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Biomedical subjects

E W Jansen

Publications and source records attributed to E W Jansen.

At least 19 recordsLinked to original sources
PubMed2002

[Pulmonary thromboendarterectomy: an effective surgical treatment for cor pulmonale due to chronic pulmonary emboli].

OBJECTIVE: To evaluate the initial experience with pulmonary thromboendarterectomy for cor pulmonale due to chronic pulmonary embolism. METHOD: In the period 1 April 1996 to 31 October 2001, 18 patients with right ventricular failure due to chronic thromboembolic pulmonary hypertension were operated on. Their mean age was 54 (SD: 14) years. Preoperatively, all of the patients were in functional New York Heart Association (NYHA) class III or IV. Pulmonary angiography revealed pulmonary hypertension with an increased pulmonary vascular resistance, as well as typical angiographic signs of unresolved chronic emboli. Pulmonary thromboendarterectomy was performed via median sternotomy, using extracorporeal circulation and intermittent deep hypothermic circulatory arrest. The patients were monitored via the outpatients' department. RESULTS: From a technical viewpoint, the procedure was performed successfully in all of the patients. Initially the pulmonary thromboendarterectomy was performed unilaterally (n = 7), which did not decrease pulmonary artery pressure significantly. The following 11 patients were treated bilaterally; in them thromboendarterectomy required an average of circulatory arrest totalling 64 (SD: 30) min with 161 (SD: 35) min of myocardial ischemia. After bilateral pulmonary thromboendarterectomy, the pulmonary artery pressure decreased from 45 (SD: 13) to 28 (SD: 9) mmHg (p = 0.001). Reperfusion pulmonary oedema, requiring prolonged ventilation, occurred in 3 patients. There was no operative or later mortality. At a mean follow-up of 28 (SD: 19) months, all but one of the patients were in functional NYHA class I or II. Echocardiography revealed reduced right ventricular dimensions and pulmonary artery pressures. One patient, with mainly distally located obstructions, exhibited no substantial improvement. CONCLUSION: The initial experience with pulmonary thromboendarterectomy for patients with cor pulmonale due to chronic pulmonary emboli demonstrated satisfactory mid-term follow-up data.

Chronic Disease↗
PubMed2001

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.

Cardiopulmonary Bypass↗
PubMed2001

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.

Endoscopy↗
PubMed2001

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.

Aged↗
PubMed2000

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.

Aged↗
PubMed2000

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.

Aged↗
PubMed2000

The Octopus Study: rationale and design of two randomized trials on medical effectiveness, safety, and cost-effectiveness of bypass surgery on the beating heart.

The Octopus Study consists of two multicenter randomized clinical trials in which coronary artery bypass grafting on the beating heart (off-pump CABG) using the Utrecht Octopus Method is compared to intracoronary stent implantation and conventional CABG. The primary endpoint in the comparison of off-pump CABG versus stent implantation (OctoStent Trial) is medical effectiveness (i.e., absence of reintervention and major adverse cardiac and cerebrovascular events at 1 year after treatment). The primary endpoint in the comparison of off-pump CABG versus conventional CABG (OctoPump Trial) is cerebral safety (i.e., absence of cognitive deficits and cerebrovascular events at 3 months after treatment). Secondary endpoints in both trials include presence and severity of angina, quality of life, exercise capacity, and cost-effectiveness. A total of 560 patients will be enrolled. A random sample of 210 patients will undergo repeat angiography at 1 year to assess angiographic restenosis rate and graft patency. Including 1-year follow-up, the study will last for 3 years. Control Clin Trials 2000;21:595-609

Angioplasty, Balloon, Coronary↗
PubMed1999

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.

Animals↗
PubMed1999

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.

Anastomosis, Surgical↗
PubMed1999

Embracing the heart: perioperative management of patients undergoing off-pump coronary artery bypass grafting using the octopus tissue stabilizer.

OBJECTIVE: To describe hemodynamic alterations during coronary artery bypass grafting (CABG) without extracorporeal circulation using the Octopus Tissue Stabilizer, and to describe the two anesthetic management protocols based on either general anesthesia with opioids (34 patients) or general anesthesia with high thoracic epidural anesthesia (TEA; 66 patients). DESIGN: A prospective observational report. SETTING: An academic university heart center. PARTICIPANTS: First 100 patients undergoing CABG using the Octopus Tissue Stabilizer. INTERVENTIONS: None. MAIN RESULTS: Current management provided satisfactory results in preventing hypoperfusion of the heart and inadequate systemic circulation without the use of major pharmacologic interventions. Movement of the heart to reach the target site of anastomosis caused hemodynamic alterations. These could easily be corrected by anesthetic interventions, such as fluid load and low doses of inotropes. High TEA allows earlier extubation compared with the opioid anesthesia technique (0.9 v 4.5 hours). Perioperative management and the incidence of postoperative complications did not differ between anesthetic techniques. Major complications, such as death, intraoperative myocardial infarction, and stroke, did not occur. CONCLUSION: Both anesthetic protocols are safe and effective in handling these patients. Off-pump CABG surgery requires anesthetic interventions because hemodynamic alterations are caused by the presentation of the heart to the surgeon. The complication rate is low but needs to be evaluated, compared with conventional CABG, in a prospective randomized study. High thoracic epidural anesthesia allows early recovery, but improved outcome could not be proved in this patient group.

Adjuvants, Anesthesia↗
PubMed1999

False aneurysm of the right internal mammary artery.

False aneurysms of the internal mammary artery are extremely rare. A case of false aneurysm of a branch of the right internal mammary artery after median sternotomy is reported. A large right-sided mediastinal mass was seen on the thoracic radiogram. A false aneurysm was suspected on CT-scan and confirmed by angiography. In the same setting percutaneous embolization was performed.

Aneurysm, False↗
PubMed1999

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.

Adult↗
PubMed1998

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.

Animals↗
PubMed1998

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.

Anastomosis, Surgical↗
PubMed1998

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.

Cardiopulmonary Bypass↗
PubMed1998

Coronary artery bypass grafting without cardiopulmonary bypass.

In off-pump coronary artery grafting, cardiopulmonary bypass and its associated maneuvers, i.e., aortic manipulation and global cardiac arrest, may be avoided, and thus its morbidity and mortality may be reduced. Modern tissue stabilizers allow accurate construction of anastomosis and are now considered indispensable. Currently, there are two groups of stabilizers, i.e., those based on suction-fixation and those based on pressure-fixation. Each has specific applications. The popularity of off-pump coronary bypass surgery is increasing, from the patient's perspective and from the perspective of cost containment. Proper patient selection is crucial. The procedure is technically demanding. It is expected that by the year 2000 10% of coronary surgery will be off-pump, particularly by direct vision techniques. From the currently available, nonrandomized, prospective studies, the preliminary conclusion seems justified that, in selected patients, off-pump bypass grafting is as accurate as conventional bypass grafting, with lower morbidity and mortality. This includes fast recovery and early resumption of premorbid activities in most patients. Particularly, therefore, the procedure is also cost saving. Prospective randomized studies are necessary to quantify these statements.

Cardiopulmonary Bypass↗