Computational fluid dynamics of a novel perfusion strategy using direct perfusion of a left carotid-subclavian bypass during hybrid thoracic aortic repair

To mitigate the risk of perioperative neurological complications during frozen elephant trunk procedures, we aimed to computationally evaluate the effects of direct cerebral perfusion strategy through a left carotid-subclavian bypass on hemodynamics in a patient-specific thoracic aorta model

Endograft Sizing for Endovascular Aortic Repair and Incidence of Endoleak Type 1A

In endovascular aortic aneurysm repair (EVAR), proximal type 1A endoleaks can occur as a result of hostile neck anatomy or over- or undersizing of the endograft. As the current standard is based on the diameter or average of the short and long axes in a central lumen reconstruction image, it can falter in irregularly shaped aortic necks. An alternative method is circumference-based, therefore minimizing the measurement error. In this study we aimed to assess the degree of discrepancy between both methods and the association of this discrepancy with the occurrence of endoleak type 1A.All patients with early (<30 days post-operative) endoleak type 1A after elective EVAR at our center between 2004 and 2016 were identified for a retrospective case-control study. Control patients were matched based on hostile neck anatomy, such as calcification, thrombus, reverse taper, and β-angulation. The aortic neck diameter was measured using the traditional, diameter-based method as well as an alternative method, based on the circumference of the aortic neck.In 482 EVAR patients, 18 early endoleak type 1A cases were found (3.9%). After exclusion, 12 cases remained and 48 matching controls were found. No significant differences were found between the two measuring methods at any level below the renal arteries. The inter-observer variability was significant for the D(mean) (0.4 ± 1.69 mm, P = .02) and was larger than the D(circ) method (-0.1 ± 1.03 mm, P = .35). In only four out of 12 cases the endograft size was 10-20% larger than the D(mean) and D(circ) measurements. The differences between the diameter of the D(mean) and D(circ) and the chosen endograft were smaller for the case group (-8 ± 25.6% and -7 ± 24%) than for the control group. (-12.4 ± 12.4% and -11 ± 10.7%).The difference between the D(mean) and D(circ) methods for aortic neck measurement was not large enough to play a significant role in the incidence of endoleak type 1A. Inadequate oversizing and considerable β-angulation of the aortic neck may have been the cause of endoleak type 1A in this population. Robust and well-investigated sizing methods are paramount for accurate endograft sizing and prevention of endoleak type 1A. Therefore the lack of studies in this field and a sizeable inter-observer variability do not justify the widespread reliance on the traditional diameter-based methods for endograft sizing

Spinal Cord Ischaemia in Endovascular Thoracic and Thoraco-abdominal Aortic Repair : Review of Preventive Strategies

Introduction: The incidence of spinal cord ischaemia (SCI) and subsequent paraplegia after thoracic endovascular aneurysm repair (TEVAR) and thoraco-abdominal endovascular aneurysm repair is estimated to be between 2.5% and 8%. The aim of this review is to provide an overview of SCI preventive strategies in TEVAR and thoraco-abdominal repair and recommend an optimal strategy. Methods: Medline, Embase, and the Cochrane Library were searched for studies on TEVAR, thoraco-abdominal endovascular repair, and the use of SCI preventive measures. The review was reported according to the PRISMA statement. Results: The final analysis included 43 studies (7168 patients). All studies are cohort studies (non-comparative cohorts n = 37, comparative cohorts n = 6) and largely performed retrospectively (n = 27). The included studies had an average MINORS score of 9 (range 6-13) for non-comparative studies and 15.5 (range 12-18) for comparative studies. Transient SCI occurred in 5.7% (450/7,168, 95% CI 4.5-6.9%), permanent SCI in 2.2% (232/7,168, 95% CI 1.6-2.8%). There was a trend towards increased SCI incidence for more "high risk" cohorts. Avoidance of hypotension resulted in a slightly lower permanent SCI rate 1.8% (102/4216, 95% CI 1.2-2.3%) than the overall cohort. A very low SCI estimate (transient and permanent) was found in the subgroup of studies (2 studies, n = 248) using (mild) peri-operative hypothermia (transient SCI 0.8%, permanent SCI 0.4%). In the subgroup using temporary permissive endoleak, there was a transient SCI estimate (15.4%), with a permanent SCI estimate of 4.8%. The remaining preventive measures did not significantly impact transient or permanent SCI estimates. Conclusion: Low overall transient and permanent SCI rates are achieved during endovascular thoracic and thoraco-abdominal aortic repair. Based on the presented data, the use of selective spinal fluid drainage in high risk patients seems justified. Peri-operative hypotension should be avoided and treated where possible. The use of mild hypothermia is promising in small cohorts, but requires further evaluation. Further high quality data are essential to establish a definitive preventive strategy

Spinal Cord Ischaemia in Endovascular Thoracic and Thoraco-abdominal Aortic Repair : Review of Preventive Strategies

Introduction: The incidence of spinal cord ischaemia (SCI) and subsequent paraplegia after thoracic endovascular aneurysm repair (TEVAR) and thoraco-abdominal endovascular aneurysm repair is estimated to be between 2.5% and 8%. The aim of this review is to provide an overview of SCI preventive strategies in TEVAR and thoraco-abdominal repair and recommend an optimal strategy. Methods: Medline, Embase, and the Cochrane Library were searched for studies on TEVAR, thoraco-abdominal endovascular repair, and the use of SCI preventive measures. The review was reported according to the PRISMA statement. Results: The final analysis included 43 studies (7168 patients). All studies are cohort studies (non-comparative cohorts n = 37, comparative cohorts n = 6) and largely performed retrospectively (n = 27). The included studies had an average MINORS score of 9 (range 6-13) for non-comparative studies and 15.5 (range 12-18) for comparative studies. Transient SCI occurred in 5.7% (450/7,168, 95% CI 4.5-6.9%), permanent SCI in 2.2% (232/7,168, 95% CI 1.6-2.8%). There was a trend towards increased SCI incidence for more "high risk" cohorts. Avoidance of hypotension resulted in a slightly lower permanent SCI rate 1.8% (102/4216, 95% CI 1.2-2.3%) than the overall cohort. A very low SCI estimate (transient and permanent) was found in the subgroup of studies (2 studies, n = 248) using (mild) peri-operative hypothermia (transient SCI 0.8%, permanent SCI 0.4%). In the subgroup using temporary permissive endoleak, there was a transient SCI estimate (15.4%), with a permanent SCI estimate of 4.8%. The remaining preventive measures did not significantly impact transient or permanent SCI estimates. Conclusion: Low overall transient and permanent SCI rates are achieved during endovascular thoracic and thoraco-abdominal aortic repair. Based on the presented data, the use of selective spinal fluid drainage in high risk patients seems justified. Peri-operative hypotension should be avoided and treated where possible. The use of mild hypothermia is promising in small cohorts, but requires further evaluation. Further high quality data are essential to establish a definitive preventive strategy

Accuracy of Routine Endoscopy Diagnosing Colonic Ischaemia After Abdominal Aortic Aneurysm Repair:A Meta-analysis

Background: Colonic ischaemia (CI) is a devastating complication after abdominal aortic aneurysm (AAA) surgery. The aim of this review was to evaluate the diagnostic test accuracy of routine endoscopy in diagnosing CI after treatment for elective and acute AAA. Patients and methods: The Pubmed and Embase database searches resulted in 1188 articles. Prospective studies describing routine post-operative colonoscopy or sigmoidoscopy after elective or emergency AAA repair were included. The study quality was assessed with the QUADAS-2 tool. Sensitivity and specificity forest plots were drawn. Diagnostic odds ratios were calculated by a random effect model. Results: Twelve articles were included consisting of 718 AAA patients of whom 44% were treated electively, 56% ruptured and, 6% by endovascular repair. Of all patients, 20.8% were identified with CI (all grades), and 6.5% of patients had Grade 3 CI. The pooled diagnostic odds ratio for all grades of CI on endoscopy was 26.60 (95% CI 8.86–79.88). The sensitivity and specificity of endoscopy for detection of Grade 3 CI after AAA repair was 0.52 (95% CI, 0.31–0.73) and 0.97 (95% CI 0.95–0.99) respectively. The positive post-test probability is up to 60% in all kinds of AAA patients and 68% in ruptured AAA patients. Conclusion: Routine endoscopy is highly accurate for ruling out CI after AAA repair. Clinicians should be aware that endoscopy is less accurate in diagnosing the presence of the clinically relevant transmural CI. Endoscopy is a safe diagnostic test to use routinely as none of the studies reported adverse events