Impact of Thoracic Duct Resection on Postoperative Body Composition Trajectory After Oesophagectomy: A Prospective Cohort Study.

Thoracic duct resection was associated with more pronounced early postoperative skeletal muscle mass decline compared to thoracic duct preservation.

• SMI declined by -11.2% in the TDR group versus -8.1% in the preservation group during the first 3 months (p = 0.036)
• FFMI showed similar early postoperative declines that were more pronounced in the TDR group
• The study included 347 patients: TDR group (n = 288) and thoracic duct preservation group (n = 59)
• Body composition was assessed at six time points using bioelectrical impedance analysis (BIA), yielding 1925 measurements

The early between-group differences in sarcopenia-related indices attenuated after propensity score matching but remained directionally consistent.

• Sensitivity analysis was performed using 1:1 propensity score matching (PSM) based on key clinical variables
• Early differences in SMI and FFMI were reduced but maintained the same directional trend after PSM
• This suggests the observed differences were not entirely attributable to baseline imbalances between groups

By 12 months postoperatively, sarcopenia-related indices were comparable between the TDR and thoracic duct preservation groups.

• SMI at 12 months: p = 0.343 between groups
• FFMI at 12 months: p = 0.733 between groups
• Recovery of muscle mass began around postoperative month 3
• This indicates the muscle loss associated with TDR was transient and reversible

BMI and fat mass index declined gradually over 12 months with no significant between-group differences.

• BMI at 12 months: TDR vs. preservation group, 21.0 vs. 20.6 kg/m2 (p = 0.809)
• FMI showed a similar gradual decline over 12 months with no significant between-group differences
• Adiposity-related indices thus followed a different trajectory than sarcopenia-related indices

Baseline operative variables were comparable between the TDR and thoracic duct preservation groups.

• Operative time: 485 min (TDR) vs. 478 min (preservation)
• Total lymph nodes: 66 (TDR) vs. 63 (preservation)
• Complication rates: 30% (TDR) vs. 32% (preservation)
• Median age was 64 years and approximately 90% of patients were male in both groups

Subgroup analysis in patients with clinical stage I disease revealed similar patterns of muscle loss following TDR.

• The pattern of greater early muscle decline in TDR patients was observed in stage I patients as well
• This suggests the observed muscle loss may reflect procedure-related effects independent of tumour burden
• The finding supports that TDR itself, rather than disease severity, contributes to early postoperative muscle loss

Exploratory nutritional markers showed no significant intergroup differences at any postoperative interval.

• Markers assessed included albumin, lymphocyte count, and cholesterol
• No significant between-group differences were observed at any time point
• This finding indicates that TDR's impact on early muscle loss was not reflected in standard nutritional laboratory markers