Despite models that predict the need for multi-access PCNL, there is a paucity in the literature outlining stone or renal characteristics that prevent the successful navigation of a wire down the ureter. The benefits of ureteral cannulation with a wire include validation of successful access into the collecting system, stability during advancement of the access sheath over a balloon or dilator, and a visual aid when the direction of the collecting system and stone is not apparent at the onset of nephroscopy. The importance of a ureteral wire has prompted a cohort of urologists toward retrograde ureteroscopy to assist with percutaneous nephrolithotomy (RIRS-PCNL).1 Advocates of RIRS-PCNL cite a direct vision of the access needle and assistance with the advancement of wire down the ureter as the benefits of this technique. However, RIRS-PCNL has been scrutinized over the need for additional equipment and personnel to run a retrograde and anterograde endoscopic equipment. Additionally, retrograde access to the renal pelvis or targeted papilla with a ureteroscope is not always possible because of a small-caliber ureter, obstructing stone, infundibular stenosis, excluded calyx. Lastly, for surgeons who do not routinely employ RIRS-PCNL, anticipating cases where the advancement of a percutaneous wire down the ureter is difficult. By optimizing the PERC-TIC technique, the reliance on RIRS is removed and predicting an inaccessible ureter is no longer required.
Based on these principles, the PERC-TIC technique provides significant value to complete a percutaneous stone procedure when ureteral access is unobtainable. The principles of the PERC-TIC technique are outlined in this article. The technique has been characterized in previous publications using both fluoroscopy an ultrasound image guidance.2 The goal of this article is to advocate for the technique but to provide insight into a subset of unique challenges associated with PERC-TIC. Our hypothesis for the study was to show that there were higher bleeding rates associated with the PERC-TIC technique compared to cases where a wire was successfully advanced down the ureter (labeled standard PCNL). We believe that the absence of a wire down the ureter resulted in a more mobile kidney that was subject to additional shear stress during tract dilation and access sheath advancement. However, hemoglobin changes, transfusion rates, and the use of large percutaneous drains after PCNL did not differ between standard and PERC-TIC PCNLs. On multivariate analysis, compared to standard PCNL, we did identify a 6-fold increase in the rates of secondary PCNLs after the PERC-TIC technique for residual stone fragments. One possibility is that more hematuria, which we feel is associated with PERC-TIC PCNL, leads to worse vision and higher rates of residual fragments. Ultimately, the PERC-TIC technique was felt to be safe and effective as complications were equivalent (approximately 12.5%) and the odds of being stone-free, after controlling for skin to stone distance and guys stone score, were comparable to standard PCNL (OR 0.39 [0.13-1.1] p=0.08). This led us to conclude that PERC-TIC PCNL should be employed when a wire cannot be advanced down the ureter; however, urologists should anticipate a higher need for secondary procedures to render the patient stone free.
Initial access into calyx with infundibular stenosis. Glide wire seen coiling within the contours of the upper pole (B) Replacement of glide wire with two removal core J wires using a 5-Fr angled image catheter and a BRITE TIP interventional sheath introducer (C) Balloon dilation of the percutaneous access track with 30F sheath (D) Nephroscopic image of stone and J wire verifying successful PERC-TIC PCNL.
Written by: Tim Large, MD, Assistant Professor of Urology, Indiana University School of Medicine, Indianapolis, Indiana; Naveen Krishnan, MD, Indiana University School of Medicine, Indianapolis, Indiana; Crystal Valadon, Amy Krambeck, MD, Michael O. Koch Professor of Urology, Indiana University School of Medicine, Indianapolis, Indiana
- Hong, Xin, Xiaofeng Wang, Bo Yang, Tian Wang, Chengfan Yu, and Hui Li. "Comparison of efficacy and safety between flexible ureteroscopy-assisted percutaneous nephrolithotomy and percutaneous nephrolithotomy monotherapy for the treatment of complicated renal calculi." Int J Clin Exp Med 9, no. 9 (2016): 18537-18542.
- Chu, Carissa, Selma Masic, Manint Usawachintachit, Weiguo Hu, Wenzeng Yang, Marshall Stoller, Jianxing Li, and Thomas Chi. "Ultrasound-guided renal access for percutaneous nephrolithotomy: a description of three novel ultrasound-guided needle techniques." Journal of endourology 30, no. 2 (2016): 153-158.