Surgical management of upper pole nonfunctioning renal moieties – the timeless debate
Treatment options for obstructed upper pole non-functioning moieties in duplicated systems vary significantly. Traditionally, an upper pole heminephrectomy was favored to avoid any potential morbidity from the nonfunctioning moiety. However, the concomitant presence of lower urinary tract obstruction from ureterocele and lower pole vesicoureteral reflux (VUR), have pushed many to argue for performing only a common sheath reimplantation without an upper pole heminephrectomy. We evaluate the surgical management and outcomes of such patients treated at our institution.
In this retrospective IRB-approved study, patients undergoing upper pole heminephrectomy, ureteroureterostomy or common sheath ureteral reimplantation from 2012-2017 were identified by CPT codes. Only patients with decreased upper pole function, classified as <25% differential renal function compared to the lower pole moiety, were included. Surgical management and outcomes were noted, as well as anatomical variations. Basic demographic variables were also collected for all included patients. </p>
A total of 27 (57%) patients underwent with upper pole preservation and 20 (43%) patients underwent upper pole heminephrectomy. Lower pole VUR was more common in patients undergoing upper pole preservation (67% v. 25%, p=0.008). No difference in postoperative complications were seen between the two groups. During heminephrectomy, four patients had concomitant lower urinary tract reconstruction and two patients required further urologic intervention for lower urinary tract obstruction postoperatively. Although VCUG was not routinely obtained postoperatively, of the five patients with VCUG, only one developed new onset reflux after an upper to lower pole ureteroureterostomy, requiring intravesical reimplantation.
Reimplantation of nonfunctioning upper pole moieties appears to be a safe alternative to upper pole heminephrectomy as no significant different in outcomes were seen between patients undergoing upper pole heminephrectomy and those undergoing upper pole preservation surgery. However, considering that 30% patients with upper pole heminephrectomy required additional lower urinary tract procedures, it seems favorable to pursue upper pole preservation as there is no associated harm.