Hepatic Artery Infusion pumps in patients with colorectal cancer with liver metastases
22 December 2020
Hepatic Artery Infusion (HAI) chemotherapy is sometimes used as adjuvant treatment (treatment that accompanies the primary treatment to increase its effectiveness) in combination with systemic chemotherapy for the treatment of colorectal liver metastases.
Hepatic Artery Infusion (HAI) involves the continuous infusion of chemotherapy drugs directly into the liver from a pump that is inserted just below the skin. A catheter leaves the pump and is surgically connected to a branch of the hepatic artery.
In colorectal cancer (CRC), the liver is the most common site of metastases. About 50% of patients with CRC develop liver metastases in the course of their disease, and surgical resection remains the only treatment that offers a chance of cure and long-term survival (Chow, 2019). Only a minority of patients, however, is eligible for upfront surgery. HAI can be used in combination with systemic chemotherapy in the following instances:
· Among most patients who have liver metastases that are considered inoperable, HAI can reduce tumour size and increase the likelihood of surgical removal of liver metastases – about a third of patients so treated will become eligible for surgery;
· Among patients with operable liver tumours, HAI can be used to reduce the chance of tumour recurrence.
A recent retrospective study showed that adjuvant HAI offered an increased overall survival, better response rates to treatment, and improved physical functioning compared to systemic chemotherapy alone (Kemeny, 2017).
The HAI pump takes advantage of the fact that liver metastases receive their blood supply from the artery that feeds the liver – the hepatic artery. While the liver receives blood flow from two different sources, one third from the hepatic artery and two thirds from the portal vein, CRC liver metastases receive blood exclusively from the hepatic artery. Beginning in the 1970s, chemotherapy was directly infused into the liver via the hepatic artery, allowing for higher concentrations of chemotherapy to be administered directly to the liver without causing high levels of toxicity to the rest of the body. Ongoing studies continue to examine the survival outcomes of HAI and any additional benefits it may offer in comparison to systemic chemotherapy. Despite the dramatic responses that HAI can offer, it remains a highly specialized technique that requires unique expertise, limiting its use to specific centres only. Take home message: Hepatic arterial infusion (HAI) is a treatment option for patients with colorectal cancer liver metastases that allows for a higher concentration of chemotherapy to be directly administered to the liver without causing high levels of toxicity to the rest of the body. HAI may be used to prevent tumour recurrence in the liver after surgery, or to help shrink liver metastases to increase the chances that they can be surgically removed.
Chow, F and Chok, K. Colorectal liver metastases: An update on multidisciplinary approach. World J Hepatol. 2019 Feb 27; 11(2): 150-172. Published online 2019 Feb 27. doi: 10.4254/wjh.v11.i2.150
Kemeny, N. et al. Updated long-term survival for patients with metastatic colorectal cancer treated with liver resection followed by hepatic arterial infusion and systemic chemotherapy. J Surg Oncol. Author manuscript; available 2017 Apr 1. doi: 10.1002/jso.24189