Classification scheme for ductal morphology in cyanotic patients with ductal dependent pulmonary blood flow and association with outcomes of patent ductus arteriosus stenting.
Qureshi AM, Goldstein BH, Glatz AC, Agrawal H, Aggarwal V, Ligon RA, McCracken C, McDonnell A, Buckey TM, Whiteside W, Metcalf CM, Petit CJ.
Catheter Cardiovasc Interv. 2019 Feb 21. doi: 10.1002/ccd.28125. [Epub ahead of print]
Select Item 30791188
Take Home Points
- PDA stent implantation is an increasingly utilized initial intervention for infants with ductal dependent pulmonary blood flow.
- The degree of ductal tortuosity is an important predictor of need for unplanned reintervention and branch pulmonary artery jailing but does not predict successful PDA stenting (ductal stenting was equally successful regardless of tortuosity).
- Pulmonary artery arterioplasty is performed more often when branch PAs are jailed, though indices of PA growth are not affected in a jailed branch PA.
Commentary from Dr. Ryan Romans (Kansas City), catheterization section editor of Pediatric Cardiology Journal Watch: Stent implantation in the patent ductus arteriosus (PDA) has become a more frequently used initial intervention in infants with ductal dependent pulmonary blood flow (PBF). The ductal anatomy in these patients can vary significantly and may play a role in the success of PDA stenting. PDA tortuosity is often seen as a contraindication to ductal stenting, though this has not been well studied. Additionally, reinterventions are fairly common in patients who have undergone PDA stenting. Risk factors for need for reintervention and procedural results that predict future outcomes (such as pulmonary artery (PA) jailing and impact on future PA growth or need for surgical PA plasty) have not been well defined.
Qureshi et al report on a multicenter retrospective cohort study of all patients less than 1 year of age with ductal dependent PBF with confluent branch pulmonary arteries who underwent transcatheter PDA stent implantation over a 7 year period. A classification scheme based on ductal morphology was created based on 3 distinct tortuosity index (TI) groups as detailed below. An additional subtype classification was made based on the ductal origin (descending aorta, underside of aortic arch, innominate artery, or ascending aorta). A curvature index (CI) was also calculated using the total length of the PDA and the length of a straight line from the aortic origin to the PA insertion (higher ratios indicate increased ductal curvature).
Type III: Multiple turns in course, often complex turns
Type I: Relatively straight (may have slight turn at origin or insertion)
Type II: One turn in course
A total of 105 patients underwent PDA stent implantation with a total of 157 stents across the 4 centers. The catheterization access sites varied (carotid, axillary, and femoral) depending on the location of the ductal origin. 40% of patients had expected single ventricle anatomy and nearly 40% had the PDA as their only source of pulmonary blood flow. The tortuosity index was type I in 55%, type II in 23%, and type 3 in 22%. Not surprisingly, patients with a higher TI tended to have a higher CI. There was no significant difference in procedure times (defined as time of sheath insertion to sheath removal) or need to implant more than 1 stent among the different PDA tortuosity types. Jailing of a branch PA (defined as partial when there was any stent protrusion into the orifice of a branch PA, or complete when a stent crossed the entire branch PA orifice) was seen in 22% of patients (19 patients with partial jailing, 4 with complete, though with preserved flow to the jailed PA). There was a higher incidence of PA jailing as the TI increased. Over a median follow up time of 13.5 months (IQR 6.9-37 months), 36% patients underwent planned reinterventions (typically PDA stent redilation at times determined by each individual center) and 11% of patients underwent unplanned reinterventions to treat cyanosis. Increased TI and the presence of PA jailing were associated more unplanned reinterventions. While there was no significant difference in indices of PA growth (Nakata index and pulmonary artery symmetry index) in patients who had PAs jailed, these patients were more likely to have PA plasty performed at the time of their next surgery. 64 patients underwent complete anatomic repair or stage II palliation.
This retrospective cohort study reports a novel standardized PDA classification scheme for infants with ductal dependent PBF. PDA stenting was successful across the range of PDA morphologies, though PDAs with a higher TI that were stented were more at risk for branch PA jailing (which increases the likelihood of PA arterioplasty) and needing unplanned reinterventions. However, initial technical success did not vary between groups in contrary to the oft held belief that tortuous ducts are not amenable to stenting. Additionally, even if the PAs were jailed, the indices of PA growth did not suffer. The authors acknowledge (and I certainly agree) that there is a learning curve for clinicians who perform ductal stenting. However, this study and other recently published data showing a favorable comparison of PDA stenting to surgical shunts indicating ductal stenting will continue to play a large role in the initial management of patients with ductal dependent PBF.