Adhesion Prevention and Removal
Doctor Bruce G Downing ( Royal Australian College of Obstetrics and Gynaecology & C.R.E.I.) has written this paper on the surgical aspects of adhesions.
Adhesions are a scourge that can create pain and reduce the normal functioning of affected areas. Adhesions are tissues that join two surfaces that normally have no permanent contact with each other. They may be seen in two forms:
* As dense adhesions where two surfaces, usually over an area of one square centimetre or more, are directly and densely stuck to each other so that it is difficult to separate them without breaking into the tissue that underlies either of the surfaces.
* As filmy or cobweb adhesions which in the extreme may envelope organs as though they were wrapped in Gladwrap so that they are still able to move in relation to each other.
CAUSES
The development of adhesions involves damage to one or both of the surfaces that become adherent to each other. Alternatively, a process that involves blood clots may occur on the surface of the peritoneum (ie the membranous tissue that covers the abdominal and pelvic organs). This process creates a mesh on which adhesions develop.
SURGERY TO REDUCE ADHESIONS
Any process designed to reduce the development of adhesions does so by reducing damage to the peritoneum and the surfaces of the abdominal and pelvic organs. Alternatively, it may work by reducing the likelihood of blood clots forming on the peritoneum.
The main aims of surgery to reduce the development of adhesions are to minimise damage by gently handling the organs and tissues and keeping them moist, and minimising the amount of blood left lying on the peritoneum covering the internal organs.
Minimising damage to the peritoneum invloves using micro-surgical techniques when operating. For example, using special non abrasive instruments to move the organs around in the pelvis. The finer the instruments used the less damage is caused to the tissue and fine instruments are preferred as a result. Ensuring the tissues are kept moist throughout the operation is vital to prevent them from drying out and becoming damaged. It is very important that the fluid used to keep them moist is of a similar composition to the normal body fluids so that the fluid itself does not cause damage. The fluid should also be at body temperature when used.
Not leaving blood in the abdomen is vital as blood clots when formed will stick to the surrounding tissues. By keeping the tissues moist the blood does not stick as readily to the peritoneum covering the organs. In addition, the fluid used to keep the tissue moist dilutes the blood making it less likely to form clots. The fluid can also have a substance known as heparin added to it which further reduces the likelihood of blood clots forming.
In some women it is impossible to prevent adhesions developing as their body has an unusual reaction to injury and adhesions form readily even when all these measures are used.
Infection is another cause of adhesions, as are chemical irritants such as bile, a substance produced by the gall bladder. Infectious organisms may penetrate through the bowel wall causing adhesions. They may also enter the pelvic cavity through the cervix, uterus and tubes and cause adhesions in the pelvic area.
ANTI-ADHESION PRODUCTS
At the end of an operation placing fluid in the pelvic cavity and encouraging the woman to move amy be enough to keep the internal tissues and organs moving around and reduce the likelihood of them sticking together. Chemicals have been tried but thay have not been effective.
Interceed is a product that is used to reduce the likelihood of adhesions developing. It is a cloth-like material that can be wrapped over areas of damaged peritoneum and the underlying organs to reduce the risk of adhesions in the area. The Interceed is laid over the raw areas when surgery has been finished and it is absorbed over the next 10-14 days, during which time the peritoneum has the opportunity to heal itself, thus reducing the risk of adhesions.
Interceed has been shown to be effective, particularly for surgery on the ovary. Three studies with a total of 363 patients showed that there were nearly 50% fewer adhesions when Interceed was used. Another study that involved 483 patients found that there were 25% less adhesions when Interceed was used.
Certainly Interceed is not a guarantee but it is better than not using it. The situations under which it can be used and the way it is applied vary. However, any bleeding whatsoever will prevent its effective use.
Intergel is a new product that is being developed. It is an adhesion prevention solution used in conjunction with a second-look laparoscopy 6-12 weeks after a laparotomy. Early studies suggest that it is effective. It will not be available in Australia until further tests are conducted and it is approved by the government.
A third method of preventing adhesions is to permanently sew a silastic sheet in the area where adhesions are likely to develop. However, in the pelvic cavity the sheet is difficult to use without getting irregularities in its surface because the organs are so small.
REMOVAL OF ADHESIONS
Once adhesions are formed they are best left alone unless they are disturbing the normal function of any organs or they are causing pain. Many adhesions can remain without causing any problems, particularly around the bowel.
When adhesions over a larger area are separated they leave a large raw area which predisposes the woman to developing further adhesions. Tissues that have been stuck in an abnormal place are less likely to reform adhesions as they will usually return to their normal position when the adhesions have been removed.
Fine filmy adhesions are more common and they are more easily removed as they usually have only a very small area of contact with the underlying organ or tissue. It is best to remove the adhesion so that it does not continue to move around the pelvic cavity like seaweed and possibly re-attach at another location leading to further problems.
Although a surgeon will do their best to remove all existing adhesions there is no guarantee that all the adhesions will be removed. Removing adhesions is best dealt with laparoscopically as the incisions into the pelvic cavity are small and therefore there is less chance of new adhesions developing. Whenever adhesions are being removed - unless they have been caused by an infection - there is a risk of developing further adhesions as that woman's chemistry may be different to that of people who do not develop adhesions. Therefore, sometimes surgery is not recommended for these women.
CONCLUSION
Adhesions are one of the biggest problems associated with surgery and every precaution should be taken to minimise their likelihood of developing.
Dr. Bruce G Downing
Royal Australian College of Obstetrics and Gynaecology. / C.R.E.I