Innovation Chronicle

Innovation chroniclE

M E R I T M E D I C A L

M E R I T M E D I C A L

Dr. Stephen ASh DiScuSSeS A new ApproAch For the DeSign oF centrAl VenouS DiAlySiS cAtheter: the centroSFlo™

Interview with Dr. Stephen AshStephen R. Ash, MD, is Chairman, Medical Director, and Director of Research and Development at Ash Ac-cess Technology, Inc. Dr. Ash is certified by the American Board of Internal Medicine, Nephrology section, and is a Fellow of the American College of Physicians. He is a Founding Member of the American Society of Diagnostic and Interventional Nephrology, he holds over thirty U.S. patents and is the author of over one hundred articles.

Why did you choose medicine as a career? “I was always interested in science, especially physics (my major in college);however, I was also impressed by the special opportunities for service that physicians have for their patients (my grandfather was a highly respected physician in South Dakota).”

Were you always inventive? “I guess I was. I loved building things. In the 4th grade in Kansas City, I invented an air conditioner for my grade school desk. The teacher showed it to the principal who said he’d love to have it on his desk, so I proudly gave it to him (which of course resolved a lot of noise and distraction in our classroom).”

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How does the Ostial Pro help to engage the aorto-ostial wall? “Once the legs of the Ostial Pro are deployed at the tip of the guiding catheter, you push the guide forward. Once the feet have engaged the wall, you will see the legs begin to bend back-ward a little bit. When the legs are touching, and the guiding catheter cannot be advanced any further forward, you have tactile and visual feedback. You can do a little puff of contrast and you will see the ostium. You will see the gold feet, and you will see exactly where the ostium is in virtually every case. You can feel it. It’s tactile. You can see the os-tium. It is visual. It will bring the tip of the guide to almost exactly 0.5 mm just outside the ostium in every case, allowing you to very precisely deliver the stent to the perfect position, flush to the ostium.”

“You will see the gold feet, and you will see exactly where the ostium is, in

virtually every case.”

Tim A. Fischell, MD, FACC is Director of Cardiovascular Re-search at Borgess Medical Center in Kalamazoo, Michigan. He is a Professor of Medicine at Michigan State University. He graduated from Cornell University Medical College and Cornell University. He is the inventor or co-inventor of more than 60 patented medical devices. He is the Medical Director of Ostial Solutions and the inven-tor of the Ostial Pro Stent Posi-tioning System.

What clinical need were you addressing with the creation of the Ostial Pro? “The main problem is angio-graphically being able to identify where the ostium is, this is true, both in the renal and perhaps even more so, in the coronary arteries. The right coronary can be particularly deceptive.”

Where did the idea of the Ostial Pro come from? “This arose out of my own frustration. In one week, about 4 to 5 years ago, I had three right coronary aorto-ostial lesions and

missed all three. I ended up hav-ing to put a second stent in, I think, at least two of them. I thought, ‘There has got to be a better way to stent aorto-ostial lesions! Let’s make a tool that’s relatively simple that will allow, even me, to get it right.’”

Is stent misplacement at the ostium a common occurrence? “In two studies that we have recently published, we looked at 100 consecutive coronary aorto-ostial cases. When using only angiographic guidance, the inci-dence of missing the ostium with the stent, by at least a millimeter, was 54-60% among highly expe-rienced interventionalists.”

Tell us about the Ostial Pro. “The Ostial Pro is a small, novel Nitinol device. It has 4 “legs.” On each of the tips of the legs, there is gold plating so you can see the legs fluoroscopically as they pop out of the distal tip of the guiding catheter. The legs are meant to go up onto the aor-tic wall to prevent the tip of the guiding catheter from going into the coronary artery, and to mark the origin of the ostia.”

The OsTial PrO® stent Positioning system helps engage the aorto-Ostial Wall for More accurate stent Placement

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Contents page

Alter, Barry MD, FACP, FACC 3 AsAP® Aspiration Catheter 2 Ash, stephen MD 1, 4 Caputo, Ronald MD, FACC, FsCAI 2 CentrosFLo™ 1, 4 Clo-sur PLUs P.A.D.™ 3 Crossword 2 Fischell, tim MD, FACC 1 Hori, shinichi MD, PhD 2, 3 Merit Maestro® 3 ostial Pro® 1 osuga, Keigo MD, PhD 4 Restaurant Guide & Map 1 Quadrasphere® Microspheres 2

Visit the Merit Medical Booth 519 at Sir in San Francisco March 25 - 28

Shinichi Hori, MD, PhD, is Director of the Gate TowerInstitute for Image Guided Therapy in Rinku, Japan. He was Head of Radiology at Izumisano Hos-pital, Rinku General Medical Center. He is a Medical Special-ist for the Japan Radiological Society, the Japanese Society of Interventional Radiology, and a Medical Specialist and Di-rector of the Japanese Society of Endovascular Intervention. Dr. Hori is an inventor of superabsorbent polymer microsphere technology that is used to manufacture QuadraSphere® Microspheres.

Tell us about the Gate Tower Institute. “I founded the Gate Tower Institute for Image Guided Therapy in 2002 as a specialty institute for endovascular in-tervention. Our mission is to improve the quality of life of patients while aiming for bet-ter treatment results by utilizing arterial chemoembolization for cancer treatment. We wish for patients suffering from recur-rence and metastasis to be able to enjoy their lives while receiv-ing this less stressful arterial che-moembolization treatment. We are treating about 100 patients per month.”

When was the technologyused in QuadraSphere Microspheres first developed? “Several colleagues, including myself, developed the superabsor-bent polymer (SAP) microsphere technology in 1992 at Osaka University Hospital, Japan.”

Why did you invent superabsorbent polymer microspheres? “I was involved with embo-lotherapy for AVMs and neo-plasms when I was in Osaka University. I was not satisfied with the performance of current embolic material because of in-sufficient effects and severe com-plications. The most important point we had to improve was to control the occlusion level of the target arteries.”

How did you choose thematerials for superabsorbentpolymer microspheres? “After testing many kinds of materials including silicon rubber, microfiber or starch, I suddenly found a superabsorbent polymer substance which was under investigation for an MRI phantom experimental study. My intuition told me it is one of the best materials. According to the investigation of superab-sorbent polymers, I came to the conclusion that the spherical su-perabsorbent polymer is the best material for clinical use.”

Tell us about the process youwent through to develop super-absorbent polymer microspheres. “Because it had been used as the material for other products, it was rather easy to confirm the safety, but it was very difficult to find the way to refine the material. Animal studies to investigate the intra-arterial behavior of super-absorbent polymer microspheres took two years. After confirma-tion of safety, we started clinical study for a patient with refrac-tory AVM. We were excited with marvelous clinical effects. This successful experience encouraged us to continue our project.”

What are the advantages of superabsorbent microspheres such as QuadraSphere Microspheres? “These superabsorbent mi-crospheres are composed of a sodium acrylate and vinyl alco-hol copolymer. They are spheri-cal in shape and have a property that allows them to expand by absorbing fluids very quickly. Once swollen, the sphere is soft and compressible, allowing it to pass through catheters easily and conform to the vasculature. This ability to conform allows it to achieve a durable occlusion in the vasculature.”

What benefits do you seein patients who are treated with embolic microspheres? “Patients benefit from fewer complications and can expect to maintain a better quality of life, the procedure may be repeated as needed, and embolization procedures such as these may reduce overall treatment cost.”

What do you see in the future for embolic microsphere technology? “Interventional oncology is the next horizon. Physicians worldwide are making great strides in developing minimally invasive procedures using em-bolic microspheres to treat can-cerous tumors.”

inventor of Superabsorbent polymer Microspheres Sees Benefits to patients treated with embolic Microspheres

IntervIew wIth Dr. ShInIchI horI

Double thrombectomy performed with the ASAp® Aspiration catheter leads to “Spectacular” result

Thrombus Aspiration has become an important tool for the removal of thrombi that lead to ST Elevat-ed Segment Myocardial Infarction (STEMI). Several studies–TAPAS, EXPIRA, and ATTEMPT, have confirmed that aspiration thrombectomy improves thrombolysis in myocardial infarction (TIMI) flow, myocardial blush scores, and ST-segment resolution (STR). This positive clinical data led to the 2009 recommendation by the American Heart Association (AHA) and the American College of Cardiology (ACC) that the use of aspiration thrombectomy is reasonable to treat STEMI in Percutaneous Coronary Intervention (PCI) cases. A build up of plaque in the arterial wall that ruptures can create thrombi and block blood flow to the heart, resulting in a heart attack. Using an aspiration catheter has proved valuable for physicians such as Dr. Ronald Caputo, MD, FACC, FSCAI, of St. Joseph’s Hospital in Syracuse, New York in treating such cases. Dr. Caputo had a recent case where he used Merit Medical’s ASAP aspiration catheter to aspirate two thrombotic clots from a patient experiencing STEMI. “I had an emergency case—52-year old man with anterior ST changes—GIANT clot in the LAD,” reported Dr. Ronald Caputo. The lesion was crossed with a 0.014” guide wire and thrombectomy was performed with an ASAP aspiration catheter yielding abundant thrombotic material from the LAD in a single run. Dr. Caputo described the results of the procedure: “I did the case trans-radial and pulled out a massive clot with the ASAP in just one aspiration run.” He then discovered an additional thrombus in the distal LAD. “I actually had to go down into the distal LAD and pull a clot out there too.” Additional thrombectomy was performed with the ASAP catheter both in the proximal and distal vessels. Final angiography revealed a widely patent LAD. Dr. Caputo stated that his use of the ASAP aspiration catheter to aspirate not one, but two thrombi, yielded a “spectacular” result. The Merit Medical ASAP aspiration catheter has a uniquely shaped aspiration lumen to enhance its ability to aspirate large volumes quickly. The single extrusion 100% stainless steel braided catheter has three levels of stiffness for kink resistance. Dr. Caputo appreciates the ASAP construction. “ASAP has worked very well for me,” Caputo said. “I think it’s deliverable, kink resistant, easy to prep and effec-tive at removing a large amount of thrombus.” It also offers three non-radiopaque marker bands at 90 cm, 100 cm, and 110 cm depths positioning. The tapered tip and hydrophilic coating were created to provide smooth transitions and ease of use. Using an aspiration catheter such as the ASAP for thrombus aspiration proved to be an efficient and productive method for treating this STEMI patient.

11. Acronym for Dr. Hori’s embolotherapy tool 12. Occludes blood vessels 13. To filter the blood to remove harmful waste 15. Aspirated with the ASAP 16. Had spectacular result with the ASAP 20. Ostial Pro helps locate the ______-ostial wall 23. Type of catheter used to deliver embolics 24. Study confirmed aspiration thrombectomy improves TIMI & STR 26. Clo-Sur PLUS PAD interviewee - Find the answers on page 4

19. Developed SAP technology and swan neck microcatheter design 21. Clo-Sur PLUS ___ 22. The excision of a thrombus 25. Compression is used to maintain__________Down1. Ostial Pro is made of 3. Inventor of the Ostial Pro 4. Placement aided by the Ostial Pro 7. Acronym for Thrombolysis in Myocardial Infarction 8. Author of bland embolization using microspheres

Across1. Braid material used in the Maestro 2. Merit Medical microcatheter 4. Most cases are treated with PCI 5. Inventor of the CentrosFLO 9. Pressure applied device used to achieve hemostasis 10. Made from the shells of crustaceans 11. Type of curve on the Maestro 14. Clo-Sur pads are _______ soluble 15. _______FLO split tip chronic dialysis catheter 17. Merit Medical aspiration catheter18. _____-Resistant

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The Clo-Sur PLUS P.A.D.™ Antimicrobial Hemostasis Pad

Achieves “Striking” ResultsInterventional Cardiologist Barry R. Alter

Discusses His Experience With Chitosan-Based Pad [The following are excerpts from an April 2010 interview that appeared in Cath Lab Digest.]

how does the clo-Sur pluS p.A.D. accelerate hemostasis? “The Clo-Sur PLUS P.A.D. is unique in that its active ingredient, which makes up the entire pad, is a substance called chitosan. Chitosan is a material that comes from the shells of crustaceans. The chitosan that is used in the Clo-Sur PLUS P.A.D. is extremely bioactive. It’s very positively charged and the minute it comes in contact with nega-tively charged red blood cells, it causes them to clump immediately, which then causes rapid stimulation of the clotting cascade and very quick clotting.”

what makes the clo-Sur pluS p.A.D. easy to use? “What we found was that it was easy to use compared to some of the other pads, because it has a thickness and body to it. That makes it easy to handle. It’s 100% active ingredient, so there is no right side or wrong side, you just open it up, put it on the wound, and that’s it.”

what time and level of pressure is required? “For the first few minutes, you can use the same amount of pressure that you would normally use with manual compression, i.e., enough to basically occlude the artery and maintain hemostasis. Within a few minutes, you can usually ease up on the pressure, and in non-coag-ulated patients, within usually 6 minutes or so, you can slowly lift up, and if there is good hemostasis, you can just stop at that point. In anti-coagulated or post-interventional patients, we usually recom-mend that you keep moderate pressure until about 10 minutes, then lift up slowly and check the wound. If it’s dry, you’re done.”

how do you remove the clo-Sur pluS p.A.D.? “The Clo-Sur PLUS P.A.D. is water soluble. As soon as the Clo-Sur PLUS P.A.D. gets wet, it dissolves, so the pad is very easy to take off. It doesn’t have to be pulled or yanked off; you leave it on and send the patient home, and they can remove it themselves the next day.”

what results have you experienced after using the clo-Sur pluS p.A.D.? “The thing we noticed that was so striking was that not only did we get excellent rapid hemostasis, but we literally stopped getting those calls, 2-4 hours after the patient went from the lab up to the floor saying that the patient coughed, or the patient tried to get out of bed and started bleeding again. Those calls virtually disappeared.”

how does the clo-Sur pluS p.A.D. perform with larger sheath sizes? “Our diagnostic cases were performed with 5 French sheaths. The interventional cases were done with 6 French sheaths. However, at the time of the study, I had personally used the Clo-Sur PLUS P.A.D. on three patients with intra-aortic balloons with 8 French sheaths. Subsequently, I used the Clo-Sur PLUS P.A.D. on many more intra-aortic balloon removals with 8 French sheaths and had 100% success.”

1Eur Radiol, 2007 Mar 17(3):693-700.

Barry R. Alter, MD, FACP, FACC served as Medical Director of the Heart & Vascular Center of Hollywood, Florida and as an interventional cardiologist at Memorial Regional Hospital in Hollywood, Florida. He is currently serving as Chairman of the Board of Scion Cardio-Vascular, the manufacturer of the Clo-Sur PLUS P.A.D.

can now be guided into almost any vessel in the body, and ad-vanced angiography systems and CT scanners can provide a highly accurate map to help the physi-cian reach the malignant lesion.” All of the Merit Maestro mi-crocatheters are constructed with a nylon ribbon braid that extends the entire length of the catheter, including the tip, giving excep-tional torque, kink recovery, and steerability in tortuous anatomy. The Merit Maestro micro-catheter features a flexible distal region designed for atraumatic vessel entry. A platinum marker band is located 1.3 mm proximal to the tip for easy identification of the distal tip under fluoros-copy and is completely encapsu-lated within the microcatheter shaft. The lubricious hydrophilic coating on the outside of the catheter results in smooth trac-tion through tortuous anatomy. The Merit Maestro microcath-eters are available in three inter-nal diameters: .020”, .024”, and .027” The .020”and .024” micro-catheters deliver coils up to .018” and spheres up to and including 700 microns. The .027” delivers spheres up to and including 900 microns. The hub is made of ma-terial that is compatible with che-motherapy drugs.

A master in the art of multipurpose microcatheters.

The Merit Maestro is a multipur-pose microcatheter designed and engineered for the controlled and selective infusion of diagnostic, embolic, or therapeutic materi-als into peripheral and coronary vasculature. The Merit Maestro microcatheter is available in three configurations: straight, 45 de-gree, and a swan neck design created by Dr. Shinichi Hori MD, PhD, the Director of the Gate Tower Institute for Image Guided Therapy in Rinku, Japan. The swan neck Merit Maestro is preshaped and designed to access and maintain position in arteries with acute angles such as the he-patic artery. The secondary curve helps seat the catheter in the vessel to reduce the recoiling effect of the embolic agent as it is introduced. “Standard microcatheters have a change in flexibility and softness at each joint,” Hori observed. “Since the Merit Maestro has no joints, the catheter movement inside the blood vessel is very smooth.” Dr. Hori now uses the swan neck mi-crocatheter for the majority of his cases where there are acute branch take offs and vessel tortuosity.

Microcatheters, such as the Merit Maestro, are used in vari-ous interventional procedures to deliver embolic materials such as coils, PVA, or microspheres. Patients with aneurysms, uterine fibroids, or various cancers are of-ten treated with microcatheters. Dr. Hori described the signifi-cance of microcatheters in his en-dovascular treatment of cancer:

The secondary curve helps seat

the catheter in the vessel to reduce the recoiling effect of

the embolic agent. “Although the idea of endovas-cular treatment for cancer has ex-isted for more than 20 years, the introduction of microcatheters has dramatically improved the neces-sary techniques. Microcatheters

Merit Maestro® Swan Neck Microcatheter Designed by Dr. Hori

has “Dramatically improved” Technique For embolic Therapy

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TIME TO HEMOSTASIS1 TIME TO MOBILIZATION1

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- Ash Interview, continued from page 1Why did you choose Interventional Nephrology as a specialty? “I went into Nephrology because I was amazed at the kidney’s ability to regenerate itself after many injuries. I was also impressed by hemodialysis, and that it could help to resolve symptoms of kidney failure in spite of its conceptual simplicity but mechanical complexity (especially in the 70s). I always enjoyed doing procedures and recognized that they were an important part of successful Nephrology practice, and then placing and using dialysis catheters gave me a better understanding of their problems and potential for improvement.”

One of the most widely used and successful hemodialysis catheters is the Ash Split Cath® which you invented in 1996. What is your latest development in catheter design? “The latest is the CentrosFLO, an innovative long-term (greater than 30 days) tunneled central ve-nous catheter for hemodialysis.”

Tell us about the process you went through to develop the CentrosFLO. “Studying the literature on how the central veins sheath catheters, I found that sheaths only form where the catheter continually touches the wall of the vein, and that a catheter supported in the middle of a vein caused much less trauma and pathology in the vein wall. From there, I had to come up with a design of a dual-lumen catheter which would always keep the tips of the catheter pointed into the middle of the vein, and also support much of the body of the catheter away from the vein wall.”

Can you describe what makes the CentrosFLO unique? What are its design advantages? “The CentrosFLO represents a new approach for the design of central venous dialysis catheters. The distal tip of the catheter has a unique curved configuration, which keeps the ports of the catheter cen-tered in the distal superior vena cava (SVC) and right atrium. Since the catheter tips are held in the center of the vein, tips cannot rest against the vein and atrial walls, and therefore should not become covered by a fibrin sheath. The outward-curved limbs contact only one or two points within the lower SVC, minimizing the irritation of the SVC versus long, straight catheters. The result should be greater preservation of catheter flow over time, and less tendency to SVC stenosis.”

Are there any additional features and benefits? “CentrosFLO has a unique guide wire slit that facilitates over-the-wire insertion, and a tip design that minimizes recirculation rates.”

What is the ideal placement? “To optimize the self-centering design, the contact point of the CentrosFLO curved arterial tip should be positioned in the lower third of the SVC, with the venous tip in the right atrium or at the junction of the right atrium and SVC. The CentrosFLO should always be placed so that the end of the arterial lumen (shorter) is positioned toward the patient’s left. This allows the venous tip to curve away from the lower SVC and right atrial wall.”

What can we expect from you next, Dr. Ash? “My coworkers and I continue to develop innovative catheter designs and will be looking to provide even more advanced technology in the near future that will help address the common challenges of to-day’s central venous catheters for dialysis.”

Will you continue on a physician-entrepreneur path? “Yes–definitely–for as long as I have health, resources, and great collaborators.”

MR12-039 Rev. A ID 031312 402550001/A

microsphere embolization is a good option to induce exten-sive tumor necrosis and signifi-cant tumor volume reduction. Similarly, as we showed in JVIR 2002, for select patients with pe-ripheral AVMs that are often as-sociated with surgical difficulty, SAP microsphere embolization was safe and effective for symp-tom palliation.”

In thinking about chemoembolization and bland embolization, can you describe the differences interms of outcomes and survival? Do both techniques play a role in your practice? “We still don’t know the real answer as to which is superior: bland- or chemo-embolization to treat liver tumors, because pa-tient backgrounds are so hetero-geneous. In general, we perform Lipi-odol® chemoembolization as se-lectively as possible for small size

What were the results of this study? “At one month, 64% of pa-tients had a reduction in tumor size. Specifically, there was com-plete elimination or necrosis in 13 cases (22%) and 50% or greater size reduction or necrosis in 25 cases (42%). The duration of treatment with bland embo-lization alone was longer than 6 months in 44 of 59 patients (75%) and longer than one year in 32 of 59 patients (54%).”

Why did you start using SAP microspheres? “For many years, gelatin sponges were the only available type of particle in our country. Gelatin sponges tend to aggre-gate and temporarily occlude a proximal vessel. In contrast, calibrated SAP microspheres achieve a long-term end-artery occlusion, thus, they are suitable for more targeted embolization.”

How do SAP microspheres fit into your treatment options for patients? “SAP microspheres are used to treat a variety of patients in my practice. For HCC patients with large tumor burden or impaired liver function where Lipiodol® chemoembolization was not always appropriate, bland SAP

Please tell us about your study, “Bland Embolization of Hepatocellular Carcinoma Using Superabsorbent Polymer Microspheres” from CVIR 2008. “Patients with previously un-treated hepatocellular carcinoma (HCC) were eligible for the study if they had large tumors, had poor hepatic or overall func-tion, or declined chemotherapy. The investigators performed se-lective bland embolization by advancing a microcatheter into the hepatic artery as close as possible to the tumor and in-jecting microspheres ranging in dry state sizes from 200 to 400 microns (hydrated) mixed with ionic contrast material into each pedicle vessel supplying the tu-mor. The aim was angiographic vascular occlusion.”

How many patients were treated? What benefits did you note in the patients? “A total of 59 patients were treated. Pain was almost negli-gible, fever was well controlled by NSAIDs, and there was no need for antibiotics prior to and during the treatment course. Liver function tests did not dete-riorate in the month after bland embolization.”

Keigo Osuga, MD, PhD, is Associate Professor of Diagnostic and Interven-tional Radiology, Osaka University Graduate School of Medicine in Osaka

Tell us about your clinical practice, your facility, and how you came to use superab-sorbent polymer microspheres. “Our hospital has 1000 beds, and four angio-rooms: two in ra-diology (one is angio-CT unit), one in emergency, and another in operation rooms. As an IR team (4 staff/3 fellows), we run out-patient/inpatient clinic for both oncologic and vascular interven-tion. Above all, embolotherapy is our most common procedure to treat hypervascular tumors, bleeding, aneurysms, and vascu-lar anomalies. Since the 1990’s, Dr. Shinichi Hori and his col-leagues, including myself, de-veloped superabsorbent polymer microspheres (SAP), also known as QuadraSphere Microspheres in the United States. SAPs have been used in embolizations in patients preoperatively or palliatively.”

and/or small number of tumors, whereas we perform bland mi-crosphere embolization for cases with certain risks such as large tumor size, impaired liver func-tion, older age, history of biliary reconstruction, etc. We can also switch from one technique to the other according to the clini-cal course (resistant, tumor re-currence, tumor complications, etc.).”

How has the practice of IR changed as a result of using embolotherapy? “It is good for IRs to be able to offer patients more treatment options than before using new devices to fit each pathological condition. I feel that the role or significance of microsphere em-bolization has been increasingly recognized among physicians, and staff throughout hospitals and cath labs and can also help to generate a good reputation for the IR practice.”

Dr. Keigo oSugA DiScuSSeS FinDingS oF eMBolizAtion uSing MicroSphereS StuDy

(C) Plain CT 1 day after SAP-TAE shows retention of contrast medium in the treated tumor. (D) After one session of SAP-TAE, CECT 3-year and 2-month follow-ups showed nonenhanced tumor with a marked reduction in size, indicating a complete response. Osuga et al. “Bland Embolization of HCC Using SAP.” Cardiovasc Intervent Radiol (2008) 31:1108–1116.

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