Elastography Improves the Accuracy of Ultrasound in the Preoperative Assessment of abdominal wall endometriosis

Abstract

Purpose: To assess the role of elastography in preoperative ultrasound assessment of abdominal wall endometriosis (AWE) location.

Materials and methods: 33 patients qualified for surgical excision of AWE were included in the study. Preoperative assessment of AWE was performed transabdominally on a Samsung Medison V20 Prestige with a transvaginal probe and Elastoscan® option. The following B-mode settings were used: focus set to the lower end of the lesion, gain adjusted to obtain best image quality, tissue harmonic imaging activated. For elastographic examinations the color map from red (soft) to purple (hard) and the alpha blend option (a blend of B-mode and elastographic image) were used. AWE location was first assessed by B-mode ultrasound as: superficial (located in SCT only; SCT visible between the fascia and the lesion; intact fascia), intermediate (located in SCT or in RAM; no subcutaneous or muscle tissue between the lesion and the fascia; fascia infiltrated); or deep (located in RAM; muscle tissue visible between the lesion and the fascia; fascia intact). Then the AWE location was assessed by alphablend elastography as: superficial (hard lesion in soft SCT; soft SCT between the fascia and the lesion; no hard areas on the fascia); intermediate (hard lesion in soft SCT or soft RAM; no soft subcutaneous or muscle tissue between the lesion and the fascia; hard areas on the fascia); or deep (hard lesion located in RAM; soft muscle tissue between the fascia and the lesion; no hard areas on the fascia). These findings were verified during surgery. The surgeons were blinded to the results of elastography. The influence of obesity on the accuracy of ultrasound and elastography in assessing the location of AWE was evaluated.

Results: During surgery superficial AWE was found in 6, intermediate in 19 and deep in 8 patients. Preoperative ultrasound assessment was correct in 33.3 % of cases, while adding the elastography option improved the accuracy of AWE location assessment to 87.9 % (p < 0.05). The diagnostic accuracy of ultrasound alone, but not with the elastography option, was significantly decreased in the preoperative assessment of AWE location in overweight and obese patients. 4 patients required implantation of a mesh. In all cases the pathological examination confirmed the diagnosis of AWE.

Conclusion: Elastography significantly improved the accuracy of ultrasound in evaluating the depth of infiltration of AWE, is not affected by increased BMI, and should be considered in patients qualified for surgical treatment of AWE.