The aim of this prospective observational and descriptive study was to compare the outcomes of a pessary or surgery in women with symptomatic POP, and the hypothesis was that continuous use of a ring pessary (without support) is as effective as surgery and less risky in not hysterectomized, postmenopausal women with advanced-stage POP using the Pelvic Organ Prolapse Quantification system (POP-Q).

Between January 2013 and June 2015, 171 non-hysterectomized, postmenopausal patients with symptomatic POP (Stages III and IV) were counselled about the two treatment options: surgery or vaginal pessary. 
Patients could choose conservative treatment with pessary or POP surgery following their preference. 
The inclusion criteria were non-hysterectomized, postmenopausal patients with symptomatic POP (stages III and IV) who agreed to use the vaginal ring pessary as treatment.
Women who had a mental illness or who refused to participate in this study were excluded. 
Ninety-four patients (age range, 47–90) agreed to use the vaginal ring pessary, and 77 (age range 50-87) choose vaginal hysterectomy. The follow up  period was up to January 2017. 
All women were followed for a minimum of 18 months (range, 18-49 months) after the start of their pessary use or after surgery. 
This study was approved by the Ethics Committee of the Hospital.

Eight different pessary sizes were used for successful pessary fittings in this study. The median follow-up time was 24 months (range, 18–49 months). The ring pessary was fitted in 94 patients at the initial visit. Fourteen [14/94 (14.9%)] patients discontinued pessary use. After discontinuing pessary use, all these patients opted for surgery. 
Thirteen [13/94 (13.8%)] patients who had extrusion of the pessary during daily activities in the 1st week opted for reinsertion.
Nine [9/94 (9.6%)] patients switched to larger pessaries, one [1/94 (1.1%)] switched to a smaller pessary, and three [3/94 (3.2%)] opted for a pessary of the same size.
Adverse events were evaluated in the patients with successful fittings at the end of the study. 
The most common adverse event was extrusion of the pessary during defecation or daily activities.
All adverse events in that group of patients [24/76(31.6%)] were of Clavien-Dindo grade I.
Transvaginal hysterectomy and anterior colporrhaphy with native tissue were the interventions performed in most women [47/77 (61%)]. Sixty-nine patients (69/77) did not have any prolapse by the end of the study (at the 27-month median follow-up), resulting in a success rate of 89.6%. 
A total of eight patients [8/77 (10.4%)] met the composite definition of prolapse recurrence with prolapse beyond the hymen and/or retreatment. 
Using the POP-Q classification, six [6/8 (75%)] patients had a third-stage vault prolapse, and the other two patients had a fourth-stage vault prolapse.
The only case of an intraoperative complication [1/77 (1.3%)] was a bladder injury; it was detected and treated immediately, followed by a week with an indwelling urethral catheter.
Using the Clavien-Dindo classification, we found grade 1 events in 11 patients [11/77 (14.3%)], grade 2 events in 8 cases  [8/77 (10.4%)], and grade 3 events in 11 women [11/77 (14.3%)] (4 grade 3a and 7 grade 3b).
At the end of the study, the successful use of a pessary was 84.4%, and 89.6% of patients in the surgical group did not complain of any prolapse recurrence (p = 0.115). 
During analysis of complications, there was a significant difference between groups when Clavien-Dindo grades were considered (p < 0.001).

In the pessary group, the success rate was 84.4%, and it was 89.6% in the surgery group, which was not a statistically significant difference (p = 0.115). 
Consequently, considering efficacy, we can assert that there were no differences between the two options for treatment for POP.
Several studies evaluated the complications of successfully fitted ring pessaries, with rates ranging from 56 to 58%.
In our study, the adverse event rate was 31.6%, which was lower than in the previous studies, and all were Clavien-Dindo grade I. For the 77 patients in the surgical group, we found a postoperative vault prolapse rate of 9.1% (7/77), while in the literature, the prevalence of post-hysterectomy vault prolapse recent data suggest an incidence of 11.6% following hysterectomy for prolapse and 1.8% for other pathologies.
One of the focal points of our analysis was adverse effects in the conservative treatment and surgical groups using the Clavien-Dindo scale to compare the clinical relevance of the complications. Patients in the surgery group had a higher rate of adverse effects (39%) than those in the pessary group (31.6%), and the difference was statistically significant (p < 0.01). Although first-degree complications were more frequent in the pessary group (31.6%), all were easily treated, and we did not find any second- or third-degree complications in those patients. 
On the other hand, in the surgery group, 24.6%of patients had a second- or third-degree adverse event, and those patients required more invasive procedures, such as drainage of a parametrial abscess percutaneously or a second surgery for vault prolapse.
Our results suggest that a ring pessary without support can be recommended as first-line treatment in patients with advanced stages of POP. 
In our opinion, it seems reasonable, when dealing with two treatments of similar efficacy, to the one with less severe adverse effects.

The pessary is effective and has mild adverse events in non hysterectomized, postmenopausal women with advanced POP.