As of 2005, multiple trials show objective tumor responses and slowed tumor progression, but questionable survival benefit compared to supportive care; greatest benefit is seen in people with preserved liver function, absence of vascular invasion, and smallest tumors. TACE is not suitable for big tumors (>8 cm), the presence of portal vein thrombus, tumors with a portal-systemic shunt, and patients with poor liver function. Selective internal radiation therapy (SIRT) can be used to destroy the tumor from within (thus minimizing exposure to healthy tissue). Similar to TACE, this is a procedure in which an interventional radiologist selectively injects the artery or arteries supplying the tumor with a chemotherapeutic agent. The agent is typically Yttrium-90 (Y-90) incorporated into embolic microspheres that lodge in the tumor vasculature, causing ischemia and delivering their radiation dose directly to the lesion. This technique allows for a higher, local dose of radiation to be delivered directly to the tumor while sparing normal healthy tissue. While not curative, patients have increased survival. No studies have been done to compare whether SIRT is superior to TACE in terms of survival outcomes, although retrospective studies suggest similar efficacy. Two products are available, SIR-Spheres and TheraSphere. The latter is an FDA-approved treatment for primary liver cancer (HCC) which has been shown in clinical trials to increase the survival rate of low-risk patients. SIR-Spheres are FDA-approved for the treatment of metastatic colorectal cancer, but outside the US, SIR-Spheres are approved for the treatment of any nonresectable liver cancer including primary liver cancer.
The initial reduction to a diastolic pressure of approximately 100 mmHg is often associated with a modest worsening of renal function; this change, however, is typically transient as the vascular disease tends to resolve and renal perfusion improves over one to three months. Antihypertensive therapy should not be withheld in this setting unless there has been an excessive reduction in BP. A change in medication, however, is indicated if the decline in renal function is temporally related to therapy with an angiotensin (ACE) converting enzyme inhibitor or angiotensin II receptor blocker, which can interfere with renal autoregulation and produce acute kidney failure in patients with bilateral renal artery stenosis. (See "Renal effects of ACE inhibitors in hypertension". )ref
Several parenteral antihypertensive agents are most often used in the initial treatment of malignant hypertension. Nitroprusside – an arteriolar and venous dilator, given as an intravenous infusion. Nitroprusside acts within seconds and has a duration of action of only two to five minutes. Thus, hypotension can be easily reversed by temporarily discontinuing the infusion, providing an advantage over the drugs listed below. However, the potential for cyanide toxicity limits the prolonged use of nitroprusside, particularly in patients with chronic kidney disease. Nicardipine – an arteriolar dilator, given as an intravenous infusion. Clevidipine – a short-acting dihydropyridine calcium channel blocker. It reduces blood pressure without affecting cardiac filling pressures or causing reflex tachycardia. Labetalol – an alpha- and beta-adrenergic blocker, given as an intravenous bolus or infusion. Bolus followed by infusion.