EAU 2018: Monoplane Fluoroscopy Simplified Technique of Percutaneous Calyx Puncture

Copenhagen, Denmark (UroToday.com) Percutaneous nephrolithotomy (PCNL) is the gold standard procedure for large kidney stones.  Obratining initial access to the kidney is the most challenging part of the procedure and it is associated with a steep learning curve. Due to its complexity there are many methods and modifications have been suggested. 

Dr. Mohammed Lezrek, a professor of clinical Urology from the Military Hospital Moulay Ismail in Meknes, Morocco, described a simplified method of monoplane fluoroscopy for efficient percutaneous access to a calyx during PCNL. Traditionally, the Bull’s Eye and Triangulation techniques use two angulations of the C-arm: 0° and then 30°. Dr. Lezrek presented their experience of percutaneous renal calyx access without rotating the C-arm in the split-leg modified lateral position under constant fluoroscopic guidance. Once the patient had been put into position and draped, the C-arm was placed in between 10° to 15°, allowing the surgeon’s hands to be outside of the field. Due to the angle of the patient on the surgical table, this angle of fluoroscopy is similar to a 0° C-arm setup in the prone or supine position. 

To determine the location of the calyx without moving the C-arm, Dr. Lezrek suggests to first center the needle over the kidney by using the needle outside of the skin with fluoroscopy to determine the lateral location of the kidney and calyx of choice. Next, the nephrostomy needle is inserted percutaneously into the retroperitoneum in a horizontal fashion above the posterior axillary line and between the 11th and 12th rib, away from any other adjacent structures. The needle is then moved from down to up in small increments until the kidney moves on the fluoroscopy scan. When the kidney location is confirmed due to recognition of renal movement, the nephrostomy needle is aligned with the calyx of choice. 

Dr. Lezrek profusely warned that all surgeons attempting this technique do not puncture the renal parenchyma when making movements to align the needle, as breaching the parenchyma may result in trauma. When the needle has successfully been inserted into the calyx, only lateral movements should be taken to avoid additional trauma to the surrounding tissue. Additionally the needle should not over advance into the infundibulum or renal pelvis in order to avoid potential injury to these two locations.

This technique has been shown to be feasible in ectopic and malformed kidneys such as sigmoid kidney. This technique can also be used in non-PCNL procedures such as percutaneous endoscopic recanalization of the UPJ due to complete stenosis. In Dr. Lezrek’s experience, this technique is easier to teach and explain over traditional methods, allowing many urologists and centers the opportunity to master the calyx puncture procedure for percutaneous renal surgery. 

Presented by: Mohammed Lezrek1, Military Hospital Moulay Ismail, Dept. of Urology, Meknes, Morocco

Co-Authors: Tazi H. 2 , Aboufaraj M. 3 , Slimani A.1 , Alami M.1 , Ammani A.1
Author Information:  1. Military Hospital Moulay Ismail, Dept. of Urology, Meknes, Morocco, 2. Al Ghassani Hospital, Dept. of Urology, Fes, Morocco, 3.  Medical University of Vienna, Dept. of Urology, Vienna, Austria

Written by: Zachary Valley and Zhamshid Okhunov, MD, (Department of Urology, University of California-Irvine) at the 2018 European Association of Urology Meeting EAU18, 16-20 March, 2018 Copenhagen, Denmark