Comparison of long-term results of 364 femoropopliteal or femorotibial bypasses for revascularization of severely ischemic lower extremities

Genesis of Crural Revascularization

BACKGROUND

The purpose of this study is to recognize those investigators responsible for initiating progress in limb salvage where runoff beyond the arterial blockage was limited to the crural vasculature and to also describe how crural bypass has evolved into the contemporary setting where endovascular options have become increasingly prominent.

METHODS

An extensive literature review of articles published from 1960 to 1979 was the basis for selecting and recognizing surgeons who pioneered infrageniculate revascularization. Documentation of patency and amputation rates were tabulated for these early series of distal limb bypass. Cases performed in the decade of interest, but not published until the 1980s, are also recognized and recorded separately.

RESULTS

Subsequent to the first tibial bypass performed in 1961 by McCaughan, a total of 746 crural bypasses were defined in the decades of interest, where possible, with overall 6-, 12-, and 36-month patencies of 76%, 59%, and 48%, respectively. There was an overall amputation rate of 17%. Life table analysis and other statistical methods were also adopted during this time.

CONCLUSIONS

Performance of crural bypass from 1960 to 1979 was analyzed in groups according to the distal anastomosis site. These results confirm the satisfactory early progress leading to further refinement in subsequent decades. It is essential that the current generation of vascular surgeons recognize the value of these early open procedures as a stable force for securing limb salvage in conjunction with evolving endovascular techniques.

Changing arteriosclerotic disease patterns and management strategies in lower-limb-threatening ischemia

From January 1, 1974 to December 31, 1989, we treated 2829 patients with critical lower-extremity ischemia. In the last 5 years, 13% of patients had therapeutically significant stenoses or occlusions above and below the groin, while 35% had them at two or three levels below the inguinal ligament. Unobstructed arterial flow to the distal half of the thigh was present in 26% of patients, and 16% had unobstructed flow to the upper third of the leg with occlusions of all three leg arteries distal to this point and reconstitution of some patent named artery in the lower leg or foot. In the last 2 years, 99% of all patients with a threatened limb and without severe organic mental syndrome or midfoot gangrene were amenable to revascularization by percutaneous transluminal angioplasty (PTA), arterial bypass, or a combination of the two, although some distal arteries used for bypass insertion were heavily diseased or isolated segments without an intact plantar arch. Limb salvage was achieved and maintained in more than 90% of recent patient cohorts, with a mean procedural mortality rate of 3.3%. Recent strategies that contributed to these results include (1) distal origin short vein grafts from the below-knee popliteal or tibial arteries to an ankle or foot artery (291 cases); (2) combined PTA and bypass (245 cases); (3) more distal PTA of popliteal and tibial artery stenoses (233 cases); (4) use of in situ or ectopic reversed autogenous vein for infrapopliteal bypasses, even when vein diameter was 3 to 4 mm; (5) composite-sequential femoropopliteal-distal (PTFE/vein) bypasses; (6) reintervention when a procedure thrombosed (637 cases) or was threatened by a hemodynamically significant inflow, outflow, or graft lesion (failing graft, 252 cases); (7) frequent follow-up to detect threatening lesions before graft thrombosis occurred and to permit correction of lesions by PTA (58%) or simple reoperation; and (8) unusual approaches to all infrainguinal arteries to facilitate secondary operations, despite scarring and infection. Primary major amputation rates decreased from 41% to 5% and total amputation rates decreased from 49% to 14%. Aggressive policies to save threatened limbs thus are supported.

Early experiences with laser-assisted thermal angioplasty for peripheral vascular disease

Laser-assisted angioplasty has been used on 47 occasions in 45 patients for the management of atherosclerosis of the superficial femoral and proximal popliteal arteries. Twenty-four procedures were performed to treat disabling intermittent claudication and 23 procedures were performed for a "threatened limb" (rest pain, ischaemic ulceration or digital gangrene). Technical success was achieved in 40 (85%) cases; the mean length of occluded segment was 7.7 cm. The presence of heavily calcified occlusions contributed significantly (P less than 0.001) to technical failure. In 28 (70%) of the successfully treated cases, the recanalized arteries were patent at one month and in 21 (53%) cases they have remained patent during the follow-up period. In five of nine cases with a nine-month follow-up, the arteries still were patent. The mean length of the occluded segments that were treated initially was 7.1 cm in those that remained patent compared with 8.2 cm in those that reoccluded. Thirty-six (77%) patients were discharged from hospital on the day after the procedure. Laser-assisted angioplasty is a promising new technique that is applied best to short-segment, non-calcified occlusions and should reduce the requirement for femoropopliteal arterial bypass surgery.

In situ tibial reconstruction. State-of-the-art or passing fancy

To further evaluate the efficacy of in situ saphenous vein bypass, the authors have reviewed their experience with in situ bypass. Between October 1981 and December 1985, 120 in situ saphenous vein bypass were performed; 81 were to infrapopliteal vessels. All procedures were performed for limb salvage. The mean patient age was 74 years, and 74% were men, 57% had diabetes mellitus, 92% were smokers, and 72% had hypertension and/or coronary artery disease. All patients were evaluated by preoperative noninvasive testing and biplanar angiography. All procedures were performed by the valve incision technique. The vein utilization rate was 91%. Grafts were routinely placed into isolated tibial segments and foot vessels without evidence of a patent pedal arch. Follow-up information was obtained at 3-month intervals. Patency and limb salvage data were calculated by life-table analysis. The cumulative patency rates were 98% at 1 month, 88% at 12 months, and 82% at 50 months. These data demonstrate that the in situ bypass maintains an excellent patency rate and provides durable limb salvage.

Pedal and distal lower leg bypasses with a distal arteriovenous fistula

In forty patients 41 feet were revascularised by means of distal tibial (the distal 10 cm of the lower leg) (17) or pedal bypasses (24). Angiographically the preoperative state was best defined as a lower leg block (LLB); All three arteries showing occlusions at several levels, leaving only isolated functioning arterial segments in the distal leg or foot with relatively good femoral and popliteal arteries. As might be expected this condition was mainly found in diabetics (75%). Only feet with severe rest pain (4) or rest pain with gangrene (37) were operated upon. To improve the distal outflow a side-to-side arteriovenous fistula (AVF) was added to the distal anastomosis. With a mean follow-up of 21 months (1-40 months) the limb salvage rate was 79% and the patency rate 67%. Special problems were experienced with cellulitis of the foot, causing the loss of three feet despite an open bypass and sufficient revascularisation. Furthermore, occlusion of the bypass after healing of the lesion did not necessarily mean a recurrence of gangrene. As this series shows, even in angiographically apparently hopeless cases, a bypass to the foot can prevent an otherwise unavoidable amputation.

In situ saphenous vein bypass for occlusive disease in the lower extremity

In situ saphenous vein bypass, using the new valve incision techniques, has shown great promise in the early clinical trials to date. This procedure allows disruption of the venous valves without removal of the vein from its bed, thus allowing preservation of the vasa vasorum and maintenance of the endothelial integrity of the veins. This has allowed an overall improvement in the patency rates of the lower extremity bypasses, particularly in the bypasses to the infrapopliteal position. Also, and perhaps most important, it has permitted the use of smaller veins, with a minimum diameter of 2 mm. This greatly increases the number of patients who can benefit from such a vein bypass since reversed vein bypasses previously have required veins to have a minimum diameter of 3.5 to 4 mm. Long-term follow-up of in situ bypasses is not yet available. However, if the encouraging preliminary results of these bypasses are substantiated on long-term follow-up, in situ saphenous vein bypass may well become recognized as the procedure of choice for lower extremity bypass.

Ankle bypass: should we go the distance?

This report reviewed the results of 47 distal arterial reconstructions to or below the level of the malleolus. The operations were performed by the techniques of popliteal-to-distal bypass (20 procedures) and in situ bypass (27 procedures). Seventy-five percent of patients had gangrene of ischemic ulceration, and all procedures were performed for limb salvage. Seventy-three percent of all patients were diabetic. The patency rates for popliteal-to-distal bypass with reversed saphenous vein were 92 percent at 24 months and 57 percent at 60 months, with a limb salvage rate of 70 percent at 60 months; the patency rates for popliteal-to-distal bypass with PTFE were 53 percent at 12 months and 0 at 36 months, with a limb salvage rate of 53 percent at 36 months; and the patency rate for in situ saphenous vein bypass was 96 percent at 24 months, with a limb salvage rate of 80 percent at 24 months. Early results are promising for ankle bypass using the techniques of popliteal-to-distal and in situ bypass.

In situ femoropopliteal and distal vein bypass for limb salvage--experience of 50 cases

The aim of this paper is to assess the in situ technique of saphenous vein femoropopliteal (and femorotibial) bypass for limb salvage, and to compare it with the reversed vein method of bypass. In our 3-year study, we have operated on 50 cases resulting in a graft patency and limb salvage rate of 78 per cent at 18 months and 72 per cent overall. There was a 2 per cent perioperative and 10 per cent overall mortality. Graft thrombosis was associated with a variety of factors, mostly notably a small vein (les than 4 mm), a low calf vessel anastomosis, wound sepsis and progressive proximal (inflow) disease. However, the strongest correlation was that between graft thrombosis and the extent of distal disease, as 11 of 12 cases with thrombosed grafts had grade 2 or 3 run-off. In our experience the in situ technique offers haemodynamic and technical advantages over the reversed vein method of performing straightforward femoropopliteal bypass. Moreover, the in situ technique has wider application in that it allows a smaller vein (greater than 2.5 mm) to be used and also makes anastomosis to a small calf vessel easier. In this series, 16 per cent of cases would have been considered unsuitable for the reversed vein method if 4 mm was accepted as the lower limit of size for a reversed vein graft.

Femorotibial bypass for limb salvage using human umbilical vein

A series of 112 consecutive femorotibial bypasses was reviewed in which glutaraldehyde-stabilized human umbilical vein was used for the bypass. The duration of follow-up was between 6 months and 2 1/2 years. Cumulative patency at 2 years for the entire group was 9 per cent. The state of the pedal arteries, site of the distal anastomosis and age of the patient influenced the results. The difference in the patency rates at 1 year between patients with 3 patent pedal arteries and those with only 1 is significant (P less than 0.001) as is that between those with 3 and those with 2 (P = 0.024). Of 49 patients with pre-gangrene, in whom the bypass worked for a period in excess of 2 months, only 7 eventually required amputation in contrast to 32 of a group of 39 similar patients in whom the bypass failed early.

Doppler evaluation of the pedal arch

The association of a patent pedal arch with early distal bypass patency has recently been emphasized. Unfortunately, in many patients information about the pedal arch can only be obtained with intraoperative angiography. An 8 mHz Doppler probe was used to noninvasively evaluate the pedal arch in 62 patients with various degrees of vascular disease. The probe was placed in the first metatarsal space, and the presence of a Doppler signal was taken as evidence of a patent pedal arch. Digital pressure was then applied over each tibial artery at the malleolar level to determine each vessel's communication with the pedal arch. Fifty-two patients were found to have patent pedal arches, while 10 did not. Preoperative hyperemic angiography or intraoperative arteriography was used to study the pedal arch in 22 of these patients. The arteriographic and Doppler findings were the same in 21 of 22 cases (96 percent accuracy). In the one case in which the results conflicted, the Doppler examination also gave information about which calf vessel contributed the most flow to the pedal arch. Preoperative Doppler evaluation of the foot combined with arteriography allows better selection of patients for distal bypass grafts.

Progress in limb salvage by reconstructive arterial surgery combined with new or improved adjunctive procedures

In the past nine years, 1196 patients whose lower extremity was threatened because of infrainguinal arteriosclerosis have been treated at Montefiore Hospital. In the last six years, limb salvage was attempted in 679 or 90% of 755 patients. Femoropopliteal (318), small vessel (204) and axillopopliteal (29) bypasses were used along with transluminal angioplasty (128) and aggressive local operations to obtain a healed foot. Immediate (one month) limb salvage was achieved in 583 or 86% of the 679 patients in whom revascularization was possible. The 30-day mortality rate was 3%. The cumulative life table (LT) survival rate of all the patients undergoing reconstructive arterial operations was 48% at five years. The cumulative LT limb salvage rate after all reconstructive arterial operations was 66% at five years. The cumulative LT patency rate of femoropopliteal bypasses was not influenced by angiographic outflow characteristics of the popliteal artery but was increased 15% by appropriate reoperations to 67% at five years. Cumulative LT patency and limb salvage rates of small vessel and axillopopliteal bypasses were more than 50% at two years. Of patients undergoing arterial reconstruction, 88% of those who died within five years did so without losing their limbs. Of all the patients in whom limb salvage was attempted, 68% lived more than one year with a viable, useable extremity, and 54% lived over two years with an intact limb. We believe this aggressive approach to limb salvage is justified, and can be undertaken with a low cost in mortality, knee loss and morbidity.

Further experience with the saphenous vein used in situ for arterial bypass

Ongoing experience with use of the saphenous vein in situ as in infrainguinal arterial bypass is presented. One hundred eighty-three bypasses were performed for limb-threatening ischemia, 92 of which were to the popliteal artery, either isolated or in continuity with one or more tibial vessels, and 91 bypasses were carried to single tibial vessels below the termination of the popliteal artery. The results were analyzed by the life table method and show an overall patency rate of 89.8 percent at 3 to 4 years. Separate life table analysis of the tibial bypass group showed a patency rate of 83 percent at 3 to 4 years. Special emphasis is placed on the ability to use veins less than 4 mm in diameter, which comprise 40 percent of those used in these procedures. The superior results provided by the in situ method are explained in part by experimental observations which show that endothelial stability is completely preserved by this method but is severely disturbed during the process of vein removal and reversal.

Indications, technique, and results in 336 tibioperoneal reconstructions

At the University of Erlangen-Nürnberg, a retrospective study was done of 336 femorotibial bypasses for limb salvage, with a follow-up of 7 years. The indication for arterial reconstruction was severe ischemia in 80.7%. Early good results were obtained in 89.6%, and the mortality rate was 1.5%. The best bypass grafts were the autologous vein and the composite graft, with patency rates of 92%. Five and 7 years after surgery, the cumulative patency rates were 50.7% and 49.1% respectively.

[Late results of 336 femorotibial bypasses (author's transl)]

A total of 336 femorotibial reconstructions were performed at the surgical clinic of the University of Erlangen and the Fürth City Hospital between 1966 and 1978. Mortality was 1.5%, and 89.6% of the patients were discharged with functioning reconstructions. The Life Table Method showed a patency of 58.7% after 5 years and 56.7% after 7 years follow-up for the saphenous vein graft.

Infrapopliteal arterial reconstruction in the severely ischemic lower extremity. A comparison of long-term results of peroneal and tibial bypasses

The feasibility of limb salvage with bypasses to the infrapopliteal arterial tree has been established. In this review, our experience with bypasses to the peroneal artery is compared with that to the tibial arteries. Autogenous saphenous veins were employed in 164 limb salvage arterial revascularizations because of gangrene, ischemic ulceration, or rest pain. These were retrospectively analyzed by the life-table method. Femorotibial (137) or femoroperoneal (27) bypasses were performed on the basis of adequate preoperative arteriograms demonstrating the distal arterial tree, but with no popliteal runoff. Overall operative mortality was 6.1%. Initial limb salvage was 71.2 +/- 3.9% following femorotibial bypass and 51.9 +/- 9.6% after femoroperoneal bypass. Five and seven year cumulative limb salvage rates for femorotibial bypass were 48.5 +/5.2% and 43.4 +/- 6.7%; those for femoroperoneal were equivalent at 38.2 +/- 9.9%. Since long-term limb salvage can be realized in a large number of patients by revascularization of the distal arterial tree, primary amputation is seldom indicated. Operative approach to the ischemic limb must be based on a thorough preoperative arteriogram which demonstrates contrast within vessels down to the distal foot. This is almost always seen and arterial reconstruction is usually feasible. Therefore, limb salvage should be attempted in lieu of primary amputation whether tibial or peroneal arteries are visualized on preoperative arteriogram.

Long-term results of femoroinfrapopliteal bypass in diabetic patients with severe ischemia of the lower extremity

In patients with severe lower extremity ischemia (ischemic necrosis or pain at rest associated with physical findings of peripheral arterial insufficiency), diabetes mellitus should not deter thorough arteriography and consideration of arterial reconstruction. Infrapopliteal bypass can produce prolonged limb salvage in diabetic patients in lieu of primary amputation.

Comparison between saphenous vein and Dacron Velour grafts for femoropopliteal bypass

One hundred and thirty-eight femoropopliteal grafts were performed for arteriosclerotic occlusive disease of the femoral artery in a five-year period. One group of patients who had 81 saphenous vein grafts was compared with a similar group who had 57 Dacron Velour grafts. At three years 90% of the vein grafts were patent, compared to 45% of the Dacron Velour grafts. Twenty-seven per cent of all patients presented with threatenened limb loss. Amputation was averted in all but 5%. Intraoperative flow measurement did not prove to be a reliable indicator of long-term patency.

The role of the peroneal artery for limb salvage

Peroneal artery revascularization was performed in 61 cases for limb salvage and compared to a comparable group of 89 tibial artery reconstructions. Preoperative arteriography is essential to define runoff quality and pedal arch integrity. Intraoperative arteriography and flow determinations minimize failures due to technical error and provide some indication of the prognosis for graft patency. Failure to augment flow by at least 50% suggests pedal arch deficiency and is predictive for early graft closure. Cumulative patency for peroneal bypass was 55 +/- 8% at 1 year and 38 +/- 10% at 30 months compared to 63 +/- 6 and 59 +/- 7% for tibial reconstructions at the same time intervals. Most graft failures occurred within the first six months. Nineteen peroneals have been followed for more than one year with only three failures occurring. Improved criteria for case selection resulted in an 80% decrease in the number of failed grafts for the second half of this series. A similar reduction was noted for secondary operations. Results obtained with good quality saphenous veins (37 +/- 13% at 30 months) and glutaraldehyde tanned umbilical veins (53 +/- 11%) depend more on technical, pathologic and biologic factors than on the particular graft material employed. The mortality rate at 30 days was 3.3% and compared favorably with other limb salvage procedures and with primary amputations. Cumulative patient survival with functional limbs was 79 +/- 9% at 30 months and was distinctly superior to reported data on survival of amputees. A cumulative limb salvage rate of 79 +/- 6% at 30 months for the peroneal group makes such reconstructions definitely favorable to uniform limb ablation.

Femoral tibial bypass grafts. The alternative to amputation

Severe ischemia and distal gangrene of lower extremities due to obstruction of the popliteal artery and its branches need not require major amputation. Autogenous vein grafts to the distal anterior tibial, posterior tibial, peroneal and dorsalis pedis arteries can avoid tissue loss in many instances.

Correlation of infrared spectroscopy with platelet morphology in blood compatibility studies of polydimethylsiloxane membranes

Oxygenator membranes, polydimethylsiloxane elastomer, exposed to flowing heparinized canine blood in a perfusion system have been studied with respect to the platelet activation and the morphology of the membranes. Utilizing Fourier transform infrared spectroscopy couple with attenuated total reflection technique (ATR) and laser Raman spectroscopy, no obvious differences in morphology and composition of the membranes have been detected while electron microscopic study shows difference in platelet aggregation.

Limb salvage procedures for lower extremity ischemia

Limb salvage procedures were performed in ninety patients during the period from 1965 to 1975. Sixteen different procedures were performed with an associated complication rate of 8.9 per cent and a mortality rate of 8.9 per cent. The patency rates were 79.7 per cent at thirty days and 72.9 per cent at last follow-up.