Laminaria Natural Cervical Dilator in Obstetrics and Gynecology
Laminaria is a 100% natural cervical dilator made from a sea-grown plant containing no synthetic materials. Osmotic dilators, also known as hygroscopic dilators, are medical implements used to dilate the uterine cervix by swelling as they absorb fluid from surrounding tissue. A laminaria stick or tent is a thin rod made of the stems of dried Laminaria, a genus of kelp. These devices provide gentle and gradual dilation and have been safely used for over a century.
Mechanism of Action
Laminaria function by absorbing fluid from the surrounding tissue and expanding. Thus exerts radial pressure on the cervix. They also cause the release of prostaglandins. Once inserted, laminaria swells several times its initial dried diameter. Over time, the osmotic dilator absorbs fluid and swells to 3-4 times the initial diameter. Most of the increase in size occurs within 6 hours after the dilator are placed in the cervix, though further expansion will continue over 12–24 hours.
Clinical Use and Placement
Osmotic dilators are most commonly used to slowly dilate and soften the cervix prior to surgical abortion, a process referred to as cervical preparation. Most abortion providers use laminaria, Dilapan-S, or both for osmotic dilation prior to surgical abortion after 16–18 weeks gestation. Osmotic dilators may also be used to achieve cervical dilation prior to gynecology procedures, such as hysteroscopy or dilation and curettage of the non-pregnant uterus.
Prior to a planned surgical abortion, osmotic dilator(s) may be inserted into a woman's cervix. The dilator is grasped with a ring forceps and is placed into the cervix so that it spans both the internal cervical os and external cervical os. Laminaria tents are usually left in place overnight. They are removed by grasping the strings of the dilator and applying gentle traction.
Product Specifications
MedGyn offers laminaria in various sizes and configurations to meet clinical needs:
| Type | Length | Available Diameters |
|---|---|---|
| Standard | approx. 60mm | 2mm, 3mm, 4mm, 5mm, 6mm, 8mm, 10mm |
| Extra Long | approx. 70mm | 4mm, 5mm, 6mm, 8mm |
| With Buttons | Standard | 2mm, 3mm, 4mm, 5mm, 6mm |
| Long-String | Standard | 3mm, 4mm, 5mm, 6mm, 8mm |
Safety and Risks
Risks of osmotic dilator insertion include pain, rupture of amniotic membranes, initiation of labor, cervical or uterine perforation, retention of the dilator, and infection. Although the incidence of complications related to osmotic dilator use prior to abortion has not been systematically studied, serious complications appear to be very rare. There may be a lower risk of uterine hyperstimulation with laminaria compared to prostaglandin E2.