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Neonatal Perirenal Urinary Extravasation
Vol. 111, January Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright © 1974 by The Williams & Wilkins Co.
Pediatric Urology NEONATAL PERIRENAL URINARY EXTRAVASATION ROBERT J. KRANE
AND
ALAN B. RETIK
From the Boston Floating Hospital for Infants and Children, Boston, Massachusetts
urethral stricture has been described. 4 With the exception of 2 cases (possibly 3) urinary ascites was present. Perirenal extravasation was diagnosed by excretory urography (IVP), voiding cystourethrography or direct visualization at time of the operation. It has been unilateral in all previously reported cases.
Perirenal urinary extravasation in the neonate is a rare complication of lower urinary tract obstruction, with only 14 cases reported previously. 1- 6 We report herein 2 additional cases with a discussion of pathogenesis, relationship to urinary tract obstruction and urinary ascites, and surgical management. HISTORICAL BACKGROUND
CASE REPORTS
In 1894 Fordyce reviewed autopsy findings and collected 63 cases of fetal ascites of which 17 had urinary tract dilatation. 7 He drew no conclusions from these associated findings and it remained for James in 1952 to show a cause-and-effect relationship between urinary tract obstruction and urinary ascites and to report on the first survivor with this disorder. 8 Shortly thereafter, m a comprehensive review of the subject, Lord proposed neonatal urinary ascites to be secondary to transudation of urine into the peritoneal cavity from dilated upper urinary tracts. 9 Before 1965 all but several of the reported cases of this disorder concerned stillborns or babies who died shortly after birth. In that year Swain and associates presented 4 cases of urethral valvular obstruction, secondary ascites and associated perirenal extravasation. 1 Since that time 12 cases (including ours) have been reported. The mortality rate in this group is 44 per cent. In all cases there was severe obstructive uropathy. Posterior urethral valves have been the most frequent associated anomaly, although 1 case of
Case 1. C. J., 740546, a 10-hour-old male newborn, was transferred to this hospital with abdominal distension and failure to void. The infant weighed 6 pounds 12 ounces at birth and was the product of a 30-year-old white woman. An abdominal mass had been palpated at the time of delivery and IVP showed no visualization after 45 minutes. The bladder was palpated 2 cm. above the umbilicus and a right flank mass was present. Blood urea nitrogen (BUN) was 11 mg. per cent and serum creatinine was 0.9 mg. per cent. Catheterization of the bladder yielded 150 cc clear urine. An IVP revealed delayed excretion bilaterally. The left kidney was hydronephrotic with moderate dilatation of the left ureter. As the IVP progressed increased dye concentration was noted in the right renal area without definite visualization of the collecting system (fig. 1). A voiding cystourethrogram revealed typical posterior urethral valves without vesicoureteral reflux (fig. 2). Within 30 hours of the child's hospitalization the BUN was 22 mg. per cent and the serum creatinine was 1.9 mg. per cent. After suitable hydration the infant underwent exploration through a right subcostal incision. Approximately 200 cc blood-tinged urine was present in the perirenal space. The site of communication with the renal collecting system could not be identified. In addition, an intrinsic obstruction at the ureteropelvic junction was identified and repaired by dismembered pyeloplasty (Hynes-Anderson technique). Bilateral nephrostomy was also performed. Convalescence was uneventful. One month later, a transurethral valvular resection was done through a perinea! urethrostomy. Both nephrostomy tubes were then removed. An IVP 6 months postoperatively revealed considerable improvement (fig. 3). The boy is now 4 years old, voids with a good stream and has sterile urine. Case 2. P. G., 836375, a 1-month-old white male newborn, was hospitalized with a history of abdominal distension 4 days in duration. The child was the product of a 27-year-old white woman and was born after 34 weeks of gestation following a partial placental separation. Birth weight was 5 pounds 8 ounces. Bilateral flank masses were palpable. The bladder was distended to the level of
Accepted for publication July 20, 1973. 1 Swain, V. A. J ., Tucker, M., Stimmler, L. and France, N. E.: Perinatal ascites due to extravasation of urine from ruptured kidneys; approaches to diagnosis and treatment. Clin. Pediat., 4: 199, 1965. 2 Dockray, K. T.: Perirenal contrast medium. A new roentgenographic sign of neonatal urinary ascites. J.A.M.A., 193: 1121, 1965. 3 Cywes, S., Wynne, J. M. and Louw, J. H.: Urinary ascites in the newborn with a report of two cases. J. Pediat. Surg., 3: 350, 1968. 'Moncada, R., Wang, J. J., Love, L. and Bush, I.: Neonatal ascites associated with urinary outlet obstruction (urine ascites). Radiology, 90: 1165, 1968. 'Dockray, K. T.: The perirenal P sign: a new roentgen_ogra_m ind.ex to the cause and treatment of urinary asc1tes m babies. Amer. J. Dis. Child., 119: 179, 1970. 'Garrett, R. A. and Franken, E. A., Jr.: Neonatal ascites: perirenal urinary extravasation with bladder outlet obstruction. J. Urol., 102: 627, 1969. . '. Fordyce, W.: Intrauterine ascites, its obstetrical sigmf1cance and pathology. Teratologia, 1: 61, 1894. 'Davis, J. A. for James, U.: Congenital urethral obstruction presenting as ascites in the neonatal period. Proc. Roy. Soc. Med., 45: 401, 1952. 'Lord, J.M.: Foetal ascites. Arch. Dis. Child., 28: 398 1953. , 96
NEONATAL PERIRENAL URINARY EXTRAVASATION
FIG. 1. Case 1. IVPs at time of hospitalization reveal large collection of contrast medium on right (seen in lateral projection in B) representing perirenal extravasation.
FIG. 2. Case 1. Voiding cystourethrogram demonstrates posterior urethral valvular deformity, trabeculated bladder and no evidence of vesicoureteral reflux.
the umbilicus and obvious abdominal distension was present. The BUN was 41 mg. per cent and serum creatinine was 2.7 mg. per cent. A voiding cystourethogram revealed a markedly trabeculated bladder, no evidence of vesicoureteral reflux and a dilated prostatic urethra characteristic of a posterior urethral valve (fig. 4). A lateral x-ray of the abdomen showed loops of bowel compressed anteriorly and a markedly enlarged retroperitoneal space. An IVP revealed surprisingly little dilatation of the upper tracts. On delayed films a large
FIG. 3. Case 1. IVP 6 months postoperatively shows good renal function bilaterally.
area of opacification in the right flank was visualized (fig. 5). The patient was initially treated with urethra\ catheterization. By hospital day 4 the BUN had returned to 9 mg. per cent and serum creatinine to 0.5 mg. per cent. At this time flank masses were no longer palpable. On day 5 resection of the urethral valves was done through a perinea! PATHOGENESIS
Perirenal extravasation as well as urinary asci.tes seems to result from increased pressure within the urinary tract. These conditions do not seem to be
98
KRANE AND RETIK
FIG. 4. Case 2. Voiding cystourethrogram demonstrates posterior urethral valvular deformity. Note markedly enlarged prostatic urethra and trabeculated bladder.
secondary to considerable tissue rupture since necropsy and operative findings would otherwise support this. It seems that a mechanism similar to forniceal backflow as described by Hinman could explain this entity. 10 Although patients with this disorder are not candidates for retrograde pyelography, when significant vesicoureteral reflux has been present extravasation seemed to emanate from 1 point of the caliceal system. 1· 4 Moncada and associates showed convincing radiological evidence for communication among the caliceal system, the perirenal space and the peritoneal cavity. Urine probably enters the peritoneal cavity by transudation through the retroperitoneum, although in 1 case a distinct tear in the retroperitoneum was reported. 4 An alternate and more direct route for urinary ascites production via bladder rupture has also been reported. 11 -13 In most cases of urinary ascites, perirenal extravasation has not been described. First, renal function is often too poor in these patients to allow for sufficient concentration of dye during an IVP. In case 1 contrast medium in the perirenal area was not appreciated until late in the course of a double dose IVP. Second, the point of extravasation may spontaneously heal before radiological examination. In case 2 an IVP showed free dye in the right flank apparently contained within Gerota's fascia. However, the left ureter was markedly displaced medially and anteriorly by a retroperitoneal collec-
tion (fig. 5, A). We think that this case exhibited bilateral extravasation with healing of the left side before IVP. It is also possible that the ureters of these infants do not overdistend but simply hypertrophy in response to increased pressure secondary to lower tract obstruction. 14 This hypertrophy would rather quickly transmit pressure to the renal collecting system, an area much more likely to permit extravasation. One could then theoretically explain the rarity of this syndrome since most children (as well as most adults) will respond to lower tract obstruction by gradual upper tract dilatation. It would also explain the consistently early presentation of perirenal extravasation secondary to urethral obstruction since this entity has been reported only in neonates. Recent experiments with rats show that serous and retroperitoneal effusions caused by bilateral ureteral ligation can be abolished by adrenalectomy.15 This raises the possibility of a humoral factor playing a role in this disorder. However, we think that perirenal extravasation is directly related to increased pressure within the urinary tract. Of the 16 cases of this entity reported, cystograms were performed in 12. When these showed unilateral vesicoureteral reflux (6 cases) it was always on the side of the extravasation. This again points to what seems to be solely a pressure phenomenon. Therefore, it would seem that the management of these patients should be directed towards decreasing the pressure within the urinary tract. MANAGEMENT
Because of the potentially dire consequences of neonatal perirenal urinary extravasation and urinary ascites we think that a consistent and reasonable approach to these patients should be proposed. In cases of neonatal ascites when obvious hepatic or intestinal anomalies are ruled out prompt radiological investigation of the urinary tract should be undertaken. Repeated paracenteses for diagnostic purposes are usually of little benefit since the ascites will quickly equilibrate with extracellular fluid. In cases of respiratory distress immediate drainage of ascites and perirenal extravasations are indicated to relieve diaphragmatic elevation. When there is an associated urinary tract infection retroperitoneal drainage seems mandatory in order to minimize the prospect of perinephric abscess. It has been stated by several authors that 10 Hinman, F ., Jr.: Peri pelvic extravasation during intravenous urography, evidence for an additional route immediate supravesical diversion is needed in for backflow after ureteral obstruction. J. Urol., 85: 385, treating patients with this disorder. 5· 6· 16 We think 1961.
11 Williams, D. I. and Eckstein, H. B.: Obstructive 14 Tanagho, E. A.: Intrauterine fetal ureteral obstrucvalves in the posterior urethra. J. Urol., 93: 236, 1965. tion. J. Urol., 109: 196, 1973. 12 Baghdassarian, 0. M., Koehler, P.R. and Schultze, 15 Stoerk, H. C., Laragh, J. H., Aceto, R. M. and G.: Massive neonatal ascites. Radiology, 76: 586, 1961. Budzilovich, T .: Edema and ascites following the ligation 13 Leonidas, J. C., Leiter, E. and Gribetz, D.: Congeniof both ureters in rats. Amer. J. Path., 58: 51, 1970. 16 Thompson, I, M. and Bruns, T. N. C.: Neonatal tal urinary tract obstruction presenting with ascites at birth: roentgenographic diagnosis. Radiology, 96: 111, ascites: a reflection of obstructive disease. J. Urol., 107:
1970.
509, 1972.
NEONATAL PERIRENAL URINARY EXTRAVASATION
99
FIG. 5. Case 2. A, IVP shows collection of dye surrounding right kidney, medial deviation of both ureters and only mild ureterectasis. B, lateral view reveals markedly enlarged retroperitoneum.
that the initial orientation should be towards lower urinary tract drainage by urethral catheter. Certainly most cases of posterior urethral valves do not have associated extravasation or ascites. In these cases the lack of success with immediate urethrovalvulotomy seems most related to the inability of the upper tracts to drain well postoperatively.17 This is caused by tortuous, overdistended ureters which are incapable of peristaltic activity. Thus, anything short of supravesical diversion proves unsuccessful in improving renal function. In cases of perirenal urinary extravasation the ureters are often only moderately dilated and thus seem capable of more prompt return of peristaltic activity. It is probable that extravasation itself decompresses the ureter from above. This would explain the lack of marked ureteral dilatation and increased potential for return of ureteral function and account for the feasibility of urethral drainage in these cases. Urethral catheters were used in both patients. In case 1 it became apparent that the patient's clinical status got worse and serum creatinine rose on urethral drainage alone. At this point we decided to establish bilateral upper tract diversion at the renal level. For technical reasons bilateral nephrostomy was performed but tubeless diversion, that is loop ureterostomies, usually proves more desirable. With urethral drainage our second 17 Rickham, P. P.: Advanced lower urinary obstruction in childhood. Arch. Dis. Child., 37: 122, 1962.
patient improved clinically, became less irritable and the serum creatinine returned to normaL The patient tolerated a urethral catheter and after a suitable period underwent transurethral valvula1 resection. We think that the surgical approach must be tailored to the individual case with the initial treatment being the simplest, namely lower tract drainage by urethral catheter. With careful monitoring of the clinical status, urine sediment and renal function one may then plan further operations: supravesical diversion if needed or a direct attack on the cause of obstruction. Whatever the urological intervention used the key to correct treatment clearly lies with early diagnosis. ploratory laparotomy and repeated paracenteses in acutely ill neonates are not indicated unless within the context of a rational therapeutic plan based on a clearcut diagnosis. SUMMARY
Early treatment for neonatal perirenal urinary extravasation is essential. Previously, reports of this syndrome have stressed the need for immediate supravesical diversion. Two patients who were initially treated with lower tract drainage are described. This conservative therapy alone was successful in treating one of these children. It is thought that lower tract drainage by a urethral catheter has an important role in the initial management of this disorder.
THE JOURNAL OF UROLOGY
Copyright © 1974 by The Williams & Wilkins Co.
Pediatric Urology NEONATAL PERIRENAL URINARY EXTRAVASATION ROBERT J. KRANE
AND
ALAN B. RETIK
From the Boston Floating Hospital for Infants and Children, Boston, Massachusetts
urethral stricture has been described. 4 With the exception of 2 cases (possibly 3) urinary ascites was present. Perirenal extravasation was diagnosed by excretory urography (IVP), voiding cystourethrography or direct visualization at time of the operation. It has been unilateral in all previously reported cases.
Perirenal urinary extravasation in the neonate is a rare complication of lower urinary tract obstruction, with only 14 cases reported previously. 1- 6 We report herein 2 additional cases with a discussion of pathogenesis, relationship to urinary tract obstruction and urinary ascites, and surgical management. HISTORICAL BACKGROUND
CASE REPORTS
In 1894 Fordyce reviewed autopsy findings and collected 63 cases of fetal ascites of which 17 had urinary tract dilatation. 7 He drew no conclusions from these associated findings and it remained for James in 1952 to show a cause-and-effect relationship between urinary tract obstruction and urinary ascites and to report on the first survivor with this disorder. 8 Shortly thereafter, m a comprehensive review of the subject, Lord proposed neonatal urinary ascites to be secondary to transudation of urine into the peritoneal cavity from dilated upper urinary tracts. 9 Before 1965 all but several of the reported cases of this disorder concerned stillborns or babies who died shortly after birth. In that year Swain and associates presented 4 cases of urethral valvular obstruction, secondary ascites and associated perirenal extravasation. 1 Since that time 12 cases (including ours) have been reported. The mortality rate in this group is 44 per cent. In all cases there was severe obstructive uropathy. Posterior urethral valves have been the most frequent associated anomaly, although 1 case of
Case 1. C. J., 740546, a 10-hour-old male newborn, was transferred to this hospital with abdominal distension and failure to void. The infant weighed 6 pounds 12 ounces at birth and was the product of a 30-year-old white woman. An abdominal mass had been palpated at the time of delivery and IVP showed no visualization after 45 minutes. The bladder was palpated 2 cm. above the umbilicus and a right flank mass was present. Blood urea nitrogen (BUN) was 11 mg. per cent and serum creatinine was 0.9 mg. per cent. Catheterization of the bladder yielded 150 cc clear urine. An IVP revealed delayed excretion bilaterally. The left kidney was hydronephrotic with moderate dilatation of the left ureter. As the IVP progressed increased dye concentration was noted in the right renal area without definite visualization of the collecting system (fig. 1). A voiding cystourethrogram revealed typical posterior urethral valves without vesicoureteral reflux (fig. 2). Within 30 hours of the child's hospitalization the BUN was 22 mg. per cent and the serum creatinine was 1.9 mg. per cent. After suitable hydration the infant underwent exploration through a right subcostal incision. Approximately 200 cc blood-tinged urine was present in the perirenal space. The site of communication with the renal collecting system could not be identified. In addition, an intrinsic obstruction at the ureteropelvic junction was identified and repaired by dismembered pyeloplasty (Hynes-Anderson technique). Bilateral nephrostomy was also performed. Convalescence was uneventful. One month later, a transurethral valvular resection was done through a perinea! urethrostomy. Both nephrostomy tubes were then removed. An IVP 6 months postoperatively revealed considerable improvement (fig. 3). The boy is now 4 years old, voids with a good stream and has sterile urine. Case 2. P. G., 836375, a 1-month-old white male newborn, was hospitalized with a history of abdominal distension 4 days in duration. The child was the product of a 27-year-old white woman and was born after 34 weeks of gestation following a partial placental separation. Birth weight was 5 pounds 8 ounces. Bilateral flank masses were palpable. The bladder was distended to the level of
Accepted for publication July 20, 1973. 1 Swain, V. A. J ., Tucker, M., Stimmler, L. and France, N. E.: Perinatal ascites due to extravasation of urine from ruptured kidneys; approaches to diagnosis and treatment. Clin. Pediat., 4: 199, 1965. 2 Dockray, K. T.: Perirenal contrast medium. A new roentgenographic sign of neonatal urinary ascites. J.A.M.A., 193: 1121, 1965. 3 Cywes, S., Wynne, J. M. and Louw, J. H.: Urinary ascites in the newborn with a report of two cases. J. Pediat. Surg., 3: 350, 1968. 'Moncada, R., Wang, J. J., Love, L. and Bush, I.: Neonatal ascites associated with urinary outlet obstruction (urine ascites). Radiology, 90: 1165, 1968. 'Dockray, K. T.: The perirenal P sign: a new roentgen_ogra_m ind.ex to the cause and treatment of urinary asc1tes m babies. Amer. J. Dis. Child., 119: 179, 1970. 'Garrett, R. A. and Franken, E. A., Jr.: Neonatal ascites: perirenal urinary extravasation with bladder outlet obstruction. J. Urol., 102: 627, 1969. . '. Fordyce, W.: Intrauterine ascites, its obstetrical sigmf1cance and pathology. Teratologia, 1: 61, 1894. 'Davis, J. A. for James, U.: Congenital urethral obstruction presenting as ascites in the neonatal period. Proc. Roy. Soc. Med., 45: 401, 1952. 'Lord, J.M.: Foetal ascites. Arch. Dis. Child., 28: 398 1953. , 96
NEONATAL PERIRENAL URINARY EXTRAVASATION
FIG. 1. Case 1. IVPs at time of hospitalization reveal large collection of contrast medium on right (seen in lateral projection in B) representing perirenal extravasation.
FIG. 2. Case 1. Voiding cystourethrogram demonstrates posterior urethral valvular deformity, trabeculated bladder and no evidence of vesicoureteral reflux.
the umbilicus and obvious abdominal distension was present. The BUN was 41 mg. per cent and serum creatinine was 2.7 mg. per cent. A voiding cystourethogram revealed a markedly trabeculated bladder, no evidence of vesicoureteral reflux and a dilated prostatic urethra characteristic of a posterior urethral valve (fig. 4). A lateral x-ray of the abdomen showed loops of bowel compressed anteriorly and a markedly enlarged retroperitoneal space. An IVP revealed surprisingly little dilatation of the upper tracts. On delayed films a large
FIG. 3. Case 1. IVP 6 months postoperatively shows good renal function bilaterally.
area of opacification in the right flank was visualized (fig. 5). The patient was initially treated with urethra\ catheterization. By hospital day 4 the BUN had returned to 9 mg. per cent and serum creatinine to 0.5 mg. per cent. At this time flank masses were no longer palpable. On day 5 resection of the urethral valves was done through a perinea! PATHOGENESIS
Perirenal extravasation as well as urinary asci.tes seems to result from increased pressure within the urinary tract. These conditions do not seem to be
98
KRANE AND RETIK
FIG. 4. Case 2. Voiding cystourethrogram demonstrates posterior urethral valvular deformity. Note markedly enlarged prostatic urethra and trabeculated bladder.
secondary to considerable tissue rupture since necropsy and operative findings would otherwise support this. It seems that a mechanism similar to forniceal backflow as described by Hinman could explain this entity. 10 Although patients with this disorder are not candidates for retrograde pyelography, when significant vesicoureteral reflux has been present extravasation seemed to emanate from 1 point of the caliceal system. 1· 4 Moncada and associates showed convincing radiological evidence for communication among the caliceal system, the perirenal space and the peritoneal cavity. Urine probably enters the peritoneal cavity by transudation through the retroperitoneum, although in 1 case a distinct tear in the retroperitoneum was reported. 4 An alternate and more direct route for urinary ascites production via bladder rupture has also been reported. 11 -13 In most cases of urinary ascites, perirenal extravasation has not been described. First, renal function is often too poor in these patients to allow for sufficient concentration of dye during an IVP. In case 1 contrast medium in the perirenal area was not appreciated until late in the course of a double dose IVP. Second, the point of extravasation may spontaneously heal before radiological examination. In case 2 an IVP showed free dye in the right flank apparently contained within Gerota's fascia. However, the left ureter was markedly displaced medially and anteriorly by a retroperitoneal collec-
tion (fig. 5, A). We think that this case exhibited bilateral extravasation with healing of the left side before IVP. It is also possible that the ureters of these infants do not overdistend but simply hypertrophy in response to increased pressure secondary to lower tract obstruction. 14 This hypertrophy would rather quickly transmit pressure to the renal collecting system, an area much more likely to permit extravasation. One could then theoretically explain the rarity of this syndrome since most children (as well as most adults) will respond to lower tract obstruction by gradual upper tract dilatation. It would also explain the consistently early presentation of perirenal extravasation secondary to urethral obstruction since this entity has been reported only in neonates. Recent experiments with rats show that serous and retroperitoneal effusions caused by bilateral ureteral ligation can be abolished by adrenalectomy.15 This raises the possibility of a humoral factor playing a role in this disorder. However, we think that perirenal extravasation is directly related to increased pressure within the urinary tract. Of the 16 cases of this entity reported, cystograms were performed in 12. When these showed unilateral vesicoureteral reflux (6 cases) it was always on the side of the extravasation. This again points to what seems to be solely a pressure phenomenon. Therefore, it would seem that the management of these patients should be directed towards decreasing the pressure within the urinary tract. MANAGEMENT
Because of the potentially dire consequences of neonatal perirenal urinary extravasation and urinary ascites we think that a consistent and reasonable approach to these patients should be proposed. In cases of neonatal ascites when obvious hepatic or intestinal anomalies are ruled out prompt radiological investigation of the urinary tract should be undertaken. Repeated paracenteses for diagnostic purposes are usually of little benefit since the ascites will quickly equilibrate with extracellular fluid. In cases of respiratory distress immediate drainage of ascites and perirenal extravasations are indicated to relieve diaphragmatic elevation. When there is an associated urinary tract infection retroperitoneal drainage seems mandatory in order to minimize the prospect of perinephric abscess. It has been stated by several authors that 10 Hinman, F ., Jr.: Peri pelvic extravasation during intravenous urography, evidence for an additional route immediate supravesical diversion is needed in for backflow after ureteral obstruction. J. Urol., 85: 385, treating patients with this disorder. 5· 6· 16 We think 1961.
11 Williams, D. I. and Eckstein, H. B.: Obstructive 14 Tanagho, E. A.: Intrauterine fetal ureteral obstrucvalves in the posterior urethra. J. Urol., 93: 236, 1965. tion. J. Urol., 109: 196, 1973. 12 Baghdassarian, 0. M., Koehler, P.R. and Schultze, 15 Stoerk, H. C., Laragh, J. H., Aceto, R. M. and G.: Massive neonatal ascites. Radiology, 76: 586, 1961. Budzilovich, T .: Edema and ascites following the ligation 13 Leonidas, J. C., Leiter, E. and Gribetz, D.: Congeniof both ureters in rats. Amer. J. Path., 58: 51, 1970. 16 Thompson, I, M. and Bruns, T. N. C.: Neonatal tal urinary tract obstruction presenting with ascites at birth: roentgenographic diagnosis. Radiology, 96: 111, ascites: a reflection of obstructive disease. J. Urol., 107:
1970.
509, 1972.
NEONATAL PERIRENAL URINARY EXTRAVASATION
99
FIG. 5. Case 2. A, IVP shows collection of dye surrounding right kidney, medial deviation of both ureters and only mild ureterectasis. B, lateral view reveals markedly enlarged retroperitoneum.
that the initial orientation should be towards lower urinary tract drainage by urethral catheter. Certainly most cases of posterior urethral valves do not have associated extravasation or ascites. In these cases the lack of success with immediate urethrovalvulotomy seems most related to the inability of the upper tracts to drain well postoperatively.17 This is caused by tortuous, overdistended ureters which are incapable of peristaltic activity. Thus, anything short of supravesical diversion proves unsuccessful in improving renal function. In cases of perirenal urinary extravasation the ureters are often only moderately dilated and thus seem capable of more prompt return of peristaltic activity. It is probable that extravasation itself decompresses the ureter from above. This would explain the lack of marked ureteral dilatation and increased potential for return of ureteral function and account for the feasibility of urethral drainage in these cases. Urethral catheters were used in both patients. In case 1 it became apparent that the patient's clinical status got worse and serum creatinine rose on urethral drainage alone. At this point we decided to establish bilateral upper tract diversion at the renal level. For technical reasons bilateral nephrostomy was performed but tubeless diversion, that is loop ureterostomies, usually proves more desirable. With urethral drainage our second 17 Rickham, P. P.: Advanced lower urinary obstruction in childhood. Arch. Dis. Child., 37: 122, 1962.
patient improved clinically, became less irritable and the serum creatinine returned to normaL The patient tolerated a urethral catheter and after a suitable period underwent transurethral valvula1 resection. We think that the surgical approach must be tailored to the individual case with the initial treatment being the simplest, namely lower tract drainage by urethral catheter. With careful monitoring of the clinical status, urine sediment and renal function one may then plan further operations: supravesical diversion if needed or a direct attack on the cause of obstruction. Whatever the urological intervention used the key to correct treatment clearly lies with early diagnosis. ploratory laparotomy and repeated paracenteses in acutely ill neonates are not indicated unless within the context of a rational therapeutic plan based on a clearcut diagnosis. SUMMARY
Early treatment for neonatal perirenal urinary extravasation is essential. Previously, reports of this syndrome have stressed the need for immediate supravesical diversion. Two patients who were initially treated with lower tract drainage are described. This conservative therapy alone was successful in treating one of these children. It is thought that lower tract drainage by a urethral catheter has an important role in the initial management of this disorder.