The term “chemo wash” is the common name for Hyperthermic Intraperitoneal Chemotherapy (HIPEC). This specialized cancer treatment is designed to treat cancers that have spread to the peritoneum, the thin membrane lining the abdomen and covering the abdominal organs. HIPEC delivers high-dose chemotherapy directly to the disease site, minimizing the drug’s exposure to the rest of the body.
HIPEC is almost always performed immediately after Cytoreductive Surgery (CRS). The purpose of CRS is to remove all visible tumors, a process often called debulking, from the peritoneal cavity and involved organs. Surgeons must reduce the tumor burden significantly, as HIPEC is intended to eliminate only the microscopic cancer cells that remain.
The combined CRS and HIPEC approach is primarily indicated for patients whose cancers have metastasized to the peritoneum but remain confined to the abdominal cavity. Diseases treated include appendiceal cancer, colorectal cancer that has spread to the abdominal lining, and peritoneal mesothelioma. This combined therapy is also used for advanced ovarian cancer and some cases of gastric (stomach) cancer.
The Surgical Procedure
The HIPEC portion begins after the surgeon completes cytoreductive surgery and confirms all visible disease is removed. The abdominal cavity is prepared to receive the chemotherapy solution, often using a “closed-abdomen” technique where the incision is temporarily sealed. Specialized tubes, known as cannulas, are inserted into the abdominal space to serve as inflow and outflow ports for the solution.
A perfusion machine circulates a sterile fluid containing concentrated chemotherapy agents into the abdomen through these tubes. The solution is heated to a precise temperature, typically ranging between 41°C and 43°C (106°F to 109°F), before entering the body. Common chemotherapy drugs used include Mitomycin C, Oxaliplatin, and Cisplatin, chosen based on the specific cancer type.
The heated solution is circulated within the abdominal cavity for a standard duration, typically between 60 and 120 minutes, ensuring maximum exposure to residual cancer cells. The perfusion system continuously monitors and maintains the temperature and flow rate during this time. Once treatment is complete, the fluid is drained from the abdominal cavity before the surgeon closes the incision.
Why Heat Matters
The hyperthermia, or elevated temperature, is a fundamental aspect of HIPEC, providing two distinct therapeutic advantages. First, the heat is directly toxic to cancer cells, which are generally more sensitive to high temperatures than healthy cells. Tumor cells often have a less efficient blood supply, making it harder for them to dissipate heat and causing them to reach lethal temperatures quickly.
The second mechanism involves the heat creating a synergistic effect that enhances the effectiveness of the chemotherapy drugs. Elevated temperatures increase the ability of the agents to penetrate peritoneal tissues and reach microscopic tumor deposits. This enhanced uptake ensures the drugs are more potent against the residual disease.
Delivering the drugs directly into the abdominal cavity creates a high concentration gradient at the disease site. This localized approach allows for a substantially higher dose of chemotherapy than could be safely administered intravenously. Since the peritoneal-plasma barrier prevents most of the drug from entering the systemic bloodstream, the patient experiences reduced toxicity and fewer severe side effects compared to traditional intravenous chemotherapy.
Recovery and Outcomes
HIPEC combined with cytoreductive surgery is a highly invasive procedure, and recovery reflects the magnitude of the operation. Patients generally require extended hospitalization, often staying for 10 to 14 days following the surgery. It is common for patients to spend time in an intensive care unit immediately after the operation for close monitoring of organ function and fluid balance.
Immediate post-operative side effects include significant fatigue, nausea, and changes in bowel function as the gastrointestinal system recovers. Pain management is a major focus, and patients typically transition from intravenous nutrition to a soft diet as their digestive system returns to normal function.
The long-term outlook depends heavily on the type and extent of the original cancer and how completely all visible disease was removed. For highly selected patients, this aggressive treatment offers the potential for long-term survival, and sometimes a cure, for diseases previously considered terminal. Patients require ongoing monitoring with imaging and blood tests to check for recurrence, as HIPEC is part of a long-term cancer management strategy.