Video Assisted Thoracoscopic Surgery is a procedure involving internal examination, biopsy, and /or resection of disease or masses within the thoracic cavity (chest). In simple terms, it is the equivalent in the chest of “laparoscopy” in the abdomen. Visualization and diagnosis is greatly enhanced when the images are magnified and displayed on a TV screen (Video assisted Thoracoscopy or VATS)
History of Video Assisted Thoracoscopic Surgery:
Thoracoscopy was first developed by Hans Christian Jacobaeus, a Swedish Physician in 1910 for the treatment of tuberculous intra-thoracic adhesions. He used a cystoscope to examine the thoracic cavity and progressively refined his technique over the next twenty years. Today, thoracoscopy is performed using specialized video assisted thoracoscopes. These instruments include a light source and a telescope for viewing and may have additional ports through which other instruments may be inserted for the purpose of tissue biopsy / resection and visualisation.
A wide variety of diagnostic and therapeutic procedures may be performed with this technique which has become very popular since the early 1990s. Around that time, instruments such as endoscopic stapler devices, scissors, grasping, and biopsy forceps were developed for thoracoscopic surgical interventions. The development of endoscopic video systems and instrumentation lead to its widespread use by Pulmonologists and Thoracic Surgeons.
Prior to this period, limited diagnostic procedures were done using variations of the cystoscope. Advances in direct optical visualization were quickly multiplied many folds when multiple chip video cameras were incorporated into the endoscopes. The advent of endoscopic stapling was also a major advance so that complicated procedures such as pulmonary resections could be performed safely.
Indications for Video Assisted Thoracoscopic Surgery:
Video Assisted Thoracoscopic Surgery approach was initially used for simple diagnostic and therapeutic procedures involving the pleura, lungs, and mediastinum. However, VATS operations continue to replace many procedures that formerly required thoracotomy. For example, pulmonary operations using VATS have evolved from simple wedge and segmental resections to complete lobectomy. In selected patients, a VATS lobectomy is a reasonable alternative to thoracotomy for both adults and children.
Video Assisted Thoracoscopic Surgery can be used for all structures in the chest, and are not limited to the lungs, pleura and mediastinum. The heart and great vessels, the esophagus and diaphragm, the spinal column and nerves can all be operated on using VATS . Each year has seen new, innovative applications of the technique. For example, intractable pain as a result of chronic pancreatitis can now be treated by inactivation of the major afferent pain nerves with the use of thoracoscopic splanchnicectomy. The current indications for Video Assisted Thoracoscopic Surgery procedures are:
General Thoracic Cavity
Diagnostic biopsy of any intrathoracic structure
Laser application for treatment of tumors
Diagnosis and drainage of pleural effusions (commonest indication)
Debride empyema Retrieval of intrathoracic foreign body
Wedge resection, segmentectomy, lobectomy
Identification of site of broncho-pleural fistula
Lysis of adhesions
Excision of mediastinal cysts
Resection of posterior mediastinal neurogenic tumors
Esophagus and diaphragm
Tumor staging or resection
Heart and great vessels
Pericardectomy / Pericardial biopsy
Ligation of patent ductus (infants)
Spine and nerves
Dorsal thoracic sympathectomy
Evacuation of clot
Technique for Video Assisted Thoracoscopic Surgery.
Patients are positioned in the lateral decubitus position, with normal lung in the dependent position. The optimal point of entry depends on the patient’s suspected disease; for pneumothorax, a higher point of entry is chosen (third or fourth intercostal space), as most abnormalities in this disease (blebs and bullae) is at the apex of the lung.
In case of suspected malignancy, a lower point of entry is preferred (sixth or seventh intercostal space), as most pleural malignancies are expected to be found in the lower area of the pleura 16. The optimal point of entry is localized in the midaxillary line because there are no large muscles to be passed by the trocar in this area. Some authors advise the creation of a pneumothorax a few hours or even the day before the video assisted thoracoscopic surgery. This technique may reduce blood flow in the periphery of the lung, and may prevent damage to the lung after the introduction of thoracoscopy instruments.
In our experience, the direct introduction of a blunt trocar into the thoracic wall, without prior induction of a pneumothorax, is safe and effective. Very occasionally, introduction of the trocar can be troublesome in the case of pleural adhesions. Therefore, introduction of the trocar is performed slowly and carefully. After the passage of the trocar through the parietal pleura and removal of the obturator, the pleural cavity is exposed to atmospheric pressure.
As a consequence of unopposed elastic recoil, the lung collapses, resulting in paradoxical respiration. During inspiration the upper lung will collapse, which causes entry of air through the trocar. The spontaneously breathing patient may have impaired gas exchange as a result of paradoxical respiration and mediastinal shift.. Therefore supplementary oxygen is administered.
Single vs Multiple Entry Points
From the patient’s viewpoint, the single entry technique for video assisted thoracoscopic surgery is preferred, especially under local anaesthesia. Discomfort due to pain and stitches is limited to a single incision of 1.5 cm, which is the same as for chest tube insertion. Most cases of diagnostic video assisted thoracoscopic surgery can be performed with a single port of entry.
After inspection of the pleura, the optical telescope is replaced by the optical biopsy forceps, consisting of forceps with an attached telescope, which allows the thoracoscopist to take biopsies under direct visual control. Another alternative is using the “operative thoracoscope” (the “bayonet” thoracoscope, (available at KG Hospital) which allows large biopsies to be taken under visual control with a single port of entry.
In the double-entry technique, the optical telescope is not removed, but a second port of entry is created under visual control. Biopsy forceps are introduced through a second (smaller) trocar. The advantage of the double-entry technique is a better view when biopsies are taken, and the possibility ofobtaining biopsies with electrocautery sealing, which is of advantage when biopsies are taken of the visceral pleura.
Anesthesia for Video Assisted Thoracoscopic Surgery:
Thoracoscopy procedures are most often performed under general anaesthesia with double lumen intubation. However, some relatively simpler diagnostic procedures can be performed under local anaesthesia. Some centres use local anaesthesia with “conscious sedation”. This refers to patients who remain awake or arousable during the procedure, while given mild anxiolytics and pain medications. There is no consensus in the literature on the appropriateness of performing thoracoscopy under local anaesthesia.
Considerations which may help in choosing the most suitable anaesthetic technique for thoracoscopy include the following. 1) The choice of the patient, those afraid of invasive medical procedures should be offered general anaesthesia. Children and patients with learning difficulties should be treated under general anaesthesia in all circumstances. 2) The suspected duration and type of thoracoscopy; when a procedure is suspected to be long or painful, e.g. multiloculated empyema, general anaesthesia is preferred.
Potentially painful procedures are those with more than two ports of entry, or procedures followed by chemical pleurodesis. Although very effective, talc poudrage is known to be painful, especially in younger patients. Painless talc poudrage can be performed with intravenous propofol and morphine in a spontaneously breathing patient.
Complications of Video Assisted Thoracoscopic Surgery:
Thoracoscopy is generally a very safe procedure when performed by an experienced Pulmonologist or a Thoracic Surgeon. Rarely subcutaneous emphysema, prolonged airleak, fever, excessive bleeding, and air embolism can occur. In properly selected patients, thoracoscopy under local anaesthesia is also very safe.
Contraindications for Video Assisted Thoracoscopic Surgery:
Most complications can be avoided by proper selection of patients for thoracoscopy. Patients with severe chronic obstructive pulmonary disease and consequent respiratory insufficiency, with hypoxaemia and hypercapnia, will not tolerate induction of a pneumothorax without further deterioration of the gas exchange, and therefore may not suitable candidates for thoracoscopy.
When there is a contralateral lung or pleural involvement, thoracoscopy is not advisable, unless general anaesthesia and endotracheal intubation are used. Patients with unstable cardiovascular status should not undergo thoracoscopy before a thorough evaluation by a Cardiologist. Cough, fever and infection are relative contraindications for thoracoscopy.
In Conclusion, Video Assisted Thoracoscopic Surgery……
The need for Video Assisted Thoracoscopc Surgery should be considered carefully in severe pulmonary fibrosis as, after induction of a pneumothorax, it can be difficult to re-expand the lung due to the loss of elasticity of the pulmonary tissue. Lung biopsy where honeycombing is present may result in prolonged leakage and impaired re-expansion of the lung. A Lung biopsy should be avoided in hydatid cysts, arteriovenous malformations and other highly vascularized lesions.
Coagulation defects should be corrected before video assisted thoracoscopic surgery. VATS will not be possible in the case of complete symphysis of the visceral and parietal pleura. In the case of pleural adhesions, it is possible to create a pleural space by extended thoracoscopy. However, this technique should only be performed by experienced thoracoscopists. Dr S.K. Varma is an expert in VATS and is available for consultation at the Heart and Lung Clinic, Coimbatore.