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

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

Official Title
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Application of Carbon Dioxide for Identifying the Intersegmental Plane in Thoracoscopic Segmentectomy: A Randomized Controlled Study

Conditions
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Lung Cancer, Pulmonary Nodule, Solitary, Segmentectomy, Pulmonary Nodule, Multiple

Intervention / Treatment
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* Procedure: 100% oxygen
* Procedure: Carbon dioxide


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18-80 years of age. Segmentectomy is feasible according to the reconstructed 3-dimensional (3D) images. 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. Ability to provide written informed consent. Unable to tolerate lobectomy as indicated by standard clinical pre-op evaluation, including pulmonary function tests and cardiac evaluation. Diagnosis confirmed or suspected of lung metastatic cancer. Exclusion Criteria: Patients who are at risk for general anesthesia. Patients with serious mental illness. Pregnancy or lactating women. Active bacterial or fungal infections. Panties with Interstitial pneumonia, pulmonary fibrosis or severe emphysema. Conversion to thoracotomy in surgery. Preoperative assessment of patients undergoing lobectomy.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Group A: 100% oxygen<br>After dividing all the targeted vascular and bronchial structures, the lung of the operating side was re-inflated with 100% oxygen. | Procedure: 100% oxygen<br>* During one-lung ventilation with an open chest, the non-ventilated lung collapses initially due to the inherent elastic recoil properties of the lung. Once passive venting has ceased, further collapse will then be wholly dependent on ongoing gaseous uptake and absorption atelectasis. Improved inflation-deflation method is currently the most widely used method in clinical practice. After dividing all the targeted vascular and bronchial structures, the lung of the operating side was re-inflated with 100% oxygen. After the operative lungs is completely expanded, perform pure oxygen mechanical single lung ventilation for the healthy lung, waiting for clear presentation of the plane between the targeted segment and the other segments.<br>|
| Experimental: Group B: Carbon dioxide<br>After the targeted segment structures were successfully dissected, the collapsed intraoperative lung was completely re-expanded with carbon dioxide. | Procedure: Carbon dioxide<br>* During one-lung ventilation with an open chest, the non-ventilated lung collapses initially due to the inherent elastic recoil properties of the lung. Once passive venting has ceased, further collapse will then be wholly dependent on ongoing gaseous uptake and absorption atelectasis. The solubility coefficient for carbon dioxide is 0.57. The rapid diffusion properties of carbon dioxide would be expected to speed lung collapse and so facilitate surgery. After the targeted segment structures were successfully dissected, the collapsed intraoperative lung was completely re-expanded with carbon dioxide. After the operative lungs is completely expanded, perform pure oxygen mechanical single lung ventilation for the healthy lung, waiting for clear presentation of the plane between the targeted segment and the other segments.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The intersegmental border appearance time during the surgery. | 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. | The time of appearance of the intersegmental plane that can be performed satisfactorily by surgeons during the surgery. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The arterial blood gas results during perioperative period. | Extracting arterial blood gas. | Immediately after the radial arterial catheterization when inhaling the air, pre-intervention, 3-minutes, 5-minutes, 15-minutes during the single lung ventilation after the intervention. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Lung segmentectomy, Intersegmental plane, Inflation-deflation method, Carbon dioxide