Gallbladder Cryoablation for Chronic Cholecystitis in High-Risk Surgical Patients: 1-Year Clinical Experience with Imaging Follow-up

Clinical question
Does gallbladder cryoablation produce safe and efficacious results in non surgical candidates?

Take away point
Cryoablation was technically successful in 6 of 7 patients, with resolution of abdominal symptoms in all 6 patients post-ablation without recurrence over the follow-up period, and 2 adverse events.

Reference
Gallbladder Cryoablation for Chronic Cholecystitis in High-Risk Surgical Patients: 1-Year Clinical Experience with Imaging Follow-up. McGregor, Hugh et al. Journal of Vascular and Interventional Radiology, Volume 31, Issue 5, 801 - 807

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Study design
Single arm, single institution, retrospective, cohort study

Funding source
No reported funding

Setting
Academic hospital, University of Arizona, USA





Figure 6
Axial T2-weighted (a) and contrast-enhanced T1-weighted (b) MR images obtained 12 months post gallbladder cryoablation demonstrating complete involution of the gallbladder (white arrow). Note the tortuous cystic duct (black arrow).

Summary

Cholecystectomy tubes are the current primary option to treat non-surgical candidates with cholecystitis, however can impact quality of life and often result in recurrence after removal. Gallbladder cyroablation is a potential alternative minimally invasive definite treatment. Recently the first human gallbladder cyroablation was reported with clinical and imaging success at 3 months. The authors currently further investigate the viability of gallbladder cryoablation and retrospectively studied 7 consecutive patients who underwent the procedure from August 2018 to July 2019 and evaluated symptoms, adverse events and imaging over the available follow up period (mean =278 days).

The patients studied were adults with cholecystitis or intractable biliary cholic deemed non-surgical candidates by their respective attending surgeons, with a variety of comorbidities, and a mean American Society of Anesthesiologists score of 3.7. At time of ablation, all patients were afebrile and without leukocytosis, 5 were with indwelling cholecystectomy tube, and 1 had ongoing intermittent abdominal pain.

Prior to procedure, intravenous antibiotics was administered and aspiration of present gallbladder contents using existing or new catheter was performed. Initially contrast dissection was performed through percutaneous Yueh catheters to create at least 1 cm separation of gallbladder from colon and/or duodenum. Cyroablation was performed with placement of cyroprobes to achieve iceball coverage of at least 5 mm beyond gallbladder wall and of the cystic duct. Cholecystectomy catheters were removed immediately post procedure in 5 patients, and at post-procedure day 11 in 1 patient due to persistent pain.

Patients were followed up with common labs up to 6 months, and CT/MR up to 12 months where possible. One of 7 procedures was not successful due to adhesions preventing safe dissection of gallbladder from colon, and was excluded from follow up analysis. All 6 were free of abdominal pain at 14 days post ablation. Follow-up labs out to 3 months were mostly unchanged compared to pre-procedure; two patients had mild leukocytosis, 3 had elevated transaminases at day 1, and 1 patient with renal failure had elevated creatine at 1 month. There were two adverse events; one patient with severe cirrhosis on day 3 developed intra abdominal hemorrhage without a source and stabilized with correction of coagulopathy. A second patient on day 5 developed abdominal pain and was found to have fluid filled gallbladder with inflammatory changes which required temporary drain. Two patients died over the follow up period of unrelated causes. Some degree of gallbladder involution was demonstrated in 5 patients over the 12 month follow-up period, with eventual complete gallbladder involution demonstrated in all 4 alive patients. All 5 patients who underwent 1 month HIDA scan demonstrated occlusion of the cystic duct.

The 46 % rate of recurrent calculous cholecystitis in general patients after cholecystectomy tube removal introduces the possibility that the study patients may have become symptom free after their tube removal regardless of ablation. However imaging evidence of gallbladder devitalization occurred in 5 of 6 patients, although the excluded patient only had one 3 month CT scan before death. The authors suggest that large gallstones may have prevented gallbladder wall apposition in the last patient, thus removing gallstones prior to cyroablation should be considered in the future. Additionally both adverse events occurred in patients with large gallstones; it is possible that gallstone bacteria incited hepatic decompensation in the cirrhotic patient and resulted in post procedural infection in the second patient who required temporary drain. Gallbladder cyroablation is anatomically feasible and demonstrated good technical success without non target ablation. Additionally, the positive study results indicate cryoablation is a viable option in the selected patient population.

Commentary

The authors in the study compounded their investigation into gallbladder cryoablation by assessing 7 consecutive ablation patients, including the previously reported first human case, over an increased follow up period of 12 months. Cholecystectomy tubes for non-surgical candidates with cholecystitis have limitations and thus the study serves an important role, to evaluate cryoablation as an alternative definite management option. The results are encouraging with high degrees of technical success, symptom resolution, imaging evidence of gallbladder devitalization, and relatively low clinical harm over the follow up period. The authors acknowledge the limitations of a small and heterogenous sample population as well as the lack of histologic confirmation of gallbladder devitalization. Thus, in addition to larger power studies, future reports with an even longer follow up period to confirm stability of gallbladder involution appearance on imaging as well as lack of recurrence of symptoms may add value. Additionally the authors suggest that the presence of large gallstones may have contributed to the adverse events as well as interfered with tracking gallbladder involution on imaging. Future studies with pre-procedural optimization to reduce gallstones would be of interest.

Post author

Ranjan Ragulojan, MD
DR resident R-1
University of Minnesota
@Ragulojan