A systematic review and meta-analysis of the occurrence of spinal cord ischemia after endovascular repair of thoracoabdominal aortic aneurysms.

OBJECTIVE: The rate of endovascular repair of thoracoabdominal aortic aneurysms (TAAA-ER) has increased considerably in recent years. Although the mortality and morbidity rates have improved, the incidence of spinal cord ischemia (SCI) has not declined significantly. The aim of the present systematic review and meta-analysis was to examine the 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 measure was the evaluation of SCI. The moderators considered were primarily the staged vs nonstaged approach, the use of cerebrospinal fluid drainage (CSFD), and TAAA extension. The permanent SCI and mortality rates were extracted. RESULTS: A total of 27 studies with 2333 patients were included in the meta-analysis. The pooled estimate for SCI was 11% (95% confidence interval [CI], 8%-15%; I2, 79%). For extent I, II, III, and V TAAA, the pooled SCI rate was 13% (95% CI, 10%-17%; I2, 69%). For extent IV TAAA, the pooled SCI rate was 6% (95% CI, 3%-10%; I2, 62%). A staged TAAA-ER approach was used in 20 studies and a nonstaged approach in 8 (1 study had included both). A lower pooled SCI rate was identified after staged than after nonstaged TAAA-ER (9% vs 18%, respectively; P = .02). Staging was accomplished in >1 month in nine studies and ≤1 month in two studies, leading to similar SCI rates (7% vs 11%, respectively; P = .26). The method of staging (thoracic endoprosthesis or temporary aortic sac perfusion) did not affect the SCI rates. Symptomatic CSFD was associated with a similar pooled rate of SCI compared with prophylactic CSFD (10% vs 10%, respectively; P = .99). The pooled permanent SCI rate was 6% (6% for extent I, II, III, and V TAAA; and 3% for extent IV TAAA). The pooled rate of 30-day mortality was 7%, with a similar incidence for the staged and nonstaged approaches (6% vs 9%, respectively). Interstage mortality was reported in 9 studies, with a pooled estimate rate of 1.6%. CONCLUSIONS: SCI had occurred in 11% of TAAA-ER, and one half of these cases were permanent. A staged approach can reduce SCI rates independently of the timing and method adopted. The overall mortality rate for staged TAAA-ER was 7%, with one fifth of the deaths (1.6%) occurring between stages.

Clamped Carotid Dissection Can Reduce Postoperative Stroke After Carotid Endarterectomy.

Background: The outcomes of carotid endarterectomy (CEA) are constantly reported in a multitude of studies; however, the specific causes of perioperative stroke have been scarcely investigated. The aim of the present study was to analyze and categorize the causes of perioperative strokes after CEA. Methods: All CEAs performed from 2006 to 2019 in a single center were collected. CEA was routinely performed under general anesthesia, with routine shunting and patching, using cerebral near-infrared spectroscopy monitoring. Carotid exposure technique was classified as either clamped-dissection (CD) or preclamping-dissection (PCD) if the carotid bifurcation was dissected after or prior to carotid clamping. Perioperative and 30-day strokes and their possible mechanisms were evaluated according to preoperative symptoms and surgical technique adopted. Results: Among 1760 CEAs performed, 30 (1.7%) perioperative strokes occurred. 14 (47%) were identified upon emergence from general anesthesia, and 16 (53%) were noted in the first 30 days following intervention. Stroke etiology was categorized as follows: technical (acute thrombosis or intimal flap or due to intraoperative complications), embolic (no recognized technical defect), hemorrhagic, or contralateral. Symptomatic patients had a significantly higher rate of any type of stroke than asymptomatic patients (3.8% vs 0.9%, P = .0001). CD was protective for postoperative stroke (0.9% vs 3.1%, P = .001) in both symptomatic and asymptomatic patients (2.5% vs 5.9%, P = .05; 0.4% vs 1.9%, P = .005), particularly for the cohort in which symptomatic patients (0.7% vs 3.2%, P = .04) suffered postoperative embolic stroke. Conclusion: Perioperative stroke in CEA may be multifactorial in etiology, including a result of technical errors. A CD technique may help reduce the incidence of perioperative stroke.

Computational Fluid Dynamics Modeling of Proximal Landing Zones for Thoracic Endovascular Aortic Repair in the Bovine Arch Variant.

BACKGROUND: To assess the endograft displacement forces (DF), which quantify the forces exerted by the pulsatile blood flow on the vessel wall and transmitted on the terminal fixation site of the endograft after its deployment in proximal landing zones (PLZs) of the bovine aortic arch variant. METHODS: Thirty healthy aortic computed tomographic angiographies of subjects with bovine arch configuration (10 per type of arch, I-III) were selected for the purpose of the study. A 3-dimensional model of the aortic arch lumen was reconstructed. Computational fluid dynamics modeling was then used to compute DF magnitude and orientation (i.e., x, y, and z axes) in PLZs of each case. DF values were normalized to the corresponding aortic wall area to estimate equivalent surface traction (EST). RESULTS: DF were highest in zone 0, consistently with the greater surface area. DF in zone 3 were much greater than in zone 2 because of a 3-fold greater upward component (z axis) (P < 0.001), being therefore mainly oriented orthogonally to the aortic blood flow and to the vessel longitudinal axis in that zone. EST progressively increased from zone 0 toward more distal PLZs, with EST in zone 3 being much greater than that in zone 2 (P < 0.001). The same pattern was observed after stratification by type of arch. CONCLUSIONS: The bovine arch is associated with a consistent fluid dynamic pattern, which identifies in zone 3 an unfavorable biomechanical environment for endograft deployment.

Geometric Pattern of Proximal Landing Zones for Thoracic Endovascular Aortic Repair in the Bovine Arch Variant.

OBJECTIVE: The aim was to investigate whether the "bovine" aortic arch (i.e. arch variant with a common origin of the innominate and left carotid artery (CILCA)) is associated with a consistent geometric configuration of proximal landing zones for thoracic endovascular aortic repair (TEVAR). METHODS: Anonymised thoracic computed tomography (CT) scans of healthy aortas were reviewed to retrieve 100 cases of CILCA. Suitable cases were stratified according to type 1 and 2 CILCA, and also based on type of arch (I, II, and III). Further processing allowed calculation of angulation and tortuosity of the proximal landing zones. Centre lumen line lengths of each proximal landing zone were measured in a view perpendicular to the centre line. All geometric features were compared with those measured in healthy patients with a standard arch configuration (n = 60). Two senior authors independently evaluated the CT scans, and intra- and interobserver repeatability were assessed. RESULTS: The 100 selected patients (63% male) were 71.4 ± 7.7 years old. Type 1 CILCA (62/100) was more prevalent than type 2 CILCA (38/100), and the two groups were comparable in age (p = .11). Zone 3 presented a severe angulation (i.e. > 60°), which was greater than in Zone 2 (p < .001), and a consistently greater tortuosity than Zone 2 (p = .003). This pattern did not differ between type 1 and type 2 CILCA. A greater tortuosity was also observed in Zone 0, which was related to increased elongation of the ascending aorta (i.e. Zone 0), than the standard configuration. The CILCA had an overall greater elongation, and Zone 2 also was specifically longer. When stratifying by type of arch, reversely from Type III to Type I, the CILCA presented a gradual flattening of its transverse tract, which entailed a consistent progressive elongation (p = .03) and kinking of the ascending aorta, with a significant increase of Zone 0 angulation to even a severe degree (p = .001). Also, from Type III to Type I, Zone 2 presented a progressively shorter length (p = .004), which was associated with increased tortuosity (p < .05). Mean intra- and interobserver differences for angulation measurements were 1.4° ± 6.8° (p = .17) and 2.0° ± 10.1° (p = .19), respectively. CONCLUSION: CILCA presents a consistent and peculiar geometric pattern compared with standard arch configuration, which provides relevant information for TEVAR planning, and may have prognostic implications.

Differences in Biomarkers Pattern Between Severe Isolated Right and Left Ventricular Dysfunction After Cardiac Surgery.

OBJECTIVE: To find out if there are any differences in biomarkers between severe isolated right ventricular (RV) dysfunction and severe isolated left ventricular (LV) dysfunction after cardiac surgery using cardiopulmonary bypass. DESIGN: Observational study. SETTING: Teaching hospital. PARTICIPANTS: A total of 46 patients who had severe isolated RV or LV dysfunction after cardiac surgery. INTERVENTION: The authors collected perioperative clinical and biomarker data. MEASUREMENTS AND MAIN RESULTS: Severe isolated RV dysfunction patients (n = 20) had higher postoperative direct bilirubin (p = 0.030), total bilirubin (p = 0.044), glucose (p = 0.011), and international normalized ratio (INR) (p = 0.050) by repeated measure analysis of variance when compared with patients with severe isolated LV dysfunction (n = 26). The RV group also showed lower preoperative alanine transferase (19.3 ± 1.5 v 32.7 ± 4.2, p = 0.001), higher 4-hour INR (1.5 ± 0.3 v 1.4 ± 0.2, p = 0.008), and higher 48-hour INR (1.8 ± 0.4 v 1.4 ± 0.1, p < 0.001). None in the LV group died, whereas 4 patients in the RV group died (all of them had preoperative atrial fibrillation and underwent double valve replacement surgery). CONCLUSION: The authors observed biomarkers differences between severe isolated RV dysfunction and severe isolated RV dysfunction.

Aortic arch variant with a common origin of the innominate and left carotid artery as a determinant of thoracic aortic disease: a systematic review and meta-analysis.

The aim of this study was to investigate whether the 'bovine' arch [i.e. arch variant with a common origin of the innominate and left carotid artery (CILCA)] is associated with an increased risk of thoracic aortic disease (TAD). The study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The PubMed, EMBASE and Cochrane databases were searched to identify all case series reporting about CILCA arch and TAD between January 2008 and December 2018. A total of 485 studies were screened. The prevalence of CILCA arch was assessed, and data analysis was performed considering the difference in the risk of TAD for presence versus absence of CILCA arch. Eight studies enrolling 11 381 subjects were retrieved for quantitative analysis. The proportion of TAD among CILCA arch patients was higher [41.5% (28.1-56.4)] than the proportion among patients with standard arch configuration 34.0% (20.1-51.4). The odds ratio of developing TAD was 1.4 times higher in subjects with CILCA arch (95% confidence interval 1.068-1.839). The test for an overall effect indicated a significant association between CILCA arch and TAD (P < 0.015). The I2 was 78.1% with a value of P < 0.001 for heterogeneity. The Egger test did not show evidence of publication bias (P = 0.317). In conclusion, our meta-analysis supports the hypothesis of a correlation between the presence of CILCA arch and the onset of TAD. Our results warrant a specific and long-term surveillance for patients with this anatomical variant, and a thorough awareness of its potential clinical implications during image interpretation.

Impact of the Bird-Beak Configuration on Postoperative Outcome After Thoracic Endovascular Aortic Repair: A Meta-analysis.

Purpose: To investigate the association between the bird-beak configuration (BBC), a wedge-shaped gap between the undersurface of a thoracic endograft and the lesser curvature of the arch after thoracic endovascular aortic repair (TEVAR), and postoperative outcome after TEVAR. Methods: The study was performed according to the PRISMA guidelines. The PubMed, EMBASE, and Cochrane databases were searched to identify all case series reporting BBC after TEVAR between 2006 and April 2018. Data analysis was performed considering the difference in the risk of complications for presence vs absence of BBC. After screening 1633 articles, 21 studies were identified that matched the selection criteria; 12 of these reported detailed information to investigate the postoperative outcome using proportion meta-analysis with a random effects model. The pooled risk difference is reported with the 95% confidence interval (CI). Heterogeneity of the included studies was assessed with the I2 statistic (low 25%, medium 50%, high 75%). Results: Complications occurred within a range of 0 to 72 months in 14.7% (95% CI 7.4% to 27.3%) of patients with BBC and in 6.3% (95% CI 2.5% to 15.4%) of patients without BBC. A cumulative incidence could not be assessed. The summary risk difference was 11.1% (95% CI -0.1% to 22.3%, p=0.052). There was significant heterogeneity (I2=85.6%). The Egger test did not show evidence of publication bias (p=0.975). When specifically considering type Ia endoleak and endograft migration, the risk difference between BBC and non-BBC patients was 8.2% (95% CI 0.3% to 16.1%, p=0.042; I2=69.0%). The specific risk difference for endograft collapse/infolding and thrombosis was 3.7% (95% CI -3.5% to 11.1%, p=0.308; I2=10.2%). Conclusion: At present the literature does not provide statistical evidence to establish an overall prognostic value of the BBC. Nevertheless, the BBC appears to be associated with a high risk of type Ia endoleak and endograft migration, which warrants specific and long-term surveillance. Clinically relevant values for BBC grading should be established to perhaps define indications for preemptive treatment based on the presence of BBC only.