CIA enlargement is a common finding in patient with AAA (Armon et al. 1998): up to 30% of AAAs have concomitant iliac artery aneurysm (CIAA) disease (Henretta et al. 1999). Dilatation of the iliac arteries is a risk factor for the development of type 1b endoleaks from the distal stent-graft sealing zone during endovascular treatment (Henretta et al. 1999).
Regardless of technique used, patients with CIAA have a higher re-intervention rate after EVAR compared with non-CIAA patients (Bannazadeh et al. 2017).
Several techniques have been developed to achieve the goal of sealing in CIAA, sacrificing or maintaining the hypogastric perfusion.
Following the first hypothesis the stent-graft can be extended into the external iliac artery (EIA), embolizing or simply overstenting the IIA. But IIA exclusion may cause major complications like buttock claudication, impotence, and bowel necrosis in up to 55% of the patients (Maleux et al. 2010) especially in bilateral setting.
To preserve the hypogastric perfusion, we have several opportunities: BBT, IBD, surgical replacement or endovascular revascularization of the internal iliac artery (banana technique or parallel graft, rarely described in literature often with unreported late results) (Lepidi et al. 2014).
In daily practice the most useful procedures are BBT and IBD. These techniques have different results and outcomes considering short, mid and long-term period.
BBT shows good early outcomes in term of technical success rate described higher than 97% (100% in our patients), low costs and shorter hospital stay because of low complexity of the procedure with lower amount of contrast medium and shorter operative time than IBD (Torsello et al. 2010; Pini et al. 2019; Naughton et al. 2012). In his review of 149 patients, Simonte et al. (2017) et al. revealed a mean higher procedural time compared to our (158 min vs 100) and others in literature (Donas et al. 2017).
The results are in favour of BBT also also considering the postoperative early re-interventions (Torsello et al. 2010), confirmed by our experience; instead IBD could need re-interventions for device limb occlusion or endoleak (1.6% in pELVIS registry) (Donas et al. 2017).
Also regarding mid-term outcomes, BBT shows excellent results especially in term of 1b endoleak that is the real critical issue of this procedure. Torsello et al. (2010) published in 2010 with regard of 89 patients and a mean follow-up of 56.5 months, a very low distal 1b endoleak rate (2 patients, 2.2%). Similar results are reported by Naughton in 2012: BBT was used to treat 166 CIAA limbs with a mean follow-up of 22 months with a re-intervention rate for type 1b endoleak of 4%.
The experience of this study mirrors the abovementioned findings confirming the literature data with only one patient with type 1b endoleak (1.4%) treated endovascularly.
During FU carried out by ultrasound, 5-year IRC low rate (4.4%) needing re-intervention (including type 1b endoleak, iliac occlusion or iliac dilatation) was found.
In the long period the BBT results demonstrate worst trend: Gray et al. (2017) presented 61 patients with a CIA diameter of > 20 mm with high type 1b rate endoleak (18%) compared with standard limbs (4%) with mean follow up of 53 months. Other reports (EUROSTAR database) (Griffin et al. 2015; Hobo et al. 2007) showed a high rate (9–14%) of late iliac complications in patients with BBT including type 1b endoleak and other iliac complications.
This study also found three patients with type 1b endoleak at 6, 7, 11 years respectively from the intervention confirming the critical issue about the long-term durability of this method.
However IBD has shown good late results with low re-intervention rate: pELVIS registry (Donas et al. 2017) reported 7% rate and Simonte et al. (2017) a > 90% freedom from re-intervention at 9 years.
These results suggest that BBT durability isn’t so well-defined in the long-term period with an increased type 1b endoleak rate. It advises for BBT using especially in old patients with no long-term expectancy of life.
Considering the stent graft type all studies reporting BBT are made by using various types of endografts; in our knowledge this is the first report using just one stent graft.
In our experience Medtronic Endurant stent graft demonstrated facility of use, good manageability and accurate deployment; we didn’t encounter technical problems stent graft related.
All patient with type 1b endoleak were treated by endovascular procedures confirming that BBT complications can be solved. In this series the only death type 1b endoleaks related occurred 1 month after the intervention for multi organ failure in patient with bad clinical conditions such as obesity, severe COPD and chronic ischaemic heart disease.
These results underline that patients treated by BBT need a careful FU to detect and quickly treat any type of procedural related problems.
Despite our study has some limitations due to be a single-centre and single-brand report, our data show that Endurant stent graft represents a good solution for the treatment of wide or aneurysmal CIA with adequate distal landing zone.