[Frequency and causes of civil and criminal proceedings in radiology. Analysis of a survey]

The eagerness of German patients to go to court on account of actual or suspected malpractice of their physicians has increased over the years, as is the case in other Western countries. Media coverage has given rise to criticism of physicians and their services rendered more than before. This naturally also concerns the discipline of radiology, even though the probability of a radiologist being accused in a lawsuit is clearly minor in comparison to the surgical disciplines. In contrast to other fields, the X-ray pictures are always available for a second opinion. In this study, 4760 radiologists were sent a questionnaire by mail and 1503 answered. The questionnaires were evaluated regarding interrogative and informative data from pending or completed proceedings. Lawsuits were directed towards the assessment of examinations (38%), the actual performance of an examination (30%) and not towards providing patients with information as we had expected. Angiographies, mammographies, and radiographies were the most frequent reasons for instituting proceedings. The majority of litigating patients was between 40 and 50 years old. The proceedings led to civil convictions in 30% and criminal convictions in 5.5%. Of the physicians accused of incorrect conduct, 73% were of the opinion that they had been treated unjustly, 26% supported the reproach as justified, and the rest had formed no opinion. Physicians in private practice and senior consultants (70%) were most frequently sued.

Virtual intra-arterial angioscopy (VIA) of the carotid artery based on helical CT data

The purpose of this study was to visualize both the vessel wall and atherosclerotic plaques in virtual intra-arterial angioscopy (VIA) based on helical CT data sets. To achieve this in vitro, the optimal reconstruction threshold of the vessel wall was determined to be 56.4% of the maximum enhancement. Using this threshold, 20 patients suffering from symptomatic carotid disease were examined in a helical CT scanner. The degree of stenosis was defined using the North American Symptomatic Endarterectomy Trial (NASCET) criteria and compared with results from digital substraction angiography (DSA). Grading of stenoses was only possible by adding the separately computed plaque geometry to the geometry of the vessel wall in a second step. Correlation between VIA and DSA in low grade, medium grade and high grade stenosis was 88%, 93% and 71%, respectively. Complete occlusions were diagnosed correctly in all patients. Sensitivity and specificity for the correct diagnosis of high grade stenosis was 93.7% and 91.3%, respectively. A realistic depiction of intraluminal structures in carotid arteries can only be generated by displaying both the vessel wall and plaque structures simultaneously.

Der Hirnabszess in der Diffusionswichtung und Unterschiede zum zystischen Hirntumor

PURPOSE

The clinical usefulness of diffusion-weighted imaging (DWI) was evaluated in patients with brain abscesses in comparison to patients with cystic brain tumors.

MATERIAL AND METHODS

Five patients with surgically confirmed brain abscesses underwent beside a brain MRI examination with contrast media application diffusion weighted imaging. Apparent diffusion coefficients (rADC) in three orthogonal diffusion gradient were calculated. The same protocol was used to examine 5 patients with cystic brain tumors.

RESULTS

Showing an rADC of 0.33 x 10(-3)/mm(2)/s abscesses have a highly restricted diffusion in comparison to cystic brain tumors with an rADC of 1,67 x 10(-3)/mm(2)/s.

CONCLUSION

Diffusion weighted imaging is a usefull diagnostic tool in the work up of brain abscesses.

Endoleaks after endovascular repair of aortic aneurysm: are they predictable?-initial results

PURPOSE

To evaluate the predictability of endoleak.

MATERIALS AND METHODS

Thirteen women and 60 men (mean age, 69.8 years) underwent transfemoral insertion of endoluminal stent-grafts for treatment of aortic aneurysms. Follow-up included helical computed tomography (CT) at 3-month intervals. In the cases of endoleak, angiography also was performed to document the number of leak sites, their size and position, the feeding artery, the size of the aneurysm, the amount of thrombus, and the visualization of the lumbar arteries and inferior mesenteric artery. These data were correlated (Student t test) with the probability of endoleak.

RESULTS

A total of seven (10%) endoleaks were identified at CT in 68 patients. The feeding vessels were lumbar arteries in three cases, the inferior mesenteric artery in three cases, and the median sacral artery in one case. Of all factors, only the number of lumbar arteries visualized preoperatively (P <.005) had a significant correlation with probability of endoleak. In 71% (five of seven patients) of the cases of lumbar endoleak, four lumbar arteries were patent, whereas among the 61 patients with successfully repaired aneurysm, only eight (13%) had four patent lumbar arteries. Endoleaks were never found in the primarily thrombosed sections of an aneurysm.

CONCLUSION

Prediction of endoleaks with absolute certainty remains elusive. The single correlating risk factor identified from the data was patency of four or more lumbar arteries visualized preoperatively at CT.

[Pancreatic interventions: biopsy, drainage, necrosectomy--from the viewpoint of the radiologist]

The following publication is an overview looking at diagnostic and therapeutic possibilities related to interventional procedures for diseases of the pancreas. We emphasize the description of the technique and show meaningful indications and limitations.

Embolization for gastrointestinal hemorrhages

Retrospective evaluation of interventional embolization therapy in the treatment of gastrointestinal hemorrhage over a long-term observation period from 1989 to 1997. Included in the study were 35 patients (age range 18-89 years) with gastrointestinal bleeding (GI) referred for radiological intervention either primarily or following unsuccessful endoscopy or surgery. Sources of GI bleeding included gastric and duodenal ulcers (n = 7), diverticula (n = 3), erosion of the intestinal wall secondary to malignancy (n = 6), vascular malformations (n = 4), and hemorrhoids (n = 2), as well as from postoperative (n = 6), posttraumatic (n = 2), postinflammatory (n = 4) or unknown (n = 1) causes. Ethibloc (12 cases) or metal coils (14 cases) were predominantly used as embolisates. In addition, combinations of tissue adhesive and gelfoam particles and of coils and Ethibloc were used (six cases). Finally, polyvinyl alcohol particles, a coated stent, and an arterial wire dissection were utilized in one case each. Bleeding was stopped completely in 29 of 35 cases (83%). In one case (3%) the source of bleeding was recognized but the corresponding vessel could not be catheterized. In five other cases (14%) there was partial success with reduced, though still persistent, bleeding. The rate of complications was 14%, including four instances of intestinal ischemia with fatal outcome in the first years, and, later, one partial infarction of the spleen without serious consequences. Gastrointestinal hemorrhage can be controlled in a high percentage of patients, including the seriously ill and those who had previously undergone surgery, with the use of minimally invasive interventional techniques. The availability of minicoils instead of fluid embolization agents has reduced the risk of serious complications.

Embolization of type II endoleaks fed by the inferior mesenteric artery: using the superior mesenteric artery approach

PURPOSE

To evaluate the use of a superior mesenteric artery (SMA) approach to embolize type II endoleaks arising from the inferior mesenteric artery (IMA).

TECHNIQUE

When reperfusion of the aneurysmal sac via the SMA occurs through the IMA, as shown by computed tomography (CT) and angiography, the IMA origin can be accessed via the marginal artery or the anastomosis of Riolan. The SMA is catheterized with a 5-F catheter, and a coaxial catheter is advanced to the leak to deliver 2- to 8-mm-diameter minicoils to embolize the IMA origin and entire aneurysmal sac. Embolization usually requires from 1 to 2 hours to complete. In our experience with this technique in 11 cases, complications have not occurred, and there has been only one very small residual leak that sealed the next day. Over a 24.5-month follow-up (range 12-39), the endoleaks have remained sealed according to serial color duplex scans.

CONCLUSIONS

Successful percutaneous treatment of type II endoleak due to IMA inflow can be accomplished using an SMA access via the Riolan anastomosis or marginal artery. The procedure appears to be safe and has no adverse effects.

CT and arteriography in the evaluation of indirect myocardial revascularization with a free-muscle transplant: initial experience

PURPOSE

To examine patients with advanced cardiovascular disease with radiology after indirect myocardial revascularization with a free-skeletal-muscle transplant and to determine whether the attached vessel remains patent over the middle and long terms.

MATERIALS AND METHODS

In 10 patients with advanced, inoperable cardiovascular disease treated with indirect myocardial revascularization with a free-muscle transplant, radiologic follow-up was performed postoperatively and every 6 months. All 10 patients underwent selective arteriography of the anastomosed vessel and contrast material-enhanced helical computed tomography (CT) (transverse sections and reconstructions).

RESULTS

All patients showed adequate vascular conditions postoperatively, as did nine of 10 patients after 1 year. In one patient, the anastomosed artery was occluded. CT showed time-dependent muscle degeneration in all patients. Postoperative, contrast-enhanced, superselective CT showed an area of high-attenuating uptake in the muscle transplant in all patients. After 1 year, CT depicted perfusion defects of the skeletal muscle in two patients. In eight patients, however, small vascular bridges from the skeletal muscle to the myocardium were detected. Radiologic results correlated well with clinical outcome and stress electrocardiograms.

CONCLUSION

Helical intraarterial CT and arteriography were sensitive in depicting enhancement and remaining vital function in nine of 10 patients after indirect myocardial revascularization with a free-muscle transplant. This combination seems promising for postoperative examination in such patients.

Treatment of leaks after endovascular repair of aortic aneurysms

PURPOSE

To evaluate leaks after the endovascular repair of aortic aneurysms and treat them with occlusive therapy.

MATERIALS AND METHODS

Seventy patients (11 women, 59 men), aged 26-82 years (mean, 69.2 years), underwent transfemoral insertion of endoluminal stent-grafts for treatment of aortic aneurysms. Indications were traumatic pseudoaneurysms (n = 5) or arteriosclerotic aneurysms (n = 65). Aneurysms were thoracic (n = 5) or infrarenal (n = 65). To exclude the possibility of leaks, spiral computed tomography (CT) was performed at 3-month intervals. Patients with leaks that persisted unchanged longer than 3 months were referred for angiography and occlusive therapy.

RESULTS

At CT, 21 leaks were identified in 17 of 70 patients (24%). Only 11 of those 17 patients (65%) had leaks identified with conventional aortography. Selective angiography, however, depicted all of these. Eighteen of 21 leaks proved amenable to occlusive treatment: surgery (n = 1), further stent implantation (n = 4), or embolization (n = 13). In one leak, spontaneous occlusion occurred after 3 months. Two leaks in either the iliolumbar or the median sacral artery were inaccessible; one remained untreated, and the other was unsuccessfully treated. Mean follow-up of occlusive therapy was 6.8 months (range, 2-14 months).

CONCLUSION

Successful occlusion of perigraft leaks is feasible in most cases and can be performed without major complications.

Malpositioned or dislocated aortic endoprostheses: repositioning using percutaneous pull-down maneuvers

PURPOSE

To present the capabilities and potential complications of 2 percutaneous techniques for repositioning malpositioned or dislodged aortic endografts.

METHODS

Seven male patients (median age 67.9 years, range 59 to 78) required correction of misplaced or dislocated endografts in the thoracic (n = 1) or infrarenal abdominal aorta (n = 6). In 1 patient, an infrarenal bifurcated stent-graft was mistakenly deployed across a renal artery; repositioning was accomplished by tugging caudally on a guidewire placed across the endograft bifurcation and exteriorized from both femoral arteries. An inflated balloon catheter was used to reposition 3 dislocated aortic devices (1 thoracic, 2 infrarenal) and 3 iliac graft limbs that had disconnected from the main graft body 6 to 12 months after implantation.

RESULTS

Repositioning maneuvers were successful in all cases, with the devices being moved from 5 to 27 mm (median 7.8 mm). There were no procedure-related complications.

CONCLUSIONS

Nonsurgical repositioning of misplaced aortic prostheses is technically feasible in individual cases. The risk associated with the procedure, however, cannot yet be evaluated.

Angiography of leaks after endovascular repair of infrarenal aortic aneurysms

OBJECTIVE

We examined whether leaks that persist after stent grafting are associated with outflow arteries.

SUBJECTS AND METHODS

Selective angiography was performed in 21 patients with persistent leaks after undergoing endovascular repair of infrarenal aneurysms of the abdominal aorta. Late leaks occurred in five patients whose prostheses were originally sealed. Before angiography, the size and position of leaks were determined with CT and color Doppler sonography.

RESULTS

Superselective angiography was successful in 19 of 21 patients. In two patients, angiography was performed over the afferent artery supplying the leak. We found one outflow artery at the site of the leak in 10 patients (47%); two outflow arteries in five (23.8%); and as many as five outflow arteries in three (14%). Angiography overlooked outflow arteries in three patients (14%). The lumbar and inferior mesenteric, urethral, and testicular arteries were identified as outflow arteries.

CONCLUSION

Other than feeder arteries, persistent leaks are associated with outflow vessels that contribute to the patency of leaks.

Leakages after endovascular repair of aortic aneurysms: classification based on findings at CT, angiography, and radiography

PURPOSE

To ascertain whether the configuration and location of leakages identified at computed tomography (CT) could provide evidence of their angiographically and fluoroscopically confirmed causes.

MATERIALS AND METHODS

Fifty patients aged 26-79 years underwent endovascular repair of traumatic (n = 4) or arteriosclerotic (n = 46) aortic aneurysms (four thoracic, 46 infrarenal). Radiographic examinations in three planes and helical CT were performed 1 week after implantation and every 3 months thereafter. Angiography was performed when there was evidence of a leakage at CT.

RESULTS

CT demonstrated evidence of leakages in 13 patients. Broad-based leakages immediately adjacent to the prosthesis were termed "perigraft leakages." If the area most affected by the leakage lay along the border of the aneurysm, then retrograde leakages were apparent at angiography. If the leakage was ventral to the prosthesis, then its source was the inferior mesenteric artery; if it was dorsolateral, then it was supplied by either the lumbar arteries or the median sacral artery through the hypogastric artery. One circumferential leakage could not be evaluated adequately at CT or angiography. Radiography depicted a rupture of the stent mesh in the middle of the prosthesis. Selective angiography demonstrated all types of leakages and permitted CT classification.

CONCLUSION

The cause of a leakage can be determined with CT on the basis of its configuration and location in the majority of cases.

[Interventional treatment of hemorrhages in advanced cervical carcinoma]

PURPOSE

Retrospective evaluation of percutaneous interventional treatment of locally advanced cervical carcinoma.

MATERIALS AND METHODS

Since 1991, 13 patients with advanced tumor disease have been referred to our department for diagnosis and therapy of an acute blood loss. In all patients (age 40-88 years, mean 61 years) hemorrhage was detected by decrease in red blood cell count. In all cases patients suffered from locally advanced or recurrent disease after surgery and/or additional radio- or chemotherapy. Embolization was performed by transfemoral access using minicoils in most cases, liquid agents less often and a covered vascular stent in one patient.

RESULTS

The site of the hemorrhage or the blood pooling of the tumor could be seen in all cases angiographically. Twenty-seven treatment cycles (2.1 per patient) were performed at intervals of 3 days to 6 months. The maximum time of follow-up and additional treatments if necessary was 1 year. In 9 of 13 patients (69%) the bleeding could be stopped immediately with a single treatment or initial treatment via both iliac arteries. One patient (7,7%) died during therapy because of an uncontrollable bleeding and consecutive decrease in red blood cells count. The remaining three patients (23%) showed slight persistent or recurrent bleeding, which could be managed interventionally until the following episode. There were two complications (15%) during therapy, representing a coil misplacement and a coil wash-out, which both could be managed interventionally.

CONCLUSION

Hemorrhage following locally advanced or recurrent cervical carcinoma can be stopped interventionally in about 70% of cases. Even in partial success it is possible to manage the acute life-threatening situation. Follow-up examinations of up to 1 year justify this therapeutic concept.

Endovascular repair of aortic aneurysms: treatment of complications

PURPOSE

To evaluate the use of interventional procedures for treating complications following endovascular repair of aortic aneurysms.

METHODS

Fifty-five patients (49 men; mean age 67.5 years) underwent endoluminal stent-graft repair of traumatic (n = 4) or arteriosclerotic (n = 51) aortic aneurysms in the thoracic (n = 3) or infrarenal (n = 52) aorta. Follow-up of therapeutic success included periodic clinical examination, angiography, and spiral computed tomography.

RESULTS

Discounting the 25 (45%) cases of postimplantation syndrome that did not require treatment, there were 22 complications observed in 20 (36%) patients over a mean 10-month follow-up (range 1 to 27). There were 2 transrenal endograft maldeployments, 1 case of twisted graft limbs, 2 access site problems (1 patient), 12 endoleaks (11 patients), 1 late graft limb thrombosis, 1 symptomatic internal iliac artery occlusion, 2 myocardial infarctions, and 1 transient psychosis. Seven (13%) patients did not undergo specific therapy, while 4 (7%) required operation (2 crossover bypass grafts, 1 suture revision, and 1 graft replacement). Among 9 (16%) patients treated with interventional techniques, 7 underwent percutaneous coil embolization for 8 endoleaks (7 successfully resolved). One late stent-graft disconnection required an additional stent-graft, and 1 of the 2 malpositioned endografts was repositioned. All patients remain alive with no increase in the diameter of the aneurysm in any patient.

CONCLUSIONS

Technical problems resulting from the endovascular repair of aortic aneurysms often respond to interventional treatment.

Non-operative management of arterial liver hemorrhages

A retrospective evaluation of embolotherapy in patients with arterial liver hemorrhages was carried out. Twenty-six patients, ranging in age from 10 days to 77 years with active arterial liver hemorrhages, underwent non-surgical embolotherapy. Bleeding was attributed to trauma (n = 21), tumor (n = 3), pancreatitis (n = 1), or unknown cause (n = 1). Twenty-nine embolizations were performed via a transfemoral (n = 26) or biliary (n = 2) approach. One bare Wallstent was placed into the common hepatic artery via to an axillary route to cover a false aneurysm due to pancreatitis. Treatment was controlled in 4 patients by cholangioscopy (n = 2) or by intravascular ultrasound (n = 2). Prior surgery had failed in 3 patients. Intervention controlled the hemorrhage in 24 of 26 (92%) patients within 24 h. Embolotherapy failed in 1 patient with pancreatic carcinoma and occlusion of the portal vein. In 1 patient with an aneurysm of the hepatic artery treated by Wallstent insertion, total occlusion was not achieved in the following days, as demonstrated by CT and angiography. However, colour Doppler flow examination showed no flow in the aneurysm 6 months later. Complications were one liver abscess, treated successfully by percutaneous drainage for 10 days, and one gallbladder necrosis after superselective embolization of the cystic artery. Embolization is a effective tool with a low complication rate in the treatment of liver artery hemorrhage, even in patients in whom surgery has failed.

[Temperature stress for patients in routine magnetic resonance examinations]

PURPOSE

To determine energy exposure and temperature changes in routine magnetic resonance imaging practice.

MATERIALS AND METHODS

Body core and skin temperatures were compared in 155 persons (143 patients, 12 volunteers) undergoing routine magnetic resonance examinations with a 1.5 T field-strength magnetic resonance tomography unit using a fluoroptic temperature measurement system.

RESULTS

Average applied energy was 0.3 W/kg for whole body and 1.92 W/kg for spatially localized SAR. The maximum whole-body SAR was 1.43 W/kg spatially localized. Body core temperatures differed from those of the control group by a median 0.1 degree C and only a few patients (16.8%) exceeded the limit (+/- 0.5%) at which regulatory mechanisms set in. All patients remained within the normal physiological circadian temperature range (+/- 1 degree C). Skin temperature rose a median 0.49 degree C, with a maximal increase of 5.31 degrees C, which may be considered to be within the limits of physiological temperature change.

CONCLUSIONS

Clinically relevant warming of the body is unlikely in routine magnetic resonance imaging practice.

[The percutaneous transarterial embolization therapy of traumatic kidney hemorrhages]

PURPOSE

To demonstrate the possibility of transarterial, superselective embolization after traumatic kidney injury and hemorrhage in patients usually treated by surgery.

METHODS

In a series of 16 patients aged 21 to 86 years (mean 37 years) external trauma led to kidney damage and consecutive bleeding. After diagnostic angiography (5 F) the exact site of hemorrhage was detected and treated by superselective embolization via a coaxial catheter system (2.7 F) either by coils (n = 5) or liquid agents (ethibloc, n = 11).

RESULTS

In all patients bleeding was stopped interventionally. Additional surgical treatment was not necessary in any case. In one older patient with preinterventionally known reduced kidney function, the excretion function decreased to creatinine levels of about 3.6 mg/dl after therapy and led to compensated nephric insufficiency. Other complications were not observed.

CONCLUSION

Interventional embolization is a well-tolerated and effective treatment modality after traumatic kidney hemorrhage. After exclusion of other injuries obligate for surgery, percutaneous transarterial therapy may help to avoid an operation. This reduces the risk of narcosis and treatment especially in multimorbid patients.

Left iliac venous thrombosis caused by venous spur: treatment with thrombectomy and stent implantation

PURPOSE

To determine the frequency of iliac venous spurs in left iliofemoral venous thrombosis and to report the results of interventional management of venous spurs after transfemoral venous thrombectomy.

METHODS

From 1990 through 1996, 77 patients with acute iliac venous thrombosis (61 left and 16 right) underwent surgical treatment. Patients with malignant disease were excluded from this series. All patients had transfemoral venous thrombectomy with construction of an inguinal arteriovenous fistula and perioperative anticoagulation with heparin with a switch to warfarin sodium for at least 12 postoperative months. Immediate results of thrombectomy were documented by means of intraoperative completion venography. Arteriovenous fistulas were ligated 3 months after control arteriovenography. Since 1995 venous spurs eventually detected during thrombectomy were treated immediately by means of stent implantation.

RESULTS

Among 61 patients with left-sided thrombosis, intraoperative phlebography revealed common iliac venous obstruction suggestive of venous spurs in 30 patients (49%). In 16 of 22 patients (73%) with untreated spurs, postoperative rethrombosis of the iliac vein was documented despite adequate anticoagulation. Only one of eight patients (13%) with stented spurs had reocclusion (chi2 test P < .01).

CONCLUSION

Venous spurs are found among about half of patients with left-sided iliac venous thrombosis. As long as the underlying venous pathologic process is left untreated, thrombectomy will not restore patency. Stent implantation is a simple and safe means to correct central venous strictures and provides excellent long-term results.

Diagnostic value of spiral-CT angiography in comparison with digital subtraction angiography before and after peripheral vascular intervention

To evaluate spiral-computed tomography (CT) angiography in primary diagnosis and/or in noninvasive follow-up after vascular intervention, we compared spiral-CT angiography and conventional angiography before and after vascular intervention. Helical-CT examinations before and after percutaneous transluminal angioplasty (PTA) or stent implantation were performed in 10 patients (mean age 63 years) with symptomatic peripheral arteriosclerotic disease. Stenoses were located in the iliac, femoral, or popliteal artery. CT examinations were done with a spiral-CT in double detector technique (CT Twin, Elscint). The parameters were as follows: slice thickness: 5.5 mm, increment: 2.7 mm, pitch: 1.5, contrast medium: 150 mL, flow rate: 2.5 mL/second, delay: 30 seconds. For evaluation, transverse planes as well as maximum intensity projections and 3-D reconstructions were used. The possible scan length reached from the aortic bifurcation down to about 10 cm below the ankle trifurcation. Preinterventional digital subtraction angiography (DSA) was superior to CT angiography (CTA: 94%, maximum intensity projection [MIP] alone: 65%), although high-grade stenoses were detected by both methods. After intervention, a resolved stenosis and improved peripheral flow could be detected by helical-CT as well as by intraarterial angiography in every patient (100%). In the primary diagnosis of vascular changes, intraarterial DSA remains the method of choice. Nevertheless, spiral-CT angiography shows comparable results after percutaneous intervention and becomes a noninvasive alternative in the postinterventional follow-up.

[Value of dynamic MRI in the diagnosis of hypophyseal microadenomas]

PURPOSE

To evaluate dynamic MR imaging of the pituitary gland.

MATERIAL AND METHODS

19 patients with suspected mass lesions of the pituitary gland were examined at 1.5 Tesla with dynamic and standard MRI using a Turbo-FLASH sequence (1 image/s for 40 s).

RESULTS

In 13/19 patients microadenomas were detected. One of the 13 microadenomas was detected using dynamic imaging and was not seen on standard MRI. The remaining 12 microadenomas were diagnosed with standard MRI.

CONCLUSION

Dynamic imaging of the pituitary gland is a time-consuming and costly diagnostic technique. If laboratory results suggest the presence of a microadenoma and conventional MRI is unable to localise it, dynamic imaging should be performed.

Mechanical thrombolysis of acute occlusion of both the superficial and the deep femoral arteries using a thrombectomy device

OBJECTIVE

Our objective was to evaluate the efficacy of the Amplatz thrombectomy device for recanalization of acute occlusions of both the superficial and the deep femoral arteries.

MATERIALS AND METHODS

Eighteen patients with acute occlusions of the femoral arteries (eight male, 10 female; 10-87 years old) were treated using the Amplatz thrombectomy clot macerator. The duration of occlusion was 16 +/- 8 hr. Eighteen patients underwent treatment of the deep femoral artery, and 16 patients had additional involvement of the superficial femoral artery. After primary recanalization of the deep femoral artery, the superficial femoral artery was also recanalized using the Amplatz thrombectomy device. Nine patients required additional aspiration thrombectomy of the tibial arteries, five patients required additional aspiration thrombectomy of side branches of the deep femoral artery, and 12 patients required additional local thrombolysis with urokinase.

RESULTS

In 14 (78%) of 18 patients, recanalization of the deep femoral artery was complete without demonstrable residual thrombi. Arterial spasms were observed in five patients (28%). The rate of limb salvage was 94% at a mean follow-up interval of 8.9 +/- 4.1 months. In the 18 patients, the ankle-brachial pressure index went from a median value of 0.56 before therapy to a median value of 0.91 after therapy. No severe complications occurred.

CONCLUSION

Mechanical thrombolysis in the deep femoral artery with the Amplatz thrombectomy device is an effective, rapid method of treatment and is rarely associated with complications. In cases of concomitant occlusion of the tibial arteries, recanalization should always be attempted because the deep femoral artery may provide a functionally decisive collateral artery between the iliac and tibial vasculature.

Virtual cystoscopy based on helical CT scan datasets: perspectives and limitations

The purpose of the study was to simulate cystoscopy based on three-dimensional helical CT scan datasets in real-time in patients with tumours of the urinary bladder. A helical CT scan with double detector technology was carried out pre-operatively in 11 patients with histologically confirmed carcinoma of the urinary bladder and one patient with chronic cystitis. A non-enhanced scan was first performed, followed by an examination in the early phase of contrast medium enhancement. Further images were acquired after adequate filling of the bladder with contrast medium, approximately 30 min after injection. These data were transferred to a separate graphic computer workstation and reconstructed. The results were then compared with the cystoscopic and histopathological findings. All tumours of the urinary bladder identified at fibreoptic cystoscopy were shown on virtual cystoscopy. The best reconstruction results were obtained from data acquired 30 min after injection of contrast medium. The ureteric orifices were not visualized at virtual cystoscopy. These data lead us to conclude that, at present, virtual cystoscopy has not reached the quality of fibreoptic examination and remains restricted to use in specific cases, for example patients with urethral strictures.

Comparison of real-time virtual and fiberoptic bronchoscopy in patients with bronchial carcinoma: opportunities and limitations

OBJECTIVE

Both helical CT and fiberoptic bronchoscopy are used in the staging of pulmonary tumors for therapeutic decision making. The improved resolution offered by helical CT has led to the clinical use of three-dimensional reconstruction techniques such as virtual bronchoscopy. We tested this new simulated endoscopic view of inner organ surfaces and compared it with corresponding fiberoptic examinations of the tracheobronchial system.

SUBJECTS AND METHODS

Twenty patients with malignancies of the lung and mediastinum were examined with both virtual bronchoscopy and fiberoptic bronchoscopy. Both examinations were reviewed by radiologists and surgeons familiar with fiberoptic bronchoscopy. Virtual bronchoscopy was calculated and reconstructed from the cross-sectional images on a separate workstation. Stenoses and tumor infiltration were classified from the fiberoptic examination. These results were compared with the virtual bronchoscopy findings.

RESULTS

Virtual bronchoscopy of diagnostic quality was achieved in 19 of 20 patients. High-grade stenoses were revealed equally well with virtual and fiberoptic techniques. Virtual bronchoscopy offered the advantage of being able to visualize areas beyond even high-grade stenoses. However, on virtual bronchoscopy discrete infiltration or extraluminal impression was not visible in five patients. In another patient, strong heart pulsation produced motion artifacts that prevented evaluation of the reconstruction.

CONCLUSION

Virtual bronchoscopy represents a new noninvasive method for evaluating helical CT findings. In comparison with fiberoptic bronchoscopy, virtual bronchoscopy offers the advantage of being able to visualize areas beyond even high-grade stenoses. In addition to the limited view of fiberoptic bronchoscopy, extraluminal causes of lumen compressions can be analyzed in the cross-sectional images and evaluated together with the virtual representation. However, it was not possible to detect small infiltrations with virtual bronchoscopy. This new representation of helical CT data might be helpful for postoperative follow-up examinations, such as after stent implantation, and can be carried out without additional risk to the patient. Radiologists do need special fiberoptic bronchoscopy knowledge and experience with three-dimensional-reconstructions to differentiate between real stenoses and artificial stenoses that might be caused by pulsation artifacts.

Displaced metallic biliary stents: technique and rationale for interventional radiologic retrieval

OBJECTIVE

We investigated the spontaneous course and the possibility of transhepatic removal of displaced biliary stents.

MATERIALS AND METHODS

Displaced biliary stents were observed in 11 patients (13-75 years old) between October 1988 and August 1996. Stent types included the Palmaz stent (n = 3), Wallstent (n = 3), and the Strecker stent (n = 5). Reasons for stent displacement included primary misplacement (n = 4), dislocation due to transhepatic endoscopy with biopsy (n = 2), dislocation resulting from a recanalization maneuver in stent occlusion (n = 3), and unknown causes (n = 2). In three cases, the stent was displaced into the proximal bile duct system. Seven patients had primary malignancy.

RESULTS

Eight of 11 displaced biliary stents were removed transhepatically. Extraction was performed using either a wire loop (n = 4) or forceps (n = 4). No complications occurred. In the remaining three patients, whose stents were displaced into the intestine, no invasive action was taken. In one of these patients, a Palmaz stent was passed spontaneously after 1 week. In the second of these patients, a 6 cm Wallstent remained innocuously at a position in the right lower abdomen, and the patient died as a result of malignancy. In the third patient, who had a 10-cm Wallstent, an abscess developed in the stent region 4 months after displacement and resulted in formation of an ileocutaneous fistula.

CONCLUSION

Transhepatic extraction of displaced biliary stents is technically possible, even in the case of rigid stents such as the Palmaz stent. Because of the risk of intestinal perforation, displaced stents should be removed.

[Therapy of acute traumatic vascular injuries using covered stents]

PURPOSE

Evaluation of percutaneously implanted covered stents in acute vascular bleeding as therapeutic alternative to conventional surgical treatment.

MATERIALS AND METHODS

8 patients aged 26 to 83 years with acute vascular lesions caused by traumas, and subsequent haemorrhage, were transferred to our department. Because of general inoperability or difficult surgical access, interdisciplinary evaluation favoured an interventional treatment. In 6 patients stents could be placed percutaneously to the aorta, subclavian and iliac arteries. In one case we had to implant three stents into the thoracic aorta.

RESULTS

In 7 interventionally treated patients the stents could be placed exactly on the lesions (88%). The bleeding could be stopped immediately in 6 cases (75%). In one patient we had to implant successfully two more stents in reintervention (12%). In another patient the available prosthesis was too short, so that the patient had to be referred to the OR for surgical treatment (12%). There were no complications during the treatment.

CONCLUSION

First results in the use of covered stents as interventional treatment of acute vascular lesions are encouraging and may represent a possible alternative to surgical therapy in locally limited bleedings, presupposing that all different types and sizes of industrially produced covered stents are available. Further investigations to compare surgical and interventional techniques are warranted.

Palliative and adjuvant regional chemotherapy in pancreatic cancer

To improve the dismal prognosis of patients (pts) with pancreatic cancer we treated 32 patients with non-resectable (UICC III, 17 pts; UICC IV, 15 pts--group 1) and 20 patients with resected (UICC I, 1 pt; UICC II, 3 pts; UICC III, 16 pts--group 2) pancreatic cancer with palliative (group I) and adjuvant post-operative (group II) coeliac axis intra-arterial cyclic infusions (CAI). CAI consisted of mitoxantrone 10 mg/m2 on day 1, folinic acid 170 mg/m2 and 5-FU 600 mg/m2 during days 2-4, and cis-platinum 60 mg/m2 on day 5 for up to 11 (group I) or six (group II) cycles. In a total of 211 cycles toxicities at the level of WHO III occurred in 0-6% and of WHO IV in 0%. The median survival times, compared with institutional historical controls (treated vs controls), were 12 vs 4.8 months in UICC III (P < 0.006) and 4 vs 2.9 months in UICC IV (P < 0.05) group I pts, and 21 vs 9.3 months in group II (P < 0.0003). Hepatic disease progression appeared to be suppressed with CAI, which also appears to be effective for palliative and adjuvant treatment in non-resectable and resected pancreatic cancer.

Sensitivity of computed tomography in detecting local recurrence of prostatic carcinoma following radical prostatectomy

The aim of this study was to evaluate CT imaging in the post-operative follow-up and in the detection of recurrence after radical prostatectomy in cases of prostatic carcinoma. In over 500 patients undergoing radical prostatectomy for prostatic carcinoma, 22 cases with local recurrence were found. CT examinations of the pelvis were retrospectively evaluated in these patients. Local recurrence was detected by PSA uptake and confirmed by transrectal ultrasound (TRUS) in combination with guided biopsy. In 22 cases of confirmed local recurrence, positive results on CT were found in eight patients (36%) and negative results in nine patients (41%). In the remaining five cases (23%), no distinction could be made between scar and local recurrence. All cases definitively classified as recurrent tumour disease showed a soft tissue mass of 2 cm or more. CT sensitivity in local recurrence of prostatic carcinoma after surgery is low. Even in a very careful follow-up, the understaging would be up to 41%. In comparison, PSA, TRUS and needle biopsy are the methods of choice and are superior to CT imaging. Based on these results, there would be no reason for including pelvic CT examinations in the follow-up of prostatic carcinoma after radical prostatectomy.

Percutaneous transluminal rotational atherectomy in the treatment of peripheral vascular disease using a transluminal endatherectomy catheter (TEC): initial results and angiographic follow-Up

PURPOSE

To evaluate the clinical results of percutaneous transluminal rotational atherectomy in the treatment of peripheral vascular disease.

METHODS

Rotational atherectomy was performed in 39 patients aged 39-87 years (mean 66.6 years). A total of 71 lesions (43 stenoses and 28 occlusions) were treated in 40 limbs. Additional balloon angioplasty was required in 54% of lesions. Fifteen patients (37.5%) presented in Fontaine stage II, 10 patients (25%) in Fontaine stage III and 15 patients (37.5%) in Fontaine stage IV. Rotational atherectomy at 750 rpm was carried out over a 0.014-inch guidewire with continuous aspiration into a vacuum bottle. Follow-up angiography and color flow Doppler examinations were performed in 22 patients (23 limbs) after a mean period of 6 months (range 2-14 months).

RESULTS

There was one primary technical failure. In 36 of 40 lesions there was a good angiographic result with residual stenoses in less than 30%. In 70 lesions treated by rotational atherectomy, however, 54% showed residual stenoses of 30%-50% and these cases required additional balloon angioplasty. The mean ankle-brachial index improved significantly (p << 0.001) from 0.49 before the procedure to 1.01 after the procedure. A single distal embolus, related to primary recanalization, occurred and there were two large inguinal hematomas. Cumulative clinical patency after 6 months was 83.8% and cumulative angiographic patency after 6 months was 79.1%.

CONCLUSION

Percutaneous rotational atherectomy is a promising approach for the treatment of chronic peripheral vascular disease. Further prospective, randomized studies are necessary to compare percutaneous transluminal angioplasty with this new technical approach.

[A new method in the determination of individual delay time in bolus application in spiral CT]

Helical-CT examinations, particularly CT angiography, require precise timing between the examination procedure and the individual dynamics of contrast medium distribution in the arteriovenous system of the patient. The necessary delay between contrast medium injection and onset of has usually been either estimated or determined by means of an additional helical CT examination. The present paper introduces a new technique which allows bolus analysis without an additional scan. Prior to a CT angiography with 10 patients, two techniques for bolus analysis (BA) were compared. Prior to diagnostic contrast medium enhanced examination, a native (BA I) and a dynamic (BA II) examination were performed. Ten seconds prior to the start of each examination, a 10 ml test bolus was applied with an injection flow rate of 3 ml/s. Both examinations lasted for 30 s. During BA I, increase in attenuation in the aorta was compared at different sites, during BA II consistently at the same site. Comparison of the individual peak times yielded a coefficient of correlation of r = 0.926. The median value for BA I was 18.4 +/- 5.4 s and 19.2 +/- 4.5 s for BA II. The difference between measurement of peak time was 1.2 +/- 1.16 s. This modified technique for bolus analysis during the primary native scan of the upper abdominal organs permits calculation of the required individual delay time between contrast medium application and scan start: no additional examination is required and the method can be performed with any helical CT unit.

[Interventional treatment of hemobilia]

PURPOSE

Aim of the study was to assess the use of embolisation in cases of iatrogenic haemobilia.

METHOD

In 18 patients with severe haemobilia after percutaneous biliary system drainage or stent implantation, an embolisation with minicoils (17 x) or gelfoam particles, was performed. To achieve a sufficient vascular obstruction, Histoacryl (4 x) or Ethibloc (1 x) were additionally used in five cases. A transarterial approach was used in 17 cases. In one patient, an approach through the biliary system was possible.

RESULTS

In all cases, the bleeding source was identified (5 false aneurysms, three biliary leaks, 9 irregularities at the junction of the artery and drainage catheter, 1 multiple collaterals at the proximal end of the stent). In 17 out of 18 cases, haemorrhage ceased definitely. In one case of a patient with pancreas carcinoma and obstruction of the portal vein as well as a simultaneous high grade stenosis of the hepatic artery propria, it was only possible to embolise small collaterals to avoid liver necrosis. This resulted in an incomplete bleeding of control. An infected haematoma was the only complication. It was treated by drainage over 10 days. During an observation period ranging approximately 7.6 months, 10 of the patients died due to their basic illness.

CONCLUSION

Embolisation is an effective procedure in the treatment of haemobilia, with a low complication rate.

Short-term results with use of the Amplatz thrombectomy device in the treatment of acute lower limb occlusions

PURPOSE

To evaluate the clinical efficacy of the Amplatz device for the treatment of acute occlusions of the lower limb arteries.

MATERIALS AND METHODS

Forty patients with acute occlusion of the lower limb arteries (3 hours to 8 days; mean, 2 days) were treated using the Amplatz clot macerator. Acute thrombotic lower limb occlusion was due to an embolic event in 32 patients and to atherosclerotic disease in eight patients.

RESULTS

Complete success, with complete clearing of thrombotic material without an adjunctive procedure, was achieved in 75% (30 of 40) of the patients. Mean thrombectomy time in these patients was 75 seconds. Partial success, with incomplete clearing of the thrombus, requiring additional procedures such as local thrombolysis, angioplasty, or atherectomy, was achieved in 20% (eight of 40) of the patients. The Doppler index increased significantly (P < .001) from .45 before intervention to .96 after intervention. There were two failures (5%). No major complications occurred.

CONCLUSION

Mechanical thrombectomy with use of the Amplatz device is a promising approach for quick recanalization of acute peripheral thromboembolic occlusions. Further studies are needed to prove the long-term patency after mechanical thrombectomy with use of this device.

Celiac artery adjuvant chemotherapy. Results of a prospective trial

CONCLUSION

Celiac artery infusion (CAI) seems to be a qualified and successful method for adjuvant treatment of pancreatic cancer. To improve the dismal prognosis of resected pancreatic cancer patients, we performed postoperative regional chemotherapy via the celiac axis.

BACKGROUND

From 1994-1995, 20 patients with pancreatic cancer (18 ductal adenocarcinoma, 2 cystadenocarcinoma) received adjuvant celiac axis intra-arterial infusions (CAI) after resection of their tumors. Sixteen patients had macroscopically complete tumor removal (R0/R1 resection, 80% of the patients), whereas four patients had gross residual disease remaining after resection (R2 resection, 20% of the patients). Postoperative tumor stages were UICC I in 1 patient, UICC II in 3 patients, and UICC III in 16 patients.

METHODS

CAI was performed for six postoperative cycles via catheters placed into the celiac artery using Seldinger's technique. The chemotherapeutic protocol consisted of mitoxantrone (Novantron), Wyeth-Lederle (Münster, Germany) 10 mg/m2 (d 1), folinic acid (Leucovorin, Wyeth-Lederle, or Rescuvolin, Medac, Hamburg, Germany) 170 mg/m2 for 10 min, followed by 5-FU (Fluoroblastin, Farmitalia, Freiburg, Germany) 600 mg/m2 for 120 min (d 2-4), and Cisplatin (Cisplatin-medac, Medac) 60 mg/m2 (d 5). The cycles were repeated after a rest period of 4 wk. Cisplatin infusions were accompanied by supportive antiemetic (8 mg Tropisetrone i.v. [Navoban, Sandoz, Nürnberg, Germany] and 8 mg Dexametason i.v.) and diuretic measures.

RESULTS

Toxicity WHO III occurred in 8% of 100 cycles, and no toxic side effects WHO IV were encountered. The median survival of 21 mo in the treated group was nearly twice as long as the 9.3 mo of a historical matched control group (p < 0.0003). CAI seems to be a qualified and successful method for adjuvant treatment of pancreatic cancer.

[Infectious spondylitis. A retrospective evaluation of MRI markers]

AIM AND METHODS

The aim of the present study was to evaluate the MRI criteria of infectious spondylitis (spondylodiscitis). The MR images of 23 patients suffering from spondylodisitis (78% unspecific, 22% specific) were retrospectively analyzed.

RESULTS

The height of the intervertebral discs involved was normal in 40%, reduced in 43% and increased in 17% of the cases. The most common findings can be summarized in an MR triad: 1) The vertebral bodies involved are hypointense in T1-weighted images (100%) with a lack of delineation of the intervertebral discs (53%). 2) The injection of Gd-DTPA yields an enhancement of the vertebral bodies involved and intervertebral discs (95% and 74% respectively). 3) The vertebral bodies and intervertebral discs are hyperintense in T2-weighted sequences (76% and 90% respectively). When present, a paravertebral or intraspinal extension of the infection was isointense compared with the adjacent involved vertebral body in the majority of the patients. A differentiation between unspecific and specific etiology based on the MR images was not possible.

CONCLUSIONS

The vertebral bodies affected were usually hypointense in T1-W with enhancement after the administration of Gd-DTPA and hyperintense in T2-W. The discs involved were usually hyperintense in T2-W and demonstrated an inhomogeneous enhancement.

Mechanical thrombectomy of embolic occlusion in both the profunda femoris and superficial femoral arteries in critical limb ischaemia

We report our preliminary experience using the Amplatz device for percutaneous thromboembolectomy in acute occlusion in both the profunda femoris artery (PFA) and superficial femoral artery (SFA) in four patients (mean age 78.5 years). All patients suffered from acute lower limb ischaemia, Fontaine Grade 3, due to cardiac embolization. Estimated occlusion times range from 3 h to 3 days. All four patients were treated successfully. Device activation time for both the PFA and the SFA was 85 s +/- 15 s. Total procedure time was 25 min +/- 10 min. There was no need for adjunctive procedures or intensive care monitoring. We conclude that the Amplatz device is a very effective and safe procedure for the quick restoration of vascular patency in cases of simultaneous embolically occluded PFA and SFA.

Stenting of central venous stenoses in hemodialysis patients: long-term results

From November 1992 through July 1996, 15 Wallstents were implanted for the treatment of symptomatic central arm vein obstructions in 14 hemodialysis patients (10 subclavian, 2 brachiocephalic vein stenoses, 2 subclavian vein occlusions). There were no acute complications. All patients were investigated by clinical examination and color-duplex sonography at regular three month intervals. When recurrent swelling predicted restenosis, phlebography was also performed. During the follow-up, high grade stenoses at the central or peripheral ends of four stents were successfully treated with five overlapping stents, giving a total of 20 Wallstent implantations. Complete occlusion of another subclavian vein distally to the stent at 16 months required ligation of the patient's arteriovenous fistula. Life table analysis including all 20 stents revealed a cumulative primary one year (two year) stent patency of 70% (50%). The cumulative secondary one year (two year) stent patency was 100% (85%). We believe that in hemodialysis patients, PTA plus Wallstent implantation is a safe and effective procedure in the treatment of central venous stenoses and even shorter occlusions. Consequent follow-up allows for timely diagnosis and treatment of restenoses, thus guaranteeing long-term patency rates comparable to those of veno-venous bypass surgery.

[Presentation of a new self-expanding vascular spiral stent]

The technical details as well as first clinical results of a newly developed Nitinol stent are presented. The spiral-shaped Nitinol stent was implanted in two patients with complicated peripheral arterial obstruction after bypass surgery. Stent implantation was very exact and technically simple using a special implantation catheter. While one patient is free of symptoms three months after stent implantation, an early obstruction was observed in the other patient one day after the interventional procedure. The specific spiral design allows a simple percutaneous extraction of the stent. A cross-over use of the stent seems principally possible, but limited due to the length of the implantation catheter of 70 cm. Prospective clinical studies are, however, warranted.

[Virtual cystoscopy based on spiral CT data]

Simulation of three-dimensional cystoscopy based on helical CT scan data in real-time in patients with tumours of the urinary bladder. In three patients with histologically confirmed carcinoma of the urinary bladder, a helical CT scan with double detector technology was carried out preoperatively. A native scan was first performed, followed by an examination in the early contrast medium enhanced phase. After adequate contrasting of the urinary bladder (30 minutes latency), further images were acquired. These data were transferred to a separate graphic computer workstation and reconstructed. The results were then compared with the cystoscopic and pathohistological findings. All tumours of the urinary bladder identified at fiberoptic cystoscopy were also visualised by virtual cystoscopy. The best reconstruction results were obtained from data acquired after the 30-minute latency period. Virtual cystoscopy represents an interesting option in helical CT scanning, which is able to visualise polypoid tumours of the urinary bladder. Its clinical relevance, however, must be demonstrated in studies with a larger number of patients examined.

[CT osteodensitometry in the area immediate to hip endoprostheses]

The value of metal artifact reduction in quantitative bone density determination in the vicinity of metallic implants was studied.

METHOD

Ten cadaver femora with hip endoprostheses implanted intra vitam were examined in CT with varying slice thicknesses, tube voltage, scan time and magnification factor. The artifact-laden images were then processed using a metal artifact reduction programme (MAR). The metallic implant was removed, allowing the bone slices to be examined again with the same imaging parameters, but without the bothersome metal artifacts. This allowed comparison of bone density values obtained before and after application of MAR with data obtained after implant removal.

RESULTS

A comparison of the bone density measurements between the sample group without implants and the group with indwelling implants prior to MAR showed an unexpected correlation coefficient r = 0.975-0.977. The correlation coefficients after MAR rose to r = 0.987-0.992 in 125 kV and r = 0.989-0.991 in 85 kV modes. The reproducibility of the density measurements for the groups without implants and with implants following MAR showed variation coefficients (VC) of 1.16% and 0.75% respectively. The reproducibility of the manual definition of the region of interest (ROI) in bone showed a VC = 2.19%.

CONCLUSIONS

Bone density in the vicinity of metallic implants can be reliably and reproducibly determined using MAR.

Endovascular stenting in patients with Iliac compression syndrome. Experience in three cases

The authors report their experience in the percutaneous treatment of the iliac compression syndrome in three women (20-53 years old) with acute iliofemoral deep venous thrombosis; in one case, there was an additional thrombus in the inferior caval vein. They were treated by percutaneous implantation of Palmaz stents in the left common iliac vein 1 day after surgical thrombectomy and construction of an arterial venous fistula. All patients showed marked improvement, as determined from venograms obtained immediately after stent implantation. The arteriovenous fistulae were closed 3 months later. At 6 months follow-up, the median clinical and color-coded duplex ultrasound indicates that all stents are patent and all patients are free of symptoms.

[The value of MR-mammography at 1.5 tesla in the differential diagnosis of non-puerperal mastitis and inflammatory breast carcinoma]

PURPOSE

The distinction between mastitis and inflammatory breast carcinoma is an important one. Current methods of evaluation including mammography, ultrasound and clinical examination do not enable this distinction. Dynamic magnetic resonance mammography (MRM) is a study with potential in this regard.

MATERIAL AND METHODS

12 patients, in whom clinical examination, mammography and ultrasound could not distinguish between both diseases, were reviewed retrospectively by means of MRM using a 1.5 T Siemens Magnetom SP and a circular mamma coil. We used dynamic 3-D gradient echo sequences with a duration of one minute.

RESULTS

At present MRM cannot definitely distinguish between mastitis and inflammatory carcinoma, 80% of the inflammatory carcinomas were found to enhance more than 100% in the first minute, compared to 43% for mastitis. No other differences were seen.

CONCLUSION

MRM proved useful in the follow-up of treated mastitis to demonstrate the success of antibiotic treatment of mastitis and to diagnose a histologically unconfirmed inflammatory carcinoma by means of a different follow-up.

[Epidurography: comparison with CT, spiral CT and MR epidurography]

PURPOSE

The purpose of this study was to explain the origin of image patterns demonstrated by conventional epidurography, which is a controversially discussed topic in recent literature.

MATERIAL AND METHODS

After introduction of thoracic epidural catheters and iopamidol injection, conventional epidurography and CT-epidurography were performed on 25 preoperative patients. After injection of Gadolinium-DTPA MR-epidurography was performed in two patients treated for chronic pain with already introduced epidural catheters. Three volunteers also underwent identical imaging after introduction of thoracic epidural catheters and in addition helical-CT epidurography using twin-beam technology.

RESULTS

40% of the patients demonstrated the railroad track phenomenon. We were able to prove that it is a sign of a rhythmically variable filling of segments of the lateral epidural space with contrast medium 76% of the patients demonstrated no ventral epidural space at the thoracic level. 56% of the patients showed a medial area of translucence combined with a band-shaped contrasting of the epidural space in the standard ap view. This was proven in all cases to be a plica mediana dorsalis by CT. In all volunteers who underwent helical-CT and MR epidurography we observed the railroad track phenomenon and the filling defect of the anterior thoracic epidural space.

CONCLUSION

CT epidurography is well suited for obtaining new insights into the interpretation of findings obtained by conventional epidurography.

[Superselective embolization of tumor nodes in solitary kidney in inoperable patients]

PURPOSE

Evaluation of superselective embolisation of renal tumours in inoperable patients with solitary kidneys.

METHODS AND PATIENTS

Eight inoperable patients with solitary kidneys bearing tumour nodules underwent 1-3 superselective embolisation procedures with ethibloc (5x) or polyvinyl alcohol (1x). Renal function was monitored with creatinine levels. Tumour size was controlled every three months by means of sonography.

RESULTS

Technical success rate was 100%. In 3/3 patients haematuria could be stopped. Post-embolisation renal function was unchanged in 6 patients and deteriorated in two patients; creatinine level rose to a maximum of 2.2 mg%. We observed no other side effects. Seven of eight patients died during a median follow-up period of 9.3 months (4-18 months); in two cases they died due to their underlying malignant disease. One patient had local tumour progress.

CONCLUSIONS

Superselective embolisation of renal tumours in patients with solitary kidneys may be a helpful, well-tolerated therapeutic option in inoperable, symptomatic patients.

CT-guided intraarterial chemotherapy in locally advanced tumors

In a retrospective study, 123 patients with tumors (the majority were recurrent pelvic or breast neoplasms) underwent 376 cycles of intraarterial chemotherapy. Contrast material-enhanced computed tomography was performed to check the position of the catheter during 221 cycles. On the basis of findings, the catheter was repositioned 46 (20.8%) times because of weak contrast enhancement in the tumor region (n=24[10.9%]), involvement of neighboring healthy tissue (n=15[6.8%]), or both (n=7[3.2%]).