Enhanced detection of vascularization in rectal endometriosis: A comparative study of microvascular flow and power Doppler.

Abstract

Background: Conventionally, rectal endometriotic nodules have been considered as poorly vascularized. However, new, more sensitive, Doppler techniques have been developed recently for assessing microvascularization. These new techniques might allow microvascularity in these lesions.

Aim: To compare the vascularization of rectal endometriotic nodules using microvascular (MV) flow and conventional power Doppler.

Methods: Thirty consecutive women diagnosed with deep endometriosis involving the rectum were recruited for this prospective study. All women underwent transvaginal ultrasound using a Samsung V8 ultrasound system (Samsung Medison, Co., Ltd., Seoul, South Korea). The scanning protocol was performed according to the International Deep Endometriosis Analysis consensus. Endometriotic lesions involving the rectum were identified as hypoechoic lesions with blurred margins. Then, power Doppler was activated and the vascularization of the lesion was assessed. Immediately after, the MV-Flow™ with the LumiFlow™ was activated and the vascularization was assessed again. Vascularization assessment was undertaken based on the subjective examiner's impression, using the vascular score proposed by International Ovarian Tumor Analysis group.

Results: The vascular score using conventional power Doppler was score 1 in 87% (n = 26) and score 2 in 13% (n = 4) of the lesions, respectively. The vascular score using MV-Flow™ was score 1 in 6% (n = 2), score 2 in 27% (n = 8), score 3 in 40% (n = 12) and score 4 in 27% (n = 8) of the cases. Grouping cases into score 1-2 vs score 3-4, there was a statistically significant difference with score 3-4 when using MV-Flow™ (67% vs 0%, P < 0.01).

Conclusion: This study shows that many rectal endometriotic nodules exhibit more vascularization than previously thought when using MV-Flow™.