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Brief Reports Indian Pediatrics 2001; 38: 1401-1404 |
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S.K. Chowdhary S. Walter R.K. Chaudhuri A. Bhagat S.C. Joseph
The presentation of hydronephrosis in children is rapidly undergoing a change from a symptomatic condition in a child to an antenatal or incidental diagnosis. The indications for surgery are controversial due to lack of reliable investigations to define obstruction accurately(1). The spontaneous resolution of obstructive drainage pattern in the infant kidney is well documented(2). Therefore, the selection of a case who is likely to benefit from surgery requires astute judgement. Satisfactory results after neonatal pyeloplasty with significant improvement in drainage have been reported from a number of centers(3). However, there is equally compelling evidence that if obstruction is indeed a problem, differential renal function must fall during the period of observation(4). We report our experience with conservative management of patients antenatally detected to have significant renal pelvic dilatation. Patients and Methods All babies with renal pelvis diameter greater than 10 mm evaluated for booked delivery at our hospital between October 1997 and October 1998 were included. An ultrasonograhic examination was done at the first visit or 24 weeks, whichever was earlier, to evaluate the kidneys. The next ultrasound was done at 4 weeks interval. A postnatal ultrasound was performed 3-7 days after delivery. Each baby with dilated pelvis was started on prophylactic amoxicillin (25 mg/kg/dose, once daily). Unless there was bilateral involvement, urine examination, serum creatinine, repeat ultrasound and isotope renogram were done at 4 weeks. These were repeated every 3 months until drainage improved, function deteriorated or atleast one year follow up was completed. Babies with evidence of obstructive uropathy i.e., obstructed renogram curve with t½ >20 min with deteriorating renal function or initial differential function <40%, fall by 10% of the initial differential renal function, presence of a palpable renal lump, or recurrent urinary tract infections were further evaluated. An intravenous pyelogram and micturating cystourethrogram were done. A retrograde pyelogram was done to demonstrate the ureteric anatomy before proceeding for pyeloplasty. Bilateral cases were managed on the same protocol. Results During October 1997–October 1998, there were 6810 babies delivered at St. Stephens Hospital, Delhi. On antenatal examination, there were 44 renal pelvic units with dilatation greater than 10 mm. Six babies had bilateral pelvic dilatation. The babies with hydroureteronephrosis or suspected multicystic dysplastic kidneys were not included. No antenatal intervention was performed. Out of these, there were ten renal units in ten babies with anteroposterior pelvic diameter of greater than 20 mm. Postnatal examination was done on them on the protocol mentioned. Fifteen renal units were found to have a improved drainage curve, with improving differential function in seven renal units. In another fifteen, the drainage curve remained obstructive without fall in function at a mean followup of fifteen months. Only five renal units in five babies required surgical intervention (Table I). The postnatal diagnosis was revised to either multicytic dysplastic kidney or vesicoureteric reflux in three babies and hence have been excluded. Four babies with six renal units with dilated pelvis were lost to follow up.
Table I__Clinical Data on Babies Who Underwent Surgery in the First Year of Life
Discussion Of 6810 deliveries during this study, 0.6% had antenatally detected hydropnephrosis. Most patients had moderately dilated pelvis with only ten babies seen with pelvis exceeding 20 mm. The earlier estimate of the incidence of hydronephrosis was 1 in 5000, which has now been quoted as 0.5%- 1.0%. Sixty per cent of these are due to impaired drainage across the pelviureteric junction(5,6). The postnatal scans were done after the first 72 hours because physiological oliguria in the postnatal period can lead to false negative results. Postnatal scans confirmed errors in the antenatal diagnosis of multicystic dysplastic kidney. Antenatal counselling for this anomaly should remain guarded till higher level of experience is available. Although multicystic kidneys are characterized by replacement of renal parenchyma by cysts of varying sizes, confirmation is possible only after birth. Similar errors in antenatal diagnosis of multicystic kidney have been reported by others(7). The indications for surgery in babies with antenatal diagnosis of pelviureteric junction obstruction should be considered in the light of transitional nephrology and awareness that a significant proportion of these will resolve on their own(8). While conservative treat-ment was followed, we did not experience any complication or loss of function even among those who showed obstructive renogram curves with maintained differential renal function. Gupta et al. have reported similar experience without the use of prophylactic antibiotics(9). Further studies are required before a change in the practise regarding the use prophylactic antibiotics can be recommended. Our protocol included performing micturating cystourethrogram in babies who showed ureteric dilatation, had symptoms or as a preoperative investigation. It is possible that a vesicoureteric reflux may have been missed in a few babies. Since they were already on prophylactic antibiotics without symptoms, the treatment would not have been any different. Of the five babies operated for pelvi-ureteric junction obstruction, 4 showed improvement in drainage and function. One patient, who had suspected vesicoureteric junction obstruction associated with pelvi-ureteric junction obstruction, demonstrated a marginal improvement in function after pyeloplasty. However, drainage curve remained obstructed with the ureter dilated upto the vesicoureteric junction. Similar case has been reported in the past(10). One baby (Case 5, Table I) was taken up for surgery with a differential function at 40%, as it had fallen by 10% during the period of observation. At the end of twelve months observation, the problem of delayed drainage with dilated pelvis remains unresolved in fifteen renal units. These babies require further followup and it is possible that few may come to surgery later. Extended period of conservatism is not without the small but definite risk of loss of renal potential to recover function. In a recent study from Manchester, the recovery after pyeloplasty was significantly less in the delayed pyeloplasty group than those were operated on early. The authors suggested that there may be a role for early surgery in babies with renal pelvis diameter greater than 20 mm and an obstructed curve, even without fall of function(11). In the long term series from Great Ormond Street Hospital, there were some renal units which did not recover function at all after conservatism and delayed surgery(12). In conclusion, conservative management with followup drainage and functional studies for antenatal diagnosis of hydronephrosis is safe in infancy. Selective cases requiring surgery do well after pyeloplasty. Asympto-matic babies with persistent obstructed drainage curve without fall in function require further study. Contributors: SKC and RKC designed the study. SW and AB did the antenatal and postnatal studies. SCJ helped in the preparation of the manuscript. SKC will act as the guarantor for the manuscript. Funding: None. Competing interests: None stated.
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