The subcutaneous injection chamber technique is used for cancer patients at risk of extravasation during chemotherapy, reducing the risk of skin necrosis and limiting drug side effects.
On May 10, Doctor II Luu Kinh Khuong, Head of the Department of Anesthesiology and Resuscitation, Tam Anh General Hospital, Ho Chi Minh City, said that chemotherapy drugs used in cancer treatment are all used through an external intravenous line. vi (veins in front of the elbow, facial veins on the hands, inguinal veins…). This method of transmitting chemotherapy drugs often causes damage to peripheral blood vessels, fibrovascular inflammation, and also has the risk of extravasation of chemotherapy drugs due to vein deviation. The patient has limited movement in the limb area where the chemotherapy drug infusion vein is placed.
Extravasation due to chemotherapy is the most common complication when injecting drugs into peripheral veins, which can cause irritation, ulcers, and skin necrosis, according to Dr. Khuong. Some severe cases require surgical excision, shaping and skin grafting. The extent of damage depends on the type of chemotherapy drug, its concentration, the location of extravasation, and the amount of time the drug penetrates into surrounding tissue.
Extravasation due to chemotherapy is common in elderly patients due to weak vessel walls, obesity, edema or skin lesions. Cancer patients who have problems with blood vessel damage, use antiplatelet drugs, corticosteroids or have mental disorders (agitation, confusion…) are also susceptible to this condition.
At Tam Anh General Hospital in Ho Chi Minh City, doctors often place a device called a subcutaneous injection chamber for patients at risk of extravasation due to chemotherapy. This device is placed under the skin of the chest wall to support intravenous drug and nutrition infusion. It is shaped like a blouse button, made mostly of titanium material, including the injection chamber port and catheter. The self-healing silicone injection port can withstand 1,000-2,000 needle punctures. The heart’s chambers have a hard, sturdy structure, helping to protect patients from the side effects of chemotherapy drugs.
Dr. Nguyen Chi Thanh, Department of Oncology, said that thanks to the support of the injection chamber, chemotherapy drugs are transmitted to where they are needed without worrying about complications like when transmitting drugs in peripheral veins. Placing this device is also convenient when taking blood for testing, giving fluids, giving nutrition… to cancer patients.
Doctor Khuong (right) surgically places an injection chamber for a patient. Image: Tam Anh General Hospital
As one of the patients who had a subcutaneous injection chamber placed, Ms. Tuyet, 63 years old, said that since using this device, her life has become more convenient. She had lymphoma, non-Hodgkin’s Lymphoma, and was treated with chemotherapy. If chemotherapy drugs are infused through a peripheral vein, there is a risk of the chemotherapy drugs escaping into the blood vessels. Patients receiving peripheral intravenous drug infusion have limited movement in the limb area where the vein is placed. The doctor placed the injection chamber under the skin for her to avoid the above limitations.
According to Dr. Thanh, patients can feel the device when touching it through the skin and can hardly see it. Most people do not know the patient using this device, ensuring aesthetics. After the first round of chemotherapy, Ms. Tuyet’s leg edema decreased by about 50%, and her cervical and abdominal lymph nodes decreased in size. After the second round of chemotherapy, ultrasound results showed that all lymph nodes on the body had decreased in size by about 80%, including completely dissolved (responsive) lymph nodes.
According to the protocol, she needs 4 more cycles of chemotherapy to complete the treatment process. “The patient’s subcutaneous injection chamber is kept for many years so subsequent chemotherapy drug infusions are still safe,” said Dr. Thanh.
Similarly, Ms. Thao, 49 years old, living in Kien Giang, had breast cancer, had mastectomy and reconstruction surgery, then received 16 cycles of chemotherapy to control the disease and prevent the risk of recurrence. Thanks to the injection chamber and 10 rounds of chemotherapy, she did not have needles or veins probed many times, her blood vessels were still normal, and her skin was not bruised or irritated.
The injection chamber is also used to take blood for testing, administer fluids, administer drugs, and administer nutrition to patients who cannot eat or drink by mouth.
Titanium injection chambers are used under the skin for cancer patients. Image: Tam Anh General Hospital
Under the guidance of an ultrasound machine, the doctor places a catheter into the patient’s central vein (either through the internal jugular vein in the neck or the subclavian vein below the collarbone). The doctor makes an incision about 2-3 cm long in the chest area, 2-3 cm below the collarbone to bury the injection chamber.
Operational steps: First, the doctor places the injection chamber port into the opening in the chest wall area. Then, create a tunnel to insert the catheter under the skin toward the base of the neck or subclavian into one of the main blood vessels in the chest (superior vena cava). The device is sutured to the fascia for stability. The incision is sterilely glued or sutured, then bandaged to prevent infection.
The entire procedure takes about 30-45 minutes. Patients have stitches removed after 7-10 days. When chemotherapy is needed or blood is taken for testing, the nurse uses a needle to go through the skin into the port of the injection chamber. Chemotherapy drugs or fluids flow through the needle, into the port and then through the catheter directly into the bloodstream.
After placing the injection chamber, the patient may have slight redness in the incision and mild pain. This is normal and symptoms subside after 24-48 hours. In case of other abnormalities, the patient should go to the hospital to consult a doctor.
Within 3-5 days after device placement, patients should avoid lifting heavy objects (more than 5 kg) or doing vigorous sports; Avoid wearing a bra that is too tight to avoid putting pressure on the injection chamber. Once the device is placed and the incision has healed, the patient can return to daily activities.
The injection chamber is located completely under the skin, so no special care is needed for the skin above. Patients can wash this skin area normally like washing another skin area on the body. The time to use titanium is usually quite long, 1-2 years; While the previous plastic type only lasted 6-12 months.
Doctors recommend that patients take out this device when they no longer need to use it because the structure of the injection chamber has a catheter. If left for a long time, there is a risk of it easily breaking and falling into the heart, making it difficult to remove from the body later. In case the injection chamber has been removed, if the patient needs to use it, a new injection chamber can still be placed.