Discussion
Since 1982[3], PBPV is a primary technique that
has been extensively used for PVS treatment. Several studies have
discussed the safety, effectiveness, feasibility, and practicality of
this technique. We performed a retrospective review of all pediatric
population definitively diagnosed with PVS, and all study participants
underwent PBPV at our institution. This is one of the largest series to
describe the outcomes of the pediatric population diagnosed with PVS
after PBPV.
Several studies reported the immediate, short-, intermediate-, and
long-term effectiveness and safety of PBPV in different
centers[11,12]. A previous study conducted by Dian
Hong et al.[13] reported a restenosis rate of
6.4% (10 of 158) and reintervention rate of 3.7% (6 of 158), and
indicated that PBPV was the primary treatment as it was safe and
minimally invasive. Recently, Hansen et al.[14]conducted a multicenter study with the longest follow-up duration of up
to 25 years, in this study, 83% of the study patients (n = 207) had a
significant decrease in PVS after undergoing initial PBPV, while 17%
required repeat intervention.
The adverse reactions caused by chronic PR were unclear. In a previous
study conducted by Merino‐Ingelmo et al.[15],
which included 53 patients who underwent PBPV, the majority of patients
did not experience PR before the procedure; however, none of the
patients showed absence of PR at the end of the study. In a larger
study, David M. Harrild et al.[16] showed that
severe PR and mild RV dilation occurred after PBPV. In this study, 34%
of patients had a PR fraction of >15%, and 40% had an RV
end-diastolic volume z-score of ≥2. However, severe PR or RV dilation
rarely occurred. In the latest multicenter research by Hansen et
al.[14], which included a larger sample size (n =
248), 42% (n = 33) of them had ≥moderate PR. This study indicated that
young age, low weight, higher baseline RV-PA PSEG, increased baseline
RV/systemic pressure ratio, and critical PVS were the risk factors for
higher PR.
Our research showed that 76 (39.4%) of the follow-up patients had
≥moderate PR. In the multivariate analysis, lower weight and higher
initial RV-PA PSEG were independent risk factors for ≥moderate PR.
Although the degree of PR was increasing, it was well tolerated, and
none of our study patients underwent pulmonary valve replacement for
severe PR.
Several studies have been conducted to determine the target BAR. In
previous studies, the finding that significant PR was uncommon in
patients with a BAR of <1.4 support the appropriateness of 1.2
to 1.4 as a target BAR range. In a study by David M. Harrild et
al.[16], patients with a smaller pulmonary valve
z-score were more likely treated with a larger BAR. However, the results
showed that using a BAR of >1.4 was
more
likely to cause severe PR. Sagar J. Pathak et
al.[17] suggested that using a BAR of
<1.2 significantly decreased the PR rate than a BAR of
>1.2 without affecting the procedure efficacy and
increasing the need for repeat intervention for residual
PVS. A latest study by Dian Hong et
al.[13] showed that the choice of BAR could affect
the immediate therapeutic effects and medium‑term follow-up results. The
BAR they selected was 1.2–1.4, which was widely accepted and has
already been widely recommended in some guidelines. Our study showed
that BAR was not a risk factor for ≥moderate PR.
Some limitations exist in the present study. This study had a short
follow-up duration, was retrospective in nature, and was conducted at a
single center. This study had a relatively short follow-up period after
initial PBPV, and the maximum follow-up time was no more than 9 years.
The participants were from a single center rather than a multicenter,
and a data bias may exist. Due to the retrospective cohort design of
this study, the collection of clinical data was inadequate.
Notwithstanding, this research can still be used as a reference for
future studies. Therefore, with these limitations, a more comprehensive
assessment is required for future work.