Cardiovascular Revascularization Medicine, 2018-07-01, Volume 19, Issue 5, Pages 540-544, Copyright © 2018 Abstract Hemodynamic support with the Impella device is an important tool during high risk percutaneous coronary intervention. This device is usually inserted via the femoral artery. However, some patients have severe peripheral artery disease precluding the use of the femoral artery for this purpose. The axillary artery is a viable alternative in these cases. We reviewed the two access techniques for inserting the Impella via the axillary artery and also described 6 cases of successful implantation. Highlights The axillary artery is a good alternative for Impella insertion in patients without optimal femoral access. Axillary access has potential advantages of early mobilization and lower risk of infection. The cutdown approach offers hemostasis by direct closure, minimizing serious complications due to bleeding. The percutaneous approach is less invasive and can be performed under moderate sedation. 1 Introduction The use of the Impella® (ABIOMED) percutaneous left ventricular assist device for hemodynamic support is an important option for interventional cardiologists. In patients undergoing high-risk percutaneous coronary intervention (PCI), the PROTECT II study showed a trend toward improvement in the 90-days composite end points of major adverse events with the use of Impella 2.5 compared to intra-aortic balloon pump. While the typical approach for the insertion of the Impella is via the common femoral artery, many patients needing high-risk PCI have co-existing severe peripheral arterial disease (PAD) precluding of this arterial access route for implantation of the device. The axillary artery however is readily accessible as an alternative site for Impella insertion. As previously reported, axillary access of the surgical counterpart (Impella 5.0) in cardiogenic shock was successful. Thus, we began to use axillary access for high risk PCI in patients not otherwise amenable to a trans-femoral access. In this review, we will discuss the different techniques of obtaining axillary access for Impella insertion. We will also describe six cases where Impella was inserted via axillary cut-down approach for high-risk PCI at our institution to demonstrate the target patient population for this approach. We also discuss the potential impact of axillary Impella access in high risk PCI in the setting of cardiogenic shock. We advocate that such approach offers both patients and clinicians expanded clinical options and potential benefits. 2 Cut down axillary access and closure technique The axillary artery, the continuation of the subclavian artery extends from the outer border of the first rib to lower border of teres major muscle. The relatively superficial location of this artery allows the artery to be readily exposed for placement of the Impella in patients with difficult femoral access. Either the right or left axillary artery can be used for this purpose. The axillary artery is exposed with an incision 2 fingers breath below the clavicle. The incision is deepened through the superficial fascia and platysma to expose the pectoral fascia. The pectoral fascia is incised, and the fibers of the pectoralis major muscle are split to expose the clavi-pectoral fascia overlying the axillary vein and artery. Tributaries of the axillary vein, which lie medial to the artery, are divided between ligatures to expose the artery. The pectoralis muscle minor may be divided to improve the exposure. The axillary artery is mobilized and looped proximally and distally with vessel loops ( Fig. 1 ). The patient is then heparinized and the axillary artery accessed using the modified Seldinger technique and a 6 French (F) sheath placed over a wire. An 0.035″ Glidewire and angled catheter are used to direct the wire into the aortic root. The floppy wire is then exchanged for a stiff wire, the sheath is withdrawn, and the arteriotomy puncture site is serially dilated over the wire to allow passage of the Impella sheath (13 to 14 F). Since the sheath is already directed toward the ascending aorta, the Impella device is easily advanced across the aortic valve and into the left ventricle without requiring the guidewire ( Fig. 2 ). At the completion of the procedure and the patient is hemodynamically stable, the device is withdrawn and the artery occluded between clamps and the arteriotomy closed with interrupted Prolene sutures. The incision is closed in layers, and the pulses in the extremity examined to ensure patency. Care should be taken when handling the axillary artery as it is extremely fragile. Potential complications may include wound hematoma, hemothorax, injury to adjacent nerves and avulsion of venous or arterial tributaries. An alternative surgical strategy to direct axillary cannulation as described above is using an end-to-side graft anastomosis and inserting the large bore sheath through this graft. An observational study comparing this method to direct cannulation for cardiopulmonary bypass found that it is associated with lower complications. For insertion of very large bore devices (such as cardiopulmonary bypass cannula or Impella 5.0), use of this latter approach is recommended. Fig. 1 Exposure of the axillary artery. 3 Percutaneous axillary access and closure technique In 2012, Lotun et al. published the percutaneous axillary access and closure technique in detail and others have reported the success of this technique thereafter. In summary, an alternative access (such as ipsilateral radial, or femoral) is obtained and an angiogram of the axillary artery is performed to identify the optimal site for access ( Fig. 3 ). Under fluoroscopic guidance, percutaneous micro-puncture technique is used to canalize the axillary artery between the subscapular artery and anterior/posterior humeral circumflex artery ( Fig. 4 ). After confirming position with an angiogram, Perclose Proglide is deployed in “pre-close” fashion (suture deployed but not tightened). The large bore sheath (13 to 14F) is placed after serial dilations and the Impella device is inserted in typical fashion. When the patient is stable for device removal, meticulous closure technique is employed since the axillary artery is not easily amendable to manual compression for hemostasis. The Impella device is removed with its sheath still in place. An appropriate sized peripheral balloon is inserted over an 0.018″ or 0.035″ wire from the ipsilateral radial sheath or femoral sheath and positioned just proximal to the arteriotomy. Once the large bore sheath is removed, the “pre-close” sutures are tightened while the peripheral balloon is inflated to assist hemostasis. Repeat axillary artery angiogram is performed to ensure hemostasis and if there is residual hemorrhage, a “bail out” covered stent can be placed. 4 Cases 4.1 Case 1 An 80-year-old man with known coronary artery disease (CAD) and chronic kidney injury was admitted with non-ST elevation myocardial infarction (NSTEMI). His left ventricular ejection fraction (LVEF) was 25–30%. He was also found to have 6.1 cm infrarenal abdominal aortic aneurysm (AAA) with large mural thrombus. His medical history is significant for: oxygen dependent chronic obstructive pulmonary disease (COPD), chronic smoker, chronic kidney disease (CKD) stage 5, tachy-brady syndrome status post dual chamber pacemaker implantation, paroxysmal atrial fibrillation, dyslipidemia, and hypertension. He underwent coronary arteriography via the radial approach and was found to have a left dominant system with severe left main and trifurcation left anterior descending (LAD), circumflex (LCx) and ramus disease. Cardiothoracic surgery consultation was obtained and deemed the patient too high risk for coronary artery bypass graft surgery (CABG) (Society of Thoracic Surgeons (STS) mortality risk 26%, morbidity or mortality 63%). The patient was offered high-risk multi-vessel PCI with Impella hemodynamic support. Due to the presence of the large AAA with thrombus, the decision was made to insert the Impella via the axillary cut down approach ( Fig. 2 ). He underwent stenting of the left main, LAD, LCx, and ramus intermedius with no complication during the procedure. The Impella was removed at the end of the case, and the Impella access site closed by the surgical team. He followed up with vascular surgery and had elective endovascular repair of the AAA with good results. Fig. 2 Fluoroscopic image of Impella placement via the left axillary artery. Fig. 3 Axillary artery angiogram from left radial access. Fig. 4 Percutaneous cannulation using fluoroscopic guidance. A J wire is positioned in the desired axillary artery location and a micropuncture needle is used to “stick the J”. 4.2 Case 2 A 79-year-old man was admitted for NSTEMI. Coronary arteriogram demonstrated severe distal left main and multivessel disease. He was also found to have severe PAD including a chronically occluded left subclavian artery, 4.7 cm infrarenal AAA, moderate bilateral carotid stenosis and right toe dry gangrene from critical limb ischemia. His LVEF was 25%. His other medical history was significant for: prostate cancer, dyslipidemia, hypertension, chronic smoker, severe COPD, diabetes mellitus, and CKD stage III. The patient was deemed too high risk for CABG by the cardiothoracic surgery team (STS mortality risk 21%). Given severe PAD including an occluded left subclavian artery and limited femoral arterial access, the Impella 2.5 was inserted via the right axillary artery cut down approach. PCI of the left main, LAD, LCx, ramus intermedius, diagonal and right coronary artery (RCA) was performed without complication. The Impella was removed at the end of the case. The patient remained hemodynamically stable from the cardiac stand point, but his hospital course was complicated by respiratory failure from hospital acquired pneumonia superimposed on severe COPD and heart failure. With no significant improvement after two weeks, the patient's family decided to pursue hospice care and he expired in the hospice unit. 4.3 Case 3 This 72-year-old man with PAD presented with an anterior ST elevation myocardial infarction. He had a severely tortuous AAA that was previously treated with endovascular repair. This required revision two months prior to admission due to extreme angulation and thrombus formation. He had an emergent coronary arteriogram showing severe, calcified distal left main disease, severe trifurcation disease (LAD, LCX, and ramus intermedius), and chronic total occlusion of the RCA. He was stabilized, given aggressive medical therapy and a cardiothoracic surgery consultation obtained. His other medical history was significant for esophageal and colon cancer treated with resection. His LVEF was 30%. While undergoing CABG evaluation, the patient decompensated and developed cardiogenic shock. The decision was made to perform high risk PCI with Impella 2.5 support via the left axillary artery cut down approach. He underwent bifurcation stenting of the left main into the LAD and ramus intermedius. He had transient asystole during balloon inflation of the left main but maintained a mean arterial pressure of 70 mm Hg from the Impella. He had persistent cardiogenic shock after the case and the Impella was kept in place for continued support. The patient initially improved and required decreasing Impella and inotropic support. However, his course was complicated by aspiration pneumonia and disseminated intravascular coagulation. He was made comfort care after one week and expired. 4.4 Case 4 A 70-year-old man with PAD was admitted for a NSTEMI and decompensated heart failure with New York Heart Association (NYHA) class IV symptoms. He had prior right femoral-to-posterior tibial artery bypass and had graft restenosis requiring angioplasty three years ago. He uses a prosthesis to walk due to prior left below the knee amputation and right foot amputation. His other comorbidities included insulin dependent diabetes mellitus, hypertension, cigarette smoking, severe COPD and bilateral moderate carotid stenosis. He underwent coronary arteriography which showed severe calcified high grade left main and three vessel disease. His LVEF was 10%. A viability study showed viable myocardium except at the true apex. Cardiothoracic surgery was consulted and determined that the patient was not a good surgical candidate due to relatively high risk (STS mortality 10%) and limited abilities to perform cardiac rehabilitation after surgery. High risk PCI with Impella 2.5 support was pursued. Due to limited vascular access, the Impella was inserted via the left axillary artery cutdown approach. He underwent stenting of the left main, LAD, and LCX uneventfully, and the Impella was removed after the procedure. He used his prosthesis to ambulate the next morning and was discharged home the following day. He had staged PCI to RCA two weeks later and at the 30 days follow up, he was angina free with NYHA class II symptoms. 4.5 Case 5 A 66-year-old man with severe claudication was being evaluated for revascularization of the right lower extremity by vascular surgery. He had dyspnea on exertion and his pre-operative work up included an echocardiogram showing a LVEF of 25% with global hypokinesis. He underwent coronary arteriography which demonstrated 60% left main stenosis, 70% ostial LAD stenosis, small first obtuse marginal (OM1) with 70% stenosis, occluded mid LCX, and occluded RCA with the small diffusely diseased posterior descending artery (PDA) filling via collaterals. His co-morbidities included severe PAD, prior stroke, diabetes mellitus, and dyslipidemia. Cardiothoracic surgery was consulted and after discussion of the risks and benefits of CABG (probably one vessel bypass due to poor LCX and RCA targets), the patient wished to pursue PCI. The Impella 2.5 was inserted via surgical cut down into the left axillary artery. He underwent stenting of the left main and mid LAD without complications. He was optimized medically for his heart failure and had successful stenting of the right common iliac artery, right superficial femoral artery, and left external iliac artery. 4.6 Case 6 A 70-year-old man with diabetes mellitus, hypertension, and PAD underwent coronary angiography after an abnormal exercise stress test. This demonstrated 90% calcified left main stenosis, 90% calcified LAD stenosis, diffusedly disease LCX with normal distal OM branch, and an 80% ostial RCA stenosis (small vessel). He subsequently had CABG with a left internal mammary artery (LIMA) to proximal LAD and saphenous vein graft (SVG) to OM. Intraoperatively, there was difficulty coming off cardiopulmonary bypass, and he had ventricular fibrillation. This was successfully treated with defibrillation and placement of two additional bypass grafts (SVG-to-distal LAD, and SVG-to-PDA). Post operatively, the patient had persistent cardiogenic shock, ventricular tachycardia, and anterolateral ST elevation. He then underwent cardiac catheterization which demonstrated that the LIMA was grafted to the diagonal branch and was occluded at the anastomotic site, the SVG-to-LAD was occluded, the SVG-to-OM was patent but anastomosed to a diseased segment, and the SVG-to-PDA was normal. An Impella CP was inserted via surgical cut down into the left axillary artery due to his severe PAD. The left main artery and proximal LAD were pre-treated with rotational atherectomy and successfully stented. He required Impella support for 5 days and was successfully weaned off all mechanical support and vasopressors. He eventually improved and was discharged to a rehabilitation facility. 5 Discussion High risk PCI with hemodynamic support has offered new options to the interventionalist grappling with patients previously deemed inoperable or unapproachable for conventional PCI. Additionally, critically ill patients with multiple co-morbidities often present in the setting of rapid cardiovascular deterioration. Hemodynamic support coupled with potential rescue PCI may provide time-sensitive stabilization in otherwise moribund conditions. The Impella can be an indispensable tool to achieve and maintain stability during such high-risk PCI. As described in case 3, the Impella provided a safety net and maintained stable hemodynamics even during a period of asystole. It can also be left in place for support if the patient has persistent cardiogenic shock as in case 6. In patients with severe PAD and limited femoral artery access, the axillary artery is a viable and safe alternative. This approach has the advantage of permitting the patient to sit up with the device in place improving mobility and potentially respiratory physiology in these critically ill patients. In those needing longer mechanical hemodynamic support, the axillary position for indwelling device is probably less prone to infection compared to the femoral area as demonstrated with central venous catheters. While axillary insertion of Impella 2.5 and CP for high-risk PCI is limited to a few case reports in the literature, this approach has been described in several case series for insertion of the surgical Impella 5.0 mainly in the setting of persistent severe heart failure. Sassard et al. published their early two cases in 2008 using the right axillary graft anastomosis approach for Impella 5.0 insertion without complications . Subsequently, several cases series reported this approach with success . The largest published series by Bansal et al. had 24 patients with persistent cardiogenic shock who were poor candidate for LVAD placement via the sternotomy approach. They found relatively low rates of complication (one patient had temporary brachial plexopathy and another had pectoralis major hematoma needing surgical evacuation) despite of the mean support duration of 17.6 days. We hypothesize that using this approach for high-risk PCI would have even lower rates of complication due to smaller device caliber and shorter duration of support. Surgical cut down approach has the advantage of direct closure which offers reliable hemostasis. This is crucial as the axillary artery is not readily compressible and critical structures including the brachial plexus can be injured if there is bleeding. Our six cases demonstrated that this can be done effectively and without vascular or neurologic complication ( Table 1 ). The disadvantages of surgical cut down include the need for vascular surgery expertise and usually general anesthesia. Percutaneous axillary access for Impella insertion has the advantages of being less invasive and can be done with moderate sedation. Residual bleeding after percutaneous suture mediated closure can occur and bail out covered stent would be needed. The procedure is more complex than routine femoral access and the operator needs to be well versed in endovascular procedures. Comparison of the two axillary strategies and percutaneous femoral approach are summarized in Table 2 . If femoral approach is not available (in patients with severe PAD or those needing extended Impella support), the choice of axillary approach depends on local expertise. Table 1 Summary of cases. PatientAge yearsSexComorbiditiesLVEFCoronary anatomyAccessOutcomeComplications 1 80 Male Infrarenal AAA with thrombus CKD, Hypertension, COPD trial fibrillation 25% LM, LAD, ramus and LCX high grade stenosis Surgical cut down Impella removed at the end of PCI. Discharged without issues. None 2 79 Male Infrarenal AAA Critical limb ischemia with severe PAD COPD 25% LM, LAD, LCX and RCA stenosis Surgical cut down Impella removed at the end of PCI Developed pneumonia and decompensated heart failure. Palliative care. 3 72 Male Recent EVAR for AAA Severe PAD 30% Distal left main stenosis and RCA CTO Surgical cut down Impella left in place after procedure due to persistent cardiogenic shock Developed aspiration pneumonia and persistent cardiogenic shock. Palliative care. 4 70 Male Severe PAD with right femoral-posterior tibial bypass Left below knee amputation Right foot amputation 10% Distal left main and RCA stenosis Surgical cut down Impella removed at the end of PCI. Discharged without issues. None 5 66 Male Severe PAD Stroke, Hypertension Diabetes 25% Left main, LAD, LCX and RCA stenosis Surgical cut down Impella removed at the end of PCI. Discharged without issues. None 6 70 Male PAD Diabetes Hypertension 10% Distal left main and LAD stenosis with occluded SVG to LAD and LIMA to diag that was atretic. Patent SVG to OM and RCA. Surgical cut down Impella left in place for 5 days due to persistent shock. Improved and discharged in stable condition. None Table 2 Comparison of Impella arterial access and closure techniques. Percutaneous femoralPercutaneous axillarySurgical cutdown axillary Access Percutaneous Percutaneous – fluoroscopic or ultrasound guidance Direct cannulation or Graft conduit Closure “Pre-close” “Pre-close” and balloon tamponade Direct suture Hemostasis Reliable, manual compression if needed Usually achievable, Bail out covered stent if needed Very Reliable Expertise needed Basic endovascular Complex endovascular Vascular surgery Anesthesia Moderate sedation Moderate sedation General anesthesia Mobility Limited Improved Improved Infection Probably higher Probably lower Probably lower Neurovascular complications Low Higher Higher 6 Final comments We recognize that this is a report of our early efforts to impact and support patients with acute critical illness and those suffering from advanced progressive CAD. “Success” is arguably limited but is also defined within the context of “real world” outcomes of survival versus expected and projected mortality in these critically ill patients. We are beginning efforts to identify the cohort of those with advanced CAD needing repetitive hospitalization and palliative medical therapy who might undergo high-risk PCI supported by Impella improving both their clinical and economic outcomes. In our experience, use of Impella devices via axillary approach proved to be a viable treatment strategy in a highly symptomatic patient population. Selection of appropriate patients may render reductions in expected mortality, economic expenditures and enhanced quality of life metrics.