Leg Ischemia Following Surgery for Abdominal Aortic Aneurysm GEORGE TCHIRKOW, M.D.,* EDWIN G. BEVEN, M.D.t
Resection of an abdominal aortic aneurysm was associated with intraoperative or postoperative leg ischemia in seven of 100 consecutive survivors of this procedure. Distal embolization of thrombus and debris is the apparent cause in the majority of cases (six). One case of stenosis at a graft-to-vessel anastomosis was identified. Early (intraoperative) thromboembolectomy averted tissue loss in four cases. The role of concurrent lumbar sympathectomy in ameliorating ischemic tissue loss is evaluated. Postaneurysmectomy leg ischemia may accompany other serious complications, particularly hypotension and renal failure.
A DEQUATE PERFUSION of the lower extremities is a major concern following resection of the abdominal aorta for aneurysmal disease. Among the many complications which may develop in the postoperative period' following aneurysmectomy and graft, leg ischemia is infrequent and poses a relatively minor threat to recovery. However, when it does occur, leg ischemia may prolong the period of recovery and frequently necessitates additional operative procedures. Peripheral thromboembolism appears to play the major role. Other factors, such as stenosis or obstruction of a graft limb and postoperative hypotension, have also been implicated in distal ischemia. To better understand the incidence and significance ofthis complication, a series of patients undergoing abdominal aortic aneurysmectomy at the Cleveland Clinic Hospital was reviewed.
Clinical Material A consecutive series of 100 patients who survived abdominal aortic aneurysmectomy was reviewed (Table 1). In order to assess the incidence of postoperative ischemia, only those patients who survived the procedure and the early postoperative period were Fellow doctor, Department of General Surgery, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, Ohio 44106. t Head, Department of Vascular Surgery, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, Ohio 44106. Reprint requests: George Tchirkow, M.D., Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, Ohio 44106. Submitted for publication: January 4, 1978. *
From the Departments of General and Vascular Surgery, Cleveland Clinic Foundation, Cleveland, Ohio
included in the study. These cases involved the period from June 1974 through March 1977. The series included both elective and urgent aneurysmectomies. Six of the 100 patients were symptomatic (back or abdominal pain related to aortic aneurysm) and three of these six had ruptured aneurysms. Patients operated upon for symptomatic aortoiliac occlusive disease who were found to have an aortic aneurysm were excluded due to presence of existing ischemic symptoms. Also, patients with aortic aneurysms who presented with distal microemboli or ischemic ulcers were excluded for the same reason. Four patients died in the postoperative period. Lower extremity ischemia is defined as inadequate leg perfusion resulting in 1) a specific procedure related directly to the ischemia (i.e. embolectomy, amputation) or 2) gangrene of lower extremity tissue managed either conservatively or surgically. Method of Surgery Preparation for elective aneurysm surgery included overnight intravenous hydration, systemic antibiotics, and nasogastric intubation for decompression of the stomach and proximal small intestine. Patients with symptomatic or ruptured aneurysms were operated upon immediately following resuscitation. In all cases, exposure of the aneurysm was accomplished through a midline abdominal incision, and control of the aorta above the aneurysm was obtained. The appropriate distal sites for clamping were selected and isolated. In 91 cases, the distal aorta, common iliac, or external iliac arteries were suitable for grafting. In nine cases, the femoral arteries were chosen for distal anastomotic sites in at least one limb. Following cross-clamping of the aorta and distal vessels, the aneurysm was opened and all aneurysmal contents were evacuated. A 2000Unit bolus of heparin was then injected distally into
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each limb while lumbar artery ostia in the posterior aortic wall were oversewn. Systemic heparinization was not used. A preclotted Dacron® graft was then placed using standard vascular anastomosis technique. The distal anastomoses were completed only after adequate backflow had been demonstrated. In two cases, renal artery revascularization was performed in conjunction with aneurysmectomy for renovascular hypertension. Lumbar sympathectomy, usually bilateral, was performed in 12 cases.
Results Ninety-three of 100 patients demonstrated no evidence of leg ischemia. These patients required neither intraoperative nor postoperative intervention for ischemia. In seven patients, ischemia was evident (Table 2). Five of the seven patients were noted to have inadequate limb perfusion (absent or decreased foot pulses, mottled skin) at the completion of graft placement and underwent intraoperative exploration of leg vessels and embolectomy. In all instances, perfusion and foot pulses were improved. Two of the patients (Cases 1 and 6), however, progressed to toe or forefoot gangrene
167
TABLE 1. Data on Patients in Study
Total cases Elective
Symptomatic (ruptured)
100 94 6
(3)
No ischemia Ischemia Gangrene with eventual loss of tissue (surgical amputation or autoamputation)
93 7 3
despite apparently successful embolectomy and conservative measures, including intravenous Rheomacrodex and lumbar sympathetic blockade. One patient (Case 7) demonstrated severe bilateral ischemia (pallor, anesthesia, absent pulses) in the immediate postoperative period which was also complicated by retroperitoneal hemorrhage requiring G-suit counterpressure. Following replacement of blood volume, femoral angiograms were performed which demonstrated bilateral popliteal emboli. Fogarty embolectomy restored foot pulses in the right foot and a popliteal pulse in the left leg. The patient survived a stormy postoperative course which included septicemia, pulmonary emboli, and renal failure which
TABLE 2.
Patient
Procedure
Presentation of Ischemia
Associated
Findings
Case 1
AAA + ABF
postoperative pallor, hypasthesia right foot, foot pulses present
-
Case 2
exposure AAA with hypotension
right lower leg pulseless, cool
intraoperative hypotension
Case 3
AAA + ABI + bilateral lumbar sympathectomy
cool, mottled, pulseless feet intraoperatively
bilateral femoral emboli on angios (intraoperative)
Case 4
AAA + ABI + Bilateral lumbar sympathectomy
Case 5
AAA + ABI + right
cool, mottled, pulseless left foot intraoperatively right foot viable but sluggish capillary flow, weakness postoperative absent right foot pulses, mottled skin right foot, anesthesia, right foot
groin exploration Case 6
Case 7
AAA + A-R femoral, A-L iliac; bilateral aorto-renal 8 mm Dacron grafts; right lumbar sympathectomy AAA + A-A; intraoperative hemodilution
both feet cool, pale, mottled postopera-
tively
Therapy
Results
intraoperative left femoral thromboembolectomy, intravenous Rheomacrodex, lumbar sympathetic blockade (Xylocaine) right popliteal thromboembolectomy (delayed) intraoperative femoral thromboembolectomy intraoperative left popliteal thromboembolectomy left femoral right femoral crossover graft
dry gangrene right 1-4 toes, autoamputation
ischemia corrected
ischemia corrected ischemia corrected
right leg claudication with prolonged ambulation fixed livedo reticularis right buttock and thigh; CPK, 19,000; renal failure
intraoperative right femoral thromboembolectomy
right gluteal muscle necrosis, ischemic neuropathy right leg
postoperative hypotension; G-suit
bilateral popliteal thromboembolectomy (delayed)
L forefoot amputation for gangrene, dry gangrene R 4-5 toes
counterpressure; renal failure
ischemia corrected
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TCHIRKOW AND BEVEN
required hemodialysis, but he required readmission for a left transmetatarsal amputation for dry gangrene. One patient (Case 5) demonstrated unilateral leg ischemia following aneurysmectomy and graft which did not progress to gangrene. The right leg was noted to be cool, pale, and demonstrated sluggish capillary filling but was viable. Following an otherwise unremarkable period of recovery, the patient demonstrated severe right calf claudication requiring restudy and subsequent femorofemoral crossover graft for stenosis of the right limb of the bifurcation graft. The patient has done well without claudication following these procedures. One patient (Case 2) became severely hypotensive at the time of aortic dissection, requiring postponement of definitive aneurysm resection. In the interval period, he was noted to have a cool, pale right lower leg with absent popliteal and foot pulses. Preoperative pulses had been present. At the time of aneurysmectomy three days later, a right popliteal embolectomy was performed restoring leg pulses and markedly improving perfusion. Gangrene was avoided and claudication has not developed. One patient (Case 6) underwent an elective aneurysmectomy in conjunction with bilateral renal artery revascularization for renal artery stenosis. Preoperative angiograms had demonstrated normal iliac and femoral arteries, and preoperative foot pulses were normal. Following dissection of the aneurysm, the right femoral pulse, which had been present preoperatively, was noted to be absent. Consequently, a right femoral artery exploration was performed, and embolic debris was removed from the femoropopliteal segment. A right lumbar sympathectomy was also performed. Following bifurcation graft placement (to the right femoral and left common iliac arteries), a pulse was present in the right femoral and anterior tibial arteries. Postoperatively, the patient had marked weakness and severe pain in the right lower leg, except for the foot which was anesthetic. Right ankle pulses were absent. The patient also developed a fixed livedo reticularis of the right buttock and thigh. Acute renal failure with hyperkalemia supervened, requiring hemodialysis. The serum CPK rose to 19,000 Units. Renal function eventually returned to normal, and the patient survived. However, he developed necrosis of the right gluteal muscles and portions of the overlying skin which was managed by open drainage and debridement with spontaneous healing. His right leg remains weak with electromyographic evidence of ischemic neuropathy. There has been no skin loss on the right foot.
Ann. Surg. o August 1978
Discussion
Symptoms of lower extremity ischemia are unusual in the patient with an abdominal aortic aneurysm unless distal microemboli are present5 or significant atherosclerosis of the leg vessels coexists. Consequently, postoperative leg ischemia is invariably a result of the operative procedure excluding the abovementioned conditions. Thromboembolism, hypotension, and graft stenosis are factors which threaten the adequacy of distal blood flow during and after aortic surgery. Peripheral thromboembolism has been recognized as a complication of aortic reconstruction since the beginning of modem vascular surgery. In 1954, Blakemore and Voorhees' reported a case of "anemic necrosis" resulting in loss of a distal phalanx of a toe following banding and electrothermic coagulation of an aortic aneurysm. In 1959, Boyd and Pastel2 reported 20 consecutive aneurysmectomies with homograft replacement. Five of these patients experienced arterial thrombotic complications. One required limb amputation, two required reoperation (thromboembolectomy) for limb salvage, and two patients would have required amputation had they survived. In this report, injection of heparin into the distal vessels and establishment of free back-bleeding is emphasized although these principles were not introduced during the period of the study. MacVaugh and Roberts6 reported in 1961 that arterial embolus or thrombosis in the leg was the most common complication (11 patients) in a series of 92 operations for nonruptured aortic aneurysms. Despite embolectomy in ten of these patients, three developed eventual loss of limb due to ischemic gangrene. The details of operative technique and the use of heparin were not mentioned in this report. Twenty of 187 aneurysmectomy patients experienced leg ischemia in a report by May7 in 1967. Five patients required surgical intervention while only one patient required amputation. Heparin was not used in these patients. More recent studies of aortic reconstruction for aneurysmal disease report a much lower incidence of distal ischemia.8'9 Imparato4 reported in 1973 that peripheral embolism can be avoided by systemic heparinization and staged aortic declamping such that all particulate matter is flushed entirely from the vessels or into the hypogastric circulation. In 94 consecutive aneurysm resections, only one patient developed peripheral ischemia. The authors also emphasize the importance of minimal manipulation of the aorta prior to cross-clamping.
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ISCHEMIA FOLLOWING SURGERY
The concept of in situ thrombosis in the leg vessels, as opposed to atheromatous emboli, deserves consideration. Particularly in difficult and lengthy cases, thrombosis in the iliac, femoral, and popliteal arteries may occur despite regional heparinization. With restoration of flow, the clots could be driven into the distal tree. DeWeese3 in 1962 reviewed 12 cases of failure of major arterial reconstruction within 24 hours of surgery. Four of these patients had placement of aortic bifurcation grafts (three for occlusive disease, one for aneurysm). Heparin was injected into distal vessels, and retrograde flow was adequate in all cases. All had initially successful arterial reconstruction as evidenced by adequate distal perfusion. In seven of the 12 cases, reoperation revealed thrombosis at an arteriotomy site, graft-vessel anastomosis, or endarterectomized segment. Only three cases involved peripheral emboli. Despite these observations, it appears likely that embolization of atheromatous debris plays the major role in postoperative distal ischemia. The findings of Thurlbeck and Castleman,10 who described atheromatous emboli to the kidneys in 17 of 22 patients dying after aortic aneurysm surgery, are pertinent. In this situation, fragmentation of aortic wall plaques with cross-clamping is postulated with subsequent flow into the adjacent renal arteries due to turbulence. Certainly, cross-clamping of the distal aorta, iliac, or femoral arteries might cause similar fragmentation of atheromatous plaques which would propagate distally with restoration of flow. Permitting backflow of limb blood prior to distal anastomosis and staged declamping to the aorta and distal vessels should minimize the threat of distal embolus. The present study suggests that intraoperative detection and prompt correction of ischemia averts tissue loss in the affected limb. Four patients (Cases 1, 3, 4, and 6) underwent intraoperative thromboembolectomy. Tissue loss did not occur in the embolectomized limbs of these patients except for the unusual situation of gluteal muscle and skin loss (Case 6) from a suspected massive embolic shower into the right hypogastric circulation. Tissue loss (dry gangrene of four toes) occurred on the right foot of one patient (Case 1), but the left limb, which had been explored intraoperatively, was spared. There was no loss of tissue associated with delayed right popliteal embolectomy in Case 2. However, in Case 7, delayed bilateral popliteal embolectomy was associated with significant tissue loss in both limbs (left forefoot, right fourth and fifth toe gangrene). The favorable results with early intervention in an ischemic extremity are predictable and follow well-
169
established principles of surgical management. The effects of sympathectomy on the course of postoperative ischemia are more difficult to judge. Interruption of one or both sympathetic chains, in conjunction with aneurysmectomy, was performed in a total of 12 patients in this study. Only one of these patients (Case 6) demonstrated tissue loss. However, when applied in cases of suspected ischemia, sympathectomy was always performed as a complementary procedure to thromboembolectomy of the affected limb. The majority of patients (nine of 12) who undervent sympathectomy had demonstrated diminished preoperative ankle pulses but no ischemic symptoms. A favorable outcome in these cases as a result of the "prophylactic" sympathectomy cannot be established from this study. One additional patient (Case 1) had a postoperative paravertebral lumbar sympathetic blockade. This measure was unsuccessful in reversing a severe ischemic necrosis of four toes on the right foot. Our study shows that leg ischemia often accompanies other serious postoperative complications, especially hypotension and/or renal failure. Indeed, in the patient with multiple life-threatening complications, inadequacy of limb perfusion may be initially overlooked. Two of the patients with postoperative ischemia had either intraoperative (Case 2) or postoperative (Case 7) hypotension. Also, two patients (Cases 6 and 7) developed postoperative renal failure requiring temporary hemodialysis. The association of early postoperative leg ischemia and subsequent renal failure lends support to the concept of massive embolic showers as the common etiology of these two complications. None of the three survivors of surgery for ruptured abdominal aortic aneurysm demonstrated leg ischemia which corresponds to the low incidence reported by van Heeckerent" for similar patients (one in 27). This report is limited to patients having surgery for aortic aneurysmal disease. The incidence of leg ischemia in patients who have aortoiliac reconstruction for occlusive disease is not well-documented. Figures significantly different from those presented for aneurysm surgery, however, would not be expected. Despite occlusive disease in the major leg arteries, a well-developed collateral flow should protect the distal tree from all but the most massive of embolic showers. Our report wishes to emphasize that distal ischemia may occur in the patient undergoing abdominal aortic aneurysmectomy despite meticulous surgical technique. The use of regional heparinization and staged
170
ISCHEMIA FOLLOWING SURGERY
aortic declamping, as described by Imparato, should minimize the incidence of this complication. The legs should be frequently inspected for adequacy of distal flow in the intraoperative and postoperative periods. Early intervention in cases of suspected thromboembolism, to include intraoperative angiography and embolectomy, is encouraged. References 1. Blakemore, A. H. and Voorhees, A. B. Jr.: Aneurysm of the Aorta: A Review of 365 cases. Angiology 5:209, 1954. 2. Body, D. P. and Pastel, H.: Results of Treatment of Aneurysm of the Abdominal Aorta. Postgrad. Med. 25:238, 1959. 3. DeWeese, J. A.: Early Failures in Arterial Reconstruction. Arch. Surg. 85:901, 1962. 4. Imparato, A. M., Berman, I. R., Bracco, A., Kim, G. E., and Beaudet, R.: Avoidance of Shock and Peripheral Embolism during Surgery of the Abdominal Aorta. Surgery 73:68, 1973.
Ann. Surg. * August 1978
5. Lord, J. W. Jr., Rossi, G., Daliana, M., Drago, J. R., and Schwartz, A. M.: Unsuspected Abdominal Aortic Aneurysms as the Cause of Peripheral Arterial Occlusive Disease. Ann. Surg. 177:767, 1973. 6. MacVaugh, H. and Roberts, B.: Results of Resection of Abdominal Aortic Aneurysm. Surg., Gynecol. Obstet. 113:17, 1961. 7. May, A. G., DeWeese, J. A., Frank, I., Mahoney, E. B., and Rob, C. G.: Surgical Treatment of Abdominal Aortic Aneurysms. Surgery 63:711, 1968. 8. Stokes, J. and Butcher, H. R.: Abdominal Aortic Aneurysms. Factors Influencing Operative Mortality and Criteria of Operability. Arch. Surg. 107:297, 1973. 9. Thompson, J. E., Hollier, L. H., Patman, R. D. and Persson, A. V.: Surgical Management of Abdominal Aortic Aneurysms: Factors Influencing Mortality and Morbidity-A 20-Year Experience. Ann. Surg. 181:654, 1975. 10. Thurlbeck, W. M., and Castleman, B.: Atheromatous Emboli to the Kidneys After Aortic Surgery. New Engl. J. Med. 257:442, 1957. 11. vanHeeckeren, D. W.: Ruptured Abdominal Aortic Aneurysms. Amer. J. Surg. 119:402, 1970.
Erratum In the article "Esophagogastrectromy: Data Favoring End-to-Side Anastomosis" by Jameson L. Chassin (Ann. Surg., 188:1, 1978) the first sentence of the addendum should have read: "Since this paper was accepted for publication, three additional patients have undergone left thoracoabdominal esophagogastrectomy with end-to-side anastomosis."
Resection of an abdominal aortic aneurysm was associated with intraoperative or postoperative leg ischemia in seven of 100 consecutive survivors of this procedure. Distal embolization of thrombus and debris is the apparent cause in the majority of cases (six). One case of stenosis at a graft-to-vessel anastomosis was identified. Early (intraoperative) thromboembolectomy averted tissue loss in four cases. The role of concurrent lumbar sympathectomy in ameliorating ischemic tissue loss is evaluated. Postaneurysmectomy leg ischemia may accompany other serious complications, particularly hypotension and renal failure.
A DEQUATE PERFUSION of the lower extremities is a major concern following resection of the abdominal aorta for aneurysmal disease. Among the many complications which may develop in the postoperative period' following aneurysmectomy and graft, leg ischemia is infrequent and poses a relatively minor threat to recovery. However, when it does occur, leg ischemia may prolong the period of recovery and frequently necessitates additional operative procedures. Peripheral thromboembolism appears to play the major role. Other factors, such as stenosis or obstruction of a graft limb and postoperative hypotension, have also been implicated in distal ischemia. To better understand the incidence and significance ofthis complication, a series of patients undergoing abdominal aortic aneurysmectomy at the Cleveland Clinic Hospital was reviewed.
Clinical Material A consecutive series of 100 patients who survived abdominal aortic aneurysmectomy was reviewed (Table 1). In order to assess the incidence of postoperative ischemia, only those patients who survived the procedure and the early postoperative period were Fellow doctor, Department of General Surgery, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, Ohio 44106. t Head, Department of Vascular Surgery, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, Ohio 44106. Reprint requests: George Tchirkow, M.D., Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, Ohio 44106. Submitted for publication: January 4, 1978. *
From the Departments of General and Vascular Surgery, Cleveland Clinic Foundation, Cleveland, Ohio
included in the study. These cases involved the period from June 1974 through March 1977. The series included both elective and urgent aneurysmectomies. Six of the 100 patients were symptomatic (back or abdominal pain related to aortic aneurysm) and three of these six had ruptured aneurysms. Patients operated upon for symptomatic aortoiliac occlusive disease who were found to have an aortic aneurysm were excluded due to presence of existing ischemic symptoms. Also, patients with aortic aneurysms who presented with distal microemboli or ischemic ulcers were excluded for the same reason. Four patients died in the postoperative period. Lower extremity ischemia is defined as inadequate leg perfusion resulting in 1) a specific procedure related directly to the ischemia (i.e. embolectomy, amputation) or 2) gangrene of lower extremity tissue managed either conservatively or surgically. Method of Surgery Preparation for elective aneurysm surgery included overnight intravenous hydration, systemic antibiotics, and nasogastric intubation for decompression of the stomach and proximal small intestine. Patients with symptomatic or ruptured aneurysms were operated upon immediately following resuscitation. In all cases, exposure of the aneurysm was accomplished through a midline abdominal incision, and control of the aorta above the aneurysm was obtained. The appropriate distal sites for clamping were selected and isolated. In 91 cases, the distal aorta, common iliac, or external iliac arteries were suitable for grafting. In nine cases, the femoral arteries were chosen for distal anastomotic sites in at least one limb. Following cross-clamping of the aorta and distal vessels, the aneurysm was opened and all aneurysmal contents were evacuated. A 2000Unit bolus of heparin was then injected distally into
0003-4932-78-0800-0166-0Q75 X J. B. Lippincott Company
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each limb while lumbar artery ostia in the posterior aortic wall were oversewn. Systemic heparinization was not used. A preclotted Dacron® graft was then placed using standard vascular anastomosis technique. The distal anastomoses were completed only after adequate backflow had been demonstrated. In two cases, renal artery revascularization was performed in conjunction with aneurysmectomy for renovascular hypertension. Lumbar sympathectomy, usually bilateral, was performed in 12 cases.
Results Ninety-three of 100 patients demonstrated no evidence of leg ischemia. These patients required neither intraoperative nor postoperative intervention for ischemia. In seven patients, ischemia was evident (Table 2). Five of the seven patients were noted to have inadequate limb perfusion (absent or decreased foot pulses, mottled skin) at the completion of graft placement and underwent intraoperative exploration of leg vessels and embolectomy. In all instances, perfusion and foot pulses were improved. Two of the patients (Cases 1 and 6), however, progressed to toe or forefoot gangrene
167
TABLE 1. Data on Patients in Study
Total cases Elective
Symptomatic (ruptured)
100 94 6
(3)
No ischemia Ischemia Gangrene with eventual loss of tissue (surgical amputation or autoamputation)
93 7 3
despite apparently successful embolectomy and conservative measures, including intravenous Rheomacrodex and lumbar sympathetic blockade. One patient (Case 7) demonstrated severe bilateral ischemia (pallor, anesthesia, absent pulses) in the immediate postoperative period which was also complicated by retroperitoneal hemorrhage requiring G-suit counterpressure. Following replacement of blood volume, femoral angiograms were performed which demonstrated bilateral popliteal emboli. Fogarty embolectomy restored foot pulses in the right foot and a popliteal pulse in the left leg. The patient survived a stormy postoperative course which included septicemia, pulmonary emboli, and renal failure which
TABLE 2.
Patient
Procedure
Presentation of Ischemia
Associated
Findings
Case 1
AAA + ABF
postoperative pallor, hypasthesia right foot, foot pulses present
-
Case 2
exposure AAA with hypotension
right lower leg pulseless, cool
intraoperative hypotension
Case 3
AAA + ABI + bilateral lumbar sympathectomy
cool, mottled, pulseless feet intraoperatively
bilateral femoral emboli on angios (intraoperative)
Case 4
AAA + ABI + Bilateral lumbar sympathectomy
Case 5
AAA + ABI + right
cool, mottled, pulseless left foot intraoperatively right foot viable but sluggish capillary flow, weakness postoperative absent right foot pulses, mottled skin right foot, anesthesia, right foot
groin exploration Case 6
Case 7
AAA + A-R femoral, A-L iliac; bilateral aorto-renal 8 mm Dacron grafts; right lumbar sympathectomy AAA + A-A; intraoperative hemodilution
both feet cool, pale, mottled postopera-
tively
Therapy
Results
intraoperative left femoral thromboembolectomy, intravenous Rheomacrodex, lumbar sympathetic blockade (Xylocaine) right popliteal thromboembolectomy (delayed) intraoperative femoral thromboembolectomy intraoperative left popliteal thromboembolectomy left femoral right femoral crossover graft
dry gangrene right 1-4 toes, autoamputation
ischemia corrected
ischemia corrected ischemia corrected
right leg claudication with prolonged ambulation fixed livedo reticularis right buttock and thigh; CPK, 19,000; renal failure
intraoperative right femoral thromboembolectomy
right gluteal muscle necrosis, ischemic neuropathy right leg
postoperative hypotension; G-suit
bilateral popliteal thromboembolectomy (delayed)
L forefoot amputation for gangrene, dry gangrene R 4-5 toes
counterpressure; renal failure
ischemia corrected
168
TCHIRKOW AND BEVEN
required hemodialysis, but he required readmission for a left transmetatarsal amputation for dry gangrene. One patient (Case 5) demonstrated unilateral leg ischemia following aneurysmectomy and graft which did not progress to gangrene. The right leg was noted to be cool, pale, and demonstrated sluggish capillary filling but was viable. Following an otherwise unremarkable period of recovery, the patient demonstrated severe right calf claudication requiring restudy and subsequent femorofemoral crossover graft for stenosis of the right limb of the bifurcation graft. The patient has done well without claudication following these procedures. One patient (Case 2) became severely hypotensive at the time of aortic dissection, requiring postponement of definitive aneurysm resection. In the interval period, he was noted to have a cool, pale right lower leg with absent popliteal and foot pulses. Preoperative pulses had been present. At the time of aneurysmectomy three days later, a right popliteal embolectomy was performed restoring leg pulses and markedly improving perfusion. Gangrene was avoided and claudication has not developed. One patient (Case 6) underwent an elective aneurysmectomy in conjunction with bilateral renal artery revascularization for renal artery stenosis. Preoperative angiograms had demonstrated normal iliac and femoral arteries, and preoperative foot pulses were normal. Following dissection of the aneurysm, the right femoral pulse, which had been present preoperatively, was noted to be absent. Consequently, a right femoral artery exploration was performed, and embolic debris was removed from the femoropopliteal segment. A right lumbar sympathectomy was also performed. Following bifurcation graft placement (to the right femoral and left common iliac arteries), a pulse was present in the right femoral and anterior tibial arteries. Postoperatively, the patient had marked weakness and severe pain in the right lower leg, except for the foot which was anesthetic. Right ankle pulses were absent. The patient also developed a fixed livedo reticularis of the right buttock and thigh. Acute renal failure with hyperkalemia supervened, requiring hemodialysis. The serum CPK rose to 19,000 Units. Renal function eventually returned to normal, and the patient survived. However, he developed necrosis of the right gluteal muscles and portions of the overlying skin which was managed by open drainage and debridement with spontaneous healing. His right leg remains weak with electromyographic evidence of ischemic neuropathy. There has been no skin loss on the right foot.
Ann. Surg. o August 1978
Discussion
Symptoms of lower extremity ischemia are unusual in the patient with an abdominal aortic aneurysm unless distal microemboli are present5 or significant atherosclerosis of the leg vessels coexists. Consequently, postoperative leg ischemia is invariably a result of the operative procedure excluding the abovementioned conditions. Thromboembolism, hypotension, and graft stenosis are factors which threaten the adequacy of distal blood flow during and after aortic surgery. Peripheral thromboembolism has been recognized as a complication of aortic reconstruction since the beginning of modem vascular surgery. In 1954, Blakemore and Voorhees' reported a case of "anemic necrosis" resulting in loss of a distal phalanx of a toe following banding and electrothermic coagulation of an aortic aneurysm. In 1959, Boyd and Pastel2 reported 20 consecutive aneurysmectomies with homograft replacement. Five of these patients experienced arterial thrombotic complications. One required limb amputation, two required reoperation (thromboembolectomy) for limb salvage, and two patients would have required amputation had they survived. In this report, injection of heparin into the distal vessels and establishment of free back-bleeding is emphasized although these principles were not introduced during the period of the study. MacVaugh and Roberts6 reported in 1961 that arterial embolus or thrombosis in the leg was the most common complication (11 patients) in a series of 92 operations for nonruptured aortic aneurysms. Despite embolectomy in ten of these patients, three developed eventual loss of limb due to ischemic gangrene. The details of operative technique and the use of heparin were not mentioned in this report. Twenty of 187 aneurysmectomy patients experienced leg ischemia in a report by May7 in 1967. Five patients required surgical intervention while only one patient required amputation. Heparin was not used in these patients. More recent studies of aortic reconstruction for aneurysmal disease report a much lower incidence of distal ischemia.8'9 Imparato4 reported in 1973 that peripheral embolism can be avoided by systemic heparinization and staged aortic declamping such that all particulate matter is flushed entirely from the vessels or into the hypogastric circulation. In 94 consecutive aneurysm resections, only one patient developed peripheral ischemia. The authors also emphasize the importance of minimal manipulation of the aorta prior to cross-clamping.
Vol. 188.o No. 2
ISCHEMIA FOLLOWING SURGERY
The concept of in situ thrombosis in the leg vessels, as opposed to atheromatous emboli, deserves consideration. Particularly in difficult and lengthy cases, thrombosis in the iliac, femoral, and popliteal arteries may occur despite regional heparinization. With restoration of flow, the clots could be driven into the distal tree. DeWeese3 in 1962 reviewed 12 cases of failure of major arterial reconstruction within 24 hours of surgery. Four of these patients had placement of aortic bifurcation grafts (three for occlusive disease, one for aneurysm). Heparin was injected into distal vessels, and retrograde flow was adequate in all cases. All had initially successful arterial reconstruction as evidenced by adequate distal perfusion. In seven of the 12 cases, reoperation revealed thrombosis at an arteriotomy site, graft-vessel anastomosis, or endarterectomized segment. Only three cases involved peripheral emboli. Despite these observations, it appears likely that embolization of atheromatous debris plays the major role in postoperative distal ischemia. The findings of Thurlbeck and Castleman,10 who described atheromatous emboli to the kidneys in 17 of 22 patients dying after aortic aneurysm surgery, are pertinent. In this situation, fragmentation of aortic wall plaques with cross-clamping is postulated with subsequent flow into the adjacent renal arteries due to turbulence. Certainly, cross-clamping of the distal aorta, iliac, or femoral arteries might cause similar fragmentation of atheromatous plaques which would propagate distally with restoration of flow. Permitting backflow of limb blood prior to distal anastomosis and staged declamping to the aorta and distal vessels should minimize the threat of distal embolus. The present study suggests that intraoperative detection and prompt correction of ischemia averts tissue loss in the affected limb. Four patients (Cases 1, 3, 4, and 6) underwent intraoperative thromboembolectomy. Tissue loss did not occur in the embolectomized limbs of these patients except for the unusual situation of gluteal muscle and skin loss (Case 6) from a suspected massive embolic shower into the right hypogastric circulation. Tissue loss (dry gangrene of four toes) occurred on the right foot of one patient (Case 1), but the left limb, which had been explored intraoperatively, was spared. There was no loss of tissue associated with delayed right popliteal embolectomy in Case 2. However, in Case 7, delayed bilateral popliteal embolectomy was associated with significant tissue loss in both limbs (left forefoot, right fourth and fifth toe gangrene). The favorable results with early intervention in an ischemic extremity are predictable and follow well-
169
established principles of surgical management. The effects of sympathectomy on the course of postoperative ischemia are more difficult to judge. Interruption of one or both sympathetic chains, in conjunction with aneurysmectomy, was performed in a total of 12 patients in this study. Only one of these patients (Case 6) demonstrated tissue loss. However, when applied in cases of suspected ischemia, sympathectomy was always performed as a complementary procedure to thromboembolectomy of the affected limb. The majority of patients (nine of 12) who undervent sympathectomy had demonstrated diminished preoperative ankle pulses but no ischemic symptoms. A favorable outcome in these cases as a result of the "prophylactic" sympathectomy cannot be established from this study. One additional patient (Case 1) had a postoperative paravertebral lumbar sympathetic blockade. This measure was unsuccessful in reversing a severe ischemic necrosis of four toes on the right foot. Our study shows that leg ischemia often accompanies other serious postoperative complications, especially hypotension and/or renal failure. Indeed, in the patient with multiple life-threatening complications, inadequacy of limb perfusion may be initially overlooked. Two of the patients with postoperative ischemia had either intraoperative (Case 2) or postoperative (Case 7) hypotension. Also, two patients (Cases 6 and 7) developed postoperative renal failure requiring temporary hemodialysis. The association of early postoperative leg ischemia and subsequent renal failure lends support to the concept of massive embolic showers as the common etiology of these two complications. None of the three survivors of surgery for ruptured abdominal aortic aneurysm demonstrated leg ischemia which corresponds to the low incidence reported by van Heeckerent" for similar patients (one in 27). This report is limited to patients having surgery for aortic aneurysmal disease. The incidence of leg ischemia in patients who have aortoiliac reconstruction for occlusive disease is not well-documented. Figures significantly different from those presented for aneurysm surgery, however, would not be expected. Despite occlusive disease in the major leg arteries, a well-developed collateral flow should protect the distal tree from all but the most massive of embolic showers. Our report wishes to emphasize that distal ischemia may occur in the patient undergoing abdominal aortic aneurysmectomy despite meticulous surgical technique. The use of regional heparinization and staged
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aortic declamping, as described by Imparato, should minimize the incidence of this complication. The legs should be frequently inspected for adequacy of distal flow in the intraoperative and postoperative periods. Early intervention in cases of suspected thromboembolism, to include intraoperative angiography and embolectomy, is encouraged. References 1. Blakemore, A. H. and Voorhees, A. B. Jr.: Aneurysm of the Aorta: A Review of 365 cases. Angiology 5:209, 1954. 2. Body, D. P. and Pastel, H.: Results of Treatment of Aneurysm of the Abdominal Aorta. Postgrad. Med. 25:238, 1959. 3. DeWeese, J. A.: Early Failures in Arterial Reconstruction. Arch. Surg. 85:901, 1962. 4. Imparato, A. M., Berman, I. R., Bracco, A., Kim, G. E., and Beaudet, R.: Avoidance of Shock and Peripheral Embolism during Surgery of the Abdominal Aorta. Surgery 73:68, 1973.
Ann. Surg. * August 1978
5. Lord, J. W. Jr., Rossi, G., Daliana, M., Drago, J. R., and Schwartz, A. M.: Unsuspected Abdominal Aortic Aneurysms as the Cause of Peripheral Arterial Occlusive Disease. Ann. Surg. 177:767, 1973. 6. MacVaugh, H. and Roberts, B.: Results of Resection of Abdominal Aortic Aneurysm. Surg., Gynecol. Obstet. 113:17, 1961. 7. May, A. G., DeWeese, J. A., Frank, I., Mahoney, E. B., and Rob, C. G.: Surgical Treatment of Abdominal Aortic Aneurysms. Surgery 63:711, 1968. 8. Stokes, J. and Butcher, H. R.: Abdominal Aortic Aneurysms. Factors Influencing Operative Mortality and Criteria of Operability. Arch. Surg. 107:297, 1973. 9. Thompson, J. E., Hollier, L. H., Patman, R. D. and Persson, A. V.: Surgical Management of Abdominal Aortic Aneurysms: Factors Influencing Mortality and Morbidity-A 20-Year Experience. Ann. Surg. 181:654, 1975. 10. Thurlbeck, W. M., and Castleman, B.: Atheromatous Emboli to the Kidneys After Aortic Surgery. New Engl. J. Med. 257:442, 1957. 11. vanHeeckeren, D. W.: Ruptured Abdominal Aortic Aneurysms. Amer. J. Surg. 119:402, 1970.
Erratum In the article "Esophagogastrectromy: Data Favoring End-to-Side Anastomosis" by Jameson L. Chassin (Ann. Surg., 188:1, 1978) the first sentence of the addendum should have read: "Since this paper was accepted for publication, three additional patients have undergone left thoracoabdominal esophagogastrectomy with end-to-side anastomosis."
