Anomalous right subclavian artery aneurysms. Report of 3 cases, with a review of the literature.

During the past 2 years, 3 anomalous right subclavian artery aneurysms have been encountered at the St. Louis Heart Institute. The 1st patient, a 72-year-old woman, was found to have an asymptomatic 5-cm-diameter anomalous right subclavian artery aneurysm after surgery for suspected rupture of an abdominal aortic aneurysm. Resection was not attempted because of her poor cardiopulmonary and renal condition. One year later, the patient remains alive with marked cardiopulmonary limitations. The 2nd patient, a 77-year-old man, experienced dysphagia and severe weight loss because of a 14-cm-diameter aneurysm. Three days after undergoing surgical repair, he required reoperation for graft occlusion with right upper-extremity ischemia. Six months after hospital discharge, he died of pulmonary insufficiency and metastatic colon cancer. The 3rd patient, a 73-year-old woman, required emergency surgical intervention because of acute rupture and hypovolemic shock. Thirteen days later, she died of aspiration, asphyxia, and cardiac arrest. On the basis of our experience and a review of the literature, we conclude that symptomatic anomalous right subclavian artery aneurysms are rare, and that surgical intervention entails a relatively high morbidity and mortality rate. If long-term survival is anticipated, associated medical illnesses should be considered before surgery is undertaken.

Relation of silent myocardial ischemia after coronary artery bypass grafting to angiographic completeness of revascularization and long-term prognosis.

The prevalence and characteristics of silent myocardial ischemia as detected by 24-hour ambulatory electrocardiography ST-segment depression were prospectively assessed in 94 patients examined early (1 to 3 months) and 184 patients examined late (12 months) after coronary artery bypass grafting (CABG), and followed for a mean of 48 +/- 11 (range 4 to 62) months. The relation of ambulatory electrocardiographic silent ischemia to evidence of completeness of revascularization as defined by cardiac angiography performed 1 and 12 months after CABG, and to prognosis by follow-up of adverse clinical events was analyzed. Silent ischemia was detected early in 20% (19 of 94) and late in 27% (50 of 184) of patients, and showed a mean frequency of episodes ranging from 6 to 10 episodes/24 hours with a mean duration ranging from 15 to 23 minutes. The circadian distribution of episodes disclosed a significant peak of ischemic activity during the period of 6 A.M. to noon and a secondary peak between 6 P.M. and midnight (p less than 0.01 and p less than 0.001, respectively). Silent ischemia was not found by univariate analysis to be associated with graft or anastomotic site occlusions, low graft flow rates, grafted arteries with significant distal residual stenoses or ungrafted stenotic native coronary arteries. Kaplan-Meier analysis of time to cardiac event showed that silent ischemia was not predictive of an adverse clinical event in the early years after CABG. Cox regression analysis of 30 covariates only disclosed age (relative risk 1.06 [95% confidence interval, 1.01 to 2.94]) as having an effect on time to adverse clinical event.(ABSTRACT TRUNCATED AT 250 WORDS)

Palliation of carcinoid heart disease.

The clinical manifestations of the carcinoid syndrome have been known for 35 years. Median survival in patients with carcinoid syndrome, although dependent on several factors, including the extent of liver metastases, is in the range of four years. In this setting, a frequent cause of death is right-sided cardiac dysfunction. When this occurs, the only definitive palliation is surgical in patients with this slow-growing tumor. Successful palliation was provided by tricuspid valve replacement and pulmonary valvoplasty in a patient with carcinoid heart disease and extensive liver metastases. This emphasizes the importance of surgery in selected patients with this slow-growing tumor.

Multiple aortic tears treated by primary suture repair.

Blunt trauma to the chest with aortic tear is not an unusual sequela of rapid deceleration. Multiple aortic tears in a viable patient are unusual. A case is reported where multiple aortic lacerations were repaired without the use of prosthetic material. The use of a primary suture repair of aortic injuries is advocated for simple aortic tears not extending proximally to the arch whether they be single or multiple.

Quantitation of CK-MB release: diagnostic utility in coronary artery bypass grafting.

The quantitative release of creatine kinase (CK-MB) into the circulation of 97 patients receiving between three and five distal aorto-coronary bypass grafts was used to quantitate the minimal operative myocardial injury and to determine the diagnostic utility of this measurement in the detection of perioperative myocardial infarction. Independently read electrocardiography (ECG) was used to define infarction. The +/- SD confidence range for traumatized heart tissue based on 88 patients without infarction was 0-40.5 g equivalents. Six patients with perioperative myocardial infarction had values significantly above this range. Three patients with indeterminate ECG both released CK-MB significantly above the reference range and were clearly abnormal from a clinical standpoint.

Improved myocardial preservation by control of the oxidation-reduction potential.

Simple cold storage remains the current method of preservation of human heart allografts between removal and transplantation, but this technique is not adequate for prolonged periods of preservation. An alternative to cold storage is machine perfusion of the isolated organ. Although this technique has yielded promising results in kidney preservation, there is limited experience with the heart. One factor limiting the effectiveness of perfusion preservation is the toxicity of oxygen free radicals generated during the perfusion. The generation and reduction of these radicals results in an electron transfer, producing an electrochemical potential known as the redox potential. This study examines the role of machine perfusion in heart preservation with and without the use of a new electrochemical cell that is able to control the redox potential during the perfusion. Hearts were preserved for twenty-four hours by either simple cold storage (Group I), or by machine perfusion with redox monitoring (Group II), or redox control (Group III). Control of the oxidation-reduction potential of the perfusate during machine perfusion of isolated hearts resulted in significantly improved systolic and diastolic function after perfusion compared to hearts that underwent machine perfusion without redox control or simple cold storage.

Heart graft arteriosclerosis. An ominous finding on endomyocardial biopsy.

Heart graft arteriosclerosis remains a severe and irreversible complication of allogeneic heart transplantation despite prophylactic therapy. Immunologically mediated endothelial damage has been proposed as a stimulus for the development of graft arteriosclerosis. The vascular lesions may accumulate large amounts of lipid resembling atheromas, or may be purely proliferative, as illustrated in the case of a 42-year-old heart transplant patient who developed slowly progressive graft dysfunction at eight months posttransplantation. Endomyocardial biopsy ten months posttransplantation revealed proliferative arteriolar occlusion, while changes on the coronary angiogram were minimal. Repeat biopsy at eleven months showed ischemic myocardial necrosis. The patient expired shortly thereafter. On postmortem examination, proliferative graft arteriosclerosis affecting both intramural and epicardial vessels was present, along with massive biventricular infarction. Tissue immunofluorescence studies demonstrated extensive vascular deposition of immunoglobulin and complement. We propose that (1) the presence of proliferative arteriolar occlusion on endomyocardial biopsy is predictive of poor heart graft survival; (2) proliferative graft arteriosclerosis may appear as advanced small vessel disease before extensive large vessel involvement is detected by coronary angiogram; and (3) immunofluorescence results support an immune-mediated mechanism of vascular injury in proliferative heart graft arteriosclerosis.

Oxidation-reduction maintenance in organ preservation.

The isolated perfused organ is more sensitive to the toxicity of oxygen since hypothermia reduces the activities of enzymes responsible for minimizing oxygen toxicity. To protect the organ under these conditions reducing agents must be added to the perfusate. Quantitation of the resulting reduction is best obtained by measurement of the oxidation-reduction potential of the perfusate. A device was designed for this purpose and, by electrochemical principle, controlled reduction of the oxidized form of the oxidation-reduction couple was affected. Kidneys were perfused with cryoprecipitated plasma. With the electrochemical cell in the circuit, the oxidation-reduction potential of the perfusate was adjusted by the addition of ascorbic acid and glutathione and the cell was driven by a battery-powered potentiostat. Kidneys subjected to 60 minutes of warm ischemia had optimal survival at -20 mV. Preservation for six days in a monitored group had no survivors, whereas kidneys with oxidation-reduction support maintained life. Optimal oxidation-reduction support maintained life. Optimal oxidation-reduction was at or near -17 mV. These data show a requirement of an optimal oxidation-reduction potential to reverse warm ischemia damage and to prolong the period of ex vivo preservation of isolated perfused organ.

Intraoperative myocardial protection: a comparison of blood and asanguineous cardioplegia.

Cardiac arrest was achieved in 84 patients using asanguineous cardioplegia and in 97 patients using cold blood potassium cardioplegia. The patient groups were similar in age, sex ratio, and preoperative risk factors. Other than the cardioplegic solution used, the conduct of each operation was identical. There were no differences in mean total pump time (118 minutes for the asanguineous cardioplegia group versus 117 minutes for the cold blood cardioplegia group) or cross-clamp time (73.5 versus 70 minutes, respectively). However, the blood cardioplegia group had a greater number of distal anastomoses per patient (3.9 versus 3.7; p less than 0.05). Myocardial protection was assessed clinically and by serial electrocardiograms. Cellular integrity was determined by release of the myocardial isoenzyme of serum creatine kinase (CK-MB). Cellular morphology was studied in 6 randomly selected patients in each group by electron microscopic examination of left ventricular myocardial samples obtained before and after bypass. Three patients given blood cardioplegia and 5 given asanguineous cardioplegia required intraaortic balloon counterpulsation at termination of bypass. There were no ultrastructural changes in either group. Electrocardiographic changes (Minnesota code) occurred in 12 of 84 patients receiving asanguineous cardioplegia versus 12 of 97 patients receiving cold blood potassium cardioplegia. To maintain a satisfactory cardiac index (greater than 2.0 L/min/m2), 38 of 84 patients given asanguineous cardioplegia versus 25 of 97 patients given blood cardioplegia required inotropic support up to 24 hours postoperatively (p less than 0.05). Infarct size determined from CK-MB release was significantly greater (p less than 0.05) in patients given asanguineous cardioplegia (36.27 gm-equivalents) than in those given blood cardioplegia (26.7 gm-equivalents).(ABSTRACT TRUNCATED AT 250 WORDS)

An experimental evaluation of nucleotide enhancement techniques for kidney transplantation.

The effect of various nucleotide-enhancing agents on renal function and intracellular nucleotide levels was evaluated in a canine autotransplant model. Thirty-five dogs (18-28 kg) underwent left nephrectomy and 30 min of warm ischemia followed by Collins C-4 flush and 24 hr of cold-storage preservation. Heterotopic autotransplantation and immediate contralateral nephrectomy was then performed. Seven equal groups were evaluated: group A--controls, group B--adenosine pretreatment (1.0 g), group C--dipyridamole pretreatment (10 mg), group D--adenosine (1.0 g), and dipyridamole (10 mg) pretreatment, group E--adenosine (200 mg) and EHNA (2.5 mg/kg) pretreatment, group F--adenosine (200 mg) and EHNA (2.5 mg/kg) in the Collins C-4 flush, and group G--adenosine (200 mg) and EHNA (2.5 mg/kg) at the time of autotransplantation. All kidneys underwent cortical biopsies at the end of preservation and 1 hr after restoration of blood flow for determinations of AMP, ADP, and ATP. In the pretreatment groups (groups B through E) there was 60% graft survival whereas the controls (group A) and the groups treated after ischemia (groups F and G) had 0, 0, and 20% graft survival, respectively. In groups B and E, ATP levels were greater than controls after preservation and 1 hr after restoration of blood flow. Group C AMP and ADP levels and group D energy charge were greater than controls in the post-transplantation biopsies. Administration of adenosine and EHNA after ischemia was not associated with increased intracellular nucleotide levels. One hour post-transplantation biopsies demonstrated greater ability to regenerate cortical nucleotides in the surviving animals but no absolute value could be identified as a predictor of viability. In conclusion, pretreatment with adenosine, dipyridamole, and EHNA alone and in combination is beneficial in ischemically injured kidneys undergoing cold-storage preservation.

The importance of biventricular failure in patients with postoperative cardiogenic shock.

To evaluate the importance of severe biventricular failure in patients with postcardiotomy ventricular failure, we analyzed the data from 30 patients treated with ventricular assist devices (VADs) over a five-year period. All patients had profound postoperative ventricular failure refractory to drugs and an intraaortic balloon (IAB). Evaluation of preoperative ventricular function did not allow prediction of which patients would require VADs. However, the development of perioperative myocardial infarction was an important determinant of the need for postoperative support with a VAD. Twenty patients received only a left VAD (LVAD). Four of them had isolated left ventricular failure; 3 were weaned, and 2 survived. None of the 16 patients with biventricular failure who received only an LVAD were weaned. Ten other patients with biventricular failure received biventricular support, either with a right VAD and IAB, or with two VADs. Of these 10 patients, 5 were weaned and 3 survived. Considering all 26 patients with biventricular failure, those receiving biventricular mechanical support (10) had a better chance (p less than 0.025) of being weaned (5/10) and surviving (3/10) than those who received only an LVAD (0/16). We conclude that biventricular failure is common in patients with postcardiotomy ventricular failure and is often the result of perioperative infarction. While patients with isolated left ventricular failure did well with an LVAD only, those with biventricular failure required biventricular mechanical support for survival.

A comparison of ductal management techniques in an in situ canine pancreas model.

Twenty-five dogs underwent right pancreatectomy leaving the tall of the pancreas in situ. Five equal groups underwent either intraperitoneal drainage (open-duct group), duct ligation, acrylate glue occlusion, neoprene glue occlusion, or Roux-en-Y pancreaticojejunostomy. On day 21 the tall of the pancreas was removed and on day 28 the dogs were killed. Daily serum glucose and amylase and biweekly insulin determinations were performed, and intravenous glucose tolerance tests ( IVGTTs ), with simultaneous insulin assays, were carried out before and after distal pancreatectomy. The mean daily blood glucose level prior to distal pancreatectomy was 95.6 +/- 3.2 mg/dL in the open-duct group, 91.6 +/- 3.0 mg/dL in the ligation group, 94.0 +/- 4.0 mg/dL in the acrylate group, 226.3 +/- 56.6 mg/dL in the neoprene group, and 94.1 +/- 2.6 mg/dL in the Roux-en-Y group. Mean K values (rate constant of glucose clearance) were as follows: open-duct group, -0.907+ +/- 0.240% per minute; ligation group, -1.024% +/- 0.253% per minute; acrylate group, -0.820% +/- 0.087% per minute; neoprene group, -0.526% +/- 0.186% per minute; and Roux-en-Y group, -1.399% +/- 0.566% per minute (normal, -2.201% +/- 0.388% per minute). Insulin release during IVGTT (basal to peak insulin difference) was greatest in the open-duct and Roux-en-Y groups. Although glucose clearance and insulin release were optimal with pancreaticojejunostomy, peripancreatic complications developed in two of the five dogs. In conclusion, the open-duct technique and Roux-en-Y pancreaticojejunostomy result in optimal endocrine function in this in situ model. Due to its simplicity, the open-duct technique is most suitable for further laboratory investigations of segmental pancreatic transplantation.

Global left ventricular impairment and myocardial revascularization: determinants of survival.

Of 2,782 patients undergoing isolated coronary artery bypass grafting (CABG) from 1970 through 1979, 196 exhibited severe global impairment of left ventricular (LV) wall motion preoperatively (LV score, greater than or equal to 15; ejection fraction, less than 0.40 in all patients and less than 0.30 in 67%). The initial 89 patients (Group 1) underwent CABG without potassium chloride cardioplegia. The subsequent 107 patients (Group 2) were given potassium chloride cardioplegia intraoperatively. Group B patients received more grafts per patient (3.1 versus 2.5; p less than 0.001) and were completely revascularized more often (72.9% versus 58.4%; p less than 0.05). Operative mortality was lower in Group B (3.7% versus 12.4%; p less than 0.025), and 5-year cumulative survival was better in Group B (88.8% versus 63.9%; p less than 0.0001). Preoperative congestive heart failure resulted in higher operative mortality (14.3% versus 4.5%; p less than 0.05) and lower 5-year survival (65.0% versus 81.8%; p less than 0.02). Complete revascularization led to higher 5-year survival (82.2% versus 66.0%; p less than 0.02) but did not alter operative mortality significantly (6.9% versus 9.1%). Potassium chloride cardioplegia may influence operative survival favorably by reducing perioperative myocardial infarction in patients with severe LV dysfunction. Long-term survival relates to completeness of revascularization and severity of congestive heart failure as variables independent of methods of myocardial protection.

High incidence of myocarditis by endomyocardial biopsy in patients with idiopathic congestive cardiomyopathy.

Thirty-five patients with unexplained congestive heart failure were evaluated with endomyocardial biopsy. Utilizing microscopic, ultrastructural and immunofluorescent studies, samples were classified as exhibiting either no inflammation (cardiomyopathy) or active lymphocytic myocarditis, grade I to IV. Twenty-two (63%) of the patients had inflammatory changes. Of these 22 patients, 18 had low grade I or II inflammation, 7 were treated with immunosuppressive agents with improvement in 5 and stabilization in 1. One patient died of progressive congestive heart failure. Three of four patients with high grade III or IV myocarditis died after a fulminant course. The results suggest that inflammatory myocarditis may be more common than previously suspected and add evidence that there may be ongoing inflammation in many cases of congestive cardiomyopathy.