Equine thoracoscopy: normal anatomy and surgical technique.

Six normal, healthy horses age 3-10 years underwent left and right thoracoscopic examination using a rigid telescope. A minimum of 30 days was allowed between procedures. Horses were restrained in stocks and sedated with a continuous detomidine infusion. After surgical preparation of the hemithorax elected for surgery, and administration of local or regional anaesthesia of the surgery sites, thoracoscopy was completed during two 15 min pneumothorax periods. During the procedures, the thoracic structures were viewed using a 57 cm, 10 mm diameter, 30 degrees rigid telescope connected to a digital camcorder to allow computer capture of digital images. The telescope was inserted into the thoracic cavity via 3 different intercostal spaces. The 8th, 10th and 12th intercostal spaces were randomly selected and used among horses. The exploration of each hemithorax started from the dorsal-caudal quadrant continued toward the cranial thorax and was completed by observing the diaphragmatic and caudal pulmonary region. Collapsed lung, aorta, oesophagus and diaphragm were viewed readily in either hemithorax. On exploration of the right hemithorax, the azygos vein, thoracic duct and pulmonary veins were also identified. Horses tolerated thoracoscopy well. Signs of discomfort, such as increased respiratory rate, coughing and decreased level of sedation, were associated with lung collapse in one horse, with pneumothorax on 2 occasions, and when the thorax was approached through the 8th intercostal space. Surgery performed via the 8th intercostal space was hindered by the rigidity of the 8th and 9th ribs, and by the presence of a greater musculature, which did not allow easy cranial and caudal movements of the telescope.

Cardiopulmonary effects of bilateral hemithorax ventilation and diagnostic thoracoscopy in dogs.

OBJECTIVE: To describe alterations in respiratory and cardiovascular variables during diagnostic thoracoscopy, using bilateral hemithorax ventilation with sustained pneumothorax. ANIMALS: 7 adult dogs. PROCEDURE: Each dog was anesthetized and instrumented for 2 episodes of cardiopulmonary monitoring that were performed at an interval of more than 14 days. The first anesthetic episode served as a control procedure for the thoracoscopy treatment performed during the second anesthetic episode. Multiple cardiopulmonary variables were evaluated by comparing changes from baseline values within treatments and between treatments. RESULTS: Arterial oxygen tension decreased significantly from baseline values during thoracoscopy but was unchanged during sham treatment. Arterial carbon dioxide tension, clinical shunt fraction, and systemic mean arterial pressure increased during thoracoscopy. In contrast, these variables were unaffected by the sham treatment. Heart rate and cardiac index increased during sham and thoracoscopy treatments; however, the increase was significantly greater during thoracoscopy. Total peripheral vascular resistance significantly decreased from baseline values for both treatments, but the decrease was greater during thoracoscopy. Significant changes were not observed for oxyhemoglobin saturation or pulmonary vascular resistance during either treatment. Dogs recovered without major clinical complications. CONCLUSIONS: Significant changes were found for several cardiopulmonary variables during bilateral hemithorax ventilation with sustained pneumothorax for diagnostic thoracoscopy of clinically normal dogs. CLINICAL RELEVANCE: Diagnostic thoracoscopy with bilateral hemithorax ventilation and sustained pneumothorax is well tolerated in clinically normal dogs and may provide a diagnostic modality enabling intrathoracic procedures with less morbidity than thoracotomy for dogs with intrathoracic disease.

Procedure for intrapleural implantation in mice by thoracotomy.

An intrapleural implantation procedure by thoracotomy was developed for application in mice. Animal survival was found to depend on the following: (A) slow induction and quick reversal of a pneumothorax by controlled pleural air injection and withdrawal, (B) keeping the pleura open for the shortest possible time by quick insertion of the implant and immediate tight closure with prepositioned sutures, and (C) use of the right, not the left, pleural cavity especially for maximum size implants which for a 30-gram mouse was 12 X 5 X 4 mm. Surgical and postsurgical mortality was below 5% (n = over 300).