Laparoscopic heminephrectomy for duplex system: observed difference in outcomes between upper and lower pole resections.

INTRODUCTION: Renal duplication is a relatively common congenital abnormality of the urinary tract, but symptomatic duplex kidney is a rare presentation in adults. Traditionally, the treatment of choice for poorly functioning moiety has been heminephrectomy. There is extensive literature detailing the outcomes of minimally invasive upper pole heminephrectomy, but comparatively little published regarding lower pole resection, especially in adult patients. We present a series of 13 patients who underwent minimally invasive heminephrectomy for duplex kidney.

MATERIALS AND METHODS: Over a 6 year period (2011-2017) 13 patients at a single center underwent laparoscopic heminephrectomy for symptomatic duplex kidney with a poorly functioning moiety. A retrospective review of case notes and imaging was undertaken.

RESULTS: Eight and 5 patients underwent upper and lower pole heminephrectomies, respectively. Laparoscopic transperitoneal approach was utilized in all cases. Median length of stay was 2 days (range 1 to 16 days). In the upper pole cohort, one patient had a postoperative infection requiring IV antibiotics. In the lower pole cohort by contrast, there were three major complications (60%). Conversion to complete nephrectomy was necessary in one case; one patient had urinary leakage requiring selective embolization and one patient required a second operation to resect remnant calyces. Furthermore, two patients (40%) developed late recurrence of symptoms.

CONCLUSIONS: Symptomatic duplex kidney is a rare presentation in adults. In our experience, heminephrectomy for non-functioning renal unit is safe and reproducible in experienced hands with no major complications and resolution of symptoms in the majority of patients. We have, however, observed a higher complication rate in those undergoing resection of a lower pole moiety. Alternative management such as uretero-ureterostomy should be considered in these cases.