Axillofemoral bypass: A critical reappraisal of its role in the management of aortoiliac occlusive disease

Axillofemoral Bypass: A Critical Reappraisal of its Role In the Management of Aortoiliac Occlusive Disease

Lance I. Ray, MD, Seattle, Washington Joseph 8. O’Connor, MD, FRCS, Seattle, Washington Christopher C. Davis, MD, Seattle, Washington Dale G. Hail, MD, Seattle, Washington Peter B. Mansfield, MD, Seattle, Washington Edward A. Rittenhouse, MD, Seattle, Washington James C. Smith, MD, Seattle, Washington Stephen J. Wood, MD, Seattle, Washington Lester Ft. Sauvage, MD, Seattle, Washington

Blaisdell and Hall [1] introduced the unilateral axillofemoral bypass in 1963, initially describing its use in the management of unilateral aortoiliac occlusive disease. In 1966, Sauvage and Wood [2] extended this unilateral procedure to a bilateral one by supplying both legs from a single axillary artery, introducing the axillobilateral femoral bypass procedure, for three patients with bilateral aortoiliac disease whom they considered poor candidates for an intraabdominal operation. LoGerfo et al [a] suggested that this bilateral configuration increased the flow rate in the main axillofemoral limb and should result in a higher long-term patency when compared with the unilateral axillofemoral graft. However, Eugene et al [4] found no difference in long-term patency between axillo-unilateral and axillobilateral femoral grafts. Parsonnet et al [5] and others [6-81 questioned whether axillofemoral bypass should be used only in poor risk patients (and those with infected aortic grafts) or whether the results were sufficiently good to warrant its use in better risk patients with bilateral aortoiliac occlusive disease. The purpose of this report is to describe a 9 year experience (1970 to 1979) with the axillofemoral bypass utilizing one type of prosthesis (USC1 Sauvage filamentous velour Dacron@) and to clarify the From the Reconstructive Cardiovascular Research Center International of Providence Medical Center and the Department of Surgery, School of Medicine, University of Washington, Seattle, Washington. Reprint recfuests should be addressed to Lester Ft. Sauvage. MD, 528 18th Avenue, Seattle, Washington, 98122. Presented at the 59th Annual Meeting of the Pacific Coast Surgical Association, Yosemite National Park, February 19-22, 1979.

Volume 139, July 1979

role of this procedure in comparison with aortofemoral [9,10] and femorofemoral [11-141 bypass grafts in the management of patients with arteriosclerotic aortoiliac occlusive disease. We shall analyze the relation of the long-term patency results of the axillofemoral bypass to four variables: (1) graft configuration, that is, whether unilateral femoral or bilateral femoral; (2) surgical indications (claudication versus limb salvage); (3) degree of patency of the competing iliac inflow source; and (4) the extent of access to and capacity of the femoral outflow bed. Material and Methods Selection of Patients. Two hundred twenty-four consecutive patients who underwent bypass grafting for aortoiliac occlusive disease at Providence Medical Center from January 1,197O through February 1,1979 were reviewed. Those with predominantly unilateral iliac occlusive disease underwent femorofemoral bypass. Good risk patients with bilateral aortoiliac disease were selected for aortofemoral bypass, whereas poor risk patients were selected for axillofemoral bypass because of advanced age, debilitation. severe coronary artery disease, severe pulmonary disease, multiple previous abdominal operations, limited life expectancy, the presence of intraabdominal sepsis or a colostomy, or an infected aortic graft [6-8,151. During this 9 year period, aortofemoral bypass grafting was performed in 105 patients (210 graft limbs) and femorofemoral bypass grafting in 65 patients (67 graft limbs). Fifty-four patients underwent axillofemoral bypass grafting involving 84 graft limbs, with 42 unilateral grafts

117

Ray et al

TABLE I

TABLE II

Risk Factors Present in 54 Patients Undergoing Axillofemoral Bypass No. of Patients

Risk Factor Smoking (>20 pack/years) Hypertension Coronary artery disease Diabetes mellitus Cerebrovascular disease Chronic obstructive pulmonary disease

39 20 12 12 6 6

placed in 33 patients and 21 axillobilateral femoral bypass grafts in 21 patients (42 graft limbs). Nineteen of these patients were female and 35 male; their ages ranged from 49 to 84 years (mean 66.7). Thirty-nine of the 54 patients (72 per cent) were chronic cigarette smokers, and associated cardiovascular risk factors were prevalent (Table I). Four (19 per cent) of the 21 patients undergoing axillobilateral femoral bypass were operated on for limb salvage with either rest pain or ischemic tissue necrosis, while 16 patients (76 per cent) underwent operation for disabling intermittent claudication that interfered with their ability to work or significantly altered their life style. One addi-

GROUPI

<

;

GROUP11

?

Indications for Operation

Presenting Symptom

Type of Graft Unilateral Bilateral No. of No. of No. of No. of Patients Grafts Patients Grafts

Disabling claudication

16

19

16

32

lschemic rest pain or tissue necrosis

13

16

4

a

1 3

1 4

. .

.

.

.

1

2

33

42

21

42

Other Coarctation of aorta Infected aortic graft Aortoenteric fistula Total

tional patient, in the bilateral group was operated on for an aortoenteric fistula. Two unilateral grafts were placed in two patients because of infected aortic grafts. One unilateral graft was placed in an elderly woman with coarctation of the aorta who was unable to tolerate her antihypertensive medications. Eighteen (43 per cent) of the 42 unilateral grafts were performed for limb salvage in 13 patients. Thus, 17 (32 per cent) of the 54 patients underwent operation for limb salvage (Table II). Preoperative angiographic studies were available in 77

;

Figure 1. Angiographic classification of 77 axillofemoral bypass grafts grouped according to the degree of iliac inflow obstruction and the patency of the femoral outflow bed. 118

The American Journal of Surgery

Axillofemoral

FILAMENTOUS

VELOUR

AORTOFEMORAL

March 4. 1970 through

February

BYPASS

1, 1979

Patients

Grafts

Mean implant

Closures

Patency

105

210

43.9 mo.

4

98.1%

FILAMENTOUS E2

VELOUR

FEMOROFEMORAL

March 3, 1971 through

February

Bypass

GRAFTS

1. 1979

P z .r G

Patients

Grafts

65

67

FILAMENTOUS

Mean implant 32.5 mo.

VELOUR

May 20. 1970 through THIS SEGMENT OF MAIN LIMB SUBJECT TO REDUCED FLOW

8 s

Patency

7

89.6%

AXILLOFEMORAL February

Grafts

Mean implant

Closures

54

84

30.0 mo.

18

Patency 78.3%

BYPASS

AXILLOFEMORAL

TO-

GRAFTS

1, 1979

Patients

AORTOFEMORAL

Figure 2. l//u&ration irom original 1966 article by Sauvage and Wood [ 21 showing how the distal portion of the axillofemoral limb below the bifurcation is subject to sudden flow reduction. (Reprinted with permission of the publisher. )

Closures

BYPASS

72.1%

i

f of 84 limbs (92 per cent); no angiograms were available for review in the remaining 7 limbs. These 77 limbs were grouped according to whether their iliac inflow was totally occluded, severely stenotic (greater than 75 per cent stenosis), or moderately stenotic (50 to 75 per cent stenosis) when assessed on single plane angiograms. They were further subdivided according to whether both the superficial and the profunda femoris arteries were patent, or whether the profunda provided the only outflow channel in the thigh (Figure 1). The aortoiliac inflow was totally occluded in 44 of these 77 limbs (57 per cent), severely obstructed in 27 limbs (35 per cent), and only moderately obstructed in six limbs (8 per cent). In 34 limbs (44 per cent) both the superficial femoral and profunda femoris arteries were patent, and in 43 limbs (56 per cent) the superficial femoral was occluded and the profunda femoris was patent. All grafts implanted in this series were USC1 Sauvage filamentous velour Dacron arterial prostheses (United States Catheter and Instrument, C. R. Bard, Inc., Billerica, MA). Thirty-six (43 per cent) of these were the random crimped type; 8 (10 per cent) were noncrimped, heat-set round type; 13 (15 per cent) were a spiral crimp type; and for the last 2 years 27 (32 per cent) were the currently used circular crimped, filamentous velour prostheses. Twenty-five (30 per cent) of the grafts implanted early in the series were 6 mm in diameter, 9 (11 per cent) were 7 mm, 13 (15 per cent) were 10 mm, l(1 per cent) was 12 mm, and the remaining 36 (43 per cent) were 8 mm in diameter. This latter size has become our standard, except for the occasional patient with very small vessels, in whom a smaller size is more appropriate.

Volume

138,

July

1979

60 t

Mar.

Years

Figure 3. Nine year patency of 64 axillofemoral bypass grafts, 210 aortQfemoral bypass grafts, and 67 femorofemoral bypass grafts by life table analysis.

Operatiue Technique. Operative details for the axillofemoral bypass have been well described [3,16,17], so we will restrict our comments to a few specific details. Prophylactic antibiotics are used routinely. Grafts are rendered blood-tight and hypothrombogenic before implantation by a four-step preclotting technique [18]. Systemic heparinization with 1.5 to 2.0 mg/kg is used in preference to regional heparinization. Until recently we constructed the contralateral limb of our axillobilateral femoral grafts so that it originated from the main limb at about the level of the umbilicus and crossed obliquely downward at about a 60” angle from the main limb to the opposite groin, as shown in Figure 2. Although this configuration does have certain hemodynamic advantages because it produces less turbulence at the bifurcation, it has the disadvantage of suddenly decreasing the flow in the distal portion of the axillofemoral limb to about 50 per cent of that in the proximal portion. Considering this point, together with the excellent long-term results of our femorofemoral crossover

119

Ray et al

UNILATERAL Patients

Grafts

Mean implant

Closures

Patency

33

42

25.6 mo.

11

73.8%

7

83.3%

BILATERAL 21

42

31.9 mo.

BILATERAL

;

E 75 VI

Figure 4. Optimal configuration of contralateral limb. Left, diagramatic representation of incorrect “bifurcation” limb to contralateral artery which subjects distalportion of main limb to a sudden drop in flow. Right, correct axillobilateral femoral bypass configuration allowing fhe main limb to have the benefit of higher flow fhroughoul the entire length.

graft series (Figure 3) with life table patency of 86.4 per cent at 8 years, we now construct the axillobilateral femoral bypass graft as a unilateral axillofemoral graft with a crossover femorofemoral limb arising from the distal hood of the axillofemoral graft where it attaches to the common femoral artery (Figure 4, right). Additional heparin is given (2,500 units intravenously every hour) to maintain full systemic heparinization. After releasing all clamps, reversal of heparin is delayed for 20 minutes. This delay has improved the 7 day patency rates of 6 cm segments of 4 mm USC1 Sauvage filamentous velour prostheses from 20 to 70 per cent in dogs [18,19]. During this 20 minutes graft blood flows are measured and operative arteriograms are done when extended profundaplasty or femoropopliteal bypass is performed. Low molecular weight dextran (dextran 40 injection) is administered at 20 cc/hour for the first 3 days, and dipyridamole (Persantinea), 100 mg/day, plus buffered aspirin (Ascriptine), 900 mg/day, are begun as soon as the patient can take oral medications. These medications are continued for 6 months [zo].

TABLE III Months Since Entry To Study O-l l-6 7-12 13-24 25-36 37-46 49-60 61-72 73-83 85-96 97-108

!I

,

,

,

,

,

TERAT

16

1

2

3

4

5

6

MOS.

Years

I

I

I

7

9

Figure 5. Comparison of the patency of unilateral versus bilateral axillofemoral bypass grafts by life table analysis. Results

The life table patency for all axillofemoral bypass grafts is presented in Figure 3, and the data from which it is drawn are presented in an actuarial table (Table III) [21]. Life table patencies of our aortofemoral and femorofemoral experience using the same graft during the same 9 year period are also presented in Figure 3 for comparison. The comparison of unilateral and bilateral axillofemoral bypass grafts by actuarial analysis is presented in life table form in Figure 5. Comparison of the results of axillofemoral grafts performed for disabling claudication versus limb salvage is shown in Figure 6. Life table patency rates for each of the six angiographic categories is presented in Table IV.

Axillofemoral Graft Patency*

No. of Grafts Entering Interval

No. of Grafts Closing During Interval

84 79 66 60 40 27 18 13 5 3 1

2 10 1 3 0 2 0 0 0 0 0

No. of Grafts Withdrawn During Interval Duration of Lost to Follow-up Follow-up Death 3 3 2 12 2 1 4 4 0 0 0

0 0

0 0

0 0 0

3 5 11 6 1 4 2 2 1

0

0 0

0 0 0

Grafts Failing During Interval (%)

Grafts Patent During Interval (%)

2.4 12.9 1.6 5.8 0 8.5 0 0 0 0 0

97.1 98.4 94.2 100.0 91.5 100.0 100.0 100.0 100.0 100.0

97.6

Cumulative Patency (%)

Standard Error

97.6 85.0 83.6 78.8 78.8 72.1 72.1 72.1 72.1 72.1 72.1

1.7 4.0 4.2 4.8 4.8 6.3 6.3 6.3 6.3 6.3 6.3

* USCI Sauvage filamentous velour prosthesis used in all cases.

120

The American Journal of Surgery

Axillofemoral

Operative flow measurements were obtained in the latter part of this series. The mean flow in 25 unilateral grafts was 313 cc/min, in contrast to 912 cc/ min in 17 bilateral axillofemoral grafts. In the grafts for which flow measurements were available, the mean flow in the six limbs of the bilateral axillofemoral grafts that subsequently occluded was 281 cc/mm, compared with 506 cc/min in the 28 graft limbs that remained patent (p CO.01). Two of 53 patients died within 30 days of operation, for an operative mortality of 3.7 per cent. One 84 year old woman died of pneumonia and respiratory failure after a unilateral axillofemoral bypass graft for limb salvage, and a 61 year old man died of overwhelming gram-negative sepsis after undergoing bilat,eral axillofemoral bypass with closure of an aortoenteric fistula secondary to a previous aortobilateral femoral bypass. There were 18 late deaths (35 per cent) in the remaining 52 patients due to the following causes: myocardial infarction, 6 patients (11 per cent); stroke, 3 (5.8 per cent); renal failure, 2 (3.7 per cent); and ruptured thoracic or suprarenal aortic aneurysms, 2 (3.7 per cent). An additional five patients (9.2 per cent) died of undetermined causes. This high rate of late mortality underscores the validity of classifying these patients as poor operative risks. Early postoperative morbidity among the 54 patients was due to the following causes: perigraft seroma, 5 patients (9.2 per cent); graft thrombosis, 3 patients (5.6 per cent); wound infection in the groin with skin breakdown requiring debridement and secondary closure, 1 patient (1.9 per cent); pseudoaneurysm at the femoral anastomosis, 1 patient (1.9 per cent); pneumonia, 1 patient (1.9 per cent); and gram-negative sepsis, 1 patient (1.9 per cent). Two of the five patients had perigraft seromas which required several aspirations but resolved without sequelae, while the other three patients underwent removal of the original graft and placement of new grafts in new tunnels at 3,8, and 48 months postoperatively. Early reoperation was necessary for acute graft thrombosis in two unilateral grafts and the crossover limb of one bilateral graft, all of which were performed for limb salvage. One of these unilateral graft closures was due to technical problems and was treated by thrombectomy and revision of the upper anastomosis. This random crimped external velour graft occluded after two unsuccessful thrombectomies at 2 months, until replaced with a new noncrimped external velour graft, which remained patent until the patient’s death 24 months later. Thrombectomy was unsuccessful in the other two grafts, leading to a below-knee amputation in one and to

Volume 139, July 1979

Patients

Grafts

Mean implant

Bypass

Closures Patency

i

CLAUDICATION 80.9%

;

LIMB SALVAGE 49.8%

50-

II

Ol

I

I

6

MO&

1

2

3

4

I

5

6

I

8

Years

Figure 6. Patency of axillofemoral grafts for claudication versus limb salvage by life table analysis,

conversion to an aortobilateral femoral bypass in the other, which has remained patent for 78 months. Late morbidity in the 84 grafts included thrombosis in 11 (13 per cent) unilateral grafts and 7 (8 per cent) bilateral graft limbs for cumulative patency by actuarial analysis of 67.2 and 77.1 per cent, respectively, at 9 years. Five additional axillofemoral grafts (Figure 5) thrombosed in five patients at intervals from 2 to 33 months (mean 14) and were successfully treated by thrombectomy and profundaplasty in four cases [22,23] and by thrombectomy and femoropopliteal bypass in one case with continued long-term patency in follow-up from 21 to 42 months (mean 33). In four unilateral grafts, thrombectomy at intervals of from 2 to 27 months was unsuccessful and new axillofemoral bypass grafts were placed. Two of these patients subsequently underwent below-knee amputation. Three additional patients developed pseudoaneurysms at the femoral anastomosis. Aneurysmal dilatation of the mid-portion of two random crimped, external velour grafts occurred three times at intervals of 31,50, and 62 months, requiring replacement of a short segment of the graft in each case. Immediately after surgery, 15 limbs (18 per cent) were asymptomatic, 64 limbs (76 per cent) were improved, and there was no change in 5 limbs (6 per cent). Thus 94 per cent of limbs were either asymptomatic or improved. Limb salvage was initially achieved in 25 of 26 limbs (96 per cent.) operated on for that purpose. Four of the remaining 16 patients subsequently required amputation after late graft closures. Twelve of 18 (67 per cent) graft thromboses occurred during the first 6 months, with all closures

121

Ray et al

UNILATERAL Patients

Grafts

Mean implant

Closures Patency

Patients

Grafts

Mean implant

16

19

31.4 mo.

3

64.2%

32

38.6 mo.

5

84.9%

g

Closures Patency

BILATERAL 16

100

BILATERAL

-5

b

;; 50

z : 75,” z s ‘;; 5or

BILATERAL 68.6%

1

83.9%

UNILATERAL

80.4%

g 9 E 25$

OL 8 16’ 1 MOS.

91il

I

2

3

4

5

6

7

Years

6I

MOS.

1I

2

3I

4,

5I

6

7

9I

91

Year5

Ftgure 7. Patency oi unilateral versus bilateral axil/ofemoral gratis lor limb salvage.

Figure 8. Patency of unilateral versus bilateral axillofemoral grafts for claudication.

occurring within 4 years (Figure 3). Cumulative graft patency for all axillofemoral bypass grafts initially performed for limb salvage at the end of 5 years was 49.8 per cent, compared with 80.9 per cent cumulative patency for all axillofemoral bypass grafts performed for claudication at the end of 5 years. These results are significant (p <0.03) and are shown in Figure 6. Although the cumulative patency of 50.4 per cent at 5 years for 18 unilateral grafts performed for limb salvage was less than the 68.6 per cent patency at 3 years for 8 bilateral graft limbs, the difference was not statistically significant (Figure 7). Similarly, the difference in the cumulative patency of 19 unilateral grafts (83.9 per cent) and 32 bilateral grafts (80.4 per cent) performed for claudication was not statistically significant (Figure 8).

In an attempt to identify angiographic patterns which might predict long-term patency, life table analyses of the six different angiographic categories based on iliac inflow and femoral outflow were performed in 77 of the 84 limbs where preoperative angiograms were available (Figure 1; Table IV). Best results (94.6 per cent life table patency at 9 years) were obtained with iliac occlusion and both femoral outflow vessels patent.

TABLE IV

Discussion We shall discuss axillofemoral bypass grafts from three aspects: (1) the patency of porous, crimped Dacron grafts in relation to an experimentally derived thrombotic threshold velocity; (2) the devel-

Axillofemoral Graft Patency by Angiographic Classification Life Table Patency

At 9 yr

At 5 yr

At 7 yr

At 8 yr

4

74.6

74.6

74.6

21

5

79.5

56.8

56.8

56.8

23

1

94.6

94.6

94.6

94.6

Severe iliac stenosis; BFA patent

9

3

77.8

62.2

62.2

V

Moderate iliac stenosis: SFA patent

2

1

50

50

VI

Moderate iliac stenosis; SFA occlusion

4

2

50

No. of Patients

I

Severe iliac stenosis; SFA occlusion

18

II

Iliac occlusion; SFA occlusion

Ill

Iliac occlusion; SFA patent

IV

Grouo

SFA = superficial

122

(% )

No. of Closures

Angiographic Status

-

.

femoral artery.

The American Journal of Surgery

Axillofemoral

opment of prostheses specific for the axillofemoral site; and (3) the clinical indications for axillofemoral bypass in the management of aortoiliac occlusive disease.

MAGNITUDE AXILLARY INFLOW = 2

Axillofemoral graft patency: its relation to an experimentally derived thrombotic threshold velocity. We have performed studies in our laboratory

to determine the minimum velocity of blood flow across a graft surface necessary to prevent the development of significant thrombus accretion on that surface [ 291. These studies involve replacement of 6 cm of the canine carotid artery with 6 cm lengths of a 4 mm diameter graft. Blood flow through the graft is controlled at specific flow rates for 6 hours, after which the graft is removed for study. If the graft occludes before termination of 6 hours, it is removed immediately and opened for study. These studies suggest that a porous, crimped Dacron graft requires a flow of approximately 8 cm/ seclcm” of graft cross-sectional area in order to minimize thrombus accretion on its flow surface. This represents the thrombotic threshold velocity. On this basis, thrombus accretion would be expected to occur on the flow surface of an 8 mm crimped Dacron graft having a flow of less than approximately 240 cclmin.* Operative flow measurements are valuable in assessing whether additional outflow channels are necessary for long-term patency of the axillofemoral bypass. For example, if the superficial femoral is closed and the profunda femoris is open and not stenotic, and the flow rate measured after completion of the graft is below the experimental thrombotic threshold velocity previously described, then an extension to the popliteal artery might be considered. Also, one should consider a crossover graft to the opposite femoral artery if there is reasonable clinical indication and favorable anatomy. For these reasons, we routinely prep and drape both legs. From the results in Table IV, it is clear that longterm patency results decrease when the aortoiliac inflow pathway contributes a significant competitive flow. A simple mathematical relation is very important in the clinical use of bypass grafts throughout the arterial system, especially the axillofemoral. Assume that the capacity of the distal bed is fixed for any one physiologic state and may he designated X. The flow contributed by the iliac inflow may be designated Y, and that by the axillary inflow Z. The magnitude of X equals Y + Z. Therefore, Y = X - Z and Z = X - Y. The higher the competing iliac inflow (Y), the lower the graft flow (Z), as the two are reciprocals to X (Figure 9). * Thrombotic threshold velocity (cm/seclcm2) min)/(ird*) . 60.

Volume 138, July 1979

= 4

* blood

flow (ccl

Bypass

1

THEREFORE, THEHIGHER MAGNITUDE ILIAC INFLOW = Y

THElL,ACINFLOW I”,. THEw

THEGRAFT

CAPACITY

OF DliTAi

ARTERIAL

BED = X

Figure 9. Hemodynamic influence of iliac inflow on axillofemoral graft flow. X = Y + Z, Z = X - Y. Therefore, the higher the competing ifiac inflow ( V), the Iower fbe f/ow rhroug/r the graH ( Z).

The extension of a crossover limb to the contralateral femoral artery increases the volume of flow (and hence, velocity) through the main limb of the axillofemoral graft and would be expected to increase its long-term patency. The mean operative flow rate for the 25 unilateral grafts in which measurements were made was 313 cc/min, and the mean operative flow rate in the main limb of axillobilateral femoral bypass grafts was 912 cc/min. These differences are statistically significant (p
123

Ray et al

DEGREE

s E V E R E

M 0

UNILATERAL

0

Indications for axillofemoral bypass in the treatment of aortoiliac occlusive disease. Based on

E R A T

BILATERAL

E

Figure 70. Selection of bypass procedure for treatment of aortoiliac occlusive disease. l Surgery indicated only if claudication is truly disabling, that is, severely limits ability to work or significantly afters life styte. l * Surgery indicated only for limb salvage, wfth conskleration given to performing a profwxfaplasty or femoropoptfteaf bypass if operative flow measurements fail to indicate a significant (> 75 mm Hg) resting gradient between mean radial artery pressure and mean common femoral artery pressure.

14 months, with an additional patient closing the crossover limb at 3 months. In view of the rheologic advantages of maintaining high flow across the entire surface of the axillofemoral graft, our current practice is to supply the opposite leg with a crossover femorofemoral graft taken off the hood of the axillofemoral graft at its attachment point to the common femoral artery (Figure 4, right). Development of an improved porous Dacron prosthesis specifically for the axillofemoral site. Our

experimental studies of the thrombotic threshold velocity of prostheses in the carotid artery of the dog [19] show that the primary criterion for an improved porous Dacron prosthesis is a smooth, flat flow surface. A noncrimped graft provides such a flow surface. However, a noncrimped fabric graft in the axillofemoral position may kink on bending of the trunk. Therefore, the second criterion for an improved fabric axillofemoral prosthesis is resistance to kinking with trunk bending, or with flexion of the hip. It would also be desirable if this noncrimped, kink-resistant prosthesis were resistant to compression, since a prosthesis in the axillofemoral position traverses the entire lateral trunk and is liable to occlusion from compression (such as from sleeping on that side). We have designed a noncrimped, kinkand compression-resistant axillofemoral prosthesis, in conjunction with the Applied Research Division of USCI. We have studied this graft extensively in experimental animals and have recently begun a

124

multi-center Food and Drug Administration clinical trial. Its desirable characteristics are obtained by fusing a spiral wind of polypropylene monofilament to the outer surface of a noncrimped USC1 Sauvage filamentous velour Dacron prosthesis. This polypropylene exoskeleton renders the graft kink- and compression-resistant. Early observations with this prosthesis in the axillofemoral position appear promising.

a 9 year experience since 1970 with the USC1 Sauvage filamentous velour Dacron prosthesis (Figure 3 and Table III), we have arrived at the recommendations given in Figure 10 for the selection of the proper bypass procedure. If severe aortoiliac obstruction is producing significant symptoms on both sides, the choice of bypass procedure lies between an aortobilateral femoral and axillobilateral femoral bypass. In selected patients with well-localized disease, an aortoiliac endarterectomy may be performed with comparable longterm patency and morbidity to an aortobilateral femoral bypass [10,25,26]. The advantages of axillobilateral femoral bypass are that it is less traumatic than an intraabdominal procedure and therefore applicable to the patient in whom an aortobilateral femoral procedure would carry an increased operative risk. The clinician’s most important question, however, remains: How good is the axillobilateral femoral bypass in comparison with the aortobilateral femoral bypass [24], and what determines its use? Long-term results of axillobilateral femoral bypass are determined to a great extent by the degree of patency of the iliac inflow and of the femoral outflow bed. If the anatomic factors are favorable (occlusion of the iliac inflow), the life table patency results of the axillofemoral bypass are good: 94.6 per cent at 9 years when both femoral vessels are patent, compared with 79.5 per cent at 5 years (Table IV) when only the profunda is patent. However, the aortofemoral bypass is a hemodynamically superior operation, especially when the proximal anastomosis is performed end-to-end [IO]. If the contralateral iliac inflow is adequate, the common femoral artery of that side may be used as the origin of a graft to the opposite femoral artery [5]. We have used the criteria published by Brief et al [13] and Plecha and Pories [27] to insure adequat,e donor inflow: (1) normal femoral pulse, (2) no claudication or significant ischemia, (3) thigh cuff pressure equal to or greater than brachial cuff pressure, (4) ankle pressure within 15 mm Hg of brachial cuff pressure,

The American Journal of Surgery

Axillofemoral

and (5) rising or stable ankle pressure after exercise. If a question as to the adequacy of the donor vessel remains, direct mean femoral arterial pressure is measured in the operating room, and a pressure differential of more than 15 mm Hg from the mean radial arterial pressure at rest indicates that a hemodynamically significant donor iliac artery obstruction exists [28--301. Injection of papaverine (30 mg) down the proposed donor femoral artery may bring out a gradient not present at rest. In this case, a drop of more than 30 per cent indicates the presence of a hemodynamically significant proximal iliac obstruction [30,31]. If the patient is elderly and a poor operative risk, axillofemoral bypass would be performed. The long-term results of femorofemoral bypass procedures (Figure 3) are superior to those of the axillofemoral bypass, and the procedure is even less traumatic to the patient. Hence, the axillofemoral bypass procedure is indicated primarily for the poor-risk patient with severe bilateral aortoiliac obstruction (Figure 10). Our data define two complementary phenomena: Iliac inflow occlusion and patency of both femoral outflow vessels favors long-term patency, while significant competing iliac inflow and significant femoral outflow obstruction strongly mitigate against long-term patency (Figure 1, Table IV). Even though a gradient develops during exercise across an area of only moderate iliac stenosis (augmentation of a short systolic murmur at rest to a continuous murmur with a concomitant drop in Doppler ankle pressure with exercise), the hemodynamic conditions must also be favorable in the resting state for long-term patency of an axillofemoral bypass. An aortofemoral bypass graft may remain patent under such adverse hemodynamic conditions because of its larger inflow source and shorter limbs not subject to external compression. Accordingly, if the patient is a good operative risk and only needs augmentation of his circulation with exercise (such as the patient with claudication), aortobilateral femoral bypass, not axillobilateral femoral bypass, is the procedure of choice. Conirersely, if the patient is a poor operative risk and has a primary need for augmentation of circulation at rest (such as the patient with rest pain or ischemic tissue necrosis), axillofemoral bypass is preferred. Conclusions

Under all but very unusual circumstances, the aortofemoral bypass remains hemodynamically superior to the extraanatomic bypass procedures in the treatment of arteriosclerotic aortoiliac occlusive disease. However, considering the needs of the spe-

Volume 138, July 1979

Bypass

cific patient in conjunction with his projected life expectancy and associated medical conditions, the following conclusions (Figure 10) can be drawn, based on the long-term results of the axillofemoral bypass presented in this paper: 1. The use of the unilateral axillofemoral bypass is indicated for the poor risk patient with severe ipsilateral lower extremity ischemia secondary to severe iliac inflow obstruction, whose contralateral iliac inflow is too severely obstructed to allow the contralateral femoral artery to serve as a suitable donor for a crossover femorofemoral graft. 2. The use of the axillobilateral femoral bypass is indicated for the poor risk patient with severe bilateral lower extremity ischemia secondary to severe bilateral aortoiliac inflow obstruction. We recommend that this bypass be constructed as a unilateral axillofemoral bypass with a crossover femorofemoral limb originating from the hood of the distal anastomosis of the axillofemoral graft to the common femoral artery. 3. When the degree of iliac inflow obstruction is severe and the femoral outflow bed is reasonably patent, excellent long-term results with axillofemoral bypass may be anticipated. In such carefully selected individuals with aortic or iliac artery occlusion and widely patent superficial and profunda femoris arteries, axillofemoral bypass can be performed as a reasonable alternative to aortofemoral bypass, with nearly equal long-term patency and significantly less postoperative morbidity. Summary

Two hundred twenty-four consecutive patients (361 graft limbs) who underwent bypass grafting with the USC1 Sauvage filamentous velour Dacron arterial prosthesis for aortoiliac occlusive disease over the 9 year period 1970 to 1979 are reviewed. Eighty-four axillofemoral (23 per cent of patients), 210 aortofemoral (47 per cent of patients), and 67 femorofemoral grafts (30 per cent of patients) had cumulative patency rates of 72.1, 91.1, and 86.4 per cent, respectively. Experimental and clinical factors influencing the patency of axillofemoral grafts are discussed, and the concept of an improved porous Dacron prosthesis specific for the axillofemoral site is presented. Acknowledgments: The authors gratefully acknowledge the invaluable work of Betty Larson and Mary O’Brien, PhD, for their aid in compiling the statistical data. Special appreciation goes to Margaret Berger, Patty Holland, Anne March, doan Strand, and Pat Swanson for their aid in preparing

125

Ray et al

the manuscript. The contributions of Mary-Ann Nelson, Lew Ogilvie, and Lou Taylor were invaluable and greatly appreciated. References 1. Blaisdell FW, Hall AD: Axillary-femoral artery bypass for lower extremity ischemia. Surgery 54: 563, 1963. 2. Sauvage LR, Wood SJ: Unilateral axillary bilateral femoral bifurcation graft: a procedure for the poor risk patient with aortoiliac disease. Surgery 60: 573, 1966. 3. LoGerfo FW, Johnson WC, Corson JD, Vollman RW, Weisel RD. Davis RC, O’Hara ET, Nabseth DC, Mannick JA: A comparison of the late patency rates of axillo-bilateral femoral and axillo-unilateral femoral grafts. Surgery 81: 33, 1977. 4. Eugene J, Goldstone J, Moore WS: Fifteen years’ experience with subcutaneous bypass grafts for lower extremity ischemia. Ann Surg 186: 177, 1977. 5. Parsonnet V, Alpert J, Brief DK: Femorofemoral and axillofemoral grafts-compromise or preference. Surgery 67: 26, 1970. 6. Mannick JA, Nabseth DC: Axillofemoral bypass graft. A safe alternative to aortoiliac reconstruction, N Engl J Med 278: 461, 1968. 7. Mannick JA, Williams LE, Nabseth DC: The late results of axillofemoral graft. Surgery 68: 1038, 1970. 8. Moore WS, Hall AD, Blaisdell FW: Late results of axillaryfemoral bypass grafting. AmJ Surg 122: 148, 1971. 9. Malone JM, Moore WS, Goldstone J: The natural history of bilateral aortofemoral bypass grafts for ischemia of the lower extremities. Arch Surg 110: 1300, 1975. 10. Brewster DC, Darling RC: Optimal methods of aortoiliac reconstruction. Surgery 84: 739, 1978. 11. Vetto RM: The treatment of unilateral iliac artery obstruction with a transabdominal subcutaneous femoro-femoral graft; Surgery 52: 342, 1962. 12. Vetto RM: The femorofemoral shunt. An appraisal. Am J Surg 112: 162, 1966. 13. Brief DK, Brener BJ, Alpert J, Parsonnet V: Crossover femorofemoral grafts followed up five years or more. Arch Surg 110: 1294, 1975. 14. Mannick JA, Maini BS: Femorofemoral grafting: indications and late results. Am J Surg 136: 190, 1978. 15. Cooperman M, Pflug B, Martin E Jr, Evans WE: Cardiovascular risk factors in patients with peripheral vascular disease. Surgery 84: 505, 1978. 16. Blaisdell FW, Hall AD, Lim RC Jr, Moore WC: Aorto-iliac arterial substitution utilizing subcutaneous grafts. Ann Surg 172: 775, 1970. 17. DeLaurentis DA, Sala LE, Russell E, McCombs PR: A twelve year experience with axillofemoral and femorofemoral bypass operations. Surg Gynecol Obsfet 147: 88 1, 1978. 18. Yates SG. Barros D’Sa AAB, Berger K, Fernandez LG, Wood SJ, Rittenhouse EA, Davis CC, Mansfield PB, Sauvage LR: The preclotting of porous fabric arterial prostheses. Ann Surg 188: 611, 1978. 19. Sauvage LR, Walker MW, Berger K, Robe1 SB, Lischko MM, Yates SG, Logan GA: Experimental evaluation of implantation in the carotid and circumflex coronary arteries of the dog. Arch Surg, in press. 20. Harker LA, Slichter SJ, Sauvage LR: Platelet consumption by arterial prostheses: the effects of endothelialization and pharmacologic inhibition of platelet function. Ann Surg 186: 594, 1977. 21. Cutler SJ, Ederer F: Maximum utilization of the life table method for analyzing survival. J Chronic Dis 8: 699, 1958. 22. Bernhard VM, Ray Lt, Militello JP: The role of profunda-femoris angioplasty in revascularization of the ischemic limb. Surg Gynecol Obsfet 142: 840. 1976. 23. McDonald PT. Rich NM, Collins GJ, Anderson CA, Kozloff L: Femorofemoral grafts: the role of concomitant extended

126

profundaplasty. Am J Surg 136: 622, 1978. 24. Johnson WC, LoGerfo FW, Vollman RW, Corson JD, O’Hara ET, Mannick JA. Nabseth DC: Is axillo-bilateral femoral graft an effective substitute for aortic-bilateral iliac/femoral graft? An analysis of ten years’ experience. Ann Surg 186: 123, 1977. 25. Mulcare RJ, Royster TS, Lynn RA, Conners RB: Long term results of operative therapy for aortoiliac disease. Arch Surg 113: 601, 1978. 26. Kouchoukos NT, Levy JF, Balfour JP, Butcher HR: Operative therapy for aortoiliac occlusive disease: a comparison of therapeutic methods. Arch Surg 96: 628, 1968. 27. Plecha FR, Pories WJ: Extra-anatomic bypasses for aortoiliac disease in high-risk patients. Surgery 80: 480, 1976. 28. Flanigan P, Pratt DG, Goadreau JJ, Burnham SJ, Yao ST. Bergan JJ: Hemodynamic and angiographic guidelines in selection of patients for femorofemoral bypass. Arch Surg 113: 1257, 1978. 29. Moore WS, Hall AD: Unrecognized aortoiliac stenosis. A physiologic approach to the diagnosis. Arch Surg 103: 633, 1971. 30. Sako Y: Papaverine test in peripheral arterial disease. Surg Forum 17: 141, 1966. 31. Van De Water JM, Thompson RR, Laska ED, Trudell LA, Broffman TK, Harrower HW: Limb salvage and selectivity. Surg Gynecol Obstet 148: 349, 1979.

Discussion

F. William Blaisdell (Sacramento, CA): I appreciate the chance to review this large series of axillofemoral bypass. Dr. Savauge has been a pioneer in the development of vascular grafts and no vascular operation is more challenging than axillofemoral bypass. I agree completely with his indications for the application of this procedure. It is important to remember that these patients had a high risk for vascular surgery when comparing series of conventional aortofemoral bypass with axillofemoral bypass. I disagree with Dr. Savauge on a few minor technical points. We place the origin of the graft as high on the axillary artery as possible so that the graft inevitably passes under the pectoralis minor on its way to the lateral chest wall. I always use a continuous suture and have not found that this compromises the anastomosis. Most are checked with operative arteriography. I developed the tunnel subfascially from the femoral artery upward rather than pass the graft subcutaneously. A nick is made in the inguinal ligament and a special tunneling instrument is passed proximally to meet the upper tunnel at about the level of the ninth rib in the midaxillary line where a small counter incision is made. We have not used the high doses of heparin intraoperatively that Dr. Sauvage recommends but use about half the dose he recommends. I would like to know if Dr. Sauvage feels strongly on this point? In regard to graft size, I have been interested in the Seattle group’s experimental flow studies. The numbers sound fine but if they are accurate and are applied to man, then there should be a significant difference in the patency rates for unilateral axillofemoral bypass as opposed to axillobilateral femoral procedures. This did not appear to be the case in Dr. Sauvage’s series. My personal experience is more like that described by Logerfo and Mannick and I believe that higher flows are associated with greater

The American Journal of Surgery

Axillofemoral

patency rates. Certainly the status of the outflow vessels supports this in Dr. Sauvage’s series since patency rates were greater in patients with claudication than in those with limb salvage and in patients with both branches of the common femoral artery open rather than closed. One problem in analyzing this series is that multiple variables were present. including the type and the diameter of the grafts used. I helieve that this accounts for the differences between my observations and those of others. Finally, I favor a 10 mm graft of the external velour type for axillofemoral bypass. Would Dr. Sauvage comment on this’? Ronald

J. Stoney

(San Francisco,

CA): 1 enjoyed

Dr.

Ray’s presentation but would like to express a more conservative application of this procedure than his group apparently advocates. The authors did not mention cardiorespiratory reserve in their patients. I can only assume that the percentage of those who were genuine cardiac cripples was no higher than that reported in comparable series by other surgeons operating on patients for the relief of claudication. In our experience, it is an extraordinarily rare patient who is unable to tolerate the more direct and less vulnerable transabdominal revascularization procedure. This is largely due to advances in anesthetic management, intraoperative monitoring, and improved postoperative critical care therapy. Our only indication for axillofemoral bypass, therefore, is to circumvent t,he abdominal cavity in instances of perigraft infection or aortoenteric fistula. In many instances, however, 6 months to 1 year later we convert this reconstruction back to an aortofemoral graft, reopening the infrarenal aorta so as to remove the juxtarenal thrombus that may otherwise propagate into and occlude the renal arteries and impair renal perfusion. Ronald W. Husuttil (Los Angeles, CA): At UCLA we have done approximately 120 extraanatomic bypasses, of which about 50 per cent were axillofemorals. I completely agree with Dr. Stoney that this operation should be reserved for selected poor risk patients who cannot have a direct aortic reconstruction, which in most cases rules out this operation for claudication. The vast ma.jority of our cases have been done for severe limb ischemia, with rest pain and impending tissue loss. Only a very small percentage of these were done in poor risk patients for disabling claudication. There are two specific indications for which the axillofemoral graft is indeed the procedure of choice. In patients with aortic graft sepsis, it, is absolutely mandatory that the aortic graft be removed, and revascularization can be most easily accomplished by extraanatomic, axillofemoral bypass. The second indication is in the treatment of aortoduodenal fistula. In our series of approximately 11 patients with this condition, the only survivors were those who had complete excision of the aortic graft and placement of axillofemoral grafts. We too have observed that unilateral axillofemoral grafts wit,h a low lying femorofemoral side arm have a higher

Volume 138, July 1979

Bypass

patency rate than bilateral axillofemorals because of improved runoff in the former group. I think that the authors’ patency rates at 4 and 5 years are higher than the rate in our series (50 per cent at 4 years) because our indications for this procedure are more restricted and very few of our patients receive axillofemorals for claudication. Albert D. Hall (Greenbrae, CA): I congratulate Dr. Ray and his co-authors for presenting a well documented analysis of a very impressive clinical experience. I agree that, axillary femoral bypass graft is a very useful operation in several clinical settings. We have heard of relatively liberal indications used in the Seattle series and less frequent use of the procedure by Dr. Stoney. My own indications include some patients who are disabled from cardiovascular disease and are prohibitive risks for abdominal operation. In our series we think we have identified some failures due to inadequate axillary artery inflow. Have you identified such patients and do you advocate preoperative axillary artery angiography? Have you had more false aneurysms in t,he groin after the axillary femoral bypass than with other bypass procedures? If these grafts are placed under tension an unacceptably high false aneurysm rate will result. The placement of the graft requires attention to detail and avoidance of tension. Lester

R. Sauvage

(closing):

Dr. Hlaisdell,

of course,

is the real pioneer in this field. The technical points that he raised are good ones, and I can’t disagree with them at all. We will pay more attention to keeping our grafts under the pectoralis minor and taking them off the proximal axillary artery. In regard to heparin dosage, I don’t see any point in giving a small amount of heparin if you are going to use it at all. It is neutralized by protamine and there is no particular disadvantage in giving more protamine if you have given more heparin. However, I can’t point to any specific experimental data to back that up. In regard to the patency rates, I t,hink that the issue is one of semantics. We have shown that t,he long-term results are excellent (94 per cent) when the iliac inflow is closed and the femoral outflow is open. Dr. Blaisdell said that in 1970 and is saying the same thing in 1979. We are merely agreeing with him. In regard to Dr. Stoney’s and Dr. Husuttil’s negative approach to using t,his operation, we, too. prefer the aortofemoral bypass, hut for poor risk patients we believe the axillofemoral bypass is an acceptable alternative. In fact, excellent resulm may be anticipated if the inflow is closed and the outflow is open. I, too, as Dr. Blaisdell does, prefer the use of this procedure in patients in whom rooting around in the upper abdomen is going t.o cause significant morbidity. Although the poor risk patient can survive an aortohilateral femoral bypass, perhaps he could have gotten a good result with the lesser procedure and recovered more quickly and easily.

127

Ray et al

In response to Dr. Blaisdell’s question about the size of the graft, we use twenty-five 6 mm grafts. A 6 mm graft is too small except in patients with very small femoral vessels. However, I think we went too far in using small caliber grafts; Dr. Blaisdell is right. We now use an 8 mm graft for most patients. In response to Dr. Hall’s question about evaluating axillary inflow, we haven’t been very scientific about our analysis. If the patient has a good axillary pulse, we perform an axillofemoral bypass even if a short systolic murmur is present over the artery. I can’t blame the closures that we have had on an inadequate inflow source. We have had three false aneurysms. The tension that Dr. Hall brought up is very important. If we put the graft in so that it is too tight, the artery must be very good or the sutures will pull out. Also, we can make a mistake that will cause false aneurysms by what we term “excessive intraanastomotic tension.” This is caused by making the incision in the artery longer than the opening in the graft. I have to overcome an enormous amount of inertia before I can force myself to correct what I have done wrong; in this regard, I think we are all quite alike. I think that the results of any procedure are determined to a degree by the type of graft used. Although I believe that the type of graft that we used is good, I am certain that

it can be better. The approach we now use in prosthesis development is to make grafts that are specific for the area in which they are going to be used. I don’t think there is any doubt from our experimental work that a smooth surface is better than a crimped one, and fibrin is a far underrated flow surface. The component that makes a fibrin surface thrombogenic is the thrombin that led to the formation of the fibrin in the first place. That is why in the last step of our preclotting technique we use a large amount of heparin to neutralize the thrombin. We are very much interested in evaluating noncrimped, supported grafts that are both kink- and compressionresistant for axillofemoral bypass. In a prosthesis that is now in clinical trial, USC1 has fused a polypropylene wind to the outer velour surface of our noncrimped filamentous velour Dacron prosthesis. The polypropylene melts at a lower temperature than the Dacron and fuses to the wall to give these grafts a flexible exoskeleton that resists both kinking and compression. We are using these noncrimped supported grafts in the femorotibial, femoropopliteal, and axillofemoral areas. Although early results are encouraging, time will tell their true value. In the years ahead we look forward to reporting the results obtained with these new prostheses, whether they are good or bad.

The American Journal of Surgery