Levator ani muscle in women with genitourinary prolapse: Indirect assessment by muscle histopathology

The objective of this study was to assess the state of innervation in levator ani muscle sites using muscle histopathology. Asymptomatic women and patients with genitourinary prolapse were included. Histopathologic analysis allows indirect assessment of a muscle's innervation. Therefore, levator ani muscle was collected in a standardized fashion during abdominal surgery and frozen in the operating room using isopentane slush cooled by liquid nitrogen. Serial sections of levator ani muscle in cross-section were studied with standard histochemical and immunohistochemical techniques. The staining patterns from these histochemical techniques allowed quantitative determination of the ratios of fiber types I, IIA, and IIB and their fiber diameters. Objective assessment of fiber type grouping was performed. The distribution of both fiber type percentage and diameter were non-parametric. Therefore, the Mann-Whitney U-test was used to analyze the data for statistical differences between the means for these variables. There was no statistical difference in levator ani muscle fiber type percentage and diameter in patients with prolapse and/or urinary incontinence when compared to asymptomatic women. Levator ani muscles have a higher proportion of slow fibers (66%) than found in other human female muscle (48%). There was no evidence for denervation/reinnervation in any of the biopsy specimens. In this study, levator ani muscle biopsies from incontinent and/or prolapse patients were neither denervated nor reinnervated. © 1996 Wiley-Liss, Inc.     

剪切波弹性成像评价绝经后盆腔器官脱垂患者肛提肌弹性

目的 观察剪切波弹性成像(SWE)评估无肛提肌损伤的绝经后盆腔器官脱垂(POP)患者肛提肌弹性的价值。方法 将40名定量POP(POP-Q)结果为0~Ⅲ度的绝经后女性分为POP 0组、POP Ⅰ组、POP Ⅱ组及POP Ⅲ组,行盆底超声检查排除肛提肌损伤,应用SWE测量静息状态下双侧肛提肌的杨氏模量,计算双侧平均值;比较组间基本资料及肛提肌杨氏模量差异,采用Pearson相关性分析评价左、右侧肛提肌及其平均杨氏模量与POP-Q分度的关系。结果 组间年龄、身高、体质量及体质量指数差异均无统计学意义(P均＞0.05);POP 0组至POP Ⅲ组左、右侧肛提肌及其平均杨氏模量逐渐增加,两两比较差异均有统计学意义(P均＜0.05)。相关性分析显示,左、右侧肛提肌及其平均杨氏模量均与POP-Q分度呈正相关(r=0.814、0.799、0.809,P均＜0.01)。结论 SWE可用于评估无肛提肌损伤绝经后POP患者静息状态下肛提肌弹性功能。     

Levator ani trigger point injections: An underutilized treatment for chronic pelvic pain

AIMS: We conducted this study to examine the role of trigger point injections in females with chronic pelvic pain (CPP) of at least 6 months duration and specific levator ani trigger points. METHODS: This prospective study included 18 consecutive female patients with CPP and specific palpable levator ani trigger points. Pain was evaluated before and after trigger point injection on a Visual Analog Scale (VAS). Patient global satisfaction (PGS) and cure rates (PGC) were also measured by a VAS on a scale of 0-100%. The trigger points were identified manually by intravaginal palpation of the levator ani bilaterally. A mixture of 10 cc of 0.25% bupivacaine, 10 cc of 2% lidocaine and 1 cc (40 mg) of triamcinolone was used for injection of 5 cc per trigger point. A 5.5' Iowa trumpet pudendal needle guide was used for injection. All but one injection were performed in the office setting without sedation. Pelvic floor muscle exercises were taught for use after injection. Success was defined as a decrease in pain as measured by a VAS of 50% or more, as well as PGS and PGC scores of 60% or greater. There was a mean follow up of 3 months after trigger point injection. RESULTS: Thirteen of 18 women improved with the first trigger point injection resulting in a comprehensive success rate of 72%. Six (33%) of 18 women were completely pain free. CONCLUSION: In the management of CPP, a non-surgical office-based therapy such as trigger point injections can be effective in selected patients.     

Interrater reliability and physical examination of the pubovisceral portion of the levator ani muscle, validity comparisons using MR imaging

AIMS: Defects in the pubovisceral portion of the levator ani muscle are seen with MR imaging. This study aims to determine interrater reliability of physical examination in detecting these defects, and to validate findings from physical examination using comparisons with MR images. METHODS: Two examiners palpated the pubovisceral muscles of 29 women to assess for defects in this muscle. Each examiner was blinded to the others findings. MR scans were acquired on a further 24 women after structured clinical examination by one examiner. These images were read to determine pubovisceral muscle defects, blinded to patient identifiers. Agreement between raters and between MR imaging and clinical examination were calculated. RESULTS: The two examiners had positive agreement (presence of a defect) of 72.7% and negative agreement (absence of a defect) of 83.3%. The positive agreement between physical examination and MR imaging was 27.3% and the negative agreement 86.5%. CONCLUSION: The structured physical examination to detect defects in the pubovisceral portion of the levator ani muscle can be learned as shown by good interrater agreement. However, examination alone underestimates these defects compared with MR imaging.     

Myogenic changes of the levator ani muscle in premenopausal women: The impact of vaginal delivery and age

The aim of this study was to evaluate the impact of parity and age on histomorphology of the pelvic floor muscles in female cadavers of reproductive age and to find out whether there is evidence of myogenic or neurogenic muscle injury. In a cross-sectional study 45 premenopausal unfixed and fresh female cadavers were studied. Four groups were defined: nulliparous and parous women under the age of 40 and over 40 years of age. The pelvic floor was biopsied at six standardized locations. For evaluation of the quantitative parameters and fiber type identification, actomyosin ATPase at pH 9.4 was used. For histomorphological evaluation, sections were stained with hematoxylin/eosin, van Gieson, and Gomori trichrome. The circumference of type I fibers is significantly larger in nulliparous women younger than 40 years compared to nulliparae older than 40 years. Comparing these groups, the form factor of type II fibers also increases significantly, presenting a more circular cell form. Compared to nulliparae, vaginal delivery led to a significant difference regarding the presence of centrally located nuclei, fibrosis, and variation in fiber diameter. In nulliparous women, these significant changes were also found with increasing age. In women with a history of vaginal delivery, no further increase in these characteristics could be detected with increasing age. Comparing the three different biopsy sites, all three changes were more pronounced in the ventral part. There was no evidence of grouped fiber atrophy, small angulated fibers, or type grouping in any of the biopsy specimens. Aging and vaginal childbirth lead to histomorphological changes of the pelvic floor muscle that are consistent with changes of myogenic origin. Evidence of neurogenic damage could not be demonstrated. Neurourol. Urodynam. 17:197–205, 1998. © 1998 Wiley-Liss, Inc.     

Histochemical and contractile properties of striated muscles of urethra and levator ani of dogs and sheep

AIMS: To understand their possible importance in long- and short-term control of continence, some properties of the striated muscles of the urethra and pelvic floor (levator ani) of dogs and sheep were investigated, especially fiber types and contractile characteristics. MATERIALS AND METHODS: Striated muscles of urethra and levator ani of 29 male and 6 female dogs and 11 male and 6 female sheep were removed and cut into strips. Some strips were frozen and stained for ATPase at pH 9.4 and 4.3 for fiber typing; others were set up in an organ bath to study contractile responses to nerve stimulation. RESULTS: All muscles contained both type I (slow) and type II fibers, ranging from 97% type II in female greyhound urethra to 60% in female sheep levator ani. For each muscle, there were fewer type II muscles in sheep than in dog. The diameters of the urethral fibers were about 60% of the levator ani in dogs and 34% in sheep. Contraction of the urethral muscle was faster than for levator ani and declined to about 80% of the peak, 500 msec after the beginning of stimulation at 20 Hz. The levator ani contraction rose to a steady level as long as stimulation continued. CONCLUSIONS: Both the levator ani and urethral striated muscles contain slow and fast fiber types. The levator ani muscles are capable of sustained contraction with rapid onset which will produce long-term closure of the urethra. The circular urethral muscle contraction was faster but less well maintained.     

超声技术评估肛提肌结构与功能研究进展

肛提肌损伤是盆底功能障碍性疾病发生的重要因素。近年来,妇产科超声成像及诊断技术不断进步。本文主要对二维超声、常规三维超声、超声断层成像技术在肛提肌结构与功能评估方面的研究进展进行综述。     

Morphologic study on levator ani muscle in patients with pelvic organ prolapse and stress urinary incontinence

The objective of this study was to determine the morphologic changes of the levator ani muscle of patients with pelvic organ prolapse and stress urinary incontinence. Histological and histochemical analyses of the biopsy specimens of the levator ani muscle obtained from patients with stress urinary incontinence (SUI), pelvic organ prolapse (POP), and a control group were performed. The striated muscle-positive biopsy rate was 26.7% in the SUI group, 15.8% in the POP group, whereas it was 100% in the control group. The diameters of types I and II fibers decreased significantly with age and menopausal time in the control group. Splitting or fragmentation of fibers with red granules, which are called ragged-red fibers, were found in the SUI group. The diameters of levator ani muscle fibers in the control group were significantly larger than those in the SUI group (p=0.034<0.05). The degenerative change in histology and decrease in relative number of levator ani muscle might be associated with women suffering from SUI.     

肛提肌标识在直肠癌腹会阴联合切除术中的作用

目的 探讨肛提肌标识在直肠癌腹会阴联合切除术中的作用.方法 回顾性分析2001年1月至2008年1月南京医科大学第一附属医院收治的109例直肠癌患者的临床资料,其中55例采用传统方法手术（传统法组）,54例采用肛提肌标识法进行手术（肛提肌标识法组）.手术遵循直肠癌全系膜切除术原则,锐性分离直肠系膜,整块切除.两组患者术前肠道准备、麻醉选择、患者体位、腹部切口、会阴部切口、会阴部缝合与Miles术相同.传统法组用电刀或超声刀切开会阴部脂肪组织,自尾骨的前方进入盆腔,与腹部手术医师会合,靠近盆壁切断两侧肛提肌未进行标识则进行后续手术操作.肛提肌标识法组采用电刀切开肛门周围间隙脂肪组织,分离两侧坐骨肛管间隙脂肪组织,切断后方肛尾韧带,直达肛提肌平面,标识肛提肌后进行后续手术操作.术后病理检查为Ⅰ期者进行随访观察;术后病理检查为Ⅱ期者,如组织学分化差、T4期、血管淋巴管浸润、检出淋巴结数目＜12枚,则行辅助化疗,如无则进行随访观察;术后病理检查为Ⅲ、Ⅳ期者,行术后化疗.术后第1年,每3个月复查1次血常规、肝肾功能、胸部X线片和肝胆B超.1年后每6个月复查1次上述检查;每年复查1次CT和肠镜检查.随访时间截至2012年12月.计数资料采用x2检验,计量资料采用t检验,Kaplan-Meier法绘制生存曲线,生存率比较采用Log-rank检验.结果 两组患者顺利完成手术,传统法组患者和肛提肌标识法组患者的会阴手术时间分别为（60±15） min和（30±10） min,术中出血量分别为（300 ±60） mL和（30±20） mL,两组比较,差异有统计学意义（t=3.936,5.687,P＜0.05）.传统法组患者中,3例直肠破损,2例尿道（阴道）破损,10例切口感染;而肛提肌标识法组患者中,只有9例切口感染.109例患者中,术后化疗周期少于12个疗程者30例,6个疗程及以上者41例.中位随访时?     

Compliance of the bladder neck supporting structures: importance of activity pattern of levator ani muscle and content of elastic fibers of endopelvic fascia

AIMS: Firm bladder neck support during cough, suggested to be needed for effective abdominal pressure transmission to the urethra, might depend on activity of the levator ani muscle and elasticity of endopelvic fascia. METHODS: The study group of 32 patients with stress urinary incontinence and hypermobile bladder neck, but without genitourinary prolapse, were compared with the control group of 28 continent women with stable bladder neck. The height of the bladder neck (HBN) and compliance of the bladder neck support (C) were assessed, the latter by the quotient of the bladder neck mobility during cough and the change in abdominal pressure. By using wire electrodes, the integrated full-wave rectified electromyographic (EMGave) signal of the levator ani muscle was recorded simultaneously with urethral and bladder pressures. The pressure transmission ratio (PTR), time interval between the onset of muscle activation and bladder pressure increment (DeltaT), and area under the EMGave curve during cough (EMGcough) were calculated. From bioptic samples of endopelvic fascia connecting the vaginal wall and levator ani muscle, elastic fiber content was assessed by point counting method. Mann-Whitney test was used to compare all the variables. Correlations between the parameters were evaluated by using the Spearman correlation coefficient. RESULTS: In the study group, HBN was significantly lower (P < 0.001), C was significantly greater (P < 0.001), and PTR was significantly lower (P < 0.001). In the study group, the muscular activation started later (median, DeltaT(l), -0.147 second; DeltaT(r), -0.150 second), and in the control group, it preceded (DeltaT(l), 0.025 second; P < 0.001; DeltaT(r), 0.050 second; P < 0.001) the bladder pressure increment. EMGcough on the left side was significantly greater in the study group (P < 0.046). Elastic fiber content showed no difference between the groups. The analysis of all patients revealed negative correlations between C and PTR (r = -0.546; P < 0.001) and between C and DeltaT(l) (r = -0.316; P < 0.018). CONCLUSIONS: Firm bladder neck support enables effective pressure transmission. Timely activation of the levator ani seems to be an important feature.     

Comparison of the growth-promoting effects of testosterone and 7-alpha-methyl-19-nor-testosterone (MENT) on the prostate and levator ani muscle of LPB-tag transgenic mice

BACKGROUND: 7-alpha-methyl-19-nortestosterone (MENT) is being considered for androgen replacement in testosterone deficient men and as a male contraceptive. Because androgenic effects on the prostate are a major concern, we have evaluated MENT in a transgenic model of prostate cancer. METHODS: LPB-Tag mice were castrated and infused with testosterone (T; 5 or 30 microg/day) or MENT (5 or 30 microg/day) for 4 weeks. Prostate, seminal vesicle, and levator ani muscle (LAM) weights were compared. RESULTS: At an equivalent dose, MENT maintained or stimulated the mean weights of these organs more than T. However, the dorsolateral prostate/LAM ratio of weights did not favor MENT, but DNA/mg tissue and Ki 67 immunostaining suggested that MENT may increase DNA less than T. CONCLUSIONS: MENT is more potent than T in maintaining or stimulating prostate, seminal vesicle, and LAM. Using doses that resulted in comparable stimulation of the levator ani muscle, MENT had similar effect on prostate weight, but increased DNA/mg prostate less than T in this transgenic mouse model of prostate cancer.