Stone surgery: Should outcome target change?

Results of a study evaluating health-related quality of life (HRQoL) in patients surgically treated for kidney stones suggest a need to rethink the outcome target and focus on patient counseling to set appropriate expectations.

The research was presented at the World Congress of Endourology and SWL in Paris. It included data from 282 adults who underwent surgical intervention for kidney stones at four centers and who completed the disease-specific Wisconsin Stone Quality of Life (WISQOL) questionnaire. Looking at the instrument’s total score and the scores for each of its four domains (social, emotional, stone-related, and vitality), the study found no significant differences between patients who were stone-free after surgery and those with residual fragments.

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Data for a question about frustration, however, showed that relative to the stone-free patients, the group with residual stones had significantly more frustration with their situation, reported Necole M. Streeper, MD, assistant professor of surgery, Penn State Milton S. Hershey Medical Center, Hershey, PA.

“Health-related quality of life is being increasingly recognized as an important outcome measurement, but to our knowledge, there has not been previous research comparing HRQoL in patients with residual fragments after surgical treatment for stone disease to those who are stone-free,” said Dr. Streeper.

Better patient counseling needed

“The findings of our study suggest that perhaps we are overtreating patients and performing unnecessary procedures to get them stone-free,” she said. “In addition, it supports the value of proper counseling. Information should be discussed with patients preoperatively so that they understand the possibility of having residual fragments and reasons for needing a secondary procedure. To mitigate frustration for patients with asymptomatic, non-obstructing residual stone fragments, postoperative counseling is needed to reassure them that observation may be an acceptable management strategy.”

Aside from Penn State, patients included in the study were treated at the University of Wisconsin, Madison, Dartmouth Hitchcock Medical Center, Lebanon, NH, and the University of British Columbia, Vancouver, BC. Data on surgical outcome for patients included in the study was identified retrospectively through review of postoperative imaging. The study cohort included 134 patients who were determined to be stone-free and 148 patients with residual stones.

Continue to the next page for more.The two groups were similar with respect to mean age and gender distribution. Stone-free patients had a significantly higher median body mass index than the residual fragment group (30.5 vs. 28.0 kg/m²) and had significantly fewer stone events (median of two vs. four).

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The WISQOL is a 28-item validated questionnaire with maximum possible scores (representing best HRQoL) of 5 for each item, resulting in a maximum possible total score of 140. Higher scores correlate to a higher HRQoL.

The mean total score was 112.9 for the group with residual stone fragments and 117.3 for the stone-free group (p=.17). Mean frustration scores were 3.73 for the residual stone fragment group and 4.08 for stone-free patients (p=.03).

Dr. Streeper acknowledged that the study has limitations because of its retrospective design. These included variation in the interval between surgery and completion of the WISQOL, which ranged from 2 months to 2 years. In addition, the methods of imaging used at the four institutions varied and included x-ray, ultrasound, and computed tomography scan, and it is possible that some patients were misclassified