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Biomedical subjects

D M Nicoloff

Publications and source records attributed to D M Nicoloff.

At least 19 recordsLinked to original sources
PubMed1997

Minimally invasive direct coronary artery bypass grafting: experimental and clinical experiences.

BACKGROUND: This communication briefly details the goals, indications, surgical approaches, and limitations of minimally invasive direct coronary artery bypass grafting (MIDCABG). The experimental experiences from various institutions are summarized. METHODS: The clinical experiences of 72 consecutive MIDCABG procedures performed at our institutions between June 5, 1995, and August 13, 1996, were analyzed. We have divided patients into two groups. Group A consists of healthy low-risk patients with single lesions of the left anterior descending coronary artery or the right coronary artery, or with both lesions of both arteries. Group B consists of high-risk patients who had major contraindications to conventional cardiopulmonary bypass procedures. There were 55 patients in group A and 17 patients in group B. Using The Society of Thoracic Surgeons preoperative predicted risk module, group A had a 1% predicted mortality versus 4% in group B. RESULTS: The 30-day mortality was 2% in group A and 6% in group B. The mean postoperative length of stay was 4 days for group A and 5 1/2 days for group B. Short-term follow-up of the survivors appears promising, and 81% of patients were angina free at the time of last follow-up. CONCLUSIONS: The MIDCABG techniques are still developing. The short-term results during the learning period appear to be quite good, but long-term results remain yet to be seen. The addition of new equipment to facilitate construction of the anastomosis will enhance application and results. The lessons learned from these approaches are already being applied to other areas of cardiac surgery including valve replacement and the repair of congenital heart defects.

Coronary Artery Bypass↗
PubMed1996

Mini-sternotomy for coronary artery bypass grafting.

This communication details the approach to the left anterior descending artery, right coronary artery, or both via a single limited incision of the chest. The mini-sternotomy incision is 10 to 12 cm long. The distal anastomosis can be accomplished, with a beating heart, through this small incision, with or without cardiopulmonary bypass.

Cardiopulmonary Bypass↗
PubMed1996

North American experience with the Perma-Flow prosthetic coronary graft.

BACKGROUND: The Perma-Flow prosthetic coronary graft is a 5-mm polytetrafluoroethylene tube into which is incorporated a Venturi flow restrictor. An aorto-superior vena caval fistula is created and coronary anastomoses are constructed proximal to the resistor in side-to-side fashion, where arterial pressure is maintained. From November 1992 through December 1995, eight investigational centers in North America have implanted this graft in 40 patients with inadequate autologous alternatives. METHODS: Patients were selected for inclusion in this study if coronary artery bypass grafting was required and adequate autologous conduit to complete revascularization was not available. Operative data were completed by the implantating surgeon and referred to a central center, the Minneapolis Heart Institute, for correlation. Follow-up was conducted by data coordinators at each institution, and follow-up data were obtained directly from these coordinators for inclusion in the study. RESULTS: Patient age ranged from 53 to 82 years, and 15 patients were undergoing reoperations (38%). On each Perma-Flow graft one to four coronary side-to-side anastomoses were constructed. In addition, left internal mammary artery (n = 26), greater saphenous vein (8), right internal mammary artery (4), and gastroepiploic artery (4) were used to complete revascularization. Aortic (2) or mitral valve replacement (1) was also carried out. There were seven operative deaths (18%) and two late deaths (4 and 6 months). After 1 to 37 months (mean, 13 +/- 9 months) of follow-up, 29 of 31 surviving patients are asymptomatic. Echocardiographic heart size has not increased from the postoperative value, indicating limited volume load has not affected heart size. Protocol catheterization (n = 32) in 28 patients 1 week to 1 year postoperatively revealed 7 of 73 studied coronary anastomoses (9.5%) and two distal extensions and resistors were occluded (7%). In 1 patient during sternal debridement at 1 year, no flow was found in the graft. CONCLUSIONS: The Perma-Flow graft is a useful adjunct to complete revascularization in patients with deficient autologous conduit.

Aged↗
PubMed1996

Utilization of the St. Jude Medical prosthesis in the aortic position.

Intensive in vitro and in vivo studies led to the clinical introduction of the St. Jude Medical (SJM) prosthesis in October 1977. Because of excellent clinical characteristics, handling, and durability, as well as the low incidence of clinically adverse events, the SJM valve has become the most commonly used prosthetic heart valve. In 1,431 patients undergoing aortic valve replacement during a 15-year period, the incidence of clinically adverse events, including thromboembolism, thrombosis, paravalvar leak, reoperation and anticoagulant-related hemorrhage, have been less than 0.8% per patient-year in both adult and pediatric patients. There have been no structural failures. The SJM prosthesis is an excellent device for the treatment of diseases of the aortic valve.

Adolescent↗
PubMed1996

Anticoagulant related complications in elderly patients with St. Jude mechanical valve prostheses.

BACKGROUND AND AIMS OF THE STUDY: This communication reports the anticoagulant-related complications (ARH) in patients who received the St. Jude Medical mechanical prosthesis and were 70 years of age or older at the time of implantation. METHODS: Our institutional data file shows that during the 15-year period from 1977 to 1992, our group implanted the St. Jude Medical mechanical prosthesis in 610 patients with aortic valve disease (AVR) and 186 patients with mitral disease (MVR), who were 70 years or older, either with or without coronary artery bypass grafts. The operative mortality was 6.4% for AVR and 16% for MVR. The mean follow up for this elderly group was 4.9 years (2,996 patient-years) for AVR and 4.2 years (771 patient-years) for MVR. RESULTS: The incidence of late death was 30% for AVR and 33% for MVR. The freedom from TE was 91.6% +/- 1.8%, from valve thrombosis 98.8% +/- 0.7%, and from ARH 95.9% +/- 1.1%. The freedom from operative death, valve-related death, and all complications was 78.8% +/- 2.4%. The data from this study shows that both the aortic and the mitral valve replacement patients who were 70 years or older have an acceptable rate of bleeding complications. Reduction of the intensity of anticoagulation in our practice (INR of 1.8-2.5 for AVR and 2.5-3.2 for MVR) may play a role in this finding. The incidence of valve thrombosis and TE rates were also low in this study. CONCLUSIONS: With increasing life expectancy in the elderly, the use of the St. Jude Medical Mechanical prosthesis and low intensity anticoagulation could be reconsidered for a selected group of elderly patients.

Aged↗
PubMed1995

Long-term follow-up of the St. Jude Medical prosthesis in pediatric patients.

BACKGROUND: The St. Jude Medical prosthesis has become the most commonly used artificial heart valve, yet few data are available in the pediatric population. This study addresses results of the use of this prosthetic valve in pediatric patients over a 13-year time frame. METHODS: From January 1982 through June 1994, 73 patients (49 male) underwent 75 valve replacements using the St. Jude Medical prosthesis at Minneapolis Children's Medical Center. Follow-up was complete in 71 patients, with a mean follow-up of 39 +/- 32 months (mean +/- standard deviation; range, 4 to 142 months). RESULTS: Valves' positions were aortic in 36 patients, mitral or left atrioventricular valve in 34, tricuspid in 1, and double valve in 2. Patient age was 8 +/- 6 years, with a range of 1 week to 19 years. Sixteen patients were less than 24 months of age at valve replacement. Prior cardiac procedures had been performed in 82% of mitral patients, 58% of aortic patients, and all of the tricuspid and double-valve patients. Elective valve replacement was performed in 62 to 73 patients (85%). Seven patients (44%) less than 24 months of age had urgent valve replacement; 4 patients (7%) older than 24 months required urgent valve replacement. Overall early mortality was 8% (6 of 73); 36% (4 of 11) in the patients undergoing urgent valve replacement and 3% (2 of 62) in the elective group. All but one of the deaths were due to cardiac dysfunction. There were four late deaths, from 4 to 125 months postoperative, primarily caused by congestive heart failure or pulmonary vascular disease. Cumulative freedom from valve-related events was 93%, 85%, and 77% at 1, 5, and 10 years, respectively. Valve-related complications included thromboembolism (4), bleeding (5), perivalvar leak requiring reoperation (2), transient ischemic attack (1), and endocarditis (1). There have been no permanent strokes or mechanical malfunction. The majority of patients are currently managed with warfarin. Five surviving patients whose initial valve replacement was at age 24 months or younger have undergone repeat valve replacement (42%). Ninety-five percent of patients enjoy good health at follow-up. CONCLUSIONS: The St. Jude Medical prosthesis offers correction of valvular disease with low morbidity and mortality, and excellent functional result.

Adolescent↗
PubMed1995

Modification of the elephant trunk procedure for treatment of acute aortic dissection.

The distal anastomosis constructed during repair of an aortic dissection is prone to bleeding, reentry, and neodissection. To protect the hemostasis, a modification of Borst's elephant trunk procedure has been devised. This "mini-trunk" protects the anastomosis with an internal buttress using the crease of an infolded graft and with a short flap of graft everted into the distal lumen preventing access of the blood stream to this newly constructed suture line.

Acute Disease↗
PubMed1994

Operative considerations in implantation of the Perma-Flow graft.

The Perma-Flow coronary bypass graft (Possis Medical, Inc, Minneapolis, MN) currently is undergoing expanded clinical trial. From November 1992 through June 1994 we have used this artificial conduit in 8 patients without autologous alternatives. These cases allowed the establishment of a technical basis for successful implantation of this graft. All studied coronary anastomoses are patent.

Aorta↗
PubMed1993

First clinical use of the Possis synthetic coronary graft.

The Possis polytetrafluoroethylene Permaflow coronary graft incorporates a Venturi resistor within the graft. Insertion is constructed by creating an anastomosis to the superior vena cava with subsequent anastomoses in sequence to coronary arteries requiring grafting. Finally, the graft is sewn to the aorta. The Venturi resistor controls flow through the aortocaval fistula, maintaining systemic pressure proximal, permitting systolic and diastolic flow to the grafted coronary arteries while maintaining constant flow through the graft. Animal studies demonstrated long-term patency. This graft was implanted in a patient with unstable angina pectoris and inadequate native conduit. Catheterization 6 weeks postoperative revealed patency of all anastomoses.

Aged↗
PubMed1989

Ten years' experience with the St. Jude Medical valve prosthesis.

Records of 1,298 consecutive patients who had received the St. Jude Medical prosthesis were reviewed (713 male and 585 female patients; mean age, 61.79 +/- 13.4 years). Early mortality was 5.7% (74 patients). Ninety-three percent complete follow-up was accomplished for the 1,224 patients who left the hospital (4,306.50 patient-years). One hundred ninety-two of these patients died, a late mortality of 16.9%. Sixty-four patients experienced thromboembolic episodes (17 major and 35 permanent). Twenty-four patients had anticoagulant-related bleeding, 4 had valve thrombosis, 7 had prosthetic valve endocarditis, 9 had paravalvular leak, and 10 underwent reoperation. There was no structural valve failure in this series. Twenty-two of the 118 patients who had valve-related complications died; another 15 patients died of sudden and unknown causes. Therefore, the total number of valve-related deaths was 37. Of those patients who survived, New York Heart Association functional class improved significantly (98% in classes II and III preoperatively and 96% in classes I and II postoperatively). Linearized rates for thromboembolism, valve thrombosis, and anticoagulant-related bleeding were 1.49% +/- 0.19%, 0.09% +/- 0.05%, and 0.56% +/- 0.11%/100 patient-years, respectively. The actuarial estimate of incidence free from all complications, operative death, and valve-related death was 66.9% +/- 8.2% at the end of 9 years. In spite of old age and advanced heart disease, the patients who received the St. Jude Medical prosthesis had very good results over a 10-year period.

Actuarial Analysis↗
PubMed1989

Ten-year follow-up study of patients who had double valve replacement with the St. Jude Medical prosthesis.

Records of 100 consecutive patients who had received double valve replacement were reviewed (41 men, 59 women, mean age, 60.86 +/- 13.0 years). The early death rate was 6% (six patients). A completed follow-up rate of 93% was accomplished in these 94 patients who left the hospital (mean, 309.8 patient-years). Twenty-three of these patients died. The late death rate was 26.4%. Four patients experienced thromboembolic episodes (one transient and three permanent; all were minor). One patient had a paravalvular leak (mitral), and another had thrombosis of the tricuspid valve. There was no clinical evidence of hemolysis, infective endocarditis, or structural failure or anticoagulant-related bleeding. One of those 23 patients who died was the patient who had thrombosis of the tricuspid valve. Another three patients died of sudden and unknown causes, 15 of cardiac-related problems and four of noncardiac problems. Of those patients who survived, New York Heart Association functional class improved significantly (from 66% class III before to 85% class I after). Linearized rates for thromboembolism and thrombosis were 1.29 +/- 0.65 and 0.32 +/- 0.32 per 100 patient-years, respectively. The actuarial estimates of incidence free of all complications and valve-related deaths were 77.9% +/- 10.6%. Despite the advanced heart disease involving two native valves, the patients who had double valve replacement with the St. Jude Medical prosthesis had very good results over a 10-year period.

Actuarial Analysis↗
PubMed1989

Mechanical circulatory support as a bridge to transplantation.

From December 1985 through April 1988, 11 patients (three female and eight males), 33.1 +/- 3.9 (+/- SEM) years of age (range, 15 to 50 years), underwent heart transplantation preceded by the use of mechanical circulatory support. The causes of cardiac failure were ischemic (four), viral cardiomyopathy (three), idiopathic cardiomyopathy (two), congenital heart disease (one), and valvular heart disease (one). All patients were preterminal. Mechanical circulatory support consisted of intra-aortic balloon pump (eight), the total artificial heart (seven), biventricular assist (three), and left ventricular assist (two). Seven patients had more than one form of support. The duration of mechanical circulatory support was 12.2 +/- 4.1 days (range, 1 to 44 days). Once listed for transplantation, patients waited for 8.1 +/- 2.4 days for a donor. Seven patients received OKT3 monoclonal antibody as prophylaxis, in addition to triple-drug immunosuppression. There were four rejection episodes and 12 serious infections. In addition, eight patients suffered a major posttransplant complication of a distant organ system: central nervous system (three), renal (two), and respiratory (three). Post transplant hospitalization was 48 +/- 22 days (range, 15 to 248 days). Two patients (18%) died after transplant, one of severe acute rejection (29 days) and one of multisystem failure (248 days). All patients surviving transplant hospitalization are alive 6 to 34 months after the transplant procedure. Eight patients are in functional class I and 1 patient class II. This patient attends school full-time but has a premechanical support system neurologic defect. In follow-up of 163 patient-months except for yearly catheterization, these nine patients required only 5 hospital days. Although the use of the mechanical circulatory support as a bridge to transplantation can result in a prolonged, complicated hospitalization after transplant, the long-term results are gratifying.

Adolescent↗
PubMed1987

St. Jude Medical prosthesis: valve-related deaths and complications.

Despite the hemodynamic improvement in cardiac valve prostheses, valve-related deaths and complications have remained a substantial source of morbidity and mortality. This follow-up study was carried out in April, 1986, in a group of 816 patients who received 876 St. Jude Medical prostheses between October, 1977, and October, 1984. One hundred fifty-five patients (37%) of the 422 having aortic valve replacement (AVR) and 88 (29%) of the 300 having mitral valve replacement (MVR) had concomitant coronary artery bypass grafting, and 94 patients (12%) had miscellaneous procedures performed in addition to valve replacement. Sixty-three patients died within the operative period, an operative mortality of 7.7%. Follow-up was complete for 98% of the patients; the mean follow-up was 42 months. At that time, 87 more patients had died, a late mortality of 11.9%. There were 13 valve-related deaths (4 in the AVR group, 7 in the MVR group, and 2 in the miscellaneous group); the causes of death were thromboembolism (7), anticoagulant-related hemorrhage (2), valve thrombosis (2), prosthetic valve endocarditis (1), and perivalvular leak (1). There were 37 thromboembolic episodes (1.78/100 patient-years) and 67 anticoagulant-related hemorrhages (3.22/100 patient-years), 46% of which necessitated transfusion. The incidence of valve thrombosis was 0.6% (4 patients). Perivalvular leak and prosthetic valve endocarditis occurred in 7 patients (1.0%) and 5 patients (0.7%), respectively. Reoperation was carried out in 6 patients (0.8%), but only for perivalvular leak. There were no deaths, no complications, and no clinical evidence of malfunction of the prosthetic valve.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

The comparative influence of prophylactic antibiotics on the prothrombin response to warfarin in the postoperative prosthetic cardiac valve patient. Cefamandole, cefazolin, vancomycin.

A prospective randomized trial was conducted comparing the effect of three antibiotics: cefamandole (CM), cefazolin (CZ), and vancomycin (V), used as prophylaxis for prosthetic valve surgery, on the prothrombin (PT) response to warfarin (W) on the third day of anticoagulant therapy. Twenty patients, with normal preoperative PTs, were randomized to each antibiotic. Their PTs were not significantly different at 2 hours after operation and the morning before W was begun. The three groups received similar W doses for 2 days, and the PT, as percentage of activity, on the morning of the third day demonstrated that V (51 +/- 18%) was significantly greater (p less than 0.005) than CM (29 +/- 14%) or CZ (38 +/- 18%). CM had a significantly greater percentage of change in PT (64 +/- 14%, p less than 0.0001) from the first to third day than either CZ (51.1 +/- 18%) or V (44.6 +/- 19%). CM also had a greater number of patients (6) with PTs greater than or equal to 30 seconds on day 3 than either CZ (1) or V (1). The antibiotic influence on the PT response to W in this study is ranked as CM greater than CZ greater than V.

Aged↗
PubMed1987

Aortic dissection presenting as pericarditis.

In five patients with aortic dissection, signs and/or symptoms of pericarditis were part of the early manifestations of the aortic disease. Signs of inflammatory pericarditis were noted clinically in four patients and were found at autopsy in one. In the three nonoperated patients who died of aortic rupture leading to fatal hemopericardium, symptoms of pericarditis preceded fatal rupture of the aorta by four to five days. A fourth patient died after surgical repair of aortic dissection 35 days after the onset of pericarditis. In the fifth patient, manifestations of chronic constrictive pericardial disease occurred over a period of seven months after which old aortic dissection was first identified. In each case, the internal tear of classic aortic dissection was located in the ascending aorta. Microscopic evidence of cystic medial necrosis of the aorta was present in each case. In each of two cases, there was a congenital bicuspid aortic valve. The phenomenon observed represents acute aortic dissection in which slow penetration of blood into the pericardial space caused inflammatory pericarditis. The interval between the onset of pericarditis and rupture of the aorta may allow sufficient time for appropriate diagnosis and potentially lifesaving treatment of the aortic disease.

Adult↗
PubMed1985

Combined techniques for double valve replacement in the infant.

A 6-month-old female infant was seen with heart failure secondary to severe aortic and mitral regurgitation. As a neonate the infant had undergone an aortic valvotomy for congenital aortic stenosis. Subsequently the infant had aortic and mitral regurgitation with an infarcted papillary muscle. Double valve replacement was carried out with the St. Jude valve. The first approach was by the Manouguian procedure with extension of the aortotomy out between the left coronary cusp and the noncoronary cusp. The posterior mitral apparatus was resected, and a 19-mm St. Jude aortic valve was sewn into the mitral position. Because the enlarged aortic valve annulus was still inadequate to accommodate a 19-mm St. Jude valve, a Konno procedure was carried out to enlarge the aortic ring anteriorly. Atrial, septal, and aortic repair and right ventricular outflow tract reconstruction were carried out with bovine pericardium. Bypass was carried out with standard techniques of hypothermia, aortic cross-clamping, and cardioplegia. Postoperative anticoagulation therapy was initially with aspirin and dipyridamole (Persantine); however, clotting of the mitral prosthesis necessitated treatment with urokinase and heparin, which completely resolved the clot. Sodium warfarin (Coumadin) therapy was then begun. One year postoperatively, the child is developing normally.

Animals↗