EAU 2017: Confederacion Americana De Urologia (Cau) Lecture: Percutaneous Nephrolithotomy In High Volume Centers: All Lessons Learnt?

London, England (UroToday.com) Dr. Gutierrez started off by discussing the indications for percutaneous nephrolithotomy (PCNL). He continued stating that the basic principle of going in through the papilla to prevent bleeding, as reported by Sampaio and colleagues two decades ago, still holds true1. Selecting the correct renal access site is crucial for optimal surgical outcomes. Upper pole renal access for PCNL was considered a very challenging but we’ve learnt not to fear the upper pole access and nowadays urologists routinely obtain their access via this approach and definitely has some advantages. Dr. Guiterrez however mentioned that in his practice, approximately 70% of procedures are performed via lower pole access. This is multifactorial process and depends on surgeons experience, patient’s anatomy and available instrumentation.

There are multiple techniques available to gain access into the kidney. Dr. Gutierrez emphasized that ultrasound guided puncture is gaining more interest in North America, whereas this has been a routine task in European, Asian and Latin American centers. In his opinion PCNL has seen 3 major advantages lately: 1. The tract dilation with balloon or one-shot dilators, which is definitive improvement over the traditional telescopic or serial dilators. 2. The use of flexible nephroscopy, which allows you to inspect the entire kidney through one access. 3. Advantages in the field of percutaneous lithotripters, mainly dual energy modalities (ballistic/ultrasound combo) and the use of laser for dusting the stone in situ.

Of course these are not the only evolutions in the field. There is continuing research on the optimal positioning in prone versus supine position for PCNL. In the end, the position elected for the procedure depends both on surgeon’s preference and on patient characteristics. Supine positioning may accommodate a combined approach somewhat better. Although a combined approach could be more time consuming and requires 2 surgeons, there are several benefits including accuracy of the access, less bleeding, potentially less risk of complications, a higher stone free rate, fewer tracts needed, and finally no need to reposition the patient.

So how can we still improve this procedure?

1. Current evolutions in kidney puncture focus on acquiring a more accurate access while minimizing radiation. Several techniques are being researched to this end such as the urodyna CT and ultrasonography combined fusion platforms.

2. In order to reduce bleeding, miniaturization of the treatment tract is being explored, with tracts as small as 5F. If the pyelogram identifies narrow renal calyces, these will have difficulties accommodating a conventional sized access sheath. Choosing a smaller size then makes sense. Smaller tracts may cause less pain and may facilitate tubeless PCNL. Indications for mini PCNL are stones up to 2.5cm, upper pole access, complementary PCNL access, stone in diverticula, patients on anticoagulation, pediatric patients, as an alternative to flex URS

3. Tubeless PCNL can be performed in select cases: if the patients have no bleeding and are stone free, after a single tract PCNL.

Dr. Guiterrez completed his lecture by stating that in the future, we will learn how to treat patients in complex situations and also treat their complex medical conditions.

Speaker(s): Jorge Gutierrez-Acevez, Winston Salem, North Carolina

Written By: Zhamshid Okhunov, MD, University of California, Irvine

at the #EAU17 - March 24-28, 2017- London, England