Management of intrinsic versus extrinsic causes of ureteropelvic junction obstruction in children- outcomes and complications from a large prospective cohort study
Jaskirat Saini1, Hark Randhawa1, Yuding Wang1, Melissa Mcgarth1, Luis H. Braga1.
1Department of Surgery, Division of Urology, McMaster University, Hamilton, ON, Canada
Introduction: Ureteropelvic junction obstruction (UPJO) can be caused by intrinsic and or extrinsic (i.e., crossing vessels[CV]) obstruction. Although different in underlying pathology, authors have commonly grouped both etiologies of UPJO together in evaluating treatment options and outcomes. The aim of this study is to evaluate clinical characteristics and outcomes of patients undergoing laparoscopic dismembered pyeloplasty (LDP) for intrinsic and extrinsic UPJO in children.
Methods: We performed a retrospective review of prospectively collected data on patients who underwent LDP between 2008 and 2020 at our institution. The etiology of UPJO was diagnosed by retrograde pyelogram at the beginning of each procedure, and intraoperative findings during laparoscopy. We compared patient characteristics and clinical outcomes between patients with intrinsic versus extrinsic UPJO using Student’s t tests for continuous variables, and Chi-squared tests for categorical variables.
Results: 154 patients underwent LDP during the study period. 103(67%) were obstructed from an intrinsic cause, and 51(33%) had CV. Patients with an intrinsic cause of UPJO were younger (mean [SD] age 73 months vs. 128 months, p<0.001), whereas patients with CV were more likely to be symptomatic (92% vs 63%, p<0.001). Among 117 patients who had a preoperative renal scan, no significant difference was seen in diuretic t1/2 (70 minutes for intrinsic group vs. 87 minutes for CV,p=0.5. Additionally, both groups had similar rates of SFU Grade 4 hydronephrosis on ultrasound preoperatively (44% intrinsic and 47% CV). A significant difference was observed in the rate of overall complications (7.8% intrinsic vs. 0% CV,p=0.041); all recurrences (n=5, 3.2%) occurred in the intrinsic group. No difference in hospital length of stay was observed between groups (median 2 days).
Conclusions: UPJO secondary to CV is associated with 0% recurrence compared to 3.2% for intrinsic obstruction in this large prospective series. Although distinct entities, both intrinsic obstruction and CV are managed safely and effectively with LDP.