Unité Mixte de Recherche 1195, University Paris Sud, Institut National de la Santé et de la Recherche médicale, Université Paris-Saclay, Le Kremlin-Bicetre, France; Department of Obstetrics and Gynecology, Hopital Universitaire de Rennes, University Rennes 1, Rennes, France.
Unité Mixte de Recherche 1195, University Paris Sud, Institut National de la Santé et de la Recherche médicale, Université Paris-Saclay, Le Kremlin-Bicetre, France.
Am J Obstet Gynecol. 2018 Jan;218(1):121.e1-121.e12. doi: 10.1016/j.ajog.2017.09.021. Epub 2017 Oct 6.
Injury to the levator ani muscle or pelvic nerves during pregnancy and vaginal delivery is responsible for pelvic floor dysfunction.
We sought to demonstrate the presence of smooth muscular cell areas within the levator ani muscle and describe their localization and innervation.
Five female human fetuses were studied after approval from the French Biomedicine Agency. Specimens were serially sectioned and stained by Masson trichrome and immunostained for striated and smooth muscle, as well as for somatic, adrenergic, cholinergic, and nitriergic nerve fibers. Slides were digitized for 3-dimensional reconstruction. One fetus was reserved for electron microscopy. We explored the structure and innervation of the levator ani muscle.
Smooth muscular cell beams were connected externally to the anococcygeal raphe and the levator ani muscle and with the longitudinal anal muscle sphincter. The caudalmost part of the pubovaginal muscle was found to bulge between the rectum and the vagina. This bulging was a smooth muscular interface between the levator ani muscle and the longitudinal anal muscle sphincter. The medial (visceral) part of the levator ani muscle contained smooth muscle cells, in relation to the autonomic nerve fibers of the inferior hypogastric plexus. The lateral (parietal) part of the levator ani muscle contained striated muscle cells only and was innervated by the somatic nerve fibers of levator ani and pudendal nerves. The presence of smooth muscle cells within the medial part of the levator ani muscle was confirmed under electron microscopy in 1 fetus.
We characterized the muscular structure and neural control of the levator ani muscle. The muscle consists of a medial part containing smooth muscle cells under autonomic nerve influence and a lateral part containing striated muscle cells under somatic nerve control. These findings could result in new postpartum rehabilitation techniques.
妊娠和阴道分娩过程中对肛提肌或盆腔神经的损伤导致盆底功能障碍。
我们旨在展示肛提肌中平滑肌细胞区域的存在，并描述其定位和神经支配。
在获得法国生物医学局的批准后，我们研究了 5 名女性胎儿。标本经连续切片，用 Masson 三色法染色，并进行横纹肌和平滑肌、躯体神经、肾上腺素能神经、胆碱能神经和一氧化氮能神经纤维免疫染色。将切片数字化进行 3 维重建。为了电镜检查，保留了 1 个胎儿。我们探索了肛提肌的结构和神经支配。
平滑肌细胞束与肛尾缝和肛提肌外部相连，并与纵向肛门肌肉括约肌相连。耻骨阴道肌的最尾部分发现在直肠和阴道之间膨出。这种膨出是肛提肌和纵向肛门肌肉括约肌之间的平滑肌界面。肛提肌的内侧（内脏）部分包含平滑肌细胞，与下腹下丛的自主神经纤维有关。肛提肌的外侧（壁侧）部分仅包含横纹肌细胞，由肛提肌和阴部神经的躯体神经纤维支配。在 1 个胎儿中，电子显微镜下证实了肛提肌内侧部分存在平滑肌细胞。
我们描述了肛提肌的肌肉结构和神经控制。该肌肉由内侧部分组成，包含受自主神经影响的平滑肌细胞，以及外侧部分，包含受躯体神经控制的横纹肌细胞。这些发现可能导致新的产后康复技术。
