Biomedical subjects
Publications and source records attributed to K V Arom.
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.
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.
Minimally invasive direct coronary artery bypass grafting offers mortality and morbidity advantages to selected patients. To broaden indications for such, an appropriate and combined disciplinary approach using angioplasty and minimally invasive direct coronary artery bypass grafting is described in a patient requiring reoperative grafting. Documentation of patency of new left internal mammary artery-to-left anterior descending artery anastomoses performed without the use of cardiopulmonary bypass was obtained intraoperatively using a Thermal Imaging Camera.
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.
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.
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.
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.
Due to concerns about complications from normothermic core temperature during cardiopulmonary bypass, we initiated a prospective randomized study of 200 consecutive patients. In one group (group A), both the heart and the body temperature were kept at 37 degree C. In the second group (group B), both the body and myocardial temperature were allowed to drift down to 34 degree C. There were no differences between these two groups in age, sex, preoperative numbers of elective, urgent, emergent, redo patients, or coronary artery bypass (CAB), valve, CAB/valve procedures. Their preoperative neurological, pulmonary, renal, and vascular disease status were similar. Preoperative EF was 53% in group A (100 patients) and 52.5% in group B (100 patients). Group A required more volume (p = 0.001) and had less urine output (p = 0.03) during and post bypass. Group A required more phenylephrine hydrochloride (p = 0.05) and had more difficulty managing blood pressure. Strokes and renal failure necessitating dialysis occurred more often in group A but without statistical significance. More difficulties occurred in the normothermic (37 degrees C) group and cardioprotective effects of warm heart surgery may remain intact at 34 degrees C. Mild "drifted/tepid" hypothermic heart surgery could be a better and safer procedure.
Thrombosis of left-sided prosthetic valves is an uncommon yet potentially serious complication. Thrombolytic therapy has been proposed as an alternative to surgical methods in treating this condition. We sought to determine from a review of the literature what outcomes may be expected subsequent to thrombolytic administration and what groups may be at risk or benefit from this approach. We searched for studies including two or more patients treated with thrombolytic agents. Ten studies were reviewed. We describe and include two patients with valve thrombosis treated at our institution. A total of 182 episodes of prosthetic valve thrombosis in 162 patients were examined. Clinical success was achieved in 72.0% of cases and there was a mortality risk of 9.9%. Clinical success from thrombolysis was significantly related to the degree of heart failure at presentation and aortic valve position. Clinical success was not related to the duration of symptoms, time from valve replacement to obstruction, or valve type. Rethrombosis of successfully treated valve occurred subsequently in 19.5% of cases. Repeated thrombolytic administration in these patients was associated with similar rates of success as those treated for their initial episode of prosthetic valve thrombosis. Candidates for thrombolytic therapy include patients with obstructive valve thrombosis with or without congestive heart failure who are hemodynamically stable. Duration of time since valve replacement or symptom onset does not limit successful outcome. Close observation and aggressive maintenance of anticoagulation after therapy is suggested.
BACKGROUND: This study examined predictors and cost-effectiveness of early extubation after coronary artery bypass grafting. METHODS: Six hundred forty-five patients admitted to intensive care units after coronary artery bypass grafting at our institutions in 1993 were reviewed. There were 455 male and 190 female patients, which included all patients in DRG 106 and DRG 107. The patients were categorized into three groups: group A (269 patients) were extubated in less than 12 hours (7.55 +/- 2.5 hours), group B (291 patients) were extubated between 12 and 24 hours (16.85 +/- 3.3 hours), and group C (376 patients) were extubated any time after 12 hours. RESULTS: The reintubation rate for the entire group was less than 1%. Univariate preoperative analyses revealed small differences between groups A and B: only 6 of 25 variables were found to reach statistical significance. Stepwise logistic regression analyses were carried out in 269 patients of group A and 376 patients of group C. Older patients (log of age, p = 0.0001), female sex (p = 0.0129; odds ratio = 1.634), use of preoperative diuretics (p = 0.0010; odds ratio = 1.965) and unstable angina (p = 0.0301; odds ratio = 1.544) were noted to be clinical factors associated with late extubation (> or = 12 hours). Early extubation was accomplished in 42%; however, further analysis revealed that many patients who were intubated overnight should have been extubated sooner. CONCLUSIONS: Early extubation shortened the postoperative length of stay, resulting in reduction of cost and resource utilization. The average hospital charge per patient was approximately $6,000 less in the early extubation group.
Desmopressin (DDAVP, 0.3 microgram/kg) has been used routinely after cardiopulmonary bypass, particularly in patients having antiplatelet therapy. Recently epsilon-aminocaproic acid (single dose of 5 g) given before cardiopulmonary bypass has been added to the protocol. One hundred consecutive patients taking desmopressin and epsilon-aminocaproic acid (group A) and another 100 taking desmopressin alone (group B) were analyzed. There was no difference among these two groups in patient age, sex, preoperative history of bleeding and drug consumption, or number of patients for elective, urgent, emergent, redo, and reoperation for bleeding. Results of routine preoperative coagulation studies were within normal limits in both groups. Preoperative hemoglobin level was 13.5 g/dL in group A and 13.8 g/dL in group B (p = 0.12). Estimated blood loss in the operating room was 513 mL for group A and 587 mL for group B (p = 0.07). The total chest drainage at the end of 24 hours was 492 mL in group A and 746 mL in group B (p = 0.0001). Amicar given before cardiopulmonary bypass does not lessen operating room blood loss, but significantly decreases postoperative chest drainage. Group B patients received more fresh frozen plasma (60 U versus 4 U), more platelets (130 U versus 16 U), and more cryoprecipitate (118 U versus 10 U) than group A patients. Adding epsilon-aminocaproic acid could save $206.18 in blood product use per patient, compared with the expense of $24.12 per patient for E-aminocaproic acid administration.
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.
Records of 144 patients who received size 19 or 21 mm (Group A) aortic Standard St. Jude Medical (SSJM) prostheses were retrospectively reviewed and compared to 219 patients who received size 25 mm SSJM valves (Group B). Group A patients were older (70 +/- 9 years vs. 62 +/- 13 years) and had smaller body surface area (BSA) (1.65 m2 vs. 1.9 m2 p < 0.05). Operative mortality (5% vs. 2%) and postoperative unadjusted Doppler mean gradient (31 mmHg vs. 22 mmHg) were higher in Group A (p < 0.05). Total follow up was 1255 patient-years (450.6 Group A/804.4 Group B). There were no perivalvular leaks, valve thrombosis, or endocarditis in either group. Freedom from thromboembolism and anticoagulant-related hemorrhage was 89% and 95% in Group A and 93% and 98% in Group B, respectively. The major causes of late death were older age and progressive cardiac disease. The five-year actuarial analysis revealed a survival rate of 74% in Group A and 83% in Group B (p < 0.05). Of those who were alive, more than 70% were in functional class I and II. These patients not only enjoy a complication-free living but are able to perform daily routine activity despite being older. 19 mm and 21 mm SSJM aortic valve prostheses had higher transprosthetic gradient, but provided satisfactory performance in adult patients with a BSA of less than 1.7 m2. This valve can be used in the small aortic annulus with a valve size index of at least 12 mm/m2 as an alternative to an annular enlargement procedure.
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From November 19, 1990 through November 18, 1991 242 consecutive patients underwent cardioplegic arrest using retrograde delivery of crystalloid cardioplegia via blind transatrial cannulation of the coronary sinus. Of these procedures 196 (81%) were coronary artery bypass procedures. The overall operative mortality was 0.4%. Ten patients (3%) had enzyme and/or ECG criteria for myocardial damage in the peri-operative period and there was one deep sternal wound infection (0.4%). Two patients required VAD assistance post-operative, one following Protamine reaction (LVAD) and one following RV infarction and failed PTCA (RVAD). Both survived. Ninety-seven patients (40%) developed supraventricular arrhythmias and 20% required temporary pacing post-op for less than 6 hours. These results indicate the safety and effectiveness of retrograde delivery of intermittent crystalloid cardioplegia solution in general cardiac surgery.
This communication stepwise describes transatrial cannulation of the coronary sinus, a technique that we found to be very simple, fast, reproducible, and free of complication.
The cases of 100 consecutive patients who underwent coronary artery bypass grafting with coronary sinus (retrograde) cardioplegia (group R) without the antegrade-retrograde approach were reviewed. To evaluate the safety and the efficacy of this technique, another 100 consecutive patients who underwent a similar procedure but with conventional aortic root (antegrade) cardioplegia (group A) were used as a comparison. The two groups were similar with respect to age, male to female ratio, associated medical problems, extent of coronary artery disease, mean preoperative ejection fraction (0.56 +/- 0.13 versus 0.53 +/- 0.18), pump time (113.1 +/- 43 versus 111.7 +/- 38 minutes), aortic cross-clamp time (57.4 +/- 20 versus 60.8 +/- 23 minutes), number of grafts per patient, level of hypothermia, complication rate, rate of postoperative myocardial infarction (4% versus 3%), and mortality rate (2% versus 2%). Hemodynamic measurements were made 6 hours after operation in 59 patients in group R and 47 patients in group A. The cardiac index, left ventricular stroke work index, and right ventricular stroke work index were better in group R but not significantly so (p greater than 0.05). However, only 27% of patients in group R required a temporary pacemaker, and only 9% needed inotropic agents after 6 hours of operation in contrast to 51% and 42%, respectively, in group A (p less than 0.05). There were no complications from catheter intubation. In group R, right ventricular wall temperature (11 degrees +/- 3.6 degrees C) was higher than the septal (10.8 degrees +/- 3.2 degrees C) and left ventricular wall temperatures (9.1 degrees +/- 2.8 degrees C) (p greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
From October 1985 through December 1989, 92 heart transplant procedures were performed in 89 patients. Nine patients (aged 19 to 66 years; 7 male, 2 female) required mechanical circulatory support after transplantation because of primary idiopathic organ failure (n = 2), implant difficulty (2), poor organ quality (2), or acute right heart failure (3). Devices used included the intraaortic balloon pump (6), centrifugal right ventricular assist device (2), left ventricular assist (1), biventricular assists (2), and total artificial heart (1). Two patients required multiple devices. One patient underwent retransplantation. Implant time ranged from 1 to 18 days. One early death occurred owing to right heart failure 6 days after transplantation, 7 hours after removal of a right ventricular assist device, for an overall mortality of 11%. The remaining 8 patients are alive 4 months to 28 months after transplantation. The actuarial 1-year survival of 89% +/- 10% compares well with the survival of 87% +/- 4% for the entire transplant group. All surviving patients are in functional class I. Echocardiographic examination in all patients revealed left ventricular ejection fraction to be normal in 7 and depressed in 1. Extending the criteria for organ donors or difficulty with the implant procedure can lead to early organ failure, which may be reversible with circulatory assistance allowing excellent survival.