Principle

Cancer Microvessel Intervention (CMI) is a targeted therapy technique based on the structural differences between tumor blood vessels and normal blood vessels. The core principles include:

1. Vascular structural differences: Tumor capillary endothelial cells have wider gaps between them (approximately 100–600 nanometers), whereas normal blood vessels have tightly connected endothelial cells (only 2–6 nanometers). By interventional techniques, micron-sized chemotherapy drug particles (usually 1–50 micrometers) are injected into the tumor-feeding arteries. These particles selectively penetrate the tumor tissue interstitium through the gaps in tumor vessels, while normal vessels block penetration due to smaller pore sizes.

2. Drug retention mechanism: Drug particles accumulate within the tumor tissue, increasing local osmotic pressure, compressing and selectively occluding tumor capillaries, thereby prolonging drug retention time (from hours to days). Particles entering normal vessels are too small and are metabolized and cleared by the bloodstream, reducing systemic toxicity.

3. Enhanced efficacy: Local drug concentrations can reach over 40 times that of systemic chemotherapy. For example, when using oxaliplatin, CMI requires only one-tenth of the standard dose to achieve higher intratumoral concentration, significantly enhancing cytotoxic effects.

Trans Arterial Pump Irrigation Chemotherapy (TAPIC)

A New Targeted Interventional Chemotherapy Model for Tumors

It is well known that interventional chemotherapy is one of the important methods for cancer treatment; however, chemotherapy drugs not only kill cancer cells but also damage normal tissue cells, causing varying degrees of complications.

The emergence of microcatheter-directed drug injection and drug-eluting microspheres has partially addressed these shortcomings; however, the use of microcatheters and drug-loaded microspheres increases treatment costs, making the therapy relatively expensive and becoming a barrier for many patients.

Our interventional team consists of China’s first-generation cancer interventional therapy experts. Over more than 30 years of interventional medicine practice, they have creatively proposed Trans Arterial Pump Irrigation Chemotherapy (TAPIC), a continuous arterial pump infusion chemotherapy via arterial catheter. This concept and technology have been applied to various solid tumors, achieving higher efficacy, fewer side effects, and a more affordable new interventional chemotherapy model.

The application of TAPIC therapy has achieved satisfactory clinical efficacy. Compared with traditional interventional therapies, this method shows better efficacy against almost all solid tumors, including common lung cancer, breast cancer, colorectal cancer, gastric cancer, liver cancer, gallbladder cancer, pancreatic cancer, ovarian and cervical cancers, nasopharyngeal and head & neck tumors, lymphoma, and soft tissue sarcomas of the limbs.

Treatment Procedure

The implementation of CMI requires image-guided minimally invasive interventional techniques, with the main steps including:

1. Preoperative evaluation and planning: Precisely locate the tumor and assess the distribution of feeding arteries using CT, MRI, or DSA (Digital Subtraction Angiography), and design a super-selective catheterization pathway.

2. Drug preparation: Chemotherapeutic drugs (such as oxaliplatin, paclitaxel) are combined with carriers to form micron-sized particles, ensuring they can pass through tumor vascular gaps but cannot penetrate normal blood vessels.

3. Interventional procedure:

  (1) Puncture and catheterization: Under local anesthesia, puncture the femoral or radial artery and super-selectively insert a microcatheter into the tumor-feeding artery.

  (2) Drug infusion: Inject drug particles under real-time imaging monitoring, observing changes in tumor vessel staining (such as vessel occlusion and disappearance of tumor staining) to confirm efficacy.

4. Postoperative observation: Patients can be discharged 3–4 hours after the procedure without the need for prolonged hospitalization. Tumor shrinkage or necrosis is evaluated through follow-up imaging (such as contrast-enhanced CT or MRI).

Advantages

Compared with traditional chemotherapy and conventional interventional treatments, CMI has significant advantages:

1. Precise targeting and high efficacy: Drugs act directly on tumor tissue with high local concentration and strong cytotoxicity, while systemic side effects are minimal. For example, in patients with liver metastases, tumor vessel staining rapidly disappears and tumor volume shrinks after treatment.

2. Minimally invasive and safe: Only a small puncture is required, avoiding major surgeries such as thoracotomy or laparotomy, making it especially suitable for elderly patients, those with poor cardiopulmonary function, or coagulation disorders.

3. Repeatability: Multiple treatments can be performed without significantly impacting the patient's quality of life, suitable for recurrent or metastatic tumors.

4. Synergistic treatment potential: When combined with radiotherapy, immunotherapy (such as PD-1 inhibitors), or targeted drugs, comprehensive efficacy is enhanced. For example, tumor antigens released after CMI can activate systemic immune responses.

5. Rapid onset: Tumor vessel occlusion can be observed intraoperatively through imaging, and tumor lesions significantly shrink or disappear within 1–3 months after treatment.

Indications

CMI is mainly applicable in the following clinical scenarios:

1. Types of solid tumors: Including liver cancer, lung cancer, breast cancer (primary or metastatic), colorectal cancer, pancreatic cancer, etc., with particularly significant efficacy for highly vascularized tumors ≤5 cm in diameter.

2. Refractory cases: Patients who are unresponsive to conventional chemotherapy, radiotherapy, or traditional interventional treatments (such as TACE) may still benefit from CMI.

3. Palliative care needs: Used for tumor debulking in mid-to-late stages to relieve pain (such as bone metastases), prolong survival, and improve quality of life.

4. Neoadjuvant therapy: Shrinking tumor volume to facilitate subsequent surgical resection or ablation. For example, breast cancer lesions may shrink after CMI, allowing for breast-conserving surgery.

5. Special populations: Elderly patients, those with multiple comorbidities (such as hypertension, diabetes), or those unable to tolerate systemic chemotherapy may prefer CMI due to its minimally invasive nature and low toxicity.