What drives unplanned returns post-URS lithotripsy?

Most unplanned returns following ureteroscopy for laser lithotripsy (URSLL) result from genitourinary infection or stent-related pain.

Related: Non-adherence to stone meds raises hospitalization risk

Factors associated with an increased risk of return are pre-stenting, longer operative time, and longer index length of stay, according to a data warehouse query and chart review of patients at Dartmouth-Hitchcock Medical Center in Lebanon, NH that was presented at the 2015 AUA annual meeting in New Orleans.

The findings were presented by Rachel Moses, MD, MPH, urology resident at Dartmouth-Hitchcock, working with Elias S. Hyams, MD, and colleagues.

The study was the first phase of a retrospective study examining all ureteroscopies performed at Dartmouth-Hitchcock Medical Center over approximately a 3-year period. The goal of this phase was to identify factors associated with 30-day emergency department (ED) visits and readmission following URSLL, performed between April 2011 and August 2014.

Overall, 550 patients were included. Researchers collected patient characteristics on demographics, comorbidities (asthma/chronic obstructive pulmonary disease, smoking status, cardiovascular disease, and diabetes), location of procedure (outpatient surgery center vs. main operating room), preoperative stenting, preoperative urine culture, empiric postoperative antibiotic coverage, referring hospital service area (reflecting distance from the hospital), and insurance type.

Nearly half (45%) of ureteroscopies were performed on females, and the average age of the entire cohort was 56.8 years. A total of 47 patients (8.5%) had an unplanned return.

The most common reasons for unplanned returns were urinary tract infection (20/47) and stent/flank pain (19/47). The remainder included medical issues thought not to be directly related to ureteroscopy, including some orthopedic issues.

No difference was found in the demographic characteristics between patients with unplanned readmission and no unplanned readmission, including age, comorbidities, and American Society of Anesthesiologists score.

Next: What was post-op antibiotics' effect?

What was post-op antibiotics’ effect?

On binary analysis, “We found that patients who were pre-stented, had a longer operative time, and lived closer to the hospital had a higher rate of return,” Dr. Moses said. “Interestingly, use of postoperative antibiotics was associated with a lower rate of return.”

Also see: Breaking new ground (and kidney stones) with ultrasound

On multivariate analysis using the significant findings from the binary analysis, pre-stenting (odds ratio [OR] 3.07; p=.004), operative time >120 minutes (OR 2.79; p=.002), and index length of stay >24 hours (OR 3.03; p=.027) continued to be significantly associated with unplanned return.

Dr. Moses reported that postoperative antibiotics continued to be associated with a decreased rate of return, with an OR of 0.17 (p<.001). Distance from the hospital no longer remained significant.

Read: Pre-op antibiotics sufficient to prevent UTI during stone Tx

Patients who were pre-stented, who required longer operative time, and those who had longer length of stay “were probably more complex, as this study suggests, and perhaps would benefit from closer follow-up and more counseling regarding postoperative pain,” Dr. Moses said. These variables may reflect increased bacterial exposure or severity of stone disease.

Next: “The finding that postoperative antibiotics are associated with a lower rate of return is thought-provoking"

“The finding that postoperative antibiotics are associated with a lower rate of return is thought-provoking, and certainly this study did not suggest a direct relationship. It may be a surrogate for more complex patients that might have prompted the surgeon to prescribe additional antibiotics,” she said.

The data are hypothesis generating for future prospective studies to explore methods to reduce the risk of unplanned return following URSLL.

Postoperative antibiotic use as “potentially protective” is an intriguing finding and suggests some patients may benefit from more aggressive prophylaxis, the authors reported.

More on Stone Disease:

Does stone-related atherosclerosis start in childhood?

Alpha-blocker may have benefit in larger stones

Stone patients are poorly adherent with medical prophylaxis

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