# Impact of intraoperative fluid therapy on postoperative complications following robotic-assisted minimally invasive esophagectomy (RAMIE)

## TL;DR

This study examines how fluid therapy during robotic-assisted esophagectomy affects postoperative complications like lung issues and heart problems.

## Contribution

The study identifies variable associations between intraoperative fluid volume and specific postoperative outcomes, suggesting a need for individualized fluid management.

## Key findings

- Higher intraoperative fluid volumes are linked to increased pulmonary complications.
- Anastomotic leakage risk peaks at moderate fluid levels.
- Fluid management should be individualized rather than following binary strategies.

## Abstract

Robotic-assisted minimally invasive esophagectomy (RAMIE) has become an increasingly adopted approach for the treatment of esophageal cancer. However, the impact of intraoperative fluid therapy on postoperative outcomes remains poorly defined. Whereas fluid overload has been linked to pulmonary and anastomotic complications, restrictive strategies may impair tissue perfusion and organ function. This study investigates the association between intraoperative fluid balance and postoperative morbidity in patients undergoing RAMIE.

We conducted a retrospective single-center cohort study including 254 consecutive patients who underwent elective RAMIE between 2019 and 2024. Intraoperative fluid balance was calculated in mL/kg/h and analyzed as a continuous variable. Primary endpoints included pulmonary complications, anastomotic leakage, postoperative atrial fibrillation (POAF), and acute kidney injury (AKI). Secondary endpoints comprised ICU length of stay (LOS), postoperative delirium, delayed gastric emptying (DGE), and complication severity according to the Clavien-Dindo classification. Multivariable regression models were adjusted for age, sex, BMI, and ASA status.

Pulmonary complications (23.2%) were significantly associated with higher intraoperative fluid volumes (mean: 5.2 vs. 4.4 ml/kg/h; p = 0.027; OR: 1.24, 95% CI: 1.05–1.46). Anastomotic leakage (18.5%) exhibited an inverted U-shaped relationship, with the highest risk at fluid levels of 4.7–8.1 ml/kg/h). POAF (16.1%) and AKI (5.5%) were not significantly associated with fluid volume in multivariable analysis. POAF showed no significant association with intraoperative fluid volume in adjusted models. Predicted probabilities illustrated a fivefold increase in pulmonary risk across the 0 to 10 ml/kg/h range, whereas POAF declined steadily over this interval. Postoperative delirium showed a trend toward association with fluid volume (OR: 1.34; p = 0.056), while DGE, ICU-LOS, and major complications demonstrated no significant associations. Subgroup analyses suggested stronger associations between fluid volume and pulmonary complications in elderly patients, and a more pronounced POAF risk in males, indicating potential effect modification by age and sex.

Intraoperative fluid volume during RAMIE is variably associatiated with postoperative outcomes. While higher volumes are linked to increased pulmonary morbidity, lower volumes may predispose patients to arrhythmias. Anastomotic complications appear to peak at moderate fluid levels. These findings challenge binary fluid strategies and support a more individualized, risk-adapted approach to intraoperative fluid management in esophageal surgery.