Discussion
Many factors affect the morbidity and mortality in surgical ventricular
septal defect closure. In most patients, surgeon experience and the
anatomical location of the ventricular septal defect are as important as
the patient’s clinical state in
deciding whether to perform an
early surgical ventricular septal defect closure. Owing to the
heterogeneous patient distribution that occurs with the combination of
these factors that affect surgical outcomes, questions are raised in
surgical planning. Despite the multifactorial features of patients and
the improvements in the surgical and perfusion approaches, outcomes in
terms of mortality and morbidity have been improving. Although total
correction of ventricular septal defect in patients with a younger age
and lower body weight sometimes seem to be ambiguous and risky for
cardiac surgeons and cardiologists, it is the first-choice approach with
the advances in congenital heart surgery. Palliative pulmonary artery
banding has lost importance together with complete repair in children
with symptomatic ventricular septal defect and pulmonary
overcirculation. It is no longer the preferred palliative surgical
approach because of complete repair can now be performed safely at a
younger age and in patients with lower body weights. In the decision
making on the surgical timing during the follow-up period, the first
factor should be the clinical condition of the patient with ventricular
septal defect. By contrast, given the improvements of the results of
neonatal total corrective surgery, the pediatric cardiologist challenges
the surgeon to proceed with surgical closure of symptomatic ventricular
septal defects in ever smaller patients [4]. Although surgical
ventricular septal defect closure in patients low body weights and ages
(<6 months) can be safely performed with a low incidence of
complications, no clear consensus
has been reached on the timing of surgical ventricular septal defect
closure.
Currently, surgical ventricular septal defect closure seems to be a
reasonably safe procedure, with near-zero hospital mortality and low
complication rates. However, mortality and prolonged PICU or hospital
stay due to complications have still been reported. According to
previous studies, the mortality rate ranges from 0% to 2.8%,
reoperation rates due to residual defects range from 0% to 4.9%,
pacemaker implantation rates range from 0% to 5.6%, and major adverse
event rates range from 2.9% to 5.9% [2–4, 6–8]. In this study,
none of the patients died, had a residual defect requiring reoperation,
and needed a permanent pacemaker, and the incidence of major adverse
event was 0.9%. In fact, on postoperative echocardiography, none of the
patients had a residual ventricular septal defect of ≥2 mm in size.
Schipper et al. found that genetic syndrome was associated with MV and
PICU hospitalization times [3]. Similarly, Anderson et al. reported
a strong relationship between genetic syndromes and prolonged
hospitalization in their study [2]. In this study, we found that
patients with genetic syndromes had longer hospitalization (p = 0.002),
PICU hospitalization (p < 0.001), and MV durations (p
< 0.001).
In the study of Anderson et al., patients who received delayed
postoperative nutrition had longer postoperative hospitalization and MV
durations [9]. Sahu et al. found that early nutritional therapy was
associated with decreased ventilation duration, infection rate, length
of hospital stay, lenght of ICU stay, and mortality [10]. Similarly,
in our study, prolonged PICU stay, hospital stay, and MV duration, as
well as the occurrence of complications, were associated with the
initiation time of nutritional therapy.
Despite the development of surgical techniques and perfusion technology,
some studies have shown that morbidity was higher in infants with lower
body weights and ages < 6 months. In their study, Anderson et
al. found that those who were aged >6 months had less
hospitalizations and lower risk of temporary or permanent heart block.
In addition, higher body weight during operation was associated with a
significant decrease in the incidence of postoperative bleeding. Again,
in the group aged <6 months, the ICU hospitalization duration
decreased by 2.3 days in every kilogram increase in body weight, and the
complication rate increased 1.8 times in every kilogram loss of body
weight [2]. In the study of Schipper et al., patients who weighed
<6 kg had longer postoperative ICU hospitalization and MV
durations [3]. In a study conducted by Kogon et al., body weight did
not affect the operation, aortic cross-clamp, bypass, and MV times, and
complication rate [4]. Aydemir et al. showed no significant
difference between age groups in terms of morbidity [7]. Ergün et
al. showed that the increase in body weight was associated with the
decrease in the risk of major adverse events and shortened ICU and
hospital stays. In the study, <4-kg body weight was a risk
factor of prolonged MV time [6]. Vaidyanathan et al. found that
younger age was associated with longer ICU and hospital stays. In this
study, no effects of body weight and height Z scores were
demonstrated [11].
In our study, the univariate analysis revealed lower age and weight in
the patients with complications and prolonged ICU and hospitalization
stays, and MV duration. In terms of the presence of complications, the
cutoff age and weight were 5 months and 5.8 kg, respectively, similar to
those in other studies.
In the study of Mildh et al., in a population-based group of patients
who underwent pediatric open-heart surgery, PRISM proved to be a poor
tool for risk stratification owing to its low discrimination and
calibration values [12]. The PIM-2 measures demonstrated good
performance regarding the capacity to discriminate between survivors and
non-survivors in a population of patients with postoperative congenital
heart disease in the study of Rezende et al [13]. These studies only
provided information about the effects of the PIM and PRISM score
systems on mortality. We evaluated the effects of these scoring systems
on morbidity. In our study, prolonged hospitalization was associated
with higher PIM-2 and PRISM scores. In addition, the PRISM score was
found to be higher in the patients who needed prolonged MV.
In the multivariable analysis of our study, prolonged PICU stay was
associated with MV time of patients (odds ratio [OR], 0.9; 95%
confidence interval [CI], -1.22–3.03; p < 0.001), and
nutritional therapy time (OR, 0.05; 95% CI, 0.01–0.1; p = 0.044).
Prolonged hospital stay was associated with MV time of patients (OR,
0.6; 95% CI, 0.44–0.74; p < 0.001). Prolonged MV time was
associated with nutritional therapy time (OR, 0.25; 95% CI, 0.13–0.35;
p < 0.001) and, PRISM score (OR, 0.43; 95% CI, 0.16–0.7; p =
0.002). In this respect, multicenter studies may provide more-precise
results.
The limitations of our study are that it had a retrospective design and
was conducted in a single center. The other limitations of the study are
the absence of long-term follow-up, small number of patients with major
adverse events, and absence of mortality cases.