Applied Radiology

The last 2 to 3 years have seen the development of new devices to assistwith closure of arterial puncture sites following diag-nostic andinterventional endovascular procedures. The basic premise is that a medicaldevice can be used to acceler-ate the time to hemostasis at the groin followingremoval of the in-dwelling sheath. Currently, most centers will pull the sheathand apply manual compres-sion, a sandbag, or an external com-pression device toachieve hemostasis. Subsequently, the patient must lie flat for at least 6hours and must be monitored continuously. This requires specialized nursingunits and is a con-siderable strain on the resources of the hospital, and asource of inconvenience and discomfort for the patient. A num-ber of studieshave also shown that sim-ple manual compression is associated withapproximately a 5% complication rate at the groin, most of which are relativelytrivial, i.e., a small hematoma. 1-3 However, a number of more seriouscomplications can ensue, notably arter-ial pseudoaneurysms, arteriovenousfis-tulae, and infection. The overall cost to the hospital for the monitoringand management of complications can be substantial.

For this reason, a number of devices have been designed to increase theeffi-ciency of arterial hemostasis, with a view to reducing complications andaccelerating discharge of patients from the hospital. These devices areparticu-larly useful in achieving hemostasis in patients who have undergoneinterven-tions requiring aggressive systemic anti-coagulation and the use ofantiplatelet agents. Often, achieving hemostasis in these patients can beextremely difficult. Arterial closure devices can be catego-rized into 2different types: suture-medi-ated and nonsuture-mediated closure devices.

Suture-mediated closure devices

Perclose systems- The first suture-mediated closure device wasmanufac-tured by Perclose (Menlo Park, CA). Recently, this company waspurchased by Abbott Laboratories (North Chicago, IL). The first generationPer-close device utilized a unique method of delivering needles and suturesinto the vessel. The needles are deployed from the inside of the artery throughthe anterior arterial wall onto the skin. A knot is then tied and advanced downto the arterial wall using a knot pusher. Initial trials have shown Perclose tobe extremely efficient, with over a 95% success rate in arterial closure. 4,5The Perclose device is available in either a Techstar or Prostar version. TheTech-star device is a 6F device that has recently been upgraded to the Closersystem.

Both the Techstar and Closer sys-tems utilize two needles with one suture.The Closer device is advanced directly into the vessel over a stan-dard0.035-inch guidewire following removal of the in-dwelling sheath. The guidewireexits the device in a mono-rail fashion. As the device is advanced into thevessel, a unique "marking sys-tem" alerts the operator when thedevice is in the appropriate position, as blood is seen to exit from the hub ofthe device. A footplate is then deployed inside the vessel and the devicewithdrawn until it is felt to become taut against the inner surface of theanterior wall of the vessel. By pushing down on the plunger in the hub, needlesare advanced through the anterior vessel wall catching sutures in the devicefootplate. These are then removed with the sutures attached, and are tied in aknot using a unique "clincher" knot-tying device. A pusher is thenused to aid advance-ment of the knot to the anterior surface of the bloodvessel (figure 1). Following successful closure of the vessel, patients can situp imme-diately, are monitored for 1 hour, and dis-charged. The suture ismanufactured from nylon and does not dissolve; it is left inside the patientpermanently.

The Prostar system is available in 8F and 10F versions and uses 4 needleswith 2 sutures. While Prostar devices use a similar system to the Closer, theneedles are advanced from within the vessel to the skin surface. This sys-temalso has a larger hub configuration, which requires some degree of"tunneling" of the device down to the vessel surface. This device issomewhat more cumbersome than the Closer system and can be associated with amoderate amount of patient discomfort.

A number of operators have used the 6F Closer, and the 8F and 10F Prostarsystems to close much larger arteriotomy sites. The basic technique involvesdeployment of the device during dilatation of the vessel. For example, for a12F sheath, the arterial puncture is made in the usual fashion. Sequentialdilatation is performed over a guidewire. After placement of the 8F dilator,the 8F Prostar device is placed and deployed. The untied sutures are left onthe skin of the patient, the device is removed over a guidewire, and sequentialdilatation continued until the 12F sheath is placed. Following the procedure,the knots are tied and the sheath removed while they are tight-ened. This"pre-close" technique, which has yet to be reported in theliterature, is extremely use-ful and has been utilized to successfully closepunctures of up to 24F in diameter.

Potential problems that can occur with the Perclose device include failureto tie a "slip-ping" knot. If the knot is tied inappropriately, itwill not slide to the anterior vessel wall, resulting in device failure. Whenthis occurs, mechanical pressure will be required to achieve hemostasis.However, the development of the "clincher" device, which guarantees aproperly tied knot, has significantly reduced this problem. The otherpotentially serious problem, which was a drawback of the first generationTechstar device and continues to be a potential problem with the 8F and 10FProstar device, is failure of the Nitinol needles to enter the hub of thedevice after exiting the anterior wall of the vessel. If this occurs, thephysi-cian can back the needles into the device and either retry or place a newdevice over the wire. Unfortunately, if the needles do not access the hubappropriately and the physician is either unaware or unable to correct theproblem, the needles can become fixed in the soft tissues of the patient. Thishas required surgical retrieval of the needles. With adequate training andexperience, this complication is extremely rare, and cannot occur when usingthe more modern 6F Closer device.

When used appropriately, the Per-close family of devices is extremelyefficient and provides the operating physician with a great deal of confi-dencein the outcome of the closure. For this reason, the Perclose suture-mediateddevice has gained wide acceptance among interventional car-diologists, and itsuse in interventional radiology is growing rapidly.

Sutura- The SuperStitch device (Sutura, Fountain Valley, CA) is anew suture-mediated closure device that has yet to receive FDA clearance foruse in percutaneous arterial closure. A variety of different-sized devices (6Fto 18F) are used to close arteriotomies of up to 24F in diameter. The device isintroduced into the vessel through the in-dwelling vascular sheath and afootplate is deployed. The device is withdrawn until the footplate is felt toencounter the anterior vessel wall. Needles are advanced from the device intothe anterior wall of the vessel, picking up sutures in the footplate of thedevice. The needles are then with-drawn and sutures tied in the usual fashion(figure 2). The basic mechanism of the device is quite similar to that utilizedwith the 6F Perclose sys-tem. The differences between the two devices are thatthe Sutura device does not enter the vessel over a guidewire, rather it isplaced through the in-dwelling vascular sheath. The Super-Stitch device willalso be available in a larger variety of sizes, up to 18F. The device hasundergone trials in Europe, and recently received 510k clearance: limitingmarketing of the device for general surgical or endo-scopic procedures. Aclinical trial to achieve approval for use of the device to close percutaneouspunctures will begin this year. Initial results from tri-als in Europe areencouraging.

Non-suture-mediated devices

A number of devices (some FDA approved and others pending FDA clearance) arein use or in trials in the United States. All of these devices use some form ofmechanical barrier or "plug" to close the vessel puncture site. Twodevices approved by the FDA have gained widespread accep-tance: AngioSeal andVasoSeal.

AngioSeal-The AngioSeal device is currently owned by St. Jude Medical(St. Paul, MN). An anchor plate placed within the vessel provides tension on acollagen plug, holding it in place on the outside of the vessel wall, therebymaintain-ing hemostasis. The system is delivered by removing the in-dwellingsheath and placing the 8F AngioSeal sheath within the vessel. The guidewire anddilator are then removed and the anchorplate delivered through the sheath intothe vessel. The sheath is then removed, and tension maintained on the anchorplug until collagen has been placed outside the vessel wall. Pressure on thecollagen is then maintained for 15 to 20 min-utes using a spring system (figure3). At this point, the spring is removed, and the device left in place tobiodegrade. Com-plete absorption of the collagen plug and the anchorplateshould be take place in 30 days. The device has shown good efficiency in earlyclinical trials, with a hemostasis rate of 95% to 98%. 6,7 A number ofcomplications have ensued from the use of this device, the most notorious beingdisplacement of the in-dwelling anchor plug down the vessel, resulting inembolization at the popliteal trifurcation. While the anchor-plug is made ofreabsorpable material, it requires 30 days to be fully absorbed andembolization of this plug prior to this time will require surgical removal.This complication has occurred in only a small number of patients. Themanufacturers received FDA clearance for a 6F rendition of this device in early2000. While this version uses a somewhat modified anchorplate, the basicdeployment of the device is the same. One significant downside of the device isthe recommendation that the puncture site not be repunctured for at least 30days. The same vessel can be accessed in a different location, however, thereare concerns that puncturing a non-absorbed anchor device may be problematic.

VasoSeal-The VasoSeal closure device (Datascope, Montvale, NJ) issomewhat similar to the AngioSeal device. It also uses a collagen plug pressedup against the anterior arterial wall at the puncture site; however, there isno prosthesis left within the vessel. The initial arterial sheath is removedover a guidewire and an 11F blunt tract dilator is used to dilate the skin tothe anterior surface of the ves-sel wall. Through this tract, a plug ofcollagen is then pressed down against the arterial vessel wall to providehemostasis (figure 4). Manual occlusive pressure must be provided up-streamfrom the puncture site while the collagen is deployed. This occlu-sive pressureis released gradually over a 30 to 60 second interval while non-occlusivemanual pressure is ini-tiated over the collagen plug. A num-ber ofcomplications have arisen from operators inadvertently delivering the 11F blunttract dilator into the vessel. The Datascope device has also shown reasonableefficiency in initial clinical trials, approaching 95% hemostasis. 8,9 Like theAngioSeal device, the vessel should not be re-entered for 30 to 60 daysfollowing delivery. Both the AngioSeal and VasoSeal devices use bovinecollagen.

Duett device-- A number of pre-FDA clearance devices areundergo-ing trials in the United States, including the Duett device (VascularSolutions, Minneapolis, MN). This device utilizes a 3F catheter advancedthrough an in-dwelling arterial sheath. The catheter has a balloon on thedis-tal end, which is inflated. The sheath and catheter are then withdrawn fromthe vessel until the intra-arterial bal-loon becomes engaged in the anteriorarterial orifice. A solution of thrombin and collagen is then delivered throughthe sheath into the periadventitial region of the artery. This solutionpro-motes rapid development of an adher-ent clot at the anterior vesselsurface, thereby promoting hemostasis. The one downside of this device is thepotential for inadvertent delivery of thrombin and collagen into the vessel,which would result in significant intra-arterial thrombosis. A number of othermanufacturers are developing non thrombogenic solutions to pro-vide materialplugging of the vessel wall, deployed in a similar fashion to the Duett device.These devices are all in pre-clinical stages and results have yet to bereleased.

Discussion

In 1998, approximately 9 million intra-arterial interventions wereper-formed worldwide. Of these, less than 500,000 were closed using amechanical closure device. The potential for an increase in this marketshare isthe dri-ving force behind further product devel-opment. The potential financialbenefits to the company that secures a significant marketshare is so huge thatthese sys-tems are likely to be here to stay.

Suture-mediated devices provide the clinician with the most reassuringfeed-back following successful closure, but they have a steep learning curveand potential complications and cost. Non-suture- mediated closure devices maygain a foothold in smaller hospitals and in patients undergoing simpleproce-dures, as these devices are less expen-sive. The cost to a hospital of aPerclose device is approximately $300 per unit, whereas an AngioSeal devicecosts approximately $150. Medicare and most HMOs do not pay for the proce-dure.However, hospitals seem willing to pick up the costs in return for reducedpatient stay and complica-tions. Any serious doubts in the profes-sion thatmechanical closure devices were simply a fad were removed when AngioSeal andPerclose were pur-chased by large corporations for $150 million and $650million, respectively. This industry is here to stay, and it is beholden uponinterventionalists to understand these devices, and to make their own decisionas to which they feel is most beneficial to their patients.

Conclusion

In summary, a number of suture-mediated and non-suture-mediated clo-suredevices are now approved and available to assist in achieving hemo-stasisfollowing arterial interventions. When compared with the more tradi-tionalmanual pressure, these systems are more efficient at achieving hemo-stasis,particularly in patients who have undergone interventions using antico-agulantor antiplatelet agents. Compli-cations are low, and cost issues can be offsetagainst more rapid discharge of patients. Additional devices are under-goingdevelopment and will be avail-able in the next 12 to 24 months. AR

REFERENCES

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2. Muller D, Shamir K, Ellis S, et al: Peripheral vascularcomplications after conventional and complex percutaneous coronaryinterventional procedures. Am J Cardiol 60:63-68, 1992.

3. Ricci M, Trevisani G, Pilcher DB, et al: Vas-cular complicationsof cardiac catheterization. Am J Surg 167:375-378, 1994.

4. Kussmal W, Buchbinder M, Whitlow P, et al: Rapid arterialhemostasis and decreased access site complications after cardiaccatheterization and angioplasty: Results of a randomized trial of a novelhemostatic device. J Am Coll Cardiol 25:1685-1692, 1995.

5. Prostar: Instructions for use. Perclose Inc, Menlo Park, CA.

6. AngioSeal: Instructions for use. Sherwood Medical Company, St.Louis, MO.

7. Chevalier B, Lancelin B, Berrthaux X, et al: Hemostatic punctureclosure device versus regular compression: A randomized study. J Am CollCar-diol Special Issue 92A:16(Feb), 1995. Abstract #918.

8. VasoSeal: Instructions for use. Datascope Corporation, Montvale,NJ.