Evidenz - Aortobifemoral bypass for peripheral arterial disease Fontaine stage IIb–III

Limb ischemia can be divided into an acute and a chronic form. The diagnosis of acute ischemia must be carried out immediately, immediate revascularization is necessary in most cases. Chronic critical limb ischemia is the most severe form of peripheral arterial occlusive disease (PAOD). It is characterized by rest pain or necrosis or gangrene.

The acute limb ischemia (“acute limb ischemia”, ALI) represents an acutely occurring hypoperfusion of the limb, which is not older than 2 weeks. The causes are usually embolizations or local thromboses on the basis of a pre-existing pathology such as PAOD.

The chronic limb ischemia (“chronic limb ischemia”, CLI) refers to rest pain or ischemic skin lesions such as ulcers or gangrene (Fontaine stage III and IV or Rutherford categories 4–6). It has a high association with cerebrovascular and cardiovascular events. Chronicity is spoken of when symptoms persist for more than 2 weeks.

TASC II Criteria

The consensus document TASC II (Transatlantic Inter-Society Consensus for the Management of Peripheral Arterial Disease) deals with aspects of revascularization in PAOD [1]. According to the TASC criteria, therapeutic treatment options can be derived depending on the local occlusion/stenosis length. The length of the stenosis and its localization regions decide on the therapy: endovascular or open vascular surgery.

Guidelines

In the S3 guideline of the German Society for Angiology/Society for Vascular Medicine on the diagnosis, therapy and follow-up of PAD, the following is noted regarding CLI, among other things [2]:

• The primary goal in CLI is rapid and sufficient revascularization independent of the treatment techniques used.
• The elimination of inflow obstructions has priority over the treatment of downstream lesions in multi-level lesions.
• In CLI, inflow and subsequent outflow lesions should be treated by interventional therapy as far as possible.
• A combination of open surgical procedures and intraoperative endovascular treatment is useful in the simultaneous presence of high-grade stenoses or occlusions of the A. femoralis communis, the A. femoralis profunda and lesions in the aortoiliac inflow tract and /or the femoropopliteal outflow tract (hybrid procedure).
• Endovascular treatment should be preferred if the angiomorphological findings suggest that a result comparable to open surgical therapy can be achieved with regard to technical success.
• Endovascular interventions should be preferred if there is an increased surgical risk for the comparable surgical procedure due to comorbidity.
• Endovascular procedures should be performed primarily in the treatment of femoropopliteal lesions. In the TASC-D situation without increased surgical risk, not significantly restricted life expectancy and availability of an autologous vein, bypass procedures should be preferred.
• In lesions of the A. poplitea, balloon angioplasty should be performed primarily.
• In patients with critical ischemia, infrapopliteal vascular lesions should be treated primarily endovascularly. Vascular surgical procedures may be considered provided that the surgical risk is acceptable and an autologous vein is available.

The recommendations of the European Society of Cardiology (ESC) in collaboration with the European Society for Vascular Surgery (ESVS) for patients with CI and CLI include, among others [3]:

1. Revascularization of aortoiliac occlusive lesions

• For short lesions < 5 cm, an endovascular first strategy is recommended.
• For aortoiliac occlusions, the aorto-(bi)-femoral bypass should be considered, provided the patients are surgically fit.
• In patients with severe comorbidity, the endovascular strategy should be considered for long-segment and/or bilateral occlusions.
• For aortoiliac lesions, with appropriate expertise, an endovascular intervention can be performed as the first measure, provided that a subsequent operative option is not impaired.
• For an aortic occlusion that extends to the renal arteries, open intervention should be considered, provided the patient is fit.
• A hybrid procedure – iliac stenting combined with femoral endarterectomy or bypass – is considered for iliofemoral occlusions.
• In the absence of alternatives to revascularization, an extra-anatomic bypass can be considered.
• Primary stent implantation should be considered rather than provisional stenting.

2. Revascularization of femoropopliteal occlusive lesions

• The endovascular first strategy is recommended for short occlusive lesions (< 25 cm).
• Primary stenting as well as drug-coated balloons can be considered for short-segment lesions (< 25 cm).
• Drug-coated balloons can be considered for the treatment of in-stent restenosis.
• Bypass surgery is indicated for long (≥ 25 cm) lesions of the superficial femoral artery, provided that the patients do not have a high risk for surgical intervention, an autologous vein is available and the life expectancy exceeds 2 years. For patients who are not fit enough, endovascular therapy can be considered.
• For the femoropopliteal bypass, the autologous saphenous vein is the bypass material of choice.

The guidelines of the  American College of Cardiology (ACC) and the  American Heart Association (AHA) provide, among other things, the following recommendations for CLI [4]:

• In CLI patients, revascularization should be performed whenever possible to minimize tissue loss.
• Before an amputation, an interdisciplinary team should assess the possibilities for revascularization.

1. Endovascular Revascularization

• Endovascular interventions are recommended to restore perfusion to the foot in patients with non-healing wounds or gangrene. For ischemic rest pain, a stepwise approach in endovascular procedures is recommended.
• An angiosome-directed endovascular treatment may be considered in patients with CLI and non-healing wounds or gangrene.

2. Surgical Revascularization

• If a bypass to the popliteal or infrapopliteal arteries is planned, it should be performed with an autologous vein.
• Surgical procedures are recommended to restore blood flow to the foot in patients with non-healing wounds or gangrene.
• If endovascular treatment fails and no suitable autologous vein is available, a prosthetic graft may be used as a substitute.
• For patients with ischemic rest pain, a stepwise approach in surgical interventions  is recommended. 

1. Percutaneous Intervention vs. Bypass Surgery in CLI

The largest meta-analysis to date on this topic includes over 45 studies with a total of nearly 21,000 patients and dates from 2018 [5]. The comparison of percutaneous vascular intervention (ER) with open bypass surgery (OR) showed:

• ER reduced the risk of 30-day mortality, major adverse cardiac and cerebrovascular events, and wound infections, but increased the risk of long-term mortality and failure of primary patency.
• ER performed worse compared to autologous bypasses in terms of secondary patency and led to more amputations in the long term.

The authors of the meta-analysis concluded that OR represents the better choice for patients in good general condition and with relatively long life expectancy, especially if autologous bypass material is available.

A Cochrane Review from 2017 examined the effectiveness of bypass surgery for chronic ischemia compared to other interventions (PTA, endarterectomy, thrombendarterectomy, thrombolysis, exercise training, and spinal cord stimulation)[6]:

• In the comparison of bypass vs. PTA, bypasses showed more frequent early, non-thrombotic complications, but were associated with higher technical success rates.
• One year after intervention, primary patency was higher in the bypass group than after PTA; four years later, no difference was found.
• Regarding mortality, clinical improvement, amputation rates, and reintervention rates, no differences could be identified between the bypass and PTA groups.

The authors concluded that there is only limited high-quality evidence regarding the effectiveness of bypass surgery compared to other treatment methods.

Gender-specific outcome differences in revascularization of the lower extremity

A systematic review with meta-analysis examined the influence of gender on the outcomes of revascularization of the lower extremity [7]. 40 studies were considered, 15 studies reported on outcomes after OR, 19 after ER, the remaining included mixed procedures:

• Women had, compared to men, a significantly higher 30-day mortality, amputation rate, early graft thrombosis, embolization rate, complications at the access site, as well as more general complications (cardiopulmonary, cerebral).
• No differences were found regarding reinterventions and renal complications.
• In the analysis of results regarding OR and ER, the increased risk for postoperative mortality and complications in women persisted. However, in the long-term outcomes, no significant differences between men and women were found.

As reasons for the less favorable outcomes in women, the authors cite, among others, the patient age (women were older than men at the time of intervention) and, compared to men, an undersupply of women with platelet aggregation inhibitors, statins, and cardiovascular medication.

Angiosome-Directed Revascularization in CLI

Angiosomes are skin and tissue areas supplied by so-called source arteries. In the human foot, there are 6 such arteries (A. plantaris medialis, - lateralis, calcaneal branch of the A. tibialis posterior, lateral and medial branch of the A. fibularis, A. dorsalis pedis). The wound healing rate is intended to be improved by direct revascularization, i.e., by creating a bypass to a segment directly supplying the angiosome.

There is a systematic review with meta-analysis on the topic of angiosome-directed revascularization in CLI from 2017, which includes nearly 4000 patients [8]. Compared to indirect revascularization (IR), direct revascularization (DR) significantly improved wound healing, major amputation rate, and amputation-free survival. In a sensitivity analysis, however, the significance for the major amputation rate in bypass surgery was lost, and there were also no differences between IR and DR regarding overall survival.

The authors concluded that the angiosome theory is supported by their analysis at least for endovascular treatment. The results between ER and IR are similar as soon as collateral vessels are present, so that patients without collaterals benefit most from DR, which is why the angiosome concept appears less useful for bypass surgery.

Polytetrafluoroethylene (PTFE) Vascular Prostheses With Heparin Bonded Luminal Surfaces vs Crude ePTFE (REPLACE)

Allogeneic Mesenchymal Stem Cells for the Critical Limb Ischemia Therapy

Peripheral Registry of Endovascular Clinical Outcomes "The PRIME Registry" (PRIME)

Best Endovascular vs. Best Surgical Therapy in Patients With Critical Limb Ischemia (BEST-CLI)

Norwegian Laparoscopic Aortic Surgery Trial (NLAST)

Guidelines 

German Society for Angiology – Society for Vascular Medicine (2015) S3 Guideline for the Diagnosis, Therapy and Follow-up Care of Peripheral Arterial Occlusive Disease. AWMF Register No. 065/003 ESC guidelines on the diagnosis and treatment of peripheral arterial diseases, in collaboration with the European Society for Vascular Surgery (ESVS): Document covering atherosclerotic disease of extracranial carotid and vertebral, mesenteric, renal, upper and lower extremity arteries. Endorsed by: the European Stroke Organization (ESO) the task force for the diagnosis and treatment of peripheral arterial diseases of the European Society of Cardiology (ESC) and of the European Society for Vascular Surgery (ESVS). Eur Heart J 2018 39:763–816 AHA/ACC guideline on the management of patients with lower extremity peripheral artery disease: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol 2016 69:e71–e126

Literature on this topic

1. Norgren L, Hiatt WR, Dormandy JA, Nehler MR, Harris KA, Fowkes FG; TASC II Working Group. Inter-Society Consensus for the Management of Peripheral Arterial  Disease (TASC II). J Vasc Surg. 2007 Jan;45 Suppl S:S5-67.

2. Lawall H, Huppert P, Rümenapf G, German Society for Angiology – Society for Vascular Medicine (2015) S3 Guideline for the Diagnosis, Therapy and Follow-up Care of Peripheral Arterial Occlusive Disease. AWMF Register No. 065/003

3. Aboyans V, Ricco JB, Bartelink MEL et al (2018) 2017 ESC guidelines on the diagnosis and treatment of peripheral arterial diseases, in collaboration with the European Society for Vascular Surgery (ESVS): Document covering atherosclerotic disease of extracranial carotid and vertebral, mesenteric, renal, upper and lower extremity arteries. Endorsed by: the European Stroke Organization (ESO) the task force for the diagnosis and treatment of peripheral arterial diseases of the European Society of Cardiology (ESC) and of the European Society for Vascular Surgery (ESVS). Eur Heart J 39:763–816

4. Gerhard-Herman MD, Gornik HL, Barrett C et al (2017) 2016 AHA/ACC guideline on the management of patients with lower extremity peripheral artery disease: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol 69:e71–e126

5. Wang J, Shu C, Wu Z, Zhao J, Ma Y, Huang B, Yuan D, Yang Y, Bian H, He Y, Wang Z (2018) Percutaneous vascular interventions versus bypass surgeries in patients with critical limb ischemia: a comprehensive meta-analysis. Ann Surg 267:846–857

6. Antoniou GA, Georgiadis GS, Antoniou SA, Makar RR, Smout JD, Torella F (2017) Bypass surgery for chronic lower limb ischaemia. Cochrane Database Syst Rev 4:CD002000

7. Wang J, He Y, Shu C, Zhao J, Dubois L (2017) The effect of gender on outcomes after lower extremity revascularization. J Vasc Surg 65:889–906

8. Jongsma H, Bekken JA, Akkersdijk GP, Hoeks SE, Verhagen HJ, Fioole B (2017) Angiosome- directed revascularization in patients with critical limb ischemia. J Vasc Surg 65:1208–1219

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Hossain S, Leblanc D, Farber A, Power AH, DeRose G, Duncan A, Dubois L. Infrainguinal Bypass Following Failed Endovascular Intervention Compared With Primary Bypass: A Systematic Review and Meta-Analysis. Eur J Vasc Endovasc Surg. 2018 Nov 1.

Isaji T, Hashimoto T, Yamamoto K, Santana JM, Yatsula B, Hu H, Bai H, Jianming G, Kudze T, Nishibe T, Dardik A. Improving the Outcome of Vein Grafts: Should Vascular Surgeons Turn Veins into Arteries? Ann Vasc Dis. 2017 Mar 24;10(1):8-16.

Lichtenberg M, Schreve MA, Ferraresi R, van den Heuvel DAF, Ünlü Ç, Cabane V,  Kum S. Surgical and endovascular venous arterialization for treatment of critical limb ischaemia. Vasa. 2018 Jan;47(1):17-22.

Patel RAG, Sakhuja R, White CJ. The Medical and Endovascular Treatment of PAD: A Review of the Guidelines and Pivotal Clinical Trials. Curr Probl Cardiol. 2018 Nov 30.

Rudofker EW, Hogan SE, Armstrong EJ. Preventing Major Amputations in Patients  with Critical Limb Ischemia. Curr Cardiol Rep. 2018 Jul 10;20(9):74.

Thompson JR, Henke PK. Contemporary Management of Critical Limb Ischemia. Adv  Surg. 2018 Sep;52(1):257-274.

Uccioli L, Meloni M, Izzo V, Giurato L, Merolla S, Gandini R. Critical limb ischemia: current challenges and future prospects. Vasc Health Risk Manag. 2018 Apr 26;14:63-74.

Yong KW, Choi JR, Mohammadi M, Mitha AP, Sanati-Nezhad A, Sen A. Mesenchymal Stem Cell Therapy for Ischemic Tissues. Stem Cells Int. 2018 Oct 8;2018:8179075.