Patient Comfort and Patient Satisfaction with the Mynx® Vascular Closure Device: A Single-Center Evaluation

At Forsyth Medical Center in Winston-Salem, North Carolina, the focus on delivering the highest-quality cardiovascular care is coupled with a focus on patient comfort and satisfaction. As a result, Forsyth Medical Center has been recognized for quality of care and ranks among the top 25 most cost-effective heart programs in the nation and among the top programs in terms of excellent patient satisfaction. In the six cath labs in this 900-bed facility, physicians performed over 6,700 coronary and peripheral artery procedures last year. Approximately 3,500 of these procedures involved femoral arteriotomy closure devices, which have been shown to reduce complications and allow for earlier ambulation and discharge compared with manual compression.1,2 Clinicians and hospital administrators appreciate closure devices because they allow earlier ambulation and discharge of patients, improving patient comfort and permitting treatment of a greater volume of patients with better resource utilization. Because patients now have the ability to go online to review facilities and frequently talk with other patients, it has become more important than ever that our patients leave the cath lab satisfied with their experience. In fact, no part of the catheterization procedure receives as much patient scrutiny as the management of the femoral artery access site. Patients typically are quite comfortable during a diagnostic or interventional procedure, but frequently cite specifics about their closure procedure and the recovery period because of discomfort caused by manual compression or a closure device. If their experience was an excellent one, positive referral patterns are maintained. If their experience was difficult, painful or a complication occurred, patients may or may not tell their doctors, but certainly will tell everyone else, and referrals may be compromised. This 21st century health care dynamic elevates the importance of patient satisfaction with the catheterization experience. Closure devices make patients happy for the same reasons they make physicians and hospital administrators happy. Patients want to ambulate quickly and go home as soon as possible. But for many patients there is pain associated with placement of a closure device, whether it be needles or clips penetrating the innervated arterial wall or compression of the arterial wall between collagen and a foot plate. The Mynx® Vascular Closure Device (AccessClosure Inc., Mountain View, CA) achieves hemostasis using an extravascular, rather than intravascular, design without sutures, plugs, or clips (Figure 1). A water-soluble, bio-inert, non-thrombogenic, resorbable sealant is delivered to the surface of the artery through the same sheath used for the catheterization procedure. When delivered to the tissue tract, a porous polyethylene glycol (PEG) sealant instantly absorbs blood and fluids from the arteriotomy, swelling 3 to 4 times its original size and sealing the arteriotomy and tissue tract. When fully expanded, the sealant is composed of 95% blood and fluids and 5% PEG, which completely dissipates through hydrolysis within 30 days. In June 2008, the Mynx device was introduced at Forsyth Medical Center cath lab. In our lab, closure devices have been used in the majority of patients. However, patients with calcified femoral arteries and sheath insertion sites at or below the bifurcation were not selected to undergo closure device procedures. A closure device option offering patient comfort and the ability to close calcified anatomy or access sites at or below the bifurcation was attractive. Moreover, a device that could minimize the potential for ischemic complications associated with intravascular components was needed. Since its introduction at our institution, the Mynx device has been routinely used in both diagnostic and interventional procedures. The volume of Mynx procedures has grown dramatically and comprises about 75 percent of all closure devices used, largely as a consequence of its safety profile, which has been excellent and without incidence of retroperitoneal bleeding or other major complications. Performance of the device has been consistent, and it is very easy to deliver and use. Physicians appreciate the lack of an intra-arterial footplate and a sealant that fully resorbs, leaving nothing behind. Especially impressive has been the comfort afforded to patients, a benefit important to all patients, but vital to those with chronic pain or low pain thresholds. Study Design and Results At Forsyth Medical Center, we conducted a prospective, post-market, single-center study to evaluate patient comfort and satisfaction with the Mynx Vascular Closure Device. This single-arm pilot study was designed to assess the feasibility of a larger, statistically powered study of patient comfort and satisfaction with closure devices. In this study, 51 patients underwent percutaneous diagnostic or interventional coronary procedures with access through the common femoral artery utilizing a 6 or 7 French (F) procedural sheath. All patients’ arteriotomies were closed with the Mynx device. Patients were asked to rate their pain on a visual analogue scale of 0 to 10 (0=no pain, 10=worst possible pain) at Mynx deployment, approximately one hour post Mynx deployment, and post ambulation. Prior to discharge, they were asked to rate their overall satisfaction with the catheterization procedure and recovery period, again on a scale of 0 to 10 (0=very satisfied, 10=not satisfied at all). No modifications were made to standard sedation protocols. The usual parameters for a closure device study were also assessed: device success, defined as successful deployment of the closure device and successful hemostasis achieved without conversion to manual compression (>10 minutes) or other closure device, as well as major and minor complications. Patients were permitted to sit upright 45 minutes post procedure and to ambulate 1-2 hours after diagnostic catheterizations and 2 hours after interventions. Patient demographics and clinical characteristics are shown in Table 1. No major or minor complications were reported. Device success was achieved in 94% of patients (3 patients required manual compression of 13, 18 and 31 minutes, respectively, without clinical sequelae). Median times to ambulation and discharge were 2.8 hours and 3.8 hours, respectively. As shown in Table 2, mean pain scores were less than 0.6 out of 10 at all assessment intervals and median scores were 0 at all intervals, indicating a near-absence of pain. Furthermore, during the course of the hospital stay, 86-92% of patients rated pain as 0, and 94-98% of patients rated pain as less than 3 out of 10. Similarly, the mean overall satisfaction score of 0.14 (where 0=very satisfied and 10=not satisfied at all) indicates a remarkably high degree of satisfaction with the catheterization procedure and recovery period. These data support observational findings regarding patient comfort and satisfaction. Study limitations include a small sample size as well as the fact that a single-arm design does not allow for comparison of comfort and satisfaction with other closure devices. Additionally, because the study was conducted at a single center, patient comfort and satisfaction outcomes could be vulnerable to the effects of operator-dependent factors. Nonetheless, this study indicates that pain is either eliminated or greatly diminished simply by using an extravascular sealant closure device. At assessment intervals, pain was completely eliminated in the vast majority of patients (86-92%) and significantly mitigated in the remainder. Discussion In delivering an extravascular sealant to the arterial surface, Mynx is less invasive to the artery than closure devices relying on mechanisms actively engaging the innervated arterial wall for closing the arteriotomy. As such, it is feasible that patients do not feel the closure procedure because the conformable sealant does not penetrate or irritate the arterial wall. Additionally, with sutures and clips there is the potential for trapping nerve bundles from the femoral nerve lying next to the femoral artery, which can result in paresthesia. In the case of plug-style devices, compressing the arterial wall between collagen and a foot plate requires a degree of pressure against the arterial wall that can create a considerable amount of discomfort. With the Mynx device, a semi-compliant balloon is used to apply mild pressure to the arterial wall that does not require pinning the arterial wall between two solid structures. The Mynx device is introduced through the existing procedural sheath, obviating a sheath exchange. Consequently, while administration of additional lidocaine is commonplace prior to placement of intravascular closure devices, it is not routinely administered before a Mynx closure in our lab. From a technical perspective, it is important to use a much gentler technique with Mynx. Very little force is required to secure the sealant position during expansion and operators familiar with other closure devices must decrease the usual force required to secure the arteriotomy. In the published literature evaluating patient discomfort and satisfaction with intravascular closure devices, some studies indicate that vascular closure devices may indeed improve patient comfort compared with manual compression, likely as a result of eliminating pressure on the groin and reducing bedrest. Other studies show that vascular closure devices are associated with discomfort compared to manual compression.3-8 Across these studies, however, there is great variability in the timing of assessments, types of pain and discomfort assessed, rating scales used, and methods of analyzing pain data. One thing that is clear from these studies is that a percentage of patients receiving intravascular closure devices do experience peri-procedural arteriotomy pain,3-8 which could be avoided using a closure device with an extravascular design. Similar to intravascular closure devices, the Mynx device can be successfully delivered in greater than 99% of catheterizations, both diagnostic and interventional, achieving hemostasis in a median 0.5 minutes and ambulation in a mean 2.6 hours.9 The Mynx device has proven very easy to deploy.10 In our lab, physicians can have the Mynx deployed in less than one minute. Cath lab technologists are responsible for removing the sealant advancer tube after the 1-2-minute hold time, freeing up the physician to move on to completing the requisite paperwork. With no foreign material left behind in the artery after closure, there is no nidus for infection or embolization and the extravascular sealant itself fully resorbs within 30 days, leaving no scar tissue. Mynx placement does not require dilation of the tissue tract, which tends to result in less oozing than devices that do require tract manipulation. This is important from a nursing management standpoint, because tract ooze means a patient will need to lay flat for extra hours, requiring more care. A patient who has to lay flat for a significant number of hours is not a satisfied patient, especially when observing other catheterization patients who are free to ambulate or go home. Complex Closures Physicians practicing in the cath lab since the advent of vascular closure devices in the mid-1990’s have experienced the evolution of closure devices and no doubt gained an appreciation for the strengths and weaknesses of each design and the proper utilization of each device in various scenarios ranging from routine, uncomplicated procedures to those involving bifurcation anatomy, high sticks, calcification, or re-puncture. While closure devices with intravascular components are typically considered unsuitable for access sites at or below the common femoral artery bifurcation and in calcified vessels, deploying the Mynx sealant to the arteriotomy surface in such cases has been proven safe and effective in our lab and in reports from other labs.10,11 Similarly, where re-puncture at the site of other closure devices is challenging in terms of penetrating scar tissue, re-puncture at or near a Mynx closure site has presented no such challenges in our lab and others.12 Cost Concerns While closure devices cost money, it is important to remember that manual compression does, too. Frequently, labor and facility costs are not incorporated in the evaluation of expenditures for closure devices. In 2005, our facility assessed the impact of closure device use and determined an economical benefit despite the monetary outlay for device purchases. Other research has also shown that the added cost of closure devices is offset by decreases in hospital length of stay, and physician and nursing time.13 Patients undergoing manual compression who are recumbent for 6 hours diminish the efficiency of the lab, as that bed cannot be utilized for another patient and nursing resources are required during the extended bedrest. An added cost results from lost referrals due to patient dissatisfaction resulting from extended bedrest or patient discomfort. Closure devices allow cath labs to serve high and expanding volumes of patients, given a finite number of beds and personnel resources. Conclusions In our evaluation of the Mynx device, patient comfort and satisfaction were very high. The paucity of complications in this study and in our overall experience with Mynx has generated enthusiasm for this approach to closure. Bolstering enthusiasm for the Mynx device is the extravascular design, sealant resorbability and clinical versatility features, experience with uncomplicated restick, and convenient and easy use. The high degree of patient satisfaction, combined with valuable advances in clinical performance, has resulted in broad use of the Mynx device in our lab. Acknowledgments The author wishes to thank Brian Coleman, Research Coordinator for Cardiovascular Research, Forsyth Medical Center, for managing data collection and Laurie LaRusso, MS, ELS, for her contribution to the writing of this article. Dr. Patterson can be contacted at jpatterson2@windstream.net

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