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| ORIGINAL ARTICLE |
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| Year : 2019 | Volume
: 30
| Issue : 6 | Page : 276-280 |
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Outcome analysis of pediatric pyeloplasty in varied presentation in developing countries
Sajni I Khemchandani
Department of Urology, Institute of Kidney Diseases and Research Center, Dr. H L Trivedi Institute of Transplantation Sciences, Civil Hospital Campus, Ahmedabad, Gujarat, India
| Date of Submission | 17-May-2019 |
| Date of Decision | 19-Sep-2019 |
| Date of Acceptance | 26-Sep-2019 |
| Date of Web Publication | 23-Dec-2019 |
Correspondence Address:
Dr. Sajni I Khemchandani
401, Sudarshan Flats, 13, Shantinagar Society, Usmanpura, Ahmedabad - 380 013, Gujarat
India
 Source of Support: None, Conflict of Interest: None
DOI: 10.4103/UROS.UROS_31_19
Objectives: The objective was to study the various presentations of pelviureteric junction (PUJ) obstruction in developing countries and its outcomes. Materials and Methods: We retrospectively reviewed the medical records of 239 children (260 renal units) who underwent surgery for PUJ obstruction between January 1994 and December 2016. Data on the patients presenting with symptoms and preoperative imaging findings of ultrasonography, intravenous urography, or diuretic renography were analyzed. Results: In all cases, we preferred dismembered Anderson-Hynes pyeloplasty with or without JJ stenting. Complications of pyeloplasty included prolonged urine leakage in 13 patients, of whom 4 responded to conservative management, 5 required percutaneous nephrostomy (PCN), and 4 were treated with endoscopic JJ stenting. Six patients had persistent obstruction: two responded to endopyelotomy, and in four, redo pyeloplasty was successful. Five patients with renal function of <10% were initially treated with PCN and ultimately required nephrectomy. Conclusions: In patients born with PUJ obstruction and impaired renal function, pyeloplasty fails to significantly improve function, possibly because of cortical loss. However, in patients with antenatal PUJ obstruction managed expectantly, there is a small but significant risk of modest permanent loss of renal function.
Keywords: Childhood, hydronephrosis, obstruction, pelviureteric junction
How to cite this article:
Khemchandani SI. Outcome analysis of pediatric pyeloplasty in varied presentation in developing countries. Urol Sci 2019;30:276-80 |
| Introduction | |  |
Congenital hydronephrosis is one of the most common problems of childhood, and its most common cause is obstruction at the pelviureteric junction (PUJ).[1],[2] PUJ obstruction is the most common cause of antenatal fetal hydronephrosis.[1],[3] Obstruction of the PUJ usually develops as a result of intrinsic neuromuscular abnormalities causing impaired peristalsis and urine drainage but could also be caused by an external compression by accessory lower polar renal vessels. The incidence increases in the presence of other urinary tract anomalies.[4],[5]
The natural history of PUJ obstruction varies considerably, but the severity of renal pelvis dilatation usually correlates with the prognosis.[6],[7] In developing countries, children present quite late; hence, PUJ obstruction is seen in children of all ages. Nowadays, with the widespread use of antenatal ultrasonography (US) as a routine screening procedure, many cases are diagnosed prenatally.[8] There are few reports on PUJ obstruction from developing countries.[9]
| Materials and Methods | | |
We retrospectively reviewed the medical records of 239 children (260 renal units) who underwent surgery for PUJ obstruction between January 1994 and December 2016. Data on the patients presenting with symptoms and preoperative imaging findings of US, intravenous urography, or diuretic renography were analyzed. Serum creatinine, urine analysis, and urine culture were evaluated in all cases. Screening for PUJ obstruction consisted of US in all patients, intravenous urography in 40%, and renography in 60%. The diagnosis of obstruction was confirmed by either intravenous urography or 99m technetium diethylenetriaminepentaacetic acid (DTPA) or mercaptoacetyltriglycine renal scans. The obstruction on DTPA renal scan was defined as prolonged T1/2 time, associated with obstructive curve on renogram. In all patients, T1/2 was more than 20 min, suggesting obstruction.
Antenatal diagnosis was made in seventy children (29.2%). In these neonates, postnatal US was done after the first 48 h of the birth. All neonates with hydronephrosis were subjected to micturating cystourethrogram (MCUG) to rule out vesicoureteral reflux (VUR) at 3 weeks of age. Male neonates with bilateral hydronephrosis were subjected to MCUG as early as feasible to rule out posterior urethral valves.
In all cases, we preferred dismembered Anderson-Hynes pyeloplasty with or without JJ stenting. Complications of pyeloplasty included prolonged urine leakage in 13 patients, of whom 4 responded to conservative management, 5 required percutaneous nephrostomy (PCN), and 4 were treated with endoscopic JJ stenting. Six patients had persistent obstruction: two responded to endopyelotomy, and in four, redo pyeloplasty was successful. Five patients with renal function of <10% were initially treated with PCN and ultimately required nephrectomy.
After surgery, antibiotic prophylaxis was administered for 6 weeks to 3 months. Routine follow-up included urine routine and microscopic examination every 15 days for 3 months, renal US after 3 months, and thereafter annually for the first 3–4 years or depending on patients' clinical course. Follow-up DTPA renography was done 6 months after surgery, whenever feasible.
| Results | | |
The PUJ obstruction was more common in male than in female children (194:45, ratio 4:1). One hundred and four children presented before 1 year of age (mean age: 6.3 months, median age: 6 months). 86 children presented between 1–5 years of age (mean: 3.16, median: 3 years). 69 children presented between 5–13 years of age (mean: 9.14, median: 9 years).
Most of the children presented with the following symptoms: pain and vomiting in 35.5%; antenatal hydronephrosis in 29.2%; abdominal distension in 26.8%; pyuria, fever, and urinary tract infections (UTIs) in 8.8%; secondary PUJ obstruction in 2%; secondary renal calculi in 2%; previous failed pyeloplasty in 1.25%; hematuria in 1.25%; failure to thrive in 1.7%; and incidental diagnosis in 3% [Table 1].
Of these, twenty-one children had bilateral PUJ obstruction, thirteen children had solitary functioning kidneys (8 – right and 5 – left), three children had ectopic pelvic kidneys, two had horseshoe kidneys, and eight had lower pole crossing renal vessels leading to PUJ obstruction. MCUG demonstrated bilateral VUR in eight patients and unilateral VUR in seven children.
Differential renal function was defined as poor, moderate, and good if <10%, >10%–30%, and >30%, respectively.
Preoperative PCN was done in 16 patients; age range in these children was between 3 months and 13 years. Four children had bilateral PUJ obstruction, and five children had solitary functioning kidney with pyonephrosis. PCN was done for either pyonephrosis or renal function of <10%. After PCN, five children underwent nephrectomy for nonfunctioning renal units or differential renal function of <10%. Renal function in the remaining 11 patients improved after pyeloplasty.
Five children had solitary functioning kidney with pyonephrosis, and after pyeloplasty, renal function improved in all children. Six other children had pyonephrosis and renal function of <10%. On exploration, kidneys appeared good; hence, pyeloplasty was done. Renal function improved >10% in four patients and >5% in one patient and deteriorated in one child with severe pyelonephritis.
JJ stent was not kept in all patients. JJ stent was placed in patients with the following:
- Technically difficult pyeloplasty
- Very stenotic PUJ or upper ureter
- Associated anomalies, for example, solitary kidney, VUR, horseshoe kidney, and pelvic kidney
- Presence of pelvic or ureteric inflammation or pyonephrosis
- Stone disease
- Redo pyeloplasty.
Thirteen postoperative children had urinary leak, all without JJ stent: four patients were treated conservatively, four patients responded to JJ stenting postoperatively, and five patients required postoperative PCN with delayed opening of PUJ. Hence, to avoid postoperative leak or secondary procedures, we prefer to keep JJ stent whenever in doubt. Six patients had failed pyeloplasty: two required endopyelotomy, and in four, redo pyeloplasty was successful. Five children required nephrectomy, all with differential renal function of <10%. Two children with solitary functioning kidneys succumbed to septicemia after pyeloplasty.
On average, 75% of these children showed more than 10% increase in function, 20% showed marginal increase in function, and only 5% showed deterioration in function. US following surgery showed reduced hydronephrosis in almost all children.
| Discussion | | |
The etiology of pediatric PUJ obstruction is mainly congenital narrowing as seen in our study and other series.[10] Other causes are aberrant renal vessels and fibrous bands.
The widespread use of antenatal US as a screening procedure has detected primary PUJ obstruction in neonates and infants; usually, those are found to have intrinsic stenosis of PUJ at surgery.[11],[12] However, the older children undergoing pyeloplasty because of recurrent colic, UTIs, or hematuria most often have extrinsic obstruction caused by lower hilar segmental vessels compressing or angulating the PUJ.[12],[13]
A total of 21 patients presented with bilateral PUJ obstruction. Of these, twenty were male patients and one was a female patient. The age ranged from 1 month to 12 years, with a mean age of 2.6 years.
Associated VUR was detected in 15 patients: 8 had bilateral and 7 had unilateral reflux. If high-grade VUR was detected on MCUG, it was treated before PUJ obstruction because sometimes secondary PUJ obstruction will subside after correction of VUR. Second, high-grade VUR leads to persistent urine leak after pyeloplasty. Third, we will like to treat distal obstruction before proximal obstruction.
Pyeloplasty was required more often in children with associated anomalies. Contralateral multicystic or dysplastic kidney was detected in 13 patients (8 on the left side and 5 on the right side).
Four times more males than females were diagnosed with PUJ obstruction in our study (194:45), the left kidney being more frequently involved than the right (159:101). The more frequent occurrence of PUJ obstruction in males with predominantly left-sided involvement, association with VUR and multicystic dysplastic kidney, and increased frequency of bilaterality were similar to historical reports.[8],[14]
Asymptomatic newborns and infants, diagnosed antenatally, were initially observed.
Indications of operative intervention included the following:
- Increasing hydronephrosis, i.e., increase in AP diameter of the pelvis
- Decreasing relative renal function of ~10% on repeat scan
- Obstructive renogram curve, with T1/2 of >20 min
- Presence or appearance of symptoms as pyelonephritis or UTI.
The laboratory investigations of Koff showed that glomerular filtration rate decreases significantly in ureteral obstruction, and delayed repair causes irreversible kidney damage.[15] King et al. reported that severe renal function impairment may be minimized by the early relief of obstruction postnatally.[16]
Stock et al. have concluded that children with differential renal function of <35% at diagnosis have a low probability of postoperative function recovery.[17] In contrast, several other studies have observed a significant improvement in split function after pyeloplasty in children with severe preoperative renal function impairment. Observations by various authors support the hypothesis that pyeloplasty may stop a progressive damage and that improved function depends on early surgery.[18] We agree with these authors that renal function assessed by renography does predict the postoperative outcome and that improvement does occur even in kidneys with severe deterioration of function, if intervention is done as early as feasible. Cornford and Rickwood also suggest that relative function was stabilized in those patients who underwent early pyeloplasty.[19] In long-standing obstruction with significant dilatation, renographic or ultrasound scans may not return to “normal” after primary treatment. In this situation, symptomatic improvement and stabilization of renal unit function are the markers of success.[20]
We have observed that renal pelvic diameter increases when children present at advanced age. Seventy-three percent of children when presenting before 1 year of age had pelvis dilation <5 cm, 50% of children between 1-5 years of age had pelvic dilation of less than 5 cm, and 56% of children between 5–13 years of age had pelvic dilation of less than 5cm. (P < 0.01, which is highly significant) [Table 2].
We observed a significant difference in preoperative differential renal function in the prenatal and postnatal groups. We agree with Mayor et al. who found that, in 24 cases of severe congenital urinary tract obstruction, improvement in renal function was most pronounced after surgical repair performed before the age of 1 year.[21] King et al. also reported on 11 patients who underwent pyeloplasty in the early postnatal period; renal function was substantially better in this group than in children who underwent repair after 5 years of age.[16] Tapia and Gonzalez also recommend early pyeloplasty for all children with reduced function of the involved kidney.[22]
Almost all children underwent Anderson-Hynes dismembered pyeloplasty, which is the gold standard.[23] Postoperative complications of urine leakage and UTIs are in keeping with other studies.[24] It is a well-known fact that children with dilated renal pelvis are susceptible to UTIs, probably related to urinary stasis[25] as seen in 8.8% of children who presented with preoperative pyonephrosis in our series. Although the prevalence of postoperative UTIs in our study was only 3%, Coelho et al. have reported a 14% prevalence of UTIs, and other previous studies have reported a 25% incidence.[26]
In children, although the gold standard for the primary management remains open dismembered pyeloplasty, however, as with the adult population, there is also an increasing use of the laparoscopic approach.[27] Success rates of pyeloplasty are over 90%, and although the majority of failures occur within the first 12 months, they can occur even up to 3 years after procedure.[28] Ultrasound scan is often used more frequently in follow-up and identifies failure with good accuracy, thus reducing the need for renography and the associated radiation exposure. Renography can be reserved for patients with increasing hydronephrosis.[28] There is a debate regarding optimum length of follow-up after primary/redo pyeloplasty. One approach suggests close surveillance in the first 12 months and then a bi-annual or annual review for at least 3 years.[29]
In open pyeloplasty failures, it appears that endoscopic treatment is inferior to redo pyeloplasty. In a series of 105 open pyeloplasty procedures, there were 7 failures (6%). In this series, six patients required open surgery with three redo pyeloplasty and three ureterocalicostomy procedures.[28] Our series had six failures (2.4%): two responded to endopyelotomy and four required redo pyeloplasty. Although there was dense scarring in all and one undiagnosed crossing renal vessel, none required ureterocalicostomy.
Stents/drains compromised the majority of secondary procedures. Redo pyeloplasty was the second most common secondary procedure. Endoscopic management was performed approximately half as frequently as redo pyeloplasty, which remains the gold standard to manage pediatric pyeloplasty failure.
Excessive leak of urine from drain seems to be precursor of persistent obstruction; probably, the extravasated urine with a secondary inflammatory response is responsible for persistent obstruction. The fibrosis of the periureteral tissues was noted in all repeat pyeloplasty cases, sometimes with complete sclerosis of the PUJ.[30]
| Conclusions | | |
In patients born with PUJ obstruction and impaired renal function, pyeloplasty fails to significantly improve function, possibly because of cortical loss. However, in patients with antenatal PUJ obstruction managed expectantly, there is a small but significant risk of modest loss of renal function.[19] We want to emphasize on early pyeloplasty, especially in our country, because usually children are coming quite late and with a decrease in renal function and associated complications. Once conservative management is advised, patients are lost to follow-up and present with either pyonephrosis or reduced renal function.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]
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