Levator defects are associated with prolapse after pelvic floor surgery

Abstract

Objectives

Pelvic organ prolapse recurrence after pelvic floor surgery is a common problem. This study was designed to assess whether avulsion defects of the puborectalis muscle are associated with recurrent pelvic organ prolapse and its symptoms.

Study design

We retrospectively evaluated 737 data sets of patients who had presented to a tertiary urogynaecology unit with symptoms of pelvic floor dysfunction. All underwent a standardised interview including a surgical history, a clinical examination and 4D pelvic floor ultrasound. Avulsion injury was diagnosed on tomographic ultrasound. The prevalence of pelvic organ prolapse and its symptoms was calculated for patients with previous hysterectomy and previous anti-incontinence and prolapse surgery, with and without confirmed avulsion injury.

Results

Out of 737 patients, 248 (33.6%) reported a previous hysterectomy, 165 patients (22.4%) had undergone incontinence or prolapse procedures, 106 (14.4%) reported a previous anterior colporrhaphy, and 45 patients (6.1%) had undergone a colposuspension in the past. In all four groups avulsion injury was significantly associated with objective prolapse (relative risks between 2.3 and 3.3, odds ratios between 3.4 and 6). Symptoms of prolapse were significantly associated with avulsion injury post hysterectomy, incontinence or prolapse procedures and after anterior colporrhaphy.

Conclusions

Avulsion injury of the puborectalis muscle is associated with prolapse in women with previous pelvic floor surgery.

Introduction

Female pelvic organ prolapse is a common condition leading to 300,000–400,000 surgical procedures per year in the United States alone [1] and the lifetime risk of such surgery seems to be over 10% [2]. With a large proportion of these being re-operations, prolapse recurrence after pelvic floor surgery constitutes a major challenge to gynaecologists and their patients, as well as to a limited health care budget.

There have been a number of studies investigating risk factors for pelvic organ prolapse (POP) after pelvic floor surgery. After hysterectomy performed for any reason, preoperative POP and a history of vaginal childbirth seem to be associated with prolapse recurrence [3]. Investigating prolapse recurrence after vaginal repair, Whiteside et al. [4] found that younger women and women with more advanced prolapse are at increased risk. Clark et al. [5] documented increased re-operation rates in women who had undergone more than one prolapse procedure in the past. In another study linking pelvic floor muscle function with recurrence, Vakili et al. demonstrated an increased recurrence rate in women with a wider genital hiatus and reduced pelvic floor muscle contraction strength [6], and in a surgical audit of patients 3–6 years after anterior colporrhaphy we recently found a relative risk of 3–4 for cystocele recurrence in women with avulsion of the puborectalis muscle [7].

The aetiology of pelvic organ prolapse has been intensively studied, and it is generally accepted that vaginal childbirth is one of the main pathogenetic factors [8], [9]. Avulsion injury, that is, trauma to the insertion of the puborectalis muscle at its insertion on the inferior pubic ramus as shown in Fig. 1, is a common consequence of vaginal delivery [10], [11], [12], [13].

Avulsion has been shown to be strongly associated with POP in studies using magnetic resonance imaging (MRI) [14] and ultrasound (US) [15]. This retrospective study was designed to assess whether avulsion injury is associated with an increased likelihood of POP and its symptoms in symptomatic women after pelvic floor surgery, thereby assessing avulsion injuries as a possible predictor of recurrent pelvic organ prolapse after surgical procedures affecting the pelvic floor.