Impact of Intraoperative Postural Transitions on Internal Carotid Artery Blood Flow During Gynecologic Laparoscopic Surgery

Abstract

Objective: Reduced internal carotid artery (ICA) blood flow can cause cerebral hypoperfusion, increasing the risk of intraoperative or postoperative cerebral ischemia. In laparoscopic surgery, postural changes and pneumoperitoneum may further compromise ICA hemodynamics. This study aims to evaluate the effects of intraoperative postural transitions on ICA blood flow in patients undergoing gynecologic laparoscopic surgery. Methods: A single-center, prospective, non-randomized observational study was performed. Measurements of ICA blood flow, heart rate (HR), and mean arterial pressure (MAP) were obtained at eight intraoperative time points: upon arrival to the operating table while awake (T1), post-induction of anesthesia in the supine position (T2), following pneumoperitoneum in the supine position (T3), immediately after placement in the Trendelenburg position (T4), 10 minutes (T5) and 20 minutes (T6) after Trendelenburg positioning, upon return to the supine position (T7), and at the conclusion of surgery (T8). Results: A total of 79 patients were enrolled in this study. A significant reduction in ICA blood flow was observed at T2 compared to T1 (263.8 ± 11.4 vs 323.5 ± 12.0 mL/min, p < 0.001), with further reduction at T3 (237.2 ± 9.8 vs 323.5 ± 12.0 mL/min [T1], p < 0.001, vs T1). No statistically significant changes were observed from T4 to T6. Upon transitioning from the Trendelenburg position to supine (T7), ICA blood flow further decreased (202.1 ± 7.5 vs 237.2 ± 9.8 mL/min, p = 0.004), accompanied by reductions in HR (60.0 ± 0.7 vs 66.9 ± 1.0 beats/min, p < 0.001) and MAP (82.8 ± 12.4 vs 93.6 ± 13.5 mmHg, p < 0.001). Conclusion: Intraoperative postural transitions during gynecologic laparoscopic surgery are associated with fluctuations in ICA blood flow. The return from the Trendelenburg to the supine position results in a marked decrease in ICA blood flow, HR, and MAP. Clinical Trial Registration: https://www.chictr.org.cn/showproj.html?proj=178094, Identifier: ChiCTR2200065104, Registered October 27, 2022.