Endovascular management performed percutaneously of isolated iliac artery aneurysms

PURPOSE

To report about the endovascular treatment of isolated iliac artery aneurysms (IIAA) with stentgraft placement and transluminal or CT-guided embolization of the internal iliac artery or the combination of these methods.

METHODS AND MATERIALS

Over a period of 5.6 years, 36 interventions were performed in 20 patients with 23 IIAAs. In a retrospective analysis patient records were reviewed. The CT-angiography follow-up was evaluated for the presence of re-perfusion of the IIAA and for change of aneurysm diameter.

RESULTS

Primary success was achieved in 15/23 aneurysms (65%), and secondary success in 21/23 aneurysms (91%). In 5/23 cases two interventions and in 1/23 cases three interventions were necessary to achieve secondary success. Embolization alone, as a therapy for aneurysms involving only the internal iliac artery, had a success rate of 27%. No procedure-related minor or major complications occurred. Mean decrease of aneurysm size during a mean observation period of 14.1 months was 6.9% which was not significant (p=0.3; 95% confidence interval +7-21%).

CONCLUSION

Endovascular therapy of isolated iliac artery aneurysms performed percutaneously has become a treatment alternative to open surgical repair. This method is feasible and safe with low procedure-related morbidity and mortality. However, on average more than one intervention has to be performed to achieve successful permanent exclusion of the aneurysm and embolization alone in isolated internal iliac artery aneurysms is not sufficient.

Quality of life after balloon angioplasty versus stent implantation in the superficial femoral artery: findings from a randomized controlled trial

PURPOSE

To investigate whether primary nitinol stenting in the superficial femoral artery (SFA) is beneficial to patients' quality of life (QoL).

METHODS

One hundred four patients (55 men; mean age 66+/-19 years) with chronic limb ischemia and SFA disease were randomly assigned to primary stent implantation (n=51) or balloon angioplasty (n=53) with optional stenting for a suboptimal angioplasty result (17 of 53). QoL was measured by the SF-36 questionnaire at baseline and at 3, 6, and 12 months post intervention.

RESULTS

QoL was significantly improved post intervention and up to 12 months in both treatment groups. Significant inverse associations were observed between QoL parameters and restenosis. Comparing primary stenting (n=51) versus balloon angioplasty with optional stenting (n=53) by the intention to treat, no significant differences in QoL were observed. Analyses of stented patients (n=68) versus balloon angioplasty (n=36) patients, however, demonstrated significantly improved measures of QoL after stenting.

CONCLUSION

Endovascular revascularization of SFA disease improves QoL, and restenosis negatively affects QoL outcomes. After stent implantation, whether primary or secondary, QoL was significantly ameliorated compared to balloon angioplasty alone. However, it remains to be proven in larger cohorts whether primary stenting yields a QoL benefit compared to balloon angioplasty with optional secondary stenting.

Sustained Benefit at 2 Years of Primary Femoropopliteal Stenting Compared With Balloon Angioplasty With Optional Stenting

Background— Primary stenting with self-expanding nitinol stents of the superficial femoral artery yielded improved morphological and clinical results compared with balloon angioplasty with optional stenting until 12 months in a randomized controlled trial. We now report 2-year data on restenosis and clinical outcomes of these patients.

Methods and Results— Of 104 patients with chronic limb ischemia and superficial femoral artery obstructions, 98 (94%) could be followed up until 2 years after intervention for occurrence of restenosis (>50%) by duplex ultrasound and for clinical and hemodynamic outcome by treadmill walking distance and ankle brachial index. Restenosis rates at 2 years were 45.7% (21 of 46) versus 69.2% (36 of 52) in favor of primary stenting compared with balloon angioplasty with optional secondary stenting by an intention-to-treat analysis ( P =0.031). Consistently, stenting (whether primary or secondary; n=63) was superior to plain balloon angioplasty (n=35) with respect to the occurrence of restenosis (49.2% versus 74.3%; P =0.028) by a treatment-received analysis. Clinically, patients in the primary stent group showed a trend toward better treadmill walking capacity (average, 302 versus 196 m; P =0.12) and better ankle brachial index values (average, 0.88 versus 0.78; P =0.09) at 2 years, respectively. Reintervention rates tended to be lower after primary stenting (17 of 46 [37.0%] versus 28 of 52 [53.8%]; P =0.14).

Conclusions— At 2 years, primary stenting with self-expanding nitinol stents for the treatment of superficial femoral artery obstructions yields a sustained morphological benefit and a trend toward clinical benefit compared with balloon angioplasty with optional stenting.

Endovascular Repair of Acute Type B Aortic Dissection: Long-Term Follow-Up of True and False Lumen Diameter Changes

BACKGROUND

The aim of this study was to determine the technical success after endovascular treatment of acute type B aortic dissections and to evaluate true and false lumen diameter changes at long-term follow-up.

METHODS

Twenty-eight patients with acute type B-dissection who were treated by stent graft repair presented with rupture (n = 1), contained rupture (n = 2), compromised branch vessels (n = 14), pleural effusion (n = 11), rapid aortic diameter progression (n = 5), persistent pain (n = 3), refractory hypertension (n = 10), and an aortic diameter of more than 4 cm (n = 4). Taking into account the perfusion status of the false lumen, diameter changes were monitored in the thoracic aorta at the level of the stented segment (L1), distal to the stent graft (L2), and at the level of the celiac trunk (L3).

RESULTS

Severe complications in 9 patients (32%) resulted in 3 deaths for a 30-day mortality rate of 10.7%. Primary sealing of the entry tear was achieved in 86%. At all levels, the true lumen diameter increased significantly after stent graft placement. At the 1-year follow-up, the false lumen in L1 was thrombosed in 90% and the mean difference of diameter reduction was highly significant. In L2, complete false lumen thrombosis occurred in 60% with a significant diameter decrease. In L3, the false lumen thrombosed in only 22%, and the mean difference of false lumen diameter increase reached significance at the 2-year follow-up.

CONCLUSIONS

Ninety percent of patients were treated successfully with thrombosis of the false lumen in the stented segment. False lumen perfusion distal to the stent graft resulted in diameter increase in several patients leaving these segments an area of concern.

Successful treatment of an aortoesophageal fistula after emergency endovascular thoracic aortic stent-graft placement

We report the case of a 57-year-old man who underwent emergency stent-graft placement in August 2003 due to a contained rupture of a distal descending aortic aneurysm. After 1 month the patient was readmitted with chest pain as well as swallowing disorders. A computed tomographic scan revealed a fistula between the distal esophagus and the excluded aneurysm sac. The patient was treated by an esophagectomy, a cervical esophagostomy, as well as a feeding gastrostomy. The infectious parietal thrombus was partially debrided and the aneurysm sac was filled with vancomycin. After 3 months continuity was reinstalled with a pedicled isoperistaltic transverse colonic conduit. The patient recovered uneventfully. At a 3 month follow-up, he showed no signs of infection. However, he is still being treated with antibiotic therapy of ciprofloxacin for a minimum of 1 year.

Balloon angioplasty versus implantation of nitinol stents in the superficial femoral artery

BACKGROUND

Because stent implantation for disease of the superficial femoral artery has been associated with high rates of late clinical failure, percutaneous transluminal angioplasty is preferred for endovascular treatment, and stenting is recommended only in the event of suboptimal technical results. We evaluated whether primary implantation of a self-expanding nitinol (nickel-titanium) stent yielded anatomical and clinical benefits superior to those afforded by percutaneous transluminal angioplasty with optional secondary stenting.

METHODS

We randomly assigned 104 patients who had severe claudication or chronic limb ischemia due to stenosis or occlusion of the superficial femoral artery to undergo primary stent implantation (51 patients) or angioplasty (53 patients). Restenosis and clinical outcomes were assessed at 6 and 12 months.

RESULTS

The mean (+/-SD) length of the treated segment was 132+/-71 mm in the stent group and 127+/-55 mm in the angioplasty group. Secondary stenting was performed in 17 of 53 patients (32 percent) in the angioplasty group, in most cases because of a suboptimal result after angioplasty. At 6 months, the rate of restenosis on angiography was 24 percent in the stent group and 43 percent in the angioplasty group (P=0.05); at 12 months the rates on duplex ultrasonography were 37 percent and 63 percent, respectively (P=0.01). Patients in the stent group were able to walk significantly farther on a treadmill at 6 and 12 months than those in the angioplasty group.

CONCLUSIONS

In the intermediate term, treatment of superficial-femoral-artery disease by primary implantation of a self-expanding nitinol stent yielded results that were superior to those with the currently recommended approach of balloon angioplasty with optional secondary stenting. (ClinicalTrials.gov number, NCT00281060.).

Endovascular repair of the thoracic aorta necessitating anchoring of the stent graft across the arch vessels

OBJECTIVE

The purpose of the study was to determine technical and clinical results in endovascular repair of thoracic aortic diseases necessitating stent-graft anchoring across the arch vessels.

METHODS

The causes for endovascular treatment in 58 patients (aged 20 to 84 years) were aneurysms (n = 32), acute type A (n = 2) and type B dissections (n = 17), posttraumatic transections (n = 4), iatrogenic dissection (n = 1), and penetrating ulcers with an intramural hematoma (n = 2). Surgical revascularization of arch vessels was performed in 26 patients before stent-graft implantation. Intentional overstenting of the left subclavian artery resulted in complete occlusion in 8 and was partial in 24 patients.

RESULTS

The 30-day mortality rate was 3.4%. Overall, 19 major postprocedural complications occurred in 14 (24%) patients. Among patients with left subclavian artery occlusion, 2 patients had major (1 paraplegia, 1 critical arm ischemia), and 3 minor (2 temporary vertebrobasilary symptoms, 1 transient arm claudication) complications. Fourteen (25%) patients had an early endoleak, of whom 5 were treated successfully with a secondary endovascular procedure, 2 necessitated open surgical conversion, and 7 were treated conservatively, with spontaneous sealing of the endoleak in 3. In 53 (91%) in whom computed tomographic follow-up was longer than 3 months (mean, 30.1 months, range, 3 to 85), the aortic diameter along the stented segment decreased in 24, was stable in 19, and increased in 10 patients.

CONCLUSION

Fixation of the stent graft in the aortic arch can expand the applicability of endovascular repair. Intentional overstenting should be performed with caution to avoid ischemic problems after complete occlusion of left subclavian artery.

Progressive attenuation of myocardial vascular endothelial growth factor expression is a seminal event in diabetic cardiomyopathy: restoration of microvascular homeostasis and recovery of cardiac function in diabetic cardiomyopathy after replenishment of local vascular endothelial growth factor

BACKGROUND

Diabetic cardiomyopathy (DCM) is characterized by microvascular pathology and interstitial fibrosis, which leads to progressive heart failure; however, the pathogenesis of DCM remains uncertain.

METHODS AND RESULTS

Using the streptozotocin-induced diabetic rat model, we evaluated the natural course of DCM over a period of 1 year by serial echocardiography, Western blot analysis for vascular endothelial growth factor (VEGF), endothelial progenitor cell assays, myocardial blood flow measurements, and histopathologic analysis that included terminal dUTP nick end-labeling (TUNEL), capillary and cardiomyocyte density, and fibrosis area. Downregulation of myocardial VEGF expression preceded all other features of DCM and was followed by increased apoptosis of endothelial cells, decreased numbers of circulating endothelial progenitor cells, decreased capillary density, and impaired myocardial perfusion. Apoptosis and necrosis of cardiomyocytes ensued, along with fibrosis and progressive diastolic and then systolic dysfunction. To provide further evidence of the central role of VEGF in the pathophysiology of DCM, we replenished myocardial VEGF expression using naked DNA gene therapy via direct intramyocardial injection of plasmid DNA encoding VEGF (phVEGF165). VEGF-replenished rats showed increased capillary density, decreased endothelial cell and cardiomyocyte apoptosis, and in situ differentiation of bone marrow-derived endothelial progenitor cells into endothelial cells. These anatomic findings were accompanied by significant improvements in cardiac function.

CONCLUSIONS

These findings suggest that downregulation of VEGF may compromise microvascular homeostasis in the myocardium and thereby play a central role in the pathogenesis of DCM.

PTA Versus Carbofilm-Coated Stents in Infrapopliteal Arteries: Pilot Study

PURPOSE

To determine the primary success and short-term patency of stent application as a primary treatment modality for high-grade lesions of the infrapopliteal arteries compared with treatment with percutaneous transluminal angioplasty (PTA) in critical limb ischemia in a randomized prospective study.

METHODS

Endovascular therapy was performed on 95 lesions in 51 patients (mean age 72.0 years, range 47-80 years) who presented clinically with Fontaine stages III and IV. One patient underwent treatment in both limbs. After angiographic lesion identification, patients were randomized for treatment by PTA (53 lesions in 27 patients) or stent application (42 lesions in 24 patients). Follow-up by clinical investigation and conventional angiography or spiral CT angiography was performed in 37 patients (57 lesions) 6 to 12 months after the procedure, or when clinically indicated. Evaluation was performed by two observers, double-blinded, with thresholds for lesion restenosis of 50% and 70%. Statistical evaluation was performed on a lesion basis by Kaplan-Meier estimated probability rates, and log-rank and Wilcoxon tests. The primary endpoint was the angiographic patency rate of treated lesions.

RESULTS

The inter-reader agreement was high (kappa = 0.82). For the stent group the cumulative primary patency at 6 months was 83.7% at the 70% restenosis threshold, and 79.7% at the 50% restenosis threshold. For PTA, the primary patency at 6 months was 61.1% at the 70% restenosis threshold and 45.6% at the 50% restenosis threshold. Both results were statistically significant (p < 0.05).

CONCLUSION

Infrapopliteal stent application is an effective treatment modality for high-grade lesions in chronic critical limb ischemia. Compared with PTA, higher patency rates can be expected after 6 months.

Successful Type II Endoleak Closure by Subclavian-to-Carotid Artery Transposition After Stent-Graft Placement of a Distal Aortic Arch Aneurysm

Endovascular stent-graft placement has become a safe and effective treatment modality for various diseases of the distal aortic arch as well as of the descending aorta. However, its effectiveness may be limited by various kinds of endoleaks resulting in persistent or recurrent perfusion of the aneurysm sac. Subsequently, systemic pressurization leads to expansion of the aneurysm sac, exposing the patient to a recurrent risk of aneurysm rupture. We report on the case of a 57-year-old male who underwent emergency stent-graft placement in March 2001 due to a contained rupture of a distal aortic arch aneurysm involving the origin of the left subclavian artery. Due to the emergency condition, a subclavian-to-carotid artery transposition had not been performed prior to stent-graft placement. During follow-up the patient developed a type II endoleak originating from the left subclavian artery with consecutive enlargement of the aneurysm sac. The endoleak was successfully treated by subclavian-to-carotid artery transposition.

Cutting Balloon: Review on Principles and Background of Use in Peripheral Arteries

This review describes peripheral use of cutting balloon (CB) angioplasty (CBA), its characteristics, and its distinction from conventional BA and describes the experimental and clinical background of its current use in peripheral arteries.

Effects of TIPS on liver perfusion measured by dynamic CT

OBJECTIVE

Our aim was to measure the arterial, portal venous, and total perfusion of the liver parenchyma with dynamic, single-section CT in patients with liver cirrhosis before and after transjugular intrahepatic portosystemic shunt (TIPS) placement and to compare the results with normal values.

SUBJECTS AND METHODS

Perfusion of the liver parenchyma was measured in 24 healthy volunteers and 41 patients with liver cirrhosis using dynamic single-section CT. Seventeen patients underwent TIPS placement, and CT measurements were repeated within 7 days. CT scans were obtained at a single level comprising the liver, spleen, aorta, and portal vein. Scans were obtained over a period of 88 sec (one baseline scan followed by 16 scans every 2 sec and eight scans every 7 sec) beginning with the injection of a contrast agent bolus (40 mL at 10 mL/sec). Parenchymal and vascular contrast enhancement was measured with regions of interest, and time-density curves were obtained. These data were processed with a pharmaco-dynamic fitting program (TopFit), and the arterial and portal venous component and the total perfusion of the hepatic parenchyma were calculated (milliliters of perfusion per minute per 100 mL of tissue).

RESULTS

Mean normal values for hepatic arterial, portal venous, and total perfusion were 20, 102, and 122 mL/min per 100 mL, respectively. In patients with cirrhosis before TIPS, mean hepatic arterial, portal venous, and total perfusion was 28, 63, and 91 mL/min per 100 mL, respectively, which was statistically significant for all values (p <0.05). After TIPS, hepatic perfusion increased to a mean value of 48, 65, 113 mL/min per 100 mL for arterial (p <0.01), portal venous, and total (p=0.011) perfusion, respectively.

CONCLUSION

In patients with cirrhosis, the hepatic arterial perfusion increased, whereas portal venous and total perfusion decreased compared with that of healthy volunteers. TIPS placement caused a statistically significant increase of the hepatic arterial and total hepatic perfusion. The portal venous parenchymal perfusion remained unchanged.

Initial Results After Combined Repair of Aortic Arch Aneurysms by Sequential Transposition of the Supra-Aortic Branches and Consecutive Endovascular Stent-Graft Placement

BACKGROUND

To evaluate safety and efficacy of a combined repair of aortic arch aneurysms by sequential transposition of the supra-aortic branches and endovascular stent-graft placement.

METHODS

Between October 2002 and September 2003, 5 patients (mean age, 79.5 years) presented with aortic arch aneurysms involving the origin of the left carotid artery. Treatment was made by sequential transposition of the left carotid artery into the brachiocephalic trunk and transposition of the left subclavian artery into the already transposed left common carotid artery with consecutive endovascular stent-graft placement into the aortic arch.

RESULTS

All patients survived both procedures. At completion angiography, a small type 1a endoleak was observed in 1 patient. After 1 week, the patient was readmitted for completion three-dimensional computed tomographic scan. The leak had already occluded spontaneously. Mean follow-up was 10 months (range, 4 to 16 months). At follow-up, all patients had normal computed tomographic scans with regular perfusion of the supra-aortic branches without any signs of endoleaks.

CONCLUSIONS

Combined repair of aortic arch aneurysms by sequential transposition of the supra-aortic branches with consecutive endovascular stent-graft placement is feasible. Extended application of this technique will enable safe and effective treatment of a highly selected subgroup of patients with aortic aneurysms by avoiding conventional arch aneurysm repair in deep hypothermia and circulatory arrest.

Transjugular intrahepatic portosystemic shunt in Vienna – A decade later

Implantation of a transjugular intrahepatic portosystemic shunt (TIPS) for therapy of portal hypertension has been available in Vienna, Austria, since 1991. Ten years of experience with this technique led the Vienna TIPS Study Group to retrospectively analyse characteristics and outcome of all patients undergoing TIPS in Vienna between 1991 and 2001. Survival and subgroup analyses were performed using Mann Whitney U-tests, log-rank tests, Spearman's correlation and Kaplan-Meier analyses. A total of 523 patients underwent TIPS; 23 for acute variceal bleeding, 350 for prevention of variceal bleeding, and 109 for therapy of refractory ascites. Portal hypertension was caused by cirrhosis in 503 patients; 20 presented with other diseases. 253 patients died within the study period, median follow-up was 5.07 years, median survival 4.51 years. The 3-month, 1-year, 3-year, and 5-year survival rates were 83%, 71%, 57%, and 49%, respectively. Etiology of cirrhosis had no effect on survival; patients with TIPS for refractory ascites had poorer survival rates than those undergoing TIPS for prevention of rebleeding. TIPS is a safe and effective therapy for patients with portal hypertension. The first decade of TIPS in Vienna has shown, in line with other publications, that good criteria for patient selection, effective post-interventional management, and close cooperation between internists, interventional radiologists and liver-transplant centers are the key for a good outcome.

Successful revascularization of acute carotid stent thrombosis by facilitated thrombolysis

A 64-year-old woman undergoing protected carotid artery stent placement developed acute stent thrombosis despite pretreatment with combined antiplatelet therapy. A reduced dose of recombinant tissue plasminogen activator and a half-dose bolus of abciximab were administered intra-arterially via superselective catherization followed by systemic intravenous infusion of abciximab for 12 hours. Control angiography showed complete restoration of blood flow paralleled by neurologic improvement.

PTA versus Stent bei Stenosen der A. femoralis und A. poplitea: Ergebnisse einer prospektiv randomisierten Multizenterstudie (REFSA)

PURPOSE

To evaluate whether stent placement is superior to percutaneous transluminal angioplasty (PTA) in the treatment of chronic symptoms in short femoropopliteal arterial stenoses.

MATERIALS AND METHODS

One hundred twenty-four limbs in 116 patients, who ranged in age from 39 to 87 years (mean age, 67 years), were randomized to PTA (n = 53) versus PTA followed by implantation of long-medium Palmaz-Stents (n = 71). Inclusion criteria were intermittent claudication or chronic critical limb ischemia, short stenosis or occlusion (lesion length < or = 5 cm), and at least one patent run-off vessel at angiography. The follow-up included clinical assessment, measurement of ankle/brachial index (ABI), color duplex ultrasound, and/or angiography at 6, 12 and 24 months. Angiographic follow-up between 12 and 36 months was available in 54 limbs (45 %).

RESULTS

Initial technical success was achieved in 50 of 53 limbs (94.4 %) in the PTA group versus 70 of 71 limbs (98.6 %) in the stent group. Overall, major complications occurred in 9.5 % (n = 11), with n = 4 in the PTA group compared to n = 7 in the stent group. No difference was found between the groups of treatment: clinical success at 1 and 2 years was 80.5 and 77.1 % in the PTA group versus 78.1 and 71.0 % in the stent group. The cumulative 1-year and 2-year angiographic primary patency rates were 66.1 and 49.1 % in the stent group versus 76.1 and 66.1 % in the PTA group. The secondary 1-year and 2-year angiographic patency rates were 88.5 and 53.3 % in the stent group versus 82.7 % and 76.2 % in the PTA group.

CONCLUSION

The primary success rate was slightly higher after stent placement than after PTA. However, the angiographic, clinical and hemodynamic success after 1 and 2 years tends to be slightly better for PTA.

MRA versus DSA in the assessment of occlusive disease in the aortic arch vessels: accuracy in detecting the severity, number, and length of stenoses

PURPOSE

To compare the diagnostic accuracy of contrast-enhanced magnetic resonance angiography (MRA) to that of digital subtraction angiography (DSA) in the detection, grading, and measurement of atherosclerotic stenoses involving the aortic arch arteries.

METHODS

The MRA and DSA studies from 28 patients (16 women; mean age 61.6 years, range 24-83) being evaluated for possible aortic arch vessel disease were examined. The aortic arch vasculature was divided into 9 segments; within each segment, the presence and severity of stenotic or occlusive disease was determined based on a 5-point scale. In addition, stenosis length and distance to the branch were measured in 5-mm increments. Image quality was assessed using a 5-point scale. The accuracy, sensitivity, and specificity values, as well as the positive and negative predictive values in MRA's identification of lesions, were evaluated in comparison to DSA.

RESULTS

In 28 patients, 189 segments were assessed by both methods. Of these, 173 were correctly rated by MRA, resulting in an accuracy of 91.5%. The accuracy dropped slightly to 86.5% when 11 "not assessable" lesions were included. Sensitivity and specificity for severity measurement were 88.5% and 95.6%, respectively. In 39 of 45 lesions, stenosis length measurements were identical by both methods, but there was a difference of 0.5 cm each in 6 lesions.

CONCLUSIONS

MRA as compared to DSA shows high accuracy in the detection and grading of lesions involving the aortic arch vessels. The noninvasive nature of this method recommends its use for screening, treatment planning, and follow-up in known or suspected arterial disease in aortic arch arteries.

Local Gene Transfer of phVEGF-2 Plasmid by Gene-Eluting Stents

Background— Drug-eluting stents represent a useful strategy for the prevention of restenosis using various antiproliferative drugs. These strategies share the liability of impairing endothelial recovery, thereby altering the natural biology of the vessel wall and increasing the associated risk of stent thrombosis. Accordingly, we tested the hypothesis that local delivery via gene-eluting stent of naked plasmid DNA encoding for human vascular endothelial growth factor (VEGF)-2 could achieve similar reductions in neointima formation while accelerating, rather than inhibiting, reendothelialization.

Methods and Results— phVEGF 2-plasmid (100 or 200 μg per stent)–coated BiodivYsio phosphorylcholine polymer stents versus uncoated stents were deployed in a randomized, blinded fashion in iliac arteries of 40 normocholesterolemic and 16 hypercholesterolemic rabbits. Reendothelialization was nearly complete in the VEGF stent group after 10 days and was significantly greater than in control stents (98.7±1% versus 79.0±6%, P <0.01). At 3 months, intravascular ultrasound analysis revealed that lumen cross-sectional area (4.2±0.4 versus 2.27±0.3 mm 2 , P <0.001) was significantly greater and percent cross-sectional narrowing was significantly lower (23.4±6 versus 51.2±10, P <0.001) in VEGF stents compared with control stents implanted in hypercholesterolemic rabbits. Transgene expression was detectable in the vessel wall along with improved functional recovery of stented segments, resulting in a 2.4-fold increase in NO production.

Conclusions— Acceleration of reendothelialization via VEGF-2 gene–eluting stents provides an alternative treatment strategy for the prevention of restenosis. VEGF-2 gene–eluting stents may be considered as a stand-alone or combination therapy.

Complicated acute aortic dissection type B caused by femoral cannulation for endoscopic coronary artery bypass surgery

PURPOSE

To report endovascular treatment of a patient with complicated acute aortic type B dissection caused by cannulation of the femoral artery for endoscopic coronary artery bypass (CAB) surgery.

CASE REPORT

A 63-year-old man underwent single-vessel CAB surgery facilitated by the Da Vinci surgical system. After the procedure, acute lower limb ischemia led to the discovery of a type B dissection from the left subclavian artery to the iliac arteries. The subclavian artery was also dissected, with only minimal flow in the left mammary artery. The visceral and renal vessels originated from the false lumen and were not perfused. Emergent stent-graft placement was undertaken to close the entry tear and re-establish perfusion of the lower extremity as well as visceral and renal organs. Additional stent-grafts were placed in the dissected left subclavian artery to perfuse the left internal mammary bypass and in the inferior mesenteric artery, which arose from the false lumen. Six months after operation, the patient is well.

CONCLUSIONS

Acute iatrogenic aortic dissection secondary to endoscopic CAB surgery can be treated emergently to restore distal perfusion to vital organs.

Inhibition of restenosis by tissue factor pathway inhibitor: in vivo and in vitro evidence for suppressed monocyte chemoattraction and reduced gelatinolytic activity

Activation of inflammatory and procoagulant mechanisms is thought to contribute significantly to the initiation of restenosis, a common complication after balloon angioplasty of obstructed arteries. During this process, expression of tissue factor (TF) represents one of the major physiologic triggers of coagulation that results in thrombus formation and the generation of additional signals leading to vascular smooth muscle cell (VSMC) proliferation and migration. In this study, we have investigated the mechanisms by which inhibition of coagulation at an early stage through overexpression of tissue factor pathway inhibitor (TFPI), an endogenous inhibitor of TF, might reduce restenosis. In a rabbit femoral artery model, percutaneous delivery of TFPI using a recombinant adenoviral vector resulted in a significant reduction of the intimamedia ratio 21 days after injury. Investigating several markers of inflammation and coagulation, we found reduced neointimal expression of monocyte chemoattractant protein-1 (MCP-1), lesional monocyte infiltration, and expression of vascular TF, matrix metalloproteinase-2 (MMP-2), and MMP-9. Moreover, overexpression of TFPI suppressed the autocrine release of platelet-derived growth factor BB (PDGF-BB), MCP-1, and MMP-2 in response to factors VIIa and Xa from VSMCs in vitro and inhibited monocyte TF activity. These results suggest that TFPI exerts its action in vivo through not only thrombotic, but also nonthrombotic mechanisms.