Further Experience with the Modified Ileal Ureter

0022-5347/95/1541-0045$03.00/0 THEJounv+uOF UROLoCY Copyright 0 1995 by AMERICAN U R O ~ I CASS~CIATION, AL bc.

Vol. 154,4548, P r i e d July in U1995 SA

FURTHER EXPERIENCE WITH THE MODIFIED ILEAL URETER AHMED A. SHOKEIR

AND

M O W E D A. GHONEIM*

From the Urology and Nephrology Center, Mansoura University, Mansoura, Egypt

ABSTRACT

A total of 50 patients for whom an ileal ureter was indicated was prospectively randomized between 2 treatment groups according to the surgical technique used. In group 1the standard ileal ureter procedure was performed, while in group 2 a tailored and valved (modified) ileal ureter was fashioned. Of the patients 19 in group 1 and 23 in group 2 were available for followup of 69 -+ 5.8 months (range 60 to 80).Among the 23 patients in group 2,5(22%) experienced reflux due to dessusception of the nipple valve and 4 (17%)had bladder stones. Metabolic acidosis was observed in 9 patients in group 1 (47%) and 4 in group 2 (17%). Urinary outflow obstruction occurred in 5 patients in group 1 and 1 in group 2. Although renal function was comparable among patients in both treatment groups, comparison between patients in group 1 and those without reflux in group 2 showed better renal function in the latter group. We conclude that reflux prevention is of central importance in preservation of renal function in patients with an ileal ureter. A distal nipple valve at the ileovesical anastornosis is associated with significant problems. These observations would urge urologists to search for a more suitable procedure that provides an efficient antireflux principle with minimal adverse sequelae. KEYWORDS: urinary diversion, ileum, ureter, vesico-ureteral reflux, urination disorders Between April 1987 and September 1988 the ureter was replaced by ileum in 45 men and 5 women of a mean age of 42 years. Of the patients 39 underwent ureteral replacement for bilharziasis of the ureter and the remainder for a variety of ureteral injuries. All patients underwent unilateral ureteral replacement. The 50 patients were prospectively randomized between 2 equal treatment groups. In group 1 a standard ileal ureter procedure was performed, while group 2 underwent a modified ileal ureter procedure. For the standard ileal ureter we used the technique described by Goodwin et al,l and Ghoneim and Shoukry.2 The modified operation consisted of 2 adjuvant procedures, that is tailoring of the ileal segment and incorporation of a distal nonrefluxing nipple valve at the site of ileovesical anastomosis. Early results of this study have been reported previously3 and indicated that the modified operation is functionally superior to the standard procedure as ultimately reflected by better renal function on renography andlor chemical creatinine clearance studies. However, the longest followup in that series was 28 months, which may not be long enough to indicate permanent functional superiority of the modified ileal ureter procedure. We present a multiple year followup of this same series. PATIENTS AND METHODS

Of the 25 patients in g o u p 1 and 25 in group 2,19and 20, respectively, were available for followup a t 69 5 5.8 months (range 60 to 80).Of the 8 patients lost to followup 1in each group died of unrelated causes and 6 leR the country. Patients were regularly followed at least once every year. A chemical profile, including serum creatinine clearance, plasma electrolytes (sodium and potassium) and blood gases, was obtained. A quantitative urine culture with identification of the organism was done. Urine flow rates, urinary tract plain x-ray and ascending cystography were performed in all patients. Excretory urography (IVP)was done in 29 patients and was deferred in the remainder due to high serum creat-

inine levels. In addition, selective renographic clearance was determined using ge”technetium-diethylenetriaminepentaacetic acid renal scans. In this series a change in renographic or creatinine clearance of greater than 20% of the preoperative value was considered objective evidence of improvement or deterioration. Changes of less than 20% of the preoperative value were considered to indicate stable function. The value of 20% was chosen to guard against errors in measurementa.4.6 RESULTS

The delayed complications are summarized in table 1.All patients in p u p 1 had reflux,and 5 of 23 in group 2 (22%) had reflux due to delayed dessusception of the nipple valve 2 to 4 years after the initial operation and no W e r reconstxuction was done. Bladder atones were not noted in group 1 and were detected in 4 patients in group 2 (17%): 2 with an intact nipple valve and 2 with a dessuscepted valve (fig. 1). All patients with bladder stones underwent tramurethral cystolitholapaxy.Five patients in p u p 1and only 1in group 2 had urinary outflow obstruction. Metabolic acidosis was observed in 9 patients in group 1 (47%),while in group 2 it was noted in 2 of 5 with a dessuscepted valve and in 2 of 18 with an intact valve. The difference in the incidence of metabolic acidosis in group 1(9of 19 patients) and group 2 without reflux (2of 18)was statistically significant (p <0.05). The correlation between the hcidence of metabolic acidosis and the preoperative creatinine clearance is shown in table 2. Regardless of the surgical

TABLE1. &laved comDlieatwns

- .

Complication

Gmun 2 Group 1 (19pte.) NoRenUr re nu^ Totale (18 pb.) (6 pb.) (23 pb.)

Deasuseeption of nipple valve Bladder stones 2 6 urinarg outflow obstruction 9 2 Metabolic aadosis A patient m a y have more than 1 eomplicatian

December 12,1994.

Urology and Nephrology Center, Man45

5 2 1 2

6 4 1 4

46

FURTHER EXPERIENCE WITH MODIFIED ILEAL URETER TABI.E3. Mean followup total creatrntne clearance conipared with

baseline preoperative clearance Group 2 Renal Function

Group 1 I 19 pts.)

Improved Stable

No Reflux I18 pts.1

Reflux ( 5 pts.)

9 9

-

3 4

-

2

12

netwinratinn

3

Totals

(23 pts.) 9 12 2

~-

Group 1 versus entire group 2 (chi-square 6.17. p = 0.0457). group 1 versus group 2 without reflux (chi-square 7.4, p = 0.02).

FIG. 1. Plain x-ray shows multiple bladder stones formed around dispersed metallic staples 2 years after tailored and valved (moditied) ileal ureter procedure. TABLE2 . Correlation between metabolic acidosis and preoperative creatinine clearance No. With Metabolic AcidosisTotal (% 1

Preop. Creatinine Clearance lml./min.)

Less than 40 More than 40

Group 1

Group 2

6/7 (86) 3/12 (251

315 (60) 1/18 15.5)

in renal function were comparable among patients in both treatment groups. On the other hand, comparison between patients in group 1 and those without reflw in group 2 showed statistically significantly better functional results in the latter group. Urine bacteriology revealed evidence of urinary tract infection in 10 of 19 patients in group 1 (53%)and in 14 of 23 in group 2 (61%,),which was not significantly different. Pseudomonas was the most common offending organism, demonstrated in a third of the infected patients. Changes in the configuration of the corresponding renal units compared to a baseline Ivp are shown in table 5. There was no significant difference between the 2 treatment groups. DISCUSSION

technique used, 69% of the patients with metabolic acidosis had a preoperative creatinine clearance of less than 40 ml. per minute. The values for total creatinine clearance are shown in figure 2. Although there was no significant difference between the preoperative values in both treatment groups (54.6 -t 22.5 versus 63.7 2 24.1 ml. per minute, p = O . l l ) , mean followup values were significantly better in group 2 (57.5 ? 22.2 versus 71.6 -t 26.8 ml. per minute, p = 0.04).The finding of an increased creatinine clearance postoperatively regardless of the type of ileoureteral replacement is obviously due to relief of ureteral obstruction. Screening of total creatinine clearance by comparison of the preoperative and followup values in every patient is summarized in table 3. Although the difference was marginal between both treatment groups (p = 0.045), a statistically significant superiority of group 2 patients without reflux was evident (p = 0.02). The preoperative and mean followup renographic selective clearance values for the corresponding renal units are shown in figure 3 and summarized in table 4. Overall, the changes

The effect of an ileal ureter with reflux is a subject of controversy. The experience gained a t the University of California a t Los Angeles is that the bowel segment acts as a bumper protecting the kidney from higher pressures in the bladder.6 Fritzsche et a1 noted that despite reflw from the bladder into the bowel segment, renal architecture and function can be well preserved if no bladder outlet obstruction exists, which can cause dilatation and s t a s i ~ .Some ~ investigators stated that when the bladder is normal an antireflux ileovesical anastomosis is not always necessary.1.6,8On the other hand, many have reported the disadvantages of reflw in an ileal ureter. Tanagho stated that the ileal ureter with reflw is constantly subjected to intermittently high vesical pressures, which will lead to gradual lengthening and widening of the ileal ureter, in turn perpetuating other pathological conditions (residual urine, infection, stone formation and urine absorption).V Hendren stated that if a bowel segment is used to connect the upper tract to the bladder in young patients with potential longevity, it is important to perform the anastomosis via an antireflux technique to prevent infection and upper tract deterioration. lo

B

A

BEFORE

AFTER

1M

,

-

8

BEFORE

AFTER

FIG.2. Total mean preoperative and postoperative creatinine clearance levels w r e 54.6 22.5 ml. per minute (rangr 20 to 100,a n d 57.2 2 25.2 ml. per minute (range 15 t o 1201, respectively, in group 1 ( A ] .and 63.7 !~ 24.1 ml. ppr minute (range 28 t o 110) and 71.6 26.8 mi. per minute (range 24 to 115,. respectively. in group 2 ( H I . +

FURTHER EXPERIENCE WITH MODIFIED ILEAL URETER

47

FIG. 3. Mean selec ive renographic clearances of correspondingre a1 units preoperatively and postoperatively were 28.2 ? 8.3 ml. per minute (range 12 to a !)and 31 5 11.5 ml.per minute (range 10 to 51 respectively,in group 1 (A), and 28.9 2 8.8 ml. per minute (range 15 to 50) and 32.2 ir 10 . ml. per minute (range 14 to 52), respectively, n group 2 (I?). TABLE 4. Mean followup selective renographic clearance compared with baseline preoperative clearance Group 2

Renal Function

Group (19pts.)

NoRefl~ (18 pts.)

~

Reflu

Totals

( 5 pts.)

(23 pts.)

~~~~~~

11 11 11 Improved 3 10 3 7 Stable 5 2 2 Deterioration Group 1 versus entire ~ O U D2 (chi-square 4.72, p = 0.09), group. 1 v e m u group 2 without reflw (ck-square 6 . 5 6 ; ~= 0.037);

TABLE5. Configurationof corresponding renal units compared with baseline N p Group 2

IVP

Group 1 (12pt.5.)

NoRefl~

Reflu

(14 pts.)

(3 pts.)

Improved 5 7 Stable 4 6 2 Deterioration 3 1 1 Group 1 versus entire p u p 2 (chi-square 0.6, p = 0.7).

Totals (17 pts.) 7 8

2

Analysis of our data has demonstrated that reflux prevention is of critical importance in the long-term preservation of renal function after ileal replacement of the ureter. Patients in group 2 who maintained a stable nipple valve have demonstrated a statistically signscant functional superiority over those with a simple ileal ureter with reflux. The absence of a sigdicant difference in morphological changes of mrresponding renal units with and without reflux in the ileal ureter could be explained by the small sample size of patients who underwent a n IVP. The observation that 5 patients in group 1 and only 1 in group 2 had urinary outflow obstruction could be explained by a functional decrease in outflow due to refluxed and retained urine. Moreover, tailoring among group 2 patients would decrease the surface area and decrease mucus formation, which is supported by our previous observation that urine viscosity was sigdicantly greater in group L3This increase in urine viscosity may also explain the greater incidence of outflow obstruction in group 1. The incidence of metabolic acidosis was greater in group 1. However, regardless of the surgical technique used, most patients who had this complication also had a preoperative creatinine clearance of less than 40 ml. per minute (6 of 7 in group 1and 3 of 5 in group 2, table 2),which indicates that total creatinine clearance of 40 ml. per minute seems to be the critical value below which the functional results of ileoureteral replacement are not satisfactory.

The antireflux surgical technique used in our series was associated with significant problems. The use of a nipple valve could not prevent reflux in 6 of 25 patients during early f0ll0~up3and in 5 of 23 during late followup. Furthermore, the use of metallic staples has resulted in formation of bladder stones in 17% of the patients. These observations urge urologists to search for another surgical technique that provides an efficient antireflux mechanism with the fewest possible complications. Hendren used a tunneling technique as an antireflux system after tailoring of the bowel conduit in children undergoing undiversion.10 A bowel conduit with a lumen diameter of approximately 1 cm.requires a tunnel length of at least 5 to 6 cm.and an adjuvant psoas hitch can be of great help in this procedure. Nabizadeh et al described a similar ileovesical anastomosis, experimentally and clinically.8 Their technique involves implantation of 3 inches of distal ileum (without tailoring) into a denuded muscular bed in the bladder. Vesical mucosa grows over the ileum, creating an effective valvular mechanism. However, the tunneling technique has not gained much popularity among most urological surgeons because of the technical difficulties. Tailoring of ileum would decrease the cross-sectional diameter, improve propulsion of the urinary bolus, limit the absorbing surface area and decreaee mucus formation.11*12The contribution of tailoring in our series is hard to evaluate. Tailoring may be partly responsible for the lower incidence of metabolic acidosis in group 2. Our overall results are markedly better when compared to our early resulta in 1983.'3 This significant difference could be attributed to better patient selection together with improved surgical techniques. CONCLUSIONS

Reflux prevention is of central importance in preservation of renal function in patients with an ileal ureter. A distal nipple valve at the ileovesical junction is associated with significant problems. These observations invite urological surgeons to search for a more suitable procedure that provides an efficient antireflux mechanism with minimal adverse sequelae. REFERENCES

1. Goodwin, W. E.,Winter, C. C. and Turner, R. D.: Replacement of the ureterby small intestine: clinical application and resulta of the Weal ureter."J. Urol., 81: 406, 1959. 2. Ghoneim, M.A. and Shouluy, I.: The use of ileum for correction of advanced or complicated bilhanial lesions of the urinary tract. Int. Urol. Nephrol., 4: 25,1972. 3. Shokeir, A.A., Gaballah,M. A., Ashamallah, A.A.and Ghoneim. M. A:Optimization of replacement of the ureter by ileum. d.

48

FURTHER EXPERIENCE WITH MODIFIED ILEAL URETER

Urol., 146:306, 1991. 4. Shokeir, A A., Gad, H. M., Shaaban, A A, el-Kenawy, M. R., El-Sherif, A., Shamaa, M. A., Bakr. M. A. and Ghoneim, M. A.: Differential kidney scans in preoperative evaluation of kidney donors. Transplant. h., 25:2327, 1993. 5. Britton, K and Whitfield, H.: The radionuclide measurement of disordered renal function. In: Scientific Foundations of Urology. Edited by G. D. Chisholm and D. I. Williams. London: William Heinemann Medical Books Ltd., chapt. 9,pp. 6&74, 1982. 6. Boxer, R. J., Fritzsche, P., Skinner, D. G., Kaufman, J. J., Belt, E., Smith, R. B. and Goodwin, W. E.: Replacement of the ureter by small intestine: clinical application and results of the ileal ureter in 89 patients. J. Urol., 121: 728,1979. 7. Fritzsche, P.. Skinner, D. G., Craven, J. D., Cahill, P. and Goodwin, W. E.: Long-term radiographic changes of the kidney

following the ileal ureter operation. J. Urol., 1 1 4 843,1975. 8. Nabizadeh, I., Reid, R. E. and Henderson, J. L.: Simplified nonrefluxing ileovesical anastomosis. Experimental study and clinical application. Urology, 1 8 11, 1981. 9. Tanagho, E. A,: A case against incorporation of bowel segments into the closed urinary system. J. Urol., 113 796, 1975. 10. Hendren, W. H.:Tapered bowel segment for ureteral replacement. Urol. Clin. N. Amer., 5 607,1978. 11. Charghi, A,: Ureteral replacement using a new variation of the tailored ileal segment. J. Urol., 121: 598,1979. 12. Waters, W.B., Whitmore, W. F., 111, Lage, A. L. and Gittes, R. F.: Segmental replacement of the ureter using tapered and nontapered ileum. Invest. Urol., 1 8 258, 1981. 13. Bazeed, M.A.,El-Rakhawy, M.,Ashamallah, A,, El-Kappany, H. and El-Hammady, S.: Ileal replacement of the bilharzial ureter: is it worthwhile? J. Urol., 130 245, 1983.