Laparoscopic liver biopsy is the single most requested minimally invasive procedure in our hospital. Internists rarely perform fine-needle or needle-guided biopsy procedures because these methods frequently yield inadequate samples for interpretation. Laparoscopic approaches allow visual examination of internal organs, enable multiple biopsies and retrieval of larger tissue samples from the abnormal areas, and permit visual confirmation of hemostasis without the invasiveness of open surgery.
Preoperative Concerns Animals with hepatic disease may have coagulation defects. Preoperative platelet count, prothrombin time, and partial thromboplastin time and buccal mucosal bleeding time may help shed light on the nature of the defect. If indicated, vitamin K and fresh or frozen plasma may be given before the procedure; however, the presence of a coagulation defect is only a relative contraindication for laparoscopic liver biopsy.
Smaller incisions do not necessarily mean less risk for animals undergoing anesthesia. Laparoscopic liver biopsies are relatively short procedures, and general anesthesia is usually recommended. Airway control is important because the increased pressure from insufflation of the abdominal cavity can decrease lung volume and make it more difficult for animals to spontaneously ventilate. Monitoring pulse oximetry and end-tidal CO2 and providing assisted ventilation are recommended during these procedures.
Positioning & Preparation The animal can be positioned in dorsal or left-lateral recumbence. Each has its advantages. The dorsal positioning allows visualization of each of the liver lobes, but is complicated by the presence of the falciform ligament, which can obscure visualization. For multifocal or systemic disease, the left lateral approach is preferred. The surgical site is prepared and draped accordingly. The Box lists necessary equipment and supplies.
Author Insight Left lateral positioning is preferred for multifocal or systemic disease.
What You Will Need • Videolaparoscopy tower with camera, light source, insufflator, and recording device • 5-mm laparoscope • 2- to 5-mm trocars • 5-mm endoscopic cup biopsy forceps • 5-mm endoscopic blunt probe • Gelfoam absorbable gelatin sponge (pfizer.com) • Application device from a Surgitie pretied loop ligature (covidien.com) • Supplies: - Culture media - 10% formalin for histopathology - Microscope slides for impression cytology - Black-topped tube for metal analysis samples