Ultrasonic measurement of rectal diameter and area in neurogenic bowel with spinal cord injury

Abstract

Objective: The aim of this study was to determine the efficacy of measuring the diameter and area of the rectum using ultrasonography as an additional parameter for the evaluation of neurogenic bowel in patients with spinal cord injury (SCI). Participants: In total, 32 patients with SCI (16 patients with upper motor neuron neurogenic bowel (UMNB) and 16 patients with lower motor neuron neurogenic bowel (LMNB)) participated in this study. We divided the patients by the type of neurogenic bowel: UMNB, patients with supraconal lesions and recovery state of spinal shock or LMNB, patients with infraconal/caudal lesions or spinal shock state). Intervention: Ultrasound was applied on the abdomen and measured the diameter and area of the rectum were measured twice each before and after defecation, respectively. Outcome measure: We compared rectal diameter and area before/after defecation between the two groups, and significant differences were found in both rectal diameter and area before/after defecation in each group. Results: After defecation, those in the UMNB group had smaller rectal diameters and areas than those in the LMNB group. Significant reduction of rectal diameter and area was observed after defecation as well. The LMNB group showed slightly increased rectal area after defecation, but the increase was not statistically significant. Conclusion: Using ultrasound to measure rectal diameter and area seems helpful for classifying neurogenic bowel types and for understanding the neurogenic bowel among SCI patients with symptoms of neurogenic bowel.

Research on biomechanical compatibility for a novel artificial anal sphincter with constant force

“…The external anal sphincter is a circular muscle bundle around the internal anal sphincter, which can expand the anus at will. Studies have shown that the mean rectal diameters are before defecation and after defection 19 …”

“…The constitutive parameters of the finite element model about the rectum in this article were determined by the existing related studies 20 . The size parameters and material parameters of the simplified rectal model are shown in Table 1 19–21 …”

“…Studies have shown that the mean rectal diameters are 4.49 ± 0.62 cm before defecation and 4.01 ± 0.54 cm after defection. 19 The laminar structure of rectal tissue mainly includes the mucosal layer, submucosa, muscle layer, and adventitial layer, and its components are mainly composed of elastic fibers, collagen fibers, and smooth muscle, as shown in Figure 1B. The greatest mechanical properties of the rectum are nonlinear mechanical behavior and obvious viscoelasticity, which are determined by the elastic fibers, collagen fibers, and smooth muscle.…”

Preliminary study of a novel artificial anal sphincter with perception reconstruction

“…Studies have shown that the average diameter of the rectum in adults is about 20 mm 20 . Since each swing arm is composed of two short rods in equal length, the length of rod is set as .…”

“…Studies have shown that the average diameter of the rectum in adults is about 20 mm. 20 Since each swing arm is composed of two short rods in equal length, the length of rod is set as l. The angle between the middle ring and the upper ring is . The defecation state is shown in Figure 2.…”