Urologic Issues in Colorectal Surgery




Introduction


Urologic issues pertaining to colorectal surgery can be broadly categorized according to the organ involved: the ureter, bladder, or urethra and their associated nerves and vessels. Because both colorectal surgeons and urologists have become more familiar with laparoscopic techniques, urologic issues encountered in colorectal surgery often may be addressed in a minimally invasive fashion without conversion to an open surgery. In this chapter we will discuss the common situations in which colorectal surgeons and urologists interact.




Infection


Perioperative urinary tract infections can be encountered after urethral catheterization and other instrumentation of the urinary tract. Both urinalysis (unless strongly positive) and irritative voiding symptoms soon after urethral catheter removal may be unreliable indicators of infection. However, if symptoms persist or other clinical signs of infection develop and are unrelated to the recent surgery, a urine sample should be collected in a sterile fashion and sent for culture. Empiric antibiotic coverage is started, using twice daily ciprofloxacin or trimethoprim-sulfamethoxazole. After the results of the urine culture are available, the antibiotics should be discontinued or changed, as appropriate.


A urinary tract infection may present outside the postoperative period. In this situation, a urinalysis may be more reliable. If a urinalysis suggests infection, a urine sample collected in a sterile fashion should be sent for culture. Treatment with the first-line agents mentioned previously should be pursued and tailored to the culture results unless prior microbiology data document resistance to such an agent. If infections are recurrent and the organism is the same, a urologic workup is required because the cause may be a foreign body (e.g., a suture or stone) or an anatomic abnormality (e.g., diverticulum). If recurrent infections with differing enteric organisms develop, a search for an enteric-urinary fistula should be considered.




Ureter


The normal anatomic position of the ureter in the retroperitoneum places it at risk when the ascending and descending colon, the sigmoid colon, and the rectum are mobilized. Furthermore, obstruction, inflammation, neoplasm, radiation, or changes caused by prior procedures may cause the ureter to deviate from its usual course. Preoperative identification of the ureters may avoid inadvertent injury, especially when a challenging or even routine but extensive retroperitoneal dissection is anticipated. This scenario prompts one of the most common preoperative, and at times intraoperative, consultations received by urologists. The placement of temporary ureteral stents is relatively low risk and not only helps with ureteral identification but also can aid in the recognition of injury and facilitation of its repair. If a ureter is denuded, crushed, subject to electrocautery at close proximity, or otherwise thought to be at risk of damage or stricture, placement of an indwelling stent (i.e., a JJ stent) that can be left for up to 2 months should be considered.


If the ureter is injured or partially excised, direct reanastomosis is preferred. The principles underlying choice of direct reanastomosis are similar to those of intestinal anastomosis and include maintenance of a robust ureteral blood supply, creation of a wide-caliber ureteroureterostomy, and a tension-free anastomosis. Mobilization of the ureter is required to facilitate this procedure, but avoidance of skeletonizing the ureter preserves its blood supply and reduces the risk of anastomotic stenosis. The two ureteral ends are spatulated, one on its anterior surface and the other on its posterior surface, and subsequently approximated with transmural resorbing stitches ( Fig. 88-1 ). Permanent suture material should never be used in the urinary tract because of the risk of calculus formation and development of a nidus for infection. Prior to placement of the last one or two stitches, a ureteral JJ stent is inserted to allow anastomotic healing and facilitate urinary drainage. Such a procedure can be performed laparoscopically, if this is the approach used by the colorectal surgeon and the urologist is skilled in minimally invasive surgery. Generally, stents are left in place for up to 6 weeks and then removed via cystoscopy with imaging (the type of imaging study used depends on the urologist’s preference) to confirm ureteral patency.




FIGURE 88-1


A ureteroureterostomy is performed after spatulating the ureteral ends on opposing surfaces to create a wide anastomosis.


Injury of the distal ureter may be better managed by reimplantation into the bladder via a ureteroneocystostomy than by ureteral reanastomosis. As with a ureteroureterostomy, mobilization of the ureter to facilitate a tension-free anastomosis is required, and avoidance of ureteral skeletonization to maintain blood supply is essential. When the surgery is performed in an open manner, and if sufficient ureteral length is available, a nonrefluxing reimplantation may be performed. Along with mobilizing the ureter, this procedure involves opening the bladder anteriorly and passing the ureter through a submucosal tunnel extending from a posterolateral bladder wall stab incision to the trigone ( Fig. 88-2, A and B ). The length of the tunnel should be two or three times the width of the ureter, with the end of the ureter spatulated and anastomosed to the trigone mucosa ( Figure 88-2, C and D ). The submucosal tunnel closure and new ureteral orifice are created with one layer of suture while the anterior cystotomy is closed in two layers, with the mucosa and detrusor approximated separately. A urethral catheter is then left indwelling for 10 to 14 days to minimize bladder pressure and facilitate healing.




FIGURE 88-2


A, A ureteroneocystostomy is started by opening the bladder anteriorly and making a stab incision for the ureter. B, A submucosal tunnel is created to prevent vesicoureteral reflux. C, The ureter is then brought through the tunnel, and the original stab incision is closed. D, The ureteroneocystostomy is completed by anchoring the end of the ureter to the bladder wall.


Loss of a critical length of ureter may make a tension-free ureteroureterostomy and a nonrefluxing ureteral reimplantation impossible. In such situations, simple reimplantation into the bladder dome with a refluxing ureteroneocystostomy may be performed. This procedure involves dissecting through the bladder wall until the mucosa is reached, spatulating the ureteral end, and then incising the mucosa and anastomosing the ureter to the bladder. The ureteroneocystostomy is reinforced by closing the detrusor over the anastomosis site. When simple reimplantation is impossible for the lack of a few centimeters of length, a psoas hitch may be performed. This procedure is performed by tacking the bladder to the ipsilateral psoas fascia on the side of ureteral injury, thus raising the bladder wall superiorly. When this procedure is not sufficient, a Boari flap may be fashioned, which involves tubularizing a full-thickness flap of bladder wall, securing it to the ipsilateral psoas fascia, and performing an end-ureteral anastomosis to this ( Fig. 88-3 ). Any of these three procedures may be performed during laparoscopic surgery.


Jul 15, 2019 | Posted by in GENERAL | Comments Off on Urologic Issues in Colorectal Surgery
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