Intra-arterial techniques

All of the percutaneous techniques are limited by the size and number of the lesions (up to three lesions each measuring up to 4 cm) as well as their location. Subdiaphragmatic lesions may be percutaneously inaccessible, and lesions close to large vascular structures respond poorly to thermal ablation techniques (RFA, MCT, Cryo, and LIPC). On the contrary, intra-arterial techniques are not limited by the number, size, or location of the lesions rather by the hepatic function reserve, as shown in Table 10.2. TACE, trans-arterial chemo-embolization TARE, trans-arterial radio-embolization MCT, microwave coagulation therapy RFA, radio frequency ablation LIPC, laser interstitial photocoagulation Cryo, cryo-ablation PEI, percutaneous ethanol injection PAAI, percutaneous acetic acid injection PCI, percutaneous chemotherapy injection... 

Local intra-arterial thrombolysis (lAT) has several theoretical advantages over IV thrombolysis. For instance, by using coaxial microcatheter techniques, the occluded intracranial vessel is directly accessible and the fibrinolytic agent can be infused directly into the thrombus. This permits a smaller dose of fibrinolytic agent to reach a higher local concentration than that reached by systemic infusion, and ideally it allows for more complete recanalization with lower total doses of thrombolytic. With the smaller dose, complications from systemic fibrinolytic effects, including ICH, can theoretically be reduced. 

Instead of inducing spasm, another recently described technique that may not require super-selective catheterization is intra-arterial platelet infusion. This has been described in a few cases where bleeding was too diffuse to allow safe embolization [24]. In one LGI case, diffuse colonic bleeding was terminated by infusing 4 units of platelets into the proximal SMA. Presumably infusing platelets, which are normally present in the blood, should carry little risk of causing ischemia but both the safety and efficacy of this technique needs to be validated in larger series. 

Kaplan WD et al. (1978) Intra-arterial radionuclide infusion a new technique to assess chemotherapy perfusion patterns. Cancer Treat Rep 62 699-703... 

Byrne JV. Colominas C, Hipwell J, et al. (2004) Assessment of a technique for 2D-3D registration of cerebral intra-arterial angiography. Br J Radiol 77 123-128... 

In some centers, intra-arterial DSA is or has been used for identifying and visualizing spinal arteries, especially the AKA. However, this semi-invasive technique may... 

Peripheral CTA has matured into an accurate, noninva-sive vascular imaging technique in patients with PAOD. Peripheral CTA can safely replace intra-arterial angiography as a fist-line diagnostic test in patients with intermittent claudication (Kock et al. 2005 OUWENDIJK et al. 2005 Heijenbrok-Kal et al. 2007), and may also... 

Edwards AJ, Wells IP, Roobottom CA (2005) Multidetector row CT angiography of the lower limb arteries a prospective comparison of volume-rendered techniques and intra-arterial digital subtraction angiography. Clin Radiol... 

Pharmacokinetic Principles 33 Dose-Response Relationship 34 Intraperitoneal Application 34 Intra-arterial Application 34 Isolated Perfusion Techniques Application Techniques 35 Intracavitary Application 35 Intra-arterial Infusion 36 Regional Perfusion Techniques Stop-Flow Perfusions 36 Isolated Extremity Perfusion (ILP) 37 Hyperthermic Peritoneal Perfusion (HIPEC) 38 Clinical Indications 38 Pancreas Carcinoma 38 Bronchial Carcinoma 39 Extremity Sarcoma 40 Peritoneum 41 Surgical Technique 41 Rationale 42 Clinical Results 43 References 44 Further Reading 45... 

In practice, despite its promising concept of design, TACE has not shown yet to be as effective and potent as in theory. Several challenging obstacles that have not been exceeded yet include chemotherapeutic dose-limiting toxicity, development of mechanisms for drug resistance and tumor revascularization. Moreover, the techniques and agents used for intra-arterial treatment of primary and metastatic liver cancer are very heterogeneous. This hinders a more systematic approach and interpretation of the results of clinical trials as well as implementation of meta-analyses. 

Intra-arterial embolization has resulted in a helpful and reliable technique in preparation for surgery, and currently is the preferred combined treatment. This procedure, when performed by an experienced team carries no significant morbidity or mortality. Reported complications or unsatisfactory results are likely related to insufficient training or knowledge or poor judgment during the procedure itself. 

Despite these encouraging preliminary results, there are no reports showing that RF ablation, performed alone or in combination with intra-arterial procedures, results in improved survival in patients with intermediate stage HCC. A randomized trial comparing an optimized RF technology with chemoembolization would be needed to establish the potential role of the technique in this patient population. 

Often the PGs formed in a perfused organ or tissue can be identified by directing the perfusate over a cascade of superfused assay tissues (6). The technique gains specificity by careful selection of the assay tissues and by addition of a mixture of antagonists (see 7) to other biologically active components (e.g. adrenaline, 5-HT, histamine). Indomethacin is also added to prevent intra-mural conversion to PGs by the assay tissues. For example, a combination of strips of bovine coronary artery (BCA), rabbit aorta (RbA), rabbit coeliac artery (RbCa), rat stomach (RS) and rat colon (RC) can be used to differentiate between most PGs and thromboxanes (see 2). 

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