Aortoiliac Occlusive Disease: Surgical and Endovascular Management

Ian O. Cook, MD, Ramyar Gilani, MD, Joseph L. Mills, MD

Division of Vascular Surgery and Endovascular Therapy, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas

CORRESPONDING AUTHOR: Please address correspondence to: Dr. Joseph Mills, MD, One Baylor Plaza, MS 390, Houston, TX 77030 | E-Mail Address: Joseph.Mills@bcm.edu | Social Media Handles (Twitter): @jmills1955, @RamyarGilaniMD, @IanCookVS

Aortoiliac occlusive disease is a common pattern of peripheral artery disease that every vascular surgeon should be prepared to manage. Patients with disease in this anatomic segment may present clinically with proximal claudication (buttocks and thighs), reduced or absent femoral pulses, sexual dysfunction (in men), pain at rest, or tissue loss. Multilevel disease with involvement of infrainguinal vessels contributes to the more severe clinical presentation of chronic limb-threatening ischaemia. Indications for intervention include severe, lifestyle-limiting claudication that is refractory to medical management and supervised exercise therapy, rest pain, tissue loss, vasculogenic impotence, and distal embolization from an aortoiliac lesion. Lesions are categorised anatomically by the Trans-Atlantic Inter-Society Consensus document, which aids decision-making of surgical versus endovascular revascularisation based on lesion severity and extent of occlusive disease. Endovascular therapy is preferred for less severe patterns of disease, while open direct surgical reconstruction is preferred for more extensive or severe disease patterns depending on the patient risk profile. Aortobifemoral bypass is the operation of choice for in-line reconstruction, though aortoiliac endarterectomy is an option for certain patients. Patients at high risk of complications or with restrictive anatomy may be best served with extra-anatomic bypass or endovascular therapy.

Atherosclerotic occlusive disease of the abdominal aorta and iliac arteries represents a common disease process with a rich history of innovation in treatment techniques. It was famously described by Leriche as thrombotic obliteration of the aortic bifurcation with the triad of absent femoral pulses, proximal claudication, and sexual dysfunction in men. He initially treated this pathology with periarterial sympathectomy, with mixed results.¹Leriche R, Morel A. The Syndrome of Thrombotic Obliteration of the Aortic Bifurcation. Ann Surg. 1948;127(2):193-206. Dos Santos went on to pioneer endarterectomy for the treatment of arterial occlusive disease.²Dos Santos JC. [On the depopulation of old arterial thromboses]. Mem Acad Chir (Paris). 1947;73(18-19):409-11. Wylie applied this technique to the treatment of aortoiliac occlusive disease (AIOD), making aortoiliac endarterectomy the treatment of choice and significantly improving outcomes.³Connolly JE, Price T. Aortoiliac endarterectomy: a lost art? Ann Vasc Surg. 2006;20(1):56-62. This approach was eventually overtaken by aortobifemoral bypass, offering improved long-term patency. Similarly, the advent of endovascular intervention and the reliability of stents in this anatomic segment have revolutionised treatment of AIOD and demonstrated efficacy with decreased morbidity. In the current era, both open surgical and endovascular options are associated with excellent durability when performed well in appropriately selected patients.

Epidemiology

Patients with isolated AIOD are frequently younger, and have a significant history of tobacco use and hyperlipidaemia.¹Paisley MJ, Adkar S, Sheehan BM, Stern JR. Aortoiliac occlusive disease. Semin Vasc Surg. 2022;35(2):162-71. Those with multilevel disease are typically older, male, and have diabetes and hypertension. Comorbid coronary, mesenteric, and cerebrovascular disease are common.²Darling RC, Brewster DC, Hallett JW, Jr., Darling RC, 3rd. Aorto-iliac reconstruction. Surg Clin North Am. 1979;59(4):565-79. AIOD may be prevalent in 15-25% of patients older than 70 years of age, however this is likely underestimated given the large number of individuals who are asymptomatic.³Criqui MH, Vargas V, Denenberg JO, Ho E, Allison M, Langer RD, et al. Ethnicity and peripheral arterial disease: the San Diego Population Study. Circulation. 2005;112(17):2703-7.

Pathology

AIOD is characterised by the development of flow-limiting atherosclerotic plaque, most commonly involving the aortic bifurcation. Proximal extension to the level of the renal arteries may occur (Figure 1). Patients may also develop occlusive disease at multiple levels affecting the lower extremities, including femoropopliteal and tibiopedal segments. A particular variant of AIOD, hypoplastic or small aortic syndrome, is seen in young women with significant smoking histories. These patients typically have smaller diameter aortoiliac vessels, which reduces intervention durability.⁴Cronenwett JL, Davis JT, Jr., Gooch JB, Garrett HE. Aortoiliac occlusive disease in women. Surgery. 1980;88(6):775-84. Flow-limiting lesions result in increased flow through a collateral circulatory network providing blood flow to the lower extremities. This network is composed of three separate arcades: first, lumbar and internal iliac artery branches reconstitute the hypogastric, circumflex iliac, common femoral, and profunda femoris arteries; secondly, the internal mammary arteries provide flow via the inferior epigastric arteries to reconstitute the common femoral arteries; and finally, the mesenteric arcade wherein blood flows from the superior and inferior mesenteric arteries along the arc of Riolan, marginal artery of Drummond, and meandering mesenteric artery to reach haemorrhoidal branches, thereby reconstituting the hypogastric arteries.⁵Katsaros I, Georgakarakos E, Frigkas K, Tasopoulou KM, Souftas V, Fiska A. Arterial collateral circulation pathways in patients with aortoiliac occlusive disease. Vascular. 2019;27(6):677-83.

Figure 1. Two instances of infrarenal aortic occlusion. A) CTA demonstrating infrarenal aortic occlusion with extension into
left common iliac artery. B) Intra-operative image of infrarenal aortic occlusion visualised following transverse aortic
transection. Bilateral renal arteries controlled with yellow vessel loops.

Clinical Presentation

The symptom severity of AIOD is variable. Patients with focal aortoiliac lesions may be asymptomatic due to well developed collateral circulation. Alternatively, they may present with claudication of varying severity, or with chronic limb-threatening ischemia (CLTI), experiencing rest pain and/or tissue loss. Proximal claudication is most common, affecting the buttocks and thighs, though calf claudication is known to occur infrequently.⁶Paisley MJ, Adkar S, Sheehan BM, Stern JR. Aortoiliac occlusive disease. Semin Vasc Surg. 2022;35(2):162-71. Up to 39% of men with AIOD present with erectile dysfunction.⁷Flanigan DP, Schuler JJ, Keifer T, Schwartz JA, Lim LT. Elimination of iatrogenic impotence and improvement of sexual function after aortoiliac revascularization. Arch Surg. 1982;117(5):544-50. CLTI typically requires multilevel disease, given the aforementioned collateral circulation. Femoral pulses are usually absent or diminished in patients with AIOD. Unilateral symptoms and absence of the ipsilateral femoral pulse may point to an ipsilateral iliac lesion, while bilateral symptoms and absence of bilateral femoral pulses are usually indicative of disease at the terminal aorta and/or aortic bifurcation.

Non-Invasive Haemodynamic Testing

Ankle-brachial index (ABI), segmental blood pressure measurement, and pulse volume recording (PVR) are appropriate first line diagnostic tests in suspected AIOD. The ABI may be normal/elevated in patients with mild or moderate occlusive disease due to a collateral circulation. However, severe AIOD will likely result in a diminished resting ABI. Normally, the upper thigh pressure will be equal to or greater than the brachial pressure, thus a significant pressure gradient (>20 mmHg) between brachial and the upper thigh measurements is indicative of haemodynamically significant AIOD. Collateral circulation can often compensate for the pressure gradient across an aortoiliac lesion at rest, however may be unable to do so during exertion. Thus, non-invasive testing with exercise may reveal clinically significant disease otherwise masked at rest, and should be performed if the diagnosis is suspected but resting ABIs are normal.¹Allison MA, Cushman M, Solomon C, Aboyans V, McDermott MM, Goff DC, Jr., et al. Ethnicity and risk factors for change in the ankle-brachial index: the Multi-Ethnic Study of Atherosclerosis. J Vasc Surg. 2009;50(5):1049-56. PVR in significant AIOD will often demonstrate a diminished, monophasic waveform with loss of dicrotic notch.

Duplex Ultrasonogrpahy

Duplex ultrasonography readily identifies haemodynamically significant aortoiliac lesions, with high sensitivity and specificity.²Rosfors S, Eriksson M, Hoglund N, Johansson G. Duplex ultrasound in patients with suspected aorto-iliac occlusive disease. Eur J Vasc Surg. 1993;7(5):513-7. It is non-invasive and does not expose the patient to radiation or iodinated contrast, which is of particular benefit in patients with renal disease. Bowel gas may limit visualisation of the aortoiliac segment. The accuracy of duplex may be reduced in the presence of severe calcification due to acoustic shadowing. However, duplex ultrasound readily characterises the common femoral artery and femoral bifurcation prior to intervention.

Digital Subtraction Angiography

Angiography was long considered the gold standard imaging modality prior to the advent of modern cross-sectional imaging capabilities, and reliably assesses degree of stenosis and branch vessel patency. However, angiography does not assess vessel wall calcification. In addition, angiography is invasive and exposes the patient to the risks of ionising radiation and iodinated contrast. In severe stenoses or occlusions, upper extremity access may be necessary to properly image the affected segment, and this carries a higher risk of access-related complications. Given these limitations, catheter-based angiography is not considered a first-line imaging modality for interventional planning.

Cross-Sectional Imaging

Cross-sectional imaging modalities, such as computed tomography angiography (CTA) and magnetic resonance angiography (MRA), provide crucial anatomic information and are essential in planning open surgical or endovascular therapy. CTA with modern scanners is fast and detects significant aortoiliac lesions (>50%) with a high sensitivity and specificity (95% and 96%, respectively).³Met R, Bipat S, Legemate DA, Reekers JA, Koelemay MJ. Diagnostic performance of computed tomography angiography in peripheral arterial disease: a systematic review and meta-analysis. JAMA. 2009;301(4):415-24. CTA also provides detailed information regarding calcific burden of disease, the presence of aneurysms and important anatomic variants, all of which have implications for operative planning and device selection in endovascular intervention. CTA does expose the patient to ionising radiation, and iodinated contrast use may present a risk in patients with chronic kidney disease. MRA provides highly detailed anatomic information, but is more time consuming and expensive than CTA currently. Assessment of calcific disease may also be limited by artifact. MRA does not reliably detect in-stent stenosis, limiting its use in post-intervention surveillance. However, MRA avoids the risks of ionising radiation or iodinated contrast.⁴Fenchel S, Wisianowsky C, Schams S, Nuessle K, Kramer SC, Gorich J, et al. Contrast-enhanced 3D MRA of the aortoiliac and infrainguinal arteries when conventional transfemoral arteriography is not feasible. J Endovasc Ther. 2002;9(4):511-9.

All patients with AIOD should receive optimal medical therapy to reduce their risk of cardiovascular events and improve limb-based outcomes.¹Aboyans V, Ricco JB, Bartelink MEL, Bjorck M, Brodmann M, Cohnert T, et al. Editor’s Choice – 2017 ESC Guidelines on the Diagnosis and Treatment of Peripheral Arterial Diseases, in collaboration with the European Society for Vascular Surgery (ESVS). Eur J Vasc Endovasc Surg. 2018;55(3):305-68.,²Society for Vascular Surgery Lower Extremity Guidelines Writing G, Conte MS, Pomposelli FB, Clair DG, Geraghty PJ, McKinsey JF, et al. Society for Vascular Surgery practice guidelines for atherosclerotic occlusive disease of the lower extremities: management of asymptomatic disease and claudication. J Vasc Surg. 2015;61(3 Suppl):2S-41S.  Smoking cessation and control of hyperlipidemia, hypertension, and diabetes mellitus are foundational tenets of management. The 2018 AHA/ACC Guidelines aid in calculating the patient’s 10-year ASCVD risk and initiating statin therapy to reduce cardiovascular mortality risk.³Grundy SM, Stone NJ, Bailey AL, Beam C, Birtcher KK, Blumenthal RS, et al. 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol. 2019;73(24):e285-e350. Smoking cessation should be supported with counseling, nicotine replacement therapy, and pharmacotherapy, as indicated.⁴Spangler EL, Goodney PP. Smoking cessation strategies in vascular surgery. Semin Vasc Surg. 2015;28(2):80-5. Supervised exercise therapy (SET), with a standardised walking program, is effective in improving walking distance and reducing pain in claudication.⁵Grundy SM, Stone NJ, Bailey AL, Beam C, Birtcher KK, Blumenthal RS, et al. 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol. 2019;73(24):e285-e350.,⁶Fowler B, Jamrozik K, Norman P, Allen Y, Wilkinson E. Improving maximum walking distance in early peripheral arterial disease: randomised controlled trial. Aust J Physiother. 2002;48(4):269-75. The recently published SVS Appropriate Use Criteria for Management of Intermittent Claudication also emphasise the overarching importance of risk factor management and exercise in such patients.⁷Woo K, Siracuse JJ, Klingbeil K, Kraiss LW, Osborne NH, Singh N, et al. Society for Vascular Surgery appropriate use criteria for management of intermittent claudication. J Vasc Surg. 2022;76(1):3-22 e1.

Antiplatelet and antigoagulant agents are effective in preventing major adverse cardiovascular and limb events in patients with PAD. The 2016 AHA/ACC Guidelines recommend antiplatelet monotherapy with aspirin or clopidogrel for prevention cardiovascular death in patients with symptomatic and asymptomatic PAD.⁸Gerhard-Herman MD, Gornik HL, Barrett C, Barshes NR, Corriere MA, Drachman DE, et al. 2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation. 2017;135(12):e686-e725. Patients undergoing surgical revascularisation should receive antiplatelet monotherapy, while those undergoing endovascular revascularisation should receive 1 month of dual antiplatelet therapy (DAPT), followed by monotherapy indefinitely.⁹Aboyans V, Ricco JB, Bartelink MEL, Bjorck M, Brodmann M, Cohnert T, et al. 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. 2018;39(9):763-816. The CAPRIE trial found that clopidogrel monotherapy provided an 8.7% relative risk reduction in the combined outcome of MI, stroke, or death, in patients with symptomatic PAD, compared to aspirin monotherapy.¹⁰Committee CS. A randomised, blinded, trial of clopidogrel versus aspirin in patients at risk of ischaemic events (CAPRIE). CAPRIE Steering Committee. Lancet. 1996;348(9038):1329-39. The COMPASS trial found that combination therapy (aspirin plus rivaroxaban 2.5mg twice daily) resulted in a significantly lower amputation rate compared to aspirin monotherapy.¹¹Anand SS, Caron F, Eikelboom JW, Bosch J, Dyal L, Aboyans V, et al. Major Adverse Limb Events and Mortality in Patients With Peripheral Artery Disease: The COMPASS Trial. J Am Coll Cardiol. 2018;71(20):2306-15. The VOYAGER PAD trial found that combination therapy (aspirin plus rivaroxaban 2.5mg twice daily) resulted in a significant reduction in major adverse limb and cardiovascular events, though with a higher rate of major bleeding, compared to aspirin monotherapy following lower extremity revascularisation (both endovascular/surgical).

Severe, lifestyle-limiting claudication, rest pain, and tissue loss are classic indications for intervention in patients with AIOD. Other indications include vasculogenic impotence and atheroembolization from an ulcerated plaque. Revascularisation for claudication requires thoughtful assessment of the severity of the patient’s ambulatory impairment and optimisation of risk factor reduction and medical therapy. Although claudicants have a higher risk of cardiovascular mortality compared to non-claudicants, their risk of progression to CLTI or amputation is low.¹Muluk SC, Muluk VS, Kelley ME, Whittle JC, Tierney JA, Webster MW, et al. Outcome events in patients with claudication: a 15-year study in 2777 patients. J Vasc Surg. 2001;33(2):251-7; discussion 7-8. Claudication is often caused by single-level disease, making it particularly amenable to endovascular intervention. However, aggressive intervention-first strategies for patients with claudication carry an increased risk of reintervention, and there are some data to suggest they may worsen limb related outcomes (increase the risk of CLTI, ALI and amputation) and are generally not recommended.²Hicks CW, Holscher CM, Wang P, Black JH, 3rd, Abularrage CJ, Makary MA. Overuse of early peripheral vascular interventions for claudication. J Vasc Surg. 2020;71(1):121-30 e1.

Revascularisation is indicated in CLTI to improve symptoms, heal wounds, and lower risk of amputation. Tissue loss usually results from multilevel disease, including concomitant infrainguinal disease.³Brewster DC, Perler BA, Robison JG, Darling RC. Aortofemoral graft for multilevel occlusive disease. Predictors of success and need for distal bypass. Arch Surg. 1982;117(12):1593-600. Unlike claudication and rest pain, which can often be treated with a single level, inflow procedure, tissue loss usually requires simultaneous inflow and outflow revascularisation to achieve pulsatile, in-line flow to the wound and maximise healing capability.

The Trans-Atlantic Inter-Society Consensus (TASC-II) document provides an anatomic classification system with which to categorise aortoiliac lesions.¹Norgren L, Hiatt WR, Dormandy JA, Nehler MR, Harris KA, Fowkes FG, et al. Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II). J Vasc Surg. 2007;45 Suppl S:S5-67. AIOD is graded from type A to type D lesions, with increasing lesion severity and extent of disease. In general, there is consensus that TASC A and B lesions should be treated with endovascular therapy first, while TASC C lesions should be addressed with either open surgery or endovascular therapy depending on the surgeon’s preference, as well as the patient’s risk profile for open surgical revascularisation. TASC D lesions should generally be treated with open surgery, although improved endovascular technology and techniques have made treating extensive AIOD more feasible.²Leville CD, Kashyap VS, Clair DG, Bena JF, Lyden SP, Greenberg RK, et al. Endovascular management of iliac artery occlusions: extending treatment to TransAtlantic Inter-Society Consensus class C and D patients. J Vasc Surg. 2006;43(1):32-9.,³Smith AH, Beach JM, Dash S, Rowse J, Parodi FE, Kirksey L, et al. Comparison of Aortobifemoral Bypass to Aortoiliac Stenting with Bifurcation Reconstruction for TASC II D Aortoiliac Occlusive Disease. Ann Vasc Surg. 2022;82:120-30. The appeal of endovascular therapy in TASC C and D lesions is significant in higher-risk patients. However, despite technical feasibility and low morbidity, endovascular therapy in TASC D lesions is associated with reduced durability and higher reintervention rates.⁴Mayor J, Branco BC, Chung J, Montero-Baker MF, Kougias P, Mills JL, Sr., et al. Outcome Comparison between Open and Endovascular Management of TASC II D Aortoiliac Occlusive Disease. Ann Vasc Surg. 2019;61:65-71 e3.

The various techniques can be broadly categorised into four groups: open direct reconstruction, hybrid reconstruction (especially applicable when significant common femoral artery disease is present), endovascular intervention, and open extra-anatomic bypass. Selection of modality should centre on the anatomy of disease (TASC II), patient risk profile, and expected patency of the intervention (Table 1).

Open Direct Reconstruction

Assessment of the patient’s risk for open surgery should consider comorbid conditions, functional status, and frailty. Myocardial infarction is a leading cause of morbidity in these patients. This risk is significantly greater in patients undergoing open aortic surgery than in those undergoing endovascular intervention.¹Bredahl K, Jensen LP, Schroeder TV, Sillesen H, Nielsen H, Eiberg JP. Mortality and complications after aortic bifurcated bypass procedures for chronic aortoiliac occlusive disease. J Vasc Surg. 2015;62(1):75-82. However, routine stress testing or cardiac catheterisation does not improve operative mortality in asymptomatic patients or those with high functional capacity. End-stage renal disease and chronic obstructive pulmonary disease requiring supplemental oxygen are additional predictors of perioperative morbidity and late mortality following open aortic surgery.²Bredahl K, Jensen LP, Schroeder TV, Sillesen H, Nielsen H, Eiberg JP. Mortality and complications after aortic bifurcated bypass procedures for chronic aortoiliac occlusive disease. J Vasc Surg. 2015;62(1):75-82.,³Khashram M, Williman JA, Hider PN, Jones GT, Roake JA. Systematic Review and Meta-analysis of Factors Influencing Survival Following Abdominal Aortic Aneurysm Repair. Eur J Vasc Endovasc Surg. 2016;51(2):203-15. Patients with heart failure and reduced ejection fraction may not physiologically tolerate aortic cross-clamping. Poor functional status and frailty are also predictors of poor outcomes.⁴Al Shakarchi J, Fairhead J, Rajagopalan S, Pherwani A, Jaipersad A. Impact of Frailty on Outcomes in Patients Undergoing Open Abdominal Aortic Aneurysm Repair. Ann Vasc Surg. 2020;67:100-4.,⁵Visser L, Banning LBD, El Moumni M, Zeebregts CJ, Pol RA. The Effect of Frailty on Outcome After Vascular Surgery. Eur J Vasc Endovasc Surg. 2019;58(5):762-9. In-line aortic reconstruction is not appropriate in those individuals with limited life expectancy.

A major advantage of direct aortoiliac reconstruction is its durability. Aortobifemoral bypass is associated with a 97% 1-year primary patency, 80-90% 5-year primary patency, and 75-85% 10-year primary patency.⁶Smith AH, Beach JM, Dash S, Rowse J, Parodi FE, Kirksey L, et al. Comparison of Aortobifemoral Bypass to Aortoiliac Stenting with Bifurcation Reconstruction for TASC II D Aortoiliac Occlusive Disease. Ann Vasc Surg. 2022;82:120-30.,⁷Mayor J, Branco BC, Chung J, Montero-Baker MF, Kougias P, Mills JL, Sr., et al. Outcome Comparison between Open and Endovascular Management of TASC II D Aortoiliac Occlusive Disease. Ann Vasc Surg. 2019;61:65-71 e3.,⁸Squizzato F, D’Oria M, Bozza R, Porcellato L, Grego F, Lepidi S. Propensity-Matched Comparison of Endovascular versus Open Reconstruction for TASC-II C/D AortoIliac Occlusive Disease. A Ten-Year Single-Center Experience with Self-Expanding Covered Stents. Ann Vasc Surg. 2021;71:84-95.,⁹Chiesa R, Marone EM, Tshomba Y, Logaldo D, Castellano R, Melissano G. Aortobifemoral bypass grafting using expanded polytetrafluoroethylene stretch grafts in patients with occlusive atherosclerotic disease. Ann Vasc Surg. 2009;23(6):764-9.,¹⁰Hertzer NR, Bena JF, Karafa MT. A personal experience with direct reconstruction and extra-anatomic bypass for aortoiliofemoral occlusive disease. J Vasc Surg. 2007;45(3):527-35; discussion 35. Aortoiliac endarterectomy, when applied to short, focal lesions, is associated with a 10-year primary patency rate of 89%, though this is reduced in long-segment disease.

Extra-Anatomic Bypass

is an alternative for patients in whom  an endovascular approach is not feasible or has failed, and in patients with “hostile abdomens”, resulting from prior abdominal surgery, intra-abdominal infection, radiation therapy or the presence of a stoma. Other options include thoracofemoral or supracoeliac aorto-femoral bypass in physiologically fit patients who may tolerate aortic cross-clamping, and axillofemoral bypass in unfit patients. Femorofemoral bypass is an additional option, but it requires patent or reconstructable inflow from the contralateral side.

A general limitation of extra-anatomic bypass is its reduced durability. Axillofemoral bypass has demonstrated reported 5-year patency rates of approximately 70-76%, while femorofemoral bypass is associated with a 5-year primary patency rate of 70%.¹¹Passman MA, Taylor LM, Moneta GL, Edwards JM, Yeager RA, McConnell DB, et al. Comparison of axillofemoral and aortofemoral bypass for aortoiliac occlusive disease. J Vasc Surg. 1996;23(2):263-9; discussion 9-71.,¹²Schneider JR, McDaniel MD, Walsh DB, Zwolak RM, Cronenwett JL. Axillofemoral bypass: outcome and hemodynamic results in high-risk patients. J Vasc Surg. 1992;15(6):952-62; discussion 62-3.,¹³Rinckenbach S, Guelle N, Lillaz J, Al Sayed M, Ritucci V, Camelot G. Femorofemoral bypass as an alternative to a direct aortic approach in daily practice: appraisal of its current indications and midterm results. Ann Vasc Surg. 2012;26(3):359-64. Thoracofemoral bypass was shown in one series to have a 80% 3-year primary patency rate.¹⁴Crawford JD, Scali ST, Giles KA, Back MR, Fatima J, Arnaoutakis DK, et al. Contemporary outcomes of thoracofemoral bypass. J Vasc Surg. 2019;69(4):1150-9 e1.

Endovascular Intervention

In patients who are poor candidates for open reconstruction, or those with more focal disease patterns, endovascular intervention may be preferable. Preoperative imaging should assess access vessel diameter, tortuosity, and degree of aortoiliac calcification to determine feasibility. Circumferential arterial calcification with thickness greater than 1mm increases risk of arterial rupture. Anatomic factors such as small or hypoplastic aortic syndrome, juxtarenal aortic occlusion, and abdominal aortic aneurysm are contraindications to endovascular intervention. For patients with multilevel disease requiring femoral endarterectomy and/or infra-inguinal bypass, hybrid/endovascular intervention for AIOD may be preferable.

Iliac artery stenting remains the most frequent intervention performed for AIOD, though the use of covered endovascular reconstruction of the aortic bifurcation (CERAB) has increased for disease involving the distal aorta. The COBEST trial compared balloon-expandable covered stents with bare metal stents in common iliac artery lesions, and found improved 5-year primary patency with covered stents in TASC C and D lesions (75% vs 63%; p=0.01).¹⁵Mwipatayi BP, Sharma S, Daneshmand A, Thomas SD, Vijayan V, Altaf N, et al. Durability of the balloon-expandable covered versus bare-metal stents in the Covered versus Balloon Expandable Stent Trial (COBEST) for the treatment of aortoiliac occlusive disease. J Vasc Surg. 2016;64(1):83-94 e1. “Kissing stents” placed at the aortic bifurcation have been associated with a 3-year primary patency of 79%.¹⁶Haulon S, Mounier-Vehier C, Gaxotte V, Koussa M, Lions C, Haouari BA, et al. Percutaneous reconstruction of the aortoiliac bifurcation with the “kissing stents” technique: long-term follow-up in 106 patients. J Endovasc Ther. 2002;9(3):363-8.

Hybrid Reconstruction

Multilevel disease with aortoiliac and infrainguinal involvement is often amenable to hybrid reconstruction. This approach typically takes the form of iliac artery stenting with adjunctive iliofemoral endarterectomy, profundaplasty, and/or infrainguinal bypass. Once the femoral patch angioplasty is completed, arterial access is obtained through the patch for the endovascular portion. Retrograde ipsilateral recanalisation is attempted, though contralateral access and antegrade crossing allows for snaring of the wire from the ipsilateral access site. This technique minimises morbidity in aortoiliac revascularisation while providing the robust durability of open femoral bifurcation (particularly profundaplasty) reconstruction. Finally, femorofemoral bypass following contralateral iliac artery stenting provides revascularisation of the ipsilateral limb in the setting of ipsilateral iliac disease not amenable to endovascular intervention.

Endovascular repair of the aortoiliac segment with open iliofemoral endarterectomy (Figure 2) has demonstrated similar 1-year primary patency (79% vs 81%) and amputation rates (2.8% vs 2.9%) to open reconstruction, however with lower 30-day mortality (1.8% vs 3.4%).¹⁷Zavatta M, Mell MW. A national Vascular Quality Initiative database comparison of hybrid and open repair for aortoiliac-femoral occlusive disease. J Vasc Surg. 2018;67(1):199-205 e1. Similarly, Ray et al. reported primary patency of 85.4% at 23 months following iliac stenting and iliofemoral endarterectomy.¹⁸Ray JJ, Eidelson SA, Karcutskie CA, Meizoso JP, DeAmorim H, Goldstein LJ, et al. Hybrid Revascularization Combining Iliofemoral Endarterectomy and Iliac Stent Grafting for TransAtlantic Inter-Society Consensus C and D Aortoiliac Occlusive Disease. Ann Vasc Surg. 2018;50:73-9.

Figure 2. Hybrid reconstruction of AIOD with extension into right common femoral artery. A) Right common femoral artery is exposed and controlled. B) Femoral endarterectomy is completed with proximal balloon occlusion. C) Balloon catheter is advanced proximally for proximal control and wire access.

Preoperative Considerations

The operation is performed under general anaesthesia with endotracheal intubation. Arterial line placement and nasogastric tube placement are routine, while central venous access is nearly routine. For a transabdominal approach, the patient is positioned supine with arms out for ease of access. For a retroperitoneal approach, the patient is positioned with the left shoulder rotated to the right and superiorly with slight angling of the left aspect of the pelvis. The bed is broken with head down to increase the space between the left costal margin and the iliac crest. An inflatable bean bag maintains the position. An axillary roll and padding of pressure points ensure safe positioning. The patient should be prepped from the nipples down to the knees. Iodinated plastic adhesive drapes should be applied to cover exposed skin.

An intraoperative blood salvage machine should be made available. In general, size 16x8mm or 18x9mm bifurcated prosthetic grafts are appropriate choices. Dacron grafts have the capacity to be soaked in Rifampin: while some surgeons do this routinely, others do so selectively, for example when a prosthetic graft is required in the setting of a previous infection  (Figure 3). The anastomoses are performed with polypropylene suture with size 5-0 for femoral vessels, 4-0 for iliac vessels, and 3-0 for the aorta.

Figure 3. Bifurcated aortobifemoral bypass graft can be soaked in Rifampin for antimicrobial prophylaxis.

Femoral Exposure

Bilateral groin exposures should be performed prior to aortic exposure to limit insensible fluid losses from an open abdominal cavity. In femoral vessels without need for further reconstruction, consideration should be given to utilising transverse or oblique groin incisions to potentially decrease the risk of wound complications. Proximal exposure should include ligation and division of the deep circumflex iliac vein overlying the distal external iliac artery to prevent injury and bleeding when tunneling graft limbs. Femoral endarterectomy and/or adjunctive profundaplasty should be performed at this time, when indicated. Once both groin dissections and exposures are complete, attention can be turned to the aortic exposure.

Aortic Exposure – Transabdominal Approach

A longitudinal midline incision is performed from the xiphoid to below the umbilicus. Care should be taken to avoid an incidental enterotomy, as this will require abdominal decontamination and conclude the operation. The risk of inadvertent enterotomy is greater if the patient has undergone a prior laparotomy, and if this is so, a retroperitoneal approach should be considered. The abdominal cavity is briefly explored, and nasogastric tube placement is confirmed. For supracoeliac aortic exposure, if the need for clamping at this level is anticipated, the left lateral hepatic lobe is mobilised, the oesophagus is identified with manual palpation of the nasogastric tube, the gastrohepatic ligament is divided, the diaphragmatic crura are divided, and the aorta is exposed. A replaced left hepatic artery may be encountered in the gastrohepatic ligament and should be avoided. Suprarenal and infrarenal aortic exposure are achieved via an inframesocolic approach. The transverse colon and greater omentum are retracted cephalad, and the small bowel is eviscerated to the right or retracted into the right hemiabdomen. The ligament of Treitz is divided to expose retroperitoneal fat overlying the aorta. Dissection is carried down, taking care to ligate and divide lymphatic vessels. The inferior mesenteric vein can be ligated and divided safely. Suprarenal aortic clamping requires mobilisation of the left renal vein (LRV). The LRV lies anterior to the aorta in 95% of patients, however preoperative imaging review should include identification of a retroaortic LRV and its level of crossing. The LRV can be mobilised by dividing the inferior lumbar, gonadal, and superior adrenal branches. Should the LRV need to be divided, the division should take place close to the caval junction and prior to division of collateral branches to ensure adequate kidney venous drainage. Some surgeons reconstruct the LRV at the end of the case if feasible. Distal dissection over the aortic bifurcation and the left common iliac artery should be limited/avoided, to prevent injury to the nervi erigentes overlying the left common iliac artery origin. Injury to this structure results in sexual dysfunction in men.

Aortic Exposure – Retroperitoneal Approach

Retroperitoneal exposure of the abdominal aorta may be preferable in patients with prior abdominal operations, limiting the need for adhesiolysis and risk of enterotomy. This exposure may limit access to the right iliofemoral vessels, but may reduce pulmonary complications and the duration of postoperative ileus. This incision can be extended for thoracoabdominal exposure for more proximal aortic clamping, or for conversion to supracoeliac or thoracofemoral bypass.

A left lateral oblique incision is performed along the left lateral aspect of the rectus sheath, with cephalad extent corresponding to the level of expected aortic clamp placement (9^th-11^th intercostal space). The external oblique, internal oblique, and transversus abdominis muscles are divided. The abdominal viscera is mobilised from lateral to medial, from the iliac fossa up to the diaphragm to remain in the extraperitoneal space. Alternatively, one can enter the peritoneal cavity via this incision and perform a left medial visceral rotation by dissecting along the white line of Toldt lateral to the descending colon. The dissection plane can be developed either anterior or posterior to the left kidney, depending on the need for suprarenal clamp placement or concomitant renal or visceral artery thromboendarterectomy. Development of the retrorenal dissection plane requires division of a large lumbar venous branch of the left renal vein to allow for safe medial rotation of the left kidney and should proceed anterior to the psoas muscle.

Tunneling of Graft Limbs

Creation of tunnels is achieved utilising blunt retroperitoneal finger dissection from both the abdominal and groin incisions. The proper plane is posterior to the ureters and when making the left sided tunnel, attention needs to be paid to the left sigmoid colon. The tracts can be preserved by passing an umbilical tape, Penrose drain or a red rubber catheter through them. The tracts should be developed directly anterior to the iliac arteries and posterior to the ureters. The graft limbs should be pressurised with arterial flow along their length prior to tunneling in order to avoid twisting or kinking of the graft limbs. Thus, the proximal anastomosis should be performed prior to passage of the limbs to the groins.

Proximal Anastomosis

An end-to-end proximal anastomosis will alter the patient’s abdominal and pelvic circulation permanently, wherein inferior mesenteric artery and hypogastric artery flow will be provided in retrograde fashion from the femoral arteries. However, this configuration allows for easier coverage of the anastomosis with retroperitoneal tissue at the conclusion of the case, reducing risk of aortoenteric fistula and graft infection. An end-to-end anastomosis is ideal following proximal aortic thromboendoarterectomy for juxtarenal aortic occlusion, and is necessary for concomitant abdominal aortic aneurysm. The distal aortic stump is oversewn, with running two-layer closure or interrupted pledgeted sutures. In the presence of severe calcific disease, the proximal or distal aortic stumps may need to be endarterectomised and the suture line reinforced with felt. The inferior mesenteric artery, if patent, should be assessed for reimplantation. If back bleeding is strong and pulsatile, the artery may be ligated. Poor back bleeding merits reimplantation to preserve colonic perfusion. A history of prior colonic surgery should prompt further consideration of reimplantation due to the likelihood of altered colonic circulation.

An end-to-side proximal anastomosis preserves antegrade aortic blood flow to the inferior mesenteric artery and the pelvis, but is more difficult to adequately cover with retroperitoneal tissue during closure. Visualisation of mural thrombus within the lumen is more challenging through the limited aortotomy, as compared to the transverse transection performed for an end-to-end anastomosis. An end-to-side is necessary in the setting of external iliac arterial occlusion, or severe iliac stenoses that would obstruct retrograde flow to the pelvis (at least one hypogastric artery) from the femoral arteries.

Distal Anastomoses and Lower Extremity Reperfusion

Following completion of the proximal anastomosis, graft limb pressurisation, and safe tunneling of the limbs, the femoral anastomoses can be performed. If there is stenosis at the origin of the profundal femoris artery, it should be addressed to ensure adequate outflow and long-term patency of the reconstruction. Following completion of the femoral anastomoses and prior to reperfusion of the legs, the anaesthesiologist should be informed before release of distal clamps. Clamp release results in suddenly increased volume of distribution and can cause profound hypotension with end organ damage (eg myocardial infarction) if not performed thoughtfully. Clamps should be released one leg at a time after communication with the anaesthesiologist.

Graft Coverage

Coverage of the prosthetic graft and exclusion of the graft and suture line from the gastrointestinal tract is crucial to prevent aortoenteric fistula development or graft erosion into the duodenum. After aneurysm repair, the graft and suture lines can be covered with aneurysm sac, however this is not an option in aortobifemoral bypass. The first option is to cover the graft and suture line with retroperitoneal fat. In certain patients, when overlying tissue is thin and inadequate for coverage, mobilisation of the greater omentum and coverage of the graft with an omental flap is a reliable option.

Endarterectomy was the open direct reconstruction of choice for treating AIOD prior to the advent of aortobifemoral bypass. Though not as widely used in contemporary practice due to technical demands and reduced patency in extensive disease, there remains a select group of patients who may benefit from aortoiliac endarterectomy.¹(3) Patients with focal, highly calcific disease limited to the infrarenal aorta and common iliac arteries are candidates for aortoiliac endarterectomy in lieu of aortobifemoral bypass. It is relatively contraindicated in patients with diminutive aortas or common iliac arteries.

The open aortic exposure is conducted in a fashion similar to that described above. A longitudinal aortotomy is made over the affected segment. The initial arteriotomy on the aorta is usually carried down the right common iliac artery beyond the endpoint of disease. A separate arteriotomy is usually made on the left common iliac artery, sparing the nerves (nervi erigentes) that cross over the origin of the left common iliac artery. A cleavage plane is developed bluntly between the plaque and the adventitial layer of the aorta. The plane is developed and extended until a natural tapering point is reached, and the plaque can be removed without an elevated residual flap. Conversely, the dissection can be sharply terminated at a desired endpoint, and the distal endpoint can be secured with tacking sutures, to prevent dissection or thrombosis. In vessels of sufficient caliber, primary closure may be attempted (Figure 4). However, it is common to perform patch angioplasty of at least the common iliac arteries with a synthetic, vein, or bovine pericardial patch to achieve adequate closure.

Figure 4. Endarterectomy for AIOD. A) Suprarenal aortic exposure with aortic and bilateral renal artery thromboendarterectomy via longitudinal aortotomy, with primary closure. B) Aortic plaque and chronic thrombus, now removed.

Thoracofemoral Bypass

Thoracofemoral bypass is an option in patients with prohibitive abdominal cavities who are physiologically fit for open surgery and aortic clamping. It is also an option in patients with extensive juxtarenal disease who lack an adequate aortic clamp site in the abdomen. Though associated with a >30% rate of major complications, it has demonstrated reasonable long-term outcomes.¹Crawford JD, Scali ST, Giles KA, Back MR, Fatima J, Arnaoutakis DK, et al. Contemporary outcomes of thoracofemoral bypass. J Vasc Surg. 2019;69(4):1150-9 e1. Briefly, the technique involves a left retroperitoneal exposure of the supracoeliac aorta via left medial visceral rotation of the stomach, spleen, and pancreas.²Mills JL, Fujitani RM, Taylor SM. The retroperitoneal, left flank approach to the supraceliac aorta for difficult and repeat aortic reconstructions. Am J Surg. 1991;162(6):638-42. If more proximal aortic exposure is needed, the incision is extended into the left chest for thoraco-retroperitoneal exposure. Anatomic tunneling can be facilitated by blunt dissection between the femoral incisions and the retroperitoneal space. Often, tunneling in non-reoperative planes is advantageous. This can be performed through blunt tunneling in the extraperitoneal plane anterior to the bladder and posterior to the pubic symphysis (Retzius space). A partially occlusive clamp is placed on the supracoeliac aorta and the proximal anastomosis is constructed in end-to-side fashion. The bifurcated graft limbs are advanced along the previously created tunnels and the distal anastomoses are completed in end-to-side fashion.

Axillofemoral Bypass

For patients who are not appropriate candidates for in-line reconstruction, axillofemoral bypass is a reasonable alternative. It should not be utilised as a first-line option for claudication, given reduced patency rates. Preoperative planning should include imaging of both the axillosubclavian and femoropopliteal arterial systems. Patients with blood pressure discrepancies in the upper extremities should be evaluated with arterial duplex. A significant subclavian stenosis merits treatment prior to ipsilateral use for inflow. The right axillary artery is frequently the inflow of choice as the innominate artery and right subclavian artery are less prone to atherosclerosis than the left subclavian artery.

The patient is positioned supine with the ipsilateral arm abducted to 90 degrees and prepped from the neck to the thighs. Exposure of the axillary artery is obtained via infraclavicular approach. A transverse incision limited to 8-10cm in length is made 1-2cm inferior to the clavicle, extending from lateral to the sternal head of the clavicle to the upper deltopectoral groove. The clavipectoral fascia is incised transversely, and the pectoralis major fibers are split to separate the sternal and clavicular heads. A 3-5cm segment of axillary artery should be exposed between the medial border of the pectoralis minor muscle and the clavicle. Lateral retraction or division of the pectoralis muscle can provide additional exposure, though the lateral pectoral nerve near the muscle’s medial border should be preserved. The proximal portion of the axillary artery is mobilised, while dissection of the mid and distal portions should be avoided, to avoid injury to the medial and lateral cords of the brachial plexus.

An 8mm externally supported graft is frequently used. The proximal axillary end-to-side anastomosis should be completed to the most medial aspect of the axillary artery possible to reduce the risk of excess tension with arm abduction. This can be facilitated by leaving the pectoralis minor intact and tunneling the graft deep to it. Creating mild graft redundancy may allow for additional laxity with abduction of the arm. The graft is tunneled in a subcutaneous plane along the anterior axillary line in the chest wall and medial to the anterior superior iliac spine when approaching the pelvis to avoid graft compression or kinking. A counterincision in the chest wall may be necessary. The bypass should be tunneled contralateral to the side the patient regularly sleeps on (if applicable), or contralateral to any present or planned stoma. Following completion of the axillofemoral graft distal anastomosis, a femorofemoral bypass is created from the hood of axillofemoral graft anastomosis to the contralateral common femoral artery.

Femorofemoral Bypass

One patent iliac artery without significant stenosis is capable of providing adequate flow to both lower extremities. When a patient is not a candidate for in-line reconstruction and endovascular intervention is either not feasible or has been unsuccessful, a bypass is another option. This configuration may be used after the donor iliac artery has been reconstructed with endovascular techniques. The patient is positioned supine and prepped to include the abdomen and thighs. Bilateral longitudinal groin incisions are made and the femoral bifurcations are exposed and controlled in the usual fashion. A 6mm, 7mm or 8mm externally supported prosthetic graft is an adequate choice. The graft is tunneled from one groin to the other in an inverted U-shape anterior to the abdominal wall fascia through a subcutaneous plane. Tunnel creation should place the superior aspect of the graft superior to the pubis to provide a rounder arc, reduce angulation at the heel of the anastomosis, and avoid kinking of the graft. Care should be taken to avoid violation of the peritoneal cavity. End-to-side anastomoses are created between graft and common femoral artery at or close to the femoral bifurcation to maximise outflow.

Endovascular therapy for AIOD provides reasonable durability with lower morbidity than open reconstructions. It can also be employed to improve inflow for concomitant infrainguinal bypass, femoral endarterectomy, or femorofemoral bypass to provide a hybrid solution for multi-level disease. Renal insufficiency and the risk of contrast-induced nephropathy can be managed with preventive regimens and techniques to minimise contrast use. Adjunctive measures such as intravascular lithotripsy (IVL) can aid in treating bulky, calcific plaque. The M5 catheter (Shockwave Medical; Santa Clara, CA) is equipped with a 6.0mm diameter balloon, making it an option for iliac vessels while the L6 catheter (Shockwave Medical; Santa Clara, CA) and its 7.0mm diameter balloon are well-equipped to manage larger iliac vessels and the terminal aorta in certain patients. IVL can be used to improve vessel compliance, facilitate passage of sheaths, stents, and stent grafts across these calcific lesions and improve luminal gain.¹Nasiri A, Kim H, Gurusamy V, Benenati JF. Management of Calcification: Rational and Technical Considerations for Intravascular Lithotripsy. Tech Vasc Interv Radiol. 2022;25(3):100841. Common iliac artery lesions are typically addressed from an ipsilateral retrograde approach, while external iliac artery lesions most often are treated from  a contralateral approach. Occasionally, upper extremity access may be necessary.

Ipsilateral Retrograde Approach

Ultrasound-guided access is important, particularly as the common femoral artery will likely be non-pulsatile when utilising an ipsilateral retrograde approach. Access is obtained with micropuncture technique using a 25-gauge needle. An 0.018-inch floppy tip wire is advanced into the external iliac artery, the needle is removed, and the micropuncture catheter is advanced over the wire. Needle access and true lumen wire entry are easy to visualise with ultrasound. The introducer is removed and a standard guidewire or short J wire is advanced under fluoroscopy into the external iliac artery. A working sheath is partially inserted into the external iliac artery and flushed with heparinised saline. Systemic heparin is given. An attempt is made to cross the lesion with an angled catheter and guidewire. After the lesion is crossed, the catheter is advanced into the patent proximal portion of the vessel. Selective angiography confirms intraluminal position following lesion crossing. In the setting of severe stenosis or chronic total occlusion, intraluminal crossing may be challenging. Subintimal crossing can be attempted, though it does risk dissection propagation into the aorta and/or contralateral iliac artery. Intraluminal re-entry into the proximal iliac artery can be facilitated with a variety of effective re-entry devices that guide the wire back into the luminal space. Alternative access sites may be necessary to connect the true lumen on either side of the lesion. Luminal re-entry is confirmed with selective angiography. The catheter is exchanged for a diagnostic flush catheter and aortoiliac angiography is performed. The length of the lesion is measured, and the location of the ipsilateral hypogastric artery is marked. Intravascular ultrasound can aid successful measurement of arterial diameters, lesion characterisation, and confirmation of true lumen re-entry.

Common iliac artery lesions are typically treated with balloon-expandable stents, and covered stents offer superior patency in TASC C and D lesions versus bare metal stents, while also providing added safety in the event of vessel rupture.²Mwipatayi BP, Sharma S, Daneshmand A, Thomas SD, Vijayan V, Altaf N, et al. Durability of the balloon-expandable covered versus bare-metal stents in the Covered versus Balloon Expandable Stent Trial (COBEST) for the treatment of aortoiliac occlusive disease. J Vasc Surg. 2016;64(1):83-94 e1. Pre-dilatation of the lesion can facilitate advancement of the stent and sheath across the lesion. Following angioplasty, the balloon is gently deflated while advancing the sheath over the balloon catheter. Once the sheath is across, the balloon catheter is exchanged for the balloon-expandable stent which is then advanced under fluoroscopic guidance. The sheath is withdrawn, and the stent deployed under nominal pressure. This technique helps ensure that the stent does not become dislodged while trying to advance it across the lesion. A confirmation angiogram is obtained to confirm luminal patency and absence of dissection or vessel rupture. Deployment of kissing common iliac artery stents follows a similar technique on the contralateral side (Figure 5). The two stents are deployed at the same time and height under nominal pressure.

Figure 5. Bilateral common iliac stenoses treated with kissing iliac stents.

Antegrade Approach

The antegrade approach to iliac lesions is typically performed via contralateral femoral arterial access, but may also be achieved through left brachial arterial access. These approaches are useful when luminal re-entry cannot be achieved following ipsilateral retrograde subintimal crossing of common iliac lesions, or for treatment of external iliac artery lesions. Crossing the lesion with this approach is aided by positioning the sheath close to the lesion; steerable sheaths may be useful in this setting. In a flush occlusion, a balloon can be inflated in the contralateral common iliac artery origin to occlude the vessel and redirect the wire towards the lesion. Following crossing, the wire can be snared from the ipsilateral common femoral artery access. A short catheter and devices can then be advanced from the ipsilateral access site from a shorter distance with greater pushability.

Aortic Bifurcation – ‘Kissing’ Stents and CERAB

AIOD involving the aortic bifurcation and/or the distal aorta has traditionally been treated with “kissing” stents in bilateral common iliac arteries which functionally elevate the bifurcation. This is often performed even in the setting of unilateral disease, in order to protect the contralateral vessel from plaque shift and occlusion. Patency rates with this approach mirror those seen in isolated iliac artery stenting.³Haulon S, Mounier-Vehier C, Gaxotte V, Koussa M, Lions C, Haouari BA, et al. Percutaneous reconstruction of the aortoiliac bifurcation with the “kissing stents” technique: long-term follow-up in 106 patients. J Endovasc Ther. 2002;9(3):363-8. However, “kissing” stents make subsequent contralateral endovascular intervention challenging due to the raised and geometrically altered bifurcation. As well, concern has been raised given radial force mismatch, stent non-apposition, and flow turbulence inherent to the “kissing” stent configuration.⁴Sharafuddin MJ, Hoballah JJ, Kresowik TF, Sharp WJ, Golzarian J, Sun S, et al. Long-term outcome following stent reconstruction of the aortic bifurcation and the role of geometric determinants. Ann Vasc Surg. 2008;22(3):346-57. An alternative technique, CERAB, is increasing in popularity for AIOD. A stent graft (aortic stent graft or aortic cuff) is deployed in the distal aorta, followed by deployment of “kissing” iliac stents from below extending into the aortic stent graft. This creates a new, covered bifurcation that may offer more favourable geometry for future intervention and improved haemodynamic performance.⁵Grimme FA, Goverde PC, Verbruggen PJ, Zeebregts CJ, Reijnen MM. Editor’s Choice–First Results of the Covered Endovascular Reconstruction of the Aortic Bifurcation (CERAB) Technique for Aortoiliac Occlusive Disease. Eur J Vasc Endovasc Surg. 2015;50(5):638-47. CERAB also lends itself for use in more extensive disease involving the distal aorta. Another alternative is use of a unibody bifurcated stent graft, which may preserve the bifurcation, facilitating further endovascular intervention.⁶Maldonado TS, Westin GG, Jazaeri O, Mewissen M, Reijnen MM, Dwivedi AJ, et al. Treatment of Aortoiliac Occlusive Disease with the Endologix AFX Unibody Endograft. Eur J Vasc Endovasc Surg. 2016;52(1):64-74. Long-term outcomes with these newer techniques have yet to be completely defined.