Proximal Arch Research Articles

Double aortic arch with atretic proximal left arch.

Aortic arch anomalies are rare and represent about 1% of all congenital cardiac lesions. Double aortic arch with atretic proximal left arch is one of the rare causes of respiratory symptoms in neonates, often missed by preoperative imaging studies. Preoperative identification and differentiating this entity from other arch anomalies is imperative to plan appropriate surgical management.

Outcomes Following Supracoronary Ascending Aortic Replacement with Aortic Valve Resuspension versus Modified Bentall's Operation for Acute Type A Aortic Dissection.

IntroductionType A acute aortic dissection (AAD) remains a challenging cardiac emergency despite the availability of various management strategies. This study compared the outcomes of supracoronary ascending aortic replacement (SCAAR) with aortic valve (AV) resuspension with those of modified Bentall's operation for type A AAD and the progression of aortic regurgitation (AR), long-term dilatation of aortic root and proximal arch, and long-term mortality in SCAAR patients.MethodsSixty patients underwent surgery for type A AAD (January 2005 to December 2015). Forty-three patients underwent SCAAR with AV resuspension and 17 underwent modified Bentall's operation. All patients were followed up.ResultsUpon follow-up of SCAAR patients (n=40), there was significant reduction in aortic root size (preoperative 39.3 mm [9.4] vs. postoperative 33.1 mm [9.1]; P<0.001). Three of these patients worsened to severe AR while others had similar or lesser degree of AR. On comparison between preoperative and postoperative dimensions of all patients (n=53), there was no significant difference in distal ascending aorta size (35.7 mm [8.1] vs. 34.4 mm [8.9]; P=0.52). However, an increase in descending thoracic aorta size (28.8 mm [7.8] vs. 33.7 mm [9.9]; P<0.001) was observed. In-hospital and late mortalities for SCAAR vs. modified Bentall's procedure were 11.7% (seven patients) (7% [3] vs. 23.5% [4]) and 28% (15 patients) (15% [6] vs. 69% [9]), respectively.ConclusionSCAAR with AV resuspension is a safe surgical option for type A AAD. Preservation of AV is associated with better long-term outcomes and reduced mortality. Modified Bentall's operation may be associated with long-term mortality.

Cholesterol crystal embolism-related cerebral infarction: Magnetic resonance imaging and clinical characteristics.

Background and aimsCholesterol crystal embolism-related cerebral infarction (CCE-CI) is frequently misdiagnosed due to the lack of specific symptoms. To aid in differential diagnosis, this study comprehensively characterized the magnetic resonance imaging (MRI) and clinical manifestations of CCE-CI and compared these features to those of atherothrombotic cerebral infarction (ACI).MethodsThis single-center, retrospective, observational study was conducted at Kitasato University Hospital, Kanagawa, Japan. We identified 37 clinically or histopathologically confirmed CCE-CI cases and 110 ACI cases treated from January 2006 to May 2020. Groups were compared for mean age, sex ratio, clinical presentations, imaging manifestations, precipitating factors, comorbid conditions, medications, and smoking history.ResultsOf 37 eligible patients with CCE-CI, 10 (27.0%) received brain MRI, of which 8 (21.6%) exhibited high-intensity signals indicative of brain lesions on diffusion-weighted imaging (DWI). However, two patients with DWI lesions exhibited no detectable neurological abnormalities. Patients with CCE-CI frequently demonstrated bilateral DWI lesions involving the bilateral anterior and posterior circulation, a pattern absent in ACI (50% vs. 0%, p < 0.001). Compared to patients with ACI, CCE-CI patients also demonstrated significantly lower estimated glomerular filtration rate (p < 0.001) as well as more frequent eosinophilia (p = 0.006), atherosclerotic plaques ≥4-mm thick in the ascending aorta or proximal arch (p = 0.001), and aortic aneurysm (p < 0.001).ConclusionsPatients with CCE-CI develop multiple DWI lesions across several vascular territories, even in the absence of neurological symptoms. Comorbid aortic aneurysm may increase CCE-CI risk. These findings could help in the differential diagnosis of CCE-CI.

Abstract 12817: Experimental Analysis of Bicuspid Aortic Valve Hemodynamics: Effect of Mild Aortic Dilatation on Systolic Flow Characteristics

Introduction: Aortic diameter is a determinant index in deciding surgical intervention for aortic aneurysm with bicuspid aortic valve (BAV). However, the treatment of a mildly dilated ascending aorta remains controversial. We experimentally investigated influence of mild dilatation of the ascending aorta on BAV-related hemodynamics in 3 BAV morphologies. Methods: An MRI-compatible pulsatile flow circulation system incorporating an aortic valve model and aortic arch model was developed. Tricuspid aortic valve (TAV) and 3 asymmetric BAV models including RL-, RN-, and LN-BAV were constructed by suturing bovine pericardium as cusps to aorta. The aortic arch models with the ascending diameters of 30 mm (non-dilatation) and 40 mm (mildly dilatation) were compared. Streamlines and the circulations (m 2 /s) of peak systolic flow in non- and mildly dilated ascending aorta were assessed using 4D-flow MRI in each BAV morphology (Fig). Results: Streamlines showed eccentric aortic valvular outflow jets impinging on the outer curvature of the ascending aorta, proximal arch, and left-anterior supra-valvular aortic wall in RL-, RN-, and LN-BAV, respectively. Regardless of the non-dilated or mildly dilated aorta, the circulations of peak systolic flow were larger in the BAVs than the TAV model (non-dilated aorta, TAV 0.005; RL- 0.016; RN- 0.026; LN-BAV 0.011 m 2 /s, mildly dilated aorta, TAV 0.009; RL- 0.017; RN- 0.028; LN-BAV 0.025 m 2 /s). Right-handed rotation was observed in RL- and RN-BAV, whereas LN-BAV presented left-handed rotation. In LN-BAV, the circulation markedly increased in the mildly dilated ascending aorta. Conclusions: Asymmetric BAV morphology was associated with highly eccentric aortic valvular outflow jet that directly impinged on the aortic wall, and the large circulation of peak systolic flow. The dilatation of the ascending aorta, even mild dilatation, might induce further increase in the circulation of systolic flow, especially in LN-BAV morphology.

A Proposal to Evaluate Proximal and Distal Arch Endovascular Repairs Separately

We congratulate the authors on a remarkable report1 – more than 4 000 aortic arch presentations over four years, 12.5% (n = 513) managed using surgeon modified arch thoracic endovascular aneurysm repair (TEVAR)/fenestrated endovascular aneurysm repair (FEVAR) with impressive early and midterm results. It echoes a similar, but smaller, recent publication.2

Modified Scalloped Endograft for Failed Endovascular Repair of an Aortic Arch Dissection

We reviewed a modified, proximal scalloped, arch endograft, the Terumo RelayPro Plus (Terumo Aortic, Bolton Medical, Sunrise, Fla; Fig A), used for endovascular salvage after thoracic endovascular aneurysmal repair (TEVAR). Current endovascular repair of proximal arch pathology has been limited by patient anatomy and the availability of Food and Drug Administration–approved devices. Through Food and Drug Administration–authorized compassionate use, we were able to repair a type Ia endoleak in a patient with continued rapid proximal arch aneurysmal degeneration after open type A dissection repair complicated by vocal cord paralysis and TEVAR failure (Fig B).

Freestyle aortic root prosthesis in combination with aortic replacement and open anastomosis: a retrospective analysis

BackgroundThe Freestyle® bioprosthesis is used for pathologies of the aortic root. Additional resection of the ascending aorta and the proximal arch in dissections or aneurysms might be indicated. The aim was to assess mid-term outcome regarding prosthetic performance, stroke, reoperations, and survival in various pathologies comparing patients with and without additional procedures on the ascending aorta and proximal arch focusing on the standardised technique of unilateral antegrade cerebral perfusion under moderate hypothermia.MethodsRetrospective data analysis of 278 consecutive patients after Freestyle® root replacement between September 2007 and March 2017. Patients were divided in three categories due to the pathology of the aortic root (re-operation vs endocarditis vs dissection). Two groups based on the aortic anastomosis technique (open arch anastomosis (OA) versus non-open arch anastomosis (non-OA) were compared (119 OA vs 159 non-OA). Cardiovascular risk, previous cardiac events, intra- and postoperative data were evaluated. Inferential statistics were performed with Mann-Whitney U-test. Nominal and categorical variables were tested with Fisher-Freeman-Halton exact test. Kaplan-Meier estimate was used to assess survival.ResultsThe follow-up rate was 90% (median follow-up: 39.5 months). There were differences in the indication (endocarditis: OA 5 (4.2%) vs non-OA 36 (24%), p < 0.0001; dissection: OA 13 (10.9%) vs non-OA 2 (1.3%); p = 0.0007). OA patients had less perioperative stroke (1 (1%) vs 15 (10%), p = 0.001) and shorter hospital stay (9 vs 12 days, p = 0.0004). There were no differences in the mortality (in-hospital: OA 8 (7%) vs non-OA 8 (5%); p = 0.6; death at follow-up: OA 5 (5%) vs non-OA 15 (11%); p = 0.1). Overall valve performance showed a well-functioning valve in 97.3% at follow-up.ConclusionThe valve performance showed excellent results regardless of the initial indication. The incidence of stroke was lower in patients receiving an open arch anastomosis using unilateral antegrade cerebral perfusion without elevated mortality or prolonged hospital stay.

Proximal aortic arch re-dilatation after external aortic wrapping.

We read with interest the article by Kim and colleagues,1 who report that the use of aortic wrapping in a moderately dilated ascending aorta in patients who underwent aortic valve replacement shows acceptable long-term outcomes. However, this procedure was accompanied with a higher risk of re-dilatation at the proximal arch than after an ascending aortic replacement.

A decade of surgical therapy in an all-comer cohort with type A aortic dissection

We reported on a decade of aortic surgery for type A aortic dissection to assess surgical techniques employed and outcomes over time in an all-comer analysis of a mid-size university cardiosurgical center. From 2009 to 2018, 283 patients (189 males and 94 females, mean age 62 years, range 30-85 years), who underwent surgical therapy for type A aortic dissection in our institution were included in a retrospective statistical analysis. Among all the patients, 55.5% of them were hemodynamically stable, 10.3% came in intubated. A neurological deficit was present in 18.9% of cases, extremity malperfusion was noted in 17.4%, and abdominal malperfusion detected in 8.2%. The extent of the aortic dissection corresponded to DeBakey type I in 88% of cases, a thoracoabdominal involvement was seen in 64%. In 51.9% of patients, only the ascending aorta replaced, another 40.6% of patients had proximal arch replacement too. A separate stent placement into the descending aorta was achieved in 13.4% of patients, during surgery (5.7%) or thereafter (7.7%). Overall survival to discharge was 79.5%. Most frequent complications were stroke and paralysis (15.2%), but only visceral malperfusion (OR 9.0) and heart failure mandating ECMO therapy (OR 29.5) were associated with significantly increased mortality. Surgery for type A aortic dissection is still challenging. Along with the refinement of surgical techniques, the indication for the various procedures has moved from a simplified general strategy to a more individualized concept.

Bicuspid aortic valve morphology and aortic valvular outflow jets: an experimental analysis using an MRI-compatible pulsatile flow circulation system

The characteristics of aortic valvular outflow jet affect aortopathy in the bicuspid aortic valve (BAV). This study aimed to elucidate the effects of BAV morphology on the aortic valvular outflow jets. Morphotype-specific valve-devising apparatuses were developed to create aortic valve models. A magnetic resonance imaging-compatible pulsatile flow circulation system was developed to quantify the outflow jet. The eccentricity and circulation values of the peak systolic jet were compared among tricuspid aortic valve (TAV), three asymmetric BAVs, and two symmetric BAVs. The results showed mean aortic flow and leakage did not differ among the five BAVs (six samples, each). Asymmetric BAVs demonstrated the eccentric outflow jets directed to the aortic wall facing the smaller leaflets. In the asymmetric BAV with the smaller leaflet facing the right-anterior, left-posterior, and left-anterior quadrants of the aorta, the outflow jets exclusively impinged on the outer curvature of the ascending aorta, proximal arch, and the supra-valvular aortic wall, respectively. Symmetric BAVs demonstrated mildly eccentric outflow jets that did not impinge on the aortic wall. The circulation values at peak systole increased in asymmetric BAVs. The bicuspid symmetry and the position of smaller leaflet were determinant factors of the characteristics of aortic valvular outflow jet.

The long-term fate of ascending aorta aneurysm after wrapping versus replacement.

The study objective was to examine the long-term fate of aortic diameter expansion at 4 cardiac regions (annulus, sinus, ascending aorta, and proximal arch) after wrapping or replacement during aortic valve surgery of the moderately dilated ascending aorta. From January 1995 to December 2018, 964 consecutive patients who underwent aortic valve replacement at our institution were reviewed. Of them, 204 (mean age, 60.7±7.4years) underwent ascending aorta wrapping (n=96) or replacement (n=108) for a moderately dilated ascending aorta (40 to 55mm). The overall fate of the aortic diameter was analyzed with a linear mixed-effect model. The median follow-up duration was 7.1years. After propensity score matching, the baseline maximal ascending aortic diameter median value was 47.3±3.1mm and 49.4±13.5mm in the wrapping and replacement groups, respectively. The annulus, sinus, and ascending aorta did not redilate in either group. The proximal aortic arch diameter significantly increased over time (0.343mm/year; P=.006) in the wrapping group but not in the replacement group (0.066mm/year; P=.649). Multivariable competing risk analysis identified the initial ascending aorta diameter at the wrapping procedure as an independent risk factor of proximal arch redilation (0.071±0.037, P<.001). The cutoff value was an initial ascending aorta diameter of 47.2mm for the prediction proximal arch redilation (area under the curve, 0.703; P=.014). Aortic wrapping and replacement may be long-term durable treatment options in patients with a moderately enlarged ascending aorta. We suggest careful evaluation of redilation in the proximal arch after an aorta wrapping procedure.

Propensity score analysis in patients with and without previous isolated coronary artery bypass grafting who require proximal aortic and arch surgery

ObjectiveThe risk posed by previous isolated coronary artery bypass grafting (CABG) in patients who require proximal aortic or aortic arch surgery is unclear. We compared outcomes of ascending aortic and arch procedures in patients with and without previous CABG. MethodsUsing propensity scores, we created 2 matched groups of patients who underwent proximal aortic surgery, including total arch repairs, at our institution: 126 patients who underwent isolated CABG before the index operation and 126 without previous CABG. Forty-four percent of aortic operations were emergency procedures. Eighty-six patients had a patent previous left internal mammary graft. We compared outcomes between the 2 groups and calculated Kaplan–Meier survival curves. ResultsThe following outcomes were recorded for the patients with previous isolated CABG versus no CABG: operative mortality, 15.9% versus 11.1% (P = .3); 30-day mortality, 13.5% versus 7.1% (P = .1); persistent stroke, 6.3% versus 4.8% (P = .6); and renal failure necessitating hemodialysis at discharge, 7.9% versus 4.0% (P = .2). Previous CABG did not independently predict any adverse outcome, even though patients who underwent previous CABG more frequently needed intra-aortic balloon support (P < .01). The P value for the overall intergroup difference in long-term survival was .06. ConclusionsThis is one of the largest studies yet reported to examine the impact of previous isolated CABG on proximal aortic or arch surgery outcomes. Although these results may be specific to aortic centers of excellence, in this complicated patient cohort, previous isolated CABG did not independently predict any adverse outcome. These results could serve as a benchmark for assessing future endovascular therapies.

Abstract 14205: Aortic Vorticity, Helicity and Aortopathy in Adult Patients With Tetralogy of Fallot: Preliminary Study Using Four-dimensional Flow Magnetic Resonance Images

Introduction and hypothesis: Flow hemodynamic parameters may relate to aortopathy in adults with tetralogy of Fallot. We aimed to employ quantitative analysis in the vorticity and helicity of the aortic root and the ascending aorta (AAo) in adults with tetralogy of Fallot (TOF), and to evaluate aortopathy and the relevant factors. Methods: Prospectively, 51 consecutive adults with TOF underwent 4 dimensional flow magnetic resonance imaging study for the assessment of vorticity and helicity of in the aortic root and AAo, wall shear stress (WSS), viscous energy loss (EL), and the left ventricular outflow tract - aortic root (LVOT-Ao) angle. Patients were divided into the two groups: dilated aortic root and/or AAo (indexed dimeter&gt;25mm/cm2), Group A (15 patients); non-dilated aortic patients, Group B (36 patients). Ten age matched controls were also enrolled. Results: Group A showed acute LVOT-Ao angle, higher incidence of aortic regurgitation, and initial anatomy of pulmonary atresia, compared to Group B (P&lt;0.0001, 0.02, 0.043). Group A showed greater vorticity at the level of Valsalva, AAo, and proximal arch, helicity, WSS, and EL than in Group B (P&lt;0.001, &lt;0.001, 0.049, 0.02, 0.026). Acute LVOT-Ao angle correlated with the diameter of the aortic root and AAo, vorticity, helicity, WSS, and EL (P=0.004, 0.023, 0.045, 0.004, 0.0004, 0.017). On a univariate logistic analysis, age, acute LVOT-Ao angle, AAo vorticity, AAo helicity, and maximum WSS were relevant factors of AAo dilatation (P=0.03, 0.02, 0.004, 0.03, 0.046). On a multivariate analysis, LVOT-Ao angle was the most important factor of AAo dilatation (odds ratio 0.66, 95%CI 0.46-0.95, P&lt;0.024). Conclusions: TOF Adults with TOF presenting dilated AAo have greater vorticity, helicity, and acute LVOT-Ao angle. Flow eccentricity correlates with vorticity and helicity, which may affect the aortopathy in adults with TOF. AAo vorticity and helicity are also relevant factors of aortic dilatation, and these flow hemodynamic parameters may be adjunctive predictions of aortopathy in this population.

Abstract 14618: Bicuspid Aortic Valve Morphology and Risk Factors of Abnormal Hemodynamics: An Experimental Investigation of Velocity, Vorticity and Eccentricity of Systolic Jet Stream, Using a Magnetic Resonance Imaging Compatible Pulsatile Flow Circulation System

Introduction: Abnormal hemodynamics with bicuspid aortic valve (BAV) is influenced by the BAV morphology. However, due to the morphological variety, the relationship between BAV morphology and hemodynamics has not been well clarified. We experimentally investigated influences of BAV morphology on hemodynamics. Methods: An MRI compatible pulsatile flow circulation system incorporating an aortic valve model and morphologically relevant aortic arch model was developed. Two types of BAV models with cusp angles of 240-120 (asymmetric BAV) and 180-180 (symmetric BAV) were prepared using bovine aorta and pericardium. The vorticity and eccentricity of jet in the aortic arch model in systolic phase were assessed using 4D-flow MRI. Streamlines at peak systole were compared among 5 BAV morphologies defined based on the symmetry and the position of leaflets (Fig). Results: Eccentric supra-valvular jets directed to the aortic wall faced to the smaller leaflet were present in the 3 asymmetric BAVs. In the ABAV-1, a markedly eccentric jet impinging on the aortic outer curvature was present. In the ABAV-2, a left-posterior directed jet shifting to the outer curvature of proximal arch was present. The asymmetric BAVs induced larger flow vorticity in the ascending aorta than the symmetric BAVs (ABAV-1 vs -2 vs -3 vs SBAV-1 vs -2, 0.018 vs 0.019 vs 0.014 vs 0.010 vs 0.011 m 2 /s). The ABAV-2 had a larger vortex in the middle arch than the ABAV-1 (ABAV-2 vs -1, 0.010 vs 0.005 m 2 /s). Conclusion: Our study indicated that the angles and orientations of the BAV impacted on the locations of jets impinging on the aortic wall and magnitudes of vorticities in systole. In the asymmetric BAVs, the direction of jet was influenced by the position of smaller leaflet. Our data suggests that the ABAV-1 morphology may be a risk factor inducing asymmetric aneurysm bulged toward the aortic outer curvature, while the ABAV-2 morphology may be a risk factor of an aortic aneurysm involving the transvers arch.

Patch Neointima Technique in Acute Type A Aortic Dissection: Midterm Results of 147 Cases

The patch neointima technique is a modified valve-sparing aortic root repair surgery for acute type A aortic dissection and the short-term outcomes are satisfactory. The midterm outcomes have not been reported. From January 2009 to December 2012, 147 patients underwent valve-sparing aortic root repair with the patch neointima technique for type A aortic dissection in our center. The midterm outcomes of the patients were evaluated by echocardiography and aortic computed tomography angiography. Of 147 patients, 32 patients (21.8%) underwent proximal arch repair, and 115 patients (78.2%) underwent proximal arch repair combined with triple-branched stent graft implantation. The perioperative mortality was 5.4%. Preoperative aortic insufficiency (AI) was observed in 94 patients (63.9%); 131 patients (89.1%) left the operating room with 0 AI; the remaining 16 patients (10.9%) had trace or less than 1+ AI. A total of 128 patients (87.1%) completed 7-year follow-up. The mean follow-up time was 5.7 ± 1.2 years. As many as 82% of patients (105) were 0 AI and 15.6% of patients (20) were 0.5+ trace or less than 1+ AI. No reoperation was performed for the aortic root. The diameters of sinotubular junction and sinus were reduced to the normal range (28.3 ± 4.2 mm and 30.5 ± 3.6 mm, respectively) and remained stable (28.9 ± 5.6 mm, P= .300, and 30.8 ± 4.2 mm, P= .540, respectively) during 7 years of follow-up. Valve-sparing aortic root repair with patch neointima technique was associated with stable function of the aortic valves and no expansion of the aortic root in the midterm.

Aortic Vorticity, Helicity, and Aortopathy in Adult Patients with Tetralogy of Fallot: Pilot Study Using Four-Dimensional Flow Magnetic Resonance Images.

To employ quantitative analysis in the vorticity and helicity of the aortic root and the ascending aorta (AAo) in adults with tetralogy of Fallot (TOF), and to evaluate aortopathy and the relevant factors. Prospectively, 51 consecutive adults with TOF underwent 4 dimensional flow magnetic resonance imaging study for the assessment of vorticity and helicity of the aortic root and AAo, wall shear stress (WSS), viscous energy loss (EL), and the left ventricular outflow tract - aortic root (LVOT-Ao) angle. Patients were divided into the two groups: dilated aortic root and/or AAo (indexed diameter > 25mm/cm2), Group A (15 patients); non-dilated aortic patients, Group B (36 patients). Ten age-matched controls were also enrolled. Group A showed more acute LVOT-Ao angle, higher incidence of aortic regurgitation, and initial anatomy of pulmonary atresia, compared to Group B (P < 0.0001, 0.02, 0.043). Group A showed greater clockwise vorticity at the level of Valsalva, AAo, and proximal arch, sagittal vorticity, AAo helicity, WSS, and EL than in Group B (P < 0.001, < 0.001, < 0.001, 0.045, 0.049, 0.02, 0.026). More acute LVOT-Ao angle correlated with the diameter of the aortic root and AAo, AAo vorticity, helicity, WSS, and EL (P = 0.004, 0.023, 0.045, 0.004, 0.0004, 0.017). On a univariate logistic analysis, more acute LVOT-Ao angle, AAo vorticity, AAo helicity, and maximum WSS were relevant factors of AAo dilatation (P = 0.02, 0.02, 0.045, 0.03, 0.046). On a multivariate logistic analysis, more acute LVOT-Ao angle was the most important factor of AAo dilatation (odds ratio 0.66, 95% CI 0.46-0.95, P < 0.024). TOF adults presenting dilated AAo have greater vorticity, helicity, and acute LVOT-Ao angle. Flow eccentricity and these flow hemodynamic parameters may be adjunctive predictions of aortopathy in this population.

A Challenging Proximal Aortic Arch Endovascular Repair

Revision proximal arch thoracic endovascular aneurysm repair (TEVAR) was performed to treat a large, 73 mm pseudoaneurysm in a 74 year old man. (A, B) A through and through guidewire was placed from the right proximal external iliac artery to the left ventricular apex via mini left thoracotomy. A 36 mm Zenith Alpha endograft (Cook Aortic Intervention, Bloomington, IN, USA) was deployed above the level of the coronary sinuses under cardiopulmonary bypass. The patient had a complex history of multiple aortic arch interventions, including a Bentall procedure for type A dissection, hybrid aortic arch TEVAR with retrograde cervical debranching, and a revision Bentall procedure for pseudoaneurysm of coronary sinus and atrial fistula.Image 1

Contributing Factor of Proximal Arch Dilation in Patients with Bicuspid Aortic Valve-Wall Shear Stress or Upward Extension of Ascending Aorta Dilation?

The dilation of proximal arch (PArc) was suspected to develop as a result of valve-related hemodynamics or in consequence to the upward extension of the ascending aorta (AAo) dilation. We aimed to investigate the one that could be the possible contributing factor in patients with bicuspid aortic valve (BAV). All enrolled BAV patients underwent four-dimensional flow magnetic resonance imaging. Contour-averaged circumferential wall shear stress (WSScirc,avg) and the diameter of the middle of AAo (mid-AAo) were compared between the patients with and without PArc dilation. Additionally, we analyzed the correlation between WSScirc,avg and aortic diameter at PArc section, as well as the correlation between the diameter of mid-AAo and that of PArc. No significant difference was observed in WSScirc,avg at PArc section between the patients with and without PArc dilation (P = .621). However, the diameter of mid-AAo in the patients who suffered PArc dilation was higher than those without it (P = .007). In addition, the aortic diameter did not correlate with the WSScirc,avg at PArc level (R = -0.068, P = .701). The correlation was observed between PArc diameter and mid-AAo diameter (R = 0.521, P = .002). Hemodynamics may not contribute to the development of PArc dilation. PArc diameter correlated with mid-AAo diameter, indicating PArc dilation may be secondary to the upward extension of AAo dilation. The influence of AAo dilation extending upward could be treated by AAo replacement; hence, a selective approach to transverse PArc replacement might be appropriate.

Ligament and Bone Arch Partition of the Carpal Tunnel by Three-Dimensional Ultrasonography.

The carpal tunnel is geometrically irregular due to the complex composition of many carpal bones intercalated by numerous intercarpal ligaments. The purpose of the study was to investigate the relative contributions of the ligament and bone arches to carpal tunnel space at the proximal, middle, and distal tunnel regions. A catheter ultrasound probe acquired fan-like images inside cadaveric carpal tunnels for three-dimensional reconstruction of the tunnel. The total tunnel volume was 5367.6 ± 940.1 mm3 with contributions of 12.0%, 6.9%, and 4.1% by proximal, middle, and distal ligament arches, respectively, and 27.0%, 25.3%, and 24.7% by proximal, middle, and distal bone arches, respectively. The bone arch occupied more tunnel space than the ligament arch at all regions (p < 0.05). The ligament arch was largest at the proximal region of the tunnel and significantly decreased toward the distal region (p < 0.05). However, the bone arch significantly decreased only from the proximal to middle region (p < 0.05) but not from the middle to distal region (p = 0.311). Consequently, it was observed that the ligament arch was the key contributor to the unequal carpal tunnel space across regions. Partitional and regional tunnel morphometric information may provide a better understanding of tunnel abnormality associated with various wrist pathological conditions. The developed framework of ultrasonography and data processing can be applied to other areas of interest in the musculoskeletal system.

Controlled autologous recellularization and inhibited degeneration of decellularized vascular implants by side-specific coating with stromal cell-derived factor 1α and fibronectin

Optimized biocompatibility is crucial for the durability of cardiovascular implants. Previously, a combined coating with fibronectin (FN) and stromal cell-derived factor 1α (SDF1α) has been shown to accelerate the in vivo cellularization of synthetic vascular grafts and to reduce the calcification of biological pulmonary root grafts. In this study, we evaluate the effect of side-specific luminal SDF1α coating and adventitial FN coating on the in vivo cellularization and degeneration of decellularized rat aortic implants. Aortic arch vascular donor grafts were detergent-decellularized. The luminal graft surface was coated with SDF1α, while the adventitial surface was coated with FN. SDF1α-coated and uncoated grafts were infrarenally implanted (n = 20) in rats and followed up for up to eight weeks. Cellular intima population was accelerated by luminal SDF1α coating at two weeks (92.4 ± 2.95% versus 61.1 ± 6.51% in controls, p < 0.001). SDF1α coating inhibited neo-intimal hyperplasia, resulting in a significantly decreased intima-to-media ratio after eight weeks (0.62 ± 0.15 versus 1.35 ± 0.26 in controls, p < 0.05). Furthermore, at eight weeks, media calcification was significantly decreased in the SDF1α group as compared to the control group (area of calcification in proximal arch region 1092 ± 517 μm2 versus 11 814 ± 1883 μm2, p < 0.01). Luminal coating with SDF1α promotes early autologous intima recellularization in vivo and attenuates neo-intima hyperplasia as well as calcification of decellularized vascular grafts.