Hello and welcome to the Stone News, a newsletter where we discuss every three months the most recent and relevant studies in stone disease.

Suscribe now

Dear Stone Fans, 

Welcome to this new edition of Stone News. Today, we will review some of the latest articles on suction with flexible ureteroscopy. So many new articles changing clinical practice confirm that aspiration is the present and future of ureteroscopy. We will also review a very interesting article that challenges an ongoing dogma for supine PCNL; Can we access safely the anterior pole? We have three excellent papers from the latest literature to discuss. Please enjoy!

2'

The study compares a novel ureteroscopic procedure, SURE (Steerable Ureteroscopic Renal Evacuation), using the CVAC Aspiration System, with traditional ureteroscopy (URS) for treating kidney stones. SURE integrates irrigation and aspiration to remove stone fragments. The ASPIRE study, a prospective, randomized, multicenter trial, aimed to evaluate the safety and effectiveness of SURE compared to URS.

The study included 123 patients with renal stones between 7–20 mm, randomizing them to either SURE or URS treatment. The primary goal was to achieve a "surgically stone-free" outcome, with secondary measures like stone clearance and Residual Stone Volume (RSV). Results showed SURE outperformed URS in terms of stone clearance and RSV, independent of the stone burden size, whereas URS efficacy declined with larger stone volumes. Both treatments had similar stone-free rates (SFR), but SURE was superior in clearing stones, with no significant differences in safety between the two methods.

SURE was shown to be effective, especially in reducing RSV, with no dependency on the stone size, contrasting with URS, where larger stones were associated with worse outcomes. However, SURE involved higher fluoroscopy time, potentially increasing radiation exposure. Despite this, the study suggests that SURE could be a valuable alternative for stone treatment, particularly for larger or more complex stones, though longer follow-up is needed to fully assess its benefits and costs compared to URS. This is one of the many examples yet to come that aspiration is the present and future of ureteroscopy. 

2'

This study investigates the safety and efficacy of anterior versus posterior calyceal access during supine percutaneous nephrolithotomy (sPCNL). Traditionally, percutaneous nephrolithotomy (PCNL) was performed in the prone position, where posterior calyx access was preferred to minimize risks like bleeding. However, the supine position (sPCNL) allows easier access to both anterior and posterior calyces, offering potential advantages, particularly for accessing difficult areas of the kidney.
However, the access to the anterior calyx in supine position may go trough more parenchyma. 

In this prospective study, 100 patients undergoing sPCNL were analyzed. Seventy-six patients had anterior calyx access and 24 had posterior access. The primary outcomes measured were intraoperative complications, blood transfusions, 30-day complications, emergency department visits, readmissions, and stone-free rates (SFR). Secondary outcomes included the stone burden and the total operative time.

The study found no significant differences between the anterior and posterior groups in terms of complications, blood transfusions, readmissions, or SFRs, suggesting both approaches are equally safe and effective. Notably, the SFR was 87% overall, with no significant difference between the groups. Intraoperative complications were rare, and the 30-day complication rate was similar between both groups.

Although anterior access was used more frequently in this study, surgeons reported that either approach could be chosen based on the patient's specific anatomy and stone location. The supine position's ability to allow easy access to both anterior and posterior calyces makes it a viable option in sPCNL, with no increase in risk compared to the traditional prone position.

The study concludes that both anterior and posterior accesses in sPCNL offer comparable safety and efficacy, suggesting that the choice of access should depend on individual patient anatomy and surgical preferences. Further research with larger sample sizes and randomized trials is needed to refine best practices for selecting the optimal calyx for sPCNL.

1'

This article investigates the comparison between two surgical techniques for renal stone removal via retrograde intrarenal surgery (RIRS): the conventional ureteral access sheath (UAS) and the flexible suctioning ureteral sheath (FANS). 

This is particularly interesting as with FANS you have to over pass the UPJ, access the collective system, and navigate within the cycles. 

The study, conducted across two institutions between January and September 2024, aimed to evaluate the efficacy, safety, and postoperative outcomes of both methods.

The research involved 132 patients with renal stones, who were randomized into two groups—one using UAS and the other FANS. Key findings include that the FANS group had a significantly higher stone-free rate (SFR) at 1 month (95% vs. 67%), with fewer patients requiring re-intervention (3 vs. 23). FANS also resulted in shorter operative times and lower rates of postoperative complications, such as hematuria and fever, compared to the UAS group. Pain scores were also lower in the FANS group.

While the study was limited by its small sample size and lack of real-time intrarenal pressure measurements, the results suggest that FANS improves surgical efficiency and outcomes. These findings highlight FANS as a promising tool for improving the management of renal stones, with better stone clearance and fewer complications. Further research with larger sample sizes and longer follow-up periods is needed to confirm these benefits.