Safety of urgent endarterectomy in acute non-disabling stroke patients with symptomatic carotid artery stenosis: an international multicenter study.

BACKGROUND AND PURPOSE: International recommendations advocate that carotid endarterectomy (CEA) should be performed within 2 weeks from the index event in symptomatic carotid artery stenosis (sCAS) patients. However, there are controversial data regarding the safety of CEA performed during the first 2 days of ictus. The aim of this international, multicenter study was to prospectively evaluate the safety of urgent (0-2 days) in comparison to early (3-14 days) CEA in patients with sCAS. METHODS: Consecutive patients with non-disabling (modified Rankin Scale scores ≤2) acute ischaemic stroke or transient ischaemic attack due to sCAS (≥70%) underwent urgent or early CEA at five tertiary-care stroke centers during a 6-year period. The primary outcome events included stroke, myocardial infarction or death during the 30-day follow-up period. RESULTS: A total of 311 patients with sCAS underwent urgent (n = 63) or early (n = 248) CEA. The two groups did not differ in baseline characteristics with the exception of crescendo transient ischaemic attacks (21% in urgent vs. 7% in early CEA; P = 0.001). The 30-day rates of stroke did not differ (P = 0.333) between patients with urgent (7.9%; 95% confidence interval 3.1%-17.7%) and early (4.4%; 95% confidence interval 2.4%-7.9%) CEA. The mortality and myocardial infarction rates were similar between the two groups. The median length of hospitalization was shorter in urgent CEA [6 days (interquartile range 4-6) vs. 10 days (interquartile range 7-14); P < 0.001]. CONCLUSIONS: Our findings highlight that urgent CEA performed within 2 days from the index event is related to a non-significant increase in the risk of peri-procedural stroke. The safety of urgent CEA requires further evaluation in larger datasets.

The Necessity for Routine Pre-operative Ultrasound Mapping Before Arteriovenous Fistula Creation: A Meta-analysis.

OBJECTIVE/BACKGROUND: Existing guidelines suggest routine use of pre-operative color Doppler ultrasound (DUS) vessel mapping before the creation of arteriovenous fistulae (AVF); however, there is controversy about its benefit over traditional clinical examination or selective ultrasound use. METHODS: This was a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing routine DUS mapping before the creation of AVF with patients for whom the decision for AVF placement was based on clinical examination and selective ultrasound use. A search of MEDLINE/PubMed, SCOPUS, and the Cochrane Library was carried out in June 2014. The analyzed outcome measures were the immediate failure rate and the early/midterm adequacy of the fistula for hemodialysis. Additionally, assessment of the methodological quality of the included studies was carried out. RESULTS: Five studies (574 patients) were analyzed. A random effects model was used to pool the data. The pooled odds ratio (OR) for the immediate failure rate was 0.32 (95% confidence interval [CI] 0.17-0.60; p < .01), which was significantly in favor of the DUS mapping group. The pooled OR for the early/midterm adequacy for hemodialysis was 0.66 (95% CI 0.42-1.03; p = .06), with a trend in favor of the DUS mapping group; however, subgroup analysis revealed that routine DUS mapping was more beneficial than selective DUS (p < .05). CONCLUSION: The available evidence, based mainly on moderate quality RCTs, suggests that the pre-operative clinical examination should always be supplemented with routine DUS mapping before AVF creation. This policy avoids negative surgical explorations and significantly reduces the immediate AVF failure rate.

Safety of early endarterectomy in patients with symptomatic carotid artery stenosis: an international multicenter study.

BACKGROUND AND PURPOSE: Although the latest recommendations suggest that carotid endarterectomy (CEA) should be performed in symptomatic carotid artery stenosis (sCAS) patients within 2 weeks of the index event, only a minority of patients undergo surgery within the recommended time-frame. The aim of this international multicenter study was to prospectively evaluate the safety of early CEA in patients with sCAS in everyday clinical practice settings. METHODS: Consecutive patients with non-disabling acute ischaemic stroke (AIS) or transient ischaemic attack (TIA) due to sCAS (≥ 70%) underwent early (≤ 14 days) CEA at five tertiary-care stroke centers during a 2-year period. Primary outcome events included stroke, myocardial infarction (MI) or death occurring during the 30-day follow-up period and were defined according to the International Carotid Stenting Study criteria. RESULTS: A total of 165 patients with sCAS [mean age 69 ± 10 years; 69% men; 70% AIS; 6% crescendo TIA; 8% with contralateral internal carotid artery (ICA) occlusion] underwent early CEA (median elapsed time from symptom onset 8 days). Urgent CEA (≤ 2 days) was performed in 20 cases (12%). The primary outcomes of stroke and MI were 4.8% [95% confidence interval (CI) 1.5%-8.1%] and 0.6% (95% CI 0%-1.8%). The combined outcome event of non-fatal stroke, non-fatal MI or death was 5.5% (95% CI 2.0%-9.0%). Crescendo TIA, contralateral ICA occlusion and urgent CEA were not associated (P > 0.2) with a higher 30-day stroke rate. CONCLUSIONS: Our findings indicate that the risk of early CEA in consecutive unselected patients with non-disabling AIS or TIA due to sCAS is acceptable when the procedure is performed within 2 weeks (or even within 2 days) from symptom onset.

The hemodynamic impact of misalignment of fenestrated endografts: a computational study.

OBJECTIVE: The hemodynamic consequences of misaligned stent-grafts (SG) in fenestrated endografts (EG) have not been adequately studied. Our aim was to study the hemodynamic effects of positional variations of SG, investigating the potential influence on the total displacement forces acting on the EG and the shear stress values at the stented segments. METHODS: This was a computational study. An idealized EG model with two renal fenestrations was computationally reconstructed and centrally extended up to the suprarenal level to treat a suprarenal aneurysm. The misalignment of SG was represented by a variable take-off angle between the SG and the EG centerline axis, corresponding to angles of 90°, 176°, 142°, 38°, and 4°, respectively. Accordingly, the maximum EG displacement forces and the shear stress within the stented segments were calculated, using commercially available software. RESULTS: The variable positions of the SG caused no effect on the maximum displacement force acting on the EG, being quite steady and equal to 5.55 N. On the contrary, the values of maximum shear stress acting on the stented segments were influenced by their orientation. The narrow transition zone between the distal end of the mating stent and the target artery showed higher stresses than any other segment. The right-angle take off SG position (90°) was associated with the lowest stresses (12.5 Pa), whereas the highest values were detected at 38° and 142° (16.5 and 16.1 Pa, respectively). The vessel segments distal to the SG exhibited constantly lower stress values (1.9-2.2 Pa) than any other segment. CONCLUSION: We detected differences in the values of shear stress exerted on the stented arteries, depending on different positions that SG can adapt after the deployment of fenestrated EG. The pathophysiologic implication of our findings and their potential association with clinical events deserve further investigation and clinical validation.

Lower-extremity arteriovenous access for haemodialysis: a systematic review.

BACKGROUND: The lower extremity is increasingly used as an access site in end-stage renal disease patients. However, reports present conflicting results, creating confusion regarding the feasibility and outcomes. Our objective is to review the available literature and analyse the patency rates and complications of various types of lower-extremity arteriovenous access. METHODS: An Internet-based literature search was performed using MEDLINE to identify all published reports on lower-extremity vascular access. The analysis involved studies comprising at least 10 arteriovenous accesses with both inflow and outflow vessels in the lower extremity, and reporting on patency rates and access-related complications. The weighted mean patency rates were calculated, and the chi-square (chi(2)) test was used to evaluate the differences in the complication rates in the subgroups of patients identified. RESULTS: Three main types of lower-extremity vascular access were identified: the upper thigh prosthetic, the mid-thigh prosthetic and the femoral vein transposition arteriovenous access. There are limited data on saphenous vein loop grafts, which report poor results. The weighted mean primary patency rates at 12 months were 48%, 43% and 83%, respectively. The weighted mean secondary patency rates at 12 months were 69%, 67% and 93%, respectively. Access loss as a result of infection was more common in upper thigh and mid-thigh grafts than femoral vein transposition arteriovenous access (18.40%, 18.33% vs. 1.61%; P<0.05). Ischaemic complications rates were higher in autologous than prosthetic arteriovenous access (20.97% vs. 7.18%, P<0.05). CONCLUSIONS: Lower-extremity vascular access has acceptable results in terms of patency, with femoral vein transposition having better patency rates than femoral grafts. Autologous access is associated with less infective complications, however, at the expense of increased ischaemic complications rates. Further research with randomised trials is required to assess the outcomes of lower-extremity vascular access.

Letters to the editor: definitely not children of a lesser god.

Letters to the editor are brief texts that are published in a special section of medical journals. There are two types of letters to the editor: the observation and the comment. The former presents original work, while the latter constitutes criticism on work already published in the same journal. Although short, letters to the editor require as much effort and discipline in writing as, indeed, any other manuscript. Clarity and brevity should be their principal values. It is also important to comply with the journals' instructions for correspondence. Thus, eloquent letters to the editor may promote knowledge and enable fruitful exchange of ideas.

Arterial spasm mimicking superficial femoral artery trauma. Case report.

The existence of traumatic arterial spasm in large arteries is questionable in current literature. We report a case of a 19-year old man with comminuted unstable femur fracture who presented with an ischemic foot. Localized arterial spasm was revealed in the middle portion of the superficial femoral artery triggered by the external pressure of a spicular bone segment was revealed by arteriography. Complete resolution of ischemic symptoms followed fracture reduction. Traumatic arterial spasm although rare does exist.

Risk factors for ipsilateral reamputation in patients with diabetic foot lesions.

This study aimed to examine the rates and risk factors for ipsilateral re-amputation in 121 patients with diabetic foot and prior amputation. Twenty-six (21.5%) patients required re-amputation during a mean follow-up of 18 months. Most re-amputations were performed within the first 6 months of the initial amputation. Re-amputation was more common among patients in whom the initial amputation had only affected one or two toes. Age (hazard ratio: 1.06) and heel lesions (hazard ratio: 2.69) were significantly associated with re-amputation. There is a high risk of re-amputation in the diabetic foot, especially within the first 6 months of the initial amputation, mainly due to poor selection of the original amputation level in an effort to save a greater part of the lower extremity. Patients 70 years and those with heel lesions are at greatest risk of re-amputation.

Transposed brachial-basilic arteriovenous fistulas versus prosthetic upper limb grafts: a meta-analysis.

BACKGROUND: Controversy exists regarding the best type of arteriovenous (AV) fistula to be formed in secondary and tertiary access procedures when primary fistulas have failed. This meta-analysis aimed to compare transposed brachial-basilic AV fistulas (BBAVFs) with upper limb AV prosthetic grafts. METHODS: A literature search of the MEDLINE and SCOPUS databases was performed to identify comparative studies reporting outcomes for both BBAVFs with upper limb AV prosthetic grafts. Meta-analysis techniques were applied to identify differences in outcomes between the two groups regarding primary and secondary 1-year failure rates. RESULTS: Eleven relevant studies, involving 1509 patients, met the inclusion criteria and were incorporated in the final analysis; however, only one was randomised controlled trial. The pooled odds' ratio (OR) estimate for the primary and secondary failure rates at 1 year was 0.67 (CI 0.41-1.09) and 0.88 (CI 0.69-1.12), respectively, showing no difference in the outcome between the two groups. The re-intervention rate was higher for prosthetic grafts (0.54 per BBAVF versus 1.32 per graft). In a small subgroup of two studies comparing BBAVFs with forearm grafts the pooled estimate for 1-year primary failure rate was in favour of the BBAVF group (OR 0.3, CI 0.15-0.58, p=0.0004) suggesting that forearm grafts were inferior having a 3-fold risk of failure at 1 year. CONCLUSION: This analysis supports the use of BBAVF early in difficult access cases prior to the use of prosthetic grafts. However, the latter conclusion is debatable due to heterogeneity, small size and non-randomised design of the included studies.

Novel Oral Anticoagulants in Peripheral Artery Disease: Current Evidence.

BACKGROUND: Peripheral artery disease is a common manifestation of systemic atherosclerosis which strongly correlates to cardiovascular morbidity and mortality. In addition, the progression of peripheral artery disease leads to an increased risk of limb loss. In order to reduce these events, the benchmark of treatment and research over the last years has been the antiplatelet therapy which aims at inhibition of platelet aggregation. Over the last years, new studies combining antiplatelet agents in different therapeutic schemes have been proven efficacious. Unfortunately, patients remain still at high risk of CV events. Novel Oral Anticoagulants have been introduced as alternatives to warfarin, in the prevention and treatment of venous thromboembolism. The rationale of using medication which acts on platelet activation and the coagulation pathway of thrombosis has led investigators to examine the role of Noac's in preventing CV events in patients with peripheral artery disease, stable or unstable. METHODS: The aim of this study is to review the current evidence with respect to recently published studies concerning the use of Novel anticoagulants in peripheral artery disease. RESULTS: The Compass trial has shown that a combination of rivaroxaban with traditional therapy may produce promising results in reducing amputation rates, stroke, cardiac events, and mortality, however, there are still safety issues with bleeding requiring acute care. The ePAD study has provided us with insight concerning safety and efficacy after peripheral angioplasty or stenting and actually the need for further research. The Voyager Pad study, following the steps of Compass, is studying the effect and safety of the addition of rivaroxaban to traditional therapy in the highest risk population aka patients undergoing peripheral revascularization. The evidence concerning patients with concomitant atrial fibrillation appears to be insufficient, however, recent guidelines propose the use of novel oral anticoagulants. CONCLUSION: For the time being, novel oral anticoagulants in combination with aspirin may provide an alternative treatment in PAD, however, it is deemed necessary to identify patient subgroups who will benefit the most.

Changes in blood flow of anterior and middle cerebral arteries following carotid endarterectomy: a transcranial Doppler study.

AIM: The aim of the present study was to evaluate the changes in blood flow of anterior and middle cerebral arteries following carotid endarterectomy, using transcranial Doppler (TCD) flow studies. PATIENTS AND METHODS: This study included 100 patients (72 men, mean age 65 years) who underwent carotid endarterectomy because of high-grade carotid stenosis or symptoms of ischemic stroke. Endarterectomy was performed by a distal shunt between the common carotid and internal carotid arteries. Blood flow in the anterior and middle cerebral arteries was assessed by TCD preoperatively and also in the postoperative period (1st and 4th day; 1st, 6th, and 12th month). Collateral circulation in the Willis circle was evaluated by common carotid compression. RESULTS: Patients with bilateral carotid stenosis > or =70% exhibited a significantly increased flow velocity in the ipsilateral anterior cerebral artery (ACA), middle cerebral artery (MCA), and in the contralateral ACA. Patients with entirely occluded contralateral internal carotid artery showed the most pronounced changes in cerebral hemodynamics. Blood flow velocities returned to the preoperative values at 1 to 12 months following endarterectomy. Hyperperfusion syndrome was manifested in 14 patients, who exhibited significantly higher flow velocities in the ipsilateral MCA compared with asymptomatic patients. CONCLUSIONS: A transient bilateral increase of blood flow velocity in the anterior part of the Willis circle may often occur in the immediate postoperative period following carotid endarterectomy. Although its clinical significance is not entirely understood, this increase may be associated with cerebral hyperperfusion syndrome.

Ankle-brachial index: a surrogate marker of microvascular complications in type 2 diabetes mellitus?

AIM: The aim of this study was to investigate the potential role of ankle-brachial index (ABI) as a marker of microvascular disease in patients with type 2 diabetes mellitus. METHODS: This study included 126 type 2 diabetic patients (64 male and 62 female) with an age of 66.6+/-5.3 years (mean+/-SD) and diabetes duration of 13.2+/-4.1 years. ABI was measured with a Doppler device. The exclusion criterion was the medial arterial calcification. Patients were also examined for microalbuminuria, retinopathy and peripheral neuropathy. RESULTS: ABI was significantly lower in patients with microalbuminuria than in those without microalbuminuria (0.91+/-0.17 vs 1.05+/-0.13, P=0.004), in patients with retinopathy than in those without retinopathy (0.91+/-0.18 vs 1.06+/-0.1, P=0.005), as well as in patients with neuropathy than in those without neuropathy (0.94+/-0.17 vs 1.06+/-0.11, P=0.001). Sensitivity and specificity of ABI <0.9 were 48.8% and 87.9% respectively for microalbuminuria, 39.1% and 93% respectively for retinopathy and 47% and 90.7% respectively for neuropathy. In multiple regression analysis, significant predictor of microalbuminuria was diabetes duration (P=0.0014), significant predictor of retinopathy was diabetes duration (P=0.001), while significant predictors of neuropathy were diabetes duration (P=0.001), male sex (P=0.001) and presence of retinopathy (P=0.047). CONCLUSION: ABI is significantly lower in patients with than in those without microvascular complications of type 2 diabetes. An ABI <0.9 has a low to modest sensitivity, but a high specificity for the diagnosis of these complications. Our results suggest a potential role for ABI as a surrogate marker of microvascular complications in type 2 diabetic patients.

Diagnostic criteria and treatment of Buerger's disease: a review.

Buerger's disease is an inflammatory occlusive disorder affecting the small and medium-size arteries and veins of young, predominantly male, smokers. The disorder has been identified as an autoimmune response triggered when nicotine is present. Tobacco abuse is the major contributing risk factor; however, smoking seems to be a synergistic factor rather than the cause of the disease. The traditional diagnosis of Buerger's disease is based on 5 criteria (smoking history, onset before the age of 50 years, infrapopliteal arterial occlusive disease, either upper limb involvement or phlebitis migrans, and absence of atherosclerotic risk factors other than smoking). As there is no specific diagnostic test and an absence of positive serologic markers, confident clinical diagnosis should be made only when all these 5 criteria have been fulfilled although not universally accepted. The angiographic findings in Buerger's disease ("corkscrew," "spider legs," or "tree roots") are helpful but not pathognomonic. A wide spectrum of medical or surgical therapeutic options have been proposed; however, total abstinence from tobacco use remains the only means of stopping the disease progression. The initial management of patients with Buerger's disease should be conservative. Because several arteries may be unaffected, claudicants should be encouraged to walk, whereas patients with "critical" ischemia should be admitted for bed rest in the hospital. Bypass grafting is seldom an option, as the location of the lesions distally leaves little to bypass because of lack of target vessels. A literature review revealed only a few series reporting vascular reconstruction (mainly femorodistal bypasses) in Buerger's disease. Bypass patency rates were suboptimal; however, the corresponding limb salvage rates were satisfactory. A possible explanation is that patent grafts, even over a short period of time, are sufficient to allow healing of ulcers in patients with Buerger's disease.

Lack of evidence for use of heparin-bonded grafts in access surgery: a meta-analysis.

The aim of this study was to evaluate the efficacy of heparin-bonded vascular grafts to offer improved outcomes compared with standard prosthetic grafts in access surgery. A systematic review and meta-analysis was performed and eight studies (seven observational studies and one randomized controlled trial) were included. The pooled 6-month and 1-year primary patency was not significantly different between heparin-bonded arteriovenous (AV) grafts and standard prosthetic AV grafts in seven studies reporting on 1,209 access procedures. The assisted primary patency and secondary patency at 1-year was not significantly different either. Heparin-bonded AV grafts offer no distinct advantage over standard prosthetic AV grafts and their preferential use in access surgery cannot be recommended based on the available evidence.

The significance of medial sural artery integrity in popliteal artery trauma: a case report.

Two patients with popliteal artery trauma who underwent secondary amputations due to refractory calf sepsis despite a patent arterial repair are presented in this case report. The medial sural artery, the main arterial supply of the medial head of the gastrocnemius, was surgically severed in both patients owing to the use of a continuous medial incision from the supra level to infragenicular level. The compromised arterial supply of the medial head of the gastrocnemius muscle may have contributed to the devitalization of the muscle and the subsequent calf sepsis, and it is speculated that this was related to the unfavorable outcome.

Femoral-anterior tibial reconstructions using cuffed PTFE grafts: routing alternatives.

BACKGROUND: The anterior tibial is the less often used artery for distal anastomosis in infrapopliteal bypass with synthetic grafts; however, several investigators argue against even an attempt to use non-autologous material for such distal reconstructions. Only few studies report patency rates mixing-up popliteal below-knee and various crural bypasses. PATIENTS AND METHODS: Nineteen consecutive femoral-anterior tibial cuffed PTFE bypass grafts, either via the lateral (n = 15) or interosseous (n = 4) route, were inserted in a 10-years period. RESULTS: The 1-year and 2-year primary patency rate was 71% and 53%, respectively. It is noteworthy that in one patient a graft positioned via the lateral route remained patient for ten years. No complications were observed regarding the routing methods, whatever increased operating time was required in the interosseous route cases. The 3-year cumulative survival rate for this particular group of patients was 32%. CONCLUSIONS: Our data indicate that femoral-anterior tibial bypasses using cuffed PTFE grafts via the lateral route result in an acceptable medium-term patency. As such patients have a limited life expectancy, these procedures should be performed when an autologous vein is not available, as opposed to primary amputation.

Computational estimation of the influence of the main body-to-iliac limb length ratio on the displacement forces acting on an aortic endograft. Theoretical application to Bolton Treovance® Abdominal Stent-Graft.

AIM: The influence of the relative iliac limb length of an endograft (EG) on the displacements forces (DF) predisposing to adverse effects are under-appreciated in the literature. Therefore, we conducted a computational study to estimate the magnitude of the DF acting over an entire reconstructed EG and its counterparts for a range of main body-to-iliac limb length (L1/L2) ratios. METHODS: A customary bifurcated 3D model was computationally created and meshed using the commercially available ANSYS ICEM (Ansys Inc., Canonsburg, PA, USA) software. Accordingly, Fluid Structure Interaction was used to estimate the DF. The total length of the EG was kept constant, while the L1/L2 ratio ranged from 0.3 to 1.5. RESULTS: The increase in L1/L2 slightly affected the DF on the EG (ranging from 3.8 to 4.1 N) and its bifurcation (4.0 to 4.6 N). However, the forces exerted at the iliac sites were strongly affected by the L1/L2 values (ranging from 0.9 to 2.2 N), showing a parabolic pattern with a minimum for 0.6 ratio. CONCLUSION: It is suggested that the hemodynamic effect of the relative limb lengths should not be considered negligible. A high main body-to-iliac limb length ratio seems to favor hemodynamically a low bifurcation but it attenuates the main body-iliac limbs modular stability. Further clinical studies should investigate the relevant value of these findings. The Bolton Treovance(®) device is presented as a representative, improved stent-graft design that takes into account these hemodynamic parameters in order to achieve a promising, improved clinical performance.

Antiplatelet treatment and prothrombotic diathesis following endovascular abdominal aortic aneurysm repair.

Prothrombotic diathesis expressed by elevated levels of coagulation-specific biomarkers has been reported in patients with abdominal aortic aneurysm (AAA) and after AAA endovascular repair (EVAR). This study investigates the effect of antiplatelet agents (APLs) on the prothrombotic diathesis in the post-EVAR period. Forty elective EVAR patients had thrombin-antithrombin complex, d-dimer, fibrinopeptide A, and high-sensitivity C-reactive protein measured before, at 24 hours, 1 month, and 6 months after EVAR. Patients receiving APLs postoperatively were compared with those not receiving APLs. All biomarkers were above the normal limits preoperatively and increased significantly 24 hours postoperatively followed by a drop at 1 and 6 months. No statistically significant changes were noted among patients receiving APLs in comparison with those not receiving APLs. The preoperative and postoperative prothrombotic diathesis of AAA following EVAR was confirmed in line with other reports. There was however no significant alteration of the examined biomarkers in patients receiving APLs.