Systematic review of chimney and periscope grafts for endovascular aneurysm repair

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.

Treatment strategies for endoleak after endovascular repair of the abdominal aortic aneurysm: A single center retrospective study

BACKGROUND

Endovascular abdominal aortic aneurysm repair (EVAR) is the most frequently used treatment for aneurysm in abdominal aorta. The endoleak after EVAR causes the aneurysm sac to remain enlarged and risk for rupture.

AIMS

The purpose of the study was to assess the efficacy of strategies and techniques for endoleak treatment.

METHODS

This study was a single center retrospective study of 30 patients who had kinds of endoleak. The 30 patients were from a cohort of 597 patients who received EVAR from the Secondary Xiangya Hospital, Central South University between Jan 2014 to Dec 2021, what is follow-up well and diagnosed as endoleak. Data included basic clinical information, aspects of the endoleak treatment techniques, and follow-up findings.

RESULTS

The 30 patients with endoleak were diagnosed by computed tomography angiography or digital subtraction angiography. Age is 69 ± 7.9 yrs. 26 patients are male with only 4 female patients. Immediate endoleak after EVAR is 46.7%and delayed endoleak is 53.3%. The classification of endoleak is type Ⅰ:76.6%; type Ⅱ 26.7%; type Ⅲ:6.7%; type Ⅳ:6.7%; type Ⅴ:13.3%. Different treatment of endoleak includes: screening, endovascular re-intervention and open surgery. There are 3 patients (10.0%) underwent emergency EVAR due to their rupture condition of aneurysm. All the endoleak patients' CTA image characteristics has been reviewed. The follow-up rate is 93.3%. There are 6 patients (21.4%) died during follow-up. No aneurysm sac rupture death has been recorded.

CONCLUSIONS

Endoleak after EVAR is the most frequent complication that directly affects survival and re-intervention rates. Our findings suggested that different treatment strategies based on the individual patient's situation is important for their endoleak treating result.

Endovascular repair of abdominal and thoracoabdominal aneurysms using chimneys and periscopes is associated with poor outcomes

OBJECTIVE

Chimneys and periscopes are often used to treat pararenal or thoracoabdominal aneurysms de novo or after failed open or endovascular repair. We sought to describe our institutional experience, given their limited success and questionable long-term outcomes.

METHODS

We retrospectively reviewed the electronic records for patients treated with chimneys/periscopes from 1997 through 2020. Baseline characteristics, procedural details, periprocedural complications, reinterventions, and midterm outcomes were collected.

RESULTS

Fifty-eight patients (86 vessels) were treated; the median follow-up was 32 months (range, 0.03-104 months). There were 36% (n = 21) juxta-renal, 2% (n = 1) para-visceral, and 21% (n = 12) thoracoabdominal aneurysms, and 41% (n = 24) had pararenal failure of prior endovascular aneurysm repair (n = 17) or open repair (n = 7). Stent configuration for the majority of the 86 vessels (n = 80; 93%) treated were chimney configuration (n = 6 periscopes; 7%). The most common stent graft utilized was Viabahn, and 8.1% (n = 7) were reinforced with a bare metal stent. Although the majority of the cases were elective, 36.2% (n = 21) of the cases were urgent/emergent. At the conclusion of the initial procedure, 16 of 58 patients had an endoleak (gutter, 50% [8/16]; type Ia, 25% [4/16]; and type II, 25% [4/16]). On follow-up, 14 of 58 patients developed one or more endoleaks, with the most common endoleaks being a gutter endoleak (35% [7/20]). Other endoleaks observed included 30% (6/20) type III, 15% (3/20) type Ia, 15% (3/20) type Ib, and 5% (1/20) type II. Eleven of 58 patients underwent interventions for one or more endoleak (gutter, 33% [5/15]; type Ib, 20% [3/15]; type II, 7% [1/15]; and type III, 40% [6/15]). Twelve of 58 patients returned to the operating room for one or more procedures during the index hospitalization (five laparotomies, three dialysis access, three acute limb ischemia, and four chimney/periscope interventions). Ten of 58 patients underwent angioplasty/stenting for chimney/periscope compression or occlusion during the follow-up period. Survival was 61.3% at 1 year by Kaplan-Meier analysis (75% for elective, 37% for urgent/emergent) (aneurysm-related death, 22%). Cox hazard modeling showed that aneurysm diameter (hazard ratio, 1.03; 95% confidence interval, 1.004-1.05; P = .02) and urgent/emergent interventions (hazard ratio, 3.6; 95% confidence interval, 1.33-9.74; P = .01) were predictors of mortality.

CONCLUSIONS

Endovascular repair of aortic aneurysms with chimneys/periscopes is associated with poor outcomes, including limited technical success and aneurysm exclusion, as well as high morbidity and mortality, with a high rate of reinterventions both in the immediate postoperative period and on follow-up. They should be used only when other surgical or endovascular options are not possible.

The use of an inner branch endograft for the treatment of failed chimney endovascular aortic repair

The chimney endovascular aortic repair technique is an established option for the treatment of juxtarenal aortic aneurysms. Failure of this repair represents a major surgical challenge. We report the case of a patient treated previously with chimney endovascular aortic repair (for a juxtarenal aortic aneurysm), who had developed a large type IA endoleak. The patient was treated with a custom-made endograft with three inner branches. All vessels were successfully cannulated and bridged, no evidence of endoleak was seen on the completion angiogram, and the patient had an uneventful recovery.

Reporting standards for endovascular aortic repair of aneurysms involving the renal-mesenteric arteries

Endovascular aortic aneurysm repair of complex aortic aneurysms requires incorporation of side branches using specially designed aortic stent grafts with fenestrations, directional branches, or parallel stent grafts. These techniques have been increasingly used and reported in the literature. The purpose of this document is to clarify and to update terminology, classification systems, measurement techniques, and end point definitions that are recommended for reports dealing with endovascular repair of complex abdominal and thoracoabdominal aortic aneurysms involving the renal and mesenteric arteries.

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.

Cerebrovascular Complications After Upper Extremity Access for Complex Aortic Interventions: A Systematic Review and Meta-Analysis

PURPOSE

The purpose of this study was to review the risk of developing cerebrovascular complications from upper extremity access during endovascular treatment of complex aortic aneurysms.

METHODS

A systematic review and meta-analysis were conducted according to the PRISMA guideline. An electronic search of the public domains Medline (PubMed), Embase (Ovid), Web of Science and Cochrane Library was performed to identify studies related to the treatment of aortic aneurysms involving upper extremity access. Meta-analysis was used to compare the rate of cerebrovascular event after left, right and bilateral upper extremity access. Results are presented as relative risk (RR) and 95% confidence intervals (CIs).

RESULTS

Thirteen studies including 1276 patients with complex endovascular treatment of aortic aneurysms using upper extremity access were included in the systematic review. Left upper extremity access (UEA) was used in 1028 procedures, right access in 148 and bilateral access in 100 procedures. The rate of cerebrovascular complications for patients treated through left UEA was 1.7%, through right UEA 4% and through bilateral UEA 5%. In the meta-analysis, we included seven studies involving 645 patients treated with a left upper extremity access, 87 patients through a right and 100 patients through a bilateral upper extremity access. Patients, who underwent right-sided (RR 5.01, 95% CI 1.51-16.58, P = 0.008) or bilateral UEA (RR 4.57, 95% CI 1.23-17.04, P = 0.02), had a significantly increased risk of cerebrovascular events compared to those who had a left-sided approach.

CONCLUSION

Left upper extremity access is associated with a significantly lower rate of cerebrovascular complications as compared to right or bilateral upper extremity access.

Fenestrated Endovascular Aneurysm Repair versus Snorkel Endovascular Aneurysm Repair: Competing yet Complementary Strategies

Juxtarenal/pararenal aortic aneurysms and type IV thoracoabdominal aneurysms pose particular technical challenges for endovascular repair as they involve the visceral segment in addition to insufficient infrarenal neck for the use of standard endovascular aneurysm repair (EVAR) devices. To overcome these challenges, complex EVAR techniques have been developed to extend the proximal landing zone cephalad with maintaining perfusion to vital aortic branches, thereby broadening the applicability of endografting from the infrarenal to the suprarenal aorta. Complex EVAR can be divided into two broad categories: fenestrated endovascular aneurysm repair (FEVAR) and snorkel EVAR. FEVAR is a valid procedure with the standardized procedure, although it remains as a relatively complex procedure with a learning curve. Given time constraints for the custom fenestrated graft, snorkel EVAR may be an alternative for complex repairs in symptomatic or ruptured patients for whom custom-made endografts may not be immediately available. This article discusses these two most commonly used complex EVAR strategies.

Midterm Results of Endovascular Treatment for the Patients with Thoracoabdominal Aortic Aneurysms

Treatment of thoracoabdominal aortic aneurysm (TAAA) remains a challenging pathology. Technologies and innovations of endovascular treatment, in particular the evolution of fenestrated and branched stent graft for complex aortic pathologies such as TAAA have provided excellent short-term results. However, the mid-term and long-term results of endovascular treatment for TAAA including endoleaks and branch patency are still unclear. This article provides an overview of available devices and results of endovascular treatment for TAAAs. (This is a translation of Jpn J Vasc Surg 2019; 28: 67–74.)

Endovascular Repair of Aortic Arch Aneurysm with Surgeon-Modified Fenestrated Stent Graft

The authors describe a technique of treating patients with aortic arch aneurysm using surgeon-modified fenestrated stent graft (SMFSG). The technique is demonstrated in a 80-year-old patient whose aneurysm was successfully excluded with a SMFSG using Cook Alpha thoracic stent graft. The device was deployed, removed from its delivery system, and a fenestration created before being mounted back on the delivery system and constrained. It was transitioned through a series of sheaths before being introduced into its original sheath. The device was implanted via a common femoral artery access site; fenestration cannulated from the left brachial artery and bridged with a stent graft.

Recent Development and Long-Term Results of Open vs EVAR for Pararenal Abdominal Aortic Aneurysms

In this article, I would like to discuss on the two different treatment options (Open vs EVAR) for pararenal abdominal aortic aneurysm (the term "PRAAA" is not clearly defined and classified). Recently, complex endovascular treatment [Fenestrated EVAR (F-EVAR), Chimney (Snorkel) EVAR (C-EVAR, S-EVAR), Branched EVAR (B-EVAR)] have been developed and applied in selected patients, with encouraging early results; however, the high rate for secondary reinterventions and long-term results remain uncertain. This article introduce new devices and a new concept with endovascular aneurysm sealing (EVAS) are currently available on the market for the treatment of PRAAA. Open repair of PRAAA can be performed with low mortality and long-term survival is favorable from single-center experience in the real world and others. We conclude that open repair remains the golden standard treatment in most centers for PRAAA. However, EVAR of PRAAA may represent an alternative option in high-risk patients. Because the indications and circumstances for PRAAA vary based on patient-specific comorbidities and anatomy, it is recommended that vascular surgeons should be familiar with both treatment strategies and tailor-made strategy for improved long-term results for PRAAA. (This is a translation of Jpn J Vasc Surg 2018; 27: 303-308.).

Secondary Fill Minimizes Gutter Size in Chimney EVAS Configurations In Vitro

Purpose: To investigate in an in vitro model if secondary endobag filling can reduce gutter size during chimney endovascular aneurysm sealing (chEVAS). Materials and Methods: Nellix EVAS systems were deployed in 2 silicone juxtarenal aneurysm models with suprarenal aortic diameters of 19 and 24 mm. Four configurations were tested: EVAS with 6-mm balloon-expandable (BE) or self-expanding (SE) chimney grafts (CGs) in the renal branches of both models. Balloons were inflated simultaneously in the CGs and main endografts during primary and secondary endobag filling and polymer curing. Computed tomography (CT) was performed immediately after the primary and secondary fills. Cross-sectional lumen areas were measured on the CT images to calculate gutter volumes and percent change. CG compression was calculated as the reduction in lumen surface area measured perpendicular to the central lumen line. The largest gutter volume and highest compression were presented per CG configuration per model. Results: Secondary endobag filling reduced the largest gutter volumes from 99.4 to 73.1 mm³ (13.2% change) and 84.2 to 72.0 mm³ (27.6% change) in the BECG configurations and from 67.2 to 44.0 mm³ (34.5% change) and 92.7 to 82.3 mm³ (11.2% change) in the SECG configurations in the 19- and 24-mm models, respectively. Secondary endobag filling increased CG compression in 6 of 8 configurations. BECG compression changed by −0.2% and 5.4% and by −1.0% and 0.4% in the 19- and 24-mm models, respectively. SECG compression changed by 10.2% and 16.0% and by 7.2% and 7.3% in the 19- and 24-mm models, respectively. Conclusion: Secondary endobag filling reduced paragraft gutters; however, this technique did not obliterate them. Increased CG compression and prolonged renal ischemia time should be considered if secondary endobag filling is used.

Fenestrated Endovascular Repair of Zones 1 and 2 Aortic Arch Pathologies

BACKGROUND

Surgical management of aortic arch pathologies is complex, and endovascular developments have now enabled total or hybrid endovascular aortic arch repair. We present our early experience with fenestrated aortic arch repairs in Ishimaru zones 1 and 2 pathologies.

METHODS

In a single tertiary institution, all consecutive endovascular aortic arch repairs were reviewed. A preoperative computed tomography aortogram was performed to assess anatomic suitability, which we defined as having a proximal sealing zone with a maximum diameter of 38 mm and minimum length of 20 mm, absence of significant aortic tortuosity, and suitable sealing zones in target vessels.

RESULTS

From September 2015 to February 2018, 5 cases of fenestrated aortic arch endovascular repairs were performed. There were 3 male patients. The patients were between 57 and 83 years old, all of whom were American Society of Anesthesiologists (ASA) class II or III. Indications for surgery included aortic arch aneurysms (n = 3), a symptomatic aortic dissection, and a left subclavian artery aneurysm. Three patients had a scallop to the innominate artery, and one patient had a scallop to the left common carotid artery. Fenestrations were made to 3 left common carotid arteries and 3 left subclavian arteries. In 2 patients, a left carotid-subclavian bypass was performed, and the left subclavian artery origin occluded with a vascular plug. Technical success was 100%. One patient developed a right occipital infarct and acute myocardial infarction. The mean duration of surgery was 164 min, and the mean length of stay was 4.2 days. The mean follow-up period was 14.4 months.

CONCLUSIONS

The use of fenestrated grafts in the aortic arch is a feasible treatment option. However, certain limitations still exist, and preoperative planning is important in ensuring clinical success. Although this procedure appears feasible in the short term, long-term results and durability remain to be seen.

Combination of Octopus and Periscope Techniques for the Management of Visceral Branches From Type V Thoracoabdominal Aortic Aneurysm: A Case Report

PURPOSE:

To describe an endovascular technique combining the octopus and periscope techniques for the treatment of a patient with type V thoracoabdominal aortic aneurysm in order to protect the patient's visceral circulation.

CASE REPORT:

An 84-year-old male patient was hospitalized for type V thoracoabdominal aortic aneurysm involving celiac axis, superior mesenteric artery, and both renal arteries. The patient's aneurysm was successfully treated by combining the octopus technique and periscope techniques. The 1-year follow-up computed tomography angiography showed that the endograft and the branches were patent. The gutters had thrombosed with no signs of endoleak. No spinal cord ischemia or impairment of the renal function was observed during the follow-up.

CONCLUSIONS:

This case is an example of the successful usage of the combined octopus and periscope techniques in protecting the renovisceral arteries arising from a type V thoracoabdominal aortic aneurysm; this combined technique might be applicable in carefully selected patients.

[Staged approach for hybrid thoracoabdominal aortic replacement]

AIM

To generalize our experience of step-by-step hybrid thoracoabdominal aortic replacement.

MATERIAL AND METHODS

Twenty-three patients were enrolled who underwent staged hybrid treatment of thoracoabdominal aortic aneurysm. There were 5 (21.7%) women and 18 (78.3%) men aged 61.4±8.3 years (37-74 years). The first stage was proximal debranching, the second - distal (abdominal) procedure and the third - stenting of the thoracoabdominal aorta.

RESULTS

There were no any complications after proximal debranching and aortic stenting. Abdominal debranching was followed by lethal outcome in 3 (13.0%) patients and early postoperative occlusion of the prosthesis brunch in 3 out of 87 cases.

CONCLUSION

Staged approach for hybrid surgical treatment is optimal solution, especially in high risk patients. In our opinion no necessity for cardiopulmonary bypass is the main advantage of this technique.

Anatomical Applicability of Endovascular Aneurysm Sealing Techniques in a Consecutive Cohort of Fenestrated Endovascular Aneurysm Repairs

PURPOSE

To determine how many endovascular aneurysm sealing (EVAS) procedures with/without off-label use of chimneys (ChEVAS) could have been performed in a cohort of patients who had undergone fenestrated endovascular aneurysm repair (FEVAR).

METHODS

Sixty patients (median age 76.3 years; 54 men) who underwent FEVAR in our institution between 2013 and 2015 were selected for the study. The median aneurysm diameter was 62.0 mm (interquartile range 59.3, 69.0). Preoperative computed tomography angiograms (CTA) were anonymized and sent to 2 physicians with experience of more than 40 ChEVAS interventions. These ChEVAS planners were blinded to the study purpose and asked to agree upon an EVAS/ChEVAS plan. The primary outcome was the percentage of the FEVAR patients in whom an EVAS/ChEVAS was technically possible. The secondary outcomes were a comparison of seal zones, number of target vessels, and device cost.

RESULTS

An EVAS-based intervention would have been technically possible in 56 (93.3%) of the FEVAR patients. The median proximal aortic seal zone was significantly more distal in the EVAS/ChEVAS procedures vs the FEVAR cases (zone 8 vs zone 7, p<0.001) and fewer target vessels were involved (median 2 vs 3, p<0.001). The cost of the EVAS/ChEVAS device was 66% of the FEVAR device. Planners would not currently advocate an EVAS-based intervention in 43 (76.8%) of these 56 patients due to concerns regarding the risk of migration associated with the lumen thrombus ratios observed.

CONCLUSION

EVAS is technically feasible in the majority of patients undergoing FEVAR in our institution but currently advocated in only 23.2%. The seal zone was more distal, fewer target vessels were involved, and the device cost was lower in the planned EVAS/ChEVAS interventions.

Combination of Chimneys and Fenestrated Endografts in the Treatment of Complex Aortic Aneurysms

PURPOSE

To present early results of fenestrated endovascular aneurysm repair (FEVAR) combined with chimney grafts in a high-volume center.

METHODS

From July 2011 to July 2016, 45 patients (mean age 73.0±8.8 years; 39 men) with complex aneurysms who were poor candidates for open repair and anatomically ineligible for standard or custom-made FEVAR were treated with chimney FEVAR (chFEVAR). Eight (18%) cases were treated in emergency. In all, 130 target vessels (2.9/patient) were addressed using 21 scallops, 42 open/18 covered chimneys, and 27 custom-made/22 homemade fenestrations.

RESULTS

Successful aneurysm exclusion, successful reconstruction, and technical success rates were 97.8% (44/45), 98.2% (107/109 vessels excluding the scallops), and 93.3% (42/45). Six (13.3%) patients died within 30 days (5 in hospital). Estimated overall survival, freedom from aneurysm-related death, and freedom from aneurysm-related reintervention were 85.9%, 88.5%, and 59.2%, respectively, at 12 months. The target vessel patency rate was 96.0%. At latest follow-up, 1 type Ia and 3 type II endoleaks were present. Sac shrinkage occurred in 18 (54%) patients.

CONCLUSION

Combined chFEVAR showed good technical feasibility and could be an effective approach in emergent settings and highly selective cases when FEVAR is not feasible. Thirty-day mortality, target vessel patency, and type Ia endoleak rates were acceptable.

Concurrent renal artery stent during endovascular infrarenal aortic aneurysm repair confers higher risk for 30-day acute renal failure

OBJECTIVE

Concurrent renal artery angioplasty and stenting (RAAS) during endovascular aneurysm repair (EVAR) of infrarenal abdominal aortic aneurysm (AAA) has been practiced in an attempt to maintain renal perfusion. The aim of this study was to identify the current practice of RAAS during EVAR and its effect on perioperative renal outcome.

METHODS

Patients with infrarenal AAA were identified from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP, 2011-2014) database. Baseline characteristics of patients with concurrent RAAS during EVAR were compared with those of patients who underwent EVAR only. Bivariate and multivariable logistic regression analyses controlling for patients' demographics, comorbidities, and operative factors were used to evaluate the predictors of 30-day acute renal failure (ARF). Sensitivity analysis was done to evaluate the role of RAAS in patients with prior kidney disease.

RESULTS

Overall, 6183 patients underwent EVAR for infrarenal AAA during the study period. Of them, 281 patients had RAAS during EVAR (4.5%). The median age of the patients was 74 years; 81.7% of the cohort was male, but a higher proportion of female patients received EVAR + RAAS compared with patients who underwent EVAR only (26.3% vs 17.9%; P < .001). There was no difference between groups in terms of comorbidities, being on dialysis, or functional status, yet the EVAR + RAAS group had a higher proportion of patients with glomerular filtration rate <60 mL/min/1.73 m2 (45.2% vs 37.2%; P = .011). RAAS was associated with significantly higher odds for development of ARF (adjusted odds ratio [aOR], 4.27; 95% confidence interval [CI], 2.06-8.84; P < .001). Other highly predictive factors of 30-day ARF were glomerular filtration rate <60 (aOR, 2.92; 95% CI, 1.47-5.78; P = .002), emergency status (aOR, 2.97; 95% CI, 1.21-7.27; P = .017), and ruptured AAA as the indication for EVAR (aOR, 4.74; 95% CI, 1.80-12.50; P = .002). Patients with prior kidney disease who had EVAR + RAAS demonstrated a 12-fold higher odds for 30-day ARF (aOR, 12.37; 95% CI, 4.66-32.89; P < .001).

CONCLUSIONS

Concurrent RAAS was found to be a significant determinant of adverse renal outcomes after EVAR for infrarenal AAA. This effect was present even after controlling for patients' risk factors that might contribute to postoperative ARF.

Influence of Anatomic Angulations in Chimney and Fenestrated Endovascular Aneurysm Repair

BACKGROUND

The lack of widespread availability of Fenestrated endovascular aneurysm repair (F-EVAR) encouraged alternative strategies. Hence, Chimney graft (CG)-EVAR spread when costs, manufacturing delays, or anatomy preclude F-EVAR. Our objective is to evaluate CG- and F-EVAR outcomes depending on the angulation of target renal arteries and hostility of iliac accesses in order to determine the potential impact of a choice made between both techniques on the basis of preoperative anatomic criteria.

METHODS

Consecutive patients treated by CG-EVAR or F-EVAR, from January 2010 to January 2015, were considered for inclusion. Anatomic parameters were defined by preoperative computed tomography angiography. A subgroup analysis was performed depending on renal arteries' angulation (cut-off: -30°) and iliac arteries' hostility (cut-off: diameter <6 mm, tortuosity index = 3).

RESULTS

Twenty-six patients were included the CG group (mean age 74.7 ± 6.9 years, 30 target vessels) and 66 in the F-EVAR group (71.7 ± 7.9 years, 133 target vessels). Infrarenal aortic neck length was significantly longer for CG-EVAR (3.3 ± 3.7 vs. 1.8 ± 3.2 mm, P = 0.04), while the distance between the superior mesenteric artery and highest renal artery was shorter in the CG group (11.7 ± 6.2 mm vs. 14.1 ± 5.9 mm, P = 0.06). Longitudinal angulation of the right renal artery was not statistically different between both groups, while the left renal artery presented with a significantly more downward angulation in the CG group (-32.0 ± 15.3 vs. -19.0 ± 19.6, P = 0.003). There were significantly more grade 3 iliac tortuosity indexes for CG-EVAR (P = 0.03) with significantly smaller external iliac diameters (7.8 ± 1.7 vs. 8.8 ± 1.6 mm, P = 0.0009). There was 1 renal artery early occlusion in the <-30° CG subgroup and 2 in the <-30° F-EVAR subgroup where severe downward angulation crushed the stents, with a tendency toward higher early occlusions compared with the ≥-30° F-EVAR subgroup (P = 0.054). Mean follow-up duration was 20 months in the CG group and 14 in the F-EVAR group. Kaplan-Meier estimates showed no significant difference in terms of overall survival, freedom from reintervention, freedom from type I or III endoleak, or patency. In the CG group, 14 patients (53.8%) presented with hostile iliac accesses without any significant difference in terms of limb events.

CONCLUSIONS

CG-EVAR is a complementary strategy to F-EVAR, and understanding which technique is applicable to which patient is important to improve outcomes. Our results suggest that considering renal artery angulation and diameter, iliac artery hostility, and aortic neck length among other parameters may help the surgeon make a decision toward the endovascular strategy that seems best suited for each specific patient.

Natural history of gutter-related type Ia endoleaks after snorkel/chimney endovascular aneurysm repair

OBJECTIVE

Alternative endovascular strategies using parallel or snorkel/chimney (chimney endovascular aneurysm repair [ch-EVAR]) techniques have been developed to address the lack of widespread availability and manufacturing limitations with branched/fenestrated aortic devices for the treatment of complex abdominal aortic aneurysms. Despite high technical success and midterm patency of snorkel stent configurations, concerns remain regarding the perceived increased incidence of early gutter-related type Ia endoleaks. We aimed to evaluate the incidence and natural history of gutter-related type Ia endoleaks following ch-EVAR.

METHODS

Review of medical records and available imaging studies, including completion angiography and serial computed tomographic angiography, was performed for all patients undergoing ch-EVAR at our institution between September 2009 and January 2015. Only procedures involving ≥1 renal artery with or without visceral snorkel stents were included. Primary outcomes of the study were presence and persistence or resolution of early gutter-related type Ia endoleak. Secondary outcomes included aneurysm sac shrinkage and need for secondary intervention related to the presence of type Ia gutter endoleak.

RESULTS

Sixty patients (mean age, 75.8 ± 7.6 years; male, 70.0%) underwent ch-EVAR with a total of 111 snorkel stents (97 renal [33 bilateral renal], 12 superior mesenteric artery, 2 celiac). A mean of 1.9 ± 0.6 snorkel stents were placed per patient. Early gutter-related type Ia endoleaks were noted on 30.0% (n = 18) of initial postoperative imaging studies. Follow-up imaging revealed spontaneous resolution of these gutter endoleaks in 44.3%, 65.2%, and 88.4% of patients at 6, 12, and 18 months postprocedure, respectively. Long-term anticoagulation, degree of oversizing, stent type and diameter, and other clinical/anatomic variables were not significantly associated with presence of gutter endoleaks. Two patients (3.3%) required secondary intervention related to persistent gutter endoleak. At a mean radiologic follow-up of 20.9 months, no difference in mean aneurysm sac size change was observed between those with or without early type Ia gutter endoleak (-6.1 ± 10.0 mm vs -4.9 ± 11.5 mm; P = .23).

CONCLUSIONS

Gutter-related type Ia endoleaks represent a relatively frequent early occurrence after ch-EVAR, but appears to resolve spontaneously in the majority of cases during early to midterm follow-up. Given that few ch-EVAR patients require reintervention related to gutter endoleaks and the presence of such endoleak did not correlate to increased risk for aneurysm sac growth, its natural history may be more benign than originally expected.

A Comprehensive Review of In Situ Fenestration of Aortic Endografts

OBJECTIVE

Despite technical advances of fenestrated and branched endografts, endovascular exclusion of aneurysms involving renal, visceral, and/or supra-aortic branches remains a challenge. In situ fenestration (ISF) of standard endografts represents another endovascular means to maintain perfusion to such branches. This study aimed to review current indications, technical descriptions, and results of ISF.

METHOD

A review of the English language literature was performed in Medline databases, Cochrane Database, Web of Science, and Scopus using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Sixty-seven relevant papers were selected. Thirty-three papers were excluded, leaving 34 articles as the basis of the present review.

RESULTS

Most experimental papers evaluated ISF feasibility and assessed the consequences of ISF on graft fabric. Regarding clinical papers, 73 ISF procedures have been attempted in 58 patients, including 26 (45%) emergent and three (5%) bailout cases. Sixty-five (89%) ISF were located at the level of the arch, and eight (11%) in the abdominal aorta. Graft perforation was performed by physical, mechanical, or unspecified means in 33 (45%), 38 (52%), and two vessels (3%), respectively. ISF was technically successful in 68/73 (93%) arteries. At 30 days, two (3.4%) patients died in the setting of an aorto-bronchial fistula and an aorto-oesophageal fistula, respectively. No post-operative death, major complication, or endoleak was described as secondary to the ISF procedure. With follow-up between 0 and 72 months, four (6.9%) late deaths were noted, unrelated to the aorta. One (1.7%) LSA stent was stenosed without symptoms.

CONCLUSIONS

Although there may be publication bias, multiple techniques were described to perform ISF with satisfactory short-term results. Long-term data remain scarce. Aortic endograft ISF is an off-label procedure that should not be used outside emergent bailout techniques or investigational studies. A comparison with alternative techniques of preserving aortic side branches is needed.

Snorkel endovascular abdominal aortic aneurysm repair versus fenestrated endovascular aneurysm repair: is it a competition?

The endovascular treatment of juxtarenal abdominal aortic aneurysm (AAA) can be performed by either a standard endovascular stent graft with additional snorkle grafts to aorta branches (snorkel endovascular aneurysm repair) or implantation of a fenestrated stent graft (fenestrated endovascular aneurysm repair). While many vascular surgeons consider snorkel endovascular aneurysm repair and fenestrated endovascular aneurysm repair to be competing techniques or alternate strategies, published procedural outcomes suggest more complementary roles. In this clinical review, the advantages and disadvantages of these two approaches are debated, as much can be learned from both strategies. Because the indications and circumstances for juxtarenal AAA repair vary based on patient-specific comorbidities and anatomy, it is recommended that vascular surgeons have access to, and experience with, both treatment strategies. Based on published outcomes, patient outcomes, stent-graft patency, and re-intervention rates are generally similar and acceptable compared with open AAA repair. We conclude that there is a time and a place for both snorkel endovascular aneurysm repair and fenestrated endovascular aneurysm repair for the endovascular management of juxtarenal and pararenal AAA anatomy.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Endovascular treatment of aortoiliac aneurysms: From intentional occlusion of the internal iliac artery to branch iliac stent graft

Approximately 20%-40% of patients with abdominal aortic aneurysms can have unilateral or bilateral iliac artery aneurysms and/or ectasia. This influences and compromises the distal sealing zone during endovascular aneurysm repair. There are a few endovascular techniques that are used to treat these types of aneurysms, including intentional occlusion/over-stenting of the internal iliac artery on one or both sides, the “bell-bottom” technique, and the more recent method of using an iliac branch stent graft. In some cases, other options include the “snorkel and sandwich” technique and hybrid interventions. Pelvic ischemia, represented as buttock claudication, has been reported in 16%-55% of cases; this is followed by impotence, which has been described in 10%-17% of cases following internal iliac artery occlusion. The bell-bottom technique can be used for a common iliac artery up to 24 mm in diameter given that the largest diameter of the stent graft is 28 mm. There is a paucity of data and evidence regarding the “snorkel and sandwich” technique, which can be used in a few clinical scenarios. The hybrid intervention is comprised of a surgical operation, and is not purely endovascular. The newest branch stent graft technology enables preservation of the anterograde flow of important side branches. Technical success with the newest technique ranges from 85%-96.3%, and in some small series, technical success is 100%. Buttock claudication was reported in up to 4% of patients treated with a branch stent graft at 5-year follow-up. Mid- and short-term follow-up results showed branch patency of up to 88% during the 5-6-year period. Furthermore, branch graft occlusion is a potential complication, and it has been described to occur in 1.2%-11% of cases. Iliac branch stent graft placement represents a further development in endovascular medicine, and it has a high technical success rate without serious complications.

Fenestrated stent grafts for the treatment of complex aortic aneurysm disease: A mature treatment paradigm

The introduction of fenestrated stent grafts (SGs) to treat abdominal aortic aneurysms (AAAs) with short proximal necks began in 1999. Nowadays, the whole visceral aorta can be treated totally by endovascular means. The established use of fenestrated devices to treat complex AAAs as a first-line management option has been previously reported. An up-to-date evaluation of the literature was performed including all types of publications regarding the use of fenestrated technology to repair complex AAAs. Fenestrated repair is now an established alternative to hybrid/chimney/snorkel repairs. However, specific criteria and prerequisites are required for the use and improvement of this method. Multiple device morphologies have been used incorporating the visceral arteries in various combinations. This modular strategy connects different devices (bridging covered stents and bifurcated SGs) with the aortic main body, thus excluding the aneurysm from the circulation. Precise deployment of the fenestrated SG is mandatory for successful visceral vessel revascularization. Accurate SG sizing and customization, a high level of technical skill, and facilities with modern imaging techniques including 3D road mapping and dedicated hybrid rooms are required. Most experience has been with the custom-made Zenith Cook platform, although off-the-shelf devices have been recently implanted. More complex repairs have been performed over the last few years, but device complexity has also increased. Perioperative, mid-term, and a few recently reported long-term results are encouraging. Secondary interventions remain the main problem, similar to that observed after traditional endovascular abdominal aortic aneurysm repair (EVAR).

Update on the use of abdominal and thoracic endografts for treating aortic aneurysms

Endovascular abdominal and thoracic aneurysm repair has heralded a paradigm shift in the management of abdominal and thoracic aortic aneurysms. Randomized controlled trials have suggested superior short-term and equivalent long-term outcomes of endovascular repair compared with open surgery. Existing endografts have undergone several modifications to meet anatomic challenges and improve patient results. In the past, endovascular repair has been limited to infrarenal abdominal aortic aneurysms and isolated thoracic aortic aneurysms. The advent of fenestrated and branched endografts have made endovascular repair of thoracoabdominal and juxtarenal aneurysms possible. Continued evolution of endograft technology will maximize the benefit and minimize complications in patients with a range of aneurysmal disease.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Advanced Endovascular Approaches in the Management of Challenging Proximal Aortic Neck Anatomy: Traditional Endografts and the Snorkel Technique

Advances in endovascular technology, and access to this technology, have significantly changed the field of vascular surgery. Nowhere is this more apparent than in the treatment of abdominal aortic aneurysms (AAAs), in which endovascular aneurysm repair (EVAR) has replaced the traditional open surgical approach in patients with suitable anatomy. However, approximately one-third of patients presenting with AAAs are deemed ineligible for standard EVAR because of anatomic constraints, the majority of which involve the proximal aneurysmal neck. To overcome these challenges, a bevy of endovascular approaches have been developed to either enhance stent graft fixation at the proximal neck or extend the proximal landing zone to allow adequate apposition to the aortic wall and thus aneurysm exclusion. This article is composed of two sections that together address new endovascular approaches for treating aortic aneurysms with difficult proximal neck anatomy. The first section will explore advancements in the traditional EVAR approach for hostile neck anatomy that maximize the use of the native proximal landing zone; the second section will discuss a technique that was developed to extend the native proximal landing zone and maintain perfusion to vital aortic branches using common, off-the-shelf components: the snorkel technique. While the techniques presented differ in terms of approach, the available clinical data, albeit limited, support the notion that they may both have roles in the treatment algorithm for patients with challenging proximal neck anatomy.