Vascular Closure Devices

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Citation
European Cardiovascular Disease 2006 - Issue 1;2006:2(1):73-75
DOI
http://dx.doi.org/10.15420/ecr.2006.1.73

Despite the recent introduction of vascular closure device (VCD) technology, vascular access site complications remain the leading source of morbidity and costs after the approximately eight to eight-and-a-half million percutaneous catheter-based procedures performed annually worldwide. VCD trials consistently demonstrate increased patient satisfaction, early ambulation, and decreased hospital resource utilisation compared with manual compression (MC). Unfortunately, these reports have not consistently demonstrated decreased complication rates, and current VCD technology has even created a new category of complications and treatments primarily involving infection and arterial thrombosis.

In 1953, Seldinger classically reported the original description of percutaneous femoral artery (FA) access and, in so doing, first reported vascular access haemostasis (VAH). Since then, significant technological advances in the field of catheter-based cardiovascular (CV) therapy have rendered most early percutaneous technology obsolete. It is remarkable that, 50 years later, the gold standard of VAH remains MC, performed almost exactly as Seldinger originally described, "20-30 minutes hand-held pressure after catheter removal followed by overnight bed rest." This gold standard remained largely unchallenged over the next four decades, until the widespread adoption of percutaneous CV interventions. These procedures require larger sheaths and more potent anticoagulation, increasing the clinical potential for complication.

The Problem Exposed

FA access complications (FAC) remain a significant source of mortality and are the leading cause of morbidity and costs after percutaneous coronary intervention (PCI). Remarkably, no standardisation exists with regard to reporting 'major' and/or 'minor' FAC rates, which vary widely from 0.4% to 27% depending on the definition of complications. Most reports site only 'major' FACs requiring surgery, and it is highly likely that many FACs go unreported or are accepted as 'part of the territory'.

Duffin et al. were among the first to identify FACs as a major problem, noting a 14% bleeding rate with PCI. In a randomised trial comparing MC with AngioSeal (St Jude Medical, St Paul, MN), Kussmall et al. reported a 27% overall 'any complication' rate in the MC group with heparin. In 2001, Danges et al. compared MC (n=4,596) with VCDs (n=497) after PCI and reported higher 'overall complication' rates with VCDs versus MC (21.4% versus 12.1%, respectively), again confirming significant 'overall complications' with MC and identifying that current VCD use may increase complications.

Pracyk et al. cited a 64% overall FAC rate with MC when patients were thoroughly scrutinised by physical examination and duplex ultrasound. A review of the literature reveals sparse data on MC with regard to a haemostatic mechanism, healing or scarring of the arteriotomy site, short- or long-term FA clinical sequelae, systemic effects of a groin haematoma, or a consensus recommendation on the safety, risks and timing of FA re-entry. After 50 years of truly remarkable CV technological achievements, it seems reasonable to ask whether MC should still be the gold standard, and why.

FAC - Clinical and Economic Costs

Aguirre et al. found FAC increased the length of patient stay to an average of 3.5 days compared with <2 days in an uncomplicated PCI. Moscucci et al. suggested that FAC may indirectly increase ischaemic complications after PCI when they reported the incidence of death and myocardial infarction (MI) among patients with FAC as 2.4% and 13%, respectively, versus 0.2% and 3.0% in 4,090 PCI patients without FAC (p<0.0001). Extrapolating financial costs to FAC is difficult, but in tracking blood transfusions after PCI, Lauer et al. estimated a single unit of blood transfusion during PCI adds an additional US$8,000 to the overall cost of that hospitalisation. The Replace-2 study has now shown increased 30-day and one-year mortalities in PCI patients who experience a bleeding complication and increased morbidities (MI, need for repeat PCI, etc.).

Limitations of Current VCD

Currently, it is estimated that only 20-25% of all catheter-based procedures performed worldwide utilise a VCD for access site haemostasis. Several potential limitations associated with current technology that limit widespread clinical VCD utilisation are summarised in Table 1.

Achieving the 'Ideal VCD'

Titanium has become the most common human metal implant material because of its superior properties of strength and pliability, biocompatibility and inertness, and cost-effectiveness compared with stainless steel, making it ideal for the intricate Angiolink staple design. Permanent braided sutures, collagen plugs, and other absorbable procoagulants used with current VCD are non-inert, highly reactive, and may be an aetiologic factor in infection and arterial thrombosis.

The one-piece introducer assembly system has been designed for simplicity, uses cost-effective materials, and has a short learning curve. The staple remains sterile within the stapler 'housing' and introducer until final deployment inside the body at the extraluminal vessel wall - much like the sterile deployment of a stent, therefore avoiding operator or skin contamination. The entire system is designed for single-operator use and, with experience, the total operator closure time should be less than 60 seconds.

The 'purse-string suture' closure concept is a well-known surgical technique used to close large arteriotomies in large vessels, with the most notable being decannulation of large-bore cannulas from the ascending aorta during cardiac surgical procedures. The technique utilises pledgets to gather only vessel adventitia and media at the arteriotomy edges, allowing for tissue approximation when the cannula is removed and the suture is tied. This results in immediate, secure, totally extraluminal vessel closure in the anticoagulated patient with pulsatile aortic blood flow. This extraluminal closure is accomplished without luminal narrowing and, therefore, this device theoretically could be utilised in any vessel regardless of 'stick' location, size or anticoagulation status and could allow almost immediate ambulation.

Conclusion

VCDs were initially designed to achieve convenience for the patient and hospital and this has largely been achieved in the 20-25% of currently treated patients. This has likely been achieved at an increased complication rate with current VCDs.