A scoring system for gallbladder polyps based on the cross-sectional area and patient characteristics

Abstract

Background: Current management guidelines for gallbladder polyps (GBPs) focus on a diameter more than 1 cm as an indication for cholecystectomy. Since most GBPs are not malignant, unnecessary cholecystectomies can lead to unnecessary complications and costs. We developed a score to identify true polyps focusing on their cross-sectional area (CSA). Methods: We retrospectively analyzed the demographic, clinical, laboratory, and sonographic characteristics of 522 patients with GBPs who had undergone cholecystectomy at our hospital between January 2010 and July 2020 (reference group). We used univariate analysis to compare these parameters between 88 true polyps and 434 pseudopolyps and multivariate logistic regression analysis to identify parameters to include in our scoring model. Receiver operating characteristics and area under the curve were used to identify cut-off values. The model was tested on a validation group of 98 patients. Results: In the multivariate analysis, a CSA >123 mm2, positive blood flow signal, age >55.5 years, alanine aminotransferase (ALT) levels > 50 U/L, and an ALT/aspartate aminotransferase ratio > 0.77 were significantly associated with true polyps (odds ratio 6.528, 2.377, 2.617, 2.445, and −0.372, respectively). A prediction model based on cut-off values was used to distinguish a low-risk and high-risk GBP group; true polyps accounted for 6.54% and 58.72%, respectively (p < 0.001). In the low-risk and high-risk validation groups, true polyps comprised 12.35% and 82.35%, respectively (p < 0.001). Conclusions: Our scoring system shows high accuracy and specificity in identifying true polyps and helps determine the need for surgical resection.

Keywords

• Adenoma
• Cholecystectomy
• Cross-sectional area
• Gallbladder neoplasms
• Predictive model