Influence of Transfusions on Perioperative and Long-Term Outcome in Patients Following Hepatic Resection for Colorectal Metastases

To the Editor:

We read with interest the article by Kooby et al on the influence of transfusions on perioperative and long-term outcome in patients following hepatic resection for colorectal metastases.¹ The study, which has analyzed blood transfusion records and clinical outcomes for 1351 patients undergoing liver resection at a tertiary cancer referral center, shows that transfusion is an independent predictor of operative mortality, complications, major complications, and length of hospital stay but is not associated with adverse long-term survival. However, this article did not give attention to the relationship between timing of transfusion and postoperative clinical outcome.

Recently, in collaboration with the Department of Surgery of the Autonomous University of Barcelona, we conducted a retrospective study that investigated whether perioperative blood transfusions significantly affected postoperative septic morbidity and mortality in patients undergoing elective surgery for gastric cancer.² Our study has shown that stratifying patients according to timing of transfusion, postoperative mortality and septic morbidity were similar in patients who did not undergo transfusion (3.7% and 22.2%, respectively) and in patients who received transfusion exclusively preoperatively and/or perioperatively (3.9% and 20.5%, respectively), whereas they were significantly higher in patients who underwent postoperative transfusion, with or without receiving preoperative or perioperative transfusion (31.4% and 72.2%, respectively, P <0.01). Moreover, postoperative but not preoperative and/or perioperative transfusion was an independent prognostic factor in multivariate analysis (odds ratio, 17.5; 95% confidence interval, 5.8–52.8). We also observed that in most patients who received postoperative transfusions, septic complications preceded or were simultaneous with transfusion, and transfusion was administered in the absence of clinical evidence of bleeding. Therefore, we suggested that extracellular fluid expansion (leading to hemodilution and a low hemoglobin value) during stress response in patients who were developing or had just developed septic complications may act as a confounder and may be considered responsible for the association between postoperative transfusion and septic morbidity. In other words, it seems that it is not blood transfusions themselves, but the circumstances necessitating transfusions that are the real determinants of prognosis. This does not mean that an immunosuppressive effect of allogenic blood transfusion does not exist, but only that it may not be clinically relevant with respect to postoperative infectious complications.

Maurizio Bossola, MD
Fabio Pacelli, MD
Rocco Bellantone, MD
Giovan Battista Doglietto, MD
Istituto di Clinica Chirurgica Università Cattolica del Sacro Cuore Rome, Italy maubosso@tin.it