Christos Argyriou

Association between periodontal disease and stroke

OBJECTIVE Periodontitis is a very common human infection. There is evidence that periodontitis is associated with cerebrovascular disease (CVD) and stroke. The aim of this study is to examine the relationship between periodontal disease and CVD in observational studies. METHODS An electronic search of the English literature using PubMed was conducted. A meta-analysis of the studies reporting on the risk of stroke in patients with periodontitis was performed. RESULTS Six prospective and seven retrospective studies met the inclusion criteria. Patients with both hemorrhagic and ischemic cerebrovascular events, fatal and nonfatal, were included. Definition of periodontitis was taken directly from included studies. Most studies have been adjusted for common cardiovascular risk factors. Separate statistical analysis was performed for prospective and retrospective studies. Overall adjusted risk of stroke in subjects with periodontitis was 1.47 times higher than in subjects without (95% confidence interval, 1.13-1.92;P = .0035) in prospective and 2.63 times (95% confidence interval, 1.59-4.33;P = .0002) in retrospective studies. The application of the trim and fill algorithm does not change the initial significant inference. CONCLUSIONS There is evidence that periodontitis is associated with increased risk of stroke. However, the results of this meta-analysis should be interpreted with caution because of the heterogeneity of the studies as well as the differences in periodontitis definition.

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.

Geometrical Factors Influencing the Hemodynamic Behavior of the AAA Stent Grafts: Essentials for the Clinician

Endovascular aneurysm repair (EVAR) is considered to be the treatment of choice for abdominal aortic aneurysms (AAA). Despite the initial technical success, EVAR is amenable to early and late complications, among which the migration of the endograft (EG) with subsequent proximal endoleak (Type Ia) leads to repressurization of the AAA sac, exposure to excessive wall stress, and, hence, to potential rupture. This article discusses the influence that certain geometrical factors, such as neck angulation, iliac bifurcation, EG curvature, neck-to-iliac diameter, and length ratios, as well as iliac limbs configuration can exert on the hemodynamic behavior of the EGs. The information provided could help both clinicians and EG manufacturers towards further development and improvement of EG designs and better operational planning.

Clinical Outcomes After Crossed-Limb vs. Conventional Endograft Configuration in Endovascular AAA Repair

Purpose: To report a case controlled analysis of endovascular aneurysm repair (EVAR) outcomes using the crossed-limb (CxL) endovascular configuration vs. the straight-limb configuration (SLC). Methods: From January 2007 to July 2012, 27 patients (25 men; mean age 73.7±7.2 years, range 53–82) were treated by EVAR with the CxL technique. These patients were matched anatomically with 27 patients (27 men; mean age 72.4±7.4 years, range 52–86) who underwent EVAR using the same endograft and the standard SLC within a ±6-month period. Primary outcome measures included technical and clinical success and freedom from graft limb thrombosis, any type of endoleak, early or late secondary interventions, and aneurysm-related death estimated using the Kaplan-Meier method. Results: The median follow-up periods for the CxL and SLC groups were 29.9 (range 6–54) and 33.5 (range 6–59) months, respectively (p=0.81). The technical success rate was 100% in both groups, but mean procedure times were significantly longer in the CxL group (116.3 vs. 90.7 minutes, p=0.035). Twelve intraoperative endoleaks (3 each for types Ia, Ib, II, and IV) occurred but without any difference between groups (p=0.51). One CxL group patient died in the early postoperative period (aneurysm-related) and another had an early graft limb thrombosis. One late type Ib intraoperative endoleak was recorded in the SLC group (p=0.51). For the CxL vs. SLC groups, the 1-year rates for freedom from endograft limb thrombosis (94% vs. 96%), any type of endoleak (96% vs. 96%), early or late reintervention (94% vs. 96%), and aneurysm-related death (94% vs. 96%) were not significantly different. Respective values at 36 months were 82% vs. 82%, 85% vs. 84%, 81% vs. 78%, and 83% vs. 84% (p>0.05). Clinical success rates at 12 months for the CxL and SLC groups were 91% and 100% (p>0.05), respectively, whereas at 36 months, the rates were 83% and 90% (p>0.05). Conclusion: No difference was found between the crossed-limb technique and the conventional endograft position as regards short- or midterm clinical outcomes.

Endograft Infection After Endovascular Abdominal Aortic Aneurysm Repair: A Systematic Review and Meta-analysis.

Purpose: To report a meta-analysis of the published evidence on the outcomes of aortic endograft infection after endovascular aneurysm repair (EVAR). Methods: A search of electronic information sources (PubMed/MEDLINE, SCOPUS, CENTRAL) and bibliographic reference lists identified 12 studies reporting on 362 patients (mean age 72 years; 279 men). The methodological quality of the selected studies was assessed using the Newcastle-Ottawa scale. Endpoints were 30-day/in-hospital mortality and follow-up mortality. Pooled estimates are reported with the 95% confidence interval (CI). The review was registered at the International Prospective Register of Systematic Reviews in Health and Social Care (CRD42016034166). Results: The incidence of graft infection after EVAR was 0.6% (95% CI 0.4% to 0.8%). The time from implantation to diagnosis ranged from 1 to 128 months (mean 25). The majority of patients (293, 81%) underwent surgical treatment (95% CI 77% to 83%); 9 (2.5%) patients (95% CI 21% to 43%) received conservative treatment. Aortic replacement with a prosthetic graft was performed in 58% (95% CI 52% to 62%), whereas cryopreserved allografts and autologous grafts were used in 31% (95% CI 28% to 33%) and 11% (95% CI% 8 to 14%), respectively. Less than half of the patients (40%) had emergency surgery. The pooled estimate of 30-day/in-hospital mortality was 26.6% (95% CI 16.9% to 39.2%). The pooled 30-day/in-hospital mortality for 9 patients treated conservatively was 63.3% (95% CI 30.7% to 87.0%). The pooled overall follow-up mortality was 45.7% (95% CI 36.4% to 55.4%) vs 58.6% (95% CI 28.8% to 83.3%) for the 9 patients receiving conservative treatment. Conclusion: Aortic endograft infection is a rare complication after EVAR. Surgical treatment with complete explantation of the infected endograft seems to be the optimal management in selected patients. Supportive medical treatment without surgical intervention has a significant associated mortality.

Aneurysm formation and infection in AV prosthesis

In contrast to autogenous arteriovenous (AV) fistulae where true aneurysms are the most frequent type, aneurysms in prosthetic AV grafts are mostly false aneurysms and less frequently anastomotic ones. Indications for repair comprise false aneurysms exceeding twofold the graft diameter, those with rapid enlargement or with skin thinning or erosion, the ruptured, those causing pain or severely limiting the cannulable area and the infected ones. They can be managed either with conventional surgery or with endovascular techniques; However, conventional surgery represents the current standard treatment consisting of either aneurysm resection and interposition graft in situ or resection/exclusion and bypass via a new route to avoid a potentially contaminated area.

Hybrid Revascularization Procedures in Acute Limb Ischemia

BACKGROUND Although the clinical efficacy of hybrid procedures in patients with chronic limb ischemia has been well reported in the literature, sufficient evidence is lacking in the acute setting. Our aim was to evaluate the immediate and midterm clinical results on 28 patients with acute lower limb ischemia treated with hybrid reconstructions on emergent basis, from January 2010 to March 2013 in our tertiary referral vascular center. METHODS A total of 28 patients (31 operated limbs) underwent emergent hybrid revascularization, with endovascular treatment performed proximally or distally to the site of open reconstruction. The median follow-up period was 6 months (range: 1-26). The immediate technical success was clinically and hemodynamically evaluated with an ankle brachial pressure index (ABPI) measurement. Six-month overall patency, limb salvage, and survival rate were also estimated. All analyses were performed with Kaplan-Meier life table method, using the STATISTICA 7.0 statistical program. RESULTS Twenty-seven patients presented with grade IIb and 1 with grade III ischemia, respectively. Technical success was achieved in all patients, whereas hemodynamic improvement rate was achieved in 98%. ABPI preoperatively was increased from 0.14 ± 0.1 to 0.69 ± 0.28 postoperatively (P < 0.05). Perioperative morbidity and mortality rates were 21% and 11% respectively. Six-month overall patency, limb salvage, and survival rate were 86%, 92%, and 79%, respectively. CONCLUSIONS Hybrid revascularization in immediately threatened limbs provides an effective and durable option with acceptable mortality and amputation rate in these high-risk patients. These findings should be further confirmed by larger scale clinical studies.

Upper limb vascular calcification score as a predictor of mortality in diabetic hemodialysis patients

OBJECTIVE This study evaluated the correlation between an upper limb vascular calcification (Vc) score (VcS) and late all-cause mortality in diabetic hemodialysis patients with distal upper limb arteries medial wall sclerosis (Mönckeberg disease). METHODS We retrospectively reviewed Vc in bilateral upper limb plain radiographs and in duplex ultrasound images performed before radial-cephalic fistula (RCF) creation in diabetic hemodialysis patients. Only medial linear calcifications outlining the vessel wall were considered positive on X-ray images, whereas for ultrasound reviews, only continuous highly echogenic plaques producing bright white echos with shadowing were considered to be medial calcification. A VcS was then applied in each patient. Every half of each of the three main arterial conduits (brachial, radial, and ulnar arteries) in each arm was counted as 1 if it contained ≥ 6 cm of linear calcification, whereas absence of calcification or minimum calcification (length <6 cm) was counted as 0. Long-term all-cause mortality was compared between patients with a low or moderate VcS <8 (group I), patients with a high VcS ≥ 8 (group II), and patients with VcS = 0 (control group). Kaplan-Meier statistics were used for comparisons among the groups. RESULTS Nineteen patients had a VcS <8, 21 had VcS ≥ 8, and 43 patients had VcS = 0. The study patients had a mean age of 68 ± 10 years (range, 42-83 years; P = .23). Before early conversion to a RCF, dialysis therapy in 59 (71.1%) had already been initiated through central venous catheters (CVCs). The mean follow-up for groups I, II, and controls was 41.4 ± 41.2 months (range, 4-144 months), 34.15 ± 31.3 months (range, 1-108 months), and 66.7 ± 32.5 months (range, 12-126 months), respectively (P = .0009). Forty-seven patients died during the follow-up period (12 in group II and 24 in the controls; P = .88). Survival rates at 12, 24, 36, and 48 months were 78.3%, 65.7%, 54.8%, and 48.1% for group I; 75.2%, 58.8%, 49.3%, and 42% for group II; and 97.7%, 93.1%, 76.8%, and 71.8% for the control group, respectively (P = .013 for all groups; P = .044 for group II vs controls). Patients with (subgroups) or without CVCs at baseline had similar late mortality rates. Patients with CVCs/Vc had lower survival rates than those with CVCs/no Vc at 1 year (73.3% vs 96.5%) and at 3 years (47.7% vs 75.8%; P = .038). CVCs were related to increased risk of death only in subgroup II patients compared with the subcontrol group patients (75.4% vs 37.9% at 5 years, respectively; P = .034). CONCLUSIONS Diabetic hemodialysis patients exposed to high levels of upper extremity arterial medial VcSs upon receiving RCFs have an increased long-term mortality risk compared with diabetic hemodialysis patients with no Vc and receiving the same access. Patients with CVCs/Vc had the lowest survival rates.

Preemptive open surgical vs. endovascular repair for juxta-anastomotic stenoses of autogenous AV fistulae: a meta-analysis.

Purpose There is controversy about the best mode of preemptive repair of juxta-anastomotic stenoses in radial-cephalic arteriovenous fistula (AVFs). The aim of the present review was to compare the outcome of surgical vs. endovascular repair of those AVF stenoses. Methods A systematic review and meta-analysis was performed for studies comparing the outcome of open surgical vs. endovascular preemptive repair of AVF stenoses located in the juxta-anastomotic region. A search was carried out in April 2015. The analyzed outcome measures were the primary patency at 12 and 18 months and the assisted primary patency at 24 months. In addition, assessment of the methodological quality of the included studies was carried out. Results Four non-randomized cohort studies (297 patients) were analyzed. A random effects model was used to pool the data. The pooled odds ratio (OR and 95% confidence intervals) for the primary patency at 12 and at 18 months was 0.42 (0.25-0.72) and 0.33 (0.2-0.56), respectively, showing statistically significant higher patency of the surgically repaired group. The pooled OR for the assisted primary patency at 24 months was 0.53 (0.28-0.98) also in favor of the surgically repaired group (p<0.04) Conclusions The available evidence, based on non-randomized cohort studies, suggests that surgery is the best way to treat ‘juxta-anastomotic’ stenotic lesions in distal radial-cephalic AVFs, although angioplasty remains a valuable but less durable option in this location of the stenosis.

A critical appraisal of endovascular stent-grafts in the management of abdominal aortic aneurysms

Endovascular repair of abdominal aortic aneurysms has widely replaced the open surgical repair due to its minimal invasive nature and the accompanying lower perioperative mortality and morbidity. During the past two decades, certain improvements and developments have provided a wide variety of endograft structural designs and geometric patterns, enabling the physician to approach a more patient-specific treatment of AAA. This review presents the currently available aortic endografts and describes the clinical, technical and mechanical characteristics of them.