Authors from Mansoura evaluated the outcome of patients with continent urinary diversion who had a single functioning kidney. They recommend a regular follow-up of renal function in such patients. They found that rectal diversion was associated with a higher renal functional loss than orthotopic or cutaneous reservoirs. In the second article, the authors from Cairo describe the value of dynamic three-dimensional spiral CT cysto-urethrography in evaluating post-traumatic posterior urethral defects.
To evaluate the outcome of patients with continent urinary diversions who had a solitary functioning kidney at the time of surgery.
PATIENTS AND METHODS
In all, 62 patients with continent urinary reservoirs and a solitary functioning kidney were reviewed (51 men and 11 women). The indications for surgery were bladder cancer in 54 and a contracted bladder in eight. The surgical procedures included an orthotopic ileal neobladder in 36 patients, a continent cutaneous ileal reservoir in 13 and rectal diversion in 13. Kidneys were evaluated using serum creatinine level, ultrasonography, intravenous urography and other radiological studies.
The follow-up was 6–173 months; 44 renal units (71%) remained stable during this period. Serum creatinine was increased in four patients with an orthotopic neobladder, with no evidence of obstruction or reflux, in one with preoperative renal impairment and one with voiding dysfunction, reflux and bacteriuria. Six renal units deteriorated because of uretero-intestinal strictures; of these patients, two were treated endoscopically, two with open ureteric reimplantation, one with conversion from a rectal reservoir to an ileal loop conduit, and one was maintained on JJ stenting. Six patients with a rectal diversion had renal deterioration because of chronic pyelonephritis.
A regular follow-up of renal function is mandatory in patients with a continent urinary diversion. Rectal diversion is associated with a higher risk of renal deterioration (54%) than are orthotopic (28%) and cutaneous reservoirs (8%).
Many different forms of continent urinary diversion are used in conjunction with radical cystectomy for bladder cancer. One of the central issues for the ideal bladder substitution is preserving kidney function. A critical evaluation of renal function is mandatory in all patients when continent urinary diversion is considered [1,2]. Hyperchloraemic metabolic acidosis is a common complication after incorporating an intestinal segment into the urinary tract , and renal impairment may enhance these changes.
A serum creatinine of up to 25 mg/L was accepted by Elmajian et al. in patients scheduled for continent reconstruction. Månsson  indicated that levels of only 15 mg/L might indicate an appreciably decreased GFR with distinct implications for acid-base balance and, eventually bone mineralization.
In patients with borderline renal function, a creatinine clearance of < 60 mL/min was considered by Stein and Skinner  to be a contraindication to continent urinary diversion. However, some patients may have reversible renal impairment secondary to obstruction and drainage before surgery should better indicate the true renal function.
In the present study we analysed retrospectively patients with continent urinary reservoirs who had a solitary functioning kidney at the time of surgery, assessing the complications of surgery and the outcome.
PATIENTS AND METHODS
We retrospectively reviewed the outcome of 62 patients (51 men and 11 women, mean age 45.5 years, sd 13.7, range 18–68) with continent urinary reservoirs and a solitary functioning renal unit at the time of surgery (between May 1986 and January 2000). The contralateral kidney was previously removed for benign lesions in 42 and for malignancy in four patients; there were 12 radiologically nonfunctioning and four hypoplastic kidneys .
The indications of surgery were bladder carcinoma in 54 patients and a contracted bladder associated with schistosomiasis in eight. Before surgery, 58 patients had a normal serum creatinine level (5–15 mg/L) and a normal radiological configuration of the kidney. Four patients had high serum creatinine levels (17–25 mg/L), a contracted bladder with reflux and various degrees of hydronephrosis; this group had an orthotopic ileal neobladder.
Those with cancer underwent a standard radical cystectomy; men with a contracted bladder underwent simple cystectomy and prostatic coring, and the neobladder was anastomosed to the prostatic capsule. Orthotopic ileal neobladders were constructed in 36 patients, using an antirefluxing ureteric implantation in all with the Kock intussuscepted ileal nipple valve in 12 and a serous-lined extramural tunnel in 24. Anal-sphincter controlled reservoirs were constructed in 13 patients, including nine with augmented and valved rectal reservoirs, and four with double-folded rectosigmoid diversions.
Continent cutaneous ileal reservoirs were created in 13 patients; the continence mechanism was constructed from a tunnelled appendix in six and a tailored ileal segment in seven. The ureters were implanted using a serous-lined extramural tunnel. The surgical techniques of such procedures were described previously [7–10].
Patients were followed regularly at 3-month intervals, with a history, clinical examination, serum creatinine measurements, urine culture and renal ultrasonography. IVU and other radiological investigations were used as clinically indicated. Other factors recorded in cancer-free patients, or at the last observation before developing treatment failure, were local pelvic recurrence or distant metastases. Patients who were lost to follow-up were excluded from the study.
No patients died during surgery; the mean (sd, range) follow-up was 67.6 (54.5, 6–173) months. The patients’ characteristics and complications of continent urinary diversions are listed in Table 1; 44 renal units (71%) remained stable during the follow-up (Fig. 1) while the remaining patients had deterioration of renal function through various causes. The mean follow-up was shorter in those with a continent cutaneous urinary reservoir. There were significant changes at the last follow-up in the serum creatinine levels of patients with an orthotopic or rectal reservoir (Table 1).
|No. of patients||36||13||13||62|
|age, years||50.6 (8.1)||35 (16.9)||40 (16)||45.5 (13.7)|
|follow-up, months||71 (57)||97 (48.9)||28.9 (25)||67.6 (54.5)|
|Early complications, n (%)|
|Urine leak||2 (6)||2 (3)|
|Prolonged ileus||1||1 (1.6)|
|Haematemesis||1 (3)||1 (1.6)|
|Wound infection||2 (6)||1||3 (4.8)|
|Acute pyelonephritis||1||1 (1.6)|
|Intestinal obstruction||1 (3)||1 (1.6)|
|Chronic pyelonephritis||5||5 (8)|
|Reflux||6 (17)||1||7 (11)|
|Uretero-intestinal stricture||4 (11.1)||1||1||6 (10)|
|Metabolic acidosis||2 (6)||5||7 (11)|
|Kidney stone||1 (3)||1 (1.6)|
|Pouch stone||3 (8)||3 (5)|
|Changes in mean (sd) serum creatinine levels, mg/L|
|Before surgery||12.4 (4.8)||11.1 (3.5)||10.8 (3.4)|
|After surgery||16.1 (6.9)*||21.2 (15.8)†||11.1 (2.2)|
Urine leakage was noted at the urethro-ileal anastomosis in two patients, which ceased spontaneously after prolonged catheter drainage. Other complications after surgery included wound infection in two and haematemesis in one patient, both treated conservatively.
During the follow-up serum creatinine levels remained stable in all but four patients, who had values up to a mean (sd) of 22 (6) mg/L with no evidence of obstruction or reflux. One patient developed a kidney stone that was treated by percutaneous nephrolithotomy. Three patients with Kock neobladders had pouch stones that were treated endoscopically. One patient had intestinal obstruction and required resection and re-anastomosis of the obstructed ileum. In the four patients who had initially high serum creatinine levels (17–25 mg/L) the levels remained stable in three and increased from 25 to 39 mg/L in the fourth.
Four patients with an ileal W-neobladder and antirefluxing serous-lined extramural tunnel had uretero-intestinal strictures; this developed 1–13 months after surgery and was initially managed by percutaneous nephrostomy drainage followed by balloon dilatation of such strictures, and fixation of a JJ stent. Two patients required revisional surgery using a direct uretero-intestinal anastomosis, and their kidneys were stable during the follow-up (Fig. 2). The third patient had a normal upper tract after endoscopic incision of the stricture and removal of the JJ stent. The fourth patient was maintained on an indwelling JJ stent because of metastatic disease.
Six cases had pouch-ureteric reflux with a normal upper tract configuration (Fig. 3); they were maintained on chronic suppressive antimicrobial therapy to sterilise their urine. Normal renal function was maintained at the last follow-up in all patients but one, who had elevated serum creatinine. This patient had voiding dysfunction and bacteriuria, and was maintained on clean intermittent self-catheterization.
Of these 13 patients, one developed wound infection and another had an episode of acute pyelonephritis after surgery. Seven patients with rectal reservoirs had a deterioration of their initially normal serum creatinine levels to 29 (19) mg/L during the follow-up. The causes of this deterioration were chronic pyelonephritis in five, chronic pyelonephritis with reflux in one and uretero-intestinal stricture in one. The last had a conversion from rectal diversion to an ileal loop conduit. Of these patients, five had episodes of clinical metabolic acidosis despite regular alkali therapy.
CONTINENT CUTANEOUS DIVERSIONS
After surgery one patient had prolonged ileus that was treated conservatively; another had an early uretero-ileal obstruction, and was managed by percutaneous nephrostomy drainage followed by antegrade fixation of a JJ stent and endoscopic incision. This patient was followed for 18 months and kidney function was maintained. Serum creatinine values remained normal during the follow-up in all patients, and all kidneys had a radiologically normal configuration during the follow-up.
The functional outcomes of the upper urinary tract after continent urinary diversion were assessed using serum creatinine, renal ultrasonography and IVU. An increase in serum creatinine in patients with a solitary functioning kidney is a suitable tool to determine renal function. In this study, 29% of all patients with a continent urinary reconstruction and solitary functioning kidney had some deterioration in renal function. Rectal diversion was associated with the highest risk (54%) when compared with orthotopic (28%) and cutaneous reservoirs (8%). Organic causes of renal deterioration, e.g. stricture formation and reflux, usually developed soon after surgery, while chronic infections lead to a gradual decline of kidney function.
A critical assessment of the causes of renal deterioration in patients with continent urinary reconstruction and a solitary functioning kidney indicate that infection, obstruction and the type of diversion are important. There was deterioration in 18 renal units (29%) from various causes, but only six (10%) were a result of uretero-intestinal anastomotic strictures. These data are comparable with those reported by others using different antirefluxing techniques [7,8,11,12]. In general, the long-term uretero-intestinal stricture rate is 3–7% if a simple direct anastomosis is used and 7–15% if there is an antirefluxing anastomosis, irrespective of the type of anastomosis or the segment of bowel used [13–16].
Obstruction is an important complication, as another procedure is usually required to preserve renal function. The incidence of uretero-intestinal obstruction in the present series was ≈ 10%. The serous-lined extramural ureteric tunnel was the antirefluxing procedure used in such cases. These six patients were initially treated by antegrade balloon dilatation of the strictured segment and JJ stenting; this was successful, with endoscopic incision, in only two cases. Two patients with orthotopic neobladders required revisional surgery by direct uretero-ileal implantation and their renal function was stabilized. One patient with rectal diversion was converted with an ileal conduit; the sixth patient had metastatic disease. As reported by others, endoscopic treatment of uretero-intestinal stricture was generally less successful than open surgery [17–19].
There was reflux in six patients with an orthotopic neobladder; only one who had voiding dysfunction, bacteriuria and reflux had deterioration of renal function. While reflux must be prevented in rectal diversion, there is controversy about the optimal method of uretero-intestinal anastomosis and whether an antireflux system should be incorporated with continent cutaneous and orthotopic neobladders. Proponents for using an antireflux system argue that detubularized pouches are not necessarily low-pressure reservoirs and are usually colonized by bacteria [7,8,20,21]. However, the potential benefits from an antireflux procedure may be outweighed if the technique has a high risk of stricture formation [22–25]. To this end, a prospective randomized study is currently underway by our group to compare the antirefluxing and direct uretero-intestinal anastomosis in orthotopic neobladders.
Selecting the type of continent urinary diversion is important in patients with a solitary functioning kidney. The continent cutaneous urinary reservoir is an excellent alternative if an orthotopic neobladder is not the diversion of choice.
The significant incidence of complications after ureterosigmoidostomy stimulated investigators to introduce refinements and improvements [9,10,26,27]. However, in the present study using the augmented and valved rectum in nine patients and the double-folded rectosigmoid bladder in four, there was renal deterioration and hyperchloraemic metabolic acidosis in half the patients. The most common cause of such complications was chronic pyelonephritis. Uretero-intestinal stricture formation and reflux were additional causal factors. Because of these disappointing results after rectal diversion in patients with a solitary kidney, this clinical situation should be considered a contraindication to such a procedure.
Thanks to all members of staff in departments of Urology and Radiology, for their active contribution and Miss Rasha Abdel Wahab for her secretarial work.