Background: In recent years, minimally invasive esophagectomy (MIE) has been used gradually in esophageal surgery. The application of CO2 aeration in minimally invasive surgeries, especially in laparoscopic surgery, has been very mature. However, the application of CO2 aeration in mediastinal esophagectomy is still in the exploration stage. This study was designed to investigate the safety of mediastinal CO2 aeration in the mediastinal esophagectomy.
Methods: A total of 15 pigs were used to construct an experimental animal model of mediastinal CO2 aeration. The effects of different inflation pressures on the circulatory respiratory function of pigs were studied by detecting the relevant physiological parameters. Heart rate (HR), mean arterial pressure (MAP) and central venous pressure (CVP) were monitored before ventilating CO2 (T0), and also monitored at 30 (T1), 60 (T2), 90 (T3) min after inflation and 30 min after deflation (T4). Arterial blood was collected for PaCO2, blood lactate concentration (cLac), PaO2/FiO2, SaO2, pH value, and cardiac output (CO) was measured by esophageal ultrasound.
Results: The results of animal experiments showed that under 5-10 mmHg CO2 inflation pressure, circulation function indicators (CVP, MAP, HR, CO) and respiratory function indicators (PaCO2, cLac, PaO2/FiO2, SaO2, pH value) in pigs had no significant difference compared with the indicators before inflation; and under 15 mmHg CO2 inflation pressure, CVP, HR, PaCO2 and blood cLac increased, while MAP, CO, PaO2, SaO2 and pH values decreased. The visual field using mediastinoscopy under 15 and 10 mmHg CO2 inflation pressure was better than that under 5 mmHg CO2 inflation pressure.
Conclusions: Mediastinal esophagectomy with 5-10 mmHg CO2 inflation pressure has no significant effect on the circulation and respiratory function of the body. Compared with the conventional non-inflated transseptal esophageal cancer (EC) surgery, it can provide a better surgical vision and reduce the difficulty of the surgery.
Keywords: CO2; Esophageal cancer (EC); mediastinal aeration; mediastinal esophagectomy; safety.