The aim of the study is to evaluate postoperative pain in patients receiving a small-bore (16F) chest drain compared to those receiving the standard large-bore (24F) chest drain after minimally invasive pulmonary lobectomy and/or segmentectomy.

Lung cancer remains the leading cause of cancer-related death worldwide, and surgical resection remains the treatment of choice for patients with resectable non-small cell lung cancer (NSCLC), particularly in early stages of the disease. Anatomical lung resections such as lobectomy and segmentectomy are commonly performed, increasingly through minimally invasive techniques like video-assisted thoracoscopic surgery (VATS) and robotic-assisted thoracoscopic surgery (RATS). Compared to traditional thoracotomy, VATS and RATS has been associated with better postoperative outcomes, including less pain, shorter hospital stays, faster recovery, and improved quality of life.

After lung resections, the standard postoperative management involves the insertion of a chest drain to remove air and fluid from the pleural space and monitor for complications such as air leaks or bleeding. Traditionally, most thoracic surgery centres use a single large-bore chest tube, typically 24F in size, which remains in place at least until the first postoperative day. However, this practice is not based on strong evidence, and there is currently no consensus on the optimal size of the chest drain. In fact, removal of the chest tube has been shown to significantly improve ventilatory function and reduce pain, particularly in the early postoperative period.

The Chest Drain 16F vs 24F Study investigates whether the use of a smaller-bore chest drain (16F) leads to less postoperative pain compared to the standard large-bore 24F drain in patients undergoing minimally invasive pulmonary lobectomy and/or segmentectomy. In addition to comparing the tube sizes, the trial explores the safety and feasibility of early chest drain removal, defined as removal within 2 to 6 hours after surgery, provided that specific clinical criteria are met (e.g., minimal air leak and no signs of complications). While retrospective data and small prospective studies suggest that early removal and the use of smaller tubes may be beneficial, high-quality prospective data are lacking. This study aims to provide evidence to potentially change clinical practice by reducing patient discomfort without compromising safety.

Inclusion Criteria:

• Informed Consent signed by the patient (all sex and gender)
• Patients' age from ≥ 18 to no age limit at time of study inclusion
• American Society of Anaesthesiologists (ASA) physical status classification I to IV
• Patients with resectable non-small cell lung cancer (NSCLC) deemed operable by minimally invasive surgical technique.
• Minimally invasive anatomical lung resections under general anaesthesia: lobectomy, lobectomy with wedge resection, lobectomy combined with segmentectomy, segmentectomy with wedge resection, bilobectomy

Exclusion Criteria:

• Previous thoracic surgery on the same side within 3 months
• Lung cancer complicated with pleural empyema
• Patients with chronic pain who receive opioids/gabapentin/pregabalin
• Patients who consume opiates/benzodiazepines
• Congestive heart failure NYHA Class III or IV
• Liver cirrhosis Child-Pugh Class B and C
• Renal insufficiency requiring dialysis and/or estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m2
• Patients with coagulopathy or bleeding disorders: von Willebrand disease, Hemophilia; Thrombocytopenia (<50 G/l), requiring platelet transfusion
• Patients with neuralgia
• Chest pain (site of surgery) without taking painkillers, measured by VAS while coughing > 10 mm
• Not consolidated rib fractures (in the last 3 months) on the side of surgical procedure
• Open anatomical lung resection, including pneumonectomy
• Insertion of 2 or more chest tubes
• Need for patient controlled intravenous anaesthesia or patient controlled epidural anaesthesia
• Patients intubated/sedated (not suitable due to difficulties to fill out the pain survey)