Shumway Ne

Treatment of patients with aortic dissection presenting with peripheral vascular complications.

The Incidence of peripheral vascular complications in 272 patients with aortic dissection during a 25-year span was determined, as was outcome after a uniform, aggressive surgical approach directed at repair of the thoracic aorta. One hundred twenty-eight patients (47%) presented with acute type A dissection, 70 (26%) with chronic type A, 40 (15%) with acute type B, and 34 (12%) with chronic type B dissections. Eighty-five patients (31%) sustained one or more peripheral vascular complications: Seven (3%) had a stroke, nine (3%) had paraplegia, 66 (24%) sustained loss of a peripheral pulse, 22 (8%) had Impaired renal perfusion, and 14 patients (5%) had compromised visceral perfusion. Following repair of the thoracic aorta, local peripheral vascular procedures were unnecessary in 92% of patients who presented with absence of a peripheral pulse. The operative mortality rate for all patients was 25% ± 3% (68 of 272 patients). For the subsets of individuals with paraplegia, loss of renal perfusion, and compromised visceral perfusion, the operative mortality rates (± 70% confidence limits) were high: 44% ± 17% (4 of 9 patients), 50% ± 11% (11 of 22 patients), and 43% ± 14% (6 of 14 patients), respectively. The mortality rates were lower for patients presenting with stroke (14% ± 14% [1 of 7 patients]) or loss of peripheral pulse (27% ± 6% [18 of 66 patients]). Mul-tivariate analysis revealed that impaired renal perfusion was the only peripheral vascular complication that was a significant independent predictor of Increased operative mortality risk (p = 0.024); earlier surgical referral (replacement of the appropriate section of the thoracic aorta) or more expeditions diagnosis followed by surgical renal artery revascularization after a thoracic procedure may represent the only way to Improve outcome in this high-risk patient subset. Early, aggressive thoracic aortic repair (followed by aortic fenestration and/or abdominal exploration with or without direct visceral or renal vascular reconstruction when necessary) can save some patients with compromised visceral perfusion; however, once visceral Infarction develops, the prognosis Is also poor. Increased awareness of these devastating complications of aortic dissection and the availability of better diagnostic tools today may Improve the survival rate for these patients In the future. The initial surgical procedure should Include repair of the thoracic aorta in most patients.

SERIAL TRANSVENOUS BIOPSY OF THE TRANSPLANTED HUMAN HEART IMPROVED MANAGEMENT OF ACUTE REJECTION EPISODES

Abstract One hundred and nineteen percutaneous transvenous cardiac biopsy procedures have been performed in sixteen patients after heart transplantation. Serial cardiac biopsies have been used to monitor acute rejection episodes in twelve of these patients, eleven of whom are alive 1-13 months after transplantation. 37 acute rejection episodes were diagnosed from histological examination of the biopsy specimens, and 35 of these episodes were successfully reversed by augmentation of immunosuppression. Reversal of acute cardiac allograft rejection was confirmed by the restoration of histologically normal endomyocardium. Serial percutaneous transvenous endomyocardial biopsy is simple, safe, and effective. It is readily accepted by patients, and represents an important advance in human cardiac transplantation.

Surgical management of life-threatening ventricular arrhythmias in patients with coronary artery disease.

Twenty-one patients with coronary artery disease and severe, symptomatic ventricular arrhythmias underwent cardiac surgery after failure of medical management. All had coronary artery disease and either localized areas of severe hypokinesis (three patients), or ventricular aneurysms (18 patients) documented angiographically prior to surgery. Operation within one month after acute infarction resulted in an 80%percnt; in-hospital mortality, whereas operationmore than one month postinfarction showed a 20%percnt; mortality. Operative treatment that included myocardial resection had a significantly lower mortality (P < 0.05) than that which did not. With an average of 36.5 months of follow-up, 13 of the 21 patients were long-term survivors, despite the persistence of ventricular arrhythmias. Surgical treatment which includes myocardial resection and occurs more than one month after infarction should be considered in patients with symptomatic ventricular arrhythmias and severe, well-localized left ventricular wall motion abnormalities.

A hemodynamic and Doppler echocardiographic study of ventricular function in long-term cardiac allograft recipients. Etiology and prognosis of restrictive-constrictive physiology.

Conventional hemodynamic measurements and Doppler echocardiography were used to assess ventricular physiology of the human cardiac allograft and to examine the influence of pertinent clinical factors on chronic myocardial performance. Sixty-four patients (18-55 years old; mean, 39 years) undergoing routine annual hemodynamic assessment were studied. Blood-flow velocity properties across the mitral, tricuspid, and aortic valves were analyzed from Doppler ultrasound recordings. Ten of these patients had elevated diastolic pressures associated with a sharp early diastolic dip followed by an exaggerated and abrupt rise in pressure, consistent with restrictive-constrictive ventricular physiology. Left ventricular dP/dt and stroke volume were lower in these patients compared with the other 54 patients. Doppler echocardiographic indexes of left ventricular filling and ejection in these 10 patients differed significantly. Isovolumic relaxation time and pressure half-time were shorter, peak early mitral and tricuspid flow velocities were higher, and mean aortic flow velocity and acceleration were lower. A higher rejection incidence was the only demonstrable clinical factor associated with impaired ventricular function. Doppler echocardiography may, therefore, noninvasively identify patients with hemodynamic evidence of restrictive-constrictive physiology. This abnormality occurs in approximately 15% of allograft recipients, is associated with impaired systolic performance, and may be related to rejection incidence.

TWENTY-EIGHT CASES OF HUMAN HEART-LUNG TRANSPLANTATION

Between March, 1981, and August, 1985, twenty-eight heart-lung transplant operations were done in 27 patients at a single institution. 8 patients died in the perioperative period and adhesions related to previous thoracic surgery proved to be a major risk factor for postoperative haemorrhage. Obliterative bronchiolitis developed in half of the 20 long-term survivors, a mean of 11.2 months (range 2-35 months) after surgery: 4 of these patients died, 3 are functionally limited, 2 were successfully treated with corticosteroids, and the remaining patient was successfully retransplanted. The other 10 long-term survivors returned to a normal life with essentially normal pulmonary function measured at a mean of 22.6 months (range 4-42 months) after transplantation. All the surviving patients have evidence of renal impairment related to cyclosporin nephrotoxicity. The results indicate that, although heart-lung transplantation is compatible with essentially normal long-term pulmonary function, the procedure should not yet be regarded as a routine clinical intervention.

An important complication of Hancock mitral valve replacement in children.

SUMMARY Nine children ages 2-15 years have undergone mitral valve replacement (MVR) with Hancock porcine heterograft valves for severe mitral insufficiency. The etiology of the mitral valve disease was rheumatic in two patients, and congenital in seven. Porcine valve sizes ranged from 19-31 mm. Follow-up has been from 1.6 to 6.1 years (mean, 4.3 years). All nine children have had marked postoperative improvement, no thromboembolic complications despite no long-term anticoagulations, and no episodes of endocarditis. There have been no early or late deaths. Although six of the nine patients remain asymptomatic, three others developed severe fibrocalcific obstruction of the heterograft, requiring valve re-replacement at 3.5, 3.6, and 4.8 years following the initial valve replacement. This complication has not been previously reported in children. It is a factor that must be considered when deciding on MVR for children and their postoperative management.

Determinants of Operative Mortality for Patients Undergoing Aortic Valve Replacement

The influence of 35 preoperative and intraoperative characteristics on operative mortality risk after 1,479 isolated aortic valve replacement procedures (1967 to 1981) was investigated utilizing univariate and multivariate logistic regression analyses. Mean age at operation was 58 +/- 13 years; 72% of patients were men. Physiology was classified as aortic stenosis (58%), regurgitation (30%), or both (9%). The overall operative mortality rate was 7% +/- 1%, but there were substantial differences in operative mortality rates among physiological subgroups (aortic regurgitation, 10% +/- 2%; aortic stenosis, 6% +/- 1%; stenosis/regurgitation, 5% +/- 2%). Independent determinants of operative mortality rate in the entire group were advanced New York Heart Association functional class, renal dysfunction, physiological subgroup, atrial fibrillation, and older age. In the aortic regurgitation subgroup, functional class, atrial fibrillation, and operative year were independent predictors. In the aortic stenosis subgroup, the significant determinants were functional class, renal dysfunction, age, prosthetic valve dysfunction, and absence of angina. Concomitant coronary bypass grafting, previous operation, endocarditis, and ascending aortic replacement had no independent predictive effect on operative mortality rate. Thus, the early results of aortic valve replacement can be related to several specific variables describing the functional and physiological status of the patient. Operative mortality rate is not independently related to previous operation or concomitant operative procedures. Specific differences in risk factors exist among the various physiological subgroups, probably reflecting the pathophysiology of the different hemodynamic lesions. This information should provide for a more rational approach to aortic valve replacement, at least in terms of early risk/benefit deliberations.

The status of cardiac transplantation, 1975.

Since December 1967, 263 human cardiac transplant operations have been performed throughout the world. Eighty-two of these were performed at Stanford University Medical Center. In 1974, 27 such operations were performed, 15 at Stanford. Survival rates for the entire Stanford series are 48% at one year and 25% at three years; survival rates at one and three years for patients surviving the first three critical months after transplantation are 77% and 42%, respectively. Recipients under the age of 55 years, with New York Heart Association Class IV cardiac disability, are selected for transplant procedures according to criteria dictated by experience over the past seven years. A routine immunosuppressive regimen for organ transplantation, incorporating prednisone, azathioprine, and antithymocyte globulin is employed early postoperatively, and prednisone and azathioprine are used for indefinite maintenance therapy. Acute cardiac graft rejection in nearly all recipients is diagnosed by clinical signs, electrocardiographic changes, and percutaneous transvenous endomyocardial biopsy. Ninety-five percent of acute rejection episodes are reversible with appropriate immunosuppressive treatment, but infectious complications are common and have accounted for 56% of all postoperative deaths. The Stanford experience in cardiac transplantation has demonstrated the potential therapeutic value of this procedure. Maximum survival now extends beyond five years. Satisfactory graft function has been documented in long-term surviving patients, the majority of whom have enjoyed a high degree of social and physical rehabilitation.

COMBINED HEART AND LUNG TRANSPLANTATION

Combined heart-lung transplantation has now been carried out in 27 patients at Stanford University Medical Center. All recipients had suffered from pulmonary hypertension, either primary or the result of Eisenmengers syndrome. The one-year survival has been approximately 70%. All survivors returned to normal activity, though later respiratory difficulty has been encountered in some of these patients and has required retransplantation in one. These late occurrences are likely the result of inadequate control of rejection. Heart and lung transplantation has been shown to be an effective therapy for otherwise progressively fatal pulmonary conditions, and, in the case of Eisenmengers syndrome, has presented a therapeutic avenue for the first time. The late complications encountered in some of these patients can probably be averted with increased experience.

CORRELATION OF HISTOCOMPATIBILITY MATCHING WITH GRAFT REJECTION AND SURVIVAL AFTER CARDIAC TRANSPLANTATION IN MAN

Abstract Lymphocytes of donors and recipients were HL-A typed for 20 specificities in thirty cases of cardiac transplantation. ABO blood-group compatibility and a negative lymphocyte crossmatch were present in all cases. Standard postoperative immunosuppression including azathioprine, prednisone, and antilymphocyte or antithymocyte globulin was used. The number of HL-A incompatibilities ranged from one to four. There was no significant relationship between number of mismatches and postoperative survival, rejection history, or clinical status. The most striking finding was that HL-A mismatching does not preclude long-term survival with satisfactory graft function. Three of four recipients living more than 2 years after transplantation were mismatched for four antigens.