the reported incidence of ureteral injury during colorectal surgery has ranged from 0.2 to 4.5 % . the use of prophylactic lighted ureteral stent ( lus ) placement has gained more importance with the advent of laparoscopic colectomy . lighted stents help in the visual identification of the ureters during a laparoscopic procedure . despite the apparent advantages of prophylactic ureteral stent placement , its effectiveness is still controversial . injury to the ureters in spite of stent placement , hematuria , and reflux anuria have also been reported . we report here our experience with prophylactic placement of lighted ureteral stents during laparoscopic colectomy and discuss the value and the outcomes of this procedure . a retrospective analysis was done of 66 patients who underwent laparoscopic colectomy ( lco ) with preoperative placement of lus at north oakland medical centers , pontiac , michigan , between april 1996 and january 2000 . the catheter used was a polyurethane bard 6 lighted ureteral catheter. the parameters evaluated included age and sex of patients , the indication for surgery , the location of the pathology , the presence or absence of preoperative urinary tract symptoms . the urologic operative reports were reviewed for pathology identified during cystoscopy and ureteral catheterization , duration of the procedure , uni - lateral or bilateral placement of the catheters , and the size of the ureteral catheter used . complications related to ureteral catheter insertion , timing of catheter removal , intraoperative ureteral injury , occurrence of postoperative urinary tract infection , hematuria , and reflux anuria were also reviewed . operating room charges were also considered along with a comparison of the complications between unilateral and bilateral stent placement . of the 32 male patients , 3 ( 9.4% ) had a history of urinary frequency and 4 ( 12.5% ) had a history of dysuria . the urologic reports for pathology identification , duration of the procedure , and the side of catheter insertion are described in table 3 . urinary tract infection ( uti ) was assessed with the urine culture reports postoperatively . in spite of the ureteral catheterization , 1 patient suffered an incomplete left ureteral injury during sigmoid colectomy , which was managed conservatively with the reinsertion of a left ureteral stent . the complications following unilateral stenting and bilateral stenting were compared as illustrated in figure 1 . the duration of hematuria ( days ) poststenting between patients who had unilateral ( 2.5  0.82 ) and bilateral ( 3.37  1.05 ) stent placement was statistically significant with p < 0.001 . the cost involved in stent placement included $ 1504.32 with an average increase of 26 minutes in operating room time costing $ 578 , the urologist 's charges of $ 452.72 , and each stent costing $ 236.80 . the total percentage of patients with unilateral and bilateral stenting with complications is depicted in the figure . the usefulness and outcomes of prophylactic ureteral stenting during open colorectal surgery has been well documented in the literature . ureteral catheter placement allows intraoperative tactile localization of the ureters and is helpful in immediate recognition of ureteral injuries . with the introduction of laparoscopic colectomy as an alternative for traditional colorectal surgery , the placement of lus during laparoscopic colectomy has gained more importance because of visual identification of the ureters . , we evaluated the value of prophylactic placement of lighted ureteral stents in laparoscopic colectomy . the majority of our patients had bilateral stents placed initially . as the surgeons gain more experience , the number of stents placed depends on the location of the pathology and the surgeon 's preference . ureteral injuries during laparoscopic colectomy have occurred and have also been reported during laparoscopic hysterectomy . ureteral injuries are of 4 types : laceration , ligation , crush , and devascularization . these injuries may be detected either intraoperatively or postoperatively . the placement of prophylactic ureteral stents helps in detecting the ureteral injuries intraoperatively and adequate action to be taken immediately . this injury was recognized on postoperative day 2 with urinary ascites and was managed by reinserting the left ureteral stent temporarily . the placement of ureteral catheters results in postoperative gross hematuria in almost all the patients . overall , this hematuria is of no clinical significance as no blood transfusion is required . on the other hand , anuria is suggested to be the result of neurogenic factors initiated by ureteral manipulation and mediated through the autonomic nervous system . studies have demonstrated that anuria after ureteral catheterization is due to edema which causes mechanical obstruction at the ureterovesical junction . recognition of this symptom , which usually requires repeated ureteral catheterization , is important . in our series , 4 ( 6.1% ) it is possible that the 2 patients who had acute renal failure could have benefited from repeated ureteral stenting . the incidence of urinary tract infections was acceptable and in most cases was not troublesome . it may be attributable to the postoperative foley catheter that these patients received rather than the ureteral stents . we conclude that prophylactic lighted ureteral catheter placement in laparoscopic colectomy is a safe and cost - effective procedure . unilateral stent placement is recommended over bilateral stent placement to reduce operative time and postoperative hematuria .