Ex vivo comparison of full-thickness biopsy techniques in the equine small intestine.

Objective: To compare the practicability and tissue sample quality between different intestinal biopsy techniques.

Study design: Experimental, randomized ex vivo study.

Sample population: Small intestine of nine horses.

Methods: Four different biopsy techniques were evaluated in the aboral jejunum and the ileum within 1 h after euthanasia. One segment was used as control (C), and the applied techniques included an 8 mm biopsy punch (BP), transverse wedge resection (TW), longitudinal wedge resection with transverse closure (LW) and a longitudinal sample using Eppendorfer biopsy forceps (EF). Defects were closed using a single-layer continuous Lembert pattern. Duration of the procedure, intestinal diameter, contamination, and bursting pressure were determined. The quality of the obtained tissue samples for histological assessment was evaluated using a semiquantitative score. The jejunal and ileal samples were analyzed separately.

Results: All biopsy procedures including defect closure were completed within 5 min, with shorter closure times for BP (p = .03). Minimal contamination could be noted in 1/8 TW and 2/8 LW cases, without significant differences between the groups. Longitudinal closure techniques (BP, EF) showed more constriction than transverse closures (TW, LW) (p < .05). Bursting pressure was >75 mmHg in all cases. Technique BP showed significantly lower biopsy quality scores (p = .009).

Conclusion: The tested biopsy techniques could all be applied effectively within a reasonable time frame, yet the biopsy punch was associated with significant artifacts and risk of missing mucosa.

Clinical significance: The findings provide insights into the possible advantages and limitations of the different techniques and alert the surgeon to potential issues with the quality of the tissue sample.