Pressurized Intra-Peritoneal Aerosol Chemotherapy (PIPAC) and Pressurized Intra-Thoracic Aerosol Chemotherapy (PITAC) are both innovative new techniques that deliver chemotherapy medications in the form of a pressurized mist that’s sprayed directly into the abdominal or chest cavity.[1] These minimally invasive procedures have introduced new treatment options for patients diagnosed with peritoneal or pleural mesothelioma who have run out of standard options.
What Are PIPAC and PITAC for Mesothelioma?
Traditionally, chemotherapy is administered either intravenously or orally. This approach circulates the medication systemically, throughout the entire body via the bloodstream. PIPAC and PITAC take a different approach, turning liquid chemotherapy drugs into a fine aerosol and delivering that aerosol directly into the affected body cavity during a minimally invasive, laparoscopic procedure.
During a PIPAC procedure, surgeons make two small incisions into the abdomen, each about the width of a finger. These incisions allow surgeons to insert a camera and a specialized multi-nozzle nebulizer, usually made up of a stainless steel wand and high-pressure tubing combined with an injector pump system.[2] Carbon dioxide is used to inflate the abdomen, creating space for the surgical team to work and helping the pressurized mist spread evenly across the thin tissue lining that peritoneal mesothelioma affects.[3]
The PITAC procedure was first introduced in 2012, adapted for patients with pleural mesothelioma or malignant pleural effusion, directly following the successful use of PIPAC for peritoneal mesothelioma.[4] It applies the same principle of using aerosol chemotherapy to the affected area, with incisions made to the chest cavity instead of the abdomen. Like PIPAC, PITAC is performed using minimally invasive, video-assisted thoracoscopic surgery (VATS) rather than open surgery. It can also be used for patients who are dealing with the fluid buildup around the lungs that is a typical effect of mesothelioma, known as pleural effusion.
Because the drugs are aerosolized under pressure rather than simply poured or infused as a liquid (as is the case with the HIPEC procedure), they penetrate more deeply into the affected tissue.[5] This means doctors can use lower overall doses of chemotherapy while still reaching cancer cells effectively, which helps limit the toxic side effects patients experience.
A Closer Look at PIPAC and PITAC for Mesothelioma
Is PIPAC the Same as HIPEC?
PIPAC and HIPEC both deliver chemotherapy directly into the abdominal cavity for the treatment of peritoneal mesothelioma, but they are not the same procedure.
HIPEC is a two-part procedure that begins with extensive cytoreductive surgery to physically remove all visible tumors. This is followed by delivery of a heated chemotherapy bath poured directly into the still-open surgical site. The chemotherapy drug is then circulated through the abdomen for roughly two hours, allowing it to kill any microscopic cancer cells left behind.
Where HIPEC is a complex and aggressive procedure, PIPAC does not require major surgery. Instead, it is performed laparoscopically, takes only about 30 minutes, and uses a much smaller dose of chemotherapy that is delivered as a pressurized aerosol rather than a heated liquid. This means that PIPAC is a viable option for those patients whose disease is deemed to be too widespread for surgery, as well as for those who are not strong enough to undergo the extensive physical impact that the HIPEC operation represents.
Additionally, PIPAC has the advantage of being able to be repeated multiple times, typically every four to six weeks. This allows doctors to monitor how the tumor responds to the treatment and to make adjustments over time.
What Happens During PIPAC Treatment for Mesothelioma?
PIPAC is performed under general anesthesia in an operating room, using a laparoscopic technique. The procedure generally follows these steps:[6]
- Two small surgical ports, or trocars, are placed through the abdominal wall.
- The abdomen is inflated with carbon dioxide gas to create a working space, and any fluid buildup (ascites) is drained and evaluated.
- A camera is inserted to allow the surgical team to examine the extent of the mesothelioma tumor tissue throughout the abdominal cavity, and samples may be taken for biopsy.
- A specialized nebulizer, connected to a high-pressure injector, is inserted through one of the ports and used to aerosolize the chemotherapy drugs directly into the abdominal cavity.
- The pressurized aerosol is left in place for about 30 minutes, allowing it to settle onto and penetrate tissue throughout the peritoneum.
- The nebulizer is then safely removed through a closed system before the ports are removed.
Most patients go home within a day or two of the procedure. This is a much shorter recovery than the seven-to-ten-day hospital stay typically required after HIPEC.
The two chemotherapy drugs most commonly used in PIPAC procedures for peritoneal mesothelioma are:[7]
Because the chemotherapy drugs are delivered locally rather than systemically, through the bloodstream, doctors are able to use a fraction of the dose used for intravenous chemotherapy while still achieving an effective concentration of the drug into the tumor tissue.
What Happens During PITAC Treatment for Mesothelioma?
The PITAC procedure is performed under general anesthesia using a laparoscopic technique. The procedure generally follows these steps:
- A special device called a double-lumen breathing tube, is inserted. This tube allows doctors to temporarily isolate the affected lung, only providing ventilation to the healthy lung during the procedure.[8]
- Two small trocars are placed between the ribs.
- Carbon dioxide gas is used to establish working space in the chest cavity and any fluid (pleural effusion) is drained and evaluated.
- A camera is inserted to allow the surgical team to examine the extent of the mesothelioma tumor tissue throughout the pleural cavity, and samples may be taken for biopsy.
- A specialized nebulizer, connected to a high-pressure injector, is inserted through one of the ports and used to aerosolize the chemotherapy drugs directly into the pleural cavity.
- The pressurized aerosol is left in place for about 30 minutes, allowing it to settle onto and penetrate tissue.
- The nebulizer is then safely removed through a closed system before the ports are removed.
As is true of PIPAC, most patients go home within a day or two of the procedure. The same two chemotherapy drugs, cisplatin and doxorubicin, are commonly used in PITAC procedures.
Beyond its ability to directly kill cancer cells, PITAC also has the practical benefit of helping control fluid buildup, offering mesothelioma patients relief from the shortness of breath and discomfort that pleural effusion brings.[9]
Do PIPAC and PITAC Improve Outcomes for Mesothelioma Patients?
PIPAC and PITAC are still emerging techniques, and most of the evidence that’s available so far has come from smaller studies and patient registries rather than from large randomized trials. Still, the early results are encouraging:
- One retrospective study followed 29 patients with recurrent malignant mesothelioma who underwent a combined total of 74 PIPAC and 5 PITAC procedures after previous surgery and standard chemotherapy had stopped working. Tumor regression was observed in about 75% of patients who received more than two PIPAC treatments, and median overall survival from the first procedure was 26.6 months.[7]
- That same study found that tumor regression became more pronounced with each additional PIPAC application, suggesting a cumulative benefit to repeated treatment.
- One case report described a patient with unresectable peritoneal mesothelioma who received 24 separate PIPAC procedures over seven years, achieving long-term disease control with no major surgical complications.[10]
- A separate study of 64 patients with various peritoneal cancers, including mesothelioma, found a severe complication rate of just 6.2%, and noted that patients who received more than one PIPAC session had improved survival compared to those who received only one.[11]
Researchers are continuing to study PIPAC and PITAC in clinical trials. One ongoing multicenter trial, known as MESOTIP, is specifically evaluating PIPAC combined with systemic chemotherapy against systemic chemotherapy alone as a first-line treatment for malignant peritoneal mesothelioma.[12]
Recovering from PIPAC and PITAC
Recovery from PIPAC and PITAC tends to be far shorter than recovery from HIPEC or other major cytoreductive surgery, since neither procedure involves extensive removal of tissue or a major incision. Many patients are sent home within one to two days, and normal side effects such as mild abdominal or chest discomfort typically resolve within a week or two.
Because the chemotherapy dose used in PIPAC and PITAC is much lower than what’s used intravenously, and because most of the drug stays localized rather than circulating through the bloodstream, patients generally experience fewer of the systemic side effects associated with traditional chemotherapy, such as significant nausea, hair loss, or profound fatigue.
Who Is Eligible for PIPAC or PITAC?
PIPAC and PITAC are most often considered for patients who:
- Have peritoneal or pleural mesothelioma that is too extensive to be treated with cytoreductive surgery and HIPEC, HITHOC (Hyperthermic Intrathoracic Chemotherapy), pleurectomy with decortication, or extrapleural pneumonectomy
- Have already tried standard chemotherapy without success, or cannot tolerate its side effects
- Have a reasonably good overall performance status, meaning they are strong enough to undergo anesthesia and a minimally invasive procedure
- Do not have cancer that has spread outside the abdominal or chest cavity, since PIPAC and PITAC are local, rather than whole-body, treatments
These procedures are still relatively new, and access can be limited to specialized cancer centers with experience in peritoneal surface malignancies. It’s worth asking your mesothelioma specialist whether a center near you offers PIPAC or PITAC, or whether a clinical trial might be available.
What Are the Benefits and Risks of PIPAC and PITAC?
The biggest advantage PIPAC and PITAC create is that they offer a targeted, repeatable, and relatively low-risk way to deliver chemotherapy directly to mesothelioma tumors, even in patients who are not candidates for more extensive surgery. Also, because these procedures are minimally invasive, hospital stays are shorter and patients tend to bounce back more quickly than they would after HIPEC or traditional open surgery. Still, long-term data is still limited compared to more established treatments.
Should You Consider PIPAC or PITAC for your Mesothelioma?
PIPAC and PITAC are not considered replacements for HIPEC or thoracic surgery when those options are available and appropriate. Instead, they represent a promising additional pathway for patients whose disease has progressed beyond what surgery can address, giving doctors another tool for extending survival and improving quality of life.
Research into both techniques is ongoing, and as more clinical trials are completed, PIPAC and PITAC may become more widely available to mesothelioma patients across the country.
If you or a loved one has been diagnosed with mesothelioma, speak with your medical team about whether PIPAC or PITAC could have a place in your treatment plan.
