Sealed rupture of abdominal aortic aneurysms Antonio V. Sterpetti, M D , Elizabeth A. Blair, M D , Richard D. Schultz, M D , Richard J. Feldhaus, M D , Silvestro Cisternino, M D , and Patti Chasan, M D , Omaha, Neb.
Sealed rupture of abdominal aortic aneurysms, even if uncommon, deserves particular attention for the possibility of misdiagnosis and for the deleterious effects of such a misdiagnosis. Sixteen patients (mean age 72 years; range 65 to 84 years) with chronic sealed rupture of abdominal aortic aneurysms are reported. Two patients had acute rupture of the aneurysm, and at operation chronic contained rupture was found along with the recent hemorrhage. One patient died after surgery. The remaining patients underwent successful resection with long-term survival and regression of symptoms. Consideration of sealed abdominal aortic aneurysm rupture should be included when examining elderly patients with history of unexplained back pain or femoral neuropathy. Computed tomography is a usefifl aid in the diagnosis of sealed rupture. Ultrasonography is less accurate; in three patients ultrasonography failed to diagnose the presence of the rupture. (J VASC SURG 1990;11:430-5.) The purpose of elective surgical treatment of abdominal aortic aneurysms (AAAs) is to prevent high mortality after rupture. When operation is performed electively, mortality ranges between 0% and 5%. 1'2 Rupture of AAAs, when untreated, is rarely associated with survival, and when operation is performed at this advanced stage, it results in a mortality ranging from 15% to more than 60%. 3-s The diagnosis of rupturing AAAs is usually straightforward when the triad of abdominal or back pain, shock, and a pulsatile abdominal mass are present. Sealed chronic rupture of AAA is unusual. This entity has been recognized for a long time, and many various clinical presentations have been described since Szilagyi et al. 6 first reported seven cases of sealed rupture of AAAs simulating sepsis. The purpose of this study was to elucidate the incidence, the presentation, the pathophysiologic features, diagnosis, and treatment of such a clinical entity. PATIENTS AND METHODS The medical records, operative, and pathologic reports of 486 patients who underwent AAA resection from January 1974 to December 1986 were reviewed. Chronic sealed rupture of the AAA was defined as evidence of perforation of the aneurysm,
From the Department of Surgery, Creighton University. Reprint requests: Antonio V. Sterpetti, MD, Richard D. Schultz, MD, Department of Surgery, Creighton University,601 North 30th St., Suite 3740, Omaha, NE 68131. 24/6/17240 430
Table I. Profile of patients with sealed ruptured aneurysm Clinical characteristics
No. of patients Age (mean) Sex (M/F) Smoking History of arterial hypertension Previous myocardial infarction by history and/or electrocardiogram Distal occlusivedisease Carotid disease
No. (%)
16 72 15/1 10 (62.5%) 1 (6%) 5 (31%) 7 (44%) 3 (19%)
contained either by old organized blood, by fibrosis, or by anatomic structures. Patients with recent retroperitoneal ruptur~ without signs of fibrotic organization of the bloou; were not included in the study. Sixteen patients had chronic sealed rupture. At operation two patients with acute rupture of the aneurysm were found to have chronic contained rupture along with the recent hemorrhage. Clinical characteristics Fifteen men and one woman (range, 65 to 84 years; mean, 72 years) had chronic sealed rupture. Associated coronary and carotid atherosclerotic disease were common. Ten patients had distal occlusive arterial disease. Table I shows the clinical characteristics of patients with sealed AAAs. Only one of 16 patients with sealed rupture had arterial hypertension, and this patient had acute rupture along with signs of sealed rupture.
Volume 11 Number 3 March 1990
Sealed rupture of abdominal aortic aneurysms 431
Table II. Clinical characteristics of 16 cases of sealed rupture of abdominal aortic aneurysm Age Case
(yr)
Sex
Initial symptoms
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
84 71 64 77 80 87 76 70 75 73 73 67 73 71 64 70
M M M M M M M M M M M M M M M F
None Back pain Back pain (severe) Abdominal pain Back pain + inguinal pain Back pain (severe) Back pain + inguinal pain None Back pain Inguinal pain None Back pain + inguinal pain ? Abdominal pain Back pain (severe) Back pain (severe)
The incidence of arterial hypertension was statistically higher in patients with frank rupture reported in other series r,8 (p < 0.05). All but three patients with sealed rupture had history of previous symptoms referable to the aneurysm (Table II). The probable time of the initial rupture ranged from 4 weeks to 4 months before surgery. Symptoms disappeared or decreased significantly in intensity after the onset in all but three patients. Two of the latter patients had large retroperitoneal hematomas, and the remaining patient had frank rupture. Findings In 10 patients (62.5%) the perforation was posterior, involving the abdominal aorta in nine cases a~cl the right common iliac artery in the remaining case. The hernatoma was of small size in seven patients (70%). It was tamponaded or walled off by the surrounding structurcs: vertebral body posteriorly and iliopsoas muscle and its aponeurosis laterally. In three cases (30%) the hematoma was of more conspicuous size, extending toward the left, between the aortic wall and the iliopsoas muscle and its aponeurosis, down to the inguinal area. In three cases (12.5%) the site of rupture was on the left lateral wall just below the origin of the renal artery. The hematoma was quite small, contained in the space between the renal artery superiorly, wall of the aneurysm inferiorly and medially, and iliopsoas muscle laterally. In both cases the aneurysm extended mostly toward the left (Fig. 1, Table III). It was not possible to ascertain the site of rupture
Symptoms on admission None None Back pain (mild) Abdominal pain None Inguinal pain (mild) Abdominal pain None None None None Shock Shock None Inguinal pain (mild) Inguinal pain (mild)
Time interval between rupture & operation (weeks) ? 18 6 8 16 3 4 ? 9 10 ? 16 ? 13 9 7
in three cases. In six patients (37.5%) the aneurysm appeared on gross examination as an "inflammatory" aneurysm with a thick layer surrounding fibrotic tissue. Microscopically, the aneurysm showed classic features of atherosclerosis with abundant periadventitial inflammatory reaction (Fig. 2). One patient with acute rupturc died after surgery of renal failure. The remaining patient underwent successful resection with long-term survival and regression of symptoms. Surgical technical problems The surgeon might recognize the presence of a sealed rupture only when entering the aneurysmal sac; a posterior perforation is usually evident only at that point. In these situations the perforation should be left untreated. In case of posterolateral or lateral perforation an abundant perianeurysmal fibrosis and inflammation is present. It is convenient to avoid entering the hematoma. Proximal and distal control should be quickly obtained. Once the aneurysmal sac is opened, the hematoma might be explored to ascertain if it is the cause of compression of adjacent structures. Otherwise, and this is in most cases, it should be left untreated. If these guidelines are followed, postoperative mortality and morbidity are acceptable. DISCUSSION
Despite progressive improvement in surgical technique and anesthesia, the mortality data of elective abdominal aortic aneurysmectomy and of repair of ruptured AAAs remain in striking contrast.
Journal of VASCULAR SURGERY
432 Sterpetti et al.
A
A
Fig. 1. The site of rupture was ascertained in 13 out of the 16 patients. A, and B, The site of perforation.
Fig. 2. Abundant perianeurysmal inflammatory infiltrate (case No. 3). (Hematoxylin-eosin stain; ×40.)
Unusual clinical presentations of ruptured AAAs frequently delay surgical treatment resulting in poor survival. Rupture of AAAs can take place in one of three waysg: (1) open rupture in the free peritoneal cavity, usually when the site of perforation is in the anterior wall; (2) closed rupture with formation of retroperitoneal hematoma; the hematoma can be very extensive eventually opening in the peritoneal cavity; (3) in rare cases the rupture is effectively sealed off by the surrounding tissue reaction, and the retro-
peritoneal hcmatoma is chronically contained. However, the sealed rupture may reopen with massive hemorrhage. Two of 16 patients in our series had frank rupture. Although sealed rupture is uncommon (3.3% in our series), the possibility of diagnostic difficulties and the high risk of subsequent frank rupture testify to the importance of a correct analysis of the phenomenon. In cases of retroperitoneal rupture of AAAs, tbe
Volume 11 Number 3 March 1990
Sealed rupture of abdominal aortic aneurysms 4 3 3
Table III. Operative findings Case
Aneurysm size
1
11 cm 9.5 cm 6 cm
2 3
cm em cm em cm cm cm
Site of rupture
Size of hematoma
Other findings
Pathology
?
Large ~ Small~ Small
Previous gastric resection Erosion spinal ligament --
ATS ATS ATS & Intl.
Small Large Small Large Large Small Small
Left iliopsoas hematoma Left iliopsoas hernatoma Erosion vertebral body Left iliopsoas hematoma -Erosion vertebral body --
ATS ATS ATS ATS ATS ATS & Intl. ATS & Intl.
Posterior Left lateral near origin renal artery Posterior Posterior Posterior Posterior ? Posterior Left lateral near origin renal artery Left lateral near origin renal artery Posterior
4 5 6 7 8 -9 10
10 6 5 15 9 5 1i
li
12 cm
12
10 cm
13 14
Not described 4 cm
Posterior
Large Small
15
5.5 cm
Posterior
Small
16
4 cm
Posterior
Small
?
ATS
Small
Large
Erosion vertebral body frank rupture Frank rupture Erosion spinous ligament Hematoma right ileopsoas Erosion spinous ligament
ATS ATS ATS & Intl. ATS & Intl. ATS & Intl.
ATS, Atherosclerosis; Intl., gross appearance o f inflammatory aneurysm. ~Large >9.5 cm in the largest transverse diameter. ~ S m a l l < 6 cm in the largest transverse diameter.
size of the hematoma is the end product of the balance between hemorrhage and the resistance of the surrounding retroperitoneal tissue and fascial compartments. A perforation can be sealed off if two events occur: slow hemorrhage and high resistance of the surrounding structures. There are several reasons that explain the possibility of a low-pressure hemorrhage m these patients. Hypertension has generally been considered to be a risk factor for aneurysm rupture. Szilagyi et al. 8 found that hypertension was present in 67% of patients who experienced aneurysm rupture but in only 23% of those without rupture. In our series all but one patient with sealed rupture were normotensive, whereas patients experiencing frank rupture often have previous history of arterial hypertension. 7 A perforation may be more easily contained in a normotensive patient. The size of the perforation is another important factor. All but two patients in our series had a very small perforation. In three cases the site of the perforation was not found. The aneurysm had penetrated the vertebral body in two patients with large perforation. Szilagyi et al.6 noted that chronically contained rupture occurs more frequently :n cases of small aneurysms.
In our series two subgroups of aneurysms were involved; seven patients had small aneurysms ( < 6 cm in the largest transverse diameter), and eight had quite large aneurysms. There were no aneurysms of medium size ( > 6 cm
Sealed rupture of abdominal aortic aneurysms, even if uncommon, deserves particular attention for the possibility of misdiagnosis and for the deleterious effects of such a misdiagnosis. Sixteen patients (mean age 72 years; range 65 to 84 years) with chronic sealed rupture of abdominal aortic aneurysms are reported. Two patients had acute rupture of the aneurysm, and at operation chronic contained rupture was found along with the recent hemorrhage. One patient died after surgery. The remaining patients underwent successful resection with long-term survival and regression of symptoms. Consideration of sealed abdominal aortic aneurysm rupture should be included when examining elderly patients with history of unexplained back pain or femoral neuropathy. Computed tomography is a usefifl aid in the diagnosis of sealed rupture. Ultrasonography is less accurate; in three patients ultrasonography failed to diagnose the presence of the rupture. (J VASC SURG 1990;11:430-5.) The purpose of elective surgical treatment of abdominal aortic aneurysms (AAAs) is to prevent high mortality after rupture. When operation is performed electively, mortality ranges between 0% and 5%. 1'2 Rupture of AAAs, when untreated, is rarely associated with survival, and when operation is performed at this advanced stage, it results in a mortality ranging from 15% to more than 60%. 3-s The diagnosis of rupturing AAAs is usually straightforward when the triad of abdominal or back pain, shock, and a pulsatile abdominal mass are present. Sealed chronic rupture of AAA is unusual. This entity has been recognized for a long time, and many various clinical presentations have been described since Szilagyi et al. 6 first reported seven cases of sealed rupture of AAAs simulating sepsis. The purpose of this study was to elucidate the incidence, the presentation, the pathophysiologic features, diagnosis, and treatment of such a clinical entity. PATIENTS AND METHODS The medical records, operative, and pathologic reports of 486 patients who underwent AAA resection from January 1974 to December 1986 were reviewed. Chronic sealed rupture of the AAA was defined as evidence of perforation of the aneurysm,
From the Department of Surgery, Creighton University. Reprint requests: Antonio V. Sterpetti, MD, Richard D. Schultz, MD, Department of Surgery, Creighton University,601 North 30th St., Suite 3740, Omaha, NE 68131. 24/6/17240 430
Table I. Profile of patients with sealed ruptured aneurysm Clinical characteristics
No. of patients Age (mean) Sex (M/F) Smoking History of arterial hypertension Previous myocardial infarction by history and/or electrocardiogram Distal occlusivedisease Carotid disease
No. (%)
16 72 15/1 10 (62.5%) 1 (6%) 5 (31%) 7 (44%) 3 (19%)
contained either by old organized blood, by fibrosis, or by anatomic structures. Patients with recent retroperitoneal ruptur~ without signs of fibrotic organization of the bloou; were not included in the study. Sixteen patients had chronic sealed rupture. At operation two patients with acute rupture of the aneurysm were found to have chronic contained rupture along with the recent hemorrhage. Clinical characteristics Fifteen men and one woman (range, 65 to 84 years; mean, 72 years) had chronic sealed rupture. Associated coronary and carotid atherosclerotic disease were common. Ten patients had distal occlusive arterial disease. Table I shows the clinical characteristics of patients with sealed AAAs. Only one of 16 patients with sealed rupture had arterial hypertension, and this patient had acute rupture along with signs of sealed rupture.
Volume 11 Number 3 March 1990
Sealed rupture of abdominal aortic aneurysms 431
Table II. Clinical characteristics of 16 cases of sealed rupture of abdominal aortic aneurysm Age Case
(yr)
Sex
Initial symptoms
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
84 71 64 77 80 87 76 70 75 73 73 67 73 71 64 70
M M M M M M M M M M M M M M M F
None Back pain Back pain (severe) Abdominal pain Back pain + inguinal pain Back pain (severe) Back pain + inguinal pain None Back pain Inguinal pain None Back pain + inguinal pain ? Abdominal pain Back pain (severe) Back pain (severe)
The incidence of arterial hypertension was statistically higher in patients with frank rupture reported in other series r,8 (p < 0.05). All but three patients with sealed rupture had history of previous symptoms referable to the aneurysm (Table II). The probable time of the initial rupture ranged from 4 weeks to 4 months before surgery. Symptoms disappeared or decreased significantly in intensity after the onset in all but three patients. Two of the latter patients had large retroperitoneal hematomas, and the remaining patient had frank rupture. Findings In 10 patients (62.5%) the perforation was posterior, involving the abdominal aorta in nine cases a~cl the right common iliac artery in the remaining case. The hernatoma was of small size in seven patients (70%). It was tamponaded or walled off by the surrounding structurcs: vertebral body posteriorly and iliopsoas muscle and its aponeurosis laterally. In three cases (30%) the hematoma was of more conspicuous size, extending toward the left, between the aortic wall and the iliopsoas muscle and its aponeurosis, down to the inguinal area. In three cases (12.5%) the site of rupture was on the left lateral wall just below the origin of the renal artery. The hematoma was quite small, contained in the space between the renal artery superiorly, wall of the aneurysm inferiorly and medially, and iliopsoas muscle laterally. In both cases the aneurysm extended mostly toward the left (Fig. 1, Table III). It was not possible to ascertain the site of rupture
Symptoms on admission None None Back pain (mild) Abdominal pain None Inguinal pain (mild) Abdominal pain None None None None Shock Shock None Inguinal pain (mild) Inguinal pain (mild)
Time interval between rupture & operation (weeks) ? 18 6 8 16 3 4 ? 9 10 ? 16 ? 13 9 7
in three cases. In six patients (37.5%) the aneurysm appeared on gross examination as an "inflammatory" aneurysm with a thick layer surrounding fibrotic tissue. Microscopically, the aneurysm showed classic features of atherosclerosis with abundant periadventitial inflammatory reaction (Fig. 2). One patient with acute rupturc died after surgery of renal failure. The remaining patient underwent successful resection with long-term survival and regression of symptoms. Surgical technical problems The surgeon might recognize the presence of a sealed rupture only when entering the aneurysmal sac; a posterior perforation is usually evident only at that point. In these situations the perforation should be left untreated. In case of posterolateral or lateral perforation an abundant perianeurysmal fibrosis and inflammation is present. It is convenient to avoid entering the hematoma. Proximal and distal control should be quickly obtained. Once the aneurysmal sac is opened, the hematoma might be explored to ascertain if it is the cause of compression of adjacent structures. Otherwise, and this is in most cases, it should be left untreated. If these guidelines are followed, postoperative mortality and morbidity are acceptable. DISCUSSION
Despite progressive improvement in surgical technique and anesthesia, the mortality data of elective abdominal aortic aneurysmectomy and of repair of ruptured AAAs remain in striking contrast.
Journal of VASCULAR SURGERY
432 Sterpetti et al.
A
A
Fig. 1. The site of rupture was ascertained in 13 out of the 16 patients. A, and B, The site of perforation.
Fig. 2. Abundant perianeurysmal inflammatory infiltrate (case No. 3). (Hematoxylin-eosin stain; ×40.)
Unusual clinical presentations of ruptured AAAs frequently delay surgical treatment resulting in poor survival. Rupture of AAAs can take place in one of three waysg: (1) open rupture in the free peritoneal cavity, usually when the site of perforation is in the anterior wall; (2) closed rupture with formation of retroperitoneal hematoma; the hematoma can be very extensive eventually opening in the peritoneal cavity; (3) in rare cases the rupture is effectively sealed off by the surrounding tissue reaction, and the retro-
peritoneal hcmatoma is chronically contained. However, the sealed rupture may reopen with massive hemorrhage. Two of 16 patients in our series had frank rupture. Although sealed rupture is uncommon (3.3% in our series), the possibility of diagnostic difficulties and the high risk of subsequent frank rupture testify to the importance of a correct analysis of the phenomenon. In cases of retroperitoneal rupture of AAAs, tbe
Volume 11 Number 3 March 1990
Sealed rupture of abdominal aortic aneurysms 4 3 3
Table III. Operative findings Case
Aneurysm size
1
11 cm 9.5 cm 6 cm
2 3
cm em cm em cm cm cm
Site of rupture
Size of hematoma
Other findings
Pathology
?
Large ~ Small~ Small
Previous gastric resection Erosion spinal ligament --
ATS ATS ATS & Intl.
Small Large Small Large Large Small Small
Left iliopsoas hematoma Left iliopsoas hernatoma Erosion vertebral body Left iliopsoas hematoma -Erosion vertebral body --
ATS ATS ATS ATS ATS ATS & Intl. ATS & Intl.
Posterior Left lateral near origin renal artery Posterior Posterior Posterior Posterior ? Posterior Left lateral near origin renal artery Left lateral near origin renal artery Posterior
4 5 6 7 8 -9 10
10 6 5 15 9 5 1i
li
12 cm
12
10 cm
13 14
Not described 4 cm
Posterior
Large Small
15
5.5 cm
Posterior
Small
16
4 cm
Posterior
Small
?
ATS
Small
Large
Erosion vertebral body frank rupture Frank rupture Erosion spinous ligament Hematoma right ileopsoas Erosion spinous ligament
ATS ATS ATS & Intl. ATS & Intl. ATS & Intl.
ATS, Atherosclerosis; Intl., gross appearance o f inflammatory aneurysm. ~Large >9.5 cm in the largest transverse diameter. ~ S m a l l < 6 cm in the largest transverse diameter.
size of the hematoma is the end product of the balance between hemorrhage and the resistance of the surrounding retroperitoneal tissue and fascial compartments. A perforation can be sealed off if two events occur: slow hemorrhage and high resistance of the surrounding structures. There are several reasons that explain the possibility of a low-pressure hemorrhage m these patients. Hypertension has generally been considered to be a risk factor for aneurysm rupture. Szilagyi et al. 8 found that hypertension was present in 67% of patients who experienced aneurysm rupture but in only 23% of those without rupture. In our series all but one patient with sealed rupture were normotensive, whereas patients experiencing frank rupture often have previous history of arterial hypertension. 7 A perforation may be more easily contained in a normotensive patient. The size of the perforation is another important factor. All but two patients in our series had a very small perforation. In three cases the site of the perforation was not found. The aneurysm had penetrated the vertebral body in two patients with large perforation. Szilagyi et al.6 noted that chronically contained rupture occurs more frequently :n cases of small aneurysms.
In our series two subgroups of aneurysms were involved; seven patients had small aneurysms ( < 6 cm in the largest transverse diameter), and eight had quite large aneurysms. There were no aneurysms of medium size ( > 6 cm
