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Biomedical subjects

K A Schumacher

Publications and source records attributed to K A Schumacher.

At least 19 recordsLinked to original sources
PubMed1993

Transhepatic topical dissolution of gallbladder stones with MTBE and EDTA. Results, side effects, and correlation with CT imaging.

Forty-two patients with symptomatic gallstones (28 women, 14 men, mean age 49.8 +/- 13.2 years) were recruited for contact dissolution therapy. Pretreatment CT scans of the gallbladder were obtained in every patient under standard conditions. For contact dissolution treatment of heterogeneous gallstones or gallstones with attenuation values of more than 50 Hounsfield units, methyl tert-butyl ether and bile acid ethylene diaminetetraacetic acid were used in alternating administration at time intervals and durations adapted to the individual tolerance of the patients. In the case of gallstones with mean attenuation values under 50 Hounsfield units, the dissolution therapy was performed with methyl tert-butyl ether alone. In 12 (28.6%) patients a complete dissolution of gallbladder stones could be achieved; 11 patients (26.2%) revealed gallbladder sludge but no radiologically or sonographically visualized residual stone debris. The remaining 19 (45.2%) patients had residual gallstone debris. Shell fragments in three of five rimmed gallstones, seven of eight laminated gallstones, and all densely calcified stones were refractory to contact dissolution therapy. Dissolution rates correlated well with mean attenuation values, whereas no significant correlation was found between stone number and dissolution rates or between stone diameter and dissolution rates respectively. The mean instillation time required for stones with a mean density of more than 50 HU was 17.7 +/- 11.5 hr of bile acid ethylene diaminetetraacetic acid and 5.8 +/- 3.2 hr of methyl tert-butyl ether. In the case of isodense stones, the average instillation time of methyl tert-butyl ether was 12.3 +/- 4.7 hr.(ABSTRACT TRUNCATED AT 250 WORDS)

Bile Acids and Salts↗
PubMed1993

[Idiopathic ulcer of the small intestine].

The authors report on a female patient, 32 years old, suffering for eight years from recurrent and progressive abdominal pain, combined with chronic anemia, due to iron deficiency. Neither anamnesis and clinical course, nor technical examinations elucidated the etiology. Finally an explorative laparotomy with segmental resection of the small intestine led to diagnosis and healing of the rare "idiopathic small bowel ulcer". Possible differential diagnoses were lacking. This case report demonstrates the need of an invasive and aggressive diagnostic approach after excluding all common causes of disease, related to the symptoms, in order to prevent patients from suffering for years.

Adult↗
PubMed1992

Computed tomography after ESWL of gallbladder calculi.

Computed tomography (CT) was performed on 88 patients before and after extracorporeal shock wave lithotripsy (ESWL) of gallstones to find the effects of ESWL on the gallbladder and surrounding liver tissue. Post-ESWL scans demonstrated a thickening of the gallbladder wall in 25 (28.4%) cases. In one patient an intrahepatic bilioma beside the gallbladder was seen 3 days after ESWL treatment. Hematoma of the gallbladder wall or the adjacent liver tissue was not seen, and neither a hydrops nor biliary-induced pancreatitis was observed. The authors conclude that while some patients undergoing ESWL will show some posttreatment abnormality on CT scans, the procedure is associated with a low frequency of serious gallbladder and liver trauma.

Cholecystography↗
PubMed1992

[MR angiography of occlusive changes in the superior thoracic inlet veins].

We used MR angiography to assess the thoracic inlet veins in 5 normal volunteers and 14 patients with thrombosis of these veins. The results were compared with conventional venography and contrast-enhanced computed tomography (CT). The normal anatomy was readily depicted by MR angiography in all normal volunteers. Pathology was assessed correctly by MR angiography in all patients. Thrombosis of the internal jugular vein was seen on MR angiography in all cases whereas conventional venography failed to demonstrate this region adequately in 3 cases. The best overview of the thoracic inlet veins was achieved in the coronal plane; however, for detailed demonstration of pathology, imaging in additional planes was necessary. We conclude that MR angiography is a promising method for non-invasive assessment of thoracic veins.

Evaluation Studies as Topic↗
PubMed1992

Extracorporeal shock wave lithotripsy in symptomatic cholesterol gallbladder stone patients with a second generation electrohydraulic lithotripter (MPL-9000): experiences with 106 patients over 15 months.

One hundred and six patients were treated with a second generation underwater spark discharge lithotripter (Dornier MPL-9000). During the 15-month study period, Kaplan-Meier analysis predicted a stone clearance rate of 16.5% after 4 months, 37% (7 months), 71% (10 months), and 81% (15 months), respectively. Patients with multiple stones had a 5% probability to be free of stones after 13 months of treatment, when compared to 100% in patients with solitary stones smaller than 2 cm (p less than 0.001). Stones with densities below 100 Hounsfield units (HU) on computed tomography disappeared in 75% of the cases within 13 months. Rim calcified stones were cleared in 100% after 10 months of treatment. Fragmentation efficacy proved to be an essential predictive parameter for stone clearance: a fragment size below 5 mm after extracorporeal shock wave lithotripsy resulted in a 100% stone clearance within 13 months regardless of the initial stone number, size, and density. None of the stones fragmented to pieces of more than 10 mm in diameter could be dissolved within the observation period. Obviously, modern generation electrohydraulic lithotripters are effective in stone fragmentation, thus providing the basis for successful bile acid therapy provided the patients are properly selected.

Adolescent↗
PubMed1992

Occult gallbladder perforation: an unusual complication of gallstone lithotripsy.

Three days following extracorporeal shock-wave lithotripsy of a solitary, calcified gallstone, a 69-year-old white male patient was re-admitted with E. coli sepsis and fever of up to 39.4 degrees C. Ultrasound and CT both revealed a smooth-rimmed hypodense paravasate in the middle portion of the left liver lobe adjacent to the gallbladder, with a density identical to gallbladder fluid. The evidence for perforation was based on CT scanning, and a diagnosis of occult gallbladder perforation was made. Conservative treatment was performed successfully. Following elective cholecystectomy two months thereafter, gallbladder histology showed signs of chronic cholecystitis and E. coli was isolated in bile cultures. The paravasate had granulated and finally cicatrized. By combining ESWL and chemical dissolution, treatment of multiple, calcified and pigment gallstones is possible and this approach has become an attractive alternative therapy modality for a selected group of gallstone patients. Further assessments of the efficacy and safety of this technique are necessary. Conservative treatment of occult gallbladder perforation is possible and should be performed in high-risk patients.

Aged↗
PubMed1991

[Malignant obstructive jaundice: decompression via an external bilio-gastric fistula].

In cases of malignant bile duct obstruction in which internal biliary drainage cannot be established by surgical intervention or by implantation of a stent, the externally drained bile can be recycled by connecting the transhepatic catheter to a percutaneous gastrostomy. Experiences on three patients treated by the above method are reported.

Adult↗
PubMed1991

[Congenital and acquired anomalies of the inferior vena cava. Differential diagnosis using digital subtraction angiography and computed tomography].

Segmental aplasias of the inferior vena cava, thrombosis of the vena cava, tumour infiltration (e.g. renal neoplasms via the renal vein) and external compression (e.g. large hepatic metastases) may produce similar radiomorphologic changes in chest x-ray DSA and CT. These radiomorphological changes are described by case reports. DSA clearly demonstrates the course of the vessels and the collaterals involved. CT may elucidate the paracaval vascular changes. It is only a synopsis of cavography (DSA) and CT with reference to embryogenesis that will lead to a reliable diagnosis and enable a definite decision on therapy and prognosis.

Adolescent↗
PubMed1991

[Radiologic study of the ileum-neobladder after radical cystoprostatectomy].

The study reports on radiographic findings obtained from 70 male patients in whom, following radical cystoprostatectomy for carcinoma, an ileum neobladder was created. Morphological appearance and postoperative complications of this continent type of bladder replacement were documented by means of cystography, excretory urography, retrograde urethrography and CT. Specific complications rarely arose from suture insufficiencies of the neobladder itself (n = 3) or from the ileourethral anastomosis (n = 2). Stenoses occurred at the site of the ileourethral (n = 9) and the ureteroileal anastomosis (n = 2). Transient dilatation of the upper urinary tract was observed in the majority of patients. Non-specific complications included pelvic abscesses (n = 2), haematomas (n = 2), lymphoceles (n = 3), and ileus (n = 2).

Adult↗
PubMed1991

[Biliary obstruction: MR-cholangiography with a rapid gradient-echo sequence (2D CE-Fast)].

Magnetic resonance (MR) was used to delineate the biliary tree in patients with obstructive jaundice originating from various types of malignant or benign processes at different locations. With the aid of a rapid sequential gradient-echo acquisition (CE-Fast) and 3D post-processing, heavily T2-weighted images could be obtained to identify the site of obstruction in ten out of eleven patients. Slices were acquired during breath-holding periods of about 12 sec with a total examination time of 10-15 min. The three-dimensional display reliably demonstrated the dilated bile ducts in pre-stenotic areas whereas in the majority of cases post-stenotic ductal segments could not be visualised.

Cholangiography↗
PubMed1991

Dilated biliary tract: evaluation with MR cholangiography with a T2-weighted contrast-enhanced fast sequence.

A heavily T2-weighted gradient-echo sequence was used for magnetic resonance (MR) imaging of the biliary system in five healthy volunteers and 13 patients with obstructive jaundice. Images were obtained in the sagittal and coronal planes during sequential breath-hold intervals and were post-processed by using a maximum-intensity projection algorithm. The extrahepatic and intrahepatic bile ducts were well visualized in 11 patients. The level of obstruction and the grade of dilatation were depicted with MR cholangiography. However, the cause of obstruction could be determined with MR cholangiography in only eight cases. The part of the biliary system below the obstruction could not be visualized with MR cholangiography. In the volunteers, MR cholangiography could demonstrate the anatomy of the biliary tract in only two subjects. Possible causes for this phenomenon are the limited spatial resolution of MR imaging, partial volume effects, or flow within the bile ducts. MR cholangiography may be a useful adjunctive tool for noninvasive evaluation of patients with obstructive jaundice. However, further technical advances are necessary to improve image quality.

Bile Ducts↗
PubMed1991

In-vivo monitoring of corticomedullary nephrocalcinosis in rats using computerized tomography.

An in-vivo method, computerized tomography (CT), was used to monitor nephrocalcinosis in female rats. CT density data correlated well with renal Ca content measured by atomic absorption spectrophotometry. In-vivo CT measurements revealed that the severity of nephrocalcinosis may change spontaneously with time. Manifest calcifications may exhibit spontaneous regression and are probably affected positively by high dietary Mg, in contrast to increased Ca. It is concluded that CT is a suitable and reliable non-invasive in vivo method to follow up time-dependent alterations in kidney calcifications in rats.

Animals↗
PubMed1990

Computed tomography evaluation of radiolucent gallstones in vivo.

Computed tomography facilitates an in vivo classification of gallstones and can aid in the identification of calcifications that escape detection with conventional radiologic procedures. Of patients with radiolucent stones, 54.8% exhibited calcifications either in the form of discrete rims (41.9%) or at the center of the stone (12.9%). Densities of the noncalcified areas of partially calcified stones averaged 40.68 +/- 6.8 Hounsfield units (HU), which was not significantly higher than the average of 31.85 +/- 3.19 HU for noncalcified stones. Calcified regions showed significantly higher densities (240.0 +/- 28.6 HU, p less than 0.001, x +/- SEM). Of the identified stones, 16.1% showed densities greater than 50 HU. These were primarily bilirubin stones, which cannot yet be treated successfully with conservative therapeutic modalities.

Adult↗
PubMed1990

[Morphological changes in the gallbladder after extracorporeal shock-wave lithotripsy].

The present study reports on 51 patients with symptomatic cholecystolithiasis, who accordingly underwent extracorporeal shock-wave lithotripsy (ESWL). In all cases, computed tomography (CT) was performed prior to and after the therapeutic procedure to delineate changes in gall-bladder morphology. Slight edematous thickening of the gall-bladder wall was found in 15 patients. One patient presented a rupture of the gall-bladder with formation of a bilioma in the adjacent liver tissue. In case of calcific concrements, CT revealed a characteristic pattern of fragment distribution following shock-wave treatment, and fragments of various sizes exhibited distinct adhesion to the gall-bladder wall.

Adolescent↗