Distribution of Substance P (SP) and Vasoactive Intestinal Peptide (VIP) in pseudocapsules of uterine fibroids

The authors examined the presence of Substance P (SP) and Vasoactive Intestinal Polypeptide (VIP) and their related fibers in the pseudocapsule of uterine fibroids (PUF) and in normal myometrium (NM) during myomectomies in 57 non-pregnant women. 4 samples were removed from the normal myometrium (NM) and from PUF. The samples were sent for histological and immune-fluorescent investigations. SP and VIP values were found non-significantly higher in PUF than in NM: SP values were 10.2 ± 0.1 conventional units (C.U.) in PUF at the fundus of the uterus (FU) vs. 8.1 ± 0.6 C.U. of NM in the FU (p > 0.05), and SP values were 25.1 ± 0.9 C.U. in PUF in the uterine body (UB) compared to. 23.2 ± 1.4 C.U. of NM in the myometrium of the UB (p > 0.05). VIP values were 11.5 ± 0.9 C.U. in the PUF in FU compared to 9.8 ± 1.4 C.U. of NM in the FU (p > 0.05), and VIP values were 33.9 ± 3.9 C.U. in the PUF in the UB vs. 32.6 ± 4.8 C.U. of the NM in the UB (p > 0.05). These findings show that SP and VIP neurofibers are present in the fibroid pseudocapsule, similar to the values in the normal myometrium of a non-pregnant uterus. An intracapsular myoma excision which respects the pseudocapsule permits a physiological healing process of the uterine scar, due to a neurotransmitter sparing at the hysterotomic site. In women planning pregnancy, the myomectomy should be preferably performed respecting the pseudocapsule in order to preserve the neurotransmission.

Research highlights▶ Substance P (SP) and Vasoactive Intestinal Peptide (VIP) are present in the pseudocapsule of uterine fibroids. ▶ This quantitative distribution is similar to theirs distribution in the myometrium. ▶ The fibroid removal by intracapsular method is neurotransmitter sparing at the hysterotomy site. ▶ This method preserves SP and VIP fibers in the uterus, allows an optimal healing of myometrium and maintains its functionality for future pregnancies and labor.