Inadvertent Splenectomy During Resection for Colorectal Cancer Does Not Increase Long-term Mortality in a Propensity Score Model: A Nationwide Cohort Study.

BACKGROUND: Previous studies suggest that long-term mortality is increased in patients who undergo splenectomy during surgery for colorectal cancer. The reason for this association remains unclear.

OBJECTIVE: The purpose of this study was to investigate the association between inadvertent splenectomy attributed to iatrogenic lesion to the spleen during colorectal cancer resections and long-term mortality in a national cohort of unselected patients.

DESIGN: This was a retrospective, nationwide cohort study.

SETTINGS: Data were collected from the database of the Danish Colorectal Cancer Group and merged with data from the National Patient Registry and the National Pathology Databank.

PATIENTS: Danish patients with colorectal cancer undergoing curatively intended resection between 2001 and 2011 were included in the study.

MAIN OUTCOME MEASURES: The primary outcome was long-term mortality for patients surviving 30 days after surgery. Secondary outcomes were 30-day mortality and risk factors for inadvertent splenectomy. Multivariable and propensity-score matched Cox regression analyses were used to adjust for potential confounding.

RESULTS: In total, 23,727 patients were included, of which 277 (1.2%) underwent inadvertent splenectomy. There was no association between inadvertent splenectomy and long-term mortality (adjusted HR = 1.15 (95% CI, 0.95-1.40); p = 0.16) in the propensity score-matched model, whereas 30-day mortality was significantly increased (adjusted HR = 2.31 (95% CI, 1.71-3.11); p < 0.001). Inadvertent splenectomy was most often seen during left hemicolectomy (left hemicolectomy vs right hemicolectomy: OR = 24.76 (95% CI, 15.30-40.06); p < 0.001).

LIMITATIONS: This study was limited by its retrospective study design and lack of detailed information on postoperative complications.

CONCLUSIONS: Inadvertent splenectomy during resection for colorectal cancer does not seem to increase long-term mortality. The previously reported reduced overall survival after inadvertent splenectomy may be explained by excess mortality in the immediate postoperative period.