Research
Urogynecology
Levator avulsion using a tomographic ultrasound and magnetic resonance–based model

https://doi.org/10.1016/j.ajog.2011.03.052Get rights and content

Objective

Delivery-related levator avulsion can cause pelvic floor dysfunction. We compared agreement between tomographic ultrasound and magnetic resonance–based models for the detection of levator defects.

Study Design

Sixty-nine Chinese women with pelvic organ prolapse were assessed prospectively by 3-dimensional ultrasound scans and magnetic resonance imaging. Levator-urethra gap (LUG), levator-symphysis gap (LSG), and puborectalis attachment width were measured offline with state-of-the-art software. Interobserver variability and agreement between the 2 methods were determined.

Results

Interobserver repeatability was moderate-to-excellent for all parameters that were measured with both methods and agreement between methods in diagnosing levator avulsion. LUG and LSG measurements were significantly higher in women with a levator avulsion. With a diagnosis of complete levator avulsion, receiver operating characteristics analysis suggested a cutoff of 23.65 mm for LUG and 28.7 mm for LSG.

Conclusion

Levator avulsion can be diagnosed reliably by tomographic ultrasound scanning and magnetic resonance imaging evaluation, and linear measures, such as LSG and LUG, can be proxy measurements for avulsion.

Section snippets

Materials and Methods

In this prospective study, 3-dimensional pelvic floor ultrasound scanning and an MRI-based 3-dimensional model were used to assess the abnormal morphologic condition of the pubovisceral muscle in women who had significant pelvic organ prolapse. It was conducted between December 2008 and February 2010 at the Fuzhou General Hospital, Fuzhou, Fujian Province, China. Over the course of 1 year, 69 women who were to undergo surgery for prolapse repair were assessed with the use of pelvic floor

Results

Because of corrupt datasets, we were unable to obtain data from 3 women, which left data from 66 women to be assessed. The mean age of the patients was 63 years (range, 41–86 years); median vaginal parity was 3.3 (range, 0–9); 65 women had given birth vaginally. Complaints at presentation were stress incontinence (31%), urge incontinence (29%), symptoms of voiding dysfunction (such as hesitancy, a poor stream, and straining to void; 59%), and prolapse symptoms (93%). The general demographic

Comment

This study compared levator defects imaged by 3-dimensional pelvic floor ultrasonography and an MRI-based model in an attempt to validate the former method as a means of assessing levator avulsion. It confirms that the 2 methods used for the diagnosis of levator avulsion correlate well with each other. There was good agreement between observers for the diagnosis of avulsion defects by TUI, which is consistent with previous studies.27 Our data on LUGs and LSGs also confirm previous study by

Acknowledgements

We are indebted to the National Cancer Imaging Archive (NCIA) in the United States for offering 3-dimensional slicer software (www.slicer.org), which is a multiplatform, free, and open source software package. We thank Professor Hans Peter Dietz for giving us instruction on tomography ultrasound imaging by e-mail.

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    Supported by Grant no. 2010Y0046 from the Fujian Provincial Key Projects Foundation of China and by Grant no. 2010Y2005 from Fujian Science and Technology Foundation of China.

    Cite this article as: Zhuang RR, Song YF, Chen ZQ, et al. Levator avulsion using a tomographic ultrasound and magnetic resonance–based model. Am J Obstet Gynecol 2011;205:232.e1-8.

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