Risk of recurrent venous thromboembolism and major bleeding according to risk factor profiles in Asian patients: a subgroup analysis EINSTEIN-Extension and EINSTEIN-CHOICE.

BACKGROUND: Risks of recurrence and major bleeding with extended anticoagulation in Asian patients with venous thromboembolism (VTE) are similar to those in non-Asian patients but risks according to baseline risk factor profiles is not well documented. METHODS: Subgroup analysis of two randomized trials, which compared once-daily rivaroxaban (20 mg or 10 mg) with placebo or aspirin (100 mg) for extended treatment in Asian patients with VTE who had completed 6-12 months of anticoagulation. Index events were classified as unprovoked, provoked by major persistent risk factors, minor persistent risk factors, minor transient risk factors, or major transient risk factors. One-year cumulative risks of recurrent VTE were calculated for these risk factor profiles. RESULTS: 367 patients received rivaroxaban, 159 aspirin, and 48 placebo. For patients with unprovoked VTE, one-year cumulative incidences of recurrence in the 202 patients given rivaroxaban, the 89 given aspirin and the 28 given placebo were 1.6%, 5.8%, and 14.8%, respectively. For patients with VTE provoked by minor persistent risk factors, these incidences were 0% in the 74 patients given rivaroxaban, 9.3% in the 36 given aspirin, and 0% in the 12 given placebo. No recurrent VTE occurred in patients with VTE provoked by major persistent or transient risk factors or minor transient risk factors. Rivaroxaban was not associated with a significant increase in major bleeding. CONCLUSIONS: Rivaroxaban seems to be an effective and safe option for extended treatment in Asian patients, especially those presenting with unprovoked VTE. Subgroups of patients with provoked risk factors were too small to draw meaningful conclusions. TRIAL REGISTRATION: NCT00439725 and NCT02064439.

Comparison of Aortobifemoral Bypass and Endovascular Treatment for Chronic Infrarenal Abdominal Aortic Occlusion From the CHAOS (CHronic Abdominal Aortic Occlusion, ASian Multicenter) Registry.

PURPOSE: To directly compare the clinical outcomes of aortobifemoral bypass surgery (ABF) and endovascular treatment (EVT) for chronic total occlusion (CTO) of the infrarenal abdominal aorta (IAA). MATERIALS AND METHODS: In this retrospective, multicenter study, we used an international database of 436 patients who underwent revascularization for CTO of the IAA between 2007 and 2017 at 30 Asian cardiovascular centers. After excluding 52 patients who underwent axillobifemoral bypass surgery, 384 patients (139 ABFs and 245 EVTs) were included in the analysis. Propensity score-matched analysis was performed to compare clinical results in the periprocedural period and the long-term. RESULTS: Propensity score matching extracted 88 pairs. Procedure time (ABF; 288 [240-345] minutes vs EVT; 159 [100-205] minutes, p<0.001) and length of hospital stay (17 [12-23] days vs 5 [4-13] days, p<0.001) were significantly shorter in the EVT group than in the ABF group, while the proportions of procedural success (98.9% versus 96.6%, p=0.620), complications (9.1% versus 12.3%, p=0.550), and mortality (2.3% versus 3.8%, p=1.000) were not different between the groups. At 1 months, ABI significantly increased more in the ABF group for both in a limb with the lower (0.56 versus 0.50, p=0.018) and the higher (0.49 versus 0.34, p=0.001) baseline ABI, while the change of the Rutherford category was not significantly different between the groups (p=0.590). At 5 years, compared with the EVT group, the ABF group had significantly better primary patency (89.4±4.3% versus 74.8±4.3%, p=0.035) and survival rates (86.9±4.5% versus 66.2±7.5%, p=0.007). However, there was no significant difference between the groups for secondary patency (100.0%±0.0% versus 93.5%±3.9%, p=0.160) and freedom from target lesion revascularization (TLR) (89.3±4.3% vs 77.3±7.3%, p=0.096). CONCLUSION: Even with recent advancements in EVT, primary patency was still significantly better for ABF in CTO of the IAA. However, there was no difference between the groups in terms of secondary patency and freedom from TLR at 5 years. Furthermore, there was no difference in procedural success, complications, mortality, and improvement in the Rutherford classification during the periprocedural period, with significantly shorter procedure time and hospital stay in the EVT group.

Characteristics and Effect of Rivaroxaban on Venous Thromboembolism in Korean Patients Compared to Western Population: A Subgroup Analysis from XALIA(-LEA) Study.

Purpose: This study aimed to compare the characteristics of venous thromboembolic disease (VTE) in Korean to Caucasian population. Materials and Methods: XALIA-LEA and XALIA were phase IV non-interventional prospective studies with identical designs that investigated the effect of rivaroxaban versus standard anticoagulation for VTE. Koreans accounted for the largest proportion of the overall enrolled population of XALIA-LEA. However, in the XALIA study, most patients were Caucasian. Therefore, Korean data from XALIA-LEA and Caucasian data from XALIA were used in this study. This study compared the clinical characteristics and primary outcomes of the XALIA program, including major bleeding, recurrent VTE, and all-cause mortality. Results: The Korean population was older, was less obese, and had more active cancer at baseline than the Caucasian population. Provoked VTE was more common in the Korean population. Interestingly, Koreans showed less accompanying thrombophilia than Caucasians, and factor V Leiden mutations were not detected. Korean analyses comparing the effects of rivaroxaban and standard anticoagulation with primary outcomes showed a lower incidence of major bleeding, recurrent VTE, and all-cause mortality with rivaroxaban. Similar results were obtained in the propensity score matching analysis. Conclusion: Characteristic differences were found between Korean and Caucasian VTE patients. Despite these ethnic differences, the effectiveness and safety of rivaroxaban therapy in these patients were consistent.

The Effects of Vasodilation Induced by Brachial Plexus Block on the Development of Postoperative Thrombosis of the Arteriovenous Access in Patients with End-Stage Renal Disease: A Retrospective Study.

Although brachial plexus block (BPB)-induced vasodilation reduces the incidence of arteriovenous access (AC) thrombosis, BPB cannot completely prevent its development. Therefore, we retrospectively investigated the factors affecting BPB-induced vasodilation and their effects on AC thrombosis development. Ninety-five patients undergoing AC surgery under BPB were analyzed. Vessel diameters were measured before and 20 min after BPB. The surgery abandoned before the BPB placement was performed when the BPB-induced increases in vessel diameters met its indications. Complete occlusive access thrombosis (COAT) was defined as loss of pulse, thrill, or bruit. Fourteen patients (14.7%) developed COAT. The outflow vein was more dilated by BPB than the inflow artery (0.6 versus 0.1 mm in median, p < 0.001). The original surgery plan was changed for seven patients (7.4%). Diabetes mellitus (DM) and ischemic heart disease (IHD) decreased the extent of increases in the inflow artery by -0.183 mm (95% confidence interval [CI] [-0.301, -0.065], p = 0.003) and outflow vein diameters by -0.402 mm (95% CI [-0.781, -0.024], p = 0.038), respectively. However, DM, IHD, and changes in the vessel diameters had insignificant effects on the development of COAT. In conclusion, although DM and IHD attenuate the vasodilating effects of BPB, they do not contribute to the development of COAT.

Peak systolic velocity ratio derived from quantitative vessel analysis for restenosis after femoropopliteal intervention: a multidisciplinary review from Endovascular Asia.

With technological improvements in the endovascular armamentarium, there have been tremendous advances in catheter-based femoropopliteal artery intervention during the last decade. However, standardization of the methodology for assessing outcomes has been underappreciated, and unvalidated peak systolic velocity ratios (PSVRs) of 2.0, 2.4, and 2.5 on duplex ultrasonography have been arbitrarily but routinely used for assessing restenosis. Quantitative vessel analysis (QVA) is a widely accepted method to identify restenosis in a broad spectrum of cardiovascular interventions, and PSVR needs to be validated by QVA. This multidisciplinary review is intended to disseminate the importance of QVA and a validated PSVR based on QVA for binary restenosis in contemporary femoropopliteal intervention.

Rivaroxaban after Thrombolysis in Acute Iliofemoral Venous Thrombosis: A Randomized, Open-labeled, Multicenter Trial.

Recently non-Vitamin K antagonist oral anticoagulants (NOAC) is replacing warfarin for the treatment of deep vein thrombosis (DVT). However, the role of NOAC after thrombolysis of acute iliofeomral DVT (IFDVT) is not yet defined. This randomized clinical trial aimed to compare the safety and efficacy of rivaroxaban versus warfarin after catheter directed thrombolysis of an IFDVT. Patients with acute DVT of both the iliac and the femoral vein (n = 72) were recruited and randomized to either standard anticoagulation (enoxaparin and warfarin, n = 35) or rivaroxaban (n = 37) after successful thrombolysis or mechanical thrombectomy. Primary efficacy outcome was a recurrence of any venous thromboembolism (VTE) within 6 months. Secondary safety outcomes included major bleeding, clinically relevant non-major bleeding (CRNMB), other adverse event, and all-cause mortality. Rate of recurrent VTE were similar in both groups (11.4% versus 12.5%; p = 0.94). Major bleeding or CRNMB was less in rivaroxaban group without significance (2.9% versus 9.4%, HR, 0.31; 95% CI, 0.03-2.96; p = 0.31). Recurrence-free survival and major bleeding-free survival at 6 months were not different in both groups. After thrombolysis of acute IFDVT, rivaroxaban was as safe and effective as warfarin in preventing DVT recurrence.

Hybrid treatment of multilevel revascularization in patients with peripheral arterial disease - a multi-centre study in Korea.

BACKGROUND: Endovascular treatment is an alternative first-line management for peripheral artery disease (PAD). Hybrid treatment (HT) is defined as a combined treatment for patients with PAD using endovascular and open surgery, simultaneously performed in an operating room. The results of HT are reportedly good for multilevel revascularization (MR) in patients with chronic limb ischaemia, and even in older high-risk patients. The goal of this study was to examine the clinical and haemodynamic outcomes of HT in patients who need MR. PATIENTS AND METHODS: Nine university hospitals in Korea participated in this multicentre study. A total of 134 patients with multilevel PAD underwent HT and MR. Patients were enrolled from July 2014 to June 2015 and were followed for 18 months. RESULTS: The mean age of the patients was 68.8 ± 9.93 years and 88.1 % were men. Patients with Rutherford category 2 to 3 and 4 to 6 comprised 59.0 % and 42.0 % of the group, respectively. The technical success rate was 100 %. The primary patency rates at 12 and 18 months were 77.6 % and 63.9 %, respectively. The primary-assisted patency rates at 12 and 18 months were both 90.0 %. The pre-operative mean ankle brachial index (0.43 ± 0.23) increased to 0.87 ± 0.23 at six months post-operatively (t-test, p < 0.05). The amputation free survival rate was 97.1 %. CONCLUSIONS: Although outcomes of multilevel PAD are reportedly poor when endovascular treatment alone is used, we have shown that HT is a feasible alternative modality for patients with multilevel PAD, with satisfactory amputation-free survival and freedom from re-intervention rates.

Radiation hazards to vascular surgeon and scrub nurse in mobile fluoroscopy equipped hybrid vascular room.

PURPOSE: The aim of the present study was to identify the radiation hazards to vascular surgeons and scrub nurses working in mobile fluoroscopy equipped hybrid vascular operation rooms; additionally, to estimate cumulative cancer risk due to certain exposure dosages. METHODS: The study was conducted prospectively in 71 patients (53 men and 18 women) who had undergone vascular intervention at our hybrid vascular theater for 6 months. OEC 9900 fluoroscopy was used as mobile C-arm. Exposure dose (ED) was measured by attaching optically stimulated luminescence at in and outside of the radiation protectors. To measure X-ray scatter with the anthropomorphic phantom model, the dose was measured at 3 distances (20, 50, 100 cm) and 3 angles (horizontal, upward 45°, downward 45°) using a personal gamma radiation dosimeter, Ecotest CARD DKG-21, for 1, 3, 5, 10 minutes. RESULTS: Lifetime attributable risk of cancer was estimated using the approach of the Biological Effects of Ionizing Radiation report VII. The 6-month ED of vascular surgeons and scrub nurses were 3.85, 1.31 mSv, respectively. The attenuation rate of lead apron, neck protector and goggle were 74.6%, 60.6%, and 70.1%, respectively. All cancer incidences among surgeons and scrub nurses correspond to 2,355 and 795 per 100,000 persons. The 10-minute dose at 100-cm distance was 0.004 mSv at horizontal, 0.009 mSv at downward 45°, 0.003 mSv at upward 45°. CONCLUSION: Although yearly radiation hazards for vascular surgeons and scrub nurses are still within safety guidelines, protection principles can never be too stringent when aiming to minimize the cumulative harmful effects.

Treating pulmonary embolism in Pacific Asia with direct oral anticoagulants.

Pulmonary embolism (PE) is the principal preventable cause of in-hospital deaths. Prevalence of PE in Asians is uncertain but undoubtedly underestimated. Asians and Caucasians have similar non-genetic risk factors for PE, and there is mounting evidence that PE affects Asians much more commonly than previously supposed; incidence, especially among high-risk patients, may approach that in Caucasians. Furthermore, PE incidence in Asia is increasing, due to both increased ascertainment, and also population ageing and growing numbers of patients with predisposing risk factors. Despite being warranted, thromboprophylaxis for high-risk patients is not routine in Pacific Asian countries/regions. There also appears to be scope to implement venous thromboembolism (VTE) management guidelines more assiduously. Anticoagulants, primarily heparins and warfarin, have been the mainstays of VTE management for years; however, these agents have limitations that complicate routine use. The complexity of current guidelines has been another barrier to applying evidence-based recommendations in everyday practice. Updated management approaches have considerable potential to improve outcomes. New oral anticoagulants that are easier to administer, require no, or much less, monitoring or dose-adjustment and have a favourable risk/benefit profile compared with conventional modalities, may offer an alternative with the potential to simplify VTE management. However, more information is required on practical management and the occurrence and treatment of bleeding complications. Increasing recognition of the burden of PE and new therapeutic modalities are altering the VTE management landscape in Pacific Asia. Consequently, there is a need to further raise awareness and bridge gaps between the latest evidence and clinical practice.

Iliac anatomy and the incidence of adjunctive maneuvers during endovascular abdominal aortic aneurysm repair.

PURPOSE: Challenging iliac anatomy remains an important issue during endovascular aneurysm repair (EVAR), and it is known that the length of the common iliac artery (CIA) is shorter in Asians than in Western groups. We analyzed both the iliac anatomy and the incidence of adjunctive maneuvers to overcome iliac artery-related difficulties during EVAR. METHODS: Seventy-four EVARs were performed for abdominal aortic aneurysm between January 2010 and March 2013. Patient demographic data, iliac anatomical characteristics (presence of iliac artery aneurysm, iliac artery diameter and length, and iliac tortuosity), and adjunctive iliac artery maneuvers were reviewed retrospectively. RESULTS: Mean CIA length was 52.8 mm (range, 6.6-98.0 mm) on the right and 56.3 mm (range, 0-94.8 mm) on the left. CIA length was ≥20 mm, except in one patient with bilateral short CIAs. Forty patients (54%) had a CIA aneurysm, and 18 had aneurysms on both sides. Iliac adjunctive procedures were performed in 38 patients (51%) as follows: 23 internal iliac artery (IIA) embolizations or ligations, seven IIA revascularizations, 16 external iliac artery (EIA) balloon angioplasties or stenting, one EIA patch angioplasty, one EIA interposition, two femoral endarterectomies with patch angioplasty, and nine femoro-femoral bypasses after EVAR with an aorto-uni-iliac device. Technical success for the adjunctive iliac procedures was achieved in all patients. CONCLUSION: Short CIA length was uncommon. Although many patients had access-related difficulties, most were overcome by an endovascular or hybrid technique. Liberal use of iliac adjunctive procedures can facilitate EVAR.

Acupuncture in subjects with cold hands sensation: study protocol for a randomized controlled trial.

BACKGROUND: Cold hands sensation is a common disorder within the Korean population. Many Korean family physicians believe that it is a mild early manifestation of Raynaud's phenomenon (RP), or may be related to RP. RP is characterized by reversible digital vasospasm provoked by cold temperatures and/or emotional stress, and doctors often prescribe medications that are used in treatment of RP for subjects with cold hands. However, this has not shown a clear benefit, and these medications can cause unwanted side effects. It is also reported that traditional Korean medicine, including acupuncture, is widely used to treat cold hands, although the current level of evidence for this approach is also poor and to date, there have been no published randomized controlled clinical trials (RCTs) evaluating the efficacy and safety of acupuncture for cold hands. We have therefore designed a pilot RCT to obtain information for the design of a further full-scale trial. METHODS/DESIGN: The proposed study is a five-week pilot RCT. A total of 14 subjects will be recruited and randomly allocated to two groups: an acupuncture plus medication group (experimental group) and a medication-only group (control group). All subjects will take nifedipine (5 mg once daily) and beraprost (20 mg three times daily) for three weeks. The experimental group will receive additional treatment with three acupuncture sessions per week for three weeks (nine sessions total). The primary outcome will be measured using a visual analogue scale. Secondary outcomes will be measured by blood perfusion in laser Doppler perfusion imaging of the hands, frequency and duration of episodes of cold hands, and heart rate variability. Assessments will be made at baseline and at one, three, and five weeks thereafter. DISCUSSION: This study will provide an indication of the feasibility and a clinical foundation for a future large-scale trial. TRIAL REGISTRATION: This study was registered at Korean Clinical Research Information Service (CRIS) registry on 5 August 2013 with the registration number #KCT0000817.

Long-term outcome of crossover femoro-femoro-popliteal bypass using side-to-side anastomosis in ilio-femoral occlusive disease.

PURPOSE: During crossover femoro-femoro-popliteal sequential bypass (CFFPB) surgery in ilio-femoral occlusive disease, proximal anastomosis of the femoro-popliteal bypass is usually performed distal to the distal anastomosis of the crossover femoro-femoral bypass. If not, it is done with a piggyback configuration. Another method is a side-to-side anastomosis. Its benefit is that this is the only anastomosis made. And it is less bulky compared with the piggyback configuration. This study was aimed to investigate the long-term outcome of CFFPB using side-to-side anastomosis. METHODS: From Sep 2006 to Aug 2012, 21 patients who underwent CFFPB using side-to-side anastomosis were enrolled. Externally supported polytetrafluoroethylene graft was used as a conduit in all patients. Patient demographic data and procedure details were investigated. Primary graft patency was calculated using the Kaplan-Meier method. RESULTS: The mean age of patients was 79 years (range, 62-81 years) and males were 17 (81%). Fifteen patients (71%) had critical limb ischemia. Inflow arteries comprised of 16 common femoral artery (CFA), 4 superficial femoral artery (SFA), and 1 deep femoral artery (DFA). Side-to-side anastomosis was performed on the CFA in 11, SFA in 2, and DFA in 8 patients. During the mean follow-up period of 21 months (1-60 months), 8 patients died. The 1-, 3-, and 5-year primary patency rates were 76%, 63%, and 63%. CONCLUSION: Long-term patency of CFFPB using side-to-side anastomosis was acceptable. It can be one of the treatment options for patients with ilio-femoral occlusive disease.

Consensus for the Treatment of Varicose Vein with Radiofrequency Ablation.

UNLABELLED: The objective of this paper is to introduce the schematic protocol of radiofrequency (RF) ablation for the treatment of varicose veins. INDICATION: anatomic or pathophysiologic indication includes venous diameter within 2-20 mm, reflux time ≥0.5 seconds and distance from the skin ≥5 mm or subfascial location. Access: it is recommended to access at or above the knee joint for great saphenous vein and above the mid-calf for small saphenous vein. Catheter placement: the catheter tip should be placed 2.0 cm inferior to the saphenofemoral or saphenopopliteal junction. Endovenous heat-induced thrombosis ≥class III should be treated with low-molecular weight heparin. Tumescent solution: the composition of solution can be variable (e.g., 2% lidocaine 20 mL+500 mL normal saline+bicarbonate 2.5 mL with/without epinephrine). Infiltration can be done from each direction. Ablation: two cycles' ablation for the first proximal segment of saphenous vein and the segment with the incompetent perforators is recommended. The other segments should be ablated one time. During RF energy delivery, it is recommended to apply external compression. Concomitant procedure: It is recommended to do simultaneously ambulatory phlebectomy. For sclerotherapy, it is recommended to defer at least 2 weeks. Post-procedural management: post-procedural ambulation is encouraged to reduce the thrombotic complications. Compression stocking should be applied for at least 7 days. Minor daily activity is not limited, but strenuous activities should be avoided for 2 weeks. It is suggested to take showers after 24 hours and tub baths, swimming, or soaking in water after 2 weeks.

Cardiac risk factors of revascularization in chronic atherosclerotic lower extremity ischemia.

PURPOSE: To identify the risk factors of major adverse cardiac event (MACE) in patients with chronic atherosclerotic lower extremity ischemia (CALEI) undergoing revascularization without noninvasive stress testing (NIST). METHODS: From January 2007 to January 2012, patients with CALEI who underwent revascularization were retrospectively reviewed. Emergent operations, revision procedures for previous surgery, or patients with active cardiac conditions were excluded. NIST was not performed for patients without active cardiac conditions. Cardiac risk was categorized into low, intermediate and high risk, according to the Lee's revised cardiac risk index. MACE was defined as acute myocardial infarction or any cardiac death within 30 days after surgery. RESULTS: A total of 459 patients underwent elective lower extremity revascularization procedures (240 open surgeries, 128 endovascular procedures, and 91 hybrid surgeries). The treated lesions comprised of 18% aorto-iliac, 58% infrainguinal, and 24% combined lesions. With regard to cardiac risk, low-, intermediate- and high risks were 67%, 32% and 2%, respectively. MACE was developed in 7 patients (2%). High or intermediate risk group by the Lee's index was related to postoperative MACE. Subgroup analysis for open surgery or hybrid surgery group identified female gender as an independent risk factor of MACE (P = 0.049; odds ratio, 5.168; confidence interval, 1.011 to 26.423). CONCLUSION: The Lee's index was a useful predictor of MACE. MACE is more common in female patients than male patients after open or hybrid surgery. Routine preoperative NIST is not suggested for all patients undergoing revascularization for CALEI, especially for those in the low risk group.

Managing venous thromboembolism in Asia: winds of change in the era of new oral anticoagulants.

Despite advances in the management of venous thromboembolism (VTE), treatment of many patients worldwide, especially in Asia, remains inadequate and/or discordant with prevailing guidelines. Although epidemiological studies consistently report lower incidences of VTE in Asians than Caucasians, VTE rates in Asia have probably been gravely underestimated, partly due to comparatively lesser ascertainment. It is becoming evident that Asians are at much higher risk of VTE than was hitherto supposed. Nevertheless, VTE risk-assessment is not routine in Asia and thromboprophylaxis rates are much lower than in Western nations. It is important to base decisions about anticoagulation on individual circumstances and weigh the potential benefits and risks. The conventional VTE management paradigm is not ideal. New oral anticoagulants offer advantages over current modalities that may help to streamline patient care and reduce healthcare costs. Initially, they will be mainly used in uncomplicated cases and, in the absence of clear differences in efficacy or safety, convenience, tolerability/adherence and cost will determine treatment choice. There is clear scope to improve VTE prevention and treatment in Asia. Key priorities are raising awareness of best practice and properly implementing guidelines. Uncertainty about the burden of VTE and concern about bleeding are barriers. High-quality Asian epidemiological data are needed to guide healthcare policy and evidence-based practice. More data on the occurrence and management of bleeding complications in Asian patients are also required. Meanwhile, physicians should remain vigilant and strive to act early, decisively and appropriately to diagnose and treat VTE, particularly in patients at high risk.

An antithrombotic fucoidan, unlike heparin, does not prolong bleeding time in a murine arterial thrombosis model: a comparative study of Undaria pinnatifida sporophylls and Fucus vesiculosus.

The antithrombotic activities and bleeding effects of selected fucoidans (source from either Undaria pinnatifida sporophylls or from Fucus vesiculosus) have been compared with heparin in the ferric chloride-induced arterial thrombus mouse model. Thrombosis was induced by applying 5% ferric chloride for 3 min on the carotid artery region of Balb/c mouse. Five minutes prior to thrombus induction, mice were infused through the tail vein with either saline (control) or polysaccharides. Either fucoidan or heparin was dosed at 0.1, 1.25, 2.5, 5.0, 10, 25, or 50 mg/kg intravenously (i.v.) The carotid blood flow was monitored until more than 60 min post-thrombus induction. Mouse tail transection bleeding time was measured up to 60 min after making a cut in the mouse tail. Both antithrombotic and bleeding effects were observed in a dose-dependent manner for both fucoidans and heparin. Thrombus formation was totally (reflected by Doppler flow meter) inhibited at either 5 or 50 mg/kg of unfractionated Undaria fucoidan or a low-molecular-weight Undaria fucoidan fraction, respectively, without prolonging the time-to-stop bleeding compared with the control (p < 0.01). The total inhibition of thrombus formation was observed for unfractionated Fucus fucoidan at 25 mg/kg where the time-to-stop bleeding was still significantly prolonged, by as much as 8 ± 1.7 min (p < 0.02). In contrast the heparin-treated group showed total inhibition of thrombus formation even at a small dose of 0.8 mg/kg (400 IU) at which bleeding continued until 60 min. In conclusion algal fucoidans are highly antithrombotic without potential haemorrhagic effects compared with heparin in the arterial thrombus model, but this property differs from algal species to species, and from the molecular structure of fucoidans.

The transition from custom-made to standardized multibranched thoracoabdominal aortic stent grafts.

OBJECTIVE: The purpose of this study was to compare the branch morphology and short-term outcome of endovascular aneurysm repair using multibranched thoracoabdominal custom-made stent grafts (CSGs) vs standard stent grafts (SSGs). METHODS: Data on patient demographics, aortic morphology, component use, and outcome were collected prospectively. Final branch length (cuff to target artery orifice) and branch angle (cuff orientation to target artery orientation) were determined using 3-D reconstruction of computed tomographic angiograms (CTAs). RESULTS: Between January 2008 and March 2010, 28 patients underwent endovascular aneurysm repair using 14 CSGs and 14 SSGs. Two patients were excluded from analysis: one patient in the CSG group had yet to undergo CTA, and one patient in the SSG group had crossed renal branches due to problems traversing a previously reconstructed aortic arch. All the stent grafts were implanted successfully. There were no perioperative deaths. There were no statistically significant differences between the CSG (n = 13) and SSG (n = 13) groups in terms of patient age (74.4 ± 7.9 years vs 73.5 ± 6.0 years), aneurysm diameter (66.1 ± 9.0 mm vs 71.2 ± 9.0 mm), operative time (311 ± 94 minutes vs 286 ± 57 minutes), fluoroscopy time (108 ± 43 minutes vs 101 ± 30 minutes), contrast volume (98 ± 39 minutes vs 91 ± 27 minutes), blood loss (458 ± 205 mL vs 433 ± 193 mL), mean branch angle (22.8 ± 19.0 degrees vs 22.0 ± 17.6 degrees), or branch length (25.3 ± 12.1 mm vs 23.4 ± 10.2 mm). CONCLUSION: The substitution of SSG for CSG had no effect on the complexity of the procedure, the branch morphology, or the perioperative outcome. The availability of an off-the-shelf SSG will broaden the application of endovascular thoracoabdominal aortic aneurysm repair by eliminating manufacturing delays.

Variation in the shape and length of the branches of a thoracoabdominal aortic stent graft: implications for the role of standard off-the-shelf components.

PURPOSE: To describe variations in the shape, orientation, and length of the branches of multi-branched thoracoabdominal stent grafts. METHOD: The branches were constructed in situ by attaching a covered stent (Fluency Plus Tracheobronchial Stent Graft; Bard Peripheral Vascular, Tempe, Ariz) to each of four caudally-oriented cuffs on custom-made stent grafts. Pre- and postoperative computed tomography (CT) scans of 38 consecutively treated patients were analyzed using a three-dimensional work station to give the orientation of celiac, superior mesenteric, and right renal and left renal orifices relative to the centerline of the aorta (planned cuff orientation [PCO]) and relative to the centerline of the stent graft (actual vessel orientation [AVO]). The orientation of each cuff (actual cuff orientation [ACO]) was also measured relative to the centerline of the stent graft. These values were used to assess the degree of stent graft malorientation (ACO-PCO), or cuff-to-artery misalignment (ACO-AVO), and combined with measurements of branch length to calculate the resulting lateral displacement (arc distance [AD]) between each cuff and its corresponding arterial orifice and the angle (longitudinal branch angulation [LBA]) between the long axis of the branch and the long axis of the aorta, all in the plane of the aortic surface. RESULTS: All 136 branches were inserted as intended. None has since migrated, disconnected, or kinked. In most cases, stent graft orientation was accurate, with a mean ACO-PCO of 18.4 + 12.1 degrees. Cuff-to-artery misalignment was correspondingly low, with a mean ACO-AVO of 19.8 + 14.0 degrees. More than 30 degrees of misalignment was present in 23.2% of branches, yet only 9% (n = 12) had an LBA of >30 degrees. CONCLUSION: Moderate degrees of cuff-to-artery misalignment had no effect on the feasibility of multi-branched stent graft insertion.

A standardized multi-branched thoracoabdominal stent-graft for endovascular aneurysm repair.

PURPOSE: To assess the feasibility of endovascular thoracoabdominal aortic aneurysm (TAAA) repair using a standard off-the-shelf multi-branched stent-graft. METHODS: The aortic anatomy of 66 patients (45 men; mean age 74 years, range 57-87) referred for endovascular repair of TAAA was measured using 3-dimensional reconstructed images from computed tomographic angiograms. In particular, the orientation and longitudinal position of the orifice of each celiac artery, right renal artery, and left renal artery were measured relative to the location of the superior mesenteric artery (SMA) orifice. Based on prior experience, branch insertion with a standard endograft was considered feasible under the following conditions: (1) no more than 4 indispensable (target) arteries to the abdominal viscera, (2) the celiac artery and SMA were 6 to 10 mm in diameter, (3) the renal arteries were 4 to 8 mm in diameter, (4) all target arteries were accessible from a transbrachial approach, (5) the distance between each cuff and the corresponding arterial orifice was 4 indispensable visceral or renal branches, and 3 patients had inaccessible upward directed renal artery branches. Three of the remaining 59 patients had renal arteries outside the boundaries defined by conditions 5 and 6 when the hypothetical stent-graft was positioned with its SMA cuff 25 mm proximal to the corresponding SMA orifice. However, if the stent-graft were deployed in a more caudal location, only 1 of these 3 renal arteries would have been out of range. Therefore, 58 (88%) of 66 patients met all the eligibility criteria for repair using the off-the-shelf stent-graft. CONCLUSION: A standardized, off-the-shelf, multi-branched stent-graft is applicable in 88% of cases of TAAA that would otherwise have been treated using customized stent-grafts. The use of a pre-made stent-graft has the potential to eliminate long manufacturing delays and expand the scope of endovascular repair of TAAA.