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Background Reoperative (redo) mitral valve surgery is still a continuing challenge to surgeons. The aim of this study was to detect the factors that affect late mortality or morbidity after redo mitral valve surgery in patients with rheumatic disease. Methods Between May 1983 and February 2003, 92 patients who underwent redo mitral valve surgery for rheumatic disease were enrolled. Risk factors influencing survival or cardiac events were investigated with univariate analysis and a Cox model. Results Operative mortality rate was 4.2%. Kaplan-Meier actuarial analysis demonstrated an 84.7% 5-year, a 69.5% 10-year, and a 65.9% 15-year survival. Multivariate analysis demonstrated that age at surgery and preoperative New York Heart Association (NYHA) class were found to be independent predictors of late deaths, and that higher age, advanced NYHA class, and previous mitral valve replacement were independent predictors of cardiac events. Conclusions Redo mitral valve surgery can be achieved with low early mortality. However, long-term results of redo mitral surgery are not necessarily satisfactory in patients with preoperative advanced NYHA class or with a previous mechanical heart valve, and especially in 60 years or older age.

Objectives: We review the outcome of coronary artery bypass grafting in patients with a severe atherosclerotic ascending aorta.Methods: Subjects were 31 patients averaging 69.4±6.9 years old studied from 1990 through 1998. Ascending aortic lesions were assessed using epiaortic echo and 2 types of aortic nonclamping techniques applied. In 29 patients operated on in the early years, bypass grafting was conducted on the hypothermic fibrillated heart in 22 and on the beating heart in 7. The remaining 2 underwent off-pump coronary artery bypass grafting more recently. For cases with multivessel disease, we used composite grafting.Results: Three patients developed mild stroke and 5 died within 30 days of surgery—4 from multiple emboli (1 accompanied by a stroke) and 1 from perioperative myocardial infarction. One hospital death occurred due to brain damage and multiorgan failure following unexpected rupture of a saphenous vein graft. No cardiac deaths occurred in the late stage of our series. Actuarial survival was .0% for 3 years and 68.0% for 5 years. Freedom from cardiac events was favorable in the remaining 25 survivors.Conclusions: Outcome was suboptimal for the risks involved. Recent technical advances, including coronary surgery on the beating heart with or without cardiopulmonary bypass using variable in-situ or free arterial grafts, associated with adequate evaluation of systemic atherosclerosis, should improve this outcome.

Objectives: The outcome of aortic arch repairs by means of three different approaches between 1990 and January 2000 was reviewed. Methods: In total 39 patients aged 71.5 ^ 6.2 years were operated on. The three different surgical approaches depended on the anatomical positions of the aneurysms and on their proximal or distal extension; a median approach was employed in 23 patients, whereas a left posterolateral approach was used in eight patients. More recently, in eight cases a left antero-lateral approach was applied. All patients underwent open aortic anastomosis without any clamp on or around the aortic arch. During the procedure, the brain was protected by a combination of profound hypothermic circulatory arrest and several techniques of retrograde cerebral perfusion. Results: Permanent cerebral dysfunction occurred in four patients: two in the median approach and two in the left postero-lateral approach. There were two hospital deaths (5.3%) and six late deaths, all of which belonged either to the median group or to the postero-lateral group. The antero-lateral approach did not produce any cerebral dysfunction, early death, or late death. Conclusions: The outcome of aortic arch repairs using profound hypothermic circulatory arrest and variable techniques of retrograde cerebral perfusion, by means of three different approaches, was satisfactory. Of the three approaches, the antero-lateral approach can be employed easily, whether aneurysms extend proximally or distally. q 2001 Elsevier Science B.V. All rights reserved.

Background: β-blocker therapy for dilated or ischemic cardiomyopathy is now an accepted and effective treatment. However, little is known about its efficacy in patients with postoperative impaired left ventricular function. This retrospective study was designed to assess the effects of β-blocker therapy in patients after aortic valve replacement (AVR) for aortic regurgitation (AR). Methods: A total of 59 patients who underwent AVR for chronic AR were assigned to four groups. Twelve patients were treated with both ACE inhibitors and β-blockers, 12 patients with only ACE inhibitors, eight patients with only β-blockers, and 27 patients without β-blockers or ACE inhibitors. A postoperative echocardiographic study was performed one year after surgery. Results: The heart rate was significantly reduced in patients with β-blockers despite the use of ACE inhibitors after surgery. Postoperative left ventricular volume was more significantly decreased in β patients than in non-β patients despite the use of ACE inhibitors. There were also significant reductions in left ventricular mass index in ACE+β patients compared to ACE+non-β patients. However, there were no significant differences in NYHA functional class and survival rate between β patients and non-β patients. Conclusions: β-blocker therapy may improve cardiac performance by reducing cardiac volume and mass in patients with impaired LV function after AVR for AR.

The authors used profound hypothermic circulatory arrest and continuous retrograde cerebral perfusion for aortic surgery that involved the distal arch through a left thoracotomy. For the first seven patients, oxygenated blood from cardiopulmonary bypass was perfused retrogradely through a venous cannula positioned into the right atrium. In the last 11 cases, venous blood, provided by a perfusion from the lower body, was circulated passively in the brain with the descending aorta clamped. The period of profound hypothermic circulatory arrest was 34.6±11.1 min, and continuous retrograde cerebral perfusion was 31.3±11.1 min. Seventeen patients survived, but there was one early death. Two patients with a severely atherosclerotic aneurysm developed permanent neurological dysfunction. The combination of profound hypothermic circulatory arrest, continuous retrograde cerebral perfusion and open aortic anastomosis through a left thoracotomy protects the brain adequately, and facilitates evacuation of debris and air in the aortic arch. It produces satisfactory results for aortic surgery that involves the distal arch.

The early and mid-term outcomes of cardiac and thoracic aortic surgery were reviewed in seventy-two consecutive patients aged 75 years and older, together with assessment of postoperative quality of life. Twenty-six patients had ischemic heart disease, twenty had valvular heart disease, one had congenital heart disease, and twenty-five had thoracic aortic aneurysm. Twenty-five (34.7%) required an emergency operation. There were 6 early deaths (8.3%) and 11 late deaths (17.2%), of which the emergency cases had higher mortality of 5 early deaths (20.0%) and 3 late deaths (15.0%). In particular, most cases with a ruptured thoracic aortic aneurysm died eventually from various complications including neurological dysfunction. The others with a non-ruptured aneurysm also had atherosclerotic aortic or arterial lesions which caused a lethal cerebrovascular accident or ischemic heart disease. The quality of life of 51 of 53 survivors was assessed using the Rosser and Watts index being based on disability and distress scores. The response was satisfactory--the disability score was 2.6 +/- 1.9 and the distress score was 1.4 +/- 0.4. The patients with a thoracic aortic aneurysm had worse quality of life scores than those of the ischemic heart disease or valvular heart disease patient-groups because of various perioperative complications. Our experiences demonstrate that the results including the postoperative quality of life following cardiac and aortic surgery in the elderly is satisfactory except for emergency cases. The results would prompt us to operate, if possible, electively in their stable conditions, even on elderly over-75-year-olds.

Aortoesophageal fistula occurring as a complication of a thoracic aortic aneurysm is difficult to repair because of the contaminated surgical field. We report the case of a 67-year-old man in whom an aortoesophageal fistula developed secondary to a dissecting thoracic aortic aneurysm. We performed in situ graft repair of the aneurysm, then covered the site with omentum and resected the esophagus to prevent graft infection. About 5 months later, the esophagus was reconstructed subcutaneously using an ascending colon pedicle. The patient recovered well and has resumed leading a normal life.

There are no guidelines for the optimal therapeutic range of anticoagulant therapy in Japanese patients with mechanical heart valves. A total of 214 patients were followed retrospectively after mitral mechanical valve replacement (mean duration of follow-up, 4.8 years; total duration of follow-up, 1,027 patient-years). The target range of the international normalized ratio (INR) for oral anticoagulation was between 1.5 and 2.5. For all patients 10,416 measurements of the INR were obtained during the follow-up period and approximately 76% of the intensity measurements were within the target range. Thromboembolism occurred in 8 patients (0.8 per 100 patient-years) and major bleeding in 5 patients (0.5 per 100 patient-years). There was no correlation between the distribution of the INR and the occurrence of thromboembolic or bleeding complications. In the univariate analysis of the various risk factors, patients who had a tilting valve or did not receive antiplatelet therapy had an increased risk of thromboembolism. However, there were no risk factors with respect to bleeding complications. A target range of 1.5 to 2.5 INR appears to be the optimal range and is safe for thromboembolism or bleeding complications. Thromboembolism may be reduced by additional antiplatelet therapy, and a tilting valve needs more intense anticoagulation.

A 69-year-old man with coronary artery disease associated with abdominal aortic aneurysm underwent a one-stage operation utilizing a low-flow cardiopulmonary bypass. Ordinary cardiopulmonary bypass was abandoned as a result of severe atheromatous finding in the entire aorta. However, coronary artery bypass grafting without cardiopulmonary bypass was hazardous as a result of heart enlargement and deteriorating function. Therefore, the abdominal aortic aneurysm was first replaced with a bifurcated graft. Coronary artery bypass grafting with two arterial grafts was then performed successfully on the beating heart with the support of a low-flow cardiopulmonary bypass connected to the bifurcated graft.

The importance of statins in cardiovascular prevention has been demonstrated in various patient subsets. This study aimed to evaluate the effects of statins on long-term outcomes of Japanese patients undergoing their first coronary revascularization.A total of 9,225 patients undergoing their first coronary revascularizations during 2000--2002 were divided into 2 groups according to the use of statins at discharge; patients with acute myocardial infarction were not included. Statins was administered to only 28.5% (n=2,630) of the patients. The median follow-up period was 3.5 years. Patients on statin therapy showed lower all-cause (5.2% vs 10.0%; p0.0001) and cardiovascular (3.2% vs 6.2%; p0.0001) mortality than those without statins (n=6,595) by Kaplan-Meier analysis and log-rank test. After adjustment by multivariate analysis according to 29 variables, statin therapy remained as an independent predictor of reduced all-cause (relative risk ratio (RR) 0.71, 95% confidence interval (CI) 0.59-0.86, p=0.0005) and cardiovascular (RR 0.72, 95% CI 0.56-0.91, p=0.0067) mortality. The validity of RR of statin therapy in multivariate analysis was further confirmed by risk adjustment using propensity scores (all-cause mortality: propensity-adjusted RR 0.70, 95% CI 0.58-0.85, p=0.0003; cardiovascular mortality: propensity-adjusted RR 0.70, 95% CI 0.54-0.89, p=0.0038).Statin therapy started at hospital discharge was associated with increased chance of survival in Japanese patients undergoing their first coronary revascularization.

We report a case of sudden leaflet fracture of an Edwards-Duromedics mitral valve 17-years after its implantation. The patient had a history of an asymmetrical motion of the valve, five months earlier. A computed tomography scan showed two fragments that had embolized to the right brachiocephalic artery and left common iliac artery. An emergency mitral replacement surgery was successfully performed. Asymmetrical closure of the valve leaflet may have contributed to valve fracture.

Gastrointestinal complications (GICs) such as gastroduodenal ulcer, enterocolitis, and ischemic colitis after coronary artery bypass grafting (CABG) are rare, but are associated with high mortality and morbidity. The present study was performed to detect risk factors and to investigate outcomes following GICs after CABG.Between January 1992 and December 2001, 17 of 549 patients (3.1%) developed GICs after CABG with cardiopulmonary bypass, presenting with gastrointestinal bleeding due to gastroduodenal ulcer, enterocolitis, or ischemic colitis. We conducted a retrospective analysis of these patients.All patients required emergent treatment for hemorrhage by means of blood transfusion and endoscopic ablation and/or clipping. The following possible predictors of GICs were identified by logistic multivariate analysis: age over 70, diabetes mellitus (particularly insulin-dependent diabetes), history of cerebrovascular disease or history of renal failure and postoperative low output syndrome (LOS).Our results suggested that GICs after CABG with cardiopulmonary bypass are rare but can be lethal. Early diagnosis and prompt intervention can be difficult but are potentially life saving for patients in whom GICs develop.

A 2-year-old boy underwent surgical repair of tetralogy of Fallot. Topical cooling of the heart with ice slush was used during the operation. Diaphragmatic paralysis occurred after the operation, inducing severe respiratory distress. To avoid repeated intubation and tracheostomy, the patient was placed on nasal mask bilevel positive airway pressure (BiPAP) ventilation. After ventilatory support with BiPAP for 40 days, the patient recovered spontaneously from the paralysis. No sedation was required during this time. This report illustrates the usefulness of BiPAP for a pediatric patient with diaphragmatic paralysis after cardiac surgery.

A successfully-treated case of acute type B aortic dissection associated with a mycotic aneurysm is reported. A 69-year-old man had a history of febrile illness and a high CRP level with increased enzyme activity of the hepatobiliary system before the onset. The culture of the abscess in the distal arch aneurysm revealed Bacteroides fragilis. A Dacron graft replacement between the distal arch and the proximal descending aorta was successfully performed with Teflon felt reinforcement, and the graft was covered with omental flap. The patient was discharged without recurrence of infection 2 months after the graft replacement.

For patients with a history of heparin-induced thrombocytopenia (HIT) who undergo cardiac or vascular surgery, the optimal anticoagulation substitute for heparin has yet to be established. Recombinant hirudin has been recommended; however, this agent is unsuitable for patients with renal dysfunction. Argatroban was used in the present patient who had a history of HIT and renal dysfunction and required peripheral vascular surgery. Argatroban was easy to monitor and control, regardless of renal function, and has advantages over other anticoagulants for such patients.

Background Whether preoperative tricuspid regurgitation (TR) will regress or progress late after surgery is unknown. The aim of this study was to evaluate predictors of significant TR late after mitral valve surgery. Methods A retrospective analysis was performed on a total of 174 patients who underwent mitral valve surgery without tricuspid valve surgery. Preoperatively, 46 patients (26%) had 2+ TR, and 128 patients (74%) had 1+ or less TR. Postoperative 3+ TR was considered significant TR. Variables were used to evaluate predictors of TR development by univariate or multivariate analysis. Results The mean follow-up was 8.2 years (range 1.0 to 14.5 years) after surgery. There was progressive TR (3+ or more) in 28 patients (16%) during the follow-up period. In univariate analysis, atrial fibrillation, rheumatic etiology, huge left atrium, left ventricular dysfunction, and preoperative 2+ TR were significant risk factors for TR development. Multivariate analysis identified preoperative 2+ TR, atrial fibrillation, and huge left atrium as statistically significant predictors for late TR after surgery. Conclusions Aggressive repair of accompanying TR should be undertaken at the time of initial surgery in patients with huge left atrium or atrial fibrillation, even if preoperative TR is 2+.

Aortobronchial fistula (ABF) is a rare condition that is almost always fatal in the absence of prompt and proper treatment. However, treatment remains challenging, particularly in the aortic arch. We present six operations for 5 such patients, in which no in-hospital deaths occurred. One patient with mycotic aneurysm died suddenly 10 months postoperatively. Another patient required reoperation 5-months after operation due to additional ABF. No pseudoaneurysms or graft-related complications were observed in the remaining patients. In patients with ABF, performance of operations as soon as possible after onset and minimal dissection of adherent lung tissue appear to improve outcomes.

This study compared the outcomes of combined coronary artery bypass grafting (CABG)/aortic valve replacement (AVR) and CABG alone in patients with moderate aortic stenosis and determined the possible indications for AVR at the time of CABG. Between December 1988 and January 2001, in Tenri Hospital, 41 patients with aortic stenosis underwent CABG: 26 patients underwent the combined procedure and 15 patients underwent CABG alone. The patients who underwent CABG alone were separated them into 2 groups on the basis of the results of annual echocardiography: the rapid progression group, defined by an increase of deltaP by >/=10 mmHg/year, and the slow progression group. Of the 15 patients who underwent CABG alone, the probability of survival at the end of the study in 2001 was 92% at 5 years and 74% at 10 years, and the respective event-free rates were 65% and 50%. Patients less than 70 years old and who were in the rapid progression group had a greater risk for re-operation. The study suggests that patients younger than 70 years old with risk factors for rapid progression should undergo CABG/AVR, and conversely, those older than 70 years old without the risk factors can undergo CABG only.

We report a 26-year-old patient with slowly developing perigraft seroma 15 years after a modified Blalock–Taussig shunt with an expanded polytetrafluorethylene graft. The mediastinal mass was first observed on a chest x-ray film 8 years after the shunt operation. The mass contained massive gelatinous or organic tissues with a severely calcified pseudocapsule, and it was adjacent to the calcified but functioning graft. No fluid collections were noted. The histological findings were compatible with a seroma. No recurrence was noted on last follow-up 1 year postoperatively.

Mitral regurgitation (MR) following endomyocardial biopsy is a rare and severe complication. A 70-year-old man with severe MR due to chordal injury caused by left ventricular endomyocardial biopsy is described. In this patient, a few chordae tendineae of the posterior-median papillary muscle were injured by the biopsy forceps. Due to the chordal rupture, both anterior and posterior leaflets were prolapsed and severe MR developed. MR was successfully treated by artificial chordal replacement using extended polytetrafluoroethylene sutures and ring annuloplasty. This mitral valve repair with artificial chordal replacement was considered suitable to treat MR resulting from iatrogenic chordal injury as the leaflets were not involved in the degenerative process and papillary muscle function was preserved. To avoid MR, the transvenous approach should be used routinely for endomyocardial biopsies; biopsy from the left ventricle is not justified.

Objective: We reviewed the surgical management of acute type A aortic dissection between 1989 and 1998.Methods: Subjects were 28 consecutive patients (mean age: 61.8±10.7 years) with acute type A aortic dissection were studied. The mean duration between aortic dissection onset and surgery was 17.5±17.0 hours. In surgery, aortic pathology and flow patterns in dissected aortic channels were evaluated using transesophageal and epiaortic echo. Simple, safe combination of profound hypothermic circulatory arrest with retrograde cerebral perfusion and open aortic anastomosis was used for brain protection. Hypothermic circulatory arrest was 46.9±24.8 minutes. Aortic repair consisted in ascending aortic replacement in 5 patients, with hemiarch repair in 17, and total arch repair in 6. Intimal tears were resected in all but 2 patients. Concomitantly resuspension of the aortic valve was done in 9 and aortic root replacement in 2.Results: No operative (30-day) deaths occurred, although 2 died from unrelated hepatic failure during hospitalization or late-stage pancreatic cancer in the late stage. In cerebral sequellae, 1 patient suffered a stroke and 2 patients developed temporary neurologic dysfunction.Conclusion: Our experience demonstrated that the simplified conjunction of hypothermic circulatory arrest with retrograde cerebral perfusion and open aortic anastomosis, associated with real-time assessment by transesophageal and epiaortic echo, is safe and useful during emergency aortic repair for acute type A aortic dissection.

Background: Partial plication annuloplasty is the main technique for congenital mitral insufficiency because this technique allows the mitral anulus to grow, in contrast to ring annuloplasty. However, this technique is not satisfactory for mitral insufficiency with some anomalies of the mitral valve apparatus. Methods: Forty-one patients underwent partial plication annuloplasty for mitral regurgitation from July 1979 to December 1998. Mitral regurgitation associated with an atrioventricular defect, an atrioventricular discordance, and a univentricular heart was excluded from this study. Results: There were no early or late deaths. In early results, partial plication annuloplasty was more effective for mitral regurgitation with abnormality of the posterior leaflet (n = 14) or normal leaflet motion (n = 8) than with abnormality of the anterior leaflet and its apparatus (n = 14) or absence of chordae (n = 4). The mean follow-up period was 145.8 months. During the follow-up period, 2 patients underwent mitral valve replacement, and a third patient underwent mitral valve repair with partial plication annuloplasty after the first repair. The main cause of mitral regurgitation of 2 of the 3 patients was absence of chordae. The actuarial freedom from reoperation rate was 94.9% ± 3.6%, 91.9% ± 4.7%, and 91.9% ± 4.7% at 5, 10, and 15 years after the operation, respectively. Conclusion: Early and long-term results of partial plication annuloplasty were acceptable for congenital mitral insufficiency with any type of malformation of the mitral valve, and results were excellent with abnormality of the posterior leaflet and its apparatus or normal leaflet motion. However, late results were suboptimal for mitral regurgitation with absence of chordae. Other techniques, such as artificial chorda replacement, should be adapted in these cases. J Thorac Cardiovasc Surg 2001;122:229-33

Constrictive pericarditis (CP) is an unusual sequela of cardiac surgery, so the present study evaluated the clinical characteristics of patients with CP after coronary artery bypass grafting (CABG). Four hundred and sixty-three patients who underwent isolated CABG between January 1989 and March 1999 were examined retrospectively. The first choice of treatment for postoperative pericardial effusion was non-steroid anti-inflammatory agents, and an increased dose of diuretics. The second treatment choice was corticosteroids or pericardial drainage. When CP was suspected during the follow-up period (mean, 54+/-31 months), cardiac catheterization was carried out to establish the diagnosis. Of the 463 patients undergoing CABG, there were 11 (2.4%) who developed CP after surgery. The median time to the onset of symptoms after CABG was 4 weeks (range, 3-96 weeks). On univariate and multivariate analysis, normal left ventricular ejection fraction, warfarin administration, and early postoperative pericardial effusion were significantly associated with a greater potential of postoperative CP. The effusion was bloody in all cases of pericardial drainage despite warfarin therapy. Not draining the postoperative effusive pericardial effusion was a risk factor for the development of CP. Pericardial drainage for patients with significant effusion after CABG is important for the prevention of subsequent CP, especially in those patients being treated with warfarin or with normal left ventricular function.

Background Docarpamine (DOC) is a dopamine prodrug which can be orally administered. It has been found that oral docarpamine transforms into dopamine in vivo, and increases cardiac output and renal blood flow as effectively as intravenous dopamine. Methods We reviewed the records of 26 patients who had developed low cardiac output syndrome (LOS) after cardiac surgery and received docarpamine during the early postoperative course. Five patients discontinued docarpamine within 2 days due to arrhythmia. There were 3 hospital deaths. The remaining 18 patients were divided into two groups according to the timing of docarpamine administration. In group A docarpamine was administered during and after weaning from intravenous catecholamines, in group B only on demand after weaning from intravenous catecholamines. Results There were 12 patients in group A and 6 in group B, and the severity of LOS was relatively milder in group B than in group A. Stable hemodynamics and sufficient daily urinary output were maintained by oral administration of DOC in both groups just as well as by drip infusion of catecholamines. Conclusion Sinse continuous drip infusion of catecholamine commonly slows recovery in LOS patients, it is considered that switching from drip infusion of catecholamines to oral DOC administration is safe and useful for earlier recovery in LOS patients after cardiac surgery.

SUMMARY 1. To clarify the mechanism of the association between I/D polymorphism of the angiotensin-converting enzyme (ACE) gene and various cardiovascular diseases, ACE mRNA levels in human atrial appendages were assessed in relation to the genotype of the ACE gene. 2. Angiotensin-converting enzyme mRNA levels were positively correlated with age and tended to show a positive correlation with mean pulmonary pressure (niPA). Multiple regression analysis indicated that age and mPA, but not the genotype of the ACE gene, were predictors of ACE mRNA levels in human atrial appendages. 3. The present study indicates that I/D polymorphism of the ACE gene is not simply reflected in ACE mRNA levels and that further study is needed to determine the mechanism of the association between this polymorphism and various cardiovascular diseases.

We report on successful surgical treatment of consecutive three patients with infection of an abdominal aortic graft, Therapy involved a combination of removal of the infected graft, elaborate debridement, irrigation with electrolyzed strongly acidic aqueous solution (ESAAS), in-situ regrafting, and omentoplasty. The use of ESAAS is discussed.

A 68-year-old man with a DeBakey type II chronic aortic dissection developed bacteremia secondary to a urinary tract infection with the Serratia species. This resulted in an infected thrombus in the false channel and a subsequent rupture of the ascending aorta. An emergency resection of the ascending aorta and a Dacron graft interposition were performed. The patient suffered from severe neurological insufficiency and died of pneumonia 6 months postoperatively. The optimal operation time and surgical options of an infected aortic dissection should be determined.

Levels of endogenous endotoxins have been reported to increase after cardiopulmonary bypass. Endotoxin levels have also been implicated in multiple organ failure and may contribute to the immunocompromised state seen after bypass. We evaluated the effects of pulsatile cardiopulmonary bypass circulation on endogenous endotoxin levels. The study population consisted of 15 consecutive adult patients who underwent cardiac operations with cardiopulmonary bypass. Pulsatile flow was used during aortic crossclamping in eight patients (group I) and nonpulsatile flow was used in the remaining seven patients (group II). Changes in blood endotoxin levels were monitored during aortic crossclamping, after release of the clamp, and after weaning from bypass. The blood endotoxin level at each stage was expressed as a percentage of the level at the beginning of bypass. Group I patients a significantly lower blood endotoxin percentage than group II (from 20 to 120 minutes after the initiation of aortic crossclamping). In group I, the blood endotoxin percentage was nearly constant during aortic crossclamping. After release of aortic crossclamping, group I also had a lower blood endotoxin percentage than group II. Endogenous endotoxin levels appear to increase in the presence of intestinal congestion and ischemia. Improvement in intestinal circulation by pulsatile cardiopulmonary bypass may prevent increases in endogenous endotoxin levels by reducing these factors. (J THORAC CARDIOVASC SURG 1994;108:620-5)