• LAN
• necrosis
• termoablation
• ultrasound
• PVE
• hepatectomy
• PISA

Purpose
To assess the impact of surgical dissection on Late Ablative Necrosis (LAN) after Percutaneous Intrahepatic Split by Ablation (PISA) during major hepatectomies in terms of perioperative and post-surgical complications.

Material and methods
This retrospective study included 10 patients, 5 males and 5 females, (mean age 70,6 ± 9,3 years) who underwent liver major hepatectomy after Percutaneous Intrahepatic Split by Ablation (PISA) at our center from January 2015 to September 2021. Portal Vein Embolization (PVE using a mixture of 80% iodized oil and 20% cyanoacrylate) was performed as first step to induce FLR hypertrophy. PISA was performed 12,7 ± 5,16 days after PVE by microwave ablation systems; single or multiple access sites were used to allow sequential overlapping of ablation fields. Abdominal CT exams were performed before and after PVE and PISA. Hepatectomy was performed 17,4 ± 6,29 days after PISA. Factors including intraoperative bleeding, blood transfusion requirement, post-hepatectomy liver failure, abdominal abscesses, laboratory tests alterations and post-surgical mortality were evaluated. We also administered to surgeons a Likert based questionnaire consisting of 7 questions (single score from 1 to 5) to understand the overall satisfaction/dissatisfaction and other key factors in performing hepatectomy on late necrotic tissue produced by thermoablative necrosis.

Results
No procedure-related complications were recorded.
The mean operation time and volume of intraoperative blood loss were 258 ± 43 min and 382 ± 137 ml. Only 1 patient required blood transfusions (1 unit) during surgery for planned vascular recostruction.
No major complications surgery-related occurred, especially no patient had a 3a-score or more according to Clavien-Dindo classification.
We reported 1 case of biliary anastomotic stenosis, 1 case of cholangitis, 1 of chiloperitoneum and no cases of bleeding. All 10 patients were dismissed and gained full recovery.
The mean Intensive Care Unit (ICU) stay and mean post-operative length of hospital stay were respectively 1,2 days and 7,7 ± 1,89 days. The. Anatomopathogical R0 resection was confirmed in all cases.
The LAN resection surgeons' judgment provided favorable average scores above neutrality.

Conclusion
According to our knowledge, this is the first experience reported regarding the execution of surgical resections on LAN. Questionnaire results and surgical data support the feasibility and safety of surgical resections on late thermo-induced hepatic necrosis in the setting of major hepatectomies.
Surprisingly the judgment of surgeons working on LAN has been positive in many aspects, overcoming the neutrality in most questions with a positive overall judgment.