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Biomedical subjects

R Baumgart

Publications and source records attributed to R Baumgart.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Instrumental diagnosis for therapy decision making--what is possible and desirable, what is essential and what is superfluous?].

With knowledge of the classical radiological characteristics of benign and malignant bone tumors, taking age and localization of lesion into consideration, and with the help of classification according to Lodwick, 90% of all cases can be diagnosed. Compared with benign lesions, malignant tumors are quite rare, so those with less experience are advised--in case of doubt--to carry out a reference evaluation, since further imaging, e.g., costly magnetic resonance imaging (MRI), is in general not of any help for diagnosis. Only when malignancy is suspected or to plan biopsy is MRI, however, not only desirable to outline the malignant lesion in bone and soft tissue, but is an absolutely necessary in modern interdisciplinary treatment concepts, without which extremity-conserving surgery with constantly increasing life expectancy together with the considerable success of chemotherapy would be unthinkable.

Biopsy↗
PubMed1996

[Intramedullary nailing in callus distraction].

Intramedullary nailing is an established fixation method in fracture treatment as well as in deformity-correction procedures on tubular bones. The interlocking nail has increased the potential for employing the intramedullary nail in the treatment of fractures in metaphysial regions. Recent developments are biased towards the use of small-diameter unreamed nails, preferably made of titanium. Callus distraction, the controlled continuous shifting of corticotomized bone, leads to new bone formation and has been known since the beginning of this century. This method, however, gained wide acceptance and popularity through the work of Ilizarov. This paper describes a fusion of the two methods into a very promising management concept for substantial bone defects resulting from trauma or resection of bone tumors, as well as for the correction of congenital or acquired uni- or bilateral differences in length of the extremities. Various systems such as the combination of callus distraction by external fixation over an intramedullary nail and a fully implantable system are presented.

External Fixators↗
PubMed1996

[Perspectives in callus distraction].

Callus distraction is an enrichment of the surgical orthopaedic way of reconstructing bone defects, but it is also an effective method of lengthening limbs. The biological facts correspond to our knowledge about fracture healing. Concerning apparatures, further development is needed. In certain cases the ring fixator is the method of choice, but in most indications it is not necessary. Every effort should be made to adapt modern technologies, including fully implantable systems, to the "biological method" of callus distraction, whenever possible.

Bone Lengthening↗
PubMed1994

[Possibilities in the reconstruction of bone defects].

The importance of the functional unit "bone-soft-tissue" for the treatment of bone defects is discussed. A division is made between non-vascular and vascular bone transport. The individual methods are explained and their clinical significance is illustrated partly using case material. In general, the best way to fill small defects in vital soft tissue is to use cancellous autografts. For bridging longer bone defects callus distraction is the method of first choice, but in individual cases vascularized bone transfer can be taken from the iliac crest or the fibula. Homo- or heterografts should only be used in cases where no autologic bone material is available or when there is not enough.

Arm Injuries↗
PubMed1993

Primary shortening with secondary limb lengthening in severe injuries of the lower leg: a six year experience.

Multiple secondary grafting procedures may be necessary in cases of complete or partial amputation of the lower limb if the aim is to preserve the initial limb length. The traditional concept of staged reconstruction often leads to a prolonged hospitalisation and a high complication rate, especially in cases with segmental nerve defects of more than one major nerve and severe skin loss. To minimize multiple secondary operations of soft tissue and bone, we have developed the concept of primary shortening with secondary limb lengthening. We perform a primary shortening of the amputation stump and the severed limb at the time of replantation, in order minimize the skin defect and to undertake a primary wound closure and/or primary nerve suture. Six to 12 months after replantation, secondary limb lengthening is started, using an external or internal distraction device. Since 1985, 7 patients presenting with complete or partial amputation of the lower leg had been treated using this concept. The indications, operative technique, complications and results are shown and discussed, comparing this new concept to the traditional concept with extensive free soft tissue transfer and secondary nerve grafting.

Adult↗
PubMed1992

Morphologic classification of the myelodysplastic syndromes (MDS): combined utilization of bone marrow aspirates and trephine biopsies.

In a retrospective and prospective follow-up study from 1975 to 1991, bone marrow biopsies, aspirates and clinical features of 495 patients with MDS were investigated. Sections of undecalcified plastic embedded biopsies and smears of bone marrow aspirates were stained according to Giemsa. Bone marrows with MDS were characterized by three main categories of morphologic alterations: (1) cellular abnormalities, (2) architectural disorganization in the bone marrow and (3) stromal changes; the combined use of aspirates and trephine biopsies enabled a more reliable and accurate diagnosis of MDS than either one alone. The bone marrow findings fell into one of 7 subtypes, with the frequencies and median survivals in brackets: (1) MDS sideroblastic (19%, 62 months), (2) MDS megaloblastoid (13%, 56 months), (3) MDS proliferative (22%, 31 months), (4) MDS blastic (15%, 9 months), (5) MDS hypoplastic (15%, 26 months), (6) MDS fibrotic (6%, 29 months), and (7) MDS inflammatory (10%, 42 months). In follow-up studies patients with secondary MDS were excluded and the prognosis and subsequent evolution for each of the morphologic subtypes were evaluated. The conclusion is drawn that aspirates and trephine biopsies are complementary procedures and both are required for diagnosis, classification and decisions on current treatment modalities of patients with MDS.

Adolescent↗
PubMed1989

[Experiences with rotation atherotomy and atherectomy].

In addition to currently available, low risk procedures for reestablishment of patency in arteriosclerotic vascular segments with bougier techniques as described by Dotter and the balloon dilatation modification according to Grüntzig, as necessary together with local thrombolysis, important new developments based on mechanical principles are the atherectomy according to Simpson as well as the rotation atherotomy with a flexible catheter and slowly rotating milling head or rapidly rotating head as used by Kensey. To provide a larger lumen of recanalization, we developed an atherotomy lathing catheter with a rapidly rotating head and various diameters which is now available for intraoperative use. The thrombendarterectomy as described by Vollmar with the "ring stripper" is used only intraoperatively and can only be performed retrograde. The effect of laser systems encompasses disintegration and ablation of occlusive material. The rotation atherotomy is based on the capability of discrimination between hard occlusive material and elastic vascular wall through suitable construction of the lathe head (Figures 1 a to 1 e). Since, in passive catheters, the capability of lathing at the tip is associated with a high risk of perforation and a lateral possibility for lathing is not achievable, the lathing performance should be small, at the center of rotation and orthogonal to the axis of rotation at the outer radius. Through combination with a spherical disc face perpendicular to the axis of rotation, which protrudes only slightly from the hemispherical catheter tip, with a maximum at the center and minimum at the lateral borders, the lathing head has only a slight risk of perforation and no undesired sheering forces (Figures 2a to 2d).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Dynamic angioplasty--a milling catheter for transcutaneous and intraoperative treatment of vascular occlusive disease.

Balloon angioplasty and bypass graft surgery are common procedures for treating vascular occlusive disease. The purpose of this preliminary investigation was to evaluate the effectiveness and the safety of a new catheter system, first introduced by KR Kensey. The system involves a flexible catheter with a high speed rotating tip, driven by an electrical motor. The tip is cooled by a continuous flow of sterile saline containing dextran 40, heparin and urokinase. Radiopaque contrast medium may be infused through the catheter to allow the device to be guided and to detect lesions and to evaluate the efficacy of treatment. The system was applied in three patients with occlusive vascular disease (Stage IIb) and segmental or total occlusion of the superficial femoral artery (SFA). The milling catheter was introduced percutaneously into the common femoral artery and guided to the area of occlusion under DSA control. In two patients total recanalisation was achieved after passage of the milling catheter. In one patient the totally occluded SFA could not be cannulated and a femoro-popliteal bypass was performed one week later. Complications such as perforation of the vessel or peripheral embolisation were not observed. Pedal pulses were improved significantly in one patient. Further investigations will be necessary to demonstrate whether the milling catheter can be safely used to revascularise patients with limb threatening peripheral vascular disease.

Angioplasty, Balloon↗
PubMed1980

An assessment of a microcolumn chromatographic method for the measurement of haemoglobin A1.

A microcolumn method for the measurement of haemoglobin A1 (Hb A1) was assessed . The between assay coefficient of variation was less than 4%. Factors influencing the assay are discussed. Fluoride oxalated blood was found to be unsuitable for Hb A1 assay. Hb A1 in whole heparinised blood was found to be stable for nine days at 4 degrees C and for longer if buffered dextrose was added to the sample. The possibility of artefactual lowering of the Hb A1 value by the selective loss of older red cells was investigated.

Blood Preservation↗