Thomas Hölzenbein

Endoluminal Stent–Grafts for Infrarenal Abdominal Aortic Aneurysms

BACKGROUNDnThe treatment of aortic aneurysms with endovascular stents or stent-graft prostheses is receiving increasing attention as an alternative to major abdominal surgery. To define the clinical value of this technique, we prospectively studied the use of stent-graft endoprostheses made of nitinol and covered with polyester fabric for the treatment of infrarenal abdominal aortic aneurysms.nnnMETHODSnWe treated a total of 154 patients at three academic hospitals. Twenty-one patients with aortic aneurysms not involving the aortic bifurcation received straight stent-grafts, and 133 patients with aortic aneurysms involving the bifurcation and the common iliac arteries received bifurcated stent-grafts. After a unilateral surgical arteriotomy, the endoprostheses were advanced through the femoral arteries and placed under fluoroscopic guidance. Computed tomography and intraarterial angiography were performed during an average follow-up of 12.5 months.nnnRESULTSnThe primary success rate, defined as complete exclusion of the abdominal aortic aneurysm from the circulation, was 86 percent in the group receiving straight grafts and 87 percent in the group receiving bifurcated grafts. In three patients the procedure had to be converted to an open surgical operation. Minor (n=13) or major (n=3) complications associated with the procedure (including 1 death) occurred in 10 percent of the patients. All patients had a postimplantation syndrome, with leukocytosis and elevated C-reactive protein levels.nnnCONCLUSIONSnOur results suggest that endovascular treatment of infrarenal abdominal aortic aneurysms is technically feasible and can effectively exclude abdominal aortic aneurysms from the circulation. With further refinement, endoluminal repair may emerge as an interventional strategy to treat infrarenal aortic aneurysms, especially in patients at high surgical risk.

Results of a policy with arm veins used as the first alternative to an unavailable ipsilateral greater saphenous vein for infrainguinal bypass

PURPOSEnAggressive policies for distal bypass and coronary revascularization increase the need to identify alternatives to autologous saphenous vein grafts. We examined the performance of arm vein as the primary alternative to contralateral saphenous vein when the ipsilateral saphenous vein was not available.nnnMETHODSnA total of 250 arm vein grafts were studied retrospectively in 224 patients (143 men, 81 women, 82.6% with diabetes, mean age 68.3 years) from February 1989 to April 1994. Intraoperative angioscopy was carried out to observe valve lysis, remove abnormalities, and select optimal vein segments.nnnRESULTSnA total of 85 primary, 103 repeat, and 62 graft revision procedures were done for limb salvage in 99.2% of the patients. A total of 41 femoropopliteal, 114 femorotibial-pedal, 33 popliteodistal, and 62 jump or interposition grafts were constructed. A total of 199 grafts were single vein, and 51 were composite vein. The source was cephalic vein alone in 50.4%, cephalic and basilic vein in 35.6%, and basilic vein only in 14%. The contralateral saphenous vein as an alternative conduit was available in 97 (38.8%) instances. Interventions guided by angioscopy to upgrade the graft were necessary in 51.6%. Overall early patency (< or = 30 days) was 94.8% (n = 13 occlusions). The cumulative primary patency rate at 1 year was 70.6%, the secondary patency rate was 76.9%, and the limb salvage rate was 88.2%. The 3-year patency rate (limb salvage) was 51.9% (92.4%) for primary grafts, 56.7% (67.1%) in revision grafts, and 42.4% (79.9%) in repeat grafts. In 22.7% (22 of 97) the available contralateral saphenous vein was used for distal revascularization within the follow-up period.nnnCONCLUSIONSnArm veins are an easily accessible autologous conduit of sufficient length to reach the midtibial level. Excellent patency rates allow durable limb salvage in otherwise difficult circumstances. Vein configuration and splicing do not affect patency rates, but vein quality and repeat operations do. Angioscopy is a valuable adjunct to upgrade graft quality. The contralateral saphenous should be saved for subsequent contralateral revascularization or coronary artery bypass grafting.

Stent-graft placement in atherosclerotic descending thoracic aortic aneurysms: midterm results.

PURPOSEnTo determine midterm durability and need for reinterventions after stent-graft placement in atherosclerotic descending thoracic aortic aneurysms.nnnMETHODSnFifty-four patients (38 men; mean age 68 years, range 33-87) underwent stent-graft repair of chronic atherosclerotic aneurysms of the descending thoracic aorta between November 1996 and December 2002. Acute aortic syndromes (type B aortic dissections, perforating ulcers, and traumatic dissections) were excluded from analysis. Two types of commercially available stent-grafts were used (Talent and Excluder).nnnRESULTSnThe primary technical success rate was 94.4%. In-hospital mortality was 3.7% (2/54). No adverse neurological events were encountered. Of 3 (5.6%) early type I endoleaks, 2 (3.7%) required reintervention; the other type I endoleak closed spontaneously. Mean follow-up was 38 months (range 1-72) in the 52 surviving patients. Four (7.7%) type I, 7 (13.5%) type II, and 4 (7.7%) type III endoleaks were seen. Three 3 patients had additional treatment for endoleaks (proximal stenting [type Ia], open thoracoabdominal repair [type Ib], and embolization [type II]). Two of the 3 reinterventions were performed in the first year of follow-up. One additional patient with a type Ia endoleak not suitable for reintervention is under close observation. There were no differences in the number of endoleaks between the 2 types of stent-grafts. Three-year event-free survival was 63%.nnnCONCLUSIONSnMidterm durability of endovascular stent-graft placement in atherosclerotic descending aortic aneurysms seems promising, as the rate of endoleaks requiring reintervention is acceptably low. In our series, endoleak formation occurred during the first year after stent-graft placement, so close follow-up of patients after aortic aneurysm repair is crucial. Further studies are warranted to evaluate long-term durability of this new treatment modality.

Elective and Emergent Endovascular Treatment of Subclavian Artery Aneurysms and Injuries

Purpose: To demonstrate our short and long-term results after transbrachial treatment of subclavian artery aneurysms and injuries with stent-grafts in elective and emergency settings. Methods: Ten of 12 consecutive patients (6 men; mean age 63.8 years, range 38–80) were treated electively with commercially prepared endografts delivered via a transbrachial access to repair a subclavian artery aneurysm (n = 3) or an injury from a misplaced central venous catheter (n = 7). Two patients required emergency treatment for a ruptured atherosclerotic aneurysm in one and an unintentional arterial puncture during placement of a central venous access in the other. Stent-graft patency during follow-up was assessed by physical examination with comparison of brachial blood pressures in all patients; computed tomography angiography (CTA) was performed in available patients. Results: Successful deployment of stent-grafts with sealing of the lesion was achieved in all cases. There were 2 (17%) procedural complications. One patient developed an access-site hematoma that required surgical revision. The second patient, who had a right subclavian injury, suffered an embolic cerebral infarction. The primary stent-graft patency during follow-up (mean 11.6 months) was 100%. CTA examinations in 7 patients at a mean 18 months showed strut dislocation at the thoracic outlet without luminal narrowing in 1 patient. A 50% intraluminal narrowing due to compression between the clavicle and the first rib occurred in another patient. Six patients with a mean follow-up of 23 months (range 0.3–4.5 years) are still alive with patent stent-grafts. Conclusions: Endovascular stent-graft treatment of subclavian artery aneurysms and injuries is a less invasive alternative to surgical repair. Long-term results must still be confirmed in further studies.

C-reactive protein and mortality in patients with acute aortic disease

AbstractObjective. The association of acute-phase reaction and outcome of patients with acute vascular diseases is controversial. The prognostic value of admission C-reactive protein (CRP) in patients with acute aortic aneurysm or dissection has not yet been investigated.n Design and setting. Cohort study including 255 consecutive patients from an aneurysm registry with symptomatic thoracic or abdominal aortic aneurysm and/or dissection in an emergency department of a tertiary care university hospital.n Patients. Patients were included who had symptoms of aortic disease admitted between 1 January 1992 and 31 November 1998 and were followed up until 31 December 1999 for survival.n Measurements. Admission CRP (mg/dl) levels were categorized in quartiles: quartile 1, less than 0.5; quartile 2, 0.50–1.30; quartile 3, 1.31–6.30; quartile 4, higher than 6.30. Each group contained about 60 patients.n Results. Cumulative mortality 1, 3, and 6xa0months after presentation was 32%, 37%, and 40%, respectively. Increased CRP levels were independently associated with mortality, adjusted for age, sex, hemodynamic shock, mechanical ventilation, coronary artery disease, aortic rupture, hemoglobin, diabetes, and treatment strategy (surgery vs. conservative). Hazard ratios in patients with CRP levels in quartiles 2–4 compared to quartile 1 were 0.7, 1.8, and 2.6, respectively.n Conclusions. Elevated admission CRP values in patients with symptomatic aortic aneurysm/dissection were independently associated with poor prognosis. CRP levels higher than 6.3xa0mg/dl indicate a high risk for short-term mortality.

MR angiography vs CT angiography in the follow-up of nitinol stent grafts in endoluminally treated aortic aneurysms

Abstract. Our objective was to evaluate the accuracy of contrast-enhanced 3D MR angiography (MRA) in the follow-up of patients with endoluminally treated aortic aneurysms and correlate these findings with uni- or biphasic CT angiography (CTA). Forty MR angiograms in 32 patients with implanted aortic nitinol stent grafts were compared to CTA. Twenty-two MR examinations were correlated with arterial-phase CTA (uniphasic), and 18 MR examinations were correlated with biphasic CTA. Uniphasic CTA demonstrated three type-1/type-3 endoleaks and four reperfusion (type-2) endoleaks. In addition, MRA depicted two type-2 reperfusion endoleaks that were missed by CTA. Using biphasic CTA, two type-1/type-3 endoleaks and three reperfusion (type-2) endoleaks were detected; of those, delayed scanning detected three reperfusion (type-2) endoleaks missed during arterial-phase CTA. In addition to the findings by CTA, MRA depicted another type-2 reperfusion endoleak. Magnetic resonance angiography is at least as sensitive as uni- or biphasic CTA for detecting endoleaks and may consequently offer advantages in patients with contraindications to iodinated contrast agents.

Acute phase reactants in patients with abdominal aortic aneurysm

BACKGROUNDnThere is increasing evidence that an inflammatory process is present in abdominal aortic aneurysms (AAAs) to varying degrees. The aim of this study was to compare acute phase reactants in patients with asymptomatic AAA, symptomatic AAA without rupture and ruptured AAA.nnnMETHODnTwo hundred and twenty-five consecutive patients treated because of AAA were included in this case-control study. Polynomial logistic regression analysis was applied to compare admission C-reactive protein (CRP) and white blood count (WBC) measured in 111 asymptomatic outpatients, 52 symptomatic patients without rupture and 62 patients with rupture of the aneurysm. We adjusted for the potentially confounding effect of age, sex, haemoglobin levels and aneurysm diameter.nnnRESULTSnPatients with symptomatic AAA and patients with ruptured AAA had significantly elevated CRP (p=0.002) and WBC (p<0.0001) levels compared to asymptomatic patients. There was no statistically significant difference in CRP and WBC between patients with symptomatic AAA and ruptured AAA. Median CRP values of asymptomatic, symptomatic and ruptured AAA were <0.5 (interquartile range (IQR) <0.5-0.85), 1.1(IQR <0.5-4.0) and 2.4 mg/dl (IQR 0.65-8.6), respectively, and median WBC values were 6.5 (IQR 5.5-8.0), 8.7 (IQR 6.8-11.2) and 13.2 (IQR 10.5-17.0), respectively.nnnCONCLUSIONnA significant elevation of CRP and WBC could be found in patients who presented with symptoms or rupture of an AAA. These indicators of inflammation were not observed in asymptomatic patients with AAA.

Spiral CT angiography in the assessment of abdominal aortic aneurysms after stent grafting : Value of maximum intensity projections

PURPOSEnOur goal was to evaluate the value of maximum intensity projections (MIPs) rendered from spiral CT in the assessment of abdominal aortic aneurysms after stent graft implantation.nnnMETHODnSpiral CT of the aorta was performed in 28 patients 1 week after implantation of covered aortic stent grafts. MIPs were evaluated in a blinded fashion. Transaxial scans and intravenous angiographs were considered the reference standard.nnnRESULTSnStent deformity was evident on the MIPs in 5 cases and stent angulation was seen in 24 cases. The excluded aneurysmal sac was visualized in 14 (50%) cases. MIPs depicted the patent inferior mesenteric artery in 20 of 23 cases (87%). Renal artery occlusion (n = 3), leaks (n = 8), and parietal thrombi, (n = 3) were detected on the MIPs in all cases.nnnCONCLUSIONnMIPs are a valuable tool in the assessment of aortic stent grafts.

Endovascular Therapy of Inflammatory Aortic Aneurysms: A Meta-Analysis

Purpose: To report a meta-analysis of results from endovascular aneurysm repair (EVAR) of inflammatory aortic aneurysms (IAA). Methods: A comprehensive literature review was performed to identify all studies reporting the results of EVAR in patients with IAA. To be included in the analysis, an article had to provide a minimum follow-up of 6 months, information about primary technical success, details of immediate and long-term complications, and evaluation of at least one of the basic outcome criteria: changes in aneurysm sac diameter, periaortic fibrosis (PAF), and/or renal impairment. All studies were reviewed by 2 independent observers for the inclusion criteria. Data were retrieved on the technical and clinical success, outcome criteria, mortality in follow-up, and reinterventions from 14 articles selected from among 701 initially identified. Results: The 14 articles encompassed 46 patients (45 men [97.8%]; mean age 65 years, range 59–75) with a mean follow-up of 18 months after endovascular repair of IAAs located in the abdominal aorta. The primary technical success rate was 95.6% (44/46) and the 30-day clinical success rate was 93.4% (43/46). The median aneurysm sac diameter regression was 11 mm. Of 43 patients with PAF prior to the intervention, 22 (51.2%) patients showed complete regression, 18 (41.8%) remained unchanged, and 3 (7.0%) showed progression after EVAR. Renal impairment disappeared in 11 (45.8%) of 24 patients. Reinterventions were reported in 8 patients. The procedure-related and follow-up mortality rates were 0% and 13.0%, respectively. Conclusions: EVAR of IAA is feasible, excludes the aneurysm effectively, and reduces PAF and renal impairment in most patients with very low periprocedural and midterm mortality and an acceptable reintervention rate.

Bioabsorbable Stent Implantation vs. Common Femoral Artery Endarterectomy: Early Results of a Randomized Trial

Purpose: To compare clinical and hemodynamic outcome in patients undergoing treatment of common femoral artery (CFA) atherosclerotic lesions by bioabsorbable stent implantation (BASI group) or by common femoral artery endarterectomy (CFE group). Methods: A randomized, controlled, single-center, open-label trial was initiated to compare outcomes of BASI or CFE in patients with chronic atherosclerotic occlusive lesions in the CFA. From May 2011 to April 2013, 116 consecutive patients were recruited; after excluding 36 patients, 80 patients (52 men; mean age 72.2±9.6 years) were enrolled 1:1 and are the subject of this intention-to-treat interim analysis (40 patients in each group). The primary endpoint was surgical site infections; secondary outcome measures were technical success, hemodynamic improvement, clinical improvement, patency, limb salvage, and survival. Results: There was no statistically significant difference between both groups regarding demographic data, cardiovascular risk factors, or CFA occlusions. The CFE patients presented with 7 surgical site infections (all minor) vs. none in the BASI group (p=0.002) and a longer mean postoperative hospital stay of 7 vs. 2 days for BASI patients (p<0.001). Technical success rates were 97.5% and 100% for the BASI and CFE groups, respectively. Postoperative ankle-brachial index means were comparable (p=0.38). The 30-day primary patency rates were 92.5% and 100% for the BASI and CFE groups, respectively (p=0.038). There were 6 reconstruction failures in CFE patients vs. none in the BASI group (p=0.02); 5 failures involved initial CFA occlusions. At 1 year, the primary and secondary patency rates were 80% vs. 100% (p=0.007) and 84% vs. 100% (p=0.01) for BASI and CFE patients, respectively. Limb salvage was equivalent, and survival rates were 88% and 90% for BASI vs. CFE patients (p=0.51) at 1 year. Conclusion: This interim analysis suggests that BASI is not an option for CFA occlusion and is only a limited option for CFA stenosis. Clinical and hemodynamic results are comparable for BASI and CFE. An increased rate of redo procedures in the BASI patients outweighs lower surgical site infection rates compared to CFE. Short-term patency rates are significantly worse in patients undergoing CFA stenting with BASI.