There is limited comparative data on the predictive value of the two most commonly employed classification systems (SFU hydronephrosis[HN] grades and urinary tract dilation[UTD] risk groups) in regards to future risk for surgical intervention and the development of fUTI. Herein we explore this topic in infants with isolated HN.
After screening 938 patients with prenatal HN (2009-2016), we selected patients with UPJO-like HN(n=322). HN grades were prospectively collected at baseline, surgery and last follow-up. Gender, circumcision status, antibiotic prophylaxis, and renal pelvis anteroposterior diameter(APD) were captured. Primary outcome was undergoing a pyeloplasty and development of fUTI. Comparative analyses between SFU grades/UTD groups and the primary outcome were performed using Fisher's exact and log- rank tests.
Mean age at presentation was 3.3±2.6months and mean follow-up was 22±19months. Pyeloplasty was performed in 32% of SFU III-IV children vs. 31% of those with UTD 2/3. The rate of fUTI in SFU III-IV patients was similar to that in those with UTD group 2/3(8%vs.10%). Children with SFU III-IV had a significantly higher rate of surgery than those with SFU I-II (32%vs.2%; p<0.01). Similar findings were seen when using UTD groups to compare low (1) vs. moderate/high risk patients (2/3).
Both grading systems equally allowed for proper risk-stratification and prediction of clinical outcomes based on baseline ultrasound, correctly separating most infants who underwent surgery or developed fUTI from those who can be managed non-surgically. The use of the new UTD classification should not affect how families of children with isolated HN are counselled regarding surgical intervention and risk of fUTI.
The Journal of urology. 2016 Aug 30 [Epub ahead of print]
Luis H Braga, Melissa McGrath, Forough Farrokhyar, Kizanee Jegatheeswaran, Armando J Lorenzo
Department of Surgery, Division of Urology, McMaster University, Hamilton, Ontario; Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario; McMaster Pediatric Surgery Research Collaborative, Department of Surgery, McMaster University, Hamilton, ON. Electronic address: ., McMaster Pediatric Surgery Research Collaborative, Department of Surgery, McMaster University, Hamilton, ON., Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario; Office of Surgical Research Services, Department of Surgery, McMaster University, Hamilton, Ontario., Division of Urology, The Hospital for Sick Children and Department of Surgery, University of Toronto, Toronto, Ontario.