Ileal biopsy is most commonly performed for diagnosis of equine dysautonomia (grass sickness) and can be useful in investigating other intestinal disease processes. A biopsy can be obtained under general anaesthesia or, less commonly, via flank laparotomy or laparoscopy, which may be performed standing.
(1) Locate and exteriorise the proximal ileum by following the ileo-caecal fold from the caecum.
(2) It is usually only necessary to decompress the ileum in to the caecum to empty it of ingesta, however if necessary atraumatic intestinal clamps may be used.
(3) Approximately 8-10cm of ileum should be isolated with saline soaked swabs.
(4) A longitudinal full-thickness biopsy is obtained, 2-3 cm length by 3-4mm wide, approximately 1-2cm from and parallel to the antimesenteric border.
(5) Care must be taken to ensure that the mucosa and submucosa do not get separated form the muscular layers and serosa
(6) The incision is closed with absorbable 2 or 3 metric suture. Usually a continuous pattern is used in the mucosa, and a double inverting layer such as a cushing is performed in the seromuscular layers
(7) The antimesenteric band of the ileum may be included in the last layer to seal off the biopsy site and prevent a focus for adhesions
(8) The site irrigated with warm sterile saline.
(9) The intestine is returned to the abdomen, any further procedures/examinations completed and the laparotomy site closed.
- Peritonitis or adhesions
- Stricture (more likely with transverse rather than longitudinal biopsies)
(1) The biopsy sample should be place immediately into 10% buffered formalin (10:1 ratio of formalin to tissue volume)
(2) If urgent processing is required – please contact the lab as soon as possible to ensure the most efficient processing/reporting