Introduction

Currently, urologists routinely use either ultrasound or conventional fluoroscopic guidance during percutaneous nephrolithotomy (PCNL).In an attempt to reduce the radiation exposure during PCNL, a novel laser Direct Alignment Radiation Reduction Technique (DARRT) was developed where the renal access is guided by a laser sight placed upon the C-arm. The purpose of this study is to compare the outcomes of these 3 techniques in patients undergoing percutaneous stone surgery.

Methods

In this chart review, the first 25 consecutive patients undergoing PCNL using laser DARRT were compared to 25 US-guided and 25 conventional access patients. These 3 cohorts were matched in terms of age, body mass index, stone burden and location. Primary outcomes were total fluoroscopy time and access fluoroscopy time. Secondary outcomes included stone burden, operative time, estimated blood loss, stone free status and major complications ( ≥Clavien III). Patients with residual fragments ≤4 mm were considered to be stone free. Statistical analysis was done using ANOVA for continuous variables and the chi-square test for categorical variables. A p value <0.05 was considered significant.

Results

There were no differences between the 3 cohorts in baseline demographics and mean stone burden (Table 1). The stone free rates between the US (68%), conventional PCNL (76%) and laser DARRT (84%) were similar (p=0.27). Major complications and EBL were not significantly different between the groups. Operative time for the laser DARRT was 20 minutes shorter than the conventional PCNL and 24 minutes shorter than the US, however, this difference did not reach significance (p=0.58). Mean access fluoroscopy time was 3, 844 and 8.9 seconds, and total fluoroscopy time was 8.5, 944.6 and 17.4 seconds for US, conventional, and laser DARRT PCNL respectively. Both US and laser DARRT had significantly lower total and access fluoroscopy times than conventional PCNL (p<0.01 for all comparisons).

Conclusions

The use of the novel laser DARRT and US-guided technique both resulted in a >98% reduction in the fluoroscopy time compared to the conventional technique. The operative time and stone free rates of the laser DARRT compared favorably with the US-guided and conventional techniques.

Funding

None