of the Descending and Thoracoabdominal Aorta
Ruptured Aneurysm
Thoracic
Analysis According to Size and Treatment
E. STANLEY CRAWFORD, M.D., KENNETH R. HESS, M.S., EVAN S. COHEN, M.D., JOSEPH S. COSELLI, M.D., and HAZIM J. SAFI, M.D.
Acute rupture was confirmed at operation in 117 patients treated for descending thoracic or thoracoabdominal aortic aneurysm. Descending thoracic (n = 80) aortic rupture occurred into lung or esophagus in 8, the pleural cavity in 49, and the mediastinum in 23. Upper abdominal aortic (n = 37) rupture occurred into peritoneal cavity in 3 and into retroperitoneal tissues in 34. Aneurysmal size (range, 5 to 17 cm; median, 8 cm) could be determined retrospectively in 86 patients; 59 (74%) descending thoracic and 27 (73%) abdominal aorta. Size (external diameter) in the former was 8 (14%), 5 to 6 cm; 21 (36%), 6 to 8 cm; 23 (39%), 8 to 10 cm; and 7 (12%) > 10 cm. Size at the abdominal site was similar. Thus size was not greater than 10 cm in 52 (88%) (range, 5 to 10 cm), which contradicts opinions that thoracic aneurysms rupture only when size exceeds 10 cm. Twentynine patients (25%) were hypotensive (systolic blood pressure less than 100 mmHg), of whom 16 (55%) had cardiac arrest before operation. Associated conditions included advanced age (.75 years) in 26 (22%), coronary artery disease in 41 (35%), chronic obstructive pulmonary disease in 46 (39%), renal insufficiency in 25 (21%), and cardiovascular disease in 22 (18%). The overall early survival rate (30-day) was 89 of 117 patients (76%); 69% in patients with hypotension, 56% of patients with cardiac arrest, 88% in good-risk patients. Five-year (KaplanMeier) survival was 28%. Because elective operation is associated with 92% survival, this should be considered before rupture when aneurysm is 5 cm or larger in good-risk patients, in patients with symptomatic aneurysms, and in most patients with larger aneurysms.
A NEURYSMS OF THE descending thoracic and thoracoabdominal aorta may be associated with a variety of complications; however the most serious is rupture because it leads to death in most cases. Natural history studies of patients with untreated aneurysms of the thoracic aorta suggest 5-year survival varying from 7% to 20%, depending on cause; dissection, 7%; and Presented at the 102nd Scientific Session of the Southern Surgical Association, Boca Raton, Florida, December 3-6, 1990. Address reprint requests to E. Stanley Crawford, M.D., Department of Surgery, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030. Accepted for publication January 9, 1991.
From the Department of Surgery, Baylor College of Medicine, and The Methodist Hospital, Houston, Texas
nondissection, 20%.'-` Similar studies of patients with thoracoabdominal aortic aneurysms indicate less than 20% survived for 5 years.4 To be sure, the cause of death in many of these patients was associated disease, but the most common cause, occurring in more than one half, was rupture of the aneurysm. Rupture of ascending aortic and abdominal aortic aneurysms has been related to size in several studies.5'6 It has been reported that rupture from laceration (simple bursting of aortic wall) or dissection occurs with increasing frequency in patients with aneurysms of the ascending aorta as the diameter increases beyond 5 cm.5 Studies indicate that most aneurysms of the abdominal aorta are 5 cm or greater in diameter at the time of rupture.6 Based on one follow-up study of descending thoracic aortic aneurysms in which rupture occurred in 10 patients, and the aneurysm in only one patient was less than 10 cm in diameter, the conclusion made was that rupture of descending thoracic aortic aneurysms rarely occurs in patients with aneurysms less than 10 cm in diameter.7 Thus the opinion expressed by some authors is that aneurysms of the descending thoracic aorta that are less than 10 cm in diameter should be treated conservatively and that operative treatment should be reserved only for those with aneurysms greater than 10 cm in diameter.8'9 Our observations in the treatment of patients with rupture of the aortic segment of aneurysms of the descending thoracic and thoracoabdominal aorta suggested that rupture occurred in smaller aneurysms and that operation should be considered in patients with aneurysms whose diameters are less than 10 cm. This report is concerned with a retrospective review of 1 17 patients treated for acute rupture of the descending thoracic and thoracoabdominal
417
Ann.
CRAWFORD AND OTHERS
418
aorta and an analysis according to size, treatment, and results in these cases as compared with those who had operation for aneurysms that had not ruptured.
Methods Acute aortic rupture for purposes of this study was defined as loss of continuity of aortic wall in the region of aneurysm associated with fresh blood outside the wall of the aneurysm. The charts and roentgenographic records of all patients with aneurysms of the descending thoracic aorta (n = 726) treated between May 1962 and June 1, 1990 and all patients (n = 1400) with thoracoabdominal aortic aneurysms treated between June 20, 1960 and June 1, 1990 were reviewed retrospectively. Acute rupture, as defined, was found in 40 (5.5%) of the former and 77 (5.5%) of the latter patients. Of these 117 patients, 73 (62%) were men and 44 (38%) were women. Their ages ranged from 16 to 87 years with a median age of 69 years. The women tended to be older, with a median age of 71 years compared to 67 years for men. Pertinent data relating to possible preoperative risk factors, intraoperative variables, and postoperative results were recorded and stored on computer for analysis. Statistical Methods Standard methods incorporating the BMDP statistical software package (BMDP Statistical Software Incorporated, Los Angeles, CA) were used. Univariate (Pearson chi square test, BMDP4F) and multivariate (stepwise logistic regression, BMDPLR) analyses were used to identify statistically significant clinical predictors of early death. The chi square test determines whether a statistically significant association exists between early death and an individual study factor (ignoring other factors). Stepwise logistic regression selects from the study factors a set of independent risk factors that demonstrated a simultaneous significant association with early mortality. The KaplanMeier technique was used to estimate long-term survival, and confidence intervals were computed to indicate the relative precision of the estimates. Factors studied include: preoperative cardiac arrest, preoperative hypotension, type of rupture (contained or free), location of rupture (lung/ esophagus, thorax, abdomen), interval from aneurysm diagnosis to aneurysm rupture, interval from acute sympTABLE 1. Interval Between Diagnosis of Aneurysm and Onset of Symptoms (108 Patients with Data) Interval
No. of Patients
1-6 days 7-29 days 1 month-2 years 2-10 years
33 (31%) 19 (18%) 30 (28%) 26 (24%)
Surg. May 1991 -
TABLE 2. Interval Between Change in Symptoms and Operation (114 Patients)
Interval
No. of Patients
Ruptured Aneurysm
Thoracic
Analysis According to Size and Treatment
E. STANLEY CRAWFORD, M.D., KENNETH R. HESS, M.S., EVAN S. COHEN, M.D., JOSEPH S. COSELLI, M.D., and HAZIM J. SAFI, M.D.
Acute rupture was confirmed at operation in 117 patients treated for descending thoracic or thoracoabdominal aortic aneurysm. Descending thoracic (n = 80) aortic rupture occurred into lung or esophagus in 8, the pleural cavity in 49, and the mediastinum in 23. Upper abdominal aortic (n = 37) rupture occurred into peritoneal cavity in 3 and into retroperitoneal tissues in 34. Aneurysmal size (range, 5 to 17 cm; median, 8 cm) could be determined retrospectively in 86 patients; 59 (74%) descending thoracic and 27 (73%) abdominal aorta. Size (external diameter) in the former was 8 (14%), 5 to 6 cm; 21 (36%), 6 to 8 cm; 23 (39%), 8 to 10 cm; and 7 (12%) > 10 cm. Size at the abdominal site was similar. Thus size was not greater than 10 cm in 52 (88%) (range, 5 to 10 cm), which contradicts opinions that thoracic aneurysms rupture only when size exceeds 10 cm. Twentynine patients (25%) were hypotensive (systolic blood pressure less than 100 mmHg), of whom 16 (55%) had cardiac arrest before operation. Associated conditions included advanced age (.75 years) in 26 (22%), coronary artery disease in 41 (35%), chronic obstructive pulmonary disease in 46 (39%), renal insufficiency in 25 (21%), and cardiovascular disease in 22 (18%). The overall early survival rate (30-day) was 89 of 117 patients (76%); 69% in patients with hypotension, 56% of patients with cardiac arrest, 88% in good-risk patients. Five-year (KaplanMeier) survival was 28%. Because elective operation is associated with 92% survival, this should be considered before rupture when aneurysm is 5 cm or larger in good-risk patients, in patients with symptomatic aneurysms, and in most patients with larger aneurysms.
A NEURYSMS OF THE descending thoracic and thoracoabdominal aorta may be associated with a variety of complications; however the most serious is rupture because it leads to death in most cases. Natural history studies of patients with untreated aneurysms of the thoracic aorta suggest 5-year survival varying from 7% to 20%, depending on cause; dissection, 7%; and Presented at the 102nd Scientific Session of the Southern Surgical Association, Boca Raton, Florida, December 3-6, 1990. Address reprint requests to E. Stanley Crawford, M.D., Department of Surgery, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030. Accepted for publication January 9, 1991.
From the Department of Surgery, Baylor College of Medicine, and The Methodist Hospital, Houston, Texas
nondissection, 20%.'-` Similar studies of patients with thoracoabdominal aortic aneurysms indicate less than 20% survived for 5 years.4 To be sure, the cause of death in many of these patients was associated disease, but the most common cause, occurring in more than one half, was rupture of the aneurysm. Rupture of ascending aortic and abdominal aortic aneurysms has been related to size in several studies.5'6 It has been reported that rupture from laceration (simple bursting of aortic wall) or dissection occurs with increasing frequency in patients with aneurysms of the ascending aorta as the diameter increases beyond 5 cm.5 Studies indicate that most aneurysms of the abdominal aorta are 5 cm or greater in diameter at the time of rupture.6 Based on one follow-up study of descending thoracic aortic aneurysms in which rupture occurred in 10 patients, and the aneurysm in only one patient was less than 10 cm in diameter, the conclusion made was that rupture of descending thoracic aortic aneurysms rarely occurs in patients with aneurysms less than 10 cm in diameter.7 Thus the opinion expressed by some authors is that aneurysms of the descending thoracic aorta that are less than 10 cm in diameter should be treated conservatively and that operative treatment should be reserved only for those with aneurysms greater than 10 cm in diameter.8'9 Our observations in the treatment of patients with rupture of the aortic segment of aneurysms of the descending thoracic and thoracoabdominal aorta suggested that rupture occurred in smaller aneurysms and that operation should be considered in patients with aneurysms whose diameters are less than 10 cm. This report is concerned with a retrospective review of 1 17 patients treated for acute rupture of the descending thoracic and thoracoabdominal
417
Ann.
CRAWFORD AND OTHERS
418
aorta and an analysis according to size, treatment, and results in these cases as compared with those who had operation for aneurysms that had not ruptured.
Methods Acute aortic rupture for purposes of this study was defined as loss of continuity of aortic wall in the region of aneurysm associated with fresh blood outside the wall of the aneurysm. The charts and roentgenographic records of all patients with aneurysms of the descending thoracic aorta (n = 726) treated between May 1962 and June 1, 1990 and all patients (n = 1400) with thoracoabdominal aortic aneurysms treated between June 20, 1960 and June 1, 1990 were reviewed retrospectively. Acute rupture, as defined, was found in 40 (5.5%) of the former and 77 (5.5%) of the latter patients. Of these 117 patients, 73 (62%) were men and 44 (38%) were women. Their ages ranged from 16 to 87 years with a median age of 69 years. The women tended to be older, with a median age of 71 years compared to 67 years for men. Pertinent data relating to possible preoperative risk factors, intraoperative variables, and postoperative results were recorded and stored on computer for analysis. Statistical Methods Standard methods incorporating the BMDP statistical software package (BMDP Statistical Software Incorporated, Los Angeles, CA) were used. Univariate (Pearson chi square test, BMDP4F) and multivariate (stepwise logistic regression, BMDPLR) analyses were used to identify statistically significant clinical predictors of early death. The chi square test determines whether a statistically significant association exists between early death and an individual study factor (ignoring other factors). Stepwise logistic regression selects from the study factors a set of independent risk factors that demonstrated a simultaneous significant association with early mortality. The KaplanMeier technique was used to estimate long-term survival, and confidence intervals were computed to indicate the relative precision of the estimates. Factors studied include: preoperative cardiac arrest, preoperative hypotension, type of rupture (contained or free), location of rupture (lung/ esophagus, thorax, abdomen), interval from aneurysm diagnosis to aneurysm rupture, interval from acute sympTABLE 1. Interval Between Diagnosis of Aneurysm and Onset of Symptoms (108 Patients with Data) Interval
No. of Patients
1-6 days 7-29 days 1 month-2 years 2-10 years
33 (31%) 19 (18%) 30 (28%) 26 (24%)
Surg. May 1991 -
TABLE 2. Interval Between Change in Symptoms and Operation (114 Patients)
Interval
No. of Patients
