Differential diagnosis of posterior compartment prolapse using transperineal ultrasound

garcia-mejido jose (Orcid ID: 0000-0002-3079-5583) sainz jose a (Orcid ID: 0000-0002-9571-3219) Differential diagnosis of posterior compartment prolapse using transperineal ultrasound J. A. García Mejido1,2, I. Ortega3, R. García-Jiménez1, J. A. Sainz Bueno1,2 1 Department of Obstetrics and Gynecology, Valme University Hospital, Seville, Spain 2 Department of Obstetrics and Gynecology, University of Seville, Seville, Spain 3 Department of Obstetrics and Gynecology, Complejo Asistencial Universitario de Gran Canarias, Gran Canarias, Spain Correspondence José Antonio Sainz Bueno Department of Obstetrics and Gynecology, Valme University Hospital, Seville, Spain. E-mail: jsa[email protected] This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1002/uog.24814 This article is protected by copyright. All rights reserved. INTRODUCTION Pelvic organ prolapse (POP) of the posterior compartment encompass various conditions that may have similar clinical presentation, like an obstructed defecation or a bulge in the vagina. However, management of posterior compartment POP requires an accurate diagnosis of the pathology causing the prolapse, to provide the correct treatment. Currently, transperineal ultrasound defines the “significant descent of the posterior compartment” as the downwards displacement of the rectal ampulla ≥15 mm below the pubic symphysis1. Nonetheless, besides diagnosing the posterior compartment POP, ultrasound can also allow us to make a differential diagnosis of pathologies that may affect the posterior compartment: rectocele, combined recto-enterocele, enterocele or rectal intussusception2. The main objective of this article is to illustrate the differential diagnosis of the various conditions that may cause posterior compartment POP, exclusively based in the image obtained by transperineal ultrasound. Figure 1 shows the different patterns of the posterior compartment pathologies. Rectocele can be seen in the transperineal ultrasound image as a herniation of the anterior rectal wall into the vagina (Figure 1B). In the case of a rectoenterocele, there is herniation of both a rectocele together with the small bowel or other abdominal content towards the vagina. (Figure 1C). Enterocele is shown as a protrusion of the abdominal content anterior to the anorectal angle, separating the vagina from the rectal ampulla (Figure 1D). Rectal intussusception can be seen as an invagination of the anterior rectal wall in the ana canal at the level of the anorectal canal angulation (Figure 1E). DISCUSSION It has been established that transperineal ultrasound has a good correlation with the POP- Q quantification system for the diagnosis of POP, with a concordance of 61,5%3. Moreover, it has proven to be useful in the differential diagnosis of the posterior compartment POP4, which evinces the importance to establish the different ultrasound patterns that differentiate the pathologies that cause the prolapse of said compartment. Although the clinical diagnosis of these conditions related to posterior compartment POP can often be difficult, studies using transperineal ultrasound have shown that rectocele is present in 53% of cases, while enterocele and rectal intussusception represent 14% and 4.3%2 of cases, respectively. In fact, transperineal ultrasound is a simple, inexpensive, and well tolerated alternative to the assessment of defecation disorders and posterior compartment POP5. All of this emphasizes the importance of studying the different ultrasound patterns of the anorectal canal in the differential diagnosis of the posterior compartment POP. REFERENCES: 1 Dietz, HP, Lekskulchai O, Ultrasound assessment of prolapse: the relationship between prolapse severity and symptoms. Ultrasound Obstet Gynecol. 2007; 29: 688-91. 2 Guzman Rojas, R., Kamisan Atan, I., Shek, KL., Dietz, HP. The prevalence of abnormal posterior compartment anatomy in urogynecological patients. Int Urogynecol J. 2016; 27(6): 939-944. 3 Lone FW, Thakar R, Sultan AH, Stankiewicz A. Accuracy of assessing Pelvic Organ Prolapse Quantification points using dynamic 2D transperineal ultrasound in women with pelvic organ prolapse. Int Urogynecol J. 2012; 23 (11): 1555-60. 4 Dietz HP, Steensma AB. Posterior compartment prolapse on two-dimensional and threedimensional pelvic floor ultrasound: the distinction between true rectocele, perineal hypermotility and enterocele. Ultrasound Obstet Gynecol. 2005; 26 (1): 73-7. 5 Dietz, H.P, Beer-Gabel M. Ultrasound in the investigation of posterior compartment vaginal prolapse and obstructed defecation. Ultrasound Obstet Gynecol, 2012. 40: 14-27. LEGENDS Figure 1: Shows the different patterns of the pathologies causing posterior compartment POP, during maximum Valsalva. A: Normal. B: Rectocele. C: combined recto-enterocele. D: isolated enterocele. E: rectal intussusception. P: pubic bone, Bl: bladder, V: vagina, U: uterus, R: rectal ampulla, Ac: anal canal, L: levator ani muscle, Re: rectocele, En: enterocele, RI: rectal intussusception.