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Ureteral stenosis after kidney transplantation: interventional radiology or surgery?
Ureteral Stenosis After Kidney Transplantation: Interventional Radiology or Surgery? A. Faenza, B. Nardo, F. Catena, M.P. Scolari, A. Buscaroli, and G.L. D’Arcangelo
U
RETERAL obstruction with impaired urine flow is the most common urologic complication following kidney transplantation (KT): some authors report a certain amount of graft loss and operative mortality.1 Ureteral stenosis (US) may appear days or years after KT with an incidence ranging from 2% to 7%.2 Because the renal graft is denervated, the evolution of a stricture is usually asymptomatic until graft failure sets in. Aware of this fact and of its frequency, today all recipients are submitted to ultrasonographic and clinical monitoring. Moreover, US deserves some attention because it can frequently be corrected with a long-lasting success rate and because the therapy of this condition has changed in the last few years; the recent advances in percutaneous radiologic maneuvers have significantly replaced surgical revision of the implant.3 The aim of this paper was to evaluate today’s indication for surgery and interventional radiology in correcting the US after KT.
MATERIALS AND METHODS Between October 1976 and December 1999 our Kidney Transplant Group performed 1000 renal allografts, 102 from living and 898 from cadaver donors. The charts of donors and recipients have been reviewed and all data were collected along with the surgical procedures, interventional radiology maneuvers, and early and late patient outcome. In 805 of 1000 transplant recipients, reestablishment of the urinary tract was performed through an ureteroneocystostomy (UNC) according to Lich-Gregoir. In 18 patients this technique was not feasible because of fragility of the bladder mucosa and we turned to the Politano technique. No stents were ever used. An end-to-end uretero-ureteric anastomosis (U-U) was adopted in 177 patients. In the cases of US submitted to surgery an U-U was used; the ipsilateral ureter or the contralateral were employed. When using the native ureter for the anastomosis, the proximal portion was always tied off performing a nephrectomy if necessary. In a few cases a new UNC was performed. In the cases of US submitted to operative radiology, a percutaneous nephrostomy catheter was inserted under local anesthesia and echographic control. After the insertion of the guide, a straight tipped nephrostomy catheter was positioned beyond the stricture and replaced by a rigid superstiff catheter. A high pressure balloon was then inserted and advanced to the stricture and inflated; when the pressure dents on the balloon disappeared the stricture had been dominated, a double pigtail stent was passed into the ureter. At the end the stent was removed by cystoscopy. © 2001 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010
RESULTS
No US was observed in the 102 patients who received a graft from living donors. Cadaver donor kidneys were used in 861 first grafts and 29 strictures were reported. Regrafts were necessary in 37 cases: two late strictures developed in the last group. Altogether 31 cases of US appeared from a few days to 13 years after transplantation among 1000 kidney grafts with an overall incidence of 3.1%. US was present from the beginning in 7 patients and in all of them it was at the UNC level; they all were reoperated, except one patient who refused and has worn a stent for 3 years. In 24 cases US was a late complication (from 3 months to 13 years after the graft) as a consequence of a variety of possible etiologies mainly acute or chronic rejection (CR); in all these cases the US was extended to long segments of all the ureter. Two of those late US patients had no treatment for bad general conditions and for advanced CR. Percutaneous dilatation and stenting was tried 12 times but in two patients it was not possible to overtake the US. Out of the remaining 10 patients a final correction was obtained in only four cases because two patients went back to hemodialysis (HD) early and four recipients had a recurrence of the US as soon as the stent was taken off and they were operated. Altogether 16 late US were surgically corrected; 1 had repeated urinary fistulas with severe acute rejection and he lost the kidney, 4 resumed HD in a short time due to CR, and 11 had a good and long lasting result (from 6 months to 13 years, average 6.2 years). DISCUSSION
Antegrade catheterization of the pelvis and ureter under radiologic guidance are employed not only in reestablishing urine flow and in assessing the true importance of the strictured ureter on renal function but also in correcting the obstruction. We agree with Rosenthal4 who states that “probably the operative intervention continues to be the mainstay for the majority of the patients,” but interventional radiology offers an excellent options to temporize From the Departments of Surgery and Transplantation Nephrology, University of Bologna, Bologna, Italy. Address reprint requests to Professor A. Faenza, Chirurgia II, Pol. S. Orsola, Via Massarenti 9, 40138 Bologna, Italy. 0041-1345/01/$–see front matter PII S0041-1345(00)02783-4 2045
Transplantation Proceedings, 33, 2045–2046 (2001)
2046
surgery, select the right patients to operate and sometimes reduce the number of patients who need an intervention more or less by 50%.5 In our patients, stricture dilatation and stent positioning were always attempted except in early “technical” US where surgery was best option in our opinion because the US was always at the UNC level and a dilatation of the ureterovescical junction could leave a reflux. Stent positioning, when successful, resulted in good urine outflow for long periods of time. In patients with advanced CR, this can be a good definitive solution that prolongs graft function. The withdrawal of the stent was followed by a permanent satisfactory dilatation of the US in four patients and recurrence in the other four. Even in these cases, the stents proved to be harmless; whenever an infection set in, the stent was simply removed and in no case did the kidney graft suffer permanent damage. We had never attempted to position stents through cystoscopy. In our opinion a percutaneous pyelostomy under local anesthesia with dilatation of the stricture is less traumatic and causes fewer infections. Our policy was never to maintain long-term pyelostomies; if the stent passed beyond the stenosis we removed the pyelostomy leaving the stent in situ to be pulled out by cystoscopy at the right moment; if the stricture was too tight and renal function remained normal we preferred to operate. In the past, revision of a strictured ureter of a transplant often caused graft loss and even a certain mortality. Kinnaert et al1 recognized the difficulty of repeat surgery, especially when using the extraperitoneal approach where tissue damage forms blood and lymphatic collections which may easily be infected.1 We met the same difficulties but without problems in our first cases then we turned to the easier and safer transperitoneal approach.
FAENZA, NARDO, CATENA ET AL
The U-U or the uretero-pyelostomy with a vital native ureter were the best solution. Preoperative assessment of the native ureter was not essential; it was sufficient to assess the absence of a reflux from the history and to verify the ureter at surgery. If the ipsilateral ureter was not available, it was possible to use the contralateral one. The proximal stump of the ureter in the U-U patients, always tied off and abandoned, did not give early or late complications. In conclusion, interventional radiology can correct some cases of US but it is most useful to temporize surgery and to select the right patients to operate; it is not always easy to understand whether an elevated creatinine level is a consequence of the US or advanced CR. Surgical correction is a good, safe, and long-lasting option preferable to long-time stenting in all the early cases and all the late cases with good renal function. Because the nontechnical US usually involve large segments of the distal ureter during the last 300 kidneys, we diminished the number of UNC adopting the U-U whenever the patient had a normal ureter and less than 300 cc of residual diuresis with the hope of diminishing the incidence of late US with a shorter transplant ureter. We used to perform a contemporary nephrectomy only in cases of marginal kidneys. REFERENCES 1. Kinnaert P, Hall M, Janssen F, et al: J Urol 133:17, 1985 2. Faenza A, Spolaore R, Selleri S, et al: Contrib Nephrol 70:75, 1989 3. Faenza A, Nardo B, Catena F, et al: Transpl Int 12:334, 1999 4. Rosenthal JT: J Urol 150:1121, 1993 5. Peregrin Filipova H, Matl I, Vitko S, et al: Transplant Proc 29:140, 1997
U
RETERAL obstruction with impaired urine flow is the most common urologic complication following kidney transplantation (KT): some authors report a certain amount of graft loss and operative mortality.1 Ureteral stenosis (US) may appear days or years after KT with an incidence ranging from 2% to 7%.2 Because the renal graft is denervated, the evolution of a stricture is usually asymptomatic until graft failure sets in. Aware of this fact and of its frequency, today all recipients are submitted to ultrasonographic and clinical monitoring. Moreover, US deserves some attention because it can frequently be corrected with a long-lasting success rate and because the therapy of this condition has changed in the last few years; the recent advances in percutaneous radiologic maneuvers have significantly replaced surgical revision of the implant.3 The aim of this paper was to evaluate today’s indication for surgery and interventional radiology in correcting the US after KT.
MATERIALS AND METHODS Between October 1976 and December 1999 our Kidney Transplant Group performed 1000 renal allografts, 102 from living and 898 from cadaver donors. The charts of donors and recipients have been reviewed and all data were collected along with the surgical procedures, interventional radiology maneuvers, and early and late patient outcome. In 805 of 1000 transplant recipients, reestablishment of the urinary tract was performed through an ureteroneocystostomy (UNC) according to Lich-Gregoir. In 18 patients this technique was not feasible because of fragility of the bladder mucosa and we turned to the Politano technique. No stents were ever used. An end-to-end uretero-ureteric anastomosis (U-U) was adopted in 177 patients. In the cases of US submitted to surgery an U-U was used; the ipsilateral ureter or the contralateral were employed. When using the native ureter for the anastomosis, the proximal portion was always tied off performing a nephrectomy if necessary. In a few cases a new UNC was performed. In the cases of US submitted to operative radiology, a percutaneous nephrostomy catheter was inserted under local anesthesia and echographic control. After the insertion of the guide, a straight tipped nephrostomy catheter was positioned beyond the stricture and replaced by a rigid superstiff catheter. A high pressure balloon was then inserted and advanced to the stricture and inflated; when the pressure dents on the balloon disappeared the stricture had been dominated, a double pigtail stent was passed into the ureter. At the end the stent was removed by cystoscopy. © 2001 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010
RESULTS
No US was observed in the 102 patients who received a graft from living donors. Cadaver donor kidneys were used in 861 first grafts and 29 strictures were reported. Regrafts were necessary in 37 cases: two late strictures developed in the last group. Altogether 31 cases of US appeared from a few days to 13 years after transplantation among 1000 kidney grafts with an overall incidence of 3.1%. US was present from the beginning in 7 patients and in all of them it was at the UNC level; they all were reoperated, except one patient who refused and has worn a stent for 3 years. In 24 cases US was a late complication (from 3 months to 13 years after the graft) as a consequence of a variety of possible etiologies mainly acute or chronic rejection (CR); in all these cases the US was extended to long segments of all the ureter. Two of those late US patients had no treatment for bad general conditions and for advanced CR. Percutaneous dilatation and stenting was tried 12 times but in two patients it was not possible to overtake the US. Out of the remaining 10 patients a final correction was obtained in only four cases because two patients went back to hemodialysis (HD) early and four recipients had a recurrence of the US as soon as the stent was taken off and they were operated. Altogether 16 late US were surgically corrected; 1 had repeated urinary fistulas with severe acute rejection and he lost the kidney, 4 resumed HD in a short time due to CR, and 11 had a good and long lasting result (from 6 months to 13 years, average 6.2 years). DISCUSSION
Antegrade catheterization of the pelvis and ureter under radiologic guidance are employed not only in reestablishing urine flow and in assessing the true importance of the strictured ureter on renal function but also in correcting the obstruction. We agree with Rosenthal4 who states that “probably the operative intervention continues to be the mainstay for the majority of the patients,” but interventional radiology offers an excellent options to temporize From the Departments of Surgery and Transplantation Nephrology, University of Bologna, Bologna, Italy. Address reprint requests to Professor A. Faenza, Chirurgia II, Pol. S. Orsola, Via Massarenti 9, 40138 Bologna, Italy. 0041-1345/01/$–see front matter PII S0041-1345(00)02783-4 2045
Transplantation Proceedings, 33, 2045–2046 (2001)
2046
surgery, select the right patients to operate and sometimes reduce the number of patients who need an intervention more or less by 50%.5 In our patients, stricture dilatation and stent positioning were always attempted except in early “technical” US where surgery was best option in our opinion because the US was always at the UNC level and a dilatation of the ureterovescical junction could leave a reflux. Stent positioning, when successful, resulted in good urine outflow for long periods of time. In patients with advanced CR, this can be a good definitive solution that prolongs graft function. The withdrawal of the stent was followed by a permanent satisfactory dilatation of the US in four patients and recurrence in the other four. Even in these cases, the stents proved to be harmless; whenever an infection set in, the stent was simply removed and in no case did the kidney graft suffer permanent damage. We had never attempted to position stents through cystoscopy. In our opinion a percutaneous pyelostomy under local anesthesia with dilatation of the stricture is less traumatic and causes fewer infections. Our policy was never to maintain long-term pyelostomies; if the stent passed beyond the stenosis we removed the pyelostomy leaving the stent in situ to be pulled out by cystoscopy at the right moment; if the stricture was too tight and renal function remained normal we preferred to operate. In the past, revision of a strictured ureter of a transplant often caused graft loss and even a certain mortality. Kinnaert et al1 recognized the difficulty of repeat surgery, especially when using the extraperitoneal approach where tissue damage forms blood and lymphatic collections which may easily be infected.1 We met the same difficulties but without problems in our first cases then we turned to the easier and safer transperitoneal approach.
FAENZA, NARDO, CATENA ET AL
The U-U or the uretero-pyelostomy with a vital native ureter were the best solution. Preoperative assessment of the native ureter was not essential; it was sufficient to assess the absence of a reflux from the history and to verify the ureter at surgery. If the ipsilateral ureter was not available, it was possible to use the contralateral one. The proximal stump of the ureter in the U-U patients, always tied off and abandoned, did not give early or late complications. In conclusion, interventional radiology can correct some cases of US but it is most useful to temporize surgery and to select the right patients to operate; it is not always easy to understand whether an elevated creatinine level is a consequence of the US or advanced CR. Surgical correction is a good, safe, and long-lasting option preferable to long-time stenting in all the early cases and all the late cases with good renal function. Because the nontechnical US usually involve large segments of the distal ureter during the last 300 kidneys, we diminished the number of UNC adopting the U-U whenever the patient had a normal ureter and less than 300 cc of residual diuresis with the hope of diminishing the incidence of late US with a shorter transplant ureter. We used to perform a contemporary nephrectomy only in cases of marginal kidneys. REFERENCES 1. Kinnaert P, Hall M, Janssen F, et al: J Urol 133:17, 1985 2. Faenza A, Spolaore R, Selleri S, et al: Contrib Nephrol 70:75, 1989 3. Faenza A, Nardo B, Catena F, et al: Transpl Int 12:334, 1999 4. Rosenthal JT: J Urol 150:1121, 1993 5. Peregrin Filipova H, Matl I, Vitko S, et al: Transplant Proc 29:140, 1997