Axillofemoral Bypass 

Updated: Mar 08, 2022
Author: Cheong Jun Lee, MD; Chief Editor: Vincent Lopez Rowe, MD 

Overview

Background

Axillofemoral bypass is a method of surgical revascularization used in the setting of symptomatic aortoiliac occlusive disease for patients who have no endovascular option or who cannot undergo an aortofemoral reconstruction.[1] The bypass depends on a healthy axillary artery for adequate inflow to the ipsilateral arm and one or both legs. This extra-anatomic reconstructive method is one of the options for managing patients presenting with infected aortic grafts or aortoenteric fistulae.[2, 3, 4]

Bypass patency rates have been estimated to be in the range of 40-80% at 5 years.[5, 6, 7, 8, 9]  A study by Samson et al cited a slightly higher figure of 83.7% overall (85.5% for unilateral bypass, 81.8% for bilateral bypass).[10] Patency rates are influenced by the characteristics of the patients; claudicants generally have better patency than patients with critical limb-threatening ischemia (CLTI). Bilateral reconstructions appear to be comparable to unilateral reconstructions with regard to patency.[11]

Indications

Indications for axillobifemoral bypass include the following:

  • Symptomatic lower-extremity ischemia (disabling claudication, rest pain, tissue loss), acute (thrombosed aortoiliac system) or chronic
  • Infected aortic grafts or prosthetics
  • Aortoenteric fistulae
  • Patients without endovascular options for management of their ischemic symptoms
  • High-risk patients with significant comorbidities that preclude inline reconstruction with inflow from the aorta (cardiopulmonary disease, multiple prior abdominal operations, prior radiation therapy to the abdomen, abdominal stoma)
  • Aortic coarctation

Monnot et al reported three cases in which a temporary axillofemoral bypass was performed to protect renal function in kidney transplant recipients undergoing open repair of an abdominal aortic aneurysm (AAA).[12]

Contraindications

Contraindications for axillofemoral bypass include the following:

  • Diseased axillary or subclavian arteries
  • Extreme medical risks for surgery (eg, nonsurvivable acidosis in the setting of acute ischemia)

Technical Considerations

Complication prevention

The importance of a thorough preoperative assessment of the inflow vessel cannot be stressed enough.

Pay strict attention to sterile technique when handling prosthetic grafts. A wide sterile field is necessary to allow for a thoracotomy, sternotomy, or laparotomy to manage intraoperative bleeding or other unexpected complications that can arise during the course of the revascularization procedure.

Place the axillary anastomosis as medially on the artery as possible (medial to the pectoralis minor) to avoid tension on the anastomosis when the arm is abducted. Tunnel the graft along the midaxillary line to prevent kinking of the graft with torso flexion.

Outcomes

A retrospective analysis by Levin et al (N = 3261) assessed the outcomes of axillofemoral bypass (AxFB; n = 436) performed for intermittent claudication in comparison with those of aortofemoral bypass (AoFB; n = 2825).[13]  Patients in the AxFB group had a shorter postoperative length of stay and fewer perioperative pulmonary and renal complications but required more perioperative ipsilateral major amputations. At 1 year, the AxFB cohort had higher rates of death; of graft occlusion or death; of ipsilateral major amputation or death; and of reintervention, amputation, or death. On multivariable analysis, AxFB was independently associated with an increased risk of 1-year reintervention, amputation, or death.

 

Periprocedural Care

Preprocedural Evaluation

Preoperative workup is essential to confirm ischemia-related claudication, rest pain, and tissue loss. Screening should begin with the ankle-brachial index (ABI). Perform at least one imaging study for assessment: computed tomography (CT) angiography (CTA) of the aorta and lower-extremity arteries, magnetic resonance angiography (MRA), or standard aortography with assessment of runoff (outflow) vessels in the lower extremities.

Patients should undergo preoperative cardiopulmonary assessment; progressive and symptomatic peripheral arterial disease likely signifies underlying cardiovascular disease.

Preoperative assessment of bypass inflow should begin with bilateral brachial blood pressure measurements to identify potential problems with the axillary or subclavian arteries. Choose the axillary artery on the side with the higher blood pressure if there is a systolic pressure discrepancy of 10 mm Hg or more between the limbs. If it will be necessary to access the thoracic aorta in the future, perform the bypass graft tunneling on the right side.

Equipment

Equipment employed for axillofemoral bypass includes the following:

  • Standard vascular clamps and instruments
  • Tunneling device (eg, Gore tunneler; W. L. Gore and Associates, Flagstaff, AZ)
  • Polytetrafluoroethylene (PTFE) or Dacron-based aortic grafts (6-10 mm) of appropriate length and configuration for either a unifemoral or a bifemoral reconstruction
  • Doppler ultrasonography (US) device to assess blood flow intraoperatively

Patient Preparation

Anesthesia

Axillofemoral bypass is most often performed with general anesthesia because exploration of the axillary artery and tunneling of the graft proximal from the chest to the distal femoral landing site can be difficult to tolerate. In cases where underlying cardiopulmonary disease precludes general anesthesia, the procedure can be performed by using local anesthesia with sedation.

Positioning

Perform the procedure with the patient supine, and prepare a wide sterile field from the neck to the anterior thigh (with the chest, flank, and abdomen included). Place a rolled towel under the ipsilateral torso to allow good visualization of the lateral chest wall during tunneling of the graft. Prepare the donor arm in a sterile fashion, allowing for intraoperative abduction of the limb to assess for graft lie after the axillary anastomosis.

Monitoring & Follow-up

The utility of routine graft surveillance with duplex US has been questioned, and limited data are available on whether noninvasive scanning is truly able to identify a threshold predictive of impending bypass failure. Follow-up with standard ABI assessment at regular intervals has been recommended.

The 2018 guidelines from the Society for Vascular Surgery (SVS) recommended clinical examination and ABI measurement, with or without the addition of duplex US, in the early postoperative period to provide a baseline for further follow-up after axillobifemoral bypass; this evaluation would be repeated at 6 and 12 months and then annually as long as there are no new signs or symptoms.[14]

 

Technique

Axillofemoral Bypass

Exposure of axillary artery

Make a transverse infraclavicular incision approximately two fingerbreadths below the clavicle. The pectoralis muscle is exposed and fibers are split superiorly and inferiorly. At this point, divide the pectoralis minor insertion to allow further exposure. The axillary fat pad, which contains the vein, artery, and brachial plexus, will be accessible. The axillary vein lies anterior to the artery and must be mobilized inferiorly to afford access to the artery. Isolate a 3- to 4-cm length of artery, which requires that some branching vessels be ligated or controlled.

Exposure of femoral artery

Obtain either unilateral or bilateral exposures of the femoral arteries, depending on the revascularization needs. Use longitudinal or oblique groin incisions for the femoral exposure. Carry the incision along the femoral pulse at the level of the common femoral artery (inguinal ligament). Dissect subcutaneous tissues, and enter the femoral sheath. The artery lies lateral to the femoral vein. Dissect the common femoral, superficial femoral, and deep femoral (profunda femoris) arteries, and control with vessel loops. Control and preserve circumflex branches.

Tunneling of graft

Perform subcutaneous tunneling before systemic heparinization. Use a graft tunneling device (eg, Gore Tunneler) to create a midaxillary tunnel, lateral to the nipple and above the abdominal fascia, from the axillary incision to the femoral incision. If necessary, create a femoral-to-femoral tunnel superior to the pubic bone for a bifemoral reconstruction. Pass the PTFE or Dacron graft(s) through the tunnel(s) with the use of the device and ensure that there are no twists or kinks. (See the image below.)

Tunneling of the axillofemoral bypass (bifemoral c Tunneling of the axillofemoral bypass (bifemoral configuration shown).

Axillary anastomosis

Administer intravenous heparin prior to vascular control for the creation of the anastomosis.

Perform the proximal axillary anastomosis first. Because the axillary and subclavian arteries are considerably more fragile than the femoral arteries are, take care to avoid aggressive handling of these vessels. Use angled clamps (ductus, angled DeBakey, or mini profunda) to obtain proximal and distal control of the axillary artery. Perform a longitudinal arteriotomy, and fashion a hood on the PTFE/Dacron graft. Then create an end-to-side running anastomosis. Assess graft inflow and distal axillary arterial outflow as the arm is abducted to ensure that there is no tension on the anastomosis.

Axillary anastomosis. Axillary anastomosis.

Femoral anastomosis

There are many configurations for creating the distal femoral anastomosis; the choice depends on the needs of the patient. If a bifemoral configuration is required, construct the distal femorofemoral anastomosis first, and land on the distal axillary graft on the ipsilateral segment of the femorofemoral graft. Otherwise, the contralateral femoral limb may come directly off the ipsilateral axillofemoral graft in an end-to-side fashion. Premade axillobifemoral grafts are also available from several manufacturers.

Once the femoral vessels are controlled, create a longitudinal arteriotomy. Create the distal femoral anastomosis in an end-to-side fashion to an appropriate branch of the common femoral artery (most often, the common femoral artery itself). If there is significant disease of the superficial femoral artery, the anastomosis may have to be performed in such a way as to incorporate the deep femoral artery. In general, spatulation of the anastomosis to the deep femoral artery is recommended. Concomitant endarterectomy of the femoral artery may be necessary if significant disease exists on the distal target vessel.

Postoperative Care

Perioperative hemodynamic monitoring is essential to good outcomes. In view of the prosthetic burden, surgical wounds should be monitored diligently for early signs of infection and managed promptly. Prophylactic antibiotics should be administered before any future surgical interventions (eg, dental procedures) that may disseminate bacteria.

Complications

Potential complications of axillofemoral bypass include the following:

  • Brachial plexus injury
  • Axillary pullout syndrome (disruption of the axillary anastomosis)
  • Graft thrombosis
  • Graft infection [15]
  • Early graft thrombosis and delayed pseudoaneurysm of the graft (may be a sign of underlying graft infection)

Shortening or lengthening of the graft has been reported as a late postoperative complication but is rare.[16]