Long Term Outcome after Application of the Angio-Seal Vascular Closure Device in Minipigs

Comparison of manual compression, Z-stitch, and suture-mediated vascular closure device techniques in dogs undergoing percutaneous transvenous intervention

INTRODUCTION/OBJECTIVES

Manual compression has been standard of care for maintaining hemostasis after percutaneous endovascular intervention, but can be time-consuming and associated with vascular complications. Alternative closure methods include the figure-of-eight suture (Z-stitch) and vascular closure device (VCD) techniques. We hypothesized that compared to manual compression, Z-stitch and VCD would significantly reduce time-to-hemostasis after transvenous access, and the proportion of dogs with vascular patency would not differ significantly among treatments.

ANIMALS

Forty-six client-owned dogs undergoing percutaneous transvenous interventional procedures.

MATERIALS AND METHODS

Dogs with vessel diameter <5 mm were randomized to undergo manual compression or Z-stitch, while those with vessel diameter ≥5 mm were randomized to undergo manual compression, Z-stitch, or VCD. Time-to-hemostasis, bleeding scores, presence of vascular patency one day and two to three months post-procedure, and complications were recorded. Data are presented as median (95% confidence interval).

RESULTS

In all 46 dogs, the right external jugular vein was used. Time-to-hemostasis was significantly shorter in the Z-stitch (2.1 [1.8-2.9] minutes) compared to VCD (8.6 [6.1-11.8] minutes; P<0.001) and manual compression (10.0 [10.0-20.0] minutes; P<0.001) groups. Time-to-hemostasis was significantly shorter in the VCD vs. manual compression (P=0.027) group. Bleeding scores were significantly greater at 5 and 10 min (P<0.001 and 0.013, respectively) in manual compression, compared to Z-stitch group. There was no difference in the proportion of dogs with vascular patency between groups (P=0.59).

CONCLUSIONS

Z-stitch and VCD are effective venous hemostasis methods after percutaneous transvenous intervention, with Z-stitch providing the most rapid time-to-hemostasis. Both Z-stitch and VCD techniques have low complication rates and effectively maintain vascular patency.

Comparison of artery diameters in the Aachen minipig serving as a human intracranial in vivo model

Minipigs are used as in vivo endovascular models, particularly in stroke and aneurysm research. However, detailed knowledge of the diameters of forelimb arteries that are commonly used as surrogates for human brain-supplying arteries are lacking. This study aimed to determine the diameters of forelimb and neck arteries in Aachen minipigs and to compare those to the diameters of human cerebral brain-supplying arteries in order to assess the validity of the Aachen minipig as a human intracranial in vivo model. We measured the diameters in the external carotid artery and eight different branches of the subclavian artery in 12 Aachen minipigs using angiographic imaging. Analysed arteries comprised the external carotid artery, axillary artery, brachial artery, subscapular artery first segment, subscapular artery second segment, external thoracic artery, caudal circumflex humeral artery, suprascapular artery and thoracodorsal artery. We compared these diameters to diameters of the following human brain-supplying arteries: terminal internal carotid artery (carotid-T and petrous segment), M1 segment of the middle cerebral artery, M2 segments of the middle cerebral artery, anterior cerebral artery, vertebral artery and basilar artery. Median diameters of porcine forelimb arteries ranged from 1.8 to 4.9 mm, and human brain supplying arteries ranged in diameter from 1.4 to 4.3 mm. Depending on the intended use, this allows porcine forelimb arteries to be selected which are statistically comparable to human brain-supplying vessels. In conclusion, we identified several equivalent arteries of the porcine subclavian branches that are comparable to human brain-supplying arteries. This may help to validate the minipig as a suitable in vivo model for neurovascular experiments.

Comparison of porcine and human vascular diameters for the optimization of interventional stroke training and research

The branches of the porcine subclavian artery are frequently used in endovascular stroke training and research. This study aimed to determine a porcine weight group, in which the arterial diameters most closely match human cerebral artery diameters, and thus optimize the porcine in-vivo model for neuroendovascular purposes. A group of 42 German Landrace swine (45–74 kg) was divided into four subgroups according to their weight. Angiographic images of the swine were used to determine the arterial diameter of the main branches of the subclavian artery: axillary artery, brachial artery, external thoracic artery, subscapular artery (at two different segments), suprascapular artery, caudal circumflex humeral artery, thoracodorsal artery, and circumflex scapular artery. The porcine arterial diameters were correlated with animal weight and compared to luminal diameters of human arteries which are commonly involved in stroke: internal carotid artery, basilar artery, vertebral artery, middle cerebral artery and M2 branches of the middle cerebral artery. Swine weight was positively correlated with porcine arterial diameter. The most conformity with human arterial diameters was found within the two heavier porcine groups (55–74 kg). We suggest the use of swine with a weight between 55–59.7 kg, as lighter animals show less similarity with human arterial diameters and heavier animals could cause more problems with manipulation and handling.

AbsorbaSeal™ 5.6.7F vascular closure device: A good laboratory practice chronic study evaluating safety and efficacy in a healthy porcine model

OBJECTIVES

Vascular closure devices (VCDs) are widely used for arteriotomy closure after percutaneous catheter-based procedures. In comparison to manual compression, VCDs have been associated with shorter time to hemostasis, shorter time to ambulation, and also decreased length of stay. Complexity of deployment, lack of immediate hemostasis, and residual deformity of the arterial wall remain as limitations of current VCDs. The aim of this study was to investigate the AbsorbaSeal™ 5.6.7F vascular closure device, a novel, completely bioabsorbable, intuitive, and easy to use VCD which uses a compressive, "sandwich"-type design comprising a low profile intravascular distal seal and gasket and an extravascular floating foot and proximal seal, in an open infrarenal aortic swine model.

METHODS

Eight fully heparinized swine at a good laboratory practices facility underwent AbsorbaSeal™ 5.6.7F VCD closure of three 6F arteriotomies each in the proximal, mid, and distal infrarenal aorta. Two swine underwent harvest at each of four time cohorts: 30, 60, 90, and 120 days. Acute and chronic procedural safety and efficacy, as well as target site vascular remodeling over time, were the primary outcomes evaluated. Secondary outcome measures included local and systemic inflammatory responses, end-organ tissue analysis, and device-related complications through the follow-up periods. Histopathological evaluation was performed by a blinded pathologist. Standard statistical methods were used.

RESULTS

In deployment of 24 AbsorbaSeal™ 5.6.7F VCDs, there were no device-related complications or mortalities. All deployments resulted in rapid arteriotomy seal (100% deployment success), with a mean time to hemostasis (cessation of arterial flow) of 21.5 s (median: 6.5 s) across a mean activated clotting time (ACT) of 356 s. Twenty of the 24 implant sites (83%) attained complete hemostasis within 20 s. Immediate post-implant and pre-termination angiographies at all time points were performed of all swine which demonstrated normal aortic appearance and tissue structure and normal downstream vascular beds. At 30 days, each implant's intravascular distal seal and gasket were removed from the circulation and completely covered with a smooth neointimal layer. Minimal inflammation and no intimal or luminal thrombus were observed at any site at every time point.

CONCLUSIONS

AbsorbaSeal™ 5.6.7F is a safe, effective, and secure VCD that demonstrates rapid hemostasis in a fully heparinized open aortic porcine model. Removal from circulation and complete coverage of the intravascular distal seal and gasket with neointima occurred within 30 days post-implant. Natural transmural vessel healing from the arteriotomy itself with minimal inflammation was noted for each implant at every time point.

The Use of Closure Devices for Aortic Stent-Graft Insertion: Outcomes Following a Paradigm Shift to Percutaneous Access in a Tertiary Vascular Center

Background:

This retrospective case series aims to evaluate the efficacy of the Perclose ProGlide system for postoperative hemostasis following aortic stent-graft insertion.

Material and Methods:

A prospectively maintained database of patients with a minimum follow-up of 12 months following percutaneous aortic procedures was interrogated. Preprocedural computed tomography (CT) scans were reviewed to assess existing stenosis in the common femoral artery (CFA). Arteries with an estimated stenosis of greater than 25% on visual inspection underwent quantification using multiplanar and curved planar reformation. The preoperative and 1-year follow-up CTs of these patients were assessed for change in stenosis. Analysis was performed by 2 independent reviewers, with senior authors reviewing any discrepancies.

Results:

One hundred forty-two endovascular aortic aneurysm repairs (EVARs) were performed. The ProGlide system was used in 235 arteries, yielding a high success rate in obtaining postprocedural hemostasis (94%). There were 13 postprocedural access-related complications, including 5 patients requiring surgical closure due to inadequate seal. Two patients required thrombectomy due to distal embolization. One patient required CFA endarterectomy at 6 months for the treatment of preexisting short distance claudication. Vessel analysis was performed in 31 arteries. Mean preoperative stenosis was 32% (range: 20%-57%). Mean postoperative stenosis was 32% (21%-57%). No significant change in degree of stenosis was detected (defined as a 5% change).

Conclusions:

The ProGlide system yielded a high success rate in obtaining postoperative hemostasis with low rate of conversion to surgical closure and low complication rates. There was no evidence of worsening vessel stenosis in arteries with preprocedural stenotic disease.

Level of Evidence:

Level 4, Case Series.

Development of a Polymer-Based Biodegradable Neurovascular Stent Prototype: A Preliminary In Vitro and In Vivo Study

Biodegradable stents are not established in neurovascular interventions. In this study, mechanical, radiological, and histological characteristics of a stent prototype developed for neurovascular use are presented. The elasticity and brittleness of PLA 96/4, PLDL 70/30, PCL, and PLGA 85/15 and 10/90 polymers in in vitro experiments are first analyzed. After excluding the inapt polymers, degradability and mechanical characteristics of 78 PLGA 85/15 and PLGA 10/90 stent prototypes are analyzed. After excluding PLGA 10/90 stents because of rapid loss of mass PLGA 85/15 stents in porcine in vivo experiments are analyzed. Angiographic occlusion rates 7 d, 1 month, 3 months, and 6 months after stent implantation are assessed. Histological outcome measures are the presence of signs of inflammation, endothelialization, and the homogeneity of degradation after six months. One case of stent occlusion occurs within the first 7 d. There is a prominent foreign-body reaction with considerable mononuclear and minor granulocytic inflammation combined with incomplete fragmental degradation of the struts. It is possible to produce a stent prototype with dimensions that fit the typical size of carotid arteries. Major improvements concerning thrombogenicity, degradation, and inflammatory response are required to produce biodegradable stents that are suitable for neurovascular interventions.

Thermic sealing in femoral catheterization: First experience with the Secure Device

BACKGROUND

Devices currently used to achieve hemostasis of the femoral artery following percutaneous cardiac catheterization are associated with vascular complications and remnants of artificial materials are retained at the puncture site. The Secure arterial closure Device induces hemostasis by utilizing thermal energy, which causes collagen shrinking and swelling. In comparison to established devices, it has the advantage of leaving no foreign material in the body following closing. This study was designed to evaluate the efficacy and safety of the Secure Device to close the puncture site following percutaneous cardiac catheterization.

METHODS

The Secure Device was evaluated in a prospective non-randomized single-center trial with patients undergoing 6 F invasive cardiac procedures. A total of 67 patients were enrolled and the device was utilized in 63 patients. Fifty diagnostic and 13 interventional cases were evaluated. Femoral artery puncture closure was performed immediately after completion of the procedure. Time to hemostasis (TTH), time to ambulation (TTA) and data regarding short-term and 30-day clinical follow-up were recorded.

RESULTS

Mean TTH was 4:30 ± 2:15 min in the overall observational group. A subpopulation of patients receiving anticoagulants had a TTH of 4:53 ± 1:43 min. There were two access site complications (hematoma > 5 cm). No major adverse events were identified during hospitalization or at the 30 day follow-up.

CONCLUSIONS

The new Secure Device demonstrates that it is feasible in diagnostic and interventional cardiac catheterization. With respect to safety, the Secure Device was non-inferior to other closure devices as tested in the ISAR closure trial.