Anatomy Answer 7

The diaphragmatic foramen of Morgagni hernia is located posterolateral to the sternum at the site of the internal mammary artery. The hernia usually occurs on the right side but may occur on the left or in the midline; it has also been described as retrosternal, parasternal, substernal, and subcostosternal. It is the least common diaphragmatic hernia and comprises only 3% of all surgically treated hernias.

First described by Giovanni Morgagni in 1761, the potential space for the hernia is produced by a congenital defect or weakened area that results from failure of the septum transversus of the diaphragm to fuse with the costal arches. This anatomic defect, best known as Morgagni's foramen, has also been referred to as Larrey's space.

It is believed that the congenital foramen (weakened area) gradually stretches and that herniation through the foramen occurs later in life, possibly because of rapid changes in intra-abdominal pressure and aging of the diaphragm.

In adults, Morgagni hernias occur most often in overweight middle-aged women and are usually asymptomatic; however, patients may have abdominal or chest discomfort (as in the current case) or dyspnea. Although the hernia usually develops slowly, increased symptoms have been associated with weight lifting or other types of straining.

Although considered to be a congenital abnormality, the foramen of Morgagni hernia is rarely diagnosed during the first years of life , and unlike other types of diaphragmatic hernias is only rarely associated with other congenital anomalies.

Some evidence has been presented of a possible association between the hernia of Morgagni and trisomy 21 .


(4th edition BDC vol 2 page no 312): it is more common on the right side & lies between the pericardium & the Rt pleura. Usually it causes no symptoms.

Category: AIIMS Nov 2006 MCQs