Thermal ablation and telemedicine to reduce resource utilization during the Covid-19 pandemic

Presenter: Juan Glinka MD ;London Health Sciences Centre Background: Liver resection for malignant indications can lead to prolonged hospitalization. A recent statement from the Society of Surgical Oncology (SSO) has advised to consider Thermal Ablation (TA) for Colorectal Liver Metastasis (CRLM) during times of resource contraction within the Covid-19 pandemic. The purpose of this study is to evaluate the impact of broader use of TA and telemedicine during the pandemic. Methods: We retrospectively reviewed consecutive patients undergoing TA with or without liver resection during the Covid-19 pandemic (since March 2020, with a minimum follow-up of 6 months), compared to patients that underwent similar liver procedures from an era immediately preceding the pandemic. Primary outcomes included healthcare resource utilization (length of stay, and readmission), complications, and oncologic adequacy of treatment were analyzed. Cox proportional hazards modeling was used for risk-adjustment and to identify predictors of the primary outcomes Results: 42 patients undergoing TA for CRLM were identified. Median age was 62.5 years (32-84) and 54.8 % (n=23) were female. 10% (n=4) had combined colorectal resection with liver ablation. All patients in the COVID-19 era (n=11) had at least 1 telemedicine consultation preoperatively and all were reviewed in a virtual liver multidisciplinary tumor board. In the pre-COVID-19 cohort, 45.2% (n=14) of patients underwent a major liver resection (MLR) in combination with TA whereas, in the COVID-19 cohort, 27.3% (n=3) underwent a combined MLR and TA. LOS in the COVID-19 era was 1.7 days (1-5) with no readmissions when MA was the primary procedure. Across both groups, the median number of ablated lesions was 2 (1-10), and the median size was 12.8 mm (4 - 35 mm). Only 2 (4.76%) patients experienced ablation-related complications (both Dindo-Clavien II). 30-day imaging follow-up demonstrated complete response to ablation in 83.3% (n=35) of patients and partial response in 16.7% (n=7). Liver recurrence within 6 months occurred in 30.9% (n=13). Of these, 6 recurred in the ablation site and 7 in a different hepatic location. 29% of patients with liver recurrence underwent re-ablation. 23.8% (n=6) of patients had distant recurrence independently of the ablation. KRAS mutation was the only predictor of overall recurrence (OR: 6.12, p=0.024, CI: 1.3 - 29.7). Conclusion: TA for CRLM is safe, effective, and reduces health care resource utilization during the pandemic. Complication rates and oncologic adequacy of treatment were favorable even in instances of multiple ablations (>5) compared to hepatic resection. KRAS mutation status is a dominant mode of TA treatment failure suggesting that either larger ablation margins or hepatic resection be employed. There were no unintended consequences of the SSO guidelines for the treatment of CRLM during the COVID-19 pandemic.