The Impella (Abiomed) intravascular microaxial blood pump delivers blood from the left ventricle into the aorta.1 The Impella 2.5 and Impella CP systems are used as temporary (≤6 hours) ventricular support devices, indicated for use during high risk percutaneous coronary interventions (PCI) in patients with depressed left ventricular ejection fraction.2 They are also intended for short-term use (≤4 days for the Impella 2.5 and Impella CP, and ≤6 days for the Impella 5.0 and Impella LD) for the treatment of ongoing cardiogenic shock following acute myocardial infarction or open heart surgery as a result of isolated left ventricular failure that is not responsive to optimal medical management and conventional treatment measures (including volume loading and use of pressors and inotropes, with or without an intra-aortic balloon pump [IABP]).3 They reduce ventricular work and provide the circulatory support necessary to allow heart recovery and early assessment of residual myocardial function.
Other than the Impella CP, which has an .035-inch guidewire repositioning access port, other models don’t have access ports for exchange that would allow escalation of hemodynamic support or exchange to another type of support. Preservation of the access site is key, especially in patients with peripheral artery disease or other difficult vascular anatomy. Also, it can be used for future interventions and saves time. There are three published case reports of techniques that seek to preserve the access site4-6, including the single-access “Trojan Horse” technique where the Impella catheter is punctured with a Cook needle. Each of the published techniques involves cutting through the catheter. We publish the first “atraumatic technique” of an Impella access site retrieval procedure, without any damage to the Impella catheter.
The cannula is a spiral-shaped, reinforced body made of nitinol and covered in polyurethane. The sheath (with hemostatic valve) is graduated from 9 French (Fr) to 15 Fr (except for Impella 5.0). It is located on the catheter shaft and allows repositioning of the catheter. It is usually hubbed to the sheath to prevent bleeding. We sought to use the transition from 9 to 15 Fr and the hemostatic valve to introduce a smaller catheter and thereby be able to secure the usual .035-inch or any wire (Table, above).
A 57-year-old man with history of diabetes mellitus presented to a non-PCI capable hospital with chest pain and inferior ST-elevation myocardial infarction. After receiving thrombolytics, he was transferred to a PCI-capable hospital, where he had pulseless electrical activity (PEA) arrest, and underwent emergent left circumflex stenting and Impella placement. Due to refractory shock, he was transferred to our institution for possible venoarterial extracorporeal membrane oxygenation (VA ECMO) placement. However, over the next few days, his condition improved and did not require ECMO. Due to residual disease and non-surgical candidate, he underwent left main and left anterior descending artery PCI, and his clinical status improved. He was then referred for Impella removal and IABP placement.
After appropriate sterile precautions and weaning Impella settings to P2, the catheter was pulled back to the descending aorta to allow a 5 Fr stiffened micropuncture catheter/dilator to advance into the hemostatic valve. The micropuncture catheter was then hubbed to prevent any bleeding. The 3 Fr introducer of the stiffened micropuncture kit was removed and the bleedback was noted (Figure 1). An .035-inch Amplatz Extra Stiff wire (Cook Medical) was introduced into the 5 Fr sheath and advanced under fluoroscopy assistance to the aortic arch. The Impella catheter was pulled under fluoroscopy up to the tip of the peel-away sheath, keeping the 0.035-inch J-wire tip at the aortic arch. The Impella as a unit and peel-away sheath were pulled out of the body with the Extra Stiff wire in place. Another 14 Fr sheath was introduced over the Extra Stiff wire, and was advanced and positioned at the arteriotomy site to achieve hemostasis (Figure 2), with balloon pump placement as part of the weaning protocol.
Previous case reports have reported exchanging the Impella catheter and sheath by puncturing the catheter with a percutaneous needle in order to preserve the arterial access. We describe the first atraumatic technique where the use of a micropuncture kit and supportive wire is all that is needed to exchange or upsize the support. Our technique does not damage the Impella catheter and is safer, as it does not affect the architecture of the Impella catheter. Based on Impella database, the vascular complication rate was 17%, with need for amputation in 4.4%.7 Vascular complications requiring surgery occurred in 2.5% of USpella registry patients.8 Knowledge regarding the use of the Impella and techniques to reuse the access site will help prevent additional vascular access procedures and also unwanted access site complications.
- Impella CP product page. Abiomed. Available online at http://www.abiomed.com/impella/impella-cp. Accessed March 18, 2019.
- O’Neill WW, Kleiman NS, Moses J, et al. A prospective, randomized clinical trial of hemodynamic support with Impella 2.5 versus intra-aortic balloon pump in patients undergoing high-risk percutaneous coronary intervention: the PROTECT II study. Circulation. 2012 Oct 2; 126(14): 1717-1727.
- Seyfarth M, Sibbing D, Bauer I, et al. A randomized clinical trial to evaluate the safety and efficacy of a percutaneous left ventricular assist device versus intra-aortic balloon pumping for treatment of cardiogenic shock caused by myocardial infarction. J Am Coll Cardiol. 2008 Nov 4; 52(19): 1584-1588.
- Cook BS, Wilson C, Kaiser B, et al. A method for maintaining vascular access when Impella exchange is required. Catheter Cardiovasc Interv. 2017 Nov 15; 90(6): 945-947.
- Khachatryan T, Lan H, Narasimha D, et al. Procedure for changing an Impella device while maintaining guide wire access: a novel technique. International Cardiovascular Forum Journal. 2016; 9: 51-53.
- Phillips CT, Tamez H, Tu TM, et al. Novel method for exchange of Impella circulatory assist catheter: the “Trojan Horse” technique. J Invasive Cardiol. 2017 Jul; 29(7): 250-252.
- Abaunza M, Kabbani LS, Nypaver T, et al. Incidence and prognosis of vascular complications after percutaneous placement of left ventricular assist device. J Vasc Surg. 2015; 62: 417-423.
- O’Neill WW, Schreiber T, Wohns DH, et al. The current use of Impella 2.5 in acute myocardial infarction complicated by cardiogenic shock: results from the USpella registry. J Interv Cardiol. 2014; 27: 1-11.