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SPONTANEOUS PROXIMAL DOUBLE PIGTAIL URETERAL STENT MIGRATION AFTER SHOCK WAVE LITHOTRIPSY: “JACK” PHENOMENON
0022-5347/01/1664-1387/0 THE JOURNAL OF UROLOGY® Copyright © 2001 by AMERICAN UROLOGICAL ASSOCIATION, INC.®
Vol. 166, 1387, October 2001 Printed in U.S.A.
SPONTANEOUS PROXIMAL DOUBLE PIGTAIL URETERAL STENT MIGRATION AFTER SHOCK WAVE LITHOTRIPSY: “JACK” PHENOMENON WOOJIN KO, WOONGHEE LEE, JINWON JUNG
AND
MOOSANG LEE
From the Department of Urology Yonsei University College of Medicine, Seoul, Korea KEY WORDS: ureter, stents, lithotripsy
Double pigtail ureteral stents are used to prevent ureteral obstruction from calculi and allow easy passage of urine after extracorporeal shock wave lithotripsy (ESWL, Dornier Medical Systems, Inc., Marietta, Georgia).1 Although rare, proximal stent migration is one of the complications of indwelling stents. We report a case of cephalad migration of a double pigtail ureteral stent after ESWL. CASE REPORT
A 62-year-old man presented with bilateral flank pain and hematuria. Abdominal ultrasound revealed grades IV to V bilateral hydronephrosis. A retrograde pyelonephrogram showed a 2.5 ⫻ 1.5 cm. stone at L3 to L4 in the right ureter and a 2.0 ⫻ 1.5 cm. stone in the left ureter. After 5Fr 26 cm. double pigtail stents were placed in both ureters, the Dornier Compact-S (Dornier Medical Systems, Marietta, Georgia) lithotripter delivered 15 Kv. shockwaves 3,000 times to the right ureter and 3,500 times to the left ureter (part A of figure). After 1 week ureteral calculi were observed in both ureters and the patient underwent ESWL again. Abdominal plain film revealed a slight proximal migration of the right stent (part B of figure). At 1 week after the second ESWL the distal end of the right stent uncurled (part C of figure). At 20 days after the second ESWL the distal end of the right stent migrated to the ureteral calculi (part D of figure). Using 3Fr foreign body forceps, the ends of the stent were placed back in the renal pelvis and bladder. After 4 days proximal migration of the right stent was observed and it was removed.
is believed that the longer the indwelling time, the more likely a stent will migrate. However, almost no complications have been reported with an indwelling time of less than 6 weeks.1 It may also be that the migration occurs when the stent length is shorter than the ureteral length.2 The locations of the ends of the stent or if they fail to curl greater than 180 degrees after insertion, have also been proposed as causes of stent migration.3 Stent movement may coincide with kidney movement during respiration. In our case stent length on the right side was adequate, the proximal and distal ends were adequately curled and proper position was maintained. Yet, the proximal migration of the right stent was observed 1 week after placement. The distal end of this stent migrated up to the ureteral stone and stopped. The shape and location of the stent on the left side, where the ureteral stone was well drained, was unchanged. The reason for the migration may have been that residual stone in the ureter worked like a “jack” used to raise a car. The residual stone held the stent and allowed only proximal migration and hindered caudal migration during respiration. When the stent in the right ureter was returned to its original position, proximal migration recurred. In conclusion, if residual calculi remain after ESWL, changes in the distal end of a stent should be closely monitored.
DISCUSSION
The proximal migration of a double pigtail ureteral stent is rare, occurring in only 0.6% to 3.5% of the cases.1 Several theories have been proposed to account for this phenomenon. It Accepted for publication May 25, 2001.
REFERENCES
1. el-Faqih, S. R., Shamsuddin, A. B., Chakrabarti, A. et al: Polyurethane internal ureteral stents in treatment of stone patients: morbidity related to indwelling times. J Urol, 146: 1487, 1991 2. Wills, M. I., Gilbert, H. W., Chadwick, D. J. et al: Which ureteric stent length? Br J Urol, 68: 440, 1991 3. Slaton, J. W. and Kropp, K. A.: Proximal ureteral stent migration: an avoidable complication? J Urol, 155: 58, 1996
Serial proximal migration of right ureteral stent. Fragmented right ureteral calculi are shown on right side at L3 to L4 level. A, after first ESWL proximal end of stent was in renal pelvis and distal end in bladder with both ends of double pigtail ureteral stent coiled well (curl of stent end was 360 degrees or greater). B, at 1 week after ESWL distal end of right ureteral stent had uncurled slightly and length of right ureteral stent above right ureteral stone appears longer. C, at 1 week after second ESWL distal end of right ureteral stent uncurled to about 180 degrees. Shape and location of left stent were unchanged and left ureteral calculi had migrated caudal. D, at 20 days after second ESWL distal end of right stent had migrated to right ureteral calculi. Left ureteral calculi had disappeared completely and left stent remained in its original condition. 1387
Vol. 166, 1387, October 2001 Printed in U.S.A.
SPONTANEOUS PROXIMAL DOUBLE PIGTAIL URETERAL STENT MIGRATION AFTER SHOCK WAVE LITHOTRIPSY: “JACK” PHENOMENON WOOJIN KO, WOONGHEE LEE, JINWON JUNG
AND
MOOSANG LEE
From the Department of Urology Yonsei University College of Medicine, Seoul, Korea KEY WORDS: ureter, stents, lithotripsy
Double pigtail ureteral stents are used to prevent ureteral obstruction from calculi and allow easy passage of urine after extracorporeal shock wave lithotripsy (ESWL, Dornier Medical Systems, Inc., Marietta, Georgia).1 Although rare, proximal stent migration is one of the complications of indwelling stents. We report a case of cephalad migration of a double pigtail ureteral stent after ESWL. CASE REPORT
A 62-year-old man presented with bilateral flank pain and hematuria. Abdominal ultrasound revealed grades IV to V bilateral hydronephrosis. A retrograde pyelonephrogram showed a 2.5 ⫻ 1.5 cm. stone at L3 to L4 in the right ureter and a 2.0 ⫻ 1.5 cm. stone in the left ureter. After 5Fr 26 cm. double pigtail stents were placed in both ureters, the Dornier Compact-S (Dornier Medical Systems, Marietta, Georgia) lithotripter delivered 15 Kv. shockwaves 3,000 times to the right ureter and 3,500 times to the left ureter (part A of figure). After 1 week ureteral calculi were observed in both ureters and the patient underwent ESWL again. Abdominal plain film revealed a slight proximal migration of the right stent (part B of figure). At 1 week after the second ESWL the distal end of the right stent uncurled (part C of figure). At 20 days after the second ESWL the distal end of the right stent migrated to the ureteral calculi (part D of figure). Using 3Fr foreign body forceps, the ends of the stent were placed back in the renal pelvis and bladder. After 4 days proximal migration of the right stent was observed and it was removed.
is believed that the longer the indwelling time, the more likely a stent will migrate. However, almost no complications have been reported with an indwelling time of less than 6 weeks.1 It may also be that the migration occurs when the stent length is shorter than the ureteral length.2 The locations of the ends of the stent or if they fail to curl greater than 180 degrees after insertion, have also been proposed as causes of stent migration.3 Stent movement may coincide with kidney movement during respiration. In our case stent length on the right side was adequate, the proximal and distal ends were adequately curled and proper position was maintained. Yet, the proximal migration of the right stent was observed 1 week after placement. The distal end of this stent migrated up to the ureteral stone and stopped. The shape and location of the stent on the left side, where the ureteral stone was well drained, was unchanged. The reason for the migration may have been that residual stone in the ureter worked like a “jack” used to raise a car. The residual stone held the stent and allowed only proximal migration and hindered caudal migration during respiration. When the stent in the right ureter was returned to its original position, proximal migration recurred. In conclusion, if residual calculi remain after ESWL, changes in the distal end of a stent should be closely monitored.
DISCUSSION
The proximal migration of a double pigtail ureteral stent is rare, occurring in only 0.6% to 3.5% of the cases.1 Several theories have been proposed to account for this phenomenon. It Accepted for publication May 25, 2001.
REFERENCES
1. el-Faqih, S. R., Shamsuddin, A. B., Chakrabarti, A. et al: Polyurethane internal ureteral stents in treatment of stone patients: morbidity related to indwelling times. J Urol, 146: 1487, 1991 2. Wills, M. I., Gilbert, H. W., Chadwick, D. J. et al: Which ureteric stent length? Br J Urol, 68: 440, 1991 3. Slaton, J. W. and Kropp, K. A.: Proximal ureteral stent migration: an avoidable complication? J Urol, 155: 58, 1996
Serial proximal migration of right ureteral stent. Fragmented right ureteral calculi are shown on right side at L3 to L4 level. A, after first ESWL proximal end of stent was in renal pelvis and distal end in bladder with both ends of double pigtail ureteral stent coiled well (curl of stent end was 360 degrees or greater). B, at 1 week after ESWL distal end of right ureteral stent had uncurled slightly and length of right ureteral stent above right ureteral stone appears longer. C, at 1 week after second ESWL distal end of right ureteral stent uncurled to about 180 degrees. Shape and location of left stent were unchanged and left ureteral calculi had migrated caudal. D, at 20 days after second ESWL distal end of right stent had migrated to right ureteral calculi. Left ureteral calculi had disappeared completely and left stent remained in its original condition. 1387