Using A Surgical Risk Predictor to Estimate Percutaneous Cryoablation Adverse Event Risk: A Single Center Comparative Analysis.

Objective: To evaluate the relevance of established surgical risk calculators for predicting complications in patients undergoing percutaneous lung cryoablation (PLC).

Methods: The institution's database was queried for PLC procedures from March 2015 to May 2024, excluding those patients with concomitant local therapies or five or more lesions treated in a single setting. Demographics, frailty metrics as defined by the surgical literature, and procedural variables were collected. To evaluate the suitability of surgical risk estimate calculators, the requisite demographic data were input into the American College of Surgery surgical risk calculator; estimates for length of stay (LOS), serious complications, 30-day readmission, and mortality were calculated to determine the comparative risk profile were the patients to have undergone surgical wedge resection instead of PLC. Additionally, to evaluate the suitability of imaging predictors of complications, the volume of emphysematous lung was calculated using a machine learning algorithm and incorporated into a generalized estimating equation logistic regression analysis of other demographic and technical variables.

Results: The study included 217 patients who underwent 314 procedures. Chest tubes were placed in 49% of procedures. The median LOS was 1 day (interquartile range: 1-1, range: 0-13). The median percentage of emphysema within the lungs was 5.9% (interquartile range: 2.4%-12.1%, range: 0.01%-50.3%). The median predicted surgical rates for serious complications (13.5%), 30-day readmission (12%), and 30-day mortality (5.9%) were all greater than actual rates after PLC (1.6%, 4.8%, and 0.3%, respectively). The estimated surgical LOS differed significantly from the actual PLC LOS (5 days versus 1 day, P < .001). In univariable analysis, the number of probes the number of tumors ablated (odds ratio 1.90, 95% confidence interval 1.18-3.05, P = .008) and the number of probes used (odds ratio 1.44, 95% confidence interval 1.06-1.96, P = .021) were significantly associated with increased LOS, but demographic and emphysema details were not.

Conclusion: Complications after PLC are significantly less frequent than the estimated complication risks for wedge resection in the same patient population. Risk estimate calculators tailored to PLC would help screen for high complication risks related to this procedure.