Gaspar Mestres

Dynamic Aortic Changes in Patients with Thoracic Aortic Aneurysms Evaluated with Electrocardiography-Triggered Computed Tomographic Angiography before and after Thoracic Endovascular Aneurysm Repair: Preliminary Results

The purpose of this study was to utilize dynamic computed tomographic angiography (CTA) on pre- and postoperative thoracic endovascular aneurysm repair (TEVAR) patients to characterize cardiac pulsatility-induced aortic motion on essential TEVAR proximal sealing zones and to study the influence of endograft placement. Six pre- and six postoperative dynamic CTA studies were obtained in six patients with thoracic aortic aneurysms (TAAs) undergoing TEVAR. Data were acquired using a retrospective electrocardiography-triggered dynamic CTA scan, with eight reconstructed phases over the cardiac cycle. Scans were acquired during a single breath hold. Multiplanar reconstructions were made perpendicular to the aorta at five surgically relevant anatomical thoracic landmarks: 1 cm proximal to the innominate trunk, 1 cm proximal and 1 cm distal to the left subclavian artery, and 1 cm proximal and 3 cm distal to the proximal end of the stent. After segmentation of the aortic lumen in the images, diameter change and area change over the cardiac cycle were measured. Diameter change was measured through the center of mass of the aortic lumen, and the average change over 180 axis is presented. We found significant distention of the thoracic aortic arch and descending thoracic aorta during the cardiac cycle before and after TEVAR. Distention ranged 3-12% in diameter and 2-20% in area. This distention was preserved after TEVAR. Patients with TAA experience aortic diameter and area changes during the cardiac cycle. The magnitude, and hence the clinical importance, of this aortic distention varies among patients. After stent-graft placement, aortic distention throughout the cardiac cycle is preserved. This may have major implications for correct sizing of the endograft as well as for stent-graft design and durability as the forces on the stents may be much larger after implantation than initially anticipated by stent manufacturers.

Endovascular Treatment of Traumatic Thoracic Aortic Injuries: Short- and Medium-term Follow-up

BACKGROUND Successful thoracic endovascular aortic repair (TEVAR) with low rates of complications has been referred to in the treatment of traumatic thoracic aortic injuries; however, we still do not know the long-term behavior. In this series, short- and intermediate-term results of TEVAR of traumatic aortic injuries are analyzed. METHODS The clinical charts and courses of 20 patients (mean age, 31.8 years; age range, 15-65 years; 14 [70%] men) with traumatic thoracic aortic injuries treated with TEVAR were retrospectively reviewed. Mean delay from trauma to intervention was 15 days (range, 0-180 days). RESULTS The initial success rate was 100%, with no deaths or intraoperative leaks, although in 4 (20%) patients, injuries were repaired in the arterial access site. The mean postoperative follow-up was 43.53 months (range, 5.5-108.0 months). Four (20%) patients required reintervention: 2 postoperative revascularizations of the left subclavian artery (20% of the patients in whom the ostium was intentionally occluded) and 2 aortic reinterventions (endovascular treatment of a collapsed stent graft and open repair after thrombosis of another stent graft). All reinterventions were successfully performed and no additional complications were registered during follow-up. Asymptomatic findings related to the stent graft included lack of proximal device-wall apposition in 8 patients (40%), intragraft mural thrombus formation during the first 6 months in 7 patients (35%), and an asymptomatic fracture of the longitudinal reinforcing bar of the stent graft 4 years later in 1 patient (5%). CONCLUSION Although not completely exempt of complications, TEVAR provides a reliable method for the treatment of traumatic thoracic aortic injuries with good results in the short- and medium-term follow-up. All complications have been treated successfully. Long-term evolution of lack of proximal device-wall apposition and intragraft mural thrombus formation should be closely monitored to prevent long-term complications.

Incidence and Evolution of Mural Thrombus in Abdominal Aortic Endografts

BACKGROUND The aims of this study were to analyze the predictive factors for intragraft mural thrombus formation and evolution during follow-up after endovascular treatment of abdominal aortic aneurysms and to evaluate its relationship with the subsequent appearance of complications. METHODS A retrospective study was performed by selecting those patients who underwent endovascular repair of an abdominal aortoiliac aneurysm between June 1998 and September 2004, with a minimum follow-up of 24 months. Preoperative clinical data, anatomical characteristics of the aneurysm, and endograft type were analyzed. In addition, clinical evaluation and abdominal computed tomography angiography (CT scans) performed at 1, 6, 12, and 24 months after the surgery were reviewed. RESULTS Eighty-nine patients were submitted for endovascular aneurysm repair in this period, and 75 completed the 24-month follow-up. Eighteen patients developed intragraft mural thrombus (24% incidence), 13 (72.2%) appearing at 1 month of follow-up, and up to 16 (88.9%) appearing during the first 6 months. Logistic regression analysis showed that the lumen percentage of mural thrombus in the native aorta and the use of aortouniiliac endografts were independent predictors of intragraft mural thrombus formation (odds ratio, 1.065; 95% confidence interval, 1.022-1.110, and odds ratio, 8.014; 95% confidence interval, 1.598-40.181, respectively). No spontaneous regression of the thrombus was observed. The area of intragraft mural thrombus had increased at 12 and 18-24 months after their diagnosis (Wilcoxon signed rank test, p = 0.028 and 0.028, respectively). The presence of intragraft mural thrombus was associated with a greater tendency to endograft body or branch occlusion (5 of 18 cases with intragraft mural thrombus (27.8%) versus 1 of 57 cases without it (1.8%), (p = 0.003). CONCLUSION Intragraft formation of mural thrombus is a common finding during the follow-up of abdominal aortic endografts, particularly in aneurysms with large mural thrombus of the native aorta, and is associated with the use of aortouniiliac endografts. The area occupied by the mural thrombus was shown to gradually increase during follow-up and was associated with a greater tendency for endograft occlusion.

Spinal cord protection and related complications in endovascular management of B dissection: LSA revascularization and CSF drainage

The endovascular repair of thoracic aorta (TEVAR) has significantly decreased the overall incidence of neurologic complications when compared with open surgery. Nevertheless, the risk of paraplegia remains an important concern, with rates ranging from 2% up to 8% (1). Risk factors for spinal cord ischemia following TEVAR include prior abdominal aortic aneurysm (AAA) repair, prolonged hypotension, severe atherosclerosis of the thoracic aorta, occlusion of the left subclavian artery (LSA) or hypogastric arteries, and more extensive coverage of the thoracic aorta by the graft (1). Different strategies have been developed over time to protect the spinal cord from ischemic insult during thoracic aortic repair (2) (see Table 1). LSA revascularization and cerebral spinal fluid (CSF) drainage are the two more invasive preventive maneuvers applied in TEVAR for treating type B dissection which may be associated with relevant pitfalls. Table 1 Suggested strategies for spinal cord protection during TEVAR Pitfalls and safeguards LSA revascularization pitfalls Since the effective contribution of the LSA to spinal cord vascularization is difficult to estimate due to anatomical variability, its revascularization may be not always necessary and should be performed selectively. Most authors agree on absolute indications to LSA revascularization in patients presenting with specific clinical situations, including left internal mammary artery-coronary bypass, dominant left vertebral artery, isolated left cerebral hemisphere, and functioning left upper extremity artery-venous dialysis fistula or bypasses. A selective revascularization approach has also been suggested based on ischemic risk stratification, such as in the presence of extensive aortic coverage, prior aortic surgery, or an occluded hypogastric artery (3). LSA revascularization may be associated with several complications, which are summarized in Table 2 (4). Table 2 Potential complications related to LSA revascularizations LSA revascularization safeguards Recommendations to avoid such complications focus on two aspects: a justified indication, and a careful and skillful surgical technique to avoid injuries to adjacent structures when a left subclavian-carotid transposition or bypass grafting is performed. Because the surgical outcome is strongly related to volume and experience, highly experienced surgeons should be in charge of these surgical preventive procedures.

Identification of optimal device combinations for the chimney endovascular aneurysm repair technique within the PERICLES registry

Objective: The ideal stent combination for chimney endovascular aneurysm repair remains undetermined. Therefore, we sought to identify optimal aortic and chimney stent combinations that are associated with the best outcomes by analyzing the worldwide collected experience in the PERformance of chImney technique for the treatment of Complex aortic pathoLogiES (PERICLES) registry. Methods: The PERICLES registry was reviewed for patients with pararenal aortic disease electively treated from 2008 to 2014. Eleven different aortic devices were identified with three distinct subgroups: group A (n = 224), nitinol/polyester; group B (n = 105), stainless steel/polyester; and group C (n = 69), nitinol/expanded polytetrafluoroethylene. The various chimney stent subtypes included the balloon‐expandable covered stent (BECS), self‐expanding covered stent, and bare‐metal stent. Deidentified aortic and chimney device combinations were compared for risk of chimney occlusion, type IA endoleak, and survival. Effects of high‐volume centers (>100 cases), use of an internal lining chimney stent, number of chimney stents, and number of chimney stent subtypes deployed were also considered. We considered demographics, comorbidities, and aortic anatomic features as potential confounders in all models. Results: The 1‐ and 3‐year freedom from BECS chimney occlusion was not different between groups (group A, 96% ± 2% and 87% ± 5%; groups B and C, 93% ± 3% and 76% ± 10%; Cox model, P = .33). Similarly, when non‐BECS chimney stents were used, no difference in occlusion risk was noted for the three aortic device groupings; however, group C patients receiving BECS did have a trend toward higher occlusion risk relative to group C patients not receiving a BECS chimney stent (hazard ratio [HR], 4.0; 95% confidence interval [CI], 0.85‐18.84; P = .08). Patients receiving multiple chimney stents, irrespective of stent subtype, had a 1.8‐fold increased risk of occlusion for each additional stent (HR, 1.8; 95% CI, 1.2‐2.9; P = .01). Use of a bare‐metal endolining stent doubled the occlusion hazard (HR, 2.1; 95% CI, 1.0‐4.5; P = .05). Risk of type IA endoleak (intraoperatively and postoperatively) did not significantly differ for the aortic devices with BECS use; however, group C patients had higher risk relative to groups A/B without BECS (C vs B: odds ratio [OR], 3.2 [95% CI, 1‐11; P = .05]; C vs A/B: OR, 2.4 [95% CI, 0.9‐6.4; P = .08]). Patients treated at high‐volume centers had significantly lower odds for development of type IA endoleak (OR, 0.2; 95% CI, 0.1‐0.7; P = .01) irrespective of aortic or chimney device combination. Mortality risk was significantly higher in group C + BECS vs group A + BECS (HR, 5.3; 95% CI, 1.6‐17.5; P = .006). The 1‐ and 3‐year survival for groups A, B, and C (+BECS) was as follows: group A, 97% ± 1% and 92% ± 3%; group B, 93% ± 3% and 83% ± 7%; and group C, 84% ± 7% and 63% ± 14%. Use of more than one chimney subtype was associated with increased mortality (HR, 3.2; 95% CI, 1.4‐7.5; P = .006). Conclusions: Within the PERICLES registry, use of nitinol/polyester stent graft devices with BECS during chimney endovascular aneurysm repair is associated with improved survival compared with other aortic endografts. However, this advantage was not observed for non‐BECS repairs. Repairs incorporating multiple chimney subtypes were also associated with increased mortality risk. Importantly, increasing chimney stent number and bare‐metal endolining stents increase chimney occlusion risk, whereas patients treated at low‐volume centers have higher risk of type IA endoleak.

Incidence and prognostic factors related to major adverse cerebrovascular events in patients with complex aortic diseases treated by the chimney technique

Objective: Endovascular aneurysm repair (EVAR) with the chimney technique (ch‐EVAR) has been used for the treatment of aortic aneurysms as an alternative approach to fenestrated endografting or open repair. Nonetheless, the need for an upper extremity arterial access may contribute to a higher risk for periprocedural cerebrovascular events. This study reports on the perioperative cerebral and major adverse cardiac and cerebrovascular events (MACCE) after ch‐EVAR. Methods: The PERICLES registry (PERformance of the chImney technique for the treatment of Complex aortic pathoLogiES) is an international, retrospective multicenter study evaluating the performance of ch‐EVAR for the treatment of complex aortic pathologies. For the purpose of the current analysis, 425 patients treated by ch‐EVAR between 2008 and 2014 were included. The primary outcome of this analysis was the incidence of procedure related cerebrovascular events defined as transient ischemic attack or stroke. The secondary end point was in‐hospital MACCE, including acute coronary syndrome, stroke, and death of any cause. Results: The incidence of clinical relevant cerebrovascular events was 1.9% (8/425). A postoperative transient ischemic attack was observed in four patients (0.95%) and a stroke in additional four (0.95%). Three patients died during the hospital stay secondary to sequelae from postoperative stroke. A prior history of stroke/transient ischemic attack, atrial fibrillation, previous carotid revascularization, or known carotid artery disease did not significantly increase the risk for adverse neurologic events. The overall MACCE rate amounted to 8.5% (36/425). Logistic regression analysis revealed that the use of bilateral upper extremity access (odds ratio [OR], 2.79; 95% confidence interval [CI], 1.04‐7.45]), aneurysm rupture (OR, 5.33; 95% CI, 1.74‐16.33), and a prolonged operation time (>290 minutes; OR, 1.005; 95% CI, 1.001‐1.008) were associated with a significantly increased risk for MACCE. Conclusions: This analysis demonstrates that ch‐EVAR is associated with a relatively low rate of cerebrovascular events. However, a postoperative stroke is associated with increased mortality. Ruptured aneurysms, bilateral upper extremity access as in case of multiple chimney graft placement, and longer operative times were identified as independent risk factors for MACCE.