We present this interesting case of an acute Morgagni hernia to raise awareness among surgical trainees and other doctors. The patient in our case had two previous admissions with similar symptoms, but the diagnosis was delayed until the features of gastric outlet obstruction due to incarcerated stomach within the hernial sac supervened.
The foramina of Morgagni () are small zones lying between the costal and sternal attachments of the thoracic diaphragm and were first described in 1761.3
This site for potential herniation is also known as the sternocostal hiatus or Larrey's triangle. There is some confusion in the surgical literature and some authors use the names Larrey and Morgagni interchangeably, while others use Morgagni for a right-sided hernia and Larrey's for a left. However, it would appear that although Larrey, who was Napoleon's surgeon, did describe the space in 1829 he did not describe a hernia. He described the space as the approach through which pericardial tamponade could be treated.4
Figure 4 Anatomical locations of the two common types of congenital diaphragmatic hernia: the foramen of Morgagni and the foramen of Bochdalek. The foramina of Morgagni are small zones lying between the costal and sternal attachments of the diaphragm. The foramen (more ...)
The incidence of Morgagni hernia among all diaphragmatic defects in adults and children is approximately 3% and it is the rarest of all diaphragmatic hernias. Morgagni hernia defects usually occur on the right hand side (91%). In 5% of cases the defect is on the left hand side of the sternocostal hiatus and the remaining 4% are bilateral.1
Although the defect is congenital in origin, presentation is rare in children. Possible presentations of a Morgagni hernia in children are with repeated chest infections or respiratory symptoms. Rarely, it may present in the neonatal period with acute respiratory distress. However, it more commonly presents in adulthood because the congenital weakness in the diaphragm is usually small and it is only with increasing age that the defect enlarges and stretches secondary to raised intra-abdominal pressure. The average age of presentation is 58 years in females and 50 years in males.1
The overall rate of emergency presentation is between 12% and 14%.5
Common predisposing features include pregnancy, obesity, chronic constipation and chronic cough. Overall, 61% of cases appear to occur in females.1
Adult patients are often asymptomatic and the hernia is detected during radiological investigations performed for other reasons. Delayed diagnosis is common and symptoms if present are often non-specific respiratory or gastrointestinal complaints, such as shortness of breath, abdominal discomfort or vomiting. Emergency presentation can be with acute respiratory distress,6
gastric outlet obstruction,7
or strangulation and ischaemia of hernial sac contents. Very late presentation can rarely occur with perforation of the entrapped gastrointestinal organs (stomach or colon) and subsequent peritonitis or mediastinitis. The hernial sac can contain a wide variety of contents, including omentum, colon, stomach, duodenum, small intestine or occasionally liver.
The diagnosis of a Morgagni hernia may be suggested on plain chest radiography by the features of a raised hemi-diaphragm, a mass at the cardiophrenic angle or an abnormal fluid level in the thorax. In patients who undergo barium investigations, the diagnosis can be revealed by contrast within the colon or stomach herniating through to the chest. CT is now a highly accurate way to confirm the diagnosis and help plan appropriate surgical repair.8 9
CT may show a para-cardiac fat density with linear densities consistent with omental blood vessels. Transverse colon, stomach or small bowel loops may be visible in the chest.
Surgical treatment is required for patients with symptoms if they are fit enough to undergo general anaesthesia and major surgery. Patients who are asymptomatic should also be considered for surgical repair as the risks of future incarceration and emergency presentation are significant.2
The precise surgical treatment is controversial and several aspects including the approach used, the requirement to excise the hernial sac and whether or not to close the defect with mesh, are a matter of debate. Because of the rarity of these hernias there are no current guidelines to help clinicians treat patients with this condition.
Surgical treatment can be either by open laparotomy or thoracotomy, or minimal access approaches (thorascopic or laparoscopic). The most common surgical approach for acute surgical presentation is by open laparotomy.1
The abdominal approach appears to offer several advantages, including easier reduction of hernial contents, inspection of the contra-lateral diaphragm for other hernia defects and easier evaluation and surgical treatment of the acute complications, such as strangulation and ischaemia of luminal abdominal organs.10
Thoracotomy appears to be the most commonly used approach in the literature and has the advantage of allowing easier dissection of the hernial sac from the mediastinal and pleural cavity. Disadvantages to thoracotomy include a more painful incision with longer postoperative recovery. The minimal access approach, via abdominal laparoscopy, has been well described in the literature.1 11 12
Laparoscopy provides excellent views of the diaphragmatic defect and abdominal contents, and the hernial contents can be reduced and systematically inspected for signs of ischaemia. The laparoscopic approach has the benefits of less postoperative pain and earlier return to activities and work, but is less suited to emergency presentations where surgical resection or treatment of necrotic or ischaemic contents may be required. The presentation with gastric outlet obstruction in our case meant that the open laparotomy approach was the most appropriate.
The defect can be closed with or without the use of prosthetic mesh. A wide variety of techniques have been described in the surgical literature. Simple suture repair may be suitable for small defects, however prosthetic mesh is generally recommended if the defect is larger than 3 cm.13
The use of mesh is usually contraindicated in peritonitis or extensive contamination. We used a prosthetic mesh in our case as the defect was fairly large and the operative site was clean and it was also felt this would reduce the risk of potential recurrence. In addition a 2 cm overlap was used to prevent recurrence if the mesh were to shrink over time. We also chose to cover the mesh with peritoneum to prevent the risk of adhesions to abdominal organs.
In summary, Morgagni hernia is a rare congenital hernia which can present in adult life. Although it is commonly asymptomatic, presentation may be with acute gastric outlet obstruction, respiratory distress or peritonitis. Surgical treatment is required and should be considered even if the patient is asymptomatic.
- Morgagni hernias develop through a defect between the diaphragm's attachments to the sternum and costal cartilages.
- They are usually right-sided.
- They constitute 3% of diaphragmatic hernias.
- The majority are asymptomatic, but such patients should still be considered for surgical repair.
- Acute presentation can be with either gastric outlet obstruction, peritonitis from infarcted contents or acute respiratory distress.