.

At the time of surgery bladder culture should be performed as concurrent urinary tract infection is common. Antimicrobial therapy should be instituted based on sensitivity patterns. Stones should be submitted for analysis and the patient should then be managed medically based on the stone analysis results.

The surgical approach to the bladder is generally dependent on surgeon preference. However, it may be safer to make a ventral cystotomy to help avoid damage to the ureters as they insert more dorsally. The cystotomy is usually enlarged enough to allow for retrieval of stones. Care should be taken to ensure that all stones are retrieved. This is usually managed by using a red-rubber catheter in anterograde and retrograde fashion in males and flushing multiple times. In females, the catheter is usually advanced in anterograde fashion only to avoid excessive contamination, given the close proximity to the anus. Once the surgeon is absolutely certain no stones remain, then it is recommended to flush again to ensure no stone remains. Radiographs are taken postoperatively as a standard of care to ensure no stone has been left behind and also for documentation in the event stones recur and the owners try to argue that stones had been left behind during the original surgery.

Closure of the bladder may be done with a simple interrupted or continuous pattern using a reliable absorbable suture such as polydioxanone. The key is to ensure excellent apposition so that there is no leakage postoperatively.

As long as the surgeon does not suspect severe damage to the bladder such that there may be detrusor muscle dysfunction, it is not generally necessary to have an indwelling catheter remain in place postoperatively. If the surgeon is highly concerned of the integrity of the bladder and feels it necessary that constant decompression be present in the early recovery period, then a catheter should be used. The main disadvantage to having a urinary catheter in the postoperative period is that it will continue to irritate the urethra and may be a nidus to infection.