Treatment of acute pulmonary embolism after catheter-directed thrombolysis with dabigatran vs warfarin: results of a multicenter randomized RE-SPIRE trial

BACKGROUND

Thrombolytic therapy is effective method in the high-risk acute pulmonary embolism (PE) treatment. Reduced-dose thrombolysis (RDT) plus oral anticoagulation therapy is effective and safe method in the moderate and severe PE treatment. It is leading to good early and intermediate-term outcomes. In the RE-COVER and RE-COVER II studies, dabigatran showed similar effectiveness as warfarin in the treatment of acute PE. Dabigatran leads to fewer hemorrhagic complications and is not inferior in efficacy to warfarin in the prevention of PE after mechanical fragmentation and RDT (catheter-directed treatment [CDT]+RDT) in patients with high and intermediate to high PE risk. We sought to evaluate the efficacy and safety (incidence of clinically significant recurrence of venous thromboembolic complications and deaths) during a 6-month course of treatment with dabigatran or warfarin in patients with high and intermediate to high acute PE risk after endovascular mechanical thrombus fragmentation procedure with RDT (CDT+RDT).

METHODS

The RE-SPIRE is a prospective, multicenter randomized double-arm study. Over a 5-year period, 66 consecutive patients with symptomatic high and intermediate to high PE risk after endovascular mechanical thrombus fragmentation procedure with RDT (CDT+RDT) were randomized into two groups within the next 48 hours. The first group continued treatment with dabigatran 150 mg twice a day for 6 months; the second group continued treatment with warfarin under the control of international normalized ratio (2.0-3.0) for 6 months. Both groups received low molecular weight heparins for 2 days after surgery. Then, group 1 continued to receive low molecular-weight-heparin for 5 to 7 days, followed by a switch to dabigatran at a dosage of 150 mg two times a day. Group 2 received both low-molecular-weight heparin and warfarin up to an international normalized ratio of >2.0, followed by heparin withdrawal. The follow-up period was 6 months.

RESULTS

There were 63 patients who completed the study (32 in the dabigatran group and 31 in the warfarin group). In both groups, there was a statistically significant decrease in the mean pulmonary artery pressure. The mean pulmonary artery pressure at the 6-month follow-up after surgery was 24 mm Hg (interquartile range, 20.3-29.25 mm Hg) in the dabigatran group and 23 mm Hg (interquartile range, 20.0-26.3 mm Hg) in the warfarin group. The groups did not differ statistically in the deep vein thrombosis dynamics. Partial recanalization occurred in 52.0% vs 73.1% in the dabigatran and warfarin groups, respectively (P = .15). Complete recanalization occurred in 28.0% vs 19.2% in the dabigatran and warfarin groups, respectively (P = .56). The groups did not differ in the frequency of major bleeding events according to the International Society for Thrombosis and Hemostasis (0% vs 3.2% in the dabigatran and warfarin groups, respectively; P = 1.00). However, there were more nonmajor bleeding events in the warfarin group than in the dabigatran group (16.1% vs 0%, respectively; P = .02).

CONCLUSIONS

The results of the study show that dabigatran is comparable in effectiveness to warfarin. Dabigatran has greater safety in comparison with warfarin in the occurrence of all cases of bleeding in the postoperative and long-term periods. Thus, dabigatran may be recommended for the treatment and prevention of PE after CDT with RDT in patients with high and intermediate to high PE risk.

Treatment of Long Femoropopliteal Occlusive Lesions With Self-expanding Interwoven Nitinol Stent: 24 Month Outcomes of the STELLA-SUPERA-SIBERIA Register Trial

PURPOSE

The efficacy and safety of the Supera stent in superficial femoral artery (SFA) have been reported mostly in shorter lesions with relatively low proportion of occlusions. There are little data on the effectiveness of the Supera stent in long lesions. The aim of this study was to assess the clinical safety and efficiency of the Supera stent in the treatment of long femoropopliteal occlusive lesions (Trans-Atlantic Inter-Society Consensus [TASC] C/D) in patients with symptomatic peripheral artery disease.

MATERIALS AND METHODS

The STELLA-SUPERA-SIBERIA is a prospective, single-center, single-arm study. Patients with symptomatic (Rutherford stages 3-6) de novo and TASC C/D occlusive lesions of the femoropopliteal segment were treated with Supera stent. The primary endpoint was the 12 month rate of primary sustained clinical improvement (upward shift on the Rutherford classification to a one level without the need for repeated target lesion revascularization (TLR) in surviving patients without the need for unplanned amputation). Secondary endpoints were the 24 month of primary sustained clinical improvement, MALE, limb salvage, the primary patency, the secondary patency, 24 month MACE. Follow-up included clinical examination, duplex scan, and biplane x-ray up to 24 months.

RESULTS

Between April 2019 and January 2020, 52 symptomatic patients with 55 long femoropopliteal occlusive lesions (52.7% TASC D lesions and 47.3% TASC C lesions) were treated. The mean target lesion length was 205±72 mm. All patients had total occlusions. The mean lesion length of the implanted Supera stents was 198±82 mm. At 12 and 24 months, the primary sustained clinical improvement rate was 80.2% and 63.6%, respectively. The Rutherford category assessment was significantly improved at 24 months compared with baseline (p=0.02). The primary patency rate at 12 and 24 months was 78.1% and 60.0%, respectively. At 12 and 24 months, freedom from TLR was 83.5% and 81.8%, respectively. There were no stent fractures at 24 months.

CONCLUSION

Supera Stent implantation for TASC C/D femoropopliteal lesions revascularization appears to be a safe and efficient implant given the complexity of the treated lesions. Head-to-head studies are mandatory to establish Supera Stent as an alternative tool to open surgery for long femoropopliteal lesions.

CLINICAL IMPACT

Our study indicated, that using self-expanding interwoven nitinol stent for TASC C/D femoropopliteal lesions revascularization appears to be a safe and efficient implant given the complexity of the treated lesions. Although bypass grafting is recommended for prolonged femoropopliteal lesions, open surgery is more traumatic and is associated with greater risks than endovascular procedures. Our findings suggest that the use of interwoven nitinol stents can overcome the disadvantages of traditional stents in such cases, which may help to improve patients' outcomes and reduce the risk of adverse events.

Bypass Versus Interwoven Nitinol Stents for Long Femoro-Popliteal Occlusions: A Propensity Matched Analysis

PURPOSE

To compare femoro-popliteal bypass and interwoven nitinol stenting for long occlusions of the femoro-popliteal segment.

MATERIALS AND METHODS

Single center retrospective propensity matching analysis of the symptomatic patients with long occlusion of the femoro-popliteal segment (> 20 cm), who underwent stenting with interwoven nitinol stent or femoro-popliteal bypass from 2012 to 2020.

PRIMARY ENDPOINTS

primary patency, primary-assisted patency, secondary patency. Secondary endpoints: major adverse cardiovascular events, major adverse limb events, primary sustained clinical improvement, survival.

RESULTS

A total of 437 patients were enrolled: 294 in the bypass group and 143 in the endovascular therapy (EVT) group. After propensity score matching, 264 and 113 patients remained in the groups, respectively. A median occlusion length was 250 mm. One-year and two-year primary and secondary patency rates were comparable in both groups (two-year primary patency: 68.5% for bypass vs. 68.9% for EVT, p = 1.00). In the "above the knee" subgroup analysis, two-year secondary patency was higher in the EVT group than in the bypass group (90.9% vs. 77.5%, p = 0.048). In "below-the-knee" subgroup analysis, primary and primary assisted patency were statistically significantly higher in the EVT group than in artificial bypass subgroup (66.7% vs. 42.4%, p = .046 and 76.7% vs. 45.5%, p = .011, respectively). However, compared to autovenous bypass, the EVT group showed lower primary patency rates, although the differences are not significant.

CONCLUSION

A nonselective endovascular strategy can allow for regular successful treatment of femoro-popliteal lesions longer than 25 cm.

[Graft-renal bypass surgery during intraoperative dissection of renal artery in a patient with high occlusion of the aorta]

Despite advances in the development of endovascular techniques of revascularization of renal arteries, in certain clinical cases still remains the need to perform extra-anatomic renal bypass grafting. To such instances belong complicated atherosclerotic aortic lesions, technical difficulties occurring during open revascularization of the aorta and its branches, as well as aneurysms of the juxtarenal portion of the abdominal aorta. Presented herein is a clinical case concerning a patient subjected to non-standard restoration of blood flow in the right renal artery after thromboendarterectomy from the juxtarenal aorta, performed from the left-sided extraperitoneal phrenolumbotomic approach and complicated by secondary dissection of the intima in the right renal artery.

[Robotic-assisted operations for pathology of the aortoiliac segment: own experience]

AIM

The present study was aimed at assessing the results of a total of 40 vascular operations carried out using the robotic-assisted da Vinci surgical system.

PATIENTS AND METHODS

Between January 2013 and September 2019, a total of 40 robotic-assisted vascular operations were performed at the Department of Vascular Pathology and Hybrid Technologies of the Centre of Vascular and Hybrid Surgery. Of these, 31 interventions were carried out for occlusion of the aortoiliac segment and 9 for removal of an aneurysm of the infrarenal portion of the abdominal aorta. The patients were arbitrarily divided into 2 groups: the first group included those subjected to aortofemoral bypass grafting procedures for atherosclerotic steno-occlusive lesions of the aorta and iliac arteries, whereas the second group comprised the patients who underwent aneurysmoectomies with linear prosthetic repair of the abdominal aorta.

RESULTS

Altogether, elective robotic-assisted operations were successfully performed in 38 (95%) cases. Conversion to a laparotomic approach was required in 2 (5%) patients. The mean time of creating an anastomosis with the abdominal aorta amounted to 51 minutes (range 30-90), being 42±4.75 min for aortofemoral bypass grafting and 83±5.00 min for aneurysmoectomies with linear prosthetic repair of the abdominal artery. The average blood loss was 316 (range 50-1000) ml, amounting to 280±209 ml and 438±322 ml for group I and group II, respectively. With the exception of one case, all patients spent 24 hours in the intensive care unit to be then transferred to the specialized ward. The average length of hospital stay amounted to 9.8 days. One patient experienced haemorrhage from the central anastomosis in the early postoperative period and was emergently operated on from a laparotomic approach. Four (10%) patients developed nonlethal complications which were treated conservatively. During the 30-day follow-up period, no lethal outcomes, thromboses, nor infections of the prostheses were observed.

CONCLUSION

From a practical point of view, the major advantages of using the robotic-assisted complex include minimal surgical trauma, reduced blood loss, a wide range of high-precision movements of the manipulators, 3-D visualization with a 5-fold magnification, thus making it possible to create a vascular anastomosis sufficiently fast in very tight spaces in the body. Our experience with laparoscopic robotic-assisted surgery demonstrated feasibility of using this technique for treatment of pathology of the aortoiliac segment.

[Autoarterial remodeling of the common carotid artery bifurcation in treatment of stenotic lesions]

Carotid endarterectomy is the main operation carried out for prevention of ischaemic stroke in haemodynamically significant stenoses of the bifurcation of the common carotid artery. Despite the literature data demonstrating some advantages of eversion carotid endarterectomy over the classical technique there arises a series of complicated, as yet unsolved problems. This concerns the control of the distal portion of an atherosclerotic plaque in prolonged lesions of the internal carotid artery, the absence of a temporary bypass graft, necessity of prosthetic repair of the internal carotid artery in detachment of the distal border of the plaque. We suggested a new technique of carotid endarterectomy making it possible to widen visual removal of atheromatous masses from the internal carotid artery, to improve the control of the distal portion of the plaque in a prolonged lesion of the internal carotid artery. We carried out a comparative assessment of efficacy and safety of the new method of carotid endarterectomy versus the classical variant in a randomized study. The proposed technique of carotid endarterectomy turned out to be compatible by safety and demonstrated similar results with the classical carotid endarterectomy by the number of ischaemic strokes, transitory ischaemic attacks, and myocardial infarctions in the early and remote postoperative periods. When comparing the groups by efficiency, the primary efficacy endpoint, including cases of restenosis >50% according to the findings of ultrasonographic examination of the brachiocephalic arteries, all cases of ischaemic events (acute impairments of cerebral circulation, transitory ischaemic attacks), as well as the presence of the clinical picture of cranial nerve paresis demonstrated a significant advantage of the new technique versus the comparison group at the expense of a lower incidence of restenoses in the area of the operation during the whole period of follow up. In the group of autoarterial remodelling, the composite endpoint of outcomes occurred in 6 patients (6.1%) and in the group with the classic carotid endarterectomy - in 19 (19.6%) patients, p=0.005.

Mechanical Properties and Biological Behavior of 3D Matrices Produced by Electrospinning from Protein-Enriched Polyurethane

Properties of matrices manufactured by electrospinning from solutions of polyurethane Tecoflex EG-80A with gelatin in 1,1,1,3,3,3-hexafluoroisopropanol were studied. The concentration of gelatin added to the electrospinning solution was shown to influence the mechanical properties of matrices: the dependence of matrix tensile strength on protein concentration is described by a bell-shaped curve and an increase in gelatin concentration added to the elasticity of the samples. SEM, FTIR spectroscopy, and mechanical testing demonstrate that incubation of matrices in phosphate buffer changes the structure of the fibers and alters the polyurethane-gelatin interactions, increasing matrix durability. The ability of the matrices to maintain adhesion and proliferation of human endothelial cells was studied. The results suggest that matrices made of 3% polyurethane solution with 15% gelatin (wt/wt) and treated with glutaraldehyde are the optimal variant for cultivation of endothelial cells.

[Modern polyurethanes in cardiovascular surgery]

Currently, there is great clinical demand for synthetic tissue-engineered cardiovascular prostheses with good long-term patency. Polyurethanes belong to the class of polymers with excellent bio- and hemocompatibility. They are known to possess good mechanical properties, but are prone to processes of degradation in conditions of functioning in living organisms. Attempts at solving this problem have resulted in the development of various new subclasses of polyurethanes such as thermoplastic polyether polyurethanes, polyurethanes with a silicone segment, polycarbonate polyurethanes and nanocomposite polyurethanes. This was accompanied and followed by offering a series of new technologies of production of implantable medical devices such as vascular grafts, heart valves and others. In the presented review, we discuss biological and mechanical properties of modern subclasses of polyurethanes, as well as modern methods of manufacturing implantable medical devices made of polyurethanes, especially small-diameter vascular prostheses.

[Comparing efficacy of recanalization with stenting of extended occlusions of superficial femoral artery and loop endarterectomy]

OBJECTIVE

The study was aimed at comparing the outcomes of loop endarterectomy (LE) and endovascular revascularization (ER) with stenting in occlusive lesions (TASC II type D) of the superficial femoral artery (SFA), as well as revealing predictors of restenosis/reocclusion.

PATIENTS AND METHODS

Between May 2011 and December 2016, a total of 234 patients presetting with occlusions of the SFA (TASC II type D lesions) were operated on. Of these, 117 patients underwent ER with SFA stenting and 117 patients were subjected to loop endarterectomy from the SFA. The obtained findings were analysed with the help of statistical methods using the Statistica 10 software package (StatSoft, USA). The level of deviation of the null hypothesis of no between-group differences was assumed at p<0.05.

RESULTS

Technical success in the ER group amounted to 94% (110 of 117 patients) and in the LE group to 90% (105 of 117 patients). The length of postoperative hospital stay in the ER group was 4 days and in the LE group - 7.5 days (p<0.05). There were significantly more complications in the LE group as compared with ER group (p=0.04). No significant difference was revealed for the number of reocclusions/restenosis between groups - 9 (8.1%) cases in the ER group vs 10 (9.1%) cases in the LE group (p=0.83).

CONCLUSION

Loop endarterectomy is a safe, effective and feasible procedure in TASC II type D lesions of the SFA, being not inferior by patency to endovascular treatment during 12 months of follow up; however, it is associated with a high risk for the development of local complications and increased number of postoperative bed-days.