Reduction of Central Venous Pressure in Elective Robotic and Laparoscopic Liver Resection: The PRESSURE Trial - A Randomized Clinical Study.

Objective: To compare perioperative outcomes in patients undergoing minimally invasive liver surgery (MILR) with or without central venous pressure (CVP) reduction (≤5 mmHg).

Background: Reduction CVP during parenchymal transection is widely accepted in open hepatectomy to reduce intraoperative blood loss, as a major predictor of postoperative outcomes. However, the effect of CVP reduction on blood loss in MILR remains unclear.

Methods: Randomized controlled, double-blinded trial. Patients undergoing elective MILR between August 2020 and April 2023 were equally randomized to either no CVP reduction (No CVP reduction group) or CVP reduction by anesthesiological interventions (CVP reduction group). The remaining perioperative care was kept identical between groups. The primary endpoint was total intraoperative blood loss.

Results: In total 120 patients were randomized and 112 were analyzed. Baseline characteristics did not differ between groups. Total intraoperative blood loss in MILR was equivalent between groups (No CVP reduction: 280 mL (120-560) versus CVP reduction: 360 mL (150-640); P=0.30), despite higher CVP values during resection in the No CVP reduction group (9.3 mmHg±4.2 versus 3.2 mmHg±2.2; P<0.001). Similarly, there was no difference in blood loss during parenchymal transection between the No CVP reduction (220 mL; 80-400) and the CVP reduction group (240 mL;110-560) (P=0.39). Postoperative 90-day mortality (No CVP reduction: n=3, 5% versus CVP reduction: n=2, 4%; P=0.68) and total morbidity rates (No CVP reduction: n=10, 18% versus CVP reduction: n=11, 20%; P=0.77) were comparable. Intraoperative hemodynamic instability was less frequent in the No CVP reduction group (n=7, 12% versus CVP reduction group: n=16, 30%; P=0.03).

Conclusions: MILR without CVP reduction during liver transection is safe and is not associated with increased intraoperative blood loss. Moreover, a no-CVP-reduction strategy might prevent potential adverse effects of fluid restriction in MILR, such as hemodynamic instability.