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Infrarenal aortic occlusion: A reassessment of surgical indications
lnfrarenal Aortic Occlusion: A Reassessment of Surgical Indications
James L. McCullough, Jr., MD, Boston, Massachusetts William C. Mackey, MD, Boston, Massachusetts Thomas F. O’Donnell, Jr., MD, Boston, Massachusetts Victor G. Millan, MD, Boston, Massachusetts Ralph A. Deterling, Jr., MD, Boston, Massachusetts Allan D. Callow, MD, Boston, Massachusetts
The traditional indications for surgical treatment of aortoiliac occlusive disease are limiting claudication and limb-threatening ischemia. In patients with infrarenal aortic occlusion, however, the risk of proximal extension of the thrombus to involve the renal and mesenteric circulations has been considered an equally important indication for aortic reconstruction [I--4]. If thrombus formation in atherosclerotic occlusive disease extends to the level of the next proximal runoff vessel, then with bifurcational aortic thrombosis the proximal extension should be to the inferior mesenteric artery or renal arteries. Although many patients may have chronic occlusion of the inferior mesenteric artery, bilateral occlusion of the renal arteries is unusual. The patency of the renal arteries should prevent proximal propagation of aortic thrombus. To determine the risk of proximal propagation of thrombosis, we reviewed the records of 38 patients with infrarenal aortic occlusion seen at the Tufts-New England Medical Center between the years 1965 and 1982. Methods The diagnosis of infrarenal aortic occlusion was made either by translumbar or transaxillary aortography. Occlusion of the abdominal aorta occurred at a level between the renal arteries and the aortic bifurcation. Each record was examined for cardiovascular risk factors, presenting signs and symptoms, noninvasive vascular laboratory data, From the Departments of Surgery and Radiology, Tufts-New England Medical Center, Boston, Massachusetts. Requests for reprints should be addressed to Thomas F. O’Donnell, Jr., MD, Department of Surgery, Tufts-New England Medical Center, 171 Harrison Avenue. Boston. Massachusetts 02111. Presented at the 1 Ith Annual Meeting of the Society for Clinical Vascular Surgery, Palm Springs, California, March 23-27, 1983.
178
angiographic findings, treatment, and operative complications. Follow-up was achieved by contact with the patient or referring physician. For purposes of comparison, the patients were divided by treatment into three groups. Group I consisted of 24 patients treated surgically, and Group II consisted of 14 patients treated nonsurgically. To determine the risk of proximal propagation of aortic thrombosis, Group III was formed by combining patients from a series of patients from Group I who had extraanatomic bypass, with the patients from Group II. This provided 22 patients who did not have aortic reconstruction, thus leaving the aortic thrombus in situ.
Results There were thirty-eight patients, 21 male and 17 female (54 and 46 percent, respectively), with infrarenal aortic occlusion.
Their mean age was 61
years. In Group I, nine patients (38 percent) presented with threatened limb loss, six (25 percent) with pain at rest and three (13 percent) with ischemic ulceration (Table I). Fifteen patients (62 percent) presented with chronic claudication or limb fatigue which usually involved the buttocks, hip, and thigh. In contrast, 13 (93 percent) Group II patients presented with claudication. One patient (7 percent) was asymptomatic. Femoral artery pulses were not palpable in 35 patients (92 percent). Cardiovascular risk factors were very prevalent: smoking in 29 patients (78 percent), hypertension in 17 (46 percent), coronary artery disease in 16 (43 percent), hyperlipidemia in 9 (24 percent), and diabetes mellitus in 5 (14 percent). Sixteen patients (42 percent) from the later portion of our series had noninvasive vascular evaluation of the lower extremity as part of their initial evaluation. The average ankle Doppler pressure was
The American Journal of Surgery
lnfrarenal Aortic Occlusion
TABLE I
Clinical Characteristics
Mean age (yr) Claudication Pain at rest Ulceration Asymptomatic Afem = aortofemoral;
Afem (n = 16)
Group I (n = 24) Axfem (n = 8)
Total
57.5 11(69%) 3(19%) 2(12%)
64.5 4(50%) 3(38%) 1(12%)
60 15(62%) 6(25 %) 3(13%)
62 13(93%)
l@k) Axfem = axillofemoral
50 mm Hg and the average pulse volume recording was 3 mm at the thigh, 4 mm at the calf, and 3 mm at the ankle. Aortography caused transient renal failure in three patients (8 percent). One patient (3 percent) died 24 hours after translumbar aortography from acute proximal propagation of aortic thrombus and extensive bowel infarction, confirmed by autopsy. In the majority of patients (25 patients, 66 percent) the site of aortic occlusion was just below the renal arteries (juxtarenal), whereas in 13 patients (34 percent), the occlusion was located below the inferior mesenteric artery. There was no correlation between the level of aortic occlusion and the symptoms, treatment, or outcome (Figure 1). Of the twenty-four patients in Group I (63 percent), 16 (42 percent) had an aortobifemoral graft and 8 (21 percent) had an axillofemoral bypass graft. The indication for operation was limiting claudication in 15 patients (62 percent), pain at rest in 6 (25 percent), and ischemic ulceration in 3 (13 percent). There were no operative deaths in the 23 elective cases. Two postoperative complications occurred in the patients in Group I (8 percent). Pancreatitis de-
Figure 1. Anatomic patferns of disiai aortfc occlusion. The number of patients and percent affected are indicated for each group. AF = aortofemoral group; AXF = axi\\ofemoral group; MA = inferior mesenteric artery: Non-surg = nonsurgical group.
Volume 146, August 1983
Group II (n = 14)
Juxta
renal
veloped in one patient after insertion of an aortobifemoral graft, and another had a left colonic infarction 3 weeks after insertion of an aortobifemoral graft. The latter patient died 6 weeks postoperatively from myocardial infarction and multiple organ system failure. The second death, the only operative mortality (4 percent), was in a patient moribund on admission who underwent an emergency axillofemoral graft procedure for limb salvage and died on the 29th postoperative day from septicemia caused by an ischemic sacral ulcer. The immediate graft patency rate (less than 30 days) was 100 percent, (16 of 16) for the aortobifemoral grafts and 88 percent (7 of 8) for the axillofemoral grafts. There were no graft failures in the aortobifemoral group during the follow-up period, but two patients in the axillofemoral group required revision of their grafts for occlusion at 4 and 5 months postoperatively. In the nine patients in Group I who presented with limb-threatening ischemia, there were three major leg amputations (two below-knee and one above-knee) because of extensive gangrene present on admission. Limb salvage was achieved in six of nine patients in this group.
o&udedf
//MA
AF II/l6
169%)
A x F 518
162 *%I
Non-surg
9114
(64%)
At level of IMA (IMA pole&f AF 5/16 AxF 3/8 Non-surg
13f%1 138%) 5/14 136701
179
McCulloughet al
100
-0 \’
Il6J
IgJ
l-
f8J
19J -----.-.-(I/
.-.
80 \
r
a?
2oL___-0
2
3
6
12
24
20
\
I
NJ O-0
(2J
t
46
TIME (months)
I 0
I
2
3
6
12
24
48
TIME (months)
Figure 2. Cumulative patient survival. Solid circles indicate the surgical group, hollow circies indicate the nonsurgical group, and the triangies indkate the group without aotfic reconstmction. The numbers in parentheses indicate the number of patients at each interval.
Figure 3. Cumulative patient survival. Solid circles indicate the aortofemorai group and hollow circles indicate the axiiiofemorai group. The numben? in parentheses indkate the number of patients at each interval.
Surgery was not carried out in the 14 patients in Group II (37 percent) because of prohibitive medical risk in 4, nonreconstructable vessels in 4, patient refusal in 3, and minimal symptoms in 2. One patient died after aortography. The mean follow-up period was 40 months in the patients in Group I and 30 months in the patients in Group II. Although there was not a significant difference in the cumulative survival rates of Groups I and II, the subgroup of patients with an aortobifemoral graft demonstrated longer cumulative survival than those with an axillofemoral graft (Figures 2 and 3). At 4 years this difference was statistically significant (p <0.05). There were 12 deaths in the entire study group during the follow-up period. Of the five late deaths in Group I (more than 30 days postoperatively), four were due to atherosclerotic disease of other organ systems (Table II). Two patients died from myocardial infarction, two from
stroke, and one from chronic renal failure 11 years after an aortobifemoral graft. In Group II, one diabetic patient died from hyperosmolar coma 1 year after the diagnosis of distal aortic occlusion, one patient died from myocardial infarction 5 years after diagnosis, and another died from stroke 6 years after diagnosis. Thus, of the 12 deaths in the entire series, 7 (58 percent) were due to either coronary artery or cerebrovascular disease. Two patients died from acute thrombosis involving visceral arteries. In one patient, an intestinal infarction developed 24 hours after translumbar aortography had demonstrated infrarenal aortic occlusion. Because of the close temporal relation, the acute proximal thrombosis was probably a complication of the aortography. The second patient presented with acute renal failure due to aortic thrombus formation extending to the superior mesenteric artery. This patient was moribund on admission so no surgical procedure was attempted and she died 4 days later. Since this patient had no previous aortogram and no history of lower extremity ischemia, it is uncertain whether she had distal aortic occlusion before the acute episode of thrombosis which involved the renal arteries. Of the 22 patients in Group III (8 patients from Group I who had axillofemoral grafts and 14 patients from Group II), 13 were available for long-term follow-up (mean 48 months). None of these patients died as a result of proximal propagation of aortic thrombus or had any evidence of intestinal ischemia or renal failure. In addition, in none of these patients did lower extremity tissue loss develop due to progression of atherosclerotic occlusive disease during the follow-up period.
TABLE II
Late Causes of Death Group I (n = 24) Afem Axfem In = 161 (n = 6) Total
Group II (n = 14)
Acute myocardial infarction Stroke Chronic renal failure Diabetes mellitus
1
1
2
1
0 1
2
...
2 1
...
...
...
1
Total
2
3
5
3
Afem = aortofemoral; Axfem = axillofemoral.
180
1
The American Journal of Surgery
lnfrarenal Aortic Occlusion
Comments Although atherosclerosis of the distal abdominal aorta and iliac arteries is common in older patients, progression of the disease to the point at which the infrarenal aorta becomes occluded is a relatively rare event. In several studies, the incidence of this lesion in patients with aortoiliac occlusive disease was between 4 and 8 percent [5-71. Atherosclerosis in the aortoiliac segment progresses from stenosis to occlusion with subsequent thrombosis of the aortic bifurcation [8,9]. As described by Haimovici and Escher [9], the development of this lesion is insidious and progressive, with adequate time for the development of collateral blood flow to the legs. Proximal extension of thrombus is limited by the next patent vessel, usually the inferior mesenteric artery or the renal arteries. Complications of arteriography: In three patients in our series (8 percent), transient renal failure developed after aortography despite adequate maintenance of intravascular volume. This incidence is higher than that in our patients with aortoiliac occlusive disease in whom the incidence of renal failure is approximately 3 percent [7]. Patients with distal aortic occlusion have an increased risk of renal damage during aortography because of direct infusion of contrast medium into the renal circulation. Consequently, at our institution, less contrast medium is used in patients with infrarenal aortic occlusion compared with routine aortography in order to decrease renal damage. Proximal aortic thrombosis: Review of the literature revealed several case reports of proximal propagation of aortic thrombus in patients with infrarenal aortic occlusion and stable claudication. In 1954, Johnson [2] reported a patient who died from intestinal infarction due to a recent thrombus which extended from an old bifurcation thrombus to the celiac axis. In 1957, Wyatt and Felson [3] presented three cases in which occlusion of a renal artery by an aortic thrombus was responsible for renovascular hypertension. Since these were isolated cases, the incidence of proximal propagation of an aortic thrombus is not known. In 1974, Starrett and Stoney [I] reported their experience with 55 patients who had aortic occlusion just distal to the renal arteries. Of 13 patients treated nonoperatively, 6 (46 percent) died from proximal propagation of a thrombus which involved the renal arteries, the superior mesenteric artery, or both, at intervals from 15 days to 214 months after diagnosis. As demonstrated in these previous reports, proximal propagation of an aortic thrombus can occur in patients with distal aortic occlusion and is often associated with a fatal outcome, especially if the mesenteric vessels are involved. In contrast to the series reported by Starrett and Stoney [I] in which almost
Volume
146,
August
1993
50 percent of the 13 patients treated without surgery died from proximal aortic thrombosis, none of 13 similar patients (Group III) in our series had this proximal propagation during the follow-up period. Our data suggest that the risk of proximal aortic thrombosis with involvement of visceral arteries may be much less than previously thought. The disparity between these studies clearly establishes the need for further investigation to more accurately define the risk of this complication. In conclusion, the decision for surgical intervention in patients with distal aortic occlusion should be arrived at, as in other patients with aortoiliac occlusive disease, by weighing preoperative symptoms and operative risks and not primarily by the level of risk of proximal aortic thrombosis present. In low-risk patients with limiting claudication or limb-threatening ischemia due to distal aortic occlusion, aortic reconstruction with an aortobifemoral graft is the treatment of choice. With present techniques, acceptable morbidity and mortality rates and excellent long-term results can be expected [IO-221. However, in patients with significant cardiovascular risk and limb-threatening ischemia, an extraanatomic bypass procedure can be considered, and for selected patients with minimal symptoms, close follow-up without surgical treatment may be an acceptable alternative.
Summary Citing a high incidence of proximal propagation of aortic thrombosis, several authors have advocated aortic reconstruction for all patients with infrarenal aortic occlusion irrespective of their preoperative symptoms and potential operative risks. To test this thesis, the records and follow-up data of 38 patients seen at our institution between 1965 and 1982 with infrarenal aortic occlusion were analyzed. Twentyfour of the 38 patients were treated surgically (Group I); 16 (42 percent) had an aortobifemoral graft and 8 (21 percent) had an axillofemoral bypass graft. When the 14 patients who did not have surgery (Group II) and the 8 patients who had an axillofemoral graft were combined, 22 patients (58 percent) did not have aortic reconstruction (Group III), thus the aortic thrombus was left in situ. There was no significant difference in cumulative survival between the three groups at 4 year follow-up. Of 13 patients in Group III who were followed for more than 6 months (mean 48 months), none died from proximal propagation of aortic thrombosis. The decision for surgical intervention in patients with distal aortic occlusion should be arrived at, as in other patients with aortoiliac occlusive disease, by weighing preoperative symptoms and operative risks and not primarily by the level of risk of proximal propagation of thrombosis.
161
McCullough et al
References 1. Starrett RW, Stoney RJ. Juxtarenal aortic occlusion. Surgery 1978;76:890-7. 2. Johnson JK. Ascending thrombosis of abdominal aorta as fatal complication of Leriche’s syndrome. Arch Surg 1954;69: 663-8. 3. Wyatt GM, Felson B. Aortic thrombosis as a cause of hypertension: an arteriographic study. Radiology 1957;69:67682. 4. Day SM, Terry JH. Mesenteric thrombosis complicating occlusive disease of the abdominal aorta: case report. Am Surg 1958;24:315-8. 5. Corson JD, Brewster DC, Darling RC. The surgical management of infrarenal aortic occlusion. Surg Gynecol Obstet 1982; 155:369-72.
182
6. Casali RE, Tucker E, Read RC, Thompson BW. Total infrarenal aortic occlusion. Am J Surg 1977;134:1809-12. 7. Kahn PC, Widrich WC, Moran JM, Callow AD. Angiography in the evaluation of patients for abdominal aortic surgery. AJR 1971;111:762-70. 8. Darling RC, Brewster DC, Hallet JW, Darling RC Ill. Aorto-iliac reconstruction. Surg Clin North Am 1979;59:565-79. 9. Haimovici H, Escher DJW. Aortoiliac stenosis. Arch SUrg 1956;72:107-17. 10. Diehl JT, Cali RF. Hertzer NR, Beven EG. Complications of abdominal aortic reconstruction. An analysis of perioperative risk factors in 557 patients. Ann Surg 1983;197:49-56. 11. Hobson RW. Rich NM, Fedde CW. Surgical management of high aortoiliac occlusion. Am Surg 1975;41:271-80. 12. Bergan JJ, Trippel OH. Management of juxtarenal aortic occlusions. Arch Surg 1963;87:60-8.
The American Journal of Surgery
James L. McCullough, Jr., MD, Boston, Massachusetts William C. Mackey, MD, Boston, Massachusetts Thomas F. O’Donnell, Jr., MD, Boston, Massachusetts Victor G. Millan, MD, Boston, Massachusetts Ralph A. Deterling, Jr., MD, Boston, Massachusetts Allan D. Callow, MD, Boston, Massachusetts
The traditional indications for surgical treatment of aortoiliac occlusive disease are limiting claudication and limb-threatening ischemia. In patients with infrarenal aortic occlusion, however, the risk of proximal extension of the thrombus to involve the renal and mesenteric circulations has been considered an equally important indication for aortic reconstruction [I--4]. If thrombus formation in atherosclerotic occlusive disease extends to the level of the next proximal runoff vessel, then with bifurcational aortic thrombosis the proximal extension should be to the inferior mesenteric artery or renal arteries. Although many patients may have chronic occlusion of the inferior mesenteric artery, bilateral occlusion of the renal arteries is unusual. The patency of the renal arteries should prevent proximal propagation of aortic thrombus. To determine the risk of proximal propagation of thrombosis, we reviewed the records of 38 patients with infrarenal aortic occlusion seen at the Tufts-New England Medical Center between the years 1965 and 1982. Methods The diagnosis of infrarenal aortic occlusion was made either by translumbar or transaxillary aortography. Occlusion of the abdominal aorta occurred at a level between the renal arteries and the aortic bifurcation. Each record was examined for cardiovascular risk factors, presenting signs and symptoms, noninvasive vascular laboratory data, From the Departments of Surgery and Radiology, Tufts-New England Medical Center, Boston, Massachusetts. Requests for reprints should be addressed to Thomas F. O’Donnell, Jr., MD, Department of Surgery, Tufts-New England Medical Center, 171 Harrison Avenue. Boston. Massachusetts 02111. Presented at the 1 Ith Annual Meeting of the Society for Clinical Vascular Surgery, Palm Springs, California, March 23-27, 1983.
178
angiographic findings, treatment, and operative complications. Follow-up was achieved by contact with the patient or referring physician. For purposes of comparison, the patients were divided by treatment into three groups. Group I consisted of 24 patients treated surgically, and Group II consisted of 14 patients treated nonsurgically. To determine the risk of proximal propagation of aortic thrombosis, Group III was formed by combining patients from a series of patients from Group I who had extraanatomic bypass, with the patients from Group II. This provided 22 patients who did not have aortic reconstruction, thus leaving the aortic thrombus in situ.
Results There were thirty-eight patients, 21 male and 17 female (54 and 46 percent, respectively), with infrarenal aortic occlusion.
Their mean age was 61
years. In Group I, nine patients (38 percent) presented with threatened limb loss, six (25 percent) with pain at rest and three (13 percent) with ischemic ulceration (Table I). Fifteen patients (62 percent) presented with chronic claudication or limb fatigue which usually involved the buttocks, hip, and thigh. In contrast, 13 (93 percent) Group II patients presented with claudication. One patient (7 percent) was asymptomatic. Femoral artery pulses were not palpable in 35 patients (92 percent). Cardiovascular risk factors were very prevalent: smoking in 29 patients (78 percent), hypertension in 17 (46 percent), coronary artery disease in 16 (43 percent), hyperlipidemia in 9 (24 percent), and diabetes mellitus in 5 (14 percent). Sixteen patients (42 percent) from the later portion of our series had noninvasive vascular evaluation of the lower extremity as part of their initial evaluation. The average ankle Doppler pressure was
The American Journal of Surgery
lnfrarenal Aortic Occlusion
TABLE I
Clinical Characteristics
Mean age (yr) Claudication Pain at rest Ulceration Asymptomatic Afem = aortofemoral;
Afem (n = 16)
Group I (n = 24) Axfem (n = 8)
Total
57.5 11(69%) 3(19%) 2(12%)
64.5 4(50%) 3(38%) 1(12%)
60 15(62%) 6(25 %) 3(13%)
62 13(93%)
l@k) Axfem = axillofemoral
50 mm Hg and the average pulse volume recording was 3 mm at the thigh, 4 mm at the calf, and 3 mm at the ankle. Aortography caused transient renal failure in three patients (8 percent). One patient (3 percent) died 24 hours after translumbar aortography from acute proximal propagation of aortic thrombus and extensive bowel infarction, confirmed by autopsy. In the majority of patients (25 patients, 66 percent) the site of aortic occlusion was just below the renal arteries (juxtarenal), whereas in 13 patients (34 percent), the occlusion was located below the inferior mesenteric artery. There was no correlation between the level of aortic occlusion and the symptoms, treatment, or outcome (Figure 1). Of the twenty-four patients in Group I (63 percent), 16 (42 percent) had an aortobifemoral graft and 8 (21 percent) had an axillofemoral bypass graft. The indication for operation was limiting claudication in 15 patients (62 percent), pain at rest in 6 (25 percent), and ischemic ulceration in 3 (13 percent). There were no operative deaths in the 23 elective cases. Two postoperative complications occurred in the patients in Group I (8 percent). Pancreatitis de-
Figure 1. Anatomic patferns of disiai aortfc occlusion. The number of patients and percent affected are indicated for each group. AF = aortofemoral group; AXF = axi\\ofemoral group; MA = inferior mesenteric artery: Non-surg = nonsurgical group.
Volume 146, August 1983
Group II (n = 14)
Juxta
renal
veloped in one patient after insertion of an aortobifemoral graft, and another had a left colonic infarction 3 weeks after insertion of an aortobifemoral graft. The latter patient died 6 weeks postoperatively from myocardial infarction and multiple organ system failure. The second death, the only operative mortality (4 percent), was in a patient moribund on admission who underwent an emergency axillofemoral graft procedure for limb salvage and died on the 29th postoperative day from septicemia caused by an ischemic sacral ulcer. The immediate graft patency rate (less than 30 days) was 100 percent, (16 of 16) for the aortobifemoral grafts and 88 percent (7 of 8) for the axillofemoral grafts. There were no graft failures in the aortobifemoral group during the follow-up period, but two patients in the axillofemoral group required revision of their grafts for occlusion at 4 and 5 months postoperatively. In the nine patients in Group I who presented with limb-threatening ischemia, there were three major leg amputations (two below-knee and one above-knee) because of extensive gangrene present on admission. Limb salvage was achieved in six of nine patients in this group.
o&udedf
//MA
AF II/l6
169%)
A x F 518
162 *%I
Non-surg
9114
(64%)
At level of IMA (IMA pole&f AF 5/16 AxF 3/8 Non-surg
13f%1 138%) 5/14 136701
179
McCulloughet al
100
-0 \’
Il6J
IgJ
l-
f8J
19J -----.-.-(I/
.-.
80 \
r
a?
2oL___-0
2
3
6
12
24
20
\
I
NJ O-0
(2J
t
46
TIME (months)
I 0
I
2
3
6
12
24
48
TIME (months)
Figure 2. Cumulative patient survival. Solid circles indicate the surgical group, hollow circies indicate the nonsurgical group, and the triangies indkate the group without aotfic reconstmction. The numbers in parentheses indicate the number of patients at each interval.
Figure 3. Cumulative patient survival. Solid circles indicate the aortofemorai group and hollow circles indicate the axiiiofemorai group. The numben? in parentheses indkate the number of patients at each interval.
Surgery was not carried out in the 14 patients in Group II (37 percent) because of prohibitive medical risk in 4, nonreconstructable vessels in 4, patient refusal in 3, and minimal symptoms in 2. One patient died after aortography. The mean follow-up period was 40 months in the patients in Group I and 30 months in the patients in Group II. Although there was not a significant difference in the cumulative survival rates of Groups I and II, the subgroup of patients with an aortobifemoral graft demonstrated longer cumulative survival than those with an axillofemoral graft (Figures 2 and 3). At 4 years this difference was statistically significant (p <0.05). There were 12 deaths in the entire study group during the follow-up period. Of the five late deaths in Group I (more than 30 days postoperatively), four were due to atherosclerotic disease of other organ systems (Table II). Two patients died from myocardial infarction, two from
stroke, and one from chronic renal failure 11 years after an aortobifemoral graft. In Group II, one diabetic patient died from hyperosmolar coma 1 year after the diagnosis of distal aortic occlusion, one patient died from myocardial infarction 5 years after diagnosis, and another died from stroke 6 years after diagnosis. Thus, of the 12 deaths in the entire series, 7 (58 percent) were due to either coronary artery or cerebrovascular disease. Two patients died from acute thrombosis involving visceral arteries. In one patient, an intestinal infarction developed 24 hours after translumbar aortography had demonstrated infrarenal aortic occlusion. Because of the close temporal relation, the acute proximal thrombosis was probably a complication of the aortography. The second patient presented with acute renal failure due to aortic thrombus formation extending to the superior mesenteric artery. This patient was moribund on admission so no surgical procedure was attempted and she died 4 days later. Since this patient had no previous aortogram and no history of lower extremity ischemia, it is uncertain whether she had distal aortic occlusion before the acute episode of thrombosis which involved the renal arteries. Of the 22 patients in Group III (8 patients from Group I who had axillofemoral grafts and 14 patients from Group II), 13 were available for long-term follow-up (mean 48 months). None of these patients died as a result of proximal propagation of aortic thrombus or had any evidence of intestinal ischemia or renal failure. In addition, in none of these patients did lower extremity tissue loss develop due to progression of atherosclerotic occlusive disease during the follow-up period.
TABLE II
Late Causes of Death Group I (n = 24) Afem Axfem In = 161 (n = 6) Total
Group II (n = 14)
Acute myocardial infarction Stroke Chronic renal failure Diabetes mellitus
1
1
2
1
0 1
2
...
2 1
...
...
...
1
Total
2
3
5
3
Afem = aortofemoral; Axfem = axillofemoral.
180
1
The American Journal of Surgery
lnfrarenal Aortic Occlusion
Comments Although atherosclerosis of the distal abdominal aorta and iliac arteries is common in older patients, progression of the disease to the point at which the infrarenal aorta becomes occluded is a relatively rare event. In several studies, the incidence of this lesion in patients with aortoiliac occlusive disease was between 4 and 8 percent [5-71. Atherosclerosis in the aortoiliac segment progresses from stenosis to occlusion with subsequent thrombosis of the aortic bifurcation [8,9]. As described by Haimovici and Escher [9], the development of this lesion is insidious and progressive, with adequate time for the development of collateral blood flow to the legs. Proximal extension of thrombus is limited by the next patent vessel, usually the inferior mesenteric artery or the renal arteries. Complications of arteriography: In three patients in our series (8 percent), transient renal failure developed after aortography despite adequate maintenance of intravascular volume. This incidence is higher than that in our patients with aortoiliac occlusive disease in whom the incidence of renal failure is approximately 3 percent [7]. Patients with distal aortic occlusion have an increased risk of renal damage during aortography because of direct infusion of contrast medium into the renal circulation. Consequently, at our institution, less contrast medium is used in patients with infrarenal aortic occlusion compared with routine aortography in order to decrease renal damage. Proximal aortic thrombosis: Review of the literature revealed several case reports of proximal propagation of aortic thrombus in patients with infrarenal aortic occlusion and stable claudication. In 1954, Johnson [2] reported a patient who died from intestinal infarction due to a recent thrombus which extended from an old bifurcation thrombus to the celiac axis. In 1957, Wyatt and Felson [3] presented three cases in which occlusion of a renal artery by an aortic thrombus was responsible for renovascular hypertension. Since these were isolated cases, the incidence of proximal propagation of an aortic thrombus is not known. In 1974, Starrett and Stoney [I] reported their experience with 55 patients who had aortic occlusion just distal to the renal arteries. Of 13 patients treated nonoperatively, 6 (46 percent) died from proximal propagation of a thrombus which involved the renal arteries, the superior mesenteric artery, or both, at intervals from 15 days to 214 months after diagnosis. As demonstrated in these previous reports, proximal propagation of an aortic thrombus can occur in patients with distal aortic occlusion and is often associated with a fatal outcome, especially if the mesenteric vessels are involved. In contrast to the series reported by Starrett and Stoney [I] in which almost
Volume
146,
August
1993
50 percent of the 13 patients treated without surgery died from proximal aortic thrombosis, none of 13 similar patients (Group III) in our series had this proximal propagation during the follow-up period. Our data suggest that the risk of proximal aortic thrombosis with involvement of visceral arteries may be much less than previously thought. The disparity between these studies clearly establishes the need for further investigation to more accurately define the risk of this complication. In conclusion, the decision for surgical intervention in patients with distal aortic occlusion should be arrived at, as in other patients with aortoiliac occlusive disease, by weighing preoperative symptoms and operative risks and not primarily by the level of risk of proximal aortic thrombosis present. In low-risk patients with limiting claudication or limb-threatening ischemia due to distal aortic occlusion, aortic reconstruction with an aortobifemoral graft is the treatment of choice. With present techniques, acceptable morbidity and mortality rates and excellent long-term results can be expected [IO-221. However, in patients with significant cardiovascular risk and limb-threatening ischemia, an extraanatomic bypass procedure can be considered, and for selected patients with minimal symptoms, close follow-up without surgical treatment may be an acceptable alternative.
Summary Citing a high incidence of proximal propagation of aortic thrombosis, several authors have advocated aortic reconstruction for all patients with infrarenal aortic occlusion irrespective of their preoperative symptoms and potential operative risks. To test this thesis, the records and follow-up data of 38 patients seen at our institution between 1965 and 1982 with infrarenal aortic occlusion were analyzed. Twentyfour of the 38 patients were treated surgically (Group I); 16 (42 percent) had an aortobifemoral graft and 8 (21 percent) had an axillofemoral bypass graft. When the 14 patients who did not have surgery (Group II) and the 8 patients who had an axillofemoral graft were combined, 22 patients (58 percent) did not have aortic reconstruction (Group III), thus the aortic thrombus was left in situ. There was no significant difference in cumulative survival between the three groups at 4 year follow-up. Of 13 patients in Group III who were followed for more than 6 months (mean 48 months), none died from proximal propagation of aortic thrombosis. The decision for surgical intervention in patients with distal aortic occlusion should be arrived at, as in other patients with aortoiliac occlusive disease, by weighing preoperative symptoms and operative risks and not primarily by the level of risk of proximal propagation of thrombosis.
161
McCullough et al
References 1. Starrett RW, Stoney RJ. Juxtarenal aortic occlusion. Surgery 1978;76:890-7. 2. Johnson JK. Ascending thrombosis of abdominal aorta as fatal complication of Leriche’s syndrome. Arch Surg 1954;69: 663-8. 3. Wyatt GM, Felson B. Aortic thrombosis as a cause of hypertension: an arteriographic study. Radiology 1957;69:67682. 4. Day SM, Terry JH. Mesenteric thrombosis complicating occlusive disease of the abdominal aorta: case report. Am Surg 1958;24:315-8. 5. Corson JD, Brewster DC, Darling RC. The surgical management of infrarenal aortic occlusion. Surg Gynecol Obstet 1982; 155:369-72.
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