Prevalence, severity, and evolution of postsurgical anemia after gastrectomy, and clinicopathological factors affecting its recovery.

Jeong O, Park YK, Ryu SY
J Korean Surg Soc 2012;82:79-86.
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Review by : J. A. García-Erce
NATA Review

This original study investigated the “clinical” features of postsurgical anemia after gastrectomy. Postsurgical anemia is frequently encountered during the early postoperative period after gastrectomy and may impair physical performance and postoperative recovery. Of 649 patients with curative surgery, the authors reviewed 406 with gastrectomy alone (without chemotherapy or cancer recurrence) during one year, with regular controls at 3, 6 and 12 months post surgery. More than one third of these patients were still anemic one year later (34.7%). Sixty-five (16%) had preoperative anemia. Of the remaining patients, 74.2% developed postsurgical anemia. Multivariate analysis revealed that older age (>60 years), female gender, lower BMI and total gastrectomy were independent risk factors for anemia. Most importantly, type of reconstruction significantly related to the development of anemia. Only those patients with microcytic or hypochromic anemia were studied (serum iron, ferritin and total iron biding capacity). Consequently, only 11 (2.7%) received oral iron supplementation.

The authors state that “patients with gastrectomy inevitably suffer from poor iron absoption from the gastrointestinal tract and, thus, this may adversely affect the physiologic recovery from postsurgical anemia”. But this is not completely true: gastrectomy reduces acid production and impairs or limits iron absorption, but not entirely. Nevertheless, gastrectomy eliminates production of “intrinsic factor” at the level of gastric parietal cells and reduces, almost fully prevents, vitamin B12 absorption. This explains why total gastrectomy produces postoperative anemia 6.6 times more frequently.

I believe the authors err when they think that less than 3% of patients have iron deficiency and that iron is the only nutrient needed. Older patients with inflammation and vitamin B deficiency almost never will be hypochromic or microcytic, unless they were thalassemic, and the laboratory profile used by the authors misdiagnosed and/or underdiagnosed true iron deficit.

To the best of my knowledge and modest opinion, this study presents a few important messages: those patients without immediate postoperative anemia may develop anemia three months after surgery (7-10%). The majority of patients with moderate postsurgical anemia will never recover one year later (70%). These figures are very worrisome for total gastrectomy (65%) or for those who undergo a reconstructive surgery (65-80%), revealing probably that the iron and B vitamins absorption is fully impaired. I agree with the authors that a proper diagnosis and treatment is required in these patients.

– José A. García-Erce