Search PubMed⌕ Search

Biomedical subjects

B Strauch

Publications and source records attributed to B Strauch.

At least 73 records · Page 4Linked to original sources
PubMed1985

[The first linear electron accelerator Therac 15-Saturne in clinical service. 2. Measurement of electron radiation].

Therac 15-Saturne is a linear accelerator for photon and electron radiation with a double scattering screen system. It has proved its worth during more than three years of clinical use. The dosimetric data of both kinds of radiation correspond to the international requirements for modern therapy units. The trimmer system for electron radiation is equipped with a continuous field size adjustment device for the whole range of field sizes. Thus a fast and precise adjustment is possible without any changing of tubes.

Electronics, Medical↗
PubMed1984

Effect of cigarette smoking on experimental microvascular anastomoses.

Cigarette smoking has been shown to cause cutaneous vasoconstriction, a decrease in digital blood flow, impaired wound healing, and it was implicated as a cause of failure of microvascular anastomoses in replanted digits. The subject of the following study was to assess the effect of cigarette smoking on experimental microvascular anastomoses. Twenty Sprague-Dawley male rats weighting 200 to 250 grams were divided into groups of ten. Both the experimental and the control groups were acclimatized to a Maddox/ORNL rat smoke inhalation exposure system for six days prior to operation. At this time they were anesthetized and bilateral femoral artery end to end anastomoses were performed by two surgeons, using standard microsurgical techniques. After a recovery period of 24 hours, both groups were started on a smoking/sham-smoking regime for 12 to 13 days. After this time they were anesthetized again, the femoral artery anastomoses were checked for patency in vivo and excised for histological evaluation. Five cm3 of blood was drawn from each animal to be analyzed for the presence of nicotine and its metabolites, and the rats were sacrificed. All the anastomoses in both groups were patent at the time of exploration and no histological difference could be demonstrated between the two groups. The radioimmunoassay of nicotine and cotinine showed large amounts in the smokers, and none in the nonsmokers.

Animals↗
PubMed1983

The effect of a simple preservation method on immediate and late patency rates of autogenous microvenous grafts.

The subject of this study was assessing in vivo a simple short-term preservation method of autogenous microvenous grafts. Forty-five autogenous vein grafts in rats were divided into groups of five and preserved in lactated Ringer's solution at 4 degrees C for 0, 1, 2, 3, 5, 8, 10, 12, and 14 days. After a designated preservation period, the veins were implanted as autografts into defects created in the animal's femoral arteries, while a small portion of each vein was processed for histologic examination. The patency was assessed immediately, at 1 week, and at 5 to 6 weeks following grafting, at which time the patent grafts were biopsied. Preserving the grafts for up to 2 days had no effect on their patency rate, which remained 100 percent, and no histologic changes were noted in the veins preserved for this period. However, longer preservation resulted in gradual necrotic changes in the veins, which were reflected in lower patencies of the grafts. The histology of the preserved veins and of the patent vein grafts 5 to 6 weeks following grafting is discussed. The model developed in this study can be used as a benchmark for further preservation studies using more sophisticated methods.

Animals↗
PubMed1983

[The first linear electron accelerator, the Therac 15 Saturne, in clinical service. I. Technical data and measurements in photon radiation].

A report is given about the linear electron accelerator operating at the Alfried Krupp Krankenhaus in Essen. This is the first accelerator of the type Therac Saturne supplied for 15 MeV. Besides a description of the most important technical data and the service instructions, dosimetric data for 12 MV photon radiation are presented. The authors communicate the clinical experiences gained hitherto with the accelerator and the patient-orientated verification and recording system which has still to be improved, especially as far as the recording part is concerned. The accelerator meets the requirements of radiologic oncology.

Documentation↗
PubMed1983

Replantation of amputated parts of the penis, nose, ear, and scalp.

The primary restoration of traumatically amputated digits is now routinely possible through the use of microvascular and microneural surgical techniques. The anatomy of the scalp, penis, ear, and nose makes them suitable subjects for application of these techniques. It has been the belief of many authors, as summarized by Grabb and Dingman, that venous congestion is the usual explanation for failure of replanted tissue without microsurgical repairs. Unsuitable veins of small caliber and venous congestion remain as the bane of the microsurgeon. The relative infrequency of these amputations makes it necessary to continue careful study of all reports regarding their microsurgical replantation. There is every reason to believe that increased surgical experience will result in more favorable outcomes.

Ear, External↗
PubMed1981

The parasternal paddle: a modification of the pectoralis major myocutaneous flap.

A modification of the pectoralis major myocutaneous flap has been described for head and neck reconstruction. The flap uses the skin overlying the sternum and parasternal area and may extend across the midline to the contralateral internal mammary perforators. The flap has been uniformly reliable in our experience. It is thin and easy to elevate, and donor-site morbidity is minimal. This flap is rapidly becoming our first-choice for head and neck reconstruction.

Adult↗
PubMed1980

Neovascularization of skin flaps: route and timing.

Axial flaps were elevated in a pig and rat model. Selective ligation of the vascular pedicles on days 1 to 7 following elevation of the flap demonstrated total necrosis of all flaps when the pedicles were ligated on the first, second, and third postoperative day in the pig, and up to 6 days inthe rat. Pedicle ligation beyond this time did not produce flap necorsis, indicating the establishment of adequate neovascularization for flap survival. Selective ligation of the artery or vein did not appear to be significant in the pig. In the rat flap, however, survival tended to occur sooner. Adequate neovascularization for flap survival was demonstrated as arising from both the wound edges and the bed, although vascular channels occurring from the bed appeared to be of greater importance. The relatively rapid rate of neovascularization that occurs for adequate flap survival suggests that if some way could be found to maintain flap viability during the first week, the feeding vessels need no longer remain patent and may be ligated or used for other purposes. This interesting observation has already allowed very early successful defatting of clinically transferred flaps.

Abdomen↗
PubMed1980

The role of lateral pharyngeal wall movement in pharyngeal flap surgery.

A total of 202 patients with pharyngeal flaps were assessed with nasopharyngoscopy and multiview fluoroscopy to determine the role of lateral pharyngeal wall movement postoperatively. Variations in the construction of flaps resulted in three categories: namely, a long narrow flap with a high insertion, a short broad flap with a low insertion, and an intermediate-size flap that is inserted in a position somewhere between the first two. It was found that in all cases where there was no evidence of velopharyngeal insufficiency, the sole determiner of velopharyngeal closure was the medical excursion of the lateral pharyngeal walls to the sides of the flap. In flap failures, the causes for velopharyngeal insufficiency were inappropriate degree, level, and symmetry of the lateral pharyngeal wall motion. The success of pharyngeal flap surgery depends largely on the preoperative assessment of the velopharyngeal mechanism and the choice of a type of pharyngeal flap that will best assist closure of the velopharyngeal port during speech.

Evaluation Studies as Topic↗
PubMed1979

Sensations from surgically transferred glabrous skin; central versus peripheral factors.

In reinnervated skin transferred from the foot to the hand, sensory thresholds approach normal values--an observation not predicted by the theoretical relationship between innervation density and tactile acuity. Therefore, we suggest that innervation density is not the major factor determining tactile acuity. Rather, the hand region of the central somesthetic map may be specialized to provide a calibre of function unavailable to other regions.

Humans↗
PubMed1979

A comprehensive study of pharyngeal flap surgery: tailor made flaps.

Three methods of pharyngeal flap surgery were analyzed with multiview videofluoroscopy and nasopharyngoscopy at least six months post-operatively. It was found that, by varying the type of insertion of the flap into the palate, post-operative flap width could be "tailored" to the size of the gap in the velopharyngeal sphincter. The value of varying flap width according to gap size was assessed by analyzing speech results in 60 patients specifically assigned for narrow, moderate, or wide flaps. Results show a marked improvement in the effectiveness of pharyngeal flap surgery when operations are prescribed according to the degree of lateral pharyngeal wall motion seen pre-operatively.

Cineradiography↗
PubMed1979

Multidetector endodosimetry probe with silicon-pn-junction-diodes for in-vivo-dosimetry.

In-vivo-dosimetry is necessary to prevent overdosage during radiation treatment techniques of great risk. New special dosemeter probes with up to five Si-pn-junction-diodes in a silicone tube were developed and tested for endodosimetry. They show high efficiency and good linearity of response, without dose-rate dependence. The steep increase of the sensitivity for low energies causes a phantom depth dependence of response. A low temperature dependence but a large anisotropy of response is found for the tested diodes. These multidetector probes proved to be sufficient for direct reading endodosimetric control of dose and dose-distribution during radiotherapy.

Brachytherapy↗
PubMed1978

Restoration of sensation to the hand by a free neurovascular flap from the first web space of the foot.

A neurovascular free flap from the first web space of the foot was used successfully in two patients for replacement of glabrous skin of the hand and fingers. The potential advantages of this flap are that (1) it may be used to replace large defects of glabrous skin, (2) it provides a rich vascular supply to the periphery of the hand, and (3) the sensation achieved approaches the normal for the intact glabrous skin of the hand.

Arteries↗
PubMed1978

Microsurgery of the peripheral nerve: a physiological approach.

Results with peripheral nerve injuries, which today still fall short of our goals, should intensify our efforts in this specialized field of microsurgery. We are living in an exciting era of functional reconstitution. Long gone are the times when a pink replanted digit or a successful free flap comprised the end-point of our surgical efforts. The direction from now on is toward achieving functional restoration by utilizing basic principles while armed with the unlimited potentials of reconstructive microsurgery. To this end we need the assistance and cooperation of other sciences since the enigma of the peripheral nerve can be deciphered only by a multidisciplinary approach.

Electrophysiology↗
PubMed1978

Replantation of digits.

Replanted digital survivals range between 85% to over 90% at established microsurgery centers around the world. The time has come that all surgeons engaged in this activity must utilize the basic principles of reconstructive hand surgery in order to achieve the maximum functional return of the replanted parts. The vascular repair is only one step in the road toward functional restoration of the replanted part.

Amputation, Traumatic↗
PubMed1978

[Homogenization of the dose to the target volume in case of irregular body-surface by means of compensation (author's transl)].

Irregular body-surface contours in the treatment part of high-energetic photon fields are producing an inhomogeneous dose distribution within the target volume. Homogenization of the dose is necessary in order to avoid over- or underdosage. A technique of making compensators is described. These are individual compensation filters substituting tissue layers which are lacking, they are correctly scaled down and optimally corrected in view of absorption and scattering according to the actual irradiation conditions. A simple mechanical device makes possible the production of a mould for heavy-metal compensators immediately in the course of scanning of the body-surface. A universal semi-automatic version of this method is appropriate to clinical practice; it records optically, and therefore without contact and quickly, all body-contours desired. By means of the image of moiré contour-lines thus obtained can be made the mould for the compensator in a second operation using an electronically controlled copy-milling machine.

Filtration↗
PubMed1977

Scintiangiographic demonstration of bleeding into a wrist ganglion.

Scintiangiography with delayed static scintiphotos may be used to demonstrate bleeding. Bleeding into a traumatic ganglion of the wrist was demonstrated by this technique following failure of conventional contrast arteriography. Scintiangiography with delayed scintiphotography is now performed in any case in which bleeding is suspected.

Adult↗