Daniel Guilmet

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)

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.

Four-year clinical experience with the gelatin-resorcine-formol biological glue in acute aortic dissection.

Because of the extreme severity of spontaneous evolution of acute dissection involving the ascending aorta, there is no controversy about the necessity of urgent surgical treatment (1–6). However, hospital mortality rate remains high in most reported experiences (1, 4, 6–9).

Assessment of systematic use of intraoperative transesophageal echocardiography during cardiac surgery in adults: A prospective study of 203 patients

OBJECTIVE To determine the usefulness of systematic intraoperative transesophageal echocardiography in a cardiac surgical unit. DESIGN Open prospective observational survey. SETTING University Hospital. PARTICIPANTS Consecutive adult patients (n = 203) undergoing elective or urgent cardiac operations. MEASUREMENTS AND MAIN RESULTS Pre-cardiopulmonary bypass imaging yielded unsuspected findings in 26 patients (12.8%) and changed the planned surgery in 22 patients (10.8%). Transesophageal echocardiography modified the diagnosis in eight patients (17%) operated on for mitral valvulopathy, in seven patients (15.5%) with aortic valvular disease, in four patients (4.6%) with coronary artery disease, in five patients operated on for thoracic aorta diseases regardless of their localization (18.5%), and in two miscellaneous cases. On the basis of the data obtained from the transesophageal echocardiography carried out at the end of cardiopulmonary bypass, an immediate reintervention was required in five cases (2.5%). CONCLUSIONS It is concluded that systematic intraoperative transesophageal echocardiography significantly affected decision making in this cardiac surgical unit. Its routine use in all cardiac surgical patients is recommended.

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.

Aortocoronary Bypass with Homologous Saphenous Vein: Long-Term Results

Between February 1973, and February, 1979, 27 homologous saphenous veins were used in 20 patients (mean age, 54 years). Seven fresh grafts were used less than 24 hours after severance. They were kept at a temperature of 4 degrees C in saline solution containing penicillin. Twenty cryopreserved grafts were used within a period of eight days to 2 months from severance. They were preserved in glycerol at a temperature of -40 degrees C. One patient (5%) died postoperatively. A perioperative myocardial infarction developed in 3 patients (15%). Average follow-up is 27 months. No late mortality was registered. Fifteen patients are free from symptoms, and 3 patients have residual angina with exercise. Control angiograms were made in 13 patients 1 to 68 months after operation; 17 homografts were seen. Early occlusion of 1 graft and late occlusion of 8 grafts were registered. The poor late patency rate does not seem to be related to either histocompatibility or technical conditions. Conversely, microscopic examination of several cryopreserved grafts showed that the mode of preservation resulted in deterioration of intimal and medial tissues of the vein. Therefore, it appears to us that the use of homologous saphenous veins should be avoided for coronary bypass.

THE USE OF BIOLOGICAL GLUE IN AORTIC SURGERY

The biologic sealants presently available on the market that are used in cardiovascular surgery and particularly during surgery of the aorta are described in this article. Two of these biological sealants, the gelatin-resorcinol-formaldehyde (GRF) glue and two-component fibrin sealant have been in use for two decades. Their respective properties are described beneficial in modifying the natural history of the disease. Certain pharmacological agents that result in improved aortic function have been identified.

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.

Late reoperations in patients with aortic dissection.

Aortic dissection is an evolving process that may require one or several reoperations after the initial emergency repair. From January 1977 to September 1993, 148 patients undement emergency surgery for type A acute aortic dissection. The replacement of the ascending aorta was extended to include the transverse arch in 43 patients (29%). One hundred fifteen patients (78%) survived surgery. During the same period, 37 patients required reoperation once (28), twice (7), or three times (2), for a total of 48 reoperations. Wenty‐one patients had undergone initial repair in our instltution; 16 patients had been operated on elsewhere. Reoperation was indicated for: aortic valve disease (4); a new dissecting process (7); threatening aneurysmal evolution of a persisting dissection (34); or false aneurysm (3). The redo procedure involved: the aortic root and/or ascending aorta in 12 cases (group I); the ascending aorta and the transverse arch in 6 cases (group 11); the transverse arch alone in 8 cases (group III); the transverse arch and descending aorta, or the descending aorta alone in 11 cams (group IV); and the thoracoabdominal aorta in 11 cases (group V). Risk factors for reoperation were analyzed in the 115 survivors initially operated on at our institution. Seven of 20 Marfan patients (35%) versus 12 of 95 non‐Marfan patients (12.6%) required reoperation (p < 0.02). None of the 31 patients surviving arch replacement at initial repair required a reoperation, versus 21 of 84 (25%) patients surviving replacement limited to the ascending aorta (p < 0.01). The overall mortality rate of reoperation was 18.9% (7/37), with a risk of 14.5% (7/48) at each procedure (group I 8.3%, group II 0%, group III 20%, group IV 18%, group V 27%). Hospital mortality was influenced by whether the operation was done as an emergency (5/10) (p < 0.005), and whether thoracoabdominal replacement was required (3/11) (p < 0.03). The late survival rate after reoperation is 67.1%± 17.6% at 1 year, and 57%± 19.6% at 5 years (Kaplan‐Meier CI 95%). The late survival rate, after initial repair, of reoperated patients is 89.6%± 11.0% at 1 year, 79.3%± 14.7% at 5 years, 53.9%± 18.1% at 10 years, and 35.9%± 21.8% at 12 years. In conclusion, elective reoperation should be considered before the occurrence of complications, especially in patients with Marfan syndrome. It entails a relatively low risk, except in the case of thoracoabdominai replacement, and allows satisfactory long‐term survival. In our experience, resection of the entry site at initial emergency operation, when it is located on or extends to the transverse arch, reduces the incidence of reoperation. (J Card Surg 1994;9:740–747)

Changes in Intrathoracic Pressures Induced by Positive End-Expiratory Pressure Ventilation after Cardiac Surgical Procedures

Abstract The consequences of controlled ventilation with positive end-expiratory pressure (PEEP) were studied, after cardiac surgical procedures, in two groups of patients supposed to have different lung and chest wall mechanical properties. The first group included 6 patients who had undergone coronary artery graft surgical procedures (CGS). The second group included 5 patients who had undergone a mitral valve replacement (MVR). Postoperatively, static lung and chest wall compliance was measured by stepwise inflation and deflation of the thorax. Esophageal, pericardial, and pleural pressures were then measured, and cardiac output was determined while PEEP was increased from 0 to 20 cm H 2 O. Lung and chest wall compliance values sharply decreased in MVR patients. This accounts for the lower values for pleural and pericardial pressures in this group than in the CGS patient group, but the transmission of airway pressure was identical in the two groups when PEEP was increased. The decrease in cardiac output induced by PEEP was similar in the two groups. The results suggest that the opposing influences of lung and chest wall compliance on airway pressure transmission could at least partly explain the hemodynamic effects of PEEP in patients in whom the mechanical properties of the lung and thorax are impaired. PEEP ventilation should be used cautiously in patients suspected of having thoracic rigidity.