Hypothesis that vagal reinervation of diaphragm could sensitise it to electrical stimulation

The hypothesis proposed is that restoration of functional capacity of denervated diaphragm may be achieved by reinervating it with vagus nerve. Following trauma, carcinomatose infiltration, and/or large thoracic surgery and neck surgery, phrenic nerve is frequently injured. Reinervation even in the most favourable conditions would not follow and diaphragm would rest permanently denervated and paralysed. This results in unilateral or bilateral paralysis of diaphragm. In principle, intermittent electrical stimulation of the phrenic nerve or diaphragm could elicit regular diaphragm contractions and maintain satisfactory respiration. While this technique could be used in upper motor neurone injury, in lower motor neurone injury and denervated diaphragm, that imposes too high electrical resistance, direct diaphragm pacing is practically impossible. In these cases, long term artificial ventilation is often necessary. Nevertheless, those patients are at high risk to suffer from atelectasis and respiratory infections. We project a hypothesis that reinervation of denervated diaphragm by vagus nerve could re-establishes its sensitivity to intramuscular electrical stimulation and may allow stimulation of the diaphragm by implanted pace-maker electrodes. An appropriate electrical stimulation might then be possible and diaphragm pacing could replace prolonged artificial ventilation in those patients. Restoration of functional capacity of denervated diaphragm could open a perspective for long term diaphragm pacing in patients with irreversible phrenic nerve injury and diaphragm paralysis.

Right diaphragm paralysis following cardiac radiofrequency catheter ablation for inappropriate sinus tachycardia

We describe a case of permanent right diaphragm paralysis following a radiofrequency cardiac ablation procedure. The relationship between the procedure and the phrenic nerve lesion is discussed with respect to the possible pathogenetic mechanisms. Radiofrequency current used in cardiac electrophysiology may cause serious thoracic nerve injuries. Means to avoid this complication are pointed out.

Central hypoventilation and diaphragmatic eventration: diagnosis and management

Congenital central alveolar hypoventilation syndrome (CCAHS) is a disorder of ventilatory control that occurs without neuromuscular blockade or pulmonary disease. It is characterized by a lack of response to habitual respiratory stimulants, especially hypercapnia. In this article, the management of this syndrome by diaphragmatic pacing is discussed. Paralysis of the phrenic nerve in small children usually results from injury during birth or during a cardiothoracic operation and results in eventration of the hemidiaphragm. Alternatively, eventration of the diaphragm may be a congenital condition. In both cases it may lead to respiratory distress in the newborn. In this article, we review the diagnosis of these conditions and their management, focusing on the surgical indications. We also discuss outcome.

Extubation failure due to phrenic nerve injury

A 26 week gestation infant had an increasingly elevated right hemidiaphragm following drainage of bilateral pleural effusions and failed extubation on numerous occasions. Electric stimulation of the phrenic nerves revealed absent activity on the right, indicating phrenic nerve injury from chest tube drain insertion. Diaphragmatic plication was performed and the infant successfully extubated four days later.

[Indications, techniques and results of laparoscopic surgery for diaphragmatic diseases]

Eleven patients with congenital, traumatic and functional extrahiatal diaphragmatic lesions are reported. Since 1991 two patients with acute, two patients with old ruptures of the diaphragm and one patient with a Morgagni-Larrey-hernia were successfully treated by laparoscopic direct suturing. In two other patients with Morgagni hernias we used a polypropylene mesh for closure of the defect. One procedure was performed in a patient with symptomatic congenital dysplasia of the diaphragm with aplasia of the pericard. Laparoscopic plication of the diaphragm was performed in three symptomatic patients with phrenic nerve palsy after cardiac surgery. The intra- and postoperative course was uneventful in all cases. During a median follow-up of 60 months there was no recurrence. Therefore the laparoscopic technique is an effective and attractive alternative for treatment of these diseases.

Diaphragm plication following phrenic nerve injury: a comparison of paediatric and adult patients

BACKGROUND

A study was undertaken to evaluate whether adults differ from children in the indications and outcome of diaphragmatic plication following phrenic nerve injury.

METHODS

A retrospective study was performed of 21 patients, 10 below the age of 5 and 11 older than 37 years. The indication for surgery for all the children was failure to wean from ventilatory support. The indications for surgery in the adult group were ventilator dependency (n=4) and symptomatic dyspnoea (n=7). All patients had at least one imaging study confirming diaphragmatic paralysis. The American Thoracic Society (ATS) dyspnoea scale, pulmonary function tests, and quantitative pulmonary perfusion scans were used as evaluation parameters. At surgery the diaphragm was centrally plicated.

RESULTS

One child died immediately after surgery due to irreversible heart failure and two children died within 2 months of surgery from ongoing complications of their original condition. These three patients were considered as selection failures. Seven children were weaned from ventilatory support within a median of 4 days (range 2-140). Only one of four ventilated adults was successfully weaned. Seven adults who underwent surgery for chronic symptoms had a marked subjective improvement of 2-3 levels in the ATS dyspnoea scale. Pulmonary function studies in the seven symptomatic adults showed a 40% improvement above baseline. Severely asymmetrical perfusion scans reverted to a normal pattern after plication.

CONCLUSIONS

Diaphragmatic plication offers a significant benefit to children with diaphragmatic paralysis and should be performed early to facilitate weaning from mechanical ventilation. While plication is of limited benefit in weaning ventilated adults, it results in significant subjective and objective lifetime improvement in non-ventilated symptomatic adults.

Critical illness neuromuscular abnormalities

CINMAs occur commonly in acutely critically ill inflamed patients, and can prolong respiratory failure, lead to ventilator dependency, and contribute to the development of chronic critical illness. The etiology of NMDs are diverse and overlap, and distinguishing different disease entities by clinical exam and electrophysiologic studies can be difficult. CIP, which has been the most widely studied CINMA, represents the peripheral nervous system manifestation of the MODS. Patients with CIP, particularly those with severely reduced nerve function, have a prolonged rehabilitation and a high mortality rate. Although there are no definitive treatments, diagnosing a CINMA may provide helpful prognostic information. Future preventative measures may include immunoglobulin, nerve growth factors, or strict glycemic control, although in the CCI phase general supportive care is given, including prevention of iatrogenic complications, nutritional support, psychosocial support, and physical therapy. The early recognition of CINMAs and prevention of associated complications are important to enabling CCI patients with CINMAs to recover and return home with an acceptable functional level and quality of life.

Diaphragmatic paralysis in extremely low birthweight neonates: Is waiting for spontaneous recovery justified?

Mortality and morbidity associated with surgical management of patent ductus arteriosus (PDA) in neonates has been reported to vary from 0% to 44%. Complications like pneumothorax, pleural effusion, recurrent nerve and phrenic nerve injury are associated with surgical closure of PDA. An extremely low birthweight neonate with diaphragmatic paralysis following phrenic nerve injury during surgical closure of PDA is reported. Delay in diaphragmatic plication for over two weeks while waiting for spontaneous recovery was associated with significant morbidity including chronic lung disease. The controversies associated with timing of diaphragmatic plication in high-risk neonates are discussed.

Infrasternal mediastinoscopic thymectomy in myasthenia gravis: surgical results in 23 patients

BACKGROUND

Infrasternal mediastinoscopic surgery is a new approach to resection of the anterior mediastinal mass.

METHODS

We evaluated this new approach in 23 patients with myasthenia gravis who underwent total thymectomy assisted by infrasternal mediastinoscopy between 1998 and 2000. The results were analyzed with special reference to morbidity and short-term improvement of the disease severity determined according to quantitative myasthenia gravis (QMG) scores.

RESULTS

Complete removal of the thymic gland with the pericardial adipose tissue was accomplished through an infrasternal mediastinoscopic approach in 21 of the 23 (91.3%) patients. The remaining 2 patients required conversion to sternotomy, the one for insufficient sternal lifting with vascular tape and the other for invasion of a thymoma to the innominate vein. There was no related mortality and only one complication, a phrenic nerve injury in 1 patient (4.3%). Significant clinical improvement of disease was achieved in the short term and several advantages were apparent.

CONCLUSIONS

Infrasternal mediastinoscopic thymectomy is safe and feasible for patients with myasthenia gravis.

Bilateral diaphragmatic paralysis after open heart surgery

The purpose of the present case report is to present a case of bilateral diaphragmatic paralysis as a complication of open-heart surgery. A 47-year-old male was operated for aortic and mitral valve replacement. After discontinuation of sedation, bilateral diaphragmatic paralysis as well as motor and sensitive dysfunction in the four extremities was observed. The patient remained with mechanical ventilation support for twenty months. Two years after the operation a complete normalisation of the diaphragmatic motion was observed. Although uncommon, bilateral diaphragmatic paralysis after open-heart surgery could take place, being necessary long term mechanical ventilation support until recovery.

Hemidiaphragmatic paralysis increases postoperative morbidity after a modified Fontan operation

OBJECTIVES

After a Fontan procedure, forward pulmonary blood flow is augmented during inspiration because of negative intrathoracic pressure. Total pulmonary blood flow is higher during inspiration. With hemidiaphragmatic paralysis, inspiratory augmentation of pulmonary flow is lost or diminished. The objective of this study was to compare early postoperative morbidity after the modified Fontan operation in patients with and without hemidiaphragmatic paralysis.

METHODS

A case-control analysis was performed comparing 10 patients with documented hemidiaphragmatic paralysis against 30 patients without paralysis who were matched for diagnosis, fenestration, and age. The following early postoperative outcomes were assessed: duration of ventilator support, duration of hospital stay, incidence of ascites, prolonged effusions, and readmission.

RESULTS

Preoperatively, there were no significant differences between the 2 groups. However, among the postoperative outcomes, the duration of hospital stay (25.4 +/- 16.6 days vs 10.8 +/- 6.3 days; P =.03), incidence of ascites (70% vs 3%; P <.001), prolonged pleural effusions (60% vs 13%; P =.007), and readmission (50% vs 7%; P =.007) were significantly greater in patients with hemidiaphragmatic paralysis than in those without hemidiaphragmatic paralysis.

CONCLUSIONS

Hemidiaphragmatic paralysis after the modified Fontan operation is associated with an increase in early morbidity. Care should be taken to avoid injury to the phrenic nerve. Patients with prolonged effusions should be evaluated for hemidiaphragmatic paralysis.

[A case of diaphragmatic paralysis in a patient with diabetes mellitus after surgery in prolonged prone position]

A 56-year-old woman with diabetes mellitus was scheduled for bilateral kidney lithotomy. She was in the prone position for about seven hours during operation. At the end of operation, arterial blood gas analysis showed PaO2 64 mmHg and PaCO2 44 mmHg under 100% oxygen inhalation through a face mask, and the chest x-rays showed elevation of the right diaphragm. Her trachea was intubated again. The right diaphragm returned to the preoperative level by positive pressure ventilation on supine position. Hypoxemia disappeared when the patient was placed in the sitting position, and the trachea was extubated. The right diaphragm returned to the normal level on the 1st postoperative day, but hypoxia continued until the 6th postoperative day with the patient on supine position. We speculate that the diaphragmatic paralysis was caused by over-extension of the neck for a prolonged period, and that the patient might have been susceptible to nerve injury due to underlying diabetes mellitus.

Bilateral phrenic nerve palsy as a complication of anterior decompression and fusion for cervical ossification of the posterior longitudinal ligament

STUDY DESIGN

A case report of bilateral phrenic nerve palsy as a complication of anterior decompression and fusion for cervical ossification of the posterior longitudinal ligament (OPLL).

OBJECTIVES

To present a case of a rare and serious complication of cervical spinal surgery and to investigate its cause.

SUMMARY OF BACKGROUND DATA

There have been a number of reports of phrenic nerve palsy after cardiac surgery, but the authors have found no previous description of this complication related to spinal surgery.

METHODS

The authors describe the clinical presentation and management of a case of bilateral phrenic nerve palsy subsequent to the surgery for cervical OPLL. Also, the literature is reviewed concerning surgical approaches for the treatment of OPLL and the occurrence of phrenic nerve palsy subsequent to any form of therapy.

RESULTS

Bilateral phrenic nerve palsy occurred after anterior decompression and fusion for cervical OPLL. Bilateral phrenic nerve palsy was diagnosed radiographically: postoperative chest radiograph showed bilateral laxity of the diaphragm. Movement of the bilateral diaphragm appeared 3 weeks after surgery. The patient successfully returned to normal daily life after ventilatory support for 3 months, although nocturnal oxygen support was still necessary at the latest follow-up, 3 years after surgery. The possible causes of this complication include bilateral C4 nerve root stretching, iatrogenic injury of the gray matter in the ventral horn, alteration of blood circulation related to spinal edema, or re-impingement on the spinal cord at the cranial part of the decompression site.

CONCLUSIONS

Bilateral phrenic nerve palsy occurred after anterior decompression and fusion for cervical OPLL. Bilateral phrenic nerve palsy should be kept in mind as a serious complication of spinal surgery. It should be considered when patients unexpectedly fail to wean from the ventilator after surgery.

Acute diaphragmatic paralysis caused by chest-tube trauma to phrenic nerve

A 3 1/2-year-old child developed unilateral diaphragmatic paralysis after chest drain insertion. Plain chest X-ray demonstrated paravertebral positioning of the chest-tube tip, and magnetic resonance imaging revealed hematomas in the region of the chest-tube tip and the phrenic nerve fibers. The trauma to the phrenic nerve was apparently secondary to malposition of the chest tube. This is a rare complication and has been reported mainly in neonates. Radiologists should notify the treating physicians that the correct position of a chest drain tip is at least 2 cm distant from the vertebrae.

Transient hemi-diaphragmatic paralysis following neck surgery: report of a case and review of the literature

Diaphragmatic paresis following trauma to the phrenic nerves is a rare complication after neck surgery. The resulting elevation of the ipsilateral hemi-diaphragm is diagnosed on post-operative chest radiography and may be confirmed by ultrasound or fluoroscopy. When unilateral, this may lead to respiratory, cardiac or gastrointestinal symptoms and atelectasis and pulmonary infiltrates on radiography. If nerve damage is bilateral a period of ventilation may be required.

Bilateral diaphragmatic paralysis after cardiac surgery: ventilatory assistance by nasal mask continuous positive airway pressure

The case of an 8-month-old boy with bilateral diaphragmatic paralysis after surgical reoperation for congenital heart disease is presented. In order to avoid repeated intubation and long-term mechanical ventilation or tracheotomy, we used nasal mask continuous positive airway pressure (CPAP) as an alternative method for assisted ventilation. Within 24 hours the boy accepted the nasal mask and symptoms such as dyspnea and sweating disappeared. Respiratory movements became regular and oxygen saturation increased. Nasal mask CPAP may serve as an alternative treatment of bilateral diaphragmatic paralysis in infants, thereby avoiding tracheotomy or long-term mechanical ventilation.

[Elevation of the diaphragma after cardiac surgery]

Phrenic nerve injury and diaphragmatic dysfunction can be induced by cardiac operation. We evaluated nonconsecutive 34 patients (pts) with elevation of the diaphragma after cardiac operation. 27 pts have coronary artery bypass grafting, 7 pts have prosthetic valve implantation. We have impression that ice/saline slush used along with cold cardioplegia for heart arrest can cause hypothermic damage of phrenic nerve. Palsy of that nerve results in raised hemidiaphragm and delayed recovery of the pts. In our pts normalisation of the diaphragm we observed 6 months after operation in 41% pts and 12 month after in 93% pts. We suggest that results depends on early and well rehabilitation.

Phrenic nerve injury following blunt trauma

Phrenic nerve trauma in the absence of direct injury is unusual and may present diagnostic difficulty. Diaphragmatic paralysis resulting from phrenic nerve injury may closely mimic diaphragmatic rupture. This case highlights the value of magnetic resonance imaging in establishing diaphragmatic integrity and of ultrasonographic assessment during respiratory excursion in confirming diaphragmatic paralysis. In cases of non-contact injury involving torsional injury to the neck, an index of clinical awareness may help to establish the diagnosis of phrenic nerve trauma.

[Diaphragmatic excursion after inter-sternocleidomastoid block depending on the site of the injection]

OBJECTIVE

To evaluate the incidence of the hemidiaphragmatic paresis after inter Sterno-Cleido-Mastoid (inter-SCM) block.

STUDY DESIGN

Prospective, comparative, single blind study.

PATIENTS

16 patients ASA I-II.

METHODS

The diaphragmatic paresis was measured by a radiologist unaware of the technique used and operated side. It was determined by the diaphragmatic excursion (DE) on double-exposure chest radiography, obtained preoperatively and postoperatively (DE-pre, DE-post) for the ipsilateral and controlateral side of the inter-SCM block. All the patients were given 20 mL 0.5% bupivacaine plus 20 mL 2% lidocaine both with epinephrine. These anesthetics were injected via the stimuling needle or via the catheter after opacified radiological control of the catheter position. The patients were divided into 2 groups. Group 1: injection via the needle after eliciting flexion of fingers, or via a catheter into infraclavicular position; group 2: injection via the needle after eliciting contraction of deltoid, or elbow flexion, or via a supraclavicular catheter.

RESULTS

All the patients had satisfactory block. The ipsilateral DE was decreased after injection of anesthetics in group 2 (P < 0.001) while it remained unchanged in group 1.

CONCLUSION

The diaphragmatic paresis is avoidable with the inter-SCM block if and only if the anesthetic solution is injected via the needle after stimulating flexion of fingers or via a catheter into infraclavicular position.

Mini-thoracotomy for diaphragmatic plication with thoracoscopic assistance

We describe a technique of mini-thoracotomy to plicate the paralyzed hemidiaphragm with thoracoscopic assistance. Most of the hemidiaphragm can be plicated expeditiously under direct vision with light derived from a posterior thoracoscope placed in the auscultatory triangle. Videoscopic vision is employed only occasionally when the view of the posteromedial hemidiaphragm is obscured. Continuous suture traction can be easily applied through the mini-thoracotomy, thus maintaining suture tension and enabling maximal inversion of the elevated hemidiaphragm.