Adaptive ECMO Therapeutics: The Integral Role of the ProtekDuo® Cannula

Abstract

This chapter provides an in-depth analysis of the ProtekDuo® (LivaNova, London) dual-lumen cannula’s application in extracorporeal membrane oxygenation (ECMO), focusing on the procedural techniques of cannulation, weaning, and decannulation. The discussion will provide the step-by-step methodologies for inserting and removing the cannula, drawing from current clinical practices. Further, the chapter will explore the range of ECMO configurations that the ProtekDuo® cannula enables. It will examine how these configurations can be tailored to the evolving clinical requirements of patients, thereby enhancing the adaptability and effectiveness of ECMO therapy. This analysis will be anchored in the latest literature, providing a contemporary overview of patient outcomes and current practices. Lastly, the chapter will project into the future of the cannula technology for venopulmonary (VP) ECMO and other configurations. It will review ongoing research and development efforts, speculate on potential technological breakthroughs, and discuss the implication of these innovations for clinical practice. This forward-looking perspective will aim to inform and inspire continued advancement in ECMO therapy and technology.

1. Introduction

Wang and colleagues first described the use of a single-site, dual-lumen cannula for a percutaneous right ventricular assist device (RVAD) with an optional membrane lung (ML) in an ovine model in 2015 [1]. The following year, Aggarwal et al. described a patient with combined cardiogenic shock due to right ventricular failure (RVF) and hypoxic respiratory failure, treated with the ProtekDuo® cannula as part of an ECMO system that provided both right ventricle (RV) and respiratory support [2]. Subsequently, the application of this device has expanded, primarily for the management of RVF, both with [3, 4, 5, 6, 7, 8, 9, 10] and without [8, 9, 11] an ML for simultaneous respiratory failure treatment. The adoption of the cannula has grown, not only within RVAD systems but also as a component of ECMO in various configurations for respiratory, cardiocirculatory, or combined support [12].

The ProtekDuo®, a dual-lumen cannula, features an innovative cannula-within-a-cannula design, establishing two concentric channels for percutaneous, single-site access. Available in two sizes—31 French (Fr) and 29 Fr—the 31 Fr consists of a 28 cm x 31 Fr proximal drainage lumen and a 51 cm x 18.5 Fr distal return lumen. The 29 Fr size is comprised of a 28 cm x 29 Fr proximal drainage lumen and a 46 cm x 16 Fr distal return lumen. The outer proximal cannula is designed with 16 circumferential side holes, while the distal return cannula incorporates six side holes near the tip, allowing for omnidirectional blood flow.

In most cases, the cannula is positioned such that the proximal drainage holes lie within the right atrium (RA) and the distal return holes open into the main pulmonary artery (PA). Used in conjunction with an extracorporeal blood pump, this arrangement facilitates a direct bypass of the RV. The flow rates achievable are 4–4.5 liters (L) for the 29 Fr cannula and 4.5–5 L for the 31 Fr cannula. With the addition of an ML into the circuit, support for both the RV and lungs is provided with minimal recirculation due to the separation of the drainage and return sites by two cardiac valves [13].

2. Cannulation technique and management

2.1 Cannula insertion

The placement of the ProtekDuo® typically employs the modified Seldinger technique. Initially, the right internal jugular vein (IJV) or the left subclavian vein (LSV) is assessed by ultrasound to ensure their capacity to accommodate an 8 Fr or 9 Fr introducer sheath. Once venous access is obtained with the introducer sheath, a balloon-tipped wedge pressure catheter is advanced into the right PA under guidance from transesophageal echocardiography (TEE) or fluoroscopy (see details below).

Subsequently, a long 0.035-inch Lunderquist (Cook Medical) or Amplatz (Boston Scientific) extra stiff wire is positioned within the right PA. The balloon catheter and introducer sheath are then removed, with meticulous attention to keep the stiff wire properly positioned in the right PA. Under fluoroscopic guidance, the entry site is progressively dilated to just below the necessary diameter for the 29 or 31 Fr ProtekDuo® cannulas, again taking great care to maintain the position of the wire in the right PA.

With the cannula introducer placed in the distal cannula lumen, the ProtekDuo® is inserted over the guidewire until the tip of the cannula is in the right PA. After the cannula is inserted, the internal dilator is removed, and both cannula ports are clamped. At this point, a primed ECMO circuit can be connected using a wet-to-wet technique to the drainage (proximal) and return (distal) ports. The clamps are then carefully removed, and the pump flow is gradually increased at the clinician’s judgment. The device is secured at the insertion site with care to avoid direct suturing to the cannula body, as this may cause cannula erosion. Instead, suture rings provided with the cannula facilitate an indirect method of fixation.

2.2 Imaging

2.2.1 Fluoroscopy

Fluoroscopy is the most precise imaging modality available and easily available in operating rooms and catheter laboratories. It may easily be brought to the intensive care unit (ICU) and used for bedside cannulations as well. Protocols for protection from radiation should be in place. Under fluoroscopic guidance, the passage of the balloon-tipped wedge pressure catheter (Figure 1a), wire (Figure 1b & 1c), and ProtekDuo® cannula (Figure 1d) can continuously be observed through all structures.

Figure 1.

Fluoroscopy images obtained during ProtekDuo® insertion. Fluoroscopic images of (a) introducer sheath with balloon-tipped wedge pressure catheter in right PA, (b) introducer sheath with stiff wire in right PA after removal of balloon-tipped wedge pressure catheter, (c) stiff wire in branch of right PA after removal of introducer, and (d) ProtekDuo® cannula positioned with a tip in main PA. Abbreviations: PA: Pulmonary artery.

2.2.2 Transesophageal echocardiography

In situations where fluoroscopy is not available, TEE may be safely utilized by an experienced echocardiographer. A standardized full TEE exam should be performed before and after the cannula placement to verify the diagnosis and treatment plan and to ensure there are no complications such as perforation of cardiac structures, pericardial effusions, or potential valve lesions.

The placement of the ProtekDuo® cannula and the associated instruments, including the balloon wedge pressure catheter and the stiff wire, can be best visualized using three specific TEE views. Initially, the midesophageal (ME) “bicaval” view, typically at 105 degrees, facilitates monitoring of the instruments as they move through the superior vena cava (SVC), the RA, and toward the tricuspid valve (TV). The operator should then transition to the “ME RV inflow/outflow” view, to monitor instrument passage through the TV, the RV, and the pulmonic valve (PV) toward the PA (Figure 2). Finally, the “upper ME ascending aortic view” at 0–10 degrees can be employed to confirm the positioning of the instrument within the PA [14].

Figure 2.

TEE modified RV inflow/outflow view in X-plane. Abbreviations: LA: Left atrium, PA: Pulmonary artery, RV: Right ventricle, RVOT: Right ventricular outflow tract, TEE: Transesophageal echocardiogram.

2.3 Anticoagulation

Prior to insertion of the cannula, a bolus of unfractionated heparin (UFH) is administered to reach an activated clotting time (ACT) of 250–300 seconds [15]. Following the initiation of ECMO flow, a continuous infusion of UFH or a direct thrombin inhibitor (DTI) [16], such as argatroban [17] or bivalirudin [18], is started to maintain a partial thromboplastin time (PTT) within the range of 40–60 seconds. This range may vary according to the specific ECMO circuit configuration utilized, and subsequent adjustments should align with the practices of the respective institution. It is important to note that every component in the heparin-coated circuit, such as stopcocks, pigtails, and bridges, can introduce proinflammatory and procoagulant risks and thus should be considered when managing anticoagulation therapy.

2.4 Weaning technique

Daily assessment of a patient’s readiness for weaning from cardiac and/or respiratory support is essential and should be based on established institutional criteria. The method of weaning ECMO support for patients with a ProtekDuo® cannula is contingent upon the primary reason for ECMO, as well as the mode of support and the configuration of cannulation employed. Several authors have described methods of device weaning though there is currently no standard method or protocol for device weaning [6, 8, 9, 19, 20]. Figure 3 illustrates our usual practice for weaning a patient from VP ECMO using the ProtekDuo® cannula.

Figure 3.

Steps for weaning a patient with RVF and respiratory failure from VP ECMO using a ProtekDuo® cannula in (dl)V-P configuration. Abbreviations: CI: Cardiac index, CVP: Central venous pressure, (dl)V-P: Percutaneously placed dual-lumen cannula for atrio-pulmonary artery venopulmonary ECMO, ECMO: Extracorporeal membrane oxygenation, MAP: Mean arterial pressure, PaCO2: Partial pressure of carbon dioxide in arterial blood, PaO2: Partial pressure of oxygen in arterial blood, ML: Membrane lung, RV: Right ventricle, RVF: Right ventricular failure. ^aEchocardiographic parameters can include RV fractional area change (>30–35%), right/left ventricle end-diastolic diameter ratio (<1/3), tricuspid annular plane systolic excursion (TAPSE) (>16 mm), pulsed doppler peak velocity at the annulus (≥10 cm/s), pulsed doppler myocardial performance index (MPI) (>0.40) [19, 21]. ^b minimal inotropic (<5 mcg/kg/min dobutamine equivalent) or vasopressor (<0.05 mcg/kg/min norepinephrine equivalent) support. ^c calculation of CI either by Fick equation or thermodilution. ^d abnormal PAPi in RVF <1.85 after LVAD or < 1.0 after acute MI [13]. We use a value <1.0 in all patients without LVAD although cutoff values have not been established for patients with RVF due to other causes.

In our practice, patients experiencing concurrent RVF and respiratory failure who are on VP ECMO with the ProtekDuo® cannula in a standard configuration are typically weaned from respiratory support first. The decision to wean is based on improvements in lung function, as indicated by oxygen saturation and PaCO2 measurements. Weaning respiratory support involves decreasing the sweep gas flow and sweep gas oxygen inlet oxygen fraction after the patient has been successfully weaned from mechanical ventilation or is on lung-protective mechanical ventilation settings. Weaning is pursued to the extent that the patient can endure, aiming to disconnect the gas source from the ECMO circuit, leaving the patient reliant solely on circulatory support via an RVAD.

Subsequently, the focus shifts to weaning from the RVAD, guided by improvements in cardiac function, particularly of the RV. Our standard weaning strategy entails a gradual reduction in pump flow by 0.25 to 0.5 L/min per day, which is roughly equivalent to 500 to 1000 rpm depending on pump parameters [6, 8, 9]. This process is continued until a constant flow rate of 2 L/min is reached and tolerated for approximately 24 hours as indicated by improved RV function on echocardiography, central venous pressure (CVP) <15 mmHg, mean arterial pressure (MAP) >65 mmHg, and cardiac index (CI) >2.2 L/min/m² with minimal to no need to inotropic or vasopressor support [6, 8, 9, 19, 20, 21]. When these criteria are met, a bedside turn down test is conducted.

The bedside turn down test involves carefully reducing pump flow in a stepwise fashion while assessing the patient’s hemodynamic parameters after each step. Our group routinely uses a Swan-Ganz catheter or pulmonary wedge pressure catheter for direct measurement of mixed venous oxygen saturation (SvO2) and calculation of RV hemodynamics, including PA pulsatility index (PAPi) during the bedside turn down test, provided the patient has not had recent cardiac surgery after which suture lines involving the PA are at risk. Of note, while the usefulness of PAPi as an indicator of RV performance has been demonstrated in patients with acute myocardial infarction (MI) and those undergoing left ventricular assist device (LVAD) implantation, its application in other scenarios and cutoff values are less frequently described [13]. Baseline hemodynamic values are noted while pump flow is at 2 L/min. The patient is anticoagulated to achieve an activated clotting time (ACT) of 250-300 seconds. Flow is progressively reduced to 1.5, 1, 0.5 L/min, and finally clamped off entirely for no longer than two minutes. If RV function by echocardiogram, CVP, MAP, CI, and other measured parameters remain stable during the bedside ramp test, cardiac support is terminated and the ProtekDuo® cannula is removed at the bedside.

For other ECMO modes and configurations using the ProtekDuo® cannula, the determination of weaning readiness should align with the level of recovery of the organ primarily supported by ECMO. In these cases, the weaning process should be in accordance with standard institutional protocols.

3. The ProtekDuo® for ECMO in acute respiratory failure

3.1 ProtekDuo® in (dl)V-P ECMO configuration

The (dl)V-P ECMO configuration represents the default or standard position and function of the ProtekDuo cannula, wherein blood is drained from the RA and returned into the main PA. Standard ECMO circuits invariably incorporate an oxygenator within the circuit; however, if the cannula is utilized solely as a component of an RVAD, an oxygenator is excluded from the circuit (Figure 4).

Figure 4.

ProtekDuo® in (dl)V-P ECMO configuration. Blood drainage occurring through proximal cannula holes in RA and blood return occurring through distal cannula holes in the main PA. Abbreviations: (dl)V-P: Percutaneously placed dual-lumen cannula for atrio-pulmonary artery venopulmonary ECMO, ECMO: Extracorporeal membrane oxygenation, PA: Pulmonary artery, RA: Right atrium.

3.2 ProtekDuo® in V(dl)V-P ECMO configuration

In this configuration, the ProtekDuo® cannula with an ML is situated in the (dl)V-P position. The system is augmented by integrating a 25 Fr femoral multistage venous drainage cannula, which serves to augment venous drainage and thereby enhance blood flow. Venous drainage from both the ProtekDuo® and the femoral cannula is combined via a 3/8-inch Y-connector. Oxygenated blood, post-pump, is then rerouted through the distal PA aspect of the ProtekDuo®. While this method has been employed in our clinical practice, it should be noted that the additional drainage typically yields only a moderate increase in overall blood flow oxygenation (Figure 5).

Figure 5.

ProtekDuo® with additional femoral venous drainage cannula in V(dl)V-P ECMO configuration. Blood drainage occurring through proximal cannula holes of ProtekDuo® in RA and femoral venous cannula holes in IVC, and blood return occurring through distal cannula holes of ProtekDuo® in main PA. Abbreviations: (dl)V-P: Percutaneously placed dual-lumen cannula for atrio-pulmonary artery venopulmonary ECMO, ECMO: Extracorporeal membrane oxygenation, IVC: Inferior vena cava, PA: Pulmonary artery, RA: Right atrium, V: Cannula in peripheral vein.

3.3 ProtekDuo® in V-(dl)VP ECMO configuration

Our group developed a novel modified configuration for a patient with COVID-19-related acute respiratory distress syndrome (ARDS) who experienced progressive hypoxia and clinical deterioration while being on (dl)V-P ECMO support. To enhance system performance, we introduced a 25 Fr femoral venous multistage drainage cannula. However, even with this addition, the modification failed to fulfill the patient’s oxygenation requirements, prompting conversion to a V-(dl)VP configuration in which the femoral venous cannula was used for drainage and both lumina of the ProtekDuo® cannula was used for the return (Figure 6).

Figure 6.

ProtekDuo® additional femoral venous drainage cannula in V-(dl)VP ECMO configuration. Blood drainage occurring through femoral venous cannula holes in IVC and blood return occurring through proximal and distal cannula holes of ProtekDuo® in RA and main PA, respectively. Abbreviations: ECMO: Extracorporeal membrane oxygenation, IVC: Inferior vena cava, PA: Pulmonary artery, RA: Right atrium, V-(dl)VP: Percutaneously peripheral venous cannula to membrane lung to percutaneously placed dual-lumen cannula for return via both lumens.

This reconfiguration resulted in a notable and immediate increase in blood flow, from 4.2 to 7.0 L/min. Of this total flow, approximately 60% (4 L/min) was delivered to the RA through the proximal cannula holes, while approximately 40% (3 L/min) was delivered to the main PA through the distal cannula, effectively reducing the burden on the RV. Consequently, oxygenation improved with SpO2 rising from 78–100%, allowing for a reduction in mechanical ventilation to “rest settings” that are more optimal for lung protective strategies. The echocardiographic assessment revealed that the RV remained decompressed, indicating that the diminished RV preload in this configuration aids in preventing RV volume overload and distension, contributing to an enhancement in RV function. Once pulmonary function improved, the patient was successfully weaned from ECMO without any complications related to the device.

3.4 ProtekDuo® in (dl)V-V configuration

A group from the United Kingdom has described the use of a ProtekDuo® cannula for respiratory support in a patient who developed acute hypoxic respiratory failure following the implantation of a total artificial heart (TAH). The authors positioned the ProtekDuo® cannula within the femoral vein, ensuring that the distal end of the return cannula was placed at the IVC-RA junction [22]. This particular placement strategy was selected to circumvent the risk of wire entrapment within the TAH, a complication that can arise when a guide wire is introduced through the internal jugular or subclavian veins.

3.5 Clinical evidence for the ProtekDuo® in respiratory ECMO support

During the COVID-19 pandemic, the use of the ProtekDuo® cannula in multiple VP ECMO configurations increased [23]. In 2020, Mustafa et al. reported their experience with VP ECMO in 40 patients with ARDS due to COVID-19 who failed conventional medical management. In their series, all patients were liberated from mechanical ventilation. Moreover, 32 (80%) patients were weaned from ECMO and 29 (73%) were discharged alive from the hospital. Finally, the authors reported minimal complications [24].

Cain and colleagues presented similarly favorable outcomes when they retrospectively compared the outcomes of 39 patients with ARDS due to COVID-19 by management strategy. In their study, the authors compared patients treated with VP ECMO (N = 18) to those treated with invasive mechanical ventilation (IMV) alone (N = 21). The authors found that patients in the VP ECMO group had a significant reduction in in-hospital (52.4 vs. 11.1%, p = 0.0008) and 30-day mortality rates (42.9 vs. 5.6%, p = 0.011) compared to patients treated with only IMV without any device-related complications. Most noteworthy, acute kidney injury (AKI) did not occur in the group of patients treated with VP ECMO, while 15 patients treated with IMV developed AKI (71.4%, p < 0.001) [25].

In 2022, Saeed and co-authors published a large multicenter retrospective study of 435 adult patients treated with ECMO for ARDS due to COVID-19. The authors compared patient outcomes based on the initial ECMO cannulation strategy: Dual-site (single cannulas either in the femoral vein or IJV), single-site with a dual-lumen cannula such as ProtekDuo® (tip in the PA), and single-site with a dual-lumen cannula such as the Avalon or Crescent cannula (tip in the inferior vena cava [IVC]). Of all 435 patients, 99 (23%) had ProtekDuo® cannulation, 247 (57%) had dual-site cannulation, and 89 (20%) had single-site IVC cannulation. The authors reported a 90-day in-hospital mortality of 55% across the cohort, with an unadjusted 90-day in-hospital mortality of 60% for dual-site, 61% for dual-lumen cannula with tip in IVC, and 41% for ProtekDuo®. After adjustment for clinical characteristics, the likelihood of in-hospital mortality in comparison to dual-site, was lower with ProtekDuo® (aHR: 0.52, 95% CI 0.32–0.85, p = 0.009) and similar with dual-lumen cannula with tip in IVC (aHR: 0.96, 95% CI 0.63–1.47, p = 0.86). However, the patients with ProtekDuo® had longer ECMO durations as compared to other modes, but had shorter mechanical ventilation times, and patients were more commonly discharged home [26].

Smith and colleagues compared the outcomes of 38 patients receiving VP ECMO to 16 patients receiving venovenous (VV) ECMO in patients with COVID-19 ARDS. The authors reported a median ECMO support time of 30.5 days (VV ECMO 35.0 days vs. VP ECMO 26.0 days). The authors demonstrated total cumulative mortality after 120-days post-cannulation of 45.7%, with 60.8% mortality for VV ECMO and 40.0% mortality for VP ECMO. The authors concluded ECMO support for COVID-19 was beneficial with VP ECMO support demonstrating a consistent survival benefit compared to VV ECMO [27].

In contrast to the studies above, which used VP ECMO as the initial configuration when commencing ECMO support, our group reported the outcomes of nine patients in whom a V-P or V-VP ECMO configuration was established approximately 1 month after the onset of ARDS and ECMO initiation. This selected group of patients experienced good outcomes with a cumulative survival rate of 67% [23].

In the overall review of these studies, the ProtekDuo for VP ECMO has become a game changer for patients with COVID-19 ARDS. However, available studies and data are scarce and are at risk for institutional bias and should be considered with caution [28]. Lastly, studies of non-COVID-19 ARDS patients treated with ECMO configurations utilizing the ProtekDuo® cannula are needed.

4. The ProtekDuo® for ECMO in cardiogenic shock

Cardiogenic shock, a condition of end-organ hypoperfusion due to profound myocardial dysfunction and low cardiac output, poses a significant challenge in cardiovascular critical care, characterized by high morbidity and mortality despite modern therapeutic interventions [29, 30, 31]. It may arise from isolated left or RVF, as well as biventricular failure due to a variety of etiologies including acute MI, acute decompensation of chronic heart failure, acute valvular dysfunction, and myocarditis, among others [30, 31, 32]. Treatment strategies extend beyond pharmacological management—encompassing diuretics, vasopressors, and inotropes—to include mechanical circulatory support (MCS) options such as ECMO for patients who do not respond to conventional medical management [29, 31, 32, 33, 34]. Despite advancements in treatment modalities, the prognosis of cardiogenic shock remains guarded, with outcomes dependent on the etiology, timing of intervention, and presence of multiorgan failure [29, 35].

Within the context of ECMO therapy for cardiogenic shock, the ProtekDuo® cannula has gained recognition for its role in supporting patients with RVF either alone or in combination with left ventricular failure [32]. This section explores the strategic integration of the ProtekDuo® cannula into an ECMO system for the management of cardiogenic shock, underscoring its utility in the spectrum of MCS.

4.1 Application of ProtekDuo® for VP ECMO in cardiogenic shock

Though venoarterial (VA) ECMO is an option for treating RVF that is refractory to medical therapy, systems designed for selective ventricular support are being increasingly adopted [36]. A growing number of publications describe the use of the ProtekDuo® cannula for VP ECMO in cases of RVF due to various etiologies with concurrent respiratory failure.

Primary graft dysfunction (PGD) post-heart transplant, which often manifests as isolated RVF, can stem from a variety of pre- and intra-operative factors [37]. Effective treatment strategies for this condition have expanded to include the use of the ProtekDuo® cannula, which can be implemented as part of a support system with or without an ML depending on the patient’s respiratory condition. Carrozzini et al. described the application of the ProtekDuo® cannula in treating a cohort of patients with RVF due to PGD post-heart transplant [19]. This cohort included a 50-year-old patient with concurrent respiratory failure, who was successfully managed with VP ECMO, utilizing the ProtekDuo® cannula in a (dl)V-P configuration. All patients in the series survived to hospital discharge, with no residual clinical or echocardiographic evidence of RV dysfunction.

Acute pulmonary embolism (PE) remains a leading cause of cardiovascular death [38], with “high-risk” or “massive” PE cases, though infrequent, exhibiting elevated mortality rates [39]. Shock in PE is predominantly due to acute RVF from PA obstruction, reducing cardiac output. Interventions such as thrombolytics and embolectomy aim to alleviate obstruction and restore circulation [38, 40]. Nevertheless, RVF may persist even after the obstruction has been cleared, and it may be further complicated by respiratory failure. Jayanna and colleagues described a case of a 72-year-old with massive PE who, following treatment with intravenous UFH and catheter-based embolectomy, developed hypoxic respiratory failure secondary to hemoptysis and sustained cardiogenic shock due to RVF. The patient received VP ECMO in a (dl)V-P configuration using the ProtekDuo® cannula, ultimately surviving to hospital discharge with restored RV function [41].

Additional cases of combined RV and respiratory failure managed with VP ECMO via the ProtekDuo® cannula have been reported. George et al. reported outcomes of 32 patients supported with the ProtekDuo® cannula as an RVAD; one required ML due to combined RVF and respiratory failure from a myasthenic crisis, though specific outcomes were not detailed [36]. Meanwhile, Maybauer & Brewer reported the case of a 25-year-old female with cardiogenic shock from acute RV failure and respiratory failure due to thyrotoxicosis, who underwent VP ECMO in a (dl)V-P configuration with the ProtekDuo® cannula. The patient survived to discharge and had eventual complete recovery of RV function [42].

4.2 Application of ProtekDuo® for VP ECMO in combination with micro-axial temporary left ventricular assist devices

4.2.1 ProtekDuo® cannula and Impella CP

A large number of procedures are performed in cardiac catheterization labs each year [43]. Among these procedures include the implantation of percutaneous, micro-axial, temporary LVADs for short-term support of conditions including cardiogenic shock, and protected percutaneous coronary intervention (PCI). Occasionally, the occurrence of new or worsening RVF requires the addition of MCS for the RV, a problem for which the ProtekDuo® cannula is well-suited.

Patel et al. first reported the combined application of an Impella CP and ProtekDuo® cannula for biventricular MCS in a 58-year-old with cardiogenic shock secondary to viral myocarditis. Though the utilization of an ML for respiratory support was not needed, this case demonstrated the feasibility of using the two devices to provide biventricular support [44].

Maybauer and colleagues, detailed a case of a 59-year-old patient with a non-ST-elevation MI leading to cardiac arrest during PCI. Although the return of spontaneous circulation was achieved, the patient had a persistent cardiogenic shock and an Impella CP was placed for support of LV function. However, the patient had hypoxic respiratory failure and refractory shock due to co-existing RVF, necessitating the initiation of VP ECMO using a ProtekDuo® in a (dl)V-P configuration (Figure 7), which provided immediate hemodynamic stabilization. Unfortunately, the patient developed an anoxic brain injury from cardiac arrest and life support was eventually withdrawn [45].

Figure 7.

ProtekDuo® with Impella CP in (dl)V-P/TVLS configuration (PROpella). Blood drainage occurring through proximal cannula holes in RA and blood return occurring through distal cannula holes in the main PA. Impella CP with blood inlet in LV and blood outlet and pump motor in the aorta. Abbreviations: (dl)V-P: Percutaneously placed dual-lumen cannula for atrio-pulmonary artery venopulmonary ECMO, ECMO: Extracorporeal membrane oxygenation, LV: Left ventricle, PA: Pulmonary artery, RA: Right atrium, TVLS: Transvalvular left ventricular support.

4.2.2 ProtekDuo® cannula and Impella 5.0 and 5.5

The use of larger, surgically-implanted, micro-axial, and temporary LVADs is increasing due to their ability to be used for a longer period of time and the capability of providing greater blood flow compared to smaller devices [46]. In cases of existing or new RV failure, implantation of temporary LVADs in the upper body complemented by the ProtekDuo® cannula for RV support, may be preferred over the use of other support modalities such as conventional peripheral VA ECMO [47, 48, 49, 50].

Ruhparwar and colleagues first reported the use of an Impella 5.0 and 5.5 in conjunction with a ProtekDuo® cannula for two patients with cardiogenic shock secondary to biventricular failure. While the patients did not require the use of an ML for respiratory support, this group demonstrated the feasibility, safety, and possible advantages of such an approach to providing MCS for biventricular failure [47].

Routh et al. described the case of a 61-year-old with cardiogenic shock who underwent implantation of an Impella 5.0 for LV support. The patient developed acute RVF and hypoxic respiratory failure and a ProtekDuo® cannula was implanted for VP ECMO in a (dl)V-P configuration (Figure 8). Once the patient’s hypoxia resolved, the ML was removed from the circuit, leaving the ProtekDuo® as a traditional percutaneous, temporary RVAD in a (dl)VxP configuration. The patient underwent heart transplantation and was discharged from the hospital [51].

Figure 8.

ProtekDuo® with Impella 5.5 in (dl)V-P/TVLS configuration (PROpella). Blood drainage occurring through proximal cannula holes in RA and blood return occurring through distal cannula holes in the main PA. Impella 5.5 with blood inlet in LV and blood outlet and pump motor in the aorta. Abbreviations: (dl)V-P: Percutaneously placed dual-lumen cannula for atrio-pulmonary artery venopulmonary ECMO, ECMO: Extracorporeal membrane oxygenation, LV: Left ventricle, PA: Pulmonary artery, RA: Right atrium, TVLS: Transvalvular left ventricular support.

4.3 Application of ProtekDuo® for VP ECMO in combination with durable left ventricular assist devices

RVF following implantation of an LVAD is a common problem in which up to one-third of patients may require MCS [52, 53, 54]. Application of the ProtekDuo® cannula as a component of an RVAD system without an ML in a (dl)VxP configuration is well-documented in this patient group [55]. However, in the setting of concomitant respiratory failure, the ProtekDuo® cannula in (dl)V-P configuration (Figure 9), coupled with an ML, emerges as an optimal support strategy [32, 56].

Figure 9.

ProtekDuo® in (dl)V-P ECMO configuration with durable LVAD. Blood drainage occurring through proximal cannula holes in RA and blood return occurring through distal cannula holes in the main PA. Durable LVAD with inflow cannula in LV and outflow graft anastomosed to aorta. Abbreviations: (dl)V-P: Percutaneously placed dual-lumen cannula for atrio-pulmonary artery venopulmonary ECMO, ECMO: Extracorporeal membrane oxygenation, LV: Left ventricle, LVAD: Left ventricular assist device, PA: Pulmonary artery, RA: Right atrium.

Schumer et al. reported the use of the ProtekDuo for VP ECMO as part of a biventricular support strategy in a patient with an existing durable LVAD who experienced ventricular fibrillation resulting in cardiogenic shock and respiratory failure [57]. The patient underwent a heart transplant and the ProtekDuo® cannula was removed several days later. Despite a prolonged hospital course, and requirement for TV repair, the patient survived to hospital discharge and six-month follow-up.

Schmack and colleagues [9] and Salna et al. [8] reported on patients post-LVAD implantation who received the ProtekDuo® cannula for RVF, noting a subset requiring ML for respiratory support. These studies, however, did not differentiate outcomes based on ML use, which represents an area for future research to enhance patient-centered outcomes including the duration of mechanical ventilation.

4.4 Application of ProtekDuo® for VA ECMO in (dl)VP-A configuration

The versatility of the ProtekDuo® cannula allows for its use in various configurations, such as a drainage cannula for a VA ECMO mode [58, 59]. Kumar et al. described a patient with COVID-19 respiratory failure, initially on VV ECMO, who developed biventricular failure and cardiogenic shock. The support mode was converted to VA ECMO, but the patient continued to deteriorate with refractory shock and hypoperfusion with a serum lactate of 28 mmol/L, LV distention, and loss of pulsatility. Prior to ECMO, a percutaneous LVAD was considered but not used owing to the small LV dimension. The patient underwent placement of a ProtekDuo® cannula for dual-lumen drainage and was reconfigured to (dl)VP-A ECMO for LV unloading, which resulted in improved LV dimension, aortic valve opening, hemodynamics, and perfusion markers [60].

Tarzia and colleagues described the use of ProtekDuo for a planned support strategy in six patients on ECMO undergoing durable LVAD implantation who were at risk for post-LVAD RV failure. A ProtekDuo® cannula was implanted at the time of surgery and used for venous drainage, whereas the existing arterial cannula was used for return, thus constituting (dl)VP-A ECMO. The authors reported no complications associated with the cannula. One patient in the series maintained the configuration after surgery for respiratory failure secondary to cardiogenic pulmonary edema. The 30-day mortality was 0%, with a 90-day mortality of 17% [61].

Maybauer et al. described the use of (dl)VP-A ECMO as a bridge to biventricular support with Impella 5.5 and (dl)V-P ECMO in a patient with cardiogenic shock following NSTEMI and cardiac arrest. Interestingly, the patient was originally supported with (dl)V-P ECMO and Impella CP, which had to be removed due to limb ischemia. However, the patient developed cardiogenic pulmonary edema and was converted to (dl)VP-Adt ECMO (Figure 10) until an Impella 5.5 could be placed [58].

Figure 10.

ProtekDuo® in (dl)VP-Adt ECMO configuration. Blood drainage occurring through proximal and distal cannula holes of ProtekDuo® in RA and main PA, respectively, with blood return occurring through a common femoral arterial cannula as well as an antegrade perfusion cannula in the superficial femoral artery. Abbreviations: (dl)VP-Adt: Percutaneously placed dual-lumen cannula for atrio-pulmonary artery drainage to membrane lung to cannula placed in a peripheral artery with antegrade perfusion cannula, ECMO: Extracorporeal membrane oxygenation, PA: Pulmonary artery, RA: Right atrium.

5. The ProtekDuo® for ECMO in transplantation medicine

Budd et al. described the technique of a ProtekDuo® in V-P configuration, with an additional 18 Fr cannula (Edwards Lifesciences) that was inserted into the ascending aorta after sternotomy. The authors drained blood through both lumens of the ProtekDuo® to the venous aspect of the ECMO circuit and returned to the outflow cannula, placed in the aorta as intra-operative central VA ECMO in (dl)VP-/AO configuration (Figure 11). The patient remained hemodynamically stable with this configuration and achieved adequate decompression of the right heart, allowing for bilateral, sequential native pneumonectomy, and donor lung transplantation. At the end of the operation, the arterial cannula was removed and (dl)V-P ECMO (Figure 4) was reinstated [62].

Figure 11.

ProtekDuo (dl)VP-/AO configuration. Blood drainage occurring through proximal and distal cannula holes of ProtekDuo® in RA and main PA, respectively, with blood return occurring through a central cannula placed directly into the aorta. Abbreviations: (dl)VP-/AO: Percutaneously placed dual-lumen cannula for atrio-pulmonary artery drainage to membrane lung to cannula placed centrally in the aorta, ECMO: Extracorporeal membrane oxygenation, PA: Pulmonary artery, RA: Right atrium.

Similarly, Settepani et al. reported a surgical technique in which they switched from percutaneous minimally invasive biventricular MCS to cardiopulmonary bypass during a heart transplantation. The authors cannulated the ascending aorta with an arterial cannula as above and used the ProtekDuo® cannula and the ProtekSolo® transseptal for combined SVC and IVC drainage connected to CPB, to perform orthotopic heart transplantation and, at the end of the procedure, the two cannulas were removed [63].

Sinha and colleagues could reproduce these results in a combined heart and lung transplantation using the same technique [64].

6. Advantages of the ProtekDuo® cannula

The ProtekDuo® cannula has emerged as a versatile and innovative tool in MCS and ECMO, offering several advantages that enhance patient management and outcomes in complex cardiopulmonary conditions [28, 65]. Its adaptability is a key benefit, enabling use across various ECMO modes and configurations [58, 59]. The cannula’s percutaneous insertion method reduces surgical complications and expedites recovery, while its single-site, dual-lumen design consolidates blood drainage and return, thereby avoiding the potential negative effects of multi-site cannulation configurations such as infection risk and reduced patient mobility.

The ability of the ProtekDuo® cannula to provide support for the RV allows the device to be used in conjunction with other minimally invasive devices for LV support in order to provide biventricular support. These devices can be placed in the upper body, thus avoiding groin access, which might allow for enhanced patient mobility.

The ability of the cannula to be used as a part of multiple cannulation configurations allows for smooth transitions between ECMO modes, thus allowing for adaptation to the evolving clinical needs of the patient without additional invasive procedures such as cannula insertion. Furthermore, the cannula’s placement within the heart minimizes recirculation, thereby increasing the efficiency of the ECMO circuit.

7. Disadvantages and complications of the ProtekDuo® cannula

The ProtekDuo® cannula, while instrumental in treating cardiorespiratory failure, has been associated with certain complications. Instances of injury to vascular access points, anticoagulation-related bleeding, and even device-related thrombosis have been reported in the literature. Specifically, Ravichandran et al. identified complications including injury to the IJV and insertion site bleeding [11]. Carrozzini et al. noted a case of IJV thrombosis [19], and Spelde et al. observed intracannula clots forming under conditions where anticoagulation was withheld [66]. Additionally, complications such as cannula fracture after prolonged use, as noted by Odish et al. [67], compression of the right coronary artery by Unger et al. [68], device migration, thrombosis, and severe TV damage requiring repair as reported by Walsh et al. [50] and Schumer et al. [50], highlight the need for vigilant monitoring.

Other potential complications including pulmonary edema from high blood flow into the PA have not been commonly reported in the literature or experienced in the authors’ centers. The risk of this complication may increase if the ProtekDuo® is malpositioned in either the left or right PA or in the setting of LV failure. Proper cannula tip position in the main PA, coupled with the cannula design, allows for omnidirectional blood flow into both branches of the PA, avoiding unilateral flow, and volume overload. Additionally, placement of LV support in addition to the ProtekDuo® or conversion to VA ECMO is required in the setting of LV failure.

Lastly, the manufacturer also cautions against the use of the cannula for extended periods beyond 30-days due to the potential for material degradation [69]. Reported and potential/theoretical complications collectively emphasize the necessity for careful patient selection, meticulous procedural technique, and ongoing post-procedural care.

8. Future innovations

As previously described, cannula and cannulation strategy are crucial components in the successful use of ECMO therapy. Next-generation dual-lumen systems seek to expand the nature of a co-axial system to allow for dynamic adjustments in length to optimize placement within blood vessels, ensuring proper positioning, and reducing the risk of complications such as suboptimal drainage or reinfusion, vessel injury, and clot formation. A telescoping feature enables clinicians to navigate variations in patient anatomy and accommodate changes in patient requirements during ECMO support. This adaptability is particularly important in the respiratory failure population, where vascular dimensions, right ventricular size, and function, can vary significantly.

The significance of a telescoping variable-length cannula lies in its ability to enhance the precision and safety of ECMO procedures, potentially contributing to improved patient outcomes. Studies have demonstrated the efficacy of dual-lumen cannulas in reducing complications associated with cannulation, such as bleeding or vessel damage, ultimately enhancing the overall success of ECMO therapy [26, 70]. Clinical studies have also highlighted variable size as a positive impact on patient outcomes, emphasizing its role in minimizing complications associated with cannulation, such as bleeding, malpositioning, and cannulation transitions [70]. As ECMO continues to play a vital role in critical care, innovations like telescoping variable-length cannulas contribute to advancing the field. This innovation is particularly significant in avoiding vessel damage, occlusion, and thrombosis, which are common challenges in ECMO, as well as assisting in the transition between support strategies while avoiding supplemental vascular access.

Beyond transitions in therapy, in as much as an escalation from bicaval VV ECMO to VP ECMO, a telescopic dual-lumen system may also serve as a novel approach to modulating end-stage pulmonary hypertension (PH). Recent preclinical modeling has demonstrated the feasibility of percutaneous right atrial-to-left atrial VA ECMO as a promising potential technique to bridge PH-RVF patients to lung transplant [71]. A telescopic system, as described, may be able to serve this population via a percutaneous trans-atrial septal approach.

Telescopic, percutaneous venous cannula systems offer a disruptive approach to traditional therapies, while addressing observed adverse events associated with fixed co-axial systems (Figure 12).

Figure 12.

Telescopic, percutaneous venous cannula system.

9. Conclusions

The ProtekDuo® cannula, as detailed in this chapter, stands out as an important innovation in the realm of MCS and ECMO. Its dual-lumen design offers a simplified approach to ECMO patients with cardiopulmonary failure, with various clinical reports underscoring its utility in the management of acute respiratory failure and cardiogenic shock as a result of its adaptability in various ECMO configurations, such as (dl)V-P, V-(dl)VP, and (dl)VP-A. Clinical experiences, particularly during the COVID-19 pandemic, have shown promising outcomes with its use, noting the ease of transition between ECMO configurations and modes, and the potential for reduced complication rates compared to traditional methods.

Nevertheless, it is important to acknowledge the associated complications, which range from vascular access injuries to anticoagulation-related bleeding and device-related thrombosis. These complications necessitate thorough patient selection, careful cannulation techniques, and diligent post-procedural monitoring.

Future innovations aim to refine the design and functionality of ECMO cannulas, with next-generation systems featuring dynamic adjustments to accommodate patient anatomical variations and clinical needs. Such advancements may further enhance the safety and efficacy of ECMO therapy, reducing complications, and improving patient outcomes.

In summary, the ProtekDuo® cannula represents a significant advancement in MCS and ECMO therapy, contributing to improved patient management in complex cardiopulmonary conditions. However, ongoing research and development are imperative to optimize its use and mitigate potential risks.

Acknowledgments

The medical illustrations were provided by Massimiliano Crespi. LivaNova, PLC covered the cost for open access publication, however, the authors have not received direct personal support.

Conflict of interest

MB: No conflicts of interest.

CD: Director and shareholder of LivaNova, PLC.

MOM: Speaker for Abbott and consultant for LivaNova, PLC.

Other declarations

Not all illustrations and techniques are cleared therapies and may include off-label applications.

Appendices and nomenclature

The nomenclature used in this chapter is in accordance with the ELSO Maastricht Treaty for ECLS Nomenclature [72, 73, 74, 75, 76].