**5. The ProtekDuo® for extracorporeal membrane oxygenation**

Conventional management for ARDS includes low tidal volume ventilation, neuromuscular blockage, and prone positioning. Pulmonary vasodilators are often used for temporary improvement of oxygenation and to bridge a patient to ECMO. Veno-venous (V-V) ECMO can be used in refractory hypoxemia and/or hypercapnia, or ventilator induced lung injury, and may typically be provided by single lumen dual site cannulation (femoro-internal jugular) or dual lumen single site cannulation (DLSC), typically via internal jugular vein approach. In the venous system, flow is dependent on the capacitance of the vessels, tricuspid competence, as well as systolic and diastolic function of both ventricles. In addition, pulmonary artery pressure, RV afterload, and total systemic cardiac output play an important role. V-V ECMO may display varying degrees of recirculation of blood depending on the flow rate, proximity of the inflow to outflow cannula(s), cannula location, and cannula size [53].

Impaired RV function occurs frequently in patients with ARDS [54, 55] and is associated with increased mortality [55, 56]. During the COVID-19 pandemic, clinicians observed a particularly high incidence of acute and subacute RV failure [57] with dramatic increases in pulmonary vascular resistance due to the combined effects of hypoxia, hypercapnia, lung injury, and attempted sedation weaning [58]. Additionally, hypercoagulation associated with COVID-19 frequently led to both macro- and micropulmonary emboli, which further increased pulmonary pressures, RV dilation, and failure of systolic pump function resulting in hypotension and need for inotropes and vasopressors [59]. Understanding RV biomechanics and, in particular, the relationship between the RV and PA is key to identifying different phases of RV dysfunction leading to RV failure, hypotension and death. ECMO cannulas bypassing the RV are now being increasingly utilized for COVID-19 ARDS to counterbalance RV dysfunction.

#### *Perspective Chapter: The ProtekDuo® Cannula for Acute Mechanical Circulatory Support DOI: http://dx.doi.org/10.5772/intechopen.111537*

The ProtekDuo® dual lumen cannula is similar to other dual lumen cannulas and may be used for V-V ECMO in cases of ARDS. If significant RV dysfunction or failure is present and resulting in the requirement of inotropes and vasopressors to counterbalance hypotension, the cannula can be used for combined V-V ECMO and RV support, a configuration commonly referred to as V-P ECMO or oxyRVAD [60]. See **Figure 1c**. The main difference between the ProtekDuo® and other dual lumen cannulas is that the tip of the ProtekDuo® terminates in the main PA and not in the inferior vena cava as it is the case with other dual lumen cannulas. The ProtekDuo®'s V-P ECMO default position may be a particularly beneficial feature in ARDS, not only because it is able to bypass the RV, but because the area of venous blood drainage from the RA and area of oxygenated blood return in the main PA are separated by two cardiac valves (tricuspid and pulmonic valve) thus preventing recirculation, a phenomenon commonly seen with other dual lumen ECMO cannulas. Considering the length and diameter of the cannula, an average flow of 4.5 LPM may be achieved, which usually provides adequate blood flow and oxygenation [53].

The COVID 19 pandemic resulted in much longer ECMO run times than ECMO teams were accustomed to, the incidence of RV failure and hypotension increased because of prolonged ARDS with the development of some degree of pulmonary hypertension and the ProtekDuo® was used more frequently in V-P ECMO configuration, even as primary device to initiate ECMO. Several interesting configurations have been developed during the COVID-19 pandemic, mostly due to clinical desperation and medical necessity, as described below.

### **5.1 ProtekDuo® in V-P ECMO configuration**

In a recent systematic review on the utilization of the Protek Duo cannula for V-P ECMO (**Figure 1c**) in ARDS secondary to COVID-19 infection, our group identified five suitable articles including 194 patients who underwent ProtekDuo® implantation in combination with an oxygenator. The ProtekDuo® demonstrated survival rates of 59–89% throughout the studies with a significant survival benefit [61].

Mustafa et al. presented their experience with the ProtekDuo® in V-P ECMO configuration for patients with ARDS secondary to COVID-19. The authors presented a case series of 40 patients with an average duration of mechanical ventilation of 13 days. They reported an 80 percent (32 patients) rate of successful ECMO weaning with a 73% (29 patients) survival rate [62].

Cain and colleagues compared 39 patients in a V-P ECMO group of 18 patients and an invasive mechanical ventilation (IMV) group of 21 patients. The authors displayed a significant reduction of in-hospital (52.4 vs. 11.1%, P = 0.0008) and 30-day mortality rates (42.9 vs. 5.6%, P = 0,011) in favor of the V-P ECMO group without complications related to the device. While the IMV group presented with 15 cases of acute kidney injury (AKI, 71.4%, P < 0.001), the V-P ECMO group did not display a single patient with AKI [63].

Saeed et al. compared the cannulation approach in a retrospective multicenter trial of 435 adult patients. They compared dual-site vs. single-site cannulation. For dual site they used the two most common approaches, femoral vein to femoral vein and femoral vein to internal jugular vein access. For the single site approach, they used either the Protek Duo, Crescent, or Avalon cannulas through an internal jugular vein. Out of 435 patients, 99 (23%) received the ProtekDuo®, 89 (20%) had single site inferior vena cava (IVC) approach, and 247 (57%) had dual site approach. The authors demonstrated that the 90-day in hospital mortality for the entire cohort was 55%. The unadjusted 90-day in hospital mortality was 60% for dual site, 41% for

ProtekDuo®, and 61% IVC approach. The 90-day in-hospital mortality was significantly lower in the ProtekDuo® group (p = 0.029), but not significantly different between single site IVC compared to dual site approach (p = 0.86). However, patients who were cannulated with the ProtekDuo® had longer duration of the ECMO runs compared to the other approaches but had shorter periods of mechanical ventilation and were more commonly discharged home [64].

A cohort of 54 patients was investigated by Smith and colleagues, comparing the ProtekDuo® with V-V ECMO for a one-year period during the pandemic. Thirty percent of their patients had V-V and 70% had V-P ECMO with a median time of 7 days from admission to ECMO cannulation. The authors reported a median ECMO support time of 30.5 days (V-V ECMO 35.0 days vs. V-P ECMO 26.0 days). Their mortality with V-P ECMO was 39.5%, with a 50.0% mortality for V-V ECMO with a total in-hospital mortality of 42.6%. The mortality after 120 days for V-V ECMO was 60.8% and only 40% for V-P ECMO, with a total cumulative mortality of 45.7%. This group concluded that ECMO support for ARDS secondary to COVID-19 is beneficial and that V-P ECMO support displayed consistent advantages in survival compared to V-V ECMO [65].

In addition to these studies, an interesting case was reported by Gianni et al., that may be very useful in patients with pulmonary embolism. In this patient, an inferior vena cava filter was positioned to prevent embolization from a left femoral deep venous thrombosis. The patient also had a large lesion of the tracheal posterior wall. Tracheal stenting required V-V ECMO support to safely perform the bronchoscopic procedure. Due to the presence of the inferior vena cava filter, the patient was cannulated with the ProtekDuo® cannula, since it does not interfere with the IVC, while dual site or double lumen cannulas typically end in the IVC. The patient could be weaned off ECMO after the procedure and the tracheal stent was removed after 40 days with full recovery, expanding the potential indications for the ProtekDuo® cannula [66].

### **5.2 Protek duo in V-VP ECMO configuration**

This new technique and configuration for the ProtekDuo® was developed by Maybauer during the COVID-19 pandemic when treating a patient with persistent, severe hypoxia while on V-P ECMO with blood flows of 4.5 to 5 LPM. In an attempt to achieve more blood flow, a 25-Fr femoral multistage cannula was inserted for venous drainage. The post-pump tubing was spliced with a 3/8-in Y-connector to distribute the blood flow to both lumina of the ProtekDuo®, which resulted in return of oxygenated blood to the right atrium and main pulmonary artery in a configuration that could be best described as V-VP ECMO [67] (See **Figure 4**).

Returning blood flow improved to 7 LPM resulting in resolution of hypoxia and maintenance of SpO2 > 90%, which finally allowed for the use of ventilator "rest settings" (Inspiratory Plateau Pressure < 25 to <30 cmH2O, Respiration Rate 4-15 breaths per minute, PEEP >10 cmH2O, FiO2 0.3 to 0.5). Using ultrasonic flow probes, blood flows to both ProtekDuo® lumina were measured and monitored independently. Due to length and diameter of the cannula, about 60% of flow returned into the RA and about 40% of flow returned into the pulmonary artery. Still, about 3 LPM bypassed the RV, which was sufficient to protect the RV in this patient. Frequently repeated transthoracic echocardiograms confirmed adequate decompression of the RV. The patient was able to separate from V-P-ECMO after 44 days with 29 days on the new configuration. The patient did not have any complications associated with this new configuration [67].

Most recently, the group of Maybauer presented a case series of nine patients, using the ProtekDuo® in V-P and V-VP ECMO configuration [19]. The authors could show

*Perspective Chapter: The ProtekDuo® Cannula for Acute Mechanical Circulatory Support DOI: http://dx.doi.org/10.5772/intechopen.111537*

#### **Figure 4.**

*Chest X-ray of ProtekDuo® in V-P ECMO position with additional 25Fr drainage cannula with tip in right atrial/inferior vena cava junction through a femoral vein. Drainage through the femoral cannula and return through both lumens of the ProtekDuo® using a Y-piece after the oxygenator. Modified from: Maybauer MO et al. The ProtekDuo® as double lumen return cannula in V-VP ECMO configuration: A first-in-man method description. Ann Card Anaesth. 2022;25(2):217-9. With kind permission from Ann Card Anaesth.*

that in contrast to the above-mentioned studies where V-P ECMO was the initial configuration, this study showed that V-P or V-VP ECMO configuration was established weeks after the onset of ARDS with initial dual site V-V ECMO. This selected group of patients still displayed good outcomes with a survival rate of 67%, indicating the Protek Duo has been a game changer when used in patients with ARDS secondary to COVID-19 [68].

#### **5.3 Protek duo in VP-A ECMO configuration**

Budd et al., described the "central" VP-A ECMO configuration for a patient who was to receive a bilateral, sequential native pneumonectomy and donor lung transplantation after having V-P ECMO in situ. Following a sternotomy, they inserted an 18-Fr cannula (Edwards Lifesciences, Irvine, CA) into the ascending aorta. Thereafter, blood was drained through both lumens of the ProtekDuo® cannula and oxygenated blood was returned into the aorta as intraoperative central V-A ECMO configuration or more precisely called central VP-A configuration. After initiation, good decompression of the heart was achieved, which allowed for completion of pneumonectomy and donor lung transplantation. Before chest closure, the arterial cannula was removed and V-P ECMO was reinstated through the ProtekDuo® [69]. Similar techniques have been described by Settepani et al. for orthotopic heart transplantation [70] and by Sinha et al. in a combined heart and lung transplantation [71]. Either ECMO or cardiopulmonary bypass was used as pump in the above-mentioned circumstances of short intraoperative support.

Most recently, Maybauer et al. described a case with a patient who had a non ST elevation myocardial infarction (NSTEMI) and suffered a cardiac arrest on the catheter laboratory table. After return of spontaneous circulation (ROSC) was achieved, the patient developed biventricular failure with severe refractory hypotension and an Impella CP was placed. The patient remained in shock, requiring high doses of inotropes and vasopressors. A follow up echocardiogram demonstrated ongoing biventricular failure. A 29 Fr ProtekDuo® cannula was placed as RVAD with ECMO circuit in V-P configuration. With the Impella CP already in situ, a PROpella configuration was created (**Figure 2**), and the patient was stabilized. After a few hours, the patient displayed signs of limb ischemia due to occlusion of the femoral artery by the Impella CP. A thrombectomy and left calf fasciotomy was necessary and the Impella CP had to be removed. Because the patient developed pulmonary edema after Impella CP removal, a 17 French arterial and 5 Fr distal perfusion cannula were placed in the contralateral proximal femoral artery. The circuit tubing connected to the ProtekDuo® was clamped, cut, and wet connected to a new ECMO circuit using a Y-piece and used for dual-lumen venous drainage from both the RA and main PA. Oxygenated blood was returned through the 17-Fr arterial cannula, creating a "peripheral" VP-A ECMO configuration (**Figure 5**). This peripheral configuration

#### **Figure 5.**

*ProtekDuo® in VP-A ECMO position for double lumen drainage from right atrium and pulmonary artery and return flow into femoral artery through 17 Fr cannula and 5 Fr distal perfusion cannula. Modified from: Maybauer MO et al. The ProtekDuo® in percutaneous peripheral venopulmonary-arterial ECMO and PROpella configuration for cardiogenic shock with biventricular failure. Ann Card Anaesth. In Press. With kind permission from Ann Card Anaesth.*

### *Perspective Chapter: The ProtekDuo® Cannula for Acute Mechanical Circulatory Support DOI: http://dx.doi.org/10.5772/intechopen.111537*

however could be used for about 24 h without complications in comparison with the use of central VP-A configuration on CPB [46].

In a similar configuration, Kumar and colleagues described left ventricular unloading utilizing pulmonary artery drainage in cardiorespiratory failure due to COVID-19 infection. They described ProtekDuo® insertion for LV venting who was first on V-V ECMO and then converted to V-A and developed LV distention [72].
