Bulky tumors
Recurrent disease
Previous radiation therapy
Previous pelvic surgery
Previous urologic surgery
Reoperative surgery
Obesity
In a study of 120 ureteral catheterizations in patients undergoing colorectal procedures for either primary or recurrent cancer, Kyzer et al. reported prophylactic ureteral catheterizations in 65 % of the patients [8]. Based on their experience, these authors concluded that prophylactic ureteral stents were beneficial in identifying the ureter in patients with large rectal or rectosigmoid cancers and in patients where the ureter may be involved by the tumor on preoperative imaging. Bothwell et al. reviewed 561 consecutive patients who underwent sigmoidectomy or rectosigmoidectomy [9]. Ninety-two patients underwent prophylactic ureteral stent placement, which was bilateral in 80 patients. There were two ureteral injuries each, in patients who underwent stent placement and in those who did not. In the former group, there was a surgical injury and an injury related to stent insertion. In the latter group, there were two surgical injuries. The authors concluded that the complications related to ureteral catheter insertion are not insignificant, but prophylactic ureteral stents may assist in recognizing transmural injuries.
Incidence of Ureteric Injury and Early Identification of Injury
Delayed recognition of ureter injuries is associated with significant morbidity [3, 6]. The timing of the diagnosis of ureteral injuries correlates with morbidity and long-term results. Following 111 abdominoperineal resections, Andersson and Bergdahi reported five ureter injuries [3]. In two patients, the injuries were recognized and repaired intraoperatively with good long-term results. In the other three patients, the injuries were recognized postoperatively. One patient underwent delayed repair and died from peritonitis. The other two patients suffered acute renal failure, with one patient subsequently undergoing nephrectomy and the other patient having a nonfunctioning kidney based on intravenous urogram. In a 20-year experience of ureteral injuries in surgical patients, Selzman and Spirnak reported that injuries detected postoperatively were more complicated and required more complex repairs compared to injuries detected intraoperatively [6]. In their study, an average of 1.6 procedures were required to repair ureteral injuries detected postoperatively compared to 1.2 procedures for injuries detected intraoperatively, ( p< 0.0006). Five nephrectomies had to be performed, four of which were for injuries discovered postoperatively. Immediate repair of a ureteral injury leads to less morbidity than delayed repair.
Placement of Ureteral Stents
Ureteral stents are placed by the urologist after induction of anesthesia and before the abdominal procedure begins. There are multiple designs of ureteral stent, which are aimed at improving patient comfort, reducing urinary tract infection, and stent handling. Prophylactic ureteral stents are primarily composed of silicone allowing the stent to be flexible, elastic, and inert, which allows them to be very well tolerated by patients. The length of the stent depends upon the patient’s height. In an average adult, the typical stent is 24–26-cm long. Stent diameters range from 4 to 7 French (Fr). In cases in which the ureteral stents are used for intraoperative identification of the ureter with planned removal at the end of the case, 5 Fr open-ended ureteral stents are commonly used and can be internalized into the lumen of the urethral catheter draining the bladder. If prolonged ureteral drainage for a period of weeks to months is needed, then double-J type ureteral stents either 6 or 7 Fr are placed. Since the double-J stents are entirely internal (and therefore invisible to the patients), it is important that patients are not lost to follow-up and that the stents are removed or exchanged at the desired time interval. Patients who are lost to follow-up can develop a stone-encrusted ureteral stent, which may damage renal function and be difficult to retrieve.
Several studies have reported on the time associated with the placement of prophylactic ureteral stents. Operative times are increased by a mean of 10–23 additional minutes with a range of 5–55 min [8, 10–13]. Pokala et al. randomized 24 patients undergoing reoperative complicated colorectal surgery into sequential (before starting the procedure) or simultaneous (intraoperative) ureteral stent placement [12]. The authors demonstrated that simultaneous insertion of ureteral stents reduced the duration time to incision and to peritoneal entry ( p = 0.0001) without an increase in morbidity. They concluded that simultaneous approach may allow for a more selective use of ureteral stents based on intraoperative findings.
Due to the lack of tactile feedback in laparoscopy, lighted stents were developed to aid in ureteral identification through light visualization. With the increasing number of colorectal procedures being done laparoscopically or robotically, the use of prophylactic lighted ureteral stent placement has increased. Senagore and Lutchtefeld reported a series of 49 consecutive laparoscopic-assisted colectomies comparing patients who had lighted stents [14] and those without stents [13, 15]. Ureters were identified in the retroperitoneum without any dissection by light visualization in 20 of 24 (83 %) patients who underwent lighted stent placement. The remaining patients in this group and all the patients in the group without stents had ureters visualized by standard retroperitoneal dissection. In the patients with lighted stents in which the ureter was not identified, two catheters had migrated into the bladder and two patients had thick retroperitoneal fibrosis impairing light transmission. The authors concluded that lighted catheters made identification of the ureter easier in potentially difficult cases. In a similar series, Chahin et al. retrospectively reviewed 66 patients that had lighted prophylactic ureteral stents placed for laparoscopic colectomy [10]. In this series, one (1.5 %) patient suffered a ureteric injury, which was identified on postoperative day 2 and was managed conservatively with replacement of the ureteral stent. In this study, the most common complication was self-limiting hematuria, which occurred in 98.4 % of patients. The average duration of hematuria was 2.5 days for unilateral stenting and 3.3 days for bilateral stenting.
Detection of Ureter Injury
Prevention of iatrogenic ureteral injury is based on knowing the anatomy of the ureter. The patient’s preoperative CT scan should be carefully assessed to determine the anatomic relationship of the colon or rectal cancer with the adjacent urinary tract, especially the course of the ureter if the tumor is bulky. Approximately 1–2 % of the population will have ureteral duplication, which can be partial or complete, and can be detected on the CT scan. Although there are several anatomic patterns of ureteral duplication, it is common for the ureters to be totally separate in the upper and mid-ureteral levels and then run side by side in a common sheath at the level of the lower ureter. Horseshoe or pelvic kidneys will also have an altered orientation of the renal pelvis and ureter [16].
During mobilization of the descending colon, the ureter will adhere to the peritoneum rather than maintaining its normal position along the psoas muscle. The most likely points where ureteral injuries occur are at the time of ligation of the inferior mesenteric vessels, at the level of the sacral promontory where they cross over the iliac artery, and during transection of the lateral rectal attachments [4, 5, 17]. Before transection of the colonic mesentery, visualization of the ureter is critical. Visualization of the ureter can be aided by observing its peristaltic activity, which can be demonstrated best by squeezing the ureter briefly with Debakey-type forceps. A key anatomic landmark for ureteral identification in the pelvis is the obliterated umbilical artery, which is the first large anterior branch of the internal iliac artery. The ureter is always medial to the obliterated umbilical artery.
There should be a high index of suspicion and a low threshold for imaging or direct ureteric exploration when there is concern for an intraoperative ureteric injury. The first step in the evaluation of a suspected injury is visual inspection of the ureter to assess its integrity and the nature and severity of the injury. In some cases, extravasation of urine can be seen from a defect in the ureter after a laceration or transection has occurred. If there is no obvious defect in the ureter, the diagnosis of a suspected ureter injury can be confirmed with the use of intravenous dye injection (methylene blue or indigo carmine). Five milliliters of methylene blue or indigo carmine is given intravenously over 5 min. After 5–10 min, the dye will begin to be excreted by the kidneys. Extravasation of blue dye is a reliable sign of ureteral injury and will allow for identification of the site of injury. Cystoscopy can be used to assess urine efflux from the ureteral orifices. Ureteral catheterization can be employed at the time of cystoscopy, but may not detect partial transection or thermal injury.
In the postoperative period, one must have a high index of suspicion for an injury to the urinary tract since early signs and symptoms may be subtle. Urinary tract injuries that are not identified intraoperatively are most likely present within the first 2 weeks after surgery [4]. During this time after surgery, signs and symptoms such as leakage of urine from abdominal incision or rectum, high drain output, unilateral or bilateral flank pain, hematuria, oliguria, anuria, ileus, and fever should raise suspicion for ureter injury [3, 18, 19]. Physical examination and laboratory studies are valuable in identifying other complications associated with ureteral injury and help determining which diagnostic studies are needed. Physical examination should assess hemodynamic stability, urine output, signs of peritonitis, ascites, and the integrity of incisions. Laboratory evaluation should consist of serum electrolytes, blood urea nitrogen (BUN), and creatinine (Cr) [5, 20]. Bilateral ureteral obstruction will result in acute renal failure, while unilateral obstruction will result in a transient increase in Cr while the other kidney compensates. If physical examination demonstrates evidence of ascites or if there is high drain output, then biochemical analysis of the peritoneal fluid by paracentesis or sending fluid from intraperitoneal drains can be performed. The BUN and Cr of the peritoneal fluid are compared to the patient’s serum levels. If the values of serum and ascites are similar, there is no urinary ascites. If the BUN and Cr are normal in the serum but elevated in the ascites fluid, this confirms a urinary tract injury that needs further evaluation. The creatinine level of the peritoneal fluid will help determine the magnitude of the urine leak. A high-volume urine leak is often associated with a drain creatinine above 30 mg/dl. A small-volume urine leak will have a drain creatinine level that is lower and closer to the serum level.
Once a ureteral injury is suspected, an ultrasound can be performed to assess for hydronephrosis or to exclude retroperitoneal fluid collections. Following the ultrasound, a computed tomography with IV contrast or cystoscopy with retrograde intravenous pyelography should be performed. Retrograde pyelogram can give the precise location of the injury, and a stent could be deployed in cases of ureteral injury without obstruction.
Management of Ureter Injury
Intraoperative recognition of ureteral injuries occurs only in 15–30 % of patients undergoing open operation [7, 8]. If the ureteral injury is recognized intraoperatively, it should be repaired during the same operation. Prior to initiating the repair, if it has not been previously done, one should assess the baseline renal function and preoperative imaging of the urinary tract to ensure there are two functioning kidneys. The patient’s prior cancer treatment including the previous radiation exposure, extent of radiation field, prior chemotherapy, and history of targeted therapy should be reviewed. A thorough surgical history should include any history of ureteral, bladder, prostate, or kidney surgery, which might prevent ureter mobilization or an elongation procedure. The surgeon should review the patient’s medical history with special attention to a history of chronic kidney failure, renal stones, or hypertension.
Once the extent and location of the injury is delineated, several general principles apply for repair. At the site of injury, the ureter should be debrided to healthy tissue with a good blood supply to ensure healing. There should be minimal grasping of the ureter with forceps. Stay sutures can be placed on the ureter to help provide exposure and move the ureter. A watertight tension-free spatulated anastomosis should be performed with fine absorbable sutures, which will decrease the risk of stricture and stone formation. The specific repair is based on the location and the extent of the injury [21, 22] (Table 34.2). Renal and bladder mobilization is extremely useful in reducing the gap of ureteral loss. The perinephric tissues (Gerota’s fascia) and the bladder itself can be on moderate tension with fixation, but any ureteral anastomosis must be tension free or it will stricture.
Table 34.2
Suggested management options for ureteral injuries at different locations
Upper ureter injury |
Direct ureteroureterostomy |
Transureteroureterostomy |
Ileal ureter |
Autotransplantation |
Middle ureter injury |
Direct ureteroureterostomy |
Transureteroureterostomy |
Boari flap |
Lower ureter injury |
Reimplantation |
Psoas hitch |
Minor contusions and thermal injuries of the ureter can be managed with stent placement and drainage. The ureter should be inspected to ensure adequate blood supply as minor injuries may stricture or break down. If the ureter is inadvertently ligated, the suture should be removed and the ureter examined for viability. If the ureter is viable, then the injury can be managed with stent placement and drainage. If there is a question of ureter viability, the injured portion should be debrided and an ureteroureterostomy should be performed.
Partial transection of the ureter can be repaired by primary repair if the ureter is viable. In order not to stricture the ureter, the injury is closed by converting a longitudinal transection into a transverse transection (Heineke–Mikulicz). The ureter is stented and the repair is drained.
Proximal Third Injuries
The proximal one-third of the ureter extends from the ureteropelvic junction to the upper border of the sacroiliac joints. Injuries in the proximal third of the ureters account for 2 % of all ureteral injuries [6]. The length and location of the damaged segment of ureter determines how the injury will be repaired. The optimal repair is a direct ureteroureterostomy for an injury in this location, provided that the length of ureteral loss is less than 5 cm (ideally only 2–3 cm). If sufficient length cannot be obtained by mobilization of the ureter, additional ureteral length can be obtained by mobilization of the kidney. Full mobilization of the left kidney can achieve an additional 3–4 cm with fixation to the psoas tendon or retroperitoneum (nephropexy). Full mobilization of the right kidney will only achieve an additional length of 1–2 cm due to the shorter right renal vein. An interrupted spatulated anastomosis with 5-0 absorbable suture is performed over a stent when sufficient length of ureter has been obtained. If the anastomosis is on tension, it will stricture. If after mobilization of the kidney sufficient ureteral length cannot be obtained to perform a direct ureteroureterostomy, then one might consider a transureteroureterostomy (TUU) with full mobilization of both the donor (index) kidney and the donor ureter and mobilization of the recipient kidney and ureter. It is important in a complex TUU to bring the lower poles of both kidneys together (but suturing Gerota’s fascia from the lower pole of each kidney together to create an iatrogenic “horseshoe kidney”). One must be sure not to devascularize the recipient ureter during mobilization. An omental pedicle flap can be placed around the repair to separate it from the aorta as the TUU anastomosis in these cases is close to the aorta. If a complex TUU is not possible, then one must consider other options such as intestinal interposition graft, autotransplantation, or a nephrectomy [22, 23]. The ileum is typically used for an intestinal interposition graft. The ureteral segments are mobilized and the ureteral–ileal anastomosis is performed in an end-to-side fashion using absorbable suture, much in the same way that an ileal conduit is constructed after cystectomy. The ileal segment should be minimized as much as possible to reduce the risk of electrolyte reabsorption. The psoas hitch or nephropexy can be performed as an adjunct to ileal ureter. Contraindications to ileal interposition repair include Crohn’s disease, radiation enteritis, and serum creatinine greater than 2.0 mg/dl [6, 22].
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