Obesity and postgastrectomy outcomes: large risks, fat chances, or no big deal?

Many Western and Asian societies face an increasing prevalence of obesity and related metabolic disorders [1]. Aside from the related issues that affect health care systems in general, surgeons specifically are faced with an increasing challenge to maintain high-quality care with good outcomes in an ever-increasing number of obese patients. Overweight patients are at greater risk for comorbidity and disability, particularly at body mass indices (BMI) of greater than 35 kg/m [2]. It is thus clear that operative care of obese patients requires greater health care resources, and frequently leads to increased length of hospital stay [3]. Associations between obesity and postoperative morbidity are less clear-cut, although many reports suggest that this is indeed so [4]. Some recent reports suggest a link between obesity and surgical site infection risk [5], while others indicate increased risks for minor complications after major cancer operations, but not major complications or death [6]. In this issue of Gastric Cancer, Sugisawa et al. [7] present a series of 206 patients undergoing curative-intent gastrectomy, in whom different fat areas as measurable components of obesity were examined for their association with postgastrectomy outcomes. The postoperative outcomes appear excellent, with low postoperative morbidity and mortality, and an acceptable (i.e., short) hospital stay for any health care system. The authors were able to link the visceral fat area (VFA), but not other measurements (total or subcutaneous fat areas, BMI), to pancreas-related infections that occurred in 8.7% of patients and anastomotic leaks seen in 4.9% of patients. The authors conclude that excessive visceral fat as represented by VFA is an independent risk factor for these untoward events, and that greater diligence is required in these patients. Can we be certain about the findings and the interpretation provided, and which aspects or conclusions are relevant to current or future care of obese patients with gastric cancer? To a ‘‘Western’’ reader, an anastomotic leak rate of 4.9% appears low, but a pancreas-related infection rate of 8.7% rather high, especially since Clavien grade 1 pancreatic ‘‘fistulae’’ are excluded. One would agree with the authors to primarily focus on clinically relevant grades (i.e., excluding grade 1), and could suspect that the radicality of the regional dissection with splenectomy may be a causative factor. We have learned that, in contrast to Asian patients, splenectomy in Western patients can be linked to increased postoperative morbidity, especially infectious complications [8]. In fact, splenectomy (and pancreatectomy) need to be considered as causative factors for the greater morbidity and mortality observed in both Western randomized controlled trials of D2 lymphadenectomy for gastric cancer [9]. Data from Sugisawa and colleagues now suggest that this is indeed the case for their patients, but that larger VFA and increased blood loss are additional identifiable links. Is an increased VFA in a patient population with a mean BMI of 23 (rather low for many Western institutions) really reflective of increased surgical risks, and does a gradual increase of the VFA number really correlate with a significantly increased complication rate? The statistical methods the authors applied would indicate so, as VFA and other fat measurements were evaluated as continuous variables. This means that, unfortunately, there seems to be no critical cutoff value This editorial refers to the article doi:10.1007/s10120-011-0099-0.