The effects of perioperative blood transfusion on morbidity and mortality after esophagectomy

The effect of blood transfusion on outcomes in esophageal surgery remains controversial. The contrasting conclusions drawn from a number of retrospective analyses with different methodologies create a landscape that is difficult to interpret. Because of the scope of esophageal resection, the need for blood transfusion cannot be eliminated. What recommendations then, if any, can be made for the practicing surgeon? First, surgeons and anesthesiologists need to reevaluate their transfusion thresholds. The age-old practice of keeping the hemoglobin above 10 g/dL has very little evidence-based support. A multicenter, randomized, controlled clinical trial in Canada demonstrated that a restrictive strategy of blood transfusion, in which patients were transfused only for a hemoglobin level of less than 7 g/dL, was at least as effective as and possibly was superior to a liberal transfusion strategy in critically ill patients. It has also been estimated that more than 25% of patients undergoing colorectal resections may receive at least one unit of unnecessary blood. Further, the immediate reduction in the hemoglobin concentration caused by the normovolemic hemodilution associated with surgery and crystalloid fluid replacement is not associated with any increased morbidity or mortality. If these data are examined in the context of the results of Langley and Tachibana indicating that a threshold amount of blood needs to be transfused to impact outcomes, it becomes even more important to limit transfusion to only the amount that is essential. Thus, surgeons and anesthesiologists should adopt a more stringent set of requirements for blood transfusion. Second, with the proven feasibility and reduction in infectious complications associated with autologous blood-donation programs, any patient who meets the criteria discussed here should be encouraged to participate in such a program. Although the effect of autologous blood on cancer outcomes remains unclear, the other advantages certainly make such a program worthy of consideration. This discussion leads to a final point, namely that patients should be encouraged, whenever possible, to participate in clinical trial research. The only way that the community of surgeons treating patients who have esophageal cancer can hope to address properly the question of how blood transfusion affects outcomes is with well-designed clinical trials. A large, multicenter, randomized trial (level I) would be ideal. Short of such a trial, inclusion criteria and study methodology should be discussed among various institutions to avoid the differences in studies that make direct comparisons of results among different investigators difficult and potentially meaningless. This measure would at least allow different level II to IV data to be compared directly with some validity.