Cardiac Pulsatile Helical Deformation of the Thoracic Aorta Before and After Thoracic Endovascular Aortic Repair of Type B Dissections.

PURPOSE: Type B aortic dissections propagate with either achiral (nonspiraling) or right-handed chiral (spiraling) morphology, have mobile dissection flaps, and are often treated with thoracic endovascular aortic repair (TEVAR). We aim to quantify cardiac-induced helical deformation of the true lumen of type B aortic dissections before and after TEVAR. MATERIAL AND METHODS: Retrospective cardiac-gated computed tomography (CT) images before and after TEVAR of type B aortic dissections were used to construct systolic and diastolic 3-dimensional (3D) surface models, including true lumen, whole lumen (true+false lumens), and branch vessels. This was followed by extraction of true lumen helicity (helical angle, twist, and radius) and cross-sectional (area, circumference, and minor/major diameter ratio) metrics. Deformations between systole and diastole were quantified, and deformations between pre- and post-TEVAR were compared. RESULTS: Eleven TEVAR patients (59.9±4.6 years) were included in this study. Pre-TEVAR, there were no significant cardiac-induced deformations of helical metrics; however, post-TEVAR, significant deformation was observed for the true lumen proximal angular position. Pre-TEVAR, cardiac-induced deformations of all cross-sectional metrics were significant; however, only area and circumference deformations remained significant post-TEVAR. There were no significant differences of pulsatile deformation from pre- to post-TEVAR. Variance of proximal angular position and cross-sectional circumference deformation decreased after TEVAR. CONCLUSION: Pre-TEVAR, type B aortic dissections did not exhibit significant helical cardiac-induced deformation, indicating that the true and false lumens move in unison (do not move with respect to each other). Post-TEVAR, true lumens exhibited significant cardiac-induced deformation of proximal angular position, suggesting that exclusion of the false lumen leads to greater rotational deformations of the true lumen and lack of true lumen major/minor deformation post-TEVAR means that the endograft promotes static circularity. Population variance of deformations is muted after TEVAR, and dissection acuity influences pulsatile deformation while pre-TEVAR chirality does not. CLINICAL IMPACT: Description of thoracic aortic dissection helical morphology and dynamics, and understanding the impact of thoracic endovascular aortic repair (TEVAR) on dissection helicity, are important for improving endovascular treatment. These findings provide nuance to the complex shape and motion of the true and false lumens, enabling clinicians to better stratify dissection disease. The impact of TEVAR on dissection helicity provides a description of how treatment alters morphology and motion, and may provide clues for treatment durability. Finally, the helical component to endograft deformation is important to form comprehensive boundary conditions for testing and developing new endovascular devices.

Mid-term results of distal anastomosis to the true lumen for chronic type B aortic dissection.

We investigated whether distal anastomosis to the true lumen in open surgical repair of descending aorta for chronic type B aortic dissection improved the long-term outcomes with aortic remodeling. We retrospectively reviewed 71 patients with chronic type B aortic dissection, excluding those with connective tissue disorder, from October 2001 to June 2021. The patients who underwent distal true lumen anastomosis (group T, n = 36) were compared to those with both lumens' anastomosis (group B, n = 35), regarding survival, overall and distal aortic events. The growth rates of the distal aorta (maximum diameter in descending thoracic, suprarenal and infrarenal abdominal aorta) were also investigated. Median age was significantly higher in group T (T; 66 vs B; 60, P = .001). Group T had significantly higher rates of complete and partial thrombosis formation in the false lumen than group B postoperatively (26.9 vs 0%, P = .01 for complete, 65.4 vs 3.9%, P < .0001 for partial, respectively). At median follow-up for 6.8 years of 63 patients (88.7%), survival, overall and distal aortic event-free rates, and the growth rates of the distal aorta were not significantly different between the groups. Distal anastomosis to the true lumen did not improve mid-term survival, aortic event-free rates and the growth rates of the distal aorta compared with that of both lumens for chronic type B aortic dissection.

Endovascular Rescue Aortic Fenestration After Accidental False Lumen TEVAR in Type B Dissection.

PURPOSE: Unintended false-lumen thoracic endovascular aortic repair (TEVAR) is under-reported and often fatal. We present percutaneous endovascular rescue techniques for true-lumen reperfusion with strategies to address the peripheral artery perfusion needs unique to each case. CASE REPORT: Two patients deteriorated 24 hours after uncomplicated and complicated acute aortic type-B dissection TEVAR treatment at a tertiary community hospital. Reevaluation of index and repeated imaging studies revealed inadvertent false-lumen TEVAR with severe visceral and peripheral ischemia. Stepwise subtraction angiography was used to confirm continuous true-lumen catheterization from femoral puncture into the thoracic aorta. Retrograde fenestration distal to the misplaced TEVAR from the true- into the false-lumen allowed for snorkeling by distal stent-extension across the dissection membrane. In one case, TEVAR stent graft extension resulted in true-lumen re-expansion and in the other case, bare-metal stent-extension for stabilization of the dissection membrane resulted in true-lumen re-expansion in addition to preservation of visceral and peripheral perfusion via the false-lumen. Despite excellent acute hemodynamic results and initial signs of recovery, both patients eventually died (multiorgan failure; cerebral hemorrhagic infarction). CONCLUSION: Correct indication and prompt recognition of potential inadvertent false-lumen stenting is critical to avoid disastrous sequelae, for example, malperfusion. Endovascular salvage is feasible for restoration of correct perfusion and must be performed in a timely manner. CLINICAL IMPACT: Clinically apparent, complicated type-B dissection necessitates instantaneous treatment. Prerequisite for an endovascular approach is a true-lumen guidewire continuously from access to the ascending aorta. DSA after TEVAR and prompt clinical re-evaluation are to verify effective visceral and peripheral restoration of blood flow. Despite these measures, inadvertent false-lumen TEVAR may occur rarely. Immediate recognition may allow for timely true-lumen re-expansion using percutaneous endovascular salvage techniques e.g. retrograde fenestration from the true- into the false-lumen for distal snorkeling of the misplaced TEVAR across the dissection membrane. However, morbidity and mortality are very high, if erroneous stent graft placement is not identified early.

Fate of the Dissected Thoraco-Abdominal Aorta Distal to TEVAR (Thoracic Endovascular Aortic Repair) for Complicated Acute and Subacute Type B Aortic Dissection.

PURPOSE: This study assessed morphological changes in the aortic true and false lumens during follow-up of patients undergoing TEVAR (Thoracic Endovascular Aortic Repair) for complicated acute and subacute type B dissection. The study analyzes the effectiveness of TEVAR in preventing distal aneurysmal progression. MATERIALS AND METHODS: All patients between 2009 and 2019 undergoing TEVAR for complicated acute and subacute type B dissection at the study institution were retrospectively reviewed. Maximal diameters were measured on the proximal descending aorta right below the left subclavian artery, thoraco-abdominal junction right above the celiac trunk, and infrarenal aortic right above the inferior mesenteric artery, pre-operatively and during follow-up, analyzing either expansion or shrinkage of true and false lumens at these 3 sites. RESULTS: Forty-one patients were included. Thirty-day incidence of death, stroke, paraplegia, and visceral ischemia was, respectively, 8% (n = 4), 6% (n = 3), 2% (n = 1), and 2% (n = 1). Three patients (6%) died from intervention-related cause. Mortality was 17% (n = 8) during a mean follow-up of 54 months. One patient had aneurysmal dilation of the descending aorta needing additional coverage and only 2 (4%) developed thoraco-abdominal aneurysms requiring re-intervention. In the remaining patients, both significant expansion of the true lumen and shrinkage of false lumen were observed at all 3 sites. CONCLUSION: Proximal coverage of the main entry tear appears to prevent aneurysmal progression in most patients (96%). With such promising results, TEVAR should be considered as a first-line treatment in acute and subacute type B dissection.

Influence of thoracic endovascular aortic repair on true lumen helical morphology for Stanford type B dissections.

OBJECTIVE: Thoracic endovascular aortic repair (TEVAR) can change the morphology of the flow lumen in aortic dissections, which may affect aortic hemodynamics and function. This study characterizes how the helical morphology of the true lumen in type B aortic dissections is altered by TEVAR. METHODS: Patients with type B aortic dissection who underwent computed tomography angiography before and after TEVAR were retrospectively reviewed. Images were used to construct three-dimensional stereolithographic surface models of the true lumen and whole aorta using custom software. Stereolithographic models were segmented and co-registered to determine helical morphology of the true lumen with respect to the whole aorta. The true lumen region covered by the endograft was defined based on fiducial markers before and after TEVAR. The helical angle, average helical twist, peak helical twist, and cross-sectional eccentricity, area, and circumference were quantified in this region for pre- and post-TEVAR geometries. RESULTS: Sixteen patients (61.3 ± 8.0 years; 12.5% female) were treated successfully for type B dissection (5 acute and 11 chronic) with TEVAR and scans before and after TEVAR were retrospectively obtained (follow-up interval 52 ± 91 days). From before to after TEVAR, the true lumen helical angle (-70.0 ± 71.1 to -64.9 ± 75.4°; P = .782), average helical twist (-4.1 ± 4.0 to -3.7 ± 3.8°/cm; P = .674), and peak helical twist (-13.2 ± 15.2 to -15.4 ± 14.2°/cm; P = .629) did not change. However, the true lumen helical radius (1.4 ± 0.5 to 1.0 ± 0.6 cm; P < .05) and eccentricity (0.9 ± 0.1 to 0.7 ± 0.1; P < .05) decreased, and the cross-sectional area (3.0 ± 1.1 to 5.0 ± 2.0 cm2; P < .05) and circumference (7.1 ± 1.0 to 8.0 ± 1.4 cm; P < .05) increased significantly from before to after TEVAR. The distinct bimodal distribution of chiral and achiral native dissections disappeared after TEVAR, and subgroup analyses showed that the true lumen circumference of acute dissections increased with TEVAR, although it did not for chronic dissections. CONCLUSIONS: The unchanged helical angle and average and peak helical twists as a result of TEVAR suggest that the angular positions of the true lumen are constrained and that the endografts were helically conformable in the angular direction. The decrease of helical radius indicated a straightening of the corkscrew shape of the true lumen, and in combination with more circular and expanded lumen cross-sections, TEVAR produced luminal morphology that theoretically allows for lower flow resistance through the endografted portion. The impact of TEVAR on dissection flow lumen morphology and the interaction between endografts and aortic tissue can provide insight for improving device design, implantation technique, and long-term clinical outcomes.

One-Year Single-Center Results of the Multilayer Flow Modulator Stents for the Treatment of Type B Aortic Dissection.

PURPOSE: To report a single-center series of patients with type B aortic dissection treated with the Multilayer Flow Modulator (MFM). MATERIALS AND METHODS: Over a 36-month period, 23 patients (median age 53 years; 20 men) with complicated type B aortic dissections (2 acute, 5 subacute, and 16 chronic) were treated with the MFM. Primary endpoints of rupture or dissection-related death, overall mortality, and reintervention were evaluated using the Kaplan-Meier method; estimates for freedom from the endpoints are reported with the 95% confidence interval (CI). Secondary outcomes included technical success, adverse events, and aortic remodeling. Clinical and imaging data were collected preoperatively, directly postoperatively, and annually to 36 months for analysis using computational fluid dynamics (CFD). RESULTS: Initial technical success was 91.3%. The estimates of the endpoints at 12 months were 100% for freedom from rupture or aortic-related death, 95.7% for freedom from overall mortality, and 91.3% for freedom from reintervention. No device-related neurological or systemic complications occurred, and no additional reinterventions were needed during follow-up. A total of 144 branches overstented by the MFM remained patent. Morphologic analysis of the aortic dissection showed progressive true lumen volume increase (75.9%, p<0.001) with concomitant false lumen volume decrease (42.8%, p<0.001); the CFD analyses showed increased laminar flow. CONCLUSION: In the current series, the MFM provided a safe and feasible treatment option for complicated acute, subacute, and chronic type B aortic dissections, with high technical success, low mortality, and active aortic remodeling. Further studies should elucidate the long-term safety of the MFM and its effectiveness in a larger patient cohort.

Clinical and angiographic outcomes of true vs. false lumen stenting of coronary chronic total occlusions: Insights from intravascular ultrasound.

OBJECTIVES: The clinical implications of subintimal stenting (SS) of the recanalized chronic total occlusion (CTO) segment have not been characterized. We evaluated the in-hospital and the long-term clinical and angiographic outcomes of drug-eluting stents (DESs) deployed in true vs. false lumen of successfully recanalized CTO. METHODS AND RESULTS: Two independent reviewers analyzed the intravascular ultrasound (IVUS) images of 173 successfully recanalized CTO lesions (157 patients), between August 2011 and October 2012. After successful guidewire (GW) crossing, lesions were classified according to IVUS evaluation into two groups: (1) true lumen (TL) stenting group and (2) SS group; and compared with regards to in-hospital and long-term clinical outcomes. In 154 lesions, DESs were deployed in the TL; and in 19 (11%) lesions, DESs were deployed in the subintimal space (95% confidence interval: 6.3-15.6%). False GW tracking in the SS group resulted in increased rates of IVUS-detected dissection flaps (84% vs. 42.6%, P ≤ 0.001), intramural hematoma (32 vs. 11%, P = 0.01), and minor perforations 6/19 (31.6% vs. 8.4%, P = 0.002). At 1-year follow-up, both groups had similar cumulative rates of binary restenosis and target lesion revascularization (P = 0.73 and P = 0.97, respectively). Six patients (4.6%, 6/129 patients) in the TL group and none in the subintimal group died at 1 year. CONCLUSIONS: Acknowledging some limitations, our observations may suggest that, subintimal stent deployment in a recanalized CTO segments, using second generation DES and IVUS guidance, might have a comparable success rate and long-term angiographic and clinical outcomes as TL stenting.

Femoral Balloon-Oriented Puncture for True Lumen Reentry in the Common Femoral Artery After Subintimal Retrograde Recanalization of Superficial Femoral Artery Ostial Occlusion: The FORLEE Technique.

Purpose: To report a new technique to reenter the common femoral artery (CFA) true lumen after retrograde recanalization of a superficial femoral artery (SFA) with flush ostial occlusion. Technique: The technique is demonstrated in a 76-year-old woman with critical limb ischemia previously submitted to several surgical revascularizations. A duplex ultrasound showed flush ostial occlusion of the SFA and patency of the anterior tibial artery at the ankle as the sole outflow vessel. After unsuccessful antegrade attempts to recanalize the SFA, a retrograde guidewire was advanced subintimally up to the CFA, without gaining reentry. A balloon catheter was inflated in the subintimal plane across the SFA ostial occlusion. Antegrade access to the distal CFA was achieved with a 20-G needle, which was used to puncture the balloon. A guidewire was advanced into the balloon and pushed forward while the collapsed balloon was pulled back to the mid SFA. The antegrade guidewire was externalized through a retrograde catheter, which was pushed in the CFA true lumen. A retrograde guidewire was advanced and externalized through the femoral sheath, establishing a flossing wire. The procedure was completed in antegrade fashion. Conclusion: The FORLEE technique is a cost-effective option to gain the CFA true lumen after subintimal retrograde recanalization of an ostial SFA occlusion.

Intravascular Ultrasound-Assisted Endovascular Treatment of Mesenteric Malperfusion in a Multichannel Aortic Dissection With Full True Lumen Collapse.

PURPOSE: To describe endovascular treatment of mesenteric malperfusion in a multichannel aortic dissection (MCAD) with full true lumen (TL) collapse following thoracic endovascular aortic repair (TEVAR). CASE REPORT: A 54-year-old man presented with chronic mesenteric ischemia and a previous TEVAR for MCAD complicated by superior mesenteric artery (SMA) malperfusion. Computed tomography angiography (CTA) demonstrated a 3-channel aortic dissection with a "false-true-false" configuration. The SMA was malperfused through the collapsed TL. CTA also showed a secondary entry tear, measuring 18 mm in diameter, at the end of the previous endograft. Direct open surgery or endovascular revascularization of the SMA was not feasible. A plan was devised to improve SMA perfusion by increasing the TL inflow. With the assistance of intravascular ultrasound (IVUS), an endograft was placed through one false lumen in the abdominal aorta and through the TL in the descending thoracic aorta to seal the secondary entry tear. Symptoms of mesenteric ischemia resolved 2 days after the procedure. At 1 year, he is asymptomatic, has gained weight, and has improved SMA perfusion and remodeling of the 3-channel dissection on CTA. CONCLUSION: IVUS imaging can help evaluate the complex hemodynamics of MCAD. Patient-specific endovascular treatment of MCAD with mesenteric malperfusion seems to be a feasible bailout alternative treatment for urgent, complex cases without reconstruction options.

Coronary artery dissection following aortic valve replacement. How can one deal with this rare yet life-threatening complication?

Coronary artery dissection following its cannulation for cardioplegia administration as a result of aortic valve replacement (AVR) is a rare but nevertheless life-threatening complication. The three cases of a patient suffering from aortic stenosis illustrated below focus on the issue of how to identify and treat the dissected artery. In all of the patients who had undergone AVR diagnosed was a periprocedural myocardial infarction. Angiography revealed the dissection of the left main in two of the patients, while in the third one that of the right coronary artery. In the case of local dissection, angiography was sufficient to identify the true lumen, whereas in a dissection encompassing the whole of the coronary tree it was necessary to either find the coronary artery not involved in the dissection or to perform intravascular ultrasound imaging. After true lumen identification, the entry of dissection was stented with the optimal angiographic result.

Primary Use of the TruePath Crossing Device for Infrainguinal Chronic Total Occlusions With Intravascular Ultrasound Evaluation.

PURPOSE: To evaluate the use of the TruePath crossing device as the primary recanalization tool for infrainguinal chronic total occlusions (CTO). METHODS: A retrospective analysis was conducted of 50 patients (mean age 75 years; 26 men) with 55 infrainguinal CTOs treated with the TruePath between March 2017 and September 2017 at a single center. The mean occlusion length was 138±55 mm, and femoropopliteal lesions accounted for 65% of the 55 lesions. The primary outcome measure was CTO crossing using the TruePath alone; secondary outcomes were assisted success (>50% lumen gain using the TruePath), device-related complications, and intraluminal crossing evaluated by intravascular ultrasound (IVUS). RESULTS: Complete success was achieved in 33 (60%) of 55 lesions having a mean occlusion length of 145±72 mm. Among these, the true lumen crossing rate was 97% according to IVUS evaluation. Assisted success was achieved in 15 (68%) of the 22 failures. Complete/assisted success, in which the TruePath was thought to have contributed to CTO crossing, was attained in 48 (87%) of the 55 lesions. Three (5.5%) complications were observed: a perforation, an access-site hematoma, and acute occlusion; only the perforation was device related (1.8%). Multivariate analysis showed PACCS grade 4 (odds ratio 4.5, 95% confidence interval 1.33 to 15.5, p=0.02) was an independent predictor of TruePath failure. CONCLUSION: Primary use of the TruePath crossing device for infrainguinal CTOs demonstrated a satisfactory complete success rate and a high rate of IVUS-documented intraluminal crossing with few device-related complications. Severe calcification is an independent predictor of TruePath failure.

Threading the Eye of the Needle: A Challenging Case of Iatrogenic Spiral Coronary Artery Dissection.

Catheter induced coronary dissection is an uncommon but potentially catastrophic complication of coronary angiography. We report a case of a 48-year-old female with normal coronary arteries on angiography complicated by extensive catheter induced spiral dissection. Wiring into the true lumen was a formidable challenge as a consequence of the large false lumen obliterating the true lumen. We present management strategies and in particular, highlight the important role of intravascular ultrasound (IVUS) imaging.

Imaging behind occluded areas with an iatrogenic perforated balloon: A safe, practical, and simple new method of visualizing the distal lumen in total occlusion.

OBJECTIVE: In the present study, we investigated the effectiveness and reliability of a new method that reveals whether guidewire advanced distal to the lesion is in the lumen in patients with acute (ATO) or chronic coronary total occlusion (CTO). METHODS: Forty-one patients with symptomatic ATO and 22 patients with CTO who were admitted into our catheterization laboratory between January 2016 and March 2017 were included. In patients in whom antegrade filling could not be demonstrated after passing 0.014″ guidewire beyond the total lesion, a 1.25 × 15 mm balloon was punctured with a needle outside the operative field to visualize the total lesion. This perforated balloon was then used to deliver an opaque substance through this hole to visualize the distal part. RESULTS: The mean age of our 63 patients was 66 ± 12 years. They had diabetes (57%), hypertension (100%), and a history of PCI (85%). The mean procedural time was 27 ± 6.8 min, and the mean volume of contrast material used was 93.9 ± 24 mL. This technique was 100% successful in accurately demonstrating the distal lumen and preventing complications. CONCLUSION: This new method we developed is much simpler and more useful than other methods for visualization of the true lumen because we can re-orient the balloon at the time of opaque injection and use 190 cm guidewire without additional costs. Additionally, one balloon is sufficient for the operation.

Endovascular Closure of Chronic Dissection Entries in the Aortic Arch Using the Amplatzer Vascular Plug II as a Sealing Button.

PURPOSE: To present a new endovascular technique to avoid open surgical arch reconstruction in selected patients with aneurysmal dilatation due to small chronic dissection entries in the aortic arch. TECHNIQUE: The true and the false lumen of the aortic arch are catheterized from the femoral arteries. An Amplatzer Vascular Plug II (AVP II) is advanced through the proximal entry from the false lumen side and deployed as a sealing button in the entry hole, with 1 disc in the true lumen and the remaining 2 discs in the false lumen. This technique was used in 4 patients with chronic dissection involving the aortic arch, three of whom had had previous surgery for acute type A aortic dissection. In 3 patients, the false lumen of the thoracic aorta was successfully obliterated, with thrombosis and aortic diameter reduction during follow-up. In 1 patient, false lumen flow persisted, and he was subsequently treated with a total arch reconstruction and frozen elephant trunk. CONCLUSION: Endovascular closure of small proximal dissection entries in the aortic arch with an AVP II used as a sealing button is feasible and may be an alternative to open surgical arch reconstruction in selected patients with chronic aortic dissection and secondary aneurysm expansion.

Standardized Protocol to Analyze Computed Tomography Imaging of Type B Aortic Dissections.

PURPOSE: To propose a standard measuring protocol for type B aortic dissections so as to improve comparability between studies reporting aortic dimensions. METHODS: Fifteen computed tomography (CT) scans of type B aortic dissections were measured with a standard protocol by 2 independent observers using postprocessing software. The following parameters were assessed: true, false, and total lumen diameter; true and false lumen volume; and entry tear size, location, and number. Diameters were measured in a perpendicular plane at 2, 10, and 20 cm from the left subclavian artery and 5 cm from the most distal renal artery. True lumen volume was assessed from the left subclavian artery to the aortic bifurcation, while the false lumen volume was from the start to end up to the aortic bifurcation. Entry tear location was assessed in relation to the left subclavian artery. Intra- and interobserver repeatability and agreement were evaluated using the Bland-Altman method, an a priori set of acceptable differences, and Lin's concordance correlation coefficient (LCCC). RESULTS: Intra- and interobserver mean differences for aortic diameter and true and false lumen volumes were generally within the limits of agreement and the a priori differences; the LCCC showed excellent agreement. Entry tear location, size, and number were difficult to measure in a repeatable manner, with inconsistent correlation coefficients, especially between the 2 observers. CONCLUSION: This protocol showed acceptable repeatability for aortic diameter and aortic volume measurements. Assessment of entry tears proved challenging and associated with less favorable results. Additionally, investigators are urged to be more transparent regarding the measurement methodology used in studies describing aortic dimensions.

Large false lumen area is a predictor of failed false lumen volume reduction after stent-graft repair in type B aortic dissection.

PURPOSE: To investigate the predictors of failed false lumen (FL) volume reduction at 12 months after stent-graft implantation in patients with type B aortic dissection. METHODS: The retrospective analysis comprised 38 patients (25 men; mean age 60±12 years) with double-barrel type B aortic dissection (9 acute) treated with thoracic endovascular aortic repair (TEVAR) and evaluated with serial computed tomography (CT) scans up to 12 months. Aortic volume changes were determined. Based on FL volume change at 1 year after stent-graft implantation, patients were dichotomized according to the presence or absence of FL volume reduction. Clinical and CT variables were compared between groups to determine risk factors of failed FL volume reduction. A major adverse event (MAE) was defined as death or reintervention. RESULTS: Patients were followed for 4.2±2.8 years. FL volume reduction (+FLVR) occurred in 27 (71%) patients, whereas 11 (29%) patients had no FL volume reduction (-FLVR). The MAE-free survival rate was significantly higher in the +FLVR patients than in the -FLVR group (88.9% vs. 27.3%, respectively; p=0.001). Chronicity of dissection, location of tear site, or the maximum total aortic lumen area was not associated with failure to achieve FL volume reduction. However, the maximum preprocedure FL area was significantly lower in the +FLVR group than in the -FLVR group (12.6±6.6 vs. 21.0±11.4 cm(2), respectively; p=0.041) and was an independent predictor for failed FL volume reduction (odds ratio 1.3, 95% confidence interval 1.02 to 1.70, p=0.031). CONCLUSION: Failed FL volume reduction after TEVAR was associated with a significantly increased rate of mortality or reintervention during follow-up. A larger preprocedure maximum FL area was a predictor of failed FL volume reduction after TEVAR in type B dissection.

Aortic hemodynamics after thoracic endovascular aortic repair, with particular attention to the bird-beak configuration.

PURPOSE: To quantitatively evaluate the impact of thoracic endovascular aortic repair (TEVAR) on aortic hemodynamics, focusing on the implications of a bird-beak configuration. METHODS: Pre- and postoperative CTA images from a patient treated with TEVAR for post-dissecting thoracic aortic aneurysm were used to evaluate the anatomical changes induced by the stent-graft and to generate the computational network essential for computational fluid dynamics (CFD) analysis. These analyses focused on the bird-beak configuration, flow distribution into the supra-aortic branches, and narrowing of the distal descending thoracic aorta. Three different CFD analyses (A: preoperative lumen, B: postoperative lumen, and C: postoperative lumen computed without stenosis) were compared at 3 time points during the cardiac cycle (maximum acceleration of blood flow, systolic peak, and maximum deceleration of blood flow). RESULTS: Postoperatively, disturbance of flow was reduced at the bird-beak location due to boundary conditions and change of geometry after TEVAR. Stent-graft protrusion with partial coverage of the origin of the left subclavian artery produced a disturbance of flow in this vessel. Strong velocity increase and flow disturbance were found at the aortic narrowing in the descending thoracic aorta when comparing B and C, while no effect was seen on aortic arch hemodynamics. CONCLUSION: CFD may help physicians to understand aortic hemodynamic changes after TEVAR, including the change in aortic arch geometry, the effects of a bird-beak configuration, the supra-aortic flow distribution, and the aortic true lumen dynamics. This study is the first step in establishing a computational framework that, when completed with patient-specific data, will allow us to study thoracic aortic pathologies and their endovascular management.

Acute type-A aortic dissection with patent false lumen through to the abdominal aorta: effects of a conventional elephant trunk on malperfusion syndromes and narrowed true lumen.

BACKGROUND: Narrowed true lumen and patent false lumen through to the terminal aorta is a high-risk condition for malperfusion syndromes (MS) in acute type-A aortic dissection. It is important to ascertain how the true and false lumens behave after surgery. PATIENTS AND METHODS: We retrospectively investigated 45 patients with this pathology. The true lumen sizes at the narrowest levels above and below the superior mesenteric artery were followed by computed tomography after surgery (0-36 months). RESULTS: Thirty-seven MS were seen in 23 patients. Hospital mortality was 8.9%. The narrowed true lumen was not enlarged in the first 6 months with a patent false lumen. The elephant trunk procedure did not improve the true lumen size. An extremely narrowed (≤3 mm) true lumen was associated with a significantly high incidence of MS and mortality. CONCLUSIONS: High incidences of MS were observed in this particular pathology. An extremely narrowed true lumen was accompanied by a high incidence of MS and mortality.