Minimally Invasive Delivery of a Novel Direct Epicardial Assist Device in a Porcine Heart Failure...

Minimally Invasive Delivery of a Novel Direct EpicardialAssist Device in a Porcine Heart Failure Model

Jeremy R. McGarvey, MD, Toru Shimaoka, MD, Satoshi Takebayashi, MD, Chikashi Aoki, MD,Norihiro Kondo, MD, Manabu Takebe, MD, Gerald A. Zsido, II, MS, Arminder Jassar, MD,

Joseph H. Gorman, III, MD, James J. Pilla, PhD, and Robert C. Gorman, MD

Objective: Despite advances in design, modern ventricular assist deviceplacement involves median sternotomy and cardiopulmonary bypassand is associated with infectious/embolic complications. In this study,we examine the feasibility and function of a novel minimally invasive,nonYblood-contacting epicardial assist device in a porcine ischemic car-diomyopathy model.Methods: Feasibility was first tested in an ex vivo thoracoscopic trainerbox with slaughterhouse hearts. Five male Yorkshire swine underwentselective ligation of the circumflex artery to create a posterolateral in-farct Twelve weeks after infarct, all animals underwent left minithora-cotomy. A custom inflatable bladder was positioned over the epicardialsurface of the infarct and firmly secured to the surrounding border zonemyocardium with polypropylene mesh and minimally invasive meshtacks. An external gas pulsation system actively inflated and deflated thebladder in synchrony with the cardiac cycle. All animals then underwentcardiac magnetic resonance imaging to assess ventricular function.Results: All subjects successfully underwent off-pump placement ofthe epicardial assist device via minithoracotomy. Ejection fraction sig-nificantly improved from 29.1% T 4.8% to 39.6% T 4.23% (P G 0.001)

when compared with pretreatment. End-systolic volume decreased(76.6 T 13.3 mL vs 62.4 T 12.0 mL, P G 0.001) and stroke volume in-creased (28.6 T 3.4 mL vs 37.9 T 3.1 mL, P G 0.05) when assisted. Nochangewas noted in end-diastolic volume (105.1 T 11.4 vs 100.3 T 12.7).On postmortem examination, mesh fixation and device position wereexcellent in all cases. No adverse events were encountered.Conclusions: Directed epicardial assistance improves ventricular func-tion in a porcine ischemic cardiomyopathy model and may provide asafe alternative to currently available ventricular assist device therapies.Further, the technique used for device positioning and fixation suggeststhat an entirely thoracoscopic approach is possible.

Key Words: Heart failure, Mechanical circulatory assist devices,MRI, Device design.

(Innovations 2014;9:16Y21)

A dverse ventricular remodeling after myocardial infarction(MI) is the most common cause of clinical heart failure

(HF)Vwith approximately one third of patients with MI prog-ressing to ischemic cardiomyopathy (ICM).1Y3 Unfortunately,5-yearmortality afterHFor ICMdiagnosis remains unacceptablyhigh at 50%.4 Because the prevalence of HFand coronary arterydisease is expected to further increase in the coming decades,5

novel therapies to treat or reverse HF remain in great demand.To date, many surgical and interventional therapies have

been described and/or used to treat HF and ICM. Traditional,criterion standard treatmentsVsuch as pulsatile or centrifugalflow left ventricular assist devices (LVADs)Voffer completemechanical unloading of the failing ventricle but often requirea ‘‘maximally’’ invasive approach with cardiopulmonary by-pass. Moreover, access to these therapies is limited by strict in-clusion criteria, cost, and prohibitive morbidities as a result ofblood activation and infection.6Y8 More recently, percutaneousmicroaxial pumps9,10 and less invasive peripheral LVAD thera-pies11,12 have shown efficacy in partial left heart offloading;however, these treatments pose similar risks due to hemolysis,bleeding/thrombosis, and infection as a result of blood-deviceinteractions.

NonYblood-contacting therapies that modify infarct mate-rial properties and border zone function offer attractive alterna-tives to invasive flow-based mechanical assistance.13Y15 Studiesof directed infarct stiffening agents and passive restraint devices(partial or complete heart wraps) have shown evidence of reverse

ORIGINAL ARTICLE

16 Innovations & Volume 9, Number 1, January/February 2014

Video clip is available online.

Accepted for publication December 12, 2013.From the Gorman Cardiovascular Research Group, Division of Cardiac Sur-

gery, University of Pennsylvania Health System, Philadelphia, PA USA.

A video clip is available for this article. Direct URL citations appear inthe printed text and are provided in the HTML and PDF versions of thisarticle on the journal’s Web site (www.innovjournal.com). Please useFirefox when accessing this file.

Supported by grants from the National Heart, Lung and Blood Institute of theNational Institutes of Health, Bethesda, MD USA (HL63954, HL73021,and HL103723).

Presented at the Annual Scientific Meeting of the International Society forMinimally Invasive Cardiothoracic Surgery, June 12 Y 15, 2013, Prague,Czech Republic.

Disclosure: The authors declare no conflicts of interest.

Address correspondence and reprint requests to Robert C. Gorman, MD,Gorman Cardiovascular Research Group, Smilow Center for TranslationalResearch, University of Pennsylvania, 3400 Civic Center Blvd, Bldg 421,11th Floor, Room 114, Philadelphia, PA 19104-5156 USA. E-mail:[email protected].

Copyright * 2014 by the International Society for Minimally InvasiveCardiothoracic Surgery

ISSN: 1556-9845/14/0901-0016

Copyright © 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery. Unauthorized reproduction of this article is prohibited.

mailto:[email protected]

ventricular remodeling and improvement of border zone andglobal function.16Y24 Further, these treatments can potentially bedelivered via transcatheter or minimally invasive approach. Pas-sive therapies, nonetheless, have shown modest benefit inclinical ICM applications thus far and do not have any directeffect on ventricular flow or provide active mechanical assis-tance. With these limitations in mind, we developed a devicethat offered minimally invasive delivery opportunities via sub-xiphoid, minithoracotomy, or thoracoscopic off-pump insertionand provided both mechanical and passive support. In this study,we evaluate the minimally invasive delivery of this novel activeepicardial assist device in a porcine model of ICM.

METHODSDevice Design

The internal components of the epicardial assist deviceconsisted of a heavy-duty 2.5 � 2.5-cm neoprene rubber in-flatable bladder that is positioned centrally within the dyskineticinfarct region and then secured to the surrounding border zonemyocardium with polypropylene mesh. For mesh fixation, weused commercially available laparoscopic mesh tacking devices(AbsorbaTack and ProTack; Covidien, Mansfield, MA USA).AbsorbaTack 5-mm mesh tacks offer absorbable, nonmetal fix-ation using glyocolide-co-L-lactid copolymer screws (Fig. 1A).ProTack mesh tacks are nonabsorbable helical titanium fas-teners25,26 (Fig. 1B). Both fixation devices have a mean tissuepenetration of approximately 3.8 mm. The inflation drive lineto the neoprene bladder was externalized through the chestwall and allowed for LV pressure-gated synchronous inflation/

deflation using an external helium-powered rapid gas ex-change pump. Because the implantable components of thedevice were entirely magnetic resonance imaging (MRI) com-patible, cardiac MRI was used to assess ventricular functionafter in vivo delivery.

Ex Vivo Thoracoscopic FeasibilityTo first assess feasibility of totally thoracoscopic insertion,

we used a thoracoscopic training box and six slaughterhousepig hearts. One 10-mm camera trocar and two 5-mm workingports were inserted. The device was inserted into the chestthrough the camera port and positioned over the posterolateralwall of the heart. A piece of mesh was cut to size externally andthen trimmed to fit internally. Taking care to avoid coronaryvessels, the mesh was fixed to the heart using the tacking de-vices. Three hearts were used for each tack design, and afterdelivery, simulated electrocardiogram triggering was used toassess fixation strength and durability after repeated inflation/deflation events. Afterward, the ventricle was opened and ex-amined for evidence of perforation.

In Vivo Infarct Creation and ImplantationWith approval from The University of Pennsylvania’s

Institutional Animal Care and Use Committee, five maleYorkshire swine weighing approximately 40 kg were enrolledin this study. These animals underwent posterolateral infarc-tion followed by insertion of the directed epicardial assist devicevia left minithoracotomy at 12 weeks after infarct. Five addi-tional healthy, weight-matched (61.2 T 1.7 kg) historical controlswere included for volumetric comparisons. These noninfarcted

FIGURE 1. A, Thoracoscopic view during ex vivo trainer box placement of the nonYblood-contacting epicardial assist deviceusing absorbable screw fixation tacks (inset). B, View from left thoracotomy of in vivo device delivery using titanium helical mesh tacks(inset). The drive line (DL) of the device was externalized through the subxiphoid abdominal wall and connected to an external gasexchange pump that controlled inflation/deflation events.

Innovations & Volume 9, Number 1, January/February 2014 Minimally Invasive Epicardial Assistance

Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery 17


animals were anesthetized in a similar fashion to the treatmentanimals and underwent MRI evaluation (described below). Allstudies were performed in compliance with the Guide for theCare and Use of Laboratory Animals (National Institutes ofHealth publication no. 85Y23, revised 1996).

The treatment animals were sedated with intramuscularketamine injection (25Y30 mg/kg), intubated, and mechanicallyventilated. General anesthesia was maintained with a mixtureof inhaled isoflurane (1.5%Y3.0%) and oxygen, delivered byvolume-controlled ventilation at a tidal volume of 10 to 15 mL/kg.Via a left thoracotomy, the animals underwent selective liga-tion of the circumflex artery or its branches with nonabsorb-able suture to produce a posterolateral infarct of uniform shapeinvolving approximately 20% to 25% of the LV. Ten custom-made 2-mm platinum markers were positioned at the peripheryof the infarct region to delineate its position during subsequentMRI acquisitions and device placement. Hemodynamic andechocardiographic data were recorded before and after infarction.After ensuring hemodynamic and electrophysiologic stability,all animals were then recovered and allowed to undergo LVremodeling for 12 weeks.

At 12 weeks after infarct, the treatment subjects wereagain anesthetized for device insertion. General anesthesia wasagain initiated, and the animals underwent 5- to 7.5-cm left mini-thoracotomy in the fifth interspace. Adhesions were carefully dis-sected, and the infarct region was identified using the previouslyplaced platinum markers. Echocardiography was used to assessadequate border zone wall thickness. The custom-made directedassist bladder was positioned centrally within the infarcted re-gion. Using polypropylene mesh (Ethicon, Bridgewater, NJUSA), the bladder was then secured to the surrounding borderzone myocardium using ProTack helical mesh tacks. Care wastaken to avoid collateral coronary vessel damage during fixation.Mesh tension was adjusted by circumferentially adding addi-tional tacks around the bladder. The inflation port of the devicewas then tunneled substernally and exteriorized from the sub-xiphoid abdominal wall. An external helium-powered pulsationdevice was connected to the inflation port, and inflation anddeflation were synchronized to the isovolemic contraction andisovolemic relaxation, respectively, using LV pressure gatingand epicardial echocardiographic guidance.

Magnetic Resonance ImagingGeneral anesthesia was maintained for the duration of

the imaging procedures, as described above. Immediately afterdevice implantation, cardiac MRI was performed to assess ven-tricular function and mitral regurgitation. A high-fidelity pressuretransduction catheter (Millar Instruments, Houston, TX USA)was positioned for LV pressure gating. Magnetic resonanceimaging was performed using a 3T Siemens Trio Magnetomscanner (Siemens, Malvern, PA USA). The treatment animalsunderwent prospectively gated cine MRI for evaluation ofventricular volumes and prospectively gated phase-contrastMRI for evaluation of mitral regurgitation in both assistedand unassisted (deflated) states. Three-dimensional SPGR(spoiled gradient echo) cine MRI acquisitions used the fol-lowing parameters: temporal resolution (TR), 24.2 milli-seconds; echo time (TE), 2.4 milliseconds; flip angle (FA),15 degrees; field of view (FoV), 300� 243 mm; matrix, 192�

156; slice thickness, 4 mm; and cardiac and respiratorygating with total acquisition time averaging approximately20 minutes. Two-dimensional phase-contrast MRI was ac-quired at themitral annulus and the aortic root with the followingparameters: TR, 40.6 milliseconds; TE, 3.29 milliseconds; FA,25 degrees; FoV, 244 � 300 mm; matrix, 156 � 192; slicethickness, 4 mm; and Venc (velocity encoding), 150 cm/s. Im-ages were archived and stored offline for postprocessing.

Image AnalysisLeft ventricular volume and function data were obtained

from MRI cine images. Short-axis endocardial contours weremanually drawn at each slice from apex to base using publicdomain image analysis software (ImageJ, Bethesda, MD USA).Contours were drawn at both end systole and end diastole.Volume at each cardiac time point was then calculated using thefollowing formula: total contour area� in-plane pixel resolutionper square millimeter � slice thickness � number of slices. Ejec-tion fraction (EF) and stroke volume (SV) were then computedusing the calculated end-diastolic and end-systolic volumes.

Mitral regurgitant fraction was derived from MRI phase-contrast images. Antegrade and retrograde flow volumes throughthe valve were determined using built-in MRI Argus software(Siemens, Malvern, PAUSA). Regurgitant fraction was definedas retrograde flow through the mitral valve divided by antegrademitral flow.

Statistical AnalysisNumerical LV function and regurgitant fraction data were

assessed using paired Student t test and is presented as mean TSEM. P G 0.05 is considered statistically significant for allcomparisons.

RESULTS

Device ImplantationWe successfully performed thoracoscopic insertion of the

epicardial assist device using a thoracoscopic model and ex vivo

FIGURE 2. Representative postmortem endocardial view ofthe posterolateral wall after in vivo device placement. Noperforations or coronary vessel injuries were identified. Dashedline delineates infarct boundaries. APM indicates anterolateralpapillary muscle; PPM, posteromedial papillary muscle.

McGarvey et al Innovations & Volume 9, Number 1, January/February 2014

18 Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery


pig hearts. Insertion time was less than 5 minutes in all cases,including port placement. Although both ProTack and Absorba-Tack fixation devices securely anchored the device to the epicar-dium, we used a greater number of absorbable screws as a resultof increased misfires compared with the titanium helices. For thisreason, we elected to use the nonabsorbable titanium tacks duringin vivo studies. After simulated device activation using electro-cardiogram triggering, no mesh dehiscence events were notedwith either fixation method. Coronary anatomy was easily visiblewith a 10-mm thoracoscopic camera, and no LV perforationswerenoted in either group.

In vivo device placement through minithoracotomy wassuccessfully performed in all cases. Dense adhesions were en-countered as a result of the prior infarct procedure. This findingincreased insertion time compared with ex vivo cases; nonetheless,

all device implantations were performed in less than 30 minutesfrom skin incision. Device fixation and function were excellentin all cases, and all treatment subjects successfully underwentMRI for volumetric analysis. No adverse bleeding events werenoted. On postmortem, no coronary vessel injuries or perfora-tions were identified (Fig. 2).

Ventricular FunctionCardiac MRI acquisitions and volumetric analyses were

successfully obtained during both unassisted (see Video, Sup-plemental Digital Object 1, http://links.lww.com/INNOV/A38)and assisted (see Video, Supplemental Digital Content 2,http://links.lww.com/INNOV/A39) states in all subjects(Fig. 3). All treatment animals showed evidence of remodeling

FIGURE 3. Short-axis midventricular cine magnetic resonance images of the device during active assistance. The device wassynchronized to inflate during systole (A) and deflate during diastole (B). Thick red arrow denotes inflation bladder. Thin greenarrows denote titanium tacks and mesh edge.

FIGURE 4. Global left ventricular function and volumes as generated from cinemagnetic resonance images. Asterisk denotes P G 0.05compared with the unassisted state. Section mark denotes P G 0.05 compared with healthy, weight-matched controls. EDV indicatesend-diastolic volume; EF, ejection fraction; ESV, end-systolic volume; SV, stroke volume.




compared with the healthy weight-matched controls. In the un-assisted state, end-systolic volume, SV, and EF were all signifi-cantly reduced from healthy, noninfarcted levels (Fig. 4). Globalventricular function significantly improved while receiving syn-chronized epicardial assistance, with EF increasing from26.0% T4.7% to37.3% T 4.5% (PG 0.01). End-systolic volume decreasedduring assistance from85.5T 12.7mL to70.1T 11.9mL(PG 0.01).End-diastolic volume did not significantly change after deviceactivation (114.0 T 9.2 mL vs 110.0 T 10.6 mL, P = 0.23).Accordingly, SV increased with assistance from 28.5 T 4.4 mLto 39.9 T 3.1 mL (P = 0.03). No significant differences werefound between the healthy, weight-matched controls and the ani-mals during active assistance. Phase-contrast MRI revealed nodifference in mitral regurgitant fraction between the unassistedand assisted states (11.9% T 1.8% vs 10.5% T 6.7%).

DISCUSSIONHeart failure after MI remains a leading cause of morbid-

ity and mortality worldwide, and evidence suggests that this medi-cal and socioeconomic burden is expected to further increaseduring the next 20 years.1,4,5 Although traditional LVAD thera-pies have long been the staple treatment of the decompensatingheart that has failed medical management, these devices requireinvasive, on-pump procedures and are plagued with high cost,limited availability, and significant long-term morbidities relatedto blood contact.6Y8 Newer technologies have emerged that pro-vide partial ventricular assistance and can be positioned via trans-catheter or peripheral approaches; however, these devices aresimilarly limited by hematologic and infectious complications.9Y12

In addition, transcatheter mechanical assist devices are currentlylimited to specialized critical care settings and are approved foronly short (6-hour) time spans.27

In this study, we present a novel approach and delivery forthe treatment of ICM with significant systolic impairment. Thesystem described takes advantage of a low-cost, minimalisticdesign and commercially available products that would poten-tially improve provider and patient access. Because the implant-able components of the devicewere entirelyMRI compatible, thissystem also affords practitioners the advantages of cardiac MRIas a tool to serially assess ventricular performance. Further, theimplantation approaches described in both ex vivo and in vivotrials suggest a small surgical learning curve. No complicationswere noted as a result of the tack fixation method, and significantimprovements in systolic function were seen in the acute settingafter implant.

The design of this device allows for essentially limitlessvariables in terms of inflation/deflation timing, speed and pres-sure of inflation, and device position. Because this study repre-sents a paired comparison of ventricular function in the acutesetting, we standardized device parameters across all treatmentanimals. Future studies will use finite element analysis and lumpedparameter modeling15 to optimize device settings for varyingventricular geometries and infarct positions. In addition, mini-aturization of the external gas exchange pump will allow for long-term assessment of ventricular size, strain/stress, and borderzone function after device placement and activation. Load-independent indices of ventricular function such as end-systolicpressure-volume and end-diastolic pressure-volume relationships

are of particular interest,28 and novel MRI techniques thatserially quantify cardiac elastance and compliance in vivo will beused in future studies as an added metric of therapeutic efficacy.

For in vivo studies, we elected to use an open approach forposterolateral infarct creation in this swine model because of thehighly reproducible infarct patterns and sizes this techniqueaffords. In our experience,29 cardioversion and recovery fromfibrillation events are also much more successful in an open chestinfarct model. Delivery of the epicardial assist device was accord-ingly done via minithoracotomy because of dense adhesion for-mation. Ex vivo studies suggest that a totally thoracoscopicapproach is feasible; however, the authors recognize that thisapproach is better assessed in vivo using a percutaneous coro-nary occlusion model. Nonetheless, more than 50% of clinicalLVAD patients have had previous cardiac procedures,7,8 and, assuch, this study demonstrates applicability for minimal accessdelivery of the epicardial assist device in a reoperative chest.

In conclusion, this device represents a novel, minimallyinvasive, and nonYblood-contacting approach for the treatmentof ICM, with the potential for totally thoracoscopic insertion.Dramatic improvements in systolic function after placement sug-gest that epicardial assistance may provide a safer and lower-costalternative to traditional therapies.

REFERENCES1. Roger VL, Go AS, Lloyd-Jones DM, et al. for the American Heart As-

sociation Statistics Committee and Stroke Statistics Subcommittee. Heartdisease and stroke statisticsV2012 update: a report from the AmericanHeart Association. Circulation. 2012;125:e2Ye220.

2. Velagaleti RS, Pencina MJ, Murabito JM, et al. Long-term trends in theincidence of heart failure after myocardial infarction. Circulation. 2008;118:2057Y2062.

3. Hellermann JP, Goraya TY, Jacobsen SJ, et al. Incidence of heart failureafter myocardial infarction: is it changing over time? Am J Epidemiol. 2003;157:1101Y1107.

4. Bui AL, Horwich TB, Fonarow GC. Epidemiology and risk profile of heartfailure. Nat Rev Cardiol. 2011;8:30Y41.

5. Heidenreich PA, Trogdon JG, Khavjou OA, et al. for the American HeartAssociation Advocacy Coordinating Committee; Stroke Council; Councilon Cardiovascular Radiology and Intervention; Council on Clinical Cardi-ology; Council on Epidemiology and Prevention; Council on Arterioscle-rosis; Thrombosis and Vascular Biology; Council on Cardiopulmonary;Critical Care; Perioperative and Resuscitation; Council on CardiovascularNursing; Council on the Kidney in Cardiovascular Disease; Council onCardiovascular Surgery and Anesthesia, and Interdisciplinary Council onQuality of Care and Outcomes Research. Forecasting the future of cardio-vascular disease in the United States: a policy statement from the AmericanHeart Association. Circulation. 2011;123:933Y944.

6. George TJ, Arnaoutakis GJ, Shah AS. Surgical treatment of advanced heartfailure: alternatives to heart transplantation and mechanical circulatory assistdevices. Prog Cardiovasc Dis. 2011;54:115Y131.

7. McCarthy PM, Smedira NO, Vargo RL, et al. One hundred patients withthe HeartMate left ventricular assist device: evolving concepts and tech-nology. J Thorac Cardiovasc Surg. 1998;115:904Y912.

8. Aaronson KD, Patel H, Pagani FD. Patient selection for left ventricularassist device therapy. Ann Thorac Surg. 2003;75(suppl):S29YS35.

9. Lemaire A, Anderson MB, Prendergast T, et al. Outcome of the Impelladevice for acute mechanical circulatory support. Innovations (Phila).2013;8:12Y16.

10. Lauten A, Engstrom AE, Jung C, et al. Percutaneous left-ventricularsupport with the Impella-2.5-assist device in acute cardiogenic shock:results of the Impella-EUROSHOCK-registry. Circ Heart Fail. 2013;6:23Y30.

McGarvey et al Innovations & Volume 9, Number 1, January/February 2014

20 Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery


11. Giridharan GA, Lederer C, Berthe A, et al. Flow dynamics of a novelcounterpulsation device characterized by CFD and PIV modeling. MedEng Phys. 2011;33:1193Y1202.

12. Anastasiadis K, Chalvatzoulis O, Antonitsis P, Tossios P, Papakonstantinou C.Left ventricular decompression during peripheral extracorporeal membraneoxygenation support with the use of the novel iVAC pulsatile paracorporealassist device. Ann Thorac Surg. 2011;92:2257Y2259.

13. Holmes JW, Borg TK, Covell JW. Structure and mechanics of healingmyocardial infarcts. Annu Rev Biomed Eng. 2005;7:223Y253.

14. Gupta KB, Ratcliffe MB, Fallert MA, Edmunds LH Jr, Bogen DK.Changes in passive mechanical stiffness of myocardial tissue with aneu-rysm formation. Circulation. 1994;89:2315Y2326.

15. Pilla JJ, Gorman JH III, Gorman RC. Theoretic impact of infarctcompliance on left ventricular function. Ann Thorac Surg. 2009;87:803Y810.

16. Kelley ST, Malekan R, Gorman JH III, et al. Restraining infarct expansionpreserves left ventricular geometry and function after acute anteroapicalinfarction. Circulation. 1999;99:135Y142.

17. Pilla JJ, Blom AS, Brockman DJ, et al. Ventricular constraint using theacorn cardiac support device reduces myocardial akinetic area in an ovinemodel of acute infarction. Circulation. 2002;106(suppl):I207YI211.

18. Enomoto Y, Gorman JH III, Moainie SL, et al. Early ventricular restraintafter myocardial infarction: extent of the wrap determines the outcome ofremodeling. Ann Thorac Surg. 2005;79:881Y887.

19. Koomalsingh KJ, Witschey WR, McGarvey JR, et al. Optimized localinfarct restraint improves left ventricular function and limits remodeling.Ann Thorac Surg. 2013;95:155Y162.

20. Ghanta RK, Rangaraj A, Umakanthan R, et al. Adjustable, physiologicalventricular restraint improves left ventricular mechanics and reduces

dilatation in an ovine model of chronic heart failure. Circulation. 2007;115:1201Y1210.

21. Hung J, Guerrero JL, HandschumacherMD, Supple G, Sullivan S, Levine RA.Reverse ventricular remodeling reduces ischemic mitral regurgitation:echo-guided device application in the beating heart.Circulation. 2002;106:2594Y2600.

22. Leor J, Tuvia S, Guetta V, et al. Intracoronary injection of in situ formingalginate hydrogel reverses left ventricular remodeling after myocardialinfarction in swine. J Am Coll Cardiol. 2009;54:1014Y1023.

23. Ryan LP, Matsuzaki K, Noma M, et al. Dermal filler injection: a novelapproach for limiting infarct expansion. Ann Thorac Surg. 2009;87:148Y155.

24. Ifkovits JL, Tous E, Minakawa M, et al. Injectable hydrogel proper-ties influence infarct expansion and extent of postinfarction left ventricu-lar remodeling in an ovine model. Proc Natl Acad Sci U S A. 2010;107:11507Y11512.

25. Covidien product website. 2009. Available at: http://products.covidien.com/imageServer.aspx/doc193970.pdf ?contentID=16523&contenttype=application/pdf. Accessed May 23, 2013.

26. Covidien product website. 2011. http://www.syneture.com/syneture/pageBuilder.aspx?contentID=37148&webPageID=0&topicID=7418&endBreadCrumbs=ProTak%E2%84%A2%20%20Fixation%20Device&breadcrumbs=0:66860,30707:0,30711:0,#Features and Benefits. Accessed May 23, 2013.

27. Abiomed. 2013. Available at: http://www.abiomed.com/products/. AccessedMay 23, 2013.

28. Witschey WR, Contijoch FJ, Pilla JJ, et al. Real time measurement ofcardiac pressure-volume relationships. J Cardiovasc Magn Reson. 2012;14(suppl 1):P227.

29. Moainie SL, Gorman JH III, Guy TS, et al. An ovine model of postinfarc-tion dilated cardiomyopathy. Ann Thorac Surg. 2002;74:753Y760.

CLINICAL PERSPECTIVEThis experimental study examined the feasibility and function of a novel minimally invasive non-blood-contacting epicardialassist device in a porcine model. A custom-made inflatable bladder was placed via a left minithoracotomy. In these fiveanimals, there was a significant improvement in ejection fraction, a decrease in systolic volume, and an increase in systolicvolume. On postmortem, the fixation of the device and device position were excellent. There were no adverse events in thisshort-term study.

This is a well-performed study and establishes feasibility. Chronic studies will be needed to see whether this will be applicableto long-term support. This may represent a promising, safer, and lower-cost alternative to traditional assist device therapies.




http://products.covidien.com/imageServer.aspx/doc193970.pdf?contentID=16523&contenttype=application/pdf




http://www.syneture.com/syneture/pageBuilder.aspx?contentID=37148&webPageID=0&topicID=7418&endBreadCrumbs=ProTak%E2%84%A2%20%20Fixation%20Device&breadcrumbs=0:66860,30707:0,30711:0,#Features and Benefits




http://www.abiomed.com/products/

Minimally Invasive Delivery of a Novel Direct Epicardial Assist Device in a Porcine Heart Failure...

Documents

Transcript of Minimally Invasive Delivery of a Novel Direct Epicardial Assist Device in a Porcine Heart Failure...