With the aid of immunohistochemistry, the present review attempts to demonstrate the composite fibers and nerve topographical anatomy in the vaginal supportive tissues. Along the tendinous arch of the pelvic fasciae, ...With the aid of immunohistochemistry, the present review attempts to demonstrate the composite fibers and nerve topographical anatomy in the vaginal supportive tissues. Along the tendinous arch of the pelvic fasciae, distal parts of the pelvic plexus extend antero-inferiorly and issue nerves to the internal anal sphincter as well as the cavernous tissues. At the attachment of the levator ani muscle to the rectum, smooth muscles in the endopelvic fascia lining the levator ani merge with the longitudinal smooth muscle layer of the rectum to provide the conjoint longitudinal muscle coat or the longitudinal anal muscle (LAM: smooth muscle). However, at the rectovaginal interface, the longitudinal smooth muscle layer of the rectum continues to the LAM without any contribution of the endopelvic fascia. The bilateral masses of the perineal smooth muscles (PSMs) are connected by the perineal body, and the PSMs receive 1) the longitudinal anal muscle, 2) the internal and external anal sphincters and, 3) the perineal membrane lining the vestibular wall. Tensile stress from the levator ani seems to be transferred to the PSMs via the LAM. Because of their irregularly arrayed muscle fibers, instead of a synchronized contraction in response to nerve impulses, the PSMs are likely to act as a barrier, septum or protector against mechanical stress because, even without innervation, such smooth muscle fibers resist (not absorb) pressure, in accordance with Bayliss’ rule. The external anal sphincter, a strong striated muscle, inserts into the PSMs and seems to play a dynamic role in supporting the rectovaginal interface to maintain the antero-posterior length of the urogenital hiatus. However, we do not think that smooth muscles play an active traction role without cooperation from striated muscle. The fibrous skeleton composed of smooth muscle in the female perineum is explained in terms of a “catamaran” model.展开更多
The perineal membrane (PM) is a thick, elastic fiber-rich, smooth muscle-poor membrane extending along the vestibule and lower vaginal wall and embedding the urethrovaginal sphincter and compressor urethrae muscles. T...The perineal membrane (PM) is a thick, elastic fiber-rich, smooth muscle-poor membrane extending along the vestibule and lower vaginal wall and embedding the urethrovaginal sphincter and compressor urethrae muscles. To provide a better understanding of the topographical relationship between the PM and the levator ani muscle, we examined histological sections from 15 female cadavers. The composite fibers of the PM were usually continuous with that of a fascia covering the inferior or lateral surface of the levator ani (fascia diaphragmatis pelvis inferior) rather than the endopelvic fascia covering the superior or medial surface of the latter muscle. However, this fascial connection was sometimes interrupted by a venous plexus. The deep transverse perineal muscle was consistently adjacent to the posterolateral aspect of the PM, but whether it extended superficially or deeply to the PM depended on size of the muscle. In contrast to the endopelvic fascia embedding abundant middle-sized nerves (cavernous and sphincter nerves;0.05 - 0.1 mm in thickness), the PM contained very thin nerves: many in 10 cadavers but few in 5 cadavers. Most of the nerves seemed to be sensory on the basis of immunohistochemistry. The levator ani muscle was considered likely to provide traction force to the PM, but active elevation appeared to be difficult because of the highly elastic nature of the PM and the interrupting venous plexus. Loss of nerves in the PM might be one of a number of factors that can accelerate pelvic organ prolapse.展开更多
BACKGROUND The prevalence of pelvic organ prolapse(POP)increases with age and parity.Specifically,the prevalence of POP among women aged 20 to 39 is 9.7%,while it rises to 49%among women over 80 years old.Additionally...BACKGROUND The prevalence of pelvic organ prolapse(POP)increases with age and parity.Specifically,the prevalence of POP among women aged 20 to 39 is 9.7%,while it rises to 49%among women over 80 years old.Additionally,as the number of deliveries increases,the prevalence of POP also rises accordingly,with a rate of 12.8%for women with one delivery history,18.7%for those with two deliveries,and 24.6%for women with three or more deliveries.It causes immense suffering for pregnant women.AIM To evaluate the relationship between the levator ani muscle’s hiatus(LH)area and POP in patients with gestational diabetes mellitus(GDM)using perineal ultrasound.METHODS The study cohort comprised 104 patients aged 29.8±3.7 years who sought medical care at our institution between January 2021 and June 2023.All were singleton pregnancies consisting of 75 primiparas and 29 multiparas,with an average parity of 1.7±0.5.According to the POP diagnostic criteria,the 104 subjects were divided into two groups with 52 members each:POP group(patients with GDM combined with POP)and non-POP group(patients with GDM without POP).Perineal ultrasound was used to measure differences in the anteroposterior diameter,transverse diameter,and LH area.Receiver operating characteristic curves were drawn to determine the optimal cutoff values for the LH anteroposterior diameter,transverse diameter,and area for diagnosing POP.RESULTS Statistically significant increase in the LH area,anteroposterior diameter,and lateral diameter were observed in the POP group compared with the non-POP group(P<0.05).Both groups exhibited markedly elevated incidence rates of macrosomia and stress urinary incontinence.For the POP group,the area under the curve(AUC)for the LH area was 0.906 with a 95%confidence interval(CI):0.824-0.988.The optimal cutoff was 13.54cm²,demonstrating a sensitivity of 83.2%and a specificity of 64.4%.The AUC for the anteroposterior diameter reached 0.836 with a 95%CI:0.729-0.943.The optimal cutoff was 5.53 cm with a sensitivity of 64.2%and a specificity of 73.4%.For the lateral diameter,its AUC was 0.568 with a 95%CI:0.407-0.729.The optimal cutoff was 4.67 cm,displaying a sensitivity of 65.9%and a specificity of 69.3%.Logistic regression analysis unveiled that age,body weight,number of childbirths,total number of pregnancies,and gestational weight gain constituted the independent risk factors for the cooccurrence of GDM and POP.CONCLUSION Three-dimensional perineal ultrasonography of LH size and shape changes can effectively diagnose POP.Age,weight,number of births,number of pregnancies,and weight gain during pregnancy are independent risk factors affecting the cooccurrence of GDM and POP.GDM can increase the LH area in patients,and an enlarged LH leads to an increased incidence of POP.展开更多
文摘With the aid of immunohistochemistry, the present review attempts to demonstrate the composite fibers and nerve topographical anatomy in the vaginal supportive tissues. Along the tendinous arch of the pelvic fasciae, distal parts of the pelvic plexus extend antero-inferiorly and issue nerves to the internal anal sphincter as well as the cavernous tissues. At the attachment of the levator ani muscle to the rectum, smooth muscles in the endopelvic fascia lining the levator ani merge with the longitudinal smooth muscle layer of the rectum to provide the conjoint longitudinal muscle coat or the longitudinal anal muscle (LAM: smooth muscle). However, at the rectovaginal interface, the longitudinal smooth muscle layer of the rectum continues to the LAM without any contribution of the endopelvic fascia. The bilateral masses of the perineal smooth muscles (PSMs) are connected by the perineal body, and the PSMs receive 1) the longitudinal anal muscle, 2) the internal and external anal sphincters and, 3) the perineal membrane lining the vestibular wall. Tensile stress from the levator ani seems to be transferred to the PSMs via the LAM. Because of their irregularly arrayed muscle fibers, instead of a synchronized contraction in response to nerve impulses, the PSMs are likely to act as a barrier, septum or protector against mechanical stress because, even without innervation, such smooth muscle fibers resist (not absorb) pressure, in accordance with Bayliss’ rule. The external anal sphincter, a strong striated muscle, inserts into the PSMs and seems to play a dynamic role in supporting the rectovaginal interface to maintain the antero-posterior length of the urogenital hiatus. However, we do not think that smooth muscles play an active traction role without cooperation from striated muscle. The fibrous skeleton composed of smooth muscle in the female perineum is explained in terms of a “catamaran” model.
文摘The perineal membrane (PM) is a thick, elastic fiber-rich, smooth muscle-poor membrane extending along the vestibule and lower vaginal wall and embedding the urethrovaginal sphincter and compressor urethrae muscles. To provide a better understanding of the topographical relationship between the PM and the levator ani muscle, we examined histological sections from 15 female cadavers. The composite fibers of the PM were usually continuous with that of a fascia covering the inferior or lateral surface of the levator ani (fascia diaphragmatis pelvis inferior) rather than the endopelvic fascia covering the superior or medial surface of the latter muscle. However, this fascial connection was sometimes interrupted by a venous plexus. The deep transverse perineal muscle was consistently adjacent to the posterolateral aspect of the PM, but whether it extended superficially or deeply to the PM depended on size of the muscle. In contrast to the endopelvic fascia embedding abundant middle-sized nerves (cavernous and sphincter nerves;0.05 - 0.1 mm in thickness), the PM contained very thin nerves: many in 10 cadavers but few in 5 cadavers. Most of the nerves seemed to be sensory on the basis of immunohistochemistry. The levator ani muscle was considered likely to provide traction force to the PM, but active elevation appeared to be difficult because of the highly elastic nature of the PM and the interrupting venous plexus. Loss of nerves in the PM might be one of a number of factors that can accelerate pelvic organ prolapse.
文摘BACKGROUND The prevalence of pelvic organ prolapse(POP)increases with age and parity.Specifically,the prevalence of POP among women aged 20 to 39 is 9.7%,while it rises to 49%among women over 80 years old.Additionally,as the number of deliveries increases,the prevalence of POP also rises accordingly,with a rate of 12.8%for women with one delivery history,18.7%for those with two deliveries,and 24.6%for women with three or more deliveries.It causes immense suffering for pregnant women.AIM To evaluate the relationship between the levator ani muscle’s hiatus(LH)area and POP in patients with gestational diabetes mellitus(GDM)using perineal ultrasound.METHODS The study cohort comprised 104 patients aged 29.8±3.7 years who sought medical care at our institution between January 2021 and June 2023.All were singleton pregnancies consisting of 75 primiparas and 29 multiparas,with an average parity of 1.7±0.5.According to the POP diagnostic criteria,the 104 subjects were divided into two groups with 52 members each:POP group(patients with GDM combined with POP)and non-POP group(patients with GDM without POP).Perineal ultrasound was used to measure differences in the anteroposterior diameter,transverse diameter,and LH area.Receiver operating characteristic curves were drawn to determine the optimal cutoff values for the LH anteroposterior diameter,transverse diameter,and area for diagnosing POP.RESULTS Statistically significant increase in the LH area,anteroposterior diameter,and lateral diameter were observed in the POP group compared with the non-POP group(P<0.05).Both groups exhibited markedly elevated incidence rates of macrosomia and stress urinary incontinence.For the POP group,the area under the curve(AUC)for the LH area was 0.906 with a 95%confidence interval(CI):0.824-0.988.The optimal cutoff was 13.54cm²,demonstrating a sensitivity of 83.2%and a specificity of 64.4%.The AUC for the anteroposterior diameter reached 0.836 with a 95%CI:0.729-0.943.The optimal cutoff was 5.53 cm with a sensitivity of 64.2%and a specificity of 73.4%.For the lateral diameter,its AUC was 0.568 with a 95%CI:0.407-0.729.The optimal cutoff was 4.67 cm,displaying a sensitivity of 65.9%and a specificity of 69.3%.Logistic regression analysis unveiled that age,body weight,number of childbirths,total number of pregnancies,and gestational weight gain constituted the independent risk factors for the cooccurrence of GDM and POP.CONCLUSION Three-dimensional perineal ultrasonography of LH size and shape changes can effectively diagnose POP.Age,weight,number of births,number of pregnancies,and weight gain during pregnancy are independent risk factors affecting the cooccurrence of GDM and POP.GDM can increase the LH area in patients,and an enlarged LH leads to an increased incidence of POP.
