An animal model for the evaluation of graft thrombosis in the acute phase on carbon-lined PTFE prosthesis

Fortyfive carbon-lined (CL) and 45 standard (ST) 4 mm internal diameter polytetra-fluoroethylene (PTFE) grafts were implanted as aortic interposition in 90 rabbits. A pilot study of 20 animals: 10 CL and 10 ST grafts were used to develop microsurgical techniques, then 60 grafts were placed in 60 New Zealand rabbits with lower morbidity. The two hours graft patency (Doppler and angiographic studies) showed better patency rate in CL group (93% versus 80%). In 10 animals, platelet accumulation was investigated in vivo using gammacamera imaging after injection of autologous platelets labeled with Indium111. In vitro, radioactivity counting of the explanted midgraft sections at 2 hours revealed 6 times greater activity in ST grafts (6.60 ± 1.98 x 103platelets/mm2 versus 0.82 ± 0.25 x 103 platelets/mm2; p<0.05). Light microscopy found platelet and fibrin deposition (PFD) in nearly all ST grafts whereas PFD were found in only 13% of the CL grafts corresponding to those thrombosed (chi2: 61.117, p<0.001). Carbon-lining decreases platelet accumulation on PTFE grafts in the acute phase of a new experimental model.

[Pediatric heart surgery in developing countries. Twenty years experience of La Chaine de L'espoir (Chain of Hope)]

Because of their high incidence, cardiac disorders in children are now a public health issue. These children require multidisciplinary management, but surgery is sometimes unavoidable. The two most frequent types of cardiac disorder in children are congenital defects and rheumatic valve disease. La Chaine de l'Espoir (Chain of Hope) is present in more than 30 countries in Africa, Asia and the Middle East. Due to the socio-economic context and lack of technical resources, pediatric heart surgery has several particular characteristics in developing countries. Infants rarely undergo cardiac surgery, given the complexity of their management and particularly the need for intensive care. Another specificity is the need to limit treatment to reparatory or conservative methods. Surgery is rarely attempted in terminally ill patients. Costs must be kept to a minimum, and this is why we have optedfor local manufacture of mitral rings, led by Daniel Roux. After 20 years of practice we have found that regional hospitals are the smallest structures that can offer acceptable results in terms of patient care and professional training

Desflurane-induced postconditioning of diabetic human right atrial myocardium in vitro

AIM

We tested the hypothesis that brief exposure to desflurane at the time of reoxygenation might be able to protect against hypoxia-reoxygenation injury in human myocardium from diabetic (insulin-dependent, ID; and non-insulin-dependent, NID) patients and non-diabetic (ND) subjects.

METHODS

The force of contraction (34 degrees C, stimulation frequency 1Hz) in the right atrial trabeculae was recorded during 30min of hypoxia followed by 60min of reoxygenation. Desflurane (at 3, 6 and 9%) was administered during the first 5min of reoxygenation. The force of contraction at the end of the 60-min reoxygenation period (FoC(60)) was compared in the study groups (means+/-SD).

RESULTS

In the ND group, desflurane at 3, 6 and 9% (FoC(60): respectively 78+/-10%, 84+/-4% and 85+/-12% of baseline) enhanced the recovery of FoC(60) compared with the ND-controls (53+/-7% of baseline; P<0.05). In the ID group, desflurane at 3% (61+/-4%) did not modify the recovery of FoC(60) compared with the ID-controls (54+/-6%), whereas desflurane at 6 and 9% (75+/-11% and 81+/-8%, respectively) enhanced the recovery of FoC(60)vs the controls (P<0.05). In the NID group, desflurane at 3% (57+/-5%) also failed to modify the recovery of FoC(60) compared with the NID-controls (52+/-10%), while desflurane at 6 and 9% (80+/-10% and 79+/-7%, respectively) enhanced the recovery of FoC(60)vs the controls (P<0.05).

CONCLUSION

Desflurane in vitro was able to postcondition diabetic (both ID and NID) human myocardium at 6 and 9%, but not at 3%.

Sevoflurane- and desflurane-induced human myocardial post-conditioning through Phosphatidylinositol-3-kinase/Akt signalling

BACKGROUND

The role of phosphatidylinositol-3-kinase (PI3K) in sevoflurane- and desflurane-induced myocardial post-conditioning remains unknown.

METHODS

We recorded isometric contraction of isolated human right atrial trabeculae (oxygenated Tyrode's at 34 degrees C, stimulation frequency 1 Hz). In all groups, a 30-min hypoxic period was followed by a 60-min reoxygenation period. At the onset of reoxygenation, muscles were exposed to 5 min of sevoflurane 1%, 2%, and 3%, and desflurane 3%, 6%, and 9%. In separate groups, sevoflurane 2% and desflurane 6% were administered in the presence of 100 nM wortmannin, a PI3K inhibitor. Recovery of force after the 60-min reoxygenation period was compared between groups (mean +/- SD).

RESULT

As compared with the Control group (49 +/- 7% of baseline) PostC by sevoflurane 1%, 2%, and 3% (78 +/- 4%, 79 +/- 5%, and 85 +/- 4% of baseline, respectively) and desflurane 3%, 6%, and 9% (74 +/- 5%, 84 +/- 4%, and 86 +/- 11% of baseline, respectively) enhanced the recovery of force. This effect was abolished in the presence of wortmannin (56 +/- 5% of baseline for sevoflurane 2%+wortmannin; 56 +/- 3% of baseline for desflurane 6%+wortmannin). Wortmannin alone had no effect on the recovery of force (57 +/- 7% of baseline).

CONCLUSION

In vitro, sevoflurane and desflurane post-conditioned human myocardium against hypoxia through activation of phosphatidylinositol-3-kinase.

Less invasive radial artery harvest

BACKGROUND

Recent studies have sparked a renewed interest in the use of autogenous radial arteries in coronary operations. Some concerns have been found about sequelae of conventional harvesting. A less invasive technique for radial artery harvesting has been proposed by others using endoscopic devices. This technique is time consuming, needs expensive instrumentation and an important learning curve.

METHODS

A new less invasive approach for radial harvesting has been developed with a light assisted retractor under direct vision. A small skin incision, median in the forearm, is followed by dissection of the proper plane of the artery. A subcutaneous tunnel is created around the vessel and all the branches are ligated or clipped. The dissection of the pedicle under the skin is completed with the aid of a modified light assisted retractor, originally designed for the saphenous vein harvesting. The incision is closed after heparin reversal with a small redon as drainage.

RESULTS

A preliminary serie of 15 patients have been operated with this technique. In all patients the radial artery was patent and functional at the postoperative angiography. Morbidity included only a light hematoma at the beginning of our experience.

CONCLUSION

This less invasive technique for the radial artery harvesting appears to be an excellent surgical compromise between the open technique and the endoscopic procedure; it is easy to perform, the learning curve is acceptable and it offers an excellent aesthetic result.

Pre-operative balloon counterpulsation and off-pump coronary surgery for high-risk patients

Coronary artery bypass surgery (CABG) can be performed less invasively without cardiopulmonary bypass (CPB). Multivessel off-pump CABG (OPCAB) is challenging in patients with critical left main stenosis (> 70%) and/or severe ventricular dysfunction (ejection fraction < 0.35) Our objective was the evaluation of efficiency of intra aortic balloon pump (IABP) preoperatively in this high-risk group in order to perform OPCABG safely.

MATERIAL AND METHOD

In a consecutive 10-month period (out of 88 OPCABG patients) 23 high-risk patients were treated and were compared with 15 on-pump patients (out of 69) with the same criteria.

RESULTS

Preoperative implantation of IABP was significantly higher in the OPCABG group (70% vs 46%, p < 0.05). No conversion to CPB was required in the OPCABG group. Post-operative angiography was systematically performed and demonstrated 97.5% patency of anastomosis. No device-related complications occurred. No difference was found concerning age, risk factors, emergency surgery, ejection fraction, mean number of grafts per patient (2.64 versus 2.75) and average operating time. In contrast, OPCABG demonstrated a trend toward reduced morbidity in terms of atrial fibrillation, reexploration for bleeding and prolonged ventilator requirement > 12 h. Mortality was less in the OPCABG group (p < 0.05).

CONCLUSION

More randomized controlled trials are needed to evaluate the true efficacy of elective IABP in OPCABG high-risk patients. Until such studies are evaluated, and therefore because older and sicker patients now constitute a greater percentage of candidates for OPCABG, the timing of application of the IABP is warranted. These results may further justify preoperative use of the IABP in a large proportion of this group of patients.

[Severe intoxication with cardiotoxic drugs: value of emergency percutaneous cardiocirculatory assistance]

Acute severe self-administration of an overdose of betablockers, calcium antagonists or antiarrhythmic drugs is rare but carries a mortality of 10-15%. Between May 1997 and March 2000, 6 patients with an average age of 34 years (range 17-55 years) had a cardiac arrest on admission requiring emergency cardiac massage and emergency intubation with ventilatory assistance following massive ingestion of cardiotoxic drugs. Echocardiography confirmed complete biventricular akinesia. The surgical team implanted a cardiovascular assist device (ECMO: Extra Corporeal Membrane Oxygenation) by the femoral approach with pre-heparinated percutaneous cannula. The first two patients died of multi-organ failure due to a delay in the installation of the assistance. The 4 other patients survived without sequellae or recurrences. The average time on ECMO was 59.25 +/- 2 hours (range 48-71 hours). The early recognition of the indication for ECMO was one of the most important predictive factors for morbidity and mortality. The strategy of patient management should be determined in the emergency room: in cases of cardiocirculatory arrest resistant to symptomatic treatment (stomach washout, intravenous fluids, isoprenaline, inotropic agents) an echocardiogram should be obtained and the cardiac surgical team alerted to the problem. The introduction of pre-heparinated circuits, percutaneous cannula and peripheral shunts has widened the indications, efficacy (detoxification, restoration of peripheral tissue perfusion) and accessibility to this material, while limiting its duration. The collaboration of experienced multidisciplinary teams (emergency room staff, cardiologists, anaesthetists and surgeons) should optimise the timing of implantation and the monitoring of these systems and improve the results of resuscitation of these patients.

Beating heart myocardial revascularization on extracorporeal circulation in patients with end-stage coronary artery disease

OBJECTIVES

To evaluate in a cohort of ESCAD patients (pts) the effects of on-pump/beating-heart versus conventional CABG in terms of early and mid-term survival and morbidity and LV function improvement.

METHODS

Between January 1993 and December 2000, 78 (Group I) ESCAD pts underwent on-pump/beating-heart surgery. Mean age in Group I was 66.2+/-6 (58-79), NYHA and CCS class were 3.2+/-0.6 and 3.3+/-0.4 respectively, Myocardial viability index 0.69+/-0.1 (%), LVEF (%) 24.8+/-4, LVEDP (mmHg) 28.1+/-5.8 and LVEDD(mm) 69.5+/-6. Group II consisted in 78 ESCAD patients undergoing conventional CABG selected in a randomized fashion from an age, sex, and LVEF corrected group of patients. Mean age in Group II was 65.7+/-5 (57-78), NYHA 3.1+/-0.7, CCS 3.4+/-0.8, LVEF(%) 25+/-5, LVEDP(mmHg) 27.9+/-4.4 and LVEDD(mm) 69.2+/-7.2.

RESULTS

Postoperatively, 5(7.7%) patients died in Group I versus 7(11.5%) patients in Group II (P>0.1). CPB time resulted to be in Group II patients (P=0.001) and the mean distal anastomoses per patient was similar between groups (P=Ns). Perioperative AMI (P=0.039), LCOS (P=0.002), necessity for ultrafiltration (P=0.018) and bleeding>1000 ml (P=0.029) were significantly higher in Group II. None of the Group I patients underwent surgical revision for bleeding versus 8(10.3%) patients in Group II (P=0.011). At 6 months after surgery, the LV function improved significantly in Group I patients, demonstrated by an increased LVEF=27.2+/-4(%)(P=0.001), lower LVEDP=26.4+/-3(mmHg)(P=0.029) and LVEDD=67+/-4(mm) (P=0.004) instead of a lower LVEDD=66.8+/-6(mm)(P=0.032) versus the preoperative data in Group II. The actuarial survival at 1, 3 and 5 yr were 90, 82 and 71% in Group I and 89, 83 and 74% in Group II (P=Ns).

CONCLUSION

In ESCAD patients who may poorly tolerate cardioplegic arrest, on-pump/beating-heart CABG may be an acceptable alternative associated with lower postoperative mortality and morbidity. Such a technique offers a better myocardial and renal protection associated with lower postoperative complications due to intraoperative hypoperfusion.

Ischemic mitral valve regurgitation grade II-III: correction in patients with impaired left ventricular function undergoing simultaneous coronary revascularization

BACKGROUND AND AIM OF THE STUDY

Mitral valve regurgitation (MVR), occurring as a result of myocardial ischemia and global left ventricular (LV) dysfunction, is predictive of poor outcome. The study aim was to assess the feasibility of mitral valve surgery concomitant with coronary artery bypass grafting (CABG) in patients with ischemic MVR grade II-III and impaired LV function.

METHODS

Between January 1996 and July 2000, 99 patients with grade II and III ischemic MVR and LV ejection fraction (LVEF) 17-30% underwent either combined mitral valve surgery and CABG (group I, n = 49) or isolated CABG (group II, n = 50). LVEF (%), LV end-diastolic diameter (LVEDD; mm), LV end-diastolic pressure (LVEDP; mmHg), LV end-systolic diameter (LVESD; mm) respectively were 27.5+/-5, 67.7+/-7, 27.7+/-4 and 51.4+/-7 in group I versus 27.8+/-4, 67.5+/-6, 27.5+/-5 and 51.2+/-6 in group II. In group I, mitral valve repair was performed in 43 patients (88%) and replacement in six (12%).

RESULTS

Preoperative data analysis showed no difference between groups. Five patients (10%) died in group I, compared with six (12%) in group II (p = NS). Within six months of surgery, LV function and geometry improved significantly in group I versus group II (LVEF, p <0.001; LVEDD, p = 0.002; LVESD, p = 0.003, LVEDP, p <0.001); only mild improvements were seen in group II. The regurgitation fraction decreased significantly in group I patients after surgery (p <0.001). Cardiac index increased significantly in groups I and II (p <0.001 and p = 0.03, respectively). In group I at follow up, four of six patients undergoing mitral valve replacement died, compared with five of 43 patients (11.5%) undergoing mitral valve repair (p = 0.007). At three years, the overall survival in group II was significantly lower than in group I (p <0.009).

CONCLUSION

Both MV repair and replacement preserving subvalvular apparatus in patients with impaired LV function offered acceptable outcome in terms of morbidity and survival. Surgical correction of grade II-III MVR in patients with impaired LV function should be taken into consideration as it provides better survival and improves LV function.

Should mild-to-moderate and moderate ischemic mitral regurgitation be corrected in patients with impaired left ventricular function undergoing simultaneous coronary revascularization?

INTRODUCTION

Mitral valve regurgitation (MR) occurring as a result of myocardial ischemia and global left ventricular (LV) dysfunction predicts poor outcome. This study assessed the feasibility of mitral valve (MV) surgery concomitant with coronary artery bypass grafting (CABG) in patients with mild-to-moderate and moderate ischemic MR and impaired LV function.

MATERIALS AND METHOD

From January 1996 to July 2000, 49 patients (group 1) and 50 patients (group 2) with grade II and grade III ischemic MR and LV ejection fraction (EF) between 17% and 30% underwent combined MV surgery and CABG (group 1) or isolated CABG (group 2). LVEF (%), LV end-diastolic diameter (EDD) (mm), LV end-diastolic pressure (EDP) (mmHg), and LV end-systolic diameter (ESD) (mm) were 27.5 +/- 5, 67.7 +/- 7,27.7 +/- 4, and 51.4 +/- 7, respectively in group 1 versus 27.8 +/- 4, 67.5 +/- 6, 27.5 +/- 5, and 51.2 +/- 6, respectively in group 2. Groups 1 and 2 were divided into Groups 1A and 2A with mild-to-moderate MR (22 [45%] and 28 [56%] patients, respectively) and groups 1B and 2B with moderate MR (27 [55%] and 22 [46%], respectively). In group 1, MV repair was performed in 43 (88%) patients and MV replacement in 6 (12%) patients.

RESULTS

Preoperative data analysis did not reveal any difference between groups. Five (10%) patients in group 1 died versus 6 (12%) in group 2 (p = ns). Within 6 months after surgery, LV function and its geometry improved significantly in group 1 versus group 2 (LVEF, p < 0.001; LVEDD, p = 0.002; LVESD, p = 0.003; and LVEDP (p < 0.001) improved significantly in group 1 instead of a mild improvement in Group 2). The regurgitation fraction decreased significantly in group 1 patients after surgery (p < 0.001). There was an inverse strong correlation between postoperative forward cardiac output and regurgitation fraction (p < 0.001). LVEF and LVESD improved significantly in group 1 versus group 2 patients (p = 0.04 and p = 0.02, respectively). The cardiac index increased significantly in group 1 and 2 (p < 0.001 and p = 0.03, respectively). LV function and geometry improved significantly postoperatively in group 1B versus group 2B (LVEDD, p = 0.027; LVESD, p = 0.014; LVEDP, p = 0.034; and LVEF, p = 0.02), instead of a mild improvement in group 1A versus group 2A (LVESD, p = 0.015; LVEF, p = 0.046; and LVEDD and LVEDP, p = 0.05). At follow-up, 4 (67%) of 6 patients undergoing MV replacement died versus 5 (11.5%) of 43 patients undergoing MV repair in group 1 (p = 0.007). The overall survival at 3 years in Group 2 was significantly lower than group 1 (p < 0.009).

CONCLUSION

MV repair and replacement-preserving subvalvular apparatus in patients with impaired LV function offered acceptable outcomes in terms of morbidity and survival. Surgical correction of mild-to-moderate and moderate MR in patients with impaired LV function should be taken into consideration since it yields better survival and improved LV function.

The in vitro effects of remifentanil, sufentanil, fentanyl, and alfentanil on isolated human right atria

Because some clinical studies have suggested that opioids used in anesthesia may have different deleterious hemodynamic effects, we compared the direct myocardial effects of cumulative concentrations of remifentanil, sufentanil, fentanyl, and alfentanil on inotropic and lusitropic variables of isolated human myocardium in vitro. Human right atrial trabeculae, obtained from patients scheduled for coronary bypass surgery or aortic valve replacement, were suspended vertically in an oxygenated (95% oxygen/5% CO(2)) Tyrode's modified solution ([Ca(2+)](o) = 2.0 mM, 37 degrees C, pH 7.40, stimulation frequency 1 Hz). The effects of cumulative concentrations (10(-11), 10(-10), 10(-9), 10(-8), 10(-7), and 10(-6) M) of remifentanil (n = 8), sufentanil (n = 8), fentanyl (n = 8), and alfentanil (n = 8) on inotropic and lusitropic variables of isometric twitches were measured. Remifentanil, sufentanil, and fentanyl did not modify active isometric force and peak of the positive force derivative as compared with the Control group. Alfentanil induced a dose-dependent decrease in active isometric force and peak of the positive force derivative. This effect was abolished in the presence of [Ca(2+)](o) = 4.0 mM. None of these opioids altered lusitropic variables.

The in vitro effects of remifentanil, sufentanil, fentanyl, and alfentanil on isolated human right atria

Because some clinical studies have suggested that opioids used in anesthesia may have different deleterious hemodynamic effects, we compared the direct myocardial effects of cumulative concentrations of remifentanil, sufentanil, fentanyl, and alfentanil on inotropic and lusitropic variables of isolated human myocardium in vitro. Human right atrial trabeculae, obtained from patients scheduled for coronary bypass surgery or aortic valve replacement, were suspended vertically in an oxygenated (95% oxygen/5% CO(2)) Tyrode's modified solution ([Ca(2+)](o) = 2.0 mM, 37 degrees C, pH 7.40, stimulation frequency 1 Hz). The effects of cumulative concentrations (10(-11), 10(-10), 10(-9), 10(-8), 10(-7), and 10(-6) M) of remifentanil (n = 8), sufentanil (n = 8), fentanyl (n = 8), and alfentanil (n = 8) on inotropic and lusitropic variables of isometric twitches were measured. Remifentanil, sufentanil, and fentanyl did not modify active isometric force and peak of the positive force derivative as compared with the Control group. Alfentanil induced a dose-dependent decrease in active isometric force and peak of the positive force derivative. This effect was abolished in the presence of [Ca(2+)](o) = 4.0 mM. None of these opioids altered lusitropic variables.

Aortic root remodeling with the "cuff" technique for stentless valve implantation

Aortic root and sinotubular junction dilatation and aneurysm of ascending aorta are considered relative contra-indications to implantation of a stentless valve prosthesis, because the modified aortic geometry leads to aortic incompetence and early failure of the prosthesis. Aortic root reconstruction can be performed according to various techniques. We present a surgical technique in which a tubular graft, replacing an ascending aortic aneurysm, allows sinotubular remodeling and satisfactory implantation of a stentless prosthesis. The native aorta is inserted into the vascular prosthesis at the level of the sinotubular junction which is wrapped in order to prevent commissure spreading. Sizing of the vascular and valve prosthesis is made according to annular diameter. Since October 1999, 6 patients have been operated using this technique with good results.

Catastrophic consequences of a free floating thrombus in ascending aorta

Floating masses in ascending aorta are an uncommon source of embolism. We report the case of a 46-year-old woman, smoker, on synthetic progestagen, with no previous history of thrombotic events, who was admitted to our emergency department for an acute anterior myocardial infarction. Coronary angiogram showed occlusion of left main coronary trunk. Recanalization of the artery was obtained. Ascending aorta angiogram revealed a free floating mass attached to the aortic wall without evidence of aortic dissection. Transesophageal echocardiography confirmed the presence of a pedunculated mobile mass attached to the aortic wall superior to the left coronary ostium. The patient underwent urgent surgery. Intraoperatively a floating thrombus was localized in the posterior wall of ascending aorta. At macroscopical examination aortic wall and leaflets were normal. Post-operative low cardiac output refractory to inotropic drugs and intraaortic balloon counterpulsation required a circulatory assist device. Consequences for the patient were catastrophic in terms of outcome.

Necrotizing granulomata of the aortic valve in Wegener's disease

Wegener's disease is an inflammatory disease of unknown etiology, characterized by a granulomatous-necrotizing general vasculitis. Cardiac involvement in the form of aortic pathology is not frequent. We report a case of Wegener's granulomatosis which required prosthetic aortic valve replacement for aortic valve insufficiency. Microscopic examination of the valve demonstrated histopathology typical of Wegener's disease.

Surgical treatment of pulmonary aspergilloma: current outcome

OBJECTIVE

This retrospective study was designed to confirm that aggressive pulmonary resection can provide effective long-term palliation of disease for patients with pulmonary aspergilloma.

METHODS AND RESULTS

From 1959 to 1998, 84 patients underwent a total of 90 operations for treatment of pulmonary aspergilloma in the Marie-Lannelongue Hospital. The mean follow-up period was 9 years, and 83% of the patients were followed up for 5 years or until death, if the latter occurred earlier. The median age was 44 years. The most common indications were hemoptysis (66%) and sputum production (15%). Fifteen patients (18%) had no symptoms. Tuberculosis and lung abscess were the most common underlying causes of lung disease (65%). The procedures were 70 lobar or segmental resections, 8 cavernostomies, and 7 pneumonectomies. Five thoracoplasties were required after lobectomy (3 patients) or pneumonectomy (2 patients). The operative mortality rate was 4%. The major complications were bleeding (23 patients), prolonged air leak (31 patients), respiratory failure (10 patients), and empyema (5 patients). The actuarial survival curve showed 84% survival at 5 years and 74% survival at 10 years. During the first 2 years, death was related to the surgical procedure and the underlying disease. In contrast, 85% of the survivors had a good late result.

CONCLUSION

Lobar resection in both the symptomatic and the asymptomatic patients was conducted in low-risk settings. For patients whose condition is unfit for pulmonary resection, cavernostomy may need to be undertaken despite the high operative risk. The better survival rate in this study may have been due to the selection of patients with better lung function and localized pulmonary disease.

Postinfarction ventricular septal rupture: early repair through the right atrial approach

OBJECTIVE

Early repair of posterior ventricular septal rupture associated with myocardial infarction by means of transinfarct ventriculotomy is technically challenging and can be associated with significant mortality and morbidity. An alternative route of exposing the septum is through the right atrium. This technique, which avoids direct incision of the ventricle in select patients, reduces postrepair bleeding and impairment of ventricular contractile function.

METHODS

The results of 12 patients operated on over a 20-year period were reviewed and analyzed. Late follow-up was obtained in all patients who survived the operation. There were 9 men and 3 women, with a mean age of 69.9 years. The mean time between acute myocardial infarction and surgery was 7.3 days (range, 2-16 days). Six patients were in New York Heart Association class IV, and 3 patients presented for surgery in cardiogenic shock. One patient had previously undergone a coronary artery bypass. The surgical technique included a standard sternotomy approach with a transatrial approach to the septal rupture. In all patients the septal rupture was repaired with a Dacron patch.

RESULTS

There were 3 early deaths and 1 late death; one patient was reoperated on for a residual shunt. Postoperative complications included low cardiac output, acute renal tubular necrosis, and supraventricular arrhythmia. Eight patients are alive and undergoing echocardiographic investigation, and only 1 patient had a small residual shunt.

CONCLUSION

Our experience shows that a posterior ventricular septal rupture can be safely repaired through a transatrial approach. Avoiding additional damage to the ventricle, it reduces the risks of the postoperative bleeding and enhances survival.

In vitro effects of desflurane, sevoflurane, isoflurane, and halothane in isolated human right atria

BACKGROUND

Direct myocardial effects of volatile anesthetics have been studied in various animal species in vitro. This study evaluated the effects of equianesthetic concentrations of desflurane, sevoflurane, isoflurane, and halothane on contractile parameters of isolated human atria in vitro.

METHODS

Human right atrial trabeculae, obtained from patients undergoing coronary bypass surgery, were studied in an oxygenated (95% O2-5% CO2) Tyrode's modified solution ([Ca2+]o = 2.0 mM, 30 degrees C, stimulation frequency 0.5 Hz). The effects of equianesthetic concentrations (0.5, 1, 1.5, 2, and 2.5 minimum alveolar concentration [MAC]) of desflurane, sevoflurane, isoflurane, and halothane on inotropic and lusitropic parameters of isometric twitches were measured.

RESULTS

Isoflurane, sevoflurane, and desflurane induced a moderate concentration-dependent decrease in active isometric force, which was significantly lower than that induced by halothane. In the presence of adrenoceptor blockade, the desflurane-induced decrease in peak of the positive force derivative and time to peak force became comparable to those induced by isoflurane. Halothane induced a concentration-dependent decrease in time to half-relaxation and a contraction-relaxation coupling parameter significantly greater than those induced by isoflurane, sevoflurane and desflurane.

CONCLUSIONS

In isolated human atrial myocardium, desflurane, sevoflurane, and isoflurane induced a moderate concentration-dependent negative inotropic effect. The effect of desflurane on time to peak force and peak of the positive force derivative could be related to intramyocardial catecholamine release. At clinically relevant concentrations, desflurane, sevoflurane, and isoflurane did not modify isometric relaxation.

Cosmetic aspects in minimally invasive cardiac surgery

The initial focus of the pioneering cardiac surgeons was appropriately centered on survival as opposed to cosmetic results. A variety of minimally invasive techniques have been introduced to perform cardiac operations through a limited incision. As the results in cardiac surgery improved, cosmetic and psychological implications of surgery become more important in the evaluation of the morbidity of these procedures. Future comparative studies will be mandatory to show whether these small incisions have an actual advantage on recovery or morbidity or whether their interest is entirely aesthetic.

Aortic balloon entrapment complicating intra-aortic balloon counterpulsation

Short-term balloon counterpulsation may be complicated by aortic balloon entrapment. We report a patient in whom video-coronary surgery was performed using beating heart anastomosis. This patient developed intra-aortic balloon (IAB) entrapment 4 days after initiation of the counterpulsation previously implanted for a preoperative low ejection fraction. No limb ischaemia was detected, but urgent removal of the balloon catheter is mandatory if blood is detected in the tubing connecting the balloon to the console, even in the presence of adequate function of the IAB assistance.

A special adapted retractor for the mini-sternotomy approach

Minimally invasive cardiac operations are now possible through different approaches. To provide the best exposure and sufficient space to manipulate the heart, a special adapted thoracic retractor has been developed for the ministernotomy approach. It is universally adjustable and provides excellent and consistent exposure especially below the incision edges. The retractor has the further advantage of a very low profile on the surgeon's side and at the cephalic and caudal extremes of the operative field, which permits the greatest possible access through a limited access. We have successfully used this retractor in more than 180 patients. A less invasive median sternotomy through a 6-9-cm incision has been our original approach.

The reversibility of cardiac neuronal function after removal of a pheochromocytoma: an I-123 MIBG Scintigraphic Study

PURPOSE

Twelve patients with proved pheochromocytoma evaluated in our institution between 1991 and 1997 are described.

METHODS

The patients' urinary excretion rates and their metabolites (vanylmandelic acid and metanephrines) were significantly greater than normal before surgery. Echocardiography showed normal left ventricular ejection fractions (72% +/- 8%). All of the patients underwent planar I-123 metaiodobenzylguanidine (MIBG) scintigraphy to assess cardiac neuronal uptake 4 hours after and locate a pheochromocytoma 24 hours after intravenous injection of 185 MBq (3 mCi) I-231 MIBG. Ten patients with pheochromocytoma had positive tumoral findings with I-123 MIBG scintigraphy. Twelve patients had significant impairment of cardiac neuronal uptake of MIBG, with a heart:mediastinum ratio averaging 142% +/- 18% (normal value, 230% +/- 30%, P < 0.05). Postoperative cardiac MIBG imaging was performed in all patients (at 6 +/- 3 months).

RESULTS

After surgical removal of the pheochromocytoma, cardiac MIBG uptake and the heart:mediastinum uptake ratios improved significantly (197% +/- 20%, P < 0.05) in all the patients. Urinary excretion rates and metabolites returned to the normal range. However, no significant correlation was found between cardiac MIBG uptake and urinary excretion rates and metabolites after the tumors were removed.

CONCLUSION

Removing a pheochromocytoma reversed cardiac neuronal function as assessed by MIBG scintigraphy.

Non-penetrating subclavian artery trauma: management by selective transluminally placed stent device

Non-penetrating injury to the subclavian artery has not often been reported. The limited experience of surgeons with this type of trauma and the difficult vascular control required for its management make it a surgical challenge. We report on two cases, one after blunt trauma and the other with a subclavian artery aneurysm following anterior dislocation of the shoulder. Percutaneous stent implantation in the subclavian artery was successfully performed with, in the second case, coil embolization of the aneurysm. Follow-up Doppler sonography and angiogram demonstrated patency and luminal integrity of the involved artery. This less invasive procedure may be a significant advance and a new approach in the conservative management of traumatic subclavian injury for selected cases.

Detection of cardiac myxoma by F-18 FDG PET

Intracardiac tumors occur infrequently and are difficult to diagnose with CT and MRI. The authors describe the successful imaging of a right atrial myxoma with F-18 FDG PET.

Minimally invasive internal thoracic artery harvest: the hybrid approach

BACKGROUND

Safe harvesting of the left internal thoracic artery is a difficult problem during minimally invasive coronary artery bypass grafting without cardiopulmonary bypass. A complete internal thoracic artery dissection through a limited approach is technically demanding and time consuming and different techniques have been proposed.

METHODS AND RESULTS

Based on our experience, the different surgical approaches and technical considerations are reviewed.

CONCLUSIONS

A hybrid technique using dissection under direct vision and completed by thoracoscopy is discussed and proposed as our preferred technique of internal thoracic artery harvesting.

Spontaneous native aortic valve thrombosis

Spontaneous thrombosis of a native aortic valve is an uncommon event that usually follows local trauma, such as cardiac surgery or left heart catheterization, or occurs as a complication of bacterial endocarditis. We report the case of a 65-year-old woman with a history of retinal artery occlusion and severe aortic valve stenosis, in whom transesophageal echocardiography revealed a mobile mass attached to the ventricular surface of the aortic valve. There was no evidence of any hypercoagulable state or infection process. Surgery was performed and a severely stenotic valve resected; a partially organized and firmly adherent free-floating thrombotic mass was observed on the ventricular surface of the aortic valve. Histologic examination demonstrated an organized thrombus. Eleven months after surgery the patient is doing well.

Pulmonary artery bullet injury following thoracic gunshot wound

Thoracic trauma occurs frequently but seldom requires surgery (10-20%, [1]). The mortality rate for gunshot wound of the chest varies from 14.3 to 36.8% [2]. We report, herein an example of bullet injury to the pulmonary artery (PA) following a thoracic gunshot wound. This patient had previous history of coronary surgery. Absolute and relative indications for exploratory thoracotomy in emergency will be reviewed.

Recurrent left-sided heart leiomyosarcoma: should heart transplantation be legitimate?

Leiomyosarcoma of the heart is an uncommon primary malignant tumor with poor postoperative survival that may be measured in months. A leiomyosarcoma of the left atrium was diagnosed in a 47-year-old man. Initial admission was for acute pulmonary edema requiring emergency surgery. The tumor involved the left atrial cavity, and a radical resection was performed. Six months later an isolated myxomatous recurrence was detected. Heart transplantation was then performed. The patient is in good health 20 months after operation with no evidence of residual disease or recurrence. The literature has been reviewed. Surgical resection is not an adequate treatment for leiomyosarcoma of the left atrium and early heart transplantation probably offers the only hope for these patients.

Impairment of cardiac neuronal function in acute myocarditis: iodine-123-MIBG scintigraphy study

Abnormalities of norepinephrine uptake have been found to reflect impairment in adrenergic nerve function that has influenced the cardiac outcome of patients with heart failure. The aim of this study was to explore the cardiac neuronal function by using 123I-metaiodobenzylguanidine (MIBG) scintigraphy in patients with acute myocarditis.

METHODS

We studied 15 patients (age range 42 +/- 10 yr) with clinical, biological, electrocardiographic and radionuclide left ventricular ejection fraction (LVEF) (41% +/- 7%) data indicating myocarditis and 10 normal subjects (age range 36 +/- 7 yr, mean radionuclide LVEF 69% +/- 8%, p < 0.05). Fourteen patients had positive histologic findings of myocarditis and 1 had nonspecific histological data. All patients underwent planar cardiac imaging after intravenous injection of 185 MBq 123I-MIBG and right ventricular biopsy within 7 days. A chest anterior view was acquired 4 hr later. Heart-to-mediastinum ratio activity was measured, as previously described in our laboratory.

RESULTS

Significant impairment of cardiac neuronal uptake of MIBG was observed and based on a reduction of heart-to-mediastinum ratio (148% +/- 16% versus 234% +/- 36%, p < 0.05). A significant correlation was observed between LVEF and MIBG uptake in patients (y = 1.58x +/- 83.7, r = 0.72, p < 0.01).

CONCLUSION

Acute myocarditis is associated with an injury of the cardiac adrenergic neuronal function. In addition to the inflammatory injury of the myocytes, the impairment of adrenergic function may be involved in the cardiac pump failure induced by myocarditis.

Minimally invasive coronary surgery: surgical considerations and assessment of cardiac troponin I

OBJECTIVE

Minimally invasive coronary artery bypass grafting (MICABG) using internal thoracic artery (ITA) without median sternotomy and cardiopulmonary bypass (CPB) become a viable option for the management of proximal left anterior descending artery (LAD) disease. Recent studies have demonstrated that cardiac troponine I (cTnI), a new highly specific diagnostic marker of cardiomyocyte damage, is a reliable marker of cardiac ischemia during heart operations under CPB.

METHODS

Between February 1996 and April 1997, 14 patients (10 males, 4 females aged 41-68) underwent MICABG with single-vessel bypass grafting for LAD stenosis (n = 9) or occlusion (n = 5). Video-assisted surgery with left anterior mini-thoracotomy was performed in ten patients and vertical parasternal thoracotomy in the other four. cTnI was measured before LAD occlusion (T0), during anastomosis (T1) and 10 min (T2), 6 h (T3), 24 h (T4), 48 h (T5), 72 h (T6) after coronary reperfusion. Assay methods used a specific enzyme-linked immunosorbent autoanalyzer (Stratus) in peripheral venous blood. Control coronary angiography was performed in all patients.

RESULTS

There were no operative complications, no reoperations for bleeding. cTnI concentrations were expressed in ng/ml +/- SD. Mean cTnI level was <3.85+/-1 ng/ml (range 0-32.8). Values were: T0 = 0, T1 = 0.5+/-0.1, T2 = 1.15+/-0.2, T3 = 2.16+/-0.6, T4 = 1.5+/-0.3, T5 = 0.6+/-0.02, T6 = 0.4+/-0.01. Angiography showed patent grafts in 12 patients. A 'no flow situation' was demonstrated in a cardiac symptom-free patient, with reestablishment of flow on repeat angiogram at 6 months. In the other case, early ITA graft occlusion in a patient with two-vessel disease was correlated with a higher cTnI concentration (17.8 ng/ml). Percutaneous angioplasty was performed on the right coronary artery, complicated with dissection and cardiac failure. This patient died 3 months after the MICABG despite ventricular assist device.

CONCLUSION

cTnI did not increase during and after coronary artery occlusion and local immobilization of the heart. It can be used to evaluate postoperative myocardial damage on the beating heart using MICABG.

Less-invasive heart surgery: the preservation of median approach

OBJECTIVE

Cardiac surgery has been traditionally performed via a median sternotomy incision where a large exposure of the mediastinum assured most of the cardiac procedures. Recently, the concepts of less-invasive surgery, well affirmed in many surgical specialties, led cardiac surgeons to develop limited accesses in coronary, valves and congenital operations.

METHODS

Between January and May 1997, 30 patients were operated on with a less-invasive approach. A short (6-9 cm) median incision followed by a subcomplete sternotomy permitted a limited opening of the chest without compromising the surgical exposure; a conventional central CPB was instituted and valve surgery and most of intracardiac procedures were performed without modification of the standard technique.

RESULTS

No mortality was observed; morbidity was minimal. Cardiopulmonary bypass time and aortic cross-clamp time averaged 84+/-9 and 61+/-11 min, respectively. The majority of patients were extubated and discharged from the ICU early. Chest drainage lost on average 290+/-180 ml/m2.

CONCLUSIONS

Despite our limited initial experience, this technique seems to provide several potential and practical advantages: there is less trauma and pain reported by patients; the small wound reduces the potential for wound infection and blood loss. Patients are extubated and discharged from the hospital earlier with lower overall costs.

Less invasive cardiac operations through a median sternotomy: 100 consecutive cases

BACKGROUND

In the beginning of 1997, we developed a routine approach to intracardiac operations through a less invasive median sternotomy. A limited (6 to 9 cm) median skin incision followed by a subcomplete (manubrium and body) median sternotomy makes opening and closing of the chest easier; conventional central cardiopulmonary bypass is instituted, and no modifications to the surgical techniques are necessary.

METHODS

In 100 consecutive patients (mean age, 62.04 years; range, 9 to 92 years), 70 aortic, 13 mitral, and 17 other cardiac procedures were performed. Surgical technique required many self-made instruments; anesthetic "fast-tracking" management was performed.

RESULTS

Four patients died. One conversion to a standard sternotomy and five reoperations for bleeding were necessary. Cross-clamp time ranged from 33 to 140 minutes (mean +/- standard deviation, 69.23 +/- 20.99 minutes) and total drainage loss ranged from 120 to 1,800 mL x m(-2) x 24 h(-1) (mean, 288 mL x m(-2) x 24 h(-1)). The postoperative course was shorter than usual, and one complication in the healing wound was observed. The scar was shorter than 9 cm in all patients.

CONCLUSIONS

Our work shows that a less invasive approach to many cardiac operations is possible through a modified median sternotomy. This technique provides many potential and practical advantages: there is less trauma and pain reported by patients, and the small wound reduces the risk of infection and blood loss. Patients are extubated and discharged from the hospital earlier.

Modified biatrial approach for the extensive resection of left atrial myxomas

Surgical excision of left atrial myxomas is usually curative. When the root of the pedicle and the full thickness of the adjacent interatrial septum are excised, the repair of the created atrial septal defect requires a pericardial or Dacron patch. The biatrial approach generally has been accepted as the technique having the advantages of well identifying the site of attachment and inspection of the four cardiac chambers. We proposed a modification of this technique that allows the reconstruction of the created septal defect without any foreign patch.

Iodine-123-metaiodobenzylguanidine SPECT of regional cardiac adrenergic denervation in Brugada syndrome

We present the case of 44-yr-old man who presented syncope with ventricular tachycardia in the setting of Brugada syndrome. In addition to the electrocardiographic evidence of the syndrome and the absence of apparent structural heart disease, clear defects of myocardial neuronal metaiodobenzylguanidine (MIBG) uptake on MIBG SPECT imaging also were found in inferior, apical and septal walls. Thallium-201 SPECT distribution was homogeneous along the left ventricle. Thus, cardiac MIBG scintigraphy provides information about left ventricular dysinnervation in a patient with Brugada syndrome, enhancing the clinical utility of myocardial MIBG SPECT imaging in life-threatening ventricular arrhythmias.

[Leiomyosarcoma of the heart and great vessels]

Leiomyosarcomas (LMS) of the heart are exceptional primary malignant tumours with a catastrophic prognosis and a mean survival measured in months. Extensive radical surgical resection clearly remains the most appropriate treatment. We report three cases observed over a 3-year period, consisting of an LMS of the inferior vena cava, an LMS of the pulmonary artery trunk and an LMS of the left atrium. The first case was treated by radical resection and reconstruction by autologous vein graft of the cavorenal junction, the second case was treated by extensive resection and prosthetic reconstruction of the pulmonary artery bifurcation and the third case was treated by a first radical resection of the left atrium, requiring total cardiectomy and orthotopic heart transplantation for local recurrence at the sixth month. The survical was significantly improved compared to other treatment options (chemotherapy, radiotherapy). The first patient is still alive without recurrence at two years; the second died 12.5 months after the surgical procedure and the medium-term follow-up of the transplanted patient revealed cerebral and hepatic metastases nine months after transplantation. The authors review the literature concerning these extremely rare malignant tumours. Recent progress of diagnostic investigations, such as spiral CT with reconstruction, MRI, positron emission tomography (PET), are now able to establish the diagnosis more rapidly and therefore allow more radical surgical resection. This resection, possibly combined with venous reconstruction, must be associated with adjuvant therapies. Heart transplantation should be considered among the treatment options for leiomyosarcomas of the heart, in order to improve the poor prognosis of these lesions affections a young population.

Safety of beating heart anastomosis during video-assisted coronary surgery attested by cardiac troponin I

Our objective was to evaluate the safety of coronary anastomosis on the beating heart by measuring the release of cardiac troponin I during minimally invasive coronary artery bypass grafting (MICABG). Cardiac troponin I (cTnI) is a reliable marker of cardiac ischemia during heart operations under cardiopulmonary bypass (CPB). Ten patients (8 males and 2 females, aged 41-63) underwent MICABG with single vessel bypass grafting for left anterior descending coronary artery (LAD) stenosis (n = 7) or occlusion (n = 3). Video-assisted surgery with left anterior minithoracotomy was performed in all patients. Serial venous blood samples were collected for measurement of cTnI before LAD occlusion (T0), during anastomosis (T1) and 10 min (T2), 6 h (T3), 24 h (T4), 48 h (T5), and 72 h (T6) after coronary reperfusion. The assay method used a specific enzyme-linked immunosorbent Stratus autoanalyzer. Control coronary angiography was performed in all patients. There were no operative complications or reoperations for bleeding. The cTnI concentrations were expressed in ng/ml +/- SD. The mean cTnI level was less than 3.05 +/- 0.2 ng/ml (range 0-32.8). Values were T0 = 0, T1 = 0.4 +/- 0.03, T2 = 1.15 +/- 0.2, T3 = 2.16 +/- 0.6, T4 = 1.5 +/- 0.3, T5 = 0.6 +/- 0.02, and T6 = 0.4 +/- 0.01. Angiography showed patent grafts in 9 patients. In one case, early internal thoracic artery (ITA) graft occlusion in a patient with 2 vessel disease was correlated with a higher cTnI concentration (17.8 ng/ml). Percutaneous angioplasty was performed on the right coronary artery, complicated with dissection and cardiac failure. This patient died 3 months after the MICABG despite support from a ventricular assist device. In conclusion, collateral circulation developed in the setting of chronic coronary occlusion may be efficient for myocardial preservation during short periods such as coronary anastomosis. cTnI immunoassay confirmed the safety of coronary anastomosis on the beating heart during minimally invasive coronary operations.

Proarrhythmic and antiarrhythmic effects of bupivacaine in an in vitro model of myocardial ischemia and reperfusion

BACKGROUND

Bupivacaine may have toxic cardiovascular effects when accidentally administered by intravascular injection. However, its electrophysiologic effects in the presence of myocardial ischemia remain unknown. The authors evaluated the electrophysiologic and anti- and proarrhythmic effects of bupivacaine in an in vitro model of the ischemic and reperfused myocardium.

METHODS

In a double-chamber bath, a guinea pig right ventricular muscle strip was subjected partly to normal conditions and partly to simulated ischemia followed by reperfusion. The electrophysiologic effects of bupivacaine were studied at 1, 5, and 10 microM concentrations.

RESULTS

Bupivacaine (5 and 10 microM) decreased the maximal upstroke velocity of the action potential (Vmax) in normoxic conditions and further decreased (10 microM) the Vmax decrease induced by ischemic conditions. Bupivacaine reduced the mean occurrence time to the onset of myocardial conduction blocks (9 +/- 3 min; mean +/- SD; P < 0.005 with 5 and 10 microM, compared with 17 +/- 6 min during simulated ischemia with no drug or control), and it increased the number of preparations that became inexcitable to pacing (55% of preparations, with 1 microM and 100% with 5 and 10 microM, compared with 17% for the control group). The incidence of spontaneous arrhythmias was reduced by 5 and 10 microM bupivacaine during ischemia and reperfusion and was enhanced by 1 microM bupivacaine during the ischemic phase.

CONCLUSIONS

In guinea pig myocardium under ischemic conditions, bupivacaine induced a loss of excitability at concentrations of 5 and 10 microM. Proarrhythmic effects observed at 1 microM were considered as lower than the cardiotoxic range in normoxic conditions. The incidence of reperfusion arrhythmias was decreased at all concentrations.

Impact of exercise rehabilitation on cardiac neuronal function in heart failure: an iodine-123 metaiodobenzylguanidine scintigraphy study

Exercise training can induce important haemodynamic and metabolic adaptations in patients with chronic heart failure due to severe left ventricular dysfunction. This study examined the impact of exercise rehabilitation on cardiac neuronal function using iodine-123 metaiodobenzylguanidine (MIBG) scintigraphy, Fourteen patients (11 men, 3 women; mean age 48 years; range: 36-66 years) with stable chronic heart failure of NYHA class II-III and an initial resting radionuclide left ventricular ejection fraction (LVEF) < 50% were enrolled in the study. Patients underwent progressive, supervised endurance training (treadmill test, Bruce protocol) during a 6-month period (60 sessions, 3 sessions per week) at a cardiac rehabilitation referral centre in order to measure exercise parameters. Planar 123I-MIBG scintigraphy provided measurements of cardiac neuronal uptake (heart-mediastinum ratio activity, 4 h after intravenous injection of 185 MBq of MIBG). Radionuclide LVEF was also assessed at the outset and after 6 months of exercise training. Workload (801 +/- 428 vs 1229 +/- 245 kpm.min-1, P = 0.001), exercise duration (504 +/- 190 vs 649 +/- 125 s, P = 0.02), and myocardial MIBG uptake (135% +/- 19% vs 156% +/- 25%, P = 0.02) increased significantly after rehabilitation. However, LVEF did not change significantly (23% +/- 9% vs 21% +/- 10%, p = NS). It is concluded that exercise rehabilitation induces improvement of cardiac neuronal function without having negative effects on cardiac contractility in patients with stable chronic heart failure.

Pulmonary artery trunk leiomyosarcoma

Pulmonary artery leiomyosarcomas are rare tumors. They cause symptoms suggestive of recurrent pulmonary emboli. As in the case reported here, the diagnosis is virtually never considered initially, despite modern diagnostic imaging methods, but usually made at autopsy or at histologic examination of material removed from the pulmonary artery at surgery. The prognosis remains poor and prolongation of life up to 6 months has not been clearly demonstrated with radical excision in conjunction with radiotherapy. The difficulty is the accurate diagnosis required to consider these tumors for curative resection, which is the only hope for a longer disease-free course.

[Ehlers-Danlos disease revealed during pregnancy through the diagnosis of aortic dissection]

Dissection of the aorta is a serious condition but rare in young women, and occurring during the 3rd trimester of pregnancy. The main risk factors are hypertension and diseases of the connective tissue or of collagen (Marfan's syndrome and Ehlers-Danlos disease). The authors report a case of dissection of the aorta managed in a pluridisciplinary manner by the anaesthetists, cardiologists, obstetricians and cardiothoracic surgeons, which resulted in a favourable outcome for both mother and baby. The diagnosis of Ehlers-Danlos disease was made from the onset and, over a period of 10 years with CT scan and annual echocardiographic follow-up, total replacement of the supra-coronary aorta was performed in several stages.