[Training of surgeons for laboratory research]

A degree in surgical research has been set up in 1986 in France. It includes a one-year full time work in a research laboratory, and seminars (one to three days long, each). General surgical research objectives are gathered in a first seminar. Then, candidates select one among four optional subjects: biomaterials-artificial organs, transplantation, oncology, and neurosciences. Two prerequisites are necessary in order to register. The first is to write a research project according to standardized rules, and the second is to attend two seminars, one dealing with scientific communication and the other with methodology in clinical research. A nation-wide valid Academic degree is delivered to candidates who pass an oral presentation of their research report and who attended all seminars according to the optional subject that they selected. From 1986 to 1993, 434 students attended the formation. They came from different regions of France, proving the nation-wide characteristic of the degree, and some from foreign countries. Seminars were held in different French University towns. An increasing number of students become Ph.D.

Double mitral homograft for recurrent bacterial endocarditis of the mitral and tricuspid valves

A young patient suffering from acute bacterial endocarditis underwent reconstructive surgery of the mitral and tricuspid valves. One year later a recurrent endocarditis occurred that could not be controlled with antibiotic therapy. Two separate mitral homografts were used to replace both the mitral and the tricuspid valves. The homografts' papillary muscles were sutured side to side to the recipient's and a circumferential suture of the leaflet tissue was accomplished. Homograft implantation was associated with Carpentier ring annuloplasty of the atrioventricular valves. In the right sided position, the mitral homograft was oriented in an anti-anatomical manner and an inverted semi-rigid prosthetic ring of the mitral type was inserted. Clinical and echocardiographic follow up at four months was excellent.

Myocardial neutrophil sequestration and activation related to the reperfusion of human heart during coronary artery surgery

OBJECTIVE

The aim was to determine if neutrophils are activated and sequestered as they pass through postischaemic human myocardium.

METHODS

The occurrence of neutrophil activation during the reperfusion of the ischaemic myocardium was investigated in 16 selected patients undergoing coronary artery bypass surgery. Neutrophils were counted and elastase and lactoferrin released into the plasma were measured simultaneously in myocardial venous blood and in peripheral venous blood, before aortic cross clamping (T0), and two (T1), 10 (T2), and 20 (T3) min after unclamping.

RESULTS

At T0, no statistically significant difference was noted between peripheral and myocardial blood with respect to the three variables studied. Reperfusion was associated with a significantly lower neutrophil count in myocardial blood compared to peripheral blood (p < 0.001), suggesting that neutrophils were trapped within the myocardium during reperfusion. In addition, levels of elastase (T1, T2, and T3), and lactoferrin (T1) were significantly higher in myocardial blood as compared to peripheral blood (p < 0.001), suggesting that activated neutrophils released their granular content into the plasma milieu.

CONCLUSION

We provide evidence consistent with local neutrophil activation during myocardial reperfusion in patients undergoing coronary artery bypass surgery, in addition to the well described systemic activation related to cardiopulmonary bypass.

Postoperative pseudoaneurysm of ascending aorta: role of ultrafast computed tomography imaging

A 34-year-old woman, who had undergone a thoracic aortic aneurysmectomy and replacement with a prosthetic tube graft several months previously, presented with a pseudoaneurysm arising from the proximal anastomotic site. This pseudoaneurysm was studied with contrast-enhanced ultrasfast computed tomography. The exact location of the suture dehiscence was located by the presence of a contrast jet flow through the aortic wall. This case shows the feasibility of demonstrating blood flow at the entry site of a pseudoaneurysm with ultrafast computed tomography which may avoid conventional angiography.

Peripheral vascular involvement in heart transplant patients

Between 1984 and 1991 a total of 200 patients underwent heart transplantation in our unit. The records of 121 patients who were followed up for more than 1 year were reviewed for peripheral vascular abnormalities, which were found in 12 (9.9%). Most of these patients underwent transplantation for ischemic heart disease, and peripheral vascular disease preceded the heart transplantation in 80%. Although surgical risks are low in this setting, particular caution should be exercised to prevent septic complications in the femoral triangle. Among the risk factors studied, only elevated blood cholesterol was frequently found in the vascular patients before or after transplantation. Peripheral vascular involvement in heart transplant patients corresponds to the natural course of atheroma rather than to an accelerated process of atherosclerosis.

Combined coronary and femoral revascularization using an ascending aorta to bifemoral bypass

OBJECTIVE

Coronary artery and aortoiliac disease frequently coexist. In rare instances simultaneous procedures may be required. This study reports our experience with ascending aorta to bifemoral bypass.

DESIGN

Prospective consecutive sample study.

PATIENTS

Ten male patients who underwent concomitant aortoiliac and coronary revascularization with the ascending aorta as the source of inflow to the femoral arteries between 1989 and 1991.

RESULTS

One hospital death was unrelated to the surgical technique. All survivors displayed an uneventful recovery and were free of symptoms. Follow-up was obtained in all nine cases, they all stayed asymptomatic in terms of coronary artery disease and peripheral vascular disease. Echo-doppler studies showed perfect patency of the aorto-femoral grafts in all cases.

CONCLUSIONS

This study shows that the ascending aorta to bifemoral bypass constitutes an interesting alternative in selected cases mainly those with severe ischemia coronary and leg ischemia. It offers the following advantages: (1) it is easy to perform, (2) does not require an intraperitoneal procedure, (3) the graft's position behind the muscles of the abdominal wall is not compressible, (4) the ascending aorta is the source of inflow, and (5) it allows a shorter duration of hospital stay.

[Mitral valve replacement with cryopreserved mitral homograft]

Mitral valve replacement using a cryopreserved mitral homograft was performed in a 49 year old patient with calcified mitral stenosis. The surgical technique is described. The postoperative course was uneventful. Transoesophageal echo performed 4 months later showed a normal function of the mitral homograft.

[Comparative vasoreactivity of the radial, internal mammary and gastroepiploic arteries. Implications in coronary surgery]

Recently, satisfactory results were obtained in a series of patients in whom the radial artery was used as a conduit for coronary artery bypass. However, spasm of this conduit was observed in four percent of patients. The aim of this study was to analyze the vasoreactive properties of the radial artery and to compare them to those of the internal mammary and the gastroepiploic arteries. Human radial (56 from n = 15 patients), internal mammary (77 from n = 20 patients) and gastroepiploic (41 from n = 12 patients) arteries ring segments were mounted on a strain gauge in oxygenated, normothermic, Krebs solution at optimal resting tension. With potassium chloride (100 mM) serving as the control, the dose response curves to norepinephrine, serotonin and thromboxane A2 mimetic were obtained, hence permitting to assess force of contraction and sensitivity. Functional endothelium was assessed by acetylcholine. Smooth muscle-dependent relaxation was assessed by sodium nitroprusside. The radial artery had stronger contractions to potassium chloride than the other vessels. The radial and the gastroepiploic arteries with endothelium presented a higher contraction force than the internal mammary artery in response to norepinephrine and serotonin. The gastroepiploic artery had a lower sensitivity to thromboxane A2 mimetic compared to the two other vessels. This increased reactivity of the radial artery explains its propensity to spasm and emphasizes the need for antispastic drugs and platelet inhibitors when the radial artery is used for coronary artery bypass.

Heparin-induced thrombocytopenia and thrombosis following open heart surgery

We recently observed five cases of early thrombus formation in patients undergoing anticoagulation with subcutaneous heparin following open heart surgery. The reasons prompting surgery were as follows: one mitral valve replacement, one double valve replacement, one mitral valve reconstruction, one aortic valve replacement associated with coronary bypass. In all cases, intravenous heparin was begun on the day of surgery and replaced by subcutaneous (SC) heparin on postoperative day 1. Acute thrombocytopenia was observed between the 6th and 11th postoperative day. This was interpreted as denoting an idiosyncratic reaction to heparin which was replaced by low molecular weight heparin (LMWH) in two cases and by acenocoumarol in the other cases. Massive thrombosis of the aortic valve resulted in the death of one patient. Thrombosis of the left atrium occurred in three patients (two of whom had a transient ischemic attack (TIA)). One patient had aorto-iliac thrombosis. Successful reoperation was carried out in four of the five patients. Although heparin-induced thrombocytopenia and thrombosis [HITT] is a rare complication of heparin therapy, serial platelet count monitoring and in vitro platelet aggregation tests are mandatory in the diagnosis of this syndrome. Discontinuation of heparin is indicated as soon as the syndrome is recognized and the institution of aspirin is recommended if the thromboembolic complication requires reoperation and reexposure to heparin.

[Use of the radial artery for coronary artery bypass. A new experience after 20 years]

Twenty years after its first introduction by A. Carpentier, the use of the radial artery (RA) for coronary bypass was reinvestigated because of unexpected good long term results in some patients. Since July 1989, 158 patients (pts) underwent myocardial revascularization using 189 RA grafts (31 pts received 2 grafts). The left internal mammary artery (LIMA) was concomitantly used as a pedicled graft in 151 cases and the right internal mammary artery (RIMA) in 31 cases, a free IMA graft was used in 29 cases and a saphenous vein graft in 40 cases. A mean of 2.8 graft/pt was performed. The target artery receiving the RA was: circumflex (n = 93), diagonal (n = 39), right coronary (n = 47) and LAD (n = 10). Two patients died (1.3%) and three presented a perioperative myocardial infarct (2.5%). Sternal wound infection was noted in three cases of double IMA implant. No ischemia of the hand was observed. All patients received diltiazem started intraoperatively and continued after discharge. In addition, aspirin (100 mg/day) was given at discharge. Early angiographic controls (< 3 weeks) were obtained in the first 60 consecutive patients and revealed: 73/73 patent RA grafts, 58/58 patent LIMA grafts, 16/16 patent RIMA grafts, 15/19 patent free IMA grafts and 10/11 patent vein grafts. Six patients presented a localized narrowing of the RA conduit unrelated to the anastomotic lines (spasm). Late angiographic control (6 to 24 months) was obtained after a mean follow-up of 11 months in 37 patients: 42/46 RA grafts were patent (91.3%) and free of spasm and 4 were occluded.(ABSTRACT TRUNCATED AT 250 WORDS)

Criteria for anatomical compatibility of the total artificial heart: computerized three-dimensional modeling of the cardiovascular anatomy

A quantitative study of cardiovascular anatomy was performed by obtaining three-dimensional reconstructions from regular computed tomography scan images in 15 patients, all candidates for heart transplantation. Volumetric estimates of the cardiovascular structures were obtained from these three-dimensional reconstructions using data directly related to total artificial heart (TAH) implantations. By using computerized three-dimensional modeling of these structures, reproducible measurements of the parameters defining the shape and the anatomical connections of the intrathoracic space available for TAH implantation could be derived. The results are intended to be used for both technical and clinical applications such as computer-assisted drawing of the pericardial cavity and the anatomical connections (useful for improving the design of TAH) and combined statistical calculations (multiple regressions, cluster algorithm) of the measurement results, which will then enable the best selection to be made among two or three TAH models for each patient.

Three-dimensional modeling of the anatomy of the heart and great vessels

The anatomic constraints imposed on a total artificial heart (TAH) require specific anatomic studies. A thoracic anatomic study was performed with a scanning device equipped with three-dimensional (3-D) reconstruction software on 15 male patients, between the ages of 41 to 63 years (52 +/- 6 years). All were candidates for heart transplantation. The 3-D reconstructions of the cardiovascular structures obtained from surgical anatomy data specific to TAH implantation allowed a volumetric measurement of these structures. A modeling diagram of these structures permitted reproducible quantitative measurements of the 35 geometrical parameters which characterized shape, orientation, and position of these structures within the thorax. Most of the measured parameters were characterized by low variability (coefficient of variation from 10 to 25%).

Vasoreactivity of the radial artery. Comparison with the internal mammary and gastroepiploic arteries with implications for coronary artery surgery

BACKGROUND

Recently, satisfactory results were obtained in a series of patients in whom the radial artery was used as a conduit for coronary artery bypass. However, spasm of this conduit was observed in 4% of patients. The aim of this study was to analyze the vasoreactive properties of the radial artery and to compare them with those of the internal mammary and the gastroepiploic arteries.

METHODS AND RESULTS

Human radial (56 from 15 patients), internal mammary (77 from 20 patients), and gastroepiploic (41 from 12 patients) artery ring segments were mounted on a strain gauge in oxygenated, normothermic Krebs' solution at optimal resting tension. With KCl (100 mM) serving as the control, the dose-response curves to norepinephrine, serotonin, and thromboxane A2 mimetic were obtained, permitting assessment of force of contraction and sensitivity. Functional endothelium was assessed with acetylcholine. Smooth muscle-dependent relaxation was assessed with sodium nitroprusside. The radial artery had stronger contractions to KCl than the other vessels. The radial and the gastroepiploic arteries with endothelium presented a higher contraction force than the internal mammary artery in response to norepinephrine and serotonin. The three vessels had equal sensitivities to norepinephrine and serotonin. The gastroepiploic artery had a lower sensitivity to thromboxane A2 mimetic than the two other vessels.

CONCLUSIONS

This increased reactivity of the radial artery explains its propensity to spasm and emphasizes the need for antispastic drugs and platelet inhibitors when the radial artery is used for coronary artery bypass.

Transposition of chordae in mitral valve repair. Mid-term results

BACKGROUND

Prolapse of the anterior mitral leaflet, unlike a posterior prolapse, is a difficult lesion to repair. Leaflet plication and triangular resection are satisfactory techniques only in case of a limited prolapse. Chordal replacement has also been proposed but uses foreign material. The purpose of this report is to assess the results of transposition of chordae for the correction of mitral regurgitation (MR) caused by anterior leaflet prolapse.

METHODS AND RESULTS

Between January 1986 and December 1990, 44 adult patients with MR caused by anterior leaflet prolapse underwent repair with transposition of chordae as one of the techniques. This population was retrospectively studied to assess the early and late results of this procedure. Chordae were transferred from the posterior to the anterior leaflet (n = 25) or from an intermediary to a free edge position on the anterior leaflet (n = 21) (two patients underwent both procedures). Two patients died (4.5%). None required early reoperation. Follow-up was complete and ranged from 18 to 82 months (mean, 40.2 +/- 19 months). No patient died during follow-up. Two patients were reoperated on 6 and 8 months after surgery for recurrent MR unrelated to chordal transfer disruption. Doppler echocardiographic studies were available in 95% of the cases at latest follow-up and showed no or minimal MR (0 to 1/4) in 87.5% of the patients and mild MR (2/4) in 12.5%.

CONCLUSIONS

Transposition of chordae appeared to be a simple and safe procedure for correction of anterior mitral prolapse. Transposition of chordae allowed extension of the indications of valve repair. A longer follow-up will be necessary to draw firm conclusions, but mid-term results are encouraging.

[Combined surgery of the mitral valve and the abdominal aorta in a case of Takayasu's disease]

The authors report the case of a 34-year-old woman, of North African origin, with mitral valve disease and abdominal aortitis. The differential diagnosis between Takayasu' disease, embolism of cardiac origin and rheumatic aortitis is discussed. Treatment of these lesions was by combined cardiac and vascular surgery in a single-stage operation.

Chromosomal aberrations and neutrophil activation induced by reperfusion in the ischaemic human heart

Imperfect myocardial protection during prolonged ischaemia results in adverse changes during reperfusion. Clinical studies carried out during cardiac surgery show that: (1) Oxygen free radicals produced during reperfusion can lead to chromosomal damage in leukocytes. However, this effect seems to be prevented by the addition of allopurinol in the cardioplegic solution. (2) Polymorphonuclear leukocytes are directly implicated in situ in the genesis of free radicals responsible for reperfusion injury. (3) Pre-treatment with trimetazidine, an anti-ischaemic drug with antioxidant properties, and addition of the drug to the cardioplegic solution reduced oxygen free radical damage, as shown by a reduced release of malondialdehyde increase and of myosin; moreover, pre-treatment with trimetazidine enabled patients to undergo surgery with improved left ventricular function.

Left ventricular outflow tract obstruction after mitral valve repair. Results of the sliding leaflet technique

BACKGROUND

Left ventricular outflow tract obstruction (LVOTO) occurs in 4% to 5% of patients after prosthetic ring mitral valve repair. Major anatomic factors incriminated in the genesis of LVOTO include degenerative mitral valve insufficiency with excess leaflet tissue, nondilated left ventricular cavity, and narrow mitro-aortic angle. We have previously reported a 14% incidence of LVOTO after prosthetic ring mitral valve repair in this high-risk group of patients. Serial echo Doppler studies demonstrated an overlapping and/or inversion of the left ventricular functional compartments generating systolic anterior motion of the posterior leaflet and paradoxical opening (eversion) of the anterior leaflet. In an attempt to eliminate LVOTO after mitral valve repair, a new surgical procedure was developed in 1988 by Carpentier: the sliding leaflet technique, which reduces the height of the posterior leaflet. The purpose of this study was to analyze the results of the new technique in terms of the occurrence of LVOTO:

METHODS AND RESULTS

Eighty-two patients undergoing prosthetic ring mitral valve repair between 1988 and 1991 and identified as high risk for LVOTO were operated on using the sliding leaflet technique. There were 52 men and 30 women. Ages ranged from 28 to 75 years. The surgical techniques used included prosthetic ring annuloplasty (n = 82), leaflet resection (n = 82), chordal shortening or transposition (n = 36), and other (n = 19). Intraoperative and/or immediate postoperative echo Doppler studies were obtained in all cases. Two patients (2.4%) died, and 2 (2.4%) required reoperation. Nonsignificant LVOTO was identified in 2 cases (2.4%), in whom instantaneous maximal subaortic gradients were 20 and 18 mm Hg, respectively.

CONCLUSIONS

This study was not done on a concomitant series of patients but on patients with the same type of pathology. It demonstrates that (1) the sliding leaflet technique eliminates significant LVOTO in the high-risk patients; (2) the sliding leaflet technique is associated with a low mortality; and (3) no reoperations for mitral insufficiency were required in this series.

Cyclosporine-induced stimulation of the renin-angiotensin system after liver and heart transplantation

To analyze the status of the renin-angiotensin system in hypertensive transplant recipients on cyclosporine, we prospectively explored 21 cardiac (CTR: 52 +/- 8.2 yr) and 12 liver (LTR: 45 +/- 10 yr) transplant recipients on a normal salt diet with 19 normotensive controls in the same age range. Systolic and diastolic blood pressure was measured in the supine and standing positions. Renal function was assessed by serum creatinine values, and 24-hr urinary sodium and potassium excretion were recorded. Plasma renin activity (PRA), active renin, total renin, angiotensinogen, aldosterone, and cortisol plasma levels were simultaneously determined. Results were expressed as mean +/- SD, and between-group differences were compared using variance analysis. Supine blood pressure (+/- SD) was 158 +/- 15/103 +/- 8.4 in CTR and 155 +/- 21.4/102 +/- 11.7 mmHg in LTR. Serum creatinine was higher in CTR (159 +/- 52 mumol/L) than in LTR (117 +/- 24.7, P < 0.05) and values in both groups were above controls (83 +/- 14.1, P < 0.05). Urinary sodium excretion tended to be lower in transplant recipients (59 +/- 42 mmol/L) for CTR and 44 +/- 36.7 in LTR than in healthy controls (117 +/- 24.7 mmol/L). Supine and upright PRA values tended to be higher in hypertensive transplant recipients than in healthy volunteers, although not significantly. Supine active renin was significantly higher in CTR (47 +/- 42 pg/ml) and in LTR (44 +/- 29.8 pg/ml) than in normal subjects (17 +/- 4.8 pg/ml, P < 0.05). Total renin levels in CTR (supine: 716 +/- 357 pg/ml) and in LTR (supine: 647 +/- 365 pg/ml) were 3- to 4-fold higher than in controls (supine: 207 +/- 69 pg/ml) (P < 0.05), as were inactive renin levels (P < 0.01). Active renin was effectively correlated with PRA (P < 0.001) and with total renin (P < 0.001) in the supine and in the upright position. Plasma aldosterone was almost within the normal range in CTR and in LTR, and it did not correlate with PRA values. Plasma angiotensinogen levels were normal in LTR (1032 +/- 226 ng/ml) but were significantly lower in CTR (938 +/- 216 ng/ml, P < 0.05). Cortisol plasma levels were lower in both CTR (7 +/- 4.4 micrograms/L) and LTR (6 +/- 1.9 micrograms/L) than in healthy controls (11 +/- 4 micrograms/L, P < 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)

Dynamic cardiomyoplasty at seven years

Since January 1985, the date of the first dynamic cardiomyoplasty, until April 1992, 52 patients with end-stage heart disease were operated on in our institution. Mean preoperative New York Heart Association functional class was 3.3 and ventricular ejection fraction 16% +/- 3%. Associated procedures in 23 patients comprised ventricular aneurysm resection (10), valve surgery (9), coronary artery bypass (8), and tumor resection (3). Thirty-eight patients had a ventricular reinforcement, 13 a ventricular substitution, and 1 an atrial reinforcement using the left latissimus dorsi muscle. Preassist mortality rate before full latissimus dorsi muscle stimulation was 7 of 13 patients (54%) in the 1985 to 1987 period and 5 of 39 (12%) in the 1988 to 1992 period. The causes of death were heart failure (4), multiorgan failure (4), septicemia (2), ventricular fibrillation (1), and sudden death (1). Multivariate analysis of factors influencing hospital mortality showed that age, cardiac suture technique, associated surgical procedures, biventricular heart failure, and hemodynamic instability plus inotropic drug support were predictors of unfavorable outcome. All patients were followed up for from 2 months to 7 years (mean 21 months). Postassist mortality rate was 8 of 40 (20%). Causes of death included heart failure (5), ventricular fibrillation (1), myocardial infarction (1), and gastric bleeding (1). Preoperative risk factors influencing long-term mortality were permanent New York Heart Association functional class IV, biventricular heart failure, atrial fibrillation, cardiothoracic ratio greater than 60%, and ejection fraction less than 15%. Actuarial survival at 7 years was 70.4% (preassist mortality excluded). Surviving patients were in a mean New York Heart Association functional class of 1.8 (preoperatively 3.3, p < 0.05). The average ejection fractions (rest/stress) were 25%/28% at 1 year, 26%/30% at 2 years, and 23%/28% at 3 years. Average cardiothoracic ratios were 57% +/- 3% at 1 year, 56% +/- 2% at 2 years, and 57% +/- 2.5% at 3 years. Catheterization obtained in 20 patients showed no significant changes at rest in capillary wedge pressure, pulmonary artery pressure, and diastolic left ventricular pressure when compared with preoperative pressures. Average ejection fractions increased from 24% to 30.6%. Maximal oxygen consumption increased from 12.8 +/- 3.5 to 18.6 +/- 4 ml/min per kilogram. The number of rehospitalizations resulting from congestive heart failure was reduced to 0.4 hospitalizations per patient per year (preoperatively 2.4, p < 0.05). In 62% of the patients, pharmacologic therapy was diminished after the operation. Three patients required orthotopic heart transplantation 6 months, 4 years, and 5 years after cardiomyoplasty.

[Phosphocalcium metabolism in patients with calcified valvular bioprosthesis]

Calcium and gla-protein content are increased in the calcifications of cardiac bioprostheses. Such calcifications are more frequent during growth, pregnancy and renal failure when bone gla-protein levels are elevated. We investigated whether bone gla-protein and other markers of calcium metabolism play a role in bioprostheses calcifications. Forty-seven patients were separated into 2 groups according to the presence (group A, n = 9) or absence (group B, n = 38) of bioprostheses calcifications, as assessed by echo-doppler and surgery. Plasma levels of calcium, phosphorus, magnesium, creatinine and alkaline phosphatases were measured by standard laboratory methods, parathormone and those of bone gla-protein by specific radioimmunoassays. Results (mean +/- SEM) were compared (group A versus group B, P < 0.01) using Student's test and one-factor variance analysis (ANOVA). Age was similar in both group (53 +/- 12.9 vs 50 +/- 12.3 yrs), whereas duration of implant was greater in group A (104 +/- 12.4 vs 66 +/- 6.5 months, P < 0.01). No statistically significant difference was found between group A and B concerning biochemical and/or hormonal markers of calcium metabolism. These negative results merit to be discussed, and further studies will be needed to explore the potential role of circulating bone gla-protein in bioprostheses calcifications.

Assessing human cardiac allograft rejection using MRI with Gd-DOTA

To explore the potential role of MRI in detecting cardiac allograft rejection in transplant recipients using gadolinium tetraazacyclododecane tetraacetic acid (Gd-DOTA) for contrast enhancement, we examined 7 normal healthy volunteers and 39 patients separated into three groups according to histological findings. Quantitative myocardial enhancement (ME), expressed as the ratio of maximum signal intensity after intravenous Gd-DOTA injection to signal intensity before intravenous injection of Gd-DOTA, was significantly lower for patients without histological rejection (n = 14; regional ME = 83 +/- 41%; mean ME = 53 +/- 24%) when compared with patients with grade 1 histological rejection (n = 18; regional ME = 122 +/- 20%, p = 0.02; mean ME = 70 +/- 14%, p < 0.05) and with patients with grade 2 or 3 rejection (n = 7; regional ME = 135 +/- 44%, p = 0.02; mean ME = 81 +/- 27%, p < 0.05). Myocardial enhancement was not significantly different in patients with grade 1 histological rejection compared with patients with grade 2 or 3 rejection. Because predominant focal areas of ME were observed in all patients, regional ME seemed a better measurement than mean ME to distinguish focal histological changes when the rejection process is beginning. More sophisticated software analysis is necessary to quantify and map high ME to establish the exact relationship between the extent of edema and the severity of rejection.

[Mitral valvuloplasty during the acute phase of endocarditis]

Thirty-five patients were operated in the acute phase of mitral valve endocarditis between 1986 and 1991. The surgical indications were hemodynamic (22), echocardiographic (9), embolic (2) and infectious (2). There were pre-existing valve lesions in 45% of cases. The causal organism was identified in 90% of cases: streptococcus (19), staphylococcus (9) and Gram negative bacilli (4). Preoperative antibiotic therapy was prescribed for an average of 18 days. The aortic valve was infected in 9 patients and tricuspid valve in 1 patient. The mitral lesions were: abscess (11), vegetations (11), perforations (16), and ruptured chordae tendinae (22). All patients underwent Carpentier's mitral valvuloplasty. The operative mortality was 5.7% (2 patients). Early reoperation was required in 1 case. Follow-up was possible in 96% of cases for an average of 23 months. No recurrences of endocarditis were observed. One patient was reoperated and 3 died. All the others were in Classes I and II of the NYHA. None had significant mitral regurgitation or stenosis. These results show that mitral valvuloplasty is possible in the acute phase of endocarditis in 90% of cases. The mortality and morbidity are low and long-term results are stable.