Introduction
Standard of care at most hospitals and interventional cardiology practices is for the attending physician (or fellow) to perform the femoral artery puncture required for vascular access. The advent of vascular closure devices has also dictated that interventionalists invest additional time and energy at the end of the catheterization procedure to ensure safe and effective deployment of these devices prior to patient transfer to the recovery area.1 Manufacturer labeling and Instructions For Use (IFU) have traditionally targeted trained hospital staff as the end user of VCDs, but randomized, pivotal trials conducted for FDA approval of these devices have exclusively engaged well-known interventional cardiologists for demonstration of initial safety and efficacy. 2-5 As a result, very little research has been published regarding the utilization of non-physician cath lab staff for performing the initial arteriotomy and subsequent closure. The primary objective of this retrospective, observational study was to evaluate the safety and efficacy of the StarClose device in achieving hemostasis following diagnostic and percutaneous coronary interventional (PCI) procedures, where femoral arterial access and closure was obtained by a trained cath lab nurse, radiology technologist or registered cardiovascular invasive specialist (RCIS).
Background
The non-physician cath lab staff at Bay Regional Medical Center (BRMC) in Bay City, Michigan has been independently performing femoral artery access and closure procedures for more than 10 years. Though not mandatory or even a requirement of the job, nearly 90% of the nurses, techs and RCISs chose to undergo and complete the training necessary for certification and independent operation. Orientation for this type of advanced practice does not begin until the practitioner has been competently functioning in their current position for at least 6 months.
Once identified as a training program candidate, the orientee is assigned a like-licensed mentor/preceptor and enters into a three-month observation period. During this time they are completely hands off and spend their days scrubbed into cases and aggressively shadowing their preceptors to learn the science of common femoral artery anatomy and the art of successful access and closure. Once this probationary period is complete, the trainee begins attempting arterial puncture on his/her own and is introduced to the StarClose device under strict supervision of the mentor (it is assumed that manual compression techniques have already been mastered). This intensive hands-on training period generally lasts about 6 weeks, and a checklist of knowledge, skills, and abilities is provided as a structured guide. Once the preceptor is comfortable with the arteriotomy skills of the orientee, a physician is assigned to train on sheath insertion, and then observes 10 consecutive placements. If performance is satisfactory, the candidate will be ‘signed off’ with the understanding that their results will be monitored by a senior staff member over the next 2-3 months. A prolonged, direct observation period is also afforded to orientees requiring additional support. During this same time, the Abbott Vascular representative is contacted to perform a proficiency evaluation with regard to the StarClose vessel closure system (VCS), and once proper deployment techniques have been demonstrated, the nurse, tech or RCIS receives a formal training certificate. The entire orientation phase can last up to 8 months.
Femoral artery access and closure for all patients at BRMC, even those at high risk for vascular complications (elderly, obese, diabetic, history of peripheral vascular disease, etc.) is generally 100% achieved by non-physician staff. As a result, a yearly re-evaluation of these skills is performed on all clinicians (via a one-week observation period), and a strict policy has been implemented whereby responsibility for the arteriotomy is handed over to the physician after two unsuccessful attempts by the nurse, tech or RCIS. Needless to say, this occurs very infrequently, and overall cardiologist satisfaction has been overwhelmingly positive. Though skeptical at first, interventionalists quickly came to realize that this unique paradigm was of a clear benefit to their patients, their cath lab flow and their overall time management.
Methods
Study Design. This study was a single-center, retrospective evaluation of 1000 consecutive femoral artery punctures and subsequent arteriotomy closures using the StarClose device. Access and closure were performed by either a cath lab nurse, radiology technologist or RCIS at BRMC between March 2006 and September 2006. Both diagnostic and interventional patients were included.
Study Procedures. All operators underwent device training and a mandatory orientation period prior to performing access/closure procedures independently (see Background). Femoral angiograms were performed on each patient prior to close and the IFU for the StarClose device was strictly followed. Patients whose angiograms demonstrated anatomy or puncture locations unfavorable for VCD use received manual compression and were not included in the study. There was no allowance for a lead-in phase within this study, so final results incorporate and reflect the operators’ learning curve.
Anticoagulation/antiplatelet therapy was administered per standard of care for BRMC.
Device Use. Four clicks cue the operator to the sequence of steps for StarClose device use (Figure 1). The hub of the introducer sheath is modified to allow insertion of the clip applier. When the primary procedure is completed, the catheter is removed and the procedural sheath is exchanged for the StarClose introducer sheath. The clip applier is attached to the introducer sheath and the clip is then advanced down the inside of the sheath (click #1). Next, the vessel locator button is depressed (click #2). The device is then apposed against the arteriotomy with gentle traction, and an atraumatic no-tension position is assumed for device stabilization. The thumb advancer slides forward, which splits the sheath as the clip is advanced to the arteriotomy (click #3). While maintaining neutral tension or pressing down slightly, the trigger button is depressed (click #4), deploying the clip. Subsequently, the clip applier and introducer sheath are withdrawn. The nitinol clip provides a secure extravascular closure that does not invade the vessel lumen (Figure 2). The StarClose VCS has been approved for use by the FDA for diagnostic and interventional indications.
Study Endpoints. The primary endpoint of this study was device success (efficacy) defined as achievement of hemostasis in the catheterization lab allowing transfer to cardiovascular holding unit. Patients who did not achieve immediate hemostasis with the StarClose device were considered failed closures, and converted to manual compression.
Analysis. Patient procedural, angiographic, and demographic information was collected and recorded for the index procedure and then de-identified per HIPPA regulations prior to being transcribed onto a secure excel database within Michigan Cardiovas-cular Institute (MCVI). To protect privacy, each patient was given a specific study number and the stored data referenced only by the investigator. Data review and analysis was then completed to calculate rate of device success.
Results
Of the 1000 consecutive patients retrospectively analyzed, 749 (75%) were diagnostic catheterization procedures while 251 (25%) were interventional procedures. Overall device success rate for the combined population was 96.3% (963/1000). Diagnostic patients demonstrated a device success rate of 96.5% (723/ 749) while interventional patients were successfully closed with the StarClose device 95.6% (240/251) of the time. There were a total of 37 failed closures; 26 of which occurred in the diagnostic population, and 11 in the interventional population.
Discussion
Careful and proper sheath placement, confirmed by femoral angiography, is the cornerstone of a successful endovascular procedure. Vascular complications at the femoral artery access site remain one of the most common and significant detriments to diagnostic and interventional catheterizations. Recent studies have observed femoral access site complications of 2% for diagnostic and up to 10% for PCI, depending on the definition used.6 Puncture sites located above the most inferior aspect of the inferior epigastric artery are associated with retroperitoneal hematoma, while those below the bifurcation of the common femoral artery are correlated with an increased incidence of pseudoaneurysm, AV fistula and dissection. 7 Training programs developed and implemented by the medical device industry have primarily focused on the end user with regard to safe deployment of VCDs, but very little emphasis has been placed on techniques to ensure optimal access. This dichotomy has contributed to a persistent and significant rate of vascular complications.
Bay Regional Medical Center has operationalized a paradigm whereby the cath lab nurses, technologists, and RCISs not only perform the femoral puncture, but also complete the close utilizing either the StarClose VCD or manual compression. This model provides consistency for the patient and affords the operator a great deal of experience upon which to establish and develop his or her arteriotomy skill set. Results of this retrospective analysis suggest that with the proper training and support, non-physician cath lab staff can have success rates for femoral artery puncture and closure that are comparable to or potentially exceed those of cardiologists.
The CLIP Study was the pivotal trial for U.S. approval of the StarClose device and provides an interesting, though not exact, comparison population. A total of 17 sites enrolled 483 subjects randomized at a 2:1 ratio to receive either StarClose or manual compression after the percutaneous procedure. The study included diagnostic (n = 208) and interventional (n = 275) arms with all deployments being performed by trained interventional cardiologists. The primary safety endpoint was major vascular complications through 30 days, with a primary efficacy endpoint of post-procedure time to hemostasis.5 Device success for this study was defined as achievement of hemostasis via the StarClose alone or with ≤ 5 minutes of adjunctive compression and freedom from major vascular complications. The diagnostic cohort had a device success rate of 94.1% (128/136), while 86.8% (160/184) of the interventional subjects were successfully closed in less than 5 minutes. Though the definition of device success varied between the two studies, Figure 3 provides a rough comparison of physician versus non-physician deployments. The CLIP trial confirmed the device was a safe and effective means of establishing circumferential clip-based closure, but the overall, protocol-defined success rate (90% for both populations) fell short of what we observed in the cath lab at BRMC (96.3%). As acknowledged, one possible explanation for this discrepancy could be that the FDA-mandated definition for device success in CLIP was much more rigorous than the one applied for the BRMC study. Additionally, the design and mechanism of action of the StarClose device was still experimental and brand new to operators during the enrollment phase of the trial. As a result, and as one might expect, the final safety and efficacy results of the study included and reflected the learning curve of (investigator) physicians.
Conclusion
Successful femoral artery access and closure when performed by trained, non-physician cath lab staff is feasible and appears to be safe and effective based on this preliminary observational study in patients who underwent diagnostic and interventional catheterization procedures. Additional, prospective studies with the StarClose device utilizing a more formalized hypothesis testing should now be attempted.
The authors can be contacted at:
karen.didonato@abbott.com
Additional information about the policies and procedures behind BRMC staff arterial access can be found in a Cath Lab Digest October 2003 Email Discussion Group, on the web at:
www.cathlabdigest.com/
article/2180
(See the final response, titled Policy and procedures provided.)
Note: This article underwent double-blind peer review by members of the Cath Lab Digest Editorial Board.
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