Joint Graduate Program in Biomedical Engineering, University of Texas, Arlington, United States; Joint Graduate Program in Biomedical Engineering, University of Texas Southwestern Medical Center, Dallas, United States; Bioengineering Department, University of Texas, Arlington, TX 76019, United States.
Joint Graduate Program in Biomedical Engineering, University of Texas, Arlington, United States; Joint Graduate Program in Biomedical Engineering, University of Texas Southwestern Medical Center, Dallas, United States; Bioengineering Department, University of Texas, Arlington, TX 76019, United States.
Eur J Obstet Gynecol Reprod Biol. 2014 Feb;173:106-12. doi: 10.1016/j.ejogrb.2013.11.012. Epub 2013 Nov 28.
In-vivo measurement of the viscoelastic properties of the prolapsed anterior vaginal wall (AVW) in post-menopausal women undergoing cystocele repair.
A BTC-2000 cutometer-like instrument was introduced during vaginal repair of symptomatic stage 2-3 AVW prolapse. Under anesthesia, 10-mm orifice probe was applied to the AVW at the level of the bladder neck. A suction pressure ramp (0 to -147 mmHg in 6s) was delivered causing tissue uplift, followed by immediate release to 0 mmHg, measuring tissue relaxation for 20s. Similar measurements were performed over the suprapubic region (SP) for comparison purpose. The rate of tissue recovery was obtained by fitting a Voigt model to the data and expressing results as the ratio E/η [(spring modulus E)/(dashpot viscosity η)]. The effective strain energy (SE) was calculated from the pressure-uplift data and evaluated from initiation to: (1) maximum storage in tissue at peak vacuum; (2) tissue recovery after vacuum release; (3) net SE loss over the entire loading-unloading cycle.
In 22 women, higher AVW peak and residual tissue uplift values, and lower E/η ratios were found compared with SP results. The AVW stored less elastic strain energy at peak vacuum than did the SP, and AVW net energy loss over the uplift-recovery cycle was greater than for SP controls. Not only was the AVW more compliant than the SP, with higher viscous damping, but the tissue was also less able to store recoverable energy upon distension.
Such in-vivo measurements quantify the biomechanical properties of the prolapsed AVW and may assist in its management.
测量绝经后行阴道前壁膨出修补术患者阴道前壁脱垂部分的粘弹性。
在阴道前壁膨出修补术中，我们引入 BTC-2000 型皮肤弹性测量仪，在麻醉下，将 10mm 探头放置在膀胱颈水平的阴道前壁。探头在 6s 内以 0 到-147mmHg 的负压抽吸组织，随后立即释放至 0mmHg，测量组织松弛 20s。同时在耻骨上区域（SP）进行类似的测量作为对照。通过将 Voigt 模型拟合到数据中，获得组织恢复率，并表示为 E/η 的比值[（弹性模量 E）/（粘性阻力 η）]。通过压力提升数据计算有效应变能（SE），并从以下三个方面评估：（1）在最大真空时组织的最大储存；（2）释放真空后组织的恢复；（3）整个加载-卸载循环的净 SE 损失。
在 22 名女性中，与 SP 相比，阴道前壁膨出的峰值和残余组织提升值更高，E/η 比值更低。与 SP 相比，阴道前壁膨出在峰值真空时储存的弹性应变能更少，并且在提升-恢复循环中，阴道前壁膨出的净能量损失大于 SP 对照组。阴道前壁膨出不仅比 SP 更具顺应性，具有更高的粘性阻尼，而且在扩张时组织恢复可储存的能量的能力也较差。
这种体内测量方法可以量化脱垂阴道前壁的生物力学特性，并可能有助于其管理。
