Elevated Visceral Obesity Quantified By CT Is Associated With Adverse Short-term Postoperative Outcomes Of Radical Colectomy For Colon Cancer Patients

Objective:Imaging technique has been developing rapidly especially in colorectal surgery recently.Preoperative quantitative computed tomography(CT)assessment of visceral adiposity may be superior to body mass index(BMI)as a predictor of surgical morbidity.Our study aimed at examining the association of CT measures of obesity and BMI with short-term postoperative outcomes in colon cancer patients.Methods:In this retrospective study,107 patients treated with colectomy for stageⅠ-Ⅲcolon cancer were classified as obese or non-obese by preoperative CT-based measures of adiposity or BMI[obese:BMI≥28 kg/m~2,visceral fat area(VFA)to subcutaneous fat area ratio(V/S)≥0.4,and VFA>100 cm~2].Postoperative complications,postoperative stay and hospitalization expenses were compared between the two groups.The Clavien-Dindo surgical complication grading system was utilized to further classify documented outcomes.Furthermore,the Clavien-Dindo scale was dichotomized into two groups:minor(gradesⅠandⅡ)vs.major(gradesⅢ-Ⅴ)for comparisons.Chi-square or Fischer’s exact tests or two sample t test with equal or unequal variance were used to determine differences in adiposity based on clinical,pathological,intraoperative and postoperative features as appropriate.TNM stage refered to the 8th edition of AJCC Cancer Staging Manual.All statistical tests were two-sided and deemed statistically significant at the level of 0.05,unless otherwise specified.Analyses were performed using SPSS(IBM SPSS Statistics 20).Results:There were no significant differences between the two groups by BMI with respect to postoperative complication rate(33.3 vs.25.0%,P>0.05).No significant differences were observed in terms of operation time(198.7±47.4 vs.174.4±48.3 min,P>0.05),postoperative stay(17.13±10.84 vs.13.82±6.22 d,P>0.05)and hospitalization expenses(78791.9±32868.7 vs.67209.1±19173.2 yuan,P>0.05)between the two groups by BMI.There was no significant difference between the two groups by V/S with respect to postoperative complication rate(28.4 vs.8.3%,P>0.05).No significant differences were observed in terms of operation time(180.4±49.7 vs.157.1±35.8 min,P>0.05),postoperative stay(14.66±7.34 vs.11.00±2.41 d,P>0.05)and hospitalization expenses(68973.3±21685.6 vs.67607.3±23694.7,P>0.05)between the two groups by V/S.While,obese patients graded by VFA were more likely to have higher postoperative complication rate compared to patients graded as non-obese(32.9 vs.11.8%,P<0.05).And obese patients graded by VFA had longer operation time(184.6±49.5min vs.163.1±44.1min,P<0.05),postoperative stay(15.21±7.59 vs.12.29±5.40 d,P<0.05)and expensed more(72083.0±21920.6 vs.61854.6±20063.6yuan,P<0.05)than non-obese.No difference was found in estimated blood loss.The severity of postoperative complications as classified by the Clavien-Dindo grading method was not significantly associated with obesity categorized by BMI,V/S,or VFA.Conclusion:Visceral obesity graded by VFA quantified through preoperative CT is associated with increased operation time,postoperative morbidity,postoperative stay and hospitalization expenses and may be superior to BMI and V/S for colon cancer outcome assessment.