Cervical internal os cerclage: description of a new technique and comparison with Shirodkar operation.

Internal os cerclage for cervical incompetence was performed in 90 patients who had previous McDonald procedure failure (70 patients) or had unfavorable cervical anatomy (short or lacerated cervix) for primary McDonald type cerclage (20 patients). Two different techniques were used: the Shirodkar operation (n = 44) with Mersilene band, and a simpler new technique (n = 46). The new technique is characterized by anterior colpotomy for exposure of the internal os, and a 0.6 mm nylon suture encircling the cervix to be tied high in the posterior fornix. The pregnancy outcome for both groups was similar. Late abortions of 8.7 and 11% and premature deliveries of 13 and 18% occurred in the new technique and the Shirodkar groups, respectively. The removal of the suture was generally difficult in the Shirodkar group and in eight patients analgesia and sedation were required. In the new technique group, the removal was easier and in only one patient was sedation required (p less than 0.0001). Severe vaginal discharge was found in 52% of the Shirodkar patients and none in the other group. Apparently the monofilament nylon suture prevented this side effect. It seems that the new technique is simpler to perform, involves fewer side effects, the removal of the suture is easier, and it is as effective as the Shirodkar procedure.