COMPARE: prospective, randomized, non-inferiority trial of high- vs. low-dose paclitaxel drug-coated balloons for femoropopliteal interventions.

AIMS: Drug-coated balloons (DCBs) for femoropopliteal interventions have not been tested against each other. We aimed to directly compare efficacy and safety of a high-dose (In.Pact™) vs. low-dose (Ranger™) DCB with nominal paclitaxel densities of 3.5 vs. 2.0 µg/mm2. METHODS AND RESULTS: Within a prospective, multicentre, non-inferiority, clinical trial 414 patients with symptomatic femoropopliteal lesions (Rutherford classification 2-4) were randomly assigned in a 1:1 ratio to endovascular treatment with either high- or low-dose DCB after stratification for lesion length. Primary efficacy and safety endpoints comprised primary patency and freedom from major adverse events (i.e. device and procedure-related deaths through 1 month, major amputations, and clinically driven target lesion revascularization through 12 months). We set a non-inferiority margin of -10% at 12 months. Total occlusions were observed frequently (>40%) and provisional stenting was performed in every fourth intervention. Non-inferiority was determined for both primary efficacy and safety endpoints at 12 months. Primary patency was 81.5% in the high-dose and 83.0% in low-dose DCB group {difference: 1.5% [lower bound of the 90% two-sided confidence interval (CI) -5.2%]; Pnon-inferiority < 0.01}. Freedom from major adverse events was determined in 92.6% in high-dose and in 91.0% in low-dose DCB group [difference -1.6% (lower bound of the 90% two-sided CI -6.5%); Pnon-inferiority < 0.01]. Overall death rate was low (2.0%) and no major amputation occurred. CONCLUSION: Two DCBs with different coating characteristics exhibited comparable results with excellent effectiveness and safety through 12 months for femoropopliteal interventions including a wide range of lesion lengths. CLINICAL TRIAL REGISTRATION: The trial is registered with ClinicalTrials.gov (NCT02701543).

Smaller-Diameter Covered Transjugular Intrahepatic Portosystemic Shunt Stents Are Associated With Increased Survival.

BACKGROUND & AIMS: We studied the effects of diameter of covered, self-expandable, nitinol stents on survival times of patients with a transjugular intrahepatic portosystemic shunt (TIPS). METHODS: We collected data from 185 patients (median age, 55 y; 30% female) who received a covered nitinol stent, from February 2006 through September 2010, using the online multicenter German TIPS registry. TIPS were given to 107 patients for refractory ascites and to 78 patients for variceal bleeding. Patients at risk of hepatic encephalopathy (owing to advanced age, prior episodes) or liver failure (bilirubin level, >3 mg/dL), and bleeding patients receiving variceal embolization at TIPS, received 8-mm stents (n = 53). The remaining patients received 10-mm stents (n = 132). Eighty-one of the 10-mm stents were underdilated using 8-mm dilation balloons. Clinical and biochemical data were collected after TIPS placement at 1 month, 3 months, 6 months, 9 months, 1 year, and thereafter every 3 to 6 months. Groups were compared using propensity score analysis. RESULTS: Patients who received 8-mm stents survived significantly longer (34 ± 26 mo) than patients who received 10-mm stents (18 ± 19 mo), regardless of whether they were fully dilated or underdilated. When we compared 10-mm stents with or without underdilation, we found that a significantly higher proportion of patients who received underdilated stents survived for 1 month after TIPS placement (95% vs 84%; P = .03), but not for 3 months (P = .10). In multivariate analysis, 1-year mortality correlated with full dilation of the stent to 10 mm (hazard ratio [HR], 2.0; 95% CI, 1.1-3.5) and with serum creatinine concentration at baseline (HR, 1.5; 95% CI, 1.0-1.7). Five-year mortality was associated with use of the 10-mm stents (HR, 1.8; 95% CI, 1.4-2.7) and baseline concentration of creatinine (HR, 1.3; 95% CI, 1.1-1.6). CONCLUSIONS: A smaller stent (nominal diameter of 8 mm, but not underdilation of a 10-mm stent) is associated with a prolonged survival compared with 10-mm stents, independent of liver-specific prognostic criteria.

Effect of TIPS placement on portal and splanchnic arterial blood flow in 4-dimensional flow MRI.

OBJECTIVES: To assess changes in portal and splanchnic arterial haemodynamics in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) using four-dimensional (4D) flow MRI, a non-invasive, non-contrast imaging technique. METHODS: Eleven patients undergoing TIPS implantation were enrolled. K-t GRAPPA accelerated non-contrast 4D flow MRI of the liver vasculature was applied with acceleration factor R = 5 at 3Tesla. Flow analysis included three-dimensional (3D) blood flow visualization using time-resolved 3D particle traces and semi-quantitative flow pattern grading. Quantitative evaluation entailed peak velocities and net flows throughout the arterial and portal venous (PV) systems. MRI measurements were taken within 24 h before and 4 weeks after TIPS placement. RESULTS: Three-dimensional flow visualization with 4D flow MRI revealed good image quality with minor limitations in PV flow. Quantitative analysis revealed a significant increase in PV flow (562 ± 373 ml/min before vs. 1831 ± 965 ml/min after TIPS), in the hepatic artery (176 ± 132 ml/min vs. 354 ± 140 ml/min) and combined flow in splenic and superior mesenteric arteries (770 ml/min vs. 1064 ml/min). Shunt-flow assessment demonstrated stenoses in two patients confirmed and treated at TIPS revision. CONCLUSIONS: Four-dimensional flow MRI might have the potential to give new information about the effect of TIPS placement on hepatic perfusion. It may explain some unexpected findings in clinical observation studies. KEY POINTS: • 4D flow MRI, a non-invasive, non-contrast imaging technique, is feasible after TIPS. • Provides visualization and quantification of hepatic arterial, portal venous, collateral and TIPS haemodynamics. • Better understanding of liver blood flow changes after TIPS and patient management.

Reproducibility study of four-dimensional flow MRI of arterial and portal venous liver hemodynamics: influence of spatio-temporal resolution.

PURPOSE: To evaluate influence of variation in spatio-temporal resolution and scan-rescan reproducibility on three-dimensional (3D) visualization and quantification of arterial and portal venous (PV) liver hemodynamics at four-dimensional (4D) flow MRI. METHODS: Scan-rescan reproducibility of 3D hemodynamic analysis of the liver was evaluated in 10 healthy volunteers using 4D flow MRI at 3T with three different spatio-temporal resolutions (2.4 × 2.0 × 2.4 mm(3), 61.2 ms; 2.5 × 2.0 × 2.4 mm(3), 81.6 ms; 2.6 × 2.5 × 2.6 mm(3), 80 ms) and thus different total scan times. Qualitative flow analysis used 3D streamlines and time-resolved particle traces. Quantitative evaluation was based on maximum and mean velocities, flow volume, and vessel lumen area in the hepatic arterial and PV systems. RESULTS: 4D flow MRI showed good interobserver variability for assessment of arterial and PV liver hemodynamics. 3D flow visualization revealed limitations for the left intrahepatic PV branch. Lower spatio-temporal resolution resulted in underestimation of arterial velocities (mean 15%, P < 0.05). For the PV system, hemodynamic analyses showed significant differences in the velocities for intrahepatic portal vein vessels (P < 0.05). Scan-rescan reproducibility was good except for flow volumes in the arterial system. CONCLUSION: 4D flow MRI for assessment of liver hemodynamics can be performed with low interobserver variability and good reproducibility. Higher spatio-temporal resolution is necessary for complete assessment of the hepatic blood flow required for clinical applications.

Normal and altered three-dimensional portal venous hemodynamics in patients with liver cirrhosis.

PURPOSE: To compare time-resolved three-dimensional (3D) phase-contrast magnetic resonance (MR) imaging with three-directional velocity encoding (flow-sensitive four-dimensional [4D] MR imaging), with Doppler ultrasonography (US) as standard of reference, for investigating alterations in 3D portal venous hemodynamics in patients with liver cirrhosis compared with healthy age-matched control subjects and healthy young volunteers. MATERIAL & METHODS: This prospective study was approved by the local ethics committee, and written informed consent was obtained from all participants. Three-dimensional portal venous hemodynamics was assessed, employing flow-sensitive 4D MR imaging with a 3-T MR system (spatial resolution, approximately 2 mm(3); temporal resolution, approximately 45 msec) in 20 patients with hepatic cirrhosis, 20 healthy age-matched control subjects, and 21 healthy young volunteers. Flow characteristics were analyzed by using 3D streamlines and time-resolved particle traces. Quantitative analyses were performed by retrospectively evaluating regional peak and mean velocities, flow volume, and vessel area. Doppler US was used as standard of reference. Independent-sample t tests or Wilcoxon-Mann-Whitney tests were applied for comparing each subject group. Paired-sample t tests or Wilcoxon tests were applied when comparing MR imaging and US. RESULTS: Three-dimensional visualization of portal venous hemodynamics was successful, with complete visualization of the vessels in 18 patients and 35 volunteers, with limitations in the left intrahepatic branches (87%, reader A; 89%, reader B). A moderate but significant correlation was observed between 4D MR imaging and Doppler US in nearly all maximum and mean velocities, flow volumes, and vessel areas (r = 0.24-0.64, P = .001-.044). With MR imaging, significant underestimation was observed of intrahepatic flow velocities and flow volumes, except vessel area, which Doppler US represented as even lower (P < .001 to P = .045). Six patients had collateralization with reopened umbilical vein, while one had flow reversal in the superior mesenteric vein visible at MR imaging only. CONCLUSION: Flow-sensitive 4D MR imaging may constitute a promising, alternative technique to Doppler US for evaluating hemodynamics in the portal venous system of patients with liver cirrhosis and may be a means of assessing pathologic changes in flow characteristics.

Peripheral vessel scout imaging based on continuously moving table acquisition of projection data.

A fast and spatially seamless peripheral vessel scout is desirable for subsequent planning of magnetic resonance (MR) angiography. We implemented a continuously moving table sequence providing projection data with time-of-flight contrast of the entire lower extremities in less than 2 minutes. Variation of arterial signal during the cardiac cycle and autocorrelation were exploited to enhance vessel-to-background contrast. Subjective image analysis revealed excellent vessel depiction, indicating that the proposed scout allows for seamless expedited visualization of major arterial structures.

Low-Dose vs High-Dose Paclitaxel-Coated Balloons for Femoropopliteal Lesions: 2-Year Results From the COMPARE Trial.

BACKGROUND: So far only 1-year data have been reported for direct comparisons of paclitaxel-coated balloons (PCBs) using different coating technologies. OBJECTIVES: The aim of this study was to report the 24-month results on the efficacy and safety of low-dose vs high-dose PCBs with nominal paclitaxel densities of 2.0 and 3.5 µg/mm2 and different coating technologies for femoropopliteal interventions from the COMPARE (Compare I Pilot Study for the Treatment of Subjects With Symptomatic Femoropopliteal Artery Disease) trial. Procedural characteristics of clinically driven (CD) target lesion revascularization (TLR) were analyzed. METHODS: Within a prospective, multicenter, clinical trial, 414 patients with symptomatic femoropopliteal lesions (Rutherford categories 2-4, maximum lesion length 30 cm) were randomly assigned in a 1:1 ratio to endovascular treatment with either a low-dose (Ranger) or a high-dose (IN.PACT) PCB after stratification for lesion length. Two-year follow-up included assessment of primary patency (defined as absence of CD TLR or binary restenosis with a peak systolic velocity ratio >2.4 by duplex ultrasound), safety, and functional and clinical outcomes. RESULTS: At 2 years, the Kaplan-Meier estimates of primary patency were 70.6% and 71.4% for the low-dose and high-dose PCBs (log-rank P = 0.96), respectively. One major amputation occurred in the high-dose group, and rates of all-cause mortality (3.6% vs 2.2%; P = 0.55) and CD TLR (17.3% vs 13.0%; P = 0.31) were similar between the groups. Among a total of 57 CD TLRs, 44.6% were performed for reocclusion and 28.1% for in-stent restenosis. Functional and clinical benefits over baseline were sustained in both groups. CONCLUSIONS: The 2-year results of the COMPARE trial demonstrate a sustained treatment benefit of both low-dose and high-dose PCBs for femoropopliteal interventions including a wide range of lesion lengths. (Compare I Pilot Study for the Treatment of Subjects With Symptomatic Femoropopliteal Artery Disease; NCT02701543).

Thoracic aorta: prospective electrocardiographically triggered CT angiography with dual-source CT--feasibility, image quality, and dose reduction.

PURPOSE: To prospectively investigate the feasibility, image quality, and radiation dose for prospective electrocardiographically (ECG) triggered sequential dual-source computed tomographic (CT) angiography of the thoracic aorta in comparison to retrospective ECG-gated helical dual-source CT angiography. MATERIALS AND METHODS: This study was approved by the institutional review board; informed consent was obtained. One hundred thirty-nine patients referred for ECG-assisted dual-source CT angiography of the thoracic aorta were prospectively enrolled. Inclusion criteria were stable sinus rhythm and heart rate of 80 beats per minute or less. Tube voltage was adjusted to body mass index (< 25.0 kg/m(2), 100 kV, n = 58; > or = 25.0 kg/m(2), 120 kV, n = 81). In both cohorts, patients were randomly assigned to prospective or retrospective ECG-assisted data acquisition. In both groups, tube current (250 mAs per rotation) was centered at 70% of the R-R cycle. The presence of motion or stair-step artifacts of the thoracic aorta was independently assessed by two readers. Effective radiation dose was calculated from the dose-length product. RESULTS: Subjective scoring of motion and stair-step artifacts was equivalent for both techniques. Scan length was not significantly different (23.8 cm +/- 2.4 [standard deviation] vs 23.7 cm +/- 2.5 for prospective and retrospective ECG-triggered CT angiography, respectively; P = .54). Scanning time was significantly longer for prospective ECG-triggered CT angiography (18.8 seconds +/- 3.4 vs 16.4 seconds +/- 3.3, P < .001). Mean estimated effective dose was significantly lower for prospective data acquisition (100 kV, 1.9 mSv +/- 0.5 vs 4.1 mSv +/- 0.7, P < .001; 120 kV, 5.3 mSv +/- 1.1 vs 9.5 mSv +/- 3.0, P < .001). CONCLUSION: Prospective ECG-gated sequential dual-source CT angiography of the thoracic aorta is feasible, despite the slightly longer acquisition time. Thus, motion-free imaging of the thoracic aorta is possible at significantly lower radiation exposure than retrospective ECG-gated helical dual-source CT angiography in certain patients with a regular heart rate.

MR-based visualization and quantification of three-dimensional flow characteristics in the portal venous system.

PURPOSE: To evaluate the feasibility of time-resolved flow-sensitive MRI for the three-dimensional (3D) visualization and quantification of normal and pathological portal venous (PV) hemodynamics. MATERIALS AND METHODS: Portal venous hemodynamics were evaluated in 18 healthy volunteers and 5 patients with liver cirrhosis. ECG- and adaptive respiratory navigator gated flow-sensitive 4D MRI (time-resolved 3D MRI with three-directional velocity encoding) was performed on a 3 Tesla MR system (TRIO, Siemens, Germany). Qualitative flow analysis was achieved using 3D streamlines and time-resolved particle traces originating from seven emitter planes precisely placed at anatomical landmarks in the PV system. Quantitative analysis included retrospective extraction of regional peak and mean velocities and vessel area. Results were compared with standard 2D flow-sensitive MRI and to the reference standard Doppler ultrasound. RESULTS: Qualitative flow analysis was successfully used in the entire PV system. Venous hemodynamics in all major branches in 17 of 18 volunteers and 3 of 5 patients were reliably depicted with good interobserver agreement (kappa = 0.62). Quantitative analysis revealed no significant differences and moderate agreement for peak velocities between 3D MR and 2D MRI (r = 0.46) and Doppler ultrasound (US) (r = 0.35) and for mean velocities between 3D and 2D MRI (r = 0.41). The PV area was significantly (P < 0.01) higher in 3D and 2D MRI compared with US. CONCLUSION: We successfully applied 3D MR velocity mapping in the PV system, providing a detailed qualitative and quantitative analysis of normal and pathological hemodynamics.

Combined assessment of aortic root anatomy and aortoiliac vasculature with dual-source CT as a screening tool in patients evaluated for transcatheter aortic valve implantation.

OBJECTIVE: The objective of our study was to investigate the feasibility, image quality, and clinical implications of a combined dual-source CT angiography (CTA) protocol to assess aortic root anatomy and aortoiliac vasculature in patients with severe aortic stenosis evaluated for transcatheter aortic valve implantation. SUBJECTS AND METHODS: Eighty consecutive patients (47 women and 33 men; mean age, 82.3 ± 7.8 [SD] years) with severe aortic stenosis evaluated for transcatheter aortic valve implantation underwent a combined single-dose contrast-enhanced dual-source CTA protocol (body weight < 70 kg, 110 mL of contrast medium; ≥ 70 kg, 130 mL) consisting of ECG-gated dual-source CTA of the chest with integrated cardiac CT and ungated CTA of the abdomen and pelvis. Two independent observers measured the dimensions of the aortic root and the aortoiliac vasculature and rated image quality semiquantitatively. Vessel attenuation was assessed. Amenability to transfemoral access was evaluated on the basis of vessel diameter (> 7 mm), anatomy, and the presence of vascular disease. RESULTS: Image quality of the aortic root was diagnostic in all 80 patients, and image quality of the aortoiliac vasculature was diagnostic in 79 patients. Vascular attenuation was greater than 200 HU at any vessel level. The mean diameter of the aortic annulus was 24.1 ± 2.9 (SD) mm. Inter- and intraobserver correlations for aortic root and aortoiliac measurements were high (r = 0.93-0.99). Aortic root dimensions were suitable for transcatheter aortic valve implantation in 65 patients (81%). Thirty-eight patients (48%) were deemed amenable to instant transfemoral access without another vasculature intervention. CONCLUSION: The dimensions of the aortic root and the aortoiliac vasculature can be assessed with a combined single-dose contrast-enhanced dual-source CTA protocol, thereby allowing determination of patient eligibility for transcatheter aortic valve implantation, prosthesis sizing, and evaluation of the access route in one examination.

Aorto-caval fistula from acute rupture of an abdominal aortic aneurysm treated with a hybrid approach.

Ruptured abdominal aneurysm is a life-threatening disease requiring immediate treatment. The outcome is even worse in cases complicated by aorto-caval fistula. Treatment is usually attempted by open surgery using direct closure of the venous tear and graft placement in the aorta. Interventional treatment in certain patients seems sensible and has been reported. We report a patient who experienced the rupture of a 13-cm infrarenal aneurysm into the inferior vena cava. He developed signs of severe heart failure and congestion of the lower half of the body. Diagnosis was confirmed by computed tomography (CT)-scan. Due to anatomy unsuitable for endovascular treatment and the potential bleeding complications associated with open surgery involving a big fistula, we decided to close the fistula with a covered stent in the vena cava and operated on the aortic rupture immediately thereafter. The ease of this hybrid approach justifies suggesting it as a possible treatment option for this severe disease.

Thoracic endovascular stent grafting inhibits aortic growth: an experimental study.

OBJECTIVE: Dilatation of the aorta at the landing zone site may be exaggerated by the radial force of stent grafts potentially limiting long-term results of endovascular therapy. We evaluated growth patterns and morphology of the thoracic aorta in young piglets after thoracic stent-graft placement. METHODS: Eight domestic piglets (37+/-2 kg) had an endovascular stent graft placed in the proximal descending thoracic aorta using retroperitoneal access. At implantation, the stent was oversized by 10%. Aortic size was documented after thoracotomy by intraoperative measurement and angiography. Subsequently the piglets were grown to adult size (181+/-42 kg). At explantation 6-15 months later, CT scan and surgical evaluation for endoleaks, defined as perigraft flow, was performed. Histopathological assessment of the explanted aorta was performed in stented and non-stented segments and compared to five normal porcine aortas. RESULTS: No endoleak (perigraft flow) or stent migration occurred even in 230kg pigs. The stent grafts expanded to full size, but there was no further growth in the stented area. The aortic diameter increased significantly by 32+/-9% 1cm proximal to the stents (p=0.0012) and by 45+/-13% 1cm distal to the stents (p=0.0033). The stented area grew less than the proximal (p=0.0011) and distal aorta (p<0.0001). In all pigs, the distal aorta was larger than the proximal overstented segment. Histology of the stented aorta showed significant thickening of the intima (p=0.018) and media (p=0.006) with neointimal formation and segmental fibrosis of the inner 1/3 of the media with loss of smooth muscle cells and compression of the elastic fibers but normal architecture in the outer 2/3 of the media. CONCLUSIONS: Endovascular stent grafting may inhibit growth of the nonatherosclerotic normal aorta and lead to intimal hyperplasia and focal fibrosis in the inner media part adjacent to the stent. Stent-graft interaction with aortic tissue over time is important and should receive more detailed evaluation. Testing this interaction in an animal model of nonatherosclerotic dilative aortic disease could be of great interest.

Incidence of neurological complications following overstenting of the left subclavian artery.

OBJECTIVE: Aortic endovascular stent-graft implantation is associated with low morbidity and mortality rates. Overstenting of the left subclavian artery may be necessary to create a satisfactory proximal 'landing zone' for the stent-graft. Few cases have been published reporting adverse neurological events after overstenting of the left subclavian artery. We thus evaluated whether this procedure is associated with a higher rate of neurological complications by focusing on the management of the supra-aortic vessels. METHODS: Twenty patients suffering from aortic arch aneurysms (n=3), descending aortic aneurysms (n=7), acute (n=6) and chronic (n=4) type-B aortic dissections underwent stent-graft repair with complete (n=14) or partial (n=6) overstenting of the left subclavian artery. Three patients underwent overstenting of the entire aortic arch with ascending aortic-bi-carotid bypass grafting. One patient with right carotid and vertebral artery occlusion underwent initial carotid-to-subclavian bypass. All patients subsequently underwent neurological examination and Doppler ultrasound for detection of neurological and peripheral vascular complications. RESULTS: Aortic stent-graft repair was successful in all patients without acute neurologic complications. Two patients developed late central adverse neurological events: right-sided vertebral artery occlusion with brainstem infarction (n=1) and impaired binocular vision combined with dizziness (n=1), necessitating secondary subclavian transposition in one patient. Peripheral symptoms related to occlusion of the left subclavian artery were observed in five patients as sensory and motoric deficits of the left hand and arm. CONCLUSIONS: Overstenting of the left subclavian artery as treatment of aortic pathologies in high-risk patients is feasible but associated with the risk of neurological complications and peripheral symptoms. Side effects were mild or transient in most of our patients. Detailed preoperative exploration of vascular anatomy and pathology via Doppler ultrasound, CT- or MRI scan is mandatory to avoid adverse neurological events. Prior surgical revascularization of the left subclavian artery is essential in patients with high-grade stenoses, occlusions, or anatomic variants of the supra-aortic branches. Delayed surgical revascularization is necessary only in patients with relevant subclavian steal syndrome or severe peripheral vascular symptoms.

Management of delayed visceral arterial bleeding after pancreatic head resection.

Despite low mortality, postoperative complications are still relatively frequent after pancreatic head resection. The occurrence of delayed visceral arterial bleeding from erosions or pseudoaneurysms of branches of the celiac trunk or from the stump of the gastroduodenal artery is a rare but life-threatening complication and is probably underreported in the literature. During a 10-year period, we diagnosed and treated 12 patients (three referred from other hospitals) with severe visceral arterial bleeding, presenting 7 to 85 days after pancreatic head resection. Clinical presentation was gastrointestinal bleeding (seven patients) or abdominal bleeding (five patients). The bleeding source was identified by angiography in 10 of the 12 cases. Definitive bleeding control was achieved by angiography in six of the 12 patients (stent 2, coiling 4), or by surgery in five patients. None of the six patients with successful angiographic intervention required further surgery for bleeding control. One patient died due to hemorrhage before bleeding was controlled. Median transfusion requirement was 12.5 (range 3-37) units. Of five patients with interventional or surgical occlusion of the common hepatic artery, three developed hepatic abscesses and two had complications of the hepaticojejunostomy. One of those five patients died four months after definitive bleeding control because of recurrent hepatic abscesses. All other patients eventually recovered completely. We conclude that delayed arterial bleeding from visceral arteries is a rare but life-threatening complication after pancreatic head resection. Angiographic stenting with preservation of hepatic blood flow, if technically possible, represents the best treatment option.

Distal aortic reintervention after surgery for acute DeBakey type I or II aortic dissection: open versus endovascular repair.

OBJECTIVES: Aortic dissection DeBakey type I and II may require distal reinterventions after initial proximal repair. We evaluated outcomes following open versus endovascular approaches to distal aortic pathologies after surgery for acute dissection. METHODS: One hundred and forty-one consecutive patients underwent 152 distal reinterventions after previous type I or II dissection repair [63 (first quartile, 55; third quartile, 72) years old; initially 86% DeBakey type I; 54% hemiarch, 39% isolated ascending, 7% total arch replacement] at two tertiary centres in the USA and Europe over the last 14 years. Among them, 56 and 85 required reintervention for the aortic arch and the descending aorta, respectively. The median follow-up was 2.1 (first quartile, 0.8; third quartile, 5.8) years (439 patient-years). RESULTS: The median time between acute aortic dissection repair and descending aortic reintervention was longer in the open group (2.7 (first quartile, 0.8; third quartile, 6.7) vs 0.6 (first quartile, 0.1; third quartile, 3.5) years, P < 0.01). There was one irreversible spinal ischaemia in the open and one stroke in the endovascular group. Two patients in the open and none in the endovascular group required re-exploration for bleeding. Two open and 4 endovascular patients required more than 1 distal reintervention (6 vs 8%, P = 1). Descending aortic open-repair patients experienced higher in-hospital mortality (23 vs 0%, P < 0.01) and lower survival at 1 and 5 years (74 ± 8% vs 96 ± 3%, 65 ± 9% vs 92 ± 5%, P < 0.01, respectively). CONCLUSIONS: Endovascular intervention for descending aortic pathologies after DeBakey type I or II dissection surgical repair is associated with lower in-hospital mortality and better survival, and does not raise the likelihood of later reinterventions at the mid-term follow-up.

Results of high-risk endovascular procedures in patients with non-dissected thoracic aortic pathology: intermediate outcomes.

OBJECTIVES: To investigate mid-term outcome in patients undergoing thoracic endovascular aortic repair (TEVAR) for non-dissected aortic pathology with favourable and unfavourable landing zone and aortic anatomy. METHODS: Between 2000 and 2011, TEVAR was performed in 208 patients with descending thoracic aortic disease. Of 105 patients with non-dissected thoracic aortic pathology, 69 presented with unfavourable anatomy as defined by short length (<15 mm), large diameter (>42 mm), angulation of >60° of the proximal or distal landing zone or extreme aortic tortuosity. The endpoints perioperative mortality, 1-year survival, endoleak occurrence and incidence of secondary intervention were compared with the remaining 36 patients with favourable anatomy. RESULTS: Median follow-up was 18 months. TEVAR was performed emergently in 24 of 69 (35%) patients with unfavourable anatomy and in 11 of 36 (31%) of those with favourable anatomy (P = 0.68). No patients underwent conversion to open surgery, no periinterventional rupture was observed. Perioperative mortality did not differ between cohorts (1/69 vs 1/36, P = 0.78). Postoperative permanent spinal cord ischaemia occurred in patients with unfavourable anatomy only (2/69 vs 0/36, P = 0.78). Early endoleak and secondary intervention were more frequent in patients with unfavourable anatomy (19/69 vs 7/36 and 13/69 vs 1/36), but not statistically significant (P = 0.5 and P = 0.13, respectively). One-year aorta-related survival rates were similar in both groups (66/69 vs 33/36, P = 0.45). CONCLUSIONS: Mid-term outcome after TEVAR does not differ between patients with favourable and unfavourable landing zone anatomy in terms of aorta-related survival. However, the more frequent need for secondary intervention warrants a more rigorous follow-up after TEVAR in patients with unfavourable anatomy.

A feasibility study to evaluate splanchnic arterial and venous hemodynamics by flow-sensitive 4D MRI compared with Doppler ultrasound in patients with cirrhosis and controls.

PURPOSE: To evaluate the feasibility of time-resolved flow-sensitive four-dimensional (4D) MRI for the visualization and quantification of splanchnic arterial and portal venous hemodynamics in patients with cirrhosis and in controls. MATERIALS AND METHODS: We applied flow-sensitive 4D MRI to evaluate arterial and portal venous three-dimensional blood flow in patients with advanced liver cirrhosis (n=5) and in healthy controls (n=10) using 3T MRI (spatial resolution=1.7×2.1×2.4 mm, temporal resolution=62.4 ms). The qualitative flow was analyzed using three-dimensional streamlines and time-resolved particle traces. Retrospective flow was quantified in nine predefined anatomic regions evaluating maximum and mean velocities, the flow volume, the vessel lumen area, pulsatility indices, and resistance indices. Doppler ultrasound (US) was our reference standard. RESULTS: Flow-sensitive 4D MRI visualized liver hemodynamics successfully in 91% of patients and 96% of volunteers with limitations for the patients' extrahepatic vessels (one case of splenic and superior mesenteric veins each) and intrahepatic portal vein branches (in five vessels). Healthy control individuals revealed reduced velocities and larger vessel areas in MRI than in Doppler US. We found no significant differences in the flow volume, pulsatility indices, and resistance indices on comparing MRI with US. Regional flow quantification within the splanchnic system of healthy volunteers and liver cirrhosis patients revealed an increase in the inflow (up to 65%), but a decrease in the patients' outflow (up to 37%). CONCLUSION: Flow-sensitive 4D MRI is feasible for profound evaluation of arterial and portal venous hemodynamics in liver cirrhosis patients, providing additional information on the pathophysiology of the altered splanchnic system.

Late complications and distal growth rates of Marfan aortas after proximal aortic repair.

OBJECTIVES: Conflicting results have been reported on late aortic growth and complication rates of the descending thoracic aorta in patients with Marfan syndrome (MFS) after proximal aortic surgery. METHODS: Of 198 Marfan patients followed up regularly, 121 (43% David-I, 7% David-II, 11% supracoronary replacement, 52% mechanical conduit, 8% arch replacement) were analysed after proximal aortic surgery retrospectively. 97% had MFS1, 3% MFS2 (Loeys-Dietz-Syndrome); 56% were male and the mean age was 35 ± 13 years. 65% were initially operated on for root/ascending aortic aneurysm and 35% for aortic dissections. Using automated computed tomography angiography and magnetic resonance angiography cross-sectional analyses, the mean diameters of the distal arch, mid-descending and distal supradiaphragmatic descending thoracic aorta were measured at early and late follow-up (mean 6.3 years for aneurysms and 4.7 years for dissections). The mean duration of clinical follow-up was 7.6 years and the cumulative clinical follow-up comprised 894 patient-years. RESULTS: At 20 years, overall freedom from distal aortic complications and/or reintervention was 76% (51-86%) for aneurysms and 52% (28-71%) for dissections (P = 0.03). In non-dissected aortas, distal aortic growth was significant, but minimal: arches grew from 25.2 ± 0.6 to 26.3 ± 0.8 mm (P = 0.01), mid-descending aortas from 22.2 ± 0.5 to 24.9 ± 1.2 mm (P = 0.05) and distal descending aortas from 22.1 ± 0.7 to 24.2 ± 1.4 (P = 0.02, 0.58 mm/year ± 0.5 mm). Dissected distal aortas increased by a mean of 0.3 ± 0.5 mm/year. Dissection (P < 0.001), urgent procedure (P = 0.02) and hypertension (0.052) were associated with larger distal aortic diameters at late follow-up and more significant aortic growth over time. CONCLUSIONS: Late distal complication rates are low for patients initially presenting with aneurysms. The risk of late distal reoperation is dictated by the initial pathology and by the presence of an initial dissection and not by faster distal aortic growth. Strategies to completely restore a non-dissected anatomy might improve late surgical outcome in Marfan's syndrome.

Standard intra-aortic counterpulsation balloon may cause temporary occlusion of mesenterial and renal arteries.

The study was to test the hypothesis that mesenteric and renal arteries may be occluded by intra-aortic balloon pumps (IABPs), despite correct positioning. Computed tomography scans of 107 patients (34.6% women and 65.4% men) were evaluated for diameter and distance measurements of the descending aorta. Renal perfusion was examined with duplex sonography. Mean distances between left subclavian artery and celiac trunk, between the left subclavian and superior mesenteric artery, and between the left subclavian and renal artery were 214.5 ± 22.3, 229.5 ± 22.3, and 242.9 ± 22.1 mm, respectively. Statistical assessment of aortic distances in patient population showed no correlation between the length of the descending aorta and body mass index (BMI) and height (men: R(2) < 0.13; women: R(2) < 0.3). An impaired arterial perfusion of the renal parenchyma existed in three of the 12 patients; three of the 12 demonstrated diastolic oscillatory flow over the renal arteries; two of the 12 patients presented both during IABP support. Autopsy observation was used to observe the position of the IABP catheter. The correlation between patient height/BMI and the distances between subclavian artery and renal/visceral branches is weak. Therefore, even if positioned correctly, intra-aortic balloon catheters may be too long and could potentially cause occlusion of aortic branches.