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Transjugular Intrahepatic Portosystemic Shunt Creation with the Viatorr Expanded Polytetrafluoroethylene–Covered Stent-Graft

PURPOSE To evaluate the midterm clinical results and patency of transjugular portosystemic shunts (TIPS) created with a commercially available expanded polytetrafluoroethylene (ePTFE)-covered stent-graft based on angiographic and ultrasonographic (US) criteria in a series of 71 patients. MATERIALS AND METHODS Seventy-one patients (61 men, 10 women; mean age, 58.6 years, range, 25-78 years) were included in this series, which was performed in two centers. Indications for TIPS creation were refractory ascites (n = 44) and recurrent esophageal bleeding (n = 27). Ten patients had Child-Pugh class A liver cirrhosis, 43 had class B disease, and 18 had class C disease. Underlying liver diseases were alcoholic cirrhosis (n = 58), cirrhosis resulting from hepatitis (n = 9), cryptogenic cirrhosis (n = 3), and Budd-Chiari syndrome (n = 1). TIPS were created with commercially available ePTFE-covered stent-grafts in all patients. The diameters of the stent-grafts were 10 mm in 58 patients and 8 mm in the remaining 13 patients. Follow-up included clinical examination and color-coded US after 5 days, 1, 3, and 6 months, and every 6 months thereafter. Shunt angiograms were obtained every 6 months. Median follow-up was 16.3 months (range, 3.8-26.6 months). RESULTS TIPS creation was successful in all patients without complications, and effective portal decompression was observed with a reduction of the mean portal gradient from 19 mm Hg to 6 mm Hg before and after TIPS creation. Four shunt occlusions were observed after 5 days, 2 months, 3 months, and 6 months. Shunt stenosis was observed in three patients at the hepatic vein, which was not fully covered by the stent-graft, after 6 months (n = 2) and 12 months, and at the portal side after 1 month in a patient who initially had portal vein thrombosis. The repeat intervention rate was 11.3%. The primary patency rates were 87.4% (95% CI, 77.7%-97.1%) after 6 months and 80.8% (95% CI, 68.2%-93.4%) after 12 months. The rate of de novo or deteriorated hepatic encephalopathy was 31%. The recurrent bleeding rate was 3.7% (one of 27), and ascites improved or resolved in 64% of patients after 1 month. CONCLUSION TIPS patency can be significantly increased if the ePTFE-covered stent-graft is used for shunt creation. The increased shunt patency contributes to low repeat intervention and recurrent bleeding rates. The rate of hepatic encephalopathy is within the range of previously reported rates.

Percutaneous nephrostomy and antegrade ureteral stenting: technique—indications—complications

In this review the technique, indication for and complications of percutaneous nephrostomy (PCN) and antegrade ureter stent insertion are described. In the majority of the cases PCN is performed to relieve urinary obstruction, which can be of benign or malignant nature. Another indication for PCN is for treatment of urinary fistulas. PCN can be performed under ultrasound and/or fluoroscopic guidance, with a success rate of more than 90%. The complication rate is approximately 10% for major and minor complications together and 4–5% for major complications only. Percutaneous antegrade double-J stent insertion usually is performed if retrograde ureter stenting has not been successful. However, especially in malignant obstructions, the success rate for antegrade stenting is higher than for retrograde transvesical double-J stent insertion. In the case of severe infection and bleeding after PCN JJ-stent insertion may be contraindicated so long as there is no sufficient concomitant drainage via a PCN . Lower urinary tract dysfunction should be excluded before stent placement. The complication rate is 2–4%. Consequent stent surveillance with regular stent exchange is mandatory.

Placement of Hemobahn stent-grafts in femoropopliteal arteries: Early experience and midterm results in 18 patients

PURPOSE To determine the outcome of a new polytetrafluoroethylene (PTFE)-covered stent-graft in the treatment of occlusive lesions of the femoropopliteal arteries. MATERIALS AND METHODS Eighteen patients with intermittent claudication (Fontaine stages IIb-IV; Rutherford classes I/2-III/5) and occlusive lesions of the superficial femoral and/or popliteal artery were treated with use of a new PTFE-covered stent-graft (Hemobahn). Indication for stent-graft insertion was an unsatisfactory result after balloon dilation. RESULTS Successful stent-graft placement was achieved in 17 patients (94%). In one patient, additional insertion of a Palmaz stent was necessary because of a stent-graft wrinkle. Mean ankle-brachial index increased from 0.72 +/- 0.15 preoperatively to 0.94 +/- 0.17 postoperatively (P =.028). Fifteen patients (83%) experienced an initial improvement of at least one clinical stage. Primary patency was 61% +/- 11% at 3 months and 49% +/- 12% at 6 months. Stent-graft occlusion was observed in 13 patients (72%). In four patients, the stent-graft was reopened percutaneously by balloon angioplasty (n = 2) and/or rotational thrombectomy (n = 2). Therefore, the secondary patency rate was 67% +/- 11% at 3 months and 61% +/- 11% at 6 months. Patency rates proved to be significantly lower for stent-grafts longer than 10 cm (P =.03). Intimal hyperplasia at the proximal or distal end of the stent-graft was observed in seven patients (39%). Complications such as access site hematoma (n = 3), distal thromboembolism (n = 2), and abscess formation around the stent-graft (n = 1) were observed. CONCLUSION Despite excellent initial angiographic results, the patency rate in lesions treated with the Hemobahn stent-graft in this small study was unsatisfactory. Use of stent-grafts longer than 10 cm and the occurrence of intimal hyperplasia proved to be major factors in the reduction of long-term patency rates.

The Outback Catheter: A New Device for True Lumen Re-entry After Dissection During Recanalization of Arterial Occlusions

Abstract To report the initial experience with a new catheter system (The Outback catheter) designed to allow fluoroscopically controlled re-entry of the true arterial lumen after subintimal guidewire passage during recanalization procedures of arterial occlusions. The catheter was used in 10 patients with intermittent claudication caused by chronic segmental occlusions of the superficial femoral or popliteal arteries. In all patients, conventional guidewire recanalization had failed. In 8 patients, successful true lumen re-entry was achieved with the Outback catheter. Percutaneous transluminal angioplasty was successfully performed in these patients without complications. Two technical failures occurred in heavily calcified arteries. The Outback catheter was safe and effective when used in complicated recanalization procedures in the superficial femoral and popliteal artery and the tibial trunk.

Aortoiliac enhancement during computed tomography angiography with reduced contrast material dose and saline solution flush: influence on magnitude and uniformity of the contrast column.

Rationale and ObjectivesTo compare the magnitude and uniformity of aortoiliac contrast enhancement obtained from uniphasic contrast material injections versus contrast material injections with reduced iodine dose followed by a saline flush in aortoiliac multislice CT angiography (CTA). MethodsTwenty-nine patients with abdominal aortic aneurysms underwent aortoiliac CTA using protocols A and B. With protocol A, 120 mL contrast material (300 mgI/mL), and with protocol B, 100 mL contrast material followed by a 40-mL saline solution flush were administered at a flow rate of 4 mL/s. Quantitative analysis was performed by calculating mean aortoiliac attenuation, mean plateau deviation, and mean difference between maximum and minimum attenuation value for both groups. Qualitative analysis was performed by visual assessment of vascular enhancement using 2-dimensional and 3-dimensional postprocessing techniques. ResultsThe mean aortoiliac attenuation with protocol A was 291 ± 62 HU, and with protocol B it was 285 ± 61 HU. The difference of 6 HU was not statistically significant (P = 0.27). Mean plateau deviation was significantly smaller using protocol A than protocol B (16 ± 9 HU vs. 20 ± 10 HU, P = 0.03). In addition, the mean difference between maximum and minimum attenuation value was significantly smaller with protocol A than with protocol B (59 ± 29 HU vs. 72 ± 32 HU, P = 0.01). Visual analysis showed no difference in contrast material magnitude and homogeneity between the protocols. ConclusionsIn aortoiliac CTA, a saline solution flush after contrast material bolus allows an iodine dose reduction of approximately 20 mL without impairing the magnitude of contrast enhancement but degrades the uniformity of the contrast column. However, the degradation does not affect visual analysis.

Graz Endocrine Causes of Hypertension (GECOH) study: a diagnostic accuracy study of aldosterone to active renin ratio in screening for primary aldosteronism

BackgroundPrimary aldosteronism (PA) affects approximately 5 to 10% of all patients with arterial hypertension and is associated with an excess rate of cardiovascular complications that can be significantly reduced by a targeted treatment. There exists a general consensus that the aldosterone to renin ratio should be used as a screening tool but valid data about the accuracy of the aldosterone to renin ratio in screening for PA are sparse. In the Graz endocrine causes of hypertension (GECOH) study we aim to prospectively evaluate diagnostic procedures for PA.Methods and designIn this single center, diagnostic accuracy study we will enrol 400 patients that are routinely referred to our tertiary care center for screening for endocrine hypertension. We will determine the aldosterone to active renin ratio (AARR) as a screening test. In addition, all study participants will have a second determination of the AARR and will undergo a saline infusion test (SIT) as a confirmatory test. PA will be diagnosed in patients with at least one AARR of ≥ 5.7 ng/dL/ng/L (including an aldosterone concentration of ≥ 9 ng/dL) who have an aldosterone level of ≥ 10 ng/dL after the saline infusion test. As a primary outcome we will calculate the receiver operating characteristic curve of the AARR in diagnosing PA. Secondary outcomes include the test characteristics of the saline infusion test involving a comparison with 24 hours urine aldosterone levels and the accuracy of the aldosterone to renin activity ratio in diagnosing PA. In addition we will evaluate whether the use of beta-blockers significantly alters the accuracy of the AARR and we will validate our laboratory methods for aldosterone and renin.ConclusionScreening for PA with subsequent targeted treatment is of great potential benefit for hypertensive patients. In the GECOH study we will evaluate a standardised procedure for screening and diagnosing of this disease.

Routine Use of Three-Dimensional Contrast-Enhanced Moving-Table MR Angiography in Patients with Peripheral Arterial Occlusive Disease: Comparison with Selective Digital Subtraction Angiography

PurposeTo compare the diagnostic accuracy of contrast-enhanced (CE) three-dimensional (3D) moving-table magnetic resonance (MR) angiography with that of selective digital subtraction angiography (DSA) for routine clinical investigation in patients with peripheral arterial occlusive disease.MethodsThirty-eight patients underwent CE 3D moving-table MR angiography of the pelvic and peripheral arteries. A commercially available large-field-of-view adapter and a dedicated peripheral vascular phased-array coil were used. MR angiograms were evaluated for grade of arterial stenosis, diagnostic quality, and presence of artifacts. MR imaging results for each patient were compared with those of selective DSA.ResultsTwo hundred and twenty-six arterial segments in 38 patients were evaluated by both selective DSA and MR angiography. No complications related to MR angiography were observed. There was agreement in stenosis classification in 204 (90.3%) segments; MR angiography overgraded 16 (7%) segments and undergraded 6 (2.7%) segments. Compared with selective DSA, MR angiography provided high sensitivity and specificity and excellent interobserver agreement for detection of severe stenosis (97% and 95%, κ = 0.9 ± 0.03) and moderate stenosis (96.5% and 94.3%, κ = 0.9 ± 0.03).ConclusionCompared with selective DSA, moving-table MR angiography proved to be an accurate, noninvasive method for evaluation of peripheral arterial occlusive disease and may thus serve as an alternative to DSA in clinical routine.

Three-dimensional gadolinium-enhanced magnetic resonance angiography used as a "one-stop shop'' imaging procedure for venous thromboembolism: a pilot study.

Pulmonary embolism and deep venous thrombosis are individual manifestations of a single entity, venous thromboembolic disease. This study aimed to assess the feasibility of 3-dimensional gadolinium-enhanced magnetic resonance angiography used as an “one-stop shop” imaging procedure visualizing both the pulmonary arteries and the deep lower venous system within a single investigation. The inclusion criterion was a proven or excluded venous thromboembolism. Diagnosis was based on an imaging work-up for pulmonary embolism including either perfusion lung scan or contrast-enhanced spiral computed tomography, or both, and an imaging work-up for deep venous thrombosis including either venous color-coded duplex sonography or ascending phlebography, or both. A gadolinium-enhanced “one-stop shop” magnetic resonance angiography was performed within 24 hours of completed diagnostic imaging work-up for pulmonary embolism and deep venous thrombosis in 20 patients. Results of pulmonary magnetic resonance angiography were concordant with perfusion lung scan and/or computed tomography in 90% of patients. Magnetic resonance angiography results of the deep lower venous system were concordant with venous duplex sonography and/or phlebography in 75% of patients and seemed to be more precise in 25% of patients. The “one-stop shop” imaging procedure using gadolinium-enhanced magnetic resonance angiography was feasible and proved to offer a reliable and rapid diagnostic approach in thromboembolic disease, sparing patients’ exposure to ionizing radiation and iodinated contrast media.

Endovascular Treatment of Mycotic Aortic Pseudoaneurysms with Stent-Grafts

Mycotic aortic aneurysms remain a therapeutic challenge, especially in patients who are not suitable for open surgery. Endovascular treatment with stent-grafts in this indication is still disputed. Between January 2002 and January 2006, six patients with mycotic aneurysms of the thoracoabdominal or abdominal aorta were admitted to our department. All patients were male, aged 57–83 years (mean, 74.6 years). The mycotic aneurysms were diagnosed on the basis of clinical signs of infection, on CT, and, in four cases, on a positive blood culture. In all patients the mycotic aortic aneurysms were treated endovascularly by stent-graft implantation. Technical and clinical success was achieved in all patients. There was no in-hospital or 30-day mortality. In the follow-up period (range, 2–47 months) four patients died of cancer, cardiac failure, or unknown cause (one case). Two patients are still alive with nearly complete regression of the aneurysms. We conclude that treatment of mycotic aortic aneurysms with stent-grafts may be an alternative in selected patients.

Vessel segmentation for ablation treatment planning and simulation

In this paper, a novel segmentation method for liver vasculature is presented, intended for numerical simulation of radio frequency ablation (RFA). The developed method is a semiautomatic hybrid based on multi-scale vessel enhancement combined with ridge-oriented region growing and skeleton-based postprocessing. In addition, an interactive tool for segmentation refinement was developed. Four instances of three-phase contrast enhanced computed tomography (CT) images of porcine liver were used in the evaluation. The results showed improved accuracy over common approaches and illustrated the methods suitability for simulation purposes.