Endovascular Repair of Abdominal Aortic Aneurysm : Time to get down to strategic

prevention of complications.

Salvatore Ronsivalle MD, Francesca Faresin, MD; Francesca Franz, MD

Vascular and Endovascular Surgery and Angiology

Cittadella Hospital, Padua, Italy

Endovascular Repair of Abdominal Aortic Aneurysm : Time to get down to strategic

prevention of complications.

The publication in 2010, in the NEJM, of the Dutch Randomized Endovascular

Aneurysm Management (DREAM) trial and the United Kingdom EVAR-1 provided

the first randomized comparisons of the endovascular and open techniques for elective

repair of abdominal aortic aneurysms. (1,2,3)

Endovascular repair was developed to provide a less traumatic alternative, even its

advent has not been without controversy. (3)

The reduction in operative mortality with endovascular repair in the United Kingdom

trial EVAR-1 was from 4.3 percent to 1.8 percent (1) but operative morbidity and

mortality rates addressed only the risk associated with repair, not the long term

benefit(3).

The DREAM trial reported that the increase in perioperative mortality in open repair

group was counterbalanced by a larger number of deaths after discharge in the

endovascular repair group (2)

And about this the long-term results of both trials showed that 24-month mortality was

the same in the endovascular-repair and open repair groups (1,2) and that at 6 and 8 years

the cumulative rate of reintervention for patients undergoing endovascular repair was

approximately 30%. (4)

Another important implication is the requirement for strict clinical and instrumental

follow-up for the rest of the patient’s life — which is proving to be a considerable

burden for both patients and medical-nursing staff (3) even due to the increasing number

of patients treated.

During the last decades,the wide spread use of ultrasound in diagnosing abdominal

diseases along with the cost effective abdominal aortic aneurysm screening, as

confirmed in Søgaard R, Laustsen J, Lindholt JS. BMJ 2012 (5), has allowed us to find

an increasing number of surgical aneurysms in younger people with a good life

expectancy.

Considering all these aspects and given the fact that EVAR is a procedure that different

specialists perform (vascular surgeons, radiologists, interventional cardiologists ), it is

necessary to evaluate carefully outcomes and cost benefit rate of EVAR versus open

surgery in long term morbidity and mortality.

One of the major risks of EVAR are endoleaks, due to persistent blood flow in the

aneurysm sac outside the endograft, they have been reported in nearly one out of every

four patients. (6)

The most serious one is proximal endoleak type I , due to breaking of the seal at the

proximal end of the stent graft, and even if it is possible to treat it, it would be better

preventing it through careful management of a difficult neck.

New additional techniques performed during EVAR such as Funnel (7), Chimney,

Fenestrated, Branching and Snorkel (8) give us the opportunity to overcome technical

difficulties and prevent complications in short, ectatic, flared and angled necks.

Another important problem is endoleak type II, due to incomplete thrombosis of the

aneurysm sac in conjunction with retrograde perfusion from aortic collateral branches.

If the sac is stable or decreasing in size, the risk of rupture is low and it can even resolve

spontaneously during follow up. (6)

If the sac increases in size, high blood pressure and a higher risk of short-medium term

rupture are implied (6) . If this occurs then open surgery is, in most of the cases, the only

choice so probably prevention would be the best strategy to manage this complication.

Using intrasac biomaterials (9) insertion or mechanical systems which consist of balloon-

expandable endoframes, surrounded by polymer-filled endobags the aneurysm sac is

filled to exclude flow from collaterals and the endograft remains in position (10) . The

durable, long-lasting, sturdy stabilization of the entire complex en bloc is a way to

prevent not only endoleak type II , but also prosthesis slipping or limb component

disconnection reducing indirectly proximal endoleak type I and endoleak type III as

well.

Another example of strategic prevention is a limb thrombosis in which it is mandatory

to treat any aortic bifurcation or iliac artery stenosis during EVAR or, in the presence of

kinking, to use a more flexible and pliable graft and land on a straight trait before or

after the kinking.

It would be advisable for industries to do their best to produce smaller and hydrophilic

devices in order to allow percutaneous mini invasive access, and therefore reduce the

risk of groin lymphocele and surgical wound infection.

It all started with Dr. Parodi and now after twenty years of experience, from first to

second and third generation endografts, much has been learned and achieved on how to

improve techniques and materials allowing us to treat an increasing number of patients.

On the other hand, not nearly so much has been done to invent a prevention strategy that

reduces not only the risk of complications but also the feeling of anxiety, of having to

live with the knowledge of the possiblitly of having to undergo another intervention

because of the high risk of complications, which alarms both patients and physicians.

In our 14 years of experience we have seen the coming out of a new burden connected

with stress. The patient has inherited a “ follow up syndrome ” caused by the repeated

number of check ups that leave the patient feeling as if they have a non- healing illness

with the risk of a possible complication occurring at any time. It can become a life of

anxiety.

The medical-nursing staff has a ” rejection reaction“ due to heavy check up

organization management. In the end they are negative about the whole follow-up

situation. It becomes an unwanted duty.

A strict follow up is also proving to be a considerably expensive burden.

At the present time, considering its low early perioperative mortality and morbidity, we

can state that EVAR is favorable only for high risk surgery patients.

In low risk patients EVAR is an unfavorable solution because of the high late rate of

complications requiring a large number of costly secondary surgery.

Only when we will be able to reduce long term complication rate and make primary

technical and clinical success rate similar to open surgery ensuring a long term

procedure success, we will be able to say that EVAR is a favorable and useful method.

But we also know that EVAR is a less invasive technique which represents the future

and the future can’t be curbed.

Research has made it clear that an early diagnosis reduces AAA-related deaths and that

the appropriate timing of surgical repair improves outcomes.(5,11)

In the future it would be advisable to screen with an echocolordoppler all adults 65 and

over with one or more cardiovascular risk factors and to use a less invasive technique

such as EVAR for aneurysm treatment, trying to anticipate and prevent the

complications and to make primary technical and clinical success rate similar to open

surgery.

It would be very useful to do our best to reduce the length of stay in hospital and to

make the follow up schedule more tolerable and less stressful.

For all these reasons it is mandatory that we invent a gold standard Prevention Strategy

for EVAR which can anticipate and prevent the complications making way for patient’s

less stressful and complete recovery.

REFERENCES

1) The United Kingdom EVAR Trial Investigators. Endovascular versus open repair of

abdominal aortic aneurysm. N Engl J Med 2010;362:1863-71.

2) De Bruin JL, Baas AF, Buth J, et al. Long-term outcome of open or endovascular

repair of abdominal aortic aneurysm. N Engl J Med 2010;362:1881-9.

3) Lederle F. A.Long-Term Outcome of Open or Endovascular Repair of Abdominal

Aortic Aneurysm N Engl J Med 2004; 351(16) 1677-9.

4) Craig K K, Endovascular Aneurysm Repair : is it Durable ? N Engl J Med 2010;

362(20)1930-1.

5) Søgaard R, Laustsen J, Lindholt JS.Cost effectiveness of abdominal aortic aneurysm

screening and rescreening in men in a modern context: evaluation of a hypothetical

cohort using a decision analytical model. BMJ 2012 Jul 5;345:e4276 doi: 10.1136/bmj.

e4276.

6) Cao P, De Rango P, Verzini F, Parlani G Endoleak after endovascular aortic repair:

classification, diagnosis and management following endovascular thoracic and

abdominal repair J Cardiovasc Surg 2010; 51:53-69.

7) Ronsivalle S, Faresin F, Franz F, Rettore, Zanchetta M, Zonta L Funnel Technique

for EVAR: ‘‘A Way Out’’ for Abdominal Aortic Aneurisms With Ectatic Proximal

Necks Ann Vasc Surg 2012; 26: 141-148.

8) Lee Jt, Greenberg JI, Dallman RL Early experience with the snorkel technique for

juxtarenal aneurysms J Vasc Surg 2012 55(4): 935-46.

9) Ronsivalle S, Faresin F, Franz F, Rettore C, Zanchetta M, Olivieri A . Aneurysm Sac

‘‘Thrombization’’ and Stabilization in EVAR: A Technique to Reduce the Risk of

Type II Endoleak J Endovasc Ther 2010;17:517–524.

10) Donayre CE, Zarins CK, Krievins DK, Holden A, Hill A, Calderas C, Velez J,

White RA. Initial clinical experience with a sac-anchoring endoprosthesis for aortic

aneurysm repair J Vasc Surg 2011 Mar ; 53 (3): 574-82.

11) Beckman JA, Is the Dream of EVAR Over? N Engl J Med 2012; 367:2041-2043.