Heart on the left, diaphragm on the right: A case of congenital diaphragmatic eventration

Abstract Congenital Diaphragmatic Eventration (DE) requires a prompt diagnosis to avert the potentially life‐threatening complications. Herein, a 5‐month‐old male presented with recurrent respiratory infections due to a right‐sided diaphragmatic eventration. Misdiagnosed from previous medical visits, timely surgical intervention by thoracoscopic plication of the diaphragm was crucial for our patient's survival.


| INTRODUCTION
Diaphragmatic eventration (DE) is a rare disease entity defined as a partial or complete elevation of one or both the hemidiaphragm, due to muscular or nervous dysfunction. 1 DE can present as a congenital defect due to paucity or absence of varying degrees of muscle fibers or, acquired due to phrenic nerve injury. 2 This report highlights the case of a right-sided DE in a 5-month-old male infant presenting with recurrent lower respiratory tract infections and ongoing pneumonia.

| CASE REPORT
A 5-month-old male infant presented to the University of Health Science, Pakistan, with recurrent episodes of fever and non-productive cough which had increased in frequency in the last month. The infant was full-term and delivered via spontaneous vaginal delivery at home to a 30-year-old mother. The mother was screened and found negative for HIV and hepatitis panel and denied any use of alcohol, tobacco, and illicit substances throughout the course of her pregnancy. The infant weighed 2500 g at birth; cried immediately after birth and has been breastfeeding without signs of distress. The infant had been meeting the required motor and language milestones along with good social maturation. Family history was significant for a consanguineous marriage along with the uneventful spontaneous vaginal delivery of two male babies who are currently healthy. The patient was immunized as per the national immunization schedule.
On admission, the infant was found to be irritable and inconsolable. General physical examination was significant for a fever (102°F). Chest examination revealed decreased movements and breath sounds in the right infra-mammary, infra-axillary, and infra-scapular areas. Upon auscultation, crepitations were present in the right lung field. Initial laboratory investigations displayed an elevated total leukocyte count of 15,000/mm 3 . Inflammatory markers such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were negative. Hemoglobin and metabolic panel were also within normal limits. Chest Xray (CXR) was performed and showed that the dome of the diaphragm was raised on the right hand side as seen in Figure 1A. CT scan of the chest confirmed the diagnosis of a right-sided diaphragmatic eventration with consolidative changes visualized in Figure 1B.
To treat ongoing pneumonia, the infant was empirically started on injection ampicillin, cloxacillin, and cefotaxime. He was also treated with albuterol and ipratropium bromide nebulization, dexamethasone, antipyretics, and multivitamin supplementation. Thoracoscopic plication of the diaphragm of the right side was planned. Under general anesthesia, the infant was placed on the left lateral decubitus position and a 3mm port was inserted in the 4th intercostal space at the posterior axillary line. A second 3mm incision in the 6th intercostal space of the right anterior axillary line was used to insert the Maryland grasper. Upon visualization of the diaphragm, right-sided eventration was confirmed. There were no adhesions with abdominal viscera present. The diaphragm was plicated using 2-0 silk. Chest tube of appropriate size was placed in the right 5th intercostal space and closure was done in layers.
The immediate postoperative period was uneventful and the infant was able to maintain normal oxygen saturation on room air. Repeat CXR displayed a flattened hemidiaphragm on the right side. After successful management the infant was discharged and was symptom-free at his 3-month follow-up appointment. CXR was repeated and was unremarkable showing adequate inflation of bilateral lungs and flattened diaphragm.

| DISCUSSION
Diaphragmatic eventration, often described as the neurogenic muscular aplasia of the diaphragm, has been found to occur in varying age groups of the population. 1 Congenital diaphragmatic eventration can be attributed to the inability of myoblasts to properly migrate to the septum transversum, thus leading to the substitution of muscle fibers by fibroelastic fibers. 3 This histopathological picture of the diaphragm can be used to differentiate it from acquired causes of DE including birth trauma, phrenic nerve injury, nerve compression, pneumonia, and multiple sclerosis. 1,4 On top of the challenging presentation of DE, barriers to health care such as poor socioeconomic status, add to the complications. Home-deliveries carried out by midwives have become a cultural norm in Pakistan in both rural and urban settings and have been correlated with a higher risk of maternal mortality. 5 These practices have been attributed to the low socioeconomic status and deeprooted cultural beliefs prevailing in these regions. The delayed diagnosis of DE in the present case, similarly, may be due to the family's psychosocial views and inaccessibility of the medical healthcare. Recognizing cultural limitations is necessary as DE has widely been underreported due to its largely asymptomatic presentation. A summary table of our patient Physical exam findings has been presented in Table 1.
The non-contracting, higher position of the diaphragm results in lung collapse followed by atelectasis F I G U R E 1 (A) CXR shows eventration on the right hand side revealing and elevated dome of the diaphragm. (B) CT scan showing liver on the right side adjacent to the heart in a higher position than normal predisposing the individual to bronchial or parenchymal infections. Presenting symptoms often include cough, dyspnea, chest pain, and cyanosis, and at times, gastrointestinal symptoms such as nausea, vomiting, abdominal pain, and acid reflux. In infants, these symptoms can be extremely debilitating due to the underdeveloped thoracic cage and intercostal muscle weakness resulting in paradoxical respiration ultimately necessitating the use of mechanical ventilation. 6 The workup of DE primarily includes imaging modalities including the use of ultrasonography, chest x-ray, and computed tomography (CT) scan. It is vital to exclude intrathoracic, mediastinal, or abdominal masses such as diaphragmatic hernia before concluding the diagnosis of DE. 7 Fluoroscopic sniff test has been used to differentiate diaphragmatic eventration and paralysis in cases of unilateral diaphragmatic paralysis, however, this test was not used in our case. 1 As recurrent lower respiratory tract infections are a common complexity arising from DE, it is of primary interest to treat the underlying infection and provide respiratory support with oxygen supplementation in patients presenting with hypoxia. A summary of previously published cases has been presented in Table 2. Nutritional supplementation is vital in infants presenting with DE as undernourishment due to poor feeding often accompanies the condition. Symptomatic DE presenting with respiratory distress, failure to thrive, recurrent pneumonia, and failure to wean of ventilator support have been shown to benefit greatly with diaphragmatic plication with a good prognosis and improvement of quality of life. 1,8 Diaphragmatic plication has been achieved through thoracotomy, thoracoscopic, and laparoscopic surgeries. Thoracoscopic surgeries have been proven to be more advantageous with a lower length of hospital stay, lower rate of complications, and better prognosis. 2 Laparoscopic surgeries are also associated with lesser pain as intercostal nerve damage is avoided. The placement of a prosthetic mesh has been successful along with plication in cases of extreme amyotrophy, however at the cost of increased cost and chance of infection. 9 Possible complications of diaphragmatic plication include pneumonia, dyspnea, pulmonary edema, and pleural effusion. 6 These complications, however, were not observed in our case.
Symptomatic diaphragmatic eventration is associated with high morbidity and failure to thrive if not treated promptly. Adequate workup to exclude underlying conditions, nutritional status, associated abnormalities, and treatment of the same is vital to ensure better survival rates in infancy. Minimally invasive procedures like laparoscopic plication of the diaphragm are found to be very effective in the treatment of diaphragmatic eventration with a low incidence of complications and a good prognosis.

| CONCLUSION
Congenital diaphragmatic eventration (DE) is a rare pathology that can be fatal if left untreated. DE's are difficult to diagnose as they can present without symptoms thus requiring intricate management. Infants dealing with DE are at an increased risk of morbidity as their thoracic cage is underdeveloped leading to life-threatening complications including failure to thrive. This case demonstrates the successful outcome of the patient due to accurate diagnosing of congenital DE, and the performance of minimally invasive procedures such as laparoscopic plication.