Application of Carbon Dioxide for Identifying the Intersegmental Plane in Thoracoscopic Segmentectomy

With the increasing acceptance of routine computed tomography (CT) screenings, early-stage lung cancer detection is becoming more frequent. For ground glass opacity predominant early-stage lung cancer, segmentectomy can get the same oncological benefits as lobectomy. In addition, lung nodules that are highly suspected to be metastases can also be performed by segmentectomy to preserve more lung function. During the surgery, the rapid and precise identification of the intersegmental plane is one of the challenges. The improved inflation-deflation method is currently the most widely used method in clinical practice. According to the dispersion coefficient of the gas, the rapid diffusion properties of carbon dioxide would be expected to speed lung collapse and so facilitate surgery. The purpose of this study was to investigate the feasibility and safety of carbon dioxide on the appearance time of satisfactory and ideal planes during segmentectomy.

This study was approved by the ethics committee of Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology. This randomized parallel group trial enrolled patients scheduled to receive thoracoscopic anatomic segmentectomy at Tongji Hospital. General anesthesia with double lumen endotracheal tube was administered to the patients. With the guidance of preoperative three-dimensional computed tomography bronchography and angiography, the targeted segment structures could be precisely dissected, and then intersegmental demarcation was confirmed by the modified inflation-deflation method in this study. In group A (100% oxygen), after dividing all the targeted vascular and bronchial structures, the lung of the operating side was re-inflated with 100% oxygen. In group B (Carbon dioxide), after the targeted segment structures were successfully dissected, the collapsed operative lung was completely re-expanded with carbon dioxide. The purpose of this study was to investigate the feasibility and safety of carbon dioxide on the appearance time of satisfactory and ideal planes during segmentectomy. The starting time point of the intersegmental plane was when the whole lungs had completely re-expanded. The end point was when the preserved segment was fully deflated, and a boundary had formed between the targeted segment and the reserved lung.

Eligibility Criteria:
Inclusion Criteria:

1. 18-80 years of age.
2. Segmentectomy is feasible according to the reconstructed 3-dimensional (3D) images.
3. Pulmonary nodule 2 cm or smaller in diameter with 50% or more ground-glass opacity (GGO) on thin-slice computed tomography, indicating an underlying malignancy.
4. Ability to provide written informed consent.
5. Unable to tolerate lobectomy as indicated by standard clinical pre-op evaluation, including pulmonary function tests and cardiac evaluation.
6. Diagnosis confirmed or suspected of lung metastatic cancer.

Exclusion Criteria:

1. Patients who are at risk for general anesthesia.
2. Patients with serious mental illness.
3. Pregnancy or lactating women.
4. Active bacterial or fungal infections.
5. Panties with Interstitial pneumonia, pulmonary fibrosis or severe emphysema.
6. Conversion to thoracotomy in surgery.
7. Preoperative assessment of patients undergoing lobectomy.