Safety and efficacy of ultrasonography as an adjunct to fluoroscopy for renal access in percutaneous nephrolithotomy (PCNL)

Abstract

Study Type – Therapy (case series) Level of Evidence 4 OBJECTIVE • To evaluate the safety and efficacy of ultrasonography (US)‐guided renal access in percutaneous nephrolithotomy (PCNL), as compared with conventional fluoroscopy‐guided renal access in a prospective randomized trial. PATIENTS AND METHODS • From January 2008 to October 2009, 224 patients with renal calculi undergoing PCNL were randomized into two groups. • Group 1 (112 patients) underwent PCNL using only fluoroscopy‐guided renal access; while in group 2 (112 patients), US guidance for puncture was used in addition to fluoroscopy. • The inclusion criteria were: normal renal functions, American Society of Anesthesiology scores 1 or 2, absence of congenital abnormalities, aged 15–70 years, and anticipated single‐tract procedure. The patients in both groups were matched for age, sex, and stone characteristics. • The Student t‐test was used for statistical analysis with an allowable error of 5%. RESULTS • The mean time to successful puncture was 3.2 min and 1.8 min in group 1 and group 2, respectively (P < 0.01). • The mean duration of radiation exposure to successful puncture was 28.6 s in group 1 and 14.4 s in group 2 (P < 0.01). • The mean numbers of attempts for successful puncture in the desired calyx was 3.3 in group 1 as compared with 1.5 in group 2 (P < 0.01). • The meantime taken for tract formation in group 1 was 7.4 min with radiation exposure of 82 s, while in group 2 it took 4.8 min with radiation exposure of 58 s (P < 0.01). • Successful access was achieved in all patients. All patients were stone‐free at the end of the operation. The hospital stay (2–3 days) was same in both groups. There was no incidence of significant bleeding requiring transfusion during or after surgery. All the patients were followed‐up for a ≥6 months. CONCLUSION • US‐guided puncture in PCNL helps in increasing accuracy of puncture and decreasing radiation exposure for the surgical team and the patients.

Renal access in PNL under sonographic guidance: Do we really need to insert an open end ureteral catheter in dilated renal systems? A prospective randomized study

“…Access to the renal collecting system from the most suitable calyx can be established either under fluoroscopic and/or sonographic guidance. Main aim of these two different guiding procedures should be a direct path which will be identified and used from the skin through the papilla of the desired calyx (14). Accumulated experience so far has clearly demonstrated that each of these methods could be associated with certain advantages as well as disadvantages.…”

Ultrasound-Guided Renal Access for Percutaneous Nephrolithotomy: A Description of Three Novel Ultrasound-Guided Needle Techniques

“…11,12 A randomized prospective trial comparing outcomes of ultrasound-guided PCNL access to traditional fluoroscopic access in 224 patients demonstrated increased accuracy of puncture, fewer number of puncture attempts, shorter operative time, and reduced radiation exposure time, with similar rates of procedural success and length of hospital stay for the ultrasound group. 7 In another study, urology residents undergoing PCNL training were able to achieve decreased radiation exposure time and higher accuracy of puncture for pure ultrasound-guided PCNL, although 6 of 32 patients required fluoroscopic adjustment. 12 In a singlecenter study of 700 patients who underwent complete ultrasound-guided PCNL in China, 92.6% of patients with a single calculus and 82.9% of patients with staghorn or multiple stones were rendered stone free.…”

“…5 In an effort to decrease radiation exposure, low-dose CT scans (*3 millisieverts [mSv]) and ultralow-dose CT scans (0.83 mSv) have been introduced. 6,7 Furthermore, to limit unnecessary radiation exposure to the stone patient, the American Urological Association has published imaging guidelines for the practicing urologist. 8 As a collaborative effort, the urologic community has done well in limiting radiation exposure through advancements in Department of Urology, Mayo Clinic, Rochester, Minnesota.…”

“…6 Advantages of ultrasound guidance over fluoroscopy include reduction of radiation exposure and financial cost, real-time imaging of the collecting system and renal parenchyma, detection of radiolucent stones, improved visualization of adjacent viscera, clearer delineation of the anterior and posterior calices, and the potential to avoid vascular injury with Doppler flow imaging. 7 This technique is often the preferred method for percutaneous nephrostomy tube placement among interventional radiologists and has been safely applied in pregnant and pediatric patients for whom radiation exposure is a significant concern.…”

Techniques for Minimizing Radiation Exposure During Evaluation, Surgical Treatment, and Follow-up of Urinary Lithiasis

“…Multiple studies have demonstrated the feasibility of utilizing ultrasound as an imaging modality during PCNL, operating on mean stone burdens ranging from 2-6 cm, producing a 63 % to 100 % stone-free rate [78][79][80][81][82]. Limitations of using ultrasound as the sole technique for access include the limited use in obese patients, those with full staghorn calculi, and those lacking hydronephrosis, due to reduced visibility.…”