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Biomedical subjects

H van der Pas

Publications and source records attributed to H van der Pas.

16 recordsLinked to original sources
PubMed1996

Endometrial ablation using a distensible multielectrode balloon.

The VestaBlate system uses a multielectrode intrauterine balloon as a device to create effective and safe endometrial ablation (EA). The surface of the distensible balloon is impregnated with thermistors and thin, platelike electrodes. It is designed to deliver low-power electroenergy to the endometrium. Unlike the resectoscope techniques that require nonelectrolytic fluids for uterine distention, moving electrodes at high power outputs, and other variables that are operator dependent, the VestaBlate is computer controlled using a standard type electrosurgical generator. A respiratory enzyme stain, nitroblue tetrazoleum, was used to determine the extent and depth of tissue necrosis to a myometrial depth of 2 to 4 mm with uniform destruction of tissue with power setting at 45 W for a 4-minute application of energy. Sixty-nine patients have been treated, with 45 followed for at least 3 to 9 months. The amenorrhea rate is 40%; the oligomenorhea-hypomenorrhea rate is 49%.

Electrodes↗
PubMed1995

The frameless GyneFix intrauterine implant: a major improvement in efficacy, expulsion and tolerance.

The CuFix (GyneFix), conceived in 1985, was developed to minimize three major problems frequently associated with discontinuation of IUD use: expulsion, bleeding and pain. Since the initial clinical investigations, over 10,000 woman years of experience and up to 8 years of follow-up in international multicenter, non-comparative and comparative clinical trials, including a large proportion of nulligravid/nulliparous women, have been collected. Based on new clinical information about the GyneFix from a long-term multicenter clinical trial, conducted in young nulligravid/nulliparous and parous women, the importance of this new contraceptive is discussed. The following conclusions were reached: The unique design characteristics of the GyneFix (frameless, flexible and fixed to the fundus of the uterus) have resulted in optimal tolerance and almost complete absence of expulsion. The result is enhanced effectiveness (comparable to OCs and male/female sterilization) and a high rate of continued use. The GyneFix reduces the IUD failure rate to a minimum and is, therefore, a welcome reversible alternative to OCs and female surgical contraception. Framelessness and flexibility explain the absence of side-effects and adverse events caused by dimensional incompatibility between the frame of conventional IUDs and the uterine cavity and may also explain the absence of PID and ectopic pregnancies in any of the clinical studies. The GyneFix is a promising new, highly effective and safe, contraceptive option for parous women and an equally effective and well-accepted method for nulliparous women.

Adolescent↗
PubMed1995

IUD expulsion solved with implant technology.

In an attempt to minimize the problem of IUD expulsion, implantation technology has been developed and tested. The trials have extended from 1985 until the present time for interval as well as for immediate postabortal and post-placental insertion and fixation of the CuFix IUD (Gyne-Fix). The present article reports on an ongoing study with GyneFix interval insertion, with an improved inserter, in 820 women, observed up to 3 years, of whom 213 (25.9%) are nulligravid/nulliparous. The cumulative expulsion rate is 0.6 per 100 women-years at 3 years and is not significantly higher in the nulligravid/nulliparous group. The cumulative pregnancy rate is 0.6 and the cumulative removal rate for medical reasons 3.2 at 3 years. The total experience in this multicenter study covers approximately 14,000 woman-months. It is concluded that the design characteristics of the GyneFix (fixed, frameless, and flexible) explain the low expulsion, high efficacy and high acceptability rates. The implantation technology is very effective and the improved inserter allows easy insertion and optimal anchoring.

Adult↗
PubMed1989

Long-term experience with Multiload intrauterine devices.

This paper reports the joint experience of three investigators who used three types of the Multiload (ML) IUD (MLCu250 Short, MLCu250 Standard, and MLCu375) in 1987 consecutive insertions during which an experience of 56,005 woman-months of use was accumulated. The material was analyzed using the life-table method and complemented with a case by case investigation, the main purpose of the study being the specific analysis of IUD-related complications. The authors also evaluated return of fertility whenever a device was removed because of wish of pregnancy. Results indicate that serious IUD-related complications were rare, continuation rate high, and reversibility of fertility unaffected by the device.

Computer Simulation↗
PubMed1988

The Copper-Fix (Cu-Fix): a new concept in IUD technology.

The Copper-Fix (Cu-Fix) is a thread-type copper-bearing device designed to overcome the most common IUD-related problems: bleeding and pain. Two distinctive features--virtual absence of a frame and provision of an anchoring system--make this new intrauterine device the first radical departure from current IUD technology. The Cu-Fix 390 was inserted at intervals in 382 women, and 4851 woman-months of experience had been accumulated at 18 months. The device was exceedingly well retained by the uterus (expulsion rate 0.6 at 18 months) and the removal rate for bleeding/pain was low (3.1 at 18 months). Serious complications did not occur; the pregnancy rate amounted to 0.3 at 18 months, with a continuation rate of 87.6%, which includes an 8.1% removal rate for pregnancy wish. Cardinal event rates were not influenced by the age or gravidity status of the recipient.

Adult↗
PubMed1987

The Ombrelle-380 IUD: a pilot study.

The initial results of a pilot trial (314 insertions and 3784 woman-months of experience at 18 months) suggest the low expulsion rate (0.0) and high clinical effectiveness (pregnancy rate 0.0) of the Ombrelle-380, a new high-load copper-releasing IUD of French origin.

Female↗
PubMed1987

The Dimélys IUD.

The Dimélys is a new lily-shaped copper-bearing IUD of French origin of which the first clinical results are reported here. This device was inserted at interval in 348 women and 8975 woman-months of experience were accumulated at 3 years. Though only moderately effective (pregnancy rates 2.8 and 5.7 at 1 and 3 years, respectively) the Dimélys is well retained by the uterus (expulsion rates 1.5 and 2.5 at 1 and 3 years, respectively). Clinical efficacy was found to be influenced by the recipient's age, and expulsion rates were significantly higher when inserted by unskilled operators.

Adult↗
PubMed1987

Immediate postpartum insertion: performance of the Nova-T-PP and randomized comparison with the Nova-T.

Clinical evaluation of the Postpartum Nova-T or Nova-T-PP (a Nova-T IUD adapted for postpartum insertion) was based on 412 insertions and showed that this model--besides being effective and safe--had a low expulsion rate (7.2% at 1 year). To prove that the Nova-T-PP's low expulsion rate is indeed the result of its special design, a randomized trial was conducted to compare the Nova-T-PP with the parent model (Nova-T) when inserted within 10 minutes of delivery of the placenta. The result of this study (408 insertions, 203 of them Nova-T) indicate that there is no significant difference in expulsion rate between the two IUD models, suggesting that the addition of two extra arms to the original Nova-T model does not improve the retention of the adapted IUD model.

Adult↗
PubMed1983

Immediate postplacental IUD insertion: a randomized trial of sutured (Lippes Loop and TCu22OC) and non-sutured (TCu22OC) models.

A randomized clinical trial concerning immediate post-placental insertion (IPPI) of the Delta Lippes Loop, Delta TCu22OC, and TCu22OC was undertaken to assess the effect of the addition of catgut strands on IUD performance. A total of 906 devices were inserted and the subjects followed for 20 months, at which time 14,136 woman-months experience had been accumulated. The Delta Loop constantly had inadmissibly high expulsion and pregnancy rates. The two T-IUD models had significantly lower rates of expulsion and pregnancy, and these rates were similar for the sutured and the non-sutured TCu22OC. Immediate postplacental insertion of the three IUD models was totally safe in terms of infection and perforation. Due to the difficulty of insertion and high expellability, the Delta Loop is considered unfit for IPPI. Performance of the TCu22OC was good but the results did not indicate that "suturing" improved the retainability of this IUD model significantly.

Adult↗
PubMed1983

Carbon dioxide hysteroscopy immediately after second trimester abortion.

The use of hysteroscopy has been restricted a.o. by the need for general anesthesia. This applies in particular to the pre- or post-partum period, because the hyperemic atonic uterus is easily over-inflated to a dangerous level. Over-inflation did not occur following 50 aspirotomy D & E procedures in the second trimester, using a para- and intracervical block with lidocaine 1% with adrenaline 1:200,000 only. The uterine cavity was always thoroughly evacuated in these cases in which final check suction had been performed. We recommend that postabortum hysteroscopy should be performed preferably under local anesthesia.

Abortion, Induced↗
PubMed1982

The ML Cu250; clinical experience in Belgium and The Netherlands.

The ML Cu250, a copper-wired intrauterine contraceptive device, was inserted in 5736 women, at interval or immediately after delivery of the placenta. Forty-eight months after insertion, the data covering 196 214 woman-months were computerized and then analysed according to the life-table method. Interval insertion was more effective than postplacental insertion. In nulligravidas interval insertion did not increase the removal rates for other medical reasons (including pelvic inflammatory disease), but expulsion rates were higher relative to the entire group (a variety of parities).

Belgium↗
PubMed1977

[Contraception with the Lippes Loop D with or without contraceptive foam (author's transl)].

Contraception with Lippes Loop D was compared in 1 group of women (N 172) who used a spermicidal preparation with intercourse and a second group (N 190) who used no spermicidal preparation. In the group with a Lippes Loop and a spermicidal preparation, there were 1.2% unplanned pregnancies compared to 6.4% unplanned pregnancies without spermicidal preparation. This combined method approaches the reliability of oral contraception. The third group of women who used a spermicidal preparation erratically is not comparable in the statistical sense to the other two groups. However in this third group there were less unwanted pregnancies than in the group without the use of spermicidal preparation.

Contraceptive Agents, Female↗