Hemi-Diaphragm Plication and/or Tracheostomy Are Valuable Adjunctive Procedures After Repair of Congenital Heart Defects in Children: A Systematic Review

Diaphragmatic paralysis (DP), whether unilateral or bilateral, often leads to extended recovery and more severe complications, particularly in neonates and infants undergoing congenital heart surgery. This condition's impact is most pronounced after single-ventricle palliative procedures. Tracheostomy prevalence is rising in pediatric patients with congenital heart disease (CHD) despite its association with high resource utilization and in-hospital mortality. This study examines the reported incidence of diaphragmatic paralysis and timing of tracheostomy in pediatric patients undergoing surgery for congenital heart disease in the literature and a retrospective analysis of cases in our institution between 2018 and 2023, offering insights for prospective management. An electronic search of PubMed databases retrieved 10 studies on pediatric tracheostomy and 11 studies on DP. Our retrospective analysis included 15 patients, of whom 10 underwent tracheostomy, four underwent diaphragmatic plication, and one underwent both. Postoperative tracheostomy had an 11.8% mortality rate in our systematic review, rising to 40% in our observational study. Diaphragm repair and early diagnosis can reduce morbidity, prevent complications, and improve patients' quality of life.


Introduction And Background
The thoracic and abdominal cavities are divided by the muscular-fibrous diaphragm.It consists of a central fibrous body, upper lumbar vertebrae, and peripheral muscular elements coming from the chest wall.This structure plays a crucial role in respiration and is a primary muscle of inspiration.Innervation is provided by the phrenic nerve, which can sustain damage during diverse cardiac surgical interventions, resulting in the occurrence of unilateral or bilateral diaphragmatic paralysis (Figure 1).Diaphragmatic paralysis (DP) stemming from phrenic nerve damage, whether reversible or irreversible, is a significant postoperative complication of pediatric cardiac surgery [1,2].Young patients and those with univentricular physiology commonly present with symptoms of DP, as it potentially disrupts the systemic and pulmonary blood flow dynamics.These include dyspnea, tachypnea, difficulties with extubation, recurrent need for intubation, prolonged ventilation, susceptibility to pneumonia, and an increased risk of sepsis [2].Timely identification of DP is crucial to improving patient outcomes, necessitating prompt weaning, clinical expertise, and vigilant suspicion.
Typically, the identification of DP is prompted by clinical indications and verified through fluoroscopic assessment of the diaphragm (Table 1).

No. Description
01 Paradoxical respiration, atelectasis that doesn't resolve, weaning failure 02 Hoover's Sign: Infants with DP frequently have indrawing of the lower chest during inspiration.

03
The Kienbock sign: chest radiograph shows an increase in elevation of the hemidiaphragm.This can also be demonstrated with bedside ultrasonography or fluoroscopy when the patient is spontaneously breathing.[1] 04 DP can be recognized on 2D echocardiography as a paradoxical diaphragmatic movement during breathing.Sensitivity ~ 100 %, specificity ~ 81 %.

05
Sniff Test: While sniffing, the affected diaphragm migrates paradoxically higher due to negative intrathoracic pressure.This is seen fluoroscopically.Sensitivity ~ 100 %, specificity ~ 74 % The recuperation of diaphragmatic function spans a variable period, ranging from days to months, with the possibility of incomplete recovery, underscoring an unpredictable trajectory [3].However, relying on the natural recovery of diaphragmatic function results in extended periods of mechanical ventilation.Conversely, early diaphragmatic plication is beneficial, resulting in swift extubation, reduced durations of intensive care unit (ICU) and hospital stays, minimized morbidity, and improved outcomes [4,5].Nevertheless, the timing of this plication procedure varies, encompassing both early and late interventions (  The survival rates among pediatric CHD patients have improved with advancements in surgical methodologies that address even the most intricate structural anomalies and enhanced capabilities within ICUs.However, while more children with complex CHD and co-morbidities achieved long-term survival, some still require tracheostomy for airway safeguarding and/or dependence on ventilatory support.Many undergo prolonged and challenging recovery and post-cardiac procedures, and even after the initial recovery phase, children with CHD exhibit heightened susceptibility to subsequent critical ailments. The objectives of this study were twofold: (i) to conduct a thorough analysis of our data from a retrospective study of pediatric cardiac surgery patients, as well as the literature that already exists on DP, and (ii) to perform a systematic review in order to assess tracheostomy's indications, performance, outcomes, and resource utilization in children with CHD.

Study Objective
The preferred reporting of systematic reviews and meta-analyses (PRISMA) standards were followed during the preparation of the systematic review to guarantee transparent and thorough reporting of the study methodology and conclusions.
From our internet database (FTP 192.168.0.5), information about 15 patients was retrieved.We enlisted patients who received tracheostomy or diaphragm plication surgeries between 2018 and 2023 at the Bhanubhai and Madhuben Patel Cardiac Centre, Karamsad, Anand, Gujarat, India.

Search Strategy
Diaphragm Plication: A systematic literature search was conducted.Keywords used to search for relevant articles included "diaphragm", "plication", "paresis", "pediatric", "infants", "neonates", "cardiac surgery", and "congenital heart disease" from 1978 until 2012, PubMed was searched using the Boolean logical operations AND and OR (Diaphragm Plication).This study period of search was used to bring out the early practice of surgery and its impact on diaphragm palsy.Only studies with a minimum of 500 patients were taken.Case reports, expert opinions, and conference abstracts were not considered in the study.The search was restricted to articles published in the English language.
Tracheostomy Mortality: The following keywords were used in the PubMed database: "paediatric tracheostomy mortality infant".The search was restricted to paediatric age group (0-10 years) and in the English language.Only original research articles, cohorts, case series, and systematic reviews were considered in the time period from January 2016 to June 2020.Articles not mentioning tracheostomy mortality were excluded.This time period was chosen to capture the data exactly during our study period for comparability.Due to the heterogenicity of the data, doing a meta-analysis was not feasible.

Data Extraction
To gather pertinent information from the included research, a consistent data extraction form was created.The current study is a retrospective observational study, and the Institutional Ethics Committee (IEC-2) at  **To review the literature for relevant information on paediatric tracheostomy mortality.The following keywords were used: "paediatric tracheostomy mortality".The search was restricted to the paediatric age group (0-10 years) and in the English language.Only original research articles, cohorts, case series, and systematic reviews were considered in the time period from January 2016 to June 2020.Articles not mentioning tracheostomy mortality were excluded.This was done to capture the data exactly during our study period for comparability.Due to the heterogenicity of the data, doing a meta-analysis was not feasible.
A comprehensive search of electronic databases yielded 11 articles for the studies on the incidence of DP and 10 articles from the tracheostomy group.Several studies investigating the causes of diaphragmatic paralysis (DP) in pediatric patients have examined its occurrence following heart surgery and have reported a range of incidence rates, typically spanning from 0.28% to 5.64% [6][7][8][9][10][11][12][13][14][15][16].Notably, DP appears to be more prevalent after specific cardiac procedures, such as ventricular septal defect (VSD) closure, bidirectional Glenn or Fontan operation, surgery for tetralogy of Fallot (TOF), the classic or modified Blalock-Taussig (BT) shunt, systemic to pulmonary artery shunts, and arterial switch operation.
In addition, Watanabe et al. [15] reported DP incidence rates of 6.7% after the mustard procedure, 5.6% following right ventricular outflow tract reconstruction, and 2.7% following TOF repair.Among patients undergoing closed-heart procedures, DP was observed in 6.2% after the Glenn anastomosis, 5.9% following the Blalock-Hanlon atrial septectomy, and 5.1% following the right BT shunt.An overview of the key findings from these selected studies is presented in Table 3.

Statistical Analysis
Descriptive statistics are used to represent the baseline characteristics of the study participants, including mean (SD), median interquartile range (IQR), range, and frequency (%).The statistical software STATA 14.2 is used for data analysis.

Results
Of 15 infants, nine were boys, and six were girls, and the mean (SD) age was 4.8 (2) months.The range of age (in months) was 2-9.The mean (SD) height and weight were 57.8 (4.1) cm and 3.8 (1.1) kg, respectively.Tracheostomy and diaphragm plication were performed in 10 and four infants, respectively, and both procedures were followed in one infant (four left-side and one right-side diaphragm).The mean (SD) postoperatively for performing diaphragm plication was 28 (12).Four deaths were reported in the tracheostomy group (n = 10), or approximately 40%.Among them, a cuffed tube was used in two patients, and a non-cuffed tube was used in the other two patients.For infants in whom diaphragm plication was performed, mean (SD) plication days, ventilator days, and hospital stay days were 12(4), 14 (9), and 26 (9), respectively.The median (IQR) ICU stay days were 27 (18,97), and the median (IQR) hospital stay was 26 (19,32).In infants that underwent tracheostomy, the mean (SD) on ventilator days was 44 (21), and inhospital stay days were 71 (32).The median (IQR) ICU stay days were 61 (27,71), and the median (IQR) hospital stay was 73 (46, 82) (Figures 6-8).

FIGURE 8: Bar chart depicting both procedures
The outcome of four patients in the tracheostomy group and the causative organisms identified are summarized in Table 6.

Discussion
The reported incidence of DP ranges from 0.33% to 5.7% in the present systematic review analysis [4][5][6][7] and from 0.5% to 12.8% in prospective studies [10].This difference could be related to the asymptomatic nature, uneventful recovery, or diagnostic difficulties associated with DP.In our retrospective observational analysis, after juvenile heart surgery, there were four left-sided and one right-sided case of DP, for a DP incidence of 1.09%.Among our cases, two patients with univentricular physiology necessitated diaphragm plication, while three bi-ventricular physiology patients underwent the procedure.Our inclination toward early plication in univentricular patients, even in cases of compensated respiratory status, may have influenced this pattern.Patients with univentricular physiology have increased respiratory effort and decreased passive venous pulmonary flow due to the absence of negative intrathoracic pressure during inhalation and elevated pulmonary vascular resistance.These result in elevated systemic venous pressure, ascites, and pleural effusion [1,7,27,28].Diaphragm plication, in such cases, ameliorates pulmonary hemodynamics and reduces systemic venous pressure [29].
A conservative approach comprising 4-6 weeks of extended mechanical ventilation was the gold standard [9,30].Diaphragm plication has gained widespread acceptance as the conventional treatment for DP cases with reduced cardio-respiratory function.However, the timing of plication differs across studies, ranging from early to late intervention; in the present study, the mean (SD) time to plication was 28 (12) days (four weeks).
Tracheostomy in pediatric patients is associated with higher complication rates compared to adults [17,18].Pediatric tracheostomy is associated with complications like infection, pneumothorax, obstruction, and fistula [20].Many studies cited in Table 4 indicated mortality rates ranging from 10% to 20% over at least a year; one reported an 8.6% mortality rate before discharge [26].However, recent trends indicate reductions in tracheostomy-related mortality rates, which are probably due to international efforts to enhance treatment for these complicated patients [18,20].Although tracheostomy-specific mortality remains low, it is significant (0.5%-3.5%).In only two recent studies, seven deaths related to tracheostomy were reported [18,19].The most important risk factors for tracheostomy-related mortality are age associated comorbidities and duration of stay [26].
In a large cohort, authors demonstrated that the indication of tracheostomy influences mortality.In this study, patients requiring tracheostomies for airway-related complications had the lowest mortality.
However, patients requiring treatment for neurological disease had the highest mortality [20].Compared to children who have the treatment for underlying pulmonary disorders, children who require tracheostomy due to underlying neoplasms or congenital cardiac defects typically have greater mortality rates [17,18,26].
In the present study, four tracheostomy-related deaths occurred among 10 tracheostomized patients.The most common causes were acute respiratory distress syndrome and septic shock.This could be attributed to the longer duration of mechanical ventilation and the underlying condition.Sicker babies are likely to undergo tracheostomies as the duration of mechanical ventilation increases.This could have been the reason for the mortality, not the procedure per se.
With the advancement of techniques and improved intensive care management, complications and mortality have significantly reduced in patients undergoing tracheostomy for prolonged mechanical ventilation [20].However, the advantage of early plication over tracheostomy is to be determined.Proper patient selection and anticipation of complications will contribute to a better patient outcome in pediatric cardiac surgery.

Limitations
Although this systematic review provides insightful information, it is crucial to highlight some drawbacks, including the limited sample size, the single-center study, and the potential for publication bias to reduce the overall reliability of the results.Nevertheless, this systematic review contributes to the existing knowledge about adjunctive procedures in pediatric cardiac surgery.A systematic review was done, but it was restricted to a few time frames, and a meta-analysis was impossible because of the heterogeneity of the data.The data collected was retrospective in nature.To ascertain the superiority or mortality benefit of plication over tracheostomy was not possible due to the limited sample size.Larger studies are required to answer this question.

Conclusions
Children who undergo open heart surgery are relatively susceptible to developing DP, which can have serious consequences for morbidity and mortality.Early diagnosis demands a heightened level of suspicion, and management approaches should be tailored to the specific clinical context.For those undergoing univentricular repair, prompt diaphragmatic plication is recommended.Furthermore, this study highlights tracheostomy and its associated resource implications.The observed practice patterns and outcomes indicate that tracheostomy is increasingly performed for congenital heart defects in children.However, it is frequently delayed (by an average of 44 days) when performed concurrently with heart surgery.

FIGURE 3 :
FIGURE 3: PRISMA search approach for paediatric tracheostomy mortality from 2016 to 2020.

TABLE 1 : Diagnosis of diaphragm palsy
DP: diaphragmatic palsy

TABLE 6 : Patients with causative organisms pertaining to infection and cause of death
P: patient