Perirenal Fixation as an Independent Factor in Aortic Remodeling after Endovascular Aortic Aneurysm Repair

Thoracic aortic remodeling with endografting after a decade of thoracic endovascular aortic repair experience

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) results have been studied in short-term time frames. This study aimed to evaluate midterm and long-term outcomes of TEVAR, emphasizing postoperative aortic remodeling and need for reintervention.

METHODS

This is an institutional retrospective review of TEVAR for isolated descending thoracic aortic aneurysms. Data were collected from 2004 to 2018. Primary outcomes studied included aneurysm sac remodeling, freedom from reintervention, and all-cause mortality. Other outcomes studied include endoleak rates, neurologic complication rates, and any overall postoperative complication rates.

RESULTS

During the study period, 219 patients underwent TEVAR for descending thoracic aortic aneurysms. The median effect of TEVAR on sac diameter was a 0.7-cm decrease in size (interquartile range, -1.4 to 0.0 cm). During the study period, 80% (n = 147) of patients experienced aneurysm sac regression or stability. Perioperative neurologic complications occurred in 16% (n = 34) of patients. Significant predictors of sac growth were endoleak (odds ratio [OR], 65; P < .001), preoperative carotid-subclavian bypass (OR, 8; P = .003), and graft oversizing <20% (OR, 15; P = .046). Every 1-mm increase in aortic diameter at the proximal TEVAR landing zone led to an increased odds of endoleak (OR, 2; P = .049). Access complications (OR, 8) and subclavian artery coverage (OR, 6) significantly increased the odds of reintervention, whereas every percentage of graft oversizing protected against reintervention (OR, 0.005). Life-table analysis revealed an overall survival of 78% (71%-83%) at median follow-up. At 3 years, survival was 88% (80%-93%) for those with aneurysm sac stability or regression, whereas it was 70% (49%-84%) for those with aneurysm sac growth (P = .0402). Cox proportional hazards model showed that the only protective factor for mortality was percentage oversizing, with every 1% of oversizing having a hazard ratio (HR) of <.001 (P = .032). This was counterbalanced by the fact that patients with graft oversizing >30% had an increased odds of mortality with HR >10 (P = .049). Other significant factors that increased the odds of mortality included endoleak (HR, 3.6; P = .033), diabetes (HR, 4.1; P = .048), age (every 1-year increase in age; HR, 1.2; P = .002), year of surgery (every year subsequent to 2004; HR, 1.3; P = .012), and peripheral artery disease (HR, 5.2; P = .041).

CONCLUSIONS

The majority of patients (80%) experience sac stability or regression after TEVAR, which offers a clear survival advantage. Endoleaks are predictive of sac growth, conferring increased mortality. Rigorous surveillance is necessary to prevent future aortic events through reintervention.

Current evidence on aortic remodeling after endovascular repair

Anatomical changes after endovascular repair (EVAR) of abdominal aortic aneurysms (AAAs) are thoroughly studied as they could affect the long-term postoperative outcome. The aim of the present study was to review the literature and summarize the recent data regarding the aortic remodeling and its clinical significance. A continuous aortic neck expansion is observed after EVAR and is more rapid at the first month and during the third postoperative year. This aortic neck dilation is not influenced by the type of proximal stent-graft fixation, is comparable to open surgical aneurysm repair and is most probably related with the natural progression of aneurismal disease. Aortic neck angulation reduces significantly immediately after EVAR and then continues to reduce slowly and gradually. Neck angulations ≥60° have a greater reduction compared to neck angulations <60°. An expansion of the common iliac arteries at the distal landing zone is also observed after EVAR and is more prominent in the first six postoperative months. A postoperative increase of the distance between superior mesenteric artery and iliac bifurcations (aortoiliac elongation) is described and is associated with increased type I endoleaks and reinterventions. The aneurysm sac diameter most frequently reduces after EVAR in absence of an endoleak and this aneurysm sac regression has been associated with the stent-graft type.

Endovascular Aortic Repair of Infrarenal Abdominal Aortic Dissection

We present two cases of infrarenal abdominal aortic dissection (IAAD) that were treated by endovascular aortic repair (EVAR). The EVAR procedure was successful, although one patient developed a proximal Type I endoleak several months after the procedure; both patients remain symptom-free more than 24 months after surgery. A literature search revealed that EVAR has been performed in only 14 cases of IAAD. Based on these 14 cases, we believe EVAR is feasible and effective for the treatment of IAAD. Moreover, this treatment strategy represents a reasonable alternative to open surgery, especially in cases of complicated juxtarenal abdominal aortic dissection.

Technique of slow deployment of Gore Excluder endograft improves accuracy of placement

The standard deployment of Gore Excluder endoprostheses involves rapid pulling of the deployment knob once the graft is thought to be properly positioned. We describe an alternative technique that involves the slow pulling of the deployment knob. The key features of this technique include anticipating the asymmetric flowering of the graft that occurs toward the contralateral limb, prompt correction of any graft malpositioning, and maintaining the slow deployment until the contralateral gate is released. Our experience with this technique demonstrates that it is accurate, safe, and reduces the need for proximal extension cuffs.