Intraperitoneal chemotherapy is a method wherein medications are administered directly into the abdominal cavity. A catheter is placed through the abdominal wall that drains into the abdominal cavity. It drains into the cavity that surrounds the organs, not into the stomach or other organs. Chemotherapy drugs are directly mixed into this cavity. The patient is asked to shift positions from one side to other to facilitate the movement of drugs across the tumor area. At times, the medication is drained out after a few hours while in some cases, it is left inside and gradually absorbed. This method allows the organs to be immersed in the medication and let the drug absorb into the tumor site. The logic behind this is that the tumor is exposed to higher concentrations of the drug without exposing the rest of the organs to the toxicity of the drugs. However, this method has been somewhat controversial because there was not much difference found in the IV method and this method as far as the end result and quality of life were concerned.

There are three ways to administer IP or intraperitoneal chemotherapy:

• Temporary single-use catheters are inserted through the abdominal wall and taken off after the treatment.

• Tenckhoff catheters are soft, flexible, silicone tubes with one or two dacron cuffs that are placed in a surgical procedure with the tip of the catheter placed near the tumor. They are placed into subcutaneous tissue and the end of the catheter is brought out of the abdomen by puncturing it. However, this could cause peritoneal infections or the catheter could be blocked.

• Port-a-cath is placed under the skin on the abdominal wall. The catheter has multiple holes that is inserted through the subcutaneous tissue into the peritoneum. This procedure takes around 1 hour and this device can be used for around 3-5 years. This can remain under the skin and medications are administered through the edges of the port with the help of a needle.

Properties of Perioperative Intraperitoneal Chemotherapy

Drugs used for intraperitoneal administration are hydrophilic with big molecules. Hence, they can pass easily through the peritoneal-plasma barrier and mix evenly in the peritoneal cavity.

A large peritoneal to plasma ratio is a part of the intraperitoneal chemotherapy as maximum concentration of the drug remains in the peritoneal cavity without increasing systemic toxicity.

Intraperitoneal chemotherapy could be administered either during the surgery after the surgery to shrink the tumor has been performed or in the early postoperative period. The drugs used for administering during the surgery should have some common properties- They should expand when heated as heat enhances the cytotoxic effects of certain drugs and it increases the penetration level of these drugs into the tumor cells. Heat itself exhausts the tumor cells.

The drugs must rapidly destroy the tumor immediately after they are administered. They should not depend on the cell division process.

The drugs that are administered during the early postoperative period are required to remain in the cells for a longer time to cause the toxic effects on the cancer cells.

Generally, their cytotoxic activity depends on the cell division process.

Usually, when drugs are administered postoperative, they remain in the form of a solution for about 23 hours. Then the solution is drained out one hour prior to the next administration. This process is repeated for 5 days after the surgery.

Intraperitoneal chemotherapy sounds more effective than intravenous chemotherapy. However, it has its own drawbacks including the risk of infection and ultimately the end result. This process had its own share of controversial debates. However, newer and more effective methods are under development as a part of the clinical research.