Comparison of bridging stent grafts in branched endovascular aortic repair

BACKGROUND

Endovascular treatment of thoracoabdominal aortic aneurysms has become common, with satisfactory results. Nevertheless, long-term durability remains an issue mainly because of target visceral vessel (TVV) instability. Currently, no covered stent has been approved as a bridging stent graft (BSG), demanding continuous research on this topic.

METHODS

This was a multicenter observational retrospective cohort study comparing the midterm results of the Bard Covera Plus and Gore VBX as BSGs during branched endovascular aneurysm repair. The primary outcome was the comparison of the target vessel instability between the two groups. Primary patency, freedom from branch-related type I and III endoleaks and reintervention, and technical and clinical success were considered secondary outcomes. Logistic regression analysis was used to assess the association between selected baseline factors and TVV instability. TVV instability during follow-up was then evaluated using the Kaplan-Meier cumulative function.

RESULTS

Three hundred forty-five TVVs in 106 patients were considered suitable for the analysis. Two hundred twenty vessels were stented with the Covera stent graft (64%) and 125 with VBX (36%). Two hundred ninety-nine TVVs received a single BSG, 45 two BSGs, and only 1 three BSGs. Bare metal stent relining was required in 36% of TVVs, mostly in the Covera group (89 [41%] vs 36 [29%]) (P = .030). The primary technical success rate was 96% (331/345), and the assisted primary technical success rate was 99% (342/345). The TVV instability rate within 30 days was 2% (one Covera and five VBX; P = .015). Three BSG occlusions (one Covera and two VBX) and three type Ic endoleaks (three VBX) were detected. The median follow-up was 13.9 months (range, 5.8-25.5 months). Sixteen TVV instabilities were detected during the follow-up. Twelve BSG occlusions (six Covera and six VBX), three type Ic endoleaks (one Covera and two VBX), and one type IIIc endoleak (VBX). The overall target vessel instability rate was 5% (16/342). TVV instability was associated with the use of Gore VBX in the univariable logistic regression (odds ratio, 3.0; 95% confidence interval, 1.1-8.0; P = .027). Aneurysm rupture and aneurysm diameter were also associated with TVV instability in the univariable analysis (P = .002 and P = .008, respectively). The only factor predisposing to TVV instability in the multivariable logistic regression analysis was the use of Gore VBX as a BSG (odds ratio, 2.9; 95% confidence interval, 1.0-8.0; P = .043). Kaplan-Meier analysis showed a significantly higher risk of TVV instability in the VBX group (P < .001).

CONCLUSIONS

Overall midterm outcomes in this cohort were satisfactory. Patency rates were similar between the two stents. Nevertheless, VBX seems to be associated with worse TVV instability. These results may be correlated with a higher incidence of type Ic endoleaks, which require an extensive learning curve for correct stent selection and deployment.

Presentation and outcomes of thoracic and thoracoabdominal aortic aneurysms in females, existing gaps, and future directions: A descriptive review

Thoracic and thoracoabdominal aortic aneurysms are more common in men. Yet, females often have worse outcomes, fewer interventions, and lower treatment rates. Females have also benefited less from the research and treatment of those diseases than men. Understanding sex- and sex-specific differences in thoracic and thoracoabdominal aortic aneurysms can improve care delivery, reduce disparities, and optimize outcomes for females with thoracic aortic aneurysms and thoracoabdominal aortic aneurysms. The authors reviewed the literature on the presentation and outcomes of thoracic and thoracoabdominal aortic aneurysms in females, discussing the existing gaps and future directions to address them.

Outcomes following Management of Complex Thoracoabdominal Aneurysm by an Open Approach

BACKGROUND

In the last decade, advances in surgical techniques, and the introduction of adjuncts for organ protection, have modified the approach for thoracoabdominal aortic aneurysm (TAAA) surgical repair. The aim of this study is to determine whether the contemporary approach influenced the outcomes.

METHODS

From 1989 to 2022, patients who had received elective open surgical repair (OSR) for TAAA at our institution were retrospectively analyzed. This series has been divided in two groups: Group 1 (1989-2009), and Group 2 (2010-2022). Patients included in Group 1 were those treated with a selective use of adjuncts, and Group 2 included patients treated with the systematic use of adjuncts.

RESULTS

A total of 1107 patients were treated (Group 1: 455; Group 2: 652). The surgical management was significantly different between the two groups. The in-hospital mortality was significantly different between the two groups (Group 1: 13.4%, Group 2: 8.1%; p 0.004), as was the rate of permanent spinal cord ischemia (Group 1: 11.9%, Group 2: 7.8%; p 0.023). Renal and respiratory failure were reduced in Group 2, but not significantly.

CONCLUSIONS

The use of the adjuncts enabled the achievement of improvement in mortality and SCI prevention in TAAA OSR. Although a refined surgical technique, mortality and morbidity are still noteworthy in this complex aortic field.

Thoracoabdominal aortic aneurysm life-altering events following endovascular aortic repair in the Vascular Quality Initiative

OBJECTIVE

Endovascular aortic aneurysm repair has lower rates of postoperative mortality and morbidity when compared with open repair. However, endovascular repair still carries the risk of postoperative dialysis, paralysis, and stroke. This study examined the rates of postoperative mortality and morbidity stratified by type of endovascular aortic aneurysm repair.

METHODS

All patients who underwent endovascular aortic aneurysm repair in the Vascular Quality Initiative registry from January 2011 - May 2022 were identified. Patients were stratified by repair type: infrarenal endovascular aortic repair (EVAR), complex EVAR, thoracic endovascular aortic repair (TEVAR), extent I-III thoracoabdominal aortic aneurysm (TAAA) repair, or aortic arch repair. The primary outcome was postoperative thoracoabdominal aortic aneurysm life-altering events (TALE) across the different treatment groups. TALE was defined as a composite outcome of postoperative mortality, dialysis, paralysis, and/or stroke. Mixed effect logistic regression modeling was used to identify procedural and anatomic factors that were independently associated with TALE.

RESULTS

A total of 52,592 EVARs, 3,768 complex EVARs, 3,899 TEVARs, 1,139 extent I-III TAAA repairs, and 479 arch repairs were identified. TALE was observed in 1.2% of EVARs, 4.8% of complex EVARs, 6.0% of TEVARs, 10% of extent I-III TAAA repairs, and 14% of arch repairs. More proximal landing zone was associated with higher odds of TALE after complex EVAR (OR 1.9 [1.2-3.1]; p=.008), TEVAR (OR 2.2 [1.4-3.5]; p=.001), and extent I-III TAAA repair (OR 2.7 [1.5-4.9]; p=.001). Aortic diameter >65mm was associated with higher odds of TALE after infrarenal EVAR (OR 1.8 [1.4-2.3]; p<.001), complex EVAR (OR 1.6 [1.1-2.3]; p=.010), TEVAR (OR 2.7 [2.0-3.8]; p<.001), and arch repair (OR 2.4; [1.3-4.4]; p=.007). The use of parallel grafting technique (chimney/snorkel/periscope) during extent I-III TAAA repair was also associated with higher odds of TALE (OR 1.8 [1.1-3.2]; p=.032). Preoperative chronic kidney disease was also associated with higher odd of TALE after infrarenal EVAR (OR 4.3 [3.0-5.7]; p<.001), complex EVAR (OR 5.2 [3.3-8.2]; p<.001), TEVAR (OR 4.5 [2.8-7.1]; p<.001), and extent I-III TAAA repair (OR 3.2 [1.6-6.7]; p=.001).

CONCLUSION

While TALE was originally described for thoracoabdominal aortic aneurysm repairs, TALE may occur after complex EVAR, TEVAR, and arch repairs as well. Therefore, TALE and its component parts should be used to evaluate the efficacy of all aortic repairs and for preoperative counseling. Additionally, surgeons should be aware of anatomic and procedural characteristics that are associated with higher odds of TALE. The anticipated need for such interventions during aortic repair should be factored into preoperative risk assessment of patients.

Open Treatments for Thoracoabdominal Aortic Aneurysm Repair

Thoracoabdominal aortic aneurysms (TAAA) represent a unique pathology that is associated with considerable mortality if untreated. While the advent of endovascular technologies has introduced new modalities for consideration, the mainstay of TAAA treatment remains open surgical repair. However, the optimal conduct of open TAAA repair requires careful consideration of patient risk factors and a collaborative team effort to mitigate the risk of perioperative complications. In this chapter, we briefly outline the history of treating TAAA, preoperative preparation and postoperative care, and our operative techniques for treatment.

Minimally Invasive Segmental Artery Coil Embolization (MISACE) Prior to Endovascular Thoracoabdominal Aortic Aneurysm Repair

PURPOSE

Minimally Invasive Segmental Artery Coil Embolization (MISACE) is a novel approach to reduce paraplegia risk in Thoracoabdominal aortic aneurysm (TAAA) repair with limited data. We report our experience with MISACE as a method of spinal cord pre-conditioning to prevent spinal cord ischemia following endovascular repair of TAAA.

MATERIAL AND METHODS

A retrospective analysis of 17 patients who had an attempted MISACE prior to endovascular TAAA repair with mean follow-up of 350 days (2017-2020). Baseline patient and aneurysm characteristics along with procedural technique and outcomes were analyzed.

RESULTS

Mean age of 69 years and 76.5% were males. TAAA Crawford classification were II, n = 6 (35.3%), III, n = 4 (23.5%) and IV, n = 5 (29.4%). The mean aortic diameter was 70.6 ± 10.9 mm. Staged repair was performed on 9 patients. Technically successful embolization occurred in 14 patients (82.4%) and was unsuccessful in 3 patients. The median number of embolized arteries was 3 and 71% of the target arteries were between T9 and T12. Mean fluoroscopy time was 51.5 ± 22.5 min and mean contrast volume used was 132.8 ± 56.1 mL. Average number of catheters used was 4.6 and 3.5 wires. No complications related to the procedure. Mean interval between embolization to endovascular TAAA repair was 51.2 days (5-110 days). All patients received spinal drainage at the time of repair. Postoperatively, 2/14 of patients developed paraparesis in the MISACE successful group and 1/3 patients developed paraplegia in the unsuccessful group.

CONCLUSIONS

MISACE is a promising strategy to prevent SCI. This data demonstrates the technique is feasible and safe but anatomic challenges remain.

Spinal Cord Ischemia After Thoracoabdominal Aortic Aneurysms Endovascular Repair: From the Italian Multicenter Fenestrated/Branched Endovascular Aneurysm Repair Registry

PURPOSE

The aim of this study is to report an Italian multicenter experience analyzing the incidence and the risk factors associated with spinal cord ischemia (SCI) in a large cohort of thoracoabdominal aortic aneurysms (TAAAs) treated by fenestrated-branched endovascular aneurysm repair (F-/B-EVAR).

MATERIALS AND METHODS

All consecutive patients undergoing F-/B-EVAR in 4 Italian university centers between 2008 and 2019 were prospectively recorded and retrospectively analyzed. Spinal cord ischemia, 30 day/in-hospital adverse events, and mortality were assessed as early outcomes. Risk factors for SCI were determined by multivariable analysis.

RESULTS

A total of 351 patients received F-/B-EVAR for a TAAA. Twenty-eight (8.0%) patients died within 30 postoperative days or during the hospitalization. Regarding SCI, 47 patients (13.4%) developed neurological symptoms related to spinal cord impaired perfusion. Among them, 17 (4.8%) had a major permanent impairment. The multivariable analysis identified that SCI was associated with Crawford extent I to III (odds ratio [OR]: 20.90, p=0.004, 95% confidence interval [CI]=2.69-162.57), and with endovascular procedures performed for ruptured TAAA (OR: 5.74, p=0.010, 95% CI=1.53-21.57). Spinal cord ischemia was also significantly associated with a grade 3 bleeding during the visceral stage (OR: 4.34, p=0.005, 95% CI=1.55-12.16) and a grade 2 renal insufficiency at 30 days (OR: 7.45, p=0.002, 95% CI=2.12-26.18).

CONCLUSION

The present study indicates that SCI is still an open issue after extent I to III TAAA endovascular repair, while its incidence in extent IV TAAA and pararenal/juxtarenal aneurysms is rare. Thoracoabdominal aortic aneurysms extension, urgent TAAA repair for rupture, severe bleeding, and 30 day renal insufficiency have been identified as significant risk factors for SCI. In the presence of such factors, adjunctive strategies may be considered to reduce SCI rates, while in low-risk patients invasive or potentially-risky maneuvers might not be justified.

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.

Perioperative and long-term outcome after ascending aortic and arch repair with elephant trunk and open thoracoabdominal aortic aneurysm repair

OBJECTIVE

To describe the outcome of open thoracoabdominal aortic aneurysm (TAAA) repair following previous aortic arch repair including elephant trunk (ET) or frozen elephant trunk (FET) for acute and chronic pathologies.

METHODS

This was a retrospective, observational, multicenter study including 32 patients treated between 2006 and 2019 in two aortic centers using identical surgical protocols. Assessment focused on perioperative and long-term outcome, namely in-hospital morbidity and mortality, as well as procedure-related reintervention rate and aortic-related mortality rate. Kaplan-Meier curves with 95% confidence intervals were used to analyze the overall survival after surgery within the cohort.

RESULTS

Thirty-two patients (mean age, 45.0 ± 13.6 years; 20 males [62.5%]) were treated because of acute (34.38% [n = 11]) or chronic (65.62% [n = 21]) aortic pathologies, including residual dissection following acute, symptomatic type A dissection (n = 7) and symptomatic mega aortic syndrome (n = 4), as well as post-dissection TAAA (n = 18) and asymptomatic mega aortic syndrome (n = 3). Twenty-eight patients (87.5%) received type II repair, and 4 patients (12.5%) received type III repair after previous ascending aorta and arch repair including ET/FET. Concomitant infrarenal and iliac vessel repair was performed in 38.7% (n = 12) and 29.4% (n = 10), respectively. The in-hospital mortality rate was 18.75% (n = 6). Spinal cord ischemia occurred in two cases, both after one-stage emergency procedure with one case of permanent paraplegia. Temporary acute kidney injury occurred in 41.94% (n = 13). The estimated 1-year survival rate was 78.1% (95% confidence interval, 63.9%-95.6%), with a median follow-up time of 1.29 years (interquartile range, 0.26-3.88 years). No procedure-related reinterventions and one case of aortic-related mortality, namely sepsis because of graft infection, was observed.

CONCLUSIONS

Open TAAA repair following aortic arch repair including ET or FET because of acute or chronic aortic pathologies is associated with a relevant perioperative morbidity and mortality rate. During follow-up, a low aortic-related mortality rate and procedure-related reintervention rate were observed.

Trends in the use of cerebrospinal drains and outcomes related to spinal cord ischemia after thoracic endovascular aortic repair and complex endovascular aortic repair in the Vascular Quality Initiative database

BACKGROUND

Spinal cord ischemia (SCI) is a dreaded complication of thoracic and complex endovascular aortic repair (TEVAR/cEVAR). Controversy exists surrounding cerebrospinal fluid drain (CSFD) use, especially preoperative prophylactic placement, owing to concerns regarding catheter-related complications. However, these risks are balanced by the widely accepted benefits of CSFDs during open repair to prevent and/or rescue patients with SCI. The importance of this issue is underscored by the paucity of data on CSFD practice patterns, limiting the development of practice guidelines. Therefore, the purpose of the present analysis was to evaluate the differences between patients who developed SCI despite preoperative CSFD placement and those treated with therapeutic postoperative CSFD placement.

METHODS

All elective TEVAR/cEVAR procedures for degenerative aneurysm pathology in the Society for Vascular Surgery Vascular Quality Initiative from 2014 to 2019 were analyzed. CSFD use over time, the factors associated with preoperative prophylactic vs postoperative therapeutic CSFD placement in patients with SCI (transient or permanent), and outcomes were evaluated. Survival differences were estimated using the Kaplan-Meier method.

RESULTS

A total of 3406 TEVAR/cEVAR procedures met the inclusion criteria, with an overall SCI rate of 2.3% (n = 88). The SCI rate decreased from 4.55% in 2014 to 1.43% in 2018. Prophylactic preoperative CSFD use was similar over time (2014, 30%; vs 2018, 27%; P = .8). After further exclusions to evaluate CSFD use in those who had developed SCI, 72 patients were available for analysis, 48 with SCI and prophylactic CSFD placement and 24 with SCI and therapeutic CSFD placement. Specific to SCI, the patient demographics and comorbidities were not significantly different between the prophylactic and therapeutic groups, with the exception of previous aortic surgery, which was more common in the prophylactic CSFD cohort (46% vs 23%; P < .001). The SCI outcome was significantly worse for the therapeutic group because 79% had documented permanent paraplegia at discharge compared with 54% of the prophylactic group (P = .04). SCI patients receiving a postoperative therapeutic CSFD had had worse survival than those with a preoperative prophylactic CSFD (50% ± 10% vs 71% ± 9%; log-rank P = .1; Wilcoxon P = .05).

CONCLUSIONS

Prophylactic CSFD use with TEVAR/cEVAR remained stable during the study period. Of the SCI patients, postoperative therapeutic CSFD placement was associated with worse sustained neurologic outcomes and overall survival compared with preoperative prophylactic CSFD placement. These findings highlight the need for a randomized clinical trial to examine prophylactic vs therapeutic CSFD placement in association with TEVAR/cEVAR.

Association between thoracoabdominal aneurysm extent and mortality after complex endovascular repair

OBJECTIVE

Traditional open surgical repair of thoracoabdominal aortic aneurysms (TAAAs) has historically resulted in 30-day mortality rates ranging from 6% to 20%, depending on the Crawford anatomic extent. Although short-term survival is important, long-term survival is essential for patients to benefit from these often elective and potentially morbid procedures. The aneurysm extent affects the long-term survival after open repair; however, effect on endovascular repair is unknown and could influence the decision process for repair. We evaluated the association between aneurysm extent and survival and identified patient and perioperative factors associated with mortality after endovascular repair.

METHODS

A retrospective cohort of patients treated for TAAAs recorded in the Society for Vascular Surgery Vascular Quality Initiative thoracic and complex endovascular aneurysm repair registry were evaluated. All patients treated for asymptomatic degenerative aneurysms from 2010 to 2019 were included. Crawford extent I to V was defined according to the proximal and distal landing zones documented in the registry. Patients without extension into the visceral aorta were used for comparison and categorized as having extent 0a or 0b, depending on the distal landing zone in the thoracic aorta. Kaplan-Meier plots were used to estimate survival, and Cox proportional hazard regression models were created to identify the predictors of mortality.

RESULTS

From 2010 to 2019, 15,333 patients were entered into the registry, of whom 2062 met the inclusion criteria. The Crawford extent was 0a for 379, 0b for 848, I for 81, II for 98, III for 130, IV for 454, and V for 72. Three groups were created in accordance with the similar outcomes noted on a preliminary analysis: (1) extent 0a and 0b; (2) extent I, II, and III; and (3) extent IV and V. The mean survival time for the extent 0a and 0b group was 70.7 ± 1.43 months and was 48.6 ± 1.65 months for the extent I, II, and III group and 57.6 ± 1.24 months for the extent IV and V group. The corresponding 1-year mortality was 8.4%, 18.4%, and 7.8%. Cox regression analysis identified the following preoperative factors were associated with mortality: chronic obstructive pulmonary disease (odds ratio [OR], 1.70; P < .001), Crawford extent I to III (OR, 1.64; P = .015), preexisting chronic kidney disease (OR, 1.37; P = .024), and age per year (OR, 1.03; P < .001). A number of postoperative factors were also associated with mortality.

CONCLUSIONS

Similar to open TAAA repair, patients with more extensive aortic disease treated with endovascular repair had worse 1-year and long-term survival. The extent of aortic disease and anticipated postoperative survival should factor prominently into the surgical decision-making process for elective endovascular TAAA repair.

Dissected thoracoabdominal aortic aneurysm repair with modified parallel endografting

A 67-year-old woman with a prior history of aortic dissection was admitted for enlarging the thoracoabdominal aortic aneurysm (TAAA). She has received multiple treatments including Bentall procedure, hemiarch replacement, and subsequent endovascular procedures for the closure of re-entry. Preoperative computed tomography revealed previously implanted thoracic endograft from distal arch to superior mesenteric artery with dissected TAAA measuring up to 70 mm in diameter. Re-entry was observed at bilateral common iliac arteries. The patient was successfully treated by endovascular treatment using a fenestrated stent graft to obtain a landing zone for parallel endograft technique to the iliac arteries for the closure of re-entry.

Early Renal Function Alterations in Renal Branches vs. Renal Fenestrations - A Dynamic Scintigraphy Based Prospective Study

OBJECTIVE

The objective of this prospective single centre study was to assess whether branches and fenestrations have different outcomes on renal function in the early phase.

METHODS

From March 2018 to June 2019, 67 patients who underwent elective fenestrated and branched endovascular aneurysm repair (F/BEVAR) procedures were enrolled in this study. The patients were divided into two groups according to the renal bridging component configuration (fenestration vs. branch). All of them underwent dynamic renal scintigraphy with ^99mTc diethylenetriaminepentaacetic acid (DTPA), two weeks pre-operatively, and three months and one year post-operatively. The primary end points were peri-procedural technical success, 30 day major adverse events, differences in glomerular filtration rate (GFR) between the branch and fenestration configurations, and variations between the pre-operative and the post-operative dynamic renal scintigraphy.

RESULTS

Overall, 135 kidneys were analysed: 63 in the 32 patients treated with fenestrations, and 72 in the 35 patients treated with branches; the mean GFR on baseline scintigraphy was 58.4 ± 30.9 mL/min in the fenestration group, and 65.1 ± 29.2 mL/min in the branch group. Only kidneys associated with a patent fenestration/branch were included in the split GFR final analysis. The mean total GFR at three month scintigraphy decreased by 6.0 ± 2.9 mL/min in the fenestration group and by 23.4 ± 6.4 mL/min in the branch group. The split GFR decreased by 3.5 ± 0.6 mL/min in the fenestration group, and by 15.4 ± 5.4 mL/min in the branch group. The GFR decrease remained stable at one year.

CONCLUSION

In this study, the use of branches for renal arteries during F/BEVAR resulted in a greater decrease in the GFR than in those patients who were treated with fenestrations alone. The scintigraphic alterations were evident at an early phase.

Arteriogenesis of the Spinal Cord-The Network Challenge

Spinal cord ischemia (SCI) is a clinical complication following aortic repair that significantly impairs the quality and expectancy of life. Despite some strategies, like cerebrospinal fluid drainage, the occurrence of neurological symptoms, such as paraplegia and paraparesis, remains unpredictable. Beside the major blood supply through conduit arteries, a huge collateral network protects the central nervous system from ischemia—the paraspinous and the intraspinal compartment. The intraspinal arcades maintain perfusion pressure following a sudden inflow interruption, whereas the paraspinal system first needs to undergo arteriogenesis to ensure sufficient blood supply after an acute ischemic insult. The so-called steal phenomenon can even worsen the postoperative situation by causing the hypoperfusion of the spine when, shortly after thoracoabdominal aortic aneurysm (TAAA) surgery, muscles connected with the network divert blood and cause additional stress. Vessels are a conglomeration of different cell types involved in adapting to stress, like endothelial cells, smooth muscle cells, and pericytes. This adaption to stress is subdivided in three phases—initiation, growth, and the maturation phase. In fields of endovascular aortic aneurysm repair, pre-operative selective segmental artery occlusion may enable the development of a sufficient collateral network by stimulating collateral vessel growth, which, again, may prevent spinal cord ischemia. Among others, the major signaling pathways include the phosphoinositide 3 kinase (PI3K) pathway/the antiapoptotic kinase (AKT) pathway/the endothelial nitric oxide synthase (eNOS) pathway, the Erk1, the delta-like ligand (DII), the jagged (Jag)/NOTCH pathway, and the midkine regulatory cytokine signaling pathways.

Cryoablation of Intercostal Nerves Decreased Narcotic Usage After Thoracic or Thoracoabdominal Aortic Aneurysm Repair

To improve surgical pain control through cryoablation of intercostal nerves and reduce narcotic usage in patients undergoing open thoracic or thoracoabdominal aortic aneurysm (TAA or TAAA) repair. From 2012 to 2018, 117 patients underwent open repair of TAA or TAAA. Of those patients, 25 (21%) received cryoablation (2016-2018) of their intercostal nerves and 92 (79%) did not (2012-2018). The primary outcome was pain scores and narcotic usage from extubation day 1 to 10 or the day of discharge. The median age (57 years), demographics, and preoperative comorbidities were not significantly different between the 2 groups. The cryoablation group had significantly more incidences of thoracoabdominal incisions (52% vs 28%), urgent operations (32% vs 11%), and longer duration of chest tubes compared to the noncryoablation group (all P < 0.05). T9-T12 intercostal arteries were selectively reimplanted. Left intercostal nerves were cryoablated from T3 to T9 if 2 thoracotomies were used; or 2 intercostal spaces above and below the thoracotomy if 1 thoracotomy was used. There were no significant differences between the noncryoablation and cryoablation groups in postoperative stroke, paraplegia (5%), pneumonia, and in-hospital mortality (0.9%). However, the average usage of narcotics was significantly reduced in the cryoablation group by 28 measured morphine equivalents (equal to four 5 mg Oxycodone)/patient/day in 10 days after extubation, P = 0.005. With cryoablation of intercostal nerves, the postoperative surgical pain was well controlled and narcotic usage was significantly decreased after TAA or TAAA repair. Cryoablation of intercostal nerves was a safe and effective measure for postoperative pain control in TAA or TAAA repair.

Extra-anatomical splanchnic revascularization for hybrid treatment of thoracoabdominal aortic aneurysms

Treatment of thoracoabdominal aortic aneurysms with endovascular or conventional surgical techniques is burdened by high risk in older patients. Furthermore, the standard hybrid approach might be not feasible in case of severe atherosclerotic disease of the peripheral vessels. This report describes an alternative hybrid procedure which consists of an innovative mini-invasive thoracic approach combined with laparotomy to perform antegrade revascularization of the visceral arteries from the ascending aorta, followed by endovascular treatment.

Impact of hybrid thoracoabdominal aortic repair on visceral and spinal cord perfusion: The new and improved SPIDER-graft

OBJECTIVES

SPIDER-graft for thoracoabdominal aortic aneurysm repair avoiding thoracotomy and extracorporeal circulation was modified, enabling reimplantation of lumbar arteries to prevent spinal cord ischemia and compared with open aortic repair (control) in a pig model.

METHODS

Graft implantation was performed in 7 pigs per group (75-85 kg). For SPIDER-graft (groups I and II), the infra-diaphragmatic aorta was exposed through retroperitoneal access. The right iliac branch was first temporarily anastomosed end-to-side to the distal aorta maintaining periprocedural retrograde visceral perfusion. SPIDER-graft was deployed in the descending thoracic aorta via the celiac artery ostium. The celiac, superior mesenteric, and renal arteries were successively connected to the corresponding side branches of the graft. In group II, the lumbar arteries were reimplanted into the former access branch. For control, complete thoracoabdominal exposure of the aorta was required. After crossclamping, proximal anastomosis was performed, and the celiac artery, superior mesenteric artery, renal arteries, and iliac arteries were reattached. Technical feasibility, ischemic times, blood flow, and visceral and spinal cord perfusion in the related organs were evaluated before implantation and 3 and 6 hours after implantation using transit-time flow measurement and fluorescent microspheres.

RESULTS

Technical success was achieved in all animals in all groups. Total aortic clamping time and selective ischemic times of related organs were significantly longer during open aortic repair compared with groups I and II (P < .0001). Fluorescent microspheres confirmed best spinal cord perfusion in group II.

CONCLUSIONS

SPIDER-graft reduced ischemic time, avoided extracorporeal circulation and thoracotomy, and improved spinal cord perfusion during thoracoabdominal aortic aneurysm repair in a pig model.

Feasibility Study of a Novel Thoraco-abdominal Aortic Hybrid Device (SPIDER-graft) in a Translational Pig Model

BACKGROUND

The hybrid SPIDER-graft consists of a proximal descending aortic stent graft and a conventional six branched Dacron graft for open abdominal aortic repair. Technical feasibility with regard to avoiding thoracotomy and extracorporeal circulation (ECC) during thoraco-abdominal aortic hybrid repair and peri-procedural safety of this novel device are unknown.

MATERIAL AND METHODS

This was a feasibility and safety study in domestic pigs (75-85 kg). The abdominal aorta including iliac bifurcation, left renal artery, and visceral arteries were exposed via retroperitoneal access. The right iliac branch was first temporarily anastomosed end to side to the distal aorta via partial clamping. During inflow reduction and infra-coeliac cross-clamping, the coeliac trunk (CT) was divided and the proximal stent graft portion of the SPIDER-graft was deployed into the descending aorta via the CT ostium. Retrograde visceral and antegrade aorto-iliac blood flow was maintained via the iliac side branch. The visceral, renal, and iliac arteries were sequentially anastomosed, finally replacing the first iliac end to side anastomosis. Technical success, blood flow, periods of ischaemia, and peri-procedural complications were evaluated after intra-operative completion angiography and post-operative computed tomography angiography.

RESULTS

Six animals underwent successful thoracic stent graft deployment and distal open reconstruction without peri-operative death. The median thoracic graft implantation time was 4.5 min, and the median ischaemia times before reperfusion were 10 min for the CT, 8 min for the superior mesenteric artery, 13 min for the right renal artery, and 22 min for the left renal artery. Angiography demonstrated appropriate graft implantation and blood flow measurements confirmed sufficient blood flow through all side branches.

CONCLUSION

In this translational pig model, thoraco-abdominal hybrid repair using the novel SPIDER-graft was successful in avoiding thoracotomy and ECC. Technical feasibility and safety appear promising, but need to be reassessed in humans.

Endovascular coil embolization of segmental arteries prevents paraplegia after subsequent thoracoabdominal aneurysm repair: an experimental model

OBJECTIVES

To test a strategy for minimizing ischemic spinal cord injury after extensive thoracoabdominal aneurysm (TAAA) repair, we occluded a small number of segmental arteries (SAs) endovascularly 1 week before simulated aneurysm repair in an experimental model.

METHODS

Thirty juvenile Yorkshire pigs (25.2 ± 1.7 kg) were randomized into 3 groups. All SAs, both intercostal and lumbar, were killed by a combination of surgical ligation of the lumbar SAs and occlusion of intercostal SAs with thoracic endovascular stent grafting. Seven to 10 days before this simulated TAAA replacement, SAs in the lower thoracic/upper lumbar region were occluded using embolization coils: 1.5 ± 0.5 SAs in group 1 (T13/L1), and 4.5 ± 0.5 SAs in group 2 (T11-L3). No SAs were coiled in the controls. Hind limb function was evaluated blindly from daily videotapes using a modified Tarlov score (0 = paraplegia, 9 = full recovery). After death, each segment of spinal cord was graded histologically using the 9-point Kleinman score (0 = normal, 8 = complete necrosis).

RESULTS

Hind limb function remained normal after coil embolization. After simulated TAAA repair, paraplegia occurred in 6 of 10 control pigs, but in only 2 of 10 pigs in group 1; no pigs in group 2 had a spinal cord injury. Tarlov scores were significantly better in group 2 (control vs group 1, P = .06; control vs group 2, P = .0002; group 1 vs group 2, P = .05). A dramatic reduction in histologic damage, most prominently in the coiled region, was seen when SAs were embolized before simulated TAAA repair.

CONCLUSIONS

Endovascular coiling of 2 to 4 SAs prevented paraplegia in an experimental model of extensive hybrid TAAA repair, and helped protect the spinal cord from ischemic histopathologic injury. A clinical trial in a selected patient population at high risk for postoperative spinal cord injury may be appropriate.