Flexible and Navigable Suction Ureteral Access Sheath Combined With a Single-Use Flexible Ureteroscope Versus Percutaneous Nephrolithotomy for Impacted Proximal Ureteral Stones: A Single-Centre Retrospective Cohort Study
This single-centre retrospective cohort study demonstrates that for impacted proximal ureteral stones, the combination of a flexible and navigable suction ureteral access sheath with a single-use flexible ureteroscope achieves stone-free rates comparable to percutaneous nephrolithotomy while offering significant advantages in reduced operative time, blood loss, hospital stay, and postoperative complications.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Kidney stones are a common and painful problem, occurring when hard mineral deposits form in the urinary system. While many stones pass on their own or can be treated with sound waves, a specific type known as an impacted proximal ureteral stone presents a unique challenge. These are stones that have become stuck in the upper part of the tube connecting the kidney to the bladder, where they have remained for more than two months. Over time, the body reacts to this blockage by growing scar tissue and swelling around the stone, effectively cementing it in place. This makes the stone difficult to dislodge and increases the risk of infection and kidney damage. For decades, the standard way to remove these stubborn stones involved a procedure called percutaneous nephrolithotomy, which requires making a small incision in the back to reach the kidney directly. However, this approach carries risks of bleeding and a longer recovery. A newer, less invasive method uses a flexible scope passed through the natural urinary tract, but until recently, it struggled to clear stones that were deeply embedded in the tissue.
Researchers at Foshan Fosun Chancheng Hospital in China set out to compare these two approaches for treating this specific type of difficult stone. They focused on a new tool called a flexible and navigable suction ureteral access sheath, used alongside a single-use flexible ureteroscope. This device is designed to be passed up the urethra and bladder, following the natural path of urine. Its tip can bend to follow the scope, and it includes a channel for continuous suction, which pulls out stone fragments as they are broken up. The team looked back at medical records from 239 patients treated between January 2024 and January 2026. Because the hospital does not force patients into one treatment or the other, the patients themselves chose which procedure they preferred after being fully informed of the risks and benefits. This resulted in a group of 169 people who received the new suction-assisted scope treatment and a group of 70 who underwent the traditional back-incision surgery. The researchers ensured that the two groups were similar in age, health, and stone characteristics before comparing their outcomes.
The study found that both methods were highly effective at removing the stones. Immediately after the procedure, about 93 percent of the patients in the suction scope group were free of stones, compared to 90 percent in the traditional surgery group. Two months later, after the body had cleared any tiny remaining fragments, the success rates were nearly identical, with roughly 98 percent of the suction group and 96 percent of the surgery group being stone-free. The key differences lay in the experience of the surgery and the recovery. The procedure using the suction scope took significantly less time, with a median duration of 34 minutes, compared to 73 minutes for the traditional surgery. This difference was largely because the suction scope approach does not require the patient to be turned over, the back to be punctured, or a long tunnel to be created through the kidney tissue.
The physical toll on the body was also markedly different. Patients who underwent the suction scope treatment lost far less blood, with their hemoglobin levels dropping by an average of 4.24 grams per liter, whereas those who had the traditional surgery saw a drop of 10.49 grams per liter. Consequently, no one in the suction scope group needed a blood transfusion, while nearly 6 percent of the traditional surgery group did. The recovery was also much faster for the suction scope group. These patients spent a median of just two days in the hospital, with many leaving within 48 hours. In contrast, patients who had the traditional surgery stayed for a median of six days, largely because they required a tube to drain their kidney and needed time to ensure there was no bleeding before going home.
Safety outcomes further favored the less invasive approach. While both groups had some complications, they were less frequent and less severe in the suction scope group. About 9 percent of the suction scope patients experienced early postoperative issues, compared to nearly 23 percent of the traditional surgery patients. The traditional surgery group also saw a higher rate of acute kidney injury, with 11 percent affected, compared to just over 1 percent in the suction scope group. The types of severe complications also differed; the traditional surgery group was more likely to require a procedure to stop bleeding in the kidney, while the few severe issues in the suction scope group were related to the ureter itself, such as a tear that required repair. One limitation of the suction scope method was that in about 9 percent of cases, the scope could not be advanced past a narrow or twisted section of the ureter, requiring a temporary stent to be placed first and the stone to be treated two weeks later. The traditional surgery did not face this specific hurdle.
The authors conclude that for patients with these difficult, stuck stones, the combination of a flexible suction sheath and a single-use scope offers a clearance rate equal to the traditional surgery but with a much gentler impact on the body. It involves less blood loss, a shorter operation, and a quicker return to daily life. However, the researchers note that because this was a retrospective study where patients chose their treatment, there may be unmeasured factors influencing the results. They suggest that while the new method appears to be the preferred option for many, the decision should be tailored to the individual, particularly considering that the new method carries a small chance of requiring a second session if the ureter is too narrow, and that the risk of ureteral scarring remains a factor to watch over the long term.
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