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Biomedical subjects

G W Kauffmann

Publications and source records attributed to G W Kauffmann.

At least 109 records · Page 6Linked to original sources

[Long-term results after TIPSS with the Palmaz stent].

Since our first clinically successful TIPSS procedure in 1988 numerous steps to improve the safety and methodology have helped to increase the technical and clinical success while the rate of complications could be significantly reduced. In our series of more than 200 patients the technical success rate is more than 95% and the early clinical success rate (< 30 days after TIPSS) 89%, respectively. Early shunt occlusion was found in 1.5% of our patients. 3 months after TIPSS, however, transjugular portography reveals significant shunt stenosis in 46% needing either shunt re-dilatation or additional stent placement. This relatively high rate of re-intervention is being significantly reduced during the further follow-up with a frequency of 17% at a 6 month interval and 6% at a 12 month interval, respectively. The need for re-intervention is strongly associated with liver function and the patients' coagulation status: Child's A patients needed re-intervention substantially more often than those in stage B or C at each given follow-up interval. The decreasing need for re-intervention over time appears to be associated with the formation of an endothelial cell layer on the surface of the shunt tract.

Catheterization↗

[Parapneumonic ARDS. The radiomorphologic transition of a pneumonia into an ARDS].

Serial chest X-rays of 14 patients with parapneumonic ARDS (PARDS) were analysed retrospectively. Typical findings on chest X-ray films occurred after a latency period of 12-24 h following the clinical start of PARDS. We found some "early signs" of PARDS, such as central interstitial paravascular edema (14/14), bilateral hilar infiltrates (9/14) and the absence of pleural effusion (12/14).

Adult↗

[The role of embolization treatment of acute hemorrhage].

137 arteries of 95 patients were treated by transcatheter embolization for massive haemorrhage using Ethibloc, Gelfoam, wire coils and Tissucol (Fibrinogen + Thrombin). The bleeding was secondary to trauma in 23 patients, to neoplasms in 16 patients and to vascular malformations or chronic inflammatory processes in 41 cases. 15 patients were treated for iatrogenic bleeding following surgery. Bleeding was referred to haemoptysis (n = 27), pelvic (n = 24), renal (n = 16) or gastrointestinal haemorrhage (n = 13) as well as several other diseases (n = 15). Most patients were poor surgical candidates. The overall bleeding control rate was 89.5% with a incidence of recurrent bleeding in 14 out of 95 patients (14.7%) treated by re-embolization or surgery. 6 patients died (6.3%) due to intractable haemorrhage, 4 patients (4.2%) died of complications related to embolization procedure (4 x bowel infarction!) and 33 patients (34.7%) died of procedure-unrelated causes such as myocardial infarction, trauma, malignancy or other underlying diseases. 58 patients (61.1%) are still alive (follow-up 16.2 +/- 4.8 months). Significant complications (5.3%) included bowel necrosis (4x) and ischaemia of the spinal cord with incomplete paralysis in one patient. One patient suffered thrombosis of the common iliac artery due to angiography. On the basis of our results, peripheral embolization using Ethibloc can be recommended as palliative treatment for devascularisation of bleeding tumours. Satisfactory results are obtained in haemoptysis, renal and pelvic haemorrhage, but gastrointestinal bleeding should not be occluded by means of Ethibloc because of its considerable risk of bowel infarction.

Acute Disease↗

Regional administration of lymphokine-activated killer cells can be superior to intravenous application.

A patient with liver metastases of human lymphocyte antigen (HLA) class II-negative malignant melanoma was treated with several cycles of adoptive immunotherapy with interleukin-2 and lymphokine-activated killer (LAK) cells. The authors evaluated the efficacy of regional transfer of LAK cells versus systemic intravenous administration. Initially, the patient was treated according to a regional treatment protocol, consisting of perfusion of the spleen with interleukin-2 and transfer of LAK cells into the portal vein; a partial remission was observed. Because of technical problems, interleukin-2 and LAK cells were administered intravenously in a second treatment cycle. This systemic treatment course resulted only in a minor mixed response of the hepatic metastases. A third treatment course was administered with the use of intravenous interleukin-2 infusion and arterial perfusion of the liver with LAK cells. The patient had separate hepatic arteries to both lobes of the liver as an anatomic variation. Because most of the tumor mass was present in the right lobe of the liver, a third of the LAK cells were injected into the right hepatic artery and the remaining cells were administered intravenously. The lesions in the right lobe of the liver regressed, but disease progression occurred in the left lobe. A fourth treatment cycle, consisting of intravenous infusion of interleukin-2 and arterial perfusion of both lobes of the liver with LAK cells, resulted in a complete response of all hepatic lesions, which has lasted 18 months to date. Because, in this patient, tumor regression was observed only in anatomic areas of the liver, which were perfused with LAK cells, it is suggested that the regional administration of LAK cells was essential for successful treatment.

Adult↗

Influence of the distance between interrupted sutures and the tension of sutures on the healing of experimental colonic anastomoses.

Certain technical factors determine the success of the creation of intestinal anastomoses. The influence of the distance between interrupted sutures and the suture tension on wound healing was investigated in an experimental study using a specially designed suture model. The combination of a long suture distance (group A, 2.5 mm) and a short suture distance (group B, 1.5 mm) with three different suture tensions, i.e., (1) no tension; (2) moderate tension; and (3) high tension, resulted in six different techniques. Tension was created by means of a spring balance. The anastomoses were examined macroscopically, histologically by microangiography, and by bursting pressure. Apposition of the bowel wall between the interrupted sutures was inappropriate due to prolapse of the mucosa in 7.9% of the patients in group A but did not occur in groups B2 and B3. The leakage rate was 4.6% in group A and 1.3% in group B. Early healing of the mucosa was noted in group B2. Bursting pressure was significantly higher on day 2 and 4 in groups B2 and B3. The results demonstrate the influence of suture technique on the wound healing of intestinal anastomoses. The best healing pattern was achieved by a small distance between the sutures and a moderate suture tension.

Anastomosis, Surgical↗

[Renal tumor embolization].

We present an update on the technical aspects and clinical efficacy of the concept of capillary embolization for the treatment of renal cell carcinoma. In preoperative indications, it is shown that only this type of occlusion can safely achieve a reliable breakdown of the peritumor vasculature to meet the surgical requirements for excision of huge tumors associated with abundant retroperitoneal tributaries. In particular, in tumors infiltrating the renal vein and the vena cava, capillary embolization proved to be extremely helpful. In palliative embolization the concept achieved local and clinical efficacy comparable to nephrectomy when applied in patients free of metastatic disease. In palliative embolization of patients with metastatic disease, no change in the natural history was found. A new but still experimental concept is the combination of chemoperfusion and chemoembolization for tumor nodules in a solitary kidney and for reoccurring retroperitoneal tumors. The application of a coaxial system that features perfect maneuverability enables tumor treatment on the level of subsegmental vessels. The first short-term results seem to be promising. If definite proof of the validity of such a concept is to be obtained, however, further long-term research needs to be conducted on larger numbers of patients.

Carcinoma, Renal Cell↗

[Pulmonary arteriovenous fistulas in Osler's disease].

In a retrospective study over a period of 10 years we found 16 patients with Osler's disease and associated pulmonary arteriovenous fistulas in the hospital of the University of Heidelberg and the Thoraxklinik Heidelberg-Rohrbach. We report about the radiologic diagnostic findings and the clinical manifestations of this defined pulmonary malformation. Radiologic findings are round or oval lobulated homogeneous masses. The size ranges from < 1 to several centimeters in diameter, most fistulas were located in the lower lobes. Feeding and draining vessels can be identified frequently on plain radiographs or tomograms/CT. Best procedure to recognize these malformations is the selective pulmonary arterial angiography.

Adult↗

[Imaging techniques in the preoperative diagnosis of soft tissue tumors. A comparison of MRT, CT, sonography, angiography and conventional x-rays].

In a study on 51 patients with histologically confirmed soft tissue tumors (STT), we retrospectively evaluated the preoperative use of imaging procedures (MRI, CT, ultrasound, angiography, plain film) for identification of tumor size, delineation, and determination of malignancy and tissue type. The findings were correlated with intraoperative findings and histological diagnosis. The overall diagnostic method of choice for preoperative imaging of STT is MRI, followed by CT. Ultrasound, although sensitive, lacks the required specificity. Angiography and plain film can only be used for specific indications, as they generally do not make it possible to stage the tumor. Combining our results with those from the more recent literature, we propose a diagnostic algorithm according to which MRI would generally be performed for preoperative staging of STT. CT and plain film should only be used if bony infiltration is suspected; angiography is indicated for planning intraarterial chemotherapy or embolization or if vascular infiltration is probable.

Adolescent↗

[Intra-arterial angio-CT as a perfusion control before intra-arterial chemotherapy in bronchial, breast and liver tumors].

Intra-arterial angio-CT is used increasingly in the diagnosis of liver metastases since the sensitivity of this method is greater than that of IV-contrast CTs. We carried out this procedure in eight patients with inoperable carcinomas of the bronchus, eight patients with carcinoma of the breast, one patient with an hepatocellular carcinoma and one patient with carcinoma metastases, before starting intra-arterial chemotherapy or tumour embolisation. The procedure permitted optimal placing of the catheter to ensure complete perfusion of the tumour. Perfusion of normal tissue can be reduced to a minimum. Failure of contrast filling on the angio-CT indicates the presence of a second vessel supplying the tumour.

Angiography, Digital Subtraction↗

[Intra-arterial chemotherapy in locally advanced breast carcinomas].

Transcatheter arterial chemotherapy with mitoxantrone was carried out in 9 patients suffering from advanced breast cancer. The anticancer agent was selectively injected in the internal mammary artery. In 2 cases the catheter was super-selectively advanced into a peripheral branch of the internal mammary artery supplying the breast carcinoma. No complication of the transcatheter treatment could be observed. CT examinations for controlling the catheter position showed perfusion of breast cancers between 40 and 90 per cent. Histological examinations of the 7 resected specimens revealed extensive necrosis in all cases. All 7 patients who underwent surgery have been without local recurrence for 3 to 12 months after treatment.

Adult↗

[4 years' experience with a balloon-expandable endoprosthesis. Experimental and clinical application].

During a 4-year period of clinical application of the balloon-expandable Palmaz stent, a randomized trial comparing stent implantation and traditional balloon angioplasty of iliac arteries in arterial occlusive disease was started. The first long-term results, recorded after 2 years, indicate statistically significant differences in the complication rate (after stenting 2/62 and after angioplasty 5/69) and patency (greater than or equal to 70% of original lumen size upon stent implantation or balloon inflation: 95% after stenting and 72% after angioplasty). Clinical improvement after 2 years was 89% after stenting and 70% after angioplasty. Parallel to the clinical trials, experimental canine artery stenting was performed to evaluate differences in the long-term patency of stents exposed to restricted flow. Significant differences in neointimal healing were found between normally perfused stents and stents with artificially reduced flow: during the total observation period of 6 months the neointimal height was up to 200% higher in flow-restricted stents, while the histological composition of the neointima was the same as with normally perfused stents.

Angioplasty, Balloon↗

[Renal artery aneurysms].

Between 1980 and 1990, 21 patients with 26 renal artery aneurysms (0.4-16.5 cm in diameter) were diagnosed and treated at the Surgical Center, University of Heidelberg. Surgical reconstructive methods were applied to treat extrarenal and interventional embolization to treat intrarenal aneurysms. The most effective diagnostic method is selective intraarterial angiography. The etiology, age distribution, localization and clinical aspects are discussed. Four bleeding intrarenal aneurysms were embolized with full preservation of renal function (one solitary kidney). After surgical reconstruction of the aneurysmatic vessel, 80% of the hypertensive patients turned normotensive. Follow-up of a nontreated sacciform aneurysm showed total thrombosis within 4 years. In the same period, fixed renal hypertension developed in the patient because of recurrent microembolism in the renal parenchyma. Therefore, we suggest immediate treatment of a renal aneurysm to prevent the development of renal hypertension.

Adult↗

[Imaging of the hip joint hyaline cartilage with MR tomography using a gradient echo sequence with fat-water phase coherence].

We have been able to display the hyaline hip joint cartilage clearly and with high signal strength in the magnetic resonance image with a gradient echo sequence with 2 different fresh hip specimens from corpses and with 10 healthy test subjects (5 m, 5 f). The chemical shift artifact at the bone-cartilage boundary could be clearly reduced by optimizing the geometrical scanning parameters. A comparison between the cartilage thickness at the head of the femur measured on the anatomical specimen with the thickness measured in the magnetic resonance tomogram showed a good correlation on suitable selection of the read-out gradient. The hyaline cartilage at the head of the femur could be differentiated from the acetabular cartilage in the region of the loading zone by magnetic resonance tomography in all 10 test subjects.

Cartilage, Articular↗