[Therapeutic strategy for totally thoracoscopic repeat mitral valve surgery under moderate hypothermia-induced ventricular fibrillation].

ABSTRACT

Objective: To examine the therapeutic strategy and its impacting factors by analyzing the perioperative outcomes of total thoracoscopic repeat mitral valve surgery under moderate hypothermia-induced ventricular fibrillation with cardiopulmonary bypass. Methods: This study is a retrospective case series. Totally 63 patients who underwent repeat mitral valve surgery by the same surgeon from January 2021 to December 2023 in Department of Cardiovascular Surgery, the First Medical Center of People's Liberation Army General Hospital were retrospectively enrolled. There were 28 males and 35 females with an age of (58.3±15.9) years (range 13 to 84 years). Surgery was performed using a totally thoracoscopic approach under moderate hypothermia-induced ventricular fibrillation. Mitral valvuloplasty was completed in 32 cases and mitral valve replacement in 31 cases. Preoperative baseline data and perioperative outcomes of the patients were collected and Logistic regression was used to analyze independent influencing factors of premature ventricular contractions in the early postoperative period. Results: The intraoperative cardiopulmonary bypass time was (191.5±50.9) minutes (range 95 to 286 minutes), and the hypothermic ventricular fibrillation time was (99.0±39.8) minutes (range 34 to 203 minutes). The anal temperature before the start of cardiopulmonary bypass was (36.3±0.5) ℃ (range 35.2 to 38.0 ℃), the lowest intraoperative anal temperature was (27.3±1.3) ℃(range 23.7 to 30.1 ℃), and the anal temperature at the time of the cessation of cardiopulmonary bypass was (36.3±0.4) ℃ (range 35.2 to 37.0 ℃), and excessive rewarming was observed in 33 cases. Six cases applied the artificial heart assist device. Seventeen cases developed premature ventricular contractions in the early postoperative period. Two cases developed neurologic complications. Five cases developed respiratory complications. One case developed urological systemic complications. Six cases were mechanically ventilated for more than 3 days, and the duration of ICU stay in 16 cases was more than 3 days and the postoperative discharge time of (M(IQR)) 8.0 (3.5) days (range 3 to 26 days). Two cases died or were discharged voluntarily. Logistic regression results showed that persistent preoperative atrial fibrillation (OR=11.424, 95%CI 1.477 to 144.564, P=0.033) and excessive rewarming (OR=15.249, 95%CI 1.357 to 279.571, P=0.038) were independent risk factors for the appearance of premature ventricular contractions in the early postoperative period. Conclusions: The technique of total thoracoscopic surgery under induced moderate hypothermic ventricular fibrillation with cardiopulmonary bypass could be applied to repeated mitral valve surgeries with less trauma and faster recovery. Persistent preoperative atrial fibrillation and excessive rewarming are independent risk factors for the occurrence of premature ventricular contractions in the early postoperative period.