Chimney Stent Research Articles

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.

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.

Critical analysis of results after chimney endovascular aortic aneurysm repair raises cause for concern

"Chimney" techniques used to extend landing zones for endovascular aortic repair (chEVAR) have been increasingly reported; however, concerns about durability and patency remain. The purpose of this analysis was to examine midterm outcomes of chEVAR. All patients at the University of Florida treated with chEVAR were reviewed. Major adverse events (MAEs) were recorded and defined as any chimney stent thrombosis, type Ia endoleak in follow-up, reintervention, 30-day/in-hospital death, or ≥25% decrease in estimated glomerular filtration rate after discharge. Primary end points included chimney stent patency and freedom from MAE. Secondary end points included complications and long-term survival. From 2008 to 2012, 41 patients (age± standard deviation, 73± 8years; male, 66% [n= 27]) were treated with a total of 76 chimney stents (renal, n= 51; superior mesenteric artery, n= 16; celiac artery, n= 9) for a variety of indications: juxtarenal, 42% (n= 17, one rupture), suprarenal, 17% (n= 7), and thoracoabdominal aneurysm, 17% (n=7); aortic anastomotic pseudoaneurysm, 15% (n= 6; three ruptures); type Ia endoleak after EVAR, 7% (n= 3); and atheromatous disease, 2% (n= 1). Two patients had a single target vessel abandoned because of cannulation failure, andone had a type Ia endoleak at case completion (technical success, 93%). Intraoperative complications occurred in seven patients (17%), including graft maldeployment with unplanned mesenteric chimney (n= 2) and access vessel injury requiring repair (n= 5). Major postoperative complications developed in 20% (n= 8). The 30-day mortality and in-hospital mortality were 5% (n= 2) and 7% (n= 3), respectively. At median follow-up of 18.2months (range, 1.4-41.5months), 28 of 33 patients (85%) with available postoperative imaging experienced stabilization or reduction of abdominal aortic aneurysm sac diameters. Nine patients (32%) developed endoleak at some point during follow-up (type Ia, 7% [n= 3]; type II, 10% [n= 4]; indeterminate, 7% [n= 3]), and one patient underwent open, surgical conversion. The estimated probability of freedom from reintervention (±standard error mean) was 96%± 4% at both 1year and 3years. Primary patency of all chimney stents was 88%± 5% and 85%± 5% at 1year and 3years, respectively. Corresponding freedom from MAEs was 83%± 7% and 57%± 10% at 1year and 3years. The actuarial estimated survival for all patients at 1year and 5years was 85%± 6% and 65%± 8%, respectively. These results demonstrate that chEVAR can be completed with a high degree of success; however, perioperative complications and MAEs during follow-up, including loss of chimney patency and endoleak, may occur at a higher rate than previously reported. Elective use of chEVAR should be performed with caution, and comparison to open and fenestrated EVAR is needed to determine long-term efficacy of this technique.

Endovascular management of total juxtarenal aortic occlusive disease in high-risk patients: technical considerations and clinical outcome.

To report our single-center experience in the endovascular treatment of juxtarenal aorto-iliac occlusions. Between December 2008 and December 2012, 13 patients with total juxtarenal aorto-iliac occlusion, considered at high risk for open revascularization, were treated by endovascular means at our Department. Inclusion criteria were severe intermittent claudication, rest pain and distal tissue loss. Antegrade recanalization from percutaneous brachial access and retrograde angioplasty and stenting from percutaneous or surgical femoral accesses were performed. The renal arteries (RAs) were protected using filters or balloons. Aorto-iliac bare-metal stents were deployed in all patients. No death was registered. Technical success was 100%. In 11 patients (84.6%) the Ankle-Brachial Index increased to 0.9-1. Renal arteries were involved in 7 cases (53.8%): 3 chimney stent grafts deployment, 2 aorto-iliac stent fenestrations and 2 aorto-iliac stents placement above the renal arteries without renal function impairment. Complication rate was 38.5%: 2 cases of thrombus dislodgement into the RAs, 1 distal artery embolization, 1 common iliac artery rupture and 1 pseudo-aneurysm. All complications were treated percutaneously, except for the distal embolization treated surgically. The patient with iliac artery rupture underwent acute renal insufficiency requiring temporary dialysis after hemorrhagic shock because of retroperitoneal hematoma. Mean follow-up was 18 months (range 6-30 months). The primary and secondary patency was respectively 92.3% and 100%. Endovascular recanalization of juxtarenal aorto-iliac occlusion in selected patients is feasible and safe, with good early and mid-term results and should be considered in high risk patients.

Experience with the sandwich technique in endovascular thoracoabdominal aortic aneurysm repair

The sandwich technique is an endovascular off-the-shelf solution for patients with thoracoabdominal aortic aneurysms (TAAAs). In a sandwich configuration, the chimney stent runs in the middle of a space created by two or three aortic endografts. All patients with TAAAs who were treated with the sandwich technique were included in the study. Self-expanding Viabahn grafts (W. L. Gore and Associates Inc, Flagstaff, Ariz) were used as parallel grafts in the renal arteries and visceral vessels. Caudad-facing chimney grafts were used for the visceral arteries and cephalad-facing periscope grafts for the renal arteries. During the study period, 32 patients with TAAAs were treated with sandwich grafts. Indication for the procedure in 43% was an acute onset of symptoms, including two patients with a rupture and a retroperitoneal hematoma. Three patients required an additional debranching procedure. A total of 104 chimney grafts were implanted. Two patients died postoperatively because of the operation. Major adverse events were recorded in five patients, including one patient with persistent paraplegia and two with permanent renal failure requiring dialysis. The incidence of chimney graft occlusion was higher in patients with three or four parallel grafts than in those with two chimney grafts only. Patients with chronic dissections had a 12-times higher incidence of chimney graft occlusion than aneurysm patients. The number of patients with type I or III endoleaks was higher in the group with three or four parallel grafts. The sandwich technique is an off-the-shelf endovascular alternative to treat patients with TAAAs in an emergent setting. The combination of chimney grafts with a periscope configuration enables a rapid endovascular aneurysm exclusion with acceptable midterm results.

Chimney and Periscope Grafts to Facilitate Endovascular Treatment of Aortic Transection in a Patient With Aberrant Right Subclavian Artery

To report the use of parallel grafts to extend the proximal landing zone for stent-graft repair of aortic transection involving an aberrant right subclavian artery (ARSA). A 28-year-old patient was referred for treatment of traumatic aortic transection with contained rupture at the level of an ARSA. Immediate thoracic endovascular aortic repair (TEVAR) was planned because of hemodynamic instability. To achieve rapid sealing and maintain perfusion to both subclavian arteries, a chimney stent to the left subclavian artery (LSA) and a periscope stent-graft to the ARSA were deployed successfully. After surgical repair of all fractures, the patient was discharged 1 month after the initial injury in good condition. Imaging follow-up at 10 months showed a stable repair, patent parallel grafts, and no complications. TEVAR with chimney and periscope grafts proved to be a safe and quick treatment for a patient requiring ARSA repair in acute aortic transection. This technique maintained blood flow to the ARSA and LSA in a totally endovascular approach, which could be very valuable in transection cases where bypass surgery to supra-aortic branches is compromised or deemed challenging due to thoracic wall and/or neck trauma. Parallel grafting can be a valuable tool to address any acute aortic pathology as it can be performed with off-the-shelf devices.

Accidental Coverage of Both Renal Arteries during Infrarenal Aortic Stent-Graft Implantation: Cause and Treatment.

The purpose of this paper is to report a salvage maneuver for accidental coverage of both renal arteries during endovascular aneurysm repair (EVAR) of an infrarenal abdominal aortic aneurysm (AAA). A 72-year-old female with a 6 cm infrarenal abdominal aortic aneurysm was treated by endovascular means with a standard bifurcated graft. Upon completing an angiogram, both renal arteries were found to be accidentally occluded. Through a left percutaneous brachial approach, the right renal artery was catheterized and a chimney stent was deployed; however this was not possible for the left renal artery. A retroperitoneal surgical approach was therefore carried out with a retrograde chimney stent implanted to restore blood flow. After three months, both renal arteries were patent and renal function was not different from the baseline. Both endovascular with percutaneous access via the brachial artery and open retroperitoneal approaches with retrograde catheterization are feasible rescue techniques to recanalize the accidentally occluded renal arteries during EVAR.

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...

Endovascular Repair With the Chimney Technique for Stanford Type B Aortic Dissection Involving Right-Sided Arch With Mirror Image Branching

To report endovascular repair with the chimney technique of type B aortic dissection involving a right-sided aortic arch (RAA). Two hypertensive men aged 48 and 42 years with symptoms of aortic dissection resistant to medical therapy underwent emergent thoracic endovascular aortic repair with the chimney technique to extend the proximal landing zones. Both patients had right-sided arches with mirror image branching. One patient required a bare metal chimney stent to maintain perfusion to the right subclavian artery, while the other patient had a chimney stent to revascularize the right common carotid artery. Short-term follow-up (1 year and 1 month, respectively) showed that there was positive aortic remodeling, and the chimney stents were patent. Chimney TEVAR seems safe and effective for Stanford type B dissection in patients having RAA with mirror image branching and no sufficient proximal fixation zone.

Endovascular repair with chimney technique of abdominal aortic aneurysm with hostile aortic neck

Abdominal aortic aneurysm (AAA) with hostile aortic neck is not a good candidate for conventional endovascular aneurysm repair (EVAR), and a recent paper showed that EVAR with chimney technique (Ch-EVAR) yielded reasonable outcome. We report here a case of successful Ch-EVAR treatment of AAA with hostile neck. An 81-year-old man presented with a 71-mm AAA during evaluation of a gastric ulcer. Aortic neck was 30 mm in diameter, 10-15 mm in length and angulated by 100°. EVAR was performed with chimney stenting to both renal arteries, and the patient recovered after transient hematuria. At one-year follow-up, AAA had increased by 7 mm with delayed type I endoleak control without renal insufficiency. The patient needed close follow-up.

The Single-centre Experience of the Supra-arch Chimney Technique in Endovascular Repair of Type B Aortic Dissections

We summarised the data performed at our centre to evaluate the feasibility of the chimney technique in type B aortic dissections (ADs) with supra-aortic vessel involvement. From September 2006 to December 2011, 34 thoracic endovascular aortic repairs (TEVARs) for ADs were performed combined with reconstruction of the arch branches with chimney stents (innominate artery, IA, n = 3; left common carotid artery, LCCA, n = 8; left subclavian artery, LSA, n = 23). Indications for these chimney stents included an inadequate proximal landing zone (<1.5 cm); high surgical-risk patients who are not suitable for open repair or hybrid procedures; and emergent endovascular repair of ADs. The series consisted of 13 acute, 12 sub-acute and 9 chronic cases. The right common carotid-left common carotid-left subclavian artery bypasses were performed in the IA chimney cases to reserve an adequate cerebral perfusion from the LCCA and left vertebral artery, while the left common carotid-left subclavian artery bypasses were performed in the cases having dominant left vertebral arteries. All the TEVARs, chimney stents and bypasses were performed as a single stage. Follow-ups were performed at 3, 6 and 12 months, and yearly thereafter. Endografts were deployed in Zone 0 (n = 3, 9%), Zone 1 (n = 8, 24%) and Zone 2 (n = 23, 67%). Twenty-five (74%) balloon-expandable and 9 (26%) self-expanding stents were used, of which seven (21%) were covered and 27 (79%) were bare stents. The technical success rate was 82% (28/34). Immediate type I endoleaks were observed in five patients (5/34, 15%), all of which underwent bare chimney-stent repairs. Three self-expanding chimney stents were compressed by endografts and another balloon expandable stent was deployed inside the first one. Five patients underwent surgical bypasses (RCCA-LCCA-LSA, n = 3; LCCA-LSA, n = 2). Perioperative morbidity included one ST-elevation myocardial infarction. No perioperative death or stroke was observed. The mean follow-up was 16.3 months (range, 3-60 months). Primary patency was maintained in all the chimney stents as well as the surgical bypasses. No stent fracture or recurrent chimney-related endoleak was observed during the follow-up period. In repairs for type B ADs, the chimney technique provides a minimally invasive way of preserving flow to the arch branches combined with a favourable mid-term outcome. The bare stents seemed to be related to a higher probability of the immediate type I endoleaks. A balloon-expandable stent should be regarded as the first choice due to its greater radial strength.

Endovascular repair of an aortic arch pseudoaneurysm by an atrial septal defect occluder combined with a chimney stent

An aortic arch pseudoaneurysm distal to the left common carotid artery (LCCA) was repaired endovascularly with an atrial septal defect occluder. Aortography showed complete closure of the pseudoaneurysm but delayed blood flow in the LCCA. A chimney stent was then placed into the LCCA to salvage it. Completion angiography suggested free flow in the LCCA and a minor perioccluder leak, which disappeared at 1-month follow-up. The patient was free from any symptoms related to the pseudoaneurysm at 1-year follow-up, with the atrial septal defect occluder in a satisfactory position, absence of leaking, and complete thrombosis in the pseudoaneurysm cavity.

Chimney grafts preserve visceral flow and allow safe stenting of juxtarenal aortic occlusion

Chimney grafts have proven useful for urgent endovascular repair of juxtarenal aortic aneurysms. Stenting of juxtarenal aortic occlusive disease is not routinely advocated due to the risk of visceral artery obstruction. We report on the potential applicability of chimney grafts in 10 patients with juxtarenal aortic stenosis or occlusion. To our best knowledge, chimney grafts have not been applied previously in this challenging setting. Ten high-risk female patients (mean age, 68 years) with severe stenosis or occlusion of the aorta at the level of the visceral arteries were offered stenting. "Chimney" stents or stent grafts (20-40 mm long) were implanted from a brachial approach into visceral arteries that needed to be covered by the aortic stent. The chimney stents were then temporarily obstructed by balloon catheters to prevent visceral embolization until the aortic stent or stent graft was deployed. All procedures were technically successful, and patency was obtained in all visceral arteries and the aorta without distal embolization. One patient died after 9 days of acute heart failure. The nine surviving patients presented no complications, and all stented vessels remained patent at up to 6 years. Another patient died after 5.5 years due to lung cancer. All three patients with renal impairment have improved renal function, and a reduction in antihypertensive medication has been possible. Chimney grafts may allow stenting of juxtarenal aortic occlusive disease by protecting the patency of visceral arteries. Further evaluation with more patients and longer follow-up is required.

Safety of elective management of synchronous aortic disease with simultaneous thoracic and aortic stent graft placement

Simultaneous treatment of multilevel aortic disease is controversial due to the theoretic increase in morbidity. This study was conducted to define the outcomes in patients treated electively with simultaneous thoracic endovascular aortic aneurysm repair (TEVAR) and abdominal aortic endovascular endografting for synchronous aortic pathology. Patients treated with simultaneous TEVAR and endovascular aneurysm repair (T&E) at the University of Florida were identified from a prospectively maintained endovascular aortic registry and compared with those treated with TEVAR alone (TA). The study excluded patients with urgent or emergency indications, thoracoabdominal or mycotic aneurysm, and those requiring chimney stents, fenestrations, or visceral debranching procedures. Demographics, anatomic characteristics, operative details, and periprocedural morbidity were recorded. Mortality and reintervention were estimated using life-table analysis. From 2001 to 2011, 595 patients underwent TEVAR, of whom 457 had elective repair. Twenty-two (18 men, 82%) were identified who were treated electively with simultaneous T&E. Mean ± standard deviation age was 66 ± 9 years, and median follow-up was 8.8 months (range, 1-34 months). Operative indications for the procedure included dissection-related pathology in 10 (45%) and various combinations of degenerative etiologies in 12 (55%). Compared with TA, T&E patients had significantly higher blood loss (P < .0001), contrast exposure (P < .0001), fluoroscopy time (P < .0001), and operative time (P < .0001). The temporary spinal cord ischemia rate was 13.6% (n = 3) for the T&E group and 6.0% for TA (P = .15); however, the permanent spinal cord ischemia rate was 4% for both groups (P = .96). The 30-day mortality for T&E was 4.5% (n = 1) compared with 2.1% (n = 10) for TA. Temporary renal injury (defined by a 25% increase over baseline creatinine) occurred in two T&E patients (9.1%), with none requiring permanent hemodialysis; no significant difference was noted between the two groups (P = .14). One-year mortality and freedom from reintervention in the T&E patients were 81% and 91%, respectively. Acceptable short-term morbidity and mortality can be achieved with T&E compared with TA, despite longer operative times, greater blood loss, and higher contrast exposure. There was a trend toward higher rates of renal and spinal cord injury, so implementation of strategies to reduce the potential of these complications or consideration of staged repair is recommended. Short-term reintervention rates are low, but longer follow-up and greater patient numbers are needed to determine procedural durability and applicability.

Use of covered chimney stents for pararenal aortic pathologies is safe and feasible with excellent patency and low incidence of endoleaks

To present the clinical experience of consecutive series with use of balloon-expandable and self-expanding chimney endografts (balloon-expandable covered stent group [BECS] vs self-expanding covered stent group [SECS]) in the endovascular treatment of challenging aortic pathologies requiring renal and/or visceral revascularization. Between January 2009 and May 2011, data for 37 high-risk patients from one center and 35 patients from another institution, with pararenal aortic pathologies treated by the chimney endovascular technique, were prospectively collected. The chimney-graft technique is based on the deployment of a covered or bare-metal stent parallel to the aortic endograft, thereby creating a conduit that runs outside the aortic main endograft, and has been proposed to ensure secure proximal fixation extending the sealing zones. Forty-six consecutive target vessels (43 renal arteries and 3 superior mesenteric arteries) were revascularized by the Advanta (Atrium, Hudson, NH) BECS (1.2 chimneys/patient); in contrast, 81 consecutive target vessels (64 renal arteries, 11 superior mesenteric arteries, and 6 celiac trunks) were revascularized by the Viabahn (Gore, Flagstaff, Ariz) SECS (2.3 chimneys/patient). The success rate for target vessel preservation was 97.8% for the BECS group and 100% for the SECS group in the entire follow up. There was one symptomatic left renal artery occlusion of the BECS group treated by open thrombectomy of the left renal artery and placement of 8-mm Dacron (BBraun, Aesculap AG, Tuttlingen, Germany) iliorenal bypass. Additionally, one patient underwent repeat balloon angioplasty with a 5-mm balloon due to high-grade in-stent stenosis of a 6 × 59 Advanta stent graft 12 months postoperatively. Overall, one perioperative (and not present in the computed tomography angiography at discharge) type Ia endoleak was detected in the BECS group. In contrast, five perioperative type Ia endoleaks were present in the SECS group; however, only one of them was persistent in the radiological imaging and was treated by proximal extension of a 5-mm cuff, 1 year postoperatively, due to continuous aneurismal sac increase. No patient of any subgroup developed postoperative persistent renal insufficiency with need of hemodialysis. Thirty-day and during the follow-up procedure-related mortality was 0% for both BECS and SECS groups. In summary, midterm results of use of covered chimney stents for pararenal aortic pathologies show safety and feasibility with excellent patency and low incidence of endoleaks.

Urgent or Emergent Endovascular Repair of Juxtarenal, Suprarenal, and Thoracoabdominal Aortic Aneurysms in Patients Unfit for Open Repair

To evaluate the early outcomes of urgent complex endovascular repair of juxtarenal, suprarenal, and thoracoabdominal abdominal aortic aneurysms in patients medically unfit for open repair. From June 2010 to February 2011, 12 patients with juxtarenal, suprarenal, or thoracoabdominal abdominal aortic aneurysms underwent endovascular repair with adjunctive techniques at one institution. These techniques included deployment of thoracic aortic endografts above modified bifurcated abdominal aortic endografts, graft modifications, and chimney stent grafts. All patients were deemed medically unfit for open repair from cardiopulmonary standpoints. Primary end points were technical success, branch patency, presence of endoleak, and 30-day mortality. Twelve patients (5 men, 7 women) underwent urgent complex endovascular repair of symptomatic abdominal aortic aneurysmal pathology. Of these, 10 presented with suprarenal or juxtarenal abdominal aortic aneurysms, 1 with a suprarenal aortic pseudoaneurysm, and 1 with a type IV thoracoabdominal aneurysm. Five thoracic endografts were deployed in the abdominal aorta above modified bifurcated abdominal endografts. Eight graft modifications and 10 chimney stents were used to achieve seal and preserve flow to select mesenteric vessels. Technical success was achieved in 100%. At 30 days, 12 of thirteen (92%) mesenteric stent branches were patent. Two endoleaks were noted on follow-up. One of 12 patients died for a 30-day mortality of 8%. Urgent complex endovascular repair of juxtarenal, suprarenal, and thoracoabdominal abdominal aortic aneurysms can be safely and successfully performed in patients medically unfit for open repair. Mid-term and long-term results are unknown and need to be further elucidated.

Chimney Stent Technique for Treatment of Severe Abdominal Aortic Atherosclerotic Stenosis

Application of the “chimney” stent technique is described in a case of complex multilevel atherosclerotic disease involving the juxtarenal aorta. A patient with significant comorbidities was unsuitable for major open reconstructive surgery. He was treated with a combined procedure consisting of chimney stent placement in the juxtarenal aorta, iliac “kissing” stent placement, and right-sided common femoral artery (CFA) replacement. This case shows that the chimney stent technique can be a feasible alternative to leaving a safety wire in the renal arteries and observation during primary angioplasty in complex atherosclerotic lesions of the abdominal aorta.

Endovascular chimney technique versus open repair of juxtarenal and suprarenal aneurysms

To compare early outcomes of endovascular repair of juxtarenal and suprarenal aneurysms using the chimney technique with open repair in anatomically-matched patients. Between January 2008 and December 2009, 21 patients underwent endovascular repair of juxtarenal and suprarenal aortic aneurysms with chimney stenting (Ch-EVAR) of 1 or 2 renal and/or superior mesenteric artery (SMA) vessels. These were compared with 21 anatomically-matched patients that underwent open repair (OR) during the same time period. Primary end points were 30-day mortality, chimney stent patency, and type Ia endoleak. Secondary end points included early complications, renal function, blood loss, and length of stay (LOS). Despite a higher proportion of women, oxygen-dependent pulmonary disease and lower baseline renal function, 30-day mortality was identical with one death (4.8%) in each group. Blood loss and total LOS were significantly less for Ch-EVAR. Six patients (29%) in the chimney group had acute kidney injury (AKI) compared with the open group, in which there were one (4.8%) AKI and four (19%) acute renal failures, of which two (9.5%) required chronic hemodialysis. Renal function at 12 months demonstrated similar declines in the overall estimated glomerular filtration rate (eGFR) in the Ch-EVAR and OR groups (11.1 ± 19.6 vs 10.4 ± 25.2, P = NS, respectively). There was one asymptomatic SMA stent occlusion at 6 months and partial compression of a second SMA stent which underwent repeat balloon angioplasty. Primary patency at 6 and 12 months was 94% and 84%, respectively. There was one type Ia endoleak noted at 30 days which resolved by 6 months. Ch-EVAR may extend the anatomical eligibility of endovascular aneurysm repair using conventional devices. It appears to have similar mortality to open repair with less morbidity. Long-term durability and stent patency remain to be determined.