Body composition in CT as a predictor of major post-operative complications in patients undergoing definitive surgery for intestinal fistulas.

Major postoperative complications occurred in 18.08% of patients undergoing definitive surgery for intestinal fistulas.

• 16 out of 88 patients developed major postoperative complications
• Postoperative complications were scored according to the Clavien-Dindo classification
• The study was a retrospective review of 88 patients with intestinal fistula who underwent definitive surgery

Lower quadratus lumborum index (QLI) was an independent risk factor for major postoperative complications in univariate and multivariable analyses.

• In univariate analysis, lower QLI was a significant risk factor (P = 0.047)
• In multivariable regression analysis, QLI remained an independent risk factor (P = 0.011; OR = 0.383)
• An OR of 0.383 indicates that higher QLI is associated with reduced odds of major complications

Longer length of stay (LOS) was an independent risk factor for major postoperative complications.

• In univariate analysis, longer LOS was a significant risk factor (P = 0.002)
• In multivariable regression analysis, LOS remained an independent risk factor (P = 0.012; OR = 1.006)
• LOS was among the strongest predictors in univariate analysis based on P-value

Additional univariate risk factors for major postoperative complications included higher CRP, lower QLA/BMI, and fewer preoperative admission histories.

• Higher C-reactive protein (CRP) was a significant risk factor (P = 0.036)
• Lower quadratus lumborum areas divided by body mass index (QLA/BMI) was a significant risk factor (P = 0.023)
• Fewer preoperative admission histories was a significant risk factor (P = 0.049)
• These variables did not remain independent predictors in the multivariable regression model

A combined model incorporating QLI, QLA/BMI, CRP, LOS, sex, and age achieved an area under the curve of 0.815 for predicting major postoperative complications.

• The AUC was 0.815 (P < 0.001)
• The model had a specificity of 64.8% and a sensitivity of 93.8%
• The six variables included were QLI, QLA/BMI, CRP, LOS, sex, and age

Body composition indices were calculated from preoperative CT scans at the level of the third lumbar vertebra.

• Each body composition index was calculated by dividing the cross-sectional area of adipose or muscle tissue at the L3 level by the square of the patient's height
• Preoperative CT scans were used to identify and measure quadratus lumborum muscle and adipose tissue areas
• The quadratus lumborum index (QLI) and QLA/BMI were the primary CT-derived body composition measures analyzed