Endovascular management of inadvertent subclavian artery catheterization during subclavian vein cannulation.

PURPOSE: To retrospectively review a 9-year experience with endovascular management of inadvertent subclavian artery catheterization during subclavian vein cannulation. MATERIALS AND METHODS: From June 2000 through July 2009 (109 months), 13 patients underwent endovascular management of inadvertent subclavian artery catheterization. All catheters were still in situ, including one 7-F catheter, six 8-F catheters, and six large-bore 10-11-F catheters. Treatment was performed with an Angio-Seal device (n = 6) or balloon catheters (n = 7) and by additional stent-graft placement (n = 4). RESULTS: Mean follow-up was 27.3 months (range, 0.4-78 months). The 30-day mortality rate was 7.7% and the late mortality rate was 46.1%. Primary technical success was achieved in nine patients (69.2%), in four with the use of a compliant balloon catheter and in the other five with an Angio-Seal device. Complications required additional stent-graft placement in four patients (30.8%), one because of stenosis after Angio-Seal device deployment and three as a result of insufficient closure of the puncture site by balloon tamponade. Stent-graft repair was successful in all four patients, for a primary assisted technical success rate of 100%. CONCLUSIONS: Endovascular techniques offer a less invasive alternative to surgery. The present limited experience shows that the use of the Angio-Seal device is not without risks, whereas balloon tamponade is not always reliable in closing the puncture site. Stent-graft placement may be required in patients in whom balloon tamponade fails or in whom the use of the Angio-Seal device is contraindicated.

Evaluation of volumetric measurements in patients with acute type B aortic dissection--thoracic endovascular aortic repair (TEVAR) vs conservative.

OBJECTIVE: The aim of this retrospective study was to evaluate aortic volume changes in patients with acute type B aortic dissection (TBD), treated either by thoracic endovascular aortic repair (TEVAR) or conservatively. MATERIALS AND METHODS: From July 1996 through March 2008, 76 patients presenting with acute TBD were referred to our department. To ensure a follow-up of at least 24 months, only 64 of them were included in the present study, with the cut-off for inclusion being March 2006. Twenty-nine of these patients underwent TEVAR and 35 patients underwent conservative treatment. Indications for TEVAR were life-threatening symptoms. Follow-up was performed postinterventionally in patients after TEVAR and at 3, 6, and 12 months, and yearly thereafter in both groups. It included clinical examinations, computed tomography (CT) scans, analysis of volume changes in true thoracic lumen (TTL), false thoracic lumen (FTL), thoracic lumen (TL), abdominal lumen (AL), and aortic diameter measurements. In addition, the extent of thrombosis and its influence on volume changes were assessed. RESULTS: Mean follow-up was 41 months after TEVAR and 46 months in the conservatively-treated patients. At 60 months, cumulative rates of freedom from dissection-related death and rupture-free survival were 82.6% and 93.1% in the TEVAR group, respectively. They were 74.9% and 88.5% in the conservatively-treated group, respectively. In the conservatively-treated patients, 3 patients died of late aortic rupture, 4 were converted to open surgery, and 2 to TEVAR. Evaluation of volume changes showed better results in the TEVAR group within 24 months. However, within 60 months the difference between the two groups was no longer relevant. Relating to thrombosis of the FTL, analyses showed slightly better overall results and promotion of thrombus formation after TEVAR. However, at 60 months the results showed a tendency towards approximation between the two groups. CONCLUSION: Our data suggest that TEVAR seems to delay the natural course of the disease but not to stop it.

Echinococcosis of the liver.

Echinococcosis, also known as hydatid disease, is an infection of larval stage animal tapeworm, Echinococcus. The larvae reside in the liver and lungs, producing multiloculated fluid-filled cysts. Imaging findings of Echinococcosis caused by E. granulosus are single, unilocular cyst or multiseptated cysts, showing "wheel-like", "rosette-like" or "honeycomb-like" appearances. There may be "snow-flakes" sign, reflecting free floating protoscoleces (hydatid-sand) within the cyst cavity. Degenerating cysts show wavy or serpentine bands or floating membranes representing detached or ruptured membranes. Degenerated cysts show heterogeneous, solid-looking pseudotumor that may show "ball of wool sign". Dead cysts show calcified cyst wall. Echinococcosis caused by E. multilocularis produces multilocular alveolar cysts with exogeneous proliferation, progressively invading the liver parenchyma and other tissues of the body. Imaging findings are ill-defined infiltrating lesions of the liver parenchyma, consisting of multiple small clustered cystic and solid components. On sonography, lesions are heterogeneous with indistinct margins, showing "hailstorm appearance" or "vesicular or alveolar appearance". CT and MR imaging displays multiple, irregular, ill-defined lesions. Multiple small round cysts with solid components are frequent. Large lesions show "geographical map" appearance. Calcifications are very frequent, appearing as peripheral calcification or punctuate scattered calcific foci. Invasion into the bile ducts, portal vein or hepatic vein may occur. Direct spread of infected tissue may result in cysts in the peritoneal cavity, kidneys, adrenal gland or bones.

Frameless stereotactic cannulation of the foramen ovale for ablative treatment of trigeminal neuralgia.

OBJECTIVE: Ablative neurosurgical treatment of trigeminal neuralgia, including percutaneous radiofrequency thermocoagulation, requires cannulation of the foramen ovale. To maximize patient security and cannulation success, a frameless stereotactic system was evaluated in a phantom study, a cadaveric study, and a preliminary clinical trial. METHODS: Frameless stereotaxy using an optical navigation system, an aiming device, and a noninvasive vacuum mouthpiece-based registration and patient fixation technique was used for the targeting of a test body based on 1-, 3-, and 5-mm axial computed tomographic slices and of the foramen ovale in three cadavers and 15 patients based on 3-mm axial computed tomographic slices. RESULTS: The mean normal (x/y) localization accuracy/standard deviation (n = 360) was 1.31/0.67 mm (1-mm slices), 1.38/0.65 mm (3-mm slices), and 1.84/0.96 mm (5-mm slices). Significantly better results were achieved with 1- and 3-mm slices when compared with 5-mm slices (P < 0.001). The foramen ovale (3 x 6 mm) was successfully cannulated at the first attempt in all cadavers and patients, which indicates clinical localization accuracies better than 1.5 mm in the anteroposterior and 3 mm in the medial-lateral directions. CONCLUSION: Based on the noninvasive Vogele-Bale-Hohner vacuum mouthpiece, there is no need for invasive head clamp fixation. Imaging, real laboratory simulation, and the actual surgical intervention can be separated in time and location. The presented data suggest that frameless stereotaxy is a predictable and reproducible procedure, which may enhance patient security and cannulation success independent of the surgeon's experience.

Dialysis-related amyloidosis revisited.

OBJECTIVE: Dialysis-related amyloidosis occurs secondarily to the deposition of beta(2)-microglobulin. Dialysis-related amyloidosis predominantly involves the osteoarticular system and is clinically manifested by erosive and destructive osteoarthropathies, destructive spondyloarthropathy, and carpal tunnel syndrome. This article illustrates the radiographic, sonographic, CT, and MRI findings of dialysis-related amyloid arthropathies. CONCLUSION: Dialysis-related amyloidosis is characterized by various imaging appearances. In evaluating amyloidosis, MRI provides considerably more information than that obtained from conventional radiographic, CT, and sonographic studies.

Type A dissection following endovascular thoracic aortic stent-graft repair.

PURPOSE: To describe our experience with endovascular stent-graft repairs in the thoracic aorta focusing on the secondary complication of type A dissection. METHODS: Between January 1996 and April 2004, 73 patients were treated for traumatic thoracic aortic rupture (n=15), type B dissection (n=22), or atherosclerotic descending thoracic aortic aneurysms (TAA, n=36). A retrospective review of the records found 5 (6.8%) patients (3 men; median age 64 years, range 43-87) who experienced a type A dissection at a median 20 days (range 2-124) after thoracic stent-graft repair for 3 type B dissections, 1 TAA, and a late type I endoleak that appeared 28 months after initial stent-graft repair of a traumatic dissection. RESULTS: In 3 patients (2 dissections, 1 endoleak), a tear in the aortic wall at the proximal stent-graft was responsible for a retrograde type A dissection. Underlying disease was the cause of the type A dissection in the 2 other patients (1 dissection, 1 TAA) and was unrelated to the stent-grafts. Three patients underwent open surgery at 3, 26, and 124 days after stent-graft placement; 2 procedures were successful, but the third patient died 3 months later due to multiorgan failure. Two type A dissections were untreated: one patient died from cardiac tamponade 14 days after successful stent-graft exclusion of the type I endoleak; the other patient refused further treatment and survived. The procedure-related mortality following acute retrograde type A dissection was 40%. CONCLUSIONS: Endovascular stent-graft repair of the thoracic aorta is associated with lower morbidity and mortality rates than surgical repair, although potentially lethal complications, acute or delayed, may occur.

Trace of diffusion tensor differentiates the Parkinson variant of multiple system atrophy and Parkinson's disease.

We have recently shown that diffusion-weighted magnetic resonance (MR) imaging (DWI) discriminates patients with the Parkinson variant of multiple system atrophy (MSA-P) from those with Parkinson's disease (PD) by regional apparent diffusion coefficients (rADC) in the putamen. Because rADCs measured in one direction may underestimate diffusion-related pathologic processes, we investigated the diffusivity in different brain areas by trace of diffusion tensor (Trace(D)) in a new cohort of patients with MSA-P and PD. We studied 11 MSA-P, 17 PD patients, and 10 healthy volunteers matched for age and disease duration. Regional ADCs in three orthogonal directions and Trace(D) values were determined in selected brain regions including the basal ganglia, gray matter, white matter, substantia nigra, and pons. MSA-P patients had significantly higher putaminal and pallidal rTrace(D) values as well as rADCs in y- and z-direction than both PD patients and healthy volunteers. Moreover, putaminal Trace(D) discriminated completely MSA-P from both PD and healthy volunteers. The rADCs in the y- and z-direction provided a complete or near complete separation. In conclusion, our study confirms the results of previous studies of our group that patients with MSA-P show an increased putaminal diffusivity due to neuronal loss and gliosis. Because rADCs in one direction are dependent on the slice orientation relative to the directions of fiber tracts, Trace(D) imaging appears to be more accurate in the separation of MSA-P from PD.

Serial CT volume and thrombus length measurements after endovascular repair of Stanford type B aortic dissection.

PURPOSE: To evaluate the outcome of stent-graft placement in Stanford type B aortic dissection using contrast-enhanced spiral computed tomographic (CT) measurements of true and false lumen volumes and thrombus length. METHODS: Among 18 consecutive patients (13 men; mean age 60 years, range 44-79) who underwent endovascular repair of Stanford type B dissection, 12 completed at least a 12-month follow-up, which included CT measurements of true and false lumen volumes and thrombus lengths prior to discharge and at 6 and 12 months postimplantation. Volumes were assessed in 3 different aortic segments (A1, A2, A3) extending from the proximal attachment site of the prosthesis to the aortic bifurcation. In addition, thrombus length was measured to evaluate the influence of clot formation on outcome of the false lumen volume. RESULTS: Mean follow-up was 27 months (range 12-60). Within 12 months, mean true lumen volumes showed statistically significant increases in the A1 (p<0.001) and A2 (p=0.003) segments; false lumen volumes showed a significant decrease in the A1 segment (p=0.002) but an insignificant increase in the A2 segment. No substantial volume changes were observed in the A3 segment. Extension of clot formation in the false lumen varied among patients and over time. Length of stent-grafts, percentage of stented dissection length, or visceral arteries originating from the false lumen did not significantly influence thrombus development, nor did these parameters or thrombus formation distal to the prosthesis have a relationship to false lumen volumes. CONCLUSIONS: Volumetric analysis after endovascular repair of Stanford type B dissection shows optimal technical outcome in the stented segment, whereas the false lumen in the segment immediately adjacent to the stent-graft seems to be a vulnerable area. Extension of clot formation beyond the endograft seems to be no reliable predictor of outcome.

Emergency endovascular treatment of traumatic aortic arch rupture with multiple arch vessel involvement.

PURPOSE: To report successful endovascular stent-graft placement for emergency treatment of a complex traumatic injury involving the aortic arch and multiple arch vessels. CASE REPORT: An 81-year-old man underwent stent-graft placement for a complex traumatic vascular injury. Computed tomography on admission documented a dissection along the course of the aortic arch, intramural hematoma along the ascending aorta, dissection of the innominate artery, and a right subclavian artery pseudoaneurysm. The dissection of the aortic arch and the pseudoaneurysm of the right subclavian artery were treated immediately, the dissection of the innominate artery 7 days later. The patient did not develop any complications. Follow-up studies performed prior to discharge and at 6 and 12 months after the interventions showed successful repair of the complex vascular injuries. CONCLUSIONS: Traumatic injury of the aortic arch with multiple arch vessel involvement can be treated effectively by means of stent-graft placement.

Pretransplantation evaluation of the cirrhotic liver with explantation correlation: accuracy of CT arterioportography and digital subtraction hepatic angiography in revealing hepatocellular carcinoma.

OBJECTIVE: The aim of this study was to determine the accuracy of CT arterioportography and hepatic digital subtraction angiography, separately and combined, for the detection of hepatocellular carcinoma in the cirrhotic liver by using thin-section liver explant histopathologic findings. SUBJECTS AND METHODS: Fifty-nine patients with liver cirrhosis were examined with CT arterioportography and digital subtraction angiography as a part of preoperative diagnostic workup for liver transplantation. Before liver explantation, CT arterioportograms and digital subtraction angiograms were prospectively evaluated in a blinded manner, separately by two CT radiologists and two angiographers, respectively, and combined by two reviewer teams, each including a CT radiologist and an angiographer. In addition, each examination was retrospectively evaluated using direct comparison with the corresponding thin-section liver explant specimens RESULTS: There were 39 histologically confirmed hepatocellular carcinomas. In both prospective and retrospective assessments, the reviewers achieved the best performance with CT arterioportography and digital subtraction angiography combined (area under the curve [A(z)] 0.82). The diagnostic confidence in the detection of hepatocellular carcinoma was higher with digital subtraction angiography (A(z), 0.81) than that with CT arterioportography (A(z), 0.68). Prospectively, sensitivity and specificity were 75% and 60% for CT arterioportography, 77% and 80% for digital subtraction angiography, and 84% and 81% for CT arterioportography and digital subtraction angiography combined, respectively. Retrospectively, sensitivity and specificity were 80% and 62% for CT arterioportography; 82% and 79% for digital subtraction angiography; 87% and 81% for CT arterioportography and digital subtraction angiography combined, respectively. Five hepatocellular carcinomas, one poorly and four well differentiated, with a mean size of 1.4 cm were not detectable on the CT arterioportography and digital subtraction angiography combination. False-positive findings were 20, 11, and 10 on CT arterioportography, digital subtraction angiography, and the CT arterioportography and digital subtraction angiography combination. CONCLUSION: Combining CT arterioportography with digital subtraction angiography enabled reliable detectability of moderately and poorly differentiated hepatocellular carcinomas in cirrhotic livers but was less sensitive for the detection of well-differentiated hepatocellular carcinomas and resulted in a relatively high rate of false-positive findings.

Placement of endovascular stent-grafts for emergency treatment of acute disease of the descending thoracic aorta.

OBJECTIVE: The aim of this study was to evaluate the feasibility, safety, and effectiveness of endovascular stent-graft placement for the emergency treatment of acute descending thoracic aortic disease. MATERIALS AND METHODS: From January 1996 through November 2001, 18 patients underwent emergency endovascular stent-graft placement for various types of acute descending thoracic aortic disease. Five patients had Stanford type B aortic dissection, six had traumatic ruptures of the thoracic aorta, five had ruptured aortic aneurysms, and two had penetrating atherosclerotic aortic ulcers. All patients presented with life-threatening symptoms requiring treatment with stent-grafts from the emergency kit. All were at high surgical risk due to serious comorbidities. The efficacy of the procedure was assessed at follow-up studies before discharge and at 3, 6, and 12 months after intervention and yearly thereafter. RESULTS: The primary technical success rate was 78%. Four patients had primary perigraft leaks. The secondary technical success rate was 83%. One patient died 20 hr after intervention from stent-graft-related causes. Follow-up studies revealed stent-graft migration in one patient. Progression of disease was observed in one patient treated for dissection and in both patients treated for penetrating ulcers. One patient died 7 months after intervention of unknown reasons; all other patients are alive. The mean follow-up time was 17.4 months (range, 0-38 months). CONCLUSION: Emergency repair of acute descending thoracic aortic disease with stent-graft placement can be successfully accomplished and may be a promising alternative to open-chest surgery, especially in patients at high risk.

3D MR angiography of renal arteries: comparison of volume rendering and maximum intensity projection algorithms.

PURPOSE: To compare volume rendering (VR) and maximum intensity projection (MIP) as postprocessing techniques of magnetic resonance (MR) angiography for detection and quantification of renal artery stenosis. MATERIALS AND METHODS: Twenty-seven patients underwent three-dimensional contrast material-enhanced MR angiography of the renal arteries with a 1.5-T imager. For each renal artery, targeted MIP and VR images were reconstructed in oblique coronal and transverse orientations. For each modality, image generation and evaluation were performed interactively by two independent radiologists blinded to angiographic results. In comparison with digital subtraction angiography (DSA) findings, stenosis quantification and detection by using MIP and VR were evaluated with the use of 50% and 70% cutoff points by using linear regression analysis and 2 x 2 tables. Overall image quality and vascular delineation on MIP and VR images were also compared. RESULTS: All main and accessory renal arteries depicted at DSA were also demonstrated on MIP and VR images. VR performed slightly better than MIP for quantification of stenoses greater than 50% (VR: r(2) = 0.84, P <.001; MIP: r(2) = 0.38, P =.001) and significantly better for severe stenoses (VR: r(2) = 0.83, P <.001; MIP: r(2) = 0.21, P =.1). For detection of stenosis, VR yielded a substantial improvement in positive predictive value (VR: 95% and 90%; MIP: 86% and 68% for stenoses greater than 50% and 70%, respectively). Image quality obtained with VR was not significantly better than that with MIP; however, vascular delineation on VR images was significantly better. CONCLUSION: The VR technique of renal MR angiography enabled more accurate detection and quantification of renal artery stenosis than did MIP, with significantly improved vascular delineation.