|Year : 2000 | Volume
| Issue : 1 | Page : 24-27
Antenatally detected pelviureteric junction obstruction: Safety of conservative management by our protocol
DK Gupta, M Bajpai, V.V.S.S Chandrasekharan, M Srinivas
Department of Pediatric Surgery, All India Institute of Medical Sciences, New Delhi, India
D K Gupta
Department of Pediatric Surgery, All India Institue of Medical Sciences, New Delhi - 1 10 029
Source of Support: None, Conflict of Interest: None
| Abstract|| |
The present study was carried out by evaluate the safety and effectiveness of the selective conservative management of antenatally detected unilateral pelviureteric junction obstruction (ADPUJ) in children who were diagnosed to have unequivocal obstruction upon DTPA renograms performed at 6 weeks of age. The study comprised of 28 patients with ADPUJ. The selective conservative management was applied to the patients with unilateral ADPUJ who were asymptomatic, had split renal function (SRF) above 40% and had the anterior posterior diameter of the pelvis less than 20 mm at 6 weeks of life. 20 of the 28 patients fulfilled the above criteria and were followed up at 3-monthly intervals with nuclear renograms and ultrasonography (US). Prophylactic antibiotics were not prescribed to these patients. The remaining 8 patients underwent pyeloplasty. None of the patients followed up without surgical intervention deteriorated enough to the SRF of 40% or below during the mean follow-up period of 30 months. Only I of these 20 patients had an episode of urinary tract infection. In conclusion, unilateral ADPUJ managed by selective conservative treatment is safe and these patients do not require any antibiotic chemoprophylaxis.
Keywords: PUJ Obstruction; Antenatal Diagnosis; Conservative Management.
|How to cite this article:|
Gupta D K, Bajpai M, Chandrasekharan V, Srinivas M. Antenatally detected pelviureteric junction obstruction: Safety of conservative management by our protocol. Indian J Urol 2000;17:24-7
|How to cite this URL:|
Gupta D K, Bajpai M, Chandrasekharan V, Srinivas M. Antenatally detected pelviureteric junction obstruction: Safety of conservative management by our protocol. Indian J Urol [serial online] 2000 [cited 2022 Jul 6];17:24-7. Available from: https://www.indianjurol.com/text.asp?2000/17/1/24/41008
| Introduction|| |
The most common condition antenatally diagnosed is hydronephrosis.  The complete natural history of this condition still remains to be well elucidated., With the popularity of routine prenatal ultrasonography (US), the number of cases being detected is apparently increasing. Initially there was much concern for the unilateral antenatally detected pelviureteric junction obstruction (ADPUJ). This concern was obvious in view of the studies which enlightened the vulnerbility of developing kidneys. , In few reports the selective conservative management in selected patients did not lead to significant loss of renal function. ,, Further evidence for the spontaneous regression of fetal hydronephrosis as well as resolution of postnatal mild hydronephrosis provided by Morin et al.  However, the proposed management protocols vary from center to center. The problem is compounded by the functional immaturity of the newborn kidney and the reports which have combined various functional groups (obstructed, equivocal, unobstructed) into one study, which makes interpretation of the results difficult.  We evolved the criteria for the selective conservative management and evaluation of this selective approach was the aim of this study.
| Patients and Methods|| |
28 newborns (27 boys, 1 girl) managed at our Pediatric Urology Clinic during 1993 to 1998 were included in the study. In most of the cases, hydronephrosis was detected on a single antenatal US performed during the third trimester. The ADPUJ was confirmed by US and the renography performed at 6 weeks of age postnatally. Diuretic renography was performed with TC 99m DTPA with augmentation by frusemide (1 mg/kg IV). A well-tempered renogram with standard F+20 protocol was performed in all babies. A modified renogram (F-15 study) was performed in equivocal cases. Obstruction was identified based on the washout pattern in the post-frusemide curve supplemented by the T 1/2 in the post-frusemide study. VUR was suspected only when the ureter was seen to be dilated on US. The VCUG was performed in 5 patients and DRCG in another 5 but only 1 patient had grade-II reflux on the side opposite to the ADPUJ. Except for this patient, none of the babies with pure ADPUJ received antibiotic prophylaxis.
The criteria followed in the management of these patients were as follows. The kidneys with split renal function (SRF) >40% were managed expectantly with regular follow-ups (US and renography 3-monthly during the first year and 6-monthly after 1 year of age). The kidneys with SRF less than 40% or anteroposterior diameter of pelvis more than 20 mm or those producing the symptoms underwent dismembered pyeloplasty. In the present protocol surgical intervention was to be considered in case of deterioration of function, i.e., fall of SRF below 40% or fall by more than 10% from the baseline value or if the patients became symptomatic during the period of regular follow-up.
| Results|| |
All 28 patients included in this study were obstructed on the initial post-frusemide study. With the criteria set forth by us 20 patients were followed up conservatively and on follow-up there was no deterioration in SRF at any time to reach the cut-off value of 40%. The mean followup period was 30 months (range 12 to 60 months). Prophylactic antibiotics were not administered in this group. Only 1 patient developed symptomatic urinary tract infection which was managed with appropriate antibiotics. The child continues on non-operative follow-up after the control of infection. 8 patients required pyeloplasty as they did not satisfy the criteria for non-operative management. All the kidneys in the operative group (n=8) improved in function to varying extent. The mean percentage function in this group prior to surgery was 26.1% (range 15-43%) and postoperatively it was 39.4% (range 25-49%). The mean age at pyeloplasty was 2.8 months (range 10 days to 6 months). The gain of function was maximum in three renal units operated before 6 weeks of age. In the present series, 5 of the 8 operated kidneys which had initial function of less than 40% improved to show a differential function of over 40% postoperatively. The 3 kidneys whose differential function did not improve beyond 40% even after pyeloplasty probably represent that group in which the function already stabilized at a lower level. There have been no operative complications.
| Discussion|| |
The proposal by Ransley et al in 1985 for the management of ADPUJ was based upon the assumption that a decrease in SRF implies the presence of unequivocal obstruction that would require surgical intervention.  The logic behind this is based upon the fact that, in the presence of putative significant obstruction, the filtration of the kidney would get affected. Conversely, in the absence of significant obstruction the function would remain stable or does not deteriorate significantly. As many centers had various criteria set forth for the non-surgical management, we evolved the criteria described above to selectively offer the surgical intervention. With this protocol only 8 of the 28 kidneys with unilateral obstructive hydronephrosis underwent early pyeloplasty in our study. How many of these kidneys would have improved on observation alone is not known. This is especially true of the kidneys with differential function between 30-40%. But it is not clear from the reports how many of the moderately functioning kidneys improved to good function during three months. In the series by Blachar et al  all the kidneys with differential function less than 30% on the initial scan ultimately required pyeloplasty. In the same series half of the renal units with initial differential function between 30-40% required pyeloplasty during followup due to deterioration in function below 30%. However, the function in these kidneys failed to improve beyond 30% even after pyeloplasty. It is therefore evident from these reviews that a safe cut-off point which could distinguish between the operative and the non-operative group is difficult.
Diuretic renography remains the noninvasive functional study of choice to assess the functional status of the kidneys and the pattern of clearance.  However, the recent knowledge on the maturation of the newborn kidneys has helped fixing the timing of the initial study after 4 weeks of life. , The reliability of the test has greatly improved with the development of standardized protocols , and with the use of the modified renogram. ,,
Experimental work ,, on partial ureteric obstruction in newborn rats suggests that loss of function in these cases occurs early and stabilizes at a lower level. Clinical evidence ,, also suggests that early intervention offers the maximum benefit for functional recovery in these kidneys. However, there is no reliable test to identify these kidneys at present. The only plausible way is to observe all hydronephrotic kidneys irrespective of initial differential function until further deterioration of function occurs.  But this involves the risk of causing irreversible functional deterioration in many other renal units, which would otherwise benefit from early surgery.
The other question in the management of these patients is what should be the cut-off function below which pyeloplasty is indicated. In the present series, all renal units below 40% initial differential function underwent early pyeloplasty. Some authors  have proposed this cut-off at 35%. We believe that the cut-off value should be high enough so that if the kidney deteriorates on follow-up, it would still retain enough function when it goes for pyeloplasty. In the present series none of the kidneys with an initial differential function above 40% deteriorated during follow-up. This is a significant difference from other reports, where about a quarter of such kidneys required pyeloplasty during the follow-up period, most commonly due to functional deterioration. ,
Lastly the need for long-term antibiotic prophylaxis in those patients with pure PUJ obstruction during non-operative follow-up needs to be confirmed. Although most authors advocate the use of antibiotic prophylaxis in these cases during the non-operative follow-up, the importance of prophylactic antibiotics in this setting has not been formally tested.  Our observations without the use of antibiotic prophylaxis indicate that the infection rate in our group is very low. Further, an episode of infection can be managed conservatively and the kidney still observed on nonoperative follow-up.
In conclusion, the protocol presented here is simple and reliable with the least risk of functional deterioration during the follow-up. In patients with obstructive hydronephrosis, most of the kidneys requiring surgery seem to do so early and the early operation offers the best chance for functional recovery. Long-term antibiotic prophylaxis in babies with isolated PUJ obstruction during non-operative follow-up is not necessary. As none of the ADPUJ kidneys with SRF more than 40% ever deteriorate to this cut-off value, it may be recommended that, in our country, if the centers have difficult or limited access to the nuclear scans the follow-up may be with 6-monthly scans rather than initial 3-monthly scans.
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