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Biomedical subjects

D Wallwiener

Publications and source records attributed to D Wallwiener.

At least 163 records · Page 9Linked to original sources

[Hysteroscopic endometrium ablation to avoid hysterectomy in "high risk" patients].

Hysteroscopic endometrial ablation under maximal anaesthesiological surveillance was performed in 34 high-risk patients to avoid hysterectomy. It was a collective of patients with heavy thrombo-embolic or thrombotic disease, either under permanent anticoagulation due to residual disease or multiple endoprosthetic treatment, or with endogenous coagulopathy. In all these women, hysterectomy was either a relative or an absolute contraindication. In 22 patients, treatment resulted in complete amenorrhoea or at least hypomenorrhoea (without menometrorrhagia) respectively cyclic spotting. In 6 further patients, amenorrhoea was achieved after a repeat procedure. Endometrial ablation was thus successful in 28 of 34 cases. In these patients, hysterectomy with the risk of major or even lethal complications, could thus be avoided. Hysterectomy, however, had to be performed in 2 women with extensive adenomyosis uteri interna. Within two respectively three years after endometrial ablation, two other patients died from causes unrelated to the surgical intervention (cardiac infarction, cerebral haemorrhage). Follow-up ranged from 1 to 5 years. Hysteroscopic endometrial ablation proved an effective therapeutic option in this selected group of patients. Other indications require further study.

Adult↗

[Incontinence operation by "Retzius-scopy"? An endoscopic modification of the Marshall-Marchetti-Krantz operation].

The operative treatment of stress incontinence with the Marshall-Marchetti-Krantz procedure has proved effective. A new, endoscopic modification of this procedure is presented here, based on the principle of vesico-urethral suspension with fibrin glueing. Open abdominal surgery is replaced by retziusscopy and a minimal invasive endoscopic intervention in the Retzius' cavity.

Female↗

[Surgical hysteroscopy: complications, safety aspects, education and training].

Hysteroscopy has become an integral part of the overall gynaecological surgical concept. On the one hand the experience of our study group as well as a literature survey have demonstrated that results of hysteroscopic metroplasty, resection of submucous myoma and synechiolysis are at least comparable to those of conventional procedures, the advantages of minimal invasive surgery being evident. However, increasing complications, even with a lethal outcome, due to deficient technical equipment or insufficient training of the surgeon are reported. Yet, a survey of complications in literature and in our own series of hysteroscopies (n = 200), shows a median complication rate below 1%. Knowledge of possible complications, symptoms and management alternatives is, however, a first requirement for application of these minimal access procedures. The second major precondition being a well structured training program for surgeon and assisting team. With the recently developed in-vitro-simulation trainer, the HysteroTrainer, training of the entire spectrum of hysteroscopic procedures, including laser and high frequency electrosurgical applications, is now feasible. The simulator may also be employed for security checking of the complex hysteroscopic equipment.

Equipment Safety↗

[Hysteroscopy syndrome. Absorption of irrigation fluid in surgical hysteroscopy].

The availability of adequate endoscopic instruments has led to an increased interest in hysteroscopic surgical procedures. An electrolyte-free irrigation fluid is essential for the distention of the uterine cavity, with acceptable uterine distention occurring at 80-150 mmHg. The HSK syndrome, the intravascular absorption of a hypotonic irrigation fluid with subsequent hypotonic hyperhydration with hyponatremia, has to be considered as a risk during hysteroscopic procedures. Analogous to the TUR syndrome, intravasation occurs through the vascular spaces opened during large ablative surgical procedures resulting in the absorption of the fluid used for irrigation. Occasionally, a tear in the lower uterine segment from dilation or perforation of the uterus may expose large vascular channels. Outflow through the tubes is not a significant factor. Continuous CVP measurement allows the detection of intravascular absorption of the irrigation fluid and may be included in the routine monitoring for these procedures. The duration of the hysteroscopic procedure should be limited to 60 min. Addition of ethanol to the irrigating fluid may be suitable for early detection of fluid absorption. However, commercial solutions are not yet available.

Absorption↗

[New aspects in therapy of proximal tubal occlusion: hysteroscopic proximal tubal catheterization].

To date, the therapy of first choice in case of proximal tubal pathology is resection of the occluded segment and microsurgical reconstruction. Essential disadvantage of this rather successful method consists in the need of a laparotomy. According to the concept of minimal invasiveness a pilot study has been undertaken to evaluate hysteroscopic proximal tube catheterization (HPTC) and balloon dilatation for recanalization. This attempt has proven intraoperatively successful in more than 80% of the cases and the first pregnancy and birth following HPTC can yet be reported.

Adult↗

[The bipolar needle electrode in surgical laparoscopy. Initial technical experimental and clinical results].

To date the tremendous spread of operative laparoscopic procedures associated with monopolar high-frequency techniques has lead to an increase in complications caused by monopolar leakage currents. Experimental-surgical measurements on minipigs have shown no significant leakage currents in clinical relevant power range during laparoscopic application of a bipolar needle electrode as compared to monopolar electrodes. Practicability and safety of the bipolar electrode was proven in 100 operative laparoscopies for organ preserving or reconstructive surgery. In summary, with the new laparoscopic bipolar needle electrode a secure surgical instrument is available, with which finest tissue handling and minimal thermal damage feasible.

Electrodes↗

[Thermal preparation techniques in gynecologic endoscopy--technical, experimental and clinical results (n=2000)].

A comparative study on thermal, mainly laser and high frequency electrosurgical techniques, was conducted. Indications, handling and morphometric results were correlated. Morphometrical findings suggest that minimal thermal tissue damage is associated by a decrease in the hemostatic effect. Additional bipolar coagulation is necessary when using the carbon dioxide laser or high frequency electrodes. As thermal tissue lesion is concerned, the two techniques differ only slightly, by fractions of millimeters. Concerning clinical handling and practicability at our department, as well as in the centers participating at the European Consensus Study on Lasers in Gynaecology, high frequency electrosurgery has proven the method of choice for endoscopic ablative procedures. The carbon dioxide laser (at laparoscopy) and the Nd:YAG contact laser (at hysteroscopy) are preferentially employed for reconstructive surgery (e.g. the carbon dioxide laser for treatment of distal tubal pathology or endometriosis, the Nd:YAG contact laser for hysteroscopic synechiolysis).

Animals↗

[Chlamydia trachomatis: screening within the scope of prenatal care and rapid diagnosis in threatened premature labor].

Cervical infection with Chlamydia trachomatis during pregnancy is related to the incidence of preterm labour and preterm rupture of membranes, causing elevated neonatal morbidity and mortality. The present study reports our two-years-experiences with a general screening on Chlamydia infection in prenatal care as well as diagnostic possibilities in case of imminent preterm delivery. In the examined population of totally n = 263 pregnant women attended in our prenatal care unit, the prevalence of cervical Chlamydia infection was 3.4%. Among the screened asymptomatic women (n1 = 179) 2.8% had positive findings. Among n2 = 84 patients with preterm labour and/or preterm rupture of membranes 4.8% revealed cervical infection. Specially in the acute situation of imminent preterm delivery, an immunological bedside assay (Clearview Chlamydia, R) tested in 203 cases versus the tissue culture as reference method proved helpful. Its sensitivity was 0.8, specificity 0.99. The test allowed to prove or exclude chlamydial infection within only 30 minutes.

Adult↗

[Microsurgical heterotopic ovary transplantation. A preclinical study].

Free heterotopic autologous ovary transplantation might be a method to prevent iatrogenic radiocastration in case of Hodgkin's disease. Though first promising clinical case reports have been published, almost no experimental basic data are available. It was the aim of this study to develop a transplantation model in order to evaluate and improve operative technique and perioperative management preclinically. Whereas results in pilot transplantations on minipigs were impaired by the disposition to wound infections on the implantation site, transplantation on Beagle dogs proved to be a suitable model. Eleven transplantations have been performed (five in minipigs, six in Beagle dogs). The success rate of intact preserved transplants was 45% with an observation time of three months for the minipigs and 9 +/- 3.7 months for the dogs.

Anastomosis, Surgical↗

An endoscopically assisted technique for construction of a neovagina.

The specific disadvantage of the commonly used Vecchietti method for reconstruction of the vagina in cases of vaginal agenesis is the need for laparotomy. We now describe a successful endoscopically assisted construction of a neovagina by a variation of the Vecchietti method. The method causes relatively little stress to the patient.

Cystoscopes↗

[Ultrasound diagnosis of blood flow in benign and malignant breast tumors].

Malignant tumours can be differentiated from the benign ones by their vascular blood supply. We employed three methods to analyse the blood flow: the angiodynograph, the duplex system, and the continuous-wave Doppler method, and measured the blood flow in 151 patients on the preoperative day. Histology revealed a malignoma in 92 cases and a benign tumour in 59 cases. It was found, that in more than 90% of the malignomas, a high blood flow was identified in or around the tumour by means of the colour method (angiodynography), which could be quantified by the pulsed-wave Doppler. A significantly lower blood flow was evident in the benign tumours with a markedly increased resistance index (by 80%) established by means of the pulsed-wave Doppler. Continuous-wave (CW) Doppler showed a significantly higher blood flow with almost all malignomas in the entire breast, than was the case with benign changes. Our studies showed, that the enhanced blood flow in and around malignant tumours can be visualised by means of update technology, angiodynography being particularly suitable for demonstrating the flow by the B-mode. Quantification, however, is, at present, only possible by employing the duplex method with pulsed-wave Doppler. CW Doppler is suitable only for blood flow diagnosis of the entire organ, but it requires great precision of working method and is time consuming; tumour blood flow cannot be visualised on-target by this method.

Blood Flow Velocity↗

[Palliative laser therapy in gynecologic oncology].

Local recurrences of carcinomas of the breast and genitals are a severe psychic and physical strain on the patients. Continuous confrontation with an often visible and generally painful tumour manifestation is an indication for palliative treatment, if other oncological therapies can no longer be employed. In these cases, the possibility of laser use represents a new therapeutic approach. In a pilot study at the University of Heidelberg, Department of Obstetrics and Gynaecology, a palliative laser therapy was performed on 45 patients with locally recurrent carcinomas of the breast (n = 29) and genitals (n = 16). Carbon dioxide and Nd:YAG lasers were utilized for tumour resection, vaporisation and coagulation. This new concept, the combined application of both wavelengths has been proved to be most efficient.

Adult↗

[Diagnosis of tubal function using intraluminal ultrasound--initial results].

The extremely small ultrasound transducers of the intraluminal ultrasound instruments, introduced via catheters, enable diagnosis to be made inside hollow organs. In order to test the possible uses and indications for this new method in gynaecology, we conducted preliminary examinations in the diagnosis of the uterus and tubes. We employed an intraluminal instrument supplied by Dornier. The intraluminal transducers of this instrument have a diameter of 3.5 and 5 F. Following in-vitro examinations, hysteroscopy and laparoscopy/laparotomy were performed in 15 patients during which the transducer was pushed up via the cervix uteri to the tubes with full vision. This was successful in all 15 patients; in 9 cases the transducer could be pushed as far as the distal end. The tubal walls were examined in detail by this method and for the first time it became possible to achieve functional diagnosis of the motility of the tubes. Strictures can be visualised. The endometrium of the uterus, however, cannot as yet be diagnosed exactly by the present-day state of examination technique. If image quality can be further improved, this method will be the first to enable a functional diagnosis of the tubes and the uterus.

Endometrium↗

[Doppler ultrasound study of breast tumors using color Doppler ultrasound, duplex ultrasound and the CW Doppler ultrasound].

The preoperative examinations by doppler-sonography of 83 patients with tumors of the breast are presented. The examinations are done with newest technique: duplex-sonography in slow-flow-technique (AI 3200, Dornier); colour-sonography in MEM-technique (AI 5200, Dornier) and synchronical colour-doppler++ (Quantum 2000, Siemens) and CW-doppler-sonography (Vasocope 3, Kranzbühler). There is a markable difference between the side of carcinoma and the normal side as well as pre- and postmenopausal patients. No difference is shown in cases of benign tumors and the normal side. The increasing blood flow of a malignant tumor is showed in changing the doppler parameters (A/B-ratio and resistance-index) and in the doppler wave form. The number of vessels found in or around a tumor is not a good criteria to find malignant diseases, the best criteria is the difference between sides of the mamma.

Blood Flow Velocity↗

Laser palliation of locoregional recurrences of breast cancer.

The paper reports on the use of carbon dioxide and Nd:YAG lasers for palliation of locoregional breast cancer recurrences. On the basis of three case reports, pros and cons of laser assisted treatment of loco-regionally recurrent breast cancer are discussed. A carbon dioxide--Nd:YAG combination therapy is proposed as the method best suited. The preliminary results indicate that laser palliation of local relapse and soft tissue metastases might enlarge the therapeutic spectrum.

Aged↗

[Improvements in 3-D ultrasonic imaging].

The problem of gaining a coordinated sequence of section cuts by ultrasound is solved by rotating the plane section around a vertical and a horizontal axle. There are two possibilities in presenting the 3D image of the examined organ: ring structure image or transparent image. Precondition in the ring structure image is time consuming and defective since it has to be done by hand using a cursor. These pitfalls can be avoided when using a method without contouring by showing the 3D image transparently. Each section cut has to be calculated transparently. Both methods are presented in this paper and compared as to their applicability in medicine. The problem of the transparent 3D presentation lies in the fact that it cannot be well presented on printed paper, as is done her. The moving picture on the computer screen gives an optimal 3D image. This new method seem to be useful in tumor diagnostic and diagnostic of malformations in early pregnancies.

Computer Graphics↗

[Fibrin gluing in surgical, laser-assisted laparoscopy].

Fibrin sealing has proved a successful procedure for a variety of indications in operative gynecologic laparoscopy. Ovaries can be reshaped after cystectomy, serosa and peritoneal defects as well as perforations of the uterus can be sealed with fibrin adhesive. At present, application for salpingotomy, fimbrial eversion and tubal anastomosis is being investigated in clinical studies. Yet larger collectives and a longer follow-up are necessary for a final evaluation of the method. No complications were observed in 75 laparoscopic fibrin sealing performed at our department for established indications. Fibrin adhesive can replace time-consuming, complicated endoscopic sutures. It is an atraumatic tissue-sealing and hemostatic technique, easy in handling, thus leading to a considerable reduction in operation times. The excellent hemostyptic and wound healing characteristics of fibrin adhesive are also an advantage.

Female↗