Claude Dubois

Antegrade cerebral perfusion with cold blood: a 13-year experience

BACKGROUND In 1986 we introduced the technique of antegrade selective perfusion of the brain with cold blood during surgery of the aortic arch. METHODS Between January 1984 and March 1998, 171 patients (118 males and 53 females) aged 25 to 83 years (mean 56.5 +/- 17), underwent replacement of the transverse aortic arch with the aid of cold blood antegrade selective perfusion. One hundred twenty two patients (71.3%) with chronic lesions were operated on electively; 49 patients (28.6%) were operated on urgently for acute aortic dissection (42 patients) or for a ruptured chronic aneurysm (7 patients). Fifty-one patients (29.8%) had previously undergone a surgical procedure on the thoracic aorta. Mean duration of cardiopulmonary bypass was 121 minutes (range: 65-248); mean duration of cerebral perfusion was 60 minutes (range: 15-90), and mean duration of systemic circulatory arrest circuit was 32 minutes (range: 10-57). The electroencephalogram, routinely recorded, showed disappearance of electrical activity in a mean of 9 minutes (range: 3-16) initial return of electrical activity after a mean of 12 minutes (range: 1-35) and normalization in a mean time of 66 minutes. RESULTS All patients but 7 (4%) showed signs of normal awakening within 8 hours postoperatively. Six patients (3.5%) had fatal neurologic complications, and 16 patients (9.3%) had a non-fatal neurologic complications. Twenty-nine patients (16.9%) died during the postoperative hospital course. There was a significant difference between patients aged less than 60 years (9%) and patients older than 60 years (mortality rate 26.4%, p < 0.02). There was also a significant difference between patients undergoing an isolated replacement of the arch, and those in whom the replacement was extended to the descending aorta in whom mortality was 36.4% (chi2, p < 0.02). Lesion and gender had no significant influence on the outcome of the patients, nor had the duration of cardiopulmonary bypass, circulatory arrest, and cerebral perfusion. In particular, no correlation could be established between the duration of cerebral perfusion and the occurrence of neurologic complications. CONCLUSION The clinical results obtained throughout this experience have demonstrated that selective antegrade cerebral perfusion with cold blood provides excellent protection during surgery of the transverse aortic arch. In addition, it avoids the use of deep hypothermia and prolonged cardiopulmonary bypass and does not limit the time allowed to perform the aortic repair. In our opinion it is the technique of choice, especially in frail patients or those requiring a long and difficult procedure.

Myocardial viability assessment in ischemic cardiomyopathy: Benefits of coronary revascularization

Patients with ischemic heart disease, congestive heart failure, and low ejection fraction are usually referred for orthotopic heart transplantation. Based on results of myocardial viability assessment, we have prospectively used either coronary artery bypass grafting or orthotopic heart transplantation. From January 1990 to June 1992, among 50 patients initially referred for heart transplantation, 46 showing myocardial viability underwent bypass grafting. Forty-five of these 46 patients were men, and the mean age was 58 +/- 12 years (range, 40 to 70 years). Congestive heart failure was present in all patients, and dyspnea was the main symptom in 80% (37/46). Patients were selected according to three criteria. (1) Myocardial viability was primarily assessed by thallium scintigraphy for up to 24 hours (28/46 patients). When results were negative, patients underwent positron emission tomography (20/46 patients). (2) Regional left ventricular function was assessed using gated blood pool single-photon emission computed tomography combined with (3) full hemodynamic evaluation. Results were as follows: end-diastolic volume, 129 +/- 35 mL/m2; ejection fraction, 0.23 +/- 0.06; cardiac index, 2.4 +/- 0.62 L.min-1.m-2; mean pulmonary artery pressure, 26 +/- 0.90 mm Hg; and mean pulmonary capillary wedge pressure, 16 +/- 1.10 mm Hg. Operative mortality was 2.17% (1/46). During follow-up (mean duration, 18 months), there were three late cardiac-related deaths (arrhythmias) and two noncardiac-related deaths. The 40 long-term survivors are in New York Heart Association class II. Angiography (15 patients) or gated blood pool single photon emission tomography (32) showed improvement in mean ejection fraction to 0.39 +/- 0.13 (range, 0.22 to 0.46).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Metaiodobenzylguanidine uptake in patients with moderate chronic heart failure : Relationship with peak oxygen uptake and prognosis

OBJECTIVES This prospective study was undertaken to correlate early and late metaiodobenzylguanidine (MIBG) cardiac uptake with cardiac hemodynamics and exercise capacity in patients with heart failure and to compare their prognostic values with that of peak oxygen uptake (VO2). BACKGROUND The cardiac fixation of MIBG reflects presynaptic uptake and is reduced in heart failure. Whether it is related to exercise capacity and has better prognostic value than peak VO2 is unknown. METHODS Ninety-three patients with heart failure (ejection fraction <45%) were studied with planar MIBG imaging, cardiopulmonary exercise tests and hemodynamics (n = 44). Early (20 min) and late (4 h) MIBG acquisition, as well as their ratio (washout, WO) were determined. Prognostic value was assessed by survival curves (Kaplan-Meier method) and uni- and multivariate Cox analyses. RESULTS Late cardiac MIBG uptake was reduced (131+/-20%, normal values 192+/-42%) and correlated with ejection fraction (r = 0.49), cardiac index (r = 0.40) and pulmonary wedge pressure (r = -0.35). There was a significant correlation between peak VO2 and MIBG uptake (r = 0.41, p < 0.0001). With a mean follow-up of 10+/-8 months, both late MIBG uptake (p = 0.04) and peak VO2 (p < 0.0001) were predictive of death or heart transplantation, but only peak VO2 emerged by multivariate analysis. Neither early MIBG uptake nor WO yielded significant insights beyond those provided by late MIBG uptake. CONCLUSIONS Metaiodobenzylguanidine uptake has prognostic value in patients with wide ranges of heart failure, but peak VO2 remains the most powerful prognostic index.

Surgery for acute type A aortic dissection: the Hopital Foch experience (1977–1998)

BACKGROUND In 1977, we proposed the use of gelatin-resorcinol-formol (GRF) biological glue during surgery for acute type A aortic dissection. METHODS From January 1977 to March 1998, 204 patients (146 men and 58 women) aged from 15 to 79 years (mean 54 +/- 11) underwent emergency operation for type A aortic dissection in our institution. One hundred sixty-five patients (84%) were operated on within 48 h after the onset of symptoms. Twenty-eight patients (13.7%) had Marfans syndrome. In 43 patients (23%), the aortic valve was replaced either independently (6, 3%) or by means of a composite graft (37, 18.1%). Because of the location of the intimal tear, aortic replacement included the transverse arch in 60 patients (29.4%). RESULTS Hospital mortality was 21% (39 patients): 25% in patients with arch replacement and 19.4% in patients without arch replacement (ns). One hundred sixty-one patients were discharged and followed from 2 months to 21 years postoperatively (mean 85 +/- 66 months). During this interval, 25 patients (15.5%) required reoperation for a total of 33 reoperations. Seven patients (28%) died at reoperation. Upon univariate analysis, presence of Marfans syndrome (p < 0.05) and absence of arch replacement (p < 0.02) were risk factors for reoperation. Emergency operation (p < 0.01) and thoracoabdominal replacement (p < 0.04) were risk factors for death at reoperation. The actuarial freedom from reoperation (Kaplan-Meier, confidence interval 95%) is 96.1% (90.9%-98.2%) at 1 year, 87.6% (79.8%-92.7%) at 5 years, 80.9% (70.8%-88.1%) at 10 years, and 66.4% (51.1%-78.9%) at 15 years. A total of 39 patients (24.3%) died during follow-up. The presence of Marfans syndrome (p < 0.01), reoperation (p < 0.02), stroke (p < 0.05), and cardiac failure (p < 0.05) were risk factors for late mortality. The actuarial late survival including hospital mortality is 71.5% (64.3%-77.8%) at 1 year, 66% (58.3%-73%) at 5 years, 56.4% (47.7%-64.7%) at 10 years, and 46.3% (36.4%-56.5%) at 15 years. CONCLUSIONS The GRF glue has proven extremely useful during emergency initial surgery for acute type A dissection, making the procedure much easier and safer. As a result of this operative improvement, the use of the GRF glue seems to have had a beneficial influence on late results, but these also depend upon the patients basic condition.

Repair of anterior leaflet prolapse by papillary muscle repositioning: a new surgical option

BACKGROUND Although mitral valve repair is considered the gold standard for treating mitral regurgitation, anterior leaflet prolapse may still remain a challenging problem. This challenge is even greater for posterior commissural prolapse. We have used papillary muscle repositioning to treat anterior leaflet prolapse and suggest it as an alternative technique for all other methods previously described. METHODS From 1989 to 1999 we performed 253 mitral valve repairs, among which 132 involved anterior leaflet prolapse. In this population there were two groups: group I (n = 92) treated with papillary muscle repositioning and group II (n = 40) treated with chordal shortening. There was no statistical difference between the two groups concerning age, functional class, and left ventricular function. Etiology was similar in both groups, a degenerative process being predominant. At echocardiography, regurgitation was graded 3.4/4 in both groups. There was no statistical difference concerning preoperative ejection fraction, end-systolic and end-diastolic left ventricular diameter. RESULTS There were one in-hospital death in group I and two deaths in group II not related to mitral valve repair. Mean follow up is 36.4 +/- 29.2 months in group I and 70.5 +/- 9.5 months in group II. No patient was lost to follow-up. Mean regurgitation at follow-up was 0.75 +/- 0.67 in group I and 0.8 +/- 0.8 in group II (p = not significant). There was no statistical difference between the two groups concerning postoperative ejection fraction, end-systolic and end-diastolic left ventricular diameter. There was no late cardiac death in either group and there were no thromboembolic events. Actuarial survival rate is 98.9% and 96.3% in group I and 92.5% and 88.1% in group II at 3 and 8 years, respectively. CONCLUSIONS Therefore, we conclude that papillary muscle repositioning is a safe technique that provides excellent results at mid-term follow-up and facilitates treatment of anterior leaflet prolapse.

Comparison of nicardipine and sodium nitroprusside in the treatment of paroxysmal hypertension following aortocoronary bypass surgery

In an open, randomized, multicenter trial, intravenous nicardipine was compared with sodium nitroprusside in 74 patients with hypertension (mean arterial pressure [MAP] greater than or equal to 100 mm Hg) following coronary artery bypass surgery. Nicardipine was administered as a 2.5- to 12.5-mg bolus followed by a 2 to 4 mg/h infusion, and nitroprusside as a 0.5 to 6.0 micrograms/kg/min infusion. The aim was to reduce MAP to less than 90 mm Hg within 50 minutes and maintain it stable at 85 +/- 5 mm Hg. Nicardipine was effective in 35 of 38 patients (92%), and nitroprusside in 29 of 36 (81%) (NS). The decrease in MAP was not statistically different, but time until reaching the therapeutic end-point was shorter with nicardipine (P less than 0.01). Significant differences follow: increase in heart rate and decreases in mean pulmonary artery, right atrial, and pulmonary capillary wedge pressures were more marked with nitroprusside (P less than 0.01 and P less than 0.05, respectively), whereas elevation of cardiac index and depression of systemic vascular resistance were more marked with nicardipine (P less than 0.01 and P less than 0.05, respectively). Postreduction MAP was more stable with nicardipine, 51% +/- 24% of readings falling within the range 85 +/- 5 mm Hg versus 41% +/- 18% on nitroprusside (P = 0.058). Dose adjustment during the following 24 hours was less frequent with nicardipine, 1.1 +/- 1.6 versus 2.7 +/- 2.6 (P less than 0.01). Transfused blood volume was lower with nicardipine (924 +/- 644 mL) than nitroprusside (1,306 +/- 901 mL) (P = 0.08), despite similar postoperative blood losses.(ABSTRACT TRUNCATED AT 250 WORDS)

Penetration of vancomycin in uninfected sternal bone.

Concentrations of vancomycin in sternal bones of 10 patients undergoing cardiac surgery were studied at steady state, 48 h after starting intravenous prophylaxis. A sample of sternal bone was taken before (group I) or after (group II) cardiopulmonary bypass. The mean vancomycin concentrations in sternal bones were not significantly different between the groups and were 9.3 +/- 3.0 micrograms/g. The concentrations of vancomycin in sternal bones were always above the MICs for staphylococci, streptococci, and enterococci.

Protection of the spinal cord during surgery of thoraco-abdominal aortic aneurysms

OBJECTIVE To assess the risk of ischemic cord injury, we have retrospectively studied the 115 patients who underwent a replacement of the thoracic descending or thoraco-abdominal aorta between January 1980 and December 1994. METHODS In 72 patients the aortic lesion was located above the diaphragm. The aortic replacement was performed with the aid of extracorporeal circulation in all but 2 patients (97.2%). Only two cases of postoperative paraplegia were observed (2.7%). In 43 patients (10 females and 33 males aged from 26 to 69 years), the occurrence of postoperative paraplegia was considered as a major risk, because of the extension of the aortic lesions (Crawford types I, II and III). Twenty-six patients (60.4%) suffered from chronic dissection and 17 patients had atheromatous aneurysms. Sixteen patients (37.2%) had Marfan syndrome. Twelve patients (27.9%) had already undergone aortic replacement. A preoperative study of the spinal cord vascularization was carried out in 36 patients (83.6%) and the Adamkiewicz artery was visualized in 28 patients (77.8%). In 17 patients (39.5%, group I), the surgical procedure was performed without the aid of extracorporeal circulation. In the remaining 26 patients (60.5%, group II), the surgical procedure was carried out with the aid of cardiopulmonary bypass and profound hypothermic circulatory arrest. Sequential unclamping of the aorta was used in all patients. The cord vascularization was surgically restored in 32 patients (74.4%). When the Adamkiewicz artery was identified, the critical intercostal artery was reimplanted together with the two pairs of adjacent intercostal arteries (25 patients). When the origin of the Adamkiewicz artery remained unknown, the two or three most important patent pairs of intercostal arteries were reimplanted (7 patients). In 8 patients (18.6%) there were no patent intercostal arteries. RESULTS Hospital mortality accounted for 37.2% (16 patients, including 5 patients with paraplegia). On univariate analysis, extension of the aortic lesions, emergency and redo surgery were the only significant risk factors of mortality (P = 0.05). Cord ischemia was observed in 9 patients (21%): permanent paraplegia in 7 patients (16.2%) and transient medullar disturbance in 2 patients (4.6%). The occurrence of paraplegia was reduced, though not significantly, in group II (16%) vs group I (29%) and in patients with preoperative assessment of the cord vascularization (18% vs 38%). CONCLUSIONS In our experience: 1) The risk of paraplegia is related to the extension and the type of the aortic lesions. 2) The preoperative study of the medullar vascularization and the use of extracorporeal circulation with deep hypothermia and sequential aortic unclamping, reduce the risk of severe cord ischemia, and 3) Occurrence of postoperative paraplegia depends on several factors and cannot be totally prevented by the surgical technique.

Repeated surgery for recurrent dissection of the aorta

Emergency surgery of acute dissection of the ascending aorta is generally a palliative procedure aimed at preventing the vessel from rupturing into the pericardium. Evolving dissecting aneurysm or recurrence of the dissection process is, therefore, a common complication and may lead to reoperation or death. Between January 1970 and December 1988, 133 patients were operated upon for acute dissection of the ascending aorta. During the same period, 22 patients underwent 26 reoperations for recurrent or evolving dissection. Eleven (50%) patients had Marfans syndrome. Thirteen patients had been operated upon previously in our institution and 8 had been operated upon elsewhere. In 10 patients, the intimal tear had not been resected during the first operation. Operative procedures varied according to the pathoanatomical features and consisted generally of an extended resection of the aortic arch. Eight reoperations were performed as emergencies and 18 were performed electively. Hospital mortality rate was 18% (4/22). Late follow-up ranged from 3 to 153 months (mean: 55 months) for a cumulative follow-up of 998 months. Late mortality was 27% (5/18) for a linearized rate of 6% pt/yr. The actuarial risk of reoperations is 13.7% +/- 7% and 21% +/- 11% at 5 and 10 years, respectively. Marfans syndrome and persistence of the primary intimal tear are considered the main risk factors of reoperation, while emergency and thoraco-abdominal replacement are the main risk factors at reoperation.

Surgery of Acute Type A Dissection : What Have We Learned during the Past 25 Years?

Every acute dissection involving the ascending aorta (Stanford type A) must undergo emergency sugical repair. However, the surgical techniques must vary according to the clinical presentation of the patients or the anatomical patterns observed. Furthermore, surgery is generally difficult because of the poor condition of the aortic tissues. To reduce those difficulties many technical artifacts have been described. In 1977, we proposed the use of gelatin-resorcin-formalin (GRF) biological glue to reinforce the suture areas. From January 1977 to July 1999, 212 patients (pts) (152 males and 60 females) aged from 15 to 80 years (mean age: 54±11 years) underwent an emergency operation for type A aortic dissection. One-hundred-seventy-eight pts (84%) were operated on within 4 hours after being referred to the hospital. Twenty-eight pts (13.2%) had Marfans syndrome. In 44 patients (20.7%), the aortic valve was replaced either independently (6 cases – 2.8%) or by means of a composite graft (38 cases – 17.9%). Because of the location of the intimal tear, the aortic replacement was extended to the transverse arch in 61 pts (28.7%). Hospital mortality amounts to 21.6% (46 pts), 25% in pts with arch replacement and 19.4% in pts without arch replacement (n. s.). Analysis of hospital mortality demonstrates that the main causes of death were cardiac tamponade, neurologic disorders and visceral malperfusion. One-hundred-sixty-six pts were discharged and surveyed from 5 months to 22 years postoperatively (mean follow-up: 85±66 months). During this period of time, 25 pts (15%) had to be reoperated for a total of 33 reoperations. Seven pts (28%) died at reoperation. Using univariate analysis, the presence of Marfans syndrome (p < 0.05) and absence of arch replacement (p < 0.02) were determinant risk factors for reoperation. Emergency (p < 0.01) and thoraco-abdominal replacement (p < 0.04) were determinant riskfactors for death at reoperation. The freedom from reoperation (Kaplan-Meier, CI: 95%) is 96% (90–98), 87% (79–92), 80% (70–88), 66% (51–78) at 1, 5, 10 and 15 years respectively. A total of 39 pts (24,3%) died during follow-up. The presence of Marfans syndrome (p < 0.01), reoperation (p < 0.02), stroke (p < 0.05), and cardiac failure (p < 0.05) were determinant risk factors of late mortality. The late survival rate (k-M. C.I.: 95%), including hospital mortality, is 71% (64–77), 66% (58–73), 56% (47–64), 46% (36–56), 37% (28–44) at 1, 10, 15 and 20 years, respectively. From our experience extending over more than 23 years, GRF glue has proved to be extremely useful, making the procedure much easier and safer. Nevertheless, many factors are of importance in the pre-, intra- and postoperative management of the patients. Cardiac tamponade and visceral malperfusion must be properly diagnosed and treated. During aortic repair, the main intimal tear must be resected. The transverse arch must be checked and replaced whenever necessary. The aortic valve should be preserved whenever possible. During CPB, perfusing the aorta in the regular antegrade manner seems to dramatically reduce the rate of malperfusion. The quality of the first emergency operation seems to have a major influence on the late results, especially concerning the rate of late reoperations and aortic ruptures. However, those late results depend also on the patients basic condition, particularly in Marfan patients.