The effects of glucocorticoid therapy on inflammatory responses to coronary artery bypass graft surgery.

HYPOTHESIS: Delayed or reduced polymorphonuclear leukocyte (PMN) apoptosis may contribute to prolongation of systemic inflammation after cardiopulmonary bypass. BACKGROUND/OBJECTIVE: Preoperative administration of glucocorticoids has been used ostensibly to attenuate the systemic inflammation associated with cardiopulmonary bypass. Therefore, this study evaluated, in patients undergoing cardiopulmonary bypass, the efficacy of glucocorticoids in restoring peripheral blood PMN apoptosis and modulating PMN surface receptors (CD95, tumor necrosis factor receptor [TNFR]) known to be involved in proapoptotic or antiapoptotic signal transduction. DESIGN: Randomized control study. SETTING: Medical school and affiliated tertiary care hospital. PATIENTS: Thirteen patients undergoing coronary artery bypass grafting. INTERVENTION: Patients were randomly assigned to the control group (n = 7) or to receive 1 g of methylprednisolone sodium succinate on anesthetic induction (n = 6). MAIN OUTCOME MEASURES: Blood samples were drawn before induction, 20 minutes after sternotomy and bypass, immediately postoperatively, and on postoperative day 1. Isolated PMNs were incubated for 6 hours with or without the CD95 agonist CH 11. Polymorphonuclear leukocyte apoptosis was measured using propidium iodide-RNAase staining and flow cytometry. Levels of PMN cell-associated receptors (TNFR and CD95), cytokines (TNF-alpha, interleukin 6 [IL-6], IL-8, and IL-10), and soluble receptors (sTNFR1 and sTNFR2) were measured. RESULTS: In all 13 patients, spontaneous and Fas-mediated PMN apoptosis decreased more than 80% from baseline (P<.001) by postoperative day 1. Polymorphonuclear leukocyte CD95 increased (P<.003) by postoperative day 1 compared with baseline, whereas PMN TNFR was unchanged. Methylprednisolone administration did not modulate PMN apoptosis or immunocyte receptor expression; however, such treatment did decrease postoperative IL-6 secretion (P<.001) and increase postoperative IL-10 secretion (P<.001). CONCLUSIONS: The complications of major surgery include persistent inflammation, which can lead to multisystem organ failure. Polymorphonuclear leukocyte resistance to apoptosis may contribute to this process. A single preoperative dose of glucocorticoids did not effect PMN apoptosis or receptor phenotype.

Based on acute outcomes, "all arterial" coronary bypass surgery should be performed on younger elective patients.

OBJECTIVES: This study evaluated acute results as a function of the number of arterial conduits used to compare procedural differences and the subsequent effects on acute outcomes in selected patient populations. BACKGROUND: All arterial operations may provide better long-term results for younger patients undergoing coronary bypass surgery (CABG). However, concerns regarding additional morbidity when using multiple arterial conduits have inhibited their use. METHODS: The study comprised a retrospective review of patients (2,586) undergoing CABG. Group 1 consists of single artery vein graft (1,755). Group 2: two arteries were used in addition to vein grafts (209). Group 3: three or more arterial conduits were used, with or without vein grafts (116). Group 4: only vein grafts were used (506). RESULTS: Patients undergoing primarily arterial procedures, Group 2 and 3, were younger, had a better exercise profile, less history of myocardial infarction (MI), had less left ventricular dysfunction. There were also fewer emergencies, co-morbidities and associated procedures in this group. The cardiopulmonary bypass and cross clamp times were longer in those procedures with three or more arteries; however, this difference was only thirteen and fourteen minutes, respectively. Post-operative complications were higher in patients in the vein only group. The hospital stay and mortality was equivalent among groups in which an arterial bypass was used and better than those in which only vein grafts were used. CONCLUSIONS: For younger patients, "all arterial operations," require only minimal increases in ischemic and operative times, which do not affect acute outcomes.

Comparison of the flow capacity of free arterial grafts and saphenous vein grafts for coronary bypass surgery.

UNLABELLED: There is controversy regarding the flow reserve and capacity of arterial conduits to meet the needs of the myocardium. This study compared flow in 22 free arterial bypasses to 15 saphenous vein grafts in procedures involving twenty patients. To assess the maximal flow possible, (flow capacity) graft flow was measured using a calibrated pump while perfusing blood cardioplegia through the conduit and distal anastomosis during cardiac arrest (no competitive flow). This assessment was subsequently confirmed with whole blood during myocardial contraction while on cardiopulmonary bypass. Twenty-two free arterial grafts were used; 15 right internal mammary artery grafts, 4 right gastroepiploic grafts, 3 inferior epigastric artery grafts, and 3 sequential bypasses. Free arterial conduit flow ranged from 50 to 180cc/ml, with an average flow of 102.5+/-28.5ml/min as compared to saphenous vein graft flow, 102+/-28 ml/min. No correlation of flow with the conduit size was found. Arterial graft flow demonstrated a mild correlation with the size of the native coronary artery bypassed (R=0.47, P

Re-exploration for hemorrhage following open heart surgery differentiation on the causes of bleeding and the impact on patient outcomes.

OBJECTIVES: To differentiate surgical bleeding requiring re-exploration from postoperative coagulopathy and determine the differences in patient outcomes. METHODS: This was a retrospective chart review of 2,263 adult patients undergoing elective and emergency open heart procedures encompassing coronary artery bypass, valvular, and a combined procedure to determine the impact of source of bleeding leading to re-exploration. RESULTS: Eighty-two patients (3.6%) required re-exploration. Sixty-six percent had surgical bleeding; the remaining 34% were coagulopathic. Postoperative coagulopathy was associated with preoperative heparin use (37% vs. 19.9% for controls p<0.05). Re-operative procedures combined bypass/ valve (p<0.001) and prolonged cardiopulmonary bypass and aortic cross-clamp times (p<0.05) were more prevalent in the coagulopathy group. Postoperative inotrope use was increased in patients who were re-explored (p<0.001), as were cardiac, pulmonary, renal and abdominal complications (p<0.001), and in all cases those patients with medically related bleeding had worse acute outcomes than the group with surgical causes for re-exploration. The hospital stay was prolonged for both patients with surgical bleeding (23.5 days) and patients with coagulopathy (27.1 days) compared to patients not undergoing re-exploration for bleeding (12.0 days, p<0.001). Survival was 91.3% for patients with surgical bleeding, 87.5% for patients with coagulopathy, and 98.0% for all others (p<0.01). CONCLUSIONS: Severe postoperative hemorrhage is associated with significant morbidity and increased mortality. Postoperative hospital stay, morbidity, and mortality were significantly worse in patients suffering from coagulopathy when compared to those patients with hemorrhage from surgical causes.

Metastatic mucinous adenocarcinoma of the heart.

A case of metastatic mucinous adenocarcinoma to the heart is described. The patient presented with neurological symptoms consistent with an embolic cerebrovascular accident. Evaluation by the referring cardiologist at that time showed what appeared to be a left atrial myxoma. In a review of the English language medical literature, no other case of this nature was found.

Role of case structure and prior experience in a case-based surgical clerkship.

BACKGROUND: As case-based methods replaced lectures in a surgical clerkship, the influences of case structure and prior experience on learning were investigated. METHODS: Early and late third-year students randomly received different cases. "Structured" cases had data presented and summarized. "Unstructured" cases required questions to faculty for information. Multiple choice tests and differential diagnosis activities were administered. An attitudinal questionnaire gauged student perceptions. RESULTS: In both multiple choice and differential diagnosis activities, the late rotation, "unstructured" group scored higher than the "structured" group. Conversely, the early rotation, "unstructured" group scored lower than the "structured" group. Combined, rotation, and structure significantly affected both multiple choice and differential diagnosis activities (ANOVA, P < or = 0.02). Early rotation, "unstructured" students described a more enjoyable experience, despite lower evaluation scores. CONCLUSIONS: Surgical clerkship case-based learning is profoundly affected by case structure and prior clinical experience. Case-based curriculum should be tailored to accommodate these interactions.

Effects of intravenous famotidine on gastric acid secretion in patients undergoing cardiac surgery.

OBJECTIVE: To determine the effects of cardiopulmonary bypass and famotidine on gastric acid secretion in adults undergoing cardiac surgery. DESIGN: Prospective, randomized, double-blind, placebo-controlled study. SETTING: University teaching hospital. PARTICIPANTS: Eighteen patients undergoing elective cardiac surgery with cardiopulmonary bypass. MAIN OUTCOME MEASURES: Famotidine 20 mg or NaCl 0.9% placebo was administered intravenously following induction of anesthesia and placement of a nasogastric pH probe. A second dose was given 12 hours after surgery in the intensive care unit. Gastric pH was measured continuously and gastric volume was measured every 4 hours for up to 24 hours after cardiopulmonary bypass. RESULTS: Following famotidine administration, pH increased by 43% within 45 minutes and remained above 5.5 throughout the study period (p < 0.05 vs placebo and baseline). The gastric pH did not increase, but remained above 4.0 in most patients in the placebo group for up to 12 hours after cardiopulmonary bypass. Gastric volumes were on average 24% lower in the famotidine group (p > 0.05). CONCLUSIONS: Gastric acid secretion is decreased during and for 12 hours after cardiopulmonary bypass. Perioperative administration of famotidine suppresses gastric secretion in cardiac surgery patients.

Hemodynamic effects of intravenous famotidine in patients undergoing cardiac surgery.

STUDY OBJECTIVE: To determine the hemodynamic effects of famotidine in patients undergoing cardiac surgery. DESIGN: A prospective, randomized, double-blinded, placebo-controlled study. SETTING: A large university teaching hospital. PATIENTS: Twenty-one patients undergoing elective cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: The patients received a rapid intravenous bolus injection of famotidine 20 mg or saline placebo after anesthesia induction. A second dose was given 12 hours after surgery in the intensive care unit. MEASUREMENTS AND MAIN RESULTS: Serial hemodynamic measurements (heart rate, arterial blood pressure, cardiac index, pulmonary arterial pressure, central venous pressure, systemic vascular resistance) were obtained after each famotidine or placebo dose and analyzed by ANOVA: The values were not altered (p > 0.05) after intraoperative or postoperative famotidine or placebo administration. CONCLUSIONS: Rapid intravenous bolus administration of famotidine does not alter patient hemodynamics after anesthesia induction or in the intensive care unit after cardiac surgery.

Aortic valvuloplasty: an alternative for aortic insufficiency.

The authors describe a technique for aortic valve repair in patients with aortic regurgitation with excellent intermediate term results avoiding the complications of prosthetic valve replacement. Conservation of native valve tissue will obviate complications associated with prosthetic valves.

Protection of the acutely injured heart--deleterious effects of hypothermia.

This experimental study was undertaken to evaluate the hypothesis that cardioplegic arrest at 37 degrees C is superior to 10 degrees C cardioplegic arrest in the myocardial protection of an acutely injured heart. The hypothesis was tested using Sprague-Dawley rat hearts that were excised and retroperfused with Krebs-Henseleit buffer as isolated, isovolumic heart preparations. After 15 min of equilibration and baseline readings, ischemic injury of the myocardium was established by cessation of perfusion for 20 min, followed by 30 min of reperfusion to obtain cardiac measurements and verify uniformity of ventricular dysfunction. All hearts were then arrested for 30 min with continuous cardioplegia (oxygenated crystalloid cardioplegia, 4 ml/min) followed by 30 min of reperfusion. In one group (N = 12), temperature of cardioplegia was 10 degrees C. In the second group (N = 12), cardioplegia temperature was 37 degrees C. The experiments showed that in acutely injured hearts, cardioplegic arrest at 10 degrees C resulted in further deterioration in ventricular dysfunction (P < 0.01). In contrast, similarly injured hearts which underwent cardioplegic arrest at 37 degrees C showed a modest deterioration in ventricular dysfunction which did not reach statistical significance (P > 0.05). The experimental findings suggest that in the presence of acute myocardial injury, cardioplegic arrest at normothermia may provide better myocardial protection.

Bilateral adrenal hemorrhage after an open heart operation.

Bilateral adrenal hemorrhage and acute adrenal insufficiency were diagnosed after coronary bypass grafting in a 65-year-old man. The symptoms were nonspecific and easily mistaken for other postoperative complications. Diagnosis was based on finding of adrenal hemorrhage on computed tomogram and confirmed biochemically with an adrenal stimulation test. Corticosteroid therapy was curative.

Coronary revascularization in a calcified ascending aorta: using the right gastroepiploic artery.

A calcified ascending aorta makes coronary bypass surgery more difficult and is a major risk factor for perioperative strokes. We describe a technique in which coronary revascularization is achieved with an in situ right gastroepiploic artery. This approach minimizes manipulation of the diseased aorta.

Homograft valve durability: host or donor influence?

Antibiotic sterilized valves have been shown to function longer than those chemically sterilized; however, the reason remains obscure. Current hypotheses cite either retention of donor fibroblasts capable of repairing the grafted valve, or host fibroblast ingrowth into and onto the leaflet ground substance. A cryopreserved aortic homograft from a male donor was explanted from a female recipient after 10 months, and subjected to immunocytochemistry, tissue culture, and karyotyping. The leaflet bases exhibited normal morphology with an intact endothelium. The distal one-third of the leaflets was devoid of fibroblasts from the leaflet bases showed them to be of host origin. This homograft seems to have been implanted with an intact ground substance which allowed for host cell repopulation of the inner one-third of the leaflets. Perhaps donor cell viability in itself is not as important to durability as is preservation of the leaflet ground substance, but rather the presence of viable cells may be an index of the structural integrity of the collagen and elastic matrix.

Gastrointestinal complications after cardiac surgery.

Gastrointestinal (GI) complications after cardiac surgical procedures are infrequent but severe. Thirty-three GI complications were identified in 25 patients who underwent cardiac surgery during a 7-year period (2.0% incidence). The mortality rate for patients having these GI complications was 44%. Acute acalculous cholecystitis was the most lethal complication (86%). Acute pancreatitis was the most common complication (eight patients). Most patients responded well to conservative measures. Five patients had upper GI hemorrhage and three had lower GI bleeding that required more than 2 U of packed red blood cells. All patient conditions were diagnosed endoscopically and none necessitated operation. Of the remaining patients, one was operated on because of perforated duodenal ulcer, one because of perforated diverticulitis, and one because of pseudo-obstruction of the colon, and one patient underwent diagnostic laparotomy and showed negative results for presumed acalculous cholecystitis. Liver failure was fatal in all three patients in whom it occurred. GI complications correlated significantly with advanced age, prolonged bypass times, valve surgery, and the female sex. We conclude that septic GI complications--particularly acute acalculous cholecystitis and perforated viscus--after cardiac surgery are uncommon but lethal. Clinical features are often subtle, and a high index of suspicion is necessary for an early diagnosis and the institution of appropriate treatment.

Clinical experience with the Jahnke-Barron heart support.

The Jahnke-Barron heart support has proven to be a useful adjunct to coronary artery surgery by allowing an easy access to the coronary arteries while maintaining a quiet operating field. Further, the use of this device eliminates the need for a surgical assistant or a heart holder.

Tension pneumopericardium following penetrating chest injury.

A 28-year-old male developed tension pneumopericardium following penetrating paraxiphoid injury to the pericardial space. We found no previous reports of this unique problem. Pneumopericardium associated with penetrating chest trauma warrants thorough exploratory surgery to rule out direct cardiac injury.

Postoperative enhancement of urinary output in patients with acute renal failure using continuous furosemide therapy.

Three cardiac surgical patients with acute postoperative renal failure were treated with a constant infusion of furosemide (Lasix) after furosemide given in bolus proved ineffective. Furosemide given continuously brought about a prompt resolution of the oliguria and tended to hasten the resolution of acute renal failure.

Two-dimensional echocardiography in dogs. Variation of left ventricular mass, geometry, volume, and ejection fraction on cardiopulmonary bypass.

Quantitative two-dimensional echocardiography was evaluated in 39 open-chest dogs placed on cardiopulmonary bypass. The correlation coefficient of left ventricular end-diastolic volume against postmortem pressure-volume curves was r = 0.89 to 0.93 (347 measurements in 15 dogs, 0 to 24 mm Hg). Ejection fraction was validated against roller pump flow and echo left ventricular end-diastolic volume (r = 0.83, n = 13). Left ventricular mass in vivo was compared with postmortem left ventricular mass (r = 0.81 in 21 early studies, r = 0.91 in 10 later studies with updated equipment) and was found to increase with ischemic injury as well as cardiopulmonary bypass with hemodilution. Left ventricular mass increased (p less than 0.001) from 119 +/- 5 (standard error of the mean) to 138 +/- 6 gm (n = 23) after 2 1/2 hours on cardiopulmonary bypass and moderate hemodilution. With the addition of ischemic arrest, left ventricular mass increased from 119 +/- 7 to 148 +/- 11 gm (p less than 0.01, n = 8), and myocardial water content increased by 2.0% +/- 0.4%, which accounted for at least 65% of the observed mass change. Mean left ventricular wall thickness increased from 13.8 to 15.5 mm (p = 0.02) after ischemia. Ventricular shape became more spherical with increasing left ventricular end-diastolic pressure. We conclude that two-dimensional echocardiography can be reliably used for accurate, serial measurements in physiological studies. The demonstrated variability in left ventricular mass is important, yet frequently ignored. Recognizing left ventricular mass changes may facilitate the detection of myocardial injury reflected as edema.

Effect of cardiopulmonary bypass and global ischemia on human and canine left ventricular mass: evidence for interspecies differences.

Previous studies in dogs suggest that global ischemia with cardiopulmonary bypass causes increased left ventricular (LV) mass and water content. To investigate effects in humans, we developed a simplified method for mass determination by intraoperative two-dimensional echocardiography. LV mass was measured as echocardiographic short-axis myocardial area. This was validated by linear regression versus postmortem LV mass in 10 dogs (r = 0.89) and versus single-plane angiography in 18 patients (r = 0.73). According to this method, there was no change in LV mass (209 gm versus 208 gm; NS) at constant preload in 20 patients during routine operations (eight coronary revascularizations, 10 aortic valve replacements, and two mitral valve replacements). The same method used in 10 dogs after 2 hours of bypass, 60 minutes of normothermic global ischemia, and reperfusion revealed an LV mass increase from 113 +/- 13 gm (SE) to 150 +/- 16 gm (p less than 0.01) at matched preload. In addition, in 14 dogs after 2 hours of bypass alone, LV mass was unchanged (98 +/- 5 gm versus 101 +/- 5 gm; NS) at matched preload. Data recently derived from a separate study in our laboratory revealed a statistically significant increase in canine LV mass when conditions of human cardiopulmonary bypass and cardioplegic arrest were reproduced. We conclude that uncomplicated cardiac operations in humans do not alter LV mass. This supports the safety of crystalloid cardioplegia in humans. While present evidence is not conclusive, it appears that the threshold for edema formation after ischemic injury may be higher in humans than it is in dogs. The clinical relevance of studies of cardioplegia in edematous dog hearts thus deserves careful scrutiny.