Miroslav Lojík

Wedged hepatic venography for targeting the portal vein during TIPS: comparison of carbon dioxide and iodinated contrast agents.

Purpose: Carbon dioxide (CO2) can traverse the hepatic sinusoids better than iodinated contrast medium and has been used by many interventionalists for wedged hepatic venography during transjugular intrahepatic portosystemic shunt (TIPS) procedures. Our study was designed to compare the extent of the portal vein opacification using either CO2 or iodinated contrast medium. Methods: Wedged hepatic venography for portal vein opacification during TIPS was performed using hand injection through a 6.5 Fr diagnostic catheter. Portograms of 36 patients performed with 10 ml of iodinated contrast medium were retrospectively compared with portograms of 45 patients performed with 30-40 ml of CO2. Opacification of the right portal vein branch including the portal vein bifurcation was defined as a successful study. Results: Using CO2 the right portal vein branch and the portal vein bifurcation were opacified in 87% of patients (39 of 45); only a part of the right portal vein branch was opacified in 6% of patients and no opacification of any portal vein branch was seen in 7% of patients. Using iodinated contrast medium, there was opacification of the portal vein bifurcation in 25% of patients (9 of 36), of a part of the portal vein branch in 36% and no opacification of any branch in 39%. There was one case of hepatic laceration from CO2 wedged venography which was treated with microcoil embolization. Conclusions: Using CO2 as a contrast medium, opacification of the portal vein bifurcation by wedged hepatic venography was seen in 87% of patients, in comparison with only 25% when iodinated contrast medium was used (p < 0.001). CO2 is superior to iodinated contrast medium for wedged hepatic venography during TIPS.

Influence of the Secondary Deployment of Expanded Polytetrafluoroethylene–covered Stent Grafts on Maintenance of Transjugular Intrahepatic Portosystemic Shunt Patency

PURPOSE To evaluate the effects of secondary deployment of expanded polytetrafluoroethylene (ePTFE)-covered stent grafts in the treatment of dysfunctional transjugular intrahepatic portosystemic shunts (TIPSs) in comparison with other common approaches (conventional angioplasty or implantation of bare metal stents). MATERIALS AND METHODS A retrospective review of 121 dysfunctional bare metal TIPS presenting between 2000 and 2004 was conducted. The group was divided into four subgroups according to the type of intervention: conventional angioplasty (52 cases; 43%), bare metal stent deployment (35 cases; 28.9%), nondedicated ePTFE-covered stent-graft deployment (15 cases; 12.4%), and dedicated ePTFE-covered stent-graft deployment (19 cases; 15.7%). In all four groups, the primary patency after the specific intervention was calculated and mutually compared. RESULTS Primary patency rates after 12 and 24 months were 49.7% and 25.3%, respectively, in conventional angioplasty; 74.9% and 64.9%, respectively, with bare metal stents; 75.2% and 64.5%, respectively, with nondedicated ePTFE-covered stent grafts; and 88.1% and 80.8%, respectively, with dedicated ePTFE-covered stent grafts. CONCLUSIONS In the treatment of dysfunctional TIPS, better patency after the intervention was obtained by deploying dedicated ePTFE-covered stent grafts in comparison with conventional angioplasty, bare metal stents, and nondedicated ePTFE-covered stents.

Endovascular Treatment of Acute and Chronic Thoracic Aortic Injury

Our aim is to present midterm results after endovascular repair of acute and chronic blunt aortic injury. Between December 1999 and December 2005, 13 patients were endovascularly treated for blunt aortic injury. Ten patients, 8 men and 2 women, mean age 38.7 years, were treated for acute traumatic injury in the isthmus region of thoracic aorta. Stent-graftings were performed between the fifth hour and the sixth day after injury. Three patients (all males; mean age, 66 years; range, 59–71 years) were treated due to the presence of symptoms of chronic posttraumatic pseudoaneurysm of the thoracic aorta (mean time after injury, 29.4 years, range, 28–32). Fifteen stent-grafts were implanted in 13 patients. In the group with acute aortic injury one patient died due to failure of endovascular technique. Lower leg paraparesis appeared in one patient; the other eight patients were regularly followed up (1–72 months; mean, 35.6 months), without complications. In the group with posttraumatic pseudoaneurysms all three patients are alive. One patient suffered postoperatively from upper arm claudication, which was treated by carotidosubclavian bypass. We conclude that the endoluminal technique can be used successfully in the acute repair of aortic trauma and its consequences. Midterm results are satisfactory, with a low incidence of neurologic complications.

Contrast-enhanced MR angiography utilizing parallel acquisition techniques in renal artery stenosis detection

Significant renal artery stenosis (RAS) is a potentially curable cause of renovascular hypertension and/or renal impairment. It is caused by either atherosclerosis or fibromuscular dysplasia. Correct and timely diagnosis remains a diagnostic challenge. MR angiography (MRA) as a minimally invasive method seems to be suitable for RAS detection, however, its diagnostic value widely differs in the literature (sensitivity 62-100% and specificity 75-100%). The aim of our prospective study was to compare the diagnostic value of contrast-enhanced MRA utilizing parallel acquisition techniques in the detection of significant RAS with digital subtraction angiography (DSA). A total of 78 hypertensive subjects with suspected renal artery stenosis were examined on a 1.5 Tesla MR system using a body array coil. Bolus tracking was used to monitor the arrival of contrast agent to the abdominal aorta. The MRA sequence parameters were as follows: TR 3.7 ms; TE 1.2 ms; flip angle 25 degrees; acquisition time 18s; voxel size 1.1 mm x1.0 mm x 1.1 mm; centric k-space sampling; parallel acquisition technique with acceleration factor of 2 (GRAPPA). Renal artery stenosis of 60% and more was considered hemodynamically significant. The results of MRA were compared to digital subtraction angiography serving as a standard of reference. Sensitivity and specificity of MRA in the detection of hemodynamically significant renal artery stenosis were 90% and 96%, respectively. Prevalence of RAS was 39% in our study population. Contrast-enhanced MRA with high spatial resolution offers sufficient sensitivity and specificity for screening of RAS.

Emergent Carotid Thromboendarterectomy for Acute Symptomatic Occlusion of the Extracranial Internal Carotid Artery

Background: Strokes secondary to acute internal carotid artery (ICA) occlusion are associated with an extremely poor prognosis. The best treatment approach in this setting is still unknown. The aim of our study was to evaluate the efficacy, safety, and outcomes of emergent surgical revascularization of acute extracranial ICA occlusion in patients with minor to severe ischemic stroke. Methods: A retrospective analysis was performed using prospectively collected data of consecutive patients who underwent carotid thromboendarterectomy for symptomatic acute ICA occlusion during the period from January 2013 to December 2015. Primary outcomes were disability at 90 days assessed by the modified Rankin Scale (mRS) and neurological deficit at discharge assessed using the National Institute of Health Stroke Scale (NIHSS). Secondary outcomes were the recanalization rate, 30-day overall mortality, and any intracerebral bleeding. Results: During the study period, a total of 6 patients (5 men and 1 woman) with a median age of 64 years (range: 58-84 years) underwent emergent reconstruction for acute symptomatic ICA occlusion within a median of 5.4 hours (range: 2.9-12.0 hours) after symptoms onset. The median presenting NIHSS score was 10.5 points (range: 4-21). Before surgery, 4 patients (66.7%) had been treated by systemic recombinant tissue plasminogen activator lysis. The median time interval between initiation of intravenous thrombolysis and carotid thromboendarterectomy was 117.5 minutes (range: 65-140 minutes). Patency of the ICA was achieved in all patients. On discharge, the median NIHSS score was 2 points (range: 0-11 points). There was no postoperative intracerebral hemorrhage and zero 30-day mortality rate. At 3 months, 5 patients (83.3%) had a good clinical outcome (mRS ≤ 2). Conclusion: Patients presenting with minor to severe ischemic stroke syndromes due to isolated extracranial ICA occlusion may benefit from emergent carotid revascularization. Thorough preoperative neuroimaging is essential to aid in selecting eligible candidates for acute surgical intervention.

Stent-grafts in TIPS

The transjugular intrahepatic portosystemic shunt (TIPS) is a percutaneous, minimally invasive method of reducing an increased portal pressure in patients with symptomatic portal hypertension. TIPS is done under local anesthesia on awake, mildly sedated patients and can be performed in emergency settings, in patients at both extremes of age, and in those with poor liver function and massive ascites who often are not considered candidates for shunt surgery. In the past decade, TIPS has been shown to be effective in variceal bleeding, refractory ascites, portal gastropathy, hepatic hydrothorax, and the Budd-Chiari syndrome [1]. During a TIPS procedure an intrahepatic shunt is performed by using an expandable stent to connect a large hepatic vein with a main branch of the portal vein. The major disadvantage of TIPS is the high rate of stenoses or occlusions necessitating careful follow-up of these patients and repeated interventional corrections of insufficient shunts. Depending on the definition of the shunt stenosis and surveillance protocols, stenoses of greater than 50% have been reported in 25% to 50% of cases within 6 to 12 months of shunt creation [2–5]. However, these patients were rarely symptomatic, and recurrent variceal bleeding was seen in fewer than 25% of patients with significant TIPS stenosis [6, 7]. The high rate of shunt stenoses is the major reason for the relatively poor cost effectiveness of TIPS when compared with endoscopic or surgical treatment. Significant research has been carried out to improve primary shunt patency. In a series of animal and human studies, several investigators have reported a significant reduction in the development of TIPS stenoses with the use of covered stents, i.e., stent-grafts. The graft material can provide a barrier between the flowing blood and the traumatized liver parenchyma. In addition to improving primary and secondary patency of TIPS, stent-grafts play an important role in sealing off an extrahepatic portal vein leak during TIPS [8]. Worsened encephalopathy after TIPS can be treated more easily by using a special design of constrained stent-graft creating shunt stenosis than by previously described shunt reduction methods [9]. The use of stent-grafts that traverse malignant hepatic tumor in TIPS potentially can prevent tumor invasion into the shunt and reduce the possibility of vascular spread and seeding of tumor in the lungs [10, 11]. The purpose of this paper is to analyze the causes of TIPS stenoses and occlusion and summarize the current results of experimental and clinical uses of stent-grafts. The role of stent-graft implantation in sealing an extrahepatic portal vein leak, a rare but potentially fatal complication of TIPS procedure, also is discussed.

Integration of Endovascular Therapy of Ruptured Abdominal and Iliac Aneurysms in the Treatment Algorithm: A Single-Center Experience in a Medium-Volume Vascular Center

Purpose: To evaluate the influence of endovascular therapy of ruptured abdominal or iliac aneurysms on total mortality. Materials and Methods: We analyzed the mortality of 40 patients from 2005 to 2009, when only surgical treatment was available. These results were compared with the period 2010 to 2013, when endovascular aneurysm repair (EVAR) was assessed as the first option in selected patients. Results: During 2005 to 2009, the mortality was 37.5%. From 2010 to 2013, 45 patients were treated with mortality 28.9%. Open repair was performed in 35 (77.8%) patients and EVAR in 10 (22.2%) patients. The 30-day and 1-year mortality rates of the EVAR group were 0% and 20%, respectively, and the total mortality rate was 30% during follow-up (median 11 months, range 1-42 months). The 30-day mortality in the surgical group remained unchanged, at 37.1%, and 1-year and total mortality rates were 45.7% and 51.4%, respectively. Conclusion: Following integration in the treatment algorithm, EVAR decreased total mortality in our center by 8.6%.

Mechanical recanalization in ischemic anterior circulation stroke within an 8-hour time window: a real-world experience

PURPOSE We aimed to assess the safety and effectiveness of mechanical recanalization in patients with ischemic stroke in the anterior circulation within 8 h since symptoms onset and with unknown onset time. We compared time intervals <6 h vs. 6-8 h/unknown onset time, as only limited data are available for a time window beyond 6 h. METHODS Our cohort included 110 consecutive patients (44 males; mean age, 73.0±11.5 years) with ischemic stroke in the anterior circulation due to the acute occlusion of a large intracranial artery who underwent mechanical recanalization within an 8-hour time window or with unknown onset time. All patients underwent unenhanced computed tomography (CT) of the brain, CT angiography of the cervical and intracranial arteries and digital subtraction angiography. Perfusion CT was performed in patients beyond a 6-hour time window/with unknown onset time. We collected the following data: baseline characteristics, presence of risk factors, neurologic deficit at the time of treatment, time to therapy, recanalization rate, and 3-month clinical outcome. Successful recanalization was defined as Thrombolysis in Cerebral Infarction score of 2b/3 and good clinical outcome as modified Rankin scale value of 0-2 points. RESULTS Successful recanalization was achieved in 82 patients (74.5%): in 61 patients treated within 6 h (73.5%), 7 patients treated within 6-8 h (63.6%), and 13 patients with unknown onset time (81.3%). Good 3-month clinical outcome was achieved in 61 patients (55.5%): in 46 patients treated within 6 h (55.4%), 5 patients treated within 6-8 h (45.5%), and 10 patients with unknown onset time (62.5%). Recanalization success or clinical outcome were not significantly different between patients treated at different time windows. CONCLUSION Our data confirms the safety and effectiveness of mechanical recanalization performed in carefully selected patients with ischemic stroke in the anterior circulation within 8 h of stroke onset or with unknown onset time in everyday practice.

Long-term experience with endovascular therapy of the descending thoracic aorta

BackgroundTo review single centre experience of endovascular treatment of descending thoracic aorta.MethodsBetween May 1999 and September 2012, 72 patients were treated overall (53 men, 19 women, mean age 60.1 years) for degenerative aneurysms (n = 5), ruptured aneurysms (n = 4), aortic ulcers (n = 8), infected aneurysms (n = 4), type B aortic dissections (n = 23), and traumatic aortic injuries (n = 28).ResultsThe technical success rate was 98.6%, 30-day mortality was 8.3%, 1-year mortality was 13.8%, and overall mortality was 22.2%. Mortality caused by the treatment of aortic diseases was 6.9%. Permanent stroke occurred in 1 patient, and paraplegia developed in 1 patient. In a group of 23 patients whose left subclavian artery (LSA) was covered, claudication of the left upper extremity developed in 2 cases.ConclusionsEndovascular therapy offers a very effective and less invasive alternative to the surgical approach for a wide range of the thoracic aortic disease. The main advantage of using TEVAR seems to be in acute conditions when a stent graft stabilizes the aorta and prevents further bleeding and organ ischemia. Regular follow-up is mandatory for early recognition of specific TEVAR complications.

Endovascular Treatment of Symptomatic Thoracic Aneurysm Due to Periaortic Lymphoma

An aggressive periaortic lymphoma could very rarely invade the aortic wall. We present a unique case of a patient with symptomatic thoracic aneurysm and imminent rupture due to the periaortic lymphoma, in which endovascular treatment using stent graft was applied. After stabilization of the aorta and histological confirmation of aggressive B-cell lymphoma by computed tomography–guided biopsy, the antilymphoma therapy was initiated. Despite the full treatment, the patient died 12 months later.