Discovering the Risks of Developing Symptoms Due to Ureteral Stent Placement

Kidney stones are small, hard structures that are sometimes found in the kidneys or in the tubes known as ureters that move urine from the kidney to the bladder. When stones are too large to pass through, they can cause blockages. Physicians often recommend a surgery called a ureteroscopy (URS) in which a small tube containing a camera is used to look inside the ureters and kidneys to find, and in some cases remove, the cause of the blockage. Sometimes the surgeon may temporarily leave a tiny tube called a stent inserted in the ureters to assist in holding them open to facilitate urine flow and passage of any stones after surgery, promoting healing. Unfortunately, these stents often cause discomfort and may themselves lead to urinary difficulties in some people. However, identifying individuals who are most at risk of experiencing severe stent-related symptoms has been difficult. The NIDDK- supported Urinary Stone Disease Research Network, therefore, conducted and published the findings of the Study to Enhance Understanding of Stent-Associated Symptoms, or STENTS, with the goal of improving understanding of stent-related symptoms and risk factors for developing them.

STENTS researchers enrolled 424 people who underwent a URS and stent placement at four hospitals across the United States. Before surgery, participants filled out four short questionnaires to report pain intensity, level of pain interference on daily activities, urinary symptoms such as incontinence, increased frequency and difficulty urinating, and the level of bother due to those symptoms. These questionnaires were repeated 1, 3, and 5 days after the URS, on the day of stent removal, and 30 days after stent removal. The study researchers found that while they observed a peak in pain and urinary symptoms 1 day post-surgery with a steady decline until day 5, the level of daily interference and bother due to pain and urinary symptoms persisted longer. Surprisingly, no specific surgical factors, such as surgery length or method, were associated with higher pain and urinary symptoms or their impact. Instead, they found that painful past stent experiences were associated with higher pain intensity and interference, higher body mass index was associated with higher urinary symptoms and bother, and younger age and history of depression were associated with higher levels of all symptoms and their impact. A month after stent removal, however, all reported symptoms were below pre-surgery levels.

Further investigation of stent-related symptoms is needed since these results may not be broadly representative, as the study population was primarily White, and the surgeries were performed at academic medical centers. However, the knowledge gained from this study can lead to new strategies, such as options for stent-less ureteroscopies, more informed patient counseling, and new potential therapies to improve experiences of patients with kidney stones.