Morphometric analysis of smooth muscle in the anterior vaginal wall of women with pelvic organ prolapse.
OBJECTIVE
The purpose of this study was to compare the smooth muscle content of the anterior vaginal wall in normal women and women with pelvic organ prolapse.


METHODS
Specimens were taken from the apex of the anterior vaginal cuff after abdominal hysterectomy from 28 women with pelvic organ prolapse and 12 control subjects. Smooth muscle cells of the anterior vaginal wall were identified by immunohistochemistry with antibodies to smooth muscle alpha-actin. Morphometric analysis was used to determine the fractional area of nonvascular smooth muscle in the muscularis in histologic cross-sections of the anterior vaginal wall.


RESULTS
The fractional area of nonvascular vaginal smooth muscle in the muscularis of women with prolapse was significantly decreased compared with that of control subjects. This decreased fraction of smooth muscle in the anterior vaginal wall was not related to age, race, or stage of prolapse. In women with prolapse, vaginal smooth muscle content was most diminished in specimens from postmenopausal women with no estrogen replacement. The fractional area of muscularis smooth muscle was also decreased significantly in premenopausal women with prolapse.


CONCLUSIONS
The fraction of smooth muscle in the muscularis of the anterior vaginal wall is significantly decreased in women with pelvic organ prolapse compared with normal control subjects.
Division of Urogynecology and Reconstructive Pelvic Surgery, University of Texas Southwestern Medical Center, Dallas, 75390-9032, USA.
Muriel K
MK
Boreham
Clifford Y
CY
Wai
Rodney T
RT
Miller
Joseph I
JI
Schaffer
R Ann
RA
Word
D000199:Actins / Q000032:analysis*; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D009130:Muscle, Smooth / Q000737:chemistry / Q000166:cytology*; D014596:Uterine Prolapse / Q000473:pathology*; D014621:Vagina / Q000033:anatomy & histology* / Q000737:chemistry / Q000473:pathology
D000199:Actins