Thoracoscopic Lung Biopsies in Heaves-Affected Horses Using a Bipolar Tissue Sealing System

To validate the use of the LigaSure[trade mark sign] Vessel Sealing System (LVSS) to perform thoracoscopic lung tissue biopsies in heaves-affected horses. Prospective clinical study. Heaves-affected horses (n=12). Lung biopsies (n=34) were collected with the LVSS (2-4 biopsies/horse) in horses with and without clinical signs of heaves. Thoracoscope (13th intercostal space [ICS]) and 2 instruments (between the 12-15th ICS) portals were used. Selected clinical and arterial blood gas variables were monitored. Postoperative pneumothorax was evaluated. Depth of thermal injury to the surrounding tissue and representativeness of the biopsies were determined. Mean surgical time was 22.9±8.0 minutes. The complication rate was 5.6%, and primarily related to a focal inadequate sealing of the biopsy margin. Five horses in exacerbation required intraoperative intranasal O₂. Mean PaO₂ was significantly lower in heaves-affected horses with clinical signs compared with those without clinical signs. Postoperative pneumothorax was detected radiographically after 20 of the 34 procedures. One horse with clinical signs of heaves developed a fatal tension pneumothorax 5 days postoperatively despite close radiographic monitoring. Thoracoscopic lung biopsy using LVSS is a rapid and effective technique to harvest peripheral lung tissues from heaves-affected horses. Although the complication rate was tolerable, tension pneumothorax was a potential life-threatening complication because of incomplete lung sealing. LVSS can be used with relative safety to perform thoracoscopic lung biopsy, but close postoperative monitoring is necessary to avoid tension pneumothorax.