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True aneurysms of the ascending aorta often remain undetected, yet their sequelae carry a high rate of mortality and morbidity. The operative risk of nonemergent replacement of the ascending aorta is low. It is important to consider quality of life in determining the most appropriate treatment for patients who have aneurysms but have not yet experienced major complications.
From January 1999 to December 2003, 134 consecutive patients underwent replacement of a dilated ascending aorta at our center. Another 124 patients with acute or chronic aortic dissections, aortic rupture, or intramural hematoma were excluded. Standard SF-36 and general health questionnaires were sent to all 124 survivors who could be traced. Follow-up was 98.4% complete. The mean age of the survivors was 61.7 ± 11 years, and 63.4% were men. Operative procedures consisted of supracoronary replacement of the ascending aorta in 35.9%, the Wheat procedure in 44%, the David procedure in 11.2%, the Bentall–DeBono procedure in 9%, and the Cabrol procedure in 2.2%. Patients were monitored until May 2005.
Thirty-day and midterm mortality rates were 3.7% and 3.9%, respectively. Morbidity due to stroke was 6%, to bleeding 6%, and to myocardial infarction 4.4%. Postoperative quality-of-life evaluation revealed many subscales of SF-36 that were below the norm when compared with a standard population in physically dominated categories.
Replacement of the dilated ascending aorta carries acceptable risk in regard to operative death and postoperative quality of life, although this last showed some decline in comparison with quality of life in a normal, healthy population.
Aneurysms of the ascending aorta are considered to be a serious disease, particularly in elderly patients, because the operative risk is generally higher due to concomitant diseases. When left untreated, aneurysms carry a high mortality rate; often, they remain undiscovered until dissection or rupture. To avoid these sequelae, early diagnosis is essential. Data from many studies regarding the progression of aneurysms show that the risk of operation is justifiable in light of the probability of lethal sequelae to chronic, asymptomatic disease. Once an aneurysm reaches a maximum diameter of 6 cm, the annual probability of rupture, dissection, or death is 14.1%.1
Aside from morbidity and mortality rates, which are widely published, there is little information about quality of life among patients who have undergone major aortic surgery before dissection or rupture. However, quality of life is also an important consideration when evaluating the success of the operation, especially in patients whose aneurysms were not symptomatic before surgery.
This study analyzes the operative outcome and quality of life among patients who have had the ascending aorta replaced, in comparison with quality of life among the general German population.
From January 1999 to December 2003, 134 consecutive patients received a replacement of the dilated ascending aorta in our center. Another 124 patients who had acute or chronic aortic dissections, rupture, or intramural hematoma were excluded from this study, whether the diagnosis was made through preoperative studies or through intraoperative findings. We included patients who underwent additional coronary artery bypass grafting (CABG) or valve procedures. There were 85 men and 49 women, whose mean age was 61.7 ± 11 years (range, 25–80 yr).
There were 4 patients with Marfan syndrome (3%). In 1 case, an infection with Treponema pallidum was confirmed as the cause of the aneurysm. Table I describes the cardiovascular risk profile of patients enrolled in the study.
Fourteen cases (10.4%) were reoperations. Concomitant procedures included aortic valve replacement in 71 patients (53%), CABG in 30 patients (22.4%), mitral valve repair in 6 patients (4.5%), replacement of the aortic arch in 4 patients (3%), closure of an atrial septal defect in 2 patients (1.5%), and myectomy for hypertrophic cardiomyopathy together with closure of an aorto–atrial fistula in 1 patient (0.8%).
Operation was classified as elective in 129 patients (96.3%), emergent in 1 patient (0.8%), and urgent in 4 patients (3%). When classified as urgent or emergent, the main indications for surgery were severe valvular dysfunction, aorto–atrial fistula, or coronary heart disease. Patients with concomitant CABG presented with significantly higher ASA (American Society of Anesthesiologists) scores than the rest of the group (3.3 ± 0.5 vs 3.0 ± 0.6; P = 0.04).
The main indications for cardiac surgery are shown in Table II. An aneurysm of the ascending aorta was not the main indication for cardiovascular surgery in all cases. In 26 of 134 cases (26.1%), a true aneurysm of the ascending aorta was the main surgical problem; and frequently the chief diagnosis before the operation was dysfunction of the aortic valve, coronary artery stenosis, or both.
Operative procedures (Table III) consisted of supracoronary replacement of the ascending aorta in 33.6% of patients, the Wheat procedure (supracoronary replacement of the ascending aorta and aortic valve replacement) in 44%, the David procedure (replacement of the ascending aorta with direct reimplantation of the coronary arteries and reconstruction of the aortic valve, and sinutubular junction) in 11.2%, the Bentall–DeBono procedure (replacement of the ascending aorta and aortic valve with a valved conduit and direct reimplantation of the coronary arteries) in 9%, and the Cabrol procedure (replacement of the ascending aorta and the aortic valve with a valved conduit and reimplantation of the coronary arteries via an additional conduit) in 2.2%.
The mean operative time was 295.5 ± 99 min. Myocardial protection was achieved in all patients with antegrade administration of cold crystalloid cardioplegic solution (Bretschneider's solution, 30 mL/kg body weight, Dr. F. Koehler Chemie; Alsbach-Haehnlein, Germany). Operative time was significantly longer for patients who had undergone previous cardiac surgery (399.1 ± 172.2 min vs 283.4 ± 79.4 min; P = 0.03). In 65 patients (48.5%), the native aortic valve was replaced, and in 6 patients (4.5%), an aortic valve prosthesis was replaced. In 30 patients (22.4%), concomitant CABG was performed.
The Short-Form-36 (SF-36) questionnaire, a tool for the assessment of 8 dimensions of health-related quality of life, has been validated for application to the German population.2 The inner consistency (Cronbach α) of the sub-scales of SF-36 ranged from 0.57 to 0.94.
All 134 patients survived the operation and were discharged from the hospital. By the time that we carried out the study in 2004–2005, 10 patients had died of causes that could not be determined. Standard SF-36 and general health questionnaires were sent to all 124 survivors. Follow-up was 98.4% (122/124) complete. Another 10 patients (7.5%) died during the follow-up period; 2 patients did not participate for personal reasons. Mean follow-up time was 36.4 ± 15.5 months (range, 11–58 mo). For comparison of SF-36 results, norm values of the 1998 Bundes-Gesundheits Survey were used.3 These norm values are adjusted in accordance with age, sex, and nationality.
All pre-, intra-, and postoperative data were collected in an Access database (Microsoft Corporation; Redmond, Wash). Continuous data were analyzed using the unpaired Student's t test, and categorical data were analyzed using the χ2 test or Fisher exact test. Values were expressed as mean ± SD. A P value of less than 0.05 was considered significant. Statistical analysis was performed using the SPSS statistical software package (Version 11.5 for Windows, SPSS Inc.; Chicago, Ill). Sub-scales of SF-36 were analyzed using scripts provided by Hogrefe (Hogrefe Verlang; Goettingen, Germany).
During their hospital stays, 8 patients (6%) underwent at least 1 additional operative intervention (for bleeding, to cite 1 example). Postoperative sequelae are summarized in Table IV.
The 30-day mortality rate was 3.7% (5/134). Midterm mortality (up to 5 yr) was 3.9% (5/129). Mean time to death was 396.3 ± 529.9 days (range, 8–1, 405 d). Causes of death are outlined in Table V.
There was a highly significant connection between previous cardiac operation and postoperative death (P = 0.001). Four of the 14 patients (42.9%) who had undergone previous cardiac surgery died by May 2005, in comparison with 6 of 114 patients (5.3%) who had not undergone previous surgery. Neither concomitant bypass surgery nor any other specific operative procedure, including the Cabrol procedure, was associated with an increased postoperative mortality rate. There was a statistically significant association between death and postoperative myocardial infarction (P < 0.001), stroke (P = 0.001), extended ventilation times (P < 0.001), increased use of transfusion products (P = 0.016), and prolonged operative times (P < 0.001) (Table VI). The relatively high incidence of perioperative myocardial infarction was linked to the high percentage of patients who had coronary artery disease.
Analysis of the questionnaires revealed that 55.7% (68/122) did not have any discomfort up to the time of primary diagnosis. There was a subjective postoperative reduction of dyspnea (P = 0.10) and thoracic pain (P = 0.02), in comparison with preoperative status. Before the operation, 57 of 122 of the polled patients were still engaged in their professional lives. Subsequently, 22.8% of those (13/57) had to reduce their time at work, and another 31.6% (18/57) of patients had to give up their jobs.
Evaluation of the completed SF-36 questionnaires showed heterogeneous results, which varied with age group. In general, the achieved values of many subscales were found to be below the reference values of the Bundes-Gesundheits Survey (Fig. 1), although there were large deviations between age groups. The results pertaining to 2 age groups are presented in Figures 2 and and33.
In particular, physical function results were below those of the reference population, and patients between 70 and 79 years of both sexes had a mean value of physical function that was significantly below standards (men, P = 0.007; women, P = 0.05). Values for physical pain were above the normal values for nearly every age group and for both sexes.
There were no consistent results in the achieved values of social and mental subscales for different subgroups. Depending on age and sex, results were above or below standards. There was little decline in general health from 12 months through over 60 months after the operation, regardless of age group. In cases wherein replacement of the ascending aorta had occurred less than a year earlier, patients experienced an improvement of health in comparison with the previous year, and a low preoperative value for general health was linked with a gain in general health. These facts have to be evaluated in light of the concomitant diseases and the mean age (64.4 yr) of the patient population (Fig. 4).
Different techniques of operation had no statistically significant influence on postoperative quality of life. However, concomitant bypass surgery missed the level of significance by a slight margin (P = 0.09). Prolonged hospital stay was significantly linked with a postoperative loss of quality of life (P = 0.04). Other values with a potential influence on quality of life are presented in Table VII.
The operative therapy in application to true aortic aneurysms and aortic dissections is similar. However, the rates of operative death and morbidity differ significantly.4,5 Most true aneurysms do not cause any symptoms for a long time and are operated upon electively, whereas dissections occur acutely and are operated upon emergently. Major complications for acute aortic dissections are stroke, renal and mesenteric ischemia, and cardiogenic shock.6–9 However, many studies do not distinguish clearly between true aneurysm and dissection. They tend to focus more on operative techniques than on the underlying diseases. Furthermore, attempts to compare operative results in the medical literature are often difficult, because there is great variability among patients in age, concomitant diseases, genetic background, and previous operations.4,10–13 Study groups with a high proportion of Marfan syndrome commonly have better operative results, since these patients are usually significantly younger than are patients with sporadic or non-Marfan-related aortic aneurysms and do not have concomitant coronary artery disease.4,10,11,13,14
This study was set up not only to assess operative results, but also to investigate quality of life after elective operations of true aneurysms of the ascending aorta. We included all patients who underwent surgery for true ascending aortic aneurysm, regardless of the underlying disease. We expressly included patients who were undergoing concomitant cardiac surgery. In many such cases, the aneurysm of the ascending aorta was not the main indication for surgery.
The 30-day mortality rate of 3.7% in our group was comparable with those reported in other studies, which vary from 1.8% to 17.9%. Operative death in populations with a high proportion of cardiac reoperations is reported to range from 8.6% to 17.9%, whereas primary operations have a lower early mortality rate of 1.8% to 8.6% after prosthetic replacement.11,12,15–17 Because 10.5% of our patients underwent reoperation, our operative mortality rate appears to be consistent with mortality rates reported previously.
In our series, the choice of operative procedure did not have the significantly statistical impact on postoperative survival that other authors have described.13,18–20 The exception in our study was the Cabrol procedure, which did have a high rate of early death: 1 patient out of 3 died (33%). Possibly this was the result of the small number. This technique has been reported to have worse results than other procedures and should be applied only if there is no other choice.21
To date, little is known about postoperative quality of life after replacement of the ascending aorta in patients with true aneurysms. Belov and Karaeva22 showed that quality of life increased in many subscale values of SF-36 after prosthetic replacement of the ascending aorta. The SF-36 is a well-established instrument, in a variety of disciplines, for measuring quality of life, and it is of course not specific to 1 disease. The interpretation of postoperative quality of life in patients with true aneurysms is difficult, because thoracic aortic aneurysms are in most cases asymptomatic before surgery; preoperative quality of life, although not tested, is most probably normal. Although Olsson and Thelin23 found that postoperative quality of life was diminished after surgery of the thoracic aorta, postoperative quality of life in patients with aneurysm can be influenced more by concomitant diseases than by the operation itself. Among these studies,22,23 there are no consistent results in quality of life after prosthetic replacement of the ascending aorta, and this is true of our results as well. Further explanations for this inconsistency may be found in the wide distribution of age in our study and, in particular, in the presence of concomitant diseases such as coronary artery disease, which are linked with a higher risk of perioperative complications.
Comparing quality of life requires an age- and sex-matched control population. Our control population was provided by the Bundes-Gesundheits Survey, which provides norm values for German people.3 Among members of our study group, we found that New York Heart Association functional class was not significantly improved, whereas Canadian Cardiovascular Society class was. In particular, physical pain—an essential measure of quality of life—was reduced in our patients, although the original pain likely arose not from the aneurysm itself but from coronary artery disease or from heart valve dysfunction.
Concomitant diseases no doubt contributed to our finding that many patients had to reduce their time at work after aortic replacement, or even to retire from professional life. Even so, this finding shows that thoracic surgery itself, which carries complications such as stroke, can have a large impact on quality of life.
We also found that prolonged hospital stay, an additional effect of a complicated perioperative course, led to worse quality of life. Reducing perioperative complications in modern cardiac surgery may be one key to improvement in postoperative quality of life. However, cardiac surgery in general (with the use of cardiopulmonary bypass) did not seem to confer a great improvement in quality of life, in comparison with aortic surgery in particular.
This study was designed to evaluate data retrospectively, which precludes the comparison of pre- and postoperative SF-36 scores. However, the medical literature says nothing about diminished quality of life among unoperated patients who are living with asymptomatic aortic aneurysms, which strengthens the probability that poorer quality of life among operated patients is an operative effect.
Although patients with true aneurysms of the ascending aorta are frequently asymptomatic, they are not healthy. Once the aneurysm reaches a diameter of more than 5 cm (regardless of cause), these patients live with a high risk of death consequent to acute dissection or rupture.
Our study of operative results and postoperative quality of life indicates that invasive intervention can be performed with good midterm results and acceptable quality of life.
Address for reprints: Christoph Schmitz, MD, Department of Cardiac Surgery, University of Munich, Marchioninistr. 15, 81377 Munich, Germany. E-mail: ed.nehcneum-inu.dem@ztimhcS.hpotsirhC