Early outcome after off-pump versus on-pump coronary bypass surgery: results from a randomized study.

BACKGROUND: The use of cardiopulmonary bypass during coronary artery bypass surgery (CABG) has been associated with substantial morbidity. The recent introduction of cardiac stabilizers facilitates CABG without cardiopulmonary bypass (off-pump CABG), but it is unknown whether cardiac outcome after off-pump surgery is similar to that for the on-pump procedure. METHODS AND RESULTS: In a multicenter trial, 281 patients (mean age 61 years, SD 9 years) were randomly assigned to off-pump or on-pump CABG. In-hospital results and cardiac outcome and quality of life after 1 month are presented. Cardiac outcome was defined as survival free of stroke, myocardial infarction, and coronary reintervention. The mean numbers of distal anastomoses per patient were 2.4 (SD 1.0) and 2.6 (SD 1.1) in the off-pump and on-pump groups, respectively. Completeness of revascularization was similar in both groups. Blood products were needed during 3% of the off-pump procedures and 13% of the on-pump procedures (P<0.01). Release of creatine kinase muscle-brain isoenzyme was 41% less in the off-pump group (P<0.01). Otherwise, no differences in complications were found postoperatively. Off-pump patients were discharged 1 day earlier. At 1 month, operative mortality was zero in both groups, and quality of life had improved similarly. In both groups, 4% of the patients had recurrent angina. The proportions of patients surviving free of cardiovascular events were 93.0% in the off-pump group and 94.2% in the on-pump group (P=0.66). CONCLUSIONS: In selected patients, off-pump CABG is safe and yields a short-term cardiac outcome comparable to that of on-pump CABG.

Coronary artery bypass grafting without cardiopulmonary bypass and without interruption of native coronary flow using a novel anastomosis site restraining device ("Octopus").

OBJECTIVE: This study assessed the feasibility of coronary artery bypass grafting on the beating heart without interruption of native coronary blood flow using a novel anastomosis site restraining device. BACKGROUND: Recently, an end-to-side bypass technique was described that does not require interruption of flow in the recipient artery. METHODS: By means of a suction device ("Octopus"), in 31 pigs the epicardium was grasped and immobilized through an arm contraption fixed to the operating table. In the first 15 consecutive pigs (study I), the two-dimensional motion of an epicardial beacon was monitored. In 16 subsequent pigs (study II), an internal mammary artery was grafted under the microscope in two steps to a proximal coronary artery segment, without cardiopulmonary bypass. First, the internal mammary artery was sutured end-to-side to the outside of the coronary artery. Secondly, an orifice was punched in the partitioning coronary wall by an excimer laser catheter introduced through a temporary side-branch of the internal mammary artery. RESULTS: Study II: During 43 suction periods in four anastomosis areas, immobilization was achieved for 15 to 169 min (>30 h in total) in 13 open- and 9 closed-chest procedures without hemodynamic deterioration. The area circumscribed by the edges of the beacon trajectory (area in which the anastomosis is to be tracked) was reduced from 73.0 +/- 43.0 mm(2) (mean +/- SD) to 1.3 +/- 0.5 mm(2) (p<0.001) in the open-chest and to 0.2 +/- 0.2 mm(2) in the closed-chest procedure. At 6 weeks, no myocardial or coronary suction lesions were found. Study II: Nonocclusive anastomosis surgery required 25 +/- 3 min. No leakage, serious arrhythmias, graft closure or hemodynamic deterioration occurred during the procedure or for 2 h after ligating the coronary artery proximally. At 6 weeks, all seven grafts were patent. CONCLUSIONS: Coronary bypass on the beating heart without interruption of coronary flow is feasible. In both open- and in closed-chest procedures, the "Octopus" reduced anastomosis site motion to about 1 X 1 mm without adverse consequences.

Off-pump coronary artery bypass surgery compared with stent implantation and on-pump bypass surgery: clinical outcome and cost-effectiveness at one year.

BACKGROUND: Coronary revascularisation by means of surgery or percutaneous intervention plays an important role in the management of patients with ischaemic heart disease. Coronary bypass surgery without cardiopulmonary bypass (off-pump surgery) has been reintroduced into clinical practice to avoid complications related to the use of cardiopulmonary bypass. It is unknown whether off-pump surgery can match the outcomes of bypass surgery with cardiopulmonary bypass (on-pump surgery) or intracoronary stent implantation. METHODS: The Octopus study comprised two multicentre randomised trials. In the Octopump trial, on-pump surgery was compared with off-pump surgery (139 vs. 142 patients). In the Octostent trial stent implantation was compared with off-pump surgery (138 vs. 142 patients). The primary cardiac endpoint was survival free from the following cardiovascular events: stroke, myocardial infarction and repeated coronary revascularisation. Secondary endpoints included quality of life and cost-effectiveness. The uncertainty surrounding the cost-effectiveness analysis was addressed by bootstrapping. RESULTS: Octopump trial: at one year, event-free survival in the on-pump group was 90.6% and in the off-pump group 88.0% (difference 2.6%, 95% CI-4.6 to 9.8). Quality-adjusted years of life were 0.83 and 0.82 (p=0.81), respectively. On-pump surgery was associated with €2089 (14.1%) additional direct medical costs per patient (p<0.01). Off-pump was more cost-effective than on-pump surgery in 95% of bootstrap estimates. Octostent trial: at one year, event-free survival in the stent group was 85.5% and in the off-pump surgery group 91.5% (difference -6.0%, 95% CI -13.5 to 1.4). Quality-adjusted years of life were 0.82 and 0.79 (p=0.09), respectively. Stent implantation reduced direct medical costs by €2813 (26.0%) per patient (p=0.01). Stent implantation was more cost-effective in 95% of bootstrap estimates. CONCLUSION: In selected patients eligible for bypass surgery, there was no difference in cardiac outcome between on-pump and off-pump surgery. Off-pump surgery, however, was more cost-effective than on-pump surgery and may be preferred from an economic perspective. In selected patients eligible for percutaneous coronary intervention, stent implantation was more cost-effective than off-pump surgery while maintaining comparable cardiac outcome. Therefore, stent implantation rather than off-pump surgery can be recommended as a first-choice revascularisation strategy.

Exposure of circumflex branches in the tilted, beating porcine heart: echocardiographic evidence of right ventricular deformation and the effect of right or left heart bypass.

OBJECTIVE: In off-pump coronary surgery, exposure of posterior vessels via sternotomy causes deterioration of cardiac function. Changes in ventricular geometry, valve competence, and hemodynamics after retraction of the beating heart were studied. Subsequently, the modifying effect of right or left heart bypass was investigated. METHODS: In six 80-kg pigs, an ultrasound probe was attached to the backside of the left ventricle and the heart was fully retracted with a suction tissue stabilizer. Five pigs underwent additional pump support. RESULTS: During retraction, the right ventricle was squeezed between the pericardium and interventricular septum, thereby decreasing its diastolic cross-sectional area by 62% +/- 6% (P <.001) while, concomitantly, right ventricular end-diastolic pressure increased to 165% +/- 19% (P =.004) of basal values. Stroke volume and mean arterial pressure decreased by 29% +/- 6% and 23% +/- 8% (P =.007 and P =.02, respectively). Left ventricular shape became somewhat elliptic without changes in preload pressure, and its diastolic cross-sectional area decreased by 20% +/- 3% (P =.001). All valves were competent. Right heart bypass restored left ventricular cross-sectional area, stroke volume, and mean arterial pressure. In contrast, left heart bypass increased blood pressure only marginally. CONCLUSIONS: Ninety-degree anterior displacement of the beating porcine heart caused primarily right ventricular dysfunction as a result of mechanical interference with diastolic expansion without concurring valvular incompetence. Right heart bypass normalized stroke volume and mean arterial pressure by increasing left ventricular preload; in contrast, left heart bypass failed to restore systemic circulation.

Coronary artery bypass grafting without cardiopulmonary bypass using the octopus method: results in the first one hundred patients.

OBJECTIVE: Cardiopulmonary bypass and global cardiac arrest enable safe coronary artery bypass grafting but have adverse effects. In off-pump coronary bypass grafting, invasiveness is reduced, but anastomosis suturing is jeopardized by cardiac motion. Therefore the key to successful off-pump coronary bypass grafting is effective local cardiac wall stabilization. METHODS: We prospectively assessed the safety and efficacy of the Octopus tissue stabilizer (Medtronic, Inc., Minneapolis, Minn.) in the first 100 patients selected for off-pump coronary bypass via full or limited surgical access. To immobilize and expose the coronary artery, two suction paddles (-400 mm Hg), fixed to the operating table-rail by an articulating arm, stabilized the anastomosis site. RESULTS: One hundred forty-one grafts (96% arterial) were used to create 172 anastomoses (17% side-to-side), up to 4 per patient, on average 23 in the full access group (46 patients) and 1.2 in the limited access group (54 patients). Complications included conversion to cardiopulmonary bypass (2%), conversion from limited to full access (3%), myocardial infarction (4%), predischarge coronary reintervention (2%), and late coronary reintervention (1%). Median postoperative length of hospital stay was 4 days (limited access) or 5 days (full access). Rapid recovery allowed 96% of patients to resume social activities within 1 month. At the 6-month angiographic follow-up, 95% of anastomoses was patent. At the 2- to 22-month follow-up (mean, 13 months), 98 patients were in Canadian Cardiovascular Society class I and 2 patients were in class II. CONCLUSION: These results suggest that off-pump coronary artery bypass grafting with the Octopus tissue stabilizer is safe. Early clinical outcome and patency rates warrant a randomized study comparing this methods with conventional coronary bypass grafting.

A novel one-shot anastomotic stapler prototype for coronary bypass grafting on the beating heart: feasibility in the pig.

OBJECTIVE: The nonpenetrating, arcuate-legged clip has proved its ability to provide a high-quality microvascular anastomosis. This study assessed the feasibility of constructing a coronary end-to-side anastomosis on the beating heart with a novel mechanical, sutureless anastomotic device that applies 12 circumferential clips simultaneously. METHODS: In 14 consecutive pigs (70-90 kg), the left internal thoracic artery (diameter, 3 mm) was grafted to the left anterior descending coronary artery (diameter, 3 mm) by means of a one-shot anastomotic stapler prototype. Endothelial denudation, medial necrosis, and intimal hyperplasia were analyzed quantitatively and compared with those seen in conventionally sutured anastomoses (n = 4). RESULTS: In 8 of 14 anastomoses, the one-shot anastomotic stapler successfully applied all 12 clips circumferentially across the everted arteriotomy edges. In the remaining, either 1 (n = 4) or 3 and 4 adjoining malaligned clips had to be replaced manually with a single-clip applicator. Coronary occlusion was limited to approximately 3 minutes. At follow-up, all anastomoses were patent angiographically. At 2 days, in 2 of 7 cases, a local coronary dissection was observed, and there was a considerable loss of endothelial cells and medial damage. At 28 days, however, minimal intimal hyperplasia was seen at the anastomotic lining, although more pronounced when compared with conventionally sutured anastomoses. CONCLUSIONS: The one-shot anastomotic stapler prototype enabled short-occlusive (3 minutes), sutureless end-to-side grafting on the beating porcine heart. In spite of early endothelial and medial damage and 2 local dissections, all anastomoses remained patent with minimal intimal hyperplasia at 4 weeks.

Heart displacement during off-pump CABG: how well is it tolerated?

BACKGROUND: Heart displacement during off-pump coronary artery bypass grafting (CABG) is necessary to expose the anastomosic sites. We analyzed the hemodynamic changes in relation to the grafted arteries. METHODS: The relationship between surgical exposure and hemodynamic management was assessed in 150 consecutive patients undergoing off-pump CABG utilizing the Octopus Tissue Stabilization System (Medtronic, Minneapolis, MN). RESULTS: Surgical exposure by anterolateral thoracotomy showed no significant hemodynamic changes. Through sternotomy, stroke volume was significantly reduced by dislocation at all target sites: by 6% at the left anterior descending artery (LAD), 25% at the diagonal branch artery (D), 14% at the right coronary artery (RCA), and 21% at the obtuse marginal artery (OM). The application of head-down positioning (LAD, 56%; D, 74%; RCA, 90%; OM, 96%) increased not only surgical exposure but also preload, producing correction of ventricular filling pressures and output. In a minority of cases, dopamine (3 to 5 microg x kg(-1) x min(-1)) was added to maintain baseline hemodynamic values (LAD, 5%; D, 15%; RCA, 7%; OM, 28%). CONCLUSIONS: Revascularization during anterolateral thoracotomy was uneventful. The sternotomy approach with heart displacement induced right heart compression. Mainly fluid redistribution was sufficient to correct cardiac output. Once stabilized, systemic circulation remained unchanged during revascularization.

Facilitated exposure of the internal mammary artery in minimally invasive direct-vision CABG.

A method is described to facilitate harvesting of the mammary artery in minimally invasive direct-vision coronary artery bypass grafting using a 10-cm anterior thoracotomy. Hoisting of the anterior thoracic wall with a modified retractor allows good exposure. Harvesting the mammary artery without the use of endoscopic tools was successful in all 10 cases.

Hemodynamic changes during displacement of the beating heart by the Utrecht Octopus method.

BACKGROUND: Coronary bypass grafting of posterior circumflex branches requires full displacement of the heart (apex pointing ventrally), which, in the beating heart, results in an arterial pressure drop. We analyzed its origin. METHODS: To facilitate displacement, the Utrecht "Octopus" method was applied in 8 anesthetized beta-blocked pigs and the beating heart was fully retracted. RESULTS: Displacement decreased stroke volume from 75 +/- 17 mL (mean +/- standard deviation) to 43 +/- 13 mL (p < 0.001), a 44% +/- 3% decrease that resulted in a decrease in cardiac output by 32% +/- 5% (mean +/- standard error of the mean; p < 0.001), a decrease in mean arterial pressure by 26% +/- 5% (p < 0.01), and an increase in heart rate by 26% +/- 6% (p < 0.01). Right ventricular end-diastolic pressure increased from 5 +/- 1 to 8 +/- 1 mm Hg (p < 0.01). Twenty degrees head-down tilt normalized cardiac output and mean arterial pressure. Right ventricular end-diastolic pressure increased to 10 +/- 2 mm Hg (p < 0.001) and left ventricular end-diastolic pressure to 11 +/- 3 mm Hg (p < 0.01). CONCLUSIONS: Displacement of the beating heart in the pig induced a 44% drop in stroke volume, which is attributed to biventricular interference with pump function. The Trendelenburg maneuver reestablished the control circulatory status at the expense of augmented right and left ventricular preloads and an increased heart rate.

Experimental off-pump grafting of a circumflex branch via sternotomy using a suction device.

BACKGROUND: We have shown previously in the pig that coronary artery bypass grafting on the beating heart may be facilitated by local cardiac wall immobilization by a suction device ("Octopus") applied to the anterolateral side of the heart. The purpose of this study was to investigate the feasibility of the method on the posterolateral side. METHODS: In a consecutive series of 8 pigs, after median sternotomy, the posterior wall was taken hold of by the Octopus and subsequently brought up anteriorly and immobilized while hemodynamics were monitored. A posterolateral branch of the circumflex artery was grafted with the left internal mammary artery. After the coronary artery was ligated proximally, the heart was repositioned. At 6 weeks, bypass graft angiography and functional testing (postocclusion hyperemia testing) were performed. After sacrifice, histologic examination of the anastomosis was performed. RESULTS: Dislocation of the heart to expose the distal anastomosis site caused a minor drop in mean arterial blood pressure from 71 +/- 14 (baseline) to 63 +/- 6 mm Hg (dislocated) (not significant) and recovery to 70 +/- 12 mm Hg, 15 minutes after repositioning. Cardiac output decreased from 4.0 +/- 1.0 to 3.2 +/- 0.7 L/min (p = 0.02) and recovered to 4.3 +/- 0.3 L/min. No inotropic drugs were necessary. Anastomosing required 21.5 +/- 6.5 minutes. Baseline graft flow was 8 +/- 3 mL/min and increased threefold to 24 +/- 10 mL/min (p < 0.05) at postocclusive hyperemia testing. At sacrifice after 6 weeks (n = 8), graft flow increased fourfold from 5 +/- 2 to 20 +/- 8 mL/min (p = 0.002) (n = 7). At histologic examination all eight anastomoses were patent without stenosis or mural thrombus. CONCLUSIONS: Off-pump coronary artery bypass grafting of the posterolateral circumflex branches using the Octopus method on the beating pig heart is feasible, with full patency maintained for at least 6 weeks.

Video-assisted coronary bypass grafting on the beating heart.

BACKGROUND: Concepts to make coronary artery bypass operations less invasive include minimization of access incisions, elimination of cardiopulmonary bypass, and no manipulation of the aorta. A spectrum of minimally invasive coronary bypass procedures now exist that eliminate the median sternotomy (port-access approach), cardiopulmonary bypass ("off-pump bypass"), or both (minimally invasive direct coronary artery bypass procedure). Although all have advantages in decreasing the morbidity of myocardial revascularization, significant limitations exist including surgeon experience, access, exposure, visualization, hemodynamic support, and technique of anastomosis. METHODS: In an attempt to extend the applicability of the current minimally invasive techniques, efforts are being made both to extend the indications for the procedure as well as to modify the technical aspects. Our current experimental protocol involves a ports-only approach with three-dimensional video imaging, percutaneous Hemopump circulatory support, Octopus coronary immobilization, and an endoscopically sutured coronary anastomosis. RESULTS: In a series of animal studies we have been able to successfully accomplish a totally endoscopic coronary artery bypass procedure on a beating heart without cardiopulmonary bypass. CONCLUSIONS: Although endoscopic coronary artery bypass without cardiopulmonary bypass is possible, many technical challenges remain. Three-dimensional video imaging, wall motion immobilization and presentation, and an axial-flow device can facilitate the procedure. Future enabling technology including motion robotics and nonvisual imaging systems may ultimately further minimize the invasiveness of surgical myocardial revascularization.

Off-pump coronary bypass grafting: how to use the Octopus Tissue Stabilizer.

Off-pump coronary artery bypass grafting requires immobilization of the coronary artery. A suction device (Octopus Tissue Stabilizer), attached to the epicardium and connected rigidly to the operating table rail, was used through limited and full surgical access for single-vessel and multivessel arterial revascularization, respectively. An outline for its application, as used by us to construct 122 anastomoses in 70 patients, including posterior wall grafting (in 9 patients) and sequential grafting on the anterior wall (in 17 patients), is presented.

Vertical displacement of the beating heart by the octopus tissue stabilizer: influence on coronary flow.

BACKGROUND: In beating heart coronary artery bypass graft operations, biventricular pump failure, as observed after exposure of the posterior circumflex branches by sternotomy, may originate from mechanical obstruction to coronary flow. METHODS: Regional coronary blood flow was measured in 8 anesthetized, paced, beta-blocked pigs, and the beating heart was fully retracted. RESULTS: Displacement decreased cardiac output from 4.8 +/- 1.1 L/min (mean +/- standard deviation) to 2.8 +/- 1.2 L/min (p < 0.001), a 42% +/- 6% decrease that resulted in a decrease in mean arterial pressure by 48% +/- 6% (mean +/- standard error of the mean; p < 0.001) and a reduction in coronary blood flow in the left anterior descending coronary artery, the right coronary artery, and the circumflex coronary artery by 34% +/- 6%, 25% +/- 8%, and 50% +/- 10%, respectively (all p < 0.05 versus baseline). Relative circumflex coronary artery flow was 20.1% +/- 8.3% lower than the combined relative value of left anterior descending coronary artery and right coronary artery flows (p = 0.046). Subsequent 20 degrees head-down tilt significantly increased ventricular preload pressures and restored cardiac output and mean arterial pressure as well as coronary blood flow. CONCLUSIONS: It is inferred that coronary blood flow was not mechanically obstructed during anterior displacement of the porcine beating heart, because augmentation of preloads by the maneuver of Trendelenburg restored coronary flow parallel to the recovery of cardiac output and mean arterial pressure while the heart remained retracted by 90 degrees.

The left gastric artery as an in-situ conduit in coronary artery bypass grafting.

Unsuitability of the in-situ right gastroepiploic artery in coronary bypass grafting occurs. Sometimes free-grafting can be performed, although this should not be considered in patients with a diseased ascending aorta. We describe the successful use of the left gastric artery as an alternative in-situ arterial conduit in a patient with a severely atherosclerotic ascending aorta.

A review of 1,582 consecutive Octopus off-pump coronary bypass patients.

BACKGROUND: Off-pump coronary bypass may provide a safer form of surgical revascularization by avoiding the unwanted complications of cardiopulmonary bypass, particularly in the increasingly complex patients being referred for operation. This study reviews the entire experience of the Medtronic Octopus System (Medtronic, Minneapolis, MN) for beating heart bypass from 7 surgeons. Demographics, operative procedures, early outcomes, and trends in usage were examined. METHODS: Patients were selected for off-pump procedures by the individual surgeons. Data were entered prospectively into locally maintained databases and then collected for collation and analysis. RESULTS: A total of 1,582 consecutive Octopus patients were entered, representing the entire Octopus experience of each surgeon. Proportions of off-pump procedures relative to standard bypass increased over time, as did the percentage of patients receiving three or more grafts, 24.6% in 1997 and 55.9% in 1999. A total of 3,653 anastomoses were performed, 1,905 to the left anterior descending system, 837 to the circumflex distribution, and 911 to the right coronary territory. Morbidity was low. Few patients required conversion to cardiopulmonary bypass (2.6%; 0.2% urgently). Permanent stroke occurred in 0.6% and myocardial infarction in 1.2%. Operative mortality was 1%. CONCLUSIONS: Octopus off-pump bypass was demonstrated to be a safe procedure with widening applicability. With experience surgeons tend to apply the system to increasing proportions of their patients and are able to revascularize all coronary territories.

A versatile tool for exposure in minimally invasive surgery.

BACKGROUND: Endoscopic surgery in a major cavity in the body requires space for manipulation and presentation of the target organ or site. For coronary artery grafting on the working heart, additional local cardiac wall immobilization is indispensible. METHODS: A passive hydraulic arm was developed to be mounted on the operating table rail. The development focused on the arm's versatility, durability, flexibility in manipulation, and extreme stiffness when in position. RESULTS: The arm was flexible and easy to manipulate. The tip did not move during tightening, and the arm was stiff once tightened. The arm was successfully used in small and full access beating heart coronary bypass grafting, through the latter(i.e., sternotomy) for multivessel revascularization. Immobilization and presentation were achieved by suction fixation, allowing accurate anastomosis suturing. CONCLUSIONS: The arm enabled effective target site presentation and stabilization on the working heart. According to these observations, it may be useful as a basic tool for endoscopic surgery.

When and how to shunt the coronary circulation in off-pump coronary artery bypass grafting.

OBJECTIVE: To assess the sequelae of temporary coronary artery occlusion in off-pump, beating heart CABG, i.e. ischemia, hemodynamic instability and the need for conversion to cardiopulmonary bypass. METHODS: In 200 patients (150 male), mean age 60 (range 35-81) years, 365 distal anastomoses were performed, i.e. 1.8 anastomoses per patient through limited and full access. One hundred seventy six LAD, 61 diagonal, 71 RCA, 7 RPD and 50 circumflex branches were grafted. Patients were pretreated with calcium antagonists, long-acting beta-blockade and had thoracic epidural blockade. The anastomosis was constructed using two microvascular clamps, preceded by ischemic preconditioning in non-occlusive disease. Myocardial ischemia was defined as > 1 mm S-T segment elevation. A simple aorto-coronary shunt, consisting of two intravenous catheters and a 10 cm connecting tube (flow > 20 ml/min), was used in critical ischemia. RESULTS: Ischemia occurred during 35 (10%) temporary coronary artery occlusions. Fifteen of these (43%) were RCA. In five of these 15 patients, all with non-occlusive disease, critical ischemia occurred with bradycardia, third-degree heart block and subsequently severe hypotension, which normally requires conversion to cardio-pulmonary bypass. Following introduction of the shunt (4 patients) electrocardiographic and hemodynamic parameters normalized within 30 s. The off-pump procedures could be continued uneventfully. There were no peri-operative infarctions. CONCLUSION: Temporary segmental occlusion is an effective method for anastomosis suturing in off-pump, beating heart CABG. Critical ischemia was observed rarely, only in the RCA and in non-occlusive disease. Temporary aorto-coronary shunting could avoid conversion to cardiopulmonary bypass and myocardial infarction.

Epicardial cryosurgery as used in ablation of accessory atrioventricular pathways: effect on valvular function in the dog.

Epicardial cryosurgery for ablation of atrioventricular accessory pathways has surgical advantages. However, it is applied directly to the valve base. To assess the risk of valve impairment, 10 anaesthetized dogs were subjected to standardized epicardial cryosurgery of the right atrioventricular junction. Two of these underwent sham procedure (dissection only). Valve function was assessed by colour Doppler echocardiography preoperatively and at 2 days, 1 week, 2 weeks and 10 weeks postoperatively. Three out of the eight animals subjected to cryosurgery developed moderate (grade 2/4) tricuspid insufficiency, which appeared at 1 week postoperatively, following regression of congestive oedema. Two out of the three cases of TI were associated with leaflet prolapse. No tricuspid insufficiency was seen in the sham-operated animals. At the end of each interval two animals were killed for histological examination. Histological examinations showed that cryolesions extended a maximum of 3 mm into the valve leaflet. The tricuspid insufficiency is attributed to the extensive scarring (including chondroid metaplasia), which causes retraction and restricted motion of the annulus. It is concluded that cryolesions may impair atrioventricular valve function. Patients undergoing cryosurgery should be monitored postoperatively by echocardiography for atrioventricular valve insufficiency.

Less invasive off-pump CABG using a suction device for immobilization: the 'Octopus' method.

OBJECTIVE: Target site immobilization is essential to enable meticulous anastomosis suturing during coronary artery bypass grafting on the beating heart. A novel device ('Octopus') was developed for local heart muscle immobilization by suction. The purpose of this study was to investigate the efficacy of the method through a limited access. METHODS: The suction device, placed on either side of the recipient coronary artery and fixed to the operating table-rail through an arm construction, restrains anastomosis site motion to 1 x 1 mm. A total of 27 patients underwent off-pump arterial bypass grafting using this method. Preoperatively, all patients had angina class III (NYHA) and were failed or unsuitable candidates for balloon angioplasty. Surgical access was via a 10-cm anterior thoracotomy (n = 26) or 10-cm subxiphoid incision (n = 1). RESULTS: Harvesting of the graft required 48 +/- 12 min (mean +/- S.D.). Immobilization with the 'Octopus' was effective and facilitated precise anastomosis suturing of 20 single and 7 sequential grafts. Immobilization did not change cardiac index and mean arterial blood pressure. During coronary surgery, however, inotropic drug support was used in 5 of 27 (18%) of patients. There was no myocardial infarction. Only minor transient complications were met. There were electro-cardiographical signs of pericarditis in 6 patients. The postoperative hospital stay ranged from 2 to 6 days, mean 4.0 +/- 1.2 days. The mean follow-up is 6.5 +/- 4 months (range, 1-12 months). All patients except one were in functional class I without angina. Social activities were resumed within 4 weeks. At 6 months angiography was performed in 15 out of 27 patients. The patency rate of 19 out of 20 anastomoses was 95%. All distal grafts were patent. One side to side anastomosis was occluded. CONCLUSIONS: The 'Octopus' immobilization method is safe and effective. It facilitates less invasive CABG in selected patients and gives way to fast recovery by reducing invasiveness.

Report of the Dutch experience with the Ross procedure in 343 patients.

OBJECTIVE: Limited information is available on outcome after autograft aortic valve replacement, in particular with respect to the durability of the autograft and of the allograft used to reconstruct the right ventricular outflow tract. A retrospective follow-up study of all patients who underwent a Ross procedure in the Netherlands since 1988 was done to obtain an overview of the Dutch experience with this procedure. METHODS: From 1988 to January 2000, 348 Ross procedures were performed in nine centers in the Netherlands. Pre-operative, peri-operative and follow-up data from 343 patients in seven centers (99% of all Dutch autograft patients) were collected and analyzed. RESULTS: Mean patient age was 26 years (SD 14, range 0-58) and male/female ratio was 2.1. Bicuspid valve or other congenital heart valve disease was the most common indication for operation. The root replacement technique was used in 95% of patients and concomitant procedures were done in 12%. Hospital mortality was 2.6% (N=9). Mean follow-up was 4 years (median 3.8, SD 2.8, range 0-12.5). Overall cumulative survival was 96% at 1 year (95% confidence interval (CI) 94-98%) and 94% at 5 and 7 post-operative years, respectively (95% CI 91-97%). At last follow-up, 87% of the surviving patients was in New York Heart Association (NYHA) class I. Independent predictors of overall mortality were pre-operative NYHA class IV/V and longer perfusion time. Autograft reoperation had to be performed in 14 patients and reintervention on the pulmonary allograft in 10 patients. Freedom from any valve-related reintervention was 88% at 7 years (95% CI 81-94%). CONCLUSIONS: The Dutch experience with the Ross procedure is favorable, with low operative mortality and good mid-term results. Although both the autograft in aortic position and the allograft in the right ventricular outflow tract have a limited durability, this has not yet resulted in considerable reoperation rates and associated morbidity and mortality.