Functional gallbladder disorders (FGDs) encompass a spectrum of conditions often characterized by symptoms suggestive of biliary pain without discernible organic pathology. One such contentious subset within this domain is biliary hyperkinesia—a condition presenting with biliary pain and an unusually high ejection fraction (EF) on cholecystokinin-stimulated cholescintigraphy. However, the precise definition of this disorder and the role of cholecystectomy in managing functional gallbladder disorders remain ambiguous.

A recent retrospective review1 conducted across three Mayo Clinic sites between 2007 and 2020 aimed to shed light on this intriguing subset of disorders. The study enrolled patients aged 18 years or older presenting symptoms of biliary disease, with an EF greater than 50% on cholescintigraphy, who underwent subsequent cholecystectomy, excluding cases with acute cholecystitis or cholelithiasis on imaging. This comprehensive investigation utilized receiver operating characteristics curve analysis to determine the optimal EF cutoff correlating with symptom resolution post-cholecystectomy within 30 days.

Key Findings and Insights

Analyzing a significant cohort of 2,929 cholescintigraphy scans revealed an average EF of 67.5% and a median EF of 77%. Among those with EFs equal to or exceeding 50%, 141 patients (8.8%) underwent cholecystectomy. Strikingly, employing an EF cutoff of 81% showed a remarkable association with symptom resolution after surgery (78.2% for EF ≥ 81% vs. 60.0% for EF < 81%). Noteworthy pathologies observed on final examination included chronic cholecystitis, particularly chronic acalculous cholecystitis (61.7%), and cholelithiasis with chronic cholecystitis (13.5%), despite the absence of initial cholelithiasis detected during preliminary investigations.

Defining Biliary Hyperkinesia and Implications

Biliary hyperkinesia, marked by biliary symptoms and an EF surpassing 81% without evidence of biliary disease on ultrasound or scintigraphy, emerged as a distinctive subset. The study unequivocally recommends cholecystectomy for this specific patient population, emphasizing the critical role of hepatobiliary iminodiacetic acid cholecystokinin cholescintigraphy (HIDA) in evaluating gallbladder function via EF measurement.

Unraveling Diagnostic Challenges and Pathophysiology

Diagnosis of biliary hyperkinesia remains intricate, often necessitating multiple emergency room visits before referral to surgeons. This diagnostic challenge can potentially lead to compromised patient satisfaction, increased costs, and treatment delays. Additionally, the imperfect correlation between biliary pain and cholescintigraphy findings underscores the complexity of this disorder.

The underlying pathophysiology of biliary hyperkinesia remains elusive, hypothesized to involve increased intraluminal pressure, mucosal injury, chronic inflammation, and altered cholecystokinin levels. While chronic inflammation emerges as a key factor, the presence of gallstones in a subset of patients despite initial negative imaging underscores the limitations of imaging studies in capturing all pathological aspects.

Limitations and Future Directions

Despite offering valuable insights, the study faces limitations, notably the small subset of patients undergoing surgery following CCK-HIDA results with EFs greater than 50%. Additionally, inconsistent documentation of Rome IV criteria in medical records hampers a detailed assessment of its application. The study's current selection algorithm, considering the reproduction of biliary symptoms during CCK-HIDA, might contribute to selection bias.

Concluding Thoughts and Recommendations

In conclusion, the study strongly advocates defining biliary hyperkinesia as biliary symptoms coupled with an EF of 81% or higher, warranting cholecystectomy for this subset. However, further research is crucial to identify patients below the 81% EF threshold who might benefit from surgery. The study's profound guidance on patient selection for cholecystectomy emphasizes the need for continued research in this intricate realm of functional gallbladder disorders.