Is Chimney EVAR an Acceptable Endovascular Technique ?

Ballesteros-Pomar et al. report a case of pararenal aneurysm treated by a chimney EVAR technique, complicated by a persistent type Ia endoleak, treated three months later by embolisation of the endoleak with coils and onyx. Although use of the Chimney EVAR technique in the management of aortic aneurysms is currently in fashion, this type of intervention constitutes an experimental model for proximal peri-prosthetic endoleak whose incidence is largely undervalued.

Among the therapeutic options to be discussed, it is logical to rule out the hypothesis of a fenestrated endoprosthesis if the patient is symptomatic, but several options could be proposed including hybrid surgery with visceral artery debranching and aortic endoprosthesis, homemade fenestrated endoprosthesis, or open surgery with retroperitoneal access. It is therefore a pararenal aneurysm that could be effectively treated by open surgery with short duration suprarenal clamping. The results of conventional AAA surgery have been detailed by several authors (Steinmetz, Aune, Ballotta, Paolini), from population databases (Jetty, Patel), national registers (Mani), major prospective trials (Zwolak), or large meta-analyses (Bahia, Hennebiens). With mortality rates at one and three months of 2.2% and 3.9%, respectively, in a population of high risk surgical patients, conventional AAA surgery is an effective and reliable strategy that can be proposed as a second line solution in the situation of anatomical contraindications to performing simple endovascular treatment. For many authors, the results of pararenal aneurysm surgery with proximal aortic clamping of less than 30 minutes are comparable.

The present authors believe that the chimney EVAR technique should only be considered after having eliminated all other solutions, because this technique is not a reliable surgical technique for the management of aortic aneurysmal pathology and should find its real indication only following accidental coverage of aortic branches.