| Objective: The aim of the study was to evaluate the pH value, the changes in the histological morphology, the tight junctions between epithelial cells of the neovaginal mucosa and the expression of Occludin, zona occluden-1 (ZO-1) and nitric oxide synthase (nNOS) in the sigmoid neovaginal mucosa of the patients undergoing vaginal construction by sigmoid colon, and to explore the putative reason for the neovaginal defense function after artificial vaginal construction.Methods: The objects were selected in the patients who underwent vaginal reconstruction by sigmoid colon in the Second Hospital of Hebei Medical University and were follow-up from October 2005 to October 2007. After having gained the consents of the Ethics Committee of the hospital and having known the fact, 15 patients agreed to take part in present study (the study group). The postoperative results were analyzed regarding the patient's anatomical and functional status through physical examination and regarding the satisfaction during sexual intercourse by self-made questionnaires. The pH value of the sigmoid neovagina was determined by high precision pH paper in the follow-up objects. Biopsy of the neovaginal mucosa was taken in the upper one-third and the lower mucosa (3 cm distal to the hymen) of the sigmoid neovagina. In control group, Biopsy of the normal colonic mucosa was taken during the operation of sigmoid vaginal construction in the corresponding time period. The morphologic changes of the sigmoid neovaginal mucosa were investigated by the microscope after the samples had been dyed with the HE dyeing method. At random, 5 samples coming from the samples of the upper one-third of the sigmoid neovagina, of the lower neovaginal mucosa and of the control group were respectively selected and investigated by the electron microscope. At the same time, the specimen immunochemically stained for the Occludin, ZO-1 and nNOS were analyzed semiquantitatively. The statistical software SASv6.12 was used to analyze the data. The measurement data were shown with mean±SD and analyzed by t test, while the ranked date were analyzed using rank-sum test. There was significant difference on statistics if P values less than 0.05.Results:1 The general situation: 80% of the objects undergoing vaginal reconstruction by sigmoid colon were satisfied with the appearance of the neovagina, which is similar to the normal vagina. The average time was 7.50±2.43 (4~12) months when the discharge of the neovagina became to decrease after the operation. The mean time of the sexual intercourse among the objects who had sexual behaviors was 18.27±13.52 (1~38) months, most of them (50%) were satisfied with their sexual lives. The mean depth and width of the neovaginal cavity were 12.5 cm and 3.9 cm, respectively. The neovaginal mucosa was moist, soft and flexible. The interval time between operation and biopsy was 19.80±14.74 (6~48) months. The average pH value of the neovagina was 7.79±0.39, compared to normal vagina, and obviously alkalinous (P<0.01).2 Pathological observations: In the upper one-third of the neovagina, there were no significant histological changes in mucosal epithelial layer, while the muscularis mucosa was hyperplasy and pachynsis. In the lower mucosa of the sigmoid neovagina, the squamous metaplasia had happened in 10 cases (76.7%). The number of the glands in the mucosa was decreased, some of which were atrophy. Moreover, the mesenchym of the mucosa was increased, the muscularis mucosa and the submucosa were thinner or disappeared.3 Observation with transmission electron microscope: The microvillus, cellular organelles and the tight junctions between epithelial cells of the normal sigmoid mucosa were intact in control group. In the sigmoid neovaginal mucosa, the microvillus became thin and rare. Some of the mitochondrial cristae were fusion or disappeared and some rough endoplasmic reticulum were slightly expanded and degranulated. The tight junctions between epithelial cells of the neovaginal mucosa became shorter and wider than the control group, even disrupt, the quantity of them were decreased or disappeared.4 The expression of the Occludin and ZO-1:In the control group, the tight-junction-associated proteins Occuldin and ZO-1 were continuous and uniform distribution localized at the apical region of cell-to-cell contact of enterocytes.In the upper mucosa of the sigmoid neovagina, the distribution of Occuldin and ZO-1 were irregular and the expression of them were significantly lower than those in the lower mucosa of the neovagina where the squamous metaplasia had happened (P<0.05) and in the control group (P<0.01).In the lower mucosa of the sigmoid neovagina where the squamous metaplasia hadn't happened, the distribution of Occuldin and ZO-1 were disrupted and nonuniform, the expression of them were significantly lower than those in the lower mucosa of the neovagina where the squamous metaplasia had happened and in the control group (P<0.05), while there is no significantly difference in expression of them between this group and the upper mucosa of the neovagina (P>0.05). Interestingly, in the lower mucosa of the neovagina where the squamous metaplasia had happened, the expression of Occuldin and ZO-1 were continuous and positive,there is no significantly difference in expression of them between this group and control group(P>0.05).5 The expression of the nNOS: Compared to control group, the expression of nNOS in the upper mucosa of the sigmoid neovagina were decreased significantly (P<0.05). In the lower mucosa of the sigmoid neovagina where the squamous metaplasia hadn't happened, the expression of them were significantly lower than control group (P<0.05); while there is no significantly difference in expression of nNOS between this group and the upper mucosa of the sigmoid neovagina (P>0.05).Conclusions:1 Most of the objects were satisfied with the appearance of the sigmoid neovagina and their sexual lives.Therefore, we consider that vaginal constrution performed using isolated sigmiod segment is a feasible method.2 The neovaginal pH value was less alkalinous than that in natural position of sigmoid colon. The changes of the functional deterioration of secretion and the decrease of the tight junctions between epithelial cells in the neovaginal mucosa manifestated that the defense function of sigmoid neovagina became weaken.3 The expression of the Occludin and ZO-1 in the upper mucosa and the lower mucosa of the sigmoid neovagina where the squamous metaplasia hadn't happened were decreased.These changes showed that the mucosal physical barrier of artificial vagina became weaken.4 The squamous metaplasia had happened in most of the lower mucosa of the sigmoid neovagina, which may be the morphologic changes of the neovagina to adapt to new enviroment and function. In the lower mucosa of the neovagina where the squamous metaplasia had happened, the expression of Occuldin and ZO-1 were similar to those in the normal sigmoid colon, these changes may showed that the defense function of neovaginal mucosa became stronger again because of the squamous metaplasia had happened.5 The decrease of the nNOS expression in the neovaginal mucosa may have some relationships with the decrease of the artificial vaginal discharge and the adaptive changes of the neovaginal defense function. |
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