Effectiveness of bi-atrial pacing for reducing atrial fibrillation after coronary artery bypass graft surgery

Atrial fibrillation (AF) is common after cardiac surgery and adds significant cost and morbidity. The use of prophylactic pacing strategies to prevent post-operative AF has been controversial. We previously performed a pilot study which suggested that the combination of beta-blockers and bi-atrial pacing (BAP) may reduce AF after cardiac surgery. We prospectively randomized 118 patients to continuous BAP for up to 96 hours post-operatively versus standard therapy. All patients were treated with beta-blockers as tolerated. Patients were paced in the AAI mode at a rate of 100 pulses per minute. The primary endpoint of the study was the occurrence of sustained AF (>10 minutes). There was a significant reduction in the incidence of AF in the BAP group among patients undergoing coronary artery bypass graft surgery with or without aortic valve replacement (35 % vs. 19 % AF; OR=0.38, 95 % CI 0.15, 0.93; p <0.05). Including patients undergoing isolated aortic valve surgery (n=7), there remained a strong trend toward a reduction of AF with pacing (no atrial pacing [NAP] vs. BAP; 35 % vs. 21 % AF; OR=0.48, 95 % CI 0.21, 1.11; p=0.08). Patients age 70 or greater benefited most from pacing (NAP vs. BAP; 55 vs. 25 % AF; p<0.05), while those less than 70 years of age did not (17 vs. 18 % p=NS). There was a significant reduction in the amount of time spent in the intensive care unit among patients receiving BAP (50+/-40 vs. 37+/-25 h; p<0.05).BAP together with beta-blockade after coronary artery bypass graft surgery reduces the incidence of post-operative atrial AF. Elderly patients (age 70 or greater) appear to benefit most, and may be a group to whom this therapy should be targeted.

Off-pump versus on-pump coronary artery bypass surgery: a case-matched comparison of clinical outcomes and costs

BACKGROUND

Results of off-pump coronary artery bypass (OPCAB) surgery have demonstrated trends toward fewer complications, faster recoveries and lower costs compared with on-pump coronary artery bypass (ONCAB) surgery. The validity of such comparisons, however, may be impacted by differences in preoperative risk factors between the two surgeries.

METHODS

A total of 76 OPCAB surgery patients were case-matched (by age, sex and Society of Thoracic Surgeons' risk scores) with an equal number of patients who underwent ONCAB surgery by the same surgeon. Postoperative clinical parameters (time on mechanical ventilation, number of blood transfusions, peak cardiac enzyme levels and metabolic acidosis) and outcomes data (intensive care unit and overall in-hospital lengths of stay, perioperative myocardial infarction, atrial fibrillation, stroke, reoperation for bleeding and mortality) were analyzed, and the variable and total costs for each patient were calculated.

RESULTS

OPCAB patients required less mechanical ventilation and fewer blood transfusions and had lower peak creatinine phosphokinase levels, as well as a reduced incidence of metabolic acidosis. There were trends toward both shorter intensive care unit and overall in-hospital lengths of stay for OPCAB patients. The average total cost for this group was 20.5% less than for ONCAB patients. There were no differences in rates of atrial fibrillation, myocardial infarction, reoperation for bleeding, stroke or mortality.

CONCLUSIONS

By reducing the need for mechanical ventilation, transfusions and intensive care unit and overall in-hospital lengths of stay, OPCAB surgery decreases the use of limited and costly resources without increasing risks. These advantages do not appear to be related to patient selection.

Successful coronary artery bypass surgery in a patient with AIDS

We report the case of a 47-year-old man with AIDS who underwent a successful quadruple coronary artery bypass operation. The improving prognosis of patients with HIV/AIDS, in addition to the reported incidence of plasma lipid abnormalities in patients receiving protease inhibitors, are laying the groundwork for a larger population in which premature coronary artery disease develops. Operative risk, immunosuppressive effect of cardiopulmonary bypass, and practical considerations in the care of these patients are discussed.

Unusual primary tumors of the heart

Primary tumors of the heart, with the exception of atrial myxomas, occur rarely; tumors metastatic to or directly invasive of the heart are far more common. About 75% of primary tumors are benign, and 75% of these are atrial myxomas. The benign tumors include rhabdomyomas, fibromas, papillary fibroelastomas, hemangiomas, pericardial cysts, lipomas, hamartomas, teratomas, mesotheliomas, and paragangliomas or pheochromocytomas. The last 3 may also be malignant. The malignant tumors consist of various sarcomas: myxosarcoma, liposarcoma, angiosarcoma, fibrosarcoma, leiomyosarcoma, osteosarcoma, synovial sarcoma, rhabdomyosarcoma, undifferentiated sarcoma, reticulum cell sarcoma, neurofibrosarcoma, and malignant fibrous histiocytoma. Cardiac tumors produce a large variety of symptoms through any of 4 mechanisms. Their mass can obstruct intracardiac blood flow or interfere with valve function. Local invasion can lead to arrhythmias or pericardial effusions with tamponade. Bits of tumor can embolize, causing systemic deficits when the tumors are on the left side of the heart. Finally, the tumors may cause systemic or constitutional symptoms. Some tumors, of course, produce no symptoms and become evident as incidental findings. The most useful diagnostic tool is the echocardiogram, which in almost all cases precisely locates the tumor and defines its extent. The echocardiographic appearance may also allow quite accurate prediction of the tumor type and whether it is malignant or benign. Magnetic resonance imaging serves as the next most important test where the density of T1 and T2 images may allow tumor cell type identification. With few exceptions, these tumors require operative excision. Most benign tumors can be resected completely; a few, because of their large size, cannot be, and only tumor debulking may be possible. Heart transplantation should be considered for these patients. Many of the malignant tumors cannot be resected completely, either because of the extent of local spread and invasion or because of the frequent distant metastases. Transplantation may also be an option for those with extensive local disease. The long-term results for resected benign tumors are excellent; the long-term results for sarcomas are very poor, and there are few survivors. For patients with unresectable sarcomas, radiation and chemotherapy may be used, but without great expectation of successful results.

Evaluation of right atrial and biatrial temporary pacing for the prevention of atrial fibrillation after coronary artery bypass surgery

OBJECTIVES

The purpose of this study was to determine if atrial pacing is effective in reducing postoperative atrial fibrillation (AF).

BACKGROUND

Atrial fibrillation after coronary artery bypass grafting (CABG) is a common problem for which medical management has been disappointing. Atrial-based pacing has become an attractive nonpharmacologic therapy for the prevention of AF.

METHODS

Sixty-one post-CABG patients (mean age = 65 years) were randomized to one of three groups: no atrial pacing (NAP), right atrial pacing (RAP) or biatrial pacing (BAP). Each patient had one set of atrial wires attached to both the right and left atria, respectively, at the conclusion of surgery. Patients in the RAP and BAP groups were continuously paced at a rate of 100 pulses per minute for 96 h or until the onset of sustained AF (>10 min). All patients were monitored with Holter monitors or full disclosure telemetry to identify the onset of AF. The primary end point of the study was the first onset of sustained AF.

RESULTS

There was no significant difference in the proportion of patients developing AF in the three groups (NAP = 33%; RAP = 29%; BAP = 37%; p > 0.7). However, for the subset of patients on beta-adrenergic blocking agents after CABG, there was a trend toward less AF in the paced groups. There were no serious complications related to pacing, although in three patients the pacemaker appeared to induce AF by pacing during atrial repolarization.

CONCLUSIONS

Continuous right or biatrial pacing in the postoperative setting is safe and well tolerated. We did not find that post-CABG pacing prevented AF in this pilot study; however, the role of combined pacing and beta-blockade merits further study.

Thoracoscopic lobectomy with endoarterial vascular control: an experimental study in swine

BACKGROUND

Video-assisted lobectomy lacks vascular control and presents the potential for serious hemorrhage in a closed cavity. The use of a lighted, flow-directed balloon catheter in the pulmonary artery as an endovascular control device was evaluated.

METHODS

A modified light-bearing Swan-Ganz catheter was placed in the left or right pulmonary artery using fluoroscopy. The lit catheter was identified easily through the arterial wall at thoracoscopy. Its inflation allowed the control of proximal blood flow as required. Fully thoracoscopic lobectomy was carried out by isolating and dividing the lobar branches of the pulmonary artery, the pulmonary vein, and the bronchus in anesthetized swine.

RESULTS

Forty-two video-assisted anatomic lobectomies were completed in 30 pigs with balloon catheter control of the pulmonary artery. The balloon effectively controlled experimental hemorrhage caused by puncturing arterial branches (n = 4). It allowed the transection of unlooped lobar arteries (n = 42) and the main interlobar pulmonary artery (n = 3). Catheter displacement back to the heart occurred in 5 animals and balloon catheter technical failures occurred in 3.

CONCLUSIONS

The lighted, flow-directed balloon catheter was an effective means of avoiding acute hemorrhage and achieving vascular control in a swine lobectomy model.

Prevention of lower extremity ischemia during cardiopulmonary bypass via femoral cannulation

Prolonged cardiopulmonary bypass requiring femoral arterial cannulation may lead to ipsilateral leg ischemia. A technique described of femoral cannulation via an end-to-side femoral artery graft allows distal femoral perfusion and eliminates the complication of leg ischemia.

Reduction of bleeding after heart operations through the prophylactic use of epsilon-aminocaproic acid

Excessive postoperative bleeding after heart operations continues to be a source of morbidity. This prospective double-blind study evaluated epsilon-aminocaproic acid as an agent to reduce postoperative bleeding and investigated its mode of action. One hundred three patients were randomly assigned to receive either 30 gm epsilon-aminocaproic acid (51 patients) or an equivalent volume of placebo (52 patients). In a subset of these patients (14 epsilon-aminocaproic acid, 12 placebo), tests of platelet function and fibrinolysis were performed.

RESULTS

By multivariate analysis, three factors were associated with decreased blood loss in the first 24 hours after operation: epsilon-aminocaproic acid versus placebo (647 ml versus 839 ml, p = 0.004), surgeon 1 versus all other surgeons (582 ml versus 978 ml, p = 0.002), and no intraaortic balloon versus intraaortic balloon pump use (664 ml versus 1410 ml, p = 0.02). No significant differences in platelet function could be demonstrated between the two groups. Inhibited fibrinolysis, as reflected by less depression of the euglobulin clot lysis and no rise in D-dimer levels, was significant in the epsilon-aminocaproic acid group compared with the placebo group.

CONCLUSION

The intraoperative use of epsilon-aminocaproic acid reduces postoperative cardiac surgical bleeding.

Heparin and protamine stimulate the production of nitric oxide

Heparin has been shown to decrease total vascular resistance while protamine stimulates endothelium-dependent vasodilation. This study was undertaken to determine whether heparin and/or protamine could enhance endothelium-derived relaxing factor (EDRF), as determined by nitric oxide (NO) production. Porcine carotid artery endothelial cells (PAECs) were seeded on multiwell plates, grown to confluence, and exposed to heparin (1-20 U/ml) or protamine (50-200 microg/ml) for 24 hours. With the addition of the NO synthase inhibitor, N(G)-monomethyl-L-arginine (NMMA), to heparin and/or protamine, the medium samples were collected in one hour. In a parallel clinical study, plasma samples were collected from patients undergoing cardiopulmonary bypass (CPB). The NO production was measured as reflected by the formation of nitrite (NO2-) and nitrate (NO3-), the stable end-metabolites of NO. NO production by PAECs was significantly increased by heparin > or = 5 U/ml or protamine > or = 50 microg/ml in a concentration-dependent manner. The increase of NO production was prevented by the addition of NMMA. In CPB patients, plasma NO2-/NO3- concentration was significantly increased after heparin administration compared to the preoperative value, at which time the mean plasma heparin level was 4.9+/-0.5 U/ml. Following slow protamine infusion, there was no significant difference in plasma NO2-/NO3- concentration compared to preoperative value. In conclusion NO production increases following exposure of PAECs to heparin and/or protamine. In patients, NO concentration significantly increased after heparin administration by IV bolus, but not with a slow infusion of protamine after CPB.

Simultaneous repair of multiple traumatic aortic tears

A 34-year-old man suffered simultaneous tears of his distal ascending and mid-descending thoracic aorta secondary to blunt trauma. Repairs of both injuries were performed via a median sternotomy approach followed by a left lateral thoracotomy using two separate methods of cardiopulmonary bypass.

Mitral valve replacement with complete retention of native leaflets

Although both mitral leaflets contribute equally to the preservation of left ventricular function after mitral valve replacement, most surgeons routinely excise the anterior mitral leaflet. Possible disadvantages of leaflet retention are left ventricular outflow tract obstruction and interference with prosthetic valve motion. In 31 patients undergoing mitral valve replacement, all mitral valvular and subvalvular tissue was completely retained using a technique that involved reefing the native leaflets into the valve sutures. Fifteen Carpentier-Edwards porcine and 16 St. Jude Medical valves were implanted. Two patients died of causes unrelated to this technique. In the others, echocardiography demonstrated either no or an insignificant left ventricular outflow tract gradient, and, in most, no valvular tissue could be seen in the left ventricular outflow tract. No interference with prosthetic leaflet mobility occurred. The salutary results of mitral valve replacement with complete leaflet retention recommend its use.

Decreasing myocardial pH reflects ischemia during continuous warm retrograde cardioplegic arrest

Warm continuous retrograde cardioplegia is thought to prevent myocardial ischemia. We tested this hypothesis by subjecting canine hearts to 2 hours of either antegrade or retrograde perfusion with normothermic blood cardioplegia. Ischemic alterations were evaluated through the measurement of myocardial pH, tissue levels of adenosine triphosphate and lactate, and the preservation of left ventricular contractility. Antegrade perfusion resulted in uniformly positive changes in the myocardial pH in both ventricles, preserved levels of adenosine triphosphate, and small increases in the myocardial lactate levels. In contrast, retrograde perfusion caused the myocardial pH to decrease, especially in the right ventricle. Tissue lactate levels rose to a significantly greater extent during retrograde perfusion and adenosine triphosphate levels declined, although not to a statistically significant degree. Finally, myocardial function, as assessed by the preload recruitable work area, was preserved (103% +/- 20% of baseline) in the antegrade group but was markedly diminished (33% +/- 6%) in retrogradely perfused left ventricles 35 minutes after the aortic cross-clamp was removed. These data suggest that ischemic metabolism and the subsequent alteration of myocardial function take place despite continuous retrograde perfusion with normothermic blood cardioplegia.

Two techniques for the control of cardiac bleeding

Two new techniques effectively control local bleeding from the heart during heart operations. Both act by achieving local tamponade of the bleeding but through different mechanisms. In the first, a glove containing a sponge is placed against the bleeding site to provide local pressure. In the second, application of focal, high vacuum suction causes forceful apposition of adjacent soft tissue. These methods have stopped bleeding in 7 patients in whom conventional methods failed.

Prolonged bradyarrhythmias after isolated coronary artery bypass graft surgery

To evaluate clinical and electrocardiographic (ECG) characteristics that may predict the occurrence of bradyarrhythmias after isolated coronary artery bypass graft (CABG) surgery, 1614 consecutive patients who had this procedure performed at our institution from January 1988 to December 1990 were reviewed. Thirteen (0.8%, 7 males and 6 females) patients had prolonged (mean 10.5 +/- 6.5 days) postoperative bradyarrhythmias and required insertion of a permanent pacemaker. Complete heart block occurred in eight patients and sinus node dysfunction in five. These 13 patients (group A) were compared with a group of 490 arbitrarily selected CABG patients (group B) without bradyarrhythmias whose preoperative ECGs were reviewed. Patients in group A were older (mean 69.2 vs 62.8 years; p = 0.0004) and had concomitant left ventricular (LV) aneurysmectomy more frequently (p = 0.02) and internal mammary graft revascularization less frequently (p = 0.022) than group B patients. Review of preoperative ECGs revealed a higher occurrence of complete left bundle branch block (LBBB) (5 of 13 vs 6 of 490; p < 0.0001) and a borderline, more leftward frontal plane QRS axis (-5.3 vs 13.1 degrees, p = 0.068) in group A patients. There were no differences between the groups with respect to gender, number of bypass grafts, location of prior myocardial infarction, and preoperative ECG intervals (PR, QRS, QTc). Multivariate analysis identified the presence of a preoperative LBBB, concomitant LV aneurysmectomy and age > 64 years as independent predictors of severe and prolonged postoperative bradyarrhythmias, mainly complete heart block.(ABSTRACT TRUNCATED AT 250 WORDS)

Retrograde coronary sinus perfusion provides non-homogeneous myocardial blood flow

The ability of retrograde cardioplegia to protect the right ventricle has been questioned. Canine myocardial circulation was assessed by infusing colored microspheres through the coronary sinus. The relative flow index (RFI), a normalized measure of tissue blood flow, was determined for 76 sections of myocardium. Three distinct flow regions were evident from these measurements. A paucity of blood flow through some basal sections of the right ventricle (RFI = 0.23 +/- 0.19) was found to be significantly different (p < 0.005) from regions of the heart with normal flow (RFI = 1.12 +/- 0.06). Sections from the right ventricular apex demonstrated augmented flow (RFI = 3.72 +/- 1.18). These data indicate that retrograde coronary perfusion provides nonuniform flow and under some conditions may provide inadequate perfusion to portions of the right ventricle.

Bidirectional bundle branch reentry tachycardia associated with Ebstein's anomaly: cured by extensive cryoablation of the right bundle branch

A 30-year-old woman with Ebstein's anomaly presented with a sustained, wide QRS complex tachycardia exhibiting a left bundle branch block morphology. Serial electrophysiological studies revealed right and left bundle branch reentry tachycardias refractory to many conventional antiarrhythmic drugs. Radiofrequency and direct current catheter ablation of the right bundle branch failed to control the tachycardias. The patient subsequently underwent extensive endocardial cryoablation to the right bundle branch resulting in cure of her arrhythmia.

Effects of long-term amiodarone therapy on the defibrillation threshold and the rate of shocks of the implantable cardioverter-defibrillator

The effects of long-term amiodarone therapy on the defibrillation thresholds and the rate of shocks were evaluated in 62 patients who had implantation of an automatic cardioverter-defibrillator (n = 53) or prophylactic implantation of patch electrodes (n = 9) who were survivors of sudden cardiac death (n = 34) or had refractory rapid ventricular tachycardia (n = 28). There were 53 men and 9 women, with ages ranging from 18 to 76 years (mean +/- SD, 60 +/- 12). Coronary artery disease occurred in 50 patients (80.6%), cardiomyopathy occurred in six (9.7%), valvular heart disease developed in two (3.2%), primary electrical disease developed in two (3.2%), hypertensive heart disease materialized in one (1.6%), and Ebstein's anomaly occurred in one (1.6%). The left ventricular ejection fraction varied from 10% to 75% (mean, 37 +/- 17%). All patients had failed a mean of 3.9 +/- 1.6 antiarrhythmic drugs prior to implantation of the device. Twenty-eight patients (45%) were taking amiodarone up to the time of surgery, with a mean daily dose of 406 +/- 147 mg (range 200 to 800) and for a mean duration of 6.0 +/- 6.7 months (range 1 to 36 months). The mean defibrillation threshold (DFT) was 12.0 +/- 4.4 joules (range 5 to 20) in the group taking amiodarone and was not significantly different from that of the group not taking amiodarone (n = 32) (mean DFT 12.3 +/- 5.5 joules, range 5 to 30; p = 0.77).(ABSTRACT TRUNCATED AT 250 WORDS)

Reduction of sternal infection by application of topical vancomycin

Sternal or mediastinal infection after heart operations occurs infrequently but carries a high cost in money, morbidity, and mortality. At our hospital, Staphylococcus nonaureus causes most of these infections and is uniformly sensitive to vancomycin. In a prospective study of 416 patients having cardiac operations, randomized by hospital record number, topical vancomycin was applied to the cut sternal edges in 223 patients (group V) and was omitted in the control group (C) of 193 patients. The vancomycin was applied in a hemostatic paste of topical thrombin and powdered absorbable gelatin; in the control group only the hemostatic paste was applied. All patients received prophylactic systemic antibiotics for 2 days. Sternal infection occurred in one patient in group V (0.45%) and in seven patients in group C (3.6%) (p = 0.02). Infection also correlated with longer operative times (p = 0.027). By multivariate testing, vancomycin (p = 0.013) and shorter operative times (p = 0.014) independently predicted reduced infection rates. In the one patient with an infection in group V, Staphylococcus aureus was cultured; this organism was also cultured in two patients in group C, with Staphylococcus nonaureus being the culprit in the other five patients with sternal infections in group C. Topical vancomycin applied to the cut sternal edges reduces the risk of postoperative sternal infection.

Mitral annular calcification: a new technique for valve replacement

Many dangers attend mitral valve replacement in the presence of dense posterior annular calcification. The procedure described has been successful in 4 patients. The major elements of this procedure include complete ultrasonic debridement of the calcification, reconstitution of the disassembled atrioventricular groove, and retention of the mitral valve leaflets.

Internal mammary artery grafts: the shortest route to the coronary arteries

Inadequate length can limit the use of the internal mammary artery (IMA) for coronary revascularization. By following the shortest route from its origin to the recipient coronary artery, IMA use can be maximized. Seven cadavers were studied to determine that shortest route for the left and right IMAs. The shortest route for the left IMA to the left anterior descending coronary, diagonal, and circumflex coronary arteries was through the pericardium (p less than or equal to 0.01). For the right IMA, the significantly shortest routes were across the anterior heart for the left anterior descending and diagonal arteries, through the right pericardium for the right coronary artery or posterior descending artery, and through the pericardium and transverse sinus for the circumflex artery. Thus, any coronary artery can be reached with an in situ IMA, and the route through the pericardium is markedly shorter to ipsilateral coronary arteries.

The role of epsilon-aminocaproic acid in reducing bleeding after cardiac operation: a double-blind randomized study

Sixty patients scheduled for elective coronary artery bypass graft operations were randomly assigned to receive epsilon-aminocaproic acid or placebo to test whether antifibrinolytic therapy would decrease postoperative bleeding. A small but significant decrease in bleeding was observed in the treated group without complications resulting from treatment with epsilon-aminocaproic acid.

Efficacy of nadolol in preventing supraventricular tachycardia after coronary artery bypass grafting

To investigate the efficacy of nadolol in the prevention of supraventricular arrhythmias after coronary artery bypass graft (CABG) surgery, 148 patients undergoing elective CABG were randomized in double-blind, placebo-controlled fashion to receive either nadolol or placebo. The test medication was started on the first postoperative morning and maintained as a single daily dose for 6 weeks. Aside from routine daily clinical evaluation and postoperative electrocardiographic monitoring, patients underwent 24-hour Holter recording once preoperatively and 3 times postoperatively. Seven patients were excluded from the evaluation of efficacy analysis because of insufficient postoperative data. There were no significant differences between the patients receiving nadolol (n = 67) and those receiving placebo (n = 74) with respect to age, preoperative heart rate, previous medications (including beta blockers), incidence of previous myocardial infarction, frequency of preoperative ventricular and supraventricular arrhythmias, concomitant valvular heart disease, mean cardiopulmonary bypass time, mean aortic cross-clamp time, use of blood and crystalloid cardioplegia, mean number of bypass grafts placed, postoperative use of inotropic agents and catecholamines and incidence of perioperative myocardial infarction. Analysis of postoperative Holter recordings showed that the heart rate was consistently and significantly higher in the placebo group throughout the period of the study (p less than 0.001). The average number of premature atrial contractions was significantly smaller in the nadolol group (p less than 0.05), and nadolol patients had fewer ventricular premature complexes, couplets and non-sustained ventricular tachycardias during the first week postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Blowgun dart aspiration

We report on two young patients with unusual airway foreign bodies: blowgun darts. These homemade darts are constructed with yarn, thread, and a common pin. Because only the pin is radiopaque, and because the child may be reluctant to disclose the nature of the foreign body, the bronchoscopist may encounter unexpected difficulty in extracting the dart. A radiograph showing a pin head down in the trachea or bronchus, coughing (especially with hemoptysis) in excess of that expected from just an aspirated pin, and a child hesitant to divulge the full history suggest blowgun dart aspiration.

Prevention of postoperative pericardial adhesions. An animal study

Following heart operations, adhesions uniformly form between the epicardium and surrounding structures such as the pericardium, mediastinal fat, pleura, and sternum. These adhesions make reoperations both difficult and hazardous. Three groups of 15 dogs each were studied to assess the effectiveness of pharmacologic manipulation in reducing the adhesions. In the control group, adhesions were created by allowing epicardial/pericardial surfaces to dry, and then adding cotton fibers and blood before closing the pericardium. In the methylprednisolone group, 500 mg of methylprednisolone was given intravenously at the time of operation, followed by 0.3 mg/kg orally three times a day for one week. In the ibuprofen group, 12.5 mg/kg of ibuprofen was given intravenously at operation and then orally three times in one day, followed by 5 mg/kg orally three times a day for six days. Dogs were killed at three to four weeks and the adhesions between pericardium and epicardium were graded. In the control group, none were adhesion-free and none had filmy adhesions; three dogs had dense patchy adhesions and 12 had dense diffuse adhesions. In the methylprednisolone group, 14 dogs had no adhesions; one had filmy adhesions; and none had dense patchy or dense diffuse adhesions. In the ibuprofen group, none were adhesion-free; one dog had filmy adhesions; four had dense patchy adhesions; and ten had dense diffuse adhesions. The near-total elimination of pericardial/epicardial adhesions utilizing methylprednisolone, if also achievable in humans, would markedly reduce the difficulty and increase the safety of cardiac reoperations.

Hospital readmissions among survivors six months after myocardial revascularization

One neglected but important measure of early morbidity after coronary artery bypass graft (CABG) operations is rehospitalization. As part of a prospective study of recovery after elective CABG procedures conducted at four academic medical centers, data from all readmissions occurring within the first six postoperative months were collected for 326 patients. A total of 24% of patients had readmissions. The most common categories of readmission discharge diagnoses were cardiac (57%), noncardiac (26%), and surgical sequelae (17%). Factors from the initial hospitalization identified as risk factors for rehospitalization included: length of stay in intensive care unit after surgery, severe noncardiac complications, duration of preoperative cardiac symptoms, intra-aortic balloon insertion, and preoperative resting angina. These findings help to identify a subset of at risk patients for whom more careful surveillance might be beneficial.

Effect of reduction of postoperative days in the intensive care unit after coronary artery bypass

The high cost of medical care prompted us closely to evaluate our practice of keeping all coronary artery bypass patients in the postoperative intensive care unit a minimum of 2 days. Thirty-seven patients were randomly assigned to a 1 or 2 day postoperative stay in the intensive care unit after routine bypass grafting. Nineteen patients in Group I stayed 1 day and 18 in Group II stayed 2 days. Eighteen Group I and 17 Group II patients were evaluated. No differences in type or rate of complications occurred in either group. No deaths occurred. Total hospital costs were $340 less for Group I (not statistically significant, p greater than 0.4), room costs were $361 less for Group I (p less than 0.01), total laboratory costs were $165 less for Group I (p greater than 0.5), and costs for arterial blood gases were $325 less for Group I (p less than 0.001). No adverse effect on patient safety was found by reducing the stay in the intensive care unit from 2 days to 1 day. This and other economies can significantly reduce hospital costs for this group of patients.

Surgical versus percutaneous removal of the intra-aortic balloon

In order to determine the best method for removal of the percutaneous intra-aortic balloon (IAB), we divided 38 patients into two groups. The IAB was removed percutaneously in Group I and surgically in Group II. There were two hemorrhagic and four thrombotic complications sufficiently severe to necessitate vascular surgical intervention in Group I. There were no vascular complications in Group II (p less than 0.1). Among the 19 patients in Group II, eight were found to have acute thrombosis of the superficial or deep femoral artery at the time of operation. It is concluded that thrombus development at the site of IAB insertion is a common event and often leads to acute ischemia. Surgical removal of a percutaneously placed IAB is recommended because it provides an opportunity for the detection and removal of thrombotic material, as well as careful closure of the puncture site.

Reversal of lower esophageal sphincter hypotension and esophageal aperistalsis after treatment for hypothyroidism

A 65-year-old woman suffered from both chronic gastroesophageal reflux, which was complicated by columnar metaplasia (Barrett's epithelium), and profound hypothyroidism. An esophageal motility tracing showed absence of peristalsis in the lower esophagus and the lower esophageal sphincter (LES) could not be identified. Thyroid replacement therapy, in conjunction with antacid and cimetidine treatment, was associated not only with improvement in the gastroesophageal reflux symptoms, but also with a return of esophageal peristalsis and LES pressure to normal. To support our clinical observations, we rendered four cats hypothyroid with 131I and documented a fall in LES pressure. We propose that abnormal smooth-muscle function of the esophagus may be another manifestation of the gastrointestinal motility disturbances which are associated with hypothyroidism.

Brachial plexus injury following median sternotomy. Part II

Brachial plexus injury may be a consequence of median sternotomy. In a previous study, we documented that median sternotomy can cause first rib fractures and that the first rib fractures may be associated with brachial plexus injury. In the current study, two groups of patients were compared for the incidence of brachial plexus injury and first rib fracture. In Group A, an Ankeney retractor was used with the crossbar placed caudal to the incision: in Group C, a Cooley sternal retractor was used with the crossbar placed cephalad to the incision. The major effective difference between these two retractors was the more caudal placement of the retractor blades with the Cooley retractor than with the Ankeney retractor. Our previous study showed that first rib fractures were caused by high placement of the sternal retractor and that they could be avoided by placing the retractor at a lower position. In the present study, 33% in Group A and 14% in Group C sustained first rib fractures (p = 0.024). Signs of brachial plexus injury occurred in 18% of Group A and 12% of Group C (p = 0.52). We found no correlation between the presence of rib fracture and the presence of neurologic symptoms, but all patients who had both neurologic symptoms and a rib fracture had the symptoms only on the same side as the rib fracture. We also found that standard chest x-ray films identified only 15% of the rib fractures seen on special first rib views. The study demonstrates that the incidence of first rib fractures following median sternotomy is reduced when the sternal retractor is placed at a lower position and that the incidence of brachial plexus injury may also thereby be reduced.

Improved myocardial preservation by improved distribution of cardioplegic solutions

Two groups of elective coronary artery bypass graft (CABG) patients were compared with respect to a single variable: method of cardioplegia administration. All patients had saphenous vein grafts and all distal anastomoses were done with continuous aortic occlusion and intermittent administration of a 4 degrees C cardioplegic solution. One hundred patients in Group I had the distal anastomoses performed before the proximal anastomoses with cardioplegic solution administered only via the aortic root. One hundred patients in Group II had the proximal anastomoses performed first so that cardioplegic solution also perfused beyond coronary obstructions as each subsequent distal anastomosis was completed. Aortic occlusion averaged 6 minutes longer in Group II (46.5 minutes) than in Group I (40.3 minutes) (p less than 0.01). Mortality from cardiac causes was six times greater in Group I than in Group II (6% versus 1% p = 0.027) and overall mortality was eight times greater in Group I than in Group II (8% versus 1%; p = 0.008). We conclude that earlier cardioplegic perfusion of myocardium beyond obstructed coronary arteries substantially improves myocardial protection.

Hemorrhage from myocardial revascularization

Four groups of 12 dogs each had ligation of the left anterior descending coronary artery (LAD) with subsequent release of the ligature and confirmed reperfusion. After 24 hours of reperfusion, the hearts were removed. sliced at 1 cm intervals along the transverse axis, and stained with triphenyltetrazolium chloride. Measurements of the infarct size as a percentage of the left ventricular area (I) and of hemorrhage as a percentage of infarct size (H) were made. The duration of ligation was 3 hours in Group 1, 6 hours in Group II, 18 hours in Group III, and 30 hours in Group IV. No significant difference in infarct size was found among the groups. Percent hemorrhage was 25.2% of infarct area in Group I, 28.3% in Group II, 18.1% in Group II, and 0.7% in Group IV. If reperfusion hemorrhage into an acute myocardial infarct is deleterious, these data suggest than danger to be decreased at 18 hours and absent at 30 hours after acute coronary occlusion.

Femoral artery embolism and rupture of abdominal aortic aneurysm

Peripheral emboli from asymptomatic abdominal aortic aneurysms are surprisingly infrequent. When they do occur, they usually consist of small bits of atherosclerotic or thrombotic debris. A case is presented of massive bilateral femoral emboli followed by aneurysmal rupture 16 days later. Excavation of the mural thrombus lining the aneurysm was demonstrated angiographically. Although apparently an unusual occurrence, dissection and embolization of a mural thrombus within an abdominal aortic aneurysm may be the initial manifestation of aneurysmal rupture and warrant early surgical intervention.

Brachial plexus injury following median sternotomy

Brachial plexus injuries are annoyingly common after median sternotomies and vary from those causing minor symptoms to those producing major disability. We compared two groups of patients operated upon with the arms either abducted to a 90 degree angle or at the sides and found no difference in the incidence of brachial plexus injury. However, the finding of Horner's syndrome in one patient and the finding in another (at autopsy) of brachial plexus penetration by a fractured first rib caused us to question traction on the brachial plexus as the correct pathogenesis of the injury. A concomitant autopsy study demonstrated fractured first ribs penetrating the brachial plexus in 11 of 15 patients whose sternum was opened with the sternal retractor placed in the usual location, but in none in 15 patients whose sternum was opened with the retractor displaced two intercostal spaces caudally. The injury can be minimized by opening the sternal retractor as little as is necessary and by placing it as caudally as possible commensurate with adequate exposure.

Traumatic aortic rupture: presentation as a femoral embolus

In patient with no conventional radiographic signs of thoracic aortic rupture, an unusual physical finding, femoral embolus with ischemia, led to the correct diagnosis.

Improved technique for insertion of intra-aortic balloon pump

Polytetrafluoroethylene (PTFE, Gortex) grafts have several advantages over woven Dacron grafts for the insertion of intra-aortic balloons (IABP). Because of the smooth inner surface of the PTFE graft, an 8-mm graft may be used instead of the 10-mm minimum size with Dacron. The pliability of the PTFE graft makes it easier to sew with fine suture material, and its comformability permits a "blood tight" seal to be obtained with a single Dacron umbilical tape tie. We have used PTFE grafts for IABP insertion in 24 patients, with no infectious or thrombotic complications. This graft material seems to offer substantial technical advantages over woven Dacron for the insertion of IABP and subsequent arterial repair.

Return to work after coronary artery bypass operation

A societal cost-benefit argument has been made for the coronary artery bypass graft (CABG) operation. Most patients experience improvement in symptoms and many can return to a productive livelihood. To estimate the rate of return to work and identify the factors influencing that outcome, we analyzed the work status before and after operation in a follow-up of 105 patients undergoing CABG operations in a new teaching hospital. Overall, relief or improvement in angina was accomplished in 92% of patients, and there was a 10% net increase to th work force after operation. Of all variables studied, preoperative work status was found to be the most statistically significant predictor of the postoperative return to work; other factors associated with return to work included symptomatic relief or improvement, age, and educational level. Preoperative and postoperative means of support did not play a major role in determining work outcome.