Information on Commissurotomy

Commissurotomy definition

A commissure has two main definitions: 1) the corner of the eye, lip, or labia OR 2) a bundle of nerves that cross from one side of the brain to the other, such as left to right. Therefore a commonly used commissurotomy definition is the surgical division of any commissure. However, in modern medical and surgical practice, a commissurotomy has been expanded to include the disruption of any fibrous band or ring as well. In fact, one of the most common commissurotomy procedures is a mitral valve commissurotomy to treat a stenotic or fibrous heart valve.

 Commissurotomy for epilepsy treatment

Epilepsy is a disease in which the brain cells fire abnormally and excessively causing loss of consciousness and uncontrollable convulsions. While the source of the epileptic seizure is different across different patients, in a particular patient, the area in which the seizure begins each time is the same. One way to prevent or treat uncontrollable seizures (intractable epilepsy) is to perform a surgical commissurotomy. In this neurosurgery, the two halves of the brain and separated at the commmissure between the two hemispheres. This commissurotomy may include the anterior commissure and the corpus callosum.

Heart valve commissurotomy

When the mitral valve becomes stenotic, meaning it does not permit blood to cross it normally, the valve can be treated in a number of ways. While a balloon valvulotomy or even mitral valve replacement are possible treatments, in the United States, an open commissurotomy is the procedure of choice. In this open heart surgery, the heart surgeon can directly visualize the heart valve and remove only the damaged area of the valve. This has the advantage over a balloon valvuloplasty which simply breaks open the stenosis. A surgical commissurotomy is less likely to leave the valve leaky, called mitral valve insufficiency.

While a mitral valve commissurotomy is most common, any heart valve with stenosis could be the target of a commissurotomy procedure. Aortic and tricuspid valves are other common commissurotomy sites. Great care must be taken not to cause insufficiency of the aortic valve since this could compromise blood flow to the entire body.

Commissurotomy for microstomia

In rare instances, commissurotomy is done to repair microstomia, that is, a mouth that is too small to support eating and possibly even breathing. Microstomia present at birth is fairly rare but may occur as a consequence of facial burns. As the lips heal, the opening to the mouth is too small to be practical or functional. In a commissurotomy to treat microstomia, the corners of the mouth (commissures) are carefully cut apart. Care is taken to make the new opening a symmetrical and centered as possible. Since a simple cutting of the corners of the lips would not actually create new lips in that area, an attempt is made to stretch the lips at the cut edge toward the new commissure. This serves an aesthetic or cosmetic purpose of having pink lips all around the mouth, but it is also functional. The lips are much more sensitive than even the skin around it. Thus a goal in this surgical commissurotomy is to provide as much surface area to the lips as possible.