AAA: Latest In Treatment & Technology

Transcription

1 AAA: Latest In Treatment & Technology Majdi Ashchi, DO, FACC, FSCAI, FSVM, FABVM C (904) W(904)

2 Educate Primary Care Physicians and providers on: AAA incidence Diagnostic modalities, Pros & Cons Surgical, Endovascular or Medical Treatment Options Discuss briefly Endoleak History, Brief Examples of cases Risk Factors If time allows, discuss Popliteal aneurysm

3 NONE DISCLOSURES

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5 Aneurysm Definition A localized dilatation of the aorta with an increase in diameter of >1.5 times its normal diameter Over the last three decades, incidence has tripled 1.5 million people in the US have AAAs Men present 4:1 over women 15,000 deaths annually due to ruptured AAAs in the US 13 th leading cause of death Most AAAs are infrarenal patients often have other aneurysms, including iliac (41%) and femoropopliteal (15%) Hypertension (30 40%) Smoking (6:1) > 50,000 procedures per year for AAA repair 6

6 AAA Incidence and Location Incidence of aortic aneurysms Each year, physicians diagnose approximately 200,000 people in the United States with AAA. ( pages/patient information)

7 Risk Factors Major Risk Factors Current or former smoker A history of smoking has been associated with a 3- to 5- fold increase in AAA prevalence across all age groups Family history of AAA Age over 60 Gender Abdominal aneurysms are 5-10x more common in men than women 5% of US males over 60 are estimated to have a AAA Incidence significantly increases >55 y.o. men & >70 y.o. in women

8 Most significant concern: risk of rupture Mortality assd with AAA rupture (raaa) Up to 67% die prior to reaching hospital 20% deaths due to rupture die before repair Overall average = 49% Annual deaths from raaa decreased since advancement of EVAR in 1990s Increase in elective repair Improved detection and management of HTN Medicare inpt admissions for raaa Decreased from 23.2 to 12.8/100,000 medicare population AAA

9 Diagnostic Methods History & Physical exam, palpation and auscultation Abdominal Ultrasound Commonly used as a primary screening tool Provides details of the vessel wall and plaque Computed Tomography Arteriography (CTA) Most accurate test to determine size and location Readily available Eliminates the need for invasive angiography but requires IV contrast

10 Aneurysm : History Possible symptoms : Abdominal pain Pain in the lower back that may extend to the buttocks, groin or legs Pulsating sensation in the abdomen Symptoms indicating a rupture : Sudden onset of severe back or abdominal pain Nausea Dizziness, fainting and/or sudden weakness

11 AAA diagnosis Many AAAs are asymptomatic Physical exam Palpable, pulsatile mass mid-abdomen Limited in obese pts Evaluate popliteal fossa 20% pts with AAA will have popliteal aneurysm May (rarely) present with blue toe syndrome Distal embolization of mural thrombus

12 BLUE TOE SYNDROME

13 AAA diagnosis: Imaging Plain film/xray Incidental finding lumbar spine/abdominal film DUS Most common initial dx tool Readily available, low cost No radiation Limitations Can underestimate absolute size Limited role in procedure planning Rules in/rules out USPSTF recommends one-time DUS screening for males 65-75yo who have EVER smoked

14 AAA diagnosis: Imaging CTA Gold standard for absolute size/dimensions Advantages Best spatial resolution of modalities Readily available Multiplanar/3D reconstructions Disadvantages Ionizing radiation Iodinated contrast

15 Preprocedural assessment CT angiography Helical imaging from celiac to CFA mm slice thickness cc iodinated contrast Post processing Sagittal & coronal reconstructions Center line measurements for length Infrarenal neck measurement Iliac diameter, tortuosity, occlusive disease

16 When to Treat DESCRIPTION OF AORTIC ANEURYSM Elective repair of AAA is recommended when the maximal aneurysm diameter is 5.5 cm or more 6 Fusiform Aneurysm Saccular Aneurysm Aneurysms that have a saccular morphology may be considered for repair even if < 5 cm in diameter Aneurysms that have a fusiform morphology may be considered for repair if they are painful, have caused distal embolization, or are rapidly enlarging (>0.5 cm/year) 5

17 AAA Treatment Options Medical Management / Monitor Wait, watch and control hypertension Typically reserved for aneurysms < 5 cm that are not rapidly expanding or causing symptoms Most commonly monitored with regular CT scans or ultrasound examinations

18 AAA: Role of pharmacology Goals Slow rate of growth Reduce perioperative morbidity in AAA repair Reduce CV risk factors which may reduce AAA growth rate Antibx Rx Tetracycline/doxycycline/roxithromycin Small studies Aneurysm expansion decreased vs. placebo Statins Affect MMP-9 expression in cell cultures At least 2 studies showing attenuation of aneurysm growth ACE inhibitors Small studies showing less aneurysm growth, less likely to present with rupture

19 AAA Treatment Options Surgical Treatment Elective repair has a perioperative mortality rate of about 3 5% 22-30% morbidity High risk surgical group includes: cardiac, renal, pulmonary disease, and morbid obesity Patients > 75 years of age have a higher perioperative mortality rate Average 7 to 10 days hospitalization Emergency repair: mortality 40 50% Coronary events are the leading cause of death following repair of AAAs

20 AAA Treatment Options Rupture Risk Diameter (cm) (% per year) < > 8 0% 0.5-5% 3-15% 10-20% 20-40% 30-50% AAA Expansion Rate 14 Although a number of studies have found that small AAAs expand at approximately 0.5 cm in diameter per year, individual patients show considerable variation in aneurysm expansion rates

21 AAA natural history: Rupture risk (ROR) Maximum AAA diameter (cm) 5-yr rupture rate (%) <4.0 2 UK Small Aneurysm Trial: Females 3x ROR vs. males >7.0 75

22 Open Surgical Repair Results of Standard Open Repair Effective and durable but 4-5% mortality in population-based studies 15,16,17 Recovery 2-4 months 18 High risk patients often denied repair 19 5-year survival rate of 46% 9

23 Endovascular Repair Principles of Endovascular Aortic Repair (EVAR) Anchoring and secure fixation of endoluminal device above and below AAA in normal arterial segments Hemostatic seals exclude AAA from circulation Exclusion and depressurization prevent AAA rupture

24 Endovascular Aneurysm Repair (EVAR) Initial work 1991 Parodi Initial FDA approval of 2 devices (AneuRx & Ancure) 1999 At least 6 currently approved devices Medtronic Talent Medtronic AneuRx Cook Zenith Gore Excluder Endologix Powerlink Several other devices undergoing investigation

25 AAA devices-soup Aptus: Endostaple, FDAapproved but not the graft; Bolton: Treovance, not approved; Cook: Zenith; Zenith Flex, FDA-approved; Zenith LP, not approved; and now Zenith Fenestrated, FDAapproved - customized; Cordis: Incraft, not approved; Endologix: Powerlink, FDA-approved; Nellix, not approved; Gore: Excluder; Excluder C3, FDAapproved; Lombard: Aorfix, not approved; Medtronic: AneuRx; Talent; Endurant, all FDA-approved; Trivascular: Ovation, HDE FDA approved; Vascutek: Anaconda, not approved.

26 The evolution of EVAR Advantages Less perioperative morbidity & mortality 25% fewer cardiac/pulmonary complications Fewer ICU days Shorter LOS Disadvantages Long term data limited vs. open repair Follow-up more regimented 1-3m, 6m, 12m, annual CT/CTA Contrast/Radiation concerns Anatomy dependent Not everyone a candidate for EVAR

27 The evolution of EVAR Clinical evidence EVAR EVAR vs 539 open repair 30-day mortality EVAR 1.7% vs open 4.7% 2 intervention rate EVAR 9.8% vs open 5.8% All-cause mortality ~28% 4yr 3% less aneurysm-related death with EVAR EVAR more expensive, higher reintervention

28 The evolution of EVAR Practice trends Increasing # AAAs treated with EVAR vs. open Device improvements Lower profile delivery systems Reliable closure devices Many physicians now performing EVAR percutaneously

29 Device toolbox

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31 AAA Endovascular Repair Potential Benefits of EVAR Shorter hospital stay; 1-3 days vs days Safer option for high risk patients: most have significant concomitant disease (e.g., CAD, COPD) Anesthesia: General = shorter time and less blood loss Regional = epidural Local = percutaneous (closure devices) Overall lower morbidity Lower mortality rate Patient comfort

32 AAA Endovascular Repair (EVAR) Lower operative mortality rate than open repair Lower operative mortality rate for ruptured AAA than open repair Short recovery period EVAR allows patients who were felt to be inoperable to be operated upon now; as a result of the lower operative mortality rates. However EVAR does not improve long term survival compared to open repair due to the very short long term survival rate among AAA patients and some late ruptures in the EVAR patients (In EVAR 1, a total of 524 of the 1252 patients (42%) Patients died during a median follow up of 6 years, but only 76 (5%) died of aneurysm rupture.)

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37 snorkling

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39 Case 86yo WM presents to ER with increasing abd pain

40 EVAR: 86 yo WM

41 Post-EVAR follow-up CT gold standard Precontrast Important to see Ca++ thrombus Arterial phase CTA protocol Best for detecting large endoleaks Delayed Can detect slow-filling, late endoleak Especially important if aneurysm sac expanding

42 Endoleak Filling and/or pressurization of the aneurysm sac following EVAR?? Is pressurization sufficient to confer same risk of rupture based on sac size?? Type 1 Proximal at infrarenal neck Distal at distal attachment site (usually common iliac arteries Frequently due to aneurysmal degeneration of neck or device migration ( passive fixation ) Type 2 Retrograde Usually from paired lumbar arteries & IMA** Type 3 At junction/overlap of graft components Type 4 porosity leak graft material/procedural anticoagulation

43 Type 1 endoleak Usually detected intraoperatively Can develop late infrarenal neck degenerates or graft undersized Resulting in device migration (passive fixation) Usually very obvious Confers significant rupture risk Treated by extension cuff

44 Type 1 endoleak

45 Type 1 endoleak

46 Type 2 endoleak Represents persistent flow in sac Requires inflow & outflow Usually from large IMA or paired lumbar arteries Can occur from ANY branch that arises from aneurysm sac Accessory renal arteries Questionable as to pressurization and rupture risk Frequently resolve spontaneously Usually only treated in setting of sac enlargement

47 Type 2 endoleak - lumbar

48 Type 2 endoleak - embolization

49 Type 2 endoleak IMA & acc renal

50 Post-EVAR follow-up Protocol Routine post-op office visit 1-2weeks Contrast-enhanced 3m, 6m, 12m, annually thereafter if no endoleak May be able to use DUS in good hands with plenty of time In CRI pts, may use DUS or noncontrast CT to assess sac size Limited info

51 Post-EVAR follow-up Other imaging Ultrasound Can be used for pts w/cri Tech-dependent, labor-intensive MRA Limited role Nuclear medicine Ability to detect late endoleak but not source Much less spatial resolution

52 Conclusion AAA frequently discovered incidentally Lspine films, CT for other reasons Early AAA dx potentially saves lives Screening efforts warranted in at risk groups EVAR assd with less periop M&M Technology improvement has led to EVAR now 60-70% all aneurysm repair 2 intervention more common with EVAR Most pts willing to accept this for easier recovery

53 g GORE DEVICE

54 Iliac Artery Aneurysms

55 Iliac artery aneurysms are similar to AAA except Harder to diagnose due to they inaccessible location to palpation and ultrasound Higher mortality rate than AAA if the rupture Usually associated with AAA Operate when they reach 3 cm Most are treated with endovascular techniques

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59 Popliteal Artery Aneurysms

60 Definition If the enlargement is 1.5 times the size of the diameter of the normal adjacent segment of artery. Most clinicians consider 2 cm as the threshold diameter for a popliteal artery aneurysm All should be operated upon to prevent complications

61 Popliteal artery aneurysms are different! Most present as asymtomatic pulsating mass behind the knee Or they cause chronic or acute ischemia due to thrombosis of the entire popliteal artery or due to distal embolization. Very unlikely to rupture as other aneurysms do; 0-7% in most series.

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63 epidemiology Occur basically in men; 95% + Frequently bilateral;50% Associated with abdominal aortic aneurysms: 36% Most common aneurysm of the lower leg;70%. They are relatively uncommon: 7.4 per 100,000 people. In a patient treated for a popliteal artery aneurysm the likelihood of developing an other aneurysm at a remote site in the next 10 years is estimated at 50%

64 Diagnosis Important to diagnose before symptoms or complication occur, especially acute limb ischemia. Physical examination may reveal a prominent pulsation felt in the popliteal space, especially with the knee in moderate flexion. Duplex ultrasound is clearly the screening test of choice and has been shown to be superior to physical examination in detecting popliteal artery aneurysms.

65 Imaging Once a decision has been made to treat, additional anatomical information is required. Traditionally, contrast-enhanced angiography has been best used to identify points of inflow and suitable outflow target vessels for bypass

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68 Natural History Popliteal artery aneurysms are an insidious process that may cause no symptoms for an extended period of time. Frequently, the first evidence of their presence is an ischemic complication. It must be recognized that the natural history of many popliteal artery aneurysms is one of progressive enlargement and the ultimate development of symptoms or ischemic complications or both. The most feared complication is irreversible limb ischemia requiring amputation secondary to either sudden aneurysm thrombosis or extensive distal embolization. On average, the risk of developing thromboembolic complications was 35% in three years with amputation rate of 25%. In cases with nonpulsatile pulses on initial presentation the likelihood of complications is far higher (86%).

69 Elective Surgical Treatment The primary objective of treatment of popliteal artery aneurysms is to exclude them from the circulation. Two approaches; medical and posterior Small or fusiform aneurysms are best approached medially by conventional bypass with aneurysm ligation. For large, saccular aneurysms, particularly those with symptoms attributable to compression or adjacent structures, direct exposure from the posterior approach with interposition grafting within the sac is preferable unless an aneurysm extends too far proximally.

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71 Elective Surgical Treatment For large, saccular aneurysms, particularly those with symptoms attributable to compression or adjacent structures, direct exposure from the posterior approach with interposition grafting within the sac is preferable unless an aneurysm extends too far proximally.

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74 Endovascular Popliteal Artery Aneurysm Repair (EPAR) Currently, long-term results of EPAR are unknown and the short-term results generally demonstrate patency rates inferior to those of open surgery and a higher rate of re-intervention. Most surgeons have generally reserved EPAR for patients in whom the risk related to anesthesia and surgery are prohibitive and who have appropriate anatomy for endograft implantation.

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76 Endovascular Popliteal Artery Aneurysm Repair (EPAR) As with endovascular abdominal aortic aneurysm repair EPAR is constrained by primary anatomy. Patients with thrombosed aneurysms or occluded SFA cannot have a stent graft placed and require conventional surgical bypass.