The McDonald procedure is done with a 5 mm band of permanent suture is placed high on the cervix. This is indicated when there is significant effacement of the lower portion of the cervix. It is generally removed at 37 weeks, unless there is a reason to remove it earlier, like infection, preterm labor, premature rupture of the membranes, etc. It is also shown that this has very little impact of the chance for vaginal delivery.
The Shirodkar is also used a frequently used technique. However, this was previously a permanent purse string suture that would remain intact for life. When this type of cerclage is done, a cesarean section will always be performed. There are physicians performing modified techniques, where the delivery does not necessarily have to be by cesarean, nor the suture left intact. Ask your practitioner which procedure they perform.
The Hefner cerclage, also know as the Wurm procedure, is used for later diagnosis of the incompetent cervix. It is usually done with a U or mattress suture, and is of benefit when there is minimal amounts of cervix left.
Uterosacral cardinal ligament cerclage is generally done after the McDonald and Shirodkar procedures have failed, or where there is a congenital shortened cervix, or subacute cervicitis. It can be done vaginally, but is frequently done abdominally. Again, cesarean delivery is mandated for birth.
The last procedure, the Lash, is performed in the non-pregnant state. It is typically done after cervical trauma that has caused an anatomical defect. There is the possible, though rare, side effect of infertility.
While these procedures are life-saving, they also have potential risks:
- Premature rupture of membranes (1-9%)
- Chorioamnionitis (Infection of the amniotic sac, 1-7%) (This risk increases as the pregnancy progresses and is at 30% for a cervix that is dilated more than 3 cms.)
- Preterm Labor
- Cervical laceration or amputation (This can be at the procedure or at the delivery, from scar tissue that forms on the cervix.)
- Bladder Injury (rare)
- Maternal hemorrhage
- Cervical dystocia
- Uterine rupture
The procedure is generally to observe the patient for 24 hours before performing the cerclage. During this time she will be observed for preterm labor and screened for infection. Generally this is done with the patient in the Trendelenburg position, feet above your head. Spinal anesthesia is used to prevent pain and maternal straining during the cerclage. Your bladder will be filled to try and move your membranes away from the os. You will be given antibiotics to help stave off infection, and Indocin to help your body ignore the prostaglandins released during the procedure.
Post-operatively you will be on bed rest for the next 24 hours, possibly in the Trendelenburg position. And monitored for uterine activity.
Once released from the hospital you will be on pelvic rest (no sex) for the remainder of the pregnancy. You will need to have periods of rest each day and decreased physical activity. You will be seen in the office at least once weekly until the birth. You will also be monitored for preterm labor. If you have any contractions you should contact your doctor right away.
Cerclage seems to be a very effective treatment for incompetent cervix. The success rates can be very high (80-90%), particularly when done earlier in a pregnancy. If you have concerns about your prenatal history or suspect an incompetent cervix ask your practitioner to examine you.