Department of Surgery, Royal College of Surgeons of Ireland (RCSI), Dublin, Ireland.
Department of Urology, Blackrock Clinic, Blackrock, Co., Dublin, Ireland.
Nat Rev Urol. 2024 Apr;21(4):197-213. doi: 10.1038/s41585-023-00831-1. Epub 2023 Dec 15.
The ureteric wall is a complex multi-layered structure. The ureter shows variation in passive mechanical properties, histological morphology and insertion forces along the anatomical length. Ureter mechanical properties also vary depending on the direction of tensile testing and the anatomical region tested. Compliance is greatest in the proximal ureter and lower in the distal ureter, which contributes to the role of the ureter as a high-resistance sphincter. Similar to other human tissues, the ureteric wall remodels with age, resulting in changes to the mechanical properties. The passive mechanical properties of the ureter vary between species, and variation in tissue storage and testing methods limits comparison across some studies. Knowledge of the morphological and mechanical properties of the ureteric wall can aid in understanding urine transport and safety thresholds in surgical techniques. Indeed, various factors alter the forces required to insert access sheaths or scopes into the ureter, including sheath diameter, safety wires and medications. Future studies on human ureteric tissue both in vivo and ex vivo are required to understand the mechanical properties of the ureter and how forces influence these properties. Testing of instrument insertion forces in humans with a focus on defining safe upper limits and techniques to reduce trauma are also needed. Last, evaluation of dilatation limits in the mid and proximal ureter and clarification of tensile strength anisotropy in human specimens are necessary.
输尿管壁是一种复杂的多层次结构。输尿管的被动机械特性、组织形态和插入力在解剖长度上存在变化。输尿管的机械特性还取决于拉伸测试的方向和测试的解剖区域。顺应性在输尿管近端最大，在输尿管远端较低，这有助于输尿管作为高阻力括约肌的作用。与其他人体组织一样，输尿管壁会随着年龄的增长而重塑，从而导致机械特性发生变化。输尿管的被动机械特性在不同物种之间存在差异，组织储存和测试方法的差异限制了一些研究的比较。了解输尿管壁的形态和机械特性有助于理解尿液运输和手术技术中的安全阈值。事实上，各种因素会改变插入输尿管的鞘管或窥镜所需的力，包括鞘管直径、安全线和药物。需要对体内和体外的人类输尿管组织进行未来的研究，以了解输尿管的机械特性以及力如何影响这些特性。还需要研究在人体中测试器械插入力的方法，重点是确定安全上限和减少创伤的技术。最后，需要评估中输尿管和近端输尿管的扩张极限，并澄清人体标本的拉伸强度各向异性。
