Efficacy and durability of the chimney graft technique in urgent and complex thoracic endovascular aortic repair

Endovascular Repair of Ruptured Abdominal Aortic Aneurysms Using the Endurant™ Endograft

Background: Endovascular aortic aneurysm repair (EVAR) represents a valid treatment modality for ruptured abdominal aortic aneurysms (rAAAs). This study aimed to present rAAA outcomes treated by EVAR using the Endurant endograft. Methods: A single-center retrospective analysis of consecutive patients treated with standard EVAR (sEVAR) or parallel graft (PG)-EVAR for infra- or juxta/para-renal rAAA using the Endurant endograft (1 January 2008-31 December 2023) was undertaken. The primary outcomes were technical success, mortality, and reintervention. Follow-up outcomes, including survival and freedom from reintervention, were assessed using Kaplan-Meier estimates. Results: Eighty-eight patients were included (87.5% sEVAR and 12.5% PG-EVAR). The mean aneurysm diameter was 73.3 ± 19.3 mm (71.4 ± 22.2 mm sEVAR and 81.7 ± 33.0 mm PG-EVAR). Among 77 patients receiving sEVAR, 26 (33.8%) received an aorto-uni-iliac device. All PG-EVAR patients were managed with bifurcated devices, one receiving a single PG, seven double PGS, and three triple PGs. Technical success was 98.8% (100.0% sEVAR and 90.9% PG-EVAR). The 30-day mortality was 47.2% (50.7% sEVAR and 27.3% PG-EVAR), with nine (10.2%) deaths recorded on the table. The mean time of follow-up was 13 ± 9 months. After excluding 30-day deaths, the estimated survival was 75.5% (standard error (SE) 6.9%) at 24 months. The estimated freedom from reintervention was 89.7% (SE 5.7%) at 24 months. Only one endoleak type Ia event was recorded during follow-up. Conclusions: Endurant showed high technical success rates and low rates of endoleak type Ia events and reinterventions, despite the emergent setting of repair. rAAA is still a highly fatal condition within 30 days, with an acceptable mid-term survival of 30-day survivors at 75.5%.

Endovascular repair combined with in situ fenestration for new-onset or residual arch dissection in patients underwent aortic replacement

INTRODUCTION

Ascending aorta or hemi-arch replacement is a frequently used treatment for patients with acute type A thoracic aortic dissection, particularly those who are elderly or have multiple comorbidities. However, in cases where there are secondary entry tears in the aortic arch or descending aorta, this procedure may not fully resolve the issue. The true lumen may remain compressed due to perfusion of the false lumen and usually require reoperation.

METHODS

Between January 2019 and July 2022, 18 patients underwent endovascular total aortic arch repair and fenestration technique without requiring median re-sternotomy. Aortic stent grafts were implanted via the femoral approach, utilizing prosthetic vessels as an appropriate proximal landing zone for aortic stent graft deployment. Based on the debranching conditions of the arch in previous surgery, single, double or triple in situ fenestrations (ISFs) were performed, respectively.

RESULTS

All 18 cases were technically successful, with a median follow-up period of 20 months (range: 18-31 months). All patients had a favourable postoperative course, with no deaths within 30 days or during their hospital stay. There were no instances of disabling stroke, paraplegia, endo-leak, stent graft migration or stent graft-induced new entry. In addition, all patients exhibited complete thrombosis of the false lumen at the level of the aortic arch.

CONCLUSION

Our preliminary experience suggests that endovascular total arch repair combined with ISF technique is a viable, effective and safe option for treatment. Our mid-term results have been promising, but we acknowledge the need for further evaluation to assess long-term outcomes and durability.

Computational study of fenestration and parallel grafts used in TEVAR of aortic arch aneurysms

To explore the differences between fenestration technique and parallel grafts technique of thoracic endovascular aortic repair, and evaluate the risk of complications after interventional treatment of aortic arch aneurysms. A three-dimensional aortic model was established from the follow-up imaging data of patient who reconstructed the superior arch vessel by the chimney technique, which was called the chimney model. Based on the chimney model, the geometric of the reconstructed vessel was modified by virtual surgery, and the normal model, fenestration model and periscope model were established. The blood flow waveforms measured by 2D phase contrast magnetic resonance imaging were processed as the boundary conditions of the ascending aorta inlet and the superior arch vessels outlets of the normal model. The pressure waveform of descending aorta was obtained using three-element Windkessel model, and specific pressure boundary conditions were imposed at reconstructed branches for the postoperative models. Through computational fluid dynamics simulations, the hemodynamic parameters of each model were obtained. The reconstructed vessel flow rate of the periscope model and the fenestration model are 33% and 50% of that of the normal model, respectively. The pressure difference between the inner and outer walls of the fenestration stent and periscope stent is 3.15 times and 7.56 times that of the chimney stent. The velocity in the fenestration stent and periscope stent is uneven. The high relative residence time is concentrated in the region around the branch stents, which is prone to thrombosis. The "gutter" part of the chimney model may become larger due to the effect of the stent-graft DF, increasing the risk of endoleak. For patients with incomplete circle of Willis, the periscope technique to reconstruct the supra-arch vessels may affect blood perfusion. It is recommended to use balloon-expandable stent for fenestration stent and periscope stent, and self-expanding stent for chimney stent. For patients with aortic arch aneurysms, the fenestration technique may be superior to the parallel grafts technique.

Tratamiento endovascular con técnica de chimenea para patologías del arco aórtico

Introducción. La patología del arco aórtico se ha tratado principalmente con cirugía por vía abierta, pero con una alta morbimortalidad. Las técnicas endovasculares híbridas y las reconstrucciones en “chimenea” son una técnica válida y segura para disminuir el riesgo y la mortalidad. Métodos. Se presentan dos pacientes con patología del arco aórtico y contraindicación de manejo quirúrgico abierto, atendidos en el Servicio de Cirugía Vascular, Hospital Universitario Clínica de San Rafael, Bogotá, D.C., Colombia. Resultados. Se realizaron dos procedimientos endovasculares del arco aórtico para tratar un aneurisma torácico roto y una úlcera aórtica sintomática, con cubrimiento de los troncos supra aórticos con una endoprótesis y canalización de los vasos supra aórticos con prótesis cubiertas y uso de la “técnica de chimenea”, de manera exitosa. Discusión. La patología del arco aórtico es de alta complejidad y se asocia con una morbimortalidad elevada por lo que, en los últimos 20 años se han desarrollado diferentes técnicas utilizando procedimientos percutáneos. Conclusión. La “técnica de chimenea” se puede realizar de una manera mínimamente invasiva en pacientes con patología del arco aórtico, no candidatos para cirugía abierta, con resultados exitosos.

Chimney Graft Technique Combined With Embolization for Treating Ruptured Aortic Arch Lesions

Background: This study aimed to share the experience in applying the chimney graft technique combined with embolization for treating aortic arch rupture under emergency conditions and evaluating early-term results in these patients. Methods: This study retrospectively included patients with ruptured aortic arch lesions who received the chimney graft technique combined with embolization between March 2016 and March 2021. The primary endpoint was a technical success, deemed as successful stent graft deployment to the planned location, patency of the target branch vessel, and absence of significant type I endoleak. The secondary endpoint was clinical success defined with the size of false lumen in follow-up remaining unchanged or decreasing over time, 30-day mortality, complication, and primary patency of chimney graft. Results: This study included 12 patients (age, 61 ± 12 years; male, 83%). Five patients (42%) received single chimney, one patient (8%) received double chimney, and six patients (50%) received triple chimney. Intraoperative type I endoleak occurred in six patients (50%) who underwent endovascular embolization in the primary operation. Post-operative type I endoleak, evaluated by computed tomography angiography examination following the primary operation, occurred in seven patients (58%), including one patient who received endovascular embolization two times. All patients with post-operative type I endoleak were successfully re-treated using coil and Onyx glue within 1 week, and the median length of stay was 22 ± 11 days (range: 7-44 days). Overall technical success was 100%. Eleven patients had completed their follow-up (median, 12 months, range: 1-34 months), and one patient was out of contact. The 30-day mortality was 9% (1/11, post-operative death of a patient with cerebral hemorrhage). No major complications and no chimney compression, migration, occlusion, or stenosis were recorded during follow-up. Seven patients (58%) have ≥6 months of clinical follow-up time with appropriate imaging. In four (57%) of these patients, diameter stabilization was detected, whereas three (43%) experienced significant reduction (≥5 mm). Conclusion: The patients in this study had satisfactory early-term outcomes. The chimney graft technique combined with coil and Onyx glue embolization may be a safe and effective treatment for ruptured aortic arch lesions under emergency conditions.

Aortic arch aneurysm repair - Unsteady hemodynamics and perfusion at different heart rates

The aortic arch aneurysm is a complex disease that requires branching of one or more aortic arch vessels and can be fatal if left untreated. In this in vitro study, we examine the effect of the treatment approach on the unsteady hemodynamics and blood perfusion to the upper vessel's in models of an aortic arch aneurysm, and of the three common repair approaches: open-chest surgical repair, chimney, and hybrid approach. A particle image velocimetry method was used to quantify the unsteady hemodynamics in the four models simulated in a mock circulatory loop, to evaluate unsteady hemodynamic parameters and measure perfusion to the brain and the upper body. According to the findings, in terms of perfusion to the brain and upper body, the surgery model has the highest flow rate comparing to the other models in most heart-rate conditions. It also shows oscillatory parameters in the upper vessels which in normal arteries are correlated with a better arterial function. Between the two endovascular procedures, the hybrid model exhibits slightly better hemodynamic characteristics than the chimney model, with lower shear stresses and more oscillatory flow and WSS in the upper vessels. The hybrid model had lower perfusion flow rates to upper vessels during rest conditions (90BPM). However, unlike the other models, perfusion in the hybrid model increased with heart rate, thus at 135 BPM, it results in flow rate to upper vessels similar to that of the chimney model. The results of this study may shed light on future endograft' design and placement techniques.

Preliminary results from a multicenter Italian registry on the use of a new branched device for the treatment of thoracoabdominal aortic aneurysms

OBJECTIVE

The study purpose was to present early outcomes of patients treated for thoracoabdominal aortic aneurysms or complex abdominal aortic diseases using endovascular repair with a new branched endograft.

METHODS

This multicenter, retrospective, observational cohort study included all patients treated with a new branched endograft. All elective patients were treated with a staged operative strategy and spinal drainage Primary outcomes of interest were technical success, early (≤30 days) mortality, and late (≥30 days) survival, and freedom from adverse aortic events.

RESULTS

A total of 16 consecutive patients were treated for Crawford's extent type I (n = 1), type II (n = 7), type III (n = 1), and type IV (n = 5) endoleaks, with an additional two complex pararenal abdominal aortic lesions (enlarging type Ia endoleak, n = 1; anastomotic pseudoaneurysm, n = 1). There were 13 male (81%) and 3 female (19%) patients with a median age of 72.5 years (interquartile range [IQR], 69-78 years). The median diameter of the aortic aneurysm was 65 mm (IQR, 58-81 mm) and the median EuroSCORE prediction for mortality was 18% (IQR, 12%-36%). Thoracoabdominal aortic aneurysm was secondary to a previous dissection in four patients. A total of 62 of the 64 visceral vessels (96.9%) were stented. Technical success was achieved in 14 (87.5 %) and the cumulative aorta-related mortality rate was 19%. Spinal cord ischemia did not occur. The mean follow-up was 8 ± 4 months (range, 2-15 months). No type I or type III endoleaks were detected. Primary bridging stent patency was 98% (one asymptomatic thrombotic occlusion of a celiac trunk branch). No aortic reintervention was required.

CONCLUSIONS

Endovascular repair of complex aortic aneurysms with this new branched endograft can be performed with high technical success and acceptable morbidity. A 19% mortality is quite high; however, it is tolerable in such a high-risk cohort. The survival rate was acceptable, and graft-related outcomes at early follow-up included an absence of threatening endoleaks and a high target visceral vessel patency.

Long-Term Outcomes after Thoracic Endovascular Aortic Repair Using Chimney Grafts for Aortic Arch Pathologies: 10 Years of Single-Center Experience

BACKGROUND

This study reports the early- and long-term outcomes of the thoracic endovascular aortic repair using the Chimney-Graft technique (ChTEVAR) for the treatment of aortic arch pathologies.

METHODS

From January 2010 to December 2019, patients who underwent aortic ChTEVAR technique in our institution were included. Early, mid, and long-term outcomes in this group of patients were evaluated. Patient follow-up data were obtained by imaging follow-up that are routinely performed after 3-6 months following initial surgery and then at yearly intervals.

RESULTS

Aortic arch repair with a ChTEVAR was performed in 54 patients. The 30-day mortality was 18.5% (n = 10). All-cause 30-day mortality was higher in the subgroup of patients operated urgently (33% vs. 14%) without a significant difference (P = 0.141). Permanent neurological deficit (PND) was observed in 15% (8/54 patients); stroke in 11% (6/54), and paraplegia 4% (2/54). During follow-up the primary and primary-assisted chimney-graft patency was 96.8% and 97.8%, respectively. The multivariate analysis identified the age >70 years and the aortic diameter as independent risk factors for elevated mortality during the follow-up (P = 0.015 and 0.001, respectively). The PND was an independent predictor for 30-day mortality (P = 0.014, hazard ratio 13.5, 95% confidence interval 1.7-106.6).

CONCLUSIONS

The ChTEVAR has noninferior results to other open and endovascular aortic arch repair methods with an acceptable long-term survival especially in elective procedures.

Anatomic feasibility of the investigational GORE EXCLUDER Thoracoabdominal Branch Endoprosthesis (TAMBE), off-the-shelf multibranched endograft for the treatment of pararenal and thoracoabdominal aortic aneurysms

OBJECTIVE

The objective of this study was to evaluate the proportion of pararenal aortic aneurysms and thoracoabdominal aortic aneurysms (TAAAs) that could theoretically be treated with the investigational GORE EXCLUDER Thoracoabdominal Branch Endoprosthesis (TAMBE; W. L. Gore & Associates, Flagstaff, Ariz) off-the-shelf multibranched endograft.

METHODS

The preoperative computed tomography scans of patients with pararenal aortic aneurysms and TAAAs treated at a single institution between 2007 and 2017 were reviewed. This cohort included both open and endovascular repairs performed in either elective or urgent/emergent settings. These studies were included in a retrospective feasibility study to verify anatomic feasibility of the TAMBE graft (with four antegrade portals) employed within the manufacturer's investigational instructions for use during the U.S. pivotal trial. The patient cohort was divided into two groups: extended thoracoabdominal aneurysm (E-TAA)-extent I, II, and III TAAA; and limited pararenal and thoracoabdominal aneurysm (L-TAA)-pararenal aortic aneurysm and extent IV TAAA. The anatomic factors determining the overall theoretical feasibility were further divided into three groups: vascular access feasibility, aortic feasibility, and visceral vessel feasibility.

RESULTS

Computed tomography scans of 227 patients with degenerative aneurysms were analyzed, 166 with E-TAA and 61 with L-TAA. In the L-TAA group, 49% of the cases could have been treated with the TAMBE endograft alone; access feasibility was 85%, aortic feasibility 74%, and visceral vessel feasibility 72%. In the E-TAA group, only 23% of the cases could have been treated with a TAMBE combined with a GORE CTAG proximal thoracic stent graft; access feasibility was 79%, aortic feasibility 48%, and visceral vessel feasibility 63%. The different feasibility rate was related to a difference in aortic feasibility between L-TAA and E-TAA (74% vs 48%; P = .0008) because of the lack of a dedicated tapered thoracic component.

CONCLUSIONS

The TAMBE multibranched endograft can theoretically be employed in half of an all-comers cohort of patients with degenerative L-TAA. Development of a dedicated tapered thoracic component is warranted to increase the feasibility for E-TAA, and comparative studies are required to investigate differences with other available off-the-shelf stent grafts.

Long-Term Outcome of Chimney Technique Using a Balloon-Expandable Bare-Metal Stent to Preserve Supra-Arch Branches in Type B Aortic Dissection

PURPOSE

This study was performed to investigate the long-term effect of chimney technique using balloon-expandable bare-metal stents (BMSs) to preserve the supra-arch branches in type B aortic dissection (TBAD).

METHODS

Fifty patients with TBAD treated by thoracic endovascular aortic repair with the chimney technique (chTEVAR) using balloon-expandable BMSs from July 2009 to December 2013 were retrospectively assessed. Follow-up computed tomography angiography was performed to assess the postoperative outcomes. The primary end point was a persistent type Ia endoleak (ELIa). The secondary endpoints were chimney stent (CS)-based complications (stenosis, occlusion, fracture, or transposition), all-cause mortality, reintervention, and stroke.

RESULTS

Fifty supra-arch branches (left common carotid artery, n = 11; left subclavian artery, n = 39) were preserved via the chimney technique with 50 balloon-expandable BMSs. The technical success rate was 100%. An immediate ELIa was discovered in 9 (18%) patients. The median survival duration during follow-up was 77.3 months. Five (10%) patients had a persistent ELIa; 3 of these patients had an immediate ELIa. Asymptomatic CS-based complications were found in 3 (6%) patients. The all-cause mortality rate was 8% (4/50); 2 deaths were aortic-related deaths. Five (10%) patients underwent a reintervention. During the estimated 36-month survival period, the survival rate, the rate of freedom from persistent ELIa, and the rate of freedom from reintervention were 93.87%, 89.48%, and 95.56%, respectively.

CONCLUSIONS

The long-term outcomes showed that chTEVAR using balloon-expandable BMSs was safe and feasible for preservation of the supra-arch branches. Evaluation of more patients with a longer follow-up period is needed.

Long-term outcomes of balloon-expandable bare stent as chimney stent in thoracic endovascular aortic repair for supra-aortic branches reconstruction

Background

To report the long-term outcomes of balloon-expandable bare stent (BEBS) as chimney stent (CS) in thoracic endovascular aortic repair (TEVAR) for supra-aortic branches reconstruction.

Methods

A total of 33 patients with thoracic aortic diseases underwent TEVAR using BEBSs as CSs for supra-aortic branches reconstruction in our center from 2010 to 2015. The demographics and procedural details were prospectively collected and retrospectively reviewed. All patients were followed up at 1, 3, 6 months and every 1 year thereafter. Postoperative complications and long-term outcomes were recorded.

Results

The technical success rate was 100%. A total of 36 BEBSs were utilized as CSs to reconstruct the supra-aortic branches during TEVAR. The rate of immediate endoleak was 42.4% (14/33), including 12 (36.4%) type Ia endoleaks and 2 (6.1%) type II endoleaks. Two of type Ia endoleaks were managed by balloon dilation and disappeared, while the rest were left with close follow-up. Two type II endoleaks were embolized by coils and excluded by a plug, respectively. One patient (3.0%) died 2 days after the procedure due to the acute rupture of aortic dissection. The mean follow-up time was 61.8 (ranged from 12 to 102) months. The unmanaged 10 type Ia endoleaks were closely observed during the follow-up, of which 7 disappeared at 1 year and 1 disappeared at 2 years. The rest 2 type Ia endoleaks existed without further dilation of the aorta. One patient (3.0%) was re-intervened for the increased false lumen due to the distal residual tears. The long-term mortality was 9.1% (3/33). All CSs kept patent till the end of follow-up. No other complications were found.

Conclusions

The balloon-expandable stent (BES) is a feasible choice as CS for supra-aortic branches reconstruction with long-term patency during TEVAR. However, BEBS may be related to a higher rate of early endoleak.

Comparison of Two Different Techniques for Isolated Left Subclavian Artery Revascularization During Thoracic Endovascular Aortic Repair in Zone 2

Purpose: To analyze the results of isolated left subclavian artery (LSA) revascularization during thoracic endovascular aortic repair (TEVAR) using carotid-subclavian bypass (CSbp) or chimney grafts (CGs). Methods: A retrospective multicenter, observational study identified 73 patients (mean age 68±13 years, range 22–87; 56 men) with acute or chronic thoracic aortic lesions who underwent TEVAR with isolated LSA revascularization using either CSbp (n=42) or CGs (n=31) from January 2010 and February 2017. Primary endpoints were TEVAR-related mortality, postoperative stroke, freedom from type Ia endoleak, and LSA patency. Results: Primary technical success was achieved in all cases. Early TEVAR-related mortality was 4.2% (CSbp 2% vs CG 6%, p=0.571). Two (3%) patients had major ischemic strokes (one in each group). Mean follow-up was 24±21 months (range 1–72; median 15). Estimated freedom from TEVAR-related mortality was 93%±3% (95% CI 84.3% to 97.0%) at 12 and 36 months, with no significant difference between CSbp and CG (p=0.258). Aortic reintervention did not differ between the groups (CSbp 5% vs CG 6%, p=0.356); nor did freedom from type Ia endoleak (CSbp 98% vs CG 87%, p=0.134). Gutter-related endoleaks occurred in 4 (13%) CG patients, but none of the patients experienced sac enlargement or the need for reintervention and none died. Primary patency of the LSA was 100% for the entire group during the observation period. Conclusion: In our experience, LSA revascularization proved most satisfactory and equally effective with both the CSbp and CG techniques, without discernible differences at midterm follow-up.

Single-center mid-term experience with chimney-graft technique for the preservation of flow to the supra-aortic branches

Objectives

To investigate the feasibility and the mid-term outcomes of the chimney-graft technique for the revascularization of supra-aortic branches in patients with thoracic aortic pathologies involving the aortic arch.

Methods

A retrospective analysis of a prospectively maintained database between January 2010 and July 2016 was performed. Primary endpoints were 30-day and overall mortality. Secondary endpoints were technical success, target vessel patency, stroke/transitory ischemic attack and type I/III endoleak rate.

Results

A total of 30 patients (80% male, median age 70.0 years) were treated using the chimney-graft technique for the supra-aortic branches. The indication was a degenerative aneurysm in nine patients (32%) and a type B Stanford aortic dissection and a penetrating aortic ulcer in the descending aorta in seven patients (23%), respectively. In six patients (20.0%), the indication was an type Ia endoleak after previous endovascular thoracic repair, whereas a pseudoaneurysm after previous open repair of the descending aorta was the indication in one patient (3%). Twenty-three patients (77%) were treated electively, five (17%) emergently and two (7%) urgently because of free rupture. Technical success was achieved in 90% of patients. The 30-day/in-hospital mortality was 17% (5/30). A retrograde dissection was presented in five patients. Four patients experienced a cerebrovascular event. Eight patients had type Ia endoleak and 10 had type II. During the median follow-up of 16 months (range: 0–56), four further patients died: one in respiratory insufficiency, one due to a ruptured abdominal aortic aneurysm, one in meningitis and the last one for unknown reason. The chimney-graft patency was 100%. According to the Kaplan–Meier curve, the estimated survival at one year was 66 ± 9%.

Conclusions

The chimney-graft technique, despite a technically demanding strategy, is a useful tool as bailout procedure in our armamentarium for high-risk patients, unsuitable for open or hybrid repair.

Aortic aneurysm endovascular treatment with the parallel graft technique from the aortic arch to the iliac axis

BACKGROUND

The chimney technique has been developed for the treatment of complex aortic aneurysms. We analyzed the midterm to long-term outcomes of this approach from a single-center experience.

METHODS

From October 2008 to July 2016, 58 patients underwent endovascular aortic aneurysm repair using the chimney technique. Indications for treatment were thoracic aortic aneurysm (TAA) (N.=11), thoracoabdominal aortic aneurysm (TAAA) (N.=2), pararenal aortic aneurysm (PAAA) (N.=15), aortoiliac/isolated hypogastric artery aneurysm (N.=25), type I endoleak after previous TEVAR/EVAR (N.=4), proximal pseudoaneurysm after AAA open repair (N.=1). Elective (82.8%) and emergent (17.2%) procedures were included.

RESULTS

The immediate technical success was 100%. Single, double and triple chimneys were performed in 46, 10, and two patients, respectively. Overall, 61 target vessels (three left common carotid arteries, eight left subclavian arteries, three celiac trunks, three superior mesenteric arteries, 19 renal arteries and 25 hypogastric arteries) were involved. Postoperative mortality was 0. No neurologic complications were registered. Primary patency rate of the chimney stent/stent graft was 98.3%. Low-flow type I endoleak was observed in four patients (6.9%). Postoperative chimney graft re-intervention rate was 1.7%. The median follow-up was 32±20 months (range 3-96 months). Overall estimated survival at 12, 50, and 80 months was 100%, 89% and 44%, respectively. Estimated freedom from endoleak at 1, 12, 24, and 36 months was 96.5%, 95%, 95%, and 93%, respectively. One hypogastric artery stent-graft occluded at the 3rd month of follow-up. No reintervention was performed.

CONCLUSIONS

Our experience with the chimney technique for aortic aneurysms from the aortic arch to the iliac axis shows promising and durable mid- and long-term results. Endograft oversizing, associated with the chimney graft diameter and length choice remain fundamental to reduce the risk of the most frequent procedure complications: type I endoleak and CG occlusion. The wider use of this technique should be justified in patients considered at high risk for open repair and/or not suitable for the custom-made branched/fenestrated endografts.

Fenestrated and Branched Aortic Grafts

BACKGROUND

Abdominal and thoracic aortic aneurysms are diagnosed in 40 and 10 to 15 out of 100 000 persons per year, respectively. Fenestrated (fEVAR) and branched (bEVAR) stent grafts have been developed for abdominal juxtarenal and thoracoabdominal aneurysms. We discuss the patency and complication rates of fEVAR and bEVAR procedures and compare them with the outcome of open surgery.

METHODS

This review is based on pertinent publications from 2011 to 2014 that were retrieved by a selective literature search. The clinical outcomes of case series involving a total of more than 1500 patients are presented. The discussion takes account of recommendations contained in the literature and the authors' own experience.

RESULTS

Open surgery and aortic stent grafting have not been compared in any randomized trial to date. We identified 7 clinical series that included a total of 1270 fEVAR patients and 5 with a total of 408 bEVAR patients. The perioperative mortality after fEVAR procedures was 0-4%. Spinal cord ischemia arose in 1% of cases. The stent patency rate in visceral vessels ranged from 93 to 98%. bEVAR procedures were associated with both higher mortality (4-7%) and more common spinal cord ischemia (4-13%). 5-8% of all patients needed dialysis perioperatively, and the stent patency rate in visceral vessels was 94-97%. Preoperative renal insufficiency was a risk factor for peri-interventional death. Impaired renal function after fEVAR/bEVAR procedures was mainly associated with intermittent lower limb ischemia.

CONCLUSION

The results of fEVAR/bEVAR procedures in the last 5 years are similar to those of open surgery. The high postoperative rate of spinal cord ischemia remains a serious problem in the endovascular treatment of thoracoabdominal aortic aneurysms. The decision to implant a stent graft by an endovascular approach or to treat surgically should be made on a case-to-case basis in an interdisciplinary vascular conference.

Simultaneous Endovascular Repair for Thoracic and Abdominal Aortic Pathologies: Early and Midterm Results

BACKGROUND

To analyze information from a single clinical center, evaluating early and midterm results of simultaneous thoracic endovascular aortic repair (TEVAR) and endovascular aneurysm repair (EVAR) for coexisting thoracic and abdominal aortic pathologies.

METHODS

From January 2005 to December 2014, 13 patients (8 men, 5 women; mean age, 75.3 years; range, 69-82 years) with concomitant thoracic and abdominal aortic disease (aneurysms, type B dissection, penetrating aortic ulcers) were treated with simultaneous TEVAR and EVAR. All patients had significant comorbidities. No preoperative cerebrospinal fluid drainage was performed. The follow-up rate was 100% during a period of 36 months (range, 1-60 months).

RESULTS

Technical success was achieved in all 13 patients, including deliberate partial or total coverage of the left subclavian artery in 3 patients, coverage of both internal iliac arteries in 1 patient, and coverage of left subclavian artery and unilateral internal iliac artery in 1 patient. The average procedural time was 160 min (range, 120-200 min). Mean blood loss was 140 mL (range, 100-250 mL). Four types of commercially available stent grafts (SGs) were used. The lengths of the thoracic SGs were 150-200 cm. Overall survival was 92.3% at 1- and 3-year follow-ups. None of the patients developed stroke or paralysis. The average hospital stay was 9 days (range, 7-12 days). No patients developed endoleak or SG migration.

CONCLUSIONS

Combined TEVAR and EVAR can be performed successfully with minimal morbidity and mortality. When anatomically feasible, simultaneous TEVAR and EVAR is a viable alternative to staged or hybrid repair.

Total aortic arch endovascular repair using an iliac branch device

A 76-year-old man who 2 years before underwent thoracic endovascular aortic repair for aneurysm of the aortic arch was admitted to our department with dysphonia and dysphagia due to an increasing diameter of aneurysm of the aortic arch because of type Ia endoleak. To obtain an adequate proximal neck for conventional thoracic endovascular aortic repair, the double chimney graft technique was chosen using a hypogastric component of the iliac branch Excluder (W. L. Gore & Associates, Flagstaff, Ariz) for the anonymous trunk. At 1-year follow-up, computed tomography scan showed patent chimney graft and no endoleaks. This is the first report in the literature using a hypogastric branch in the aortic arch.

Outcome of visceral chimney grafts after urgent endovascular repair of complex aortic lesions

OBJECTIVE

Endovascular abdominal aortic repair requires an adequate sealing zone. The chimney graft (CG) technique may be the only option for urgent high-risk patients who are unfit for open repair and have no adequate sealing zone. This single-center experience provides long-term results of CGs with endovascular repair for urgent and complex aortic lesions.

METHODS

Between July 2006 and October 2012, 51 patients (16 women) with a median age of 77 years (interquartile range, 72-81 years), were treated urgently (within 24 hours [61%]) or semiurgently (within 3 days [39%]) with endovascular aortic repair and visceral CGs (n = 73). Median follow-up was 2.3 years (interquartile range, 0.8-5.0 years) for the whole cohort, 3 years for 30-day survivors, and 4.8 years for patients who are still alive.

RESULTS

Five patients (10%) died within 30 days. All of them had a sacrificed kidney. All-cause mortality was 57% (n = 29), but the chimney- and procedure-related mortality was 6% (n = 3) and 16% (n = 8), respectively. Chimney-related death was due to bleeding, infection, renal failure, and multiple organ failure. There were two postoperative ruptures; both were fatal although not related to the treated disease. The primary and secondary long-term CG patencies were 89% (65 of 73) and 93% (68 of 73), respectively. Primary type I endoleak (EL-I) occurred in 10% (5 of 51) of the patients, and only one patient had recurrent EL-I (2%; 1 of 51). No secondary endoleak was observed. Chimney-related reintervention was required in 16% (8 of 51) of the patients because of EL-I (n = 3), visceral ischemia (n = 4), and bleeding (n = 2). The reinterventions included stenting (n = 5), embolization (n = 3), and laparotomy (n = 2). Thirty-one visceral branches were sacrificed (9 celiac trunks, 9 right, and 13 left renal arteries). Among the 30-day survivors, 8 of 17 patients (47%) with a sacrificed kidney required permanent dialysis; of these, seven underwent an urgent index operation. The aneurysm sac shrank in 63% (29 of 46) of cases.

CONCLUSIONS

The 6% chimney-related mortality and 93% long-term patency seem promising in urgent, complex aortic lesions of a high-risk population and may justify a continued yet restrictive applicability of this technique. Most endoleaks could be sealed endovascularly. However, sacrifice of a kidney in this elderly cohort was associated with permanent dialysis in 47% of patients.

Late Retrograde Migration of a Left Subclavian Artery Chimney Stent-Graft Into the Innominate Artery

PURPOSE

To report an uncommon case of chimney stent-graft migration in the aortic arch.

CASE REPORT

A 29-year-old man presented with chronic left arm hyposthenia after late displacement and thrombosis of a left subclavian artery (LSA) chimney graft that migrated retrogradely into the innominate artery 2 years after deployment. The self-expanding LSA chimney was placed during a redo procedure to repair a pseudoaneurysm and type I endoleak after an index emergency thoracic endovascular aortic repair for traumatic aortic rupture 1 year earlier. The patient was successfully treated in an elective procedure via a median sternotomy, with arch aortotomy under circulatory arrest to remove the proximal end of the thrombosed chimney graft from the ostium of the innominate trunk. Three months later, a left carotid-to-subclavian bypass was performed to restore flow to the left arm.

CONCLUSION

Migration of the proximal end of an overly long chimney graft that moved freely in the aortic arch exposed the patient to a high risk of stroke and death. Because of the high-risk situation, open repair under circulatory arrest was elected to remove the proximal end of the chimney graft, with no major complications.

Chimney Grafts in Aortic Stent Grafting: Hazardous or Useful Technique? Systematic Review of Current Data

BACKGROUND

The chimney graft (CG) technique was introduced to rescue accidentally covered aortic branches during aortic endovascular repair. It extends the sealing zone. There is concern about "gutter" type I endoleak (EL-I) and about the durability of CGs. The aim of the present report was to analyze the rapidly increasing existing data.

METHODS

A search was performed (PRISMA criteria) for all studies of visceral and thoracic/arch chimney grafts. Technical and clinical details and outcome were assessed.

RESULTS

The present review includes 831 patients who underwent EVAR/TEVAR (endovascular aneurysm repair/thoracic endovascular aneurysm repair) with one or more chimney, periscope, or sandwich grafts. For aortic visceral vessels 517 patients received 911 visceral CGs and 314 patients received 364 arch CGs. Most procedures (81% visceral and 69% arch CGs) were elective. Thirty day mortality was 4% for both groups. The rate of early EL-I was 13% (visceral CGs) and 11% (arch CGs). Most EL-I were handled conservatively (observation: 70% for visceral CG and 45% for arch CG). Early CG patency was high (97-99%) and remained high during follow up (median 17 months). Late (after 30 days) EL-I was reported in nine visceral (2%) and 12 arch (4%) CG cases. Few other late complications were reported, but those losing a kidney at the initial repair seemed to have a high risk of requiring permanent hemodialysis.

CONCLUSION

Increasing amounts of data support the benefit of visceral and arch chimney graft techniques. In particular, the low early mortality and complication rates and high long-term patency seem advantageous; however, the majority of cases have been treated electively, and there is a high risk of bias in all studies. Mid- to long-term data suggest few late complications, except in cases where one renal artery was sacrificed. The CG technique is valuable for complex urgent patients and needs further documentation for other patient groups.

Endovascular repair of a mycotic thoracic aortic aneurysm in a patient with aortic coarctation

This report describes the management of a 28-year-old female patient who presented with septicemia and mediastinal mass-effect secondary to a proximal mycotic aneurysm of the descending aorta. The patient had an infected bicuspid aortic valve, aortic coarctation, and a left vertebral artery arising directly from the aortic arch. Evidence of disseminated embolization affecting her posterior cerebral circulation, the left axillary, and the superior mesenteric arteries was noted. The patient had a considerably small aorta. An urgent thoracic endovascular aortic repair was performed successfully with a chimney stent to the left vertebral artery. The report discusses the planning and technique used in managing this complex case.