Overview
Definition:
Diaphragmatic eventration is a condition where one hemidiaphragm is elevated abnormally, often due to congenital absence or weakness of diaphragmatic muscle fibers, leading to impaired respiratory function
Diaphragmatic plication is a surgical procedure aimed at correcting this by tethering the elevated diaphragm to the abdominal wall or chest wall, thereby reducing its excursion and improving lung volumes.
Epidemiology:
Congenital diaphragmatic eventration is rare, with an estimated incidence of 1 in 10,000 live births
It can occur unilaterally or bilaterally, with unilateral left-sided eventration being more common
Acquired eventration can occur secondary to phrenic nerve injury, trauma, or thoracic surgery
It can present at any age, though congenital forms are diagnosed in infancy.
Clinical Significance:
Diaphragmatic eventration can lead to significant respiratory distress, recurrent pneumonias, and failure to thrive, particularly in infants
In adults, it may present with exertional dyspnea, chronic cough, or post-prandial fullness
Accurate diagnosis and timely surgical intervention are crucial for improving pulmonary mechanics, reducing morbidities, and enhancing the quality of life for affected individuals, making it a vital topic for surgical trainees.
Clinical Presentation
Symptoms:
In infants: Tachypnea
Retractions
Nasal flaring
Grunting
Cyanosis
Poor feeding
Failure to thrive
In adults: Dyspnea, especially with exertion
Chronic cough
Recurrent pneumonia
Abdominal distension or discomfort
Paradoxical abdominal breathing.
Signs:
Physical examination may reveal diminished breath sounds over the affected hemithorax
Scars of previous thoracic surgery may be present
A bulging or retracted intercostal space on the affected side
Paradoxical abdominal movement during respiration
Cyanosis or accessory muscle use in severe cases.
Diagnostic Criteria:
Diagnosis is primarily based on imaging
The key diagnostic criterion is the demonstration of significant paradoxical movement of the diaphragm during respiration on fluoroscopy, or a persistently elevated hemidiaphragm on plain radiographs
Absence of a clear etiology for diaphragmatic paralysis is usually established before diagnosing eventration.
Diagnostic Approach
History Taking:
Detailed birth history for congenital cases
History of trauma, surgery, or neurological conditions affecting the phrenic nerve
Characterization of respiratory symptoms and their diurnal variation
Associated gastrointestinal symptoms may be present
Red flags include severe dyspnea, cyanosis, or failure to thrive.
Physical Examination:
A thorough respiratory examination is paramount, noting chest wall asymmetry, respiratory rate, effort, and breath sounds
Auscultation for adventitious sounds
Palpation for accessory muscle use
Abdominal examination to assess for paradoxical movement
Cardiac examination to rule out concomitant cardiac anomalies.
Investigations:
Chest X-ray: shows elevated hemidiaphragm
Fluoroscopy: demonstrates paradoxical movement ("seesaw" movement) during breathing, confirming eventration
Pulmonary Function Tests (PFTs): can reveal restrictive lung disease, reduced vital capacity, and decreased inspiratory pressures
CT scan of the chest: can delineate the diaphragm, identify associated anomalies, and rule out other intrapulmonary or pleural pathology
Electromyography (EMG) of the diaphragm: to assess for phrenic nerve integrity if paralysis is suspected
Arterial Blood Gases (ABGs): to assess oxygenation and ventilation status.
Differential Diagnosis:
Diaphragmatic paralysis (complete or partial)
Congenital diaphragmatic hernia
Eventration due to phrenic nerve palsy
Subdiaphragmatic pathology (e.g., subphrenic abscess, subphrenic mass)
Pleural effusion or thickening
Lung atelectasis
Subcutaneous emphysema.
Management
Initial Management:
For symptomatic patients, especially infants with respiratory distress, initial management focuses on respiratory support
This may include supplemental oxygen, non-invasive ventilation (CPAP/BiPAP), or mechanical ventilation
Nutritional support is crucial for infants with failure to thrive.
Medical Management:
Medical management is generally supportive and aims to optimize respiratory status and manage secondary infections
This includes bronchodilators if bronchospasm is present, antibiotics for pneumonia, and diuretics if pulmonary edema is suspected
However, medical management alone rarely resolves the underlying mechanical issue of eventration.
Surgical Management:
Surgical intervention, typically diaphragmatic plication, is indicated for symptomatic patients with significant respiratory compromise, failure to thrive in infants, or recurrent pulmonary infections
The goal is to restore normal diaphragmatic mechanics and improve lung function
Common surgical approaches include: Thoracotomy: open surgical approach
Video-Assisted Thoracoscopic Surgery (VATS): minimally invasive approach
The procedure involves creating plications in the diaphragm using sutures to reduce its upward excursion
The diaphragm is often tethered to the ribs or abdominal wall.
Supportive Care:
Postoperatively, patients require close respiratory monitoring
Chest physiotherapy is important for secretion management and lung expansion
Pain management is critical
Gradual weaning from mechanical ventilation if required
Nutritional support should be continued to promote recovery and growth.
Complications
Early Complications:
Pneumothorax
Hemothorax
Persistent air leak
Infection (pleural or wound)
Injury to adjacent organs (lung, spleen, liver)
Hemorrhage
Recurrence of eventration symptoms.
Late Complications:
Chronic pain at the surgical site
Adhesions and scarring
Chronic respiratory insufficiency if plication is not fully effective
Recurrent pneumonia
Wound dehiscence.
Prevention Strategies:
Meticulous surgical technique, especially regarding phrenic nerve preservation during thoracic procedures
Careful handling of tissues
Adequate chest tube management postoperatively
Prompt diagnosis and intervention to avoid severe respiratory compromise
Early mobilization and chest physiotherapy to prevent atelectasis and pneumonia.
Prognosis
Factors Affecting Prognosis:
Age at diagnosis and intervention
Severity of diaphragmatic dysfunction
Presence of associated congenital anomalies
Degree of respiratory compromise preoperatively
Technical success of the surgical procedure
Postoperative complications.
Outcomes:
With successful surgical correction, the prognosis is generally good, leading to significant improvement in respiratory symptoms, resolution of failure to thrive in infants, and reduced frequency of pulmonary infections
Long-term respiratory function may improve substantially
For neonates with severe respiratory failure, the prognosis can be guarded.
Follow Up:
Regular follow-up is essential to monitor respiratory status, lung volumes, and the effectiveness of the plication
PFTs may be repeated periodically
Patients should be advised to avoid factors that exacerbate respiratory symptoms and to seek prompt medical attention for any signs of infection or worsening dyspnea
Surveillance for potential recurrence is also important.
Key Points
Exam Focus:
Diaphragmatic eventration vs
paralysis
Indications for surgical plication
Thoracoscopic vs
open approach
Potential complications of diaphragmatic surgery
Importance of fluoroscopy in diagnosis.
Clinical Pearls:
Always consider diaphragmatic eventration in infants with persistent respiratory distress not explained by other common causes
Paradoxical abdominal breathing on examination is a key clue
VATS offers a less invasive approach with comparable outcomes to open surgery for selected patients
Careful preoperative assessment of pulmonary function is vital.
Common Mistakes:
Misdiagnosing eventration as simple lung pathology
Delaying surgical intervention in symptomatic patients
Performing unnecessary phrenic nerve interventions on a paralyzed diaphragm
Inadequate postoperative respiratory support leading to complications.