Chimney Technique Research Articles

Endovascular repair of a juxtarenal saccular aneurysm using the Multilayer Flow Modulator: report of the first case performed in a Public Hospital in Brazil

Endovascular treatment of abdominal aortic aneurysms (AAA), involving the exits of the renal and visceral arteries still constitutes a considerable challenge. Many different techniques have been developed over the years in attempts to surmount the difficulties presented by these cases. Techniques that have gained prominence include fenestrated or branched stents, methods involving parallel prostheses, such as the chimney, periscope and sandwich techniques, and, more recently, flow modulation with Multilayer stents. We describe a case of a complex juxtarenal saccular AAA with a high surgical risk, both according to cardiological assessment and because the patient had a difficult airway caused by a total laryngectomy for early stage laryngeal neoplasm. In view of the technical simplicity of using Multilayer stents, the presence of chronic obstructive aortoiliac disease, ostial stenosis of the renal artery and a small diameter suprarenal aorta, options involving fenestrated/branched stents and techniques involving parallel prostheses were ruled out, because of the need for multiple accesses. In view of the dilemma it presented, we describe this case as a therapeutic challenge and present the treatment option employed, which has been successful over the short term.

Initial Experience and Lessons Learned From Complete Endovascular Zone 0 TEVAR and Triple Chimney Technique for Innominate, Carotid and Subclavian Revascularization

Initial Experience and Lessons Learned From Complete Endovascular Zone 0 TEVAR and Triple Chimney Technique for Innominate, Carotid and Subclavian Revascularization

Results of Bi-tubular Prostheses in the Laparoscopic Treatment of the Aneurysms of the Abdominal Aorta

performances of robotic navigation with the Magellan system (Hansen Medical) for the endovascular treatment of complex aortic aneurysms (CAA) and peripheral vascular pathologies (PVP). Materials and Methods: Between February and October 2013, the robotic catheter was used in 28 patients presenting a CAA (n1⁄413) or a PVP (n1⁄415). The CAA included: five thoracoabdominal aneurysms (three type III, one type II and one type IV), four juxtarenal aneurysms, twopara-renal aneurysms and two suprarenal aneurysms. The patients were treated with fenestrated (n1⁄49), fenestrated and branched (n1⁄42), branched (n1⁄41) SG or by a chimney technique (n1⁄41). In theCAAgroup, the robotic systemwasused for the catheterization of 34 target arteries (24 renal arteries, 8 superiormesenteric arteries and two celiac trunks) vascularized via 26 fenestrations, six branches and two chimney stents. The PVP included: six embolizations, five obliterating arterial diseases of the lower extremities, three carotid stentings and one renal stenting. For each target artery, 15minutes were allocated to robotic navigation. In the event of failure of catheterization after 15minutes of robotic navigation, conventional catheters were used. Results: In the CAA group, 27/34 (79%) target arteries could be catheterized in less than 15minutes, with amedian time of catheterization of 4min 10sec (range: 40sec 10min 25s). For seven renal arteries vascularized via seven fenestrations, the robotic system did not allow catheterization in less than 15 min. These seven arteries could be catheterized by using conventional catheters with a median time of 32 minutes. All the target arteries vascularized by branches or chimney stents could be catheterized in less than 15 minutes with the robotic system. In the PVP group, all the lesions (n1⁄415) could be reached or crossed in less than 15 minutes by using the robotic system. Among the 28 patients included, no traumatic lesion was noted with the vascular site of access, nor at the level of the treated site. Conclusion: The use of the robotic system for arterial catheterization is feasible and safe. In our experiment, these performances were optimal for PVP and the catheterization of stentgraft branches or the deployment of chimney-stents.

Compilations of Chimney Techniques and Fenestrated Stentgrafts in the Treatment of Juxta-renal Aneurysms

Compilations of Chimney Techniques and Fenestrated Stentgrafts in the Treatment of Juxta-renal Aneurysms

The chimney technique for preserving the left subclavian artery in thoracic endovascular aortic repair.

OBJECTIVESThe objective of the present study was to evaluate short- and mid-term outcomes of the left subclavian artery (LSA) chimney stent implantation (LSACSI) during thoracic endovascular aortic repair (TEVAR), and to summarize our experience with this technique.METHODSFrom June 2010 to September 2012, 59 patients (49 men; mean age of 57.4 ± 13.3 years, range from 26 to 83 years) who underwent TEVAR and LSACSI were enrolled. Patients suffered from Stanford type B aortic dissection (n = 27), penetrating aortic ulcer (n = 18), aortic arch aneurysm (n = 9), pseudoaneurysm of the aortic arch (n = 4) and proximal type I endoleak after TEVAR of aortic dissection (n = 1). Elective settings were performed in 72% and emergent in 38% of all patients. Follow-up was performed at postoperative 3 months, 6 months and yearly thereafter.RESULTSThe technical success rate was 98.3% (58/59), and 69 thoracic stent grafts were used. Sixty-two chimney stents, including 55 uncovered and 7 covered stents, were implanted in 59 LSAs. The overall immediate endoleak rate was 15.3% (9/59); type I endoleak was observed in 5 patients and type II in 4 patients. The difference in the immediate endoleak rate related to the anatomy between the outer and the inner curvature was statistically significant (35 vs 4%, P = 0.018). Chimney stent compression was observed in 3 patients and another stent was deployed inside the first one. Perioperative complications included stroke (3.4%, 2/59) and left upper limb ischaemia (1.7%, 1/59). The median follow-up period was 16.5 (range 1–39 months). The mortality rate during follow-up was 5.4% (3/56). Complications during follow-up included endoleak [overall, n = 8 (14.3%, 8/56); type I, n = 5; type II, n = 3], retrograde type A aortic dissection (n = 1), collapse (n = 3, 5.4%) or occlusion (n = 2, 3.6%) of the chimney stent.CONCLUSIONSShort- and mid-term results showed that it is feasible to preserve the patency of the LSA in TEVAR with the chimney technique for thoracic aortic pathologies close to the LSA. However, TEVAR combined with LSACSI was not advocated for lesions located at the outer curve of the aortic arch due to a high possibility of endoleak.

Outcomes of patients with mild to moderate ischemic mitral regurgitation after coronary artery bypass graft surgery alone.

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. 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. 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. 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.

Chimney technique for aortic arch pathologies: an 11-year single-center experience.

To report our single-center experience with the chimney technique for aortic arch pathologies and the mid- to long-term results in these patients. From June 2002 to May 2013, 26 patients (18 men; mean age 71.2 years, 53-86) underwent thoracic endovascular aortic repair (TEVAR) combined with chimney technique. Indications for treatment were: a proximal landing zone <15 mm long distal to the left subclavian artery (LSA), thoracic aortic aneurysm (n=13), complicated type B aortic dissection (n=10), type I endoleak after previous TEVAR (n=2), and penetrating aortic ulcer (n=1). Treatment was performed in the emergency setting in 7 cases. The 28 chimney stent-grafts (double chimneys in 2 patients) were deployed in the innominate artery (n=7), left common carotid artery (n=10), and LSA (n=11). All patients underwent computed tomography before discharge, at 1, 6, and 12 months, and yearly thereafter. Technical success was 100%. One (3.8%) perioperative death was due to a cerebral hemorrhage. No major stroke was registered, but 3 (11.5%) minor strokes occurred (all resolved). Paraparesis developed in 2 (7.7%) patients. Median follow-up was 36.8 months (range 1-131), during which an additional 4 (15.4%) patients died, but only 1 death was aneurysm-related. Chimney graft patency was 89.3% (25/28); an asymptomatic fracture was found in a patent chimney stent-graft at the 18-month follow-up. The type I endoleak rate was 23% (n=6); 3 endoleaks associated with aneurysm sac enlargement were treated. The chimney technique for aortic arch pathologies is safe and feasible and may be an option in patients considered at high risk for surgery or who are ineligible for conventional TEVAR, especially in the emergency setting. Concern persists regarding type I endoleak, and long-term follow-up remains mandatory.

Chimney and Periscope Technique for Emergent Treatment of Spontaneous Aortic Rupture

Aortic rupture comprises a potentially fatal condition necessitating emergent treatment. Endovascular sealing of the rupture site is often combined with the use of chimney- and periscope stent placement to preserve perfusion of aortic branches. We present a case of successful endovascular management of contained aortic rupture in a 78-year-old patient. The left brachial access facilitated stenting of the celiac and superior mesenteric arteries, whereas the left femoral route served stenting of the renal artery. One-month follow-up confirmed complete sealing, stent patency, and absence of endograft migration. The combined periscope and chimney technique is feasible and effective in the emergency setting.

Use of Tube Stent-Grafts Combined with the Chimney Technique in Juxtarenal Saccular Aortic Aneurysms with Sufficient Distal Neck

Use of Tube Stent-Grafts Combined with the Chimney Technique in Juxtarenal Saccular Aortic Aneurysms with Sufficient Distal Neck Purpose: To present the utility of the chimney technique combined with tube grafts in the management of juxtarenal aortic aneurysms (JAAAs) of saccular shape with long distal neck. Case reports: Three patients, one female and two males presented with symptomatic JAAAs. The CT angiography reveled saccular JAAAs with a proximal neck of 20mm in all cases. The therapeutic approach was based on the morphologic characteristics of the aneurysms with placement of triple tube grafts in each case. Use of chimney technique was preferred due to the need for urgent treatment. The patients were treated successfully. No persistent endoleak occurred during the mean follow up of 30.5 months. Conclusion: Properly selected aneurysms with short proximal and long distal neck can be treated with tube endografts in combination with the chimney procedure. This approach may be beneficial for urgent treatment.

Endovasküler Aort Tamirinde Chimney, Periskop ve Sandviç Teknikleri

Endovasküler Aort Tamirinde Chimney, Periskop ve Sandviç Teknikleri

How to size the main aortic endograft in a chimney procedure

The application of endovascular aortic repair in difficult circumstances, such as juxtarenal, pararenal, or thoracoabdominal aortic aneurysms, is limited. To address this difficulty, the chimney technique has been expanded and applied widely. Other than the surgeon’s individual experience and preference, however, there is currently no consensus regarding how to choose the appropriate size for the main aortic graft (MAG) parallel to the visceral chimney graft (CG) so that they accommodate each other properly inside the native aorta. Isoperimetric inequality states that among all closed curves in the plane of a fixed perimeter, a circle maximizes the area of its enclosed region. In this study, we propose a mathematical formula that was based on isoperimetric inequality to select the size of the MAG inside a known diameter of the native aorta and visceral CG:

Open Conversion after Endovascular Aortic Aneurysm Repair with the Ovation Prime™ Endograft

Advances in abdominal aortic aneurysm (AAA) endograft device technology have contributed to improved outcomes and durability of endovascular aortic aneurysm repair (EVAR), even in complex infrarenal aortic anatomies. However, stent graft failure secondary to endoleaks, migration, endotension and sac enlargement are persistent problems that can result in aneurysm rupture following EVAR.A symptomatic infrarenal AAA (4mm proximal neck) was treated initially with an Ovation Prime™ device (TriVascular, Inc., Santa Rosa, CA) in an off-label fashion, leading to type Ia endoleak moderately reduced by additional proximal neck ballooning. A failed Chimney technique to the single patent, but severely stenosed, right renal artery preceded the use of this device. A large type Ia endoleak was evident at 6-month follow-up, but following a failed supplementary endovascular intervention with coils to seal the endoleak, the patient presented with hemorrhagic shock from AAA rupture, requiring urgent open conversion. Intraoperatively it was impossible to explant this new type of endograft. Circumferential tying of the infrarenal aorta with a Teflon band was unable to stop the bleeding. However, after dividing the body of the stent-graft below the two proximal polymer rings, the endoleak was successfully treated by suturing the graft with the proximal aortic neck. The procedure was completed with extension of the stump to the common femoral arteries using a bifurcated Dacron prosthesis.The body of an Ovation Prime™ endograft may be impossible to explant in open conversion conditions. Large prospective studies with longer follow-up are required to adequately reflect the behavior of this particular device.

Mini-invasive Treatment of Abdominal Aortic Aneurysms: Current Roles of Endovascular, Laparoscopic, and Open Techniques

Endovascular aortic repair (EVAR), laparoscopic aortic surgery (LAS), and open surgery (OS) are three established treatment methods of abdominal aortic aneurysms (AAA). While these techniques are often percieved as competitive between them, they are complementary for the vascular surgeon, whose goal is to provide a treatment adapted to each case that is noninvasive and durable. The objective of this study was to report our results of AAA repair to better define the roles of the three techniques. From January 2009 to December 2011, we operated on 235 patients for AAAs. Patients for whom the three technical methods were discussed preoperatively were selected. Cases where the three techniques were not discussed were excluded (ruptured AAA, technique not available). One hundred seventy-five (75%) patients were included. Four groups were established based on the surgical risk and the anatomic EVAR criteria of the French Health Authority (Haute Autorité de Santé [HAS]), including: (1) good risk and favorable anatomy (GR-FA); (2) good risk and unfavorable anatomy (GR-UA); (3) high-risk and favorable anatomy (HR-FA); and (4) high-risk and unfavorable anatomy (HR-UA). Data collection was prospective. The numerical data were expressed as median and range. There were 166 (95%) men, aged 74 years (range 38-97 years). AAA diameter was 51 mm (range 30-81 mm). Mini-invasive treatment (EVAR or LAS) was chosen in 156 (89%) cases. Mortality at 30 days was 3.4% (6 patients, 1 EVAR, 1 LAS, and 4 OS), including 3 patients presenting with a "shaggy aorta." There were 58, 19, 65, and 33 patients in groups GR-FA (33%), GR-UA (11%), HR-FA (37%), and HR-UA (19%), respectively. The distribution of the three techniques (EVAR, LAS, OS) according to the groups was as follows: GR-FA (9, 46, 3); GR-UA (0, 13, 6); HR-FA (50, 13, 2); and HR-UA (12, 13, 8), respectively. The results by subgroups are presented. Based on our results, we present a new algorithm for AAA treatment. Among GR-FA patients, EVAR and LAS should be discussed according to life expectancy and wish of the patient. In GR-UA patients, LAS and OS can be proposed. For HR-FA patients, EVAR remains the first choice, but LAS can be used in cases with good life expectancy. In the HR-UA patients, LAS is the best choice because of the late complications of EVAR, but a broader use of fenestrated stent grafts or the chimney technique may be beneficial. Last, the surgical threshold should be pushed back among AAA patients presenting with a shaggy aorta.

Endovascular Aortic Repair With the Chimney Technique Using the Ultra Low–Profile Ovation Stent-Graft for Juxtarenal Aneurysms Having Small Iliac Access Vessels

To report the first experience using the chimney technique in combination with the latest-generation low-profile stent-graft to seal abdominal aortic aneurysms having a very short neck (proximal sealing zone) and difficult access due to very small iliac vessels. Use of an ultra low-profile 14F delivery aortic stent-graft system (Ovation; Trivascular, Santa Rosa, CA) with chimneys to the lowermost renal arteries in two patients who were not anatomically suitable for endovascular aortic aneurysm repair (EVAR) and too frail for open surgery. Implantation of stent-grafts and chimneys was technically successful without endoleak or other postinterventional complications. Follow-up after >1 year confirmed complete aneurysm exclusion, shrinkage of the aneurysm sac, and patent renal perfusion by way of the chimney. Ultra low-profile aortic stent-graft systems are particularly helpful in case of inadequate small iliac access vessels and allow EVAR for short-necked aortic aneurysms if technical contraindications obviate FEVAR and physical impairment discourages open surgical repair.

Commentary: Chimneys Are Smoking Hot: Midterm Results of the Chimney Technique in the Repair of Pararenal and Thoracoabdominal Aneurysms

Commentary: Chimneys Are Smoking Hot: Midterm Results of the Chimney Technique in the Repair of Pararenal and Thoracoabdominal Aneurysms

Endovascular stent-graft procedures in aorto-iliac pathologies: a single center experience

Methods 117 endovascular stent-graft procedures in 113 patients for thoracic, abdominal and iliac pathologies was performed at our institute between January 2009-April 2013. 94(83.1%) patients were male. Indications for endovascular interventions were as follows; 58 for abdominal aortic aneursym, 14 for descending aortic aneursym, 4 for both descending and abdominal aortic aneursyms, 2 for thoraco-abdominal aneurysm including visceral arteries, 22 for aortic dissection, 2 for penetrating ulcer, 6 for traumatic aortic rupture, 1 for intramural hematoma, 1 for bronchial artery aneurysm and 3 for common iliac artery aneursym. Chimney and periscope techniques were used in 2 patients and iliacbranched endograft was placed in 2 patients.

Anatomic Feasibility of Endovascular Treatment of Abdominal Aortic Aneurysms in Emergency in the Era of the Chimney Technique: Impact on an Emergency Endovascular Kit

Despite promising results, endovascular aortic repair (EVAR) of ruptured/painful abdominal aortic aneurysms (RPAAA) continues to have limited use due to anatomic constraints linked to RPAAA morphology. Currently, EVAR for RPAAA is reserved for patients presenting with a long infrarenal aortic neck, because commercially available fenestrated stent grafts are not available in an emergency setting. Recently, the chimney technique (ChT) has been utilized to treat infrarenal abdominal aortic aneurysms (AAA) with short necks, but this technique requires specific materials. The aim of this study was to determine the rate of RPAAA eligible for EVAR since the advent of the ChT and to ascertain the standard materials needed in this context. We carried out a retrospective study of patients operated on for RPAAA (<24 hours after admission) at our center between 2006 and 2011. Patients' computed tomography (CT) scans were analyzed by two independent operators using 3-dimensional reconstruction software with a centerline of flow. To perform standard EVAR, the anatomic criteria used were those provided by the manufacturer (proximal neck diameter 18-32 mm with length >15 mm, angulation <60°, iliac diameter >7 mm). ChT anatomic feasibility criteria were: (1) a healthy aortic area >15 mm between the renal arteries and celiac trunk; (2) caudal orientation of renal arteries; and (3) a healthy descending thoracic aorta. Patients were classified according to the feasibility or nonfeasibility of standard EVAR and ChT. In total, over the period of study, 55 patients were operated on for RPAAA. In 5 patients (9%), CT scan quality was unsatisfactory and thus 50 patients (mean age 76 years, 75% men) were analyzed. Among them, 35 (70%) had a ruptured aneurysm and 17 (34%) were unstable. Anatomically, 22 (44%) patients were eligible for standard EVAR. Taking the ChT into consideration, an additional 11 (22%) patients were eligible for EVAR. Among these EVAR-eligible patients, mean proximal neck diameter was 23 ± 3 mm and stent grafts with 24-, 28-, and 32-mm diameters could fit in 33% (11 of 33), 51% (17 of 33), and 12% (4 of 33) of the cases, respectively. These results enabled us to determine the material that should be made available in the emergency setting in centers treating RPAAA. Among the 17 patients who were not eligible for EVAR, an iliac pathology (calcifications, stenosis) and a very hostile proximal neck (angulation, thrombus), respectively, were involved in 88% (15 of 17) and 12% (2 of 17) of the cases. The ChT increases EVAR feasibility by 50% in RPAAA. Taking into consideration our results, we recommend continued availability of emergency kits, including suitable aortouni-iliac stent grafts and basic material for performing ChT to allow surgeons to provide EVAR to the greatest number of RPAAA cases.

Fenestrated and Chimney Endografts for Juxtarenal Aneurysms: Early and Midterm Results

To assess the early and short-term outcome of fenestrated and chimney grafting for juxtarenal aortic aneurysms. A prospective vascular registry of 28 patients who had undergone elective primary endovascular repair for abdominal aortic aneurysm between December 2007 and August 2011 with infrarenal neck anatomy unacceptable for conventional endovascular repair. Fenestrated endografts were designed based on reconstructed computed tomography (CT) data by the authors. Off-the-shelf grafts and stents were used for chimney cases. Patients were followed up until 31 May 2012. A total of 21 (75%) patients were treated with fenestrated endografts, while 7 (25%) received chimney grafts. The mean aneurysm diameter was 65 mm (standard deviation = 7 mm) and the median neck length 2.5 mm (range: 0-10 mm). Altogether, 63 (mean = 2.3/patient) visceral arteries were incorporated (42 renal, 21 superior mesenteric arteries). The overall primary technical success rate was 93% (one type I and one type III endoleak). The mean follow-up was 22 months (standard deviation: 14 months). The primary type III endoleak resolved spontaneously with thrombosis of the target vessel, while the patient with primary type I endoleak died of acute myocardial infarction 3 weeks after the procedure. Two late endoleaks developed: one type II endoleak without aneurysm sac growth remains under surveillance, while in another patient, multiple attempts to treat type I endoleak proved unsuccessful and the patient later died of gastrointestinal bleeding. A total of 4 (14%) patients so far required additional procedures. Two patients died within 30 days of the device implantation and another six during the follow-up. No rupture occurred. The cumulative survival for patients with fenestrated endografts was 85% at 1 year and for those treated with chimney technique 57%. The treatment of juxtarenal aortic aneurysms seems to be feasible by exploiting various endovascular techniques. Even with a low volume of cases, good immediate and short-term results can be achieved, especially with fenestrated endografts.

The Chimney Technique Has a Complementary Role in the Endovascular Repair of Juxtarenal Aortic Aneurysms: There Is No Need for a Paradigm Shift but for Accurate Patient Selection

The Chimney Technique Has a Complementary Role in the Endovascular Repair of Juxtarenal Aortic Aneurysms: There Is No Need for a Paradigm Shift but for Accurate Patient Selection

GW24-e3928 Endovascular chimney technique versus fenestrated endovascular aneurysm repair of juxtarenal abdominal aortic aneurysms

ObjectivesTo compare early outcomes of endovascular repair of juxtarenal abdominal aortic aneurysms (JAAAs) using the chimney technique with fenestrated endovascular aneurysm repair (FEVAR) in anatomically-matched patients.MethodsBetween January 2008 and December...