Final Report 868 Cordis ARTS Deliverability Research Study: Formative Ethnography Study Date: December 23, 2010 Originator: Sean Hägen, Mary Beth Privitera Overview Contents Overview Methodology Objectives Terms Insights Requirements The following report summarizes an analysis of the Arterial Revascularization Therapies Study (ARTS) ethnographic deliverability study. The study captured user preference input in a double-blind, qualitative design research project to better understand physicians’ current and ideal definition of stent “deliverability” and it’s associated system attributes for percutaneous coronary intervention (PCI) stent delivery devices. The study benchmarked user requirements to support the Cordis ARTS by visually mapping the procedure in a static diagram poster and an interactive asset. The study methodology included ethnographic research (contextual observation) of PCI procedures and brief face-to-face interviews. The current respondent sample is summarized in Figure 1: Personas Interventions Conclusions # Appendix Total Case observed Persona Exp Sites Interview PCI Transrad Femoral Cases Transrad Femoral 1 Veteran 15 1 1 2 0 2 5 0 5 2 Common 2 1 1 1 0 1 2 0 2 3 Veteran 10 1 1 0 0 0 2 0 2 4 Common 6 1 1 2 2 0 2 2 0 5 Expert 19 2 1 2 2 0 3 3 0 6 Expert 17 2 1 0 0 0 2 2 0 7 Educator 30 3 1 1 0 1 4 1 3 8 Common 8 4 0 1 0 1 1 0 1 9 Veteran 8 4 1 0 0 0 1 1 0 10 Educator 9 4 1 0 0 0 3 1 2 11 Common 4 4 1 0 0 0 2 1 1 12 Veteran 19 5 1 0 0 0 1 1 0 13 Common 10 5 1 1 0 1 1 0 1 14 Expert 15 5 1 0 0 0 0 0 0 15 Veteran 31 5 1 0 0 0 0 0 0 16 Educator 17 6 1 1 0 1 3 0 3 17 Educator 20 7 1 1 0 1 1 0 1 # Persona Exp Sites Interview PCI Transrad Femoral Cases Transrad Femoral 7 16 12 4 8 33 12 21 17 Figure 1 116104588 1 Methodology The research methodology included contextual observation (ethnography) followed by interviews utilizing a projective mapping exercise that captured the emotional perspective of the primary users. The projective mapping exercise enables the respondent to communicate visually by choosing from provided metaphoric images to represent their experiences relative to a particular moment in time (step) during the usage scenario. The respondent then explains why they chose the particular photographic metaphor image which results in a story-telling opportunity in the interview. The ethnographic observations serve as a source of questions for the subsequent interview as well as providing unbiased contextual behavior as opposed to verbal opinion. The protocol for the study may be referenced in the appendix. The study included seven (7) sites, sixteen (16) interviews, thirty-three (33) diagnostic procedures (12 transradial and 21 femoral approaches) of which 12 resulted in interventions (4 transradial and 8 femoral – see Figure 1). During each site visit, a multichannel video approach was employed which simultaneously captured activity at both the proximal and distal ends of the devices in use. The videos were synchronized during post-production. Observations of the user’s focus of attention were also noted and captured with still images. The site visits were concluded by interviewing users that were digitally recorded. All data was documented (transcribed) for analysis and archiving. Note that data (video, still photography, audio, etc.) excludes any patient specific (identity) data in order to conform to HIPAA compliance requirements. Objectives ► Map the PCI Usage Characteristics during the DES Delivery Steps Characterize and codify the optimal stent delivery experience from the user’s perspective, key current facilitators and barriers, and identify target design criteria for successful delivery system development from device removal from package to device disposal. Visualize the characteristics in a Procedure Map. ► Characterize User Sample Identify and rank User Personas in order to augment the User Preference Inputs. ► Document User Preference Rationale Capture how physicians define deliverability, what procedural factors influence it, how it is measured, and ultimately, what are the attributes of a PCI-system that enables optimal deliverability. 116104588 2 Terms Interviewer: “During the selection of devices are there certain risk states or anatomy situations where you wish you could use a stent, but there’s just not one that’s maneuverable enough?” Interviewee: “Yeah. Mostly, that’s the heavily calcified lesions or the highly tortuous vessels. Those are the two biggest areas where you really have to try to…” - Veteran The following terms highlight basic definitions derived from user interviews and discussions in order to provide additional perspective and meaning towards inherent product design implications and actionable product requirements. Deliverability: A general term related to the use-scenario for advancing the stent catheter along the guidewire to the target lesion and how readily this is accomplished through to stent deployment. The term is interrelated with the definition of Tracking. Trackability: A specific term used to describe the qualities of friction for either the balloon or stent traversing the guidewire. The term is interrelated with Pushability. Pushability: A specific term used to describe the firmness and/or device response from the user’s manual input on the catheter and the device response at the distal end. The term is counter to Flexibility. Flexibility: A general term related to the ability of both wires and catheters to bend around highly contoured and tortuous vasculature. The term is interrelated to Deliverability and counter to Pushability. Crossability: The amount of effort required for a guidewire and/or catheter to reach the distal most portion of an artery beyond a target. The target may either be an untreated lesion or a previously placed stent. The term is interrelated with Deliverability. Insights The following insights that drove the recommendations, conclusions and details articulated in this report as well as the Procedure Map (both the static poster and the interactive asset): Set-up 1. There are three queuing areas for instruments and devices: non-sterile device staging table (unopened packages), sterile instrument table, sterile draped patient (legs and torso). 2. Devices are pulled from decentralized storage located within each cath lab suite as well as centralized areas throughout the catheter lab ward on an “as needed” basis throughout the procedure. 3. The non-sterile device staging table is intentionally visible by the Interventionist, Assistant and Control Room Technician so that the unopened packages can be ascertained if the Circulating Nurse is not in the room. 4. Other than introducing sheaths and preferred diagnostic catheter/guidewire for initial assessment, not many other devices are prepared. 5. Physician and assistant (if used) are always on the patient’s right side. This does not vary between user personas or sites visited. See figure below. 6. Typical set-up includes either a rotating hemostatic valve or 3-port mandrel for Heparin/flush-Nitro access/contrast (see Figure 2). 116104588 3 Insights continued Figure 2 Stent Selection 1. Users may not vary stent brand within the same artery if an artery has a previously placed stent (Physicians 1, 5, and 7). 2. Users base their decision on: initial training, previous stents, literature, use experience, stents in which they haven't used in awhile (spread usage around due to sales rep relationships). “So, there’s a. All stents are specifically picked for anatomical size and location (tortuosity tortuosity, there’s in access) requirements. length, there’s a lot b. Tortuosity and size are equal in importance in stent selection of different criteria. A c. The BMW wire is the most common initial selection bifurcation lesion can 3. Time for decision varies dependent upon clinician: Decision not to stent is almost be very complex immediate for some e.g. some physicians determined the patient was not a good because you might stent candidate within seconds of diagnostic angiogram. end up having the 4. Once they determine to “fix” (intervene), determining size requirements/stent bifurcation stenting characteristics for patient is at minimum 2-3x longer than initial diagnostic or ejective stenting, angiogram review. things like that.” 5. The use of an IVUS system is more common with inexperienced users and/or is of - Educator routine practice for others during pre-dilation. 116104588 4 Insights continued Figure 3 Navigation & Deployment 1. The left hand typically stabilizes and guides the catheter into the sheath while the right hand typically provides control/manipulation/pushing force (see Figure 3). Interviewer: a. This is true regardless of experience level and/or assistant vs. physician. “Is that your preferred b. The forefinger, middle finger and thumb are the primary digits used for drug-eluting stent the detailed motor control manipulation. (Cypher) for c. The user discerns subtle haptic feedback to understand torque, plaque deliverability? structure, tortuosity, disengagement from deployed stent, etc. through a Interviewee: pair of wet surgical gloves. “No, it’s actually less d. Significant coordination between the primary user and the assistant is deliverable. That’s why required to maintain sterility of the devices during preparation, insertion I am saying that there and withdrawal (see Figure 2). might be some give 2. Puff injections (small amounts of contrast) are routinely used to re-inform the and take in radial user of the vascular road map. strength and flexibility a. A referential image is commonly used on one screen while advancement and less deliverable.” is observed on another. - Educator b. It is common that physicians have to adjust to different imaging systems from suite to suite within a single cath lab. 116104588 5 Insights continued “Oh it's night and day. I mean that Cypher is not a really trackable device. Um...it's -- it's much more metal. And uh...and it's -- and it's a less flexible type of metal. So I think it's -- it's definitely hard to get Cypher in places. That was why Taxus became the big stent.” – Veteran “You need the compliant 3. In order to prevent the guidewire from moving, users will bring the stent catheter down (towards patient’s leg) and subtly oscillate catheter during withdrawal. a. In detail: “shake” to get catheter started in reverse then gently pull back with fingers of their dominant hand keeping tension between hands. With left hand maintaining control of the catheter at the entrance of the sheath. Pull down slowly till balloon is in sight (outside patient) grab guidewire with left hand while right hand continues to remove stent catheter. b. Users want to preserve guidewire placement although stent has been deployed. 4. Tracking along the guidewire, or lack thereof, can result in an exchange of devices (e.g. the guidewire may be changed out, the buddy wire system employed) and/or the stent catheter may be removed unused if tracking becomes a formidable issue. 5. The initial Deployment: Atmospheric pressures and length of time vary widely between patients and physicians; ranging between 10-15 atmospheres held for 15-30 seconds. 6. The performance characteristics (compliancy) for the stent deployment balloon are not the same as those for post-dilation. It would be ideal if it were possible to combine or change those characteristics (by the user) without having to introduce an entirely new device. 7. The balloon and catheter getting caught on the stent during removal is a concern (specific events noted from interviews were associated with the Taxus system). balloon for the structure and the non-compliant balloon for the deliverability.” – Educator 116104588 6 The following table is a compilation of brand preferences and associated comments by the respondents: Stent Brand Taxus Boston Scientific Trackability is good but less then Xience (Veteran) Pretty good overall (Educator) Does not have a specific strength that sets it better from any other stents (Educator) Drug is too strong (Educator) Promus Boston Scientific No data Cypher Cordis Nevo Cordis Endeavor Medtronic Driver (bare metal) Medtronic Xience V Abbott Vacular Pro Comments Struts and thinner (Common) Best delivery (Common) Best pushability by far (Common) Flexibility is good (Common) Trackability is good (Veteran) Best data according to patient outcomes, especially patients with diabetes. (Common) Best radial Strength overall (Veteran) Higher radial strength than other stents (Educator) Tracking is just as good as the Driver (Educator) Flexibility is good (Educator) Unique design (Educator) Able to go through tortuous anatomy (Educator) Drug delivery is good, polymer is different than other stents because after 90 days stent is a bare metal (Educator - see transcript example below) Note: usage not observed Flexibility and delivery is best (Expert) Same stent platform as Driver but has DES (Educator) Deliverable because of profile and metal (Common) Crossability is best (Expert) Low profile makes it the best (Veteran) Tracking is good (Educator) Flexibility and takes bends better (Educator) Struts are thinner (Common) Maneuvers the best because of struts (Educator) Drug Data and trackability is good (Veteran) Overall restenosis rate is best (Educator) Crossing profile is good (Educator) Good Data (Veteran) Profile is good (Common) Goes where you want it to go due to low profile (Educator) Best data and good "work horse wire" (Educator) Good Data and well develop (Educator) Con Comments Platform is the worst (Common) Not the best mechanically (Common) Stiffer stent and is not as easy to go through calcium into tortuous vessels (Common) Stiffer Stent causes difficulties for acute bends(Expert) Not very good at trackability (Veteran) Stent has more metal and less flexible (Veteran) Less flexible, less deliverable (Educator) No data Data says the stent is more prone to restenosis (Educator) No data Low Radial Strength (Educator) Issues traveling through highly tortuous calcified arteries when delivering (Educator) Figure 4 116104588 7 Insights continued The following is an example of an interview transcript from Physician 7 commenting on his preferred stent in Figure 4. Physician 7 is an Educator with 30 years of experience preferring the transradial approach yet teaching the femoral approach as an entry level practice (note, English is not the first language of Physician 7). Interviewee: Because one, this Nevo is unique, because it's built on Conor technology, they make it extremely flexible. Interviewer: So, flexibility is... Interviewee: Deliverability, They make the stent very, very smooth... Interviewer: So, the flexibility comes into play when you are maneuvering through torturous anatomy? Interviewee: reservoir Torturous anatomy, right. And not only that, the Nevo they have a Interviewer: Oh, the way the drugs are in the stents? Interviewee: Yeah. They have reservoirs and this is typically the polymer and it washes out in ninety days. After ninety days, you don’t have any more polymer left. So, the polymer is the major offender now. What happens is you get the stent thrombosis, that polymer is blamed for it. Because what happens, if this is your stent and this is the vessel wall like that, this is at the beginning of the deployment, after two years the anatomy changes. This is the stent and this is the vessel wall – you will get a big aneurysm and separation of the medial – this is the medial – you get separation of the medial from the stent and basically this is free floating area and blood flows here and the patient starts Plavix and they get central thrombosis, but the polymer is gone in ninety days and that’s big advantage that you don’t have polymer anymore. So, this is going to be a winner here; it's 1) flexible, 2) is deliverable, and 3) has a polymer which is gone in ninety days. After ninety days the stent is bare metal stent… 116104588 8 Requirements “Because, in my opinion they have the best data according to patient outcomes, especially in patients The following usability requirements (per the Cypher PD) address the entire user experience from unpacking the system to withdraw after deployment (detailed in the Procedure Map). The original requirement copy is in italics. An evaluation of each requirement is provided discussing observed behavior and compiled opinion. Finally a recommendation is provided to indicate where, if appropriate, the users experience may be enhanced with further design considerations. with diabetes.” – Common Interventionist “If it’s something that I think will be demanding of radial strength, I'll tend to still use the Cypher or something. I think Cypher probably has the most radial strength” – Veteran 1. It should be easily removed from its packaging without significant risk of damage to the product. a. Current packaging design meets this need, however, when the sterile bag is opened the contents are often dropped on the instrument table and therefore if the packaging is round it has the risk of rolling off the table. b. Recommend: Inner packaging tray geometry shall not be capable of rolling. 2. It should be easy to prepare and flush prior to use. a. Preparation and flushing of the stent catheter is primarily completed by an assistant (tech or fellow) during this task the attending will coach them on technique for insuring sterility (e.g. monitoring both ends of the device, how to coil it for immersion in the saline bath, etc). b. Observed challenges include threading stent catheter on guidewire in the inconsistently illuminated alignment conditions. c. Recommend: consider packaging tray that also functions as a “bird bath” for use in the flushing process 3. The user requires product that is easy to handle and will not easily damage, beginning with removal from packaging through actual use with dim lighting and readily accessible preparation equipment (syringes, stopcocks, etc). a. This requirement is redundant to requirement #1; in both instances the definition of damage is not defined. b. Damage is commonly communicated by users as those actions/manipulations that results in inadvertent kinks in the guidewire and/or guide catheter. Kinks in these tools may require a device exchange resulting in increased overall procedure time as well as an increase in expense to patient. c. Recommend: Focus a unique requirement on potential damage for each phase of use: preparation, advancing-deployment, and withdrawal. 4. During use, it should be designed such that it is easy to maneuver: advance and retract through the guiding catheter and over the guide wire. 116104588 9 a. Ease of maneuver, advancement and retraction can be broken into 4 distinct phases or steps: threading/loading onto guidewire, navigate stent catheter towards target lesion, deployment and removal/withdrawal. b. Users interact with the stent catheter differently for each phase: i. Threading: fine motor control with precise hand-eye coordination which can be accomplished as a team (physician and assistant) or independently to insure the entire device does not inadvertently exit the sterile field. ii. Navigation towards/through lesion: intermittent pushing motions whereby non-dominant hand serves as a stabilizer guiding the stent catheter within the guide catheter while the dominant hand completes the majority of pushing motion. These motions are generally swift and confident through the aorta to the distal edge of the guide catheter. Once advancement to the target lesion has been grossly achieved, users complete more subtle small micro-motions with the forefinger, middle finger and thumb of their dominant hand to finesse stent device into final placement. Two disparate forms of feedback guide the clinician: haptic (sense of touch specific to the resistance of the devices within the anatomy) and visual (much of the visual feedback is not in real-time and requires cognitive mapping due to the nature of fluoroscopy, i.e., maximum dosage of contrast agent). c. Deployment: Adherence to the IFU regarding inflation pressure/duration are subject to context and technique. d. Removal/Withdrawal: Rate and oscillation varies depending on users and phase of the procedure (e.g. exchange catheter vs. closure). i. The haptic perception that the balloon/catheter is catching on the stent during removal is a constant concern. ii. Guidewire position preservation for exchanges during the procedure is critical. Observed techniques to maintain position include pulling the catheter down (towards patient bed) at a steep angle then using quick fine oscillating motions as the catheter is removed. iii. Removing the guide catheter too quickly upon final withdrawal may result in a “whipping” effect that can compromise wound closure. e. Recommend: Focus a unique requirement on ease-of-use for each phase of use: preparation, advancing/navigation, deployment, and withdrawal. Consider haptic biomechanical capabilities of the user (wearing surgical gloves) when developing and testing delivery systems (e.g., ungloved finger sensitivity is capable of discerning micron level texture changes) 116104588 10 5. The stent will be visible such that accurate placement will be possible (e.g., crossing, sizing, dilation, overlapping, confirmation). a. For accurate placement of the stent users can readily see the stent but rely heavily on a mental map of the vessel roadmap to navigate positioning. b. IVUS is typically used for accurate sizing and prediction of dilation response either as routine practice or to inform decisions. c. Recommend: no change to this requirement, however, IVUS compatibility should be accommodated and may require a modification and/or additional requirement. 6. The stent and delivery system will be designed such that delivery through distal and tortuous vessels will be possible. a. Delivering to distal vessels remains a challenge as verbalized in interviews. Users refer to the definition of distal vessels as the delivery of a stent at the farthest most point reachable along the guidewire as well as the ability to deliver a stent distal from a previously placed stent. b. Tortuosity also remains a challenge. Users define tortuosity as the natural three dimensional curvature course of the anatomy. In extreme cases this is observed as a corkscrew formation traversing considerable vasculature length. Users note the change in natural shape as a result of accessplacement e.g. anatomy straightens when stent is deployed. While this is not necessarily problematic, clinically, users perceive this as a considerable change. Considering the Hippocratic creed of “do no harm”, this represents an opportunity for stents to better conform to the natural anatomic geometry. c. This requirement does not address the additional challenge of the users to cross heavily calcified regions. d. Recommendation: Requirement should consider individual elements within each condition – distal vessel, tortuosity and calcification and revise accordingly. 116104588 11 Personas The following stereotypes generalize the personalities of the typical user population observed during the study. The intention of these generalizations is to codify user types so that performance expectations can be prioritized by user group. Expert A key opinion leader; a Veteran that has performed over 200 PCI procedures a year, upwards to 400 per year Extremely self-confident; highly involved in the interventional cardiac community Enjoys a challenging case (minor complications or torturous anatomy) Works with a consistent team Has a very strong ego, respected by staff and colleagues Advocates his optimized procedural techniques and has strong opinions Less interested in minor advancements to devices/procedure Leads research to develop devices/techniques to match his protocols Has seen it all and claims to not be challenged or anxious Is easily frustrated by device deficiency and impatient with new technology Educator A Veteran or Expert who has additional academic responsibilities such as fellowship training and/or clinical research Level of case volume varies due to teaching responsibilities but typically performs over 200 PCI procedures per year Highly enthusiastic, contributes to the greater good of healthcare Enjoys discussing the benefits and techniques of the procedure Open to experimenting with new devices and techniques A good listener who enjoys problem-solving and helping others A team player, but has an inconsistent team; typically has a fellow as an assistant Open to try new technologies and is patient with minor device iterations Veteran Performs over 200 PCI cases per year Enjoys telling others about the benefits and techniques of the procedure Very confident in his technique, yet often modest and open to optimization Loves a challenging case (minor complications) Comfortable with current procedure; willing to try new protocols that promise to advance patient outcome/business case Is focused on throughput and volume of procedures per year Techniques are optimized – systematic/repeatable work flow Frustrated when issues during procedure cause delays Impatient with technology unless an early adopter (function of demographic) 116104588 12 Personas continued Common Interventionist Performs fewer than 200, PCI procedures per year Frustrated with most complications Very cautious about device selection and protocol to prevent complications Eager to learn new ideas, techniques, and devices, but follows the lead of a mentor – highly influenced by opinion leaders Is familiar with the entire procedure and performs the procedure in the same manner following same steps and approach each time – has not developed techniques beyond original training Little variance in procedural practice unless confronted with complications Conclusions “It’s planning based on risk of the lesion in the sense of sometimes, if you got a heavily calcified lesion, there’s the risk in the sense of it being a very difficult and is it likely to be a successful intervention. But then also a risk, in the sense that if it’s a bifurcation lesion, is it high risk ’cause you’re gonna close In the past stent delivery systems were expected to enable interventionists to treat lesions in vessels that were readily accessible. As technology improved and the design of the systems was optimized within the constraints of currently utilized materials and processes, the systems have become commoditized. This is evident in the fact that no one manufacturer “owns” the entire procedure (providing a kit that includes all the primary devices need for stent delivery) from one lab to the next. Developing a system of devices that would enable Cordis to be the primary brand for PCI procedures within an institution is a strategic opportunity. The physicians’ skills and techniques have also evolved to optimize the current product offerings. The result is a changing definition of what a “readily accessible lesion” means according to the physicians. The really challenging cases where deliverability is significantly tested (e.g., bifurcations, crossing an existing stent, smaller vasculature, etc) are becoming more common and place more demand on the performance requirements of future stent delivery system development. Utilizing this insight to drive an intervention system that starts at the sheath introducer and ends with a post dilation device could change the paradigm. down a side branch that you’re crossing.” - Veteran 116104588 13 Conclusions continued The following list summarizes the trends identified so far during this study: “The compliance of the balloon that a system is Pre-dilation occurs 75% of cases (N=12). Preferred approach (radial vs. femoral) has no influence on stent choice. The domestic occurrence of the transradial approach is becoming significantly more common than previous study 5 years ago (from 15% to 30%; N=12 of Rx cases; 36%; N=33 of Dx). Xience is the preferred brand of stent based on deliverability. I have to, once I have to that what I prefer over a to be a bit stiffer about getting around bends. Of course, will be knowing the data or restenosis.” - Expert Navigating a wire through the struts of an existing stent into a bifurcation is a difficult challenge. A means to visualize the extent to which two over-lapping stents are engaged would be useful. going to be bigger. So if compliant, you’re going o need a 3.0, I think it’s stent that is non- Bifurcations and existing stent location are also challenges requiring higher performance of the stent delivery system. Use of marker wire varies and is experience/preference/imaging equipment driven; commonly used but less often by the more experienced (current marker spacing is sufficient; those that use a variety of imaging equipment use them more often due to inconsistence magnification). talked earlier about. non compliant balloon. A o compliant balloon, we it into to go up higher so Selecting the appropriate guidewire to provide adequate support traversing the lesion is directly correlates to procedural success. The interventionist has to be able to discern subtle haptic feedback to understand torque, plaque structure, tortuosity, disengagement from stent, etc. with the forefinger, middle finger and thumb through a pair of wet surgical gloves. These criteria should be accounted for during bench-top testing (new device design and development). like a little bit more see it and dilate and look o on, I tend to personally Sometimes thinking I will Tortuosity and calcification are the most difficult challenges. 116104588 o Preference is based upon deliverability specifically communicated as thin struts/low profile as well as complimentary available data (demonstrated success in published literature). o Cypher is used because of the data available for the pharmaceutical outcome despite an acknowledged deficiency in the deliverability relative to the Xience system (5 comments in 14 interviews; Figure 2). o Radial strength is perceived to be better in the Cypher than the Xience by those that use the Xience yet they choose to sacrifice that attribute in exchange for better deliverability. 14 Appendix ARTS Protocol 868_ARTS Protocol_082610.doc Discussion Guide 868_Discussion Guide_071410.doc Interview Data 868_Interview Data_120810_r1.xls 116104588 15