Perioperative outcomes of sinusoidal obstruction syndrome in patients undergoing liver resection for colorectal metastases after neoadjuvant chemotherapy: a retrospective cohort research.

Purpose: We investigated the factors that affect the occurrence of sinusoidal obstruction syndrome (SOS) and the effect of SOS on the patient's perioperative outcomes through histological review of liver resection specimens from patients who underwent chemotherapy.

Methods: From December 2007 to December 2020, liver specimens from patients who underwent liver resection for colorectal liver metastasis after neoadjuvant chemotherapy were analyzed regarding liver damage in the nontumorous lesion. Through pathological review, patients with grade 1-3 sinusoidal dilatation were categorized into the SOS (+) group, compared to a control group (grade 0, SOS [-]).

Results: Of 286 patients, 175 were included. Preoperative factors were similar between the groups. Although not statistically significant, the SOS (+) group had a shorter chemotherapy-free interval before resection (7.96 weeks vs. 10.0 weeks, P = 0.069). The SOS (+) group had higher intraoperative blood loss (889.1 ± 1,126.6 mL vs. 555.3 ± 566.7 mL, P = 0.012) and transfusion rates (46.6% vs. 25.3%, P = 0.003). SOS correlated with increased liver surgery-specific complications (40.9% vs. 26.4, P = 0.043). Patients with SOS experienced adverse effects on intrahepatic recurrent-free survival and overall survival (5-year survival, 46.0% vs. 33.9%; P = 0.014).

Conclusion: SOS development during liver surgery is associated with increased intraoperative blood loss, transfusion volume, and liver surgery-specific complications and has a higher risk of early recurrence and decreased overall survival. Thus, it is crucial to exercise caution during liver surgery in these patients.