**4. ProtekDuo® as a ventricular assist device**

The ProtekDuo® cannula, when placed in the intended location and connected to an extracorporeal pump, is able to provide direct bypass of the RV. As clinicians have become more experienced with using the cannula, its use has been adapted to other situations where ventricular assistance is needed.

## **4.1 ProtekDuo® as an RVAD**

In studies of RVADs as treatment for acute RV failure, survival has improved with earlier initiation of mechanical support [16, 23, 26, 31]. RVADs can be inserted surgically, via sternotomy or thoracotomy, or percutaneously. Most RVADs, especially the percutaneous type, are intended for temporary use. The ProtekDuo® cannula is a particularly advantageous component of a percutaneous RVAD system as it allows for expedient, upper body, percutaneous access with a single cannula, thus avoiding surgical implantation and explantation via sternotomy. See **Figure 1b**.

Use of the ProtekDuo® cannula as a component of an RVAD has been increasingly reported in the literature since its approval for use in humans in 2016. Retrospective cohort studies, case reports, and case series have described its use alone for isolated acute RV failure as well as in combination with a left ventricular assist device (LVAD) for biventricular support in the setting of concomitant left ventricular failure [23, 24, 26, 32–35].

## *4.1.1 ProtekDuo® for isolated acute RV failure*

Acute RV failure can occur due to multiple etiologies including after temporary and durable left ventricular assist device (LVAD) implantation [23, 35], primary graft dysfunction after heart transplant [36], myocardial infarction [32], as well as other causes [24, 26, 33, 34].

Nicolais and colleagues [37] were among the first groups to report a larger series of patients with acute RV failure treated with the ProtekDuo®. In the series of 13 patients; four had acute myocardial infarction; three were bridge to lung or heart transplant; two had severe pulmonary hypertension; and one patient each had acute myocarditis, post-LVAD RV failure, or post-heart transplant graft dysfunction. The group reported a median duration of support of 6 days and 54% survival to device explantation. They concluded that the ProtekDuo® cannula could be used for shortterm isolated RV support or in conjunction with a left ventricular support device for cases of biventricular failure while using single-site access [37].

Kremer et al. [32] conducted a retrospective study of 10 patients with acute myocardial infarction complication by acute RV failure who underwent ProtekDuo® implantation for RVAD support. Patients had significant reduction in right heart filling pressures and increase in cardiac output after device implantation. The mean duration of RVAD support with ProtekDuo® was 10 ± 7.4 days. The authors reported a 30-day and 1-year survival of 60% with four patients having complete recovery and two patients requiring placement of durable RVAD. A total of four patients required an interposed membrane oxygenator and there were no device-related complications. The authors concluded that the use of the ProtekDuo® cannula as a temporary RVAD was safe and feasible for patients with acute RV failure secondary to myocardial infarction [32].

Badu et al. [24] conducted a retrospective cohort study of 40 patients with acute RV failure grouped by primary cause: post-cardiotomy (n = 18), other cardiac causes including myocardial infarction and exacerbation of heart failure (n = 12), and severe respiratory failure (n = 10). The authors reported a significant reduction in vasopressor and inotrope requirements in all groups within 48 hours of device implantation. Devicerelated complications were reported including cannula migration in three patients, SVC syndrome in three patients, and right internal jugular vein thrombus in one patient. The authors reported duration of RVAD support with ProtekDuo® for patients who successfully weaned from support and patients who died on support. For patients who successfully weaned, the overall duration of support was a median of 14 days with patients in the post-cardiotomy group requiring support for a median of 15 days, other cardiac causes group 11 days, and respiratory failure group 10 days. For patients who died on support, the overall duration of support was a median of 5 days with patients in the post-cardiotomy group requiring support for a median of 43 days, other cardiac causes group 3 days, and respiratory failure group 15 days. The authors reported overall survival to discharge of 68% in the cohort. When survival to discharge was analyzed by cause of acute RV failure, the authors reported 89% survival in the post-cardiotomy group, 42% survival in the group of other cardiac causes, and 60% survival in the group with respiratory failure. The authors concluded that use of the ProtekDuo® cannula resulted in improved hemodynamics with reduced need for vasopressors and inotropes as well as high rates of weaning, low complications, and low mortality [24].

Oliveros and colleagues [34] conducted a retrospective study of 11 patients with acute RV failure from multiple causes including post-partum cardiomyopathy (with biventricular failure requiring simultaneous V-A ECMO support), following lung transplant, massive pulmonary embolism, myocardial infarction, and acute respiratory distress syndrome. The mean duration of RVAD support with ProtekDuo® was 58 ± 47 days. The authors reported 30-day survival of 82% and 180-day survival of 73%. The authors did not report device-related complications for the cohort [34].

Carrozzini et al. [36] reported a case series of three patients with acute RV failure due to primary graft dysfunction after heart transplant. Of note, all three patients required V-A ECMO prior to transplant due to end-stage biventricular failure. The authors reported complete unloading of the failed RV without distention of the LV by transesophageal echocardiogram. One patient experienced a right internal jugular vein thrombus. The patients required support from four to 12 days. All patients were successfully weaned and discharged alive. In treating these patients, the authors were able to avoid V-A ECMO or central right ventricular support. The authors concluded that the ProtekDuo® cannula was easy to insert, safe and effective and is the preferred temporary mechanical support device for patients with isolated RV primary graft dysfunction after heart transplant [36].

#### *4.1.2 ProtekDuo® for biventricular failure*

Biventricular shock is characterized by elevated CVP (>14 mmHg), normal or elevated PCWP (>18 mmHg) and hypotension, along with reduced LV function. At least 40% of patients diagnosed with LV-dominant CS, in fact have biventricular failure [5].

The use of temporary [38] and durable [39, 40] LVADs has continued to increase over the last decade. Acute RV failure after LVAD implantation is reported to occur in up to 40% of cases [26, 41–44]. Multiple causes, either alone or in combination, including unmasking of chronic RV dysfunction once RV preload increases, distortion of RV geometry due to bowing of the intraventricular septum toward the LV due

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

to mechanical LV unloading, ventricular dysrhythmias, and embolic phenomenon to the coronary or pulmonary circulation are thought to precipitate RV failure [45]. Patients with LVADs who develop additional acute RV failure and require biventricular support have a high mortality [26].

Patients with shock in the setting of biventricular failure refractory to medical management are usually supported with V-A ECMO. However, if an LVAD is present, then the addition of isolated RV support can provide adequate cardiovascular support while avoiding potential challenges imposed by V-A ECMO including retrograde flow with increased LV afterload, complications of arterial access including extremity ischemia, and low transpulmonary flow [36]. The ProtekDuo® cannula may offer additional benefits including non-surgical, single-site access in the upper body, which may allow for earlier extubation and/or mobilization.

#### *4.1.2.1 ProtekDuo® with temporary LVADs*

A number of authors have presented cases of the ProtekDuo® cannula used in combination with an Impella temporary percutaneous LVAD for biventricular support. Our group has reported our experience with the combination of devices, which we describe using the novel portmanteau "PROpella" [46].

The Impella CP is a percutaneous LVAD capable of delivering up to 3.5 liters per minute of flow. Patel and colleagues reported a case of a patient with biventricular failure who was supported with the combination of a ProtekDuo® and Impella CP inserted via the axillary artery thus allowing the patient to be awake and ambulate. Chivasso et al. reported a case of a 38-year-old patient who underwent emergent coronary artery bypass grafting that was complicated by electrical storm initially supported with V-A ECMO, but was later converted to biventricular support with ProtekDuo® cannula and Impella CP. See **Figure 2**.

The Impella 5.0 (no longer available) and the newer Impella 5.5 are surgically placed and capable of delivering up to 5.5 liters per minute of flow. Routh and coauthors reported a case of a 61-year old man with inotrope-dependent nonischemic cardiomyopathy who developed acute cardiogenic shock initially treated with Impella 5.5. The patient subsequently developed acute RV failure and a ProtekDuo® cannula was placed, allowing for biventricular support [45]. Ramamurthi et al. reported a case series of six patients who underwent carotid placement of an Impella 5.5 for left ventricular support. One patient in the series, a 49-year-old woman, required placement of a ProtekDuo® cannula for concomitant RV failure. Care was later withdrawn due to inability to wean from mechanical support [47]. Kataria and colleagues described three cases of successful use of ProtekDuo® for acute right heart failure in patients with Impella 5.5 placed for heart failure-related cardiogenic shock, though specific outcomes of these patients were not discussed [48]. See **Figure 3**.

### *4.1.2.2 ProtekDuo® with durable LVADs*

A number of authors have presented larger case series and retrospective cohort studies of patients supported with ProtekDuo® after implantation of durable LVAD.

Ravichandran and co-authors published a case series of 17 patients with acute RV failure supported with ProtekDuo® cannula. In their series, acute RV failure occurred mostly following implantation of an LVAD: 12 patients after durable LVAD implantation and one patient after temporary percutaneous LVAD implantation. The remaining four patients had acute RV failure due to other causes. Device-related

#### **Figure 2.**

*PROpella approach with ProtekDuo® and oxygenator in RVAD/V-P ECMO position and Impella CP in LVAD position. Modified from: Maybauer MO et al. The ProtekDuo® in percutaneous peripheral venopulmonaryarterial ECMO and PROpella configuration for cardiogenic shock with biventricular failure. Ann Card Anaesth. In Press. With kind permission from Ann Card Anaesth.*

complications including vessel injury occurred in one patient and bleeding from the cannula site in two patients. The mean duration of RVAD support with ProtekDuo® was 10.5 ± 6.5 days and six patients required conversion to surgical or durable RVAD for extended support [26].

In a retrospective study of 11 patients with acute RV failure at the time of durable LVAD implantation, Schmack et al. reported a mean duration of support with ProtekDuo® of 16.8 ± 9.5 days. The authors reported no device-related complications. In the series, 91% of patients survived to device weaning. The cohort had a 30-day survival of 73% and 180-day survival of 64% [35].

Salna and colleagues performed a retrospective study of 27 patients who underwent durable LVAD implantation and subsequently developed acute RV failure. All patients were placed on RVAD support using a ProtekDuo® cannula and were supported a median duration of 11 days. The median reported dose of required vasopressor and inotrope was significantly lower at 6-hours post-insertion. The authors reported an 85% survival to both discharge and at 30-days. Complications related to the ProtekDuo® cannula were few with cannula migration occurring in two patients and device-related thrombosis occurring in one patient. A total of three patients required conversion to surgical RVAD for prolonged support [23].

Lim and colleagues conducted a retrospective analysis of 11 patients with acute RV failure due to various etiologies. Most patients in the series had RV failure after LVAD: *Perspective Chapter: The ProtekDuo® Cannula for Acute Mechanical Circulatory Support DOI: http://dx.doi.org/10.5772/intechopen.111537*

#### **Figure 3.**

*PROpella approach with ProtekDuo® and oxygenator in RVAD/V-P ECMO position and Impella 5.5 in LVAD position. Modified from: Maybauer MO et al. The ProtekDuo® in percutaneous peripheral venopulmonaryarterial ECMO and PROpella configuration for cardiogenic shock with biventricular failure. Ann Card Anaesth. In Press. With kind permission from Ann Card Anaesth.*

seven after durable LVAD and two with end-stage heart failure cardiogenic shock after temporary percutaneous LVAD implantation. The remaining two patients had post-heart transplant graft dysfunction. The authors reported a significant reduction in right heart filling pressures, but no significant difference in vasopressor and inotrope dose at 3-hours post-cannulation. The patients in this cohort required RVAD support with ProtekDuo® for a median duration of 10 days and had a 90-day survival of 64%. Device-related complications were not reported in this study [33].

#### **4.2 ProtekDuo® as a left ventricular assist device**

While uncommon, the ProtekDuo® cannula has also been used as an LVAD. Rao and colleagues described the use of a combined 21-Fr peripheral venous drainage cannula with a transapical 31-Fr ProtekDuo® cannula inserted via mini-thoracotomy for biventricular support in a 44-year-old with non-ischemic cardiomyopathy in cardiogenic shock [49]. Alaeddine and co-authors described the transapical placement of a 29-Fr ProtekDuo® cannula in a 10-year-old for temporary mechanical support prior to implantation of a total artificial heart [50]. Goodwin et al. described the use of a transapical 31-Fr ProtekDuo® cannula inserted via mini-thoracotomy for temporary left heart support in a 51-year-old patient with ischemic cardiomyopathy and cardiogenic shock, who was not expected to tolerate peripheral V-A ECMO due to significant aortic valve pathology [51].

### **4.3 ProtekDuo® as a biventricular assist device**

Khalpey and colleagues first described the use of dual ProtekDuo® cannulas for biventricular support in three patients. The first patient was a 22-year-old with non-ischemic cardiomyopathy complicated by acute decompensated biventricular heart failure. The second patient was a 46-year-old with ischemic cardiomyopathy who underwent coronary artery stent placement with Impella support complicated by electrical storm. In both patients, a 29-Fr ProtekDuo® was modified and placed transapically into the left ventricle through a mini-thoracotomy followed by standard placement of a 29-Fr ProtekDuo® cannula in the pulmonary artery. This configuration allowed for extubation and ambulation of both patients until placement of total artificial heart while awaiting heart transplant in the first patient and recovery in the second patient. The third patient was a 63-year-old with anterior STEMI complicated by cardiogenic shock despite intra-aortic balloon counterpulsation. He underwent transapical placement of a ProtekDuo® cannula for LV support but had electrical storm and required placement of a ProtekDuo® cannula for RV support. The ProtekDuo® RVAD was weaned, but his family later consented to withdraw life support. The authors concluded that use of dual ProtekDuo® cannulas for biventricular support was a safe and effective method of establishing biventricular assist device (Bi-VAD) placement allowing avoidance of sternotomy, cardiopulmonary bypass with its associated complications, and peripheral ECMO while allowing for early extubation and ambulation [52].
