Neurovascular bundle in fibroid pseudocapsule and its neuroendocrinologic implications

Abstract

The myoma pseudocapsule is a surgical-anatomical entity surrounding the fibroid that separates the myoma from normal uterine tissue. The myoma pseudocapsule has a delicate vascular network rich with neurotransmitters analogous to the neurovascular bundle surrounding the prostate. The pseudocapsule neurovascular bundle is extremely important during myomectomy to promote uterine myometrial healing and, consequently, for uterine reproductive function. New advancements in surgery, including the use of laparoscopic myomectomy by an intracapsular technique and magnification of the myoma pseudocapsule to enhance visualization are comparable to the dissection during a radical prostatectomy. Fibroid detachment occurring inside the pseudocapsule causes less bleeding, spares the neurovascular bundle and promotes better uterine healing. The maintenance of myometrial integrity after laparoscopic myomectomy maintains uterine function and therefore improves reproductive outcomes, including labor.

Myoma pseudocapsule - a biological and surgical structure to respect during myomectomy

“…Analyzing the biology of the myometrial scar after myomectomy, the spared neuropeptides enhance the correct myometrial healing at the hysterotomic site, and most of the abovementioned neuropeptides have been found in the fibroid pseudocapsule, as a neurovascular bundle surrounding the fibroid [14][15][16][17]. To date, it has not been clarified if the pseudocapsule vasculature network could be sustained by mechanical and inflammatory effects of the fibroid on myometrium, or produced by a sort of "neoplastic-type" neoangiogenesis, due to the myoma growth or even to a muscle and tissue healing process [18].…”

Uterine leiomyosarcomas and leiomyomas: Two similar uterine solid tumors, totally different for prognosis

“…The fibroid pseudocapsule is composed by fibrotic tissue, vessels and a neurovascular network rich of neurofibers, as the neurovascular bundle surrounding prostate, but of this intriguing structure I'll discuss later in more detail. 13 Returning to discuss the difference among fibroids and LMS, the leiomyomas cut surface has a characteristic whorl-like, trabeculated appearance, their size of uterine leiomyomas is variable, ranging from microscopic to large tumors that fill the abdomen and leiomyomas may be single or, more frequently, multiple. 3,6,10,11 Although little is known about the factors responsible for the initial neoplastic myometrial transformation, it is hypothesized that each leiomyoma arises from a single cell in the myometrium.…”

“…1,14 Several observations suggest that estrogens and progesterone play an important role in the growth of uterine fibroids: they occur in women of reproductive age, often enlarge during pregnancy or during oral contraceptive use, and regress after menopause. 3,13,15 As fibroids enlarge, they may outgrow their blood supply, recently evaluated as possible marker of leiomyoma transformations. In fact, the myoma pseudocapsule vessels were studied by a preliminary three-dimensional mathematical model, who showed an increase vascular tortuosity, disarray, an abnormal branching and the presence of ''cul-de-sac'' pseudocapsule vessels.…”

“…6 Last evidences on the neurofibers and neuropeptides in fibroid pseudocapsule suggest a new horizon in endoscopic gynecological surgery, which can be called: intracapsular fibroid nerve-sparing laparoscopic "microsurgery", or intracapsular fibroid nerve-sparing robotic assisted "nanosurgery", in case of robotic magnification. 13 A great advantage of intracapsular laparoscopic myomectomy is the reproducibility of its application for all laparoscopic myomectomies, as a safe, feasible and minimally invasive technique.…”

“…Moreover, allowing corrected myometrial healing, intracapsular myomectomy should preserve reproductive outcomes and normal labor and delivery, for less bleeding, better neurovascular bundle sparing for scar quality, and post-operative adhesions reduction. 6,13 Concluding, differently from uterine leiomyoma, LMS is a rare but extremely aggressive subtype of uterine malignancy from mesenchymal elements, that account for 3% of uterine cancers, consists of several histological types, and the strongest prognostic factor for all the sarcomas is the stage at diagnosis. Recently, a new International Federation of Gynecology and Obstetrics (FIGO) classification and staging system was specifically designed for uterine sarcomas in an attempt to reflect their differing biological behavior.…”