Mini-nephroscope combined with pressure suction: an effective tool in MPCNL for intrarenal stones in patients with urinary tract infections.

We report our experience with a mini-nephroscope connected to pressure suction as a modified minimally invasive percutaneous nephrolithotomy (MPCNL) technique to manage intrarenal stones in patients with a urinary tract infection (UTI). We used a mini-nephroscope connected to pressure suction to aspirate infected urine and reduce intrapelvic pressure. From January 2010 to June 2014, we treated 683 patients with intrarenal stones and UTI with this modified MPCNL technique in our department (Group A). Patients with an intrarenal stone and without UTI treated by this modified MPCNL (Group B, N = 422) and patients with an intrarenal stone and UTI but treated by traditional MCPNL without pressure suction (Group C, N = 95) were collected as control groups. In group A, 635 of the 683 patients (93 %) had a positive urine culture preoperatively and the other 48 patients (7 %) were diagnosed with pyonephrosis intraoperatively. The mean stone bulk was 843 ± 151.4 mm(2) and mean operative time was 71.0 ± 11.5 min. The mean stone bulk and operative time were similar to those of group B and group C. However, the rates of infectious complications for groups A (6.4 %) and B (4.9 %) were similar, but higher in group C (28.4 %). In group A, only 38 patients had fever and 6 patients developed sepsis. None of the patients showed progression to multiple organ dysfunction syndrome or died in all of patients. Our results demonstrated that this modified MPCNL technique is safe, feasible, and efficient for managing intrarenal calculi in patients with an UTI.