Hemodynamic Consequences of Femoral Arteriovenous Bovine Shunts HENRY J. FEE, JR., M.D., JORGE A. LEVISMAN, M.D., JOHN P. DICKMEYER, M.D., ARTHUR L. GOLDING, M.D.
Seventeen patients with femoral arteriovenous bovine shunts (FAVBS) were evaluated to delineate the cardiovascular consequences of the procedure. The resting cardiac index (CI), as estimated by echocardiography, was increased in 8 patients (47%). Twelve of the 17 patients (71%o) had more than a 20% reduction in CI after 5 minutes of shunt occlusion. In 6 of these, the CI returned to normal from an abnormally high value. As a group, the decrease in CI was significant (P = 0.001). This was accomplished mainly by a significant decrease in stroke volume (P c 0.004). Signs and symptoms of congestive heart failure developed in 10 of the 17 patients during the year following FAVBS. Because of the marginal cardiac reserve in patients with renal failure and the significant increase in cardiac index resulting from FAVBS, alternative forms of vascular access should be used whenever possible. IGH OUTPUT CONGESTIVE heart failure (HOCHF)
has been observed with chronic anemia,2 pregnancy,4 hyperthyroidism,5 Beriberi,' Paget's Disease,6 trumati 7, skin diseases, 14 and traumatic arteriovenous fistulas.7'10'" Recently HOCHF has been associated with femoral arteriovenous bovine shunt (FAVBS) for vascular access in patients on hemodialysis.8 The paucity of objective hemodynamic data in this group of patients was the impetus for the present investigation. Methods
Fourteen men and three women from 18 to 72 years of age, on chronic hemodialysis, were included in the study. Patient 6 had an FAVBS and a radial arteriovenous fistula; all others had only an FAVBS. Patients with congenital, valvular, and overt coronary disease were excluded. All patients had hematocrits in the 18% to 27% range. Submitted for publication November 4, 1975.
From the Departments of Surgery and Medicine, UCLA School of Medicine, Los Angeles, California 90024
The cardiac output (CO) was estimated echocardiographically with an Ekoline 20 ultrasonograph machine with a 2.25 MHZ 10 cm focus transducer 1.2 cm in diameter. The echocardiograms were recorded on a Honeywell 1856 strip chart recorder with a simultaneous electrocardiographic (ECG) tracing. Tracings were taken with the patient at rest in the supine position and repeated during the last minute of a 5-minute period of occlusion of the graft. The grafts were occluded by manual compression until disappearance of the bruit and pulse. All tracings were obtained immediately before the patient's regularly scheduled hemodialysis. In 9 patients, repeat tracings at rest were obtained 5 minutes apart prior to occlusion to establish the variability of this technique in estimating CI. This was determined to be 5 + 1.23% (standard error of the mean). The echocardiograms were evaluated for left ventricular systolic (LVSV) and diastolic volumes (LVDV) and stroke volume (SV) with the formulas LVDV = Dd3, LVSV = Sd3, SV = LVDV - LVSV where Dd is diastolic diameter and Sd is systolic diameter of the left ventricular cavity.9'12 The heart rate (HR) was measured on the ECG recording. CO and CI were then calculated: CO = SV x HR, CI =
BSA
where BSA is body surface
in m2. All data were checked for statistical significance using the Student's t test. The echocardiographic studies were performed about 1 year (9 to 15 months) after FAVBS in 11 patients, about 2 years (24 to 27 months) after in 4 area
103
CHANGES IN CARDIAC INDEX 4.31
o
July 1976
Of the 12 patients who demonstrated a marked de(>20%o) in CI after 5 minutes of occlusion, all but one (Patient 6) had a significant decrease in SV (P = 0.004) (Fig. 2). This patient had a radial fistula and an FAVBS, and only the latter was occluded. Excluding Patient 6, those patients with greater than 20% decrease in CI had no significant change in HR (P = 0.10) (Fig. 3). Evaluation of the clinical signs and symptoms in the 17 patients studied showed that 10 (59%) had congestive heart failure (CHF) in the year after FAVBS. Five patients had acute CHF within the first month. Four of these recovered with frequent dialysis and have remained stable. The fifth patient (Patient 8) died of severe heart failure with cardiogenic shock 3 weeks after FAVBS. Five patients (30%) had a gradual onset of CHF within one year of their FAVBS. Two were controlled with dialysis, and three required surgical banding of the FAVBS. Only 7 of the 17 patients (41%) did not develop CHF following FAVBS. Three of these had an insignificant change in CI with occlusion of the shunt. The C/T ratio showed a greater than 10% increase in nine of the 13 patients who had an FAVBS for at least one year. In the 4 patients studied by radiography at 2 years, there was no further increase in C/T ratio in the second year. Four of the five patients with less than a 10% change in C/T at one year had less than a 20%o change in CI with graft occlusion. Eight of 12 patients with greater than cerase
10
9 8
_7A
6 -L
4-
32
0
Ann. Surg.
FEE AND OTHERS
104
I
Preocclusion FIG. 1. Change in cardiac index (CI) after occlusion (P = 0.001).
After 5 min of occlusion 5
minutes of shunt
CHANGES IN STROKE VOLUME 218 1
patients, and within 4 months after in the remaining 3 patients. Medical records of the 17 patients were reviewed for signs or symptoms of CHF. Posteroanterior chest radiographs taken prior to the FAVBS and at the time of the echocardiographic study were reviewed to evaluate changes in cardiothoracic ratio (C/T) or the presence of pulmonary congestion. In the 4 patients studied at 2 years, chest radiographs taken at one year were also available.
1751
1Ein I
a
125-
0
-J
>
100-
Results Eight of the 17 patients had an estimated resting CI which was elevated above the normal of 2.5 to 4.5 liters/min/m2. In 6 of these patients, the CI decreased to normal after occlusion of the shunt; in the other two patients, although there was a 32% and 34% reduction in CI with occlusion, the CI remained above nor30 mal. Nine patients had a normal resting CI. In 5 of these, Preocclusion After 5 min of there was a marked decrease (greater than 20%o) in CI occlusion with occlusion. In the 4 remaining patients, the CI did FIG. 2. Change in stroke volume (SV) after 5 minutes of shunt not change appreciably with occlusion (Fig. 1). occlusion (P = 0.004).
Vol. 184 . No. 1
FEMORAL ARTERIOVENOUS BOVINE SHUNTS
20% decrease in CI with occlusion exhibited postoperative symptoms of CHF. Discussion Increased survival of patients with multiple systemic diseases on chronic renal dialysis has led to a search for better techniques of vascular access. Recent reports have referred to femoral arteriovenous bovine shunts (FAVBS) using an enzymatically treated bovine carotid artery.16 These reports have stressed their advantages without sufficiently discussing their long-term consequences. Our data suggest that these patients have a high CI and that it is secondary to their FAVBS. Many of these patients developed CHF subsequent to the FAVBS and there was a significant correlation (P = 0.004) between the per cent increase in C/T ratio one year post FAVBS and the per cent decrease in CI with shunt occlusion (Fig. 4). The high CI in our patients was accomplished by increasing SV with insignificant change in HR. These data concur with previous observations in patients with traumatic arteriovenous fistulas10,5 and are in conflict with "Branham's sign," which is a decrease in HR with occlusion of arteriovenous fistula.3 Hypertension did not cause cardiac decompensation in these patients since none had a systolic pressure greater than 160 mmHg, and the two patients with diastolic blood pressures greater than 95 mmHg had stable C/T for one year before FAVBS with marked increase in C/T 1 year after the procedure. An unsuccessful attempt was made to identify those factors such as age, sex, hypertensive disease, or diabetes 125-
CHANGES IN HEART RATE
100-
-
105
+40 ci
a:
@17 Pericardial effusion
+30-
>
.4
cr +20-
*6
IL
o E.
7 1
*12
w
+10-
@2
*14
.1O
.
*K
C\)
o
-10
-
+10
0 -30 -10 -20 % ACI AFTER 5 min OCCLUSION
-40
-50
FIG. 4. Change in cardiothoracic ratio (CT) correlated with change in cardiac index (CI) after 5 minutes of shunt occlusion (P = 0.004).
mellitus that might correlate with the development of CHF after an FAVBS. Although significant increase in CI occurs frequently with FAVBS, there is no way to predict which patient will experience this complication. Thus, FAVBS should not be performed until all alternative routes of vascular access have been explored. When an FAVBS is deemed necessary, serial chest radiographs and echocardiographic determinations of CI should be obtained in order to evaluate the hemodynamic effects of this procedure. EDITORIAL COMMENT-The hazards of high cardiac output cardiac failure from construction of an arterio-venous shunt should be emphasized. The magnitude of this hazard can be determined by serial measurements of cardiac index. The reliability of the echocardiogram technique for this purpose is the main weakness of the current paper and should be confirmed by other methods of determination of cardiac output.
Acknowledgments The authors wish to thank Dr. Rex MacAlpin for reviewing the manuscript and Nancy Ellis for her excellent technical assistance.
75-
li-i0________________________ References
r 50 Li-tr I
25-
Preocclusion
After 5 min of occlusion
FIG. 3. Change in heart rate (HR) after 5 minutes of shunt occlusion (P = 0.10).
1. Akbarian, M., Yankopoulos, M. A. and Ablemann, W. H.: Hemodynamic Studies in Beriberi Heart Disease. Am. J. Med., 41: 197, 1966. 2. Binak, K., Regan, T. J., Christensen, R. C. and Hellems, H. K.: Arteriovenous Fistula: Hemodynamic Effects of Occlusion and Exercise. Am. Heart J., 60:495, 1960. 3. Branham, H. H.: Aneurismal Varix of the Femoral Artery and Vein Following a Gunshot Wound. Internat. J. Surg., 3:250, 1890. 4. Burwell, C. S. and Metcalfe, J.: Heart Disease and Pregnancy. Boston, Little, Brown and Co., 1958.
106
FEE AND OTHERS
5. DeGroot, W. J. and Leonard, J. J.: Hyperthyroidism as a High Cardiac Output State. Am. Heart J., 79: 265, 1970. 6. Edholm, 0. G., Howarth, S. and McMichael, J.: Heart Failure and Bone Blood Flow in Osteitis Deformans. Clin. Sci., 5:249, 1945. 7. Epstein, F. H., Shadle, 0. W., Ferguson, T. B. and McDowell, M. E.: Cardiac Output and Intracardiac Pressures in Patients with Arteriovenous Fistulas. J. Clin. Invest., 32:543, 1953. 8. Fee, H. J., Levisman, J., Doud, B., Golding, A. L.: High output Congestive Failure from Femoral Arteriovenous Shunts for Vascular Access. Ann. Surg., 183:321, 1976. 9. Feigenbaum, H., Wolfe, S. B. and Popp, R. L.: Correlation of Ultrasound with Angiocardiography in Measuring Left Ventricular Diastolic Volume. Am. J. Cardiol., 23:111, 1969. 10. Muenster, J. J., Graettinger, J. S. and Campbell, J. A.: Correlation of Clinical and Hemodynamic Findings in Patients with Systemic Arteriovenous Fistulas. Circulation, 20:1079, 1959. 11. Nickerson, J. L., Elkin, D. C. and Warren, J. V.: The Effect
12.
13. 14.
15.
16.
Ann.
Surg. * July
1976
of Temporary Occlusion of Arteriovenous Fistulas on Heart Rate, Stroke Volume, and Cardiac Output. J. Clin. Invest., 30: 215, 1951. Pombo, J. F., Troy, B. L. and Russell, R. D.: Left Ventricular Volumes and Ejection Fraction by Echocardiography. Circulation, 43:480, 1971. Varat, A., Adolph, R. J. and Fowler, N. O.: Cardiovascular Effects of Anemia. Am. Heart J., 83:415, 1972. Voigt, G. C., Kronthal, H. L., and Crounse, R. G.: Output in Erythrodermic Skin Disease. Am. Heart J., 72:615, 1966. Warren, J. V., Nickerson, J. L. and Elkin, D. C.: The Cardiac Output in Patients with Arteriovenous Fistulas. J. Clin. Invest., 30:210, 1951. Zincke, H., Hirsche, B. L., Amamoo, D. G., et al.: The Use of Bovine Carotid Grafts for Hemodialysis and Hyperalimentation. Surg. Gynecol. Obstet., 139:350, 1974.
Seventeen patients with femoral arteriovenous bovine shunts (FAVBS) were evaluated to delineate the cardiovascular consequences of the procedure. The resting cardiac index (CI), as estimated by echocardiography, was increased in 8 patients (47%). Twelve of the 17 patients (71%o) had more than a 20% reduction in CI after 5 minutes of shunt occlusion. In 6 of these, the CI returned to normal from an abnormally high value. As a group, the decrease in CI was significant (P = 0.001). This was accomplished mainly by a significant decrease in stroke volume (P c 0.004). Signs and symptoms of congestive heart failure developed in 10 of the 17 patients during the year following FAVBS. Because of the marginal cardiac reserve in patients with renal failure and the significant increase in cardiac index resulting from FAVBS, alternative forms of vascular access should be used whenever possible. IGH OUTPUT CONGESTIVE heart failure (HOCHF)
has been observed with chronic anemia,2 pregnancy,4 hyperthyroidism,5 Beriberi,' Paget's Disease,6 trumati 7, skin diseases, 14 and traumatic arteriovenous fistulas.7'10'" Recently HOCHF has been associated with femoral arteriovenous bovine shunt (FAVBS) for vascular access in patients on hemodialysis.8 The paucity of objective hemodynamic data in this group of patients was the impetus for the present investigation. Methods
Fourteen men and three women from 18 to 72 years of age, on chronic hemodialysis, were included in the study. Patient 6 had an FAVBS and a radial arteriovenous fistula; all others had only an FAVBS. Patients with congenital, valvular, and overt coronary disease were excluded. All patients had hematocrits in the 18% to 27% range. Submitted for publication November 4, 1975.
From the Departments of Surgery and Medicine, UCLA School of Medicine, Los Angeles, California 90024
The cardiac output (CO) was estimated echocardiographically with an Ekoline 20 ultrasonograph machine with a 2.25 MHZ 10 cm focus transducer 1.2 cm in diameter. The echocardiograms were recorded on a Honeywell 1856 strip chart recorder with a simultaneous electrocardiographic (ECG) tracing. Tracings were taken with the patient at rest in the supine position and repeated during the last minute of a 5-minute period of occlusion of the graft. The grafts were occluded by manual compression until disappearance of the bruit and pulse. All tracings were obtained immediately before the patient's regularly scheduled hemodialysis. In 9 patients, repeat tracings at rest were obtained 5 minutes apart prior to occlusion to establish the variability of this technique in estimating CI. This was determined to be 5 + 1.23% (standard error of the mean). The echocardiograms were evaluated for left ventricular systolic (LVSV) and diastolic volumes (LVDV) and stroke volume (SV) with the formulas LVDV = Dd3, LVSV = Sd3, SV = LVDV - LVSV where Dd is diastolic diameter and Sd is systolic diameter of the left ventricular cavity.9'12 The heart rate (HR) was measured on the ECG recording. CO and CI were then calculated: CO = SV x HR, CI =
BSA
where BSA is body surface
in m2. All data were checked for statistical significance using the Student's t test. The echocardiographic studies were performed about 1 year (9 to 15 months) after FAVBS in 11 patients, about 2 years (24 to 27 months) after in 4 area
103
CHANGES IN CARDIAC INDEX 4.31
o
July 1976
Of the 12 patients who demonstrated a marked de(>20%o) in CI after 5 minutes of occlusion, all but one (Patient 6) had a significant decrease in SV (P = 0.004) (Fig. 2). This patient had a radial fistula and an FAVBS, and only the latter was occluded. Excluding Patient 6, those patients with greater than 20% decrease in CI had no significant change in HR (P = 0.10) (Fig. 3). Evaluation of the clinical signs and symptoms in the 17 patients studied showed that 10 (59%) had congestive heart failure (CHF) in the year after FAVBS. Five patients had acute CHF within the first month. Four of these recovered with frequent dialysis and have remained stable. The fifth patient (Patient 8) died of severe heart failure with cardiogenic shock 3 weeks after FAVBS. Five patients (30%) had a gradual onset of CHF within one year of their FAVBS. Two were controlled with dialysis, and three required surgical banding of the FAVBS. Only 7 of the 17 patients (41%) did not develop CHF following FAVBS. Three of these had an insignificant change in CI with occlusion of the shunt. The C/T ratio showed a greater than 10% increase in nine of the 13 patients who had an FAVBS for at least one year. In the 4 patients studied by radiography at 2 years, there was no further increase in C/T ratio in the second year. Four of the five patients with less than a 10% change in C/T at one year had less than a 20%o change in CI with graft occlusion. Eight of 12 patients with greater than cerase
10
9 8
_7A
6 -L
4-
32
0
Ann. Surg.
FEE AND OTHERS
104
I
Preocclusion FIG. 1. Change in cardiac index (CI) after occlusion (P = 0.001).
After 5 min of occlusion 5
minutes of shunt
CHANGES IN STROKE VOLUME 218 1
patients, and within 4 months after in the remaining 3 patients. Medical records of the 17 patients were reviewed for signs or symptoms of CHF. Posteroanterior chest radiographs taken prior to the FAVBS and at the time of the echocardiographic study were reviewed to evaluate changes in cardiothoracic ratio (C/T) or the presence of pulmonary congestion. In the 4 patients studied at 2 years, chest radiographs taken at one year were also available.
1751
1Ein I
a
125-
0
-J
>
100-
Results Eight of the 17 patients had an estimated resting CI which was elevated above the normal of 2.5 to 4.5 liters/min/m2. In 6 of these patients, the CI decreased to normal after occlusion of the shunt; in the other two patients, although there was a 32% and 34% reduction in CI with occlusion, the CI remained above nor30 mal. Nine patients had a normal resting CI. In 5 of these, Preocclusion After 5 min of there was a marked decrease (greater than 20%o) in CI occlusion with occlusion. In the 4 remaining patients, the CI did FIG. 2. Change in stroke volume (SV) after 5 minutes of shunt not change appreciably with occlusion (Fig. 1). occlusion (P = 0.004).
Vol. 184 . No. 1
FEMORAL ARTERIOVENOUS BOVINE SHUNTS
20% decrease in CI with occlusion exhibited postoperative symptoms of CHF. Discussion Increased survival of patients with multiple systemic diseases on chronic renal dialysis has led to a search for better techniques of vascular access. Recent reports have referred to femoral arteriovenous bovine shunts (FAVBS) using an enzymatically treated bovine carotid artery.16 These reports have stressed their advantages without sufficiently discussing their long-term consequences. Our data suggest that these patients have a high CI and that it is secondary to their FAVBS. Many of these patients developed CHF subsequent to the FAVBS and there was a significant correlation (P = 0.004) between the per cent increase in C/T ratio one year post FAVBS and the per cent decrease in CI with shunt occlusion (Fig. 4). The high CI in our patients was accomplished by increasing SV with insignificant change in HR. These data concur with previous observations in patients with traumatic arteriovenous fistulas10,5 and are in conflict with "Branham's sign," which is a decrease in HR with occlusion of arteriovenous fistula.3 Hypertension did not cause cardiac decompensation in these patients since none had a systolic pressure greater than 160 mmHg, and the two patients with diastolic blood pressures greater than 95 mmHg had stable C/T for one year before FAVBS with marked increase in C/T 1 year after the procedure. An unsuccessful attempt was made to identify those factors such as age, sex, hypertensive disease, or diabetes 125-
CHANGES IN HEART RATE
100-
-
105
+40 ci
a:
@17 Pericardial effusion
+30-
>
.4
cr +20-
*6
IL
o E.
7 1
*12
w
+10-
@2
*14
.1O
.
*K
C\)
o
-10
-
+10
0 -30 -10 -20 % ACI AFTER 5 min OCCLUSION
-40
-50
FIG. 4. Change in cardiothoracic ratio (CT) correlated with change in cardiac index (CI) after 5 minutes of shunt occlusion (P = 0.004).
mellitus that might correlate with the development of CHF after an FAVBS. Although significant increase in CI occurs frequently with FAVBS, there is no way to predict which patient will experience this complication. Thus, FAVBS should not be performed until all alternative routes of vascular access have been explored. When an FAVBS is deemed necessary, serial chest radiographs and echocardiographic determinations of CI should be obtained in order to evaluate the hemodynamic effects of this procedure. EDITORIAL COMMENT-The hazards of high cardiac output cardiac failure from construction of an arterio-venous shunt should be emphasized. The magnitude of this hazard can be determined by serial measurements of cardiac index. The reliability of the echocardiogram technique for this purpose is the main weakness of the current paper and should be confirmed by other methods of determination of cardiac output.
Acknowledgments The authors wish to thank Dr. Rex MacAlpin for reviewing the manuscript and Nancy Ellis for her excellent technical assistance.
75-
li-i0________________________ References
r 50 Li-tr I
25-
Preocclusion
After 5 min of occlusion
FIG. 3. Change in heart rate (HR) after 5 minutes of shunt occlusion (P = 0.10).
1. Akbarian, M., Yankopoulos, M. A. and Ablemann, W. H.: Hemodynamic Studies in Beriberi Heart Disease. Am. J. Med., 41: 197, 1966. 2. Binak, K., Regan, T. J., Christensen, R. C. and Hellems, H. K.: Arteriovenous Fistula: Hemodynamic Effects of Occlusion and Exercise. Am. Heart J., 60:495, 1960. 3. Branham, H. H.: Aneurismal Varix of the Femoral Artery and Vein Following a Gunshot Wound. Internat. J. Surg., 3:250, 1890. 4. Burwell, C. S. and Metcalfe, J.: Heart Disease and Pregnancy. Boston, Little, Brown and Co., 1958.
106
FEE AND OTHERS
5. DeGroot, W. J. and Leonard, J. J.: Hyperthyroidism as a High Cardiac Output State. Am. Heart J., 79: 265, 1970. 6. Edholm, 0. G., Howarth, S. and McMichael, J.: Heart Failure and Bone Blood Flow in Osteitis Deformans. Clin. Sci., 5:249, 1945. 7. Epstein, F. H., Shadle, 0. W., Ferguson, T. B. and McDowell, M. E.: Cardiac Output and Intracardiac Pressures in Patients with Arteriovenous Fistulas. J. Clin. Invest., 32:543, 1953. 8. Fee, H. J., Levisman, J., Doud, B., Golding, A. L.: High output Congestive Failure from Femoral Arteriovenous Shunts for Vascular Access. Ann. Surg., 183:321, 1976. 9. Feigenbaum, H., Wolfe, S. B. and Popp, R. L.: Correlation of Ultrasound with Angiocardiography in Measuring Left Ventricular Diastolic Volume. Am. J. Cardiol., 23:111, 1969. 10. Muenster, J. J., Graettinger, J. S. and Campbell, J. A.: Correlation of Clinical and Hemodynamic Findings in Patients with Systemic Arteriovenous Fistulas. Circulation, 20:1079, 1959. 11. Nickerson, J. L., Elkin, D. C. and Warren, J. V.: The Effect
12.
13. 14.
15.
16.
Ann.
Surg. * July
1976
of Temporary Occlusion of Arteriovenous Fistulas on Heart Rate, Stroke Volume, and Cardiac Output. J. Clin. Invest., 30: 215, 1951. Pombo, J. F., Troy, B. L. and Russell, R. D.: Left Ventricular Volumes and Ejection Fraction by Echocardiography. Circulation, 43:480, 1971. Varat, A., Adolph, R. J. and Fowler, N. O.: Cardiovascular Effects of Anemia. Am. Heart J., 83:415, 1972. Voigt, G. C., Kronthal, H. L., and Crounse, R. G.: Output in Erythrodermic Skin Disease. Am. Heart J., 72:615, 1966. Warren, J. V., Nickerson, J. L. and Elkin, D. C.: The Cardiac Output in Patients with Arteriovenous Fistulas. J. Clin. Invest., 30:210, 1951. Zincke, H., Hirsche, B. L., Amamoo, D. G., et al.: The Use of Bovine Carotid Grafts for Hemodialysis and Hyperalimentation. Surg. Gynecol. Obstet., 139:350, 1974.
