Types of pessaries
The numerous kinds of pessaries available fall into 3 general categories: support, space filling, and lever, and devices within each group have modifications and variations. As with most areas of prescribing and treatment in medicine, it is best to become very familiar with just a few kinds of pessaries, know their indications, and use them when appropriate.
Most pessaries are constructed of inert silicone which, unlike earlier rubber pessaries, does not absorb odor or discharge. They are easy to clean, long lasting, and are autoclavable and hypoallergenic.
Support pessaries
Support pessaries look like contraceptive diaphragms. They are easy to place and remove, are comfortable, and do an excellent job correcting moderate POP. They also can control or eliminate symptoms of SUI by the pressure they exert on the urethra and their alteration of the urethrovesicular angle.
Ring pessaries. The most commonly used type of pessary, the ring pessary,10 comes in 4 variations:
- a simple open ring
- a ring with a web of material, called a “support shield,” that fills the ring
- an open ring with a firm 2-cm “incontinence knob” attached that is positioned over the urethra
- a ring with support shield and incontinence knob.
When in position, the deepest edge of a ring pessary fits behind the cervix (or in the vaginal apex for women who have had a hysterectomy) while the front of the ring slips into place behind the pubic symphysis, just like a diaphragm. When a ring with an incontinence knob is used, the ring is rotated until the knob is directly over the urethra.
Sexual intercourse is possible with any of the ring pessaries in place. Of the various types of pessaries, the ring pessary is the easiest to insert and remove. Some women tie a piece of dental floss to the edge of the ring to make its removal even easier.
The ring pessary is available in sizes 0 (44.5 mm) to 13 (127 mm). For most women a size 3, 4, or 5 ring pessary fits well.
The Marland pessary is similar to the ring pessary with the addition of a wedge-shaped piece of material approximately 3 cm in height that arises from half of the ring. It rarely is used in the United States because most American gynecologists are unfamiliar with it, and there is little evidence that it is more effective than the ring pessary.11
The Shaatz pessary is a rigid round pessary, smaller in diameter than the standard ring pessary, and similar to the Gellhorn pessary (discussed below) but without a stem. It is placed the same way one places a ring pessary but with its concave surface up against the cervix or, if there is no cervix, against the upper anterior vaginal wall. Its main benefit is that it provides firmer support than the ring pessary. This pessary is not widely used in the United States.
The Gehrung pessary looks like a flat strip of material that has been bent into the shape of a “U.” It is designed to correct severe cystoceles and rectoceles. For insertion, the edges at the open end of the pessary are squeezed together and the pessary is inserted with the closed part of the “U” facing the anterior vaginal wall. The upper edge is advanced until it rests in the anterior fornix of the vagina (or in the vaginal apex in women who have had a hysterectomy). Although it is more efficacious than some other pessaries for control of vaginal wall prolapse, its unfamiliarity to clinicians and its unusual shape result in it being used rarely.
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