Chen Xiaosang, Xue Shuanggen, Xu Jun, Zhong Ming, Liu Xiaochuan, Lin Guangyi, Shen Yaxing, Tan Lijie
Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China.
Jiangyan Hospital of Traditional Chinese Medicine Affiliated to Nanjing University of Traditional Chinese Medicine, Nanjing, China.
J Thorac Dis. 2020 Nov;12(11):6505-6513. doi: 10.21037/jtd-20-1905.
Transcervical esophagectomy is a less invasive procedure performed within mediastinum. However, the mediastinum offers limited surgical space and the surgery via this route differs from conventional minimally invasive esophagectomy. Therefore, the physiological study of this surgical approach on an animal model would be necessary before the procedure gained more popularity.
We conducted transcervical minimally invasive esophagectomy on animal model (swine) under CO pneumomediastinum. The hemodynamic parameters were monitored using float catheter cannulated via right jugular vein. At different anatomical level (the upper, middle, and lower thoracic part of the animal esophagus), increased artificial pneumomediastinal pressures (0, 4, 8, 12, and 16 mmHg) were consecutively allocated to record the intra-operative changes of blood pressure, cardiac output (CO), central venous pressure (CVP), pulmonary artery pressure (PAP) and extravascular lung water (EVLW). Meanwhile, the surgical field under different pneumomediastinum pressure was recorded and balanced with animals' hemodynamic changes to determine the optimal pressure for transcervical minimally invasive esophagectomy.
The animal procedures were accomplished without conversions. During the upper thoracic stage, increased CO pressures did not lead to significant changes in hemodynamic parameters including the blood pressure, CO, CVP, PAP or the level of EVLW. During the middle thoracic stage, pneumomediastinum under 4-12 mmHg did not lead to significant changes in hemodynamic parameters. However, pneumomediastinum at 16 mmHg resulted in lower CO (P=0.038) when compared to 0-12 mmHg. During lower thoracic stage, as the pneumomediastinum pressures increased from 0 to 16 mmHg, significant decrease in CO (P=0.022), and increase in CVP (P=0.036) was recorded. In compared to 4 mmHg pneumomediastinum, the surgical field under 8-16 mmHg artificial CO pneumomediastinum was suitable for mediastinal manipulation.
During transcervical minimally invasive esophagectomy on animal model, the mobilization of swine thoracic esophagus with optimal pneumomediastinum pressure 8-12 mmHg is safe and effective based on hemodynamic analysis.
经颈段食管切除术是在纵隔内进行的一种侵入性较小的手术。然而，纵隔提供的手术空间有限，且通过该途径进行的手术与传统的微创食管切除术不同。因此，在该手术更广泛应用之前，有必要在动物模型上对这种手术方式进行生理学研究。
我们在猪动物模型上于纵隔积气状态下进行经颈段微创食管切除术。使用经右颈静脉插入的漂浮导管监测血流动力学参数。在动物食管的不同解剖水平（上、中、下胸段），依次施加递增的人工纵隔积气压力（0、4、8、12和16 mmHg），以记录术中血压、心输出量（CO）、中心静脉压（CVP）、肺动脉压（PAP）和血管外肺水（EVLW）的变化。同时，记录不同纵隔积气压力下的手术视野，并与动物的血流动力学变化相平衡，以确定经颈段微创食管切除术的最佳压力。
动物手术均顺利完成，无中转情况。在上胸段手术期间，纵隔积气压力增加并未导致包括血压、CO、CVP、PAP或EVLW水平在内的血流动力学参数发生显著变化。在中胸段手术期间，4 - 12 mmHg的纵隔积气未导致血流动力学参数发生显著变化。然而，与0 - 12 mmHg相比，16 mmHg的纵隔积气导致CO降低（P = 0.038）。在胸段手术的下胸段，随着纵隔积气压力从0增加到16 mmHg，记录到CO显著降低（P = 0.022），CVP升高（P = 0.036）。与4 mmHg纵隔积气相比，8 - 16 mmHg人工纵隔积气下的手术视野适合纵隔操作。
在动物模型上进行经颈段微创食管切除术时，基于血流动力学分析结果，8 - 12 mmHg的最佳纵隔积气压力用于猪胸段食管的游离是安全有效的。
