WEDNESDAY MORNING, APRIL 28, 2004

7:00 a.m. EMERGING TECHNOLOGIES AND TECHNIQUES FORUM

(7 Minutes Presentation, 8 Minutes Discussion) North Bldg., Hall C, Metro Toronto Convention Centre

Moderators: D. Craig Miller

Craig R. Smith

T1. Antegrade Off Pump Versus Retrograde On Pump Delivery Valved Stents For Surgical Suture less Aortic Valve Replacement on The Search For The Right Direction

Christoph H. Huber*, Bettina Marty*, Pierrgiorgio Tozzi*, Antonio F. Corno*, Enrico Ferrari*, L. K. Von Segesser; Lausanne, Switzerland

Discussant: W. Randolph Chitwood

OBJECTIVE: Extra corporal cardiopulmonary bypass still remains a necessity for surgical aortic valve replacement. We evaluated feasibility of ante grade off-pump suture less aortic valve replacement using Valved Stents.

METHODS: Feasibility of A) suture less ante grade off-pump aortic valve replacement (3 pigs (65.0±10Kg) was evaluated comparing handling, access method and delivery technique of a self-expanding Valved Stent (3F Therapeutics) to B) a retrograde on-pump approach (6 calves, 74.3±2.4 Kg). Prior to implantation all valved Stents were tested under dynamic pulsatile mock loop conditions.

Assessment was performed using intravascular (IVUS) and intracardiac ultrasound (AcuNav™) including: leaflet motion, planimetric valve orifice and residual-coronary-sinus-stent-index (distance stent to aortic wall/coronary diameter) calculations, transvalvular gradient, regurgitation and paravalvular leaking. Macroscopic analyse was performed at necropsy.

RESULTS: In the off-pump group A) all Valved Stent were placed correctly, in B) 5 of 6 Valved Stents were deployed at target site. In both groups, two-dimensional intracardiac ultrasound showed good leaflet motion, with full valvular opening and closing. In A) no paravalvular leak was found, in B) 2 of 6 valves showed minor to moderate paravalvular leak due to size mismatch and 1 valve shoed mild to moderate regurgitation. In both groups, all implanted Valved Stents showed a low transvalvular gradient of 5.2±4.2mmHg (mean, peak to peak) on invasive measurements and 5.8±3.5 mmHg in two-dimensional intracardiac sonography. Planimetric valve orifice was 1.8±0.2 cm2. There were no signs of coronary flow impairment. Residual-coronary-sinus-stent-index was 1.9±1.4.

At necropsy in A) all and in B) 4 of 6 Valved Stents were correctly placed and safely anchored to the aortic wall.

CONCLUSIONS: Suture less aortic valve insertion into the orthotropic aortic position is feasible. Using an ante grade approach via the left ventricular apex makes beating heart aortic valve implantation possible. Furthermore it's low transvalvular gradient, absence of interference with the coronary blood flow as well as excellent acute valve function are promising character for further long-term studies.

*By Invitation

T2. Epidural Anesthesia Results in More Efficient Use of Hospital Resources in Minimally Invasive Direct Coronary Artery Bypass Surgery

Haldun Y. Karagoz*, Murat Kurtoglu*, Berlin Sonmez*, Beyhan Bakkaloglu*, Taner Cetintas*, Sanser Ates*, Ayhan Yigit*, Kemal Bayazit*; Ankara, Turkey

Discussant: ¹Lisbon Aklog

OBJECTIVE: Minimally invasive direct coronary artery bypass (MIDCAB) surgery in the awake patient with epidural anesthesia had been previously reported. However, there is no prospective randomized study comparing MIDCAB surgery with epidural anesthesia versus general anesthesia.

METHODS: Between January 2002 and May 2003,76 patients who consented for awake MIDCAB surgery were randomly assigned into either MIDCAB under general anesthesia (GA Group) or MIDCAB under epidural anesthesia (EA Group). EA Group patients did not receive concomitant general anesthesia and they were conscious throughout the procedure. All patients had a left internal thoracic artery to left anterior descending coronary artery bypass using the same MIDCAB techniques. There were 42 patients in the GA Group and 34 patients in the EA Group. The demographic characteristics of the groups were similar.

RESULTS: Results are depicted in the Table. There were no mortality or major morbidity in both groups. EA Group patients had lower arterial oxygen saturations and higher partial carbon dioxide pressures, but these were not clinically significant. EA Group patients had significantly less intensive care unit (ICU) and hospital stay periods, as well as significantly less postoperative pain and blood loss. There was not any difference in regard to patient satisfaction after the procedure between the two groups.

CONCLUSIONS: It can be concluded that, similar surgical results can be achieved by MIDCAB surgery with general or epidural anesthesia. Although epidural anesthesia has no impact on the degree of patient satisfaction after the procedure, it yields significantly shorter ICU and hospital stay periods, which may result in more efficient use of hospital resources.

Values are expressed as mean ± standard deviation

NS: Not significant

VAS: Visual analog score

*By invitation

¹1998-99 International Fellow

T3. The Completely Robotic Oncologie Minimally Invasive Esophagectomy

Kemp H. Kernstine*, Daniel T. Dearmond*, Mohsen Karimi*, Dany M. Shamoun*, Jeffrey E. Everett*; Iowa City, IA

Discussant: Scott J. Swanson

OBJECTTVE: Esophagectomy is a palliative and potentially curative treatment for esophageal cancer. To improve long-term survival, induction chemoradiotherapy and lymphadenectomy have been added, at the expense of increased surgical difficulty, morbidity and mortality. Success has been demonstrated with a minimally invasive esophagectomy. We investigated the use of robotics to perform esophageal resection and a three-field lymphadenectomy after induction therapy.

METHODS: Ten patients, 66 ± 13 y, BMI 30.9 + 3.7 underwent esophagectomy with the da Vinci™ (Intuitive Surgical) robot. Lesion characteristics: 8 cancer, 2 high-grade dysplasia, 5 adenocarcinoma, 3 squamous cell cancer; 2 middle third, 6 lower third; 2 T2N1, 2 T3N0, 3 T3N1 and 1 T4N1 at presentation. Key patient characteristics: 6 preoperative chemoradiotherapy, 4 prior abdominal surgeries, 2 prior upper abdominal surgeries, and 1 prior gastrostomy. Patients were chronologically grouped, Group I (3), thoracic only, robotic-assisted esophagectomy was performed; Group II (3), robotic-assisted thoracic esophagectomy plus thoracic duct ligation, with a laparoscopic gastric conduit and no pyloric procedure; Group III (4), a completely robotic esophagectomy. In Groups II and III a 4 cm wide gastric tube was created.

RESULTS: In Group III, the total operating room time was 11.9 ± 0.8 hours (11.3-13) and console time was 5.1 ± 0.5 hours (4.8-5.8). The estimated blood loss was 600 ± 200 ml (200-950). In-Group I, 1 had a thoracic duct leak. In Groups II and III, a thoracic duct ligation resulted in no further leaks. Other postoperative complications included: atrial fibrillation (3), cervical anastomotic leak (1), wound infection (1), renal failure (1), azotemia (1), and bilateral vocal cord paresis requiring tracheostomy (1). There were no cases of gastric outlet obstruction. In 5 no ICU time was required. The survival to date is 100%.

CONCLUSIONS: Robotics facilitates an oncologically sound esophageal resection, even with prior induction therapy and abdominal surgery. Proper initial port placement and the operating room team are critical to reduce operating time. Larger scale trials are needed to define the role of this technique.

*By Invitation

T4. The Incidence of Emboli During Cardiac Surgery: A Histopathologic Analysis of 2,297 Patients

Keith A. Horvath, Gerald Berry*, for the ICEM Investigators*; Chicago, IL, Stanford, CA

Discussant: Curtis G. Tribble

OBJECTIVE: Manipulation of the atherosclerotic aorta during cardiac surgery is assumed to cause immobilization, which can contribute to adverse outcomes. Recently, as a result of worldwide trials deploying the EMBOL-X intra-aortic filter during cardiac surgery, such emboli were captured and processed for histopathologic analysis.

METHODS: Filters with a pore size of 120 microns were placed in 2,297 patients who underwent the following operations: CABG (68%), valve (16%), combination CABG/valve (11%), and other (2%).

RESULTS: Filters captured at least one embolus in 98% of the patients. An average of 8.3 particles were captured per filter (range of 0-74). The surface area of the emboli were on average 5.8mm2 (range of 0-188mm2). Histologic analysis of the captured particles indicated that in 79% of the filters fibrous atheromata were noted, in 44% there were platelets and fibrin, 8% had red blood cell thrombus, 3% had fibro fatty/adventitial tissue, 2% had other material including cartilage, myocardium, lung, suture, and a Teflon pled get. Of the patients enrolled, 1,569 were high-risk. The average number of particles captured in the high-risk patients was 8.5 vs. 5.8 for the low to moderate risk patients (p<.0001). Concomitantly there was an increase in the embolic burden between the higher and lower risk patients (surface area 6.6 vs. 4.0mm2, p<.0001). In these high-risk patients, intra-aortic filtration led to fewer complications, particularly a reduction in neurologic injury.

CONCLUSIONS: These data show the ubiquitous incidence of emboli during cardiac procedures. Intra-aortic filtration should reduce adverse outcomes as was demonstrated for the high-risk patients in this study.

*By Initiation

T5. The Hybrid Surgical-Transcatheter Approach for the Treatment of Congenital Heart Disease: An Emerging Strategy

Mark Galantowicz*, John P. Cheatham*, Samuel Weinstein*, Terrance J. Davis, Craig Fleishman*, Sharon Hill*, Vyas M. Kartha*; Columbus, OH

Discussant: Emile Bacha

OBJECTIVE: A collaborative interaction between pediatric cardiothoracic surgeons and interventional cardiologists, coupled with new technology has enabled the development of hybrid treatment strategies for patients with congenital heart disease. These new hybrid treatments may improve short-term and long-term outcomes. We describe our experience with 7 different hybrid procedures in 21 patients.

METHODS: From 7/2002 to 10/2003, 21 patients, ages 5 days to 4.3 years, weighing 1.2-11. 5kg, underwent one of the following procedures. 1) 13 patients with HLHS were initially palliated with bilateral PA bands and a PDA stent. 2) 3 patients had intra-operative stents placed in pulmonary arteries (2) or pulmonary vein (1). 3) One patient (1.6kg) with PA/VSD had per ventricular placement of a RVOT stent. 4) One patient had per ventricular device closure of two VSDs. 5) One patient (1.2kg) underwent balloon aortic valvuloplasty via a Tran carotid cut down. 6) One patient (2.5kg) had a combined balloon pulmonary valvuloplasty and epicardial pacemaker insertion. 7) One patient had a transcatheter Fontan completion after a modified hemi-Fontan. Procedures 1 -4 were performed in a modified OR outfitted with a mobile, digital, cardiac C-arm while procedures 5-7 were in a biplane cath-lab adapted for surgical procedures.

RESULTS: All devices were successfully delivered to the target lesions with protection of pulmonary blood flow & PDA patency, relief of stenoses, occlusion of defects, and completion of a Fontan circuit. Balloon valvuloplasties were successful. One patient required a 2^nd PDA stent within 24 hours. The only death was in a patient (2.1 kg), with HLHS, undergoing PA bands & PDA stent. Autopsy revealed an unsuspected congenital stenosis (<1.5mm) of the origin of the transverse arch compromising retrograde coronary and cerebral perfusion after stent placement.

CONCLUSIONS: These examples of collaborative management of congenital heart disease build on the strengths of the shared techniques and technology while minimizing the weakness of either a surgical or interventional procedure alone. This level of hybrid thinking will lead to novel treatment strategies, such as PDA stent & PA banding for HLHS, which may significantly reduce the cumulative impact of interventions, thereby improving quality of life and survival. Venue modifications in either the operating room or cath-lab facilitate hybrid procedures. Success in this small cohort of patients warrants further investigation and follow-up of hybrid procedures.

*By Invitation

T6. 3-Dimensional Echo Guided Beating-Heart Surgery Without Cardiopulmonary Bypass: Feasibility Study

Yoshihiro Suematsu*, Gerald R. Marx*, Jeffrey A. Stoll*, Pierre E. Dupont*, Robert D. Howe*, John K. Triedman*, Tomislav Mihaljevic*, Bassem N. Mora*, Bernie J, Savord*, Ivan S. Salgo*, Pedro J. Del Nido; Boston, Cambridge and Andover, MA

Discussant: Patrick M. McCarthy

OBJECTIVE: Techniques for beating-heart coronary bypass surgery have evolved substantially. For intracardiac beating heart interventions however, only catheter based techniques are currently in use. To develop surgical techniques for reconstructive beating-heart repair of atrial septal defect (ASD) in children, and mitral valve plasty (MVP) in adults, we have gathered a multidisciplinary team to adapt real-time 3-dimensional echocardiography (RT3DE) with specialized instrumentation to facilitate ASD closure and MVP procedures.

METHODS: Exp. I: a modified RT3DE system with x4 matrix transducer (Sonos 7500, Philips Medical Systems, Andover, MA) was compared to 2-D echo in the performance of common surgical tasks. Completion times, deviation from an ideal trajectory using an electromagnetic tracker, and deviation of suture from an echogenic target (mm) were measured. Exp. II: porcine ASDs were created and closed with an original design semi-automatic suturing device (n=4), and in separate exp. ASDs were closed with a 5-mm endoscopic stapler and pericardial or 0.1mm PTFE patch (n=4). Exp. III: A pulsatile porcine mitral valve model was developed and suture placement through the anterior and posterior mitral leaflets (Alfieri et al) was performed determining suture placement at the end of each surgical task (n=8). During all experiments the operator was blinded to the target and operated only under ultrasonic guidance.

RESULTS: Compared to 2DE guidance, completion times improved by 23±5 % (p<0.01) with high trajectory accuracy, and deviation of suture was significantly smaller (2DE: 4.3± 1.9 mm, 3DE: 1.3±0.5 mm, p<0.05) in RT3DE guided tasks. In both ASD closure and MVP, RT3DE provided satisfactory images and sufficient anatomical detail for suturing and patch deployment. The needles and staples penetrated the tissue and/or patch material consistently, and all surgical tasks were successfully performed with accuracy. In both procedures, collateral tissue injuries were not observed.

CONCLUSIONS: RT3DE provides adequate imaging and anatomic detail to act as a sole guide for surgical task performance. These initial experiments demonstrate the feasibility of beating-heart direct or patch closure of ASD and MVP without cardiopulmonary bypass.

*By Invitation

T7. Surgical Ventricular Restoration Improves Mechanical Dyssynchrony in Post-Infarction Ischemic Cardiomyopathy

Marisa Di Donate*, Michel Sabatier*, Vincent Dor, Anna Toso*, Lorenzo Menicanti*; The Restore Group; Firenze, Italy, Monaco Cedex, Monaco, San Donate Milanese, Italy

Discussant: Edward D. Verrier

OBJECTIVE: In ischemic Cardiomyopathy, dyssynchrony of left ventricular (LV) mechanical contraction produces adverse hemodynamic consequences. This study tests the capacity of geometric rebuilding by surgical ventricular restoration (SVR) to restore a more synchronous contractile pattern following a mechanical, rather than electrical intervention.

METHODS: A prospective study of the global and regional components of dyssynchrony were studied in 30 pts (58±8 years) undergoing SVR The protocol used simultaneous measurements of ventricular volumes and pressure, in order to construct Pressure/Volume (P/V) to study global function, and Pressure/Length (P/L) loops to evaluate endocardial regions contributing to global function. Angiograms were done before and after SVR to study a 600 msec cycle during Pacing at 100 beats/min .

RESULTS: Mean QRS duration was similar at 100±17 pre and 114±28 msec post-operatively (NS). Pre-operative LV contraction was highly asynchronous , as P/V loops showed abnormal isometric phases with a right shifting. The contributing components of regional endocardial time-motion was either early or delayed at the end systolic phase so that P/L loops were markedly abnormal in size, shape and orientation. Post operatively, SVR resulted in leftward shifting of P/V loops and increased area (Fig); endocardial time-motion and P/L loops almost normalized to allow a better contribution of single regions to global ejection.

The hemodynamic consequences of SVR, that produced these components of global and regional synchrony included improved Ejection Fraction (30±13 to 45±12%, 0.001); reduced End Diastolic and End Systolic Volume Index (202±76 to 122±48 and 144±69 to 69±40 ml/ m2, 0.001); more rapid Peak Filling Rate (1.75±0.7 to 2.32±0.7 EDV/sec, 0.0001); Peak Ejection Rate (1.7±0.7 to 2.6±0.9; 0.0002) and Mechanical Efficiency (0.56±0.15 to 0.65±0.18, 0.04). Fig shows PA⁷ loops in one pts before and after SVR.

CONCLUSIONS: These global and regional effects that changed preoperative dyssynchrony were independent of conduction delay, did not need biventricular pacing, and show that SVR produces a mechanical intra-ventricular "re-synchronization" that improves LV performance.

*By Invitation

T8. A New Mechanical Connector for Distal Coronary Artery Anastomosis in CABG: A Randomized Controlled Study

Lars Wiklund*, Luis Bonilla*, Eva Berglin*; Gothenburg, Sweden, St. Paul, MN

Discussant: Randall K. Wolf

OBJECTIVE: Recently, special interest has been taken in mechanical anastomotic devices in order to facilitate minimal invasive techniques or limited access surgery in patients undergoing coronary artery bypass grafting.

METHODS: Between April and December 2002,60 patients scheduled for elective multivessel bypass grafting were prospectively randomized. One vein graft-to-coronary artery anastomosis per patient was either performed by the St. Jude Medical ATG coronary connector system (n=30) or hand sewn (n=30). A selective coronary angiography or coronary magnetic resonance imaging of the studied graft and vessel was included in the 6-month follow-up.

RESULTS: Twenty-eight of the connectors were successfully implanted. Two were excluded from the study because of conversion to hand-sewn anastomoses. The intraoperative graft blood flow after weaning from CPB in the connector group was 47 ± 8 ml/min and in the control group 46 ± 4 ml/min indicating that all anastomoses were patent at the end of the procedure. Six connector-made anastomoses were bleeding at the anastomotic site. At the time of follow-up (190 days postoperatively) all control anastomoses/grafts were patent whereas 26% (7 out of 28) of the connector-anastomoses were occluded.

CONCLUSIONS: The St. Jude Medical ATG coronary connector system for distal anastomoses represents a new concept for suture-less anastomoses in cardiac surgery. This randomized controlled study shows lower graft patency in anastomoses performed with the connector compared to hand-sewn controls. It illustrates the importance of controlled studies when evaluating new technical equipment in medicine

*By Invitation

WEDNESDAY MORNING, APRIL 28, 2004

7:00 - 9:00 a.m.

GLOBAL INITIATIVES IN CARDIOTHORACIC SURGERY: AN UPDATE

North Bldg., Ste 205, Metro Toronto Convention Centre

Co-Chairmen: James I. Cox

Marko I. Turina

7:00 a.m. Evolution of Global Strategies in Humanitarian Cardiothoracic Surgery

A. Thomas Pezzella, The World Heart Foundation

7:10 a.m. Pediatric Cardiology and Cardiovascular Surgery in Iraq

Ra-id Abdulla, University of Chicago

7:20a.m. Plans for a New Pediatric Cardiac Program in Iraq

Richard A. Jonas, Boston Children's Hospital

7:30 a.m. Cardiac Surgery in an Underdeveloped Country - the Beginning and the Way Forward

Ahmed Sayed Ahmed Elsayed, Sudan Heart Center

7:40a.m. Various Modes of Medical Cooperation in Developing Areas. A Personal Experience

Jean E. Bachet, Institute Mutualiste Montsouris

7:50 a.m. Panel Discussion

Moderators: James L. Cox and Marko I. Turina

CONTROVERSIES IN CARDIOTHORACIC SURGERY PLENARY SESSION

North Bldg., Hall C, Metro Toronto Convention Centre

9:15 a.m. Topic: The Legal Profession is the Guardian of Medical Standards

Moderator: Joseph J. Bongiovi, III

Pro: John S. Romano

Con: Michael E. Royce

CONTROVERSIES IN CARDIOTHORACIC SURGERY ACQUIRED CARDIAC CONTROVERSIES

North Bldg., Hall C, Metro Toronto Convention Centre

10:30a.m. Topic: Atrial Fibrillation Surgery Should Be Performed On Patients Undergoing Mitral Valve Replacement

Moderator: W. Randolph Chitwood

Pro: Delos M. Cosgrove

Con: Tirone E. David

11:15a.m. Topic: The Ross Operation Is The Procedure of Choice For a 40 Year Old Patient With Aortic Valve Disease

Moderator: Andrews. Wechsler

Pro: Vaughn A. Starnes

Con: Lawrence H. Cohn

12:00 noon ADJOURN

*By Invitation

Wednesday Morning, April 28, 2004

CONTROVERSIES IN CARDIOTHORACIC SURGERY GENERAL THORACIC CONTROVERSIES

North Bldg., Rm 105, Metro Toronto Convention Centre

10:30a.m. Topic: Minimally Invasive Esophagectomy is a Major Advance in the Care of the Patient with Esophageal Cancer

Moderator: Richard F. Heitmiller

Pro: Mark J. Krasna

Con: Nasser Altorki

11:15a.m. Topic: Post-Operative Adjuvant Therapy Should Be Offered To All Patients With Resected Lung Cancer

Moderator: Larry R. Kaiser

Pro: David Johnson

Con: Harvey I. Pass

12:00 noon ADJOURN

WEDNESDAY MORNING, APRIL 28, 2004

CONTROVERSIES IN CARDIOTHORACIC SURGERY CONGENITAL HEART CONTROVERSIES

North Bldg., Rm 107, Metro Toronto Convention Centre

10:30a.m. Topic: Catheter-Delivered Devices Are Preferred Over Surgery For Management of Secundum ASD

Moderator: Constantine Mavroudis

Pro: Andrew Redington

Con: Richard A. Jonas

11:15a.m. Topic: The Symptomatic Infant Less Than 6 Months of Age With Tetralogy Should Be Managed With a Shunt

Moderator: William G. Williams

Pro: Charles D. Fraser

Con: Ross M. Ungerleider

12:00 noon ADJOURN

*By Invitation