SpyGlass Direct Visualization System: A Cost-Effective Approach Enhancing Nutritional and Immune Recovery in Difficult Bile Duct Stone Management

Abstract

Purpose: The SpyGlass DS II Direct Visualization System (SpyDS) is increasingly used as an alternative to percutaneous transhepatic cholangioscopy (PTCS) for difficult bile duct stones (DBDSs). This study compared clinical outcomes, costs, and post-procedural recovery between SpyDS and PTCS. Materials and Methods: A prospective interventional study was conducted including patients with DBDSs who underwent Spy-DS-guided lithotripsy between December 2020 and December 2022. Patients treated with PTCS-guided lithotripsy between July 2018 and July 2020 were used as a comparison group. Primary endpoints were technical success rate and total hospital cost. Secondary endpoints included length of hospital stay, procedure-related cost, adverse events, and markers of recovery, such as nutritional status, immune balance, and skeletal muscle mass. Results: Forty-three patients were included: 20 patients in the SpyDS group and 23 patients in the PTCS group. Technical success rates were 95.0% for SpyDS and 100% for PTCS. Median total hospital cost was lower in the SpyDS group in univariable analysis (p=0.018), although this difference was not significant after multivariable adjustment. Length of hospital stay was significantly shorter (6.5 days vs. 21.0 days; p<0.001). The SpyDS group showed more favorable early recovery patterns, including higher albumin levels and lower neutrophil-to-lymphocyte ratios at follow-up, as well as less rapid muscle loss. Conclusion: SpyDS achieved comparable technical success to PTCS and was associated with a markedly shorter hospitalization period. Although adjusted analyses did not show a significant cost difference, the shorter length of stay and favorable recovery trends suggest potential clinical and economic advantages. SpyDS may represent a practical alternative for DBDSs management. ClinicalTrials.gov trial number: NCT04743089