Histopathologic advantages of compression ring anastomosis healing as compared with stapled anastomosis in a porcine model: a blinded comparative study.

Background: The performances of compression and stapled devices were compared previously in porcine colorectal anastomosis. The compression anastomosis was associated with elevated bursting strength and anastomotic patency in this model as compared with the stapled anastomosis.

Objective: The purpose of this work was to compare the histopathologic features between compression and stapled methods in the healing of colorectal anastomoses using a porcine model.

Design: This was a blinded comparison study.

Settings: The study was conducted at a single university surgery department.

Patients: Fifty crossbred pigs were used in this study.

Main Outcome Measures: Fifty crossbred pigs underwent rectal transection 20 cm from the anal verge and end-to-end compression or stapled anastomosis. The anastomotic tissues were harvested 3, 7, 30, and 90 days postoperatively (n = 5-6). Tissue repair parameters associated with the wound healing were analyzed using image analysis morphometry and histological architecture assessments.

Results: A different microscopic pattern of the anastomotic area was shown between groups. Foreign body response was rated (p < 0.001) as minimal in the compression and moderate in the stapled group. The scarring area in the compression anastomosis group, on postoperative day 90 (4 ± 3 × 10(5) μm) was lower (p = 0.016) than in the stapled group (2 ± 1 × 10(6) μm). In addition, the anastomotic line was narrower (p = 0.003) 90 days after surgery in the compression samples (0.77 ± 0.20 mm) compared with that in the stapled group (1.86 ± 0.19 mm). Lastly, in terms of inflammatory cells, the compression biopsies showed lower (p < 0.001) numbers of mononuclear cells, polymorphonuclear cells, and lymphocytes in the anastomotic tissues 30 and 90 days from surgery.

Limitations: The long-term effect of the compression technique on the anastomotic patency in colorectal anastomoses should be further investigated in human studies.

Conclusions: Compression anastomotic healing was associated with less foreign body reactions, scarring, and inflammation as compared with stapled anastomoses in a large animal model.