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Popliteal-to-distal bypass for limb-threatening ischemia
Popliteal-to-distal bypass for limb-threatening ischemia Jeffrey Marks, M D , Terry A, King, M D , H e n r y Baele, M D , Jeffrey Rubin, M D , and Cynthia M a r m e n , R N , Cleveland, Ohio In a subset of patients requiring lower extremity revascularization, the popliteal artery may be used for inflow, thereby minimizing dissection and the length of vein required for bypass. This retrospective study was done to define the risks and benefits of arterial reconstruction in a population of patients having popliteal-to-distal bypass procedures. Between 1986 and 1990, 32 surgical procedures were performed on 29 patients. The patient's ages ranged from 46 to 86 years, with a mean age of 68 years. Twenty-four of 29 (83%) were men and 19 of the 29 (66%) had diabetes. Most patients had multiple indications for surgical intervention, and these included rest pain (54%), nonhealing ulcers (64%), and gangrene (29%). Arterial bypass with use of the popliteal artery for the proximal anastomosis was performed with in situ saphenous vein (50%), reversed saphenous vein (41%), and orthograde autologous vein (9%). Distal anastomoses were to the posterior tibial artery in 11 bypasses (33%), the peroneal artery in 10 (30%), the anterior tibial artery in two (6%), and the dorsal pedal artery in 10 (30%). Two deaths occurred in the perioperative period for an operative mortality rate of 6.9%. With use of fife-table analysis, the cumulative graft patency rate was 97% at I year, 97% at 2 years, and 63.5% at 4 years. The overall cumulative limb salvage rate was 90.1% at i year, 90.1% at 2 years, and 78.8% at 4 years. Four patients required below-knee amputation; two of these amputations were performed in the perioperative period in patients with persistent and intractable pedal sepsis despite patent bypasses, and two were due to graft failure and subsequent ischemia during the late follow-up period. The remainder of the patients were ambulatory throughout their period of follow-up. The findings of this study support the selective use of the popliteal artery for proximal inflow, as excellent long-term patency and limb salvage rates may be anticipated. (J VASC SURG 1992;15:755-60.)
The superficial femoral artery is the most commonly diseased vessel in patients with limbthreatening ischemia, and the common-femoral artery is usually used for inflow because of the progressive nature ofatherosclerosis in the superficial femoral artery. However, a subset of patients exists with atherosclerosis and limb-threatening ischemia who are admitted with extensive tibial artery occlusive disease that begins at the popliteal artery trifurcation? In these patients the popliteal artery may be used for inflow in distal reconstruction, minimizing dissection and the length of vein required for bypass. This retrospective study was done to From the Department of Surgery,The Mt. SinaiMedicalCenter and Case Western ReserveUniversity, Cleveland. Presented at the Fifteenth Annual Meeting of the Midwestern Vascular SurgicalSociety,Chicago,Ill., Sept. 20-21, 1992. Reprint requests: Terry A. King, MD, Department of Surgery, Head, Section of Vascular Surgery, The Mt. Sinai Medical Center, One Mt. Sinai Dr., Cleveland,OH 44106. 24/6/36607
define the risks and benefits of vascular reconstruction in a population of patients having popliteal-to-distal bypass procedures. PATIENTS AND METHODS Between Jan. 1, 1986, and Dec. 31, 1990, 32 popliteal-to-distal artery bypass procedures were performed on 29 patients at the four hospitals comprising the Case Western Reserve University system. The patients' ages ranged from 42 to 86 years, with a mean age of 68 years. Twenty-four of 29 patients were men (83%), and 19 of 29 had diabetes (66%). Most patients had multiple indications for surgical intervention including rest pain in 16 extremities (54%), nonhealing ulcers in 19 (64%), and gangrene in eight circumstances (29%). No procedures were done for intermittent claudication. Patients with previous femoropopliteal bypass, popliteal trifurcation injuries, and popliteal aneurysms were excluded from analysis. Preoperative angiography was performed in all patients to verify 755
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the clinical and vascular laboratory diagnosis of popliteal trifurcation occlusive disease as well as to help select the appropriate site for proximal and distal anastomoses. Adequate inflow to the popliteal artery was documented by the presence of a palpable popliteal pulse and systemic pressures at the low thigh or calf level on the segmental Doppler pressure examination. Pulse velocity tracings and pulse volume recordings also verified the adequacy of flow in the popliteal artery. Patients with abnormal electrocardiograms, signs or symptoms of congestive heart failure, or histories of remote myocardial infarction were evaluated by a cardiologist. Noninvasive stress testing, such as dipyridamole or adenosine stress thallium testing was used. More recently, dobutamine echocardiography was used in the noninvasive evaluation of the cardiac status. The selection of tests was at the discretion of the attending cardiologist. Coronary angiography and coronary bypass surgery were performed, when indicated, before the lower extremity bypass procedure. Arterial bypass by use of the popliteal artery for the proximal anastomosis was performed with in situ saphenous vein in 16 extremities (50%), reversed saphenous vein in 13 (41%), and orthograde autologous vein in three bypasses (9%). No patient received a prosthetic bypass graft. The proximal anastomosis was placed on the popliteal artery, either above or below the knee, on the basis of the appearance of the popliteal artery on angiography. Above-knee grafts were placed anatomically when the vein was harvested and subcutaneously when the in situ technique was used. The distal anastomosis was placed on the posterior tibial artery in 11 bypasses (34%), the peroneal artery in 8 (25%), the dorsal pedal artery in 11 (34%), and the anterior tibial artery in two (6%) instances. Operative systemic heparinization was performed routinely, and low molecular weight dextran 40 was used during and after the operation at the discretion of the surgeon. Intraoperative completion angiography was performed in all patients to assess the technical adequacy of the distal anastomosis and to detect the presence of any residual arteriovenous fistulas in patients with in situ bypasses. Postoperative long-term anticoagulation consisted of aspirin on a daily basis; no patients were on warfarin (Coumadin) therapy. Closed space soft tissue infections were aggressively debrided before revascularization. Areas of dry gangrene, osteomyelitis, and/or open infected areas were debrided and/or amputated several days to a week later. Although some surgeons prefer to amputate at the time of bypass surgery, the authors
prefer to wait to allow maximal reperfusion after bypass, in an attempt to minimize tissue loss. 2'3 Minor amputations were defined as forefoot amputations, up to and including a Chopart's amputation. Major amputations included Symes procedures, as well as above-knee and below-knee amputations. Cumulative graft patency and limb salvage calculations were evaluated by means of life-table analysis and were based on primary limb salvage and patency rates without inclusion of secondary patency. Primary patency intervals were ended at the time of graft occlusion, major amputation, death, or loss to follow-up. The limb salvage interval was ended at the time of major amputation, death, or loss to followup. RESULTS
Two deaths occurred in the perioperative period as a result of myocardial infarction and mesenteric infarction at 2 weeks and 3 weeks, respectively, for an operative mortality rate of 6.9%. Both patients had patent grafts at the time of death. Four additional patients died in the late postoperative period at 12 months, 15 months, 33 months, and 42 months, respectively. All late deaths were caused by myocardial infarctions. These four patients had undergone a total of six bypass procedures. Five of six grafts were patent at the time of death. The overall mortality rate in the study was 21.0%. Follow-up ranged from 1 to 48 months, with a mean of 17 months. Three graft occlusions occurred, one at three weeks, one at 26 months, and one at 44 months. By use of life-table analysis, the cumulative primary graft patency rate was 97% at i year, 97% at 2 years, and 63.5% at 4 years (Table I). Four patients required below-knee amputations at 3 weeks, 2 months, 2.5 months, and 26 months, respectively. Two of the four amputations were done for persistent pedal sepsis despite patent bypass grafts, and the other two below-knee amputations were performed for graft thromboses and limb ischemia. The overall cumulative limb salvage rate was 90.1% at 1 year, 90.1% at 2 years, and 78.8% at4 years (Table I). The remainder of the patients were ambulatory throughout their period of follow-up. Comparison of the in situ versus harvested saphenous vein bypass patency rates and limb salvage revealed no statistically significant difference (p = 0.24 and 0.20, respectively), although small sample size may account for this finding. Also, with the short nature of these bypasses, several of the in situ bypasses actually had the major portion of the vein mobilized for the proximal and distal anasto-
Volume 15 Number 5 May 1992
Popliteal-to-distal bypass for limb-threatening ischemia
75 7
Table I. Cumulative graft patency and limb salvage Time period 0 1 3 6 12 24 36
-
1 mo 3 mo 6 mo 12 m o 24 mo 36 mo 48 mo
Grafts at risk 32 29 24 21 16 9 6
Thrombosed grafts 1 0 0 0 0 1 1
Cumulative graft patency
Limbs at risk
Limbs amputated
Cumulative limb salvage, %
Standard error
96.8% 96.8% 96.8% 96.8% 96.8% 84.7% 63.5%
32 29 24 21 16 9 6
1 2 0 0 0 1 0
96.8% 90.1% 90.1% 90.1% 90.1% 78.8% 78.8%
0.0308 0.0308 0.0308 0.0308 0.0308 0.0368 0.2030
moses. It is difficult to conceive of the benefits of the in situ technique in these circumstances, and conceptually these grafts functioned as harvested vein grafts. Except for the four patients requiring major amputation, all minor wounds and amputations healed. Wound problems at the bypass sites were minor, and all surgical wounds healed without reoperation for wound complications and/or graft infections. Thrombosed grafts were investigated with noninvasive Doppler examinations and arteriography when indicated by clinical circumstances. All thrombosed grafts "were irretrievable, and therefore secondary patency is not reported. DISCUSSION
Popliteal and tibial artery occlusive disease is a pattern of atherosclerotic disease often seen in the elderly diabetic patient population. 1,4 Operative decisions must be carefully weighed in this patient population, with consideration of the risks of progressive limb-threatening ischemia and primary amputation versus the risks of perioperative morbidity and death for limb salvage operations. In a recent multicenter study, the mortality rate of major amputations equaled that of peripheral bypass operations in similar patient populations.5 The 30-day and 2-year mortality rates for the present study were 7.0% and 13.8%, respectively, and are comparable to the cooperative study. 6 Also, Plecha et al.7 reported a 30-day operative mortality rate (6.7%) after lower extremity bypass grafting in a population of patients averaging 75 years of age. Comparing patients with and without popliteal trifurcation disease, Kallero et al.8 reported a significant increase in perioperative deaths and a twofold increase in late deaths as a result of myocardial infarctions in the population with trifurcation occlusion.4,8 This group of patients, therefore, warrants aggressive cardiac evaluation before distal revascularization to minimize operative deaths. With aggressive management, our 2-year and 4-year survival rates at 87% and 79% do not differ
greatly from recently generated life expectancy tables for this population of patients. 9 Presumed increases in operative risk and an underestimation of the benefits of bypass surgery in the elderly patient may be deterrents to the use of lower extremity revascularization in this population. Veith et al. 1° recently outlined their changing patterns of management in the severely ischemic patient. The authors described aggressive efforts at limb salvage, including vein grafts originating at the popliteal artery or beyond, with a combined 30-day mortality rate of 3.3%, with decreasing rates of primary and secondary amputation over the 16 years of the study? ° The recent literature concerning popliteal-todistal bypass is summarized in Table II. Veith et al) 1 first suggested the use of the distal superficial femoral artery or the popliteal artery as the inflow site for infrapopliteal bypass. The popliteal artery was used if there existed a less than 20% luminal narrowing in the superficial femoral artery. He reported an 82% 4-year cumulative patency rate in patients having popliteal-to-distal bypass, although 25% of his reported bypasses required secondary operations to maintain patency. In his analysis of failures, only one was due to progressive atherosclerosis proximal to the inflow site. Another report from the same institution outlines the superior patency rates of short vein bypasses when compared with longer grafts. 12 The data in this reference, however, were not in a format that allowed extraction for inclusion in Table II.
Schnler et al.ls achieved a 70% limb salvage rate at 31 months with no operative deaths. Four late deaths in this series were due to myocardial infarction. They attribute the high early patency rates to the routine use of graft assessment. This included completion angiography early in the study, and completion duplex ultrasonography in the latter half of the study. They found no significant correlation between patency and pedal arch continuity. Diabetes corre-
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Journal of VASCULAR SURGERY
Marks et al.
Table II. Popliteal-to-distal bypass results Study Veith et al.10 1981
No. of bypasses
No. of patients
24
24
Percent with diabetes N.A.
Operative mortality, percent N.A.
i yr patency, percent 82
Extended patency, % (years offollow-up) 82
(4) Schuler et al. 13 1983 Cantelmo et al. is 1986
23 32
23 30
74
0
N.A.
84
(2.5) 77
0
79
79
(3) Rhodes et al) 6 1987
26
26
96
12
95
95
(2.5) Rosenbloom et al. 14 1988
49
46
76
0
83
41
(5) Marks et al. 1991 current study
32
29
68
7
97
64
(4)
lated with a statisfcaUy higher risk of amputation. Five of six below-knee amputations were done for pedal sepsis in the face of patent bypasses. In an update of that series, Rosenbloom 14 described 46 patients who underwent bypasses with use of the distal superficial femoral or popliteal artery as the source of inflow. That study showed a 1- and 5-year bypass graft patency of 83% and 41%, respectively, and a limb salvage rate of 69% at 6 years. Cantelmo et al. 15 performed 32 reversed saphenous vein bypasses using the popliteal artery for inflow in 30 patients and noted limb salvage at 1 and 3 years of 89% and 82%, respectively. Four grafts failed early, and three required below-knee amputations because of persistent pedal sepsis in the face of patent bypasses. Rhodes et al)6 were the first authors to describe the use of in situ techniques for popliteal-to-distal bypasses, and performed 26 such operations on 26 patients. A limb salvage rate of 95% at 30 months was obtained. Rhodes et al.16 emphasized transcutaneous oxygen tension mapping for delineation of persistent areas of ischemia in these patients, and showed that slow healing wounds were associated with low transcutaneous oxygen tensions in the region. The use of the short vein bypass has several distinct attributes. The short length of conduit needed allows minimal dissection in the region of the thigh, thereby minimizing wound complications. 12 In the current study, all vein segments were harvested in the ipsilateral leg, sparing other limbs the risk of vein harvest. This can potentially influence rehabilitation in a positive fashion in the early postoperative setting. The need for short conduits is also important in patients that have had coronary revascularization, with prior saphenous vein harvest for the bypass.
These benefits occur in the setting of patency rate. that are comparable to more standard femorodistal bypass procedures, where the origin of the bypass is the common femoral artery in the groin. These findings also support the growing evidence that shorter, more distal bypasses perform as well as the longer and more standard femorodistal bypass. 12,17 It is our preference therefore, to use the most distal popliteal artery either above or below the knee, for distal reconstruction for limb salvage if the superficial femoral artery is less than 20% stenotic or uninvolved in the atherosclerotic process. We performed 32 arterial bypass procedures in 29 patients with extensive popliteal and tibial artery occlusive disease. The popliteal artery was used for proximal inflow with long-term graft patency and limb salvage rates that are comparable with those achieved with femorodistal bypasses. By using the popliteal artery for inflow, the length of saphenous vein conduit needed for bypass can be reduced without sacrificing overall graft patency. This is especially important in this patient population, where existing saphenous vein may be of inadequate length or quality for femorodistal bypass. This helps minimize the amount of dissection in the thigh, and therefore minimizes the risk of wound healing complications. This study supports the use of the popliteal artery for proximal inflow in distal artery bypass procedures. REFERENCES 1. Haimovici H. Atherosclerosis: biological and surgical considerations. Vascular surgery: principles and techniques. East Norwalk: Appleton & Lange, 1984:140-1. 2. Kubin JR, Pitluk HC. Tibial artery revascularization in the face of pedal sepsis: do operative results justify an aggressive surgical approach? Am J Surg 1988;155:144-7. 3. Rhodes GR, King TA. Delayed skin oxygenization following
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4.
5. 6.
7.
8.
9. 10.
distal tibial revascularization (DTR): implications for wound healing and late amputations. Am Surg 1986;52:519-25. Kallero KS, Bergqvest D, Cederholm C, Jonsson K, Ollson PO, Takolander R. Late mortality and morbidity after arterial reconstruction: the influence of arteriosclerosis in popliteal trifurcation. J VAsc SURG 1985;2:541-6. Gregg R. Bypass or amputation. Concomitant review of bypass arterial gaffing and major amputations. Am J Surg 1985;149:397-402. Veterans' Administration Cooperative Study Group 141: comparative evaluation of prosthetic reversed and in sire vein bypass grafts in distal popliteal and tibial-peroneal revascularization. Arch Surg 1988;123:434-8. Plecha FR, Bertin VI, Plecha EJ, et al. The early results of vascular surgery in patients 75 years and older: an analysis of 3529 cases. J VASCSURG 1985;2:769-74. Kallero KS, Berggnist D, Cererholm C, Jonsson K, Olsson PO, Takolander R. Arteriosclerosis in popliteal artery trifurcation as a predictor for myocardial infarction after arterial reconstructive operation. Surg Gynecol Obstet 1984;159: 133-8. Life Table, Connecticut Mutual Life Insurance Company, 1991: Hartford, Conn. Veith FJ, Gupta SK, Wengerter KR, et al. Changing arteriosclerotic disease patterns and management strategies in lower-limb-threatening ischemia. Ann Surg 1990;212:40214.
Popliteal-to-distal bypassfor limb-threatening ischemia 759 11. Veith FJ, Gupta SK, Samson RH, Flores SW, Janko G, Scher LA. Superficialfemoral and popfiteal arteries as inflow sites for distal bypasses. Surgery 1981;90:980-90. 12. Ascer E, Veith H, Gupta SK, White SA, Bakal CW, Wengetter K. Short vein grafts: a superior option for arterial reconstructions to poor or compromised outflow tracts? J VAsc SURG 1988;7:270-8. 13. Schuler JJ, Flanagan DP, Williams LR, Ryan TI, Castronuovo JJ. Early experience wiiahpopfiteal to infrapopliteal bypass for limb salvage. Arch Surg 1983;118:472-6. 14. Rosenbloom MS. Long-term results of infragenicular bypasses with autogenous vein originating from the distal femoral and popliteal arteries. J VASC SURG 1988;7:691-6. 15. Cantelmo NL, Snow R, Menzoian JO, LoGerfo FW. Successful vein bypass in patients with an ischemic limb and a palpable popfiteal pulse. Arch Surg 1986;121:217-9. 16. Rhodes GR, Rollins D, Sidawy A, Skudder P, Buchbinder D. Popfiteal-to-tibial in sire saphenous vein bypass for limb salvage in diabetic patients. Am J Surg 1987;154:245-8. 17. Wengerter KR, Yang PM, Veith FJ. A twelve-year experience with the popliteal-to-distal bypass: the significance and management of proximal disease. [1VAsc SURG1992; 15:14351. Submitted Oct. 15, 1991; accepted lan. 27, 1992.
DISCUSSION Dr. James Schuler (Chicago, Ill.). When this procedure was first described in the first large series o f these patients by Frank Veith and his group in 1981, and then a similar size series was described by our group in 1983, even though the results were good at that time, both Veith and our group were criticized somewhat in that we did not have long enough follow-up on these patients, even though the 2- and 3- and sometimes 4-year graft patency rates were in the 70% to 80% range, and the limb salvage rates were in the 70% to 80% range. The admonition was that if we waited a few more years we would find that most of the grafts had failed, and most of them had failed on the basis o f progression of atherosclerotic disease in the popliteal or superficial femoral artery. In 1987 before this Society we presented our 8-year follow-up with a cumulative limb salvage rate at 6 years o f 69% in our patients. At the SVS meeting this past June, Veith's group presented 153 popliteal-to-distal bypasses with a maximum follow-up o f 12 years and a cumulative limb salvage rate at 5 years o f 73%. I think these two papers with longer follow-up have documented that not only is this bypass very efficacious, it is in fact quite durable. I think the authors o f the present paper have borne out that fact with their report here, this makes a total of six papers presented over the past 10 years all of which present graft patency rates in the 70% to 80% and sometimes 90% range at 2 to 5 years, and limb salvage
rates that are in the 70% to 80% range at 5 years. I think we can put to rest the prior misconception that this is a bypass that does not have a place in the standard armamentarinm of most vascular surgeons. I have three questions. In your series, you did not have any patients who underwent popliteal-to-distal bypass with prosthetic material. Is that because you have denied to these patients without autogenous vein the opportunity for bypass with prosthetic material, or was it simply the fact that all of your patients happened to have vein? Second, I also noticed that you did not use any arm veins. Is it again for the same reason? They all had leg vein or do you intentially not do these bypasses with arm veins? The third, and I think at least in our experience the most serious question that remains to be answered for these patients, revolves around the question of continued foot sepsis requiring major amputation in those patients who have a patent bypass graft. In our experience approximately three quarters o f all the patients who went on to have a major amputation, had their amputation in the presence of a patent hemodynamically normal bypass. Have you had any experience with either transcutaneous oxygen tension measurements or any other device where you can ideally predict before operation what patients are going to end up in this condition, wherethe bypass is working but you lose the leg anyhow?
760 M a r k s et al.
Dr. Jeffrey Marks. In terms of our patency rates being slightly better than all the previous studies, I think I would have to relate that to the fact that we did use autologous vein for all of our grafts instead of prosthetics. I think that rather than saying that we did it preferentially, it was just due to the fact that we did have adequate saphenous vein in all our patients. Obviously, because it is a shorter bypass graft, the amount of conduit needed is shorter, and we had adequate saphenous vein for either reversed or in situ bypass in all of our patients. With respect to preference for in situ versus reversed, we used in situ bypass when it was technically possible. A long-term prospective study will elucidate patency rates. In terms of not using arm veins, again, I think that goes back to the fact that we were able to find adequate saphenous vein of a short segment. Previous studies have also shown that the short saphenous vein is adequate as well for this shorter segment bypass. In terms of the continuous foot sepsis, Dr. Rhodes in 1987 discussed the use of transcutaneous oxygenation pressures. We did not use transcutaneous oxygen pressures, as this 4-year period basically encompassed the evolution of our vascular labs. Dr. Rhodes, however, did find that transcutaneous oxygenation was helpful in determining which patients would maintain patent grafts. Dr. Peter Gloviczki (Rochester, Minn.). We have had a very similar positive experience at the Mayo Clinic. In almost 60 patients on whom we performed bypass to the foot, approximately half originated from the popliteal artery. My first question is about the cause of graft failure in
Journal of VASCULAR SURGERY
these patients-is it proximal occlusion of the superficial femoral artery or progression of the disease proximal to your graft that we have seen in some of these patients or is it indeed poor runoff or problems with the graft? The second question concerns the postvasculatization edema in these patients. The incidence of that in our series is almost 100%. The swelling in these patients is sometimes quite disabling. Do you have any suggestions for us? Dr. Marks. With respect to progression of disease in our three graft occlusions, the one at 3 weeks was most likely a technical complication. The other two, however, were related to distal disease. Of the 160 patients that we reviewed in the literature in the previous five papers, only Dr. Veith reported one related to proximal superficial femoral artery occlusive disease as a source for graft occlusion. The remaining patients, therefore, were probably related to progression o f distal disease. Edema is always a problem in terms of healing of wounds. If you are going to a posterior tibial artery, it is usually just one incision. To a dorsal pedal artery, most authors would recommend parallel incisions in the foot. Edema is best managed by postoperative elevation and wrapping with elastic bandages. Dr. John Corson (Iowa City, Iowa). It was not clear to me whether any patients in this series had any inflow fix up procedures of the superficial femoral artery or popliteal such as bypass, atherectomy, angioplasty, or endarterectomy before or at the same time as your distal bypass. If they did, what happened to those patients? Dr. Marks. All patients with previous femoropopliteal bypasses were excluded from our analysis.
The superficial femoral artery is the most commonly diseased vessel in patients with limbthreatening ischemia, and the common-femoral artery is usually used for inflow because of the progressive nature ofatherosclerosis in the superficial femoral artery. However, a subset of patients exists with atherosclerosis and limb-threatening ischemia who are admitted with extensive tibial artery occlusive disease that begins at the popliteal artery trifurcation? In these patients the popliteal artery may be used for inflow in distal reconstruction, minimizing dissection and the length of vein required for bypass. This retrospective study was done to From the Department of Surgery,The Mt. SinaiMedicalCenter and Case Western ReserveUniversity, Cleveland. Presented at the Fifteenth Annual Meeting of the Midwestern Vascular SurgicalSociety,Chicago,Ill., Sept. 20-21, 1992. Reprint requests: Terry A. King, MD, Department of Surgery, Head, Section of Vascular Surgery, The Mt. Sinai Medical Center, One Mt. Sinai Dr., Cleveland,OH 44106. 24/6/36607
define the risks and benefits of vascular reconstruction in a population of patients having popliteal-to-distal bypass procedures. PATIENTS AND METHODS Between Jan. 1, 1986, and Dec. 31, 1990, 32 popliteal-to-distal artery bypass procedures were performed on 29 patients at the four hospitals comprising the Case Western Reserve University system. The patients' ages ranged from 42 to 86 years, with a mean age of 68 years. Twenty-four of 29 patients were men (83%), and 19 of 29 had diabetes (66%). Most patients had multiple indications for surgical intervention including rest pain in 16 extremities (54%), nonhealing ulcers in 19 (64%), and gangrene in eight circumstances (29%). No procedures were done for intermittent claudication. Patients with previous femoropopliteal bypass, popliteal trifurcation injuries, and popliteal aneurysms were excluded from analysis. Preoperative angiography was performed in all patients to verify 755
756
Journal of VASCULAR SURGERY
M a r k s et al.
the clinical and vascular laboratory diagnosis of popliteal trifurcation occlusive disease as well as to help select the appropriate site for proximal and distal anastomoses. Adequate inflow to the popliteal artery was documented by the presence of a palpable popliteal pulse and systemic pressures at the low thigh or calf level on the segmental Doppler pressure examination. Pulse velocity tracings and pulse volume recordings also verified the adequacy of flow in the popliteal artery. Patients with abnormal electrocardiograms, signs or symptoms of congestive heart failure, or histories of remote myocardial infarction were evaluated by a cardiologist. Noninvasive stress testing, such as dipyridamole or adenosine stress thallium testing was used. More recently, dobutamine echocardiography was used in the noninvasive evaluation of the cardiac status. The selection of tests was at the discretion of the attending cardiologist. Coronary angiography and coronary bypass surgery were performed, when indicated, before the lower extremity bypass procedure. Arterial bypass by use of the popliteal artery for the proximal anastomosis was performed with in situ saphenous vein in 16 extremities (50%), reversed saphenous vein in 13 (41%), and orthograde autologous vein in three bypasses (9%). No patient received a prosthetic bypass graft. The proximal anastomosis was placed on the popliteal artery, either above or below the knee, on the basis of the appearance of the popliteal artery on angiography. Above-knee grafts were placed anatomically when the vein was harvested and subcutaneously when the in situ technique was used. The distal anastomosis was placed on the posterior tibial artery in 11 bypasses (34%), the peroneal artery in 8 (25%), the dorsal pedal artery in 11 (34%), and the anterior tibial artery in two (6%) instances. Operative systemic heparinization was performed routinely, and low molecular weight dextran 40 was used during and after the operation at the discretion of the surgeon. Intraoperative completion angiography was performed in all patients to assess the technical adequacy of the distal anastomosis and to detect the presence of any residual arteriovenous fistulas in patients with in situ bypasses. Postoperative long-term anticoagulation consisted of aspirin on a daily basis; no patients were on warfarin (Coumadin) therapy. Closed space soft tissue infections were aggressively debrided before revascularization. Areas of dry gangrene, osteomyelitis, and/or open infected areas were debrided and/or amputated several days to a week later. Although some surgeons prefer to amputate at the time of bypass surgery, the authors
prefer to wait to allow maximal reperfusion after bypass, in an attempt to minimize tissue loss. 2'3 Minor amputations were defined as forefoot amputations, up to and including a Chopart's amputation. Major amputations included Symes procedures, as well as above-knee and below-knee amputations. Cumulative graft patency and limb salvage calculations were evaluated by means of life-table analysis and were based on primary limb salvage and patency rates without inclusion of secondary patency. Primary patency intervals were ended at the time of graft occlusion, major amputation, death, or loss to follow-up. The limb salvage interval was ended at the time of major amputation, death, or loss to followup. RESULTS
Two deaths occurred in the perioperative period as a result of myocardial infarction and mesenteric infarction at 2 weeks and 3 weeks, respectively, for an operative mortality rate of 6.9%. Both patients had patent grafts at the time of death. Four additional patients died in the late postoperative period at 12 months, 15 months, 33 months, and 42 months, respectively. All late deaths were caused by myocardial infarctions. These four patients had undergone a total of six bypass procedures. Five of six grafts were patent at the time of death. The overall mortality rate in the study was 21.0%. Follow-up ranged from 1 to 48 months, with a mean of 17 months. Three graft occlusions occurred, one at three weeks, one at 26 months, and one at 44 months. By use of life-table analysis, the cumulative primary graft patency rate was 97% at i year, 97% at 2 years, and 63.5% at 4 years (Table I). Four patients required below-knee amputations at 3 weeks, 2 months, 2.5 months, and 26 months, respectively. Two of the four amputations were done for persistent pedal sepsis despite patent bypass grafts, and the other two below-knee amputations were performed for graft thromboses and limb ischemia. The overall cumulative limb salvage rate was 90.1% at 1 year, 90.1% at 2 years, and 78.8% at4 years (Table I). The remainder of the patients were ambulatory throughout their period of follow-up. Comparison of the in situ versus harvested saphenous vein bypass patency rates and limb salvage revealed no statistically significant difference (p = 0.24 and 0.20, respectively), although small sample size may account for this finding. Also, with the short nature of these bypasses, several of the in situ bypasses actually had the major portion of the vein mobilized for the proximal and distal anasto-
Volume 15 Number 5 May 1992
Popliteal-to-distal bypass for limb-threatening ischemia
75 7
Table I. Cumulative graft patency and limb salvage Time period 0 1 3 6 12 24 36
-
1 mo 3 mo 6 mo 12 m o 24 mo 36 mo 48 mo
Grafts at risk 32 29 24 21 16 9 6
Thrombosed grafts 1 0 0 0 0 1 1
Cumulative graft patency
Limbs at risk
Limbs amputated
Cumulative limb salvage, %
Standard error
96.8% 96.8% 96.8% 96.8% 96.8% 84.7% 63.5%
32 29 24 21 16 9 6
1 2 0 0 0 1 0
96.8% 90.1% 90.1% 90.1% 90.1% 78.8% 78.8%
0.0308 0.0308 0.0308 0.0308 0.0308 0.0368 0.2030
moses. It is difficult to conceive of the benefits of the in situ technique in these circumstances, and conceptually these grafts functioned as harvested vein grafts. Except for the four patients requiring major amputation, all minor wounds and amputations healed. Wound problems at the bypass sites were minor, and all surgical wounds healed without reoperation for wound complications and/or graft infections. Thrombosed grafts were investigated with noninvasive Doppler examinations and arteriography when indicated by clinical circumstances. All thrombosed grafts "were irretrievable, and therefore secondary patency is not reported. DISCUSSION
Popliteal and tibial artery occlusive disease is a pattern of atherosclerotic disease often seen in the elderly diabetic patient population. 1,4 Operative decisions must be carefully weighed in this patient population, with consideration of the risks of progressive limb-threatening ischemia and primary amputation versus the risks of perioperative morbidity and death for limb salvage operations. In a recent multicenter study, the mortality rate of major amputations equaled that of peripheral bypass operations in similar patient populations.5 The 30-day and 2-year mortality rates for the present study were 7.0% and 13.8%, respectively, and are comparable to the cooperative study. 6 Also, Plecha et al.7 reported a 30-day operative mortality rate (6.7%) after lower extremity bypass grafting in a population of patients averaging 75 years of age. Comparing patients with and without popliteal trifurcation disease, Kallero et al.8 reported a significant increase in perioperative deaths and a twofold increase in late deaths as a result of myocardial infarctions in the population with trifurcation occlusion.4,8 This group of patients, therefore, warrants aggressive cardiac evaluation before distal revascularization to minimize operative deaths. With aggressive management, our 2-year and 4-year survival rates at 87% and 79% do not differ
greatly from recently generated life expectancy tables for this population of patients. 9 Presumed increases in operative risk and an underestimation of the benefits of bypass surgery in the elderly patient may be deterrents to the use of lower extremity revascularization in this population. Veith et al. 1° recently outlined their changing patterns of management in the severely ischemic patient. The authors described aggressive efforts at limb salvage, including vein grafts originating at the popliteal artery or beyond, with a combined 30-day mortality rate of 3.3%, with decreasing rates of primary and secondary amputation over the 16 years of the study? ° The recent literature concerning popliteal-todistal bypass is summarized in Table II. Veith et al) 1 first suggested the use of the distal superficial femoral artery or the popliteal artery as the inflow site for infrapopliteal bypass. The popliteal artery was used if there existed a less than 20% luminal narrowing in the superficial femoral artery. He reported an 82% 4-year cumulative patency rate in patients having popliteal-to-distal bypass, although 25% of his reported bypasses required secondary operations to maintain patency. In his analysis of failures, only one was due to progressive atherosclerosis proximal to the inflow site. Another report from the same institution outlines the superior patency rates of short vein bypasses when compared with longer grafts. 12 The data in this reference, however, were not in a format that allowed extraction for inclusion in Table II.
Schnler et al.ls achieved a 70% limb salvage rate at 31 months with no operative deaths. Four late deaths in this series were due to myocardial infarction. They attribute the high early patency rates to the routine use of graft assessment. This included completion angiography early in the study, and completion duplex ultrasonography in the latter half of the study. They found no significant correlation between patency and pedal arch continuity. Diabetes corre-
758
Journal of VASCULAR SURGERY
Marks et al.
Table II. Popliteal-to-distal bypass results Study Veith et al.10 1981
No. of bypasses
No. of patients
24
24
Percent with diabetes N.A.
Operative mortality, percent N.A.
i yr patency, percent 82
Extended patency, % (years offollow-up) 82
(4) Schuler et al. 13 1983 Cantelmo et al. is 1986
23 32
23 30
74
0
N.A.
84
(2.5) 77
0
79
79
(3) Rhodes et al) 6 1987
26
26
96
12
95
95
(2.5) Rosenbloom et al. 14 1988
49
46
76
0
83
41
(5) Marks et al. 1991 current study
32
29
68
7
97
64
(4)
lated with a statisfcaUy higher risk of amputation. Five of six below-knee amputations were done for pedal sepsis in the face of patent bypasses. In an update of that series, Rosenbloom 14 described 46 patients who underwent bypasses with use of the distal superficial femoral or popliteal artery as the source of inflow. That study showed a 1- and 5-year bypass graft patency of 83% and 41%, respectively, and a limb salvage rate of 69% at 6 years. Cantelmo et al. 15 performed 32 reversed saphenous vein bypasses using the popliteal artery for inflow in 30 patients and noted limb salvage at 1 and 3 years of 89% and 82%, respectively. Four grafts failed early, and three required below-knee amputations because of persistent pedal sepsis in the face of patent bypasses. Rhodes et al)6 were the first authors to describe the use of in situ techniques for popliteal-to-distal bypasses, and performed 26 such operations on 26 patients. A limb salvage rate of 95% at 30 months was obtained. Rhodes et al.16 emphasized transcutaneous oxygen tension mapping for delineation of persistent areas of ischemia in these patients, and showed that slow healing wounds were associated with low transcutaneous oxygen tensions in the region. The use of the short vein bypass has several distinct attributes. The short length of conduit needed allows minimal dissection in the region of the thigh, thereby minimizing wound complications. 12 In the current study, all vein segments were harvested in the ipsilateral leg, sparing other limbs the risk of vein harvest. This can potentially influence rehabilitation in a positive fashion in the early postoperative setting. The need for short conduits is also important in patients that have had coronary revascularization, with prior saphenous vein harvest for the bypass.
These benefits occur in the setting of patency rate. that are comparable to more standard femorodistal bypass procedures, where the origin of the bypass is the common femoral artery in the groin. These findings also support the growing evidence that shorter, more distal bypasses perform as well as the longer and more standard femorodistal bypass. 12,17 It is our preference therefore, to use the most distal popliteal artery either above or below the knee, for distal reconstruction for limb salvage if the superficial femoral artery is less than 20% stenotic or uninvolved in the atherosclerotic process. We performed 32 arterial bypass procedures in 29 patients with extensive popliteal and tibial artery occlusive disease. The popliteal artery was used for proximal inflow with long-term graft patency and limb salvage rates that are comparable with those achieved with femorodistal bypasses. By using the popliteal artery for inflow, the length of saphenous vein conduit needed for bypass can be reduced without sacrificing overall graft patency. This is especially important in this patient population, where existing saphenous vein may be of inadequate length or quality for femorodistal bypass. This helps minimize the amount of dissection in the thigh, and therefore minimizes the risk of wound healing complications. This study supports the use of the popliteal artery for proximal inflow in distal artery bypass procedures. REFERENCES 1. Haimovici H. Atherosclerosis: biological and surgical considerations. Vascular surgery: principles and techniques. East Norwalk: Appleton & Lange, 1984:140-1. 2. Kubin JR, Pitluk HC. Tibial artery revascularization in the face of pedal sepsis: do operative results justify an aggressive surgical approach? Am J Surg 1988;155:144-7. 3. Rhodes GR, King TA. Delayed skin oxygenization following
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4.
5. 6.
7.
8.
9. 10.
distal tibial revascularization (DTR): implications for wound healing and late amputations. Am Surg 1986;52:519-25. Kallero KS, Bergqvest D, Cederholm C, Jonsson K, Ollson PO, Takolander R. Late mortality and morbidity after arterial reconstruction: the influence of arteriosclerosis in popliteal trifurcation. J VAsc SURG 1985;2:541-6. Gregg R. Bypass or amputation. Concomitant review of bypass arterial gaffing and major amputations. Am J Surg 1985;149:397-402. Veterans' Administration Cooperative Study Group 141: comparative evaluation of prosthetic reversed and in sire vein bypass grafts in distal popliteal and tibial-peroneal revascularization. Arch Surg 1988;123:434-8. Plecha FR, Bertin VI, Plecha EJ, et al. The early results of vascular surgery in patients 75 years and older: an analysis of 3529 cases. J VASCSURG 1985;2:769-74. Kallero KS, Berggnist D, Cererholm C, Jonsson K, Olsson PO, Takolander R. Arteriosclerosis in popliteal artery trifurcation as a predictor for myocardial infarction after arterial reconstructive operation. Surg Gynecol Obstet 1984;159: 133-8. Life Table, Connecticut Mutual Life Insurance Company, 1991: Hartford, Conn. Veith FJ, Gupta SK, Wengerter KR, et al. Changing arteriosclerotic disease patterns and management strategies in lower-limb-threatening ischemia. Ann Surg 1990;212:40214.
Popliteal-to-distal bypassfor limb-threatening ischemia 759 11. Veith FJ, Gupta SK, Samson RH, Flores SW, Janko G, Scher LA. Superficialfemoral and popfiteal arteries as inflow sites for distal bypasses. Surgery 1981;90:980-90. 12. Ascer E, Veith H, Gupta SK, White SA, Bakal CW, Wengetter K. Short vein grafts: a superior option for arterial reconstructions to poor or compromised outflow tracts? J VAsc SURG 1988;7:270-8. 13. Schuler JJ, Flanagan DP, Williams LR, Ryan TI, Castronuovo JJ. Early experience wiiahpopfiteal to infrapopliteal bypass for limb salvage. Arch Surg 1983;118:472-6. 14. Rosenbloom MS. Long-term results of infragenicular bypasses with autogenous vein originating from the distal femoral and popliteal arteries. J VASC SURG 1988;7:691-6. 15. Cantelmo NL, Snow R, Menzoian JO, LoGerfo FW. Successful vein bypass in patients with an ischemic limb and a palpable popfiteal pulse. Arch Surg 1986;121:217-9. 16. Rhodes GR, Rollins D, Sidawy A, Skudder P, Buchbinder D. Popfiteal-to-tibial in sire saphenous vein bypass for limb salvage in diabetic patients. Am J Surg 1987;154:245-8. 17. Wengerter KR, Yang PM, Veith FJ. A twelve-year experience with the popliteal-to-distal bypass: the significance and management of proximal disease. [1VAsc SURG1992; 15:14351. Submitted Oct. 15, 1991; accepted lan. 27, 1992.
DISCUSSION Dr. James Schuler (Chicago, Ill.). When this procedure was first described in the first large series o f these patients by Frank Veith and his group in 1981, and then a similar size series was described by our group in 1983, even though the results were good at that time, both Veith and our group were criticized somewhat in that we did not have long enough follow-up on these patients, even though the 2- and 3- and sometimes 4-year graft patency rates were in the 70% to 80% range, and the limb salvage rates were in the 70% to 80% range. The admonition was that if we waited a few more years we would find that most of the grafts had failed, and most of them had failed on the basis o f progression of atherosclerotic disease in the popliteal or superficial femoral artery. In 1987 before this Society we presented our 8-year follow-up with a cumulative limb salvage rate at 6 years o f 69% in our patients. At the SVS meeting this past June, Veith's group presented 153 popliteal-to-distal bypasses with a maximum follow-up o f 12 years and a cumulative limb salvage rate at 5 years o f 73%. I think these two papers with longer follow-up have documented that not only is this bypass very efficacious, it is in fact quite durable. I think the authors o f the present paper have borne out that fact with their report here, this makes a total of six papers presented over the past 10 years all of which present graft patency rates in the 70% to 80% and sometimes 90% range at 2 to 5 years, and limb salvage
rates that are in the 70% to 80% range at 5 years. I think we can put to rest the prior misconception that this is a bypass that does not have a place in the standard armamentarinm of most vascular surgeons. I have three questions. In your series, you did not have any patients who underwent popliteal-to-distal bypass with prosthetic material. Is that because you have denied to these patients without autogenous vein the opportunity for bypass with prosthetic material, or was it simply the fact that all of your patients happened to have vein? Second, I also noticed that you did not use any arm veins. Is it again for the same reason? They all had leg vein or do you intentially not do these bypasses with arm veins? The third, and I think at least in our experience the most serious question that remains to be answered for these patients, revolves around the question of continued foot sepsis requiring major amputation in those patients who have a patent bypass graft. In our experience approximately three quarters o f all the patients who went on to have a major amputation, had their amputation in the presence of a patent hemodynamically normal bypass. Have you had any experience with either transcutaneous oxygen tension measurements or any other device where you can ideally predict before operation what patients are going to end up in this condition, wherethe bypass is working but you lose the leg anyhow?
760 M a r k s et al.
Dr. Jeffrey Marks. In terms of our patency rates being slightly better than all the previous studies, I think I would have to relate that to the fact that we did use autologous vein for all of our grafts instead of prosthetics. I think that rather than saying that we did it preferentially, it was just due to the fact that we did have adequate saphenous vein in all our patients. Obviously, because it is a shorter bypass graft, the amount of conduit needed is shorter, and we had adequate saphenous vein for either reversed or in situ bypass in all of our patients. With respect to preference for in situ versus reversed, we used in situ bypass when it was technically possible. A long-term prospective study will elucidate patency rates. In terms of not using arm veins, again, I think that goes back to the fact that we were able to find adequate saphenous vein of a short segment. Previous studies have also shown that the short saphenous vein is adequate as well for this shorter segment bypass. In terms of the continuous foot sepsis, Dr. Rhodes in 1987 discussed the use of transcutaneous oxygenation pressures. We did not use transcutaneous oxygen pressures, as this 4-year period basically encompassed the evolution of our vascular labs. Dr. Rhodes, however, did find that transcutaneous oxygenation was helpful in determining which patients would maintain patent grafts. Dr. Peter Gloviczki (Rochester, Minn.). We have had a very similar positive experience at the Mayo Clinic. In almost 60 patients on whom we performed bypass to the foot, approximately half originated from the popliteal artery. My first question is about the cause of graft failure in
Journal of VASCULAR SURGERY
these patients-is it proximal occlusion of the superficial femoral artery or progression of the disease proximal to your graft that we have seen in some of these patients or is it indeed poor runoff or problems with the graft? The second question concerns the postvasculatization edema in these patients. The incidence of that in our series is almost 100%. The swelling in these patients is sometimes quite disabling. Do you have any suggestions for us? Dr. Marks. With respect to progression of disease in our three graft occlusions, the one at 3 weeks was most likely a technical complication. The other two, however, were related to distal disease. Of the 160 patients that we reviewed in the literature in the previous five papers, only Dr. Veith reported one related to proximal superficial femoral artery occlusive disease as a source for graft occlusion. The remaining patients, therefore, were probably related to progression o f distal disease. Edema is always a problem in terms of healing of wounds. If you are going to a posterior tibial artery, it is usually just one incision. To a dorsal pedal artery, most authors would recommend parallel incisions in the foot. Edema is best managed by postoperative elevation and wrapping with elastic bandages. Dr. John Corson (Iowa City, Iowa). It was not clear to me whether any patients in this series had any inflow fix up procedures of the superficial femoral artery or popliteal such as bypass, atherectomy, angioplasty, or endarterectomy before or at the same time as your distal bypass. If they did, what happened to those patients? Dr. Marks. All patients with previous femoropopliteal bypasses were excluded from our analysis.