Postoperative phrenic nerve palsy: early clinical implications and management

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.

Effect of Vitamin C Infusion on Cerebral Oximetry During General Anesthesia for Carotid Endarterectomy in Diabetic Patients

Background

There is conflicting information about the effect of vitamin C on brain oxygenation during anesthesia.

Objectives

The current study was designed and performed to assess the effect of vitamin C infusion and brain oxygenation with cerebral oximetry on improving brain perfusion during general anesthesia in vascular surgery of diabetic patients.

Methods

This randomized clinical trial was performed on patients candidates for endarterectomy under general anesthesia and referred to Taleghani Hospital in Tehran, Iran, during 2019 - 2020. Considering inclusion criteria, the patients were divided into placebo and intervention groups. The patients in the placebo group received 500 mL of isotonic saline. In the intervention group, the patients received 1 g of vitamin C diluted in 500 mL of isotonic saline by infusion half an hour before anesthesia induction. Patients' oxygen levels were continuously measured by a cerebral oximetry sensor. The patients were put in a supine position for 10 minutes before and after anesthesia. At the end of the surgery, the indicators considered in the study were evaluated.

Results

No considerable difference was observed between systolic and diastolic blood pressure, heart rate, mean arterial pressure, partial pressure of carbon dioxide, oxygen saturation, regional oxygen saturation, supercritical carbon dioxide, and end-tidal carbon dioxide in total and between the two groups in the three stages before and after anesthesia induction and at the end of surgery (P > 0.05). Additionally, there was no significant difference between blood sugar (BS) levels in the study groups (P > 0.05) but in BS levels at three stages before and after anesthesia induction and at the end of the surgery, with a significant difference (P < 0.05).

Conclusions

The amount of perfusion in the two groups and, therefore, in total at the three stages before and after anesthesia induction and at the end of surgery is not different.

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.

A New Methodology for Intraoperative Monitoring of the Functional Integrity of the Phrenic Nerve During Cardiothoracic Surgery

INTRODUCTION

The phrenic nerve could be easily injured during cardiothoracic surgeries because of its anatomical relationships. The aim of this study is to describe a new, feasible, and reproducible methodology to achieve a continuous intraoperative neuromonitoring of the phrenic nerve.

METHODS

Consecutive patients who underwent open-chest surgery were included. The recording active electrode was placed 5 cm superior to the tip of the xiphoid process, and a hook wire inserted at the motor point of the ipsilateral hemidiaphragm was used as the reference electrode.

RESULTS

We studied 45 patients (92% men, mean age 67 years). Mean height and weight were 167 ± 6.9 cm and 75.6 ± 12.3 kg, respectively. A reproducible compound motor action potential was recorded in 38 (85%) subjects. The mean latency and amplitude values were 9.68 ± 2.40 ms and 1.36 ± 3.83 mV, respectively. No intraoperative events were recorded.

CONCLUSIONS

We reported a new methodology which allows the assessment of phrenic nerve functional integrity during surgical procedures.

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.

Reinnervation of the Diaphragm After Bilateral Phrenic Nerve Resection and Immediate Reconstruction Using a Contralateral Phrenic Nerve Autograft

A patient affected by a voluminous synovial sarcoma of mediastinum received radical surgery, resulting in injury of both phrenic nerves. Because of the cancer location, reconstruction of the left phrenic nerve was not possible, so to prevent the patient's ventilator dependence, the right phrenic nerve was reconstructed via an autograft from the residual proximal stump of the contralateral one. In 3 months, the right hemidiaphragm function showed a full recovery, documented by ultrasonographic and radiographic assessment of diaphragmatic excursion, and the patient was weaned from mechanical ventilation. When a nerve autograft is indicated, the sural nerve still remains the criterion standard, because of the low morbidity of the donor site and ease of harvesting; however, in particular situations, such as in this unique case, the choice of an orthotopic graft may offer promising results.

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.

Ultrasonographic postoperative evaluation of diaphragm function of patients with congenital heart defects

Background

This study aims to investigate the role of ultrasonography in the postoperative evaluation of diaphragm function in patients with congenital heart defect.

Methods

This prospective study included a total of 360 patients (176 males, 184 females; mean age 2 years; range, 1 month to 8 years) who underwent congenital heart surgery and 44 patients (22 males, 22 females; mean age 1 years; range, 1 month to 4 years) who underwent diaphragm ultrasonography between September 2018 and March 2019. Ultrasonography was performed for the patients who had difficulty in weaning from mechanical ventilation or who were thought to have diaphragm dysfunction due to pathological findings on postoperative chest X-rays. The findings were interpreted as normal, paresis, or paralysis.

Results

Diaphragm dysfunction was demonstrated in 23 patients (6.3%), paralysis in 11 patients (3%), and paresis in 12 patients (3.3%). A median sternotomy was performed in 21 patients (91%), and seven of them (30%) were redo cases. Five patients (21%) had single ventricle physiology. Six patients (1.6%) needed an intervention due to diaphragm dysfunction. The interventional procedures were diaphragm plication in three patients (0.8%) and tracheotomy in three patients (0.8%). Three of these patients had a single ventricle and three had biventricular physiology. The median time after surgery for these procedures was 36 days. One patient (0.2%) died in the intensive care unit. The mean length of stay in the intensive care unit and hospital was 36±12 and 48±21 days, respectively.

Conclusion

Diaphragm dysfunction should be kept in mind in patients undergoing congenital heart surgery and in those who need prolonged intubation during the postoperative period. Ultrasonography is a non-invasive diagnostic tool which can be used to identify diaphragm dysfunction and the best course of management of this clinical condition.

Diaphragmatic palsy after cardiac surgery in adult and pediatric patients

Background

Important differences in the mechanism of respiration between adults and children warrant distinction in the management of diaphragmatic paralysis as a complication of cardiac surgery. We describe the management and outcomes of this complication in both groups.

Methods

We retrospectively analyzed 16 patients (5 adults and 11 children) with diaphragmatic paralysis after cardiac surgery performed between 2008 and 2018. Clinical examination, chest radiography, and confirmation with fluoroscopy in selected cases were our modalities of diagnosis. All adults were managed conservatively, whereas plication was performed in all children.

Results

The incidence of diaphragmatic paralysis was 0.98% in pediatric patients and 0.43% in adults. The mean age was 2.33 ± 2.59 years in children and 53.2 ± 17.99 years in adults. All adults were symptomatic. All children showed difficulty in weaning from mechanical ventilation after cardiac surgery. The period of mechanical ventilation before plication was 2–6 days (median 4 days). Death occurred as a result of low cardiac output in a 10-year-old boy, and due to respiratory failure in a 30-year-old woman. Children were successfully weaned from mechanical ventilation after diaphragmatic plication. The median time to extubation after plication was 2.5 days (range 1–13 days). The median period of recovery in adults was 52 days (range 32–85 days). All survivors had acceptable outcomes at 6 months to one year.

Conclusion

Conservative management in adults and early plication in children are viable treatment options for diaphragmatic palsy after cardiac surgery, with acceptable outcomes.

[Postoperative complications after major lung resection]

INTRODUCTION

The advent of the minimally invasive techniques has allowed an expansion of the indications for thoracic surgery, particularly in older patients and those with more comorbidities. However, the rate of postoperative complications has remained stable.

STATE OF THE ART

Postoperative complications are defined as any variation from the normal course. They occur in 30% but majority of them are minor. The 30-day mortality rate for lung resection varies range between 2 % and 3% in the literature. Complications can be classified as: (1) early (occurring in the first 24hours) including both "generic" surgical complications (especially postoperative bleeding) and complications more specific to lung surgery (Acute respiratory syndrome, atelectasis); (2) in-hospital complications and those occurring during the first 3 months; these are dominated by infectious events in particular pneumonia but also bronchial (bronchopleural fistula), pleural (pneumothorax, hydrothorax) or cardiac complications; (3) late complications are dominated by chronic pain, affecting 60% of patients having a thoracotomy at three months. Lobectomy is the most common lung resection. Pneumonectomy is a distinct procedure requiring a specific peri- and postoperative management. Right pneumonectomy is associated with a higher risk with a treatment related-mortality ranging between 7 and 10%.

CONCLUSION

Major lung resection has benefited from minimally invasive approaches and fast track to surgery. However, it is important to note the occurrence of new and specific complications related to those news surgical access.

Bilateral Diaphragmatic Paralysis Following Paediatric Cardiac Surgery: Experience of four cases at the Royal Hospital, Muscat, Oman

Bilateral diaphragmatic paralysis (BDP) is a rare complication of paediatric cardiac surgery. We report four children who developed BDP following cardiac surgery who were managed at the Royal Hospital, Muscat, Oman, between 2009 and 2014. All four children suffered severe respiratory distress soon after extubation and required re-intubation within two hours. In addition, all of the children underwent a tracheostomy as an interim method for ventilation. The four children were successfully weaned from positive pressure ventilation following the functional recovery of at least one side of the diaphragm.

The advantage of early plication in children diagnosed with diaphragm paresis

BACKGROUND

In this single-center study, we sought to determine the frequency of phrenic nerve injury leading to diaphragm paresis (DP) in children following open cardiac surgery over the last 10 years, and to identify possible variables that predict the need for plication and associated clinical outcomes.

METHODS

Patients diagnosed with DP were identified from departmental databases and a review of clinical diaphragm ultrasound images. A cohort was analyzed for predictors of diaphragm plication and associations with clinical outcomes. Cumulative proportion graphs modeled the association between plication and length of stay.

RESULTS

DP was diagnosed in 161 of 6448 patients (2.5%) seen between January 2002 and December 2012. All diagnoses but 1 were confirmed by ultrasound. Plication of the diaphragm was performed in 30 patients (19%); compared with patients who did not undergo plication, these patients were younger (median age, 10 days vs 138 days; P < .001), more likely to have undergone deep hypothermic circulatory arrest (47% vs 18%; P = .005), had a longer duration of positive pressure ventilation (median, 15 days vs 7 days; P < .001), and had longer lengths of stay in both the intensive care unit (median, 23 days vs 8 days; P < .0001) and the hospital (median, 37 days vs 15 days; P < .0001). Early plication was associated with reduction in all intervals of care.

CONCLUSIONS

Early plication should be considered for patients with diaphragm paresis requiring prolonged respiratory support after cardiac bypass surgery. Longer follow-up evaluation is required to better define the long-term implications of plication.

Laparoscopic Diaphragmatic Hemiplication in Children with Acquired Diaphragmatic Eventration After Congenital Heart Surgery

PURPOSE

To report our technique and experiences in the laparoscopic diaphragmatic hemiplication (LDHP) in children with acquired diaphragmatic eventration after congenital heart surgery.

SUBJECTS AND METHODS

Between October 2007 to December 2013, 3498 children with congenital heart disease underwent cardiac surgery in our hospital, and 40 (1.14%) of them had unilateral diaphragmatic elevation on postoperative chest X-ray (mean elevation, 2.5 ± 0.26 intercostal spaces [ICS]) and were diagnosed as having diaphragmatic eventration due to diaphragmatic hemiparesis as a result of phrenic nerve injury. These 40 patients were followed up, and 22 of them recovered after conservative treatment; the other 18 needed surgical intervention. We conducted a retrospective study relating to surgical indications, surgical technique, complications, and outcomes.

RESULTS

There were 24 boys and 16 girls with a mean age of 10.0 ± 4.5 months old (range, 2 months-4 years). Twenty-two patients did not require surgical intervention. Eighteen patients underwent LDHP (12 cases left-sided and 6 cases right-sided); 2 of them had emergency LDHP with a history of ventilator dependency after cardiac surgery, and 16 of them had planned LDHP with a history of recurrent pneumonia and dyspnea. The operative time was 60 ± 7.9 minutes (range, 45-105 minutes), with minimal blood loss (3 ± 1.5 mL [range, 1-9 mL]), no intra- or postoperative complications, and postoperative hospital stay of 7 ± 1.3 days (range, 5-10 days). The diaphragmatic drop was 2.4 ± 0.2 (range, 2-4 ICS) without recurrence, and the follow-up time for all 40 patients was 14.8 ± 1.6 months (range, 11-36 months).

CONCLUSIONS

Our study further shows that LDHP is feasible and effective in selected patients after congenital heart surgery. Our technique is convenient and provides excellent clinical and radiological results.

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.

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 palsy after cardiac surgical procedures in patients with congenital heart

Paralysis of diaphragm on one or, exceptionally, both sides is a common cause of delayed recovery and excessive morbidity following pediatric cardiac surgery. The consequences of this complication after all forms of congenital heart surgery in newborns and young infants can be potentially serious. The impact of diaphragmatic palsy on the physiology after single ventricle palliations is particularly significant. It is necessary for all professionals taking care of children with heart disease to be familiar with the etiology, diagnosis, and management of this condition. Early recognition and prompt management of diaphragmatic palsy can potentially reduce the duration of mechanical ventilation and intensive care in those who develop this complication. This review summarizes the anatomy of the phrenic nerves, reasons behind the occurrence of diaphragmatic palsy, and suggests practical guidelines for management.

Hemidiaphragmatic paralysis in preterm neonates: a rare complication of peripherally inserted central catheter extravasation

Unilateral diaphragmatic paralysis was diagnosed in 2 preterm neonates born at 29 and 25 weeks of gestation, respectively. In both instances, the pathophysiology was phrenic nerve injury after extravasation of parenteral nutrition fluid. Misplacement and infection were predisposing factors. Diaphragmatic movement analysis by time-motion-mode ultrasonography was helpful in achieving a diagnosis. The first neonate required a diaphragmatic placation, whereas the other infant was managed nonoperatively. These cases confirm a rare etiology of diaphragmatic paralysis and possible spontaneous recovery. In neonates with very low birth weight, general anesthesia and thoracic surgery may be associated with a high morbidity, suggesting that nonoperative medical treatment, when possible, is preferable if the neonate does not require supplemental oxygen.

Reinnervation of the paralyzed diaphragm: application of nerve surgery techniques following unilateral phrenic nerve injury

BACKGROUND

Unilateral phrenic nerve injury often results in symptomatic hemidiaphragm paralysis, and currently few treatment options exist. Reported etiologies include cardiac surgery, neck surgery, chiropractic manipulation, and interscalene nerve blocks. Although diaphragmatic plication has been an option for treatment, the ideal treatment would be restoration of function to the paralyzed hemidiaphragm. The application of peripheral nerve surgery techniques for phrenic nerve injuries has not been adequately evaluated.

METHODS

Twelve patients presenting with long-term, symptomatic, unilateral phrenic nerve injuries following surgery, chiropractic manipulation, trauma, or anesthetic blocks underwent a comprehensive evaluation, including radiographic and electrophysiologic assessments. Surgical treatment was offered following a minimum of 6 months of conservative management. Operative planning was based on preoperative and intraoperative testing using one or more established nerve reconstruction techniques (neurolysis, interpositional grafting, or neurotization).

RESULTS

Measures of postoperative improvement included pulmonary function testing, fluoroscopic sniff testing, and a standardized quality-of-life survey, from which it was determined that eight of nine patients who could be completely evaluated experienced improvements in diaphragmatic function.

CONCLUSIONS

Based on the favorable results in this small series, we suggest expanding nerve reconstruction techniques to phrenic nerve injury treatment and propose an algorithm for treatment of unilateral phrenic nerve injury that may expand the current limitations in therapy.

Diaphragmatic paralysis associated with neonatal brachial plexus palsy

Phrenic nerve palsy can occur in the context of neonatal brachial plexus palsy, yet neither outcomes nor definitive treatment guidelines have been established. Diaphragmatic paralysis alone in the newborn results in significant respiratory sequelae and failure to thrive. Reviewing the available literature revealed little information about the incidence of phrenic nerve palsy associated with neonatal brachial plexus palsy, or whether outcomes are associated with the severity of the brachial plexus palsy. Of patients with brachial plexus palsy evaluated during 2005-2009 (n = 166) at our institution, a minority (2.4%; n = 4) had clinically significant diaphragmatic palsy. Of these, a majority (75%; n = 3) manifested respiratory complications sufficient to warrant diaphragmatic plication. The severity of brachial plexus palsy failed to correlate with severity of respiratory consequences. None of the patients underwent nerve repair or reconstruction. We suggest that diaphragmatic paralysis should not be overlooked during a brachial plexus examination, and diaphragmatic paralysis in the very young may require aggressive intervention before the treatment of brachial plexus palsy.

Neonatal phrenic nerve injury due to traumatic delivery

AIMS

To describe the clinical course of infants recovering spontaneously from diaphragmatic paralysis due to perinatal phrenic nerve injury as well as those that underwent plication of the diaphragm.

METHODS

Between 1990 and 2006, 14 newborns admitted to the Neonatal Intensive Care Unit (NICU) of the Wilhelmina Children's Hospital in Utrecht, The Netherlands, were diagnosed with diaphragmatic paralysis due to obstetric phrenic nerve injury. The clinical and follow-up data were studied retrospectively.

RESULTS

Four infants recovered spontaneously and could be weaned from mechanical ventilation within nine days without further treatment. Plication of the diaphragm was performed in 10 infants because of failure to wean from ventilatory support or serious persistent respiratory distress. Time between birth and plication ranged from 10 to 51 days, with a median of 19 days. Satisfactory respiratory outcome was achieved in 86% of the cases.

CONCLUSIONS

The minority of infants suffering from diaphragmatic paralysis due to perinatal phrenic nerve injury recovers spontaneously. Infants who fail to wean from ventilatory support and undergo early plication have a quick recovery and can be extubated successfully within a few days.

Subdiaphragmatic venous hemodynamics in patients with biventricular and Fontan circulation after diaphragm plication

OBJECTIVE

Diaphragm paralysis owing to phrenic nerve injury can result in significant morbidity in children undergoing surgical management of congenital cardiac defects. Diaphragm plication is the accepted therapy for diaphragm paralysis. We have investigated subdiaphragmatic venous hemodynamics in patients with biventricular and Fontan circulation after diaphragm plication.

METHODS

Doppler ultrasound was used to evaluate flows in the hepatic vein, portal vein, and subhepatic inferior vena cava under respiratory monitoring and with a tilt table. Twenty-nine patients with biventricular circulation were studied: 19 with normal diaphragms and 10 after diaphragm plication. Twenty-eight patients with total cavopulmonary connections after the Fontan procedure were also studied: 19 with normal diaphragms and 9 with plicated diaphragms. Inspiratory/expiratory flow ratios in supine and upright positions were calculated to investigate respiratory effects, and upright/supine flow ratios were calculated to assess gravity effects.

RESULTS

In patients with biventricular circulation and normal diaphragms, hepatic venous flow was augmented by inspiration; this effect was reduced in patients with a plicated diaphragm (upright inspiratory/expiratory flow ratios: 2.4 vs 1.4, respectively; P = .01). Portal venous flow was higher during expiration; this effect was lost in patients with a plicated diaphragm (supine inspiratory/expiratory flow ratios: 0.8 and 1.0; P < .05). In Fontan patients with normal diaphragms, hepatic venous flow depended heavily on inspiration. This effect was blunted in patients with a plicated diaphragm (supine inspiratory/expiratory flow ratios: 3.2 vs 2.3; P < .05). Expiratory augmentation of portal flow was absent in Fontan patients with normal diaphragms and reversed in patients a plicated diaphragm (supine inspiratory/expiratory flow ratios: 1.0 vs 1.6; P = .02). Gravity reduced Fontan portal venous flow; having a plicated diaphragm did not alter this effect (upright/supine flow ratios: 0.7 vs 0.7).

CONCLUSIONS

In patients with biventricular and those with Fontan circulation with a paralyzed diaphragm, plication does not completely restore normal subdiaphragmatic venous hemodynamics. In Fontan patients with a plicated diaphragm, important inspiration-derived hepatic venous flow is suppressed, and portal venous flow loses its normal expiratory augmentation. These flow dynamics share similarities with those observed in patients with failing Fontan circulation. This suboptimal splanchnic circulation may contribute to early problems of prolonged pleural effusions and ascites and potentially may promote late Fontan failure. Phrenic nerve injury should consequently be avoided at all costs before or at the time of the Fontan operation.

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.