John A. Waldhausen

Ventricular-Assist Pumping in Patients with Cardiogenic Shock after Cardiac Operations

A ventricular-assist pump was used to support the circulation in eight patients who could not be separated from cardiopulmonary bypass after open-heart operations. In five patients with left ventricular failure, the systemic circulation was maintained with pumping from the left atrium to the aorta for 7.0 +/- 1.8 days (mean +/- S.E.M.); three of these patients were well four to 17 months after surgery. In two patients with biventricular failure, right and left ventricular bypass supported the circulation, but neither patient survived. One other patient had isolated right ventricular failure; pumping from the right atrium to the pulmonary artery maintained the pulmonary circulation for 2.2 days. This patient lived for 18 months. Use of the ventricular-assist pump in our patients provided complete support of the systemic or pulmonary circulation or both. Profoundly depressed ventricular function is potentially reversible if technical problems in employing the pump can be avoided.

Pulmonary sequestration in infants and children: a 20-year experience and review of the literature.

Abstract Pulmonary sequestration is a relatively rare condition in which a portion of lung tissue develops without communication with the tracheobronchial tree or the pulmonary artery. Blood supply is derived from one or more branches of the aorta. Its embryogenesis is uncertain, but it occurs in two forms, extralobar (ELS) and intralobar (ILS). In ELS the abnormal lung tissue is completely separate from the normal lung. It occurs in males four times as frequently as in females and is usually discovered in infancy. It is associated with an ipsilateral diphragmatic hernia in the majority of cases, and occasionally bronchial connections from the ELS to the esophagus or stomach have been described. ELS almost always occurs on the left side and, rarely, may be found below the diaphragm. Venous drainage is to the systemic veins or to the portal system. The ELS itself usually does not become diseased; symptoms are produced either by cystic degeneration and resultant compression of adjacent lung or by an associated diaphragmatic hernia. On the other hand, ILS typically occurs in the posterior basal segment of one of the lower lobes, most often the left. It occurs in males and females with equal frequency, and usually it makes its appearance later in childhood. Only very occasionally are associated anomalies present. Venous drainage is to the inferior pulmonary vein together with the rest of the lower lobe. The sequestered segment very frequently becomes infected and gives rise to symptoms of pneumonia. Arteriography is useful in diagnosis, and segmental resection or lobectomy is the indicated treatment.

Aortic valve replacement and combined aortic valve replacement and coronary artery bypass grafting: predicting high risk groups

To determine which groups of patients are at highest risk for operative or late mortality, 259 consecutive patients who underwent operation between 1978 and 1984 were studied; 170 underwent aortic valve replacement and 89 underwent aortic valve replacement combined with coronary artery bypass grafting. Multivariate analysis of risk factors selected emergency operation and patient age older than 70 years as the strongest predictors for operative death. Although patients having aortic valve replacement and coronary artery bypass grafting had a higher operative mortality rate (13.5 versus 3.5%), the combined operation had no independent predictive effect on early or late results. At a mean follow-up time of 48 months after surgery, 72% of the survivors of operation were living, 10% were lost to follow-up and 18% were dead. Seventy-seven percent of long-term survivors were in New York Heart Association functional class I or II. The incidence of thromboembolism, paravalvular leak, bacterial endocarditis and hemorrhage each occurred at a rate of less than 1% per patient-year. The factors associated with late death were preoperative age, male sex, left ventricular end-diastolic pressure, cardiac index and functional class. Despite an increase in operative mortality, patients undergoing emergency operation were not at higher risk of late death. Operative mortality is concentrated among several high risk groups. For patients undergoing elective operation, operative mortality is low, especially if the patient is less than 70 years old. Late results are good for all groups of patients undergoing operation, including those who are at greater risk of dying at operation.

Survival and Complications Following Ventricular Assist Pumping for Cardiogenic Shock

Thirty patients (pts) have undergone ventricular assist pumping for up to 25.4 days (mean 6.8 days). Twenty-eight pts could not be weaned from cardiopulmonary bypass (CPB) after open heart operations and two pts sustained myocardial infarctions (MI), with cardiogenic shock unresponsive to medical therapy previous to surgery. Twenty-two pts required left ventricular assistance (LVA); 55% (12/22) were weaned from the pump and 32% (7/22) survived. Two pts required right ventricular assistance (RVA); both were weaned from the pump and survived. Six pts required right and left ventricular assistance (BVA) and none survived. Postoperative survival for program years 1976 through 1979 (14 pts) was 14% (2/14). Postoperative survival for program years 1980 through 1982 (16 pts) was 44% (7/16), reflecting improved pump insertion techniques (left atrial cannulation) and pt management. Since 1980, 12 pts have required LVA, nine have been weaned from the pump, and six pts have survived (50%). One pt has required RVA and has survived, and three pts requiring BVA did not survive. Seven pts have been alive and well 5, 9, 14, 19, 24, 30 and 36 months after surgery. Five are NYHA functional Class I status and two pts are NYHA Class II status. Current data indicates that single ventricular assistance in pts who cannot be weaned from CPB is “reasonable and therapeutic treatment to extend life.”

Supravalvular Aortic Stenosis Clinical, Hemodynamic and Pathologic Observations

In 3 patients obstruction to left ventricular outflow was shown to be due to a localized narrowing of the aortic root at the point of insertion of the aortic leaflets. The site of obstruction was localized by left heart catheterization and selective angiography. The pathologic findings in 2 patients are described and the problem of the surgical management of this unusual form of aortic stenosis is discussed.

Use of Ultrasound in the Diagnosis of Pericardial Effusion

Excerpt Pericardial effusion is a potentially life-threatening condition and warrants prompt recognition. However, it is often difficult to differentiate this particular process from a large, dilat...

STUDIES ON DIGITALIS. II. EXTRACARDIAC EFFECTS ON VENOUS RETURN AND ON THE CAPACITY OF THE PERIPHERAL VASCULAR BED

The decline in cardiac output following the administration of digitalis to experimental animals (1-5) and to normal human subjects (6-10) would appear to be inconsistent with the well known positive inotropic action of this drug. The latter has been further confirmed by direct measurement of myocardial contractile force in both man and dog in the absence of heart failure ( 5, 11, 12). Peripheral pooling of blood leading to a decreased return of venous blood to the heart has been suggested by several investigators as a possible explanation for this phenomenon (13-15). Tainter and Dock (16) observed an increase in portal venous pressure following digitalis administration in the dog and postulated that hepatic vein constriction resulted in pooling of blood in the splanchnic bed. It is now clear that digitalis glycosides act directly on the peripheral circulation of both dog and man (12, 17). To define further the peripheral actions of these drugs, a preparation was developed which permitted characterization of the effects of digitalis on the capacity of the peripheral vascular bed and on venous return.

Volume requirements for cardiac surgery credentialing: A critical examination

New volume requirements for coronary artery bypass grafting are being imposed on cardiac surgeons by hospitals, managed care groups, and others. The rationale for this is unclear. The available literature as well as additional sources relating volume and outcomes in cardiac surgery were extensively reviewed and reexamined. There are no data to conclusively indicate that outcomes of cardiac operations are related to a specific minimum number of cases performed annually by a cardiac surgeon. Each cardiothoracic surgeon should participate in a national database that permits comparison of his or her outcomes on a risk-adjusted basis with other surgeons. Until conclusive data become available that link volume to outcome, volume should not be used as a criterion for credentialing of cardiac surgeons by hospitals, managed care groups, or others. Instead, each surgeon should be evaluated on his or her individual results.

Use of reflected ultrasound in detecting pericardial effusion

Abstract Reflected ultrasound offers the clinician another diagnostic aid in the evaluation of patients with possible pericardial effusion. With its ability to detect interfaces between liquid and solid, this ultrasound technic makes it possible to demonstrate pericardial fluid both anterior and posterior to the heart. As with almost all diagnostic procedures, there are some limitations and potential difficulties. Sound waves travel poorly through air; therefore, the hyperinflated lung tissue associated with pulmonary emphysema seriously interferes with recording ultrasound echoes from the heart. In addition, although few in number, both false positive and false negative results have been obtained. Despite these problems, the clinical experience with this technic thus far has been very good. With a little experience the accuracy and reliability of this procedure is as good as, if not better than, any of the currently used radiographic methods of diagnosing pericardial effusion. Furthermore, the simplicity and safety of the commercially available ultrasound equipment reduce the examination to a simple bedside procedure that can be done in a matter of minutes. Thus, diagnostic ultrasound provides a quick, safe and fairly reliable method of detecting or excluding pericardial effusion.

Lessons learned in the management of hemolytic uremic syndrome in children

Escherichia coli O.157:H7 is a serious and common human pathogen that can cause diarrhea, hemorrhagic colitis, and the hemolytic uremic syndrome (HUS). During a massive outbreak of infection with E coli O157:H7 in January 1993 in Washington State, more than 600 people, mostly children, acquired symptomatic infection, and 37 were hospitalized with HUS at Childrens Hospital and Medical Center in Seattle, and six at other hospitals in Washington. Twenty-one (57%) required dialysis. Nineteen (51%) had significant extrarenal pathology: gastrointestinal in 14 patients (38%), cardiovascular in 13 (35%), pulmonary in 9 (24%), and neurological in 6 (16%). Most patients were managed nonoperatively, but three required total abdominal colectomy and one a left colectomy. No child had perforation. Three patients died, all of whom had multisystem disease. The authors recommend (1) that all patients with bloody diarrhea undergo microbiological evaluation for E coli O157:H7 before any surgical intervention; (2) avoidance of antibiotics and antimotility agents in patients with proven or suspected infection with E coli O157:H7 until the safety and efficacy of such interventions have been established in controlled trials; (3) that patients with E coli O157:H7 infections be evaluated for microangiopathic changes consistent with HUS in the week after onset of diarrhea; (4) nasogastric suction for severe symptoms, and frequent abdominal evaluations, tests (electrolytes/amylase), and roentgenograms to exclude treatable abdominal disorders; and (5) institution of hemodialysis for oliguria/anuria, acidosis, or rising creatinine. The authors recommend surgical exploration for toxic megacolon, colonic perforation, acidosis unresponsive to dialysis, or recurrent signs of obstruction or colonic stricture.