Videoendoscopy: an effective and efficient way to perform multiple visceral biopsies in small animals

Because major surgery is usually required to obtain biopsies of abdominal organs, regulations tend to limit the number of procedures on individual animals to one. This study was conducted to develop a more humane, minor, comparatively cost-effective, minimally invasive surgical procedure, which reduces surgical trauma and the number of animals used. Biopsy techniques were developed in two nonsurvival rabbit surgeries. Safety and efficacy of multiple procedures were assessed in survival studies on four rabbits. Anesthesia was induced with ketamine/xylazine and maintained with isoflurane. Initial carbon dioxide insufflation (6 mmHg) was achieved through a Veress needle. A triangulated 5-mm port technique allowed introduction of pediatric 3.5- to 5.0-mm laparoscopic instruments. Biopsies of liver, spleen, kidney, and full-thickness bowel were obtained and evaluated for suitability (size) for polymerase chain reaction, in-situ hybridization, and histopathology studies. Animals in survival studies were assessed for infection, pain, bleeding, adhesion development, bowel function, and intestinal stenosis. All had normal appetite and stools within 48 h postoperatively. Biopsies obtained from either a Tru-Cut Biopsy Needle, 3.5- to 5.0-mm biopsy cups, or with the aid ofa pre-tied loop were adequate for all studies. There was no postoperative bowel obstruction, wound infection, or bleeding. Mean hematocrit decrease at 24 h postoperative was 3.4% +/- 6.7%. Adhesions formed at 9/52 (17%) evaluable sites. Multiple visceral organ biopsy under videoendoscopic guidance constitutes a minor procedure and is a promising means for longitudinal studies in animals. Utility for ill animals remains to be determined.