Urgent urinary drainage is the standard of care in patients with obstructive calcular anuria (OCA) and post-renal acute renal failure (ARF). This is done with retrograde ureteric stenting or a percutaneous nephrostomy tube (PCN); however, the indications for use have not been studied. Although few studies compared ureteric stenting with PCN in obstructive urolithiasis associated with infection [1-2] or pain , but this comparison is lacking in literature as regard obstructive urolithiasis associated with anuria and ARF particularly in children.
In this study, we compared PCN versus double J ureteric stent (JJ) as an initial urinary drainage (ID) in children with OCA and ARF due to ureteric calculi to identify the selection criteria for ID method to improve the urinary drainage, to decrease complications and to facilitate subsequent definitive clearance of stones.
Patients and methods
A series of 90children ≤12years old presenting with OCA and ARF due to bilateral ureteric calculi were included in this study. They were managed at Pediatric Urology Department, Cairo University from March 2011 to September 2013. Examination was done to detect signs of acidosis, sepsis or fluid retention in addition to evaluation of serum creatinine (Cr), electrolytes, blood urea and arterial blood gases. Abdominal ultrasound and plain urinary tract imaging were done to determine the degree of obstruction and the size and level of obstructing stones. Plain CT scan was used to detect radiolucent stones. The Society for Fetal Urology grading system for hydronephrosis was used to classify patients into 5grades . Patients with congenital anomalies or grade 0-1 hydronephrosis were excluded.
Critically ill patients, who had signs of overload, had elevated serum potassium>7meq/l and/or blood pH<7.1, were stabilized by peritoneal dialysis. Stable patients (or patients stabilized by dialysis) were randomized into 2groups (bilateral JJ vs PCN). No patient had any contraindication to both methods of drainage (urinary diversion, urethral stricture or uncontrolled coagulopathy).
ID was performed under general anesthesia (GA) and fluoroscopic guidance. We used 4.8-6Fr JJ or 6-8Fr PCN. After Cr normalization, the number of subsequent interventions needed for clearance of stones (NSICS) was detected.
The 2groups were compared in operative and imaging times, complications, period for return to normal Cr, and NSICS. Factors affecting each group outcome were also analyzed.
Comparison of study groups was done using Student t, Mann Whitney U, Chi square or Exact tests using computer program SPSS version15. P values <0.05 were considered statistically significant.
This study has included 64boys and 26girls presented with OCA for 1-2 days. Peritoneal dialysis was done in 19patients. Postoperative polyuria was observed in all patients. This decreased gradually to normal within 6days. The perioperative data are presented in table 1.