**10. Role of transcatheter PDA closure in the future**

Transcatheter therapy has evolved significantly in the last decade. Emerging technology has paved the way for the use of this therapy in smaller and smaller infants [34, 35]. The Amplatzer Piccolo Occluder (Abbott Structural Heart, Plymouth, MN, USA) is a self-expandable, Nitinol mesh device with a central cylindrical waist and low-profile retention discs that are marginally larger than the waist, resulting in a nearly isodiametric device. The device comes pre-loaded on a delivery wire, which has a soft floppy distal end with a microscrew attachment at the tip. It is delivered through a catheter using a loading device. The APO has ideal characteristics (size, shape, delivery system) for closure of PDAs in premature neonates including ELBW infants. With an increasing need for a less invasive therapy for PDA closure in this population, a clinical study evaluating the safety and efficacy of the APO was conducted that led to the approval of this device by the U.S. Food and Drug Administration (FDA) for children ≥700 g [36].

While transcatheter closure of the PDA is common among larger children and adults, several modifications specific for ELBW patients are necessary to ensure success and minimize complications.


**49**

**Figure 3.**

**Figure 4.**

[24, 34, 40].

*the PA or the aorta caused by the device.*

*PDA Closure in ELBW Infants: If, When, and How to Do It*

• The central waist of the APO is designed to fill the ductal lumen, and the retention discs are designed to deploy in the pulmonary and the aortic ends of the PDA. However, when treating small infants, especially those ≤2 kg, implantation of both retention discs completely within the duct (intraductal placement) to avoid protrusion into the aorta or the LPA (**Figure 4**) is essential to avoid inadvertent stenosis of these vessels by the device discs

*Angiograms performed during transcatheter device closure of the PDA of patient described in Figures 1 and 2. Prior to closure (A), a large PDA is demonstrated shunting left to right between the aorta and the pulmonary artery (PA). Following device implantation within the PDA (B), there is no residual PDA, and no stenosis of* 

*TTE with color Doppler interrogation of the PDA of patient described in Figures 1 and 2 before (A) and after transcatheter device closure (B). The PDA is completely closed following intraductal implantation of the occlusion device. There is no stenosis of the left pulmonary artery (LPA) or the aorta caused by the device (B).*

• Minimization of contrast dosing, intracardiac catheter manipulation, and unnecessary hemodynamic measurements that prolong procedure time are

recommended to achieve optimal outcomes [24, 34, 40].

*DOI: http://dx.doi.org/10.5772/intechopen.88857*

#### **Figure 3.**

*Update on Critical Issues on Infant and Neonatal Care*

closure by pharmacotherapeutics in preterm infants.

in this high risk, ELBW population more important than ever.

**10. Role of transcatheter PDA closure in the future**

Drug Administration (FDA) for children ≥700 g [36].

success and minimize complications.

infants with a moderate-to-large PDA that did not close spontaneously within the first week. In so doing, the number of infants who spontaneously closed the ductus was reduced, though not eliminated. Early routine therapy (ERT) with pharmacological treatment was then compared to conservative management. As in previous trials, ERT did not always result in constriction of the ductus. Results indicated that ERT did not improve the incidence of NEC, IVH, BPD or death but instead delayed full feeding and may have increased the rate of sepsis and death in infants between 26 and 28 weeks gestation. Again, evidence did not support broad, routine ductal

With evidence mounting against the use of COX inhibitors and surgical ligation, the trend towards permissive conservative observation of this lesion has developed, reserving surgery for only the most severe cases [13–17, 32]. Unfortunately, recent data suggests that this approach is associated with an increased risk for the development of chronic lung disease and death, especially in infants born ≤26 weeks' gestation [8–17]. More recently in the United States, survival of infants born as early as 22 weeks' gestation is now possible [33], making the need for effective PDA therapy

Transcatheter therapy has evolved significantly in the last decade. Emerging technology has paved the way for the use of this therapy in smaller and smaller infants [34, 35]. The Amplatzer Piccolo Occluder (Abbott Structural Heart,

Plymouth, MN, USA) is a self-expandable, Nitinol mesh device with a central cylindrical waist and low-profile retention discs that are marginally larger than the waist, resulting in a nearly isodiametric device. The device comes pre-loaded on a delivery wire, which has a soft floppy distal end with a microscrew attachment at the tip. It is delivered through a catheter using a loading device. The APO has ideal characteristics (size, shape, delivery system) for closure of PDAs in premature neonates including ELBW infants. With an increasing need for a less invasive therapy for PDA closure in this population, a clinical study evaluating the safety and efficacy of the APO was conducted that led to the approval of this device by the U.S. Food and

While transcatheter closure of the PDA is common among larger children and adults, several modifications specific for ELBW patients are necessary to ensure

• Transportation of ELBW infants to the catheterization lab poses challenges for these fragile patients, but with proper coordination of team members, can be accomplished without complication [37]. Special accommodations for temperature control and ventilator support are essential. One operator has thus far reported success with procedures performed at the bedside. While this procedure may eventually become common at the bedside, transport to the

• Arterial access in these small patients is very likely to cause damage leading to limb ischemia and should be avoided [34, 38]. Instead, antegrade access

• The lack of arterial access and resulting inability to perform aortography postdeployment necessitates the use of TTE [39] to assess aortic flow, residual PDA

catheterization lab will likely be necessary in most institutions.

through the femoral vein is the method of choice.

shunting, and left PA (LPA) flow (**Figure 3**).

**48**

*TTE with color Doppler interrogation of the PDA of patient described in Figures 1 and 2 before (A) and after transcatheter device closure (B). The PDA is completely closed following intraductal implantation of the occlusion device. There is no stenosis of the left pulmonary artery (LPA) or the aorta caused by the device (B).*

#### **Figure 4.**

*Angiograms performed during transcatheter device closure of the PDA of patient described in Figures 1 and 2. Prior to closure (A), a large PDA is demonstrated shunting left to right between the aorta and the pulmonary artery (PA). Following device implantation within the PDA (B), there is no residual PDA, and no stenosis of the PA or the aorta caused by the device.*


• Following deployment, but prior to device release, in addition to echocardiographic assessment as noted above, angiography should be performed to check for stenosis of the proximal LPA caused by the device [39].

By observing these precautions, transcatheter therapy in ELBW infants can be safely performed. This new therapy could shift the paradigm of treatment. Future randomized trials using TCPC are necessary to determine whether PDA closure would impact the short term and long term outcomes of children born prematurely. The benefit of this therapy over other therapies must be demonstrated before it can become standard of care for premature infants [41, 42], but this new option may offer a solution to the substantial unmet need in this population for a minimally invasive, definitive closure of the ductus.
