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Biomedical subjects

G W Kauffmann

Publications and source records attributed to G W Kauffmann.

At least 73 records · Page 4Linked to original sources
PubMed1997

Degree of carotid artery stenosis. Comparison of selective and non-selective angiographic findings with surgical specimens.

OBJECTIVE: To compare the degree of vessel narrowing seen on selective and non-selective carotid artery catheter angiograms using criteria set by NASCET and ECST with the results obtained from corresponding surgical specimens. SUBJECTS: In 40 preoperative angiograms (20 non-selective, 20 selective) the 'distal' degree of internal carotid artery (ICA) stenosis according to NASCET criteria and the 'local' degree of stenosis according to ECST criteria was assessed. These data were compared with the 'distal' and 'local' degree of ICA stenosis obtained by measuring the specimens and the diameter of the distal ICA intraoperatively. RESULTS: The median 'local' degree of stenosis was 86.5% in the specimen and 83.5% in the selective angiograms (difference not significant). In non-selective angiography the median 'local' degree of stenosis was 77.5% compared to 84% in the corresponding specimens (P < 0.01). The median 'distal' degree of stenosis in selective angiography was 76.5 versus 75.5% in the specimens (n.s.). The median 'distal' degree of non-selective angiography was 67% compared to 77.5% in the corresponding specimens (P = 0.02). The trend to underestimate high grade stenosis (above 90%) was more pronounced in non-selective than in selective angiography. Medium grade stenosis (60-80%) was slightly overestimated in selective angiography. CONCLUSION: Selective angiography is more accurate in determining the 'true' degree of stenosis in internal carotid artery disease, taking into account a slight overestimation of medium grade stenosis. High grade stenosis is underestimated in both selective and non-selective angiography. These observations extend to both the ECST and NASCET criteria of measuring the degree of stenosis, which differ by about 10%.

Aged↗
PubMed1997

[Bipolar radiofrequency energy in arteries--the experimental results with a new catheter system].

PURPOSE: To evaluate the effects of radiofrequency heated bipolar probes on the human arterial wall. METHODS: Under standardised conditions, lesions were set on the inner layer of a piece of human cadaver arterial wall, using a radiofrequency-heated bipolar catheter. These lesions were measured and described both macroscopically and microscopically. Lesion size, applied energy levels and application conditions were correlated. RESULTS: The size of a lesion depended significantly on the size of the catheter, angle and pressure of catheter application (p < 0.05) and length of impulse (p = 0.002). There was no influence from the energy level employed. It proved impossible to treat calcified plaques. The depth of a lesion depended on the angle of catheter application only. No perforations were seen. CONCLUSIONS: Radiofrequency-heated bipolar catheters ablate the tissue of the arterial wall. Increasing tissue resistance resulting from higher energy levels prevents perforation in the experimental set-up. Calcified plaques cannot be treated by this method.

Aorta, Abdominal↗
PubMed1997

[The hydro-MRT of chronic inflammatory bowel diseases].

PURPOSE: Evaluation of hydro-MRI in the diagnosis of chronic inflammatory bowel disease (IBD). MATERIAL AND METHODS: 33 patients with suspected Crohn's disease or ulcerative colitis were studied prospectively. After distension of the colon by a rectal enema, breathhold MR imaging was performed during bowel relaxation. Results were compared to the clinical diagnosis, endoscopy, barium studies and histopathology. RESULTS: 24/24 patients with active Crohn's disease were correctly diagnosed by MRI. Conversely, MRI was positive in only 2/5 patients with ulcerative colitis. In 5 patients the presence of IBD was excluded. There were no false positives. CONCLUSION: Hydro-MRI is a very reliable modality in the diagnosis of Crohn's disease. In the differentiation of Crohn's disease from ulcerative colitis, hydro-MRI seems to be a promising imaging procedure.

Adolescent↗
PubMed1997

[Changes in liver perfusion caused by transjugular intrahepatic stent shunt (TIPSS)].

PURPOSE: to demonstrate and document TIPSS-induced changes of the perfusion pattern of the liver with special reference to several rheologic, morphologic, functional and biochemical parameters. Our analysis was based on a study in 100 consecutive cases. PATIENTS AND METHODS: Evaluation and assessment of the following parameters before and within a 30-day post TIPSS period: portosystemic gradient; morphologic delineation of the portal circulation; invasive scintigraphic determination of the portal perfusion fraction (PPF) and the total liver perfusion (GLP); transcatheter intraarterial flow change measurement; serum levels of albumin and bilirubin; assessment of hepatic encephalopathy by appropriate testing; assessment of recurrent variceal bleeding RESULTS: by TIPSS variceal filling was widely reduced; as assessed morphologically and rheologically portal liver perfusion was significantly reduced. However, there was immediate onset of compensated liver perfusion by increased arterial inflow. Total liver perfusion was not significantly altered. In TIPSS portal decompression was readily achieved with reduction of the portosystemic gradient from an average of 24 mmHg to 10.5 mmHg. In our series we could not demonstrate an increased incidence of hepatic encephalopathy during the 30-day post TIPSS period. Bilirubin levels were significantly increased after TIPSS from 2.45 to 2.61 mg/dl (p = 0.0067), while albumin levels were not altered. Early mortality was 4% and early re-bleeding rate 3%, respectively. CONCLUSION: the concept of TIPSS represents an individually calibrated H-shunt. The significant reduction of post TIPSS portal perfusion appears to be compensated by increased arterial inflow. This is reflected by invasive flow measurement results and by the clinical results. Letality of TIPSS is low.

Blood Flow Velocity↗
PubMed1996

[Cicatricial small intestinal stenosis following chemotherapy for a gastrointestinal lymphoma].

HISTORY AND CLINICAL FINDINGS: 4 weeks after completing a course of chemotherapy for non-Hodgkin lymphoma of the jejunum a 45-year-old woman developed pain in the left upper abdomen and postprandial vomiting so that she could no longer take food by mouth. INVESTIGATIONS: On admission she looked cachectic and had obviously lost weight. Plain abdominal X-ray gave no evidence of perforation or ileus. Gastroduodenoscopy showed no local recurrence. But contrast jejunal radiography (after Sellink) demonstrated two severe band-like stenoses of the jejunum with prestenotic dilatation. As she had not had any previous operation or radiotherapy, cicatricial stenosis was considered as the most likely cause. As the symptoms continued and stenosing local recurrence could not be excluded, surgical resection was indicated. TREATMENT AND COURSE: Two cicatricial intramural stenoses of the proximal jejunum were found and histologically confirmed without evidence of lymphoma recurrence. After the operation the patient was again able to take food by mouth without problem. Follow-up examination 8 months later showed no recurrence and she was free of gastrointestinal symptoms. CONCLUSION: After chemotherapy for gastrointestinal lymphoma obstruction of the small intestine may occur due to chemotherapy-induced scarring.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

[Hydrosonography of the pancreas. Initial results of a pilot study].

PURPOSE: To evaluate a new ultrasonographic imaging technique of the pancreas (hydrosonography), based on a combination of chemical intestinal paralysis and water distension of the stomach and duodenum, regarding its significance for tumor detection, staging and assessment of tumor resectability. MATERIAL AND METHODS: In an open prospective study 51 patients with suspected pancreatic neoplasm were examined between July 1995 and October 1995. The technique of hydrosonography included intravenous injection of 40 mg N-butyl-scopolaminiumbromid (Buscopan) and maximum gastric and duodenal wall distension by oral administration of an average of 11 warm tap water (0.5-1.51). A detailed evaluation form was used to assess (1) overall imaging quality; (2) accuracy of identification of the pancreas in its various anatomic regions and of peripancreatic vessel structures relevant for resectability, such as splenic, superior mesenteric, and portal veins, celiac trunk, and superior mesenteric, splenic and hepatic arteries; and (3) tumor size, sonographic structure and level of organ and vessel infiltration. As gold standards for positive tumor detection and description, surgery and microscopic diagnosis were used, and for negative tumor detection, event-free survival of 6 months. RESULTS: All examinations were diagnostic. Identification of the pancreas was complete in all 51 patients with an excellent overall imaging quality in 53%. In 86% of cases the various examined organ and vessel structures were depicted with either good or average imaging quality. In 48 of the 51 patients diagnosis positive for tumor or other organ pathology was made. A total of 16 pancreatic carcinomas and 5 benign tumors were diagnosed. Twenty-seven patients had pathology not related to a pancreatic neoplasm. For tumor detection, sensitivity was 82% and specificity 100%. For correct assessment of tumor resectability, sensitivity was 86% and specificity 100%. CONCLUSION: The new technique of hydrosonography combines the value of routine non-invasive abdominal ultrasound with increased sensitivity and specificity for tumor detection and assessment of resectability by improved imaging accuracy.

Adult↗
PubMed1996

[Hydrospiral CT of the pancreas in thin section technique].

PURPOSE: To evaluate a new technique for imaging the pancreas (spiral hydro-CT) based on a combination of pharmacological intestinal paralysis and water distension of the stomach and duodenum with specific reference to tumor detection rate, differentiation of malignant versus benign tumors, differential diagnosis and assessment of tumor resectability. MATERIAL AND METHODS: In an open prospective study, 151 patients with a suspected pancreatic neoplasm based on clinical, laboratory or other imaging data were examined between May 94 and October 95. Our newly developed Hydro-CT methodology included intravenous injection of 40 mg N-butylscopolaminium bromide (Buscopan) for intestinal paralysis, gastric and duodenal wall distension by oral administration of an average of 1.51 warm tap water, 30 degrees RAO patient positioning, an individualized contrast injection technique as determined beforehand by time-to-peak measurement in the portal vein and thin-slice spiral CT (3 mm increment, 6 mm table feed and 3 mm secondary reconstruction). A detailed evaluation form was used to assess (1) tumor detection rate, (2) differentiation of malignant versus benign disease, (3) differential diagnosis, and (4) accuracy of assessment of resectability by identification of infiltration into adjacent organs and vessel structures relevant for resectability such as splenic, superior mesenteric, portal vein and celiac trunk, superior mesenteric, splenic and hepatic arteries. As the gold standard for positive tumor detection surgery and microscopic diagnosis were used, and for negative tumor detection an event-free survival of 6 months. RESULTS: Almost all examinations were well tolerated. In only 4% was on-site administration of a gastric tube required because of vomiting. In 2% of the patients a slight allergic reaction to the contrast medium was seen. The prevalence of a pancreatic neoplasm was 38%. In tumor detection Hydro-CT reached an overall accuracy of 97.4% with a sensitivity of 100% and a specificity of 95.9%. In the differentiation of benign versus malignant disease Hydro-CT reached an overall accuracy of 89.7% with a sensitivity of 92.5% and a specificity of 83.3%. The prevalence of a pancreatic carcinoma was 24%; 4% other malignant tumors were found (distal common bile duct carcinoma, cystadenocarcinoma). Fifty-eight patients underwent surgical exploration. In those assessment of resectability reached an overall accuracy of 95% with a sensitivity of 90.5% and specificity of 100%. CONCLUSION: The new technique of Hydro-CT based on thin slice and spiral methodology, including pharmacological intestinal paralysis and water distension, results in a high tumor detection rate and increases sensitivity and specificity of tumor differential diagnosis and of assessment of resectability.

Adult↗
PubMed1996

[Ultrasound guided puncture of the portal vein in transjugular intrahepatic portasystemic stent shunt (TIPSS)].

Successful completion of a transjugular intrahepatic portosystemic stentshunt (TIPSS) relies on knowledge of the individual hepatic vascular anatomy. The patients referred for TIPSS have an increased risk of contrast-medium-induced renal failure, and therefore the potential for a complete angiographic work-up during the procedure is limited. The same patient population also carries an increased risk of bleeding, which necessitates a rather accurate guiding technique for portal punctures. We have established transcutaneous sonographic guidance as a standard technique for transjugular portal puncture, reducing complication rates and intervention time. Competing imaging modalities for guidance are discussed.

Humans↗
PubMed1996

[CT-guided puncture].

Sonographic and CT-guided punctures allow the evaluation of suspected lesions in the head, thorax, abdomen, retroperitoneum and skeletal system. The size of the lesion to be evaluated determines the size and the diameter of the puncture needle. The quantity of the material obtained will be defined by the diameter of the needle, i.e. fine-needle biopsy is more adequate for cytological than for histological evaluation. Strict adherence to the indications and contraindications for puncture and painstaking performance of the procedure go a long why towards minimizing the complications. The advantage of CT-guided puncture, in contrast to an ultrasound-guided procedure, is visualization during the puncture procedure free from overshadowing. This permits punctures of lesions located deep in the thorax or the abdomen which are overshadowed by the lungs, by air in the small or large bowel or by bone structures. Moreover, this technique yields much more information about the tissues and organs surrounding the suspected lesion. This information is much more investigator-related with ultrasound-guided puncture. Therefore, the CT-guided puncture has become mandatory in the evaluation of suspected lesions. Moreover, using the same technique, percutaneous drainage of fluids in the interpleural space, abscesses in organs, hematomas, lymphoceles and urinomas; ablation of metastases; and sympathicolysis can be carried out. CT-guided puncture thus changes from a minimally invasive diagnostic procedure to a minimally invasive therapy.

Biopsy, Needle↗
PubMed1996

[CT-guided neurolysis. Status of the technique and current results].

INTRODUCTION: Both thoracic and lumbar sympathectomy and celiac ganglion block could be established as effective methods; side effects are rarely reported. Only the high accuracy of CT-guided positioning can make this possible. Severe side effects are merely sporadic if the proper technique is applied. MATERIAL AND METHODS: We used 21G or 22G fine needles. All CT-guided percutaneous neurolysis methods require a proper blood coagulation. Most common CT scanners are suitable for neurolysis if there is enough room for maintaining sterile conditions. All neurolysis methods involve sterile puncture of the ganglia under local anesthesia, a test block with anesthetic and contrast agent to assess the clinical effect and the definitive block with a mixture of 96% ethanol and local anesthetic. This allows us to correct the position of the needle if we see improper distribution of the test block or unwanted side effects. Though inflammatory complications of the peritoneum due to puncture are rarely seen, we prefer the dorsal approach whenever possible. RESULTS: Seven of 20 legs showed at least transient clinical improvement after CT-guided lumbar sympathectomies; 13 legs had to be amputated. Results of the methods in the literature differ. For lumbar sympathectomy, improved perfusion is reported in 39-89%, depending on the pre-selection of the patient group. DISCUSSION: It was recently proved that sympathectomy not only improves perfusion of the skin but also of the muscle. The hypothesis of a steal effect after sympathectomy towards skin perfusion was disproved. Modern aggressive surgical and interventional treatment often leaves patients to sympathectomy whose reserves of collateralization are nearly exhausted. We presume this is the reason for the different results we found in our patient group. For thoracic sympathectomy the clinical treatment depends very much on the indications. Whereas palmar hyperhidrosis offers nearly 100% success, only 60-70% of patients with disturbance of perfusion have benefited. Results in celiac ganglia block also differ. Patients with carcinoma of the pancreas and other organs of the upper abdomen benefit in 80-100% of all cases, patients with chronic pancreatitis in 60-80%.

Humans↗
PubMed1996

[Colorectal hydrosonography in diagnosis of tumorous and inflammatory diseases of the large intestine].

PURPOSE: Evaluation as to whether diagnosis of large bowel disease and TNM staging of colorectal carcinoma are possible by colorectal hydrosonography (HUS). METHOD: 52 patients with suspected neoplastic or inflammatory large bowel disease, underwent HUS. Before performing abdominal ultrasound, the colon was filled with fluid. Morphological alterations of the bowel wall were judged benign or malignant. Colorectal carcinomas were classified according to the TNM system. RESULTS: Laparotomy was performed in 46 of 52 patients. Correlation with surgery and histopathology showed that 77% of morphologic alterations of the colonic wall were detected by HUS. While benign lesions of the colonic wall occasionally mimicked malignant disease, colonic carcinomas were reliably diagnosed by HUS, because destruction and invasion of the bowel wall was visible. Carcinomas of the lower part of the rectum, however, were missed in most cases. Accuracy to determine the infiltration depth of colorectal carcinomas was 89%, but hydrosonographic N-staging was unreliable. Inflammatory disease of the large bowel as well as changes complicating the inflammatory bowel disease were accurately diagnosed by HUS. CONCLUSION: In selected patients, colorectal HUS is suited for diagnosis and staging of colonic tumours. It also helps to evaluate inflammatory bowel disease, because small and large bowel can be reliably distinguished from each other and the degree of stenosis of inflamed colonic segments becomes visible. Furthermore, HUS increases the visibility of fistulas.

Colon↗
PubMed1996

[Ultrasound of extracerebral spaces in infants: standardized examination technique].

High resolution ultrasound (5/7.5 MHz, linear array) allows imaging of the extracerebral space in infants. A standardised state-of-the-art imaging technique is described that can be performed during routine cranial sonography. Diagnosing dilated subarachnoid space is possible by comparison to normal values. Pathological findings of the subarachnoid and subdural space can be differentiated. Evaluation of the following conditions is possible: external hydrocephalus, cortical atrophy, pyogenic meningitis, subdural hematoma and hygroma. High resolution ultrasound can add helpful information in situations in which magnetic resonance imaging or computed tomography were previously needed. Since it is a noninvasive method, ultrasound is ideal for follow-up studies and hence the method of choice.

Dilatation, Pathologic↗
PubMed1996

[The accuracy of angiography and CT angiography of the carotid bifurcation compared to macro-morphological correlation].

PURPOSE: To compare the degree of carotid artery stenosis in angiography and CT angiography with the degree of stenosis measured in an intact eversion endarterectomy specimen. METHODS: Preoperative angiograms (intraarterial DSA, 512 x 512 matrix) and CT-angiograms (24 sec spiral scan, slice thickness 2 mm, pitch 1.5) were taken in 12 patients with symptomatic carotid stenosis. Evaluation of the degree of stenosis was performed according to the NASCET ("distal" degree) and ECST ("local" degree) methods. These data were compared with measurements of the surgical specimens. RESULTS: The median "local" degree of stenosis in angiograms was 81.5% (range: 70-99%), in CT angiograms 83% (59-94%) and in specimens 85.5% (65-96%). The "distal" degree of stenosis was 79% (50-99%) in angiograms, 85.5% (55-99%) in CT angiograms and 81% (52-95%) in specimens. CT angiography slightly overestimated the degree of stenosis compared with the specimen, whereas angiography slightly underestimated the true degree of stenosis. However, these differences were not statistically significant. CONCLUSION: CT angiography is able to predict the degree of internal carotid stenosis when compared with an intact surgical specimen. It is as accurate as the "gold standard" of invasive angiography.

Angiography, Digital Subtraction↗
PubMed1996

[Gastrointestinal diagnosis with hydrosonography and hydro-CT. 1: Stomach carcinoma].

PURPOSE: Hydrosonography (HUS) and hydro-CT (HCT) were evaluated for diagnostic accuracy and staging efficiency of gastric carcinomas. MATERIAL AND METHODS: 68 patients suspected for gastric carcinoma were examined. At HUS the gastric wall is distended by water, the tumour is localised and enlarged to judge the depth of infiltration. At HCT the stomach is filled with water and after paralysis of the gut a spiral-CT optimised for parenchymal and vessel contrast is performed. Gastric carcinomas were classified according to the TNM-system and histopathological correlation was achieved. RESULTS: The number of normal/pathologic examinations was 10/30 (HUS) and 9/31 (HCT), the detection rate of gastric tumours was 77% (HUS) and 94% (HCT). The T-stage was correctly determined in 27% (HUS) and 55% (HCT), the N-stage in 65% and 45% and the M-stage in 81% and 73% of all cases, respectively. CONCLUSION: HCT is a reliable screening method for gastric tumors. Staging of gastric carcinomas, however, is not improved. Tumour extension beyond the wall and metastases can be assessed by a single examination.

Adult↗
PubMed1996

[Gastrointestinal imaging with hydrosonography and hydro-CT].

AIM: To determine the accuracy of hydrosonography (HUS) und hydro-CT (HCT) for staging colon carcinoma. MATERIAL AND METHODS: 74 patients in whom colorectal carcinoma was suspected were examined. At HUS the colonic wall ist distended by a methylcellulose/water suspension and the carcinoma is enlarged to perform staging of the tumour. HCT is a spiral-CT optimised for parenchymal and vessel contrast. Before the scan is started, up to two litres of fluid are given rectally and spasmolytics are administered to reduce peristalsis. Colorectal carcinomas were classified according to the TNM system and histopathologic correlation was achieved. RESULTS: Out of 43 (HUS) and 39 (HCT) colonic lesions 33 (77%) and 36 (92%), respectively, were diagnosed. T-stage accuracy was 88% (HUS) and 66% (HCT), N-stage accuracy 33% and 46% and M-stage accuracy 88% and 85%, respectively. CONCLUSION: The T-stage of sonographically visible tumours of the colon is determined precisely by HUS. In contrast to predicting lymph node involvement distant metastases are reliably detected by both methods. If performed together, HUS and HCT achieve high diagnostic accuracy for staging carcinoma of the colon.

Adult↗
PubMed1996

[Liver transplantation and diagnostic radiology: socioeconomic aspects].

PURPOSE: For calculating cost-effectiveness in the context of diagnosis related groups (DRG) we analysed all radiological examinations for 56 consecutive liver transplantations during the primary stay in the surgical department (1052 chest x-rays, 296 ultrasonographies, 216 colour coded duplex sonographies, 72 cholangiographies, 35 CT, 23 angiographies, one MRI and one embolisation). METHODS: For calculation we used the reimbursement that the surgical wards received per patient day and the special fee for liver transplantation. We compared this with the refunds received by the department of radiology. RESULTS: The hospital was reimbursed a total of 143785.80 DM per patient. The diagnostic and interventional procedures that were requested for the 56 patients amounted to a total of 225118.63 DM and 4019.96 DM per patient, respectively. CONCLUSIONS: This means that only 2.8% of all the costs during and after liver transplantation were caused by the radiological examinations. This represents only a small portion of the expenses during the time in hospital, taking into account especially that patients after liver transplantation are at high risk for developing complications.

Adolescent↗
PubMed1996

[Magnetic resonance tomography of liposarcoma].

PURPOSE: Liposarcoma is the most common soft tissue sarcoma in adults. The purpose of the study was to correlate MR imaging features with the four ICD subclasses. METHODS: 28 patients with liposarcoma were examined preoperatively on a 1.0 T MRI system, using spin echo sequences, gradient echo imaging and STIR sequences. In all patients, classification of the liposarcomas was made by histologic diagnosis (ICD-10-M-classification). RESULTS: Well differentiated liposarcomas (9 patients) showed a number of MRI features consistent with lipoma (well defined mass high signal intensity (SI) on T1 images, low signal on T2 images, no or only little signal increase of tumour tissue after contrast material application, no necrosis). Not well differentiated liposarcomas (myxoid 14 patients, pleomorphic three patients, round cell two patients) revealed the largest part of the mass to be of low SI on T1-weighted images. Only scattered fatty islands and septa (9 patients with myxoid liposarcoma had more SI in T1-weighted images. T2-weighted image showed most of the mass to be of intermediate to high SI are the fatty island of relatively low SI. The probability of tumor necrosis increased with lower tumour grading. CONCLUSION: MRI seems to be valuable to identify well differentiated liposarcomas.

Adult↗