EAU 2018: The Matrioska Technique in Percutaneous Nephrolithotomy

Copenhagen, Denmark (UroToday.com)  Dr. Stefano P. Zanetti, a clinical urologist from the University of Milan, Department of Urology, presented on the Matrioska technique in percutaneous nephrolithotomy. The Matrioska technique is one of the most recent advancements is minimally invasive PCNL (MIP). The MIP system is composed of 3 different nephroscopes with 7 different tract sizes, allowing the surgeon to tailor access according to the patient anatomy and stone size. 

Previous to the Matrioska technique, stones occupying the narrow calyx made passage of the guide wire impossible without damage to the surrounding tissue. However, development of the Matrioska technique allowed for circumvention of this complication. In general, the procedure started with a small sized tract (11/12 Ch) to create space for the guide wire by partially breaking up the stone with a laser. The guide wire was then inserted into the calyx and the access was widened for use of a medium sized tract (15/16 - 16.5/17.5 - 21/22 Ch), which allowed for better in-flow/out-flow, vision, lower pressure, and wider instrument choice for further fragmentation. If really large stones were involved, a large sized tract (23/24 – 25/26 Ch) was used for lithotripsy to complete fragmentation. 

In the video, three examples were shown. The first involved a large standard stone in the calyx. The second concerned a stone obstructing the lower calyx preventing the guide wire to pass. Lastly, a stone that left no space for access was shown. The same procedure was used in all three examples as described above, only varying in tract sizes.

In conclusion, the Matrioska technique makes the PCNL procedure flexible and less invasive, allowing the surgeon ability to accommodate to the patient and stone size, while also limiting calyx neck injury.

Presented by: Stefano P. Zanetti, MD University of Milan, Department. of Urology

Co-Authors: De Lorenzis E. , Fontana M. , Gallioli A. , Palmisano F. , Sampogna G., Boeri L. , Longo F. , Montanari E.
Author Information: University of Milan, Dept. of Urology, Milan, Italy

Written by: Whitney Zhang Department of Urology, University of California-Irvine at the 2018 European Association of Urology Meeting EAU18, 16-20 March, 2018 Copenhagen, Denmark