A new methodologic approach for clinico-pathologic correlations in invasive placenta previa accreta.

BACKGROUND: The development of new management strategies for women presenting with placenta accreta spectrum requires quality epidemiology data, which have so far been limited by the high variability in clinical and histopathologic data confirming the diagnosis at birth. OBJECTIVE: To evaluate the role of a new methodologic approach for the correlation of clinical and pathological data for women with a history of prior cesarean delivery diagnosed prenatally with placenta previa accreta. MATERIALS AND METHODS: A modified pathologic technique for gross examination of hysterectomy specimens with placenta in situ consisting of intraoperative examination, immediate postoperative examination, and guided histologic sampling was used prospectively in a cohort of 24 patients with singleton pregnancies complicated by placenta low-lying/placenta previa accreta. Maternal characteristics, detailed ultrasound findings, surgical outcomes, and histopathologic examination were compared with those of a group of 24 patients with similar clinical characteristics and in whom a standard pathologic examination method was used. RESULTS: The median reporting time for obtaining the complete histopathology results including the microscopic examination was significantly shorter (7 versus 15 days; P < .001) and the median number of samples taken for histologic examination significantly lower (4 versus 14 samples; P < .001) in the study group than in the controls. The number of histologic slides showing villous invasion was significantly higher (2 versus 1 slide; P = .002), and the ratio of the number of samples taken to the numbers of slides confirming villous invasion was significantly lower (2 versus 9; P < .001) in the study group than in the controls. In all cases in the study group, intraoperative examination identified a dense tangled bed of vessels or multiple vessels running laterally and cranio-caudally in the uterine serosa above the placental insertion that were no longer visible during immediate gross postoperative examination of the hysterectomy specimens. Immediate postoperative dissection enables the differential diagnosis between focal and large increta areas, and between abnormally adherent placenta and invasive placenta accreta. CONCLUSION: Valuable clinical information on the serosal vascularity, uterine dehiscence, and extension of the accreta area is added with the description of the macroscopic examination during the surgical procedure and immediate dissection of the specimen. This methodological approach is cost-effective and increases the quality of the histologic sampling. It thus provides more accurate correlations with the clinical data and more accurate epidemiologic data collection. Perinatal pathologists should be part of multidisciplinary teams involved the management placenta accreta spectrum disorders.