M H F Resende, K More, D Nicholls, J Ting, A Jain, P J McNamara

The decision to perform patent ductus arteriosus (PDA) ligation is controversial. Patient selection is oftentimes poorly standardized, leading to delays in referral and inappropriate intervention. A system for PDA ligation categorization and triaging process was introduced in 2006 at a quaternary hospital in Canada to streamline referrals and enhance perioperative care. We aimed to evaluate the impact of this dedicated PDA ligation triaging system comparing pre- and postimplementation of this system. We performed a retrospective chart review. Demographic and cardiorespiratory data of neonates ⩽30 weeks gestation age at birth, who were referred for and/or had a PDA ligation performed during two distinct epochs (EPOCH 1 (2003 to 2005) and EPOCH 2 (2010 to 2012)), were analyzed. All surgeries were performed at The Hospital for Sick Children, the regional referral center for PDA ligation. The primary outcome was incidence of PDA ligation and procedural cancellations. Secondary outcomes included postoperative need for cardiovascular or respiratory support. Subgroup analysis was performed in neonates <1000 vs >1000 g at the time of surgery during both epochs. A total of 198 neonates underwent surgery with no difference in baseline demographics between epochs. The incidence of PDA ligation as a proportion of total live births under 30 weeks in Central East Region of Ontario was lower in the second epoch (EPOCH 1: 117/1092 (10.7%) vs EPOCH 2: 81/1520 (5.3%)). During the second epoch, 24% of referrals for surgery were canceled after review by our PDA ligation team. There were no overall differences in the proportion of neonates with oxygenation failure, ventilation failure or Post-Ligation Cardiac Syndrome (PLCS), after surgery, between epochs. The proportion of neonates who developed systemic hypotension was higher in patients <1000 g (n=34 (34%) vs n=17 (17.4%), P=0.01) at the time of surgery. In addition, we identified a reduction in the proportion of neonates <1000 g who developed PLCS in EPOCH 2. On the contrary, there was an increase in the proportion of neonates >1000 g who developed ventilation failure in EPOCH 2. The presence of dedicated triaging and management system enhances efficiency of referral process through careful selection of patients for PDA ligation and optimizes perioperative management. We demonstrated a reduction in the incidence of PDA ligation without any negative impact on short-term neonatal morbidity. The use of targeted neonatal echocardiography in the assessment of PDA shunt volume and guiding postoperative decision making is likely to have contributed to these findings.Journal of Perinatology advance online publication, 14 January 2016; doi:10.1038/jp.2015.213.