Trans-Sternal Repair of Incidentally Diagnosed Morgagni Hernia during Ventricular Septal Defect Closure in a Sickle Cell Trait Infant

Sir,

Anterior variety of congenital diaphragmatic hernia (CDH) is variably referred to as Morgagni, retrosternal, or parasternal hernia which amounts to only 3%–5% of all diaphragmatic hernias.[1] Unlike Bockdalek hernia, Morgagni hernia (MH) is anterior; more often right-sided (90%), female predominance (70%) and rare variety with low risk of prolapse. Contents might be transverse colon with omentum, part of the stomach, and left lobe of the liver.[2]

Our patient is an 11-month-old male infant brought with frequents episodes of respiratory tract infection, tachypnea, feeding difficulty, and excessive diaphoresis on exertion. On evaluation, he was found to have a large perimembranous ventricular septal defect (VSD) with severe pulmonary artery hypertension (88 mm of Hg). Hemoglobin electrophoresis done showed the presence of sickle cell trait with HbS value of 3.5% and HbA2 value of 3%. As the HbA2 value was less, we have not done any preoperative exchange transfusion. He was posted for surgical VSD closure. Post median sternotomy and pericardiotomy, we were surprised by a sac in the pericardial cavity herniating through a defect in the anterior portion of the diaphragm (measured 4 cm × 5 cm) with reducible omental sac and part of the left lobe of the liver as its content. We could not identify the MH preoperatively, as cardiomegaly along with murmurs of VSD masked the finding. Post VSD closure, we reduced the sac contents and closed the defect using bovine pericardium transsternally itself [Figure 1]. The postoperative course went uneventful and discharged on the 7^th postoperative day.

Figure 1.

Intra-operative image showing unrepaired (left hand side) and repaired (right hand side) Morgagni hernia

In 1769, GiovaniMorgagni[3] was the first person to describe substernal herniation of abdominal contents into the thoracic cavity. At the 3-mm stage, diaphragm gets muscularized due to the invasion of mesenchyme by myotomes in the dorsal to the ventral direction. Meanwhile, sternum also gets fused from above downward. Fusion failure leads to the foramen of Morgagni.[4]

Most cases of MH occur as an isolated defect. One-third of CDH patients will have associated major congenital malformations, predominantly cardiovascular and pulmonary, musculoskeletal, and central nervous. The presentation may vary from asymptomatic to either abdominal or respiratory or both symptoms. The diagnosis of MH can be confirmed by chest radiographs and barium enema; still, in some cases, the diagnosis can be missed. Computed tomography imaging is considered as an accurate method of diagnosis. Magnetic resonance imaging is equally effective, but it is seldom done. Based on patient factors and the surgeon's preference, repair of MH can be performed through transthoracic or transabdominal employing the open or laparoscopic technique.

The main predictor of the outcome of MH depends on whether it is isolated or complex, other associated anomalies, defect size, the presence of pulmonary hypoplasia and sidedness of hernial defect.[5] Even though it is rare to come across MH, every cardiac surgeon should be familiar to tackle the MH through transsternal approach itself until unless intestinal obstruction and incarceration are suspected. A cornerstone in adequate repair lies on tension-free repair using a patch or mesh. Early surgical intervention should be considered even in asymptomatic, to prevent life-threatening complications such as obstruction or strangulation.

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