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Saudi Journal of Kidney Diseases and Transplantation
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ORIGINAL ARTICLE Table of Contents   
Year : 1998  |  Volume : 9  |  Issue : 4  |  Page : 430-434
Outcome of Congenital Hydronephrosis in Qatar

1 Department of Nephrology, Hamad Medical Corporation, Doha, Qatar
2 Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
3 Department of Radiology, Hamad Medical Corporation, Doha, Qatar

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Three hundred and eleven patients diagnosed to have congenital hydronephrosis proven by postnatal ultrasonography in a ten-year period between 1987 and 1996 were studied retrospectively. These were classified into mild degree of hydronephrosis in H (64%), moderate in 94 (30%) and severe in 18 (6%) patients, according to first post natal sonography and depending on the measurement of the anterio-posterior transverse diameter of the pelvi-calyceal system. Significant obstructive uropathy was documented in 66 patients by Technetium-Diethylene triamine penta acetic acid renogram (Tc99m DTPA Renogram Vesicoureteric reflux was found in 22 patients by voiding cysto-urethrogram. On follow­up the hydronephrosis regressed spontaneously in 99 (31.8%), was stable in 167 (53.6%) and needed operative intervention in 45 (14.4%) patients. The types of surgical operations were pyeloplasty in 49% and ureteric re-implantation in 27%. Fifteen (83%) of the children with severe hydronephrosis and 32 (34%) of the moderate hydronephrosis group were operated o while none of the children with the mild form required operative intervention. We recommend ultrasound follow-up for mild hydronephrosis and a coordinated approach and work-up for congenital moderate and severe hydronephrosis. Surgery should only be considered if renal function is affected.

Keywords: Prenatal hydronephrosis, Fetal ultrasonography obstructive uropathy.

How to cite this article:
Saad TS, Al-Zamer J, Al-Thani GM, Al-Khateeb D, Salman M. Outcome of Congenital Hydronephrosis in Qatar. Saudi J Kidney Dis Transpl 1998;9:430-4

How to cite this URL:
Saad TS, Al-Zamer J, Al-Thani GM, Al-Khateeb D, Salman M. Outcome of Congenital Hydronephrosis in Qatar. Saudi J Kidney Dis Transpl [serial online] 1998 [cited 2021 Apr 15];9:430-4. Available from: https://www.sjkdt.org/text.asp?1998/9/4/430/39101

   Introduction Top

Congenital nephropathies and uropathies account for more than one third of pediatric end-stage renal disease [1] . Hydronephrosis is the most common fetal abnormality encountered in obstetric ultrasound. Most cases are found incidentally in women scanned for routine obstetric indications.

Hydronephrosis may be due to obstruction or reflux. The sites of possible obstruction include the uretero-pelvic junction, ureter, uretero-vesical junction, and urethra. [2]

Asymptomatic neonates with congenital hydronephrosis are discovered antenatally or during screening sonography in the neonatal period. Symptomatic patients are often discovered during work-up of patients with urinary tract infection or other urological presentations.

Early recognition of hydronephrotic changes in neonates by antenatal ultra­sonography may minimize renal damage by appropriate postnatal investigations and management. Approximately 80% of neonates with antenatal diagnosis of uropathy are asymptomatic. [3] Management of these patients should be simple, safe and cost effective.

For these reasons, a retrospective study was performed to determine the incidence of congenital hydronephrosis in Qatar. Further investigations and management in these children and suggested guidelines in these cases are discussed.

   Patients and Methods Top

All children confirmed to have congenital hydronephrosis by postnatal ultrasound examination between January 1987 and December 1996 were included in this study retrospectively.

Ultrasound imaging is done routinely in nearly all pregnant women in Qatar at 22­23 weeks of gestation and the fetuses with pelvic renal dilatation equal or more than 4 mm in anterior-posterior transverse renal pelvic diameter are considered abnormal and a repeat ultrasound at 32-33 weeks is performed. If the anterior-posterior pelvic renal diameter remains > 4 mm, it is considered to be abnormal and post-natal ultrasound is carried out, as a renal pelvis of > 4 mm is highly-sensitive for pathological renal abnormalities in all stages of gestation. [4] If this dilatation regresses (to < 4 mm) by 6-7 weeks post-natally, no further follow-up is required and the findings are considered normal. If, on the other hand, the dilatation persists, regular follow-up is arranged.

This group of children represents all patients with congenital hydronephrosis in Qatar, as ours is the only clinic set up for this purpose in the country. Ultrasound examination was done at 6-8 weeks inter­vals for at least one year. For the purpose of this study the degree of hydronephrosis was defined as mild, moderate or severe on the postnatal findings, according to the recommendations of Blachar et al [5] .

The investigations carried out were intravenous urogram (IVU) for all severe and all moderate cases suspected of having obstruction on Technetium-Diethyl en e triamine penta-acetic acid (DTPA) renogram and voiding cystourethrogram (VCUG) for patients who did not show obstruction on DTPA renogram and/or IVU.

DTPA renogram was interpreted on half time method and the slope of the first component of washout curve was calculated. The time taken for tracer activity to diminish by half was extrapolated from that curve. A half time of less than 15 minutes was considered to exclude obstruction, whereas a prolonged half-time of more than 20 minutes confirmed obstruction. A half time between 15 and 20 minutes was considered equivocal and the procedure needed to be repeated.

In every DTPA renogram, the changes in the radioactivity in the pelvi-calyceal system was observed visually in the sequential images, and the differential filtration percentage was measured.

   Results and Outcome Top

A total of 391 kidneys (in 311 patients) were discovered to have congenital hydro­nephrosis in the 10-year study period (1987-1996). This gives an overall incidence of 1:330 live births. However, the incidence dropped to 1:186 and 1:149 in 1995 and 1996 respectively. The mean period of follow-up was 2.7 years (range 3 month to 10 years). The male to female ratio was 3.78:1 with a rate of Qatari to non-Qatari of 1.2:1. Based on the ultra­sound examination, the hydronephrosis was classified as mild, moderate or severe. Mild hydronephrosis constituted 64% of the patients and the moderate and severe from constituted 30% and 6% respectively.

Forty-five patients (14.4%) required operative intervention while 99 patients (31.8%) improved spontaneously. The remaining 167 patients (53.6%) remained stable on follow-up. The operative inter­vention consisted of pyeloplasty for correction of uretero-pelvic juncture obstruction in 22 (49%), ureteric implantation, for uretrovesical obstruction (UVJ) in 12 (26.5%) and correction of associated reflux in three patients. Five patients (11%) had nephrostomy, four patients (9%) had nephrectomy, and two patients (4.5%) had collagen-teflon injection for associated reflux [Figure - 1]

Of the 99 children who improved spontaneously, the vast majority 87% had mild hydronephrosis, 12 % had moderate hydronephrosis and only 1% had severe hydronephrosis.

DTPA renogram was done initially in 145 patients (46.5%). Obstruction was documented in 66 patients (45.5%), and good drainage with no obstruction was found in 79 patients (54.5%). Voiding cysto urethrogram (VCUG) was performed in 94 patients (30%) who showed no obstruction on DTPA renogram and for patients with evidence of persisting or increasing degree of severity of hydro­nephrosis. There were 22 patients (23.4%) who showed evidence, of vesicoureteric reflux associated with hydronephrosis. There was no evidence of reflux in the remaining 72 patients (76.6%). Urine culture and renal function was done in same patients and antibiotic prophylaxis was given to patients with DTPA-proven obstruction or reflux. Associated anomalies were found in 39 patients (12.5%) of which half were genitourinary.

Outcome of wild hydronephrosis

In the 199 patients with mild hydro­nephrosis, 88 (44%) regressed to normal and three (2%) progressed to moderate or severe hydronephrosis. None of these, however, required operative intervention. The remaining 108 patients (54%) remained stable with mild hydronephrosis.

Outcome of moderate hydronephrosis

Ninety-four (30%) of the patients had moderate hydronephrosis. Of these 12 (13%) regressed to normal and 29 (31%) required operative intervention and the remaining 53 patients (56%) remained stable at follow-up.

Outcome of severe hydronephrosis

Of the 18 (6%) patients with severe hydronephrosis, one patient normalized his hydronephrosis spontaneously, two became moderate and remained stable and one refused the operation. The remaining 14 patients (78%) were operated upon.

   Discussion Top

Over a period of 10 years, 311 children with congenital hydronephrosis were discovered by postnatal ultrasounds giving an incidence of 1:330 live births. If we include other uropathies (cystic diseases, dysplasia, hypoplasia and posterior urethral valve), the overall incidence would be 1:258. The incidence of congenital hydronephrosis in 1995 was 1:186 and in 1996 was 1:149. We believe that, as physicians become more aware of the problem and radiologist become more expe­rienced and as ultrasound machines become more sensitive and accurate, the pickup rate increases, which may explain this increase. Different studies listed in Thomas Review [3] gave a range of 1:154 to 1:1200 and reported large post mortem studies of 245,000 autopsies showing an incidence of renal abnormalities of 1 in 650. In the Chitty study [7] , the prevalence of fetal pelvic dilatation was 1:121 in 45,350 pregnancies studied.

Ultrasound of kidneys (U/S) postnatally is the usual initial investigation and proved to be a very sensitive, accurate, simple and non-invasive investigation for screening. A sensitivity of 100% and specificity of 96% using U/S has been reported.[8]

We repeated the U/S at 6-8 weeks postnatally and at regular intervals there­after until stabilization, regression or operative intervention was indicated.

None of the 199 children with mild hydronephrosis were operated on. Only three of this group progressed to a moderate stage but even in these all that was required was follow-up.

In the ninety-four patients with moderate hydronephrosis, 31% required operative intervention, 13% regressed and the rest remained stable with no functional deterioration.

In the severe form (18 patients), the majority (78%) required operating upon. We recommend that full investigation (DTPA, VCUG, kidney function tests and 1VU) should be carried out in all children with moderate or severe hydronephrosis. Early collaboration between the pediatric nephrologist and the pediatric urologist is essential. Surgical intervention should be considered with worsening of the degree of hydronephrosis, presence of infection and obstruction or/and deteriorating renal function.

Courtvile et al [9] showed that 70% of affected infants have morbidity related to abnormal renal function or to a surgically correctable defect. Mayor et al [10] demon­strated progressive deterioration in the renal function as a consequence of obstruction and this could be halted or improved if surgery was done in the first year of life.

Urine culture results were available in 44 patients. In the first urine culture taken, 33 (75%) were negative, and 11 (25%) were positive. Prophylaxis with antibiotics was given to patients with vesicoureteric reflux (VUR). Patients with severe hydronephrosis and patients with obstruction affecting the kidney function as proven by DTPA renogram, were given prophylactic anti­biotics till the surgery was carried out. The matter of prophylaxis is a controversial issue in many studies and needs to be cleared up with prospective studies involving large numbers of patients.

Intrauterine ultrasonography imaging of fetal renal system identifies babies who may be in need of postnatal ultrasono­graphy and who require further evaluation. Early identification of the anomaly is not sufficient but needs appropriate post-natal plan, communications and coordination between the parents and all care providers like obstetricians, ultrasonographers, neo­natologists, pediatricians, nephrologists, and pediatric surgeons or urologists.[11]

   Acknowledgment Top

We thank Mr. Jassim Darwish who helped us with biostatistics, Ms. Ma Bella T. Santiago, our Secretary; and Ms. Maha Jumaa, Nephrology Team Nurse.

   References Top

1.Becker N, Avner ED. Congenital nephropathies and uropathies. Pediatr Clin North Aml995;42:1319-41.  Back to cited text no. 1    
2.Fleischer AC, Romero R, Manning FA;Jeanty P, James AE Jr. Abnormalities of the ureters, bladder and urethra. Ultrasono­JQgraphy in obstetrics and gynecology; 4 th edition. Appleton and Lange. 1991;260­-6.  Back to cited text no. 2    
3.Thomas DF. Fetal uropathy. Br J Urol 1990;66:225-31.  Back to cited text no. 3    
4.McGahon JP, Porto M. The fetal abdomenand pelvis; diagnostic obstetrical ultrasound.J.B. Lippincott Company 1994;371-4.  Back to cited text no. 4    
5.Blachar A, Blachar Y, Livne MP,Zurkowski L, Pelet D, Mogilner B. Clinicaloutcome and follow-up of prenatal hydronephrosis. PediatrNephrol 1994;8;30-5.  Back to cited text no. 5    
6.Homsy YL; Saad F, Laberge I, Williot P, Pison C. Transitional hydronephrosis of the newborn and infant J Urol 1990;144:579­83.  Back to cited text no. 6    
7.Chitty L, Chudlergh T, Cambell S, et al. Incidence, natural history and clinical significance of mild fetal pyelectosis. Br J Radioll992;65:636-41. 8. 8.  Back to cited text no. 7    
8.Tsai TC Lee HC; Huang FY. The size of the renal pelvis on ultrasonography in children. J Clin Ultrasound 1989;17:647-51.  Back to cited text no. 8    
9.Corteville JE, Gray DL, Crane JP. Congenital hydronephrosis: correlation of fetal ultrasonographic findings with infant outcome. Am J Obstet Gynecol 1991:165: 384  Back to cited text no. 9    
10.Mayor G, Genton N,Torrado A, Gugnard JP. Renal function in obstructive nephropathy: long-term effect of reconstructive surgery. Pediatrics 1975;56:740-7.  Back to cited text no. 10    
11.Ransley PG, Dhillon HK, Gordon I, Duffy PG 5 Dillon MJ, Barratt TM. The postnatal management of hydronephrosis diagnosed by prenatal ultrasound. J Urol 1990;144: 584-7.  Back to cited text no. 11    

Correspondence Address:
Tayseer S Saad
Department of Nephrology, Hamad Medical Corporation, P.O. Box 3050, Doha
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PMID: 18408313

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