Abstract: PD21-06
Sources of Funding: None.

Introduction

Minimally Invasive PCNL (MIP) is a promising modality in the treatment of small size renal calculi. There is no consensus regarding ideal size of Nephrostomy Tract/Sheath for minimally invasive treatment modality. We prospectively compared outcomes in use of three different sizes of Sheaths ( 7.5, 12, 15.5 F ) during MIP for 10-20 mm size Renal Calculi.

Methods

: A total of 153 patients having Renal Calculi of 10-20 mm size were treated at our center between July 2015 and April 2016. Computer generated randomization Schedule was used to assign the use of Outer sheath size during MIP. 7.5 F sheath(n=42), 12F (n=66), and 15.5 F( n=45) was used in our study, where mean stone size was 13.4, 14.6, and 14.1 mm respectively. Rest of the patient demographics were comparable in each group. Hardness of all calculi were evaluated by the use of House Field Units on CT Scan. Pressure Irrigation pump was used for irrigation and Holmium Laser(20-40W) Lithotripsy with quartz fiber was used for stone fragmentation. OR time, Stone free rates, Post-operative Analgesic Use, Clavien Complication rate, Hospital Stay and Ancillary procedure requirement was noted in each group. X-ray KUB, Sonography and non-contrast CT Scan was used on post-operative day 3 to confirm stone free status. Use of DJ stent or Nephrostomy tube was decided as per merits of the case.

Results

Primary Stone free rate was defined as complete clearance on Non contrast CT scan on postoperative day 3. There was no significant difference (p=.124) in Primary stone free rate in 7.5 F (83.4%) and 12 F(84.9%) sheath group. 15.5F(96.5%) sheath group stone free rate was significantly higher(p>0.05) and OR Time(38±5) was lower (p=0.004) compared to other two groups. There was no significant difference in postoperative complications (Clavien Grade I &II) in either groups. Analgesic use in all groups was similar. 2 patients in 7.5 F sheath group and 4 in 12 F Sheath group needed ancillary procedure for complete stone clearance. Mean hospital stay was not significantly different in either groups. Primary stone free rate was 99% in Calculi with Housfield Unit <790±32 compared to those (81.5%) with Housefield Unit of >1150±89 in all groups.

Conclusions

Efficacy of miniaturized equipment with 7.5 F, 12 F and 15.5 F outer Sheath in treatment of 10-20 mm renal calculi is similar and has lower morbidity. Higher Primary Stone free rate with lower OR Time in 15.5 F Sheath group, irrespective of hardness of calculus, makes it more preferred size of equipment in Minimally Invasive PCNL.

Funding

None.