ESPU Congress 2018 - Abstract Book

62 29 th CONGRESS OF THE ESPU S6: OBSTRUCTION & HYDRONEPHROSIS 1 Moderators: Josef Oswald (Austria), Darius Bagli (Canada) ESPU Meeting on Thursday 12, April 2018, 09:34–10:20 09:34–09:39 S6-1 (LO) ★ SUPRANORMAL RENAL FUNCTION IN UNILATERAL HYDRONEPHROTIC PAEDIATRIC KIDNEYS: PREOPERATIVE AND POSTOPERATIVE PECULIARITIES Oriol MARTIN-SOLE, Sonia PEREZ-BERTOLEZ, Jenny ARBOLEDA, Andrea SORIA‑GONDEK, Francisco Javier VICARIO LATORRE and Luis GARCIA-APARICIO Hospital Sant Joan de Déu, Paediatric Urology Division, Paediatric Surgery Department., Esplugues De Llobregat, SPAIN PURPOSE The meaning of supranormal (SN) differential renal function (DRF) on unilateral hydronephrotic kidneys remains controversial. Our objective was to compare preoperative and postoperative characteristics in SN DRF patients with non-SN DRF patients. MATERIAL AND METHODS Our prospectively collected pyeloplasty database was reviewed. Patients operated between 2012 and 2017 were included (n=91). We excluded 13 patients with bilateral hydronephrosis, vesicoureteral reflux, redo pyeloplasty or solitary kidney. SN-group was formed by the 9 patients (11.5 %) who had preoperative supranormal DRF defined as DRF ≥ 55 %. Remaining 69 patients formed the non-SN group. The following parameters were collected: age, sex, anteroposterior renal pelvis diameter, SFU hydronephrosis grade, laterality, aetiology, ultrasound measured kidney volume and renal pelvis volume and pre and postoperative DRF. RESULTS The preoperative anteroposterior pelvis diameter (27.4 mm vs. 35.4 mm, p=0.026) and the ratio between preoperative pelvis volume and kidney volume (0.34 vs. 0.93, p<0.0025) were higher in SN group. Preoperative pelvis diameter was a good predictor of supranormal DRF, with an AUC of the ROC curve of 0.804 (95 %CI: 0,707–0,902). A pelvis diameter ≥30 mm predicts a supranormal DRF with 88.9 % of sensitivity and 73.9 % of specificity. Pelvis volume/kidney volume ratio was an independent risk factor on multiple regression analysis (p=0.037). There was a greater postopera- tive loss of function in SN-group compared to non-SN group (-0.3 % vs -6.4 %, p=0.0049). CONCLUSIONS Patients with supranormal DRF had larger renal pelvis, higher pelvis volume/kidney volume ratio and function decreased more after pyeloplasty. This suggest that preoperative DRF was overestimated, questioning the role of preoperative function as the main parameter to indicate surgical procedure.