Presented by: Heiko Yang MD,PhD
University of California San Francisco

Introduction

The natural history of isolated lower pole stones has not been well characterized in symptomatic patients. The goal of this study is to describe the outcomes for symptomatic patients with newly diagnosed lower pole stones managed with surgery or observation.

Materials

Prospective data on patients enrolled in the Registry for Stones of the Kidney and Ureter (ReSKU) between 2015 to 2021 with symptomatic isolated lower pole stones [YH1] and followed up accordingly were reviewed. Patients were stratified into those managed with upfront surgery vs observation. The presence of symptoms, defined as pain, hematuria, and nausea or vomiting, during the follow-up period was the primary outcome. Secondary outcomes were other stone-related events during the observation period including any of stone passage, stone growth, or need for surgery. Univariate statistics were used to compared outcomes between the two groups. A multivariate model was constructed to identify risk factors associated with symptoms. 

Results

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115 patients with symptomatic isolated lower pole kidney stones and follow-up were identified with a median stone burden of 10 mm and median time to first follow-up of 3.3 months. 65 patients underwent surgery and 50 patients opted for observation. Patients in the observation group were more likely to remain symptomatic within a 12-month follow-up period (36% vs 17%, p = 0.03). No patient-associated risk factors were identified for symptom persistence aside from the decision to undergo observation. In patients who elected for observation, 11 (22%) ultimately underwent surgery, 5 (10%) had spontaneous stone passage, and 11 (22%) had increase in size of their lower pole stone. In patients who underwent surgery, 4 (6%) underwent another surgery and 3 (5%) had spontaneous stone passage.

Conclusion

Patients with symptomatic lower pole stones are twice as likely to remain symptomatic if they choose observation compared to upfront surgery. An understanding of these outcomes should be used during the shared decision-making process.

Funding

NA

Lead Authors

Kevin Chang, BA
UCSF

Co-Authors

Leslie Charondo, MD
UCSF

Gregory Hosier, MD
University of Manitoba

Fadl Hamouche, MD
McGill University Health Centre

David Bayne, MD,MPH
UCSF

Wilson Sui, MD
UCSF

Marshall Stoller, MD
UCSF

Tom Chi, MD
UCSF