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Aneurysm sac size signals need for endoleak intervention

Key findings

  • A Mass General study found that persistent type IA endoleaks after endovascular aneurysm repair (EVAR) may not require re-intervention, as many type IA endoleaks will resolve on their own
  • An increase in aneurysm sac size on serial imaging indicates the need for re-intervention for type IA endoleaks following EVAR
  • Extensive neck calcification was the only independent predictor of persistent type IA endoleaks following endovascular aneurysm repair
  • 79% of patients with a persistent type IA endoleaks were alive one year beyond case end compared to 91% of patients without one. However long-term survival rates are similar

Despite the 11% prevalence of early type IA endoleaks after endovascular aneurysm repair (EVAR), their risk factors and prognosis are not well understood. The Society for Vascular Surgery currently states that they typically require “urgent attention due to a high risk of sac enlargement and rupture.” Recent data suggest that type IA endoleaks that persist at the end of the procedure may not carry such a dire prognosis as previously believed because most resolve on their own. Mass General Hospital researchers aimed to identify risk factors for persistent type 1a endoleaks and determine their effects on EVAR outcomes.

Led by Mark Conrad, MD, director of Clinical Research and assistant program director in the Division of Vascular and Endovascular Surgery, and Thomas O’Donnell, MD, a team reviewed the records of all patients who underwent infra-renal EVAR at a single center from 1998 to 2015.

Reported in the Journal of Vascular Surgery, notable findings include:

  • Most persistent type IA endoleaks resolve on their own but these patients require close follow-up
  • An increase in aneurysm sac size and a lack of spontaneous resolution of a type 1A endoleak signals a need for re-intervention
  • Only 79% of patients with persistent type IA endoleaks were alive one year beyond case end compared to 91% of patients without one. Long-term survival rates are similar
  • Extensive neck calcifications were the only independent predictor of a persistent endoleak

They concluded that an increase in aneurysm sac size on serial imaging signaled a need for re-intervention, although most endoleaks resolve on their own.

As part of the study, researchers retrospectively reviewed records, Social Security Death Index and CT angiography of 1484 EVAR patients, of which 122 were marked by type IA endoleaks on arteriography after graft deployment. Patients were followed for a median of four years and had one-month and one-year follow-ups during that period. The primary outcome was survival, and the secondary was persistent endoleak at case conclusion.

Of those 122 patients marked by a type Ia endoleak, 43 persisted at the end of the case—16 persisted at one month and only six were present at one year.

52 of the 122 patients with a type Ia endoleak received additional ballooning of the proximal site (with 62% having successful resolution), while most remaining patients who received treatment had either placement of an aortic cuff or Palmaz stent. Of note, none of those patients whose type lA endoleak resolved in the operating room had an endoleak at one year.

Analysis found that re-intervention is needed if the size of an aneurysm sac increases and the endoleak does not resolve by case end.

Importantly, researchers note that an improving rate of persistent endoleak at case end are attributed not only to improvements in grafts but also to surgeons’ advances in knowledge and skills.

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