Nelaton catheter in non-gravidas for a safe and gradual cervical softening and dilatation: a possible involvement of prostaglandins.

A short Nelaton catheter (No. 7 or 8; diameter: 4.5 or 5 mm) was inserted for 24 hours in the uterine cervix in 89 non-gravidas, including 67 nulliparas. Patients were distributed in four groups depending on the purpose of cervical dilatation: I.U.D. insertion (n = 16), diagnostic curettage (n = 37), hysteroscopy (n = 12), and insertion of radiation applicator in uterine cancer (n = 24). Comparative studies with a smaller number of patients (n = 18) were also performed with a laminaria tent prior to study of the Nelaton catheter. In both the Nelaton and laminaria groups, significant cervical softening and dilatation of the cervix was attained in all cases. After treatment, a Hegar dilator No. 6 to 10 (diameter: 6.5 to 8.8 mm) could be inserted easily without resistance and without the necessity for anesthesia in either group. In the Nelaton catheter group, the tigher the catheter in the cervical canal upon insertion, the higher was the efficiency. The overall efficiency of the Nelaton catheter did not differ significantly from that of laminaria. The Nelaton catheter had several advantages over that of laminaria. No serious side-effects were encountered during the use of the Nelaton catheter compared with laminaria. This simple device proved to be useful as a convenient clinical instrument, particularly in the field of fertility control and for diagnostic and therapeutic purposes of intra-uterine abnormalities. The possible involvement of prostaglandins in the mechanism of action of the catheters is discussed.