| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
|
Interact CardioVasc Thorac Surg 2007;6:S223-S280. doi:10.1510/icvts.2007.0000S7 © 2007 European Association of Cardio-Thoracic Surgery
AbstractsSuppl. 3 to Vol. 6 (September 2007)
F1 FLOW-SENSITIVE 4D MAGNETIC RESONANCE IMAGING: PATHOLOGICAL BLOOD FLOW PATTERNS IN ASCENDING AORTIC ANEURYSMS E. Weigang1, F. Kari1, M. Luehr1, J. Kobba1, A. Frydrychowicz2, M. Markl2, C. Heilmann1, F. Beyersdorf1 1University Cardiovascular Centre, Freiburg, Bad Krozingen, Germany; 2University Medical Centre, Freiburg, Germany Objectives: Aortic aneurysms are characterized by pathological blood flow patterns. However, these changes are poorly understood. We therefore analysed local blood flow in aneurysms of the ascending aorta using flow-sensitive 4D-MRT. Methods: Data were acquired on a 3 Tesla-MRT with a 4D (time-resolved 3D) sequence protocol (ECG-gating, respiration control). Flow was visualised as 3D-streamlines and 3D-particle traces using the software EnSight. Healthy volunteers and six patients with ascending aortic aneurysms were investigated. Results: Healthy individuals presented a right-handed helix extending into the proximal arch (1.5 revolutions) and vortical flow in the sinuses. Two patients with atherosclerotic aneurysms had either increased right-handed helical flow (3.5 revolutions) with flow acceleration along the great curvature, or multiple vortical flows in the sinuses and middle of the ascending aorta, respectively. One typical Marfan-associated aneurysm exhibited increased vortical flow in the dilated sinuses. One aneurysm of the proximal anastomosis of a supracoronary replacement showed extensive vortex formation inside the aneurysm's lumen. An aneurysm in one patient with a bicuspid aortic valve revealed a major vortex formation directly above the valve with unusual spatial and directional orientation. An aneurysm following congenital valvular stenosis and commissurotomy in childhood was characterised by a vortex along the small curvature and helical diastolic backflow in the central ascending aorta. Conclusions: Six patients with similar pathomorphology presented considerable differences in local flow patterns in the ascending aorta compared to healthy volunteers and among themselves. Insight into the role of flow may contribute to predicting the individual course of ascending aortic aneurysms.
1Leids Universitair Medisch Centrum, Leiden, The Netherlands; 2HemoLab Cardiovascular Engineering, Eindhoven, The Netherlands Objectives: The isolated heart model provides a multifunctional test platform in which function and physiology can be studied. In order to achieve satisfactory pre- and after load of the left and right side of the heart respectively we created an ex-vivo working heart-lung model. Methods: Porcine heart and lungs are isolated from slaughterhouse pigs following a special, authorized protocol. The protocol takes into account that no additional suffering to the animal takes place and that the quality of heart and lungs are preserved. The heart is arrested with cardioplegia and the lung circulation flushed with ringer-heparin solution. The heart-lung is prepared so that it can be mounted to the test platform. The heart is resuscitated and working in Langendorff mode and the lungs ventilated. After achieving good right venricular function the membrane oxygenation in the Langendorff circulation is being switched off so that the oxygenation is fully depending on the ventilation of the lungs. Results: We were able to achieve and maintain an ex-vivo working 2-chamber heart-lung model for at least 3 h with good right ventricular function and sufficient oxygenation by the lungs. Conclusions: After successfully achieving a four chamber working heart-model with the ability to visualize all heart valves this is the first step in achieving a fully working ex-vivo four-chamber heart-lung model test platform.
Division of Cardiac Surgery, S Raffaele Hospital, Milan, Italy Objectives: Despite its efficacy and swiftness, bipolar radiofrequency is generally not used on the left isthmus for concern of injuring a coronary branch. Incomplete lesion sets or use of an additional unipolar device are often considered. We report a technique to perform a full left lesion set involving the mitral line using a standard bipolar radiofrequency device. Methods: Coronary angiogram is carefully pondered. After beating-heart pulmonary vein isolation on-pump, coronary anatomy is inspected to identify the coronary-free area of the A-V groove. An hypodermic needle is stuck in the middle of such area, into the left atrial wall, behind the coronary sinus. The projection of the needle marker on the mitral annulus is then identified through the atriotomy. The needle is removed. An ablation is performed clamping the bipolar device endo-epicardially on the atrial wall, involving the A-V groove, the coronary sinus, and the annulus. The lesion set is then completed by connecting the encirclings and the left appendage, which is then sutured. Results: Since May 2005, 65 mitral patients with atrial fibrillation had the described ablation. Haematoma of the A-V groove was observed during retrograde cardioplegia in one case. All patients survived. No patient had myocardial ischaemia or re-exploration for bleeding (median 310 cc, 240; 400 cc). At nine months (5; 13 months), 55/65 patients (85%) were free from atrial fibrillation. No patient had left flutter. Conclusions: The mitral line can be safely performed with bipolar radiofrequency in all patients. A transmural, complete lesion set performed with a single device yields excellent early results.
Ege University Medical Faculty, Department of Cardiovascular Surgery, Izmir, Turkey Objectives: Problems in the distal aorta after proximal aortic operation in young patients with Marfan syndrome affects the long-term outcome. Progressive dilatation of the aorta as well as development of aneursyms from the Carrel patches after repair of thoracoabdominal aortic aneurysms (TAAA) are major concerns. Replacement with commercially available multi-branched grafts may be a solution. We present a case of Marfan syndrome who underwent replacement of extensive TAAA by using a multi-branched graft. Operation and perfusion techniques were shown in this video presentation. Methods: A 25-year-old man with Marfan syndrome was admitted to our clinic due to progressive enlargement of his thoracoabdominal aorta detected in follow-up CT scans. He underwent Bentall operation and replacement of the proximal descending aorta after development of acute type III dissection, 8 and 3 years ago, respectively. Thoracoabdominal incision with retroperitoneal approach was used for aortic exposure. Operation was performed under hypothermic circulatory arrest and selective visceral and pelvic perfusion by using femorofemoral bypass. The period of brain ischemia was 18 min. Results: Patient awoke neurologically intact. He did not develop any complications and was discharged seven days after the operation. Conclusions: The use of multi-branched graft enables anastomosis of visceral and renal arteries without large buttons of diseased aorta in repair of extensive TAAA. This graft has other advantages like possibility to perfuse individual branches and easier visualisation and control of anastomotic leakage.
Hopital Jean Minjoz, Besancon, France Objectives: This aggregate video describes the monobloc aorto-mitral homograft implantation technique, from two such implantations performed in our department. Methods: Both patients were males in their thirties. The first episode of endocarditis involved only the mitral valve in the first, and both the aortic and mitral valves, with an abscess of the aortic annulus, in the second patient. The first operation consisted in a complex mitral valvuloplasty in the first patient. In the second patient both, aortic and mitral valves were replaced by mechanical prostheses, the abscess was removed and replaced by an autologous pericardium. Results: The second episode treated by monobloc aorto-mitral homograft implantation, happened respectively 7 and 3 months after the first episode. Conclusions: Both patients are doing well with 9 and 4 months follow-up.
001 PREOPERATIVE LONG SAPHENOUS VEIN MAPPING PREDICTS VEIN QUALITY AND ANATOMY LEADING TO IMPROVED POSTOPERATIVE LEG MORBIDITY H. Luckraz1, T.B. Esmael1, N. Pugh2, J. Lowe1, A. Luer-English1, D. Mehta1, E.N. Kulatilake1, A.A. Azzu1 1Cardiothoracic Unit University Hospital of Wales, Cardiff, UK; 2Doppler Ultrasound Department University Hospital of Wales, Cardiff, UK Objectives: Long saphenous vein harvesting for coronary bypass surgery is associated with significant morbidity. Furthermore, vein quality is often variable sometimes requiring incisions in both legs. The aim of this study was to assess the usefulness of preoperative long saphenous vein mapping in terms of conduit quality and location, incision lengths and postoperative morbidity.
Methods: A prospective randomisation control trial was carried out with patients either having their long saphenous vein assessed and mapped preoperatively by venous Doppler ultrasound (n=31) or not (n=30). The study was powered to 0.9 with an Results: There was no significant difference between the two groups in terms of age, gender and pre-op incidence of diabetes, peripheral vascular disease, smoking history, ejection fraction, priority of surgery and body surface area. The size and anatomical distribution of the long saphenous vein was well predicted by the ultrasound study (correlation coefficient=0.87). Intra-operatively, the mean length of leg wound per vein graft performed was significantly less in the mapped group [16.8 (4.0) vs. 24.1 (10.4) cm, P=0.005]. This translated in a shorter operative time for vein harvesting per length of vein graft needed [36 (13) vs. 47 (17) min, P=0.04]. Postoperatively there was a tendency to less leg wound complications in the mapped group (P=0.08). Conclusions: Long saphenous vein mapping preoperatively predicts the size and anatomy of the vein appropriately. This led to a selective leg wound incision and reduced operative time with the benefit of reduced leg complication postoperatively.
Katholieke Universiteit Leuven, Leuven, Belgium Objectives: A heart valve prosthesis constructed from acellular, moderately cross-linked photo-oxidised bovine pericardium (POP) can become completely recellularised after three day intraperitoneal preseeding. In this study we tested these valves (n=19) up to five months implantation in pulmonary position in sheep and compared them to controls (n=20). Methods: Haemodynamics were evaluated by transthoracic echocardiography (TTE) at 1 week and 1, 3 and 5 months. Post-mortem we assessed calcification, morphometry, matrix properties, recellularisation and biophysical properties. Results: TTE revealed that all valves remained functional and that IP valves had a slight, but significantly increased, peak gradient and regurgitation prevalence. This might be caused by the observed remodelling of these valves: in contrast to controls they became thicker but shorter. All valves studied had calcium contents in the range of native valves. The POP was slowly degradable, as shown by the significant decreases in organised collagen, E modulus, strength and maximal force. The IP valves were completely recellularised in contrast to the controls. The cells did produce new extracellular matrix containing collagen and ground substance but the amount of new matrix was 4.4-fold higher in IP valves, which coincided with the 2.7-fold increase in cell number in these valves. The cell fractions expressing myofibroblast or smooth muscle cells markers (ASMA, SMMS-1 and Smoothelin) were similar in both groups but significantly exceed those of native pulmonary valves. Conclusions: IP seeding resulted in complete recellularisation and neomatrix deposition. However, remodelling, most probably caused by an increased fraction of cells with contractile properties, influenced haemodynamic and biophysical properties.
Day General Hospital, Tehran, Iran Objectives: The aim of this study was to investigate the feasibility of performing papillary muscle repositioning for subvalvular-sparing mitral valve replacement procedures in an LV- dysfunction population and to determine the early and late effects of this procedure on the clinical outcome and left ventricular mechanics. Methods: One hundred patients with ejection fraction <40, who were candidates for isolated surgical correction of mitral insufficiency, were prospectively randomized into either total chordal-sparing or papillary muscle repositioning mitral valve replacement groups. Fifty subjects underwent papillary muscle repositioning (PMR group), and the remaining 50 had complete preservation of all chordal structures (CMVR group). Echocardiography was performed preoperatively, at discharge and after two years to determine dimensions, left ventricular shape and function. Results: End-diastolic and systolic volumes decreased in both groups initially and continued to decline. Decreasing volumes, however, were more significant in the PMR group, in which the significant decrease in the sphericity index continued for another two years. In contrast, the sphericity index in the CMVR group had no significant changes at discharge and at two years. In terms of systolic performance, ejection fraction had no significant changes in the CMVR group, whereas it exhibited a significant increase in the PMR group. Conclusions: Papillary muscle repositioning could result in more favourable left ventricular remodelling compared with complete retention of the mitral subvalvular apparatus during mitral valve replacement. It confers a significantly early and late advantage by causing a more significant reduction in the left ventricular chamber volume, sphericity index and systolic performance.
004 INDIVIDUAL RISK PREDICTION OF METASTASIS FOR PATIENTS WITH TYPICAL BRONCHIAL CARCINOID TUMOURS J.C. Neves-Pereira2, J.F. Bernaudin2, J.R. de-Campos-Milanez1, M. Riquet2, V.L. Capelozzi1, C. Danel2, P. Bagan2, F.B. Jatene1 1Sao Paulo University Medical School, Sao Paulo, Brazil; 2Pierre et Marie Curie University, Paris, France Objectives: Despite bronchial-typical-carcinoid tumours being low-grade malignancies, metastasis are diagnosed in some patients. It is imperative to predict the individual risk of metastasis. Predictive models can be used with this aim. Our objective is to predict the individual risk of metastasis for patients operated-on by bronchial-typical-carcinoid based on a logistic regression model in function of candidate clinical, pathological and tumour biomolecular variables. Methods: A multicentre retrospective cohort study, including 330 (202 French/128 Brazilian) consecutive patients operated-on by bronchial-typical-carcinoid and followed-up during a period longer than ten years in two university hospitals was performed. Logistic regression was used as a predictive model (SPSS Illinois-Chicago). The following clinical, pathological and tumour biomolecular data were analysed as independent variables candidates to predict individual risk of metastasis: age, gender, ethnical-group, weight loss, chest pain, TNM-staging, tumour diameter and location (central/peripheral) and tumour p53, Ki67 and Bcl-2/Bax immunostaining and microscopic density of: collagen/elastic fibres and angiogenesis (neoformed microvessels immunostained by the monoclonal antibody anti-CD34). Results: Lymph node metastasis incidence was 11% and 10% for Brazilian and French patients respectively and 5% for haematogenic metastasis in both groups. Univariated analysis related metastasis (P<0.05) to: elder age, male gender, ethnic group (African-American), weight loss, chest pain, low extracellular fibers density, high Ki67 and elevated angiogenesis (neoformed CD34-immunostained microvessels density). Multivariated logistic regression analysis showed that angiogenesis (neoformed CD34-immunostained microvessels density) is an independent variable that predicts these metastasis (B=0.3; P=0.0001). Conclusions: Individual risk of metastasis for patients operated on for bronchial typical carcinoid can be predicted by a logistic regression model in function of tumour-neoformed microvessels density (angiogenesis).
St Luc Hospital UCL, Brussels, Belgium Objectives: Non-small cell lung cancer (NSCLC) has a poor prognosis even for early stages of the disease (Stage I and II). Adjuvant chemotherapy is currently advised only for Stage II tumours. This is to evaluate whether FDG uptake can predict survival in Stage I and II NSCLC. Methods: Retrospective study of 97 patients with NSCLC. 18F-FDG-PET performed for pretherapeutical staging. Histopathological stage was either Stage I (n=76) or Stage II (n=21). FDG uptake was measured as maximal SUVbw (SUVmax). Mean follow-up time was 45+30 months (1–142 months). Death or survival occurrences were recorded. Results: SUVmax were higher for Stage II than for Stage I (10.5±4.5 vs. 8.5±5, P=0.04). Mean tumour volumes were equivalent for both stages (33 cm3), excluding a partial volume effect. Median SUVmax was 7.8. Mean actuarial survival was significantly reduced for patients with higher tumour uptake: 127 months if SUVmax7.8 (P=0.0003). For Stage I tumours (n=76), high FDG uptake was associated to reduced survival: 127 months if SUVmax7.8 (P=0.0017). For Stage II tumours (n=21), no statistical difference was observed: 72 months vs. 40 months for SUVmax7.8, respectively (P=0.11). Conclusions: FDG uptake is a prognostic indicator for overall survival in NSCLC. However, this prognostic value applies only to Stage I tumours (i.e. T1N0, T2N0). This study suggests that a subgroup of patients with stage I disease (i.e. those with a high FDG uptake, SUVmax>7.8) have a reduced survival and might therefore benefit from adjuvant chemotherapy.
National Cancer Centre, Goyang, Korea (South) Objectives: Delayed gastric emptying after oesophagectomy occurs in up to 50%. Good quality of life after oesophagectomy may depend on both dietary adaptation and the improvement of gastric motility itself. The objective of study was to investigate the effect of pyloric balloon dilation on delayed gastric emptying after oesophagectomy. Methods: Between April 2003 and March 2006, balloon dilatation of pylorus was performed in 14 patients who suffered from sustained symptoms of delayed gastric emptying after oesophagectomy for oesophageal cancer despite the use of prokinetics. Gastric drainage procedure was routinely undergone during oesophagectomy. Intrathoracic gastric emptying of solid food was evaluated by radioisotope before and after the balloon dilatation of pylorus in nine patients. The 50% gastric emptying time over 180 min was defined as delayed. We assessed the changes of the intrathoracic gastric emptying time and symptoms after pylorus dilatation for delayed gastric emptying. Results: The symptoms for delayed gastric emptying were improved after pylorus dilatation in most of patients. Pyloric balloon dilatation was performed twice in two patients. In four of nine patients (44.4%), delayed gastric emptying rate was much improved from 24.2% to 77.0% together with symptoms. The others showed the sustained delay of gastric emptying. Conclusions: This result shows the objective effect of balloon dilatation of pylorus on delayed gastric emptying by measuring gastric emptying time with radioisotope. Balloon dilatation of pylorus is useful to treat the sustained delay of intrathoracic gastric emptying after oesophagectomy. However, factors other than pylorus would be considered to determine the intrathoracic gastric emptying rate.
007 DOES CONTEGRA MATCH ALLOGRAFT PERFORMANCE IN INFANT TRUNCUS ARTERIOSUS REPAIR? E.J. Hickey1, B.W. McCrindle1, E.H. Blackstone2, T. Yeh Jr3, F. Pigula4, D. Clarke7, C. Tchervenkov6, J. Hawkins5 1The Congenital Heart Surgeon's Society, Toronto, Canada; 2Cleveland Clinic Foundation, Cleveland, USA; 3University of Texas Southwestern Medical Center, Dallas, USA; 4Boston Children's Hospital, Boston, USA; 5Primary Children's Medical Centre, Salt Lake City, USA; 6Montreal Children's Hospital, Montreal, USA; 7Children's Hospital, Denver, USA Objectives: Limited availability and durability of allograft conduits require that alternatives be considered. We compared Contegra and allograft performance in 107 infants who survived truncus arteriosus repair. Methods: Children were prospectively recruited between 2003 and 2007 from 17 institutions. Median age and weight at conduit implantation were 11 days (range 1–127) and 3.1 kg (range 1.7–9) respectively and were not different between the groups. The median z-score for Contegra (n=27, all 12 mm) was +2.1 (range +1.2 to +3.2) and allografts (n=80, 9–15 mm) was +1.7 (range –0.4 to +3.6). Propensity-adjusted comparison of conduit survival and function (using 745 available echocardiograms) was undertaken using parametric risk-hazard analysis and bootstrap resampling. Results: Overall conduit survival was 66±6% at three years. Conduit replacement was for conduit stenosis (n=16), pulmonary artery stenosis (n=18) or regurgitation (n=1). The propensity-adjusted 3-year freedom from replacement for conduit stenosis was 97% (±4) for Contegra and 69% (±7) for allograft (P=0.05). The risk of intervention for branch pulmonary artery stenosis was independent of conduit type. Smaller conduit z-score predicted poor conduit performance (P<0.01) with best outcome between +1 and +3. Although Contegra conduits were a uniform diameter, their z-score more consistently matched this ideal. Contegra exhibited a non-significant trend towards slower RVOT gradient progression. However, catheter intervention was more successful at slowing gradient progression with Contegra than with allograft (P=0.01). Conclusions: Contegra does match allograft performance and may be advantageous. It is an appropriate first choice for repair of truncus arteriosus, and perhaps other small infants requiring RVOT reconstruction.
1Department of Cardiac Surgery, Birmingham Children's Hospital, Birmingham, UK; 2Paediatric Intensive Care Unit, Birmingham's Children Hospital, Birmingham, UK; 3Statistical Advisory Service, Birmingham Children's Hospital, Birmingham, UK Objectives: To investigate tissue lactate, pyruvate and lactate: pyruvate (LP) ratio post cardiac surgery and the relationship of cardiac index and oxygen delivery to ‘late onset’ hyperlactataemia, developing during the first 12 h in ICU. Methods: Prospective study of 10 children, mean (S.D.) age 4.9 (0.4) years, post-Fontan operation admitted to ICU with a normal blood lactate (<3 mmol l–1). Tissue lactate, pyruvate and LP ratio were monitored postoperatively every 30 min for 12 h via a subcutaneous microdialysis catheter placed in the abdominal wall subcutaneous tissue. Blood lactate and cardiac index, measured by femoral artery thermodilution (PiCCO), were measured at 0, 4, 8, and 12 h. Results: Mean (S.D.) blood lactate rose from 2.23 (0.49) to 3.73 (1.16) mmol l–1 in the first 4 h (P=0.006), and only one child failed to show an increase in blood lactate above 3 mmol l–1. Tissue monitoring revealed a corresponding rise in lactate (Pearson correlation 0.73, P=0.02), with a parallel rise in pyruvate. LP ratio remained constant and below 20, suggesting a cause for hyperlactataemia other than tissue oxygen debt. Cardiac index increased from 2.83 (0.63) to 3.77 (1.34) l min–1 m–2 over the same 4 h period (P=0.05), with a corresponding increase in oxygen delivery from 4556 (1094) to 6076 (2322) ml min–1 (P=0.04). Conclusions: Tissue microdialysis is a simple technique that provides continuous measurement of lactate, pyruvate and other metabolites. A rise in blood and tissue lactate is common in children post cardiac surgery. This is not associated with a low or falling cardiac index.
1UCL Institute of Child Health and Great Ormond Street Hospital for Children, London, UK; 2Policlinico San Donato Milanese IRCCS, Milan, Italy Objectives: To evaluate the effects on ventricular function and volumes following percutaneous pulmonary valve implantation (PPVI) and right ventricular outflow tract reconstruction (RVOTR) with pulmonary homograft replacement (PVR). Methods: Thirty-six patients were prospectively examined. (Group 1) Those who had PPVI for pulmonary regurgitation alone (11, mean age 20±9 years, 64% Tetralogy of Fallot) were compared to (Group 2) those who had PVR with RVOTR (25, mean age 21±13 years, 96% Tetralogy of Fallot). Mean age at primary repair did not differ between the two groups (4.3±6.6 years) Magnetic resonance imaging was performed prior to, and one year following interventions. Results: Before procedure, NYHA was similar in both groups 2.1±0.5. Following interventions, there was a significant reduction of RV volumes in both groups, this was greater in the surgical patients [end-diastolic: 106±27 to 89±25 ml/m2 (1) vs. 151±49 to 97±32 ml/m2 (2), P=0.004; end-systolic: 49±20 to 40±16 ml/m2 (1) vs. 80±43 to 46±23 ml/m2 (2), P=0.002]; both group had a similar significant improvement in RV [53±14 to 67±16 ml/beat (1) vs. 63±20 72±16 ml/beat (2), ns] and LV effective stroke volume [60±25 to 74±17 ml/beat, (1) vs. 61±18 to 73±16 ml/beat, (2), ns]. Conclusions: Following PVR with RVOTR and PPVI, there was a significant reduction in RV volumes and an improvement in RV function. Importantly, in both groups, LV effective stroke volume increased, and this may be the parameter to judge the success of the procedure. These preliminary results support PPVI as an extra dimension in complex RVOT management.
010 ASCENDING AORTIC CURVATURE AS AN INDEPENDENT RISK FACTOR FOR TYPE A DISSECTION, AND ASCENDING AORTIC ANEURYSM FORMATION: A MATHEMATICAL MODEL M. Poullis1, R. Warwick1, M. Field1, A. Oo1, R.J. Poole2 1CTC, Liverpool, UK; 2Department of Engineering, Liverpool University, Liverpool, UK Objectives: To develop a mathematical model to demonstrate that ascending aortic curvature is an independent risk factor for type A dissections, in addition to hypertension, bicuspid aortic valve, aneurysm of ascending aorta, and intrinsic aortic tissue abnormalities, like Marfans syndrome. Methods: A steady state one-dimensional flow analysis was performed, utilising Newton's third law of motion. For calculation purposes the following cardiovascular values were utilised, cardiac output 5 l/min, systolic blood pressure 110–150 mmHg, ascending aortic diameter 20–40 mm. Aortic curvature from 10 to 90 degrees. Results: As the angle of curvature of the ascending aorta increases from 10° to 90°, the force imparted on the aortic wall increases by a factor of 11. As aortic diameter increases from 20 mm to 40 mm, with a 90° aortic curvature, the force imparted on the aortic wall increases from 8 N to 33 N, a 4-fold increase. Increasing systolic blood pressure from 110 to 150 mmHg, resulted in a 1.4-fold increase on the force exerted on the aortic wall. Conclusions: Aortic curvature is more important that aortic diameter or blood pressure, with regard to the force acting on the aortic wall. This may explain why some patients with normal diameter ascending aorta and no connective tissue defects develop type A dissections, and aneurysms. Aortic curvature should influence timing of aortic replacement surgery.
1University of Freiburg Medical Center, Freiburg, Germany; 2University of Pittsburgh Medical Center, Pittsburgh, USA Objectives: Dilatation of the aorta at the landing zone potentially limits long-term results of endovascular therapy. After thoracic stent graft placement, we evaluated growth patterns and morphology of the growing thoracic aorta in young piglets. Methods: Eight domestic piglets (37±2 kg) had an endovascular stent placed in the proximal descending thoracic aorta using retroperitoneal access. Aortic size was documented after thoracotomy by intraoperative measurement and angiography. At implantation, the stent was oversized by 10%. Subsequently the piglets were grown to adult size (181±42 kg). At explantation 10 months later, CT-scan and surgical evaluation for endoleaks was performed. Pathological assessment of the explanted aorta was performed.
Results: No endoleak or stent migration occurred even in 230-kg pigs. The stents expanded to full size, but there was no further aortic growth in the stented area. The aortic diameter increased significantly by 33±8% 1 cm proximal to the stents (P=0.0006) and by 52±12% 1 cm distal to the stents (P=0.0022). The stented area grew less than the proximal and distal aorta (P Conclusions: Endovascular stent grafting inhibits growth of the non-atherosclerotic normal aorta and leads to fibrosis in the inner media part adjacent to the stent. This observation could lead to review of the concept that non-atherosclerotic dilatative aortic disease should not be treated with endovascular therapy.
Mount Sinai School of Medicine, New York, USA Objectives: Spinal cord blood flow (SCBF) after sacrifice of thoracic and abdominal aortic segmental arteries (TAASA) during thoracoabdominal aortic aneurysm (TAAA) repair remains poorly understood. Methods: Fourteen juvenile Yorkshire pigs underwent complete serial TAASA sacrifice (T4-L5). Six control pigs underwent cooling to 32 °C with no TAASA sacrifice. In the experimental animals, spinal cord function was continuously monitored using motor evoked potentials (MEP) until 1 h (h) after clamping. Fluorescent microspheres enabled segmental measurement of SCBF before, and 5 min, 1 h, 5 h, 24 h and 72 h after complete TAASA sacrifice. A modified Tarlov score was obtained for three days postoperatively. Results: All the pigs with complete TAASA sacrifice retained normal cord function (MEP) until 1 h after TAASA ligation. Seven pigs (50%) with complete TAASA sacrifice recovered after 72 h; seven pigs suffered paraparesis (5) or paraplegia (2). Intraoperatively, and until 1 h postoperatively, SCBF was similar among the three groups. Postoperatively, SCBF in pigs with ischaemic cord injury was significantly lower at 5 h than in controls in the T8-L2 (P=0.0002) and L3-S segments (P=0.0007): the T8-L2 values predicted functional recovery (P=0.003). At 24 h, SCBF in injured pigs remained marginally lower from T8 caudally; at 72 h, SCBF was similar in all groups. Conclusions: This study suggests that critical spinal cord ischemia after complete TAASA sacrifice does not occur immediately, but is delayed 1–5 h or longer after clamping. The short duration of low SCBF suggests that haemodynamic manipulation lasting only 24–72 h might safeguard cord function despite sacrifice of all TAASA during surgical or endovascular repair of TAAA.
013 PERIVASCULAR TISSUE OF INTERNAL THORACIC ARTERY RELEASES POTENT NITRIC OXIDE AND PROSTACYCLINE-INDEPENDENT ANTICONTRACTILE FACTOR M. Malinowski1, M.A. Deja1, K.S. Go  ba2, T. Roleder2, S. Wo 1 1Second Department of Cardiac Surgery, Medical University of Silesia, Katowice, Poland; 2Department of Cardiology, Medical University of Silesia, Katowice, Poland Objectives: It was recently suggested that perivascular tissue releases hypothetic adipocyte derived relaxing factor (ADRF). The aim of the study was to assess anticontractile properties of perivascular adipose tissue of human internal thoracic artery (ITA). Methods: Human ITA rings were studied in vitro. First, skeletonised and pedicled ITA reactivity to serotonin was compared. In subsequent experiments fragments of ITA were skeletonised and divided into two preparations. One was incubated alone, the other together with adipose perivascular tissue floating freely in the bath. Concentration response curves to serotonin (n=10) and angiotensin (n=11) were constructed. Tissue was then transferred from one to the other bath and dose-response curves were reconstructed. The same protocol was applied with the inhibition of nitric oxide synthase with L-NMMA (10–4 M) and cyclooxygenase with indomethacin (10–5 M) (n=13). Results: Skeletonisation augmented contractile response to serotonin (Emax 16±2 vs. 43±4 mN, pedicled and skeletonised ITA respectively; P<0.001). Presence of perivascular tissue in the bath caused Emax decrease from 40±9 to 19±3 mN; P=0.04 and from 32±5 to 12±2 mN; P=0.002 (serotonin and angiotensin, respectively). Adipose tissue presence did not change ITA sensitivity (EC50) to serotonin or angiotensin. NO and prostacycline inhibition failed to abolish anticontractile properties of perivascular tissue. Perivascular fat decreased Emax from 43±3 to 33±4 mN, P=0.03 for serotonin and from 32±4 to 19±2, P=0.01 for angiotensin. Conclusions: Perivascular tissue of ITA releases potent, soluble, nitric oxide and prostacycline-independent anticontractile factor. Preservation of perivascular tissue may thus protect against vasospasm of ITA graft in clinical settings.
Wakayama Medical University School of Medicine, Wakayama, Japan Objectives: Neuronal nitric oxide synthase (nNOS) is apparently related to cardiac function, both under physiological conditions and in disease states. Direct nNOS delivery could thus constitute a powerful therapeutic tool. However, direct delivery of nNOS into the heart in vivo has not been reported. We developed a novel technique for directly delivering biologically active protein into cardiomyocytes in vivo. We used this technique to investigate the effect of targeted, direct delivery of nNOS and the Japan envelope (HVJ-E) vector transduced with a haemaglutinating virus into rat cardiomyocytes after acute myocardial infarction (AMI). Methods: We ligated the left anterior descending branch of the coronary arteries of Wistar rats to induce AMI and then 90 min later, we injected nNOS with the HVJ-E vector (NV group, n=8), ß-galactosidase with HVJ-E vector (BV group, n=7), nNOS alone (N group, n=6) or HVJ-E vector alone (V group, n=6) into the hearts and removed them 3 h later. Sections were histochemically stained with TTC and infarcted areas were colorimetrically evaluated. Results: The infarcted areas in sections from the NV group were significantly narrower than those from the B, N and V groups (P=0.001). Conclusions: Our findings suggest that direct nNOS transduction into cardiomyocytes rapidly diminished the size of infarcted areas after AMI. This type of targeted delivery should have wide application in terms of delivering therapeutic nNOS to the heart, and provide a powerful therapeutic tool with which to treat ischaemic heart disease.
Beth Israel Deaconess Medical Centre, Boston, USA Objectives: Growth-factor based angiogenesis, with or without cell therapy, is a promising therapeutic modality for patients with coronary artery disease (CAD). We compared the relative efficacies of surgically delivered VEGF and FGF-2 in a swine model of hypercholaesterolemia-induced endothelial dysfunction which captures many of the pathophysiological abnormalities of human CAD. Methods: Yucatan mini-swine (20–30 kg), fed a high cholesterol diet for 13 weeks, underwent circumflex ameroid placement to create chronic myocardial ischaemia, followed three weeks later by perivascular administration of VEGF (n=6), FGF-2 (n=6), or placebo (n=7) in the ischaemic territory. Normocholaesterolemic animals (n=7) served as controls. Four weeks later, endothelial function, collateral-dependent perfusion, as well as myocardial protein and mRNA levels of angiogenic mediators were assessed. Results: Endothelial dysfunction was demonstrated in all hypercholaesterolemic animals. VEGF administration improved baseline-adjusted collateral-dependent perfusion (–0.03±0.04 vs. –0.11±0.05, VEGF vs. placebo, P=0.07), but FGF-2 delivery caused a significantly greater improvement in perfusion compared to either group (+0.15±0.03, P<0.01 vs. placebo), both at rest and with pacing. Molecular analysis revealed increased eNOS expression (135%±8%, P=0.03 vs. placebo) in growth factor treated animals and increased expression of FGF receptor, FGFR1, (156%±13%, P=0.03 vs. placebo) in FGF-2 treated animals. No significant changes were demonstrated in other angiogenic mediators including Akt, Syndecan-4, or iNOS. Conclusions: In the setting of hypercholaesterolemic endothelial dysfunction, FGF-2 is more effective than VEGF at enhancing collateral-dependent perfusion and thus, may be a better candidate than VEGF for angiogenic therapy in patients with end-stage CAD.
016 AGE CUT-OFF FOR THE LOSS OF BENEFIT FROM BILATERAL INTERNAL THORACIC ARTERY GRAFTING S. Mohammadi, F. Dagenais, D. Doyle, P. Mathieu, R. Baillot, J. Perron, E. Charbonneau, P. Voisine Quebec Heart Institute, Quebec City, Canada Objectives: To identify the age-related benefit of single and bilateral internal thoracic artery (ITA) grafting on long-term cardiac-related survival in patients who survived from primary isolated coronary artery bypass grafting (CABG). Methods: A unicenter study was conducted on 13,172 consecutive survivors from primary isolated CABG who received single (n=10,400 patients) or bilateral (n=1470 patients) ITA grafts, or vein grafts only (n=1302 patients) between 1992 and 2004. The follow-up study was extended two years after the last enrolled patient. Age was a significant covariate into the statistical model. Results: The mean follow-up was 6.2±3.7 years. After adjustments for patient selection and length of follow-up, the cardiac-related survival benefit in patients undergoing CABG with two ITAs was superior to that of single ITA grafting up to 65 years of age, displaying a constant decrease over time (40–45 years old: HR=0.2, P=0.007; 46–50 years old: HR=0.4, P=0.005; 51–55 years old: HR=0.5, P=0.007; 56–60 years old: HR=0.7, P=0.01; 61–65 years old: HR=0.8, P<0.05; 66–70 years old: HR=1.1, P=0.7; 71–75 years old: HR=1.4, P=0.5; >75 years old: HR=1.8, P=0.4). The use of a single ITA was beneficial on cardiac-related survival in all age groups, including octogenarians, compared to patients receiving only vein grafts. The rate of benefit reduction was linearly correlated with ageing. Conclusions: The use of at least one ITA is associated with increased cardiac-specific survival in all age groups compared to venous-only CABG. The additional survival benefit of using a second ITA, however, is lost after 65 years of age.
1Department of Thoracic and Cardiovascular Surgery, Frankfurt, Germany; 2Department of Heart Surgery, Lübeck, Germany Objectives: Increasing interest in the use of pulmonary autografts for replacements of the diseased aortic valve has been reported with excellent long-term results. Aim of the study was the evaluation of postoperative endocarditis of the auto (AG)- and homograft (HG) after Ross procedures. Methods: Between 1990 and 2007, a total of 1040 patients of the German Ross registry were evaluated for overall mortality, death due to endocarditis, reoperation and echocardiography results. One hundred and ninety seven patients were operated on due to aortic valve endocarditis. Results: The overall mortality was 4% (40/1040). Twenty-five patients died due to cardiac, 14 due to non-cardiac and one to unknown reasons. In 22 endocarditis (AG 14, HG 8) occurred during the follow-up period, 14 patients were reoperated and 8 were treated conservatively. Nine of the 14 AG endocarditis patients were reoperated, 4 were explanted and 5 repaired. Five of the 8 HG endocarditis were reoperated, in all cases an explantation was necessary. Two of the 22 endocarditis patient died. One patient showed a Grade III° and four showed a Grade II° aortic regurgitation at mean 4.6 years after re-operation. No endocarditis occurred in one of the 197 patients operated due to aortic valve endocarditis. Conclusions: Our long-term follow-up data shows excellent results with a low rate of postoperative endocarditis. AG endocarditis can be repaired in >50%, but HG infections results in an explantation. Excellent echocardiographic results can be expected even after repair. The Ross procedure is an excellent therapeutic option for patients after endocarditis and provides low mortality and re-endocarditis. Further studies aimed at clarifying risk factors for endocarditis as well as preventing pulmonary homograft explantation in case of endocarditis.
1Division of Cardiothoracic Surgery, Saint Vincent Mercy Medical Centre, Toledo, Ohio, USA; 2Department of Surgery, University of Toledo College of Medicine, Toledo, Ohio, USA Objectives: The fact that multiple arterial grafts are associated with improved long-term survival in the general CABG population is well-accepted. Yet, a large study comparing single vs. bilateral internal thoracic artery (ITA) grafting in diabetic patients did not demonstrate a 10-year survival benefit of two arterial grafts. Whether this is true when radial is the second arterial conduit is unknown. Methods: We obtained complete death follow-up in 1516 consecutive diabetic [64±10 years (mean±S.D.); 540 insulin-dependent] primary isolated CABG patients, all with ITA grafts, at a single institution. Using a radial-use propensity score and accounting for insulin-dependence, we one-to-one matched 477 of 626 (76%) radial grafting patients to 477 vein patients. Kaplan–Meier 11-year survival was calculated. Results: Before risk-matching, survival was markedly better (P<0.0001) for radial (94.3%, 86.7% and 70.4% at 1, 5 and 10 years) vs. vein (91.8%, 74.5% and 53.8%, respectively) patients. Propensity matching removed inequalities in demographics, comorbidities, coronary disease severity and completed grafts. In matched-patients, 1-, 5- and 10-year survival was essentially identical for radial (93.7%, 85.4% and 69.4%) vs. vein (95.4%, 83.0% and 66.2%) cohorts (P=0.85). Conclusions: As in the case of two vs. one ITA, utilisation of a radial artery as a second arterial conduit did not confer a 10-year survival benefit in diabetic patients. The lack of multiple arterial grafts benefit is possibly related to the more malignant coronary atherosclerosis characteristic of diabetics. Our results suggest that the survival advantage of multiple arterial grafts demonstrated in the general CABG population lies primarily in non-diabetics where this advantage may be underestimated.
Department of Cardiac Surgery, San Raffaele University Hospital, Milan, Italy Objectives: To assess the evolution of tricuspid regurgitation (TR) in dilated cardiomyopathy (DCM) patients undergoing mitral repair for functional mitral regurgitation (MR).
Methods: 91 DCM patients (mean age 61±11.3) submitted to MV repair (±tricuspid repair) for functional MR were included. Preoperative EF was 37±10%, LV end-diastolic volume 150±56 ml, LV end-systolic volume 103±51 ml, functional MR
Results: At follow-up (mean 1.8±1.2 years), echocardiographic assessment of the tricuspid valve showed that 12% of the patients (11/91) still had 3–4+ TR due to failure of the tricuspid repair or progression of untreated
Conclusions: A significant number of patients undergoing mitral repair for functional MR present
020 FUNCTIONAL AND HAEMODYNAMIC OUTCOME ONE YEAR AFTER PULMONARY THROMBOENDARTERECTOMY D.H. Freed, B. Thomson, S.S. Tsui, K. Shears, J. Pepke-Zaba, D.P. Jenkins Papworth Hospital, Cambridge, UK Objectives: Chronic thromboembolic pulmonary hypertension (CTEPH) results in severe symptoms and impaired survival. Pulmonary thromboendarterectomy (PTE) is considered the gold standard treatment. Many units have reported excellent early results post PTE, but there is little information on whether benefit is sustained. We sought to determine the medium term functional and haemodynamic outcome for patients following PTE.
Methods: Data was collected prospectively on all patients who underwent PTE in the UK between 1997 and 2005. Patients were reassessed at 3 and 12 months after operation. Postoperative data was compared to initial assessment values using a paired t-test and Results: One hundred and sixty three patients underwent PTE, survived to hospital discharge, and completed follow-up. At three months after operation, there was a significant reduction in mean pulmonary artery pressure (47–27 mmHg, P<0.0001), a significant increase in cardiac index (1.9–2.5, P<0.0001) and a significant increase in 6-min walk distance (270–374 m, P<0.0001). At 12 month follow-up, the haemodynamic improvements were sustained and there was a further increase in 6-min walk distance (374–401 m, P=0.01). NYHA class was significantly reduced at three months, with the improvement sustained at 12 months. Conclusions: PTE is a very effective therapy for CTEPH. This is the first report, from a continuous national series, to fully characterise haemodyamic and functional outcome one year after PTE. Patients enjoy continued improvement in haemodynamics that translates into better exercise capacity and reduced symptoms.
1Toronto General Hospital, Toronto, Canada; 2Princess Margaret Hospital, Toronto, Canada Objectives: The role of induction therapy for NSCLC invading the thoracic inlet is unclear. We reviewed our experience with induction chemo-radiation followed by surgical resection for NSCLC invading the thoracic inlet. Methods: Retrospective review of 44 consecutive patients with NSCLC invading the thoracic inlet treated with induction chemo-radiation (2 cycles of cisplatin and etoposide concurrently with 45 Gy of radiation) followed by surgical resection between 1996 and 2007. Results: All patients underwent chest wall resection (1–5 ribs, mean 3) with resection of the first rib through an anterior (n=15), posterior (n=18), or combined approach (n=11). Lobectomy was performed in 40 cases (90%), pneumonectomy in 2 (5%), and wedge resection in 2 (5%). Resection of subclavian vessels or portions of vertebrae was performed in 5 (11%) and 15 (34%) patients, respectively. Hospital mortality was 5% (n=2). R0-resection was achieved in 39 patients (89%). On pathological examination, 13 patients (30%) showed complete response (pCR) to induction therapy, and 15 (34%) showed minimal residual disease (90%–99% tumour necrosis). The mean follow-up was 32±37 months and overall 5-year survival was 58%. Sixteen patients (36%) developed recurrence, either local (n=5) or distant (n=11). The 5-year survival in patients with pCR was 91%, 77% in those with minimal residual disease, and 12% in those with no relevant response, (P=0.0005). Response to induction therapy was the only significant prognostic factor in multivariate analysis. Conclusions: Resection of NSCLC invading the thoracic inlet can be performed safely after induction chemo-radiation therapy. The response rate after induction therapy is a strong predictor of survival
Cliniques Universitaires Saint Luc, Brussels, Belgium Objectives: In recent studies focusing on the prognostic significance of histologic features of NSCLC tumours, vessels invasion was correlated to survival across all surgical stages. We similarly analyzed whether intra-tumoral permeation could affect survival in subgroups of Stage I and II NSCLC. Methods: A single institution retrospective analysis of a prospectively computed database. Specimens were analyzed for intra-tumoral vascular, lymphatic and nervous permeation. Overall mortality was determined and for each stage, a Cox-regression analysis of selected variables was performed. Detailed histologic information was available in 328 patients. Follow-up was 100% complete (mean=54 months). Results: From 1989 to 2004, we operated on 240 patients with pStage I (73.1%) and 88 patients with pStage II (26.9%). Sixty-seven pneumonectomies, 255 lobectomies and 6 lesser resection were performed (respectively 20.4%, 77.8% and 1.8%). In-hospital mortality was 2%. The completeness resection rate was 97%. The incidence of intra-tumoral permeation was 13.7% (44/321). Permeation correlated both with T status (P=0.02), N status (P=0.04) and stage (P=0.001). Median survival and overall 5-year survival for patients with and without permeation were 37.6 and 72.1 months respectively; and 43% and 54%, respectively (P=NS). Intra-tumoral permeation was a not a significant predictor for overall death [HR=1.2 (CI=0.8–1.8)]. Conclusions: In this large institutional study of early stage NSCLC, the presence of intra-tumoral permeation was correlated both to T, N status, as well as to stage. However, in contrast to recent reports, we did not found that intra-tumoral permeation adversely affects long-term survival.
Hopital Marie Lannelongue, Le Plessis Robinson, France Objectives: To identify factors that could affect operative mortality and morbidity and long-term survival after completion pneumonectomy (CP). Methods: A retrospective study was conducted at our department in Marie Lannelongue Hospital to review all patients who underwent CP. Results: From January 1996 to December 2005, 69 consecutive patients underwent CP for either a benign (n=22) or a malignant disease (n=47), accounting for 15% of all pneumonectomies performed during the same period. Malignant disease included a second primary lung cancer (n=22), a local recurrence (n=19) and metastasis (n=6). There were 50 males and 19 females with a mean age of 60 years (range, 29–80 years). Postoperative mortality and morbi |
Top
Monday 17 September 2007...
Monday 17 September 2007...
of 0.01. 
0.0002). In all pigs, the distal aorta was larger than the proximal overstented segment. Histology showed fibrosis of the inner 1/3 of the media with loss of smooth muscle cells and compression of the elastic fibers but normal architecture in the outer 2/3 of the media. 
3+/4+. Tricuspid regurgitation was classified as 
2-test where appropriate.