Comparing Efficiency and Stone-Free Rates Mini PCNL vs Flex URS

With the advent of mini-PCNLs, some endourologists have been utilizing the technique to treat renal calculi up to 3cm in size with better stone free rates and similar comorbidity compared to ureteroscopy. These procedures require percutaneous renal access, and it is associated with greater length of stay and fluoroscopy time.

The ClearPETRA ureteral access sheath has shown great promise with improving stone free rates, decreasing intra-renal pressure and delivering some of the benefits of mini-PCNL without the added risk associated with obtaining percutaneous renal access.

The ClearPETRA flexible suction ureteral access sheath anecdotally improves efficiency and allows endourologists to better clear stone debris when compared to traditional ureteral access sheaths. We have yet to see a comparison between suction ureteral access sheaths and mini-PCNL with the suction renal access sheath.

Study Hypothesis: Compared to traditional access sheaths, using ClearPETRA access sheaths will result in an improvement in stone free rates with both modalities, with lower complications. Using ClearPETRA access sheaths in both modalities compared to traditional access sheaths should result in less of a difference in stone free rates between the ureteroscopy group and the mini-PCNL group.

Inclusion criteria

• Patients 18 years or older
• Have a CT scan showing renal stones 1-3cm in length
• Patients who will be able to read, understand, and complete patient questionnaires

Exclusion criteria

• Pregnant individuals
• Those with anomalous renal anatomy
• Patients with a urinary diversion (ex: Ileal conduit, reservoir, bladder substitute, etc.)
• Any condition rendering patient medically unfit to undergo either procedure (Bleeding diasthesis)
• Patients who lack decisional capacity
• Patients who are non-english speakers*

• Non-recruitment of non-english speakers is due to the study being a small pilot study that is used to assess the stone free rate for patients treated with a ureteroscopy or mini-PCNL using ClearPETRA suction access sheaths in a small portion of our patient population seeking treatment for stones. The team also does not possess the bandwidth or personnel to consent patients who are non-English speaking.