Diameter Of Segment Research Articles

Pill or pump? Nitroglycerin 0.5 mg tablet vs 0.8 mg spray: Effect on proximal vessel diameters at Coronary CT Angiography (CCTA)

IntroductionThe administration of sublingual Nitroglycerin (NTG) prior to CT coronary angiography (CCTA) can be perfomed using pump spray or tablets. Choice of method seems to be based on local preference, rather than published guidelines. This retrospective analysis tested whether proximal coronary diameters differed dependent on the sublingual administration of 0.5 mg Nitroglycerin (NTG) tablets or 0.8 mg NTG spray. Methods287 ECG-gated CCTA studies with optimal image quality and Agatston scores<400 were included in this retrospective analysis. 143 of the patients were dosed with NTG tablets at a dose of 0.5 mg prior to CCTA. 144 patients received 2 puffs of 0.4 mg NTG spray for a total dose of 8 mg.All were scanned on a second-generation Dual Source CT. Diameters of proximal segments of Left Main (LM), Right (RCA), Left Anterior (LAD) and circumflex (CX) coronary arteries were measured using semi-automatic electronic callipers by two blinded readers. Results were summarised as the mean of maximum and minimum diameters. Sex-specific analysis of diameters was carried out using repeated-measures ANOVA for each vessel. Agreement between readers was examined with Bland-Altman analysis and intra-class-correlation coefficient (ICC). ResultsNo significant differences in coronary diameters were found except in the RCA for women and LM for men. In both cases, diameters were smaller in the spray group (11 and 9%, respectively). Reader agreement was excellent, with ICC>0.96 for all vessels, and no significant bias, except in CX (0.03 mm). ConclusionsWe found no evidence for the systematic superiority of either administration method in proximal coronary vessels. Implications for practiceChoosing between tablet or spray NTG prior to CCTA can be guided by practical, economical and hygienic considerations alone.

Coronary artery ectasia associated with IgG4-related disease: a case report and literature review

BackgroundCoronary artery ectasia is defined as a local or diffuse dilatation of the coronary artery more than 1.5 times the diameter of the adjacent normal segment. The etiology of coronary artery ectasia is diverse, and rarely complicated with immunoglobulin G4-related disease (IgG4-related disease). A limited number of cases have been reported, with insidious onset, slow progression but poor prognosis.Case presentationwe report a patient with coronary artery ectasia combined with IgG4-related disease. He has been diagnosed with IgG4-related disease 5 years after his first percutaneous coronary intervention (PCI). Despite routine treatment with steroids, he develops a large coronary aneurysm and eventually died.ConclusionsIt is suggested that a thorough evaluation should be performed when coronary artery ectasia is diagnosed. The factors such as manifestations of coronary artery thickening, typical imaging features, other aortas involvement, increased serum IgG4 level, etc. should be considered for early diagnosis of key etiologies.

Quantitative analysis of external carotid artery bypass donor vessels by recipient and approach

IntroductionUtilization an in-situ pedicle of the external carotid artery (ECA) as an arterial donor can allow for the successful augmentation or replacement of flow to a large vascular territory. We propose a mathematical model for quantitatively analyzing and grading the suitability of donor and recipient bypass vessels based on a set of anatomical and surgical variables in order to predict which pair has the greatest possibility for success. Using this method, we analyze all of the potential donor-recipient pairs for each ECA donor vessel—including the superficial temporal (STA), middle meningeal (MMA), and occipital (OA) arteries. MethodsThe ECA pedicles were dissected in frontotemporal, middle fossa, subtemporal, retrosigmoid, far lateral, suboccipital, supracerebellar, and occipital transtentorial approaches. For each approach, every potential donor-recipient pair was identified, and donor length and diameter were measured as well as depth of field, angle of exposure, ease of proximal control, maneuverability, and length and diameter of the recipient segment. Anastomotic pair scores were determined by adding the weighted donor and recipient. ResultsThe best overall anastomotic pairs were OA-vertebral artery (V3, 17.1) and STA-insular (M2, 16.3) and STA-sylvian (M3, 15.9) segments of the middle cerebral artery. Other strong anastomotic combinations were OA- telovelotonsillar (15) and OA- tonsilomedullary (14.9) segments of the posterior inferior cerebellar artery, and MMA-lateral pontomesencephalic segment of the superior cerebellar artery (14.2). ConclusionsThis novel model for anastamotic pair scoring can serve as a useful clinical tool for selecting the optimal donor, recipient, and approach combination that can help facilitate a successful bypass.

Carotid Artery Remodeling After Modified Eversion Carotid Endarterectomy

Modified eversion carotid endarterectomy (meCEA) is an alternative to classical patch angioplasty or eversion. An meCEA involves everting the carotid plaque through a longitudinal incision over the common carotid artery without transecting the internal carotid artery (ICA). Those who advocate patch angioplasty cite the propensity of luminal narrowing from the procedure or restenosis as a reason to avoid primary repair. We seek to objectively quantify the outcome of the carotid artery after primary repair of the longitudinal incision employed in this technique. We retrospectively reviewed all meCEAs performed at our institution and included those with preoperative and postoperative computerized tomography angiography. Pre- and postoperative centerline measurements, by two independent observers, were obtained at 1 cm and 2 cm proximal to the ICA ostium within the common carotid artery (CCA), the ICA ostium, and 1 cm and 2 cm distally within the ICA. The sum of the diameter changes at each segment was defined as the overall remodeling (OR). Segmental remodeling of the CCA and ICA (ICAR) were defined as the sum of the CCA and ICA changes, respectively. In total, 40 individual carotid arteries treated with meCEA with both pre- and postoperative computerized tomography angiographies (over a range of 0-1183 days) were included. On average, the ICA diameter increased by 5% at its ostium, 12.6% and 9.3% at 1 cm and 2 cm distal to its ostium, respectively. The CCA decreased in diameter, −8% and −3% at 1 cm and 2 cm proximal to the bifurcation, respectively. OR was −0.81 mm for the entire cohort, predominantly driven by remodeling of the CCA (−1.51 mm), whereas ICAR was favorable at +0.48 mm. Interestingly, female patients had more favorable remodeling overall, with less narrowing of the CCA (−0.96 mm vs −1.51 mm in male patients) and positive ICAR compared with preoperative imaging (+1.58 mm vs −0.25 mm in male patients). We found that postoperatively, despite a decreased segmental diameter of the CCA after meCEA, the ICA diameter remains largely intact and also remodels favorably over time. Our findings suggest that meCEA does not yield adverse narrowing of the ICA after primary repair or significant restenosis in this series. Although there may be a gender-related difference in OR, more evaluation is necessary.TablePostendarterectomy percent change in diameter of the common and internal carotid arteries at five locationsOverall cohort (N = 40)% change in diameterCCA 2 cm from bifurcation−3.3CCA 1 cm from bifurcation−8.2Ostial ICA+5.1ICA 1 cm from bifurcation+12.6ICA 2 cm from bifurcation+9.3Male (n = 24) CCA 2 cm from bifurcation−2.8 CCA 1 cm from bifurcation−9.4 Ostial ICA+1.0 ICA 1 cm from bifurcation+1.9 ICA 2 cm from bifurcation+5.5Female (n = 16) CCA 2 cm from bifurcation−4.1 CCA 1 cm from bifurcation−6.4 Ostial ICA+11.3 ICA 1 cm from bifurcation+28.7 ICA 2 cm from bifurcation+14.9CCA, Common carotid artery; ICA, internal carotid artery. Open table in a new tab

P141 ACUTE MYOCARDIAL INFARCTION OR SOMETHING MORE? CASE REPORT AND CHALLENGES ASSESSMENT OF GIANT CORONARY ANEURYSM MANAGEMENT

Abstract Background Coronary Artery Aneurysms (CAA) are defined as localized coronary artery dilations more than 1.5 times the diameter of the adjacent segments. Giant CAA (GCAAs) are rare coronary diseases and the presence of multiple CAAs, located in more than one coronary artery, is even more uncommon. The pathophysiology is unknown but the majority are due to atherosclerosis. There is currently no consensus concerning the management. Case presentation: We report the case of a 72–year–old man, referred to our emergency department due to chest pain. The patient’s electrocardiogram was consistent with myocardial infarction with inferior leads ST–segment elevation. Two-dimensional echocardiography showed hypertrophic Left Ventricle (LV) with akinesia of the infero–postero-lateral LV wall and hypokinesia of the remaining LV segments (LVEF = 40%). Coronary angiography and computed tomography revealed multiple CAAs, some of them giant, associated with significant coronary artery disease: two CAAs on the right coronary artery, including a giant one (Dmax 11 mm and Dmax 32 mm); one large aneurism on the circumflex artery (D max 20.5 mm) and one on the left main descendent artery (D max 8 mm). The patient had a previous history of hypertension, dyslipidemia and abdominal aortic aneurysm. He had no history of percutaneous coronary intervention or cardiac surgical procedures. Serological studies for vasculitis or connective tissue disease were all negative. The patient underwent surgical exclusion of the giant right CAA with ligation of the proximal and distal ends of the aneurysm and double bypass surgery to the obtuse marginal and right posterior descending coronary arteries. Conclusions CAAs’ treatment options include medical treatment, interventional or surgical management. No clear evidence about the better option exists, but it seems that surgical option should be favored in cases of bigger, more tortuous and more calcified CAAs. Based on these evidences and the anatomic lesions of our patient, we opted for surgery and he successfully underwent CAAs resection with coronary bypasses. We reported our experience and we examined the current knowledge on CAA/GCAA. Overall, management is hampered by lack of evidence. We need prospective studies and registries to further our knowledge in the management of this disorder and prognosis. From our attitude, surgical treatment should be performed for multiple GCAA to prevent fatal complications.

Occipital artery-posterior inferior cerebellar artery bypass: a cadaveric feasibility study

PurposeTo demonstrate that occipital artery (OA)-p1 posterior inferior cerebellar artery (PICA) bypass can be an alternative for complex posterior circulation aneurysms.MethodsA far-lateral approach to craniotomy was performed on 20 cadaveric specimens, and the OA was obtained 'in-line.' Its length, diameter, and the number of p1/p2 and p3 segmental perforators were determined, and the relationship between the caudal loop and cerebellar tonsil position was also assessed. The distance between the PICA’s origin and the cranial nerve XI (CN XI), the buffer length above the CN XI after dissection, the OA length required to complete the OA-p1/p3 PICA bypass, and the p1 and p3 segment diameters were all measured. A bypass training practical scale (TSIO) was used to evaluate the quality of the anastomosis.ResultsAll specimens underwent OA-p1 PICA end-to-end bypass and had favorable results for the TSIO score, 15 sides underwent OA-p3 PICA end-to-side bypass, and the other bypass protocols were less common. The buffer length above the CN XI after dissection, the distance between the PICA’s origin and the CN XI, and the first perforator were all of sufficient length. The direct length of the OA needed to complete the OA-p1 PICA end-to-end bypass was significantly less than the available length and the OA-p3 PICA end-to-side bypass, with the OA matching the p1 segment diameter. The number of p1 perforators was less than that of p3, and the OA diameter was equal to that of the p1 segment.ConclusionOA-p1 PICA end-to-end bypass is a feasible alternative in cases in which p3 segment has high caudal loops or anatomic anomalies.

Vessel-Specific Shear Stress Distribution and Heterogeneity in Angiogenic Rat Mesenteric Microvascular Networks

Fluid shear stress has been identified as an important player in regulating endothelial cell behaviors and angiogenesis, defined as the sprouting of new blood vessels from existing vessels. However, the correlative or functional linking of shear stress to vessel-specific endothelial cell dynamics requires a better understanding of the shear stress values at the capillary level in microvascular networks. Critical questions remain unanswered. What is the shear stress experienced by endothelial cells along capillaries? Do all capillaries experience similar shear stress magnitudes? Can variations in shear stress along different capillary segments explain vessel-specific responses? The objective of this project was to estimate shear stress values in regions of angiogenic microvascular networks. Rat mesenteric tissues were harvested from adult male Wistar rats post the stimulation of angiogenesis via 48-80 mast cell degranulation. Microvascular networks were identified by perfusion of a 40kDa fixable dextran prior to harvesting and immunolabelling for PECAM. Dextran presence identified perfused segments along the hierarchy of microvascular networks, which were characterized by increased vessel density indicative of angiogenesis. Representative network regions with arteriole input and venule output vessels were selected for analysis. Vessel segments were defined by adjacent nodes, and the measurements of lengths and diameter. Assuming an inlet pressure of 75 mmHg and outlet pressure of 10 mmHg, a network segmental Newtonian flow model was used to computationally estimate vessel-specific shear stresses and velocities. Viscosity was set to 4 cP and assumed to be constant. In the results, shear stresses along vascular segments in 3 medium microvascular regions ranged from 0.1 to 1114.3 dyne/cm2 (average = 81.3 ± 3.5 dyne/cm2), in 4 small regions ranged from 0.1 to 518.7 dyne/cm2 (average = 61 ± 3.4 dyne/cm2), and in 1 large region ranged from 0.003 to 2328.1 dyne/cm2 (average = 39.8 ± 1.6 dyne/cm2). For all regions, the highest shear stress values located at capillary segments, defined as vascular segments with diameters lower than 10 μm. As segment diameters increased, the matched maximum shear stresses decreased accordingly. Also, the high heterogeneity of shear stresses in capillaries indicates the possibility for segment-specific regulation. For 3 medium regions, shear stresses along proximal capillaries branching from arteriolar inlets to venular outlets were higher than stresses along capillaries in regions distal to inlets and outlets. The results highlight the variability of segment-specific shear stresses along capillaries in microvascular regions and motivate research looking into how endothelial cells respond to segment-specific microenvironment and regulation. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Outlook of coronary ectasia at the National Institute of Cardiology Ignacio Chávez: a cross-sectional study.

Coronary Ectasia (CE) is a pathological remodeling with a low worldwide prevalence. It is defined as a diffuse dilatation greater than 1.5 times the diameter of the adjacent segments of the same or different coronary arteries. To document the clinical and angiographic characteristics, and medical treatment at the discharge of patients diagnosed with coronary ectasia who attended the National Institute of Cardiology (INC). Cross-sectional study with a non-experimental descriptive design, with a non-probabilistic convenience sampling. Of 69 patients who attended the INC with a diagnosis of CD, most were men, with a mean age of 56 + 11 years, the most common coronary risk factor in patients with CE was smoking 58% (40); it was associated mostly with an acute myocardial infarction ST-segment elevation (STEMI) 65.2% (45), of frequent location in the lower face 40% (18), correlated with the most affected artery is the Right Coronary Artery (CD) 69.6% (48), followed by the circumflex (Cx) 56.5% (39). A mean LVEF of 47 + 9.72 was evident within the ventricular function. As well as the preferential use of dual antiplatelet therapy with anticoagulant (DAP + OAC) in 58% (40) at the discharge of each patient from the INC. CE is a not uncommon pathological remodeling in INC. This study showed that STEMI is the most typical manifestation of CE, diagnostic coronary angiography identified a type 3 Markis, so a low rate of mortality and recurrence of cardiovascular events would be expected, and despite the lack of consensus on the ideal therapy, at the INC individualized treatment is preferred, recommending lifestyle changes, and using triple therapy (DAP + OAC) as a medical treatment only at the time of patient discharge.

Evaluation of the normal gastrointestinal tract in cats using dual-phase computed tomography.

In cats, although ultrasonography remains the preferred modality to evaluate the gastrointestinal tract, computed tomographic (CT) examination of the abdomen is commonly performed. However, a normal description of the gastrointestinal tract is lacking. This study describes the conspicuity and contrast enhancement pattern of the normal gastrointestinal tract in cats using dual-phase CT. Pre- and dual-phase postcontrast (early scan at 30 seconds and late scan mean at 84seconds) abdominal CT exams of 39 cats without history, clinical signs or diagnosis of gastrointestinal disease were reviewed. The gastrointestinal tract was examined for conspicuity and enhancement pattern using commercially available viewing software (Osirix, v.6.5.2), and diameters of 16 gastrointestinal segments were recorded and compared with published radiographic and ultrasonographic reference values. Of the 624 gastrointestinal segments, 530 (84.9%) were identified on precontrast studies and 545 (87.3%) segments on postcontrast studies. Of the gastrointestinal wall segments, 257 (41.2%) were identified on precontrast studies and 314 (50.3%) on postcontrast studies. Gastrointestinal segment diameters correlated well with published normal values, whereas wall thickness measurements usually were smaller compared with sonographic normal values. Early mucosal surface enhancement was frequently seen in the gastric cardia and fundus and ileocolic junction, and a mainly transmural wall enhancement in other gastrointestinal segments. Dual-phase CT allows for the identification of gastrointestinal tract segments and walls in cats. Contrast enhancement improves conspicuity and demonstrates wall layering in the cardia, fundus and ileocolic junction.

Lactobacillus johnsonii CPN23 vis-à-vis Lactobacillus acidophilus NCDC15 Improves Gut Health, Intestinal Morphometry, and Histology in Weaned Wistar Rats.

The present investigation was carried out with the aim to establish the comparative efficacy of a canine-sourced probiotic meant for canine feeding and a conventional dairy-sourced probiotic. For this purpose, canine-origin Lactobacillus johnsonii CPN23 and dairy-origin Lactobacillus acidophilus NCDC15 were evaluated for potential probiotics health benefits in the rat model. Forty-eight weaned Wistar rats enrolled in this experiment of 8weeks were fed a basal diet and divided into three dietary treatments. Rats of group I enrolled as control (CON) were given MRS placebo at 1mL/head/day, while rats of group II (LAJ) and III (LAC) were administered with overnight MRS broth grown-culture of L. johnsonii CPN23 and L. acidophilus NCDC15, respectively, at 1mL/head/day (108cfu/mL). The average daily gain and net gain in body weight were significantly higher (p < 0.05) in LAJ and LAC than in CON. Fecal and digesta biochemical attributes altered (p < 0.05) positively in response to both probiotics. Total fecal and pooled digesta SCFAs were higher (p < 0.05) in both LAJ and LAC than in CON. The microbial population in cecal and colonic digesta responded (p < 0.05) positively to both probiotics. The diameter of intestinal segments was higher (p < 005) in LAJ as compared to CON. The number and height of villi in jejunum tended to be higher in LAJ as compared to CON. The humoral immune response to sheep erythrocytes as well as chicken egg-white lysozyme was higher in LAJ as compared to CON. Overall, the results of the study have demonstrated the effectiveness of the canine-sourced L. johnsonii CPN23 as a potential probiotic, with a comparatively better response than the dairy-sourced L. acidophilus NCDC15. It could thus be recommended for use in feeding dogs to help augment their health.

The Features of the Circle of Willis on Multislice Computed Tomography in Humans Without Cerebral Vascular Malformations

Abstract: A study of 135 cases without cerebral vascular malformations who were scan MSCT of cerebral arteries at Bach Mai hospital during the period from January 2019 to December 2019. Result: mean diameter of cerebral artery segments: left and right A1 segments: 2.28 ± 0.47 and 2.19 ± 0.53 mm; AcomA: 1.71 ± 0.68 mm; left and right M1 segments: 2.82 ± 0.46 mm and 2.8 ± 0.49 mm; left and right PcomA: 1.62 ± 0.5 mm and 1.67 ± 0.48 mm; left and right P1 segments: 2.22 ± 0.49 mm and 2.22 ± 0.56 mm; left and right P2 segments: 2.32 ± 0.38 mm and 2.35 ± 0.36 mm; BA: 3.41 ± 0.69 mm. The diameters of the cerebral arteries were similar in both sexes, with no difference on the right and left sides of the ring of Willis. The diameter of the edges of the Willis circle varied from aplastic and hypoplastic, which was mainly seen in the AcomA, PcomA, the A1 segment of the anterior cerebral artery, and P1 of the posterior cerebral artery. The transformations of the Willis ring included 17 forms, of which four simple transformations of the anterior part, four simple transformations of the posterior part, and nine combined transformations between the anterior and posterior parts. Mainly found aplasia or hypoplasia of the AcomA 14.1% and the PcomA 12.6%. Conclusion: the index of normalization of the segments of the Willis polygon and its variant forms contributed to bolder intervention planning in cerebrovascular disease treatment.&#x0D; Keywords: Circle of Willis, Cerebral arteries, MSCT.

Effect of different vaccination programs on production parameters, carcass, leg bones, and digestive system characteristics of broilers

The purpose of the present study was to compare the effects of two commercial vaccination programs using Prevexxion or Vaxxitek vaccines on production parameters, carcass weight and composition, and selected anatomical characteristics of Ross 308 broiler chickens. During the rearing period of broiler chickens, body weights were determined at 1, 10, 35, and 42 d of age, and feed intake and mortality of birds were recorded each day. On d 42 of the rearing period, 20 chickens were selected for dissection, 10 birds from each group. After slaughtering, the weight of the eviscerated carcass and the proportion of carcass elements, the lengths and diameters of individual intestinal segments, the weight of selected internal organs, and the dimensions of the femur and tibia were determined. The Prevexxion vaccination program had a positive significant effect on eviscerated carcass yield, dressing percentage, breast meat, wing and carcass remains content, as well as duodenum length, proventriculus content of slaughter weight and smallest breadth of the corpus of tibia bone. Broiler chickens treated with Prevexxion vaccines had higher European Production Index. The results indicate that Prevexxion vaccines have a more favorable effect on the production performance and slaughter characteristics of Ross 308 broiler chickens than with the use of Vaxxitek vaccines.

Risk factors for target vessel endoleaks after physician-modified fenestrated or branched endovascular aortic arch repair: A retrospective study.

Fenestrated or branched endovascular aortic arch repair (fb-arch repair) is an effective option for treating complex aortic arch lesions, including thoracic aortic aneurysms and aortic dissections. However, the relatively high rate of re-intervention due to target vessel (TV)-related endoleaks have raised concerns. This study aimed to determine risk factors for TV-related endoleaks after fb-arch repair. This was a retrospective analysis of all patients undergoing fb-arch repair between 2017 and 2021in nanjing drum tower hospital of China. All the patients underwent computed tomography angiography (CTA) before surgery; at discharge; and at 3 months, 6 months, and yearly post-discharge. All procedures are performed with physician modified grafts. Two experienced vascular surgeons used CTA and vascular angiography data to assess endoleaks. The study endpoints were mortality, aneurysm rupture, and emergence of and re-intervention for TV-related endoleaks. During the follow-up period, 218 patients underwent fb-arch repair. There were seven perioperative deaths and four deaths during follow-up (two myocardial infarctions and two malignancies). There were nine additional patients who were excluded from the study (two strokes, three with abnormal aortic arch anatomy, and four with insufficient clinical data). Among the 198 patients considered (mean age, 59 ± 13.3 years; 85% male), 309 branch arteries were revascularized. A total of 35 TV-related endoleaks were identified in 28 patients during a mean follow-up of 23 ± 14 months (median 23, IQR 26.3): six type Ic, 4 type IIIb, and 20 type IIIc endoleaks. Patients in the endoleak group had greater aortic arch segment diameters (43.1 ± 5.1 vs. 40.3 ± 4.7; P = 0.004) and a greater number of TVs revascularized (2.0 ± 0.8 vs. 1.5 ± 0.8; P = 0.004) than those in the non-endoleak group. However, the morphological classification of the aortic arch did not seem to affect the occurrence of TV endoleaks (13%, 14%, and 15% for type І, II, and III aortic arches, respectively; P = 0.957). Pre-sewing branch stents in the fenestration position reduced the risk of TV endoleaks (5% vs. 14%; P = 0.037). Additionally, in TVs affected by aortic aneurysm or dissection, the risk of endoleaks increased after reconstruction (17% vs. 8%; P = 0.018). The incidence of secondary TV-related endoleaks after fb-arch repair was 14.1%. The data from this study showed that the incidence of secondary target vessel related endoleaks after fb-arch repair is approximately 14.1%. Additionally, patients with a larger aortic arch diameter or more revascularized arteries during surgery were at increased risk TV-related endoleaks. The target vessels originating from the false lumen or aneurysm sac are more prone to endoleaks after reconstruction. Finally, prefabricated branch stents reduced risk of TV-related endoleaks.

A machine learning approach for predicting descending thoracic aortic diameter.

To establish models for predicting descending thoracic aortic diameters and provide evidence for selecting the size of the stent graft for TBAD patients. A total of 200 candidates without severe deformation of aorta were included. CTA information was collected and 3D reconstructed. In the reconstructed CTA, a total of 12 cross-sections of peripheral vessels were made perpendicular to the axis of flow of the aorta. Parameters of the cross sections and basic clinical characteristics were used for prediction. The data was randomly split into the training set and the test set in an 8:2 ratio. To fully describe diameters of descending thoracic aorta, three predicted points were set based quadrisection, and a total of 12 models at three predicted points were established using four algorithms included linear regression (LR), support vector machine (SVM), Extra-Tree regression (ETR) and random forest regression (RFR). The performance of models was evaluated by mean square error (MSE) of the prediction value, and the ranking of feature importance was given by Shapley value. After modeling, prognosis of five TEVAR cases and stent oversizing were compared. We identified a series of parameters which affect the diameter of descending thoracic aorta, including age, hypertension, the area of proximal edge of superior mesenteric artery, etc. Among four predictive models, all the MSEs of SVM models at three different predicted position were less than 2 mm2, with approximately 90% predicted diameters error less than 2 mm in the test sets. In patients with dSINE, stent oversizing was about 3 mm, while only 1 mm in patients without complications. The predictive models established by machine learning revealed the relationship between basic characteristics and diameters of different segment of descending aorta, which help to provide evidence for selecting the matching distal size of the stent for TBAD patients, thereby reducing the incidence of TEVAR complications.

Upper-Bound Limit Analysis of Ultimate Pullout Capacity of Expanded Anchor Cable

Expanded anchor cables have been widely used in the rapid development of underground engineering. However, there are still some deficiencies in the computation of the ultimate bearing capacity of expanded anchor cables. Based on the upper-bound theorem of limit analysis, the upper-bound solution of the ultimate bearing capacity of an expanded anchor cable was derived. For this calculation, the instability mechanism of the soil at the front surface of the anchorage segment of the expanded anchor cable was assumed to satisfy the logarithmic spiral failure model, its 3D velocity discontinuity surface was generated using the spatial discretization technique, and the optimal solution was determined through the particle swarm optimization (PSO) algorithm. The breakage mechanism of the anchorage side surface was assumed to appear at the interface between the anchorage body and the soil, and its velocity field satisfied the requirements of the associated flow rule. The accuracy of the proposed analytical solution was well-verified through a comparison with three-dimensional numerical simulations, and its superiority was also well-demonstrated in comparison to the existing theoretical calculation method. Subsequently, the influence of the key parameters of the anchor cable on the ultimate lateral resistance, end resistance, and total pullout capacity was discussed. The results showed that: the anchorage segment diameter, anchorage segment length, and buried depth of the expanded anchor cable had a great influence on the ultimate lateral resistance, ultimate end resistance, and total ultimate pullout capacity; however, the anchorage segment length had little influence on the ultimate end resistance, and the inclination angle of the anchor cable had relatively little influence on the resistance.

Impact of pre-existing conditions on peri-procedural coronary diameters

Background: Reperfusion therapy for acute myocardial infarction (AMI) by percutaneous coronary intervention (PCI) with stent implantation is associated with a significant reduction in immediate mortality. A long-term critical complication of PCI is in-stent restenosis (ISR). However, the factors leading to restenosis remain unclear, albeit changes in coronary diameters post-PCI have been suggested to be important in stent restenosis. We hypothesize that pre-existing conditions such as hypertension, diabetes, dyslipidemia, and smoking can affect the coronary artery diameters after PCI and contribute to in-stent restenosis.Project Methods: We recruited 26 AMI patients (age: 50-70 years; male 22) who were revascularized with PCI and studied whether pre-existing hypertension (HTN; n=10), type II diabetes mellitus (DM; n=5), dyslipidemia (DLP; n=3), and smoking (n=8) had independent contribution to changes in coronary artery diameter pre- and post-PCI. We measured segment-wise end-diastolic luminal cross-sectional diameter of left main (LM), left anterior descending (LAD), left circumflex (LCx), and right coronary arteries (RCA) from invasive coronary angiograms before and after PCI.Results: We found that the LM showed insignificant change in cross-sectional diameter in HTN, DM, and smoking groups. However, DLP group of patients showed an increase in diameter post-PCI. Proximal segment of LAD in HTN patients and all LAD segments in DM group were significantly increased in diameter. Proximal LCx was reduced in diameter in DLP group. RCA distal and PDA segments in HTN group as well as PDA segment in DM group were reduced in diameter post PCI.Potential Impact: Although following PCI, proximal and mid segments increase in diameter by 5-20%; and distal segments by 20-30%, our early findings indicate that changes in cross-sectional diameter of the coronary segments can fall outside these ranges when pre-existing conditions are present. Follow-up studies are needed to evaluate the relation between changes in coronary diameters and in-stent restenosis.

Effect of fuse damper on cyclic performance of self-centring bridge pier

The effects of a fuse damper on the cyclic performance of a self-centring bridge pier were investigated. To this end, a three-dimensional finite-element model of a self-centring concrete column with a fuse damper was developed. The model has three main components – a support block, the concrete column and a fuse damper. The fuse damper includes a fuse plate, a steel jacket and a bolt. The column was subjected to axial dead load and lateral cyclic load. The response of the column was obtained through a non-linear static analysis. To check the validity of the model, the model results were compared with results reported in the literature. A parametric study was carried out to investigate the effects of several parameters (e.g. plate thickness, bolt diameter, ultimate strengths of plate and bolt) on the cyclic response of the self-centring column. The results obtained from the parametric study indicated that the fuse damper improved the cyclic response of the column. In addition, as the fuse plate thickness, bolt diameter and height of the base segment were increased, the energy dissipated by the column and the lateral strength of the column both increased.

Dynamic Morphology of the Ascending Aorta and Its Implications for Proximal Landing in Thoracic Endovascular Aortic Repair.

In this study, we assessed the dynamic segmental anatomy of the entire ascending aorta (AA), enabling the determination of a favorable proximal landing zone and appropriate aortic sizing for the most proximal thoracic endovascular aortic repair (TEVAR). Methods: Patients with a non-operated AA (diameter < 40 mm) underwent electrocardiogram-gated computed tomography angiography (ECG-CTA) of the entire AA in the systolic and diastolic phases. For each plane of each segment, the maximum and minimum diameters in the systole and diastole phases were recorded. The Wilcoxon signed-rank test was used to compare aortic size values. Results: A total of 100 patients were enrolled (53% male; median age 82.1 years; age range 76.8−85.1). Analysis of the dynamic plane dimensions of the AA during the cardiac cycle showed significantly higher systolic values than diastolic values (p < 0.001). Analysis of the proximal AA segment showed greater distal plane values than proximal plane values (p < 0.001), showing a reversed funnel form. At the mid-ascending segment, the dynamic values did not notably differ between the distal plane and the proximal segmental plane, demonstrating a cylindrical form. At the distal segment of the AA, the proximal plane values were larger than the distal segmental plane values (p < 0.001), thus generating a funnel form. Conclusions: The entire AA showed greater systolic than diastolic aortic dimensions throughout the cardiac cycle. The mid-ascending and distal-ascending segments showed favorable forms for TEVAR using a regular cylindrical endograft design. The most proximal segment of the AA showed a pronounced conical form; therefore, a specific endograft design should be considered.

Surgically proven small bowel intussusception in children: Analysis of 36 cases

Background: Intussusception is one of the most common abdominal emergencies in children. While the majority of childhood intussusceptions are ilecolic and idiopathic, small bowel intussusceptions are rare and a pathological trigger is often blamed for the etiology. Ultrasonography is the most commonly used diagnostic tool in the diagnosis of intussusception.&#x0D; Objectives: To determine auxiliary diagnostic criteria for ultrasonography in the differentiation of small bowel intussusceptions based on ultrasonography, reduction and surgical findings of surgically confirmed small bowel intussusceptions and to contribute to the diagnosis and treatment algorithm of small bowel intussusceptions based on our clinical experience.&#x0D; Methods: The records of patients who underwent surgery for small bowel intussusception at the Faculty of Medicine, Department of Pediatric Surgery between January 2008 and December 2020 were retrospectively reviewed. Demographic characteristics, ultrasonographic findings, onset and duration of symptoms, treatment method, intraoperative findings and histopathological results of the patients were recorded.&#x0D; Results: Thirty-six pediatric patients with small bowel intussusception were operated. The average age of these patients was 59 ± 49.7 months and %78 was male. The location of the small bowel intussusception detected by ultrasound scan was the paraumbilical area and left quadrant in 19 (53%) patients and the right quadrant in 15 (42%) patients. In ultrasonography, the mean diameter of the invaginated segment was 3 (1.2-6.5) cm and the mean length was 6.7 (3-15) cm. Pathological lead points were detected in the etiology of nineteen (53%) patients. Thirteen (36%) patients underwent segmental resection and anastomosis due to necrosis.&#x0D; Conclusions: Small bowel intussusceptions are often localized in the paraumbilical and left upper quadrant. However, it should be kept in mind that it may be localized in the right lower quadrant like ileocolic invaginations. Enema reduction can be used as an adjunctive diagnostic method to exclude ileocolic invaginations rather than treatment in these patients. The diameter and length of the invaginated segment may be decisive in the surgical decision of the small bowel intussusception.

304 CORONARY COMPUTED TOMOGRAPHY ANGIOGRAPHY FOR THE ASSESSMENT OF SIROLIMUS-ELUTING RESORBABLE MAGNESIUM SCAFFOLD

Abstract Background Coronary computed tomography angiography (CCTA) is an established technique for non-invasive evaluation of the coronary arteries. Whereas artifacts limit the assessment of the stented vessels, studies supported its performance in vessels treated with first generation bioresorbable scaffold (BRS). Anatomical findings can be integrated with non-invasive fractional flow reserve (FFR-CT) to discriminate the presence or not of flow-limiting disease. After the failure of the first BRS generation, alternative platforms have been developed, including the second-generation resorbable magnesium scaffold (RMS). Ongoing studies investigate the long-term safety and effectiveness of RMS, but few evidence describes their performance with CCTA. Aims The present investigation aims to report the luminal measurement, FFR-CT assessment, and clinical outcomes, in the first patients treated with RMS in the Scaffold Implantation in Emilia-Romagna Plus Multi Absorbable Gears Intra Coronary (SHERPA-MAGIC) study. Methods As prespecified sub-study, patients underwent CCTA 18 months after RMS implantation. Three-dimensional models were reconstructed for simulation of coronary flow and pressure. FFR-CT analysis was performed using the DeepVessel FFR software (Keya Medical, Seattle, WA, USA). Results From December 2017 to July 2018, 34 patients underwent RMS implantation. After exclusion of 7 patients due to additional drug eluting stent (DES) implantation, poor CCTA quality and CCTA refusal, the population included 26 patients. Overall, 29 vessels were treated with 35 RMS. Median stent length was 25 [20-25] mm, with a median diameter of 3 [3-3.5] mm. Three-year follow-up was available for all patients. One patient received revascularization of the target vessel after 18-month CCTA. Another patient was admitted for atypical chest pain 12 months after index procedure. Quantitative analysis was feasible in all vessels (n=29). Complete RMS reabsorption was observed in 27 cases. Median minimal lumen diameter (MLD) and area (MLA) of the scaffolded segments were 2.5 [2.1-2.8] mm and 6.4 [4.4-8.4] mm2, respectively. Non-invasive FFR analysis was feasible in 23 vessels (80%). The causes for missing computation were artifacts and the incomplete documentation of the entire coronary artery. Median FFR-CT in the target vessels was 0.88 [0.81-0.91]. Ttwo target vessels showed a flow-limiting FFR-CT value. In the first case, the patient underwent coronary artery angiography. Invasive FFR confirmed a flow-limiting stenosis (FFR value 0.74), and a new PCI was performed. In the second case, the patient was asymptomatic in optimal medical therapy, and mid-distal LAD was involved (FFR-CT value 0.79). Conclusions In a highly selected population of patients undergoing RMS implantation with a standardized technique, CCTA is feasible and allows to discriminate long-term anatomical and functional performance of scaffolded segments.