Laser Endoscopic X-Ray-Guided Intrarenal Tract: Comparison Among Renal Access Modalities in the Porcine Kidney.

Laser endoscopic X-ray-guided intrarenal tract (LEXIT) is a recently described holmium laser retrograde access technique for creating percutaneous access during a percutaneous nephrolithotomy. We compared bleeding, ease of access, and the time to achieve access for each of the following three modalities: LEXIT, retrograde Lawson puncture wire, and antegrade 18-gauge nephrostomy needle access in the porcine kidney. Eight pigs underwent an average of five nephrostomy accesses per kidney under simultaneous laparoscopic vision at 5 mm Hg insufflation pressure. Data collected included: access time (seconds), bleeding intensity (scale: 1 [no bleeding] - 10 [severe bleeding]), bleeding duration (seconds), accuracy of caliceal entry, and surgeon comfort with the technique (scale: 1 [very easy] - 10 [very difficult]). A total of 64 nephrostomy accesses were obtained. The speed of nephrostomy access with LEXIT was significantly faster than the nephrostomy needle and Lawson wire ( < 0.001). Bleeding intensity ( = 0.002) and severity ( = 0.001) were lower with the Lawson puncture wire, followed by LEXIT and then by the nephrostomy needle. LEXIT was rated as easier in acquiring access within the upper pole ( = 0.003) and interpolar calices ( < 0.001). Histopathology demonstrated no difference in parenchymal damage between LEXIT and nephrostomy needle ( = 0.18); however, LEXIT was associated with significantly increased peri-tract thermal injury, although within a narrow focus of 1.6 mm ( < 0.01). Among the three renal access techniques, LEXIT provided the fastest access times and greatest ease of access specifically for upper pole and interpolar calices. Also, bleeding with LEXIT was significantly less compared with the standard antegrade nephrostomy needle access. Histopathological analysis demonstrated that the holmium laser resulted in focal thermal tissue effects similar in range to the blunt tissue trauma caused by the 18-gauge nephrostomy needle.