[Transplantation of cryopreserved carotids in the rabbit: effect of cryoprotective agents]. / Transplantation de carotides cryopréservées chez le lapin: effet des agents cryoprotecteurs.

The cryopreservation of blood vessels has been carried out for some decades with variable results. In order to study the behaviour of cryopreserved allografts by using new technique of cryopreservation a study on the ultrastructure arterial tissue consequences by microscopic techniques has been carried. The graft has been harvested from carotid artery of donor rabbit, implanted to a carotid artery of a recipient rabbit and extracted at 1, 3 and 5 months after the operation. An intimal thickening and a cellular loss in the media have been observed. However, good patency has been observed in all cryopreserved allografts. Manifestations of rejection are delayed in groups with polyethylene glycol.

Doppler echocardiographic study of three different mechanical valves in the aortic position: the use of external nominal diameter indexed to body surface area.

BACKGROUND AND AIMS OF THE STUDY: Previous studies have demonstrated the benefit of indexing body surface area (BSA) with ventriculo-arterial orifice diameters (or calculated effective surface dynamics) and with nominal external diameters of valves in order to study hemodynamic profiles in vivo or determine the clinical influence of this parameter. This study analyzes the relationship between BSA and nominal external diameter of mechanical valves implanted in the aortic position. It also evaluates the potential interest of using these diameters indexed to BSA in an echo-Doppler study of valves. METHODS: During 1994, a prospective echo-Doppler study of three models of mechanical valves in the aortic position was carried out. RESULTS: The echo-Doppler parameters of the aortic St. Jude Medical, Sorin Bicarbon and Dideco Monostrut prostheses have been studied with regard to nominal external diameters and were found identical to published data. There were no significant differences in these parameters between the three valves. In 128 patients, prosthetic external diameters were evenly distributed heterogeneously with regard to BSA. Indexing of nominal external diameter with BSA appeared a more reliable reference to study different echo-Doppler parameters, minimizing the effect of cardiac output. CONCLUSION: The in vivo echo-Doppler determination at rest of valve hemodynamic profiles should be carried out with reference to the nominal external diameter indexed to the BSA.

Mitral annuloplasty with a flexible linear reducer.

Although the ideal technique is still controversial, mitral valve reconstruction for mitral insufficiency usually includes an annuloplasty. From August 1985 to June 1993, 126 cases of pure, acquired mitral insufficiency were repaired by means of a posterior annuloplasty. Whatever the etiology, all types of mitral insufficiency allowing a mitral reconstruction were included. The annuloplasty, performed with a flexible linear reducer, was associated with valvular (62%) and subvalvular (11%) repairs. An associated surgical procedure was necessary in 62% of the patients. Operative mortality was 2.4%, and follow-up (mean 29 months) was complete for all survivors. Five-year survival was 90%. Five-year complication-free rate for emboli was 91%. Only one patient at 12 months underwent reoperation to treat recurrent mitral insufficiency. Ninety-seven patients were in New York Heart Association Class I or II. Follow-up echocardiographic studies on 75% of eligible patients showed a free rate for significant regurgitation of 99%. Mean valve area was estimated at 2.88 +/- 0.85 cm2. These findings suggest that the flexible linear reducer seems to be a reliable device and a valid alternative for annuloplasty.

[Revascularization of distal arteriopathies: a new approach]. / Revascularisation des artériopathies distales: une nouvelle approche.

The diffuse nature of arterial occlusions in Buerger's disease compromises the effect of revascularization. Nevertheless, the muscle branches are quite often unaffected by the occlusive disease making revascularization of collateral arterial branches a promising alternative to conventional procedures. Revascularization by a short autologous venous graft from the grand anastomotic or gastrocnemius artery can be an alternative technique. Advances in microsurgery have made such revascularizations possible.

Metabolic and functional evidence that retrograde warm blood cardioplegia does not injure the right ventricle in human beings.

BACKGROUND: Retrograde warm blood cardioplegia is now recognized as an effective method of myocardial protection, but concerns persist about its ability to adequately preserve the right ventricle. METHODS AND RESULTS: A total of 75 patients in whom warm blood cardioplegia was continuously given through the coronary sinus were included in this three-part study. Part 1, which involved 30 patients undergoing coronary artery bypass grafting operations, was designed to assess whether the right ventricle incurred a greater degree of anaerobic metabolism than the left ventricle during warm arrest. Immediately before aortic unclamping, antegrade perfusion was resumed and, within 1 minute of washout, blood samples were simultaneously taken from the right ventricle and coronary sinus and assayed for lactate. There was no significant difference in lactate concentrations between the two sampling sites (right ventricle, 2.53 +/- 0.1 mmol/L; coronary sinus, 2.47 +/- 0.1 mmol/L). Part 2 focused on recovery of function. A complete set of postoperative hemodynamic measurements was obtained in 15 among the 30 patients enrolled in part 1 and compared with that obtained in 15 case-matched patients who received conventional cold antegrade crystalloid cardioplegia. Postoperative right ventricular stroke work index was not significantly different between the two groups (retrograde warm, 4.6 +/- 0.2 g.m-1.m-2; antegrade cold, 4.8 +/- 0.2 g.m-1.m-2). Part 3 was also targeted at functional end points but in 30 additional patients undergoing reoperative mitral valve replacement and consequently deemed to be at higher risk of right ventricular ischemia. Fifteen patients who received retrograde warm cardioplegia were compared with 15 case-matched control subjects in whom antegrade cold crystalloid cardioplegia was used. In keeping with data of part 3, postoperative right ventricular stroke work index was not significantly different between the two groups (retrograde warm, 6.9 +/- 0.4 g.m-1.m-2; antegrade cold, 7.7 +/- 0.5 g.m-1.m-2), nor was there a difference in clinical outcomes or biological recoveries of hepatic function. CONCLUSIONS: Inadequate protection of the right ventricle associated with the use of retrograde warm blood cardioplegia does not appear to be a clinically founded concern since this technique preserves right ventricular function to the same extent as conventional antegrade cold cardioplegia does.

Utility of C-reactive protein measurements for empyema diagnosis after pneumonectomy.

Serum C-reactive protein (CRP) levels were studied serially during the postoperative period in 151 consecutive patients who underwent pneumonectomy. Virtually all patients who had a simple postoperative course (115 of 120), as well as 9 patients who had a bronchial infection of the remaining lung, 3 with a pulmonary embolus, and 2 who suffered postoperative bleeding requiring reoperation, demonstrated a similar postoperative evolution in their CRP values: a rapid postoperative rise until a peak or a plateau (mean peak value, 132 +/- 25 mg/L) was reached within 3 to 6 days, followed by a progressive decline to a value of less than 75 mg/L on day 9, and less than 50 mg/L on day 12. Conversely, all 12 patients who suffered empyema postoperatively, as well as 3 patients with bacterial pneumonia, 1 patient with chylothorax, and 1 patient with inflammatory pericarditis, demonstrated either a markedly persistent elevation in their CRP values or a secondary rise in the levels which exceeded 100 mg/L. Because of the high sensitivity (100%) and specificity (91.4%) of the CRP levels in detecting postpneumonectomy empyema, we recommend the routine use of this measure. Furthermore, a low CRP value after pneumonectomy (less than 50 mg/L) may help in deciding whether to confidently discharge a patient from the hospital in the absence of empyema. The negative predictive value of this method was found to be 100%.

Limitation of vasodilation associated with warm heart operation by a "mini-cardioplegia" delivery technique.

Peripheral vasodilation is commonly seen during and after warm heart operations and can become of clinical concern when it requires vasopressors because some of these drugs adversely affect coronary artery bypass graft flows. As hemodilution lowers systemic vascular resistance, we assessed whether peripheral vasodilation could be limited by a drastic reduction of the volume of infused cardioplegia. Fifty patients underwent isolated coronary artery bypass grafting procedures using normothermic (35 degrees to 37 degrees C) bypass and normothermic continuous retrograde blood cardioplegia. They were divided into two equal groups: in group 1, blood was diluted 4:1 with hyperkalemic crystalloid cardioplegia, whereas in group 2, the cardioplegic "solution" was limited to the sole arresting agents that were concentrated in a small volume (16 mEq potassium chloride and 3 mEq magnesium chloride in a 20-mL ampoule). This "mini-cardioplegia" was continuously added to arterial blood so as to keep the heart arrested. The average volume of cardioplegia per patient was 1,000 mL in group 1 and 58 mL in group 2 (p < 0.0001). The mini-cardioplegia technique resulted in a reduced incidence of perioperative systemic vasodilation: group 2 patients required significantly less vasopressors (p < 0.05) and less volume loading, as reflected by significantly lower right atrial and pulmonary capillary wedge pressures (p < 0.05 and p < 0.03 at 12 hours postoperatively, respectively), compared with group 1 patients who received traditional high-volume cardioplegia. There were no differences between the two groups with respect to myocardial recovery, as assessed by standard clinical and hemodynamic end points.(ABSTRACT TRUNCATED AT 250 WORDS)

Is the internal mammary artery an acceptable graft in the elderly patients with left main coronary artery disease?

Age over 70 years and critical stenosis of the left main coronary artery trunk are two situations in which the use of the internal mammary artery has been questioned. Because the coexistence of these two conditions is increasingly seen, we reviewed our experience with 53 patients 70 years of age or older that underwent myocardial revascularization for left main disease. In 17 patients, the left anterior descending coronary artery was grafted with the left internal mammary artery whereas the 36 remaining patients were exclusively revascularized by means of saphenous vein conduits. There was no significant difference in postoperative mortality or morbidity between the two patient groups. We conclude that elderly patients with left main disease should be offered the benefits of a mammary artery graft provided they are hemodynamically stable.