Comparison of chimney technique and single-branched stent graft in a cohort of patients with type B aortic dissections: a retrospective cohort study.

Background: Single-branched stent grafts and the chimney technique are widely used in the treatment of type B aortic dissection (TBAD). The main objective of this study was to compare the outcomes of single-branched stent grafts and the chimney technique in the treatment of TBAD. Methods: From January 2019 to December 2021, the retrospective cohort study contained a cohort of 91 patients with TBAD undergoing thoracic endovascular aortic repair (TEVAR) using single-branched stent grafts and the chimney technique. Group A included 55 patients treated with single-branched covered stents, and Group B included 36 patients treated with the chimney technique. We compared the effects of the procedures on peri-/post-operative outcomes between the two groups. The primary endpoint is clinical death, and the secondary endpoints include the patency of branch stents, the incidence of cerebral infarction, false lumen thrombosis, and the proportion of paraplegia. Results: For the baseline data, the two groups of patients show no differences in terms of age, gender, and associated symptoms. All procedures were successfully performed in both groups. The median follow-up period was 17.6 months (range, 10-34 months). During TEVAR, 5 (9.1%) type I endoleaks occurred in group A, and 11 (30.6%) occurred in group B (P<0.05). During follow-up, there were 2 cases (3.6%) of paraplegia and 1 case (1.8%) of cerebral infarction in Group A, while Group B had 1 case (2.8%) of paraplegia. Three patients in group B reported retrograde type A aortic dissection (RTAD), and 1 of them died (2.8%); however, there were no RTAD cases in group A. Complete thrombosis of the false lumen in the thoracic aorta was observed in 45.5% (25/55) of patients in group A and in 41.7% (15/36) in group B (P=0.72). No significant difference in the thrombosis-volume ratio in the whole false lumen was found during follow-up between group A (81.0%±2.9%) and group B (81.8%±2.6%; P=0.23). Conclusions: Branched stent grafts can be used in cases with insufficient proximal landing zones and reduce the occurrence of type 1 endoleak compared to the chimney technique. This may help to prevent RTAD. Further research, including more cases and longer follow-up periods, is needed to substantiate these results.

Coronary Risk in Transcatheter Aortic Valve Replacement, Overview of Data, Challenges, and Best Practices.

Coronary artery obstruction is a rare complication of transcatheter aortic valve replacement (TAVR). This risk increases in TAVR-valve-in-valve procedure. Several anatomic risk factors were described in many studies to identify the predictive elements of coronary artery occlusion on computed tomography cardiac scan. Rescue percutaneous coronary intervention was the first approach described to treat this complication with a high mortality rate. Later on, preventive chimney stenting technique was evaluated and results showed that is a safe and effective strategy but it leads to a difficult coronary access later. New preventive techniques are being evaluated recently (Basilica and Shorctut).

Cleaning Up the Chimney: Early Renal Stent Graft Thrombosis Following Endovascular Treatment of a Juxtarenal Aortic Aneurysm With the Chimney Technique.

The endovascular management of juxtarenal aortic aneurysms with the chimney technique (ch-EVAR) has gained popularity in recent years. It provides an alternative to open repair, allowing treatment of challenging anatomies with devices readily available in any vascular suite. The primary drawback persists as the occurrence of type-Ia endoleak from gutters and renal stent thrombosis. We present two cases of early renal stent graft thrombosis following chimney endovascular aneurysm repair. The first patient was an 80-year-old man who underwent single ch-EVAR and came back on the fifth post-op day with renal stent graft thrombosis. He was re-operated for recanalization and additional stenting of his chimney graft. The patient recovered well with no complications. The second case involved a 72-year-old man with a juxtarenal aneurysm, treated with ch-EVAR on both renal arteries. Unfortunately, on the 10th post-op day, he was referred to our department due to lumbar pain and acute renal failure due to chimney graft thrombosis bilaterally. The left renal chimney graft was recanalized by endovascular means. On the contrary, despite efforts of the endovascular and open approach, the right chimney graft and the right renal artery remained occluded. While ch-EVAR is a viable and off-the-shelf solution for urgent and complex juxtarenal aortic aneurysms, it should be performed with awareness of the potential for graft thrombosis and persistent endoleaks. Despite these complications, the chimney technique can still be a viable treatment option. A better understanding of the indications and advancements in the devices used can lead to better long-term results.

Systematic Review and Meta-analysis of Fenestrated and Chimney/Snorkel Techniques for Endovascular Repair of Juxtarenal Aortic Aneurysms.

OBJECTIVES: Comparative effectiveness of fenestrated endovascular aneurysm repair (FEVAR) and chimney graft endovascular aneurysm repair (ChEVAR) for juxtarenal aortic aneurysms (JAAs) remains unclear. Our objective was to identify and analyze the current body of evidence comparing the effectiveness of both techniques for JAA. METHODS: We performed a systematic review and meta-analysis comparing the effectiveness of FEVAR and ChEVAR for JAA repair. We searched MEDLINE, EMBASE, and Cochrane Register for Controlled Trials from January 1, 1990, for randomized and non-randomized studies assessing outcomes of FEVAR and ChEVAR for JAA repair. Screening, data extraction, risk of bias assessment, and GRADE (Grading of Recommendations, Assessments, Development, and Evaluations) certainty of evidence were performed in duplicate. Data were pooled statistically where possible. RESULTS: Nine retrospective cohort studies comparing the use of FEVAR and ChEVAR for juxtarenal aneurysm were included for meta-analysis. The FEVAR and ChEVAR arms of the meta-analysis consisted of 726 participants and 518 participants, respectively. There were 598 (86.8%) and 332 (81.6%) men in each arm. The mean diameter was larger in the ChEVAR arm (59 mm vs 52.5 mm). Both techniques had similar rates of postoperative 30-day mortality, 3.38% (8/237) versus 3.52% (8/227), acute kidney injury, 16.76% (31/185) versus 17.31% (18/104), and major adverse cardiac events, 7.30% (46/630) versus 6.60% (22/333). The meta-analysis supported the use of FEVAR for most outcomes, with significant advantage for technical success (odds ratio [OR]: 3.24, 95% CI: 1.24-8.42) and avoidance of type 1 endoleak (OR: 5.76, 95% CI: 1.94-17.08), but a disadvantage for spinal cord ischemia (OR: 10.21, 95% CI: 1.21-86.11), which had a very low number of events. The quality of evidence was "moderate" for most outcomes. CONCLUSION: Both endovascular techniques had good safety profiles. The evidence does not support superiority of either FEVAR or ChEVAR for JAA. CLINICAL IMPACT: While lack of equipoise has hampered the design of randomised trials of open versus endovascular repair of juxtarenal aortic aneurysms, concern about the durability of endovascular repair highlights the need for stronger evidence of the comparative efficacy of endovascular techniques. This review performed meta-analysis and evidence appraisal of recent data from large observational studies comparing fenestrated and chimney techniques, using a comprehensive outcome set. Superiority of either intervention could not be established due to differences in participants' baseline risk in each study arm. However, data suggests that both techniques are safe and suitable for use when indicated.

Early and Mid-Term Outcomes of Using the Chimney Technique in Redo Mitral Valve Replacement in Patients with a Small Mitral Annulus.

The outcomes of redo mitral valve replacement (Re-MVR) in a small mitral annulus with the use of the chimney technique are not well documented. The purpose of this study is to present our early experience with this group of patients, illustrating the periop-erative complications and mortality outcomes. From 2019 to 2020, 77 consecutive patients underwent Re-MVR with the use of the chimney technique because of a small mitral annulus. To evaluate heart structural integrity and clinical outcomes, postoperative clinical data and echocardiograms were examined. The mean age was 56.7 ± 15.98 years. All patients underwent mitral valve surgery, of which 62 were mitral valve replacements, 7 mitral valve repairs, and 8 double valve replacements. The preoperative mitral valve mean gradient was 18.07 ± 9.40 mmHg, and the postoperative mitral prosthesis size was 28.51 ± 1.22 mm. The median increment of mitral size enlargement was 4 (0, 6) valve sizes. The mean mitral gradient coming out of the operating room was 10.34 ± 2.12 mmHg, and at the follow-up echocardiogram performed at 3 years after the procedure, it was 10.36 ± 1.70 mmHg. One-year survival was 93.3%, while the 4-year survival rate was 89.3%, with no reoperation. The use of the chimney technique in small mitral valve re-mitral valve replacement results in larger valve sizes. Moreover, the mean gradients over the mitral valve are acceptable both intraoperatively and over time.

Outcomes of Clampless Real Chimney Technique with Dacron Graft and Sleeve Banding of the Ascending Aorta for Total Debranching Endovascular Arch Repair.

BACKGROUND: Hybrid aortic arch repair with debranching of the supra-aortic vessels carries a high risk of cerebral infarction and fatal complications associated with side clamping of the ascending aorta. A previous study had reported the "real chimney" technique, a novel method for clamp-free total debranching thoracic endovascular aortic repair with the ascending aortic sleeve banding with dacron. In this study, we aim to build upon this foundation by presenting our experience with the early and midterm outcomes of this technique. METHODS: We retrospectively reviewed the medical records of 61 consecutive older adult patients with aortic arch pathologies and a high risk of open repair who underwent total debranching thoracic endovascular aortic repair using the real chimney technique at our institution between January 2014 and June 2022. This technique was used to anastomose the ascending aorta with the main trunk of the triple-branched prosthetic graft. RESULTS: The mean patient age was 75.1 years, and 54% of patients were transferred from medical facilities with cardiothoracic surgery departments. The comorbidities included chronic obstructive pulmonary disease (49.2%), chronic kidney disease (63.9%), coronary artery disease (27.9%), and history of stroke (31.1%). No 30-day mortality was observed. Complications included postoperative renal failure requiring permanent hemodialysis (4; 6.6%), stroke (modified Rankin scale score: ≥2 in 5; 8.2%), permanent paraplegia (1; 1.6%), and permanent paraparesis (4; 6.6%). The median follow-up period was 40.5±28.5 months. The postoperative survival rates at 5 years were 66.8%. No patients experienced complications associated with the aorta or anastomosis site; only 1 patient required an additional procedure for stenosis of the anastomosis site (midterm). An aneurysmal diameter reduction of ≥3 mm was observed in 37 cases (60.7%), and the mean aneurysmal diameter reduction was 5.3 mm. CONCLUSIONS: The postoperative outcome of total debranching thoracic endovascular aortic arch repair is not only acceptable but also promising, particularly in patients at high risk of open repair. CLINICAL IMPACT: Our novel real chimney technique for total debranching thoracic endovascular aortic repair of aortic arch pathologies in patients who were at a high-risk for open repair resulted in no 30-day mortality and no complications related to the aorta or the real chimney anastomosis site.The real chimney technique is effective for managing aortic arch pathologies and enables less invasive total debranching thoracic endovascular aortic arch repair without the need for extracorporeal circulation and clamping of the ascending aorta.

Case Report: Double chimney in valve-in-valve procedures for high-risk coronary obstruction.

The chimney technique has been utilized to minimize the risk of coronary artery obstruction during valve-in-valve procedures. Here, we present a case involving an 89-year-old female patient with low coronary ostia, severe aortic regurgitation, and intractable heart decompensation caused by degenerated aortic bioprosthesis. The patient underwent a successful transcatheter aortic valve implantation procedure using the chimney technique in both coronary ostia.

Outcomes of Castor Single-Branched Stent Graft for Reconstruction of Multiple Supra-Aortic Branches in Aortic Arch Disease.

PURPOSE: To report the outcomes of a combination of Castor single-branched stent grafts with other techniques for the reconstruction of multiple supra-aortic branches in aortic arch disease. MATERIALS AND METHODS: Between December 2019 and December 2021, 20 patients with aortic arch disease underwent thoracic endovascular aortic repair (TEVAR) at our institution using a Castor single-branched stent graft combined with the fenestration, chimney, or bypass techniques. Thoracic endovascular aortic repair is indicated for complicated or acute type B aortic dissection (TBAD), nonruptured aneurysms with a maximum aneurysm diameter >5.5 cm or showing rapidly expanded, ruptured, or threatened aneurysms, and penetrating aortic ulcers (PAUs) with a maximal aortic diameter >5.5 cm or with PAUs >10 mm deep or >20 mm in diameter. Preoperative, intraoperative, and postoperative clinical data were recorded. RESULTS: The median age of the patients was 56 (range=52-69 years) years, and 19 patients were men. Seven patients underwent the Castor single-branched stent graft and left common carotid artery (LCCA) chimney technique, 8 patients underwent the Castor single-branched stent graft and fenestration technique, and 5 patients underwent the Castor single-branched stent graft and bypass technique. The technical success rate was 100%. Major adverse events included 2 endoleaks, 1 spinal cord ischemia, and 1 early-stage retrograde type A aortic dissection. No cerebral stroke-related complications were observed. The mortality rate was 10% (2/20 patients). One patient with thoracic aortic aneurysm (TAA) died because of a sudden decrease in oxygen saturation and blood pressure after surgery. Relatives declined autopsy, and the cause of death was not determined. Another patient died of a retrograde type A dissection after surgery. The median follow-up period was 6 months (range=3.5-12 months). During follow-up, 1 patient with type I endoleak underwent thoracotomy again after a year. The remaining patients recovered well. CONCLUSIONS: The combination of a Castor single-branched stent graft with fenestration, chimney, or bypass techniques may be an effective treatment for preserving multiple supra-aortic branches in aortic arch disease. CLINICAL IMPACT: This study introduced three methods of reconstruction of multiple supra-aortic branches using a Castor single-branched stent graft (Castor single-branched stent graft combined with fenestration, chimney, or bypass technique) and analysed their advantages and shortcomings to provide experience for the future treatment of aortic arch diseases.

Comparison of Chimney and Fenestrated Techniques for Supra-Aortic Branch Revascularization During Thoracic Endovascular Aortic Repair: A Systematic Review and Meta-Analysis.

PURPOSE: To compare the technical and clinical outcomes of fenestrated thoracic endovascular aortic repair (F-TEVAR) and chimney thoracic endovascular aortic repair (CH-EVAR) of aortic disease. METHODS: PubMed, Embase and Cochrane databases were systematically searched to identify studies on the management of thoracic aortic pathologies using chimney or fenestrated techniques published between 2000 and 2022. Individual studies provided at least one of the following essential outcomes: technical success, immediate and follow-up type I endoleak, 30-day and aorta-related mortality, cerebral events and supra-aortic branch patency. RESULTS: 24 chimney (1106 patients) and 21 fenestrated technique studies (1040 patients) were included. The scope of the study encompassed various thoracic aortic conditions, such as thoracic aortic dissection, thoracic aortic aneurysm, thoracic aortic ulcer, and other thoracic aortic diseases. Technical success was defined as the handling of the principal ailment affecting the aorta, devoid of any instances of complications. The technical success rates were higher in fenestrated group compared with chimney group (98.0% vs. 95.8% p < 0.001), and the rate of type I endoleak either immediately or during follow-up was higher in the chimney technique group (9.3% vs. 1.3% p < 0.001, 4.0% vs. 0.0% p < 0.001). The chimney technique group had higher 30-day mortality and aorta-related mortality than those in the fenestrated technique group (2.1% vs. 0.3% p < 0.001, 0.4% vs. 0.0% p < 0.001). Morbidity rates of cerebral events and supra-aortic branch patency were same in both groups (2.2% vs. 1.1% p = 0.116, 98.2% vs. 99.4% p = 0.094). The chimney technique group had longer operative time (110.0 min vs. 90.8 min p < 0.001). Two groups had same fluoroscopy time (34.0 min vs. 33.4 min p = 0.614). CONCLUSIONS: The finding suggest that both the chimney and fenestrated techniques are efficacious in supra-aortic branch reconstruction. However, the fenestrated technique exhibits potential superiority as an interventional strategy, as it demonstrates a lower incidence of type 1 Endoleak, 30-day mortality, and aorta-related death following TEVAR.

Intracoronary Pacing during "Chimney Technique" in Transcatheter Aortic Valve-in-Valve Implantation: An Alternative Temporary Rapid Ventricular Stimulation?

Temporary rapid ventricular pacing (TRVP) is required during transcatheter aortic valve implantation (TAVI) in order to reduce cardiac output and to facilitate balloon aortic valvuloplasty, prosthesis deployment, and post-deployment balloon dilation. The two most frequently used TRVP techniques are right endocardial (RE)-TRVP and retrograde left endocardial temporary rapid ventricular pacing (RLE)-TRVP. The first one could be responsible for cardiac tamponade, one of the most serious procedural complications during TAVI, while the second one could often be unsuccessful. Intracoronary (IC)-TRVP through a coronary guidewire has been described as a safe and efficient procedure that could avoid such complications. We describe two clinical cases in which IC-TRVP has been effectively used during valve-in-valve TAVI with coronary protection via the "chimney technique", after unsuccessful RLE-TRVP.

Single-Center Preliminary Experience with Gutter-Plugging Chimney Stent-Graft for Aortic Dissection.

PURPOSE: To report the early 2-year results and experience of a novel gutter-plugging chimney stent-graft in a single center that participated in the clinical trial of Prospective Study for Aortic Arch Therapy with stENt-graft for Chimney technology. MATERIALS AND METHODS: Patients diagnosed with aortic dissection were treated with the novel chimney stent-grafts named Longuette™ for the left subclavian artery revascularization. Primary study outcomes were the incidence of freedom from major adverse events within 30 days and success rate of the operation over 12 months. RESULTS: A total of 34 patients were enrolled between September 2019 and December 2020. The immediate technical success rate (stent-grafts successfully deployed without fast-flow type Ia or type III endoleak intraoperatively) was 100%, and there were no conversions to open repair. Type Ia and type II endoleaks were noted in three patients (8.8%) and one patient (2.9%) at discharge, respectively. One patient (2.9%) with type Ia endoleak underwent coil embolization at 12 months because of false lumen dilation, and one (2.9%) case of type Ia endoleak resolved spontaneously at 24 months. One chimney stent (2.9%) was revealed with stenosis at discharge and occluded with thrombosis at 6 months postoperatively. During the 2-year follow-up, there was no death, rupture, stroke, paraplegia, left arm ischemia, retrograde dissection, stent-graft induced new entry, or stent migration. CONCLUSION: The initial results of the Longuette™ stent-graft for revascularization of the left subclavian artery are encouraging with a high technical success rate. Further multicenter follow-up outcomes are required to assess the long-term durability. LEVEL OF EVIDENCE: Level 4, Case Series.

Endovascular repair using parallel grafts to treat a suprarenal pancreatitis-related abdominal aortic pseudoaneurysm.

Arterial pseudoaneurysms represent an uncommon complication of acute pancreatic inflammation or chronic pancreatitis. We describe a contained rupture of a suprarenal abdominal aortic pseudoaneurysm. An aorto-uni-iliac stent-graft was adopted as the aortic main body and was combined with two chimneys and two periscope stents for celiac/superior mesenteric artery and renal arteries, respectively. The procedure was complicated by the entrapment of the celiac sheath into the barbs of the aortic stent-graft and the attempts to remove the sheath resulted in an upward migration of the stent-grafts. A bail-out endovascular procedure was used to reline the stent-grafts and the pseudoaneurysmal sac was embolized with coils.

Management of an Isolated Left Vertebral Artery on the Arch During Zone 2 Landing Thoracic Endovascular Aortic Repair: A Multicentre Retrospective Study.

OBJECTIVE: To compare the early and midterm outcomes of three different strategies for an isolated left vertebral artery on the arch (LVoA) revascularisation during thoracic endovascular aortic repair (TEVAR) with a proximal zone 2 landing. METHODS: Between January 2016 and December 2021, 67 patients with LVoA and aortic arch pathologies who underwent zone 2 landing TEVAR at four medical centres were enrolled. These patients were divided into three groups for comparison: the novel chimney (group A, n = 28) with the right brachial-left brachial through and through (RLT) procedure; in vitro fenestration (group B, n = 24); and transposition (group C, n = 15). The flow direction and velocity of the LVoA was examined by Doppler ultrasound in the pre-, intra-, and post-operative periods. Primary outcomes were all cause mortality and new neurological symptoms. RESULTS: No deaths or new neurological symptoms occurred within 30 days. Early type Ia endoleak rates were 18% (n = 5), 17% (n = 4), and 0% in groups A, B, and C, respectively (p = .22). All patients had antegrade flow of the LVoA. The mean ± standard deviation duration of follow up was 63.6 ± 4.0 months. No deaths were observed during follow up. The rates of new neurological symptoms were 0%, 8%, and 33% in groups A, B, and C, respectively. The rates of midterm type Ia endoleak were 7%, 12%, and 0% in groups A, B, and C, respectively (p = .35). Bidirectional flow rates in the LVoA were 0%, 21%, and 27% in groups A, B, and C, respectively (p = .021). Two (8%) and three (20%) patients in groups B and C underwent a secondary procedure because of mild dizziness, but this was not necessary in group A (p = .058). CONCLUSION: The novel chimney technique of the RLT procedure may be feasible for patients with a LVoA requiring zone 2 anchoring. Accurate determination of the safety and feasibility of this novel technique requires larger sample sizes and longer follow up.

Clinical effect of in vitro fenestration on reconstruction of left subclavian artery in endovascular treatment of aortic dissection / 中国胸心血管外科临床杂志

@#Objective    To investigate the effect of in vitro fenestration on reconstruction of left subclavian artery in endovascular treatment of aortic dissection. Methods    A total of 89 patients with aortic dissection involving left subclavian artery were treated by endovascular treatment in the Second Affiliated Hospital of Fujian Medical University from February 2017 to January 2020. There were 44 patients in the test group, including 36 males and 8 females, with an average age of 58.02±13.58 years. There were 45 patients in the control group, including 35 males and 10 females, with an average age of 54.10±12.32 years. The left subclavian artery was reconstructed by in vitro fenestration in the test group and by chimney technique in the control group. The clinical data were compared between the two groups. Results    The operation time of the test group was longer than that of the control group (126.16±7.53 min vs. 96.49±6.52 min, P<0.01). The median follow-up time was 31 (13-48) months. The incidence of endoleak in the test group (4.7%) was lower than that in the control group (18.6%, P=0.04) during the follow-up. There was no statistical difference in the incidence of stroke, myocardial infarction, false lumen thrombosis, retrograde aortic dissection or left subclavian artery occlusion between the two groups (P>0.05). Conclusion     In vitro fenestration for reconstructing left subclavian artery in thoracic endovascular aortic repair of aortic dissection is safe and feasible, which is worthy of further clinical promotion.

Outcomes of thoracic endovascular aortic repair with chimney technique for aortic arch diseases.

Objective: This study aimed to summarize the long-term experience of using the chimney technique in thoracic endovascular aortic repair (TEVAR) for aortic arch diseases. Methods: From November 2007 to June 2021, a total of 345 consecutive patients (mean age 56 ± 11.3 years, range 28-83, 302 men) with aortic arch pathologies underwent TEVAR combined with chimney technique (cTEVAR). Their medical data and follow-up results were retrospectively reviewed and analyzed. Results: Among the 345 patients, 278 (80.6%) received single chimneys, 53 (15.4%) received double chimneys, 7 (2%) received triple chimneys, and 7 (2%) underwent cTEVAR accompanied by other techniques (two with extra-anatomical bypass, two with in situ fenestration, and three with physician modified fenestration). A total of 412 chimney stents were used, including 27 in the innominate artery (IA), 113 in the left common carotid artery, 270 in the left subclavian artery, and two in the aberrant right subclavian artery. Early type IA endoleaks were found in 38 (11%) patients, including 12 with the double or triple chimney technique. Early type II endoleak was found in nine (2.6%) patients. Early re-intervention occurred in two patients with double chimney technique, one for chimney stent migration and the other for compression of chimney stent. The 30-day mortality was 1.2% (4 in 345). During a mean follow-up of 42 ± 22 months (range 1-108 months), major stroke occurred in nine (2.6%) patients, chimney occlusion or stenosis occurred in six (1.7%), and retrograde type A aortic dissection occurred in four (1.2%). Fourteen (4.1%) patients received the secondary intervention. The all-cause mortality was 6.7% (23 in 345). Additionally, the total adverse event rate after cTEVAR was 13.9% (48 in 345). Conclusion: TEVAR with chimney technique provides a minimally invasive alternative with good chimney graft patency and low postoperative mortality during follow-up. However, the double and triple chimney techniques should be used cautiously as they seem to have a higher risk for type IA endoleak and adverse events after the operation.

Mid-term Comparison of One-Piece Branched Stent-Graft and Chimney Technique Treating Aortic Arch Pathologies.

PURPOSE: We compared the mid-term outcomes of a one-piece branched stent-graft with the chimney technique in the treatment of aortic arch pathologies. METHODS: Between August 2012 and December 2017, a retrospective analysis of 279 patients with thoracic aortic dissection (TAD) or aneurysm (TAA) who underwent thoracic endovascular aortic repair with b-TEVAR (n = 69, 58 TAD and 11 TAA) or c-TEVAR (n = 210, 151 TAD and 59 TAA) was performed. RESULTS: Forty-five double-chimney for the left subclavian artery (LSA) and left common carotid artery LCCA and 165 single-chimney for the LSA were performed in chimney-TEVAR (c-TEVAR) and 69 branched-TEVAR (b-TEVAR) with 36 single-branched stent-grafts and 33 branched stent-grafts combined with fenestration technique. The c-TEVAR group experienced more in-hospital complications than the b-TEVAR group (19.5 vs. 7.2%, p = 0.017), primarily because the c-TEVAR group experienced more in-hospital cerebral ischemia events (6.2 vs. 0%, p = 0.043) and intra-operative type I endoleaks (31.9 vs. 5.8%, p < 0.01). There were significantly more follow-up type I endoleaks (21.9 vs. 4.3%, p = 0.002), cerebral ischemia events (11.0 vs. 2.9%, p = 0.042), and re-interventions (12.9 vs. 4.3%, p = 0.048) in the c-TEVAR group than in the b-TEVAR group. However, follow-up mortality was not significantly different between the c-TEVAR and b-TEVAR groups (5.2 vs. 2.9%, p = 0.638). CONCLUSION: In patients with aortic pathologies involving the arch branches, customized b-TEVAR may result in fewer cerebral ischemia events and endoleaks than c-TEVAR. However, c-TEVAR should be considered an off-the-shelf treatment option for patients in need of emergency treatment. LEVEL OF EVIDENCE: Level 4, Case Series.

Early Results of a Novel Gutter-Free Chimney Stent-Graft System to Treat Aortic Arch Dissection: Single-Center Data from a Prospective Clinical Trial.

AIMS: Discuss the clinical value, technique characteristics, and early follow-up results of a newly designed gutter-free chimney stent-graft system for aortic arch pathology. METHODS AND RESULTS: About 13 patients with aortic arch dissection were enrolled in a clinical trial testing a novel gutter-free stent-graft between February 2019 and December 2020. All 13 patients were male, age 52.6±10.4 years. The implantation time was 14.0±6.9 minutes; total procedure time was 89.5±19.8 minutes. The volume of contrast was 79.6±7.2 ml. And 15 aortic stent-grafts were implanted, and all 13 patients had chimney branch stent-grafts implanted into the left subclavian artery (LSA). There were 3 (23.1%) cases of immediate type Ιa endoleak after thoracic endovascular aortic repair (TEVAR), and 7.7% type Ιa endoleaks occurred in delayed fashion. Survival at 2 years was 100%, and the 2-year patency of chimney stent-grafts was 100%. CONCLUSIONS: This study reports early success with good freedom from endoleak using a novel stent-graft designed for chimney TEVAR to treat aortic arch dissection. Postoperative survival and patency of the branch stent-grafts were excellent. Additional data from this multicenter clinical trial will be forthcoming.

Chimney stent in acute Stanford type B aortic dissection with insufficient anchorage zone / 中华普通外科杂志

Objective:To investigate the effect of chimney stent for reconstruction of left subclavical artery (LSA) in thoracic endovascular aotic repair (TEVAR) for acute Stanford type B aortic dissection with insufficient anchorage zone and non-thrombotic false lumen.Methods:TEVAR with chimney stent for LSA in 39 cases of acute Stanford type B aortic dissection with insufficient anchorage zone and non-thrombotic false lumen was done from Feb 2013 to Jan 2021.Results:Covered chimney stents was used in 11 cases and bare chimney stents in 28 cases. There was no postoperative stroke, left upper limb ischemia, paraplegia, hemiplegia and death. No stent migration, reverse tear and dissection rupture were observed. One bare stent was obstructed after 18 months, and all the remaining stents were patent during follow-up. The rate of immediate type Ⅰa endoleak in covered chimney stent group and bare chimney stent group were 0(0/11) and 32.1%(9/28) respectively ( P=0.04). The distance from proximal tear to LSA in covered chimney stent group, endoleak subgroup and non-endoleak subgroup in bare chimney stent were (5.1±2.3)mm, (14.4±5.2)mm and (7.8±7.0)mm respectively ( P<0.05). False lumen thrombosis was formed in endoleak subgroup 2-8 weeks after operation, and endoleak disappeared. Conclusions:There is a correlation between immediate type Ⅰa endoleak in bare chimney stent for LSA and the distance from proximal tear to LSA, covered chimney stent can reduce the incidence of immediate type Ⅰa endoleak in TEVAR for acute Stanford type B aortic dissection with insufficient anchorage zone and non-thrombotic false lumen.

Chimney reconstruction provides a wider subaortic space and reduces the risk of pulmonary artery compression in the Norwood-type aortic arch reconstruction without patch supplementation.

OBJECTIVES: Pulmonary artery (PA) compression by the neoaorta is a serious complication after the Norwood-type palliation (NP) for hypoplastic left heart syndrome. Either excess patch tailoring or limited use of autologous tissue may cause narrowing of the subaortic space. The chimney technique could theoretically provide a wide subaortic space. METHODS: Twenty-nine patients with both pre- and post-NP computed tomography data available of the 37 consecutive patients who underwent NP in our institution were reviewed. Arch height, arch width, sinus of Valsalva diameter, area under the neoaortic arch and arch angle were measured. These patients were divided according to the neo-arch reconstruction technique, chimney reconstruction technique (CR) or conventional direct reconstruction technique (DR). RESULTS: Median age and weight at NP were 2.1 months and 3.5 kg, respectively. Twenty-two patients underwent previous bilateral PA banding. During NP, 17 CR and 12 DR were performed. Four patients in the DR group developed PA compression. No neoaortic arch dilatation was found in either group. Post-NP arch width, area under the neo-arch and the arch angle were significantly larger in the CR group. Pre-NP arch height was significantly smaller in DR patients with PA compression than in those without. CONCLUSIONS: The chimney technique decreased the risk of PA compression and provided a wider subaortic space and a less acute arch angle. This technique had no short-term effect on the neoaortic root. Small preoperative arch height is a potential risk factor for PA compression in DR, and the chimney technique could be an effective solution.