**7.2 Surgical ligation**

Surgical ligation through a limited left thoracotomy, although invasive, offers definitive, immediate closure of the PDA. Robert Gross performed the first successful PDA surgical ligation at Children's Hospital of Boston in 1939 while his chief was out of town. While surgical ligation carries minimal risk of mortality, other risks include pneumothorax, recurrent laryngeal nerve paralysis, chylous effusions, and post-ligation syndrome [12, 24, 26, 27]. Post-ligation syndrome occurs in the first 6–24 h in approximately 30% of neonates who undergo surgical ligation; neonates experience hypotension, which in some cases may be resistant to catecholamines, as a result of changes in myocardial function and impaired vascular tone [20, 21]. Long term complications such as thoracic scoliosis and neurosensory impairment have been reported in some cases following surgical ligation [24, 26, 27]. Only one trial has compared surgical ligation to nonintervention and found that infants undergoing ligation required longer ventilation, oxygen therapy, and hospitalization than control subjects, although differences did not reach statistical significance [28]. Even so, surgical ligation may still be desirable in infants for whom medical therapy has failed and transcatheter closure is not possible [12].

### **7.3 Transcatheter therapy**

Transcatheter PDA closure (TCPC) is a minimally invasive therapy associated with low rate of adverse events that has become the procedure of choice for children >5 kg [29]. Historically, transcatheter closure of PDA has not been performed in premature neonates for a variety of reasons including: fear of patient fragility, concerns regarding vascular access and arterial injury, unknown effects of intravenous contrast media, concerns regarding catheter manipulation, and most importantly, absence of a suitable PDA closure device. Recently, a growing body of clinical evidence has emerged suggesting that transcatheter closure of PDA can be performed safely and effectively in premature infants [24, 30]. Risks of transcatheter therapy include embolization requiring surgery, cardiac perforation, aortic coarctation, and LPA obstruction, however these risks are very low even among ELBW infants.

**47**

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

**8. Highlights of transcatheter PDA closure**

• No arterial access is needed for the procedure.

• Therapy is definitive and minimally-invasive.

• Risks of pharmacotherapeutics and surgery can be avoided.

in premature infants may have influenced these opinions [16, 22].

• The procedure can be safely performed in infants as small as 700 g using an

Controversy regarding if, when, and how to close the PDA abounds. Survey results of neonatologists and cardiologists in 2018 describe the practice variations in management of the PDA [31]. Some neonatologists responded that even a large, hemodynamically significant PDA in a premature baby never requires treatment including medical management as the majority are likely to close, while no cardiologists agree with this option. Nearly half the neonatologists believe that closing the PDA does not alter outcomes in children born <28 weeks' gestation, while most of the cardiologists disagree with this opinion. When institutions do believe that closure is needed after failed medical therapy, the majority of neonatologists and cardiologists currently still prefer surgical ligation to TCPC, while watchful waiting was still preferred by some neonatologists. There are immense variations in the practice of managing PDAs in ELBW infants in the United States. Neonatologists and cardiologists have differing opinions of the consequence of a hsPDA on the eventual outcomes. Certain landmark papers questioning the utility of PDA closure

In 2010, William Benitz performed a meta-analysis of 49 RCTs involving nearly 5000 preterm infants who underwent pharmacological or surgical treatment to close the PDA [16]. Evidence showed that while treatment was effective in achieving ductal closure, only a single study showed improvement in other outcomes such as pulmonary hemorrhage, BPD, NEC, or death. Correlations between PDA and IVH were and did not support the hypothesis that closure of the ductus improves neurological outcomes [16–22]. It was concluded that the association of comorbidities with PDA might arise from prematurity itself rather than through prolonged patency of the ductus. Benitz recommended prolonging treatment of the PDA in infants ≤1000 g until the second week after birth to increase the odds of spontaneous closure, and refraining from all treatment specifically intended to close the ductus in infants >1000 g. Fluid restriction, diuretics, supplemental oxygen, and other treatments were recommended in lieu of COX inhibitors and surgical ligation [16]. Certain patients at special risk for complications related to PDA would still require ductal closure and should be identified via a scoring system, such as the one proposed by McNamara and Sehgal [21]. Benitz's study provided impetus for the trend against early routine treatment of the PDA in premature infants and towards a more selective approach wherein

only certain infants at increased risk received intervention to close the ductus.

In 2018, Ronald Clyman designed the PDA Tolerate Trial [13] to further examine early routine therapy versus conservative management by controlling for variables that had confounded many of the previous RCTs. Inclusion criteria was limited to

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

• The procedure time is minimal.

FDA-approved device.

**9. Controversy and practice variation**
