Brief Bronchial Suction for Lung Collapse During Uniportal VATS

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.

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.

• bronchial suction (Other): Participants will receive bronchial suction at -30 cmH₂O through the bronchoscopy port of the operative lumen of the double-lumen endotracheal tube on two occasions: (1) during a 60-second apnea period immediately before initiation of one-lung ventilation and (2) during a 60-second apnea period immediately after pleural opening. Following the first suction period, the bronchoscopy port of the operative lumen will be closed. The bronchoscopy port of the operative lumen will be opened to ambient air following the second suction period after pleural entry.
• Sham Control (Other): Participants will undergo the same 60-second apnea periods as the bronchial suction group immediately before initiation of one-lung ventilation and immediately after pleural opening. The suction device will be activated for 60 seconds to produce sham suction noise but will not be connected to the patient.

Primary outcomes

• Quality of lung collapse at 1 minute after pleural opening [At 1 minute after pleural opening]: Surgical team to assess quality of lung collapse at 1 minute after pleural opening by using lung collapse score (LCS). The higher the LCS, the better the lung collapse.

Secondary outcomes

• Quality of lung collapse at pleural opening, 5 minutes and 10 minutes after pleural opening [At pleural opening, and at 5 and 10 minutes after pleural opening]: Quality of lung collapse assessed by the surgical team using the Lung Collapse Score (LCS) immediately after pleural opening, and at 5 minutes and 10 minutes after pleural opening.
• Time to satisfactory lung collapse [From pleural opening until the first LCS of 8 or greater, assessed up to 10 minutes after pleural opening]: Time from pleural opening to the first Lung Collapse Score (LCS) of 8 or greater
• Requirement for rescue maneuvers for inadequate lung collapse [From pleural opening until the end of one-lung ventilation during the index surgery up to 6 hours]: Need for additional intraoperative maneuvers to improve lung collapse due to inadequate surgical exposure
• Incidence of intraoperative hypoxemia [From initiation of one-lung ventilation until resumption of two-lung ventilation during the index surgery up to 6 hours]: Occurrence of intraoperative hypoxemia during one-lung ventilation, defined as SpO2 < 90%
• Incidence of postoperative pulmonary complications [From end of surgery through postoperative day 7 or hospital discharge, whichever occurs first]: Occurrence of postoperative pulmonary complications within 7 days after surgery or until hospital discharge, whichever occurs first. These include, but are not limited to, atelectasis, pneumonia, pulmonary aspiration, respiratory infection, pleural effusion, pneumothorax, bronchospasm, pulmonary edema, and respiratory failure.
• Total operative duration [From surgical incision to completion of surgery during the index operation, up to 6 hours]: Duration of surgery measured from surgical incision to completion of surgery.
• Duration of one-lung ventilation [From initiation of one-lung ventilation until resumption of two-lung ventilation during the index operation, up to 6 hours]: Total duration of one-lung ventilation during surgery

Sex: All, ages: 18 Years to any, accepts healthy volunteers

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

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• Nattaya Raykateeraroj, MD, Principal investigator, Siriraj Hospital