Collecting System Percutaneous Access Using Real-Time Tracking Sensors: First Pig Model In Vivo Experience

Abstract

DISCLAIMER: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our subscribers we are providing this early version of the article. The paper will be copy edited and typeset, and proof will be reviewed before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to The Journal pertain.All press releases and the articles they feature are under strict embargo until uncorrected proof of the article becomes available online. We will provide journalists and editors with full-text copies of the articles in question prior to the embargo date so that stories can be adequately researched and written. The standard embargo time is 12:01 AM ET on that date. Materials and Methods:Six anesthetized female pigs underwent ureterorenoscopies in order to place a catheter with an EMT sensor into the desired puncture site and to ascertain the success of puncture. Subsequently, a tracked needle with a similar EMT sensor was navigated into the sensor inside the catheter. Four punctures were performed by two surgeons in each pig: one in the kidney and one in the middle ureter, on both right and left pig sides. Number of attempts and time needed to evaluate the virtual trajectory and to perform the percutaneous puncture were outcomes measurements. Results:Overall 24 punctures were easily performed without any complications.Surgeons required more time to evaluate the trajectory during ureteral puncture than kidney (median 15 versus 13 seconds, range 14 to 18 and 11 to 16 seconds, respectively; p= 0.1). The median renal and ureteral puncture time were 19 and 51 seconds respectively (range 14 to 45 and 45 to 67; p=0.003). Two attempts were needed to achieve a successful ureteral puncture. The presented technique demands presence of renal stone for testing. Conclusions:The proposed EMT solution for renal collecting system puncture proved to be highly accurate, simple and quicker. This method might represent a paradigm shift in percutaneous kidney access techniques.

Ureteroscopy-assisted Percutaneous Kidney Access Made Easy: First Clinical Experience with a Novel Navigation System Using Electromagnetic Guidance (IDEAL Stage 1)

“…Precise puncture of the collecting system was obtained in 100% of cases, with a median time to successful puncture of 20 s, without X-ray exposure and without any complications. This system was previously tested in an ex vivo model and in an in vivo animal model [10]. In the preliminary investigation, six female pigs were subjected to ureteral and kidney punctures, and four punctures were performed by two surgeons in each animal, including one in the kidney and one in the middle ureter, on both sides.…”

“…In an in vitro experiment the same technique had a success rate of 80% for the first attempt [18], suggesting that it may need to be enhanced before regular use is feasible. Puncture techniques guided by electromagnetic sensors also seem to offer a shorter learning curve, with only 12 cases required to reach the level of expert surgeon [10], which is much lower than the 60 cases previously reported for standard techniques [6]. Ultrasonography using SonixGPS navigation for puncture of the renal collecting system is also easier than conventional techniques, as the needle position can be monitored throughout the procedure [20].…”

“…We recently described experimental use of a novel visual-assisted navigation system in a porcine model using real-time electromagnetic sensors to allow kidney puncture for PCNL [10]. Here we report the first use of this device in humans and describe in detail the surgical technique and analyze early clinical outcomes.…”

A New Model with an Anatomically Accurate Human Renal Collecting System for Training in Fluoroscopy-Guided Percutaneous Nephrolithotomy Access

“…Moreover, anatomically accurate models such as those described here may be a cheaper and more representative alternative when developing new technologies to facilitate caliceal targeting. 7 It is hoped that this anatomically accurate model can be adapted and developed for training in flexible ureteroscopy.…”

“…Recently, new localization techniques have been described that might simplify percutaneous access. 6,7 Until these new technologies become mainstream, there is a need for a good training model for PCNL. Several training models have been described.…”