Abdominal Aortic Bifurcation Research Articles

Subclinical association of aortic stiffness with cardiac structure and function in African-Americans: The Jackson Heart Study.

Cardiovascular disease (CVD) morbidity and mortality are high among black adults. We aimed to study the granular subclinical relations of aortic stiffness and left ventricular (LV) function and remodeling in blacks, in whom limited data are available. In the Jackson Heart Study, 1050 U.S. community-dwelling black adults without CVD underwent 1.5T cardiovascular magnetic resonance. We assessed regional and global aortic stiffness and LV structure and function, including LV mass indexed to body surface area (LVMI), end-diastolic volume (LVEDV), ejection fraction (EF), and global and regional circumferential strain (Ecc). Phase contrast images of the cross-sectional aorta at the pulmonary artery bifurcation and abdominal aorta bifurcation were acquired to measure pulse wave velocity of the aortic arch (AA-PWV) and thoracic aorta (T-PWV). Results of multivariable-adjusted analyses are presented as SD unit change in LV variables per SD change in PWV variables. Participants were 62% women with mean age of 59 ± 10years. Higher AA-PWV and T-PWV were associated with greater LVMI: for T-PWV, β = 0.10, 95% CI = 0.03-0.16, p = 0.002. Higher AA-PWV and T-PWV were associated with worse (more positive) Ecc at the LV base (for AA-PWV, β = 0.13, 95% CI = 0.05-0.20, p = 0.0007), but not mid-LV or apex. AA-PWV and T-PWV were not associated with LV mass/LVEDV or EF. In this cross-sectional study of blacks without CVD in the U.S., aortic stiffness is associated with subclinical adverse LV function in basal segments. Future studies may elucidate the temporal relationships of aortic stiffness on the pattern and progression of LV remodeling, dysfunction, and associated prognosis in blacks.

Variations in origin level of superior mesenteric artery, inferior mesenteric artery, and coeliac trunk in Indian population.

The abdominal aorta is a continuation of the thoracic aorta and gives off the coeliac trunk, superior mesenteric artery, and inferior mesenteric artery. The focus of our study is to evaluate variations in the origin level in the coeliac trunk, superior mesenteric artery, inferior mesenteric artery, and aortic bifurcation in the Indian population and compare with various demographics. The study was retrospective and the local ethics committee approval was taken before starting it. Three hundred patients who were more than 18 years of age and required contrast-enhanced CT studies were included in this. The vertebral origin level of the arteries from the abdominal aorta and aortic bifurcation level was analysed. The most common origin level of the coeliac trunk for both males and females was T12-L1 disc level. The most common origin level of the superior mesenteric artery was L1 upper level. The most common origin level of the inferior mesenteric artery was L3 upper level. The most common level of aortic bifurcation was L4 middle level. There was no statistical difference between the origin of any arteries in males and females in the Indian population. As per our study of the Indian population and the published literature, it is realized that there are significant variations in the origins of the coeliac trunk, superior mesenteric artery, inferior mesenteric artery, and abdominal aorta bifurcation in different populations. This study elaborates on potential anatomical variations in the Indian population, particularly the Mumbai city population. Also, our study compares it to different countries' data and their results in variations found in abdominal aorta branches.

A clinical case of surgical treatment of a child with aneurysms of the abdominal aorta and aortic bifurcation, superior mesenteric artery and multiple aneurysms of the main arteries

A brief literature review on abdominal aortic aneurysms in children and our own observation of surgical treatment of a 5-year-old child with an aneurysm of the abdominal aorta and aortic bifurcation, an aneurysm of the superior mesenteric artery, and multiple aneurysms of the arteries of the lower extremities has been presented in the paper. Staged replacement of the aortic aneurysm and superior mesenteric artery with synthetic polytetrafluoroethylene prostheses was performed. The features of surgical interventions, difficulties and complications that the authors encountered during the treatment of the child are described.

A Whole Spine MRI Based Study of the Prevalence, Associated Disc Degeneration and Anatomical Correlations of Lumbosacral Transitional Vertebra.

Retrospective cohort study. Lumbosacral transitional vertebra (LSTV) results in numerical alterations of the lumbar and sacral segments. Literature concerning true prevalence, associated disc degeneration, and variation in numerous anatomical landmarks concerning LSTV is lacking. This is a retrospective cohort study. The prevalence of LSTV was determined in whole spine MRIs of 2011 poly-trauma patients. LSTV was identified as sacralization (LSTV-S) or lumbarization (LSTV-L) and further sub-classified into Castellvi's and O'Driscoll's type respectively. Disc degeneration was evaluated using Pfirmann grading. Variation in important anatomical landmarks was also analysed. Prevalence of LSTV was 11.6% with 82% having LSTV-S. Castellvi's type 2A and O'Driscoll type 4 were the commonest sub-types. LSTV patients demonstrated considerably advanced disc degeneration. The median termination level of conus medullaris (TLCM) in non- LSTV and LSTV-L groups was at middle L1 (48.1% and 40.2%) while in the LSTV-S group, it was at upper L1 (47.2%). The median level of right renal artery (RRA) in non- LSTV patients was at middle L1 in 40.0% of individuals while in the LSTV-L and LSTV-S groups, it was at upper L1 level in 35.2% and 56.2% respectively. The median level of abdominal aortic bifurcation (AA) in non-LSTV and LSTV-S patients was at middle L4 in 83.3% and 52.04% respectively. However, in the LSTV-L group, the most common level was middle L5 (53.6%). The overall prevalence of LSTV was 11.6%, with sacralization accounting for more than 80%. LSTV is associated with disc degeneration and a variation in the levels of important anatomical landmarks.

Abstract 11095: Abdominal Paraganglioma: A Rare but Non-Negligible Etiology of Severe Dyspnea in Late Gestation

With a history of cesarean delivery of a dead baby at 36 weeks of pregnancy due to severe dyspnea two years ago, a 25-year-old woman with 32 weeks of pregnancy complained severe dyspnea again and was transferred to our emergency department. Her serum test showed extremely elevated NT-proBNP. Her echocardiography exhibited normal left ventricular ejection fraction (LVEF) but diffused myocardial hypertrophy/edema, resulting in decreased inner diameters in the left ventricle and left atrium, which is quite different from other diastolic heart dysfunctions usually showing an enlarged left atrium. After emergency cesarean delivery, her cardiac walls became thinner, and the left ventricle and atrium inner diameters increased correspondingly on echocardiography along with the relieved dyspnea, but the baby did not survive either. The prominent elevation in serum norepinephrine as well as the abdominal vascular ultrasound indicated the probability of a paraganglioma below the abdominal aorta bifurcation, which was finally confirmed by pathology. However, whole exome sequencing did not exhibit the usual gene mutation reported but exhibited the RYR2 heterozygous mutation in c.2642T>G, which was likely pathogenic according to bioinformatic analysis. Therefore, the severe dyspnea in her late gestation was due to the occupancy of the enlarged uterus on the paraganglioma below the abdominal aorta bifurcation, thus inducing considerable catecholamine excretion and the incidence of catecholamine cardiomyopathy (Takotsubo syndrome). To the best of our knowledge, this is the first report showing the special location of a paraganglioma exacerbated by pregnancy. The adverse pregnancy outcome emphasized the importance of the early diagnosis of paraganglioma-induced cardiomyopathy, which is rare and easily neglected by clinical obstetricians. Our case implicates that for pregnant patients with diastolic dysfunction who are contraindicated for cardiac MRI, the diffused myocardial hypertrophy/edema, especially the decreased left atrium inner diameter displayed in echocardiography, could suggest the incidence of paraganglioma-induced cardiomyopathy rather than other diastolic heart dysfunctions, such as hypertensive heart failure of pregnancy.

Changes in aortic diameter induced by weight loss: The HELENA trial- whole-body MR imaging in a dietary intervention trial.

Obesity-related metabolic disorders such as hypertension, hyperlipidemia and chronic inflammation have been associated with aortic dilatation and resulting in aortic aneurysms in many cases. Whether weight loss may reduce the risk of aortic dilatation is not clear. In this study, the diameter of the descending thoracic aorta, infrarenal abdominal aorta and aortic bifurcation of 144 overweight or obese non-smoking adults were measured by MR-imaging, at baseline, and 12 and 50 weeks after weight loss by calorie restriction. Changes in aortic diameter, anthropometric measures and body composition and metabolic markers were evaluated using linear mixed models. The association of the aortic diameters with the aforementioned clinical parameters was analyzed using Spearman`s correlation. Weight loss was associated with a reduction in the thoracic and abdominal aortic diameters 12 weeks after weight loss (predicted relative differences for Quartile 4: 2.5% ± 0.5 and -2.2% ± 0.8, p < 0.031; respectively). Furthermore, there was a nominal reduction in aortic diameters during the 50-weeks follow-up period. Aortic diameters were positively associated with weight, visceral adipose tissue, glucose, HbA1c and with both systolic and diastolic blood pressure. Weight loss induced by calorie restriction may reduce aortic diameters. Future studies are needed to investigate, whether the reduction of aortic diameters via calorie restriction may help to prevent aortic aneurysms.

Nodular leiomyoma of the uterus of giant size on the background of combined extragenital pathology (Case study)

The article presents a clinical case of nodular uterine leiomyoma of giant size on the background of type 2 diabetes mellitus, chronic hypertension and obesity with a classic picture of metabolic syndrome and the development of severe vascular pathology with steno-occlusive atherosclerotic lesions of the abdominal aorta bifurcation (Lerich’s syndrome) and acute circulatory disorders in the left lower extremity with gangrene of the toes of the left foot. The patient was hospitalized and comprehensively examined in the Department of Vascular Surgery of the Kyiv Regional Clinical Hospital (KRCH), which is the clinical base of the Department of Obstetrics and Gynecology №1 of the Shupyk National Healthcare University of Ukraine. The diagnosis was confirmed in the department and simultaneous two-stage surgery was successfully performed by gynecologists and vascular surgeons: first stage – pangysterectomy with revision of the abdominal organs and access to the abdominal aorta, second stage – thrombendarterectomy of the bifurcation of the abdominal aorta. In the postoperative period we restored peripheral blood flow, performed complete regression of ischemia, necrosis of the toes of the left foot dry, limited with a tendency to delimitation. Amputation of the first and second toes of the left foot was performed. Postoperative period was uneventful, on day 9 the patient was discharged home in satisfactory condition for further outpatient treatment. Diabetes mellitus type 2, chronic hypertension and obesity with a classic clinical picture of metabolic syndrome have led to the development of uterine leiomyoma and atherosclerotic changes in the abdominal aorta and main vessels of the lower extremities (Lerich’s syndrome). The successful outcome of this clinical case was made possible by the coordinated work of a multidisciplinary team of KRCH specialists both at the stage of comprehensive examination and diagnosis, and during simultaneous surgery.

"Two spaces" lateral lymph node dissection based on fascia anatomy for low rectal cancer

As a treatment of rectal cancer, lateral lymph node dissection (LLND) is still a controversial issue. The argument against LLND is that the procedure is complicated, and consequently results in a high incidence of postoperative urogenital dysfunction. The surgical modality from fascia to space is adopted by lateral lymph node dissection in "two spaces". This operation has significant advantages of clear location of nerves and blood vessels and simplified surgical procedures, so the surgical procedure can be repeated and modulated. The fascia propria of the rectum, urogenital fascia, vesicohypogastric fascia and parietal fascia constitute the dissection plane for lateral lymph node dissection.Two spaces refer to Latzko's pararectal space and paravesical space. During the establishment of fascia plane, the dissection of external iliac lymph node (No.293), commoniliac lymph node (No.273) and abdominal aortic bifurcation lymph node (No.280) can be performed. While in the "space" dissection, internal iliac lymph node (No.263), obturator lymph node (No.283), lateral sacral lymph node (No.260) and median sacral lymph node (No.270) can be removed. LD2 or LD3 lateral lymph node dissection prescribed by the Japanese Society of Colorectal Cancer can be completed according to the needs of the disease. This article describes the anatomical basis and standardized surgical procedures.

Leriche syndrome diagnosed due to polytrauma: a case report

BackgroundLeriche syndrome is caused by atherosclerosis and is often characterized by symptoms such as intermittent claudication and numbness and coldness of the lower limbs. Its exact prevalence and incidence are unknown because it is a rare disease. We report a case of Leriche syndrome diagnosed incidentally on trauma pan-scan computed tomography (CT).Case presentationA 61-year-old Asian male was driving a passenger car and had a head-on collision with a dump truck that required an emergency call. The patient was transported to our hospital in a doctor’s helicopter. Physical examination revealed the following vital signs: respiratory rate, 23 breaths per min; SpO2, 98% under a 10-L administration mask; pulse rate, 133 beats per min; blood pressure, 142/128 mmHg; Focused Assessment with Sonography for Trauma, positive; Glasgow Coma Scale assessment, E3V5M6; and body temperature, 35.9 °C.Trauma pan-scan CT showed bilateral mandibular fractures, bilateral multiple rib fractures, bilateral pneumothorax, sternal fractures, hematoma around thoracic spine, small bowel perforation, mesenteric injury, right clavicle fracture, right ankle debridement injury, and thrombotic occlusion from just above the abdominal aortic bifurcation to the bilateral common iliac arteries. Although thrombotic occlusion needed to be differentiated from traumatic aortic injury, the presence of collateral blood vessels led to the diagnosis of Leriche syndrome, and conservative treatment was performed.Damage control surgery was required for the small bowel injuries. From the second day of admission, the patient was treated with continuous intravenous heparin and prostaglandin preparations. However, impaired blood flow and reperfusion injury in the right lower extremity progressed. On the fifth day of admission, right thigh amputation was performed. The patient required renal replacement therapy for 2 weeks starting from the third day of admission.ConclusionsIn this case, conservative therapy was initially chosen for Leriche syndrome. However, the complex factors in the acute phase of trauma led to development of hemorrhagic necrosis, requiring amputation of the lower extremity. Our findings indicate the need to carefully consider the unique factors affecting Leriche syndrome patients when considering treatment indications and choices for trauma.

Experimental study of the flow in the elastic model of the abdominal aortic bifurcation

This paper reflected preliminary results of physical modeling of pulsating flow in a model of abdominal aortic bifurcation with taking into account the physiological elasticity of the vessel walls. Elastic vessel models were made via molding from a silicone mixture based on Lasil-T4 silicone rubber. The auxiliary study was performed to assess the elastic properties of the silicone mixture and select a necessary composition. The experiment on the pulsating flow in the rigid and elastic models of the abdominal aortic bifurcation was carried out using a blood flow simulator with circulation of blood-emulating fluid. It was revealed that interaction between the elastic model and closed rigid circuit of the blood flow simulator resulted in generation of intense parasite flow oscillations and prevented from getting similar flow conditions for rigid and elastic models. A way to solve the problem is to include dampers with liquid in the hydraulic circuit of the blood flow simulator at the inlet and the outlets of the elastic model.

Wall Shear Stress-Based Hemodynamic Descriptors in the ‎Abdominal Aorta Bifurcation: Analysis of a Case Study

The knowledge of hemodynamic behaviour in the abdominal aorta artery bifurcation is of great ‎importance for the early diagnosis of several cardiovascular diseases common in this bifurcation. The ‎work developed focuses on a case study of hemodynamic in the abdominal aorta artery bifurcation, ‎based on a realistic 3D geometric model reconstructed from 2D medical images of a real patient. ‎Hemodynamic quantities based on the wall shear stress (WSS) of the abdominal aorta bifurcation are ‎analysed and is presented an alternative analysis of the well-established stress hemodynamic descriptors ‎to identify specific zones of the artery with a higher probability of developing cardiovascular diseases. ‎The individual analysis of different zones of the artery allowed to obtain information that can remain ‎masked when whole artery is considered as a single zone. The reported results provide a correlation ‎between the analysed stress hemodynamic descriptors and the area of the wall artery. Then, the aim of ‎this work is the identification of regions at the luminal surface subject to atherosusceptible WSS ‎phenotypes. For the patient studied, the analysis presented allowed the identification of the patient's ‎propensity to develop atherosclerosis, according to the hemodynamic descriptors time-averaged WSS ‎‎(TAWSS), oscillatory shear index (OSI), and relative residence time (RRT). Thus, this work offers a new ‎way of looking to the stress hemodynamic descriptors.‎

Extrasystolic arrhythmia as a risk factor of atherosclerosis

Abstract Funding Acknowledgements Type of funding sources: None. Aim To determine the relationship between hemodynamic changes in extrasystolic arrhythmia and atherosclerosis of main arteries. Materials and methods We included 286 patients (175 men and 111 women). The investigation was made to reveal the signs of atherosclerosis. All patients were performed 24-hours ECG monitoring, blood lipid spectrum, TTE, TOE, ultrasound doppler of brachiocephalic arteries, abdominal aorta branches, lower extremities arteries, renal arteries. If prescribed - stress Echo, coronary angiography, renal arteries angiography, pancerebral angiography. All patients were made apexcardiography (ACG) and arterial vessels sphygmography (SG) of aa. carotis, ulnaris, radialis, femoralis, tibialis posterior. The main parameters included speed, acceleration, power, work in each phase of cardiocycle. In accordance with amount of extrasystoles per 24 hours all the patients were divided into 2 groups: 1 – less than 3000 (144 patients), 2 – 3000 and more (142). They were grouped due to the age (see table 1 on the picture). Groups were common in age, sex, comorbidities. Results In group 2 the development and severity of atherosclerosis was more in group 2 (see table 2 on the picture). We determined the hemodynamic main parameters increase in first post-extrasystolic contraction with the following tendency: if earlier extrasystole appeared in cardiocycle, than more changes were observed. Conclusion Extrasystoles are additional risk factors of atherosclerosis. Hemodynamic changes after the first post-extrasystolic contraction is the important mechanical trauma factor for the arterial vessels which can take part in atherosclerotic process. Weak places – carotid bifurcation, abdominal aorta bifurcation, large radius of aorta arch. We suppose that it’s necessary to treat the extrasystoles more than 3000 per 24 hours that appear early in cardiocycle (before the mitral valve opening and before the transmitral blood flow peak).

Feasibility of anterior pedicle screw fixation in lumbosacral spine: a radiographic and cadaveric study

BackgroundThe anterior pedicle screw (APS) technique for L5 and S1 is crucial for proper anterior lumbar interbody fusion (ALIF). This study aimed to determine the projection, screw trajectory angle, and bone screw passageway length (BSPL), as well as the screw insertion regularity and the operating area within which it is safe to perform insertion.MethodsForty patients with low back pain, all of whom had lumbar computed tomography scans available, was included in this retrospective analysis. Radiographic parameters were measured, including: the distances from the projection to the upper endplate, lower endplate, and midline; the transverse and sagittal screw angles; and the BSPL. In addition, 10 fresh adult cadaveric lumbosacral spine segments were selected to determine the safe anatomic area in which to operate. Finally, APSs were inserted in L5 and S1 to determine the regularity of APS insertion.ResultsWe measured the anterior projection parameters, including: the distances to the upper endplate (L5: 12.5±1.3 mm; S1: 4.54±0.87 mm), lower endplate (L5: 17.3±1.6 mm), and midline (L5: 6.6±0.7 mm; S1: 6.6±0.6 mm); the screw trajectory angle, including the transverse screw angle (L5: 25.3±2.8°; S1: 25.7±2.6°), sagittal screw angle (L5: 17.1±1.7°; S1: 22.4±1.1°); and the BSPL (L5: 48.6±3.5 mm; S1: 48.0±3.5 mm). The regularity of APS insertion in L5 and S1 was determined. Upon the needle reaching a point in the lateral view, it reached the corresponding point in the anteroposterior (AP) view. The anatomic parameters of the safe operating area were as follows: the distance from the abdominal aortic bifurcation to the L5 lower edge (40.50±9.40 mm); the distance from the common iliac vein confluence to the L5 lower edge (27.80±8.60 mm); and the horizontal distance from the inner edge of the common iliac vein to the L5 lower edge (37.50±1.30 mm). We also determined the distance between S1 holes (29.30±1.30 mm), the L5/S1 intervertebral height (17.20±1.50 mm), and the safe operating area (2,058.20±84.30 mm2).ConclusionsThis study has determined the projection, screw trajectory angle, and BSPL of APSs in L5 and S1, their insertion regularity, and the area in which the operation can be safely performed.

Effects of inlet velocity profile on the hemodynamics of the abdominal aorta bifurcation

Effects of inlet velocity profile on the hemodynamics of the abdominal aorta bifurcation

False Lumen Stent-Grafts for Repair of Postdissection Aortic Aneurysms

PurposeTo evaluate the safety and efficacy of false lumen (FL) stent-grafts in the treatment of postdissection aortic aneurysms. Materials and MethodsEleven patients who underwent endovascular repair using FL stent-grafts from January 2016 to June 2019 were included. Among them, 2 patients had a prior history of type A aortic dissection, whereas 9 had undergone a prior endovascular repair for type B aortic dissection. Computed tomography angiography was performed to evaluate the reintervention and technical success rate, aortic remodeling, and other related aortic complications. ResultsThe mean age of patients was 55.6 ± 10.4 years. Technical success was achieved in all patients, and neither early mortality nor paralysis occurred. In total, 8 visceral branch arteries originating from the FL were reconstructed. The true lumen areas at the celiac axis, superior mesenteric artery, renal artery, and abdominal aortic bifurcation were significantly increased from 230.1 mm2 to 312.3 mm2, 212.1 mm2 to 277.5 mm2, 209.1 mm2 to 291.6 mm2, and 214.4 mm2 to 300.6 mm2, respectively (P < .05). The total diameter of the aorta at the 4 designated levels was stable or had shrunk in all patients. At a mean follow-up of 18.9 ± 7.6 months, 1 patient received re-intervention owing to iliac stent-graft occlusion. No aortic-related mortality occurred. ConclusionsFL stent-grafts can safely and effectively treat patients with postdissection aortic aneurysms. This strategy can be used to promote thrombosis of the FL and aortic remodeling. A larger sample and an extended follow-up period are needed to produce more conclusive results.

Surgical treatment of mega aorta syndrome: a single-center experience

To present our experience in the treatment of severe patients with mega aorta syndrome. There were 49 patients with mega aorta syndrome for the period from May 2015 to March 2021. All patients underwent total aortic replacement from sinotubular junction (with staged aortic root repair, if necessary) to abdominal aorta bifurcation. All surgeries were elective. All patients were divided into two groups: group I (n=33; 67.3%) - staged replacement, group II (n=16; 32.7%) - one-staged replacement of the aorta via thoracophrenolumbotomy. The primary endpoints were mortality, perioperative parameters and complications. We also analyzed long-term freedom from aortic redo surgery and survival rate. Both groups were comparable by pre-, intra- and postoperative parameters. The interval between surgeries for staged approach was 7.1±2.3 months. Rehabilitation time considering two stages was longer in group I (13±2 vs. 5.5±1.1 months, p=0.0001). Between-stage mortality rate was 12% (n=4). Intraoperative mortality was absent in both groups. In-hospital mortality was 3% and 12% (p=0.25), overall mortality with between-stage interval - 10.2% and 12% (p=1.000), respectively. The follow-up period was similar (18±22.7 (range 1-71) and 23.3±19.1 (range 1-51) months, respectively (p=0.63)). In group I, 1-year, 3-year and 5-year survival rate considering between-stage mortality was 89% (95% CI 78-100%), 77.1% (95% CI 60.1-98.8%), 77.1% (95% CI 60.1-98.8%), respectively. In group II, 1-year and 3-year survival rate was 86.5% (95% CI 70.5-100%), plog-rank=0.88. Overall freedom from redo surgery was 92.9% (95% CI 80.3-100%) vs. 90.9% (95% CI 75.4-100%), plog-rank=0.072. One-stage total aortic replacement via thoracophrenolumbotomy is safe surgical treatment for mega aorta syndrome, especially in young patients with low surgical risk. Favorable outcomes may be expected in specialized centers with extensive experience in aortic surgery. Compared to staged approach, total aortic replacement eliminates the risks of between-stage aortic rupture. Therefore, it is a worthy alternative to other methods.

Numerical simulation of the spatio-temporal evolution of the flow in the model of abdominal aorta bifurcation with stenosis in the one of the common iliac arteries

The structure of the pulsating flow in the model of the average configuration, including the bifurcation of the abdominal aorta and subsequent bifurcation of the iliac arteries with axisymmetric hemodynamically significant stenosis in the right common iliac artery, is researched by numerical method. It has been shown that the presence of stenosis in this artery affects the flow structure both downstream and upstream: reverse-flow zones are formed and transverse flow evolution differs significantly from the structure of the flow in a healthy branch. The stenosis with the spatial curves of the model leads to the formation of a stable single-vortex flow in the external iliac artery most of the cardiac cycle. In the mentioned artery of the healthy branch various unstable patterns of two-vortex structure form during the cycle. In both internal iliac arteries, there is a transitional flow, from a two-vortex to a single-vortex motion, forms during the cycle. The influence of the presence of stenosis on the structure of the transverse flow in the internal iliac artery is insignificant. The most likely regions for atherosclerotic lesions of the vascular wall, characterized by the minimum values of time-averaged wall shear stresses and the maximum values of oscillatory shear index, are the stenosis region and the external wall of the common iliac artery.

Evaluation of inferior mesenteric vessel and ureter by contrast-enhanced abdominal pelvic CT and its clinical influence on laparoscopic rectal surgery

Objective: To assess the anatomic relationship of inferior mesenteric artery (IMA)/inferior mesenteric vein (IMV) with ureter by contrast-enhanced abdominal pelvic CT, in order to provide guidance for vascular management and ureteral protection in laparoscopic rectal surgery. Methods: A retrospective cohort study was conducted. Image data of contrast-enhanced abdominal pelvic CT at Department of Medical Radiography of Peking University First Hospital in November 2018 were enrolled. Exclusion criteria: (1) previous history of abdominal or pelvic surgery; (2) scoliosis deformities; (3) missing images; (4) minors; (5) inferior mesenteric vascular disease or tumor involvement resulting in suboptimal imaging; (6) poor image quality. Finally, contrast-enhanced abdominal pelvic CT data of 249 cases were collected, including 120 males and 129 females with mean age of (60.1±13.4) years. Multi-planar reconstruction (MPR) and maximum intensity projection (MIP) were used to evaluate the anatomic relationship of IMA/IMV with ureter. IMA root location, IMA length, branch types of IMA, distance between major branches, distance between IMA/IMV and ureter at the level of root of IMA, left colic artery (LCA) root, abdominal aortic bifurcation, and sacral promontory were measured and association between IMA/IMV and ureter site was summarized. Results: The distance from IMA root to the aortic bifurcation and sacral promontory was (42.0±8.5) mm and (101.8±14.0) mm, respectively. The length of IMA was (38.5±10.7) mm. The proportion of IMA roots locating at levels of the 2nd, 3rd, and 4th lumbar vertebra was 3.2% (8/249), 79.5% (198/249), and 17.3% (43/249), respectively. The higher the level of the lumbar vertebra, the longer the IMA [length of IMA originating from the 2nd, 3rd, 4th lumbar vertebra level: (42.4±10.9) mm, (39.5±10.4) mm, (33.0±10.9) mm, respectively; F=7.48, P<0.001]. In 111 cases (44.6%), LCA arose independently from IMA (type 1), and the distance between LCA and the first branch of sigmoid artery (SA) was (15.0±7.4) mm; in 56 cases (22.5%), LCA and SA had a common trunk (type 2), with a length of (11.0±8.5) mm; in 78 cases (31.3%), LCA branched with SA at the same point (type 3); LCA was absent in 4 cases (1.6%)(type 4). The length of IMA in LCA-deficient type 4 was (54.8±18.0) mm, which was longer than (38.2±10.5) mm in LCA-presence type (type 1, type 2 and type 3) and the difference was statistically significant (t=-3.11, P=0.002). The distance between the ureter and IMA was the longest at the level of IMA root [(35.7±8.1) mm], was the shortest at the level of the aortic bifurcation [(22.4±6.4) mm], and the distance between the ureter and IMA in different planes was significantly different (F=185.70, P<0.001). The distance between the ureter and IMV was the longest at the level of the sacral promontory [(21.1±9.0) mm], was the shortest at the level of LCA root [(12.0±5.7) mm], whose difference was also statistically significant (F=87.66, P<0.001). Conclusions: CT post-processing techniques including MPR and MIP can efficiently and accurately assess the branch types of IMA and anatomical relationship between IMA/IMV and ureter, and provide insights into laparoscopic rectal surgery for surgeons. IMA/IMV and ureter depart farthest at the level of IMA root. Artery first and plane second strategy in the middle approach of laparoscopic rectal surgery is considerable and feasible.

Aortic and iliac thrombosis in a dog with adrenal-dependent hypercortisolism due to bilateral adrenocortical adenoma

ABSTRACT: Hypercortisolism is a common endocrinopathy in dogs; however, in a few cases, bilateral functional adrenocortical adenomas cause spontaneous disease, and thrombotic events are considered uncommon complications. The aim of this report was to describe a case of bilateral adrenocortical adenoma in a dog with hyperadrenocorticism associated with distal aortic and iliac thrombosis, with emphasis on clinical and pathological aspects. A 15-year-old spayed female Dachshund with a previous clinical history of hyperadrenocorticism presented with acute bilateral hindlimb paraparesis. A vertebral thoracolumbar radiography was performed and did not present any evidence of intervertebral disk disease or vertebral abnormalities; however, abdominal ultrasound and vascular Doppler evaluation revealed bilateral adrenal enlargement in addition to an aortic and external iliac artery thrombus. The animal was euthanized. At necropsy, both adrenal glands were enlarged by well-demarcated neoplastic nodules in the parenchyma, and a thrombus caudal to the abdominal aorta bifurcation within the external iliac arteries that extended to the left external iliac artery was noted. Histological evaluation revealed a well-differentiated neoplastic proliferation of cortical epithelial cells, consistent with bilateral adenoma, and muscular necrosis in the pelvic limbs was also observed. Bilateral functional adrenocortical adenoma; although, very rare, should be considered as a cause of hypercortisolism, and aortic thrombosis in dogs should be considered as a possible consequence.

Numerical study of blood flow in the spatial model of the abdominal aorta bifurcation: effect of an inlet conditions

The structure of the flow in a model configuration including a healthy bifurcation of the abdominal aorta, common, external and internal iliac arteries is investigated by a numerical method. It has established that the structure of the flow in the common, external and internal iliac arteries is characterized by a two-vortex secondary flow structure, and only in the phase of return flow, a single-vortex secondary flow develops at the exit of the internal iliac arteries. The influence of the inlet velocity profile skewness is significant only in the region upstream of the actual abdominal aorta bifurcation. In the iliac arteries, the influence of the inlet velocity profile shape is felt only through relatively weak changes in the cross-flow velocity field. Introducing a significant non-uniformity in the inlet velocity distribution does not change significantly general estimates of the minimum values of the cycle-averaged wall shear stress, TAWSS, and maximum values of the oscillation wall-shear index, OSI. This information is important for identification of the places mostly exposed to atherosclerotic vascular lesions for atherosclerotic lesions.