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Biomedical subjects

H Strohmer

Publications and source records attributed to H Strohmer.

35 records · Page 2Linked to original sources
PubMed1995

Hystero-salpingo scintigraphy: a routine investigation in sterile women?

Based on the spontaneous migration of radioactive tracer from the posterior vaginal fornix to the ovaries and peritoneal cavity, several attempts were made to assess hystero-salpingo scintigraphy (HSS). The low acceptance rate by sterile women of routine investigation of tubal function may be due to a fear of radiation exposure and unpleasant examination procedures. Our protocol for HSS adopts a low dose of radioactive tracer (0.2-0.3 mCi), a defined mode of application (between the external and internal os of the cervical canal) and a short imaging time (60 min). From 1990 to 1992, we investigated 60 fallopian tubes in 32 sterile women by HSS, hystero-salpingography (HSG) and/or chromopertubation during laparoscopy (LPSC). The results of HSG and HSS corresponded in 15 of 49 fallopian tubes, LPSC and HSS in 9 of 24. None of the 32 patients had become pregnant naturally during the average observation period of 17 months. Two patients became pregnant after in-vitro fertilization. HSS, performed according to our protocol, causes less pain and results in a lower dose of radiation than HSG (about 50%). It is well accepted by patients and is easy to perform. As an investigation of tubal function, HSS may serve as an additional examination technique in cases of presumed tubal sterility.

Adult↗
PubMed1994

Relationship of the individual uterine size and the endometrial thickness in stimulated cycles.

At present there is no agreement regarding the usefulness of monitoring the endometrial thickness in stimulated cycles. We tested prospectively the hypothesis of a linear relationship of the given individual uterine size and the endometrial thickness in stimulated cycles using a 240 degrees transvaginal sector scanner. There was a strong correlation of the uterine dimension with the endometrial thickness in the midfollicular and the early luteal phase. Our findings suggest that the endometrial thickness is determined by the individual uterine architecture and therefore not predictive of the likelihood of implantation.

Adult↗
PubMed1994

[In vitro fertilization in male subfertility--micromanipulation and special techniques for semen preparation].

Poor semen quality is increasingly the reason for human infertility. For couples who cannot be helped by conventional in vitro fertilization (IVF) treatment, micromanipulation methods and special sperm preparation techniques in in vitro fertilization hold considerable promise to enhance fertilization of the egg. "Partial zona dissection" (PZD n = 59) or "subzonal insemination" (SUZI n = 36) were performed in 88 IVF cycles obtaining a fertilization rate between 12.2% and 34.8% depending on the micromanipulation technique applied and a pregnancy rate of 19.2% per embryo transfer. So far ten ongoing pregnancies have occurred and five healthy children have been born. In certain cases of male factor infertility micromanipulation and special sperm preparation techniques therefore represent the only possibility of conceiving.

Adult↗
PubMed1994

Use of lasers in assisted fertilization and hatching.

The erbium-yttrium-aluminium-garnet (Er:YAG) laser has been applied to micromanipulation in humans. It was used in the fertilization process for both subzonal insemination (SUZI) and for partial zona dissection (PZD). Laser-assisted micromanipulation achieved significantly higher fertilization rates (34.8%) when compared to mechanical SUZI (16.1%), but use of the laser did not improve the PZD results (laser 14.8% versus mechanical 14%). The Er:YAG laser was used to assist hatching. In the mouse it significantly improved the hatching rate (80 versus 29.3%) 110 h after administration of human chorionic gonadotrophin. This technique was applied in two different centres to patients with previous in vitro fertilization (IVF) failures. the implantation rate per embryo (14.4% laser-assisted hatching versus 6% control group) and the pregnancy rate per transfer (40 versus 16.2%) were improved.

Adult↗
PubMed1994

[Assisted hatching and micro-fertilization].

Erbium-YAG laser has been applied for micromanipulation in human beings. In a first series of attempts it was used in the fertilization process for subzonal insemination (SUZI): laser assisted micromanipulation achieved significant higher fertilization rates (34.8%) when compared to mechanical SUZI (16.1%), and for partial zona dissection (PZD): in this case laser did not improve the results (laser 14.8% vs mechanical 14%). Erbium-YAG laser was used to assist hatching. In the mouse it significantly improved the hatching rate (80% vs 29.3%) 110 hours post hCG. This technique was applied in two different centres to patients with previous IVF failures. The implantation rate per embryo (14.4% laser assisted hatching vs 6% control group) and the pregnancy rate per transfer (40% vs 16.2%) were improved.

Animals↗
PubMed1993

Laser surgery under sonographic control: preliminary experimental investigations.

The laser has gained increasing importance during recent years as a useful addition to the physician's therapeutic armoury. Reports on successful prostatectomy by ultrasound-guided laser coagulation in an animal model encouraged us to evaluate the possibility of using this technique for gynecological indications (for example, ectopic pregnancy, endometriosis, ovarian cysts, and other areas of medicine). We used two different laser systems. The devices consisted of a real-time abdominal scanner (4-5 MHz) or a transvaginal sector scanner (5-7.5 MHz) coupled to a neodymium : YAG laser with a 1064 nm wavelength or a holmium : YAG laser with 2120 nm wavelength. An experimental set-up using a water bath revealed clear visibility of the fiber tip and the laser irradiation in real-time ultrasound at 7.5 MHz. Subsequently, a needle (routinely used in transvaginal puncture of ectopic pregnancy) was placed in animal and human tissue specimens and the laser fiber was inserted. The tissue was exposed to both laser systems at different energy densities, pulse rates and pulse widths. The sonographic appearance was recorded and correlated with the macroscopic findings. Results indicate that the holmium : YAG laser at a pulse rate of 5 Hz and a power of 2 watts is effective in removing substantial amounts of tissue. Moreover, it offers immediate visualization and control of the damaged area by producing a strongly echogenic focus. The neodymium : YAG laser showed comparatively poorer sonographic visibility and a precarious thermal mode of action, which are important considerations influencing its applicability. The holmium : YAG laser system with its non-thermal mode of action seems promising for the further clinical application of ultrasound-guided laser surgery.

Journal Article↗
PubMed1993

Agricultural work and male infertility.

Data from couples (n = 103) seeking artificial insemination with donor sperm because of poor sperm quality and a control group of couples treated by in-vitro fertilization due to female causes were analysed according to the occupations of the spouses. Comparison of occupational categories revealed a significant difference in the prevalence of agricultural occupation (11/103 vs. 1/103, p < 0.01) between the group with male factor infertility and the normospermic controls. These patients also reported more long-term exposure to several insecticides and other pesticides. These toxic chemicals probably have a detrimental effect on male fertility and therefore we suggest more caution in the way they are handled.

Adult↗
PubMed1993

[Micromanipulation of human gametes within the scope of assisted reproduction].

Poor function of spermatozoa accounts for half of all human infertility. Micromanipulation methods within the framework of in vitro fertilization treatment may enhance fertilization of the egg and may allow the establishment of an ongoing pregnancy in cases of severe male infertility. This review presents different methods of micromanipulation which are routinely applied in male factor infertility and for preimplantation diagnosis.

Embryo Implantation↗
PubMed1992

Successful clinical application of laser for micromanipulation in an in vitro fertilization program.

This is a report of our preliminary experience with assisted hatching by laser with a case of an ongoing twin pregnancy. We used an erbium laser to create a 20 to 30-micrometer opening in the zona pellucida of human embryos to facilitate the embryonic hatching after the embryo transfer. Our report proves that it is possible to obtain a pregnancy using a simple and quick laser method instead of mechanical or chemical procedures within the scope of micromanipulation.

Adult↗
PubMed1992

The use of fibrin sealant for embryo transfer: development and clinical studies.

Many embryo transfers after in-vitro fertilization may fail because of expulsion of the embryos from the uterus. Approximately 5-8% of pregnancies resulting from embryo transfer are ectopic. The aim of our study was to find a technique to avoid ectopic pregnancies and to improve the pregnancy rate. We used a two-component fibrin sealant which also contains a fibrinolysis inhibitor (aprotinin) at various concentrations. After gaining experience with mouse embryos, the sealant was used in human embryo transfer with great success. The results of a pilot study encouraged us to perform a prospective randomized study on 546 patients (270 with fibrin sealant, 276 conventional embryo transfers). There were 47 (17.0%) orthotopic pregnancies and 6 (2.2%) ectopic pregnancies in the control group, whereas there were 51 (18.9%) intrauterine and no ectopic pregnancies in the treatment group. The difference in ectopic pregnancies was statistically significant (P less than 0.05). With regard to the aprotinin concentration, there was a trend towards better results with 100-150 kIU (28.5% clinical pregnancies) in comparison to 250-300 kIU (19.2%) or no aprotinin (20.4%) (not significant). Further improvements of the technique may raise the pregnancy rate when fibrin sealant is used. As shown in our prospective randomized study, ectopic pregnancies may be completely avoided.

Adult↗
PubMed1992

'Chemical curettage' using intrauterine methotrexate injection.

A 22-year-old woman with multiple urogenital anomalies presented for the second time with a blighted ovum situated in the rudimentary right horn of a uterus communicans bicornis. A dilatation and curettage was not possible owing to the inaccessibility of this horn. The first blighted ovum was aborted in 1989 (at age 21 years) following the use of intramuscular prostaglandin therapy. On this occasion, therapy was by the transvaginal, intrauterine (intra-amniotic) instillation of 100 mg methotrexate and a complete abortion of the products of conception occurred. Similar to the treatment of ectopic pregnancy, in certain cases, termination of intrauterine pregnancies using local methotrexate injection may be considered.

Abortion, Therapeutic↗
PubMed1991

Prognostic appraisal of success and failure in an in vitro fertilization program by transvaginal Doppler ultrasound at the time of ovulation induction.

In 323 stimulated cycles of women participating in in vitro fertilization treatment, a transvaginal Doppler examination was performed on the day of ovulation induction to investigate the value of blood flow velocimetry of the uterine artery. The results showed a significantly lower pulsatility index in patients who conceived (n = 42) compared with those who did not become pregnant (n = 272). The differences were especially marked during the first cycles. These results suggest that studies of the uterine hemodynamic response are useful in appraising the likelihood of success of implantation after embryo transfer.

Journal Article↗
PubMed1991

[Vaginal ultrasonographic observation of uterine contractions in embryo transfer and its relevance to treatment success].

441 patients were treated by in-vitro fertilisation and embryo transfer (ET) from January 1989 to May 1990. Transvaginal ultrasound allowed pre-transfer assessment of the uterine architecture and confirmation of successful transfer after the procedure. The length and direction of the cervical and uterine cavity were noted. The real-time image was observed for one minute to see, if uterine contractions occurred. These can be clearly seen as pulsatile movements, which can be distinguished from breathing motions. We also recognised the localisation and the movement of the transferred air bubble. A "double bubble sign" occurs as a result of the two air bubbles being seen in sagittal transvaginal ultrasound. The embryos are sandwiched between the two visible bubbles. As far as the subjective methods used permit a definitive statement, there is no connection between contractions, localisation and movement of the air bubble with the success or failure of the E.T.

Embryo Transfer↗