Intraocular pressure and steep Trendelenburg during minimally invasive gynecologic surgery: is there a risk?

Study Objective: Steep Trendelenburg position is frequently used during gynecologic minimally invasive surgery (MIS). However, little attention has been given to the potential impact of this nonphysiologic positioning on patients, specifically intraocular pressure (IOP). The purpose of our study was to evaluate IOP changes during laparoscopic or robotic hysterectomy conducted in the steep Trendelenburg position.

Design: Prospective cohort study (Canadian Task Force classification II-2).

Setting: John Sealy Hospital at the University of Texas Medical Branch, Galveston, TX.

Patients: Female patients with no history of ocular pathology who underwent elective robotic or laparoscopic hysterectomy.

Interventions: The anesthesia protocol was standardized for all study patients. IOP and mean arterial pressure (MAP) were obtained before anesthesia, after general anesthesia and intubation were achieved, after 1 hour of steep Trendelenburg positioning, after 2 hours of steep Trendelenburg positioning, and after the patient was returned to the supine position. Ocular perfusion pressure (OPP) was calculated using the following equation: OPP = MAP - IOP.

Main Results: A total of 10 patients were included in this prospective study. A significant increase in IOP from baseline was observed after 1 hour and 2 hours of steep Trendelenburg positioning (p = .005 and .002, respectively). There was a statistically significant trend of increasing the IOP from baseline to the second hour of steep Trendelenburg positioning (p < .001). The IOP remained significantly elevated once the patient was returned to the supine position when compared with the baseline IOP (p = .006). OPP significantly decreased from baseline after 2 hours of steep Trendelenburg positioning (p = .03).

Conclusions: IOP increases significantly when patients are placed in the steep Trendelenburg position. Although further studies are needed to better characterize this process, given the aging population of our MIS patients in whom risk for glaucoma is significant, preoperative ocular health assessment should be considered in certain cases.