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Acute hemodynamic effects of lumbar sympathectomy
Acute Hemodynamic Effects of Lumbar Sympathectomy
George J. Collins, Jr, MD, FACS, LTC MC USA, Washington, DC Norman M. Rich, MD, FACS, COL MC USA, Washington, DC Charles A. Andersen, MD, LTC MC USA, Washington, DC Robert W. Hobson, Ill, MD, FACS, Newark, New Jersey Paul T. McDonald, MD, LTC MC USA, Washington, DC Louis Kozloff, MD, MAJ MC USA, Washington, DC
Considerable controversy and confusion surrounds the question of whether or not lumbar sympathectomy is of value in patients with lower extremity arterial insufficiency. At one time, DeBakey, Creech, and Woodhall [I] stated that it was the procedure of choice in patients with arteriosclerotic peripheral vascular disease. An alternate viewpoint was offered by Strandness [2], who stated: “Sympathectomy either at the Ls to Lq level or higher is ineffective in relieving or significantly improving intermittent claudication.” He also stated: “There is no sound basis for or objective evidence available to suggest that sympathectomy should be performed either before or at the time of direct arterial surgery.” Cannon, Kawakami, and Barker [3], on the other hand, believed that their best results were obtained when direct arterial surgery, such as bypass or endarterectomy, was combined with lumbar sympathectomy. Part of the confusion results from technologic limitations, because precise objective criteria for establishing whether or nor sympathectomy has effected a beneficial response have been and remain lacking. Early enthusiasm for sympathectomy diminished because of the good results obtained with bypass procedures. Enthusiasm also waned because of the results of some experiments demonstrating that sympathectomy did not increase muscle blood flow [4,5] and others demonstrating that it opened
arteriovenous shunts which might divert blood away from those areas of skin needing it most [6,7]. For it to be of significant benefit in the management of ischemic limbs, sympathectomy should, at the very least, increase total blood flow to the extremity. The degree and duration of benefit then become a function of the amount of increase in total blood flow, the distribution of total blood flow, the degree of decrease in peripheral resistance, and the rate of development of an adaptive response, which seems to account, in some cases, for an initial good response followed after a variable period of time by no observable effect of the sympathectomy. There is a minimum, albeit not conclusively known, flow rate below which patency of arterial revascularizations to the lower extremities cannot be reliably predicted. In patients with postrevascularization flow rates less than this minimum, a technic to increase total limb blood flow would be worthwhile. While one option is to add an additional direct revascularization procedure, another is to perform lumbar sympathectomy. With the above in mind, the following experiment was designed to study the acute hemodynamic effects of three ganglion lumbar sympathectomy in patients with aortoiliac arteriosclerotic occlusive disease undergoing aortofemoral bypass.
Material and Methods From the Peripheral Vascular Surgery Service, Department of Surgery. Walter Reed Army Medical Center, Washington, DC, and the Uniformed Services Universityof the Health Sciences, Bethesda, Maryland. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense. Reprint requests should be addressed to George J. Collins, Jr, MD, LTC MC, Peripheral Vascular Surgery Service, Walter Reed Army Medical Center, Washington, DC 2002 1. Presented at the Thirtieth Annual Meeting of the Southwestern Surgical Congress, Palm Springs California, April 17-20, 1978.
714
Eight patients ranging in age from forty-five to sixty-five years (mean age, 53.3 years) with aortoiliac disease underwent intraoperative blood flow measurements before and after aortofemoral bypass and after addition of three ganglion lumbar sympathectomy. Preoperative evaluation included resting ankle pressures, ankle pressures after exercise, treadmill times, hyperemia testing using strain gauge plethysmography in ten extremities, and arteriog-
The American Journal of Surgery
Lumbar Sympathectomy
raphh. These studies were repeated at selected intervals in the postoperative period. The indication for operation was intermittent claudication in all patients. In seven patients, bilateral sympat,hectomies were done, and in one patient unilateral sy npathectomy was done. Flow rates before and after bypass were measured in fifteen limbs, and flow rates after syinpathectomy were measured in fourteen limbs. Flow rar es were measured using an electromagnetic flowmeter and factory-calibrated flow probes (Biotronex Laboratories, Silver Spring, MI>). Flow measurements were made before bypass by placing the flow probe around the common femoral artery, with the superficial femoral artery and any side branches of the common femoral artery occluded. Using this method, common femoral artery flow becomes equivalent to profunda l’emoris artery flow. and it is not necessary to dissect out a long portion of the profunda femoris artery. After bypass. profunda femoris flow rates were measured by plccing the tlow probe around the limb of the bypass, with the common and superficial femoral arteries occluded. Ot ler authors have also measured flow rates by placing the flow probe around prosthetic conduits [8]. Using this method, flow through the bypass limb becomes equivalent to profunda femoris artery flow. These technics of measuring flow are illustrated in Figure 1. .:n addition to blood flow measurements, the pressure gradient between the aorta just distal to the renal arteries and the profunda femoris artery just distal to its orifice was measured before and after bypass and after sympathec-
torly using mercury-calibrated
strain gauges (Statham,
Hato Rey, Puerto Rico). Pressure in ,311fifteen extretnities.
measurements
were done
Results
13aseline flow rates, flow rates after bypass, and flow rates after lumbar sympathectomy were calculated in fifteen extremities. The difference between the, mean baseline flow rate (&SEM) of 99.3 f 24.4 cc/minute and the mean flow rate after bypass of 190.6 f 25.5 cc/minute was significant (p < 0.025). Similarly, the mean flow rate after sympathectomy of 296.3 f 50.6 cc/minute was significantly higher than the mean flow rate after bypass (p < 0.005). In all instances, it was possible to identify three lumbar sympathetic ganglia, and their removal along with the intervening sympathetic chain was confirmed histologically. There were no complications associated with performance of sympathectomy. The mean pressure gradient (fSEM) across the aor:oiliac segment prior to bypass was 21.1 f 4.1 mm Hg. This decreased to 7.2 f 2.5 mm Hg after bypass. The difference between the mean gradients before and after bypass was significant (p < 0.01). After sympathectomy, the gradient was 9.2 f 3.0 mm Hg and was not significantly different from the gradient after bypass (p > 0.1).
Volume 136, December 1976
The mean resting ankle pressure (&SEM) preoperatively was 100.5 f 7.4 mm Hg. This decreased to a mean of 65.3 f 10.5 mm Hg after exercise. Serial postoperative mean resting ankle pressures were as follows: at two weeks, 131.5 f 6.2; at, two months, 148.9 f 11.1; and at six months 13X1 f 8.9. Ankle pressures after exercise were 105.1 f 16.7, 121.5 f 19.4, and 126.5 f 17.1 mm Hg at two weeks, two months, and six months after operation, respectively. The preoperative ankle to arm blood pressure index was extremely variable, ranging from as low as 0.34 to as high as 1.13, with a mean (&SEM) of 0.74 f 0.06 mm Hg. Reactive hyperemia test responses were also extremely variable. Plethysmographic wave height and area under the pulse wave increased in four extremities, decreased in four extremities, and was unchanged in the remaining two extremities. Comments
These data demonstrate that three ganglion lumbar sympathectomy increases flow rates acutely after aortofemoral bypass. This was true even when the profunda femoris artery alone was used as the outflow vessel. Our data suggest that this response can be expected in a high percentage of cases; flow rates increased in 78.6 per cent of extremities tested after sympathectomy was performed. Similarly, Terry, increased flow Allan, and Taylor [9] d emonstrated rates after sympathectomy in 67.5 per cent of extremities. Nonetheless, the question of whether or not lumbar sympathectomy should be added to proximal revascularizations remains unanswered, and its value may relate to the amount of outflow available. We deliberately occluded the superficial femoral artery during the flow measurements for several reasons. First of all, the superficial femoral artery was either occluded or tightly stenotic in most but not all extremities studied (6 occluded, 2 stenotic). In the remaining extremities, the superficial femoral artery was either normal or moderately involved with arteriosclerotic disease. The profunda femoris artery, on the other hand, was patent in all extremities. Therefore, for the sake of homogeneity it became necessary to occlude the superficial femoral artery during flow studies in those extremities in which it was patent. Secondly, in contrast to the superficial femoral artery, the profunda femoris artery, except in its proximal portion, is often relatively spared from arteriosclerotic involvement [ 201. Since many patients with aortoiliac disease have concomitant superficial femoral artery disease, the profunda femoris artery is an important source of runoff in such patients. It, seemed reasonable to test the effects of
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Collins et al
id
-RENAL
-RENAL ARTERY
ARTERY
IC
ARTERY
-COYYONILIAC
!a--
HYPOQASTRIC
PROFUNOA FEMORIS ARTERY
/’
ARTERY ARTERY
’ “----S~l”“‘Z!AL ‘SUPERFICIAL yR?%tL OCCLUDED
Figure 1. Left, flow measurements were taken before bypass with the flow probe around the common femoral artery. Right, subsequent flow measurements were taken with the flow probe around the limb of the bypass graft.
lumbar sympathectomy on blood flow through this single proximal outflow vessel, since in many cases patency will ultimately depend on its ability to sustain satisfactory flow rates. The minimum flow rate needed to maintain patency of an aortofemoral bypass is not known with certainty, but Okike and Bernantz [II] believe the optimum rate to be roughly 300 cc/minute. The flow rate of 190.6 cc/minute achieved after aortofemoral bypass in our series obviously does not approximate that value, but the value of 296.3 cc/minute after the addition of lumbar sympathectomy does. Our data are comparable to theirs, since they routinely added lumbar sympathectomy to the inflow procedure. Martin, Renwick, and Stephenson [12] reported postrevascularization mean profunda femoris flow rates of 213 cc/minute. Our mean postrevascularization profunda femoris flow rate of 190.6 cc/minute compares favorably with that, and the increase to 296.3 cc/minute after sympathectomy is an obvious improvement. Intraoperative blood flow studies have led other authors to perform concomitant lumbar sympathectomy with direct arterial revascularization. Scheinin and Inberg [13] found that lumbar sympathectomy in association with arterial revascularization caused a marked increase in blood flow in most extremities even with limited outflow. They, therefore, recommended concomitant lumbar sympathectomy particularly when outflow was limited. Similarly, Allan, Terry, and Taylor [14] demonstrated more than a 100 per cent increase in flow rates after lumbar sympathectomy was added to direct arterial procedures. They suggested that the aug-
716
mentation of flow may be important to prevent early thrombosis. The true value of concomitant lumbar sympathectomy could best be judged by trials comparing patency rates and/or limb survival rates between two groups of patients undergoing direct arterial revascularizations with and without sympathectomy. The data bearing on this are contradictory. Shanik et al [15] clearly demonstrated that the postoperative peripheral arterial resistance in patients undergoing proximal revascularization and concomitant lumbar sympathectomy was lower than in patients undergoing proximal revascularization alone. Subsequently, they were unable to demonstrate an effect of sympathectomy on patency rate [16]. Terry, Allan, and Taylor [9], on the other hand, demonstrated an improved patency rate in a small group of patients undergoing femoropopliteal reconstruction when lumbar sympathectomy was added. Similarly, Casten, Sadler, and Forman [17] demonstrated a remarkably improved patency rate of small vessel anastomoses when sympathectomy was added. To further appreciate the controversy surrounding the entire subject of concomitant sympathectomy, one need only contrast the statement of Strandness [2] (“There is no sound basis for or objective evidence available to suggest that sympathectomy should be performed either before or at the time of direct arterial surgery”) to that of Douglas, Howie, and Tyall [18] (“There is no convincing evidence that the addition of bypass grafting to lumbar sympathectomy has given better results than sympathectomy alone”). Although it is appealing to think that this issue will be resolved by prospective, randomized, and perhaps
The
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Journal
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Lumbar Sympathectomy
multicenter trials, enormous difficulties mount as one attempts to develop randomized parallel series of pat,ients with similar amounts and distributions of lower extremity arteriosclerotic disease. This was our original intent, but it became obvious that the degree of stratification necessary to validate the compariscns would so dilute the numbers that, from a practical standpoint, we could not complete the study. Because of these constraints, one must continue, at present, to rely to some degree on clinical and laboratory experience, rather than on scientific proofs, to make judgments regarding whether or not sympathectomy alone or in conjunction with a direct arterial procedure is of value in the treatment of the ischemic limb. The continued use of intraoperative flow measurements should help further define the indications for and benefits of concomitant lumbar sympathectomy. The dat,a obtained thus far provide a basis of support for the observations of authors such as Cannon, Kawakami, and Barker [3] that results are better when sympathectomy is added to direct arterial revascularizations. Moreover, lumbar sympathectomy adds insignificantly to the morbidity of direct arterial revascularization. In the absence of objective evidence to the contrary, one should not recoil from a suggestion that it be used as an adjuvant to direct arterial revascularization particularly when outflow is compromised. Summary
Lumbar sympathectomy increases total limb blood fl(~w after aortofemoral bypass in a high percentage of cases. This was true in eleven of fourteen extremities (78.6 per cent) in our series even though no specific selection criteria for entry into the study, other than the need for aortofemoral bypass, were used: t,hat is, patients were entered into the study irrespective of preoperative ankle/arm pressure indexes or results of hyperemia testing. Overall, flow rates after sympathectomy was added to aortofemoral bypass were 1.55 times greater than after aortofemoral bypass alone. This degree of augmentat.ion of flow may be important, particularly in cases of limited outflow. References 1. DeBakey ME, Creech 0, Woodhall JP: Evaluation of sympathectomy in arteriosclerotic peripheral vascular disease. JAMA 144: 1227, 1950. 2. Strandness DE Jr: Long-term value of lumbar sympathectomy. Geriatrics 21: 144, 1966. 3. Cannon JA, Kawakami IG, Barker WF: The present status of aorto-iliac endarterectomy for obliterative arteriosclerosis. Arch Surgt32: 51, 1961.
Volume 136, December 1976
4. Hoffman DC, Jepson RP: Muscle blood flow and sympathectomy. J Surg Res 14: 151, 1973. 5. Rutherford RB, Valenta J: Extremity blood flow and distribution: the effects of arterial occlusion, sympathectomy. and exercise. Surgery 69: 332, 1971. 6. Scarpino JH, Delaney JP: Lumbar sympathectomy and arteriovenous shunting. Surg Forum 22: 176, 1971. 7. Cronenwett JL, Lindenauer SM: Direct measurement of arteriovenous anastomotic blood flow after lumbar sympathectomy. Surgery 82: 82, 1977. 6. Sako Y, Woyda WC, Ferguson DJ: Direct flow measurements in evaluation for surgery for ateriosclerosis. Sufg Forum 10: 479, 1959. 9. Terry HG, Allan JS, Taylor GS: The effect of adding lumbar sympathectomy: current role in the treatment of arteriosclerotic occlusive disease. Br J Surg 57: 5 1, 1970. 10. Leeds FH, Gilfillan RS: Revascularization of the ischemic limb. Arch Surg 62: 45, 1961. 11. Okike N, Bernantz PE: The role of the deep femoral artery in revascdarization of the lower extremity. Mayo C/in Proc 51: 209, 1976. 12. Martin P, Renwick S, Stephenson C: On the surgery of the profunda femoris artery. Br J Surg 55: 539, 1966 ‘13. Scheinrn TM, lnberg MV: lntraoperative effects of sympathectomy on ipsi- and contralateral blood flow in lower limb arterial reconstruction. Ann C/in Res 1: 260, 1969. 14. Allan JS, Terry HJ, Taylor GW: The effect on blood flow of adding lumbar sympathectomy to reconstructive arterial surgery in the lower extremity. Br J Surg 55: 861, 1968. 15. Shanik GD, Ford J, Hayes AC, Baker WH, Barnes RW: Pedal vasomotor tone following aortofemoral reconstructions. Ann Surg 163: 136, 1976. 16. Barnes RW, Baker WH, Shanik G, Maixner W, Hayes AC, Lin R, Clarke W: Value of concomitant sympathectomy in aortoiliac reconstruction. Arch Surg 112: 1325, 1977. 77. Casten DF, Sadler AH, Forman D: An experimental study of the effect of sympathectomy on patency of small vessel anastomoses. Surg Gynecol Obstet 115: 462. 1962. 18. Douglas DM, Howie G, Lyall M: Late results of autogenous vein grafting and lumbar sympathectomy in ischemic limbs. Lancef 1: 459, 1973.
Discussion
Harrison M. Lazarus (Salt Lake City, UT): Is your principal goal to achieve short-term benefit or long-term benefit? We have been investigating the effects of medical sympathectomy with reserpine in the perioperative period, and we find we do get decreased resistance in the first week after this adjuvant therapy. If you are trying to achieve long-term goals, then there would be a different reason for the added procedure. Do you have any measurements of normal profunda flow and how this profunda flow would be affected by sympathectomy?
Bernard
W. Thompson
(Little Rock, AR): We have
been trying to do a similar type of study in which an adjuvant one sided sympathectomy was added to a bilateral aortofemoral bypass graft. We have found that when this is done, plethysmographic pulsations in the toes as well as skin temperatures return to within normal limits 12 to 36 hours sooner on the side with sympathectomy. Unfortunately, we are not yet prepared to say that these findings are of clinical significance. Recently two series were carried out that showed there is no early or late difference when sympathectomy is added to peripheral vascular procedures. The first was a double blind study by Barnes, who added
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sympathectomy to aortofemoral bypass graft procedures and could find no difference in the early or late results. Likewise, Buda in New York studied patients with femoropopliteal grafts, 100 without sympathectomy and 100 with sympathectomy, and again could find no significant difference in early or late results. It has been recently shown that not only the halogenated hydrocarbons, but also the muscle relaxants and the neuroleptics, cause varying changes in the vascular system. They cause different results in cardiac output, peripheral resistance, as well as vascular tone. Therefore, it is probably very important to use a standard anesthetic agent in cases in which one is going to estimate peripheral blood flow. Cliff Buckley (San Antonio, TX): Dr. Collins, can you postulate the mechanism by which the flow is so dramatically increased after sympathectomy? If flow measurements are made at the completion of the revascularization procedure, and on opening of the limb of the graft, the limb has been ischemic during the period when blood flow is occluded and the anastomosis completed, that period of ischemia usually produces a maximum stimulus to vasodilatation and decreases tone in the vascular bed in that extremity. It would seem that if sympathectomy is providing an increase in flow, it must be through some means other than a change in the tone in the vascular bed. Dennis E. Weiland ommend concomitant teal bypass?
(Scottsdale, AZ): Would you recsympathectomy with femoropopli-
George J. Collins (closing): Our overall objective was simply to study the hemodynamics of this procedure. Overall, the objective should be to increase short- and/or
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long-term patency rates of aortofemoral bypasses. The patency rates with aortofemoral bypass alone, by and large, are excellent. The study of Dr. Barnes has been cited by Dr. Thompson. One of the problems with that study, I believe, is that there was only one failure, and that was in the group that did not have sympathectomy. When you are comparing about fifty limbs in each group with only one failure, the results are difficult to evaluate, and the experiment needs to be run for a longer period of time in a larger group of patients. We have not been doing anything such as Dr. Lazarus has with papaverine injection or reserpine. It would be interesting to compare reserpine in one extremity and lumbar sympathectomy in the other, because sympathectomy has been shown by some authors to increase flow and to decrease peripheral resistance_ for upwards of ten years. Certainly, it has been shown experimentally that sympathectomy increases arteriovenous shunting. This increases total limb flow, and this might be the mechanism whereby patency would be improved. I do not believe that we need to add sympathectomy when there is good outflow. In the proximal bypasses, when the superficial femoral, profunda femoris, and trifurcation vessels are all patent, the flow rates are going to be extremely high, and one probably need not add sympathectomy. If there are one or two vessel obstructions below the trifurcation, then I think it would be a reasonable thing to add sympathectomy first. We have had no experience with doing sympathectomy first, before aortofemoral bypasses, but we have in a few cases gone ahead and done sympathectomy before femoropopliteal bypass.
The American Journal of Surgery
George J. Collins, Jr, MD, FACS, LTC MC USA, Washington, DC Norman M. Rich, MD, FACS, COL MC USA, Washington, DC Charles A. Andersen, MD, LTC MC USA, Washington, DC Robert W. Hobson, Ill, MD, FACS, Newark, New Jersey Paul T. McDonald, MD, LTC MC USA, Washington, DC Louis Kozloff, MD, MAJ MC USA, Washington, DC
Considerable controversy and confusion surrounds the question of whether or not lumbar sympathectomy is of value in patients with lower extremity arterial insufficiency. At one time, DeBakey, Creech, and Woodhall [I] stated that it was the procedure of choice in patients with arteriosclerotic peripheral vascular disease. An alternate viewpoint was offered by Strandness [2], who stated: “Sympathectomy either at the Ls to Lq level or higher is ineffective in relieving or significantly improving intermittent claudication.” He also stated: “There is no sound basis for or objective evidence available to suggest that sympathectomy should be performed either before or at the time of direct arterial surgery.” Cannon, Kawakami, and Barker [3], on the other hand, believed that their best results were obtained when direct arterial surgery, such as bypass or endarterectomy, was combined with lumbar sympathectomy. Part of the confusion results from technologic limitations, because precise objective criteria for establishing whether or nor sympathectomy has effected a beneficial response have been and remain lacking. Early enthusiasm for sympathectomy diminished because of the good results obtained with bypass procedures. Enthusiasm also waned because of the results of some experiments demonstrating that sympathectomy did not increase muscle blood flow [4,5] and others demonstrating that it opened
arteriovenous shunts which might divert blood away from those areas of skin needing it most [6,7]. For it to be of significant benefit in the management of ischemic limbs, sympathectomy should, at the very least, increase total blood flow to the extremity. The degree and duration of benefit then become a function of the amount of increase in total blood flow, the distribution of total blood flow, the degree of decrease in peripheral resistance, and the rate of development of an adaptive response, which seems to account, in some cases, for an initial good response followed after a variable period of time by no observable effect of the sympathectomy. There is a minimum, albeit not conclusively known, flow rate below which patency of arterial revascularizations to the lower extremities cannot be reliably predicted. In patients with postrevascularization flow rates less than this minimum, a technic to increase total limb blood flow would be worthwhile. While one option is to add an additional direct revascularization procedure, another is to perform lumbar sympathectomy. With the above in mind, the following experiment was designed to study the acute hemodynamic effects of three ganglion lumbar sympathectomy in patients with aortoiliac arteriosclerotic occlusive disease undergoing aortofemoral bypass.
Material and Methods From the Peripheral Vascular Surgery Service, Department of Surgery. Walter Reed Army Medical Center, Washington, DC, and the Uniformed Services Universityof the Health Sciences, Bethesda, Maryland. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense. Reprint requests should be addressed to George J. Collins, Jr, MD, LTC MC, Peripheral Vascular Surgery Service, Walter Reed Army Medical Center, Washington, DC 2002 1. Presented at the Thirtieth Annual Meeting of the Southwestern Surgical Congress, Palm Springs California, April 17-20, 1978.
714
Eight patients ranging in age from forty-five to sixty-five years (mean age, 53.3 years) with aortoiliac disease underwent intraoperative blood flow measurements before and after aortofemoral bypass and after addition of three ganglion lumbar sympathectomy. Preoperative evaluation included resting ankle pressures, ankle pressures after exercise, treadmill times, hyperemia testing using strain gauge plethysmography in ten extremities, and arteriog-
The American Journal of Surgery
Lumbar Sympathectomy
raphh. These studies were repeated at selected intervals in the postoperative period. The indication for operation was intermittent claudication in all patients. In seven patients, bilateral sympat,hectomies were done, and in one patient unilateral sy npathectomy was done. Flow rates before and after bypass were measured in fifteen limbs, and flow rates after syinpathectomy were measured in fourteen limbs. Flow rar es were measured using an electromagnetic flowmeter and factory-calibrated flow probes (Biotronex Laboratories, Silver Spring, MI>). Flow measurements were made before bypass by placing the flow probe around the common femoral artery, with the superficial femoral artery and any side branches of the common femoral artery occluded. Using this method, common femoral artery flow becomes equivalent to profunda l’emoris artery flow. and it is not necessary to dissect out a long portion of the profunda femoris artery. After bypass. profunda femoris flow rates were measured by plccing the tlow probe around the limb of the bypass, with the common and superficial femoral arteries occluded. Ot ler authors have also measured flow rates by placing the flow probe around prosthetic conduits [8]. Using this method, flow through the bypass limb becomes equivalent to profunda femoris artery flow. These technics of measuring flow are illustrated in Figure 1. .:n addition to blood flow measurements, the pressure gradient between the aorta just distal to the renal arteries and the profunda femoris artery just distal to its orifice was measured before and after bypass and after sympathec-
torly using mercury-calibrated
strain gauges (Statham,
Hato Rey, Puerto Rico). Pressure in ,311fifteen extretnities.
measurements
were done
Results
13aseline flow rates, flow rates after bypass, and flow rates after lumbar sympathectomy were calculated in fifteen extremities. The difference between the, mean baseline flow rate (&SEM) of 99.3 f 24.4 cc/minute and the mean flow rate after bypass of 190.6 f 25.5 cc/minute was significant (p < 0.025). Similarly, the mean flow rate after sympathectomy of 296.3 f 50.6 cc/minute was significantly higher than the mean flow rate after bypass (p < 0.005). In all instances, it was possible to identify three lumbar sympathetic ganglia, and their removal along with the intervening sympathetic chain was confirmed histologically. There were no complications associated with performance of sympathectomy. The mean pressure gradient (fSEM) across the aor:oiliac segment prior to bypass was 21.1 f 4.1 mm Hg. This decreased to 7.2 f 2.5 mm Hg after bypass. The difference between the mean gradients before and after bypass was significant (p < 0.01). After sympathectomy, the gradient was 9.2 f 3.0 mm Hg and was not significantly different from the gradient after bypass (p > 0.1).
Volume 136, December 1976
The mean resting ankle pressure (&SEM) preoperatively was 100.5 f 7.4 mm Hg. This decreased to a mean of 65.3 f 10.5 mm Hg after exercise. Serial postoperative mean resting ankle pressures were as follows: at two weeks, 131.5 f 6.2; at, two months, 148.9 f 11.1; and at six months 13X1 f 8.9. Ankle pressures after exercise were 105.1 f 16.7, 121.5 f 19.4, and 126.5 f 17.1 mm Hg at two weeks, two months, and six months after operation, respectively. The preoperative ankle to arm blood pressure index was extremely variable, ranging from as low as 0.34 to as high as 1.13, with a mean (&SEM) of 0.74 f 0.06 mm Hg. Reactive hyperemia test responses were also extremely variable. Plethysmographic wave height and area under the pulse wave increased in four extremities, decreased in four extremities, and was unchanged in the remaining two extremities. Comments
These data demonstrate that three ganglion lumbar sympathectomy increases flow rates acutely after aortofemoral bypass. This was true even when the profunda femoris artery alone was used as the outflow vessel. Our data suggest that this response can be expected in a high percentage of cases; flow rates increased in 78.6 per cent of extremities tested after sympathectomy was performed. Similarly, Terry, increased flow Allan, and Taylor [9] d emonstrated rates after sympathectomy in 67.5 per cent of extremities. Nonetheless, the question of whether or not lumbar sympathectomy should be added to proximal revascularizations remains unanswered, and its value may relate to the amount of outflow available. We deliberately occluded the superficial femoral artery during the flow measurements for several reasons. First of all, the superficial femoral artery was either occluded or tightly stenotic in most but not all extremities studied (6 occluded, 2 stenotic). In the remaining extremities, the superficial femoral artery was either normal or moderately involved with arteriosclerotic disease. The profunda femoris artery, on the other hand, was patent in all extremities. Therefore, for the sake of homogeneity it became necessary to occlude the superficial femoral artery during flow studies in those extremities in which it was patent. Secondly, in contrast to the superficial femoral artery, the profunda femoris artery, except in its proximal portion, is often relatively spared from arteriosclerotic involvement [ 201. Since many patients with aortoiliac disease have concomitant superficial femoral artery disease, the profunda femoris artery is an important source of runoff in such patients. It, seemed reasonable to test the effects of
715
Collins et al
id
-RENAL
-RENAL ARTERY
ARTERY
IC
ARTERY
-COYYONILIAC
!a--
HYPOQASTRIC
PROFUNOA FEMORIS ARTERY
/’
ARTERY ARTERY
’ “----S~l”“‘Z!AL ‘SUPERFICIAL yR?%tL OCCLUDED
Figure 1. Left, flow measurements were taken before bypass with the flow probe around the common femoral artery. Right, subsequent flow measurements were taken with the flow probe around the limb of the bypass graft.
lumbar sympathectomy on blood flow through this single proximal outflow vessel, since in many cases patency will ultimately depend on its ability to sustain satisfactory flow rates. The minimum flow rate needed to maintain patency of an aortofemoral bypass is not known with certainty, but Okike and Bernantz [II] believe the optimum rate to be roughly 300 cc/minute. The flow rate of 190.6 cc/minute achieved after aortofemoral bypass in our series obviously does not approximate that value, but the value of 296.3 cc/minute after the addition of lumbar sympathectomy does. Our data are comparable to theirs, since they routinely added lumbar sympathectomy to the inflow procedure. Martin, Renwick, and Stephenson [12] reported postrevascularization mean profunda femoris flow rates of 213 cc/minute. Our mean postrevascularization profunda femoris flow rate of 190.6 cc/minute compares favorably with that, and the increase to 296.3 cc/minute after sympathectomy is an obvious improvement. Intraoperative blood flow studies have led other authors to perform concomitant lumbar sympathectomy with direct arterial revascularization. Scheinin and Inberg [13] found that lumbar sympathectomy in association with arterial revascularization caused a marked increase in blood flow in most extremities even with limited outflow. They, therefore, recommended concomitant lumbar sympathectomy particularly when outflow was limited. Similarly, Allan, Terry, and Taylor [14] demonstrated more than a 100 per cent increase in flow rates after lumbar sympathectomy was added to direct arterial procedures. They suggested that the aug-
716
mentation of flow may be important to prevent early thrombosis. The true value of concomitant lumbar sympathectomy could best be judged by trials comparing patency rates and/or limb survival rates between two groups of patients undergoing direct arterial revascularizations with and without sympathectomy. The data bearing on this are contradictory. Shanik et al [15] clearly demonstrated that the postoperative peripheral arterial resistance in patients undergoing proximal revascularization and concomitant lumbar sympathectomy was lower than in patients undergoing proximal revascularization alone. Subsequently, they were unable to demonstrate an effect of sympathectomy on patency rate [16]. Terry, Allan, and Taylor [9], on the other hand, demonstrated an improved patency rate in a small group of patients undergoing femoropopliteal reconstruction when lumbar sympathectomy was added. Similarly, Casten, Sadler, and Forman [17] demonstrated a remarkably improved patency rate of small vessel anastomoses when sympathectomy was added. To further appreciate the controversy surrounding the entire subject of concomitant sympathectomy, one need only contrast the statement of Strandness [2] (“There is no sound basis for or objective evidence available to suggest that sympathectomy should be performed either before or at the time of direct arterial surgery”) to that of Douglas, Howie, and Tyall [18] (“There is no convincing evidence that the addition of bypass grafting to lumbar sympathectomy has given better results than sympathectomy alone”). Although it is appealing to think that this issue will be resolved by prospective, randomized, and perhaps
The
American
Journal
of Surgery
Lumbar Sympathectomy
multicenter trials, enormous difficulties mount as one attempts to develop randomized parallel series of pat,ients with similar amounts and distributions of lower extremity arteriosclerotic disease. This was our original intent, but it became obvious that the degree of stratification necessary to validate the compariscns would so dilute the numbers that, from a practical standpoint, we could not complete the study. Because of these constraints, one must continue, at present, to rely to some degree on clinical and laboratory experience, rather than on scientific proofs, to make judgments regarding whether or not sympathectomy alone or in conjunction with a direct arterial procedure is of value in the treatment of the ischemic limb. The continued use of intraoperative flow measurements should help further define the indications for and benefits of concomitant lumbar sympathectomy. The dat,a obtained thus far provide a basis of support for the observations of authors such as Cannon, Kawakami, and Barker [3] that results are better when sympathectomy is added to direct arterial revascularizations. Moreover, lumbar sympathectomy adds insignificantly to the morbidity of direct arterial revascularization. In the absence of objective evidence to the contrary, one should not recoil from a suggestion that it be used as an adjuvant to direct arterial revascularization particularly when outflow is compromised. Summary
Lumbar sympathectomy increases total limb blood fl(~w after aortofemoral bypass in a high percentage of cases. This was true in eleven of fourteen extremities (78.6 per cent) in our series even though no specific selection criteria for entry into the study, other than the need for aortofemoral bypass, were used: t,hat is, patients were entered into the study irrespective of preoperative ankle/arm pressure indexes or results of hyperemia testing. Overall, flow rates after sympathectomy was added to aortofemoral bypass were 1.55 times greater than after aortofemoral bypass alone. This degree of augmentat.ion of flow may be important, particularly in cases of limited outflow. References 1. DeBakey ME, Creech 0, Woodhall JP: Evaluation of sympathectomy in arteriosclerotic peripheral vascular disease. JAMA 144: 1227, 1950. 2. Strandness DE Jr: Long-term value of lumbar sympathectomy. Geriatrics 21: 144, 1966. 3. Cannon JA, Kawakami IG, Barker WF: The present status of aorto-iliac endarterectomy for obliterative arteriosclerosis. Arch Surgt32: 51, 1961.
Volume 136, December 1976
4. Hoffman DC, Jepson RP: Muscle blood flow and sympathectomy. J Surg Res 14: 151, 1973. 5. Rutherford RB, Valenta J: Extremity blood flow and distribution: the effects of arterial occlusion, sympathectomy. and exercise. Surgery 69: 332, 1971. 6. Scarpino JH, Delaney JP: Lumbar sympathectomy and arteriovenous shunting. Surg Forum 22: 176, 1971. 7. Cronenwett JL, Lindenauer SM: Direct measurement of arteriovenous anastomotic blood flow after lumbar sympathectomy. Surgery 82: 82, 1977. 6. Sako Y, Woyda WC, Ferguson DJ: Direct flow measurements in evaluation for surgery for ateriosclerosis. Sufg Forum 10: 479, 1959. 9. Terry HG, Allan JS, Taylor GS: The effect of adding lumbar sympathectomy: current role in the treatment of arteriosclerotic occlusive disease. Br J Surg 57: 5 1, 1970. 10. Leeds FH, Gilfillan RS: Revascularization of the ischemic limb. Arch Surg 62: 45, 1961. 11. Okike N, Bernantz PE: The role of the deep femoral artery in revascdarization of the lower extremity. Mayo C/in Proc 51: 209, 1976. 12. Martin P, Renwick S, Stephenson C: On the surgery of the profunda femoris artery. Br J Surg 55: 539, 1966 ‘13. Scheinrn TM, lnberg MV: lntraoperative effects of sympathectomy on ipsi- and contralateral blood flow in lower limb arterial reconstruction. Ann C/in Res 1: 260, 1969. 14. Allan JS, Terry HJ, Taylor GW: The effect on blood flow of adding lumbar sympathectomy to reconstructive arterial surgery in the lower extremity. Br J Surg 55: 861, 1968. 15. Shanik GD, Ford J, Hayes AC, Baker WH, Barnes RW: Pedal vasomotor tone following aortofemoral reconstructions. Ann Surg 163: 136, 1976. 16. Barnes RW, Baker WH, Shanik G, Maixner W, Hayes AC, Lin R, Clarke W: Value of concomitant sympathectomy in aortoiliac reconstruction. Arch Surg 112: 1325, 1977. 77. Casten DF, Sadler AH, Forman D: An experimental study of the effect of sympathectomy on patency of small vessel anastomoses. Surg Gynecol Obstet 115: 462. 1962. 18. Douglas DM, Howie G, Lyall M: Late results of autogenous vein grafting and lumbar sympathectomy in ischemic limbs. Lancef 1: 459, 1973.
Discussion
Harrison M. Lazarus (Salt Lake City, UT): Is your principal goal to achieve short-term benefit or long-term benefit? We have been investigating the effects of medical sympathectomy with reserpine in the perioperative period, and we find we do get decreased resistance in the first week after this adjuvant therapy. If you are trying to achieve long-term goals, then there would be a different reason for the added procedure. Do you have any measurements of normal profunda flow and how this profunda flow would be affected by sympathectomy?
Bernard
W. Thompson
(Little Rock, AR): We have
been trying to do a similar type of study in which an adjuvant one sided sympathectomy was added to a bilateral aortofemoral bypass graft. We have found that when this is done, plethysmographic pulsations in the toes as well as skin temperatures return to within normal limits 12 to 36 hours sooner on the side with sympathectomy. Unfortunately, we are not yet prepared to say that these findings are of clinical significance. Recently two series were carried out that showed there is no early or late difference when sympathectomy is added to peripheral vascular procedures. The first was a double blind study by Barnes, who added
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sympathectomy to aortofemoral bypass graft procedures and could find no difference in the early or late results. Likewise, Buda in New York studied patients with femoropopliteal grafts, 100 without sympathectomy and 100 with sympathectomy, and again could find no significant difference in early or late results. It has been recently shown that not only the halogenated hydrocarbons, but also the muscle relaxants and the neuroleptics, cause varying changes in the vascular system. They cause different results in cardiac output, peripheral resistance, as well as vascular tone. Therefore, it is probably very important to use a standard anesthetic agent in cases in which one is going to estimate peripheral blood flow. Cliff Buckley (San Antonio, TX): Dr. Collins, can you postulate the mechanism by which the flow is so dramatically increased after sympathectomy? If flow measurements are made at the completion of the revascularization procedure, and on opening of the limb of the graft, the limb has been ischemic during the period when blood flow is occluded and the anastomosis completed, that period of ischemia usually produces a maximum stimulus to vasodilatation and decreases tone in the vascular bed in that extremity. It would seem that if sympathectomy is providing an increase in flow, it must be through some means other than a change in the tone in the vascular bed. Dennis E. Weiland ommend concomitant teal bypass?
(Scottsdale, AZ): Would you recsympathectomy with femoropopli-
George J. Collins (closing): Our overall objective was simply to study the hemodynamics of this procedure. Overall, the objective should be to increase short- and/or
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long-term patency rates of aortofemoral bypasses. The patency rates with aortofemoral bypass alone, by and large, are excellent. The study of Dr. Barnes has been cited by Dr. Thompson. One of the problems with that study, I believe, is that there was only one failure, and that was in the group that did not have sympathectomy. When you are comparing about fifty limbs in each group with only one failure, the results are difficult to evaluate, and the experiment needs to be run for a longer period of time in a larger group of patients. We have not been doing anything such as Dr. Lazarus has with papaverine injection or reserpine. It would be interesting to compare reserpine in one extremity and lumbar sympathectomy in the other, because sympathectomy has been shown by some authors to increase flow and to decrease peripheral resistance_ for upwards of ten years. Certainly, it has been shown experimentally that sympathectomy increases arteriovenous shunting. This increases total limb flow, and this might be the mechanism whereby patency would be improved. I do not believe that we need to add sympathectomy when there is good outflow. In the proximal bypasses, when the superficial femoral, profunda femoris, and trifurcation vessels are all patent, the flow rates are going to be extremely high, and one probably need not add sympathectomy. If there are one or two vessel obstructions below the trifurcation, then I think it would be a reasonable thing to add sympathectomy first. We have had no experience with doing sympathectomy first, before aortofemoral bypasses, but we have in a few cases gone ahead and done sympathectomy before femoropopliteal bypass.
The American Journal of Surgery