Thoracoscopic approaches, techniques and clinical indications

Thoracoscopy has gained popularity in recent years as more surgeons are familiar with the techniques and instrumentation used for laparoscopic procedures. Thoracoscopy can be used for obtaining biopsies of lung or intrathoracic masses, assessment and treatment of pleuritis or pleuropneumonia, assessment and treatment of thoracic trauma or aid in the repair of diaphragmatic hernias. Case selection and management are important and pre-operative preparation is crucial to the successful management of the surgical procedure. Thoracoscopy can be performed standing or under general anaesthestic. General anaesthesia is commonly reserved for diaphragmatic hernia repair whilst most other procedures can be performed safely in the standing and sedated horse. Recently a report of standing diaphragmatic hernia repair has been published and if the hernia is dorsally located this technique would be preferred (Rocken et al 2013).

The sedation of horses for standing thoracoscopy is relatively standard with a constant rate infusion of detomidine being the most common with the addition of butorphanol if required. It is recommended to maintain the level of sedation relatively light to minimize cardiovascular depression. What is necessary in the preparation of thoracoscopic patients compared to laparoscopic patients is the provision of nasal insufflation with oxygen and the availability of suction, otherwise the instrumentation and set-up are similar. As a pneumothorax is induced during the procedure the suction is used to regulate the extent of the pneumothorax and remove the air in the event of respiratory distress or at the end of the procedure. Having an intravenous catheter placed beforehand is strongly recommended to facilitate the rapid delivery of drugs as necessary. Local anaesthesia is used at the location of the various portals both subcutaneously and in the intercostal muscles. When contemplating performing thoracoscopy under general anaesthesia careful preparation needs to be had and the involvement of an anaesthesiologist is highly recommended. One lung ventilation has been performed in horses but is not common and at the minimum plans need to be made for mechanical ventilation and respiratory support during the recovery period. Avoiding these complications by performing the procedure standing when possible is recommended. [...]