Phrenic nerve paralysis after pediatric cardiac surgery

Towards Zero Phrenic Nerve Injury in Reoperative Pediatric Cardiac Surgery: The Value of Intraoperative Phrenic Nerve Stimulation

BACKGROUND

Phrenic nerve injury is a devastating complication that results in significant morbidity and mortality. We developed a novel technique to localize the phrenic nerve and evaluate its success.

METHODS

Two groups of children underwent repeat sternotomy for a variety of indications. Group I (69 patients, nerve stimulator) and Group II (78 patients, no nerve stimulator).

RESULTS

There was no significant difference in the mean age and weight between the two groups: (6.4 ± 6.5 years vs. 5.6 ± 6.4 years; p = 0.65) and (25.2 ± 24.1 vs. 22.6 ± 22.1; p = 0.69), respectively. The two groups were comparable in the following procedures: pulmonary conduit replacement, bidirectional cavopulmonary anastomosis, aortic arch repair, and Fontan, while Group I had more pulmonary arterial branch reconstruction (p = 0.009) and Group II had more heart transplant patients (p = 0.001). There was no phrenic nerve injury in Group I, while there were 13 patients who suffered phrenic nerve injury in Group II (p < 0.001). No early mortality in Group I, while five patients died prior to discharge in Group II. Eleven patients underwent diaphragm plication in Group II (p = 0.001). The mean number of hours on the ventilator was significantly higher in Group II (137.3 ± 324.9) compared to Group I (17 ± 66.9), p < 0.001. Group II had a significantly longer length of ICU and hospital stays compared to Group I (p = 0.007 and p = 0.006 respectively).

CONCLUSION

Phrenic nerve injury in children continues to be associated with significant morbidities and increased length of stay. The use of intraoperative phrenic nerve stimulator can be an effective way to localize the phrenic nerve and avoid its injury.

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.

Management of phrenic nerve injury post-cardiac surgery in the paediatric patient

BACKGROUND

Phrenic nerve injury is a common complication of cardiac and thoracic surgical procedures, with potentially severe effects on the health of a child. This review aims to summarise the available literature on the diagnosis and management of PNI post-cardiac surgery in paediatric patients with CHD.

MAIN BODY

The presence of injury post-surgery can be difficult to detect and may present with non-specific symptoms, emphasising the importance of an effective diagnostic strategy. Chest X-ray is usually the first investigation for a suspected diagnosis of PNI, which is usually confirmed using fluoroscopy, ultrasound scan, or phrenic nerve stimulation (gold standard). Management options include supportive ventilation and/or invasive diaphragmatic plication surgery. While the optimal timing of plication surgery remains controversial, it is now the most widely accepted treatment for PNI in children post-CHD surgery, especially for very young patients who cannot be weaned off supportive ventilation. Further research is needed to determine the optimal timing of surgical intervention for positive outcomes and to explore the benefits of using minimally invasive surgical techniques in children.

CONCLUSION

PNI is a common and serious complication of CHD surgery, therefore, its diagnosis and management in the paediatric population are of major importance. Further research is needed to determine the optimal timing of surgical intervention for positive outcomes and to explore the benefits of using minimally invasive surgical techniques in children.

Outcome analysis of a conservative approach to diaphragmatic paralysis following congenital cardiac surgery in neonates and infants: a bicentric retrospective study

 

OBJECTIVES

Diaphragmatic paralysis following congenital cardiac surgery is associated with significant morbidity and mortality. Spontaneous recovery of diaphragmatic function has been described, contrasting with centres providing early diaphragmatic plication. We aimed to describe the outcomes of a conservative approach, as well as to identify factors associated with a failure of the strategy.

METHODS

This is a retrospective study of patients admitted after cardiac surgery and suffering unilateral diaphragmatic paralysis within 2 French Paediatric Cardiac Surgery Centers. The conservative approach, defined by the prolonged use of ventilation until successful weaning from respiratory support, was the primary strategy adopted in both centres. In case of unsuccessful evolution, a diaphragmatic plication was scheduled. Total ventilation time included invasive and non-invasive ventilation. Diaphragm asymmetry was defined by the number of posterior rib segments counted between the 2 hemi-diaphragms on the chest X-ray after cardiac surgery.

RESULTS

Fifty-one neonates and infants were included in the analysis. Patients' median age was 12.0 days at cardiac surgery (5.0-82.0), and median weight was 3.5 kg (2.8-4.9). The conservative approach was successful for 32/51 patients (63%), whereas 19/51 patients (37%) needed diaphragm plication. There was no difference in patients' characteristics between groups. Respiratory support prolonged for 21 days or more and diaphragm asymmetry more than 2 rib segments were independently associated with the failure of the conservative strategy [odds ratio (OR) 6.9 (1.29-37.3); P = 0.024 and OR 6.0 (1.4-24.7); P = 0.013, respectively].

CONCLUSIONS

The conservative approach was successful for 63% of the patients. We identified risk factors associated with the strategy's failure.

Early diagnosis of diaphragm palsy after pediatric cardiac surgery and outcome after diaphragm plication - A single-center experience

Objective :

The aims of our prospective observational study were to evaluate the (1) reliability of clinical signs in the early detection of diaphragm palsy (DP); (2) reliability of ultrasonography using echo machine as a bedside tool for the diagnosis of DP; and (3) does early diaphragm plication result in the improved outcome? We also sought to determine the incidence and predominant risk factors for DP and diaphragm plication at our center.

Materials and Methods :

This prospective observational study included patients with suspected DP from January 2015 to December 2018. Patients with suspected DP were initially evaluated by bedside ultrasonography using echo machine and confirmed by fluoroscopy. Diaphragm plication was considered for patients having respiratory distress, difficult weaning, or failed extubation attempt without any obvious cardiac or pulmonary etiology. Patients were followed for 3 months after discharge to assess diaphragm function.

Results:

A total of 87 patients were suspected of DP based on clinical signs. DP was diagnosed in 61 patients on fluoroscopy. The median time from index operation to diagnosis was 10 (1–59) days. Diaphragm plication was done among 52 patients and not done in nine patients. Bedside ultrasonography using echo machine was 96.7% sensitive and 96.15% specific in diagnosing DP. Early plication (<14 days) significantly reduced the need for nasal continuous positive airway pressure (65% vs. 96%, P = 0.02), duration of mechanical ventilation (12 vs. 25 days, P = 0.018), intensive care unit (ICU) stay (25 days vs. 39 days, P = 0.019), and hospital stay (30 days vs. 46 days, P = 0.036).

Conclusion :

Hoover's sign and raised hemidiaphragm on chest X-ray are the most specific clinical signs to suspect unilateral DP. Bedside ultrasonography using an echo machine is a good diagnostic investigation comparable to fluoroscopy. Early plication facilitates weaning from the ventilator and thereby decreases the ICU stay and hospital stay.

Impact of prior diaphragm plication on subsequent stages of single ventricle palliation

BACKGROUND

Phrenic nerve injury is a known cause of morbidity after single ventricle palliation. Previous studies have shown that hemidiaphragm plication improves short-term outcomes. The effect of plication on the outcomes of subsequent stages of single ventricle palliation is unknown.

METHODS

From 1997 to 2015, 1146 patients underwent surgical management of single ventricle physiology at our institution. We reviewed the records of 30 patients who had undergone diaphragm plication for phrenic nerve injury before Fontan completion. Each patient was compared with 2 propensity-matched controls identified from patients who underwent the Glenn or Fontan procedure during the same period without diaphragm plication. Propensity matching was achieved for each test subject using the nearest neighbor algorithm. Data are presented as the median and quartiles or numbers and percentages.

RESULTS

The cohort included 18 boys (60%). Of the 30 patients, 19 (63%) had undergone plication after first-stage palliation. Of these, 13 have undergone completion Fontan, 5 were awaiting Fontan at the last follow-up, and 1 had died. An additional 11 patients had undergone plication after Glenn and proceeded to Fontan completion. Thus, 24 patients with diaphragm plication have undergone Fontan completion. No difference was found in pulmonary pressure or resistance between the plicated patients and their propensity-matched controls. Both groups had comparable chest tube output and hospital lengths of stay. Equal proportions of patients in both groups required pulmonary vasodilator therapy and/or supplemental oxygen at hospital discharge.

CONCLUSIONS

Prior diaphragm plication does not adversely affect Fontan completion in children with single ventricle physiology. The hospital course during subsequent stages of palliation for plicated patients was no different than that of matched controls.

Unilateral diaphragmatic paralysis associated with surgical mitral valve repair in dogs

OBJECTIVES

Unilateral diaphragmatic paralysis (UDP) due to phrenic nerve injury is a potential complication of thoracic surgery. This study evaluated the prevalence of UDP associated with surgical mitral valve repair (MVR) and its effect on surgical outcomes in dogs.

ANIMALS, MATERIALS AND METHODS

Two hundred ninety-four dogs that underwent MVR were included in the study. A retrospective review of medical records was performed for dogs surviving surgery. Diagnosis of UDP was based on preoperative and postoperative thoracic dorsoventral radiographs.

RESULTS

A total of 284 dogs survived until the day after surgery. The prevalence of UDP on the day after surgery, on the day of discharge, and after the first postoperative month was 30%, 24%, and 9%, respectively. One case of UDP was observed at 3 months after surgery. Unilateral diaphragmatic paralysis was exhibited by nine of the 21 patients that died in the hospital. The proportion of patients with UDP was higher in dogs that died of respiratory failure than in dogs that died of other causes (p = 0.002). Most dogs whose deaths were suspected to have been related to respiratory failure also had pre-existing respiratory diseases. The occurrence of UDP did not relate to the lengths of stay in the intensive care unit or the hospital.

CONCLUSIONS

Our findings suggest that UDP is a common complication in dogs after MVR and that the prevalence of UDP decreases with time after surgery. Unilateral diaphragmatic paralysis is a risk factor for postoperative death, especially in patients with pre-existing respiratory disease.

Management of phrenic nerve palsy following cardiac surgery

Phrenic nerve palsy (PNP) is a potential complication of cardiac surgery. It may prolong ventilation and hospitalization and result in significant morbidity and mortality. The diagnosis and management of PNP following cardiac surgery is reviewed.

Bilateral diaphragmatic paresis following pediatric liver transplantation

Background:

Although diaphragm paresis or paralysis is fairly common following cardiac procedures; it is a less common complication following liver transplantation. Unilateral diaphragm paresis, usually right sided, has been described following liver transplantation in adults and has been rarely described in children.

Purpose:

Diaphragmatic injury following LT is often unrecognized and is typically unilateral, involving the right hemidiaphragm. Bilateral diaphragm dysfunction following liver transplantation in children is a rare complication.

Methods:

This is a case report of bilateral diaphragm paresis in a young child following a repeat liver transplantation.

Conclusion:

Bilateral diaphragm paresis following liver transplantation in children is rare and spontaneous resolution is possible. A conservative approach with noninvasive ventilation as a first line treatment to allow the diaphragm to regain function should be considered.

Ultrasonography and Lung Mechanics Can Diagnose Diaphragmatic Paralysis Quickly

Diaphragmatic paralysis after cardiovascular surgery requires early diagnosis prior to extubation. The effectiveness of ultrasonography and a lung mechanics assessment was evaluated. Paralysis of the diaphragm was diagnosed when the diaphragm failed to move or moved in a cephalad direction during inspiration. It was diagnosed in 3 of 40 patients (7.5%) who underwent cardiovascular surgery from 1998 to 1999. Patients were extubated when all parameters met the extubation criteria, irrespective of the presence or absence of diaphragmatic paralysis. One patient required prolonged assisted ventilation and died from mediastinitis on the 35th postoperative day. The other 2 patients required assisted ventilation for an additional 1–3 days. Ultrasonography and a lung mechanics assessment are effective tools for the early diagnosis of diaphragmatic paralysis and assessment of respiratory function after cardiovascular surgery.

The Effects of Phrenic Nerve Degeneration by Axotomy and Crush on the Electrical Activities of Diaphragm Muscles of Rats

The aim of this study was to investigate the effect of axotomy and crush-related degeneration on the electrical activities of diaphragm muscle strips of experimental rats. In the present study, twenty-one male Wistar-albino rats were used and divided into three groups. The animals in the first group were not crushed or axotomized and served as controls. Phrenic nerves of the rats in the second and third groups were crushed or axotomized in the diaphragm muscle. Resting membrane potential (RMP) was decreased significantly in both crush and axotomy of diaphragm muscle strips of experimental rats (p < 0.05). Depolarization time (T DEP) and half-repolarization (1/2 RT) time were significantly prolonged in crush and axotomy rats (p < 0.05). Crushing or axotomizing the phrenic nerves may produce electrical activities in the diaphragm muscle of the rat by depolarization time and half-repolarization time prolonged in crush and axotomy rats.

Thoracoscopic plication for diaphragmatic eventration after surgery for congenital heart disease in children

OBJECTIVE

The aim of this study was to clarify the role of thoracoscopic plication for diaphragmatic eventration after surgery for congenital heart disease (CHD) in children.

PATIENTS AND METHODS

We retrospectively reviewed the medical charts of pediatric patients who had undergone thoracoscopic plication of diaphragmatic eventration after surgery for CHD between 2008 and 2013 at our department.

RESULTS

Five patients were identified during the study period. The median age and body weight of the patients were 7.6 months and 6.6 kg, respectively. The associated CHDs were pulmonary artery atresia in 3 patients, truncus arteriosus in 1 patient, and double-outlet right ventricle in 1 patient. Four patients needed preoperative mechanical respiratory support. At operation, all the patients received CO2 insufflation (4 mm Hg), and single-lung ventilation was attempted in 3 patients using a bronchial blocker. A sufficient operative field was maintained by CO2 insufflation in all the patients regardless of single-lung ventilation. The procedure was not converted to open operation in any patient. Postoperative extubation was performed in the operating room in 1 patient, on the day of operation in 2 patients, and on postoperative Days 1 and 2 in 2 patients. Air embolism was not observed in any of the patients. Diaphragmatic eventration did not recur in any of the patients after thoracoscopic plication.

CONCLUSIONS

Thoracoscopic plication is a safe and effective procedure for pediatric diaphragmatic eventration after surgery for CHD. Considering the sufficient operative field maintained by CO2 insufflation, single-lung ventilation using a bronchial blocker would be unnecessary for this procedure. With its safety and good outcome, early thoracoscopic plication is a good treatment option for pediatric patients with symptomatic diaphragmatic eventration after surgery for CHD.

Aggressive coil embolization for connected aortopulmonary collateral arteries with large shunts developed after diaphragmatic plication performed after cavopulmonary connection to facilitate Fontan circulation

We present two patients of univentricular physiology, who underwent diaphragmatic plication following the complication of diaphragmatic paralysis resulting from a bidirectional Glenn procedure. Over several months, complex connections developed between aortopulmonary collateral arteries, resulting in large shunts around the plication sites and an increased central pulmonary artery (PA) pressure to 14-15 mmHg. Most blood flow from these connections was reversed in the lower PAs of the affected side, reaching the contralateral lungs through the central PAs. Selective angiography identified almost all of the feeding arteries and complex connections. Aggressive coil embolization at these sites decreased the PA pressure to approximately 10 mmHg, enabling the Fontan procedure.

Diaphragmatic Nerve Palsy After Cardiac Surgery in Children in Egypt

Introduction: Diaphragmatic paralysis (DP) due to phrenic nerve injury is a complication which occurs in association with congenital cardiac surgery and may be a life-threatening event in infants and young children. Information about this complication is still scarce from the developing countries. Methods: Retrospective study evaluated the incidence of DP among 414 patients who underwent congenital cardiac surgery in Abo Elriesh Children’s Specialized Hospital, Cairo University, Egypt, in the duration from April 2009 to December 2011. Results: Incidence of DP was 3.6% (15 of 414 cases). Median age of affected patients was 10 months (ranged from 1 month to 13 years). Diagnosis of DP was observed after ventricular septal defect repair (3.9%), Glenn anastomosis (8.6%), Tetralogy of Fallot repair (4.3%), Senning operation (10%), arterial switch operation (3.2%), Fontan procedure (33%), coarctation of the aorta repair (7%), and pulmonary artery banding (6.4%). Diaphragmatic plication was performed in 4 of 15 cases. Patients with DP had significantly prolonged mechanical ventilation duration as compared to unaffected patients (median 120, range 48-600 vs 4, range 0-48 hours, P < .000). They also had a higher incidence of nosocomial pneumonia in 8 of 15 (53%) cases, longer duration of intensive care unit stay (median 15, range 4-62 days, P < .006), and significant mortality in 7 of 15 (46%; P < .004). Mortality among patients who underwent diaphragm plication was 1 of 4 (25%). Conclusion: Diaphragmatic paralysis is a relatively rare complication of congenital cardiac surgery in children. Its occurrence is associated with increased morbidity and mortality. A high index of clinical suspicion, utilization of bedside diagnostic tools, and a policy of early plication for certain patients may lead to improved outcomes.

Diaphragmatic paralysis after pediatric heart surgery: usefulness of non-invasive ventilation

Diaphragmatic paralysis after cardiac surgery is an important complication especially in infants. We report a child who developed diaphragmatic paralysis, atelectasis, bronchomalasia and respiratory failure following cardiac surgery. Ventilatory support alleviated respiratory distress in this child. This report illustrates the usefulness of invasive and non-invasive ventilatory support for a pediatric patient with diaphragmatic paralysis.

Satisfactory Results of Diaphragmatic Plication for Bilateral Phrenic Nerve Paralysis

Bilateral diaphragmatic plication was performed in a 44-year-old man who underwent complete resection of a thymoma infiltrating the right lung, bilateral brachiocephalic vein, pericardium, and bilateral phrenic nerves. The plication procedure allowed him to be weaned from the ventilator on postoperative day 4. He demonstrated no restrictive or obstructive pattern of lung function, and after respiratory rehabilitation he returned to work full time 5 weeks after the operation. The present results indicate that ventilatory movement of the thoracic cage can compensate for loss of bilateral diaphragmatic ventilation for at least 18 months.

Mid-term follow-up in patients with diaphragmatic plication after surgery for congenital heart disease

OBJECTIVE

Diaphragmatic palsy (DP) is a rare but severe complication after surgery for congenital heart disease. Transthoracic diaphragmatic plication is an effective means of treatment for those with respiratory impairment due to DP, but little is known about the mid-term effects of diaphragmatic plication.

DESIGN

We performed a study in 24 patients with history of DP. Diaphragm movement was assessed using ultrasound. Patients with DP who were old enough were additionally followed-up with lung function and exercise testing. A group of patients with similar age, diagnoses and operations served as controls.

RESULTS

Ultrasound showed that in the majority of cases with history of DP the paralysed diaphragm was static, independently of whether it was plicated or not. Patients with DP had a more restrictive lung function pattern (VC: 54.3 vs. 76.4% predicted, p<0.001; FEV(1): 58.4 vs. 86.2% predicted, p<0.001) and a lower exercise capacity compared with the control group (peak VO2: 24.5 vs. 31.3 ml/kg/min, p=0.03). Comparing patients with and without plication for DP, only a tendency towards lower lung function values in patients after diaphragmatic plication, but no differences regarding exercise capacity, could be found.

CONCLUSIONS

Our results provide evidence that DP is a serious surgical complication with a reduction in lung function and exercise capacity, even at mid-term follow-up; however, diaphragmatic plication, a useful tool in treating post-surgical DP in children with respiratory impairment, seems to be without mid-term risk in terms of recovery of phrenic nerve function, lung function values, and exercise capacity.

Hybrid approach to surgical correction of tetralogy of Fallot in all patients with functioning Blalock Taussig shunts

BACKGROUND

In total surgical correction of tetralogy of Fallot (TOF) with functioning Blalock Taussig shunts (BTS), shunt take down increased surgical time, bleeding, and might injure phrenic and recurrent laryngeal nerve and thoracic duct.

OBJECTIVES

A routine hybrid approach using transcatheter BTS closure immediately before total surgical correction of TOF in all patients might reduce these problems. We analyze the safety and feasibility of this approach.

METHODS

Transcatheter BTS closure was achieved using single or multiple stainless steel embolization coils, Amplatzer vascular plugs, or duct occluders. When coils were released without control by bioptome forceps, coil migration in larger shunts was prevented by proximal or distal balloon occlusion.

RESULTS

This routine hybrid strategy was followed in 22 consecutive patients aged 1-13 years over 4-year-period and 21 procedures were successful. Among the 16 patients attempted with coils, 13 had successful closure, 2 needed Amplatzer duct occluder devices, and 1 sent for surgical shunt takedown due to acute angulation of the shunt. New Amplatzer vascular plugs were used in six patients. Bioptome was used in six patients and proximal or distal balloon occlusion of flow was used in three patients. Four patients had closure of associated aortopulmonary or chest wall collaterals.

CONCLUSION

Hybrid approach using routine transcatheter closure of all BTS immediately before surgical correction of TOF shunts with coils/plugs/devices is safe, feasible, and reproducible.

Postoperative phrenic nerve palsy: early clinical implications and management

OBJECTIVE

We examined the clinical impact of diaphragmatic palsy (DP) as a result of phrenic nerve injury following cardiothoracic surgery, specifically its effects on morbidity and mortality, early regeneration capacity of the phrenic nerve, and role of surgical diaphragmatic plication.

METHODS

A retrospective case control study was performed in 74 children with DP and 74 matched controls after cardiothoracic surgery within the past 14 years.

RESULTS

Following 5,128 surgical procedures in children (aged under 18 years) we found an incidence of DP of 1.4%. There were no differences in mortality between the groups, and the cause of death was not related to DP or plication in any of the patients. However, patients with diaphragm impairment had significantly longer duration of mechanical ventilation (median 3 days vs. 1), ICU stay (7 days vs. 3.5), duration of hospital stay (16 days vs. 12), and for antibiotic treatment (16 days vs. 7). Because of prolonged respiratory problems 40 children (54%) underwent surgical diaphragmatic plication to flatten the diaphragm in its inspiratory position. In children with DP younger age was a strong predictor for plication (median 3.8 months vs. 12.1).

CONCLUSIONS

Especially in newborns and young infants with DP the length of mechanical ventilation, ICU stay, and hospital stay are prolonged. Early spontaneous recovery of the phrenic nerve is rare. In cases of respiratory impairment early transthoracic diaphragmatic plication is an effective means of treatment.

Bilateral diaphragm paralysis following cardiac surgery in children: 10-years' experience

OBJECTIVE

To review the incidence and complications of conservative management of bilateral diaphragm paralysis following pediatric cardiac surgery.

DESIGN AND SETTING

Retrospective clinical review based on computerized database with daily follow-up in a pediatric cardiac intensive care unit in a tertiary care center. PATIENT AND PARTICIPANTS: Were reviewed the data on nine patients with bilateral diaphragm paralysis from the 3,214 consecutive children (0.28%) after operations performed between 1995 and 2004.

MEASUREMENTS AND RESULTS

A fluoroscopy-confirmed diagnosis of bilateral diaphragm paralysis was made in all nine patients. Mechanical ventilation was required for 14-62 days; maximum time to recovery was 7 weeks. Three patients underwent unilateral plication. Patients with a complicated postoperative course required longer mechanical ventilation. All patients were managed with a nasotracheal tube. One patient had minor subglottic stenosis. All patients survived.

CONCLUSIONS

Bilateral diaphragm paralysis can be managed conservatively with good prognosis and minor complications. The recovery time is relatively short, less than 7 weeks.

Diaphragmatic paralysis after cardiac surgery in children: incidence, prognosis and surgical management

Diaphragmatic paralysis (DP) after cardiac surgery is an important complication especially in infants. We analyzed the incidence, clinical course, surgical management and follow up of the patients with DP, retrospectively. Between 1996 and 2005, 3,071 patients underwent cardiac surgery. Total number of patients with DP was 152 (4.9%). Out of 152 patients, 42 were surgically treated with transthoracic diaphragm plication (1.3%). The overall incidence of diaphragm paralysis was higher in correction of tetralogy of Fallot (31.5%), Blaloc-Taussig (B-T) shunt (11.1%) and VSD closure with pulmonary artery patch plasty (11.1). The incidence of DP which require plication was higher in B-T shunt (23.8%) arterial switch (19%) and correction of tetralogy of Fallot (11.9%). Mean and median age at the time of surgery were 17.8 +/- 3.6 and 6 months, respectively. Median time from cardiac surgery to surgical plication was 12 days. Indications for plication were repeated reintubations (n = 22), failure to wean from ventilator (n = 12), recurrent lung infections (n = 5) and persistent respiratory distress (n = 3). Mortality rate was 19.1%. Being under 1 year of age, pneumonia and plication 10 days after mechanical ventilation were associated with higher incidence mortality (P < 0.05). Phrenic nerve injury is a serious complication of cardiac surgery. It is more common after some special procedures. Spontaneous recovery is very rare. Being under 1 year of age, plication after 10 days from the surgery and pneumonia are major risk factors for mortality even in plicated patients. Transthoracic plication is helpful if performed early.

Thoracoscopic diaphragmatic procedures under artificial pneumothorax

Diaphragmatic plication is technically simple using a conventional operative technique, but it requires a large skin incision and rib injury. We present an alternative technique for thoracoscopic plication of the diaphragm and evaluate the advantages of the procedure. Six patients (five with diaphragmatic eventration and one with diaphragmatic hernia with a sac) ranging in age from 8 to 20 months were treated by this method. Three of the six cases were right-sided, and three were left-sided. The operation was performed under artificial pneumothorax using carbon dioxide gas at 4 mmHg. Three trocars for laparoscopy were inserted at the 4th and 5th intercostal spaces. An adequate operative view was obtained by pressing the diaphragm throughout the operation. The eventrated diaphragm was plicated with several rows of nonabsorbable sutures in the anterolateral-to-posterolateral direction to prevent injury to the main phrenic nerve. A tight diaphragm was confirmed by decompressing the artificial pneumothorax. The technique was successfully performed in all cases, and the patients' postoperative courses were uneventful. During the operation, the hemodynamic effects of carbon dioxide gas at 4 mmHg were minimal. Over a mean follow-up period of 3.1 years (range, 1-6 years), no recurrence of diaphragmatic eventration was seen. Judging from the satisfactory postoperative course, this procedure is suitable for children with all forms of diaphragmatic eventration.

Nasal mask bilevel positive airway pressure ventilation for diaphragmatic paralysis after pediatric open-heart surgery

A 2-year-old boy underwent surgical repair of tetralogy of Fallot. Topical cooling of the heart with ice slush was used during the operation. Diaphragmatic paralysis occurred after the operation, inducing severe respiratory distress. To avoid repeated intubation and tracheostomy, the patient was placed on nasal mask bilevel positive airway pressure (BiPAP) ventilation. After ventilatory support with BiPAP for 40 days, the patient recovered spontaneously from the paralysis. No sedation was required during this time. This report illustrates the usefulness of BiPAP for a pediatric patient with diaphragmatic paralysis after cardiac surgery.

Transient phrenic nerve paralysis associated with status asthmaticus

Phrenic nerve paralysis is a condition typically occurring after invasive procedures in the chest and neck. Here we describe a case of transient unilateral diaphragmatic paralysis in a child with status asthmaticus complicated by complete right lung atelectasis. Common causes of this disorder and possible implications for our case are discussed.

Transient phrenic nerve palsy after cardiac operation in infants

OBJECTIVE

The aims of this study were to prove the presence of transient phrenic nerve palsy in children after cardiac surgery by successive recordings of diaphragmatic action potentials (DAPs), and to decide the indication of diaphragmatic plication in infants with postoperative phrenic nerve palsy.

METHODS

The DAPs were recorded from 11 infants (age 0-54 months) under artificial ventilation after cardiac surgery. The successive DAP recordings were performed within 3-4 days (0W), 1 week (1W) and 2 weeks (2W) after operation to make a final decision for diaphragmatic plication to wean artificial ventilation.

RESULTS

The patients were divided into 3 groups according to the DAP changes in successive recordings, namely, patients with normal DAPs at 0W, patients with transient depression of DAPs at 0W followed by recovery to normal DAPs by 1W and/or 2W, and patients with persistent depression of DAPs of the affected side necessitating plication of hemidiaphragm.

CONCLUSIONS

In infants with phrenic nerve palsy after cardiothoracic surgery, persistently abnormal DAPs in repeated electrophysiologic examinations for at least 2 weeks after surgery are a useful guidance to support clinical and radiological evidence for an indication of diaphragmatic plication.

Risk factors prolonging ventilation in young children after cardiac surgery: Impact of noninfectious pulmonary complications

OBJECTIVE: To determine risk factors for prolonged ventilation after cardiac surgery in young children and assess the impact of noninfectious pulmonary complications on ventilatory duration. DESIGN: Retrospective case series analysis. SETTING: A tertiary pediatric cardiac center. PATIENTS: Clinical records of 222 consecutive children aged </=3 yrs undergoing cardiac surgery for congenital heart disease were reviewed. Fifteen patients, consisting of six premature babies and nine who died within 72 hrs of surgery, were excluded. MEASUREMENTS AND MAIN RESULTS: The demographic data, preoperative risk factors, surgical procedures performed, intraoperative variables, and postoperative complications of the remaining 207 children were reviewed. Univariate analysis was performed to compare patients who required prolonged ventilation (>72 hrs) to those who could be extubated at </=72 hrs, and multivariate analyses were performed to identify significant determinants on ventilatory duration and impact of noninfectious complications. Of the 182 patients undergoing open heart surgery, 45 (25%) required prolonged ventilation for a median of 8 days. The latter were significantly younger in age and lighter in weight and were more likely to have Down syndrome, preoperative pulmonary hypertension and ventilatory support, undergone more complex surgery requiring longer bypass and circulatory arrest time, postoperative cardiovascular and pulmonary complications, and extubation failure (all p values <.01). Of the 25 patients who had closed heart surgery, five (20%) required prolonged ventilation for a median of 14 days. The latter were more likely to require preoperative ventilation, have undergone more complex surgery, had postoperative cardiovascular and pulmonary complications, and had extubation failure (all p values <.05). Cox proportional hazard regression identified body weight (p <.001), Down syndrome (p =.02), need for preoperative ventilation (p <.001), complexity of surgery (p <.001), cardiovascular complications (p <.001), and infective (p <.001) and noninfective (p <.001) pulmonary complications to be significant factors that determined the ventilatory duration. Noninfectious pulmonary complications occurred in 31.9% (58/182) and 20% (5/25) of patients after open and closed heart surgery, respectively. In the absence of other risk factors, the median time to extubation was similar between patients with and without noninfectious complications (1 vs. 0.8 day). However, in the presence of other risk factors, noninfectious pulmonary complications prolonged the median time to extubation from 8 to 18 days. Logistic regression identified Down syndrome (p =.005), preoperative ventilation (p =.001), complexity of surgery (p =.006), and bypass time (p =.005) as risk factors for development of noninfectious pulmonary complications. CONCLUSIONS: Noninfectious pulmonary complications that occurred commonly after cardiac surgery in young children prolong ventilatory duration only in the presence of other risk factors, with which it acts in a synergistic fashion.

Cardiopulmonary interactions in children with congenital heart disease: physiology and clinical correlates

Cardiopulmonary interaction is the term that is used to describe the inseparable connection between the heart and lungs. In health, the cardiovascular and pulmonary systems are in perfect balance. In disease, derangements of either system leads to dysfunction in the other. Physicians attempt to improve health with therapeutic interventions (positive pressure ventilation) typically aimed at treating disease (pneumonia with hypoxia) in one system (lungs) with resultant positive (recruitment of alveoli) and negative (ventilator induced lung injury) consequences and secondary impact on the other system (heart with decreased cardiac output). This manuscript will review the physiologic basis of normal cardiopulmonary interactions and the pathophysiology that occurs in specific disease processes affecting children with congenital cardiac disease. Lastly, we will present current data highlighting therapeutic interventions aimed at improving cardiopulmonary interactions.

Pulmonary risk factors compromising postoperative recovery after surgical repair for congenital heart disease

STUDY OBJECTIVES

To identify pulmonary risk factors associated with prolonged ICU stay in young children (< or = 2 years) undergoing surgical repair for congenital heart disease (CHD).

DESIGN

Retrospective case series analysis.

SETTING

Tertiary-care facility.

PATIENTS

Clinical records of 134 consecutive patients aged < or = 2 years undergoing cardiac surgery for CHD were reviewed, and 37 were excluded according to inclusion criteria. Thus, 97 patients were allocated to two groups based on the duration of ICU stay: < or = 7 days (group 1, n = 57), and > 7 days (group 2, n = 40).

RESULTS

Mean ICU duration for groups 1 and 2 was 3.0 +/- 0.4 days and 28.1 +/- 4.4 days, respectively (p < 0.001). In group 1, there were three extubation failures, whereas 41 extubation failures occurred in group 2 (p < 0.0001). A total of 22 patients (4 in group 1 and 18 in group 2) developed noninfectious pulmonary complications, such as airway problems, including extrinsic airway compression and tracheobronchomalacia (n = 6); pulmonary hypertension (n = 5); phrenic nerve palsy (n = 7); and pleural effusion (n = 8). These 22 patients (23%) contributed to the majority of total ventilator days (67%) as well as ICU stay (61%).

CONCLUSIONS

Pulmonary complications in general, and central airway problems in particular, are a frequent cause for delayed recovery following cardiac surgery in young children.

Impact of diaphragmatic paralysis after cardiothoracic surgery in children

OBJECTIVES

We sought to determine the prevalence and clinical impact of diaphragmatic paralysis caused by phrenic nerve injury after cardiothoracic surgery in children.

METHODS

A search of cardiology, radiology, and hospital databases identified 170 episodes of diaphragmatic paralysis after cardiothoracic surgery in 168 children operated on from 1985 to 1997. Medical records were reviewed to determine demographics, details of the operation and postoperative course, diagnostic features and management of diaphragmatic paralysis, and follow-up status.

RESULTS

The prevalence of diaphragmatic paralysis was 1.6% (95% confidence interval 1.4%-1.8%). Median age at operation was 6 months (range <1 day-14.4 years). Median time from the operation to the initial investigation was 5 days (range <1 day-61 days), with 57% of patients receiving mechanical ventilation at diagnosis. Diaphragmatic plication was performed in 40% of the patients at a median interval from the initial investigation of 15 days (range 3 days-11.1 months). Significant independent factors associated with increased postoperative hospital stay were lower patient weight at operation, previous cardiothoracic operations, bilateral diaphragmatic paralysis, increased interval from operation to investigation, mechanical ventilation at the time of investigation, and diaphragmatic plication. Confirmed recovery of diaphragmatic function was noted before hospital discharge in only 15 episodes.

CONCLUSIONS

Diaphragmatic paralysis complicating cardiothoracic surgery continues to occur in the current era, with a significant impact on morbidity. Smaller patients with bilateral hemidiaphragmatic paralysis, requiring mechanical ventilation, may represent a higher risk subgroup to target for increased diagnostic suspicion and more aggressive management; early spontaneous recovery is rare.

Phrenic nerve injury following cardiac surgery: a review

Phrenic nerve injury following cardiac surgery is variable in its incidence depending on the diligence with which it is sought. Definitive studies have shown this complication to be related to cold-induced injury during myocardial protection strategies and possibly to mechanical injury during internal mammary artery harvesting. The consequences are also variable and depend to a large extent on the underlying condition of the patient, particularly with regard to pulmonary function. The response of the patient may range from an asymptomatic radiographic abnormality to severe pulmonary dysfunction requiring prolonged mechanical ventilation and other associated morbidities and even mortality. Two cases are presented to demonstrate the variability in clinical responses to diaphragmatic dysfunction secondary to phrenic nerve injury from cardiac surgery. In addition, treatment strategies are reviewed including early tracheostomy and diaphragmatic plication, which appear to be the most effective options for patients who are compromised by phrenic injuries.

Diaphragmatic eventration in infants and children: is conservative treatment justified?

PURPOSE

The purpose of this study is to examine the justification of diaphragmatic plication to treat diaphragmatic eventration. A retrospective review of 50 patients who underwent diaphragmatic plication for phrenic nerve injury (PNI) or congenital muscular deficiency (CMD) of the diaphragm was conducted.

METHODS

During the last 26 years, 50 patients, aged 4 days to 7 years, were surgically treated for diaphragmatic eventration. Twenty-five patients had iatrogenic PNI and another 25 had CMD. Respiratory distress developed in all patients who had PNI and 10 required mechanical ventilatory support for 13 to 78 days (mean, 41 days) before operation. Respiratory symptoms developed in 17 of 25 patients who had CMD, and four required ventilatory support. In those who were asymptomatic, we justified surgical repair to optimize future lung growth. All patients underwent diaphragmatic plication by a thoracic approach. Reefing mattress sutures on pledgets were used for the plication.

RESULTS

In patients who had PNI, ventilatory support could be discontinued within 0 to 6 days (mean, 3 days) after operation, with a dramatic improvement in their respiratory status. Two patients required reoperation because the plication was not tight enough. Seven patients died in this series, but none because of the diaphragmatic plication.

CONCLUSION

This study suggests that symptomatic patients who have diaphragmatic eventration should be operated on immediately with an expected dramatic resolution of their respiratory problems.

Clinical implications of phrenic nerve injury after pediatric cardiac surgery

Phrenic nerve injury with resulting diaphragm paralysis occurred in 25 (1.5%) of 1,656 cardiac surgical procedures in children during a 10-year period. Phrenic nerve injury was most commonly noted in patients who had undergone previous cardiac surgery (16 of 165, 10%; P < .0001), typically after a previous Blalock-Taussig shunt (10 of 53, 19%; P = .007). Plication of the diaphragm (7 thoracic, 4 abdominal) was performed in 11 patients (44%). Indications for plication were inability to wean from mechanical ventilation (5 patients) and persistent or recurrent respiratory distress (6 patients). The patients who needed diaphragm plication were significantly younger than those who were managed conservatively (median, 11 months [4 days to 23 months] versus 20 months [4 months to 16 years]; P = .01). All patients older than 2 years were extubated within 3 days (mean, 1.5 days) and did not need any surgical intervention. The median follow-up period was 3.2 years, and no patient has had recurrent respiratory problems. There were no deaths as a direct result of phrenic nerve injury. Phrenic nerve injury after cardiac surgery is a serious complication that often leads to respiratory insufficiency in patients under than 2 years of age. For such patients, early diaphragm plication is a simple and effective procedure that prevents the complications of prolonged mechanical ventilation.

Fatal bilateral phrenic nerve injury following hypothermic open heart surgery

A 30-year-old woman underwent mitral valvotomy for severe mitral stenosis. Extracorporeal circulation by means of cardiopulmonary bypass and systemic hypothermia, in addition to local topical hypothermia using iced saline solution and slushed ice, was used. Fatal bilateral phrenic nerve paralysis with inability to wean her from the ventilator occurred. This report is presented to illustrate the pathophysiology, pathology, and means of possible prevention of such a potentially highly fatal injury following hypothermic open heart surgery.

Diaphragmatic paralysis in children: diagnosis by TM-mode ultrasound

Diaphragmatic paralysis, a difficult diagnosis in the pediatric age group, has classically been made by fluoroscopy or B-mode ultrasound. We report our experience with TM-mode exploration. Twenty-seven patients suspected to have diaphragmatic paralysis were examined by means of inspiratory and expiratory chest radiography, fluoroscopy and B-mode ultrasound. The diaphragmatic echo was recorded on TM-tracing during spontaneous breathing using coronal oblique scans. Direction, excursion and the pattern of the transition between inspiration and expiration were analysed. In 7 patients examination was normal and TM mode demonstrated movement of normal direction and excursion with a sharp aspect of the transition zone. Diaphragmatic paralysis was present in 11 patients: unilateral in 9 and bilateral in 2 cases. TM mode demonstrated paradoxical movement, reduced excursion and a smooth transition zone. In 9 patients with diaphragmatic dysfunction TM mode demonstrated movement in the normal direction but with reduced excursion and a smooth transition zone. Compared to other imaging modalities, TM-mode records diaphragmatic movements more objectively. It can identify direction of the movement even if they are fast and of weak amplitude and in the case of bilateral paralysis. TM can differentiate paralysis from dysfunction. Moreover, this low-cost, non-irradiating made of imaging can be performed at the bedside and is available on all basic devices.

Neonatal phrenic nerve paralysis resulting from intercostal drainage of pneumothorax

Four cases of phrenic nerve paralysis complicating chest tube placement in the newborn for pneumothorax are presented. This complication is related to abnormal location of the medial end of the chest tube. It is suggested that on the frontal chest radiograph, the medial end of the chest tube should be no less than 1 cm from the spine.

Phrenic Nerve Injury Following Cardiac Surgery, with Emphasis on the Role of Topical Hypothermia

Phrenic nerve dysfunction that develops after cardiac surgery has generally been attributed to the topical hypothermia used for myocardial preservation and protection. Although studies relying on postoperative radiographic findings to establish the diagnosis reveal an incidence as high as 73%, investigations employing electrophysiological assessment indicate a 10% incidence. Most patients who sustain phrenic injury during cardiac surgery do not suffer major respiratory morbidity; those who do generally recover. In addition to the role of topical hypothermia as a major etiological factor, physical trauma or compromise of the vascular supply to the phrenic nerve and diaphragm may also be important factors. Although a number of measures have been advocated to lower the incidence of the problem, none have been evaluated in a prospective, randomized study using electrophysiological techniques. This review focuses on the incidence, underlying mechanisms, and clinical and electrophysiological recognition of phrenic nerve dysfunction following cardiac surgery.

Percutaneous transluminal balloon angioplasty of stenotic standard Blalock-Taussig shunts: effect on choice of initial palliation in cyanotic congenital heart disease

To date, attempted balloon dilation of stenotic standard Blalock-Taussig shunts has been largely disappointing. It has been suggested that this may be due to the use of balloons of insufficient diameter. Balloon dilation of stenotic Blalock-Taussig shunts was attempted with use of relatively large balloons in five patients (11 to 67 months old) with cyanotic heart disease who were becoming progressively cyanotic and polycythemic (hemoglobin 17.9 +/- 1.1 g/dl) because of discrete shunt stenosis at the site of pulmonary anastomosis. Balloon diameters selected were equal to or within 1 mm of the unobstructed proximal shunt diameter. Before balloon dilation the diameter at the site of the stenosis was 2.8 +/- 0.8 mm (range 1.7 to 4); after balloon dilation it was 5.7 +/- 1.1 mm (range 4.5 to 7.5). The diameter increased in all patients (range 2.0 to 3.5 mm); the mean increase was 2.8 +/- 0.2 mm (p less than 0.005). Expressed as a percent, the increase in diameter at the stenosis ranged from 80% to 182.4% (mean 108.2 +/- 16.8%). Before balloon dilation the systemic oxygen saturation was 72.8 +/- 9.2% (range 55% to 80%) and after balloon dilation it was 83.6 +/- 2.9% (range 80% to 87%). A satisfactory increase (range 6% to 25%) in blood oxygen saturation was seen in all patients; the mean increase was 10.8 +/- 3.2% (p less than 0.01). At follow-up, the oxygen saturation by pulse oximetry was 85.8 +/- 2.9% (mean 5.8 +/- 1.7 months after balloon dilation) and the hemoglobin was 15.6 +/- 1.9 g/dl (mean 6.6 +/- 1.5 months after balloon dilation).(ABSTRACT TRUNCATED AT 250 WORDS)

Phrenic nerve injury in infants and children undergoing cardiac surgery

Fifty infants and 50 children less than 15 years undergoing palliative or corrective cardiac surgery in the Brompton Hospital between March and October 1988 had direct percutaneous stimulation of the phrenic nerve before and after operation. Ten patients, six under 1 year of age and four over, developed unilateral phrenic nerve injury. In those aged less than 1 year recovery after operation was prolonged because their diaphragmatic palsy made it difficult to wean them from the ventilator. Older children had symptoms but their rate of recovery did not seem to be affected by the phrenic nerve injury. Phrenic nerve damage was no more frequent after a lateral thoracotomy than after a median sternotomy. There was no significant association with the type of operation performed, the experience of the surgeon, the use of bypass or topical ice, the duration of bypass, circulatory arrest or aortic cross clamping, or the age of the patient at the time of operation. In patients who had cardiopulmonary bypass the risk of injury was significantly higher in those who had undergone previous operation. The 10% frequency of phrenic nerve injury determined in this prospective study was higher than that seen in earlier retrospective reports. Direct percutaneous stimulation of the phrenic nerve can be used at the bedside in infants and children to facilitate early and accurate diagnosis of phrenic nerve palsy, and the results may influence early management.

Unusual varieties of diaphragmatic herniae

Unusual varieties of diaphragmatic herniae can be classified into two major groups, congenital and acquired. The late-presenting Bochdalek herniae often present difficulties in diagnosis which may lead to inappropriate treatment. The prime example is the herniated stomach, which is mistaken for a tension pneumothorax. Strangulation is a rare, but an important, complication of Bochdalek herniae. A number of techniques for closure of large diaphragmatic defects are described with recommendation of those procedures which can be performed rapidly and effectively in a critically ill infant. The literature concerning eventration is confusing due to different definitions of the condition by different authors. It may be difficult to distinguish preoperatively between this condition and congenital diaphragmatic hernia with a sac. Such distinction is often not important as the decision for intervention is based on evaluation of clinical and radiological considerations. The majority of Morgagni herniae are asymptomatic and only rarely does strangulation supervene. There is a small group of infants with Morgagni hernias who present in early infancy with respiratory symptoms. Paralysis of the diaphragm due to phrenic nerve palsy recovers spontaneously in the majority of patients. The selective use of diaphragmatic plication for this condition is widely accepted, but the decision and appropriate timing for surgical intervention is often difficult. The results of surgery are very good both in the early postoperative period and also on long-term follow-up. The diagnosis of traumatic diaphragmatic hernia is often overlooked in the presence of other major injuries. The danger of strangulation of contents of this hernia is ever present and repair should be undertaken without delay once the diagnosis is made.