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Unusual presentation of ureteropelvic junction obstruction in an incomplete duplex system
UNUSUAL PRESENTATION
OF URETEROPELVIC
JUNCTION
IN AN
OBSTRUCTION
INCOMPLETE GERALD
DUPLEX SYSTEM
R. JERKINS,
M.D.
H. NORMAN NOE, M.D. From the University of Tennessee, Center for the Health Sciences, Department of Urology, Division of Pediatric Urology, Memphis, Tennessee
ABSTRACT-Ureteropelvic junction obstruction in an incomplete duplex system is seen infTequently. This case represents an unusual presentation of such an obstruction. Recommendations are made for preoperative evaluation and surgical management of these patients.
Ureteropelvic junction obstruction is one of the most common forms of urinary tract obstruction seen in children. The majority of these obstructions occur in a single collecting system with infrequent reports of obstruction in only one segment of an incompletely duplicated system. Herein we report a ureteropelvic junction obstruction in an incomplete duplex system affecting the lower pole, presenting as a large abdominal mass. Case Report A two-year-old white male was seen in the emergency room with an abdominal mass. No pain had been associated with the mass, and the child had no history of urinary tract infection, recent febrile illnesses, or abnormal voiding symptoms. Physical examination revealed a large nontender abdominal mass extending from the right lower rib cage to the anterior iliac spine on the right. The mass also extended well past the midline toward the left side of the abdomen. Initial laboratory data revealed the blood urea nitrogen (BUN), creatinine, and hematocrit levels to be normal. An intravenous pyelo-
402
gram (IVP) showed the dilated collecting system in the right upper quadrant with a mass inferior to it (Fig. 1A). Delayed films showed no evidence of contrast material in the mass. Ultrasonography revealed a large cystic mass on the right, without evidence of a hydronephrotic ureter. The patient underwent cystoscopy and right retrograde pyelogram. There was no suggestion on any of the retrograde films, including the initial bulb retrograde, of an accessory ureter. These studies revealed a ureter markedly deviated past the midline, but showed continuity only with the dilated collecting system noted on the previously obtained IVP (Fig. 1B). The bladder anatomy, including the trigone and ureteral orifice position, was normal. Because of the size of the mass, the patient was explored through a midline abdominal incision. A ureteral catheter was left in the right ureter at cystoscopy. The large cystic mass was identified and noted to be in the retroperitoneum, markedly displacing the colon and small intestine to the left. Inspection of this mass revealed it to be the obstructed lower pole of the right duplicated collecting system. The obstruction was at the lower pole ureteropelvic junction. The duplicated upper ureters could be
UROLOGY
/ OCTOBER
1985
/ VOLUME
XXVI, NUMBER 4
FIGURE 1. (A) Delayed intravenous pyelogram showing hydronephrotic collecting system in right upper quadrant with mass below. (B) Retrograde pyelogram shows marked deviation of right ureter by mass below visualized collecting system.
traced to a point of intersection approximately 3 to 4 cm below the right lower pole ureteropelvic junction. The ureter of the upper pole could be easily seen coursing over the surface of the dilated lower pelvis (Fig. 2). The dilated collecting system was decompressed and approximately 400 cc of clear urine was obtained. Though the renal parenchyma was thin, a l-cm thickness of parenchyma was noted in the upper pole. The lower pole, however, had little identifiable renal tissue. A lower pole heminephrectomy was performed which the patient tolerated well. In the postoperative period, an IVP revealed persistence of the dilated system on the right, but there was prompt function and good emptying of that collecting system . Comment Hydronephrosis in completely duplicated systems usually affects the upper pole. However, reported cases of hydronephrosis associated with incompletely duplicated systems have uniformly found the lower pole segment to be affected. The malformation occurs in about 2 per cent of children with ureteropelvic junction obstruction. 1.2 Initial diagnosis of this anomaly can sometimes be difficult if the lower pole segment is poorly functioning and does not reveal contrast material even on delayed films. The differential diagnosis of such a radiographic appearance includes not only obstruction to the lower pole of
UROLOGY
!
OCTOBER
1985
/ VOLUME
XXVI.
NUMBER
2. Ureter (A) from obstructed lower pole collecting system and (B) ureter to upper pole collecting system crossing obstructed lower pole collecting system.
FIGURE
4
403
a duplex system, but also renal tumor of the lower pole of the kidney, segmental cystic changes of the lower pole of the kidney, and extrarenal retroperitoneum cysts or tumors. Thus, all of these possibilities must be taken into account when planning the proper operative approach to these patients. Adjuncts to the IVP, which are helpful in making the diagnosis, include ultrasonography, computerized tomography, and retrograde pyelogram. An antegrade pyelogram through a percutaneous nephrostomy can be helpful when the diagnosis of a hydronephrotic segment is strongly indicated from the other studies. Surgical treatment of the obstructed segment must be planned so that as much functioning renal tissue as possible will be saved. Ossandon, Androulakakis, and Ransley3 have reported the technical aspects that must be considered when the lower pole can be preserved. In the case presented, the small amount of parenchyma noted with the obstructed segment did not justify an attempt to salvage this portion of the
404
kidney. Histologic examination revealed only a thin rim of atrophic renal tissue associated with the excised hydronephrotic segment. The radiographic appearance of a mass below a visualized collecting system should alert the examiner to the possibility of a hydronephrotic segment of the kidney. Careful preoperative assessment of these patients is important and can lead to a well planned surgical procedure allowing for preservation of the maximum amount of functioning renal tissue. LeBonheur Children’s Hospital 848 Adams, Suite 403 Memphis, Tennessee 38103 (DR. JERKINS) 1. Johnston JH, Evans JR Glassberg KI, and Shapiro SR: Pelvic hydronephrosis in children: a review of 219 personal cases, J Urol 117: 97 (1977). 2. Snyder HM, et al: Ureteropelvic junction obstruction in children. Urol Clin North Am 7: 273 (1980). 3. Ossandon F, Androulakakis P and Ransley PG: Surgical problems in pelvioureteral junction obstruction on the lower moiety in incomplete duplex systems, J Urol 125: 871 (1981).
UROLOGY
/ OCTOBER
1985
/ VOLUME
XXVI, NUMBER
4
OF URETEROPELVIC
JUNCTION
IN AN
OBSTRUCTION
INCOMPLETE GERALD
DUPLEX SYSTEM
R. JERKINS,
M.D.
H. NORMAN NOE, M.D. From the University of Tennessee, Center for the Health Sciences, Department of Urology, Division of Pediatric Urology, Memphis, Tennessee
ABSTRACT-Ureteropelvic junction obstruction in an incomplete duplex system is seen infTequently. This case represents an unusual presentation of such an obstruction. Recommendations are made for preoperative evaluation and surgical management of these patients.
Ureteropelvic junction obstruction is one of the most common forms of urinary tract obstruction seen in children. The majority of these obstructions occur in a single collecting system with infrequent reports of obstruction in only one segment of an incompletely duplicated system. Herein we report a ureteropelvic junction obstruction in an incomplete duplex system affecting the lower pole, presenting as a large abdominal mass. Case Report A two-year-old white male was seen in the emergency room with an abdominal mass. No pain had been associated with the mass, and the child had no history of urinary tract infection, recent febrile illnesses, or abnormal voiding symptoms. Physical examination revealed a large nontender abdominal mass extending from the right lower rib cage to the anterior iliac spine on the right. The mass also extended well past the midline toward the left side of the abdomen. Initial laboratory data revealed the blood urea nitrogen (BUN), creatinine, and hematocrit levels to be normal. An intravenous pyelo-
402
gram (IVP) showed the dilated collecting system in the right upper quadrant with a mass inferior to it (Fig. 1A). Delayed films showed no evidence of contrast material in the mass. Ultrasonography revealed a large cystic mass on the right, without evidence of a hydronephrotic ureter. The patient underwent cystoscopy and right retrograde pyelogram. There was no suggestion on any of the retrograde films, including the initial bulb retrograde, of an accessory ureter. These studies revealed a ureter markedly deviated past the midline, but showed continuity only with the dilated collecting system noted on the previously obtained IVP (Fig. 1B). The bladder anatomy, including the trigone and ureteral orifice position, was normal. Because of the size of the mass, the patient was explored through a midline abdominal incision. A ureteral catheter was left in the right ureter at cystoscopy. The large cystic mass was identified and noted to be in the retroperitoneum, markedly displacing the colon and small intestine to the left. Inspection of this mass revealed it to be the obstructed lower pole of the right duplicated collecting system. The obstruction was at the lower pole ureteropelvic junction. The duplicated upper ureters could be
UROLOGY
/ OCTOBER
1985
/ VOLUME
XXVI, NUMBER 4
FIGURE 1. (A) Delayed intravenous pyelogram showing hydronephrotic collecting system in right upper quadrant with mass below. (B) Retrograde pyelogram shows marked deviation of right ureter by mass below visualized collecting system.
traced to a point of intersection approximately 3 to 4 cm below the right lower pole ureteropelvic junction. The ureter of the upper pole could be easily seen coursing over the surface of the dilated lower pelvis (Fig. 2). The dilated collecting system was decompressed and approximately 400 cc of clear urine was obtained. Though the renal parenchyma was thin, a l-cm thickness of parenchyma was noted in the upper pole. The lower pole, however, had little identifiable renal tissue. A lower pole heminephrectomy was performed which the patient tolerated well. In the postoperative period, an IVP revealed persistence of the dilated system on the right, but there was prompt function and good emptying of that collecting system . Comment Hydronephrosis in completely duplicated systems usually affects the upper pole. However, reported cases of hydronephrosis associated with incompletely duplicated systems have uniformly found the lower pole segment to be affected. The malformation occurs in about 2 per cent of children with ureteropelvic junction obstruction. 1.2 Initial diagnosis of this anomaly can sometimes be difficult if the lower pole segment is poorly functioning and does not reveal contrast material even on delayed films. The differential diagnosis of such a radiographic appearance includes not only obstruction to the lower pole of
UROLOGY
!
OCTOBER
1985
/ VOLUME
XXVI.
NUMBER
2. Ureter (A) from obstructed lower pole collecting system and (B) ureter to upper pole collecting system crossing obstructed lower pole collecting system.
FIGURE
4
403
a duplex system, but also renal tumor of the lower pole of the kidney, segmental cystic changes of the lower pole of the kidney, and extrarenal retroperitoneum cysts or tumors. Thus, all of these possibilities must be taken into account when planning the proper operative approach to these patients. Adjuncts to the IVP, which are helpful in making the diagnosis, include ultrasonography, computerized tomography, and retrograde pyelogram. An antegrade pyelogram through a percutaneous nephrostomy can be helpful when the diagnosis of a hydronephrotic segment is strongly indicated from the other studies. Surgical treatment of the obstructed segment must be planned so that as much functioning renal tissue as possible will be saved. Ossandon, Androulakakis, and Ransley3 have reported the technical aspects that must be considered when the lower pole can be preserved. In the case presented, the small amount of parenchyma noted with the obstructed segment did not justify an attempt to salvage this portion of the
404
kidney. Histologic examination revealed only a thin rim of atrophic renal tissue associated with the excised hydronephrotic segment. The radiographic appearance of a mass below a visualized collecting system should alert the examiner to the possibility of a hydronephrotic segment of the kidney. Careful preoperative assessment of these patients is important and can lead to a well planned surgical procedure allowing for preservation of the maximum amount of functioning renal tissue. LeBonheur Children’s Hospital 848 Adams, Suite 403 Memphis, Tennessee 38103 (DR. JERKINS) 1. Johnston JH, Evans JR Glassberg KI, and Shapiro SR: Pelvic hydronephrosis in children: a review of 219 personal cases, J Urol 117: 97 (1977). 2. Snyder HM, et al: Ureteropelvic junction obstruction in children. Urol Clin North Am 7: 273 (1980). 3. Ossandon F, Androulakakis P and Ransley PG: Surgical problems in pelvioureteral junction obstruction on the lower moiety in incomplete duplex systems, J Urol 125: 871 (1981).
UROLOGY
/ OCTOBER
1985
/ VOLUME
XXVI, NUMBER
4