First clinical experience with the DeBakey VAD continuous-axial-flow pump for bridge to transplantation.

BACKGROUND: A shortage of donor organs and increased numbers of deaths of patients on the waiting list for cardiac transplantation make mechanical circulatory support for a bridge to transplantation a standard clinical procedure. Continuous-flow rotary blood pumps offer exciting new perspectives. METHODS AND RESULTS: Two male patients (ages 44 and 65 years) suffering from end-stage left heart failure were implanted with a DeBakey VAD axial-flow pump for use as a bridge to transplant. In the initial postoperative period, the mean pump flow was 3.9+/-0.5 L/min, which equals a mean cardiac index (CI) of 2.3+/-0.2 L. min(-1). m(-2). In both patients, the early postoperative phase was characterized by a completely nonpulsatile flow profile. However, with the recovery of heart function 8 to 12 days after implantation, increasing pulse pressures became evident, and net flow rose to 4.5+/-0.6 L/min, causing an increase of mean CI up to 2.7+/-0.2 L. min(-1). m(-2). Patients were mobilized and put through regular physical training. Hemolysis stayed in the physiological range and increased only slightly from 2. 1+/-0.8 mg/dL before surgery to 3.3+/-1.8 mg/dL 6 weeks after implantation. CONCLUSIONS: The first clinical implants of the DeBakey VAD axial-flow pump have demonstrated the device to be a promising measure of bridge-to-transplant mechanical support.

Pulsatile flow in patients with a novel nonpulsatile implantable ventricular assist device.

BACKGROUND: Ventricular assist devices (VADs) are an accepted therapy for patients with end-stage heart failure. The implantable devices that are available produce a pulsatile flow and are very large. In 6 patients, beginning in November 1998, we started to use the continuous-flow implantable DeBakey VAD device, which weighs 93 g. To detect the flow in peripheral vessels, we measured transcranial Doppler signals in patients after implantation. METHODS AND RESULTS: Transcranial Doppler studies were performed with the MULTI-DOP X4 device with two 2-MHz probes (for the middle cranial arteries) in 4 patients for up to 12 weeks twice weekly after implantation. The blood velocity was measured, and the pulsation index (PI) calculated. The measured pump flow and rotations per minute were registered. The preoperative echocardiographic assessment values were compared with those acquired 6 weeks after implantation. The PI increased continually in all patients after VAD implantation, left ventricular (LV) ejection fraction did not improve, but right ventricular (RV) ejection fraction after implantation improved compared with preoperative values. The LV end-diastolic diameter after implantation decreased between 11% and 46% intraindividually. There was no correlation between PI and blood pressure or, except in 1 patient, between PI and blood flow through the VAD. CONCLUSIONS: The DeBakey VAD unloads the LV, which leads to a decrease in LV end-diastolic LV diameter and to the restoration of RV function. The unloaded LV and partially recovered RV provide a nearly physiological pulsatile flow despite the continuous flow of the VAD. Pulsatility is independent of peripheral vascular resistance. The first clinical experience with the DeBakey VAD was positive and has resulted in its continued use.

Cardiac echinococcal cyst: diagnosis by two-dimensional echocardiography.

A case of an intracardiac echinococcal cyst is presented. The diagnosis was made by two-dimensional echocardiography, which clearly identified a large multiseptated cystic structure in the right ventricular outflow tract. The findings were verified at surgery. It is suggested that two-dimensional echocardiography may be the procedure of choice in the diagnosis of cardiac echinococcal disease.

The St. Jude valve prosthesis: analysis of the clinical results in 815 implants and the need for systemic anticoagulation.

Between July 1979 and December 1984, 785 patients received 815 St. Jude Medical valve prostheses. Valve-related mortality in the follow-up period was due to thromboembolism in seven cases, anticoagulant-related hemorrhage in three and perivalvular leak in two. Freedom from valve-related death or reoperation at 3 years was 96.4% for aortic valve replacement and 98.3% for mitral valve replacement. The overall rate of thromboembolism was 2.6%/patient-year with warfarin, 9.2%/patient-year with antiplatelet medication and 15.6%/patient-year in patients with no anticoagulant therapy. One episode of thrombotic obstruction of a mitral valve, in a patient receiving no anticoagulant therapy, resulted in an occurrence rate of such obstruction of 0.22%/patient-year. Valve replacement with the St. Jude valve produced excellent clinical results, but long-term anticoagulation with warfarin was required to minimize thromboembolic complications. The use of antiplatelet agents alone provided inadequate protection.

Surgical treatment of atherosclerotic heart disease.

Because the surgical mortality rate in patients older than age 70 years is significantly higher than that of patients aged 50 to 60 years, surgical treatment of atherosclerosis in the elderly should be used after medical measures have failed. Balloon angioplasty is the surgical treatment of choice, but coronary artery bypass may be performed when necessary. In most patients older than 65 years, the rate of progression of atherosclerosis is slow, and additional surgical treatment may not be required for many years. In the elderly, atherosclerosis is often found in more than 1 of the 4 major arterial beds. About 15% of patients with coronary artery disease requiring operation have atherosclerosis in a second major arterial bed. Previously unpublished data on risk factors and survival rates in patients who have undergone coronary artery bypass surgery are reviewed.

Patterns of atherosclerosis: effect of risk factors on recurrence and survival-analysis of 11,890 cases with more than 25-year follow-up.

A series of 11,890 patients from the senior investigator's surgical service between 1949 and 1998 is analyzed for the significance of distinct risk factors for recurrence of, and survival from, atherosclerotic occlusive disease. Eight risk factors have been assessed for their importance in 4 defined arterial categories (the coronary arterial bed, the branches of the aorta, the abdominal visceral [celiac, superior mesenteric, and renal] arteries, and the terminal abdominal aorta and its major branches) in determining survival rate of the entire group and their impact on rate of recurrence of atherosclerosis in a subgroup of 5,568 patients who had > or =1 postoperative arteriogram, permitting precise identification of changes in the atherosclerotic process. Patients in these 2 groups were followed for > or =25 years; univariate and multivariate analyses were used. On admission all patients had symptomatic atherosclerotic occlusive disease in a single vascular category. Each patient was treated surgically for alleviation of the disease. Two primary outcomes are included: (1) survival, by atherosclerosis category, in all 11,890 patients; and (2) recurrence, also by category, in the subset of 5,568 patients. Multivariate results for recurrence showed little consistency across categories. Only 1 risk factor, diabetes, appeared in 2 of the 3 categories fully analyzed. Other variables that are significant in only a single category are male sex, cholesterol, hypertension, and smoking. Survival showed much greater consistency, with age, diabetes, and hypertension significant in all 3 categories, male sex and smoking in 2, and cholesterol in only Category I. Univariate results followed much the same trend. For recurrence and survival, the response of the arterial bed to the risk factors in each of the 4 categories is distinctly different, an observation that we have not found to be previously reported.

Renovascular reconstruction: factors affecting long-term prognosis in 919 patients followed up to 31 years.

During the 31-year period from May 3, 1955, to May 12, 1986, renovascular reconstructions were performed on 919 patients. The mean age of the 529 men was 54 +/- 0.58 (SE) years and, of the 390 women, 48 +/- 0.7 years. Mean preoperative diastolic blood pressure was 110 +/- 0.6 mm Hg. The most common causes of renal artery stenosis were atherosclerosis in 647 patients, fibromuscular disease in 161 patients, and renal artery aneurysm in 51 patients. In the remaining 60 patients, other causes were present, including kinks and fibrous bands. The most common surgical procedures were Dacron bypass graft (780 arteries) and endarterectomy with or without a patch graft (329 arteries). Four hundred sixty-nine patients had associated operations, the most common of which were abdominal aortic aneurysmectomy in 231 and aortoiliofemoral reconstruction in 141 patients. The perioperative mortality rate was 5.5% (51 of 919 overall); for renal procedures alone, it was 1.7% (8 of 450) and for combined surgical procedures, 9.2% (43 of 469). The overall graft patency rate at a follow-up of 18.8 +/- 1.9 months was 88.6% (381 of 430) and at a second follow-up of 50 +/- 4.3 months, 86.7% (111 of 128). Analysis of long-term blood pressure response and factors affecting late survival indicated that patients with preoperative diastolic pressures of greater than 100 mm Hg and renal artery stenosis of greater than 70% had the best blood pressure responses and that male sex, increasing age, bilateral renal stenosis, and associated vascular operations lowered the survival rate whereas fibromuscular disease enhanced the duration of survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Right coronary artery-to-right pulmonary artery fistula: surgical correction.

A case is described of a patient with angina pectoris in whom a diagnosis of a coronary arterial fistula arising from the right coronary artery and terminating in the right pulmonary artery had been made. The anginal pain was relieved by closure of the defect via the lumen of the pulmonary artery with the use of temporary cardiopulmonary bypass. We have been unable to find a previous description of such a condition.

Can retrograde cardioplegia alone provide adequate protection for cardiac valve surgery?

BACKGROUND: When aortic insufficiency is present, antegrade delivery of cardioplegia requires coronary cannulation. Use of retrograde cardioplegia simplifies administration. The efficacy of the retrograde route alone in ensuring adequate myocardial protection may be assessed by the clinical outcome. METHODS AND RESULTS: We used closed transatrial coronary sinus perfusion as the sole method of cardioplegia delivery in 100 patients who underwent valve operations, either isolated or combined with coronary (n=24), ascending aortic aneurysm (n=8), or other procedures. Eighty-one patients were in New York Heart Association (NYHA) Class III or IV; 23 had undergone previous heart operations; 23 were admitted from the coronary care unit (CCU); and 20 had left ventricular ejection fraction (LVEF) of < or = 40%. Operative mortality was 2%. An intra-aortic balloon pump was required in eight patients. On univariate analysis, perioperative use of inotropes (n=26) was related to age > or = 70 years (p=0.02), COPD (p=0.05), pulmonary hypertension (p=0.005), higher NYHA Class (p=0.0006), preoperative heart failure (p=0.006), lower LVEF (p=0.0003), urgency (p=0.00001), admission from the CCU (p=0.006), repeat operation (p=0.03), coronary artery disease (p=0.02), and longer ischemic (p=0.02) and bypass times (p=0.0003). On multivariate stepwise logistic regression analysis, use of inotropes was related to preoperative lower LVEF (p=0.02) and urgency of operation (p=0.0002). Perioperative complications included ventricular arrhythmia in six, heart block in one, renal dysfunction in nine, and stroke in two patients; no patient had myocardial infarction. CONCLUSION: Good clinical results can be obtained by using retrograde cardioplegia alone without prior doses of antegrade cardioplegia in all valve operations.

Localization of endovascular infection by selective catheterization with serial cultures.

Pseudomonas infection developed at the suture line of an aortic graft in a patient 13 years after the operation. The site of the infection was localized by quantitative blood cultures taken with the aid of selective arterial catheterization. This technique may be of great help in localizing the source of endovascular infection in difficult cases.

Anatomic constraints for a total artificial heart in orthotopic heart transplant recipients.

The anatomic constraints and design parameters for a heart prosthesis have not yet been defined in heart transplant recipients (i.e., the population most eligible for total artificial heart implantation). The parameters regarding anatomic constraints were measured in 26 consecutive patients undergoing orthotopic heart transplantation (median body surface area 1.9 m2) after cardiectomy. A full-sized contour model of the cylindric total artificial heart (diameter 97 mm; width 81 mm) was inserted into the pericardial cavity to decide the pump configuration and to verify its fit. The dimensions of this model were based on the miniature electromechanical total artificial heart that is currently under development. Fit was found to be adequate in most of the cases with no identifiable compression of adjacent vascular structures. The median intraoperative measurements that define pericardial constraints for a heart prosthesis were pericardial length (130 mm), width (160 mm), and depth (140 mm). We also took measurements from the excised hearts, which should provide a useful reference for other prosthetic devices. The current dimensions of our implantable total artificial heart were found acceptable for orthotopic implantation. Length of the pericardium and cardiothoracic ratio were identified as variables related to adequacy of fit.

Postoperative course of S-100B protein and neuron-specific enolase in patients after implantation of continuous and pulsatile flow LVADs.

BACKGROUND: In the early post-operative period after implantation of a continuous flow left ventricular assist device (LVAD) a non-pulsatile flow occurs. We compared the post-operative time-courses of protein S-100B (S100B) and neuron-specific enolase (NSE) as biochemical markers of brain injury in patients after implantation of a continuous flow LVAD and patients receiving a pulsatile flow LVAD. METHODS: Since 1998 the continuous flow DeBakey VAD has been implanted in 8 patients at our institution. For comparison purposes, a group of 7 consecutive patients in whom a pulsatile Novacor N100 LVAD was implanted were investigated. In both groups cardiopulmonary bypass (CPB) with cardiotomy suction was used. S100B and NSE were measured in serum pre-operatively, 4 hours after CPB, and on days 1, 3, 7, and 14 after implantation of the LVAD. A neurologic examination was performed pre-operatively and post-operatively on days 3 and 14. RESULTS: No differences were found between groups in pre-operative characteristics. The analysis of variance with repeated measurements for S-100B and NSE showed significant time effects (p = 0.004, p = 0.009, respectively) but no group effects (p = 0.06, p = 0.26, respectively) and no interaction between groups and time (p = 0.12, p = 0.48, respectively). The pre-operative serum level of S100B was significantly higher (p = 0.03) in the DeBakey VAD group. The pre-operative serum level of NSE was similar in the 2 groups (p = 0.7). In both groups there was a significant increase of S100B and NSE immediately after surgery (S100B: p = 0.006, p = 0.019; NSE: p = 0.01, p = 0.001). The values returned to pre-operative levels in the DeBakey VAD group on day 1 after implantation and in the Novacor group for S100B on day 3 and NSE on day 1. Post-operatively the mean values of S100B and NSE in the DeBakey VAD group compared with the Novacor group were significantly elevated only on day 3 (p = 0.005, p = 0.023).No neurologic complications were noted in patients with a continuous flow LVAD, whereas in the pulsatile LVAD group 2 patients presented neurologic abnormalities during the study period. CONCLUSIONS: The similar course of biochemical markers of brain damage in both groups may indicate that the non-pulsatile flow in the early post-operative period does not lead to increased brain injury or permeability of the brain blood barrier.Elevated levels of S100B and NSE in the post-operative period can be used as diagnostic markers of brain injury in patients after implantation of both types of LVAD.

Cytomegalovirus genome and the immediate-early antigen in cells of different layers of human aorta.

A number of data suggest that reactivation of cytomegalovirus (CMV) latent in arterial wall cells may contribute to atherogenesis; however, there is no direct evidence available. To address this issue, we have examined, using in situ hybridization or immunohistochemical staining, the frequency of occurrence of cells containing viral genome and of those expressing the IE 70 viral antigen in the endothelial layer and in deeper layers of human aortas with or without visible atherosclerotic lesions. Using endothelial cell cultures or tissue endothelial preparations, we found CMV-hybridizing endothelial cells in 6 of 8 grossly normal aortas and in 16 of 18 lesioned aortas. Antigen-positive endothelial cells were detected in 1 of 5 grossly normal vessels and in 6 of 7 lesioned vessels. Infected endothelial cells were abundant in areas adjacent to orifices of intercostal arteries of grossly normal aortas and in fatty spots of lesioned aortas, but no infected endothelial cells were observed in most plaques examined. In paraffin sections of grossly normal vessels, we detected CMV genome in cells adjacent to lumen and in cells randomly scattered through subendothelial intima and the media; however, no immunoreactive viral protein was found in the same tissue samples. In sections of lesioned vessels, clusters of CMV-hybridizing cells were found in the media in addition to infected cells randomly scattered through the intima and the media. In these samples of lesioned vessels, viral antigen was detected in cells adjacent to lumen and in cells clustered at the intima/media border. We found antigen-positive cells in grossly normal areas of lesioned aortas and in fatty lesions, but not in plaques of the same vessels. The data suggest that accumulation of the immediate-early CMV antigen in cells of endothelial layer and development of antigen-positive cell clusters in deeper layers of vascular wall accompany early atherogenic events in human aorta.

Long-term results of treatment of the totally occluded renal artery in forty patients with renovascular hypertension.

A study of 40 patients with renovascular hypertension and a totally occluded renal artery was made to determine the optimal management of such lesions. There were 20 men and 20 women, ranging in age from 9 to 73 years (mean age, 51.4 years). Associated contralateral renal artery stenosis was present in 31 patients. Twenty-one patients underwent reconstruction of the occluded renal artery; 15 of the 21 experienced long-term success (up to 223 months) and six experienced failure. Sixteen patients underwent follow-up arteriography. The 14 patients who were treated by primary nephrectomy and reconstruction of a contralateral stenotic kidney had excellent results. In five patients, only a contralateral reconstruction was performed. Factors that were analyzed to determine the best predictors of success included age, sex, total renal function, contralateral reconstruction, associated vascular procedure, surgical technique, nephrogram or excretion of dye on intravenous pyelography, visualization of the distal renal artery on aortography, length of the kidney, and weight and pathology of the nephrectomy specimens. Only the size and weight of the kidney were consistent predictors of outcome. The preoperative demonstration of function in the kidney supplied by a totally occluded renal artery was unimportant. As a result of this study, we recommend reconstruction only for kidneys > 9.5 cm in length and nephrectomy or no treatment for smaller kidneys supplied by totally occluded renal arteries except when preservation of renal tissue is important. In such cases, revascularization of a small kidney can be accomplished but is associated with a significant risk of subsequent nephrectomy.

Injuries to the visceral arteries.

Injuries of the major visceral arteries are among the more difficult to manage and rarely occur without serious associated injuries. Sixty-six patients are presented with injuries to the celiac, superior, and inferior mesenteric arteries. Fifty-three injuries resulted from gunshot wounds, nine from stab wounds, and four from blunt trauma. Operative management included vessel ligation in 11 patients, arteriorrhaphy in 43, resection and end-to-end anastomosis in six, Dacron graft interposition in four, and aortic reimplantation in two. Twenty-three patients died, 16 from failure to control hemorrhage. In two patients failure to restore adequate visceral circulation resulted in bowel ischemia and infarction. The successful management of patients with visceral arterial injuries is dependent upon rapid and adequate exposure followed by primary repair or revascularization utilizing available surgical techniques.

Myocardial revascularization prior to subsequent major surgery in patients with coronary artery disease.

Of our series of patients undergoing direct myocardial revascularization, we selected 60 patients who had subsequent major surgical and cardiovascular operative procedures. Thirteen of these patients had a second subsequent operative procedure, and four of the original 60 patients had a third subsequent operation. None of the patients died during the subsequent operation and none sustained a myocardial infarction. During the 77 subsequent procedures, there were eight different episodes of cardiac complications: seven patients had supraventricular arrhythmias and one patient had acute pulmonary edema. All patients responded to medical therapy. These results are suggestive that myocardial revascularization should be performed prior to other major indicated operative procedures in patients with documented coronary artery disease.

Intraoperative arteriography during femoral-popliteal bypass.

Minor technical errors may jeopardize the patency of femoral-popliteal bypass grafts. In an attempt to detect such errors, intraoperative arteriography has been routinely employed. It allows immediate recognition and correction of the most common abnormal findings: intraluminal debris, intimal dissection, distal thrombosis, arterial spasm, and kinking of the graft.

Cardiopulmonary bypass surgery. Platelet aggregation during induction of anesthesia and following heparinization of patients.

Measurements of platelet count and platelet aggregation in response to adenosine diphosphate and epinephrine were made before and after administration of preanesthetic medications and at intervals during induction of anesthesia, before and after thoractomy, and before and after systemic heparinization in patients undergoing cardiopulmonary bypass operations. Substantial decreases in circulating platelet count occurred only after induction of anesthesia and following thoracotomy. There was no notable change in the percent of platelets involved in aggregation over the period studied, but the reactivity of platelets was increased after induction of anesthesia and after thoracotomy.

Traumatic injuries of the inferior vena cava.

Three hundred and one patients with injury to the inferior vena cava have been treated over the past 30 years. Penetrating injuries predominated, with gunshot injury in 228 patients. The inferior vena cava was injured above the renal veins in 84 patients. One hundred and forty-eight patients had shock, 55 without palpable pulse or blood pressure. Vascular repair was accomplished in 234 patients. Ligation or packing was performed in 32 patients. Thirty-five patients died prior to vascular control or repair. Placement of intravascular shunts or occluding balloons was utilized in 25 patients. Mortality has decreased from a high of 100% in 1955 to 30% during the last six years of this experience. Reduction in mortality probably has resulted from shortened wounding to therapy intervals with more effective resuscitation and vascular control.

Injury to popliteal vessels.

Between 1969 and 1981, 61 patients with 85 popliteal vascular injuries were seen. In the nine patients who required amputation, common risk factors included (1) extensive time delays (greater than 36 hours) between injury and repair, (2) associated bone and soft-tissue injuries leading to postoperative wound infection. amd (3) early occlusion of popliteal artery repair or delay in performance of fasciotomy. The low amputation rate in patients without operative delay or associated bone and soft-tissue injuries (2/54 = 3.7%) was attributed to the careful application of standard vascular surgery techniques in combination with early use of leg fasciotomy when indicated. Polytetrafluoroethylene grafts as substitute vascular conduits in the popliteal artery have an excellent patency rate and seem to be an acceptable prosthesis when segmental resection of the artery is necessary.