Schumacher Ka

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< 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.

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, methyltert-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 methyltert-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 methyltert-butyl ether. In the case of isodense stones, the average instillation time of methyltert-butyl ether was 12.3±4.7 hr. There was a statistically significant difference in methyltert-butyl ether instillation time between the both groups (P<0.001), but the total instillation time required for stones with a mean density of more than 50 HU was significantly longer (P<0.0001); consequently, in these patients the incidence of severe complications was higher without reaching statistical significance. Mild complications occurred in 95.2% of patients and severe complications were observed in 16.8% of cases. Posttreatment CT examinations after intravenous application of contrast media revealed gallbladder mural hyperemia followed by edematous swelling of the pericystic tissue layer in 96.3% of patients. Eight of eleven patients (72.7%) with gallbladder sludge revealed gallstone recurrence in the course of a 12-month observation period. In the successfully treated group, only one patient experienced gallstone recurrence (P=0.0066). In principle, the use of bile acid ethylene diaminetetraacetic acid dissolution medium made the dissolution of calcified or pigment stones possible, although the side effects are greater than with cholesterol stones. More effective and safer solvents for these more difficult to dissolve stones should be sought.

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.

Regional Chemotherapy in Liver Metastases of Colorectal Carcinoma: Monitoring with Arterial Computed Tomography

Continuous chemotherapy was administered to 82 patients through the hepatic artery via Infusaid pumps. In order to obtain a primary status and to evaluate the success of therapy, the perfusion patterns of the liver and of the existing tumor masses in the liver were estimated by conducting arterial angiocomputed tomographies (AACTs) immediately after pump implantation of every 3 months thereafter. In 70% of the patients, findings showed both liver lobes to be homogeneously perfused, 24% demonstrated distinct inhomogeneities. The response of the latter cases should depend primarily on the efficacy of the administered cytostatic agent. Six percent of the patients showed selective perfusion of either the left or right hepatic lobe. In these cases, only the perfused liver regions exhibited stable disease or regression of the metastases, whereas the metastases of the nonperfused regions progressed. At 3-month follow-up, the majority of the patients (50-57%) showed homogeneous hepatic perfusion. Inhomogeneities were found in 26-36% of the patients, 12 patients demonstrated incomplete perfusion. There was no association between the perfusion patterns of the metastases or of the prechemotherapeutic liver involvement and the response of the metastases to regional chemotherapy. In regional chemotherapy, liver perfusion should be controlled both intraoperatively or directly postoperatively and during therapy.

Radiographic aspects in transcatheter contact dissolution of calcified gallbladder concrements

The present study on 10 patients reports upon an attempt to perform percutaneous contact dissolution of partially calcified gallbladder concrements. These gallstones, which exhibited structural calcifications on CT scans, required time-consuming complex dissolution procedures with transcatheter administration of methyl tert-butyl ether (MTBE) and ethylene diamine tetraacetic acid (EDTA). Insertion of the catheter system (5 F) was performed via a percutaneous transhepatic route. Catheter placement was maintained for a maximum of 4 days. Complete lysis was achieved in seven of the ten cases. In six patients, significant regional or disseminated chemically induced cholecystitis and pericholecystitis could be observed on CT examination. However, on follow-up CT examinations, these changes proved to be completely reversible. It has been demonstrated that tolerance of the gallbladder wall and adjacent tissue layer against the lytic media employed is rather limited and that meticulous controlling of the morphological reaction can be helpful in minimizing complications.

Flushable stent-system for internal drainage in occlusive jaundice

The effectiveness of biliary stents may be reduced as a result of obstruction by tumor material, bile salts or detritus. To circumvent this problem we developed a prosthesis system, which allows flushing and repetitive radiological control via a subcutaneous port. Prostheses were implanted in 26 patients presenting with inoperable occlusive lesions of the bile duct. Patency was regularly monitored by checking the bilirubin and alkaline phosphatase levels and using port-cholangiography. Catheter function was easily maintained in 92% of the patients and ended upon malignancy related death. In case of dysfunction, drainage could generally be restored with intensive flushing. This new flushable stent-system was easily implantable, could be exchanged without renewed percutaneous transhepatic puncture and allowed flushing, external drainage, bile probes for bacteriological examinations and follow up cholangiography via the subcutaneous placed port.

Regional Chemotherapy in Hepatic Metastases of Colorectal Carcinoma: Continuous Intra-arterial Versus Continuous Intra-arterial/Intravenous Therapy

About 25% of patients have already liver metastases when the diagnosis of colorectal carcinoma is established. In another 30%–40% of the patients, metachronic metastases of a primary tumor settle in the liver, indicating that liver metastases are a significant factor for the prognosis of colorectal carcinoma [1]. The median survival time of the patients is approximately 6 months; only 7% live longer than 1 year [3]. Lymphogenous spread of metastases is not the decisive factor; rather, it is the invasion of the primary tumor into the vascular system [4].

[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.