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Balloon Dilation of Upper Ureteral Strictures in Primates
0022-5347 /86/1361-0342$02.00/0 Vol. 136, July
THE JOURNAL OF UROLOGY
Copyright © 1986 by The Williams & Wilkins Co.
Printed in U.S.A.
BALLOON DILATION OF UPPER URETERAL STRICTURES IN
PRIMATES NEAL SHORE, FRANCIS F. BARTONE, ANDREW MILLER, LOWELL R. KING AND DION DU PLESSIS From the Department of Urology and H. A. Grove Research Center, University of Pretoria, Pretoria, South Africa; Division of Urology, Duke University Medical Center, Durham, North Carolina, and Section of Urology, University of Nebraska Medical Center, Omaha, Nebraska
ABSTRACT
We report the successful creation of ureteral strictures in primates and their successful management by balloon dilation 3 months later without ureteral stenting. This experimental work confirms the sporadic clinical reports of the effectiveness of balloon dilation in the management of ureteral strictures and suggests that ureteral stenting is not necessary for a successful result. We have reported balloon dilation of ureteral strictures using dogs as an animal model.1 Of 17 dogs with narrow upper ureters hydronephrosis developed in 14. Of 8 animals undergoing dilation 3 weeks to 5 months after the hydronephrosis 7 improved or returned to normal. We also reported a similar clinical experience in 12 patients. 2 Several articles have been published in which balloon dilation of ureteral strictures3- 7 and ureteropelvic junction obstruction8 has been performed successfully. An experiment was designed to create upper ureteral obstructions in baboons, which simulate failed pyeloplasties in humans, and to treat them with balloon dilation. The adult baboon ureters are approximately the size of the ureters of a 4 to 10-year-old child. In all previous clinical studies stents were used after dilation, and we were interested in determining if stents were necessary. MATERIALS AND METHODS
Twelve adult baboons had the right ureters narrowed as close to the ureteropelvic junction as possible (baboons have intrarenal pelves). The ureter was exposed through a flank incision via a retroperitoneal approach. A third of the circumference of a 1.5 cm. segment of ureter was excised and the defect was closed with 5 or 6-zero chromic sutures over a 4F ureteral catheter. The catheter was left indwelling for 6 days and was removed via a cystotomy incision. Excretory urograms (IVPs) were made at intervals of approximately 2 months, beginning 6 weeks postoperatively. The animals in which strictures developed had the strictures dilated by passing a balloon catheter, 4 mm. in diameter with a 3 cm. balloon, into the stricture over a guide wire that had been passed previously. In 5 instances this was done via a cystostomy and in 1 case via a percutaneous nephrostomy. The balloon was distended to a pressure of 6 atmospheres and the dilation lasted 20 seconds. If the entire balloon could be distended without a "waist" on the first attempt, no further attempts were made to dilate the stricture (1 case). It was necessary to distend the balloon twice in 4 animals and 3 times in 1. The ureters were dilated within 3 months of the original operation and in some instances as early as 2 months. In no case was the ureter stented after dilation. The treated animals and the controls then were maintained for an additional 7½ months. RESULTS
In 10 of the 12 baboons the ureters were narrowed successfully. One animal died postoperatively and in 1 hydronephrosis did not develop. Supported in part by W ellcome S. A. Grant Kidney Project and The Barringer Endowment Fund. 342
Of the 10 animals with strictures 6 underwent balloon dilation and 4 were kept as controls. The balloon dilation was technically successful in all instances. The final IVP at 7½ to 8 months after dilation showed that 5 of 6 ureters exhibited improvement in the degree of hydronephrosis (see figure). In 1 instance the ureter seemed to be completely normal (see table). Hydronephrosis persisted in all 4 of the control animals. A nephrectomy was done in the baboon with persistent hydronephrosis after dilation, in several animals successfully treated and in 1 control. The animal that had persistent hydronephrosis after balloon dilation is of particular interest. A large polyp was in the lumen of the ureter, which probably represented viable mucosa that was turned-in at the time of the ureteral narrowing. Because the polyp virtually filled the lumen of the ureter, it is not surprising that balloon dilation was unsuccessful. In the other treated animals the ureter remained slightly narrowed microscopically but the lumen was intact, covered circumferentially with smooth, healthy-appearing mucosa and of normal thickness. Microscopic examination of the stricture did not reveal abnormal changes in the ureteral mucosa or musculature, except for slightly increased, patchy infiltration with lymphocytes that were seen in only 2 specimens. DISCUSSION
Several individual case reports and small series attest to the effectiveness of balloon dilation in the treatment of secondary strictures of the ureteropelvic junction. 3•8 Most of the success has been reported in cases in which the dilation occurred within approximately 4 months of the original operation. The standard treatment has been the insertion of a nephrostomy tube for drainage, in the hope that the edema will subside and the junction will open. It is our contention that balloon dilation of ureteral obstruction, either by the transurethral or percutaneous route, carries less morbidity than an interval of nephrostomy drainage. In most of the clinical studies in which balloon dilation has been used to correct obstruction internal stents have been used after the dilation. 2 • 5 - 7 In this study and the dog study the result has been successful without stenting. The disadvantage of stenting is that internal stents require cystoscopy and anesthesia in children for removal. External stents have even greater disadvantages, especially in the young patient. Several authors have reported incising the ureteropelvic obstruction with a cold knife inserted through a dilated percutaneous nephrostomy tract. 9• 10 The consensus seems to be that the procedure is limited to patients who have short ureteral strictures, low ureteral insertions and moderately enlarged pelves. Balloon dilation can be used in any case in which a guide wire can be passed through the stricture, making balloon dilation a much more attractive technique if successful.
BALLOO~J DILATIOis.J
or
343
U?PEft Uf{ETE~:AL STRICTU-ItES
Baboon 172-83. A, IVP 3½ months after upper ureteral narrowing shows guide wire in ureter. B, balloon dilation of ureteral stricture. C, slight residual hydronephrosis remains 7½ months after single balloon dilation. No stent was used after dilation.
Baboons in treatment group: outcome of balloon dilation of upper ureteral strictures Animal No. 75-82 164-183 73-82 47-83 172-83
156-83
IVP After Stricture Mild hydronephrosis Mild hydronephrosis Moderate to severe hydronephrosis Moderate hydronephrosis Moderate hydronephrosis Moderate hydronephrosis
Duration of Obstruction
Dilation Route
IVP After Balloon Dilation
Duration of Subsequent Observation (mos.)
3V2 mos. 3½ mos. 14 wks.
Biadder Bladder Bladder
Normal Normal No change
8
14 wks.
Bladder
Mild hydronephrosis improved Slight residual hydronephrosis improved Mild hydronephrosis improved
8
3½ mos.
Bladder
3½ mos.
Percutaneous nephrostomy
Although we have confirmed the results in had obtained in and successfully many questions need to be answered. The diameter of ureteral stretching, time of dilation and the pressme used to dilate the ureter have not been v.~'""v~, nor has the ne,ces:sn,y or usefulness of stenting. We have confirmed the PvnP,r11cnsm method of ureteral strictures and have contributed further evidence that balloon dilation may be an effective method of LH,at,LH,', C:,SCvVH.U
8 8
7½
8
dilatation of benign ureteral strictures. Radiology, 14 7: 427, 1983. 4. Reimer, D. E. and Oswalt, G. C., Jr.: Iatrogenic ureteral obstruction tl·eated with balloon dilation. J. Urol., 126: 689, 1981. 5. it.h,Prini,tn,n R. and Shelor, vV. C.: Treatment of postoperative stricture by catheter dilation: a forgotten procedure. 16: 1980. P. and H. M.: Dilatation of ureteral stenoses: .••.. _•.•,..•• and e::perience in 44 patients. Amer. J. Roentgen., 1984. D. H., Butt, K., Rubin, B., Hong, J. and Sclafani, · Percutaneous transrenal balloon dilatation of the ureter. 149: 101, 1983. R. I., Jr. and Engel, R.: Balloon dilatation of a obstruction. Radiology, 143: 263, 1982. Mills, V., Miller, R. A. and Wickham, J. E. A.: an alternative to pyeloplasty. Brit. J. 1983. 10. Miller, R. A., Kellett, M. J., Blackford, H. N., Wickham, J.E. and Whitfield, H. N.: Percutaneous pyelolysis: indications, complications and results. Brit. J. Urol., 56: 586, 1984.
THE JOURNAL OF UROLOGY
Copyright © 1986 by The Williams & Wilkins Co.
Printed in U.S.A.
BALLOON DILATION OF UPPER URETERAL STRICTURES IN
PRIMATES NEAL SHORE, FRANCIS F. BARTONE, ANDREW MILLER, LOWELL R. KING AND DION DU PLESSIS From the Department of Urology and H. A. Grove Research Center, University of Pretoria, Pretoria, South Africa; Division of Urology, Duke University Medical Center, Durham, North Carolina, and Section of Urology, University of Nebraska Medical Center, Omaha, Nebraska
ABSTRACT
We report the successful creation of ureteral strictures in primates and their successful management by balloon dilation 3 months later without ureteral stenting. This experimental work confirms the sporadic clinical reports of the effectiveness of balloon dilation in the management of ureteral strictures and suggests that ureteral stenting is not necessary for a successful result. We have reported balloon dilation of ureteral strictures using dogs as an animal model.1 Of 17 dogs with narrow upper ureters hydronephrosis developed in 14. Of 8 animals undergoing dilation 3 weeks to 5 months after the hydronephrosis 7 improved or returned to normal. We also reported a similar clinical experience in 12 patients. 2 Several articles have been published in which balloon dilation of ureteral strictures3- 7 and ureteropelvic junction obstruction8 has been performed successfully. An experiment was designed to create upper ureteral obstructions in baboons, which simulate failed pyeloplasties in humans, and to treat them with balloon dilation. The adult baboon ureters are approximately the size of the ureters of a 4 to 10-year-old child. In all previous clinical studies stents were used after dilation, and we were interested in determining if stents were necessary. MATERIALS AND METHODS
Twelve adult baboons had the right ureters narrowed as close to the ureteropelvic junction as possible (baboons have intrarenal pelves). The ureter was exposed through a flank incision via a retroperitoneal approach. A third of the circumference of a 1.5 cm. segment of ureter was excised and the defect was closed with 5 or 6-zero chromic sutures over a 4F ureteral catheter. The catheter was left indwelling for 6 days and was removed via a cystotomy incision. Excretory urograms (IVPs) were made at intervals of approximately 2 months, beginning 6 weeks postoperatively. The animals in which strictures developed had the strictures dilated by passing a balloon catheter, 4 mm. in diameter with a 3 cm. balloon, into the stricture over a guide wire that had been passed previously. In 5 instances this was done via a cystostomy and in 1 case via a percutaneous nephrostomy. The balloon was distended to a pressure of 6 atmospheres and the dilation lasted 20 seconds. If the entire balloon could be distended without a "waist" on the first attempt, no further attempts were made to dilate the stricture (1 case). It was necessary to distend the balloon twice in 4 animals and 3 times in 1. The ureters were dilated within 3 months of the original operation and in some instances as early as 2 months. In no case was the ureter stented after dilation. The treated animals and the controls then were maintained for an additional 7½ months. RESULTS
In 10 of the 12 baboons the ureters were narrowed successfully. One animal died postoperatively and in 1 hydronephrosis did not develop. Supported in part by W ellcome S. A. Grant Kidney Project and The Barringer Endowment Fund. 342
Of the 10 animals with strictures 6 underwent balloon dilation and 4 were kept as controls. The balloon dilation was technically successful in all instances. The final IVP at 7½ to 8 months after dilation showed that 5 of 6 ureters exhibited improvement in the degree of hydronephrosis (see figure). In 1 instance the ureter seemed to be completely normal (see table). Hydronephrosis persisted in all 4 of the control animals. A nephrectomy was done in the baboon with persistent hydronephrosis after dilation, in several animals successfully treated and in 1 control. The animal that had persistent hydronephrosis after balloon dilation is of particular interest. A large polyp was in the lumen of the ureter, which probably represented viable mucosa that was turned-in at the time of the ureteral narrowing. Because the polyp virtually filled the lumen of the ureter, it is not surprising that balloon dilation was unsuccessful. In the other treated animals the ureter remained slightly narrowed microscopically but the lumen was intact, covered circumferentially with smooth, healthy-appearing mucosa and of normal thickness. Microscopic examination of the stricture did not reveal abnormal changes in the ureteral mucosa or musculature, except for slightly increased, patchy infiltration with lymphocytes that were seen in only 2 specimens. DISCUSSION
Several individual case reports and small series attest to the effectiveness of balloon dilation in the treatment of secondary strictures of the ureteropelvic junction. 3•8 Most of the success has been reported in cases in which the dilation occurred within approximately 4 months of the original operation. The standard treatment has been the insertion of a nephrostomy tube for drainage, in the hope that the edema will subside and the junction will open. It is our contention that balloon dilation of ureteral obstruction, either by the transurethral or percutaneous route, carries less morbidity than an interval of nephrostomy drainage. In most of the clinical studies in which balloon dilation has been used to correct obstruction internal stents have been used after the dilation. 2 • 5 - 7 In this study and the dog study the result has been successful without stenting. The disadvantage of stenting is that internal stents require cystoscopy and anesthesia in children for removal. External stents have even greater disadvantages, especially in the young patient. Several authors have reported incising the ureteropelvic obstruction with a cold knife inserted through a dilated percutaneous nephrostomy tract. 9• 10 The consensus seems to be that the procedure is limited to patients who have short ureteral strictures, low ureteral insertions and moderately enlarged pelves. Balloon dilation can be used in any case in which a guide wire can be passed through the stricture, making balloon dilation a much more attractive technique if successful.
BALLOO~J DILATIOis.J
or
343
U?PEft Uf{ETE~:AL STRICTU-ItES
Baboon 172-83. A, IVP 3½ months after upper ureteral narrowing shows guide wire in ureter. B, balloon dilation of ureteral stricture. C, slight residual hydronephrosis remains 7½ months after single balloon dilation. No stent was used after dilation.
Baboons in treatment group: outcome of balloon dilation of upper ureteral strictures Animal No. 75-82 164-183 73-82 47-83 172-83
156-83
IVP After Stricture Mild hydronephrosis Mild hydronephrosis Moderate to severe hydronephrosis Moderate hydronephrosis Moderate hydronephrosis Moderate hydronephrosis
Duration of Obstruction
Dilation Route
IVP After Balloon Dilation
Duration of Subsequent Observation (mos.)
3V2 mos. 3½ mos. 14 wks.
Biadder Bladder Bladder
Normal Normal No change
8
14 wks.
Bladder
Mild hydronephrosis improved Slight residual hydronephrosis improved Mild hydronephrosis improved
8
3½ mos.
Bladder
3½ mos.
Percutaneous nephrostomy
Although we have confirmed the results in had obtained in and successfully many questions need to be answered. The diameter of ureteral stretching, time of dilation and the pressme used to dilate the ureter have not been v.~'""v~, nor has the ne,ces:sn,y or usefulness of stenting. We have confirmed the PvnP,r11cnsm method of ureteral strictures and have contributed further evidence that balloon dilation may be an effective method of LH,at,LH,', C:,SCvVH.U
8 8
7½
8
dilatation of benign ureteral strictures. Radiology, 14 7: 427, 1983. 4. Reimer, D. E. and Oswalt, G. C., Jr.: Iatrogenic ureteral obstruction tl·eated with balloon dilation. J. Urol., 126: 689, 1981. 5. it.h,Prini,tn,n R. and Shelor, vV. C.: Treatment of postoperative stricture by catheter dilation: a forgotten procedure. 16: 1980. P. and H. M.: Dilatation of ureteral stenoses: .••.. _•.•,..•• and e::perience in 44 patients. Amer. J. Roentgen., 1984. D. H., Butt, K., Rubin, B., Hong, J. and Sclafani, · Percutaneous transrenal balloon dilatation of the ureter. 149: 101, 1983. R. I., Jr. and Engel, R.: Balloon dilatation of a obstruction. Radiology, 143: 263, 1982. Mills, V., Miller, R. A. and Wickham, J. E. A.: an alternative to pyeloplasty. Brit. J. 1983. 10. Miller, R. A., Kellett, M. J., Blackford, H. N., Wickham, J.E. and Whitfield, H. N.: Percutaneous pyelolysis: indications, complications and results. Brit. J. Urol., 56: 586, 1984.