Bio


Dr. Currie is a board-certified, fellowship-trained cardiothoracic surgeon. She is also a clinical assistant professor at Stanford University School of Medicine. With subspecialty training in heart failure, Dr. Currie treats all forms of cardiomyopathy, ischemic heart disease, and valvular heart disease. She performs heart transplant, lung transplant, and combined heart-lung transplant procedures as part of a multidisciplinary team. She excels at valve surgery and the implantation of mechanical circulatory support systems.

Dr. Currie welcomes referrals from cardiologists and primary care physicians as early as possible when cardiovascular disease is suspected. Understanding that early intervention can prevent later complications, she invites communication about screening, diagnostics, and treatment strategies.

For each patient, Dr. Currie’s goal is to achieve the best possible outcome using the most advanced minimally invasive cardiac care techniques and technology available. Combined with technical expertise and a focus on excellent clinical outcomes, Dr. Currie delivers empathetic, thoughtful patient care. She ensures that patients are well informed about what they can expect both before and after their surgical procedure.

Dr. Currie is passionate about improving the safety of cardiac surgery. Her research includes translational studies on new ways to visualize anatomic structures that are difficult to see during minimally invasive surgery. One published study investigated the use of augmented reality (AR) guided by transesophageal echocardiography in minimally invasive mitral valve repair. Her work has appeared in The Journal of Thoracic and Cardiovascular Surgery, The Annals of Thoracic Surgery, The International Journal of Medical Robotics and Computer Assisted Surgery, Transplant Immunology, and other peer reviewed publications.

Dr. Currie’s interest in technological advances is rooted in her commitment to the evolution of technology and technique in the fast-changing, relatively young field of cardiac surgery. Also driving her interest is her PhD background in biomedical engineering. She has made presentations on the use of AR systems, 3D visualization technology, and robotics-assisted surgical procedures at the American Association for Thoracic Surgery Annual Meeting, International Society for Minimally Invasive Surgery Annual Scientific Meeting, and other conferences.

Dr. Currie has won numerous awards for her research achievements and scholarship. She is a Fellow of the Royal College of Surgeons of Canada. She is also a member of The Society of Thoracic Surgeons, the International Society for Heart and Lung Transplantation, the International Society for Minimally Invasive Cardiothoracic Surgery, Women in Thoracic Surgery, and the Association of Women Surgeons. With its long legacy of leadership in cardiac surgery and research, Dr. Currie feels Stanford Health Care enables her to pursue her research interests and offers her patients access to the latest innovations, along with expertise across specialties including engineering and statistics.

Clinical Focus


  • Cardiothoracic Surgery

Academic Appointments


Professional Education


  • Fellowship: Stanford University Heart-Lung Transplantation Fellowship (2018) CA
  • Board Certification, Royal College of Physicians and Surgeons of Canada, Cardiac Surgery
  • Surgery Residency, Western University, Cardiac Surgery
  • PhD, Western University, Biomedical Engineering
  • MD, Dalhousie University

All Publications


  • Relation of Length of Survival After Orthotopic Heart Transplantation to Age of the Donor. The American journal of cardiology Shudo, Y., Guenther, S. P., Lingala, B., He, H., Hiesinger, W., MacArthur, J. W., Currie, M. E., Lee, A. M., Boyd, J. H., Woo, Y. J. 2020

    Abstract

    We aim to evaluate the impact of donor age on the outcomes in orthotropic heart transplantation recipients. The United Network for Organ Sharing database was queried for adult patients (age; ≥60) underwent first-time orthotropic heart transplantation between 1987 and 2019 (n = 18,447). We stratified the cohort by donor age; 1,702 patients (9.2%) received a heart from a donor age of <17 years; 11,307 patients (61.3%) from a donor age of 17 ≥, < 40; 3,525 patients (19.1%) from a donor age of 40 ≥, < 50); and 1,913 patients (10.4%) from a donor age of ≥50. There was a significant difference in the survival likelihood (p < 0.0001) based on donor's age-based categorized cohort, however, the median survival was 10.5 years in the cohort in whom the donor was <17, 10.3 years in whom the donor was 17 ≥, < 40, 9.4 years in whom the donor was 40 ≥, < 50, and 9.0 years in whom the donor was ≥ 50. Additionally, there was no significant difference in the episode of acute rejection (p = 0.19) nor primary graft failure (p = 0.24). In conclusion, this study demonstrated that patients receiving hearts from the donor age of ≥50 years old showed slight inferior survival likelihood, but appeared to be equivalent median survival.

    View details for DOI 10.1016/j.amjcard.2020.06.036

    View details for PubMedID 32736794

  • Malignancy Following Heart Transplant: Few and Far Between Chang, E., Moayedi, Y., Hoppenfeld, M., Lafreniere-Roula, M., Fan, S., Henricksen, E. J., Feng, K., Morales, D. P., Purewal, S., Duclos, S., Lee, R., Lyapin, A., Currie, M., Ross, H. J., Teuteberg, J. J., Khush, K. K. ELSEVIER SCIENCE INC. 2020: S282–S283
  • Impact of Surgical Approach in Double Lung Transplantation: Median Sternotomy vs Clamshell Thoracotomy. Transplantation proceedings Shudo, Y. n., Rinewalt, D. n., Lingala, B. n., Kim, F. Y., He, H. n., Boyd, J. H., Lee, A. M., Hiesinger, W. n., Currie, M. E., MacArthur, J. W., Woo, Y. J. 2020

    Abstract

    Double lung transplantation (DLT) remains the gold standard for end-stage lung disease. Although DLT was historically performed via clamshell thoracotomy, recently the median sternotomy has emerged as a viable alternative. As the ideal surgical approach remains unclear, the aim of our study was to compare the short- and long-term outcomes of these 2 surgical approaches in DLT.We retrospectively reviewed 192 consecutive adult patients who underwent primary DLT at our institution between 2012 and 2017 (sternotomy, n = 147; clamshell, n = 45). The impact of each surgical approach on post-transplant morbidity was investigated, and the overall survival probability analyses were performed.There were no significant differences in recipients' baseline and donors' characteristics and bilateral allograft ischemic time. Freedom from primary graft dysfunction, acute rejection episodes, postoperative prolonged ventilator support, tracheostomy, postoperative stroke, and airway dehiscence were comparable between these 2 groups. The duration of cardiopulmonary bypass and operative time were significantly longer in the clamshell thoracotomy group. Postoperative extracorporeal membrane oxygenation usage tended to be more frequent in the clamshell thoracotomy group than the median sternotomy group, despite no statistical significance. Length of hospital and intensive care unit stay were not influenced by the type of incision. There was no significant difference in overall survival between these 2 procedure groups (P = .61, log-rank test).The median sternotomy approach in DLT decreases operative time and more importantly leads to a shorter duration of cardiopulmonary bypass. The type of surgical approach did not show any statistically significant impact on adult DLT recipients' morbidity and survival.

    View details for DOI 10.1016/j.transproceed.2019.10.018

    View details for PubMedID 31911057

  • Impact of Surgical Approach in Double Lung Transplantation: Median Sternotomy Decreases Operative and Cardiopulmonary Bypass Time Compared to Clamshell Thoracotomy Shudo, Y., Rinewalt, D., Lingala, B., Kim, F. Y., He, H., Boyd, J. H., Lee, A. M., Hiesinger, W., Currie, M. E., MacArthur, J. W., Woo, J. ELSEVIER SCIENCE INC. 2019: S414
  • Comparison of Patients Undergoing Multiorgan Transplantation with or without Prior Ventricular Assist Device Currie, M. E., Banerjee, D., Shudo, Y., Lingala, B., Zhu, Y., Haddad, F., Woo, J. ELSEVIER SCIENCE INC. 2019: S216–S217
  • Successful Heart-Lung Transplant for a Patient on Continuous-Flow Left Ventricular Assist Device Support Complicated With Amiodarone-Induced Pulmonary Fibrosis TRANSPLANTATION PROCEEDINGS Currie, M. E., Shudo, Y., Mooney, J., Woo, Y. J. 2019; 51 (2): 593–94
  • Successful Heart-Lung Transplant for a Patient on Continuous-Flow Left Ventricular Assist Device Support Complicated With Amiodarone-Induced Pulmonary Fibrosis. Transplantation proceedings Currie, M. E., Shudo, Y., Mooney, J., Woo, Y. J. 2019; 51 (2): 593–94

    Abstract

    In this case report, we present a successful case of en bloc heart-lung transplant in a patient with advanced cardiopulmonary respiratory failure from amiodarone-associated pulmonary fibrosis that occurred post-left ventricular assist device implantation.

    View details for PubMedID 30879597

  • Evaluation of Risk Factors for Heart-Lung Transplant Recipient Outcome: An Analysis of the United Network for Organ Sharing Database. Circulation Shudo, Y. n., Wang, H. n., Lingala, B. n., He, H. n., Kim, F. Y., Hiesinger, W. n., Lee, A. M., Boyd, J. H., Currie, M. n., Woo, Y. J. 2019; 140 (15): 1261–72

    Abstract

    Heart-lung transplantation (HLTx) is an effective treatment for patients with advanced cardiopulmonary failure. However, no large multicenter study has focused on the relationship between donor and recipient risk factors and post-HLTx outcomes. Thus, we investigated this issue using data from the United Network for Organ Sharing database.All adult patients (age ≥18 years) registered in the United Network for Organ Sharing database who underwent HLTx between 1987 and 2017 were included (n=997). We stratified the cohort by patients who were alive without retransplant at 1 year (n=664) and patients who died or underwent retransplant within 1 year of HLTx (n=333). The primary outcome was the influence of donor and recipient characteristics on 1-year post-HLTx recipient death or retransplant. Kaplan-Meier curves were created to assess overall freedom from death or retransplant. To obtain a better effect estimation on hazard and survival time, the parametric Accelerated Failure Time model was chosen to perform time-to-event modeling analyses.Overall graft survival at 1-year post-HLTx was 66.6%. Of donors, 53% were male, and the mean age was 28.2 years. Univariable analysis showed advanced donor age, recipient male sex, recipient creatinine, recipient history of prior cardiac or lung surgery, recipient extracorporeal membrane oxygenation support, transplant year, and transplant center volume were associated with 1-year post-HLTx death or retransplant. On multivariable analysis, advanced donor age (hazard ratio [HR], 1.017; P=0.0007), recipient male sex (HR, 1.701; P=0.0002), recipient extracorporeal membrane oxygenation support (HR, 4.854; P<0.0001), transplant year (HR, 0.962; P<0.0001), and transplantation at low-volume (HR, 1.694) and medium-volume centers (HR, 1.455) in comparison with high-volume centers (P=0.0007) remained as significant predictors of death or retransplant. These predictors were incorporated into an equation capable of estimating the preliminary probability of graft survival at 1-year post-HLTx on the basis of preoperative factors alone.HLTx outcomes may be improved by considering the strong influence of donor age, recipient sex, recipient hemodynamic status, and transplant center volume. Marginal donors and recipients without significant factors contributing to poor post-HLTx outcomes may still be considered for transplantation, potentially with less impact on the risk of early postoperative death or retransplant.

    View details for DOI 10.1161/CIRCULATIONAHA.119.040682

    View details for PubMedID 31589491

  • Successful Outcome Following Orthotopic Heart Transplantation With a Donor Half Way Across The Country. Transplantation proceedings Currie, M. E., Shudo, Y., Woo, Y. J. 2018; 50 (10): 4062–63

    Abstract

    Orthotopic heart transplantation is the criterion standard treatment for end-stage heart failure and the number of recipient candidates has been increasing. Despite this increasing demand, there is limited donor organ supply. In order to surmount this challenge, we propose harvesting donor hearts from more distant locations and accepting longer cold ischemic times. The usual accepted total ischemic time limit for the transplanted human heart is up to 4 hours. Here, we report the successful use of a donor heart from 1268 miles away with a total allograft ischemic time greater than 6 hours.

    View details for PubMedID 30577315

  • Successful Outcome Following Orthotopic Heart Transplantation With a Donor Half Way Across The Country TRANSPLANTATION PROCEEDINGS Currie, M. E., Shudo, Y., Woo, Y. J. 2018; 50 (10): 4062–63
  • The role of visual and direct force feedback in robotics-assisted mitral valve annuloplasty INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY Currie, M. E., Talasaz, A., Rayman, R., Chu, M. A., Kiaii, B., Peters, T., Trejos, A., Patel, R. 2017; 13 (3)

    Abstract

    The objective of this work was to determine the effect of both direct force feedback and visual force feedback on the amount of force applied to mitral valve tissue during ex vivo robotics-assisted mitral valve annuloplasty.A force feedback-enabled master-slave surgical system was developed to provide both visual and direct force feedback during robotics-assisted cardiac surgery. This system measured the amount of force applied by novice and expert surgeons to cardiac tissue during ex vivo mitral valve annuloplasty repair.The addition of visual (2.16 ± 1.67), direct (1.62 ± 0.86), or both visual and direct force feedback (2.15 ± 1.08) resulted in lower mean maximum force applied to mitral valve tissue while suturing compared with no force feedback (3.34 ± 1.93 N; P < 0.05).To achieve better control of interaction forces on cardiac tissue during robotics-assisted mitral valve annuloplasty suturing, force feedback may be required.

    View details for DOI 10.1002/rcs.1787

    View details for Web of Science ID 000411294000020

    View details for PubMedID 27862833

  • Phantom study of an ultrasound guidance system for transcatheter aortic valve implantation COMPUTERIZED MEDICAL IMAGING AND GRAPHICS McLeod, A., Currie, M. E., Moore, J. T., Bainbridge, D., Kiaii, B. B., Chu, M. A., Peters, T. M. 2016; 50: 24–30

    Abstract

    A guidance system using transesophageal echocardiography and magnetic tracking is presented which avoids the use of nephrotoxic contrast agents and ionizing radiation required for traditional fluoroscopically guided procedures. The aortic valve is identified in tracked biplane transesophageal echocardiography and used to guide stent deployment in a mixed reality environment. Additionally, a transapical delivery tool with intracardiac echocardiography capable of monitoring stent deployment was created. This system resulted in a deployment depth error of 3.4mm in a phantom. This was further improved to 2.3mm with the custom-made delivery tool. In comparison, the variability in deployment depth for traditional fluoroscopic guidance was estimated at 3.4mm.

    View details for DOI 10.1016/j.compmedimag.2014.12.001

    View details for Web of Science ID 000376833600004

    View details for PubMedID 25595049

  • Augmented Reality System for Ultrasound Guidance of Transcatheter Aortic Valve Implantation INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY Currie, M. E., McLeod, A., Moore, J. T., Chu, M. A., Patel, R., Kiaii, B., Peters, T. M. 2016; 11 (1): 31–39

    Abstract

    Transcatheter aortic valve implantation (TAVI) relies on fluoroscopy and nephrotoxic contrast medium for valve deployment. We propose an alternative guidance system using augmented reality (AR) and transesophageal echocardiography (TEE) to guide TAVI deployment. The goals of this study were to determine how consistently the aortic valve annulus is defined from TEE using different aortic valve landmarks and to compare AR guidance with fluoroscopic guidance of TAVI deployment in an aortic root model.Magnetic tracking sensors were integrated into the TAVI catheter and TEE probe, allowing these tools to be displayed in an AR environment. Variability in identifying aortic valve commissures and cuspal nadirs was assessed using TEE aortic root images. To compare AR guidance of TAVI deployment with fluoroscopic guidance, a TAVI stent was deployed 10 times in the aortic root model using each of the two guidance systems.Commissures and nadirs were both investigated as features for defining the valve annulus in the AR guidance system. The commissures were identified more consistently than the nadirs, with intraobserver variability of 2.2 and 3.8 mm, respectively, and interobserver variability of 3.3 and 4.7 mm, respectively. The precision of TAVI deployment using fluoroscopic guidance was 3.4 mm, whereas the precision of AR guidance was 2.9 mm, and its overall accuracy was 3.4 mm. This indicates that both have similar performance.Aortic valve commissures can be identified more reliably than cuspal nadirs from TEE. The AR guidance system achieved similar deployment accuracy to that of fluoroscopy while eliminating the use and consequences of nephrotoxic contrast and radiation.

    View details for DOI 10.1097/IMI.0000000000000235

    View details for Web of Science ID 000377677200006

    View details for PubMedID 26938173

  • Dual antiplatelet therapy use by Canadian cardiac surgeons JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Yanagawa, B., Ruel, M., Bonneau, C., Lee, M. M., Chung, J., Al Shouli, S., Fagan, A., Al Khalifa, A., White, C. W., Yamashita, M. H., Currie, M. E., Teoh, H., Mewhort, H. M., Verma, S. 2015; 150 (6): 1548–U260

    Abstract

    Dual antiplatelet therapy is the cornerstone treatment for patients with acute coronary syndrome. Recent Canadian Guidelines recommend the use of dual antiplatelet therapy for 1 year after coronary artery bypass grafting in patients with acute coronary syndrome, but considerable variability remains.We performed a survey of 75 Canadian cardiac surgeons to assess the use of dual antiplatelet therapy.Whereas 58.6% of respondents indicated that the benefits of dual antiplatelet therapy were seen irrespective of how patients were managed after acute coronary syndrome, 36.2% believed that the benefits of dual antiplatelet therapy were limited to those treated medically or percutaneously. In regard to the timing of dual antiplatelet therapy administration, 57% of respondents indicated that dual antiplatelet therapy should be given upstream in the emergency department, whereas 36.2% responded that dual antiplatelet therapy should be given only once the coronary anatomy has been defined. The majority surveyed (81%) weighed bleeding risk as being more important than ischemic risk reduction. In stable patients after acute coronary syndrome, the majority of surgeons would wait approximately 4 days after the last dose of P2Y12 antagonist before coronary artery bypass grafting. Only 44.6% indicated that they routinely use dual antiplatelet therapy postrevascularization in the setting of acute coronary syndrome. Rather, most surgeons use dual antiplatelet therapy for select patients, such as those with a stented vessel without a bypass graft, endarterectomy, or off-pump coronary artery bypass grafting.Cardiac surgeons exhibit variation in their attitudes and practice patterns toward dual antiplatelet therapy after coronary artery bypass grafting, and in approximately half of cases, their practice does not adhere to current guideline recommendations. New trials focusing on coronary artery bypass grafting cases in their primary analysis and educational initiatives for surgeons that focus on guideline recommendations may be warranted.

    View details for DOI 10.1016/j.jtcvs.2015.08.066

    View details for Web of Science ID 000365040700051

    View details for PubMedID 26395051

  • Recalcitrant Prosthetic Valve Endocarditis Requiring Repeated Reconstruction: Running Out of Options CANADIAN JOURNAL OF CARDIOLOGY Pepe, D. L., Anantha, R. V., Currie, M. E., McCormick, J. K., Mele, T., Chu, M. A. 2014; 30 (12): 1732.e5–8

    Abstract

    In this report we describe a previously healthy 36-year-old man who presented with septic shock secondary to bacterial endocarditis with multiple cerebral, mesenteric, and peripheral embolic phenomena. He underwent emergent porcine prosthetic valve replacement with aortic annular reconstruction. Subsequently, he developed recalcitrant Candida parapsilosis endocarditis requiring treatment with multiple antifungal agents and 4 repeated complex reconstructions of the aortic root and fibrous trigones over 3 years, before the infection was successfully controlled. This case underscores the significant morbidity associated with fungal endocarditis and importance of an early combined medical and surgical approach.

    View details for DOI 10.1016/j.cjca.2014.09.003

    View details for Web of Science ID 000345584400048

    View details for PubMedID 25475479

  • Myocardium at Risk Is Associated With Adverse Clinical Events in Women but Not in Men, After Coronary Artery Bypass Grafting CANADIAN JOURNAL OF CARDIOLOGY Ouzounian, M., Currie, M. E., Buth, K. J., Yip, A. M., Hassan, A., Hirsch, G. M. 2014; 30 (7): 808–13

    Abstract

    Women undergoing coronary artery bypass grafting (CABG) are at increased risk for morbidity and mortality. Factors responsible for this observation include smaller coronary size and delayed presentation. To date, no studies have examined the effect of the degree of myocardium at risk (MAR) on the relationship between female sex and adverse postoperative events.Consecutive patients undergoing first-time isolated CABG at a single institution from 2002-2007 were identified. MAR was calculated using the weighted Duke Index and was categorized as low, moderate, or high. Multivariable logistic regression models were created to compare the impact of MAR on adverse clinical events.We identified 3741 patients, 3325 (89%) of whom had complete angiographic data. Women (n = 755) were older (P = 0.0001) and presented more often with hypertension (P = 0.0001), diabetes (P = 0.0001), heart failure (P = 0.0001), and an urgent/emergent situation (P = 0.002). After surgery, women experienced greater rates of adverse events (15.2% vs 9.3%; P = 0.0001). In a fully adjusted logistic regression model, the nested interaction of sex in MAR showed that women had a significantly greater risk of major adverse cardiovascular events (MACE) when MAR was high (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.3-2.6; P = 0.0004). Greater severity of MAR emerged as an independent predictor of adverse events among women (high: OR, 2.9; 95% CI, 1.2-7.3; moderate: OR, 2.2; 95% CI, 0.8-5.7; low: OR, 1.0), but not among men.MAR was independently associated with higher rates of adverse events among women but not in men undergoing CABG. This finding may help explain differences in outcomes seen between women and men after revascularization.

    View details for DOI 10.1016/j.cjca.2014.03.039

    View details for Web of Science ID 000339981300015

    View details for PubMedID 24880935

  • Knowledge, attitudes, and practice patterns in surgical management of bicuspid aortopathy: A survey of 100 cardiac surgeons JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Verma, S., Yanagawa, B., Kalra, S., Ruel, M., Peterson, M. D., Yamashita, M. H., Fagan, A., Currie, M. E., White, C. W., Sang, S., Rosu, C., Singh, S., Mewhort, H., Gupta, N., Fedak, P. M. 2013; 146 (5): 1033–40

    Abstract

    Clinical practice guidelines have been established for surgical management of the aorta in bicuspid aortic valve disease. We hypothesized that surgeons' knowledge of and attitudes toward bicuspid aortic valve aortopathy influence their surgical approaches.We surveyed cardiac surgeons to probe the knowledge of, attitudes toward, and surgical management of bicuspid aortopathy. A total of 100 Canadian adult cardiac surgeons participated.Fifty-two percent of surgeons believed that the mechanism underlying aortic dilation in those with bicuspid aortic valve was due to an inherent genetic abnormality of the aorta, whereas only 2% believed that altered valve-related processes were involved in this process. Only a minority (15%) believed that bicuspid valve leaflet fusion type is associated with a unique pattern of aortic dilatation aortic phenotype. Sixty-five percent of surgeons recommended echocardiographic screening of first-degree relatives of patients with bicuspid aortic valve. Most surgeons (61%) elected to replace the aorta when the diameter is 45 mm or greater at the time of valve surgery. Fifty-five percent of surgeons surveyed suggested that in the absence of concomitant valvular disease, they would recommend ascending aortic replacement at a threshold of 50 mm or greater. Approximately one third of surgeons suggested that they would elect to replace a mildly dilated ascending aorta (40 mm) at the time of valve surgery. The most common surgical approach (61%) for combined valve and aortic surgery was aortic valve replacement and supracoronary replacement of the ascending aorta, and only a minority suggested the use of deep hypothermic circulatory arrest and open distal anastomosis. More aggressive approaches were favored with greater surgeon experience, and when circulatory arrest was chosen, the majority (68%) suggested they would use antegrade cerebral perfusion. In the setting of aortic insufficiency and a dilated aorta, 42% of surgeons suggested that they would perform valve-sparing surgery. Of note, 40% of respondents used an index measure of aortic size to body surface area in addition to absolute aortic diameter in assessing the threshold for intervention.This large survey uncovered significant gaps in the knowledge and attitudes of surgeons toward the diagnosis and management of bicuspid aortopathy, many of which were at odds with current guideline recommendations. Efforts to promote knowledge translation in this area are strongly encouraged.

    View details for DOI 10.1016/j.jtcvs.2013.06.037

    View details for Web of Science ID 000325603300008

    View details for PubMedID 23988289

  • Evaluating the Effect of Three-Dimensional Visualization on Force Application and Performance Time During Robotics-Assisted Mitral Valve Repair INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY Currie, M. E., Trejos, A., Rayman, R., Chu, M. A., Patel, R., Peters, T., Kiaii, B. B. 2013; 8 (3): 199–205

    Abstract

    The purpose of this study was to determine the effect of three-dimensional (3D) binocular, stereoscopic, and two-dimensional (2D) monocular visualization on robotics-assisted mitral valve annuloplasty versus conventional techniques in an ex vivo animal model. In addition, we sought to determine whether these effects were consistent between novices and experts in robotics-assisted cardiac surgery.A cardiac surgery test-bed was constructed to measure forces applied during mitral valve annuloplasty. Sutures were passed through the porcine mitral valve annulus by the participants with different levels of experience in robotics-assisted surgery and tied in place using both robotics-assisted and conventional surgery techniques.The mean time for both the experts and the novices using 3D visualization was significantly less than that required using 2D vision (P < 0.001). However, there was no significant difference in the maximum force applied by the novices to the mitral valve during suturing (P = 0.7) and suture tying (P = 0.6) using either 2D or 3D visualization. The mean time required and forces applied by both the experts and the novices were significantly less using the conventional surgical technique than when using the robotic system with either 2D or 3D vision (P < 0.001).Despite high-quality binocular images, both the experts and the novices applied significantly more force to the cardiac tissue during 3D robotics-assisted mitral valve annuloplasty than during conventional open mitral valve annuloplasty. This finding suggests that 3D visualization does not fully compensate for the absence of haptic feedback in robotics-assisted cardiac surgery.

    View details for DOI 10.1097/imi.0b013e3182a3200e

    View details for Web of Science ID 000217630100005

    View details for PubMedID 23989813

  • A Navigation Platform for Guidance of Beating Heart Transapical Mitral Valve Repair IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING Moore, J. T., Chu, M. A., Kiaii, B., Bainbridge, D., Guiraudon, G., Wedlake, C., Currie, M., Rajchl, M., Patel, R. V., Peters, T. M. 2013; 60 (4): 1034–40

    Abstract

    Traditional surgical approaches for repairing diseased mitral valves (MVs) have relied on placing the patient on cardiopulmonary bypass (on pump), stopping the heart and accessing the arrested heart directly. However, because this approach has the potential for adverse neurological, vascular, and immunological sequelae, less invasive beating heart alternatives are desirable. Emerging beating heart techniques have been developed to offer high-risk patients MV repair using ultrasound guidance alone without stopping the heart. This paper describes the first porcine trials of the NeoChord DS1000 (Minnetonka, MN), employed to attach neochordae to a MV leaflet using the traditional ultrasound-guided protocol augmented by dynamic virtual geometric models. The distance errors of the tracked tool tip from the intended midline trajectory (5.2 ± 2.4 mm versus 16.8 ± 10.9 mm, p = 0.003), navigation times (16.7 ± 8.0 s versus 92.0 ± 84.5 s, p = 0.004), and total path lengths (225.2 ± 120.3 mm versus 1128.9 ± 931.1 mm, p = 0.003) were significantly shorter in the augmented ultrasound compared to navigation with ultrasound alone, indicating a substantial improvement in the safety and simplicity of the procedure.

    View details for DOI 10.1109/TBME.2012.2222405

    View details for Web of Science ID 000316812200020

    View details for PubMedID 23047858

  • Can internal thoracic arteries be used for both coronary artery bypass and breast reconstruction? INTERACTIVE CARDIOVASCULAR AND THORACIC SURGERY Currie, M. E., Fox, S. A., Greer-Bayramoglu, R. J., Fortin, A. J., Chu, M. A. 2012; 15 (5): 811–15

    Abstract

    Recently, the internal thoracic arteries have been preferentially used in autologous breast reconstruction at the levels of the third or fourth intercostal spaces. This may compromise future treatment of occult coronary disease. We hypothesized that internal thoracic artery length at the fourth intercostal space would allow both breast reconstruction and future coronary artery bypass grafting (CABG).Anatomic analysis of 20 female patients undergoing CABG was performed examining internal thoracic artery length from its origin to the third, fourth, fifth intercostal spaces and the left anterior descending (LAD) artery target.The left internal thoracic artery was anastamosed to the LAD target at a mean length of 11.4 ± 1.4 cm. The mean lengths of the pedicled left internal thoracic artery from its origin to the third, fourth and fifth intercostal space were 8.5 ± 1.0, 10.9 ± 1.2 and 13.0 ± 1.4 cm, respectively. Therefore, the left internal thoracic artery length was adequate at the fourth intercostal space in 6 of 20 (30%) patients.Dissection of the left internal thoracic artery to the fourth intercostal space would allow for concomitant use in CABG and breast reconstruction in one-third of cases. However, skeletonization of the internal thoracic artery at the level of the fourth intercostal space would be sufficient for CABG in all cases following autologous breast reconstruction.

    View details for DOI 10.1093/icvts/ivs366

    View details for Web of Science ID 000310224000001

    View details for PubMedID 22899665

    View details for PubMedCentralID PMC3480617

  • Augmented Reality Image Guidance Improves Navigation for Beating Heart Mitral Valve Repair INNOVATIONS-TECHNOLOGY AND TECHNIQUES IN CARDIOTHORACIC AND VASCULAR SURGERY Chu, M. A., Moore, J., Peters, T., Bainbridge, D., McCarty, D., Guiraudon, G. M., Wedlake, C., Lang, P., Rajchl, M., Currie, M. E., Daly, R. C., Kiaii, B. 2012; 7 (4): 274–81

    Abstract

    Emerging off-pump beating heart valve repair techniques offer patients less invasive alternatives for mitral valve (MV) repair. However, most of these techniques rely on the limited spatial and temporal resolution of transesophageal echocardiography (TEE) alone, which can make tool visualization and guidance challenging.Using a magnetic tracking system and integrated sensors, we created an augmented reality (AR) environment displaying virtual representations of important intracardiac landmarks registered to biplane TEE imaging. In a porcine model, we evaluated the AR guidance system versus TEE alone using the transapically delivered NeoChord DS1000 system to perform MV repair with chordal reconstruction.Successful tool navigation from left ventricular apex to MV leaflet was achieved in 12 of 12 and 9 of 12 (P = 0.2) attempts with AR imaging and TEE alone, respectively. The distance errors of the tracked tool tip from the intended midline trajectory (5.2 ± 2.4 mm vs 16.8 ± 10.9 mm, P = 0.003), navigation times (16.7 ± 8.0 seconds vs 92.0 ± 84.5 seconds, P = 0.004), and total path lengths (225.2 ± 120.3 mm vs 1128.9 ± 931.1 mm, P = 0.003) were significantly shorter in the AR-guided trials compared with navigation with TEE alone. Furthermore, the potential for injury to other intracardiac structures was nearly 40-fold lower when using the AR imaging for tool navigation. The AR guidance also seemed to shorten the learning curve for novice surgeons.Augmented reality-enhanced TEE facilitates more direct and safe intracardiac navigation of the NeoChord DS tool from left ventricular apex to MV leaflet. Tracked tool path results demonstrate fourfold improved accuracy, fivefold shorter navigation times, and overall improved safety with AR imaging guidance.

    View details for DOI 10.1097/imi.0b013e31827439ea

    View details for Web of Science ID 000217612800008

    View details for PubMedID 23123995

  • Long-Term Angiographic Follow-Up of Robotic-Assisted Coronary Artery Revascularization ANNALS OF THORACIC SURGERY Currie, M. E., Romsa, J., Fox, S. A., Vezina, W. C., Akincioglu, C., Warrington, J. C., McClure, R., Stitt, L. W., Menkis, A. H., Boyd, W., Kiaii, B. 2012; 93 (5): 1426–31

    Abstract

    Robotic-assisted coronary artery bypass grafting (CABG) has been shown in short-term studies to increase patient satisfaction and to reduce surgical morbidity and recovery times. However, the long-term patency rate of robotic-assisted CABG is unknown. Therefore, the objective of this study was to assess the long-term patency rate of robotic-assisted coronary artery bypass grafts.The study cohort included all patients who underwent robotic-assisted conduit dissection for CABG at London Health Sciences Centre between September 1999 and December 2003. These patients had selective graft patency assessment using cardiac catheterization or computed tomography angiography (CTA), or both, and stress myocardial perfusion scintigraphy (MPS) 5 to 10 years after surgery to evaluate graft patency and to give functional information on the hemodynamic significance of any graft stenosis. Patients also completed quality of life questionnaires.From a total of 160 patients who underwent robotic-assisted CABG, 82 eligible patients were followed with graft patency assessments for a mean period of 8 years±16.3 months. The patency rate of all robotic-assisted CABG grafts in this patient cohort was 92.7%. The patency rate of left internal thoracic artery grafts to the left anterior descending artery after robotic-assisted CABG in this patient cohort was 93.4%. Patients consistently attained high scores on quality of life questionnaires after surgery.The long-term patency rate of grafts after robotic-assisted CABG was 92.7% at a mean follow-up period of 95.8±16.3 months. Specifically, the patency rate of left internal thoracic artery grafts to the left anterior descending artery after robotic-assisted CABG was 93.4%.

    View details for DOI 10.1016/j.athoracsur.2011.11.031

    View details for Web of Science ID 000303539200013

    View details for PubMedID 22342992

  • The role of three-dimensional visualization in robotics-assisted cardiac surgery Currie, M., Trejos, A., Rayman, R., Chu, M. A., Patel, R., Peters, T., Kiaii, B., Holmes, D. R., Wong, K. H. SPIE-INT SOC OPTICAL ENGINEERING. 2012

    View details for DOI 10.1117/12.911714

    View details for Web of Science ID 000305070200015

  • Immunologic targets in the etiology of allograft vasculopathy: Endothelium versus media TRANSPLANT IMMUNOLOGY Currie, M., Zaki, A. M., Nejat, S., Hirsch, G. M., Lee, T. G. 2008; 19 (2): 120–26

    Abstract

    The respective roles of the endothelium and the media as allo-immune targets in the generation of allograft vasculopathy (AV) have yet to be clearly defined. Although endothelial damage has been implicated in the progression of AV, evidence from mechanical vascular injury models suggests that medial injury may play a more dominant role. The overall objective of this research was to determine the relative importance of the endothelium versus the media as a target for immune injury and induction of AV. To investigate this we developed a novel model which involved the creation of chimeric aortic segments. To accomplish this we removed aortic segments from C3H/HeJ (C3H) mice and stripped them of endothelium by a short pulse with EDTA. The stripped C3H grafts were implanted into immunodeficient C57BL/6 (B6) RAG1(-/-) mice for a period of 21 days. As the immunodeficient mice did not mount an allo-immune response to the grafts, the endothelium was renewed by normal repair mechanisms. The new endothelium was recipient in origin, resulting in a chimeric graft with C3H media and B6 endothelium. We confirmed complete denudement by immunocytochemistry for endothelial specific markers, as well as by transmission and scanning electron microscopy. Replacement of endothelium with recipient endothelial cells was confirmed by immunocytochemistry, electron microscopy and by using a green fluorescent protein mouse transplant combination. Subsequent re-transplantation of the chimeric grafts into either B6 or C3H recipients demonstrated that an allogeneic media is more important than an allogeneic endothelium in inducing robust AV.

    View details for DOI 10.1016/j.trim.2008.03.002

    View details for Web of Science ID 000257002400005

    View details for PubMedID 18503887