Lamichhane Ramesh, Gautam Misha, Fletcher Joel G, Bailey Kent R, Chen Jun, Feuerhak Kelly J, Bharucha Adil E
Mayo Clinic School of Graduate Medical Education, Mayo Clinic College of Medicine and Science, Rochester, Minnesota.
Department of Radiology, Mayo Clinic, Rochester, Minnesota.
Gastroenterology. 2025 Apr 30. doi: 10.1053/j.gastro.2025.04.013.
High-resolution anorectal manometry (HR-ARM) and fluoroscopic defecography, which are used to diagnose dyssynergic defecation (DD), are performed asynchronously and in different positions. This limits our understanding of the relationship between anorectal pressures and rectal evacuation and the diagnostic utility of HR-ARM. We aimed to assess anorectal pressures in isolation and synchronously with defecography.
We evaluated anorectal pressures during evacuation with left lateral HR-ARM, seated HR-ARM, and seated, concurrent fluoroscopic barium proctography/manometry (proctomanometry). Rectal evacuation was assessed with proctomanometry and rectal balloon expulsion time (BET).
Forty-two (86%) of 49 healthy (22 women) vs 25 of 55 (45%) constipated participants (28 women) evacuated ≥25% barium ("evacuators") (P < .001). During the preparatory phase of defecation, rectal and anal pressures increased concurrently; anorectal descent followed. During evacuation, the anal canal opened and evacuation occurred. During preparatory and evacuation phases, rectal pressure, anorectal descent, and widening of anorectal angle independently predicted evacuation (P < .05). During evacuation, the rectoanal gradient was (1) lower in participants with a prolonged BET and/or reduced rectal evacuation (P ≤ .001) and (2) greatest with proctomanometry, lower during seated HR-ARM, and lowest during left lateral HR-ARM (P < .001). Four clusters based on pressure and motion were associated with evacuator status and BET (P < .001).
Early events-increased rectal pressure (propulsive force), anorectal angle (puborectalis relaxation), and anorectal descent (perineal relaxation)-determine evacuation. Body position and rectal filling affect the rectoanal gradient. Most DD patients have both impaired propulsion and relaxation. Constipated patients with a prolonged BET and/or reduced evacuation have DD.
用于诊断排便协同失调（DD）的高分辨率肛门直肠测压法（HR-ARM）和荧光排便造影是在不同体位下异步进行的。这限制了我们对肛门直肠压力与直肠排空之间关系以及HR-ARM诊断效用的理解。我们旨在单独并与排便造影同步评估肛门直肠压力。
我们通过左侧卧位HR-ARM、坐位HR-ARM以及坐位同时进行荧光钡剂直肠造影/测压法（直肠测压法）来评估排便期间的肛门直肠压力。通过直肠测压法和直肠气囊排出时间（BET）评估直肠排空情况。
49名健康参与者（22名女性）中有42名（86%）与55名便秘参与者（28名女性）中的25名（45%）排出了≥25%的钡剂（“排出者”）（P <.001）。在排便准备阶段，直肠和肛门压力同时升高；随后是肛门直肠下降。在排便过程中，肛管打开并发生排便。在准备和排便阶段，直肠压力、肛门直肠下降和肛门直肠角增宽可独立预测排便情况（P <.05）。在排便过程中，直肠肛管压力梯度在以下情况时较低：（1）BET延长和/或直肠排空减少的参与者（P≤.001）；（2）直肠测压法时最大，坐位HR-ARM时较低，左侧卧位HR-ARM时最低（P <.001）。基于压力和运动的四个聚类与排出者状态和BET相关（P <.001）。
早期事件——直肠压力升高（推进力）、肛门直肠角（耻骨直肠肌松弛）和肛门直肠下降（会阴松弛）——决定排便情况。身体姿势和直肠充盈会影响直肠肛管压力梯度。大多数DD患者同时存在推进和松弛功能受损。BET延长和/或排便减少的便秘患者患有DD。
