Impact of intercostal artery occlusion on spinal cord ischemia following thoracic endovascular aortic repair

Antegrade Hybrid Chimney TEVAR Endograft in a Patient with Blunt Aortic Injury: A Challenging Case with Technical Success but Unfavorable Result

Thoracic Endovascular Aortic Repair (TEVAR) has modified aortic medicine, particularly in patients with traumatic aortic injury (TAI). Conventional repair of TAI in the aortic arch is technically demanding as it requires cardiopulmonary bypass and deep hypothermic arrest with still a significant number of complications. Despite recent improvements in endovascular techniques, many patients have been excluded from endovascular repair due to unfavorable anatomy. To increase the feasibility of endovascular repair, adjunctive open extra-anatomical bypasses may be required to provide an adequate proximal landing zone. Several methods, for instance, chimney technique, hybrid technique, and fenestrated or branched stent-grafts, have been proposed as options to preserve the supra-aortic branches, each with its own advantages and disadvantages. We herein present a patient with complex anatomical features and blunt aortic injury, who underwent antegrade chimney stent-graft deployment through the ascending aorta, not otherwise amenable to standard retrograde delivery because of severe peripheral artery disease. The remarkable aspect, in this case, is that both stents were placed antegrade, through the ascending aorta.

New Preoperative Spinal Cord Ischemia Risk Stratification Model for Patients Undergoing Thoracic Endovascular Aortic Repair

PURPOSE

Our objective was to determine significant predictors of spinal cord ischemia (SCI) following Thoracic Endovascular Aortic Repair (TEVAR) and to further develop a simple and clinically orientated risk score model.

METHODS

A retrospective review of data from the Society of Vascular Surgery/Vascular Quality Initiative national data set was performed for all patients undergoing TEVAR from January, 2014 to June 2018. Preoperative demographics, procedure-related variables, and clinical details related to SCI were examined. A SCI risk score was developed utilizing a multivariable logistic regression model.

RESULTS

For the 7889 patients in the final analysis who underwent TEVAR during the study period, the mean age was 67.6 ± 13.9, range 18 to 90 years, and the majority was male (65%). Postoperative outcomes included stroke (3.0%), myocardial infarction (2.9%), inhospital mortality (5.4%), transient SCI (1.5%), and permanent SCI (2.1%). Nearly half of the overall cases were performed in high volume centers. Predictors of increased risk for SCI included age by decade (odds ratio [OR]: 1.2), celiac coverage (OR: 1.5), current smoker (OR: 1.6), dialysis (OR: 1.9), 3 or more aortic implanted devices (OR: 1.7), emergent or urgent surgery (OR: 1.5), adjunct aorta-related procedure (OR: 2.5), adjunct not related (OR: 2.6), total estimated length of aortic device (19-31 cm, OR: 1.9 and ≥32 cm, OR: 3.0), ASA class 4 or 5 (OR: 1.6), and procedure time ≥154 minutes (OR: 1.8). Two predictors decreased the risk of SCI, cases from high-volume centers (OR: 0.6) and eGFR ≥ 60 (OR: 0.6). To evaluate the risk score model, probabilities of SCI from the original regression, raw score, and raw score categories resulted in area under the curve statistics of 0.792, 0.786, and 0.738, respectively.

CONCLUSIONS

Spinal cord ischemia remains one of the most feared complications of TEVAR. Incidence of SCI in this large series of patients with TEVAR was 3.6% with nearly 60% being permanent. The proposed model provides an assessment tool to guide clinical decisions, patient consent process, risk-assessment, and procedural strategy.

CNB-001 reduces paraplegia in rabbits following spinal cord ischemia

Spinal cord ischemia associated with trauma and surgical procedures including thoraco-abdominal aortic aneurysm repair and thoracic endovascular aortic repair results in devastating clinical deficits in patients. Because spinal cord ischemia is inadequately treated, we studied the effects of [4-((1E)-2-(5-(4-hydroxy-3-methoxystyryl-)-1-phenyl-1H-pyrazoyl-3-yl) vinyl)-2-methoxy-phenol)] (CNB-001), a novel curcumin-based compound, in a rabbit SCI model. CNB-001 is known to inhibit human 5-lipoxygenase and 15-lipoxygenase and reduce the ischemia-induced inflammatory response. Moreover, CNB-001 can reduce the level of oxidative stress markers and potentiate brain-derived neurotrophic factor and brain-derived neurotrophic factor receptor signaling. The Tarlov scale and quantal analysis technique results revealed that CNB-001 administered as an intravenous dose (bolus) 30 minutes prior to spinal cord ischemia improved the behaviors of female New Zealand White rabbits. The improvements were similar to those produced by the uncompetitive N-methyl-D-aspartate receptor antagonist memantine. At 48 hours after aortic occlusion, there was a 42.7% increase (P < 0.05) in tolerated ischemia duration (n = 14) for rabbits treated with CNB-001 (n = 16), and a 72.3% increase for rabbits treated with the positive control memantine (P < 0.05) (n = 23) compared to vehicle-treated ischemic rabbits (n = 22). CNB-001 is a potential important novel treatment for spinal cord ischemia induced by aortic occlusion. All experiments were approved by the CSMC Institutional Animal Care and Use Committee (IACUC #4311) on November 1, 2012.

Complications and Perioperative Management of Patients Undergoing Thoracic Endovascular Aortic Repair

Endovascular treatments have become increasingly common for patients with a variety of thoracic aortic pathologies. Although considered less invasive than traditional open surgical approaches, they are nonetheless complex procedures. Patients undergo manipulation of an often calcified aorta near the origin of the carotid and subclavian vessels and have stents placed in a curved vessel adjacent to a perpetually beating heart. These stents can obstruct blood flow to the spinal cord, induce an inflammatory response, and in rare cases erode into the adjacent trachea or esophagus. Renal complications range from contrast-induced nephropathy to hypotension and ischemia to dissection. Emboli can lead to strokes and mesenteric ischemia. These patients have complex medical histories, and skilled perioperative management is critical to achieving the best clinical outcomes. Here, we review the medical management of the most common complications in these patients including stroke, spinal cord ischemia, renal injury, retrograde dissections, aortoesophageal and aortobronchial fistulas, postimplantation syndrome, mesenteric ischemia, and endograft failure.

3D Image Fusion to Localise Intercostal Arteries During TEVAR

Purpose

Preservation of intercostal arteries during thoracic aortic procedures reduces the risk of post-operative paraparesis. The origins of the intercostal arteries are visible on pre-operative computed tomography angiography (CTA), but rarely on intra-operative angiography. The purpose of this report is to suggest an image fusion technique for intra-operative localisation of the intercostal arteries during thoracic endovascular repair (TEVAR).

Technique

The ostia of the intercostal arteries are identified and manually marked with rings on the pre-operative CTA. The optimal distal landing site in the descending aorta is determined and marked, allowing enough length for an adequate seal and attachment without covering more intercostal arteries than necessary. After 3D/3D fusion of the pre-operative CTA with an intra-operative cone-beam CT (CBCT), the markings are overlaid on the live fluoroscopy screen for guidance. The accuracy of the overlay is confirmed with digital subtraction angiography (DSA) and the overlay is adjusted when needed. Stent graft deployment is guided by the markings. The initial experience of this technique in seven patients is presented.

Results

3D image fusion was feasible in all cases. Follow-up CTA after 1 month revealed that all intercostal arteries planned for preservation, were patent. None of the patients developed signs of spinal cord ischaemia.

Conclusion

3D image fusion can be used to localise the intercostal arteries during TEVAR. This may preserve some intercostal arteries and reduce the risk of post-operative spinal cord ischaemia.

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3D image fusion is feasible for intra-operative guidance during TEVAR.

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Fusion technique allows intra-operative visualization of intercostal artery origins.

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3D image fusion can help preservation of intercostal artery patency, known to be important in reducing the risk of spinal cord ischemia.

[Management of anesthesia in endovascular interventions]

Cardiovascular diseases are one of the leading causes of morbidity and mortality in Germany. In these patients, the high-risk profile necessitates an interdisciplinary and multimodal approach to treatment. Endovascular interventions and vascular surgery have become established as an important element of this strategy in the past; however, the different anatomical localizations of pathological vascular alterations make it necessary to use a wide spectrum of procedural options and methods; therefore, the requirements for management of anesthesia are variable and necessitate a differentiated approach. Endovascular procedures can be carried out with the patient under general or regional anesthesia (RA); however, in the currently available literature there is no evidence for an advantage of RA over general anesthesia regarding morbidity and mortality, although a reduction in pulmonary complications could be found for some endovascular interventions. Epidural and spinal RA procedures should be carefully considered with respect to the risk-benefit ratio and consideration of the recent guidelines on anesthesia against the background of the current study situation and the regular use of therapy with anticoagulants. The following article elucidates the specific characteristics of anesthesia management as exemplified by some selected endovascular interventions.

Sonographic Changes in Optic Nerve Sheath Diameter Associated with Supra- versus Infrarenal Aortic Aneurysm Repair

BACKGROUND AND PURPOSE

Quantification of changes in optic nerve sheath diameter (ONSD) using ocular sonography (OS) constitutes an elegant technique for estimating intracranial and intraspinal pressure. Aortic aneurysm repair (AAR) is associated with a reasonable risk of increased spinal fluid pressure, which is largely dependent on the extent of aneurysm repair (supra- vs. infrarenal). The aim of this study was to compare ONSD measurements in patients with suprarenal AAR (sAAR) or infrarenal AAR (iAAR).

METHODS

Thirty patients who underwent elective endovascular repair of infrarenal aortic aneurysms (Group iAAR) were included in the study; the characteristics in these cases were prospectively analyzed and compared with those in a previously investigated group of 28 patients treated for suprarenal aortic aneurysms (Group sAAR). Six measurements of ONSDs were performed in each patient at five consecutive time points. Statistical analysis was performed using the Wilcoxon test. A P value < .05 was considered statistically significant.

RESULTS

A highly significant difference between pre- and postinterventional values could be detected in both patient groups (P < .01). In Group sAAR, there was a mean .3-mm increase of the ONSD, whereas in Group iAAR, a mean .2-mm decrease could be detected. Both groups roughly reached baseline values by the end of their inpatient stay.

CONCLUSIONS

ONSD changes seem to be a reliable marker to estimate spinal perfusion. Since OS provides a suitable bedside tool for rapid reevaluation, it may guide physicians in the identification and treatment of patients at high risk for spinal cord ischemia.

Preoperative prediction of spinal cord ischemia after thoracic endovascular aortic repair

OBJECTIVE

Spinal cord ischemia (SCI) is a devastating but potentially preventable complication of thoracic endovascular aortic repair (TEVAR). The purpose of this analysis was to determine what factors predict SCI after TEVAR.

METHODS

All TEVAR procedures at a single institution were reviewed for patient characteristics, prior aortic repair history, aortic centerline of flow analysis, and procedural characteristics. SCI was defined as any lower extremity neurologic deficit that was not attributable to an intracranial process or peripheral neuropathy. Forty-three patient and procedural variables were evaluated individually for association with SCI. Those with the strongest relationships to SCI (P < .1) were included in a multivariable logistic regression model, and a stepwise variable elimination algorithm was bootstrapped to derive a best subset of predictors from this model.

RESULTS

From 2002 to 2013, 741 patients underwent TEVAR for various indications, and 68 (9.2%) developed SCI (permanent: n = 38; 5.1%). Because of the lack of adequate imaging for centerline analysis, 586 patients (any SCI, n = 43; 7.4%) were subsequently analyzed. Patients experiencing SCI after TEVAR were older (SCI, 72 ± 11 years; no SCI, 65 ± 15 years; P < .0001) and had significantly higher rates of multiple cardiovascular risk factors. The stepwise selection procedure identified five variables as the most important predictors of SCI: age (odds ratio [OR] multiplies by 1.3 per 10 years; 95% confidence interval [CI], 0.9-1.8, P = .06), aortic coverage length (OR multiplies by 1.3 per 5 cm; CI, 1.1-1.6; P = .002), chronic obstructive pulmonary disease (OR, 1.9; CI, 0.9-4.1; P = .1), chronic renal insufficiency (creatinine concentration ≥ 1.6 mg/dL; OR, 1.9; CI, 0.8-4.2; P = .1), and hypertension (defined as chart history or medication; OR, 6.4; CI, 2.6-18; P < .0001). A logistic regression model with just these five covariates had excellent discrimination (area under the receiver operating characteristic curve = .83) and calibration (χ(2) = 9.8; P = .28).

CONCLUSIONS

This analysis generated a simple model that reliably predicts SCI after TEVAR. This clinical tool can assist decision-making about when to proceed with TEVAR, guide discussions about intervention risk, and help determine when maneuvers to mitigate SCI risk should be implemented.

Thoracic endovascular aortic repair: are we approaching total endovascular solutions for thoracic aortic disease?

Thoracic endovascular aortic repair (TEVAR) has become an attractive alternative treatment option for thoracic aortic disease. New devices and advanced image-guided procedures are continuously expanding the indications. This article focuses on currently available endovascular solutions for thoracic aortic disease and future 'all endovascular' directions of TEVAR. Currently available endovascular solutions, such as hybrid operations, chimney stent grafting and transapical stent graft deployment, for ascending aortic pathologies are presented. Additionally, the impact of upcoming new technologies, such as endovascular treatment of Stanford Type A dissections of the ascending aorta, is elaborated. With improving device technology, diverse available stent grafts and imaging modalities, TEVAR has become safer and holds promising potential to expand treatment options, especially for the ascending aorta and the aortic arch.

Fate of patients with spinal cord ischemia complicating thoracic endovascular aortic repair

OBJECTIVE

Spinal cord ischemia (SCI) is a potentially devastating complication of thoracic endovascular aortic repair (TEVAR) that can result in varying degrees of short-term and permanent disability. This study was undertaken to describe the clinical outcomes, long-term functional impact, and influence on survival of SCI after TEVAR.

METHODS

A retrospective review of all TEVAR patients at the University of Florida from 2000 to 2011 was performed to identify individuals experiencing SCI, defined by any new lower extremity neurologic deficit not attributable to another cause. SCI was dichotomized into immediate or delayed onset, with immediate onset defined as SCI noted upon awakening from anesthesia, and delayed characterized as a period of normal function, followed by development of neurologic injury. Ambulatory status was determined using database query, record review, and phone interviews with patients and/or family. Mortality was estimated using life-table analysis.

RESULTS

A total of 607 TEVARs were performed for various indications, with 57 patients (9.4%) noted to have postoperative SCI (4.3% permanent). SCI patients were more likely to be older (63.9 ± 15.6 vs 70.5 ± 11.2 years; P = .002) and have a number of comorbidities, including chronic obstructive pulmonary disease, hypertension, dyslipidemia, and cerebrovascular disease (P < .0001). At some point in their care, a cerebrospinal fluid drain was placed in 54 patients (95%), with 54% placed postoperatively. In-hospital mortality was 8.8% for the entire cohort (SCI vs no SCI; P = .45). SCI developed immediately in 12 patients, delayed onset in 40, and indeterminate in five patients due to indiscriminate timing from postoperative sedation. Three patients (25%) with immediate SCI had measurable functional improvement (FI), whereas 28 (70%) of the delayed-onset patients experienced some degree of neurologic recovery (P = .04). Of the 34 patients with complete data available, 26 (76%) reported quantifiable FI, but only 13 (38%) experienced return to their preoperative baseline. Estimated mean (± standard error) survival for patients with and without SCI was 37.2 ± 4.5 and 71.6 ± 3.9 months (P < .0006), respectively. Patients with FI had a mean survival of 53.9 ± 5.9 months compared with 9.6 ± 3.6 months for those without improvement (P < .0001). Survival and return of neurologic function were not significantly different when patients with preoperative and postoperative cerebrospinal fluid drains were compared.

CONCLUSIONS

The minority of patients experience complete return to baseline function after SCI with TEVAR, and outcomes in patients without early functional recovery are particularly dismal. Patients experiencing delayed SCI are more likely to have FI and may anticipate similar life-expectancy with neurologic recovery compared with patients without SCI. Timing of drain placement does not appear to have an impact on postdischarge FI or long-term mortality.

Neurological complications of thoracic endovascular aortic repair

Thoracic endovascular aortic repair (TEVAR) has decreased the morbidity and mortality associated with open surgical repair of descending thoracic aortic diseases, but important complications unique to the procedure remain. Spinal cord ischemia and infarction is a recognized complication caused by endovascular coverage or injury to spinal cord collateral vessels. Stroke is a consequence of thromboembolism or coverage of aortic arch branch vessels with insufficient collateral circulation. Understanding the risk factors and the pathophysiology of neurological complications of TEVAR are important for the successful anesthetic and surgical management and treatment of patients undergoing endovascular procedures involving the thoracic aorta.