Clinical Outcomes of Spinal Cord Ischemia after Fenestrated and Branched Endovascular Stent Grafting during Total Endovascular Aortic Repair for Thoracoabdominal Aortic Aneurysms

Prospective randomized pilot trial comparing prophylactic and therapeutic cerebrospinal fluid drainage during complex endovascular thoracoabdominal aortic aneurysm repair

BACKGROUND

Endovascular techniques have transformed the management of thoracoabdominal aortic aneurysms (TAAAs). However, spinal cord ischemia (SCI) remains a prevalent and devastating complication. Prophylactic drainage of cerebrospinal fluid (CSF) is among the proposed strategies for prevention of SCI. Although prophylactic CSF drainage is widely used and conceptually attractive, prophylactic CSF drains have not been demonstrated to definitively prevent the occurrence nor mitigate the severity of SCI in endovascular TAAA repair. Whether or not outcomes of prophylactic drains are superior to therapeutic drains remains unknown. This pilot study was performed to determine the feasibility of a randomized clinical trial designed to investigate the role of prophylactic vs therapeutic CSF drains in the prevention of SCI in patients undergoing endovascular TAAA repair using branched and fenestrated endovascular aortic repair (FBEVAR).

METHODS

This was a prospective multicenter randomized pilot clinical trial conducted at The University of Alabama at Birmingham and The University of Massachusetts. Twenty patients were enrolled and randomized to either the prophylactic drainage or therapeutic drainage groups, prior to undergoing FBEVAR for extensive TAAAs and arch aortic aneurysms. This was a pilot feasibility study that was not powered to detect statistical differences in clinical outcomes. The primary outcome was feasibility of randomization and compliance with a shared lumbar drain protocol. Secondary outcomes included rate of drain complications and SCI.

RESULTS

Twenty patients were enrolled and successfully randomized, without any crossovers, to either the control cohort (n = 10), without prophylactic drains, or the experimental cohort (n = 10), with prophylactic drains. There were no differences in age, comorbidities, or history of prior aortic surgery across the cohorts. All patients were treated with FBEVAR. Aneurysm classifications were as follows: Extent I (10%), Extent II (50%), Extent III (35%), and Extent IV (5%). The average length of aortic coverage was 207 ± 21.6 mm. The length of aortic coverage did not vary across cohorts, nor did procedural times or blood loss volume. Compliance with the SCI prevention protocol was 100% across both groups. Within the prophylactic drain cohort, one patient experienced an adverse event related to lumbar drain placement, manifested as an epidural hematoma requiring laminectomy, without neurologic deficit (n = 1/10; 10%). There was one SCI event (n = 1/20; 5%), which occurred in the prophylactic drain cohort on postoperative day 9 following an episode of hypotension related to a gastrointestinal bleed.

CONCLUSIONS

The role of prophylactic CSF drains for the prevention of SCI following endovascular TAAA repair is a topic of ongoing research, with many current practices based on expert opinion and experience, rather than rigorous scientific data. This study demonstrates the feasibility of a multicenter randomized clinical trial to evaluate the role of prophylactic vs therapeutic CSF drains in the prevention of SCI in patients undergoing endovascular TAAA repair.

Expert-Based Narrative Review on Contemporary Use of an Off-The-Shelf Multibranched Endograft for Endovascular Treatment of Thoracoabdominal Aortic Aneurysms: Device Design, Anatomical Suitability, Technical Tips, Perioperative Care, Clinical Applications, and Real-World Experience

Advanced endovascular techniques, such as fenestrated stent grafts, are nowadays available that permit minimally invasive treatment of complex abdominal aortic aneurysms. However, thoracoabdominal aortic aneurysm patients have anatomic limitations to fenestrated stent-grafts given a large lumen, that is, the gap between the endograft and the inner aortic wall. This has led to the development of branched endovascular aneurysm repair as the ideal option for such patients. The Zenith t-Branch multibranched endograft (Cook Medical, Bloomington, IN), which has been commercially available in Europe to treat thoracoabdominal aortic aneurysm since June 2012, represents a feasible off-the-shelf alternative for treatment of such pathologies, especially in the urgent setting, for patients who cannot wait the time required for manufacturing and delivery of custom-made endografts. The device's anatomical suitability should be considered, especially for female patients with smaller iliofemoral vessels. Several tips may help deal with particularly complex scenarios (such as, for instance, in case of narrow inner aortic lumens or when treating patients with failure of prior endovascular aneurysm repair), and a broad array of techniques and devices must be available to ensure technical and clinical success. Despite promising early outcomes, concerns remain particularly regarding the risk for spinal cord ischemia and further assessment of long-term durability is needed, including the rate of target vessel instability and need for secondary interventions. As the published evidence mainly comes from retrospective registries, it is likely that reported outcomes may suffer from an intrinsic bias as most procedures reported to date have been carried out at high-volume aortic centers. Nonetheless, with the never-ceasing adoption of new and refined techniques, outcomes are expected to ameliorate.

A national census for the off-label treatment of complex aortic aneurysms

OBJECTIVE

Despite regulatory challenges, device availability, and rapidly expanding techniques, off-label endovascular repair of complex aortic aneurysms (cAAs) has expanded in the past decade. Given the lack of United States Food and Drug Administration-approved endovascular technology to treat cAAs, we performed a national census to better understand volume and current practice patterns in the United States.

METHODS

Targeted sampling identified vascular surgeons with experience in off-label endovascular repair of cAAs. An electronic survey was distributed with institutional review board approval from the University of Rochester to 261 individuals with a response rate of 38% (n = 98).

RESULTS

A total of 93 respondents (95%) reported off-label endovascular repair of cAAs. Mean age was 45.7 ± 8.3 years, and 84% were male. Most respondents (59%) were within the first 10 years of practice, and 69% trained at institutions with a high-volume of off-label endovascular procedures for complex aortic aneurysms with or without a physician-sponsored investigational device exemption (PS-IDE). Twelve respondents from 11 institutions reported institutional PS-IDEs for physician-modified endografts (PMEGs), in-situ laser fenestration (ISLF), or parallel grafting technique (PGT), including sites with PS-IDEs for custom-manufactured devices. Eighty-nine unique institutions reported elective off-label endovascular repair with a mean of 20.2 ± 16.5 cases/year and ∼1757 total cases/year nationally. Eighty reported urgent/emergent off-label endovascular repair with a mean of 5.7 ± 5.4 cases/year and ∼499 total cases/year nationally. There was no correlation between high-volume endovascular institutions (>15 cases/year) and institutions with high volumes of open surgical repair for cAAs (>15 cases/year; odds ratio, 0.7; 95% confidence interval, 0.3-1.5; P = .34). Elective techniques included PMEG (70%), ISLF (30%), hybrid PMEG/ISLF (18%), and PGT (14%), with PMEG being the preferred technique for 63% of respondents. Techniques for emergent endovascular treatment of complex aortic disease included PMEG (52%), ISLF (40%), PGT (20%), and hybrid-PMEG/ISLF (14%), with PMEG being the preferred technique for 41% of respondents. Thirty-nine percent of respondents always or frequently offer referrals to institutions with PS-IDEs for custom-manufactured devices. The most common barrier for referral to PS-IDE centers included geographic distance (48%), longitudinal relationship with patient (45%), and costs associated with travel (33%). Only 61% of respondents participate in the Vascular Quality Initiative for complex endovascular aneurysm repair, and only 57% maintain a prospective institutional database. Eighty-six percent reported interest in a national collaborative database for off-label endovascular repair of cAA.

CONCLUSIONS

Estimates of off-label endovascular repair of cAAs are likely underrepresented in the literature based on this national census. PMEG was the most common technique for elective and emergent procedures. Under-reported off-label endovascular repair of cAA outcomes data appears to be limited by non-standardized PS-IDE reporting to the United States Food and Drug Administration, and the lack of Vascular Quality Initiative participation and prospective institutional data collection. Most participants are interested in a national collaborative database for endovascular repair of cAAs.

Trends in hospitalization of patients undergoing endovascular treatment of thoracoabdominal aortic aneurysms based on cerebrospinal fluid drainage strategy

OBJECTIVE

The aim of this study was to identify trends in hospital length of stay (HLOS) and intensive care unit length of stay (ICULOS), and the relationship with cerebrospinal fluid drainage (CSFD) protocols in patients undergoing fenestrated-branched endovascular aortic repair (FB-EVAR) of thoracoabdominal aortic aneurysms (TAAAs).

METHODS

A retrospective review of patients who underwent elective FB-EVAR for extent I to IV TAAAs between 2008 and 2023 at a single aortic center of excellence was conducted. Patient demographics, cardiovascular comorbidities, surgical risk, technical details, CSFD strategy (prophylactic or therapeutic), procedural success, and perioperative outcomes were collected. Patients were divided into two groups based on CSFD protocol. Group 1 included patients treated before 2020 when prophylactic CSFD was performed widely, and Group 2 consisted of patients treated since 2020 with therapeutic CSFD. Primary end points were HLOS, ICULOS, major adverse events, and perioperative mortality.

RESULTS

FB-EVAR was performed in 702 patients; 412 underwent elective TAAA repair and were included in the analysis. Mean age was 73 ± 8 years and 68% were male. Patient-specific manufactured devices were used in 252 patients (61%), physician-modified endografts in 110 (27%), and 50 patients (12%) were treated with off-the-shelf devices. Demographics, aneurysm extent, major adverse events (including spinal cord ischemia [SCI]), and mortality were similar in both groups. A significant reduction in mean HLOS between the groups (9 ± 9 vs 6 ± 5 days; P = .02) coincided with decreased use of prophylactic CSFD (70% vs 1.2%; P < .001), with similar rates of SCI (7.6% vs 4.9%; P = .627) and ICULOS (3 ± 3 vs 2.5 ± 3; P = .19). Patients in the therapeutic drainage cohort (group 2) had a higher incidence of congestive heart failure (24% vs 11%; P = .003), hypercholesterolemia (91% vs 80%; P = .015), chronic obstructive pulmonary disease (55% vs 37%; P = .004), and peripheral artery disease (39% vs 19%; P < .001) compared with group 1, suggesting treatment of a more complex patient cohort. On adjusted multivariable analysis accounting for American Society of Anesthesiologists score, comorbidities, and device type, the difference in HLOS remained statistically significant (P = .01).

CONCLUSIONS

HLOS decreased over time in patients undergoing FB-EVAR for TAAA after transition from a prophylactic to a therapeutic CSFD protocol. This transition was the only modifiable, independent risk factor for a shorter HLOS, without an increase in SCI, albeit with similar ICULOS.

Systematic Review and Meta-analysis of Short-term and Mid-term Outcomes After Use of t-Branch Off-the-shelf Multibranched Endograft for Elective and Urgent Treatment of Thoracoabdominal Aortic Aneurysms

OBJECTIVE

To conduct a meta-analysis to assess the safety and efficacy of t-Branch off-the-shelf multibranched endograft for the treatment of thoracoabdominal aortic aneurysm (TAAA).

DATA SOURCES

PubMed, Embase, and Web of Science.

REVIEW METHODS

Online databases were searched from June 2012 to March 2023. The data were pooled together using a random-effects model of proportions. The outcomes overall included technical success, spinal cord ischemia, target vessel occlusion, type I or III endoleak, reintervention, early mortality (30-day), and mid-term outcomes. Subgroup meta-analyses and meta-regression were performed to explore variation among studies.

RESULTS

A total of 15 studies containing 1238 patients were included in the meta-analysis. The overall study quality assessment was found to be moderate to good. The pooled technical success was 97.0% (95% confidence interval [CI]=95.5-98.6, I2=53.01%, 1185/1238 cases, 15 studies). Overall, early mortality was 7.3% (95% CI=4.4-10.1, I2=74.48%, 124/1238 cases, 15 studies). Early spinal cord ischemia was 13.4% (95% CI=9.6-17.2, I2=67.24%, 160/1238 cases, 15 studies), and early type I or III endoleak was 6.0% (95% CI=3.4-8.5, I2=53.71%, 68/1032 cases, 9 studies). Mid-term outcomes showed target vessel occlusion was 4% (95% CI=1.4-6.5, I2=65.18%, 28/528 cases, 10 studies, 5-21.2 months), type I or III endoleak was 4.7% (95% CI=2-7.5, I2=49.74%, 38/512 cases, 10 studies, 5-21.2 months), reintervention was 11.2% (95% CI=8.1-14.3, I2=31.06%, 85/650 cases, 10 studies, 5-21.2 months), and pooled mortality was 13.9% (95% CI=7.2-20.7, I2=76.32%, 84/550 cases, 11 studies, 5-21.2 months). Meta-regression found a significant linear association between higher technical success and earlier publication year (p=0.014) and studies with anatomic inclusion criteria (p=0.037). Urgent patients (p=0.021) and later publication year (p=0.048) were significantly associated with higher early mortality.

CONCLUSION

The use of the off-the-shelf t-Branch multibranched endograft for elective or urgent endovascular TAAA repair is associated with high technical success rates and proved to be safe and effective at early and mid-term follow-up. However, the heterogeneity between the included studies is high, and prospective, randomized studies along with future larger studies with long-term follow-up are needed.

CLINICAL IMPACT

The Zenith t-Branch (Cook Medical, Bloomington, Ind) was approved as a commercially available device in Europe in June 2012. Although a decade has past, the outcomes of t-Branch have rarely been synthesized at the global level. This meta-analysis included 15 studies containing 1238 patients. The meta-analyses included technical success, major adverse events, reintervention, early mortality, and mid-term outcomes. The outcome was very meaningful and representative for the use of t-Branch. It is helpful for endovascular surgeons to make decisions on the treatment of TAAA patients.

Suitability of current off-the-shelf devices for endovascular TAAA repair: a systematic review

INTRODUCTION

The aim of the present study is to perform a systematic review of published papers regarding the suitability of the current off-the-shelf (OTS) devices for endovascular thoracoabdominal aortic aneurysm (TAAA) repair.

EVIDENCE ACQUISITION

A systematic review of the MEDLINE database via PubMed was performed in March 2023. All studies reporting the outcomes of the three currently available OTS stent-grafts: the Zenith t-Branch (Cook Medical, Bloomington, IN, USA), the Gore Excluder thoracoabdominal branch endoprosthesis (TAMBE; W.L. Gore & Associates, Flagstaff, AZ, USA) and the E-nside Multibranch Stent-Graft System (Artivion, Kennesaw, GA, USA), were retrieved and further analyzed. The main endpoints were technical success, reintervention rate, and primary branch patency. Theoretical feasibility studies of these OTS devices were also included and separately analyzed.

EVIDENCE SYNTHESIS

A total of 19 studies were published between 2014 and 2023. Thirteen clinical studies and six theoretical feasibility studies were included. Eleven studies reported the clinical outcomes of the t-Branch stent-graft, one detailed the observational results of the use of the E-nside endoprosthesis, and one described the TAMBE stent-graft results. The following data primarily involve the t-Branch device outcomes. A total of 1131 patients that underwent aneurysm repair using an OTS stent-graft were identified. Among those, 1002, 116 and 13 patients received a t-Branch, E-nside, and TAMBE stent-grafts, respectively. A total of 767 (67.8%) were men, with a mean age of 71.6±7.4 years old, and a mean Body Mass Index (BMI) of 26.3±3.8 kg/m2. Technical success ranged from 64% to 100%. A total of 4172 target visceral vessels (TVV) were planned for bridging, with a success rate ranging from 92 to 100%. The total of early and late reinterventions reported were 64 and 48, respectively, mainly due to endoleaks and visceral branch occlusions. Among the theoretical feasibility studies, six described the feasibility of the t-Branch device in a total of 661 patients, two described the E-nside and the TAMBE devices feasibility comprising 351 patients for each stent-graft. The overall feasibility of the t-Branch device varied from 39% to 88%, the E-nside from 43% to 75%, and the TAMBE stent-graft ranged from 33% to 94%.

CONCLUSIONS

This systematic review demonstrated a good suitability for the use of OTS endografts for the treatment of TAAA.

Two-year target vessel-related outcomes following use of off-the-shelf branched endografts for the treatment of thoracoabdominal aortic aneurysms

OBJECTIVE

The aim of this study was to assess clinical outcomes and target vessel patency through 2 years following thoracoabdominal aortic aneurysms (TAAA) repair with the off-the-shelf Zenith t-Branch Thoracoabdominal Endovascular Graft (William Cook Europe).

METHODS

This post-market observational study was conducted at three European sites with ambispective enrollment from 2012 to 2017. Patients underwent endovascular TAAA repair with the t-Branch graft and bridging stent grafts (BSGs) for the celiac (CA), superior mesenteric (SMA), left renal (LRA), and/or right renal (RRA) arteries. Follow-up was through 2 years, per sites' standard of care. Procedural and 1-year results were reported previously.

RESULTS

Eighty patients (mean age, 71.0±7.4 years; 70.0% men) were enrolled; six patients had symptomatic TAAAs, and 15 patients had contained ruptures. Technical success was achieved in 98.8% of patients (79/80). Median follow-up was 22.2 months (interquartile range, 9.2-25.1 months). At 24 months, Kaplan-Meier (KM) freedom from all-cause and aneurysm-related mortality were 78.5% and 98.6%, respectively. Beyond 12 months, 38 adverse events occurred in 20 patients, including two aortic ruptures (one study aneurysm and one non-study aneurysm) and six deaths (none aneurysm-related, as reported by the site). Compared with postprocedure, maximum aneurysm diameter decreased (>5 mm) in 84.6% (44/52), remained unchanged in 3.8% (2/52), and increased (>5 mm) in 11.5% (6/52) of patients with imaging follow-up after 12 months. No conversions to open repair, and no t-Branch graft or other endograft component migration or integrity issues were reported. No loss of patency was reported in the t-Branch or iliac limb grafts throughout the study. Throughout study duration, four patients had five imaging-reported BSG compressions, none of which required secondary intervention. KM freedom from secondary intervention was 76.3% at 24 months. Fourteen target vessel-related secondary interventions were performed, primarily consisting of stent placement for endoleak, stenosis, or occlusion. KM freedom from loss of primary patency was 94.8%, 100%, 91.3%, and 89.3% for the CA, SMA, LRA, and RRA, respectively, at 24 months. KM freedom from loss of secondary patency in the CA, SMA, LRA, and RRA were 96.3%, 100%, 98.2%, and 98.3% at 24 months, respectively. A total of 298 vessels were targeted, of which 12 were occluded over the study period.

CONCLUSIONS

Primary and secondary target vessel patency rates through 2 years demonstrated durable repair with the t-Branch graft in patients treated for symptomatic or asymptomatic thoracoabdominal aortic aneurysms.

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.

Predictors and Outcomes of Spinal Cord Injury following Complex Branched/Fenestrated Endovascular Aortic Repair in the US Aortic Research Consortium

OBJECTIVE

Spinal cord ischemia (SCI) is a well-known complication of thoracoabdominal aortic aneurysm (TAAA) repair and is associated with profound morbidity and mortality. The purpose of this study was to describe predictors for the development of SCI, as well as outcomes for patients who develop SCI, after branched/fenestrated endovascular aortic repair (FB-EVAR) in a large cohort of centers with adjudicated physician-sponsored investigational device exemption studies.

METHODS

We utilized a pooled dataset from 9 United States Aortic Research Consortium (US ARC) centers involved in investigational device exemption (IDE) trials for treatment of suprarenal and thoracoabdominal aortic aneurysms. SCI was defined as new transient weakness (paraparesis) or permanent paraplegia after repair without other potential neurologic etiologies. Multivariable analysis was performed to identify predictors of SCI, and life-table analysis and Kaplan-Meier methodology were used to evaluate survival differences.

RESULTS

A total of 1,681 patients underwent FB-EVAR over the period 2005-2020. The overall rate of SCI was 7.1% (3% transient and 4.1% permanent). Predictors of SCI on multivariable analysis were Crawford Extent I, II, and III distribution of aortic disease (OR 4.79 95% CI 4.77- 4.81, P<.001), age ≥70 (OR 1.64, 95% CI, 1.63-1.64, P=.029), packed red blood cell transfusion (OR 2.00, 95% CI, 1.99-2.00, P=.001), and history of PVD (OR 1.65, 95% CI, 1.64-1.65, P=.034). Median survival was significantly worse for patients with any degree of SCI compared to those without SCI (any SCI - 40.4 vs no SCI - 60.3 months, Log Rank <.001), and also worse in those with a permanent deficit (24.1 months) vs. those with a transient deficit (62.4 months) (Log Rank <0.001). One year survival for patients who developed no SCI was 90.8%, compared to 73.9% in patients who developed any SCI. When stratified by degree of deficit, survival was 84.8% at one year for those who developed paraparesis, and 66.2% for those who developed permanent deficits.

CONCLUSIONS

The overall rates of any SCI at 7.1% and permanent deficit at 4.1% observed in this study compare favorably to those reported in contemporary literature. Our findings confirm that increased length of aortic disease is associated with SCI and those with Crawford Extent I-III TAAAs are at highest risk. The long-term impact on patient mortality underscores the importance of preventive measures and rapid implementation of rescue protocols if and when deficits develop.

Comparative Effectiveness of Treatment Modalities for Complex Aortic Aneurysms: A Network Meta-Analysis of Observational Studies

BACKGROUND

To conduct a network meta-analysis comparing multiple treatments for complex aortic aneurysms (CAAs).

METHODS

Medical databases were searched on November 11, 2022. Twenty-five studies (5,149 patients) and four treatments (open surgery [OS], chimney/snorkel endovascular aneurysm repair [CEVAR], fenestrated endovascular aneurysm repair [FEVAR], and branched endovascular aneurysm repair) were selected. Outcomes were branch vessel patency, mortality, and reintervention at short- and long-term followup, and perioperative complications.

RESULTS

Regarding branch vessel patency, OS was the most effective treatment and had higher 24-month branch vessel patency rates than CEVAR (odds ratio [OR], 10.77; 95% confidence interval [CI], 2.08-55.79). FEVAR (OR, 0.52; 95% CI, 0.27-1.00) and OS (OR, 0.39; 95% CI, 0.17-0.93) were better than CEVAR regarding 30-day mortality and 24-month mortality, respectively. Regarding 24-month reintervention, OS was better than CEVAR (OR, 3.07; 95% CI, 1.15-8.18) and FEVAR (OR, 2.48; 95% CI, 1.08-5.73). Regarding perioperative complications, FEVAR had lower acute renal failure rates than OS (OR, 0.42; 95% CI, 0.27-0.66) and CEVAR (OR, 0.47; 95% CI, 0.25-0.92) and lower myocardial infarction rates than OS (OR, 0.49; 95% CI, 0.25-0.97) and was the most effective treatment in preventing acute renal failure, myocardial infarction, bowel ischemia, and stroke, while OS was the most effective treatment in preventing spinal cord ischemia.

CONCLUSIONS

OS might have advantages regarding branch vessel patency, 24-month mortality, and reintervention and is similar to FEVAR regarding 30-day mortality. Regarding perioperative complications, FEVAR might confer advantages in preventing acute renal failure, myocardial infarction, bowel ischemia, and stroke, and OS in preventing spinal cord ischemia.

Endovascular Reintervention for Stent-Graft Dislocation after Open Surgical Conversion for Thoracoabdominal Aortic Aneurysm Treated by Thoracic Endovascular Aortic Repair

Complex anatomical restrictions can lead to further interventions after the emergence of a postoperative aneurysm enlargement in thoracic endovascular aortic repair (TEVAR) for a thoracoabdominal aortic aneurysm (TAAA). A 75-year-old male underwent a TEVAR for a Crawford extent I TAAA. The main device and the distal extension were placed using a fenestrated technique, outside of the instructions for use. The aneurysm expanded because of an endoleak and stent graft migration; and was surgically repaired by fully salvaging the previous endografts 38 months after the first TEVAR. However, the distal extension, which was the proximal anastomosis site with a prosthetic graft, became completely dislocated from the main device eight months after the open surgical conversion, resulting again in the enlargement of the aneurysm. An additional TEVAR was successfully performed to correct the dislocated stent graft. An appropriate treatment strategy is crucial to prevent multiple reinterventions for TAAA with complex anatomical restrictions.

Midterm Outcomes for Endovascular Repair of Thoracoabdominal Aortic Aneurysms

Objective

To investigate technical and clinical outcomes in patients with thoraco-abdominal aortic aneurysms treated with the multibranched off the shelf Zenith t-Branch stent graft or a custom made device (CMD).

Methods

A retrospective study was conducted of patients operated on at a single tertiary vascular centre in Norway. Twenty eight t-Branch and 17 CMD patients were identified. Demographic, aneurysm, and peri-operative data were summarised and compared.

Results

Thirty day mortality was 4% (2/45), with mortality rates of 7% (2/28) and 0 in t-Branch and CMD patients, respectively (p = .52). Technical success was 87% (39/45), with a non-significant difference between t-Branch and CMD procedures of 89% (25/28) and 82% (14/17), respectively (p = .63). Stent graft coverage was significantly longer in t-Branch patients (p = .020). Paraparesis or paraplegia developed in 18% (5/28) of t-Branch patients and 12% (2/17) of CMD patients (p = .69), and spinal cord ischaemia was associated with Crawford type II aneurysms (p = .010) and aortic coverage >400 mm (p = .050). The estimated survival at one and two years for t-Branch patients was 93% and 88%, and 100% and 92% for CMD patients. Freedom from re-intervention was estimated at 70% and 43% at one and two years for t-Branch patients, and 58% and 50% for CMD patients.

Conclusion

The study showed low 30 day mortality rates, acceptable technical success rates, high medium term survival, and no statistically significant differences in clinically relevant outcomes between t-Branch and CMD patients.

•

Clinical outcomes do not vary significantly between t-Branch and CMD patients.

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30 day mortality was low among both t-Branch and CMD patients.

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Midterm survival was high in both groups.

Temporary Reperfusion of the Aneurysm Sac as a Prevention of Spinal Cord Ischemia After Endovascular Treatment of Thoracoabdominal Aortic Aneurysm: Systematic Review and Meta-analysis

BACKGROUND

Spinal cord ischemia (SCI) is still a feared complication for patients suffering from thoracoabdominal aortic aneurysm (TAAA) who undergo endovascular treatment. The aims of this work are to review the available literature on different reperfusion methods of the aneurysm sac, and to analyze whether the different reperfusion methods, also in combination with other factors, are effective in reducing SCI risk and if the impact varies with the patient's age.

METHODS

PubMed/MEDLINE library was searched for studies published until November 2020 concerning TAAA, endovascular repair, and SCI preventive measures. Systematic review and meta-analysis were conducted according to Preferred Reporting Items for Systematic reviews and Meta-Analyses criteria. Primary outcome consisted of correlation between endovascular repair techniques (type A: single step; type B: staged approach with reperfusion branches; type C: staged sequential approach with positioning of the thoracic component). A logistic-weighted regression for each event (SCI, transient, and permanent) was then performed with type of treatment, age, and interaction between them as input factors. Finally, another logistic-weighted regression was performed to analyze the other relevant factors for which observations are available together with the endovascular technique.

RESULTS

Data from 53 studies with a total of 3095 patients were analyzed. Type A, type B, and type C endovascular strategies were adopted in 75%, 13%, and 12% of studied patients, respectively. Data showed that both type B and type C treatments are associated with lower risk of SCI, with a higher reduction of type C with respect to type B, although this positive trend is limited for elder patients. Moreover, a greater aortic diameter, a reduced aneurysm extent, and the absence of cerebrospinal fluid drainage positioning contribute to lower the risk of SCI. Concerning permanent SCI, both type B and type C are effective in reducing percentages for all ages, with type C treatment more beneficial for younger patients and type B for elder ones.

CONCLUSION

According to the anatomy and the endovascular repair feasibility criteria, staged endovascular treatment appears to offer relevant advantages over single-step treatment in reducing the risk of SCI, regardless of the reperfusion method adopted.

A Systematic Review of Spinal Cord Ischemia Prevention and Management After Open and Endovascular Aortic Repair

OBJECTIVE

Spinal cord ischemia (SCI) is one of the most devastating complications after descending thoracic aortic (DTA) and thoracoabdominal aortic (TAA) repairs. Patients who develop SCI have a poor prognosis with mortality rates reaching 75% within the first year after surgery. Many factors have been shown to increase the risk of this complication, including extent of TAA repair, length of aortic and collateral network coverage, embolization, and reduced spinal cord perfusion pressure. As a result, a variety of treatment strategies have evolved. We aimed to provide an up-to-date review of SCI rates with associated treatment algorithms from open and endovascular DTA and TAA repairs.

METHODS

Using PRISMA guidelines, a literature review with the Medical Subject Headings (MeSH) terms "spinal cord ischemia; spinal cord ischemia prevention and mitigation strategies; spinal cord ischemia rates; spinal cord infarction" was performed in the Cochrane and PubMed databases to seek all peer-reviewed studies of DTA and TAA repairs with SCI complications, limited to 2012-2021 and the English language. MeSH subheadings including diagnosis, complications, physiopathology, surgery, mortality, and therapy were used to further restrict the articles. Studies were excluded if they were not in humans, not pertaining to SCI in DTA/TAA operative repairs, and if the study primarily discussed neuromonitoring techniques. Additionally, studies with <40 patients or limited information regarding SCI protection strategies were excluded. Each study was individually reviewed by two researchers to assess for type and extent of aortic pathology, operative technique, SCI protection or mitigation strategies, rates of overall and permanent SCI symptoms, associations with SCI on multivariate analysis, and mortality.

RESULTS

Of 450 studies returned by the MeSH search strategy, 41 met inclusion criteria and were included in the final analysis. For endovascular DTA repair patients, overall SCI rates ranged from 0-10.6% with permanent SCI symptoms ranging from 0-5.1%. Endovascular and open TAA repairs had rates of overall SCI of 0-35%. Permanent SCI symptom rate was reported by only one open study at 1.1% while endovascular TAA repairs had between 2-20.5%.

CONCLUSION

This review provides an up-to-date review of current rates of SCI as well as prevention and mitigation strategies for DTA and TAA repairs. We find that a multimodal approach, including a bundled institutional protocol, staging of multiple repairs, preservation of collateral blood flow network, augmented spinal cord perfusion, selective cerebrospinal fluid drainage, and distal aortic perfusion in open TAA repairs, appears to be important in reducing the risk of SCI.

A systematic review and meta-analysis of the occurrence of spinal cord ischemia following endovascular repair of thoraco-abdominal aortic aneurysms

OBJECTIVE

The rates of endovascular repair of thoracoabdominal aortic aneurysms (TAAA-ER) have increased considerably in the last years. While mortality and morbidity rates have improved, spinal cord ischemia (SCI) rates have not declined significantly. The aim of this systematic review and meta-analysis was to examine SCI rates with respect to the efficacy of the different approaches.

METHODS

Cohort studies and case series (>20 patients) reporting SCI rates after TAAA-ER were eligible for inclusion. The primary outcome was the evaluation of SCI. Moderators considered were primarily the staged/non-staged approach, the use of cerebrospinal fluid drainage (CSFD) and TAAA extension. Permanent SCI and mortality rates were extracted.

RESULTS

Twenty-seven studies (n=2333 patients) were included in the meta-analysis. The pooled estimate for SCI was 11% (95% confidence interval [CI]: 8%-15%; I²:80%). For extent I,II,III and V TAAA, the pooled SCI rate was 13% (95% CI: 10%-17%; I²=71%), while for extent IV TAAA it was 6% (95% CI: 3%-10%; I²=62%). A staged TAAA-ER approach was used in 18 studies and a non-staged approach in 6 (one study included both). A lower pooled SCI rate was identified following staged compared with non-staged TAAA-ER (9% vs. 18%, respectively; P=.02). Staging was accomplished in >1 month in 9 studies and ≤1 month in 2, leading to similar SCI rates (7% vs. 11%, respectively; P=.29). The method of staging (thoracic-endoprosthesis or temporary aortic sac perfusion) did not affect SCI rates. Symptomatic CSFD was associated with a similar pooled rate of SCI compared with prophylactic CSFD (10% vs. 10%, respectively; P=.95). Pooled permanent SCI was 5% (6% following extent I,II,III and V TAAA; 3% following extent IV TAAA). Prophylactic or symptomatic CSFD have a similar rate of SCI (10% vs. 10%, respectively; P=.89). The pooled rate of 30-day mortality was 7%, with a similar incidence for the staged and non-staged approaches (6% vs. 9%, respectively). The inter-stage mortality was reported in 10 studies, with a pooled estimate rate of 1.6%.

CONCLUSIONS

SCI occurs in 11% of TAAA-ER and half of these cases are permanent. A staged approach can reduce SCI rates independently from the timing and the method adopted. The overall mortality rate for staged TAAA-ER is 6%, with one fourth of deaths (1.6%) occurring between stages.

Early outcomes of t-Branch off-the-shelf multibranched stent-graft in urgent and emergent repair of thoracoabdominal aortic aneurysms

OBJECTIVE

We compared the outcomes between elective, urgent, and emergent treatment of thoracoabdominal aortic aneurysms (TAAAs) using the t-Branch off-the-shelf multibranched stent-graft (Cook Medical, Bloomington, Ind).

METHODS

All consecutive patients treated for TAAAs using the t-Branch between September 2012 and June 2019 were included in the present study. The patients were divided into three groups according to the urgency of repair: (1) elective, (2) urgent, and (3) emergent. The periprocedural details and 30-day outcomes were analyzed. Survival and reinterventions were analyzed using Kaplan-Meier curves and log-rank tests.

RESULTS

The t-Branch stent-graft was used for 100 patients during the study period. Of the 100 patients, 30 (73% male; mean age, 65 ± 10 years) were treated electively, 49 (54% male; mean age, 72 ± 7 years) urgently, and 21 (81% male; mean age, 75 ± 9 years) emergently. Transfemoral access with a steerable sheath was used more frequently for target vessel catheterization in the elective group (57%) than in the urgent (8%) and emergent (5%) groups (P = .021). The total number of targeted vessels was 111 of 120 (93%) in the elective group vs 185 of 196 (94%) in the urgent group and 82 of 84 (98%) in the emergent group. The corresponding technical success rates were 97% (29 of 30), 98% (48 of 49), and 95% (20 of 21). The median intensive care unit stay was shorter in the elective group (3 days; range, 1-41 days) than in the urgent group (5 days; range, 1-41 days) and emergent group (11 days; range, 3-37 days; P = .004). The 30-day mortality rate was lower in the elective group (2 of 30; 7%) than in the urgent group (8 of 49; 16%) and emergent group (5 of 21; 24%; P = .049). The acute kidney injury rate was lower in the elective group (2 of 30; 7%) than in the urgent group (11 of 49; 22%) and emergent group (8 of 21; 38%; P = .002). The spinal cord ischemia rate was also lower in the elective group (5 of 30; 17%) than in the urgent group (5 of 49; 10%) and emergent group (8 of 21; 38%; P = .051). The median follow-up was 8 months (interquartile range, 3.2-18.5 months). The cumulative survival rate was 95%, 87%, and 87% at 6, 12, and 24 months, respectively. The cumulative freedom from reintervention during follow-up was 92%, 86%, and 77% at 6, 12, and 24 months, respectively.

CONCLUSIONS

The technical success of TAAA repair using t-Branch stent-graft was not affected by an urgent or emergent presentation. However, the occurrence of worse periprocedural morbidity and mortality was significantly associated with an urgent or emergent presentation.

Towards rapid intraoperative axial localization of spinal cord ischemia with epidural diffuse correlation monitoring

Spinal cord ischemia leads to iatrogenic injury in multiple surgical fields, and the ability to immediately identify onset and anatomic origin of ischemia is critical to its management. Current clinical monitoring, however, does not directly measure spinal cord blood flow, resulting in poor sensitivity/specificity, delayed alerts, and delayed intervention. We have developed an epidural device employing diffuse correlation spectroscopy (DCS) to monitor spinal cord ischemia continuously at multiple positions. We investigate the ability of this device to localize spinal cord ischemia in a porcine model and validate DCS versus Laser Doppler Flowmetry (LDF). Specifically, we demonstrate continuous (>0.1Hz) spatially resolved (3 locations) monitoring of spinal cord blood flow in a purely ischemic model with an epidural DCS probe. Changes in blood flow measured by DCS and LDF were highly correlated (r = 0.83). Spinal cord blood flow measured by DCS caudal to aortic occlusion decreased 62%. This monitor demonstrated a sensitivity of 0.87 and specificity of 0.91 for detection of a 25% decrease in flow. This technology may enable early identification and critically important localization of spinal cord ischemia.

Short-term outcomes of the t-Branch off-the-shelf multibranched stent graft for reintervention after previous infrarenal aortic repair

OBJECTIVE

The purpose of this study was to evaluate the outcome of t-Branch (Cook Medical, Bloomington, Ind) stent graft for the treatment of thoracoabdominal and pararenal aortic aneurysms in patients who had previous infrarenal aortic repair.

METHODS

A retrospective two-center study was undertaken. All consecutive patients who underwent endovascular repair using t-Branch stent graft after previous infrarenal aortic repair between January 2010 and August 2018 were included. Demographics, past medical history, cardiovascular risk factors, and intraoperative and perioperative details were recorded. Technical success and early (30-day) mortality, morbidity, target vessel patency, and presence of endoleak were analyzed. During the first year of follow-up, survival, freedom from reintervention, and patency rates were recorded.

RESULTS

There were 32 patients (mean age, 74 ± 7 years; 81% male) included in the study; 24 (75%) patients had prior open surgical repair, and 8 (25%) patients had undergone standard endovascular aneurysm repair. The index operation was performed 9 ± 5 years earlier, including 10 ± 5 years for open surgical repair and 8 ± 6 years for endovascular aortic repair. The indication was progression of the disease in 26 patients (81%) and type IA endoleak in 6 patients (19%). The total number of target vessels incorporated was 117 arteries (3.8 ± 0.6 target vessels per patient). Eleven patients had only three vessels incorporated; celiac trunk was occluded in three patients, and eight patients had one functioning kidney. Technical success rate was 97% (31/32). There was a single technical failure in one patient who had a type IA endoleak after endovascular repair with suprarenal fixation. The stenotic right renal artery was not catheterized at the initial procedure, and retrograde access was achieved through a right subcostal incision 3 days later with successful completion of the repair. Early mortality rate was 13%, and spinal cord ischemia rate was 22% (7/32); four patients had permanent and three had transient neurologic deficits. Early target vessel patency was 100%, and the rate of any endoleak was 9% (3/32); two patients had type II endoleaks and one patient had type III endoleak. The mean follow-up was 5.4 ± 5.9 months. The cumulative survival rate was 82% and 73% at 6 and 12 months, respectively. The freedom from aorta-related mortality was 92% at 6 and 12 months. The cumulative freedom from reintervention during follow-up was 90% at 6 and 12 months. The overall target vessel patency rate was 100% and 97.5% at 6 and 12 months, respectively.

CONCLUSIONS

The use of t-Branch off-the-shelf stent graft for the treatment of aortic disease in patients who had previous infrarenal aortic repair appears to be feasible, with acceptable early outcomes in terms of morbidity and mortality.

Endovascular Treatment for Thoracoabdominal Aortic Aneurysm and Complex Abdominal Aortic Aneurysm Using Fenestrated and Branched Grafts

Fenestrated and branched endovascular aneurysm repair (F/B-EVAR) is a less invasive treatment for thoracoabdominal aortic aneurysm (TAAA) and complex abdominal aortic aneurysm. Fenestrated and branched (cuff) grafts facilitate safe and durable repair, and bail-out maneuvers for target vessel cannulation and stenting have been established; however, the available bridging stent grafts have differences. The present article discusses the optimal selection of fenestrated or branched grafts, the cannulation of target vessels that have difficult anatomies, and the advantages and disadvantages of various bridging stents. We review the causes and risk factors of spinal cord injury (SCI), the protocol for prevention of SCI, and the outcomes of target vessel stent grafting, including patency and endoleak.

Although conventional open surgery is the gold standard for the repair of thoracoabdominal aortic aneurysm (TAAA), it is highly invasive. To reduce invasiveness, hybrid surgery that combines open surgery and endovascular therapy has been developed [1, 2], and fenestrated and branched endovascular aneurysm repair (F/B-EVAR) is frequently performed at centers in the USA, Europe, and Japan [3-5]. Additionally, a hostile neck may be an independent factor for sac enlargement after EVAR for abdominal aortic aneurysm (AAA) [6], but a previous study reported that 41% of AAA cases presented with neck lengths outside the range prescribed by the traditional instruction for use [7]. Stark et al. showed that extending the graft above the highest renal artery would create an augmented neck length in 90% of patients with AAA [7]. F/B-EVAR is based on this principle. However, there are some technical tips for, and limitations of, fenestrated and/or branched graft. F/B-EVAR for TAAA and complex AAA will be reviewed in the present article.

Current status of endovascular treatment for thoracoabdominal aortic aneurysms

Open surgical repair (OSR) for thoracoabdominal aortic aneurysms (TAAAs) is maximally invasive and associated with high rates of operative mortality and perioperative complications including spinal cord ischemia (SCI), despite improvements in surgical techniques and perioperative care. Elderly patients, patients with a history of aortic surgery, and patients with severe comorbidities are often considered ineligible for this surgery and endovascular treatment may be their only treatment option. Total endovascular aneurysm repair (t-EVAR) without debranching surgery does not require thoracotomy and laparotomy and could improve the outcomes of these patients. t-EVAR includes fenestrated EVAR (f-EVAR), multi-branched EVAR (b-EVAR), and physician-modified fenestration endograft (PMFG). Although these techniques have achieved lower mortality rates than OSR, there are concerns about perioperative complications including limb ischemia, SCI, and long-term outcomes such as endograft migration and endoleaks (ELs). This article provides an overview of available endovascular devices for TAAAs and reviews the short and mid-term results of t-EVAR, as well as alternative options.

Systematic review of contemporary outcomes of endovascular and open thoracoabdominal aortic aneurysm repair

OBJECTIVE

The purpose of the study was to provide a systematic review of the literature reporting the contemporary early outcomes after endovascular and open repair of thoracoabdominal aortic aneurysms (TAAAs).

METHODS

MEDLINE and Embase were searched for studies from January 2006 to March 2018 that reported either endovascular (using branched or fenestrated endografts) or open repair of TAAA in at least 10 patients. Outcomes of interest included perioperative mortality, spinal cord injury (SCI), renal failure requiring dialysis, and stroke. Pooled proportions were determined using a random-effects model.

RESULTS

The analysis included 71 studies, of which 24 and 47 reported outcomes after endovascular and open TAAA repair, respectively. Endovascular cohort patients were older and had higher rates of coronary artery disease, chronic obstructive pulmonary disease, and diabetes. Endovascular repair was associated with higher rates of SCI (13.5%; 95% confidence interval [CI], 10.5%-16.7%) compared with open repair (7.4%; 95% CI, 6.2%-8.7%; P < .01) but similar rates of permanent paralysis (5.2% [95% CI, 3.8%-6.7%] vs 4.4% [95% CI, 3.3%-5.6%]; P = .39), lower rates of postoperative dialysis (6.4% [95% CI, 3.2%-9.5%] vs 12.0% [95% CI, 8.2%-16.3%]; P = .03) but similar rates of being discharged on permanent dialysis (3.7% [95% CI, 2.0%-5.9%] vs 3.8% [95% CI, 2.9%-5.3%]; P = .93), a trend to lower stroke (2.7% [95% CI, 1.9%-3.6%] vs 3.9% [95% CI, 3.0%-4.9%]; P = .06), and similar perioperative mortality (7.4% [95% CI, 5.9%-9.1%] vs 8.9% [95% CI, 7.2%-10.9%]; P = .21).

CONCLUSIONS

This systematic review summarizes the contemporary literature results of endovascular and open TAAA repair. Endovascular repair studies included patients with more comorbidities and were associated with higher rates of SCI but similar rates of permanent paraplegia, whereas open repair studies had higher rates of postoperative dialysis but similar rates of being discharged on permanent dialysis. Perioperative mortality rates were similar. Universally adopted reporting standards for patient characteristics, outcomes, and the conduct of contemporary comparative studies will allow better assessment and comparisons of the risks associated with the two surgical treatment options for TAAA.

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 Treatment of Various Aortic Pathologies: Review of the Latest Data and Technologies

The technologies and innovations applicable to endovascular treatment for complex aortic pathologies have progressed rapidly over the last two decades. Although the initial outcomes of an endovascular aortic repair have been excellent, as long-term data became available, complications including endoleaks, endograft migration, and endograft infection have become apparent and are of concern. Previously, the indication for endovascular therapy was restricted to descending thoracic aortic aneurysms and abdominal aortic aneurysms. However, its indication has expanded along with the improvement of techniques and devices, and currently, it has become possible to treat pararenal aortic aneurysms and Crawford type 4 thoracoabdominal aortic aneurysm (TAAA) using the off-the-shelf devices. Additionally, custom-made devices allow for the treatment of arch or more extensive TAAAs. Endovascular treatment is applied not only to aneurysms but also to acute/chronic dissections. However, long-term outcomes are still unclear. This article provides an overview of available devices and the results of endovascular treatment for various aortic pathologies.

Early Outcomes of the t-Branch Off-the-Shelf Multibranched Stent-Graft in Urgent Thoracoabdominal Aortic Aneurysm Repair

Purpose: To assess the short-term outcomes of the multibranched off-the-shelf t-Branch stent-graft for urgent thoracoabdominal aortic aneurysm (TAAA) repair and to evaluate the impact on outcomes of the learning curve and adherence to the instruction for use (IFU). Methods: Between 2014 and 2017, 42 patients (mean age 73.3±7 years; 26 men) underwent urgent TAAA treatment using the t-Branch stent-graft [18 in the early (2014–2015) period and 24 in the late (2016–2017) period]. Nearly half the patients were symptomatic (n=18) and 12 had contained rupture. Aneurysm diameter >80 mm was present in 12 (mean diameter 77.7±13.2 mm). Nineteen patients did not meet the IFU for the t-Branch due to target vessel anatomy. The primary endpoints were spinal cord ischemia (SCI), renal function impairment, and 30-day mortality. Target vessel patency and endoleak incidence were assessed at 30 days. Multivariate analyses examined associations between perioperative variables and outcomes; the results are presented as the odds ratio (OR) and 95% confidence interval (CI). Results: The technical success rate was 93% (39/42). Successful catheterization was achieved in 150/155 target vessels (97%). The postoperative SCI rate was 21% (5 paraplegia/4 transient paraparesis) and was correlated with age (OR 1.26, 95% CI 1.01 to 1.56, p=0.04). The renal function impairment rate was 23% (10/42; 2 temporary, 2 permanent dialysis) and was correlated with early experience (OR 7.74, 95% CI 1.3 to 43.9, p=0.019). The 30-day mortality was 14% (no intraoperative deaths); no factor was associated with mortality. During the first month, the incidences of type I, II, and III endoleaks were 0%, 43%, and 0%, respectively; branch patency was 99% (150/151). Procedure time decreased in the later experience (479±333 vs 407±25 minutes, p=0.09), though it was increased in cases outside the IFU (497±135 vs 389±118 minutes, p=0.009), along with fluoroscopy time (121±48 vs 92±33 minutes, p=0.036). Conclusion: Endovascular repair of urgent TAAA using the t-Branch is a feasible treatment option with acceptable 30-day mortality and morbidity in terms of SCI and renal function impairment. Adherence to the IFU prolonged procedure time but had no effect on outcomes. Increased experience of such cases over time may improve outcomes.