Urinary diversion and bladder reconstruction after cystectomy are a subject that urologists have been studying for many years. Ureterosigmoidostomy, firstly reported by Simon［13］in 1852, was the first form of continent urinary diversion. Because of severe postoperative complications, such as reflux pyelonephritis, electrolyte imbalance, impairment of renal function, renal calculus and ureteric implantation site secondary tumor, the promotion of ureterosigmoidostomy was subject to limitations.
In1993, Fisch et al［14］, carried out a modified ureterosigmoidostomy (Mainz Ⅱ) based on the original ureterosigmoid anastomosis. The total length of 15-20cm selected sigmoid colon and rectum were detubularized and side-to-side anastomosed to form a large capacity and low-pressure reservoir without the need for colostomy, which did not disrupt the continuity of the intestinal tract［15］. This technique was a simple and elegant method to obtain satisfactory continence after operation［16］. Turk et al［17］, first described their experience of laparoscopic radical cystectomy with intracorporeal continent urinary diversion (rectal sigmoid pouch) in 5patients. In their series, the results are promising, operation time was 6.9 to 7.9 hours, and estimated blood loss was 190 to 300 ml.
In this study, the 30-d complication rate (23.81%,20/84) was like other series of studies［10, 18, 19］. The most common early complications included wound infection, hypoproteinemia, fever, electrolyte disturbance, and intestinal obstruction. The 90-d complication rate was 19.05%(16/84), with ureteric implantation site stenosis being the most important complication in 6 renoureteric units (3.57%,6/168). No difference in the complication rates at 30-d and 90-d was noted between the two groups. Will different ureteric implantation techniques cause anastomotic stenosis. Patrick et al［20］, found no significant difference in the incidence anastomotic stenosis for three ureteric implantation techniques consist of Goodwin-Hohenfellner technique, Abol-Enein modification, and Le-Duc procedure.
There is still controversy over whether to implement ECUD or ICUD. In most medical centers, ECUD is still the first choice of urologists, attribute to the advantage of shorter operation time［21］. Although the procedure of ICUD is time-consuming and laborious, the pressure provided by the pneumoperitoneum in laparoscopic surgery has a certain hemostatic effect, with advantages for better surgical vision, less intraoperative blood loss and lower intraoperative blood transfusion rate. Besides, excessive bowel manipulation during the procedure and loss of body fluids contributed to the long postoperative bowel recovery time. In this study, IMUUD group had shorter Postoperative length of stay (P=0.033) compared to OMUUD group. Although the difference in operative time between the two groups was not statistically significant (462.24±99.71 vs. 498.57±121.44, P=0.175), it was great labor intensity for the operator during the IMUUD.
In order to reduce operation labor intensity, stainless steel staples have been generally utilized in the urinary tract after RC［22］, and gradually, methods have emerged for applying linear cut closures to make a new reservoir. Gastrointestinal anastomosis (GIA) does not impact the time to bowl recovery following RC［23］.The use of the GIA stapler device was associated with a significant decrease in operation time and provides a good functional effect with acceptable complication rates［24］. Radical cystotomy is a relatively complex procedure with a long learning curve. The low-volume surgeons will be benefited more by using stapling devices in radical cystectomy, it make the surgical procedure safer and faster［25］. The application of GIA makes it easier to intracorporeal urinary diversion and reduces operator labor intensity.
Compared with other types of continent urinary diversion, low-pressure rectal reservoir represents an ideal choice for continent urinary diversion using anal sphincter. Modified sigmoidorectal pouch can reduce the retrograde infection and renal function damage caused by urine reflux to the proximal colon. At the same time, it has good urinary control rate, and the daytime urinary control rate can reach 100%. In these cases, urinary continence was available during the daytime was 95.2% and 100%, with a complete urinary control rate of 87.3% (55/63) and 90.5% (19/21) between OMUUD and IMUUD respectively.
This study, however, has some limitations. First, it was a retrospective controlled trial at a single institution with small sample size. Second, despite our patient baseline and the pathological characteristics being similar between groups, there remains a degree of selection bias due to the non-randomized nature. Third, the IMUUD group comprised worse cases, which affected the results considering the influence of the learning curve. In general, larger samples and multicenter randomized controlled trials are needed to further explore the effect evaluation and prognostic implications of patients with IMUUD.