Lung Cancer Surgery and Mediastinal Tumours by VATS or Robot

Most lung cancer surgery, including operations for large tumours, tumours invading the chest wall and central tumours needing a pneumonectomy or sleeve lobectomy, can be done by video-assisted thoracoscopic surgery (VATS) or robotic surgery. Dr. Shaiwal Khandelwal, Director - Thoracic Surgery, Max Hospital, Gurugram, India, adds a systematic mediastinal lymph node dissection to every resection and typically discharges robotic lobectomy patients on day three.

The same minimally invasive platforms now handle most tumours of the mediastinum, the central compartment of the chest, including thymectomy for myasthenia gravis. This article covers both. The wider specialty is summarised in the complete guide to thoracic surgery from basics to robotics, and pleural and benign lung disease is covered in empyema, pneumothorax and benign lung surgery by VATS.

Lung cancer surgery by VATS and robotics

VATS uses a camera and long instruments passed through small incisions between the ribs. Robotic surgery uses the same small incisions, but the surgeon controls wristed instruments and a high-definition three-dimensional camera from a console. In Dr. Khandelwal's practice, most lung cancer surgery is done by one of these two routes, whatever the size of the tumour.

The extent of resection depends on the stage:

• Lobectomy: removal of one lobe of the lung, the standard operation for most operable lung cancers.
• Segmentectomy: removal of one or more anatomical segments within a lobe, which preserves more lung.
• Pneumonectomy: removal of an entire lung, reserved for tumours that cannot be cleared any other way.

Whatever the resection, it is followed by an extensive, systematic mediastinal lymph node dissection in every lung cancer case.

Many tumours are found by chance

The robotic case he demonstrated was a mass of around 4 cm in the right lower lobe. In his experience, many lung cancers are detected incidentally, when the patient has been investigated for some other problem.

Robotic lobectomy: why the lymph nodes come first

In his practice the systematic mediastinal lymph node dissection is done at the start of a robotic lobectomy, not at the end. He begins with the inferior mediastinal nodes and the subcarinal nodes, the packet below the point where the trachea divides, clearing it until both the right and left main bronchi are visible. He then moves to the upper (right paratracheal) nodes, dissecting alongside the superior vena cava and the phrenic nerve.

The advantage is practical. Clearing the nodes automatically exposes the bronchovascular structures, the bronchus, pulmonary artery and pulmonary veins of the lobe, so the lobectomy itself proceeds with ease.

Steps of a robotic right lower lobectomy

1. The fissure is dissected until the pulmonary artery branches are visible at its base.
2. The posterior fissure is completed with a stapler.
3. The pulmonary artery branches to the right lower lobe are looped and stapled.
4. The inferior pulmonary vein is looped and stapled.
5. The right lower lobe bronchus is looped and the stapler is closed across it, but not fired. The anaesthetist inflates the lung: if the upper and middle lobes expand fully, the middle lobe bronchus has not been caught, and only then is the stapler fired.
6. The specimen is placed in a bag and delivered, the chest is washed out and the bronchial stump is checked for any air leak.
7. Intercostal nerve blocks are given for pain control.

The drain is removed after 48 hours and the patient is discharged on the third day.

Lung-preserving surgery: sleeve resection instead of pneumonectomy

Dr. Khandelwal describes himself as a great fan of lung-preserving surgery. For central tumours that reach the main airway, his preference is a sleeve resection: the lobe is removed together with a ring of the main bronchus, and the remaining airway is rejoined, so the patient keeps the rest of the lung rather than losing it to a pneumonectomy.

One case shows what is at stake. A medical student had a carcinoid tumour, a slow-growing neuroendocrine tumour, arising from the left upper lobe bronchus and extending into the left main bronchus. Bronchoscopy showed that clear margins might have required a left pneumonectomy. Instead, the team performed a left upper lobe sleeve resection: the left upper lobe was removed and the left main bronchus was joined directly to the left lower lobe bronchus. A postoperative bronchoscopy showed a very good anastomosis, and at seven years after surgery she had no recurrence.

Lung metastasectomy by laser

Lung metastasectomy, the removal of cancer that has spread to the lungs from elsewhere, is indicated when the disease is limited to the lungs and all the metastases can be removed. In one of his patients the lung metastases came from a malignant bone tumour, and the team resected them with a laser. The advantage of laser resection is that very little normal lung is sacrificed, and the lung tissue is not distorted in the way that staple lines can distort it.

Diagnosing enlarged mediastinal lymph nodes: EBUS, VATS biopsy and mediastinoscopy

The mediastinum is the central compartment of the chest, between the two lungs, behind the sternum and in front of the spine. Enlarged mediastinal lymph nodes (mediastinal lymphadenopathy) can be caused by cancer, tuberculosis or other diseases, and the diagnosis depends on obtaining enough tissue.

EBUS first

Endobronchial ultrasound (EBUS), a bronchoscope with an ultrasound probe that guides a needle into nodes next to the airway, is today the best first test for undiagnosed mediastinal lymphadenopathy.

VATS mediastinal lymph node biopsy

When EBUS is inconclusive, Dr. Khandelwal performs a VATS mediastinal lymph node biopsy. This reaches all the lymph nodes on the same side of the chest, including the subcarinal and paratracheal nodes. Because the whole lymph node packet is removed and handed to the pathologist, the amount of tissue is never the limiting factor.

Video mediastinoscopy

The alternative is video mediastinoscopy. Through a small incision in the neck, the surgeon samples the lymph nodes on both sides: the upper and lower paratracheal nodes and the subcarinal nodes. It is a day-care procedure: the patient is admitted in the morning and the mediastinoscopy is done the same day. Whole lymph nodes can be removed, and in his words there is no way the procedure will fail to give an answer.

Thymectomy for myasthenia gravis

In myasthenia gravis, an autoimmune disease that causes fatigable muscle weakness, removing the thymus gland (thymectomy) is an established treatment, whether or not the patient has a thymoma (a tumour of the thymus).

The operation Dr. Khandelwal performs is radical. The whole thymus, including any tumour, and all the pre-pericardial fatty tissue from the neck to the diaphragm and between the two phrenic nerves is removed, by VATS or robotics. With a bilateral VATS approach, the gland is dissected first from the left side and then from the right, and both thymic horns are excised, with the brachiocephalic vein visible underneath.

The robotic subxiphoid approach

The latest approach is robotic, through the subxiphoid space, a midline entry just below the lower end of the sternum. Its advantage is the view: both phrenic nerves can be seen at the same time, and the neck is well visualised. In his assessment this approach has greatly enhanced both the radicality and the safety of thymectomy. Specimens are placed in a bag and removed through a port.

Robotic surgery near nerves and major vessels

The robot's main strength, in Dr. Khandelwal's view, is vision. Nerves that are difficult to identify by VATS are seen very clearly through the robotic system, which also allows a very fine dissection, so the nerves are better identified and better protected.

Mediastinal parathyroid adenoma

A parathyroid adenoma, a benign tumour that overproduces parathyroid hormone, sometimes lies in the mediastinum rather than the neck. Once it has been localised on a sestamibi scan, a nuclear medicine scan that picks up overactive parathyroid tissue, it can be removed by VATS or robotics.

Tumours at the thoracic outlet

The thoracic outlet, the narrow passage at the top of the chest through which the subclavian vessels and nerves pass to the arm, is a very delicate area, and Dr. Khandelwal regards the robot as a great tool there. An overseas patient had a tumour at the left apex of the chest closely abutting the left subclavian artery and vein. It was a high-grade tumour arising from the sympathetic chain, so it had to be removed completely with negative margins, and the sympathetic chain was resected with it. The high-definition three-dimensional vision and wristed movement of the robotic system allowed the team to do this safely, with the subclavian vessels lying just behind the tumour, and the patient was discharged the very next day.

Mediastinal tumour removal: cysts, leiomyoma, teratoma and neurogenic tumours

• Bronchogenic and oesophageal duplication cysts, congenital cysts of the middle mediastinum, can be removed by VATS or robotics.
• Oesophageal leiomyoma, a benign smooth-muscle tumour of the oesophageal wall, can be removed by VATS or robotics whatever its size.
• Teratomas, germ-cell tumours of the mediastinum, are removed by VATS.
• Pericardial cysts are resected, and pericardial windows (drainage of fluid around the heart into the chest) are created by the same minimally invasive route.

Neurogenic tumours

Neurogenic tumours, arising from the nerves along the spine, are very common in the posterior mediastinum. In one case a 12 cm neurogenic tumour sat just above the diaphragm on the left side. The pleura over the tumour was excised. Such tumours usually draw their blood supply from the intercostal vessels, which the robotic system showed clearly. The tumour encased a segment of the azygos venous system, which was clipped above and below and divided as part of the resection.

Boerhaave syndrome treatment: a thoracic emergency

Boerhaave syndrome is a spontaneous rupture of the oesophagus caused by retching or forceful coughing against a closed glottis. The tear is usually at the lower end of the oesophagus, on the left side, and the leak can spread into the chest: the patient he described had developed a left-sided empyema. It is a very dangerous condition that must be identified and treated promptly.

Dr. Khandelwal's approach is minimally invasive. In one patient, the first step was endoscopy and stenting: a large tear at the lower end of the oesophagus was sealed with a stent to control the leak. The patient was then taken to the operating theatre, where the mediastinal collection was drained and debrided. The patient was discharged after seven days, and the stent was removed after six weeks.

Oesophageal cancer and oesophagectomy are a different field, covered in depth in the complete guide to oesophageal cancer diagnosis and treatment, with the operation itself, including minimally invasive and robotic oesophagectomy, set out in locally advanced oesophageal cancer treatment and surgery.

The pattern across cancer and mediastinal surgery

Three choices recur through these operations: clear the lymph nodes first and use the exposure to make the resection safer; preserve lung wherever the cancer allows it; and use the robot where vision and fine dissection matter most, around nerves, major vessels and the thoracic outlet. Dr. Khandelwal's answers to doctors' questions on robotic nerve protection are recorded on the Live Discussion page, the wider specialty is on the thoracic surgery hub, and his work on hyperhidrosis is covered in robotic hyperhidrosis surgery and ETS reversal.