Evidence - Interventional management of type Ia endoleak after endoluminal repair of bilateral internal iliac artery aneurysms - Vascular Surgery - vascular surgery

Endoleaks are defined as persistent blood flow outside the lumen of the endograft but within the aneurysm sac, as verified by imaging study.[1] Endoleaks can be classified according to Veith et al.[2]

Endoleaks can be subdivided into three groups based on when they manifest.[3]

• Early endoleak: within 24 hours
• Intermediate endoleak: postinterventional day 1 to 90.
• Late doleak: after 90 days

Type Ia endoleak

With type I endoleaks, there is a significant increase in pressure in the aneurysm sac with a corresponding risk of rupture. The incidence of type 1a endoleaks increases with::

• Short aneurysm neck (<15 mm)
• Wide neck diameter (>32 mm)
• Aaneurysm neck with distal enlargement
• Increased angulation (>60°)
• Calcification and thrombus material in the landing zones

If possible, type I endoleaks should therefore be repaired before patients leave the OR [5, 6], although this is not always possible. In a cohort study by the Vascular Study Group of New England (VSGNE), 80 (3.3%) of 2402 patients who underwent elective EVAR had persistent endoleak type I.[6]  Patients with type I endoleak suffered higher in-hospital mortality compared with others but did not differ in their 1-year mortality, and in 94% of cases, the endoleak had resolved within 1 year without intervention. Similar experiences have been reported from other studies.[7] If interventional repair in endoleak type I is not successful, the above data suggest that watchful waiting is an option, but patients must be carefully followed up. Any increase in size of the aneurysm sac can be followed by ultrasonography if suitable expertise is available; a follow-up interval of three months appears to be adequate.

Early type I endoleaks can undergo balloon remodeling, and so-called extension cuffs and bare metal stents may also be used. There is also the endoluminal option of pinning stent graft components to the vessel wall with staples or endo-anchors.[8]

In late phases with persistent type I endoleak, an attempt can be made to fill the lumen between the endograft and arterial wall by embolization. If the aneurysm diameter continues to grow, extension of the proximal or distal landing zone by stent graft or open surgery may be considered.

Type II endoleak

There is a systematic review of the significance of type II endoleaks based on 32 nonrandomized retrospective studies involving 21,744 patients.[9] Type II endoleaks were observed in 10.2% of patients after EVAR, and spontaneous regression was seen in 35.4% of cases. Aneurysm rupture was seen in 14 patients (0.9%) with isolated type II endoleak, although in 6 of these patients the aneurysm had not expanded. Out of 393 interventions for type II endoleaks, 28.5% were unsuccessful. The authors of this review article concluded that nonsurgical management of type II endoleak is safe, which is in line with data from other studies.[10] Another systematic review did not identify a cutoff point at which type II endoleaks require intervention.[11] Considering the uncommon nature of aneurysm sac enlargement and rupture in type II endoleak, it is considered a "benign complication" with treatment decisions on a case-by-case basis. A retrospective study from 2014 also came to this conclusion.[12]

Large caliber lumbar arteries can result in type II endoleaks [13] as can a large inferior mesenteric artery. Endoleak management can include embolization of the above-mentioned vessels via microcatheters. After EVAR, the inferior mesenteric artery is accessed via the arc of Riolan with probing of the superior mesenteric artery; the lumbar arteries are accessed via the collateral circulation from the internal iliac artery. Eembolization often has to be repeated, because after occlusion of the vessels, other collateral vessels may develop. If arterial access is not available, therapy may also proceed by direct puncture of the aneurysm sac and localization of the endoleak (from posterior under local anesthesia). [14] Minimally invasive stapler transection of the inferior mesenteric artery is another treatment option. The success rate of interventional management in type II endoleaks is 60% to 80%.  Surgical treatment is indicated if the feeder vessels cannot be disrupted by interventional measures and an increase in size is observed.

Type III endoleak

The incidence of type III endoleaks is less than 4% at 1-year follow-up.[15, 16]   Leakage is associated with an increased risk of rupture and should be treated promptly.[17]  Repair is effected by endoluminal lining all or part of the endograft with a second endograft. The same also applies to the disconnection of individual stent graft components. Open surgical repair is rarely required.

Type IV endoleak

Type IV endoleaks result from endograft porosity or leakage. Typically, toward the end of the intervention, the leaks present as a perigraft contrast cloud persisting for several seconds during the final verification angiogram.[17] In most cases, the leaks resolve within 24 hours once the heparin effect wears off.  Persistent type IV endoleaks generally do not require treatment.[18] In case of unexpected progressive aneurysm growth, internal stenting ("relining") of the endograft becomes necessary.

Type V endoleak

In this endoleak type, also known as endotension, there is a continuous increase in the size of the aneurysm sac with no apparent contrast leakage. Usually, these endoleaks are self-limiting. An increase in size and imminent rupture require reintervention, either by implanting a second endograft within the first endoluminal graft or by open surgical repair.

ANEUFIX for Endoleaks Type II (ACP-T5)

Prevention of Type II Endoleaks During Endovascular Treatment of Abdominal Aortic Aneurysm: Endovascular Treatment Versus Combination With Coil Embolisation of the Aneurysmal Sac (SCOPE1)

1. Chaikof EL, Blankensteijn JD, Harris PL et al.; Ad Hoc Committee for Standardized Reporting Practices in Vascular Surgery of The Society for Vascular Surgery/American Association for Vascular Surgery. Reporting standards for endovascular aortic aneurysm repair. J Vasc Surg 2002; 35: 1048-1060.

2. Veith FJ, Baum RA, Ohki T et al.; Nature and significance of endoleaks and endotension: summary of opinions expressed at an international conference. J Vasc Surg 2002; 35: 1029-1035.

3. Rand T, Uberoi R, Cil B, Munneke G, Tsetis D. Quality improvement guidelines for imaging detection and treatment of endoleaks following endovascular aneurysm repair (EVAR). Cardiovasc Intervent Radiol 2013; 36: 35-45.

4. Wyss TR, Brown LC, Powell JT, Greenhalgh RM. Rate and predictability of graft rupture after endovascular and open abdominal aortic aneurysm repair: data from the EVAR Trials. Ann Surg 2010; 252: 805-812.

5. Chaikof EL, Brewster DC, Dalman RL, Makaroun MS, Illig KA, Sicard GA, Timaran CH, Upchurch GR Jr, Veith FJ; Society for Vascular Surgery. The care of patients with an abdominal aortic aneurysm: the Society for Vascular Surgery practice guidelines. J Vasc Surg 2009; 50(4 Suppl): S2-49.

6. Tan TW, Eslami M, Rybin D, Doros G, Zhang WW, Farber A. Outcomes of patients with type I endoleak at completion of endovascular abdominal aneurysm repair. J Vasc Surg 2016; 63: 1420-1427.

7. Millen AM, Osman K, Antoniou GA, McWilliams RG, Brennan JA, Fisher RK. Outcomes of persistent intraoperative type Ia endoleak after standard endovascular aneurysm repair. J Vasc Surg 2015; 61: 1185- 1191.

8. Hogendoorn W, Schlösser FJ, Aruny JE, Indes JE, Sumpio BE, Muhs BE. Successful treatment of a proximal type I endoleak with HeliFX EndoAnchors. Ann Vasc Surg 2014; 28: 737.e13-7.

9. Sidloff DA, Gokani V, Stather PW, Choke E, Bown MJ, Sayers RD. Type II endoleak: conservative management is a safe strategy. Eur J Vasc Endovasc Surg 2014; 48: 391-399.

10. Walker J, Tucker LY, Goodney P, Candell L, Hua H, Okuhn S, Hill B, Chang RW. Type II endoleak with or without intervention after endovascular aortic aneurysm repair does not change aneurysm-related outcomes despite sac growth. J Vasc Surg 2015; 62: 551-561.

11. Karthikesalingam A, Thrumurthy SG, Jackson D, Choke E, Sayers RD, Loftus IM, Thompson MM, Holt PJ. Current evidence is insufficient to define an optimal threshold for intervention in isolated type II endoleak after endovascular aneurysm repair. J Endovasc Ther 2012; 19: 200-208.

12. Cieri E, De Rango P, Isernia G, Simonte G, Ciucci A, Parlani G, Verzini F, Cao P. Type II endoleak is an enigmatic and unpredictable marker of worse outcome after endovascular aneurysm repair. J Vasc Surg 2014; 59: 930-937.

13. Ward TJ, Cohen S, Patel RS, Kim E, Fischman AM, Nowakowski FS, Ellozy SH, Faries PL, Marin ML, Lookstein RA. Anatomic risk factors for type-2 endoleak following EVAR: a retrospective review of preoperative CT angiography in 326 patients. Cardiovasc Intervent Radiol 2014; 37: 324-328.

14. Moll RK, Range P, Schindler G. CT- gesteuerte Thrombininjektion zur Behandlung des Typ- 2 Endoleak nach endovaskulärer Aneurysmatherapie. Fortschr Röntgenstr 2005;177 – PO_240.

15. Cao P, De Rango P, Verzini Fetal . Endoleak after endovascular aortic repair: classification, diagnosis and management following endovascular thoracic and abdominal aortic repair. JCardiovasc Surg(Torino) 2010 51:53–69.

16. Skibba AA, Evans JR, Greenfield DT et al. Management of late main-body aortic endograft component uncoupling and type IIIa endoleak encountered with the Endologix Powerlink and AFXplatforms. JVascSurg2015 62(4):868–875.

17. Chavan A (Hrsg). Vaskuläre Interventionen. 2017 Thieme, Stuttgart, NewYork

18. Chen J, Stavropoulos SW. Management of endoleaks. SeminInterventRadiol 2015 32:259–264