目的 通过有限元分析方法，探索不同形态的膀胱内前列腺突出（intravesical prostatic protrusion，IPP）对排尿过程的影响。 方法 基于1例前列腺中叶和双侧叶突入膀胱的良性前列腺增生患者MRI图像，重建其下尿路有限元模型（模型3）。通过图像修改突出部分，构建双侧叶突出模型（模型1）和中叶突出模型（模型2）。结合有限元分析软件进行双向流固耦合仿真分析，比较3种模型的前列腺尿道形变和流体动力学参数。 结果 排尿过程中，模型3前列腺尿道角减小的程度最大，其次是模型2。模型3中的液体压强损失最严重。在每种膀胱内压下，模型1的流体速度大于其他模型，模型3的最大流率低于其他模型。在相同的膀胱出口截面积，模型3的最大流率低于其他模型，且增加膀胱出口截面积会进一步扩大这一差距。 结论 与具有相同IPP长度但只有中叶突出或只有双侧叶突出的患者相比，中叶和双侧叶均突出的患者具有更大的尿道阻力和更小的最大尿流率。评估IPP不仅要测量其长度，还要注意IPP形态。
Abstract
Objective To explore the effect of intravesical prostatic protrusion with different forms on urination by the finite element analysis method. Methods The finite element models for male lower urinary tract was reconstructed based on MRI images of a patient with middle lobe and bilateral lateral lobes protrusion into the bladder model 3. Other models with only the bilateral lateral protrusion and only the middle lobe protrusion were created by adjusting the shape of the protruded part. The two-way fluid-structure interaction of the lower urinary tract was simulated by the finite element analysis software. The deformation of prostatic urethra and flow dynamics parameters were compared between models with different IPP shapes. Results The largest reduction of prostatic urethra angle was found in model 3 during urination, followed by model 2 and model 1. The liquid pressure loss was most severe in model 3. The velocity in majority part of model 1 was higher than that of other two models. The maximum flow rate of model 3 was lower than that of other two models. Under the same bladder outlet cross-sectional area, the maximum flow rate of model 3 was lower than that of other models, and increasing bladder outlet cross-sectional area would further widen this gap. Conclusions This study reveals that patients with middle lobe and bilateral lateral lobes protrusion have greater urethral resistance and smaller maximum flow rate than those having comparable-length IPP with only middle lobe protrusion or only bilateral lateral lobes protrusion. When evaluating IPP, we should measure its length, as well pay attention to its form.
关键词
良性前列腺增生 /
/
/
膀胱内前列腺突出 /
/
/
有限元分析 /
/
/
流固耦合
Key words
Benign prostatic hyperplasia /
/
/
Intravesical prostatic protrusion /
/
/
Finite element analysis /
Fluid-structure interaction
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] Zhang W, Zhang X, Li H, et al. Prevalence of lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH) in China: results from the China Health and Retirement Longitudinal Study[J]. BMJ Open, 2019, 9(6): e022792. DOI: 10.1136/bmjopen-2018-022792.
[2] Ito K, Takashima Y, Akamatsu S, et al. Intravesical prostatic protrusion is not always the same shape: evaluation by preoperative cystoscopy and outcome in HoLEP[J]. Neurourol Urodyn, 2018, 37(7): 2160-2166. DOI: 10.1002/nau.23428.
[3] Chen HS, Liu X, Zhang ZC, et al. Computational fluid dynamics modeling approaches to assess lower urinary tract hydraulic dynamics in posterior urethral valve before and after endoscopic valve ablation: a pilot study[J]. World J Urol, 2022, 40(2): 505-511. DOI: 10.1007/s00345-021-03875-3.
[4] Cohen AJ, Baradaran N, Mena J, et al. Computational fluid dynamic modeling of urethral strictures[J]. J Urol, 2019, 202(2): 347-353. DOI: 10.1097/JU.0000000000000187.
[5] Zheng J, Pan J, Qin Y, et al. Role for intravesical prostatic protrusion in lower urinary tract symptom: a fluid structural interaction analysis study[J]. BMC Urol, 2015, 15: 86. DOI: 10.1186/s12894-015-0081-y.
[6] Ishii T, Ho CK, Nahas H, et al. Deformable phantoms of the prostatic urinary tract for urodynamic investigations[J]. Med Phys, 2019, 46(7): 3034-3043. DOI: 10.1002/mp.13558.
[7] Eze BU, Mbaeri TU, Orakwe JC. Anterior bladder wall thickness, post-void urine residue, and bladder emptying efficiency as indicators of bladder dysfunction in Nigerian men with benign prostatic hyperplasia[J]. Niger J Clin Pract, 2020, 23(9): 1215-1220. DOI: 10.4103/njcp.njcp_67_20.
[8] Cosson M, Rubod C, Vallet A, et al. Simulation of normal pelvic mobilities in building an MRI-validated biomechanical model[J]. Int Urogynecol J, 2013, 24(1): 105-112. DOI: 10.1007/s00192-012-1842-8.
[9] Spirka T, Kenton K, Brubaker L, et al. Effect of material properties on predicted vesical pressure during a cough in a simplified computational model of the bladder and urethra[J]. Ann Biomed Eng, 2013, 41(1): 185-194. DOI: 10.1007/s10439-012-0637-x.
[10] 黄小平, 张冀桂, 冯贵新, 等. 前列腺增生症引起膀胱逼尿肌变化的临床研究[J]. 中国临床解剖学杂志, 2005(4): 443-444. DOI: 10.3969/j.issn.0253-4304.2004.07.013.
[11]Korkmaz I, Rogg B. A simple fluid-mechanical model for the prediction of the stress-strain relation of the male urinary bladder[J]. J Biomech, 2007, 40(3): 663-668. DOI: 10.1016/j.jbiomech.2006.02.014.
[12] 高炜, 袁武, 韩悦, 等. 前列腺解剖带区的断层切片与MRI图像对照研究[J]. 中国临床解剖学杂志, 2011, 29(4): 413-417. DOI: 10.13418/j.issn.1001-165x.2011.04.015.
[13] Shim M, Bang WJ, Oh CY, et al. Correlation between prostatic urethral angulation and symptomatic improvement after surgery in patients with lower urinary tract symptoms according to prostate size[J]. World J Urol, 2020, 38(8): 1997-2003. DOI: 10.1007/s00345-019-02990-6.
[14]Foo KT. What is a disease? What is the disease clinical benign prostatic hyperplasia (BPH)[J]? World J Urol, 2019, 37(7): 1293-1296. DOI: 10.1007/s00345-019-02691-0.
[15] Keqin Z, Zhishun X, Jing Z, et al. Clinical significance of intravesical prostatic protrusion in patients with benign prostatic enlargement[J]. Urology, 2007, 70(6): 1096-1099. DOI: 10.1016/j.urology.2007.08.008.
基金
国家自然科学基金资助项目（31871212）
PDF(3770 KB)
京ICP备08002354号-3
