[Percutaneous transhepatic endoscopy and targetted tissue removal with an F-10.2 maneuverable thin cholangioscope]

Due to the flexibility and an external control mechanism of our thin calibrated cholangioscope (10.2 F) an inspection of the bile ducts via percutaneous transhepatic access is possible without too much discomfort for the patient. A 3.6 F working channel enables target-specific biopsies under optical control. It does not only enable histological diagnosis of the tumour itself but above all the exact definition of the proximal and distal tumour borders. This is a decisive criterion of operability and operation planning especially in tumours of the hepatic bifurcation. Expansion of the compressive lesion may be determined for palliative treatment. Percutaneous stone extraction by contact lithotripsy or with a Dormia basket is technically possible via the working channel under endoscopic view. An inspection of the peripheral branches of the same and the other liver lobe from one access only is made possible by easy maneuverability and flexibility of the endoscope.

[CT-guided biopsy. Comments on the puncture technique]

Computed tomography is an universally applied method of controlling diagnostic puncture of unrecognized processes in practically any region of the human body. The conditions required, the puncture technique, the various pathways and the types of needles used are discussed.

[Percutaneous diagnosis and therapy of the bile ducts and gallbladder. Feasibility and status]

Percutaneous transhepatic access to the bile duct has opened up new possibilities not only for diagnosis by means of cholangiography and cholangioscopy with endoscopically guided biopsy by small-bore equipment, but also for the treatment of benign and malignant obstructive jaundice. In malignant disease recanalization of the obstruction is possible by means of laser, intracavitary irritation, internal bile drainage in Klatskin tumors, large-diameter endoprostheses (e.g., a Y-shaped prosthesis) or metal stents. In benign disease, balloon dilatation of inflammatory stenoses, stone extractions from the bile duct or gallbladder by means of Dormia baskets, ultrasound or piezoelectric shockwave-contact lithotripsy and chemical litholysis are possible. Very often percutaneous access is a real alternative to surgical intervention.

Diagnostic imaging in metastatic lung disease

Chest radiographs, full lung tomography and computed tomography of the chest provide increasing sensitivity for evaluation of pulmonary metastases. Pulmonary nodules of 5-10 mm diameter are detectable with increasing frequency by use of high kilovoltage chest radiographs. Full lung linear tomography provides an overall accuracy of 72-97% in diagnosis of pulmonary nodules. Chest CT delineates pulmonary nodules as small as 3 mm within 10 mm slice sections. However, as sensitivity increases, specificity diminishes in identifying metastatic nodules. Sensitivity in CT is also reduced by false negative findings due to unequal respiratory cycles. Comparative radiologic-pathologic evaluation of nodule detection proved CT to be the most sensitive screening method for pulmonary metastases. Timing of follow-up studies for pulmonary nodule detection in cancer patients can be determined by tumor growth kinetics; 3-6 month intervals proved to be useful.

[Computed tomographic-guided fine-needle biopsy of the pancreas for histology determination]

Computed tomography-guided fine-needle biopsies of the pancreas were performed in 54 patients. In 46/54 biopsies, the material obtained permitted a histological diagnosis despite the small external needle diameter of only 0.95 mm. The only complication was due to laceration of an artery of the transverse mesocolon. The prevalence of malignant tumors was 67%. Adenocarcinoma was diagnosed in more than 80% of all biopsies; rare findings were malignant carcinoid or centroblastic lymphoma. Benign tumors included mucinous adenocystoma and serous microcystic adenoma. Within the group of patients where pathologic-anatomic evaluation was possible, the sensitivity of fine-needle biopsy for malignant tumors was 87% and the specificity 100%. A positive needle biopsy diagnosis for a malignant tumor reduces the number of exploratory laparotomies needed and is helpful in the planning of surgery.

[Wide-gauge bile duct endoprostheses with a port irrigation system. A new method of prolonging the drainage function]

The maintenance of adequate drainage by the bile ducts is crucial in all the endoscopic or percutaneous transhepatic procedures used today for the treatment of obstructive jaundice. We use wide-gauge polyurethane bile duct endoprostheses (F16; 5.3 mm - F20; 6.7 mm). Occlusion need not be expected to occur earlier than 4-6 months after placement. The implantation of a subcutaneous port system connected to the prosthesis by means of an F5 (1.6 mm) catheter allows not only X-ray examination of the function, but also lavage of the prosthesis and the biliary ducts. It is possible to add bile-dissolving substances, thus preventing crystallization of bile. In this way the patency of the prosthesis can be maintained for substantially longer. This also means a definite improvement in the quality of life.

[Limitations of computed tomographic differential diagnosis of focal liver changes]

Computed tomography of the liver is essential when there are discrepancies between ultrasonography, physical examination and laboratory findings. However, sometimes the referring clinicians overestimate the true accuracy of CT. Some of its major pitfalls include the limited spatial resolution and consequent false-negative results in the case of small focal lesions; further disadvantages are the inadequate contrast between a lesion and surrounding liver parenchyma, and limited specificity even in perfusion studies. When typical patterns in contrast and density of a cyst, hemangioma and focal nodular hyperplasia are present an accurate diagnosis is achieved. In atypical cases and in all other liver lesions further investigations will be necessary.

[Predictive value of magnetic resonance tomography in comparison with sonography and computed tomography in the diagnosis of focal liver lesions]

Ultrasonography and computed tomography are widely used for the diagnosis of focal lesions of the liver. However, the possibilities for tumor characterization and determination of potential malignancy are limited in many cases. Evaluation by magnetic resonance imaging shows a good correlation of relaxation time with the amount of stroma as a proportion of the total cell content of a lesion. This allows differentiation for a number of lesions. Thus, the combination of ultrasonography and magnetic resonance imaging could provide the ideal diagnostic procedure in many cases.

[Bone biopsy of uncertain bone lesions using a new biopsy cannula measuring 1.4 mm]

Bone biopsy for the clarification of ambiguous lesions has until now been the last resort in diagnostic procedures because obtaining the material for histological evaluation has involved very traumatizing methods (biopsy by surgical intervention, percutaneous biopsy with high-caliber needles). A new bone-biopsy apparatus has now been developed that is provided with a cannula not much larger than a fine needle (1,4 mm); it can be used to obtain histologically evaluable biopsy material from almost all regions of the skeletal system. As the procedure can be carried out under local anesthesia, there is no undue stress to the patient. The complication risk is no higher than when using conventional fine-needle biopsy. Despite the small diameter of this needle it is possible to obtain biopsy specimens not only of osteolytic but also of osteoplastic lesions. An electric motor (20 rotations/min) is the power source for apparatus. The value of bone biopsy in diagnostic procedures has increased considerably.

[A new Y-endoprosthesis for drainage of bile duct obstruction of the hepatic bifurcation]

Biliary decompression in cases of central tumorous biliary obstruction requires surgical or internal/external catheter bypass techniques. The development of a 14-F Y-shaped-polyurethane endoprosthesis stent provides the possibility to drain the left and right biliary system simultaneously. The endoprosthesis is placed by a combination of external transhepatic and endoscopic approach. The tip of the singular choledochal stent segment is placed within the choledochus or duodenum.

[Early postoperative control of internal thoracic artery-coronary artery anastomoses using intra-arterial DSA]

Early postoperative angiographic control is important for prognosis and medical therapy for patients undergoing coronary bypass surgery. Grafts from the internal mammary artery had been shown to be superior to venous bypasses for anastomoses to the left anterior descending coronary artery. Thus, the need for angiographic demonstration of graft patency and function is increasing. We report on the angiographic analyses of 73 patients after left internal mammary artery (LIMA) bypass surgery by filling of the graft via retrograde injection of contrast medium into the left brachial artery. In all cases the bypass, anastomosis and downstream vessel were clearly visualised. No complications or side effects were observed.

Significance of early angiographic follow-up after internal thoracic artery anastomosis in coronary surgery

The authors report about the radiological checking of the patency of the internal thoracic artery transplant in 75 patients with coronary artery disease, using intraarterial DSA in the early postoperative phase (between 6th and 8th postoperative day). The left or the right brachial artery was punctated and the contrast medium was injected at a dosage of 50 ml in counter-current. Only one angiogram series per patient was necessary to appraise the anastomosis and the perfusion of the bypass applied. In 5 patients a stenosis and in 4 patients an occlusion of the transplant could to be diagnosed. Early postoperative angiography enables quality control. In case of occlusion reoperation may be indicated.

[Initial clinical experiences with RARE-MR urography]

Potentials and limitations of a new, facultative non-tomographic Fast-Imaging sequence "RARE-MR-Urography" are presented. Its results in urological diseases are discussed on the basis of a pilot study of 35 patients. The images (4 s-32 s acquisition time) are extremely T2-weighted and display unbounded free water (urine). They reveal valuable information, not available with ultrasound or conventional radiology without application of contrast agents in the presence of urine retention. S/N problems reduce the accuracy of this method if the urinary tract contains only small amounts of urine.

[Preoperative tumor staging in rectal cancer--a prospective study]

A precise preoperative tumor staging is the prerequisite of distinct treatment planning and subtle operative regimen. Diagnostic contribution of the various examination techniques especially of imaging modalities were determined in a prospective study and correlated to intra- and postoperative findings. The TNM classification of malignant tumors of the UICC, both in its present valid and the modified form to be introduced in January 1987, formed the basis of our clinical diagnostic staging. Diagnostic accuracy in tumor staging increased significantly from 63.4% to 83.9%, if digital rectal examination, rectoscopy and barium enema were accompanied by computed tomography. Staging prediction solely concerning the surgically important differentiation between tumors "organ limited" (T1/T2 stage) and "organ extended" (T3/T4 stage) achieved an accuracy of 91/4 (97.0%).

[Preoperative staging of rectal cancer with computer tomography]

The correlation of the preoperative staging by CT with the postoperative staging was prospectively investigated in 112 patients with carcinoma of the rectum. The influence of CT on the choice of surgical treatment was also proven. The evaluation of the infiltration of perirectal tissue and especially of other organs is possible with CT. According to TNM classification the pre- and postoperative staging showed identical results by conventional diagnostic methods in T1 in 7/16, in T2 in 22/38, in T3 in 37/49 and in T4 in 5/9 patients. With the additional CT identical results were found in T1 in 7/14, in T2 in 25/31, in T3 in 49/53 and in T4 in 13/14 cases. Thus, the preoperative staging turned out to be correct with CT in 94/112 cases (83.9%). By conventional diagnostic methods identical results were found in 71/112 patients (63.4%). The infiltration of other organs was suspected preoperatively in 24 cases with CT and was found intraoperatively in 30/112 (accuracy 94.6%, sensitivity 88%, specificity 96%). Metastases of lymph nodes were suspected in the tomograms in 32/49 patients (65.3%). By the differentiated interpretation of the tumor growth with special regard to the "Grenzlamellen" of the rectum the CT gives important information for planning therapy.

[Echinococcus cysticus of the liver--sonographically a solid tumor]

In a patient with Hodgkin's disease, an intrahepatic echodense mass was diagnosed incidentally by ultrasonography. The sonographic pattern suggested a solid tumor. Despite negative or border-line serology, computed tomography established the diagnosis of Echinococcus cysticus by documentation of one "daughter" cyst; this diagnosis was confirmed by surgery. The criteria of Echinococcus cysticus in modern imaging methods like sonography and computed tomography are summarized and the diagnostic value of various procedures including diagnostic procedure in seronegative cases are discussed.

[The cutting biopsy cannula for histological diagnosis of abdominal and retroperitoneal masses. Sonographic or computed tomographic guided puncture?]

A new cutting biopsy needle has been used to obtain histologically useful material while causing the minimum of trauma. It permits biopsies of organs, but its small external diameter of 0.8 or 0.95 mm makes it possible to carry out transperitoneal puncture of the stomach, colon or liver and of the retroperitoneal space, using a ventral approach. Tissue samples were obtained in 96% of 63 patients. The risk of complications is no higher than for conventional needles used for cytology. The accuracy with which the material can be obtained is therefore the most important problem. The position of the area to be biopsied should determine whether the biopsy is to be aided by sonography or CT. Biopsies of organs can be appropriately carried out under ultrasound control, but processes in the pelvis and in retroperitoneal-paravertebral and extra-peritoneal positions are best biopsied under CT control.

[Acute pseudoobstruction of the colon (Ogilvie syndrome)]

Pseudo-obstruction of the colon was observed in six patients. The cardinal feature is acute distension of the large bowel without distal obstruction. Apart from few idiopathic cases, the syndrome usually is associated with postoperative, posttraumatic or metabolic disorders of extraintestinal origin. Without treatment, increasing distension leads to cecal perforation with a high mortality. Treatment is conservative initially. If decompression by colonoscopy fails, cecostomy or right hemicolectomy are mandatory. The pathophysiologic mechanism of acute colonic pseudoobstruction is unknown. Whether Ogilvie's syndrome is a genuine clinical entity or a complication of associated diseases is still on question.

[After-care problems and complications of percutaneous biliary drainage]

This is a follow-up study of 171 patients concerning the patients' care and complications following biliary drainage. Complications caused by puncture and drainage are considered separately. External biliary drainage resulted in 39%, internal in 26% with complications. The influence of advantages and side effects upon the indications of biliary drainage is discussed. Prognosis concerning the survival rate depends on the underlying pathology: In obstructive jaundice caused by metastases the patients only survived two months while the mean survival rate in carcinoma of the biliary ducts is 18 months.

[Transvenous atrial septal defect occlusion in an animal experiment]

Preliminary results concerning the occlusion of experimental atrial-septal defects (ASDII) of the secundum type are reported. An occlusion element was inserted transvenously and its passage across the atrial-septal defect was controlled by open-heart surgery in dogs. Subsequently, the defect was occluded using a single-piece element. In all 5 surgical experiments the occlusion was possible without dislocation or embolism of the element during an atrial stimulation of the heart for more than 1 hour. In additional experiments without open-heart surgery, atrial-septal defects were produced in 7 dogs by transseptal punction and perforation under X-ray control. The atrial-septal defects could be closed for a short time in 2 dogs. In 1 of the 2 dogs the element embolized into the right pulmonary artery, and in the other into the abdominal aorta. Transvenous occlusion of experimental atrial-septal defects is possible, but more experimental work is necessary with respect to the technical problems.