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

Early and Midterm Outcomes of Chimney Endovascular Aortic Repair for Ruptured Abdominal Aortic Aneurysms

PURPOSE

To compare the outcomes of endovascular aortic aneurysm repair using a chimney technique (ch-EVAR) with those of the standard EVAR (st-EVAR) for ruptured abdominal aortic aneurysms (RAAA).

MATERIALS AND METHODS

We implemented ch-EVAR for juxtarenal RAAA based on obvious anatomical indications after converting the strategy for RAAA from open repair to EVAR. A retrospective, cohort-based study was conducted on patients with RAAA who were treated using EVAR in our hospital between July 2011 and March 2022. EVAR cases were extracted, and outcomes were compared between ch-EVAR and st-EVAR. Patient clinical status, anatomical variables, treatment, and follow-up data were evaluated.

RESULTS

A total of 56 (82%) and 12 (18%) patients were treated by st-EVAR and ch-EVAR, respectively. Thirty-day mortality rates were comparable between the 2 groups [8.9% in st-EVAR vs 8.3% in ch-EVAR (p= 0.95)]. Short-term outcomes showed that no type Ia endoleak occurred in either group. Midterm outcomes, including sac enlargement [7.5% in st-EVAR vs 0% in ch-EVAR (p= 0.37)], shrinkage [77.5% in st-EVAR vs 80.0% in ch-EVAR (p= 0.86)], and overall survival and freedom from aneurysm-related reintervention at 3 years [64.7% and 96.4% in the EVAR group vs 91.7% and 100% in the ch-EVAR group, respectively (p= 0.30 and 0.52)], were not significantly different between the 2 groups.

CONCLUSION

Ch-EVAR for RAAA showed remarkably excellent outcomes, comparable to those of st-EVAR. Ch-EVAR is considered technically feasible in experienced centers. The indications for EVAR for RAAA may be further expanded using the chimney technique, resulting in overall improved outcomes for RAAA.

CLINICAL IMPACT

This is a retrospective, single-center analysis of 68 patients with ruptured abdominal aortic aneurysms (RAAAs) treated by endovascular repair (EVAR) to investigate the efficacy of the chimney technique for juxtarenal RAAA. Thirty-day mortality rate was 8.3% for the chimney EVAR group, which was equivalent to that in the standard EVAR group. Mid-term outcomes including sac enlargement/shrinkage, overall survival, and freedom from aneurysm-related reintervention were comparable between the two groups. This report suggests the possibility of broadening the selection criteria of the current endovascular strategy using the chimney technique.

Emergent endovascular treatment options for thoracoabdominal aortic aneurysm

For a long time, parallel grafting, physician-modified endografts, and, more recently, in situ fenestration were the only go-to endovascular options for ruptured thoracoabdominal aortic aneurysm, offered mixed results, and depended mainly on the operator's and center's experience. As custom-made devices have become an established endovascular treatment option for elective thoracoabdominal aortic aneurysm, they are not a viable option in the emergency setting, as endograft production can take up to 4 months. The development of off-the-shelf (OTS) multibranched devices with a standardized configuration has allowed the treatment of ruptured thoracoabdominal aortic aneurysm with emergent branched endovascular procedures. The Zenith t-Branch device (Cook Medical) was the first readily available graft outside the United States to receive the CE mark (in 2012) and is currently the most studied device for those indications. A new device, the E-nside thoracoabdominal branch endoprosthesis OTS multibranched endograft (Artivion), has been made commercially available, and the GORE EXCLUDER thoracoabdominal branch endoprosthesis OTS multibranched endograft (W. L. Gore and Associates) is expected to be released in 2023. Due to the lack of guidelines on ruptured thoracoabdominal aortic aneurysm, this review summarizes the available treatment options (ie, parallel grafts, physician-modified endografts, in situ fenestrations, and OTS multibranched devices), compares the indications and contraindications, and points out the evidence gaps that should be filled in the next decade.

Endovascular Repair of Ruptured Abdominal Aortic Aneurysm in COVID 19 Pandemic

Abdominal aortic aneurysms are pathological dilatations of the abdominal aorta that occur because of unknown causes and are associated with cardiovascular risk factors excluding diabetes. Ruptured abdominal aortic aneurysms are catastrophic events with high mortality and morbidity. This case report describes successful management of a ruptured abdominal aortic aneurysm treated with endovascular aortic repair through the bell-button technique, with a short hospital course.

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.

Total abdominal debranching hybrid thoracoabdominal aortic aneurysm repair versus chimneys and snorkels

Open thoracoabdominal aortic aneurysm (TAAA) repair remains a surgical challenge. Hybrid and total endovascular repair have emerged as alternatives in treating TAAA. Total endovascular TAAA repair may be best performed with branched/fenestrated stent grafts. However, these technologies are not yet widely available. Thus, currently total endovascular TAAA repair using the chimney/snorkel techniques is considered a viable option in many centers.

In this article, we briefly review 2 readily available techniques with off-the-shelf devices, hybrid procedure using total abdominal debranching, and total endovascular repair using chimney/snorkel procedures. The hybrid TAAA repair avoids thoracotomy but requires laparotomy and carries high morbidity and mortality (eg, operative mortality, 4%-26% and renal failure, 4%-26%), comparable to traditional open repair. The staged hybrid approach has been proposed to minimize the invasiveness of the procedure, whereas the associated risk of interval aortic deaths is not negligible. Total endovascular repair reduces the morbidity and mortality after TAAA repair (eg, operative mortality, 3%-20% and renal failure, 0%-20%). However, it is technically demanding and the risks of future reinterventions—and need for repetitive surveillance—is inevitable (eg, immediate type I endoleak, 7%-16% and 1-year branch patency, 93%-98%). Currently, there are not enough data to determine which less-invasive option for open repair in patients with TAAA is superior. These alternatives should complement each other and be applied to carefully selected populations as a part of the overall toolbox in treating TAAA.

Outcomes of chimney/snorkel endovascular repair for symptomatic and ruptured abdominal aortic aneurysms

OBJECTIVE

Symptomatic and ruptured abdominal aortic aneurysms (AAAs) are increasingly being managed with endovascular aneurysm repair (EVAR). We aimed to identify the outcomes of symptomatic and ruptured AAAs that had undergone EVAR with a chimney or snorkel technique (ChEVAR).

METHODS

A retrospective cohort study was performed using the Vascular Quality Initiative registry from March 2013 to July 2019. All patients with symptomatic and ruptured AAAs with a proximal aortic zone of disease from 6 to 9 who had undergone ChEVAR were included. The outcomes were analyzed in accordance with the Society for Vascular Surgery reporting standards for EVAR.

RESULTS

ChEVAR was performed in 77 patients (ruptured, 35 [45.5%]; symptomatic, 42 [54.5%]). The median age was 73.0 years (interquartile range [IQR], 67.0-81.0 years), and 54 patients (70.1%) were men. The median maximum aneurysm diameter was 67.5 mm (IQR, 54.5-83.3 mm). All patients had American Society of Anesthesiologists class ≥III. For the patients with ruptured AAAs, the mean lowest preoperative systolic blood pressure was 95.3 ± 29.3 mm Hg. The fluoroscopy time was 57.4 minutes (IQR, 41.2-79.0 minutes). The proximal aortic zone of disease was zone 6 in 9 (11.7%), zone 7 in 21 (27.3%), zone 8 in 36 (46.8%), and zone 9 in 11 (14.3%) patients. ChEVAR involved more than one vessel in 55 patients (71.4%). No significant difference was found in 30-day mortality between the patients with ruptured vs symptomatic AAAs (11.4% vs 7.1%; P = .695). Reintervention was required for 10 patients (13.0%) at a median of 9 postoperative days, 2 (20.0%) of whom died. Postoperatively, 31 patients (40.3%) had experienced a major complication. A type I endoleak had occurred in nine patients (11.7%), two (22.2%) of whom died. Long-term follow-up data were available for 38 patients (49.4%) at a median of 406.5 days (IQR, 326.8-602.0 days) postoperatively. Of the 18 patients with long-term radiographic data, sac growth was detected in 4 (22.2%). A total of 14 patients had died at a median of 26.5 days (IQR, 3.0-468.5 days).

CONCLUSIONS

ChEVAR for symptomatic and ruptured AAAs can be performed with acceptable rates of morbidity and mortality. Long-term data are needed to determine the durability.

Endovascular Treatment of a Ruptured Pararenal Abdominal Aortic Aneurysm in a Patient With Coronavirus Disease-2019: Suggestions and Case Report

The aim of this report is to discuss emergent repair for complex aortic diseases in patients affected by novel coronavirus pneumonia (coronavirus disease-2019 [COVID-19]), describing a case of ruptured pararenal aortic aneurysm. An eighty-year-old man with COVID-19 was admitted for ruptured aneurysm of the pararenal aorta and hemorrhagic shock. Endovascular repair was chosen, and a proximal extension of the previous abdominal endograft was performed with parallel stents in the right renal artery and the superior mesenteric artery. Endovascular treatment and early anticoagulation are the key for success for vascular emergencies in patients with COVID-19, despite the risk of late endoleak.

Parallel graft techniques for urgent complex aortic diseases: Mid-term results of 12 cases

OBJECTIVES

Open repair is still the first choice for thoraco-abdominal and para-renal aortic aneurysms, but surgical treatment is burdened by significant morbidity and mortality, especially in urgent setting. Endovascular treatment by fenestrated or branched endografts is feasible and safe; but in urgent/emergent settings, custom-made endografts are hardly available in due time, and the repair with standard multibranched devices is still debated in cases with complex anatomy. Parallel grafting, on the other hand, which exploits covered stents to preserve patency of the visceral vessels, has been shown as a valuable option and can be performed in urgency, though some concerns still remain regarding its durability and complications. The purpose of this case series is to review the outcomes of all consecutive cases of complex aortic diseases treated with this technique in emergent/urgent setting.

MATERIALS AND METHODS

All cases of endovascular aortic repair of thoraco-abdominal and para-thoraco-abdominal performed in urgency or emergency from 2016 to June 2019 were retrospectively reviewed, recording clinical records, operative technique, primary technical success, and long-term outcomes. Each patient was followed-up by computed tomography angiography three months after the procedure and yearly thereafter.

RESULTS

Twenty consecutive patients (median age: 68, range: 47-89, male/female ratio: 16:4) affected by para-thoraco-abdominal (12) or thoraco-abdominal (8) were treated in urgent or emergent setting by chimney and/or periscope technique. A total number of 37 visceral vessels were stented (29 renal arteries, 1 polar artery of the kidney, 3 superior mesenteric arteries, and 4 coeliac trunks). Primary technical success was 100%, with one perioperative death. One patient died on post-operative month III for unrelated cause. Two type II endoleaks were detected at the first post-operative imaging studies and were managed conservatively. One type IB endoleak was treated by endovascular repair with a custom-made endograft (overall re-intervention rate: 5%). Over a median 22 months follow-up (range: 4-40, interquartile range: 12 months), all stentgrafts were patent.

CONCLUSION

Parallel graft is a feasible and safe option that should be considered in urgent and emergent treatment of para-thoraco-abdominal and thoraco-abdominal, when fenestrated and branched endografts cannot be used.

Gutter Characteristics and Stent Compression of Self-Expanding vs Balloon-Expandable Chimney Grafts in Juxtarenal Aneurysm Models

Purpose: To assess in silicone juxtarenal aneurysm models the gutter characteristics and compression of different types of chimney graft (CG) configurations. Materials and Methods: Fifty-seven combinations of Excluder C3 or Conformable Excluder stent-grafts (23, 26, and 28.5 mm) were deployed in 2 silicone juxtarenal aneurysm models with 3 types of CGs: Viabahn self-expanding (VSE; 6 and 13 mm) or Viabahn balloon-expandable (VBX; 6, 10, and 12 mm) stent-grafts and Advanta V12 balloon-expandable stent-grafts (ABX; 6 and 12 mm). Setups were divided into 4 groups on the basis of increasing CG and main graft (MG) diameters. Two independent observers assessed gutter size and type as well as CG compression on computed tomography scans using postprocessing software. Results: In the smaller diameter combinations (6-mm CG and 23-, 26-, and 28.5-mm MGs), both VSE (p=0.006 to 0.050) and ABX (p=0.045 to 0.050) showed lower gutter areas and volumes compared with VBX. In turn, the VBX showed a nonsignificant tendency to decreased compression, especially compared to ABX. Use of the Excluder C3 showed a 6-fold increase in type A1 gutters (related to type Ia endoleak) as compared to the Conformable Excluder (p=0.018). Balloon-expandable stent-grafts (both ABX and VBX) showed a 3-fold increase in type A1 gutters in comparison with self-expanding stent-grafts (p=0.008). Conclusion: The current study suggests that use of the Conformable Excluder in combination with VSE chimney grafts is superior to the other tested CG/MG combinations in terms of gutter size, gutter type, and CG compression.

Sealing Devices in Chimney Aortic Repair (CH EVAS) Versus Chimney Aortic Repair with Conventional Devices (CH EVAR): A Systematic Review

AIM

The aim of this study was to review the literature about the occurrence of postoperative type I endoleak (EL) and chimney graft thrombosis (CGT) after the use of sealing devices in chimney endovascular aortic repair (Ch EVAS), compared to chimney EVAR using conventional devices (Ch EVAR).

METHODS

A systematic review of the literature on PubMed and MEDLINE with the terms "Chimney" and "Parallel grafts" was performed. The review was set up following the PRISMA guidelines. Case series about the use of the chimney/snorkel technique during endovascular repair of juxtarenal/pararenal aneurysms (AAA) were considered. Only papers with full text available in English and reporting complete data with at least 1 month of follow-up about at least 5 cases were included in the analysis.

RESULTS

In total, 90 papers were assessed for eligibility. According to the inclusion criteria, only 25 papers could be analyzed (20 in the Ch EVAR group and 5 in the Ch EVAS group). A type I EL occurred in 9.3% after Ch EVAR (95% CI 7.1-12.2%) and in 8.3% after Ch EVAS (95% CI 3.5-18.5%), being not significantly different. CGT occurred in 10.7% of cases after Ch EVAR (95% CI 8.8-13%) and in 8.8% of cases after Ch EVAS (95% CI 3.3-21.3%), being also not significantly different.

CONCLUSIONS

The reported rate of type I EL and CGT occurring after Ch EVAR tended to be slightly higher than those reported after Ch EVAS, even if the difference was not statistically significant.

Extended use of endovascular aneurysm sealing: Chimneys for juxtarenal aneurysms

Hostile infrarenal aortic neck anatomy presents a challenge for the endovascular treatment of abdominal aortic aneurysm. Open surgical repair has been seen as the gold standard treatment for juxtarenal abdominal aortic aneurysm; however, endovascular techniques are now becoming more prevalent, particularly in patients deemed high risk for morbidity and mortality with open repair. The morphology of an aneurysm is a determinant of long-term outcomes, and short aneurysm necks are associated with poorer outcomes and a higher rate of secondary reinterventions. Parallel grafts have been used in combination with endovascular aneurysm repair to elongate the sealing zone into the paravisceral segment of the aorta. This technique is associated with a risk of proximal Type I endoleak due to "guttering." This risk may be decreased when parallel grafts are used in combination with endovascular aneurysm sealing and, as such, this technique may represent an alternative to current techniques for the treatment of juxtarenal abdominal aortic aneurysm, such as the use of conventional bifurcated grafts (with or without parallel grafts) and fenestrated endovascular stent grafts.