Angioplasty
In medicine, angioplasty is "endovascular reconstruction of an artery, which may include the removal of atheromatous plaque and/or the endothelial lining as well as simple dilatation. These are procedures performed by catheterization. Dilation is done by inflating a balloon at the distal end of the catheter. Removal of plaque by mechanical or laser techniques is called atherectomy.
When reconstruction of an artery is performed surgically, it is called endarterectomy."[1] Stents may help maintain the effects of angioplasty.
Indications
Angioplasty may be used to treat coronary heart disease, renal artery stenosis, and carotid stenosis. Angioplasty of the heart is called percutaneous transluminal coronary angioplasty.
Procedures
Most commonly, access is gained through the femoral artery in the groin; this is called the Judkins techniques. Other approaches include the radial artery in the wrist and the brachial artery in the shoulder. Local anesthesia is always used at the entry point, and the patient may be sedated. Additional intravenous lines are established to administer fluids and medication.
The procedure is usually performed in a dedicated angiography and catheterization suite, under aseptic technique comparable to an operating room. While there is less of a tendency than in the past to have a cardiovascular surgeon and operating room on standby, catastrophic events during the procedure may require transfer to a cardiothoracic surgical facility.
At the femoral and radial sites, it is usually possible to insert a guidewire catheter through a needle puncture, and then follow it with the larger catheter with the balloon or other procedural device. The brachial site usually needs a small incision for access.
As the blocked area is approached, radioopaque contrast media ("dye") is injected so the vessels may be visualized on a fluoroscope. The patient will often experience a localized or bodily flushing, which can be intense; some patients have laughed and said it was the first time in their lives they truly experienced "heartburn". Patients also may sense a metallic taste from the iodine in the contrast agent. Reactions to contrast agents are a concern, although the use of low-ionic variants have reduced them. Still, part of the premedication includes an antihistamine such as diphenhydramine.
Percutaneous transluminal coronary angioplasty
When the catheter reaches the proximal end of the partial or full occlusion, the balloon is inflated to press the material into the arterial wall. Especially if the occlusion has been partial, the patient may experience ischemic pain from the full block of the artery. This pain can be severe, and may be managed with a short-acting intravenous analgesic such as fentanyl, as well as a vasodilator such as nitroglycerin.
Effectiveness
As compared to surgery:
- Angioplasty is probably better than surgery for renal artery stenosis. Surgery leads to improved patency rates at 4 years (88% versus 68%); however, angioplasty improves renal function and tends to have less mortality after 4 years (18% vs 25%).[2]
- Angioplasty is less effective than surgery for myocardial revascularization of coronary heart disease[3], especially for patients with diabetes who have stenosis of three coronary arteries.[4] Angioplasty did not include stents in this study.
- For carotid stenosis, angioplasty with stents have less short term effect, but similar intermediate term effect as carotid endarterectomy.[5]
References
- ↑ Anonymous (2024), Angioplasty (English). Medical Subject Headings. U.S. National Library of Medicine.
- ↑ Balzer KM, Pfeiffer T, Rossbach S, et al (March 2009). "Prospective randomized trial of operative vs interventional treatment for renal artery ostial occlusive disease (RAOOD)". J. Vasc. Surg. 49 (3): 667–74; discussion 674–5. DOI:10.1016/j.jvs.2008.10.006. PMID 19135837. Research Blogging.
- ↑ Bravata DM, Gienger AL, McDonald KM, et al (2007). "Systematic Review: The Comparative Effectiveness of Percutaneous Coronary Interventions and Coronary Artery Bypass Surgery". Ann Intern Med. PMID 17938385. [e]
- ↑ (July 1996) "Comparison of coronary bypass surgery with angioplasty in patients with multivessel disease. The Bypass Angioplasty Revascularization Investigation (BARI) Investigators". N. Engl. J. Med. 335 (4): 217–25. PMID 8657237. [e]
- ↑ Meier P, Knapp G, Tamhane U, Chaturvedi S, Gurm HS (2010). "Short term and intermediate term comparison of endarterectomy versus stenting for carotid artery stenosis: systematic review and meta-analysis of randomised controlled clinical trials.". BMJ 340: c467. DOI:10.1136/bmj.c467. PMID 20154049. Research Blogging.