What is Cystostomy?

Cystostomy is a possible form of treatment for a cyst

A cyst is a cavity within the tissue which is enclosed by a small skin (epithelium), which usually is full of fluid or pulp and which may consist of several chambers.

"Cystostomy" means "opening the cyst", whereby the volume of the cyst is reduced.

In the picture you see a skull x-ray and, in the lower jaw, left, you can clearly see a swelling – a so-called follicular cyst. The cyst is too large to be removed as the lower jaw could be broken. The size of the cyst can also be made out from outside due to the deformed tissue.

A cystostomy will first be carried out. A hole will be drilled in the cyst and a drain – in this case, a tube – will be inserted which will communicate with the outside (in this case with the mouth cavity). In this way the cyst will get smaller and smaller over months – think of it as a balloon from which you let the air out bit by bit - when the cyst (the balloon) will have reached a certain size, the cystectomy can then take place. That means the removal of the cyst. More about it in the eponymous clip.

 The cyst has already been opened and in order that the opening doesn’t close a small plastic tube has been inserted - in the picture marked with the red arrow. The black lines are stitches that will be removed after a week. The tube remains in the mouth until the cyst becomes small enough to be completely removed safely along with the tube.

Apart from large cysts, cystostomy is also recommended when, for e.g. important anatomical structures that could be damaged by the removal of the cyst, that is to say the cystectomy, lie close to the cyst.

When the cyst has been reduced in size by opening it and it therefore no longer lies in immediate proximity to important anatomical structures the removal of the cyst may take place. The removal of large cysts generally involves a certain risk of problems with the healing of the wound since a large injury to the bone is caused by the removal of the cyst.

Immediately after the operation the bone injury usually bleeds profusely. Later, the blood dries and as a result, the blood clot shrinks. A large blood clot contracts more than a small scab. Indeed, it can pull itself together so much that it no longer has any contact with the walls of the wound anymore. It’s no longer possible for a blood vessel from the wall of the wound to grow into the coagulated blood, so the blood clot cannot be supplied with oxygen, nutrients and lastly with bone cells, which are necessary preconditions for bone regeneration.

Later, the coagulated blood decomposes – creating pus and leading to infection of the wound. In order to avoid this complication in the case of large cysts, it is usual to try and stabilize the coagulated blood and to reduce its contraction.

For example by filling the hole in the bone with a granulate made up of bone replacement material – as can be seen here. In this way a contraction of the clot is inhibited, blood vessels can grow in from the walls and the foundation has been laid for the subsequent regeneration of the bone.

The only alternative to the planned operation is the immediate removal of the cyst – that is to say the cystectomy. Left untreated cysts in the mouth, jaw or facial area will as a rule increase to a great size over the years and will thereby sooner or later cause the complications one would expect.

The operational risks are negligible when the surgeon is experienced. Nonetheless, there could be complications occasionally which could then possibly make further measures necessary. With every further necessary measure further complications, which could even be life-threatening, may once again crop up. We’re only going to mention the special complications particular to cystostomy and these are:

• Injury to surrounding structures such as nerves, cheeks, blood vessels, tooth roots, and teeth when affecting the opening with the relevant consequences
• incorrectly performed cystectomy on malignant masses which should simply be removed outright
• Infection of the cyst through the intervention
• in the case of deep-lying and/or many-chambered cysts, incorrect piercing of the cyst leading to further development of cysts as a result
• Blockage of the drain, leading to the necessity of a second operation
• 
  Loss of drainage, which may lead to the healing of the cyst and thereby to another operation being required

Fortunately, due to the improvement in medicine in the last decades, the likelihood of such complications happening is very slight.