Including the Hollow Viscera (Stomach or Bowel) within the Ice Ball during Cryoablation: A Review of Adverse Events

Purpose: To evaluate the safety of including hollow viscus (stomach or bowel) in the ice ball during cryoablation. Materials and Methods: Forty-three patients who underwent 50 cryoablations between January 1, 2012, and February 1, 2023, were retrospectively reviewed and compared with a control cohort of those who underwent cryoablation without hollow visceral involvement (n = 86). Adverse events (AEs) were stratified by the Society of Interventional Radiology (SIR) AE classification system, 2017. AEs occurring within 12 months and factors that may affect the AE rate, such as degree of hollow visceral involvement and segment of gastrointestinal tract involved, were reviewed. Results: Fourteen AEs occurred in 13 patients (13/43, 30.2%). This included 7 Grade 1 (7/43, 16.3%), 3 Grade 2 (3/43, 7.0%), and 4 Grade 3 (4/43, 9.3%) AEs. Of them, 1 Grade 3 AE was judged to be related to bowel involvement (1/43, 2.3%). When comparing AEs by degree of visceral wall involvement, there were more injuries with the full-thickness visceral wall cases (6/9, 66.7%) than with partial-thickness visceral wall cases, but the findings were not statistically significant (P = .140). When investigating AEs by segment of the gastrointestinal tract involved, 7 (7/14, 50%), 10 (10/17, 58.8%), and 4 (4/19, 21.1%, P = .055) were found when the stomach, small bowel, and large bowel were involved, respectively. No significant differences in AEs (13/43, 30.2%, vs 31/86, 36%; P = .511) or severe AEs (4/43, 9.3%, vs 9/86, 10.5%; P = .836) were found between the study and control cohorts. Conclusions: Findings from this single-center retrospective experience suggest that hollow visceral wall involvement by the ice ball during cryoablation resulted in a lower-than-expected rate of AEs for bowel-related injuries.