Wednesday, December 3, 2008

EVAR pertama di Angio Suite

Definition of EVAR
EVAR: Endovascular aneurysm repair. Satu prosedur merawat aneurisma aorta. Satu 'stent' ditempatkan dalam kawasan aneurisma. Prosedur ini adalah sama dengan menempatkan 'stent' dalam arteri koronari.
Aneurisma aorta adalah bengkak atau pelebaran aorta, arteri terbesar dalam tubuh manusia. Aneurisma ini melemahkan dinding aorta dan akhirnya berupaya untuk mengoyak aorta. Kebarangkalian untuk aorta koyak semakin tinggi sekiranya lebar aneurisma bertambah. Aneurisma yang besar adalah sangat berbahaya disamping ianya senyap tanpa simpton atau kurang simpton. Kejadian aneurisma lebih tertumpu kepada pesakit yang berumur 60 tahun ke atas.
EVAR is done percutaneously (through the skin). It usually involves two small incisions made in the groin to expose the femoral arteries. A synthetic graft and stents are fed through these arteries with catheters and guidewires until the graft is positioned correctly at the top and bottom of the defective portion of the aorta. Removal of the sheath with or without balloon expansion allows barbs or other fixing devices to attach to the artery wall and hold the graft firmly in place, allowing blood to pass through it and remove pressure from the weakened aortic wall.
Before the introduction of EVAR, aortic aneurysms were treated by open surgical repair, a major operation done under general anesthesia. It requires a laparotomy (an incision to open the abdomen) and clamping of the aorta (to shut off blood flow in it) for at least a half hour. Open surgical repair of an aortic aneurysm carries a 30-day mortality (death rate) of between 4 and 12%. However, the grafts are durable for 20-30 years and function effectively in most patients for the rest of their lives.
EVAR was invented in the early 1990s by surgeons in the Ukraine and Argentina as a less invasive endovascular method of repair of an abdominal aortic aneurysm (AAA). Improvement of the devices and development of the technology led EVAR to be used worldwide.
With large AAAs, EVAR reduces the 30-day operative mortality by two-thirds compared with open surgery. Thus, EVAR is superior in terms of saving lives. However, there is a tradeoff because a further procedure is more often needed after EVAR than after open surgery.

EVAR Offers Better Results Than Open Repair In High Risk Patients

Endovascular aneurysm repair (EVAR) yields better results than open surgical repair (OSR) in high risk patients with similar costs, according to a one-year trial study which appears in the October issue of the Journal of Vascular Surgery, published by the Society for Vascular Surgery.

Data was collected from 342 patients who had an abdominal aortic aneurysm (AAA) of more than 5.5 centimeters and required elective AAA repair at London Health Sciences Center (LHSC), London, Ontario, Canada, where EVAR has been used since 1997. Of the 192 patients at a high risk of postoperative complications, 140 received EVAR and 52 had OSR.

In this one-year non-randomized prospective study, demographic, medical, health care resource utilization, cost and quality of life data were collected to determine incremental costs and effects associated with each of these procedures. Sensitivity analyses were conducted to extrapolate the one-year mortality results to a five-year time horizon under various assumptions regarding convergence of mortality rates and re-intervention rates (for EVAR patients only).

"Even with similar baseline characteristics, postoperative complications occurred more frequently in OSR patients at a high-risk of surgical complications," said Dr. Guy De Rose, MD, medical director of surgical care at LHSC and an associate professor of surgery from the division of vascular surgery at the University of Western Ontario in London, Ontario, Canada. "The 30-day mortality rates were 0.7 percent for EVAR and 9.6 percent for OSR and significantly fewer EVAR patients had postoperative complications such as pulmonary edema, pneumonia or sepsis. In addition, the EVAR patients spent less time in the hospital and were less likely to be admitted to the ICU."

Dr. De Rose noted that, despite the cost of the endograft (approximately $10,000), the total average initial costs of hospitalization for high risk EVAR and OSR patients were similar ($28,139 vs. $31,181 respectively). He added that total one-year medical and indirect costs also were similar at $34,146 vs. $34,170 respectively. At one-year, all cause mortality was statistically lower in EVAR patients (7.1% vs. 17.3%). Five-year extrapolations indicated that EVAR may be cost-effective compared to OSR in high-risk patients over the long-term.

"Our study found that EVAR was a cost-effective strategy compared to OSR in high risk patients and had lower postoperative complications and lower mortality rates," said Dr. De Rose. He added that the quality of life experienced by the participating patients was similar between the two groups during the year following surgery.

"We are continuing to collect data on these patients and the longer-term results will provide more information regarding the cost-effectiveness of EVAR compared to OSR in high risk patients," explained Dr. De Rose.

The LHSC collaborated with the Programs for Assessment of Technology in Health (PATH) Research Institute, St Joseph's Healthcare Hamilton/McMaster University in Hamilton, Ontario, Canada on the current study. This study was conducted at the request of the Ontario Ministry of Health and Long-Term Care to provide evidence to the Ontario Health Technology Advisory Committee to support policy recommendations regarding the use of EVAR in Ontario.

About Journal of Vascular Surgery

Journal of Vascular Surgery provides vascular, cardiothoracic and general surgeons with the most recent information in vascular surgery. Original, peer-reviewed articles cover clinical and experimental studies, noninvasive diagnostic techniques, processes and vascular substitutes, microvascular surgical techniques, angiography and endovascular management. Special issues publish papers presented at the annual meeting of the Journal's sponsoring society, the Society for Vascular Surgery. Visit the Journal web site at

About the Society for Vascular Surgery

The Society for Vascular Surgery (SVS) is a not-for-profit society that seeks to advance excellence and innovation in vascular health through education, advocacy, research and public awareness. SVS is the national advocate for 2,600 vascular surgeons dedicated to the prevention and cure of vascular disease.

Patient screening

Example of a Stent used in an EVARBefore patients are deemed to be a suitable candidate for this treatment, they have to go through a rigorous set of tests. These include a CT scan of the aorta and blood tests. The CT scan gives precise measurements of the aneurysm and the surrounding anatomy. In particular the calibre/tortuosity of the iliac arteries and the relationship of the neck of the aneurysm to the renal arteries are important determinants of whether the aneurysm is amenable to endoluminal repair.

The procedure

The procedure is carried out in a sterile environment, usually a theatre, under x-ray fluoroscopic guidance. It is carried out by a vascular surgeon or an Interventional Radiologist who collaborate on most cases. The patient is either given a full GA (general anaestheic) or an epidural.

Vascular 'sheaths' are introduced into the patient's femoral arteries, through which the guidewires, catheters and eventually, the Stent Graft is passed.

Diagnostic angiography images or 'runs' are captured of the aorta to determine the location on the patient's renal arteries, so the stent can be deployed below these. The main 'body' of the stent graft is placed first, with the 'limbs' which join on to the main body and sit in the iliacs, placed later.

The idea is that the covered stent, once in place acts as a false lumen for blood to travel down, and not into the surrounding aneurysm sac. This therefore immediately takes the pressure off the aneurysm, which itself will thrombose in time.[1]

Sagital MPR of an AAA


Myocardial infarction, congestive heart failure, arrhythmias, respiratory failure, renal failure

Procedure related

Dissection, malpositioning, renal failure, thromboembolizaton, ischemic colitis, groin hematoma, wound infection

Device related

Migration, detachment, rupture, stenosis, kinking

[edit] Endoleaks

An endoleak is a leak into the aneurysm sac after endovascular repair. Four types of endoleaks exist:[1]

Type I - Perigraft leakage at proximal or distal graft attachment sites (near the renal and iliac arteries)
Type II - Retrograde flow from collateral branches such as the lumbar, testicular and inferior mesenteric arteries
Type III - Leakage between different parts of the stent (at the anastomosis between components)
Type IV - Leakage through the graft wall
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