Department of Veterinary Clinical Medicine, University of Illinois Urbana-Champaign, Urbana, IL, USA.
Equine Vet J. 2020 Nov;52(6):876-883. doi: 10.1111/evj.13267. Epub 2020 Apr 30.
Diseases affecting the internal umbilical remnant are common in foals. Ultrasound is used to diagnose abnormalities of these structures, and to monitor treatment. However, little is known about the progression of normal internal umbilical remnant regression.
To document normal regression of the umbilical remnant in foals over the first 6 weeks of life.
Prospective, longitudinal cohort study.
Weekly ultrasound examinations were performed beginning at 1 day of age in 34 healthy Standardbred foals. The umbilical vein was measured in cross section just cranial to the external umbilicus, at the level of the liver and midway between these points. The umbilical arteries were measured in cross section just caudal to the external umbilicus, at the apex of the bladder and at the midpoint of the bladder. The urachus was imaged longitudinally as it exited the bladder. Reduction in size over time was evaluated as percentage change in diameter.
Structure diameter decreased linearly over time. The largest measurements were at 24 hours of age with a median umbilical vein diameter of 0.83 cm (IQR 0.77-1.02 cm), median umbilical artery diameter of 0.61 cm (IQR 0.56-0.70 cm) and median urachal diameter of 1.07 cm (IQR 1.02-1.14 cm). There was a significant reduction in diameter for all structures (16.0%-21.9%; corrected P < .001) within the first week of life.
All foals were of a single breed, and examinations and measurements were performed by multiple individuals.
The internal umbilical remnants (umbilical vein/arteries, and urachus) rapidly regress over the first few weeks of life. The median internal umbilical remnant diameters reported here are smaller than previously reported values, emphasising the importance of accounting for age when diagnosing umbilical abnormalities. In a healthy Standardbred foal, normal structures are difficult to definitively identify via transcutaneous ultrasound by 5-6 weeks of age.
影响内部脐残端的疾病在驹中很常见。超声用于诊断这些结构的异常，并监测治疗。然而，对于正常内部脐残端退化的进展知之甚少。
记录出生后第一周内正常的脐残端退化。
前瞻性纵向队列研究。
34 匹健康标准马驹在出生后第 1 天进行每周一次的超声检查。在脐部外部的头侧，肝脏水平和这些点之间的中间位置，对脐静脉进行横截面测量。在脐部外部的尾侧，膀胱顶点和膀胱中点，对脐动脉进行横截面测量。沿着膀胱出口的方向对脐尿管进行纵向成像。随时间的尺寸减小被评估为直径的百分比变化。
结构直径随时间呈线性减小。最大测量值在出生后 24 小时，中位数脐静脉直径为 0.83cm（IQR 0.77-1.02cm），中位数脐动脉直径为 0.61cm（IQR 0.56-0.70cm）和中位数脐尿管直径为 1.07cm（IQR 1.02-1.14cm）。在生命的第一周内，所有结构的直径均显著减小（16.0%-21.9%；校正 P < 0.001）。
所有驹均为单一品种，检查和测量由多个人进行。
内部脐残端（脐静脉/动脉和脐尿管）在生命的前几周内迅速退化。此处报告的中位数内部脐残端直径小于以前报道的值，强调了在诊断脐异常时考虑年龄的重要性。在健康的标准马驹中，正常结构在 5-6 周龄时通过经皮超声很难明确识别。
