Thoracoscopy

Thoracoscopy is the use of a rigid telescope and light source for visualization of the thorax (chest cavity) through small incisions.

The advantages of minimally invasive surgery of the thorax are self-evident, given the postoperative pain and morbidity associated with opening of the sternum or ribs during open chest surgery.

Indications for Thoracoscopy

Thoracoscopy is an excellent technique for thoracic exploration and biopsy in animals with pneumothorax (air in the chest), pleural effusion (fluid in the chest), mediastinal masses and focal or diffuse lung disease. One advantage to this technique is that the surgeon can view both sides of the chest cavity through a single, minimally invasive approach. Another common indication for thoracoscopic surgery is pericardiectomy in dogs with benign pericardial effusion.

Anesthetic concerns

Anesthetic concerns associated to thoracoscopic procedures are similar to those associated with open chest surgery. Thoracoscopy typically does not require insufflation, as penetration of the thoracic wall allows viscera to fall away from the rigid thoracic wall and permits safe excursions of instruments within the thorax. However, creation of a pneumothorax in this manner does require mechanical ventilation and close supervision of the patient. Monitoring should be performed with a pulse oximeter, arterial blood pressure, and blood gas analyses. In some hemithoracic procedures, selective intubation of one lung is performed to allow deflation of the contralateral lung and safe manipulation of instruments in the thoracic cavity. Selective intubation requires the use of a bronchoscope and is highly skill-dependent.

Specific procedures

Pericardiectomy:
There are several reasons for fluid accumulation in the heart sac (pericardial effusion), including cancer, infections and idiopathic (unexplained) causes. Many times, pericardial effusion can be treated by removing the fluid from the heart sac with ultrasound imaging guidance. Unfortunately, recurrence of fluid accumulation is relatively common, causing signs of collapse and fluid backup into the abdomen. Recurrent pericardial effusion can be successfully treated by removal of the pericardial sac, allowing fluid to be reabsorbed by the lining of the chest cavity. Traditional pericardiectomy techniques involve making a large incision in the chest wall ad retracting the rib to gain access to the heart. Thoracoscopic techniques allow safe and effective removal of a portion of the pericardial sac, allowing long term resolution of pericardial effusion in most dogs. The technique can be performed through 3 incisions that are less than 1cm in diameter, minimizing pain and expediting recovery from surgery.

Lung biopsy:
Lung biopsy can be performed safely and with minimal pain using thoracoscopic techniques. Lung biopsy may be performed using either the subxyphoid approach (under the sternum) or the intercostal (between the ribs) approach. After the camera is placed in a subxyphoid position, the lungs are examined to locate appropriate sites for biopsy. After obtaining a biopsy, a thoracostomy tube is placed to allow removal of air from the chest cavity after surgery.