To investigate the impact of the triple-layered circular stapler compared with the double-layered circular stapler on anastomotic leakage after rectal cancer surgery.

The bursting pressure was compared between porcine ileocolic anastomoses created using a double- or triple-layered stapler. We also retrospectively analyzed the incidence of severe anastomotic leakage in 194 patients who underwent colorectal anastomosis using a double- or triple-layered circular stapler during rectal cancer resection performed in two cancer centers between January 2015 and April 2021.

In the porcine model, the bursting pressure was higher in anastomoses created using the triple-layered stapler than the double-layered stapler (end-to-end anastomosis: 26.4 ± 6.2 mm Hg vs 14.5 ± 4.3 mm Hg, P = .0031; side-to-side anastomosis: 27.7 ± 5.0 mm Hg vs 18.0 ± 2.9 mm Hg, P = .0275). Intersectional leakage occurred in 41% and 83% of anastomoses created using the triple- or double-layered stapler, respectively (P = .0821). In the clinical cohort, the double- and triple-layered stapler was used in 153 and 41 patients, respectively. The incidence of anastomotic leakage was lower for anastomoses created using the triple-layered stapler vs the double-layered stapler (0.0% vs 5.8%, P = .0362). In multivariate analysis, the factors independently associated with a lower incidence of anastomotic leakage were female sex (odds ratio: 0.16, 95% confidence interval: 0.01-0.90, P = .0354) and triple-layered stapler usage (odds ratio: 0.00, 95% confidence interval: 0.00-0.96, P = .0465).

Anastomoses created using a triple-layered circular stapler had high bursting pressure, which might contribute to a lower incidence of anastomotic leakage after rectal cancer surgery.

Anorectal manometry (ARM) provides comprehensive assessment of pressure activity in the rectum and anal canal. Absolute pressure values might depend on the catheter used.

Our aim was to compare the results obtained by different anorectal catheters in children with functional anorectal disorders.

Children diagnosed with functional defecation disorders based on the Rome IV criteria were prospectively enrolled. ARM was performed in the supine position successively using 2 different probes in each patient in random order. Resting, squeeze pressures, and bear-down maneuver variables obtained by high-resolution (2-dimensional [2D]) and high-definition (3-dimensional [3D]) catheters were compared.

We prospectively included 100 children {mean age 7.5 [standard deviation (SD) ± 4.3] years; 62 boys}. Mean resting pressures were significantly higher when measured with the 3D than with the 2D catheter (71 [SD ± 19.4] vs. 65 [SD ± 20.1] mm Hg, respectively; p = 0.000). Intrarectal pressure measured by 3D and 2D catheters was similar (35 vs. 39 mm Hg, respectively; p = 0.761), but the percent of anal relaxation appeared to be higher for the 3D than for the 2D probe (12 vs. 5%, respectively; p = 0.002). Dyssynergic defecation (DD) was diagnosed in 41/71 patients (57.7%) using the 3D probe and in 51/71 children (71.8%) using the 2D probe (p = 0.044). Cohen's kappa showed only fair agreement between the catheters (κ = 0.40) in diagnosis of DD.

Our study demonstrated significantly different values of pressures obtained with different types of catheters. Normal ranges for conventional manometry cannot be applied to high-resolution systems, and results obtained by different types of manometry cannot be compared without adjustments (NCT02812823).