The goal of this clinical trial is to learn whether a brief suction of the airway going to the surgical lung (bronchus) can help the lung collapse faster and more completely during uniportal video-assisted thoracoscopic surgery (UVATS). This type of surgery is performed through a small incision in the chest, and good lung collapse helps the surgeon see and work safely. The main questions it aims to answer are

1. Does brief bronchial suction improve the quality of lung collapse 1 minute after chest cavity is opened?
2. Does brief bronchial suction help reach satisfactory lung collapse faster?

Researchers will compare patients who receive brief bronchial suction and those who do not. This is to see if suction improves and fastens lung collapse, reduce the need for additional steps if lung is not adequately collapsed, affect inflammation, oxygenation, postoperative pulmonary complications, operative time, and the duration of one-lung ventilation. Participants will

1. Undergo UVATS under general anesthesia
2. Have a double-lumen breathing tube placed as part of the standard anesthetic care
3. Be randomly assigned to either receive bronchial suction for one minute or receive no bronchial suction
4. Have the surgical team assess the quality of lung collapse at different time points
5. Have blood samples taken for interleukin-6, a marker related to inflammation, once during and once after surgery. These samples are collected through a small tube in a vein that is placed as a standard anesthetic care while the participant is under general anesthesia. No extra puncture is required for blood collection.
6. Have information collected from the routine anesthesia and surgical records such as oxygen levels during surgery, length of surgery and lung-related complications within 7 days after surgery

Uniportal video-assisted lung surgery (UVATS) is increasingly being performed in many centers. Due to a short interval between the skin incision and pleural opening, a rapid and adequate surgical lung collapse is important for optimal surgical exposure and operative efficiency. Delayed or inadequate lung collapse may interfere with the operative field, increase the need for manual lung manipulation by surgeons and possibly a resultant increase in lung inflammation. Brief bronchial suction through a double lumen tube has been used to facilitate lung collapse although its effectiveness is questionable in three-port VATS. This study aims to investigate if a brief bronchial suction helps achieve a better and faster lung collapse in UVATS.

Study objectives This randomized controlled trial aims to evaluate whether a brief suction through a tube in the non-ventilated lung leads to a better quality of lung collapse at one minute after the surgeon enters the chest. The study will compare the results between patients who receive a brief bronchial suction and those who do not.

Study design This is a randomized controlled trial conducted at a single university hospital in Thailand. Adult patients undergoing UVATS will be enrolled. A double-lumen endotracheal tube will be placed under general anesthesia as part of a standard anesthetic care. Patients will be randomly assigned to either receive a bronchial suction for one minute or no bronchial suction. The intervention group will undergo bronchial suction on two occasions: before pleural opening and immediately after pleural opening. Each suction period will last for 60 seconds.

The quality of lung collapse will be assessed by the surgical team at different time points during the surgery, including one minute after chest opening. Time to satisfactory lung collapse will also be evaluated.

Other perioperative data and outcome including requirement for additional steps in case of inadequate lung collapse, duration of one-lung ventilation, duration of surgery, incidence of intraoperative hypoxemia and postoperative pulmonary complications will also be collected.

To investigate the inflammatory response associated with suction and lung surgery, levels of interleukin-6 will be collected twice during and after surgery through an intravenous access placed under general anesthesia as part of a standard anesthetic care.

Potential significance The findings from this study may help to optimize anesthetic management for patients undergoing VATS, particularly UVATS, and provide evidence on the effectiveness of bronchial suction on the quality and speed of lung collapse. The information may contribute to evidence-based recommendations on intraoperative strategies to improve lung collapse during minimally invasive lung surgery.

Inclusion Criteria:

• Age ≥ 18 years old
• BMI ≤ 35 kg/m2
• American Society of Anesthesiologists (ASA) physical status I to III
• Scheduled for elective single-port video-assisted thoracoscopic surgery (VATS) at Siriraj Hospital
• Requirement for one-lung ventilation using a double-lumen tube (DLT)
• Surgery performed in the lateral decubitus position
• Ability to provide written informed consent

Exclusion Criteria:

• Previous thoracic surgery
• Known or suspected severe pleural adhesions based on preoperative imaging or clinical history
• Tracheobronchial anatomical abnormalities
• Pulmonary bullae identified on chest radiography or computed tomography, or a history of recurrent pneumothorax
• Forced vital capacity (FVC) < 50% of predicted
• Pregnancy

There is no current plan to share individual participant data outside the study team