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N Ad

Publications and source records attributed to N Ad.

15 recordsLinked to original sources
PubMed2000

Current status of the Maze procedure for the treatment of atrial fibrillation.

Since the first patient underwent the Maze procedure on September 25, 1987, 346 patients have undergone this operation for the treatment of atrial fibrillation. The procedure was designed as an open-heart operation performed through a median sternotomy. It underwent 2 major modifications relatively early in the series, evolving into the so-called Maze-III procedure, which has been used exclusively since April 16, 1992. Since that time, the Maze-III procedure has been adapted to allow it to be done by minimally invasive techniques. In addition, we recently performed the entire procedure in 2 patients without the use of cardiopulmonary bypass. The operative mortality rate has remained at 2% to 3%. This includes patients undergoing concomitant high-risk cardiac surgical procedures and all re-do cases. The overall success rate in curing atrial fibrillation has been 99%. The procedure itself has been shown to cause no permanent damage to the sinus node. The left atrium has been documented to function long-term postoperatively in 93% of patients and the right atrium functions in 99% of patients. The Maze-III procedure remains the surgical procedure of choice for the treatment of medically refractory atrial fibrillation.

Atrial Fibrillation↗
PubMed2000

The importance of cryoablation of the coronary sinus during the Maze procedure.

Although the Maze procedure has proven to be very effective in the treatment of atrial fibrillation, some authors have chosen to delete some of the important steps of the technique. Both our experimental and clinical experiences with the Maze procedure indicate that 1 of the most important principles is to interrupt conduction across the posterior-inferior portion of the left atrium. This is accomplished by creating a transmural lesion in the myocardium and then creating a circumferential lesion at the same site in the coronary sinus. We have used surgical incisions in the atrium and a cryolesion in the coronary sinus to block conduction in this area. If either fails, there is a high rate of arrhythmia recurrence.

Atrial Fibrillation↗
PubMed2000

The Maze-III procedure combined with valve surgery.

Previous studies have suggested that the Maze procedure is not as effective in controlling atrial fibrillation when the arrhythmia is associated with significant valvular heart disease. In this study, we evaluate our own results in 83 patients who underwent 96 valve procedures in combination with the Maze-III procedure. Our results indicate that the Maze-III procedure is just as safe and effective in controlling atrial fibrillation associated with valvular heart disease as it is in controlling atrial fibrillation not associated with valvular heart disease.

Aged↗
PubMed2000

Stroke prevention as an indication for the Maze procedure in the treatment of atrial fibrillation.

The Maze procedure has proven to be extremely effective in curing medically refractory atrial fibrillation. This analysis of our surgical results with the Maze procedure indicates that the Maze procedure, with or without associated cardiac surgery, has the lowest perioperative stroke rate of any major cardiac surgical procedure. This is surprising in view of the fact that all of the patients who undergo the Maze procedure have an elevated risk of stroke because of the presence of atrial fibrillation. In addition, many of the patients have already had strokes, further increasing the likelihood of perioperative stroke. Only 1 patient has had a stroke in the 12-year follow-up period following the Maze procedure. This is comparable to the risk of stroke in the general population and indicates that the Maze procedure essentially abolishes the risk of stroke associated with atrial fibrillation.

Adult↗
PubMed2000

Observations on the perioperative management of patients undergoing the Maze procedure.

In addition to the usual measures that constitute optimal perioperative care after cardiac surgery, the Maze procedure demands several other measures because of certain complications that are unique to this particular operation. These complications include preoperative conditions such as amiodarone therapy, thromboembolism, diastolic dysfunction of the left ventricle, and associated valvular heart disease, as well as intraoperative differences that include multiple atriotomies and excision of both atrial appendages. The most common postoperative complications are atrial arrhythmias, excessive fluid retention, and pulmonary complications. In this article, we outline our own approach to the perioperative care of patients undergoing the Maze procedure.

Atrial Fibrillation↗
PubMed2000

New surgical and catheter-based modifications of the Maze procedure.

There is currently an intense interest in applying the principles of the Maze procedure in a less invasive manner so that a wider group of patients with atrial fibrillation can be treated safely and effectively. These efforts have centered around surgical attempts to curtail the number of lesions placed in the atria at the time of valve surgery and catheter-based attempts to re-create a part or all of the Maze procedure with radiofrequency ablation. Thus far, these techniques remain highly experimental and largely without merit. Many of the problems that we encountered several years ago in developing the surgical Maze procedure are now being repeated in patients undergoing these highly experimental and inadequately evaluated procedures. Nevertheless, there are occasional flashes of promise with some of these approaches. Moreover, it is clear that only a miniscule percentage of the patients with atrial fibrillation will ever become candidates for the open-heart Maze procedure as it is now performed. Therefore, the continuing struggle to relieve the invasive downside of the Maze procedure is warranted but with the caveat, especially to our cardiologist colleagues, to proceed with caution.

Animals↗
PubMed1999

Coarctation of the aorta with right aortic arch: surgical technique and new classification.

BACKGROUND: The combination of right aortic arch and coarctation of the aorta has seldom been reported. This rare abnormality occurs as an isolated lesion or in association with other congenital defects, such as mixed gonadal dysgenesis and Turner's syndrome. METHODS: The medical records of 2 patients who underwent operation for right aortic arch and aortic coarctation in our institution were reviewed together with case reports in the literature. Various surgical options have been reported: synthetic grafts, subclavian flap, and end-to-end anastomosis. End-to-end anastomosis is our method of choice for coarctation of the aorta and for right aortic arch with coarctation, even though an excessive amount of dissection is needed. RESULTS: Both patients from our institution are doing well, with no sign of recoarctation in either patient. Our experience and recent advances in the understanding of the anatomy of this lesion led us to develop an alternative simplified classification for right aortic arch, which is presented here. CONCLUSIONS: Right aortic arch and coarctation of the aorta is a rare morphologic combination. On the basis of our experience with repair of coarctation of the aorta and our review of the literature, we think that end-to-end anastomosis is the operative technique of choice with the best long-term results. Our simplified classification is easy to understand when dealing with right aortic arch.

Anastomosis, Surgical↗
PubMed1999

Impact of the maze procedure on the stroke rate in patients with atrial fibrillation.

OBJECTIVE: The incidence of stroke associated with atrial fibrillation, even in high-risk patients, can be reduced significantly by adequate anticoagulation. However, anticoagulation does not abolish the stroke rate, and unfortunately only 40% of patients with atrial fibrillation actually receive anticoagulant therapy, even in areas where adequate health care is available. METHODS: During the past 11.5 years, we have performed the maze procedure for the treatment of medically refractory atrial fibrillation in 306 patients, 58 of whom presented with a history of having had a stroke (n = 40) or transient ischemic attack (n = 18) before surgery. All patients with atrial fibrillation are at an increased risk for these complications, but they are especially prevalent in those patients with previous thromboembolic events and those with other recognized risk factors. RESULTS: Among the 306 patients who had surgery, there were only 2 perioperative strokes (0. 7%), and in the 265 patients followed for up to 11.5 years after the maze procedure, there has been only 1 late minor stroke that has now completely resolved. CONCLUSIONS: The ability of the maze procedure to decrease the risk of stroke associated with atrial fibrillation so dramatically is likely due to the restoring of sinus rhythm and atrial transport function in combination with surgical removal or obliteration of the left atrial appendage, where most thrombi associated with atrial fibrillation develop.

Atrial Appendage↗
PubMed1999

Potential preoperative markers for the risk of developing atrial fibrillation after cardiac surgery.

Postoperative atrial arrhythmias after cardiac surgical procedures are common, with a reported overall incidence of approximately 50%. The pathophysiological mechanisms responsible for atrial fibrillation after a cardiac procedure remain unclear, although several clinical studies published during the past decade have identified certain preoperative risk factors associated with postoperative atrial fibrillation. In this study, we attempted to identify the histopathological changes in atrial cardiomyocytes that might predict the development of atrial fibrillation during the postoperative period. Atrial tissue from 60 patients was sampled before and after a cardiopulmonary bypass. Fifteen patients (25%) developed postoperative atrial fibrillation. The only clinical independent risk factor for the development of postoperative atrial fibrillation was chronic obstructive pulmonary disease (COPD) (P = .037). Histologically, there were 3 findings in the atrial myocardium that were more common in patients who developed postoperative atrial fibrillation: (1) vacuolation size (P = .017), (2) vacuolation frequency (P = .0136), and (3) lipofuscin content (P = .013). The identification of these histological markers for the development of postoperative atrial fibrillation may contribute not only to our understanding of the underlying pathophysiology that leads to postoperative atrial fibrillation but also to a method of preventing this troublesome complication of cardiac surgery.

Adult↗
PubMed1999

The myocardial profile of the cytosolic isozymes of creatine kinase is apparently not related to cyanosis in congenital heart disease.

BACKGROUND: CKMB, the cardiac-specific heterodimer of cytosolic creatine-kinase (CK), is developmentally and physiologically regulated, tissue hypoxia being a proposed regulator. In patients with cyanotic heart disease the myocardium is perfused with partially saturated blood. We questioned whether the myocardium of cyanotic subjects contains higher proportions of CKMB. MATERIALS AND METHODS: CK activity, the distribution of cytosolic CK isozymes, activity of lactic dehydrogenase (LDH), and tissue protein content were determined in obstructive tissues removed at corrective surgery of patients with congenital heart defects. Cyanotic (n = 13) and acyanotic (n = 12) subjects were compared. RESULTS: In cyanotic and acyanotic patients, CK activity was 8.4 +/- 0.6 and 7.6 +/- 0.6 IU/mg protein and the proportion of CKMB was 21 +/- 1.4 and 22 +/- 2. 0% (mean +/- S.E.M), respectively. In the two groups of patients, the activity related to the B subunit corresponded to the steady-state level of the CKBmRNA. The tissue content of protein and the activities of CK and LDH were similar in cyanotic and acyanotic subjects and increased with the age. CONCLUSIONS: The lack of difference in CKMB distribution between the cyanotic and acyanotic patients may either indicate that hypooxygenation is not a regulator of CK isozyme expression, or may be attributed to the already high proportion of this isozyme in hypertrophied, obstructive tissues. Recruitment of additional CKMB, in the cyanotic hearts, may thus not be required.

Adolescent↗
PubMed1996

A one-way valved atrial septal patch: a new surgical technique and its clinical application.

Patients who undergo surgical repair of congenital heart defects, characterized by a hypoplastic right ventricle or high pulmonary vascular resistance, are at high risk for the development of postoperative right heart failure. This risk may discourage the surgical team from carrying out a biventricular or complete repair in such patients. To reduce the risk for right heart failure, we developed a one-way, valved, atrial septal patch to serve as an artificial one-way foramen ovale and tested it in an animal model. By permitting right-to-left shunt, this device decompresses the failing right ventricle and maintains systemic cardiac output. The device has been used in 15 patients divided into three different groups: group 1 (n = 8), patients with a hypoplastic right ventricle and pulmonic stenosis or atresia, seven of whom underwent a biventricular repair; group 2 (n = 5), patients with evidence of pulmonary disease after longstanding left-to-right shunt caused by a correctable atrial or ventricular septal defect, all of whom had a complete repair; group 3, two patients with acute right heart failure in whom the device was used as a last option of treatment to wean them from cardiopulmonary bypass. This article presents our data in regard to the use of the one-way, valved, atrial septal patch and the indications for its clinical use.

Adolescent↗
PubMed1996

Surgical results in cardiac patients over the age of 80 years.

Improved medical care over the years has increased life expectancy and consequently the number of aged persons suffering from cardiac disease. During the past 3 years, 42 consecutive octogenarians, with an average age of 82.1 years, were evaluated. Thirty patients had coronary artery bypass graft surgery (CABG), 5 had aortic valve replacement (AVR), and 7 had combined CABG-AVR surgery. Among the ischemic patients 70% had suffered from unstable angina pectoris, and an average of 2.78 +/- 1 grafts per patients were performed. The left internal mammary artery was used in 12 patients (32%). Overall mortality was 7.1% (3 patients), while operative mortality was 2.4% (1 patient). Another two patients who expired during the 34 month follow-up period underwent AVR. The average hospitalization period was 10.2, 12 and 17.6 days for patients undergoing CABG, combined CABG-AVR, and AVR alone, respectively. Complications occurred in 10 patients (24%) and included neurologic deficits (in 2 patients), severe wound infection (in 2), cardiac arrhythmia (in 4), renal failure (in 1) and adult respiratory distress syndrome (in 1). The use of the left internal mammary artery was not associated with an increased incidence of complications. The low rate of mortality and major complications and the substantial improvement in quality of life led us to conclude that, when indicated, surgical treatment should be offered to selected elderly individuals who otherwise are in good physical and mental health.

Aged↗
PubMed1996

Use of the modified technique of ultrafiltration in pediatric open-heart surgery: a prospective study.

The use of cardiopulmonary bypass (CPB) in children is associated with significant morbidity due to the accumulation of an excessive amount of water. This can be decreased by massive diuresis, peritoneal dialysis, or conventional ultrafiltration technique (CUF) during bypass. However, we were dissatisfied with their effect on the outcome of our young patients, and recently began to use the modified technique of ultrafiltration (MUF) with good results. MUF was carried out for 15 min after completion of CPB to a hematocrit of 40%. Eighty patients were equally divided into two groups--MUF (group A) and control (group B)--and prospectively studied. There was one death in group A and two deaths in group B. The chest was left open in one patient in group A and in three patients in group B. At the end of MUF, the cardiac size was smaller, performance was better, and systemic blood pressure was higher in group A. Hematocrit levels in the two groups were similar during preoperative and CPB time, but post-CPB hematocrit in group A was significantly higher, 39.4% mean (range 35-50) vs. 28.5 (range 22-38) in group B (P <0.05). Blood loss was 10.56 ml/kg per 24 h (2-48.7) in group A vs. 20.8 (4.5-105.6) in group B (P <0.05). Blood transfused was 7.2 ml/kg per 24 h (0-29) in group A vs. 17.3 (3.1-49) in group B (P <0.05). Colloids transfused were 16.7 ml/kg per 24 h (0-64) in group A vs. 27.5 (0-58.6) in group B (P <0.05). No significant difference was found in urine output or the use of diuretics between the two groups. MUF results in better hemodynamic status in children, with the added advantage of less transfused blood and blood products. We believe that the use of accepted surgical techniques in combination with MUF will further improve the outcome of complex cardiac malformations.

Blood Loss, Surgical↗
PubMed1994

A one-way, valved, atrial septal patch in the management of postoperative right heart failure. An animal study.

Patients who undergo surgical repair of congenital heart defects that are characterized by hypoplastic right ventricle or pulmonary hypertension are at high risk for the development of postoperative right heart failure. To minimize this risk, a new one-way, valved, atrial septal patch was developed that serves as an artificial one-way foramen ovale. The feasibility of this device was tested in five dogs in which reversible right heart failure had been induced. Use of the one-way valved patch significantly improved right ventricular performance and reduced right ventricular hydrostatic pressures. The interatrial pressure gradient was reduced from 10 +/- 3.5 mm Hg during right heart failure to 4.4 +/- 1.4 mm Hg. When the device was opened, cardiac output increased significantly. This hemodynamic improvement was achieved at the expense of systemic arterial desaturation, which was, however, well tolerated. When the state of right heart failure was reversed, the one-way valved patch spontaneously closed, allowing no interarterial shunting. The results of this experimental trial suggest that this device can play a useful role in selected patients in whom postoperative right heart failure can be anticipated after surgical repair of certain congenital heart defects.

Animals↗