3D ultrasound to assess the position of tubal sterilization microinserts

The aim of this study was to assess the diagnostic accuracy of three-dimensional ultrasound (3D-US) for determining the position of Essure microinserts and the success of sterilization by the Essure method.

This retrospective observational study examined the case records of 311 women who underwent hysteroscopic sterilization from October 2002 through October 2008. Imaging with 3D-US or pelvic X-radiography or both was performed 3 months after the procedure to verify device position. Hysterosalpingography (HSG) was performed when a bilateral procedure was not completed because of a history of salpingectomy or blocked tube, when doubt persisted after 3D-US or pelvic radiography, or for comparative purposes in a prospective study. The positions seen on 3D-US were classified in four categories according to a specific scale we devised.

The insertion procedure was completed in 94.2% patients. Only 90.5% underwent imaging verification of the device 3 months afterwards. In all, 227 3D-US, 175 pelvic radiography and 64 HSG imaging procedures were performed. Visualization of the device was possible in 99.6% of the 3D-US images. According to our classification, 3D-US was appropriate for assessing device position for 195 (85.9%) patients. The need for HSG confirmation was significantly lower with 3D-US than radiographic imaging (14.1 versus 26.8%, P = 0.001). 3D-US examinations, compared with the results of HSG as the reference test, had a sensitivity of 100% and a specificity of 76.6%. Neither pregnancy nor early expulsion occurred when 3D-US found that the devices were correctly placed.

3D-US is a simple technique for assessing the position of Essure(®) microinserts, even after concomitant endometrial surgery. The 3D-US classification presented here appears to make it possible to use HSG for back-up confirmation only when the microinsert is found in a very distal position on 3D-US and thus to protect the majority of women from the negative effects of pelvic radiography and HSG.