INTRODUCTION: The rate of colorectal anastomotic leakage has remained unchanged for the last decades. The limitations of current anastomotic methods have generated an interest in alternative anastomotic techniques, such as compression anastomosis. The aim of this experimental study was to evaluate the early mechanical strength in left colonic anastomoses, comparing C-REX LapAid and circular stapled anastomotic methods. METHODS: A total of 48 pigs underwent open sigmoid resection with end-to-end colorectal anastomoses 15 cm above the anal verge, where 21 anastomoses were constructed with traditional circular staplers and 27 with the C-REX LapAid device. Bursting pressure was measured at different time intervals postoperatively through an attached anal plug while the upper limit of the bowel segment was closed with a bowel clamp. Early histological changes were assessed 6-24 h after the anastomotic formation with vascular CD31 and collagen Masson Trichrom staining. RESULTS: All animals recovered uneventfully after the surgical procedure. The circular stapled anastomoses exhibited a median bursting pressure of 36 mbar (28-64) at 1 h, 45 mbar (43-69) at 6 h, and 145 mbar (85-185) 12 h after surgery. In comparison, the C-REX LapAid anastomoses demonstrated a median bursting pressure of 195 mbar (180-240) at 1 h, 192 mbar (180-220) at 6 h, and 180 mbar (160-180) 12 h after surgery, representing a 2-5-fold higher median bursting pressure in the early anastomotic healing phase. Early microscopic architecture showed little evidence of vascular and collagen formation. CONCLUSION: The novel C-REX LapAid device demonstrated significantly higher bursting pressure values in the early phase of the anastomotic healing process compared to the circular stapled method. A clinical study to further verify the benefits of C-REX LapAid is warranted. INTRODUCTION: The rate of colorectal anastomotic leakage has remained unchanged for the last decades. The limitations of current anastomotic methods have generated an interest in alternative anastomotic techniques, such as compression anastomosis. The aim of this experimental study was to evaluate the early mechanical strength in left colonic anastomoses, comparing C-REX LapAid and circular stapled anastomotic methods. METHODS: A total of 48 pigs underwent open sigmoid resection with end-to-end colorectal anastomoses 15 cm above the anal verge, where 21 anastomoses were constructed with traditional circular staplers and 27 with the C-REX LapAid device. Bursting pressure was measured at different time intervals postoperatively through an attached anal plug while the upper limit of the bowel segment was closed with a bowel clamp. Early histological changes were assessed 6-24 h after the anastomotic formation with vascular CD31 and collagen Masson Trichrom staining. RESULTS: All animals recovered uneventfully after the surgical procedure. The circular stapled anastomoses exhibited a median bursting pressure of 36 mbar (28-64) at 1 h, 45 mbar (43-69) at 6 h, and 145 mbar (85-185) 12 h after surgery. In comparison, the C-REX LapAid anastomoses demonstrated a median bursting pressure of 195 mbar (180-240) at 1 h, 192 mbar (180-220) at 6 h, and 180 mbar (160-180) 12 h after surgery, representing a 2-5-fold higher median bursting pressure in the early anastomotic healing phase. Early microscopic architecture showed little evidence of vascular and collagen formation. CONCLUSION: The novel C-REX LapAid device demonstrated significantly higher bursting pressure values in the early phase of the anastomotic healing process compared to the circular stapled method. A clinical study to further verify the benefits of C-REX LapAid is warranted.