Methods for Three-Dimensional Geometric Characterization of the Arterial Vasculature

Complex vascular anatomy often affects endovascular procedural outcome. Accurate quantitative assessment of three-dimensional (3D) in-vivo arterial morphology is therefore vital for endovascular device design, and preoperative planning of percutaneous interventions. The aim of this work was to establish geometric parameters describing arterial branch origin, trajectory, and vessel curvature in 3D space that eliminate the errors implicit in planar measurements. 3D branching parameters at visceral and aortic bifurcation sites, as well as arterial tortuosity were determined from vessel centerlines derived from magnetic resonance angiography data for three subjects. Errors in coronal measurements of 3D branching angles for the right and left renal arteries were 3.1 ± 3.4° and 7.5 ± 3.7°, respectively. Distortion of the anterior visceral branching angles from sagittal measurements was less pronounced. Asymmetry in branching and planarity of the common iliac arteries was observed at aortic bifurcations. The renal arteries possessed considerably greater 3D curvature than the abdominal aorta and common iliac vessels with mean average values of 0.114 ± 0.015 and 0.070 ± 0.019 mm⁻¹ for the left and right, respectively. In conclusion, planar projections misrepresented branch trajectory, vessel length, and tortuosity proving the importance of 3D geometric characterization for possible applications in planning of endovascular interventional procedures and providing parameters for endovascular device design.     

3D morphometric analysis of the arterial switch operation using in vivo MRI data

The arterial switch operation (ASO) is widely used nowadays as the surgical strategy of choice to repair transposition of the great arteries (TGA). Residual morphological and geometrical abnormalities of the aorta, pulmonary arteries and coronary arteries, however, have not been fully studied in a three‐dimensional (3D) domain. These morphometric complications might have implications on long‐term outcomes of ASO patients, hence the need to explore them in detail and study them with reference to healthy controls of comparable age and body surface area. These anatomical characteristics were examined using 3D patient‐specific anatomical models reconstructed from cardiovascular magnetic resonance (CMR) images of 20 ASO patients (mean age 14.4 ± 2.4 years, 16 males and 4 females) compared with healthy controls (mean age 15.2 ± 2.0 years, 17 males and 3 females). It was found that the aorta, pulmonary arteries and re‐implanted coronary arteries of ASO patients were significantly different morphologically and geometrically to those of healthy controls. In particular, the aortic root was dilated, with abnormal 3D angulation and additional acute angulation of the curvature of the aortic arch in the ASO group compared with controls. This could theoretically impinge on aortic flow profiles and physiological stresses, which can act as a primer for the development of early atherosclerotic disease in the ASO population. Clin. Anat. 27:1212–1222, 2014. © 2014 Wiley Periodicals, Inc.     

An anatomical study on the lingual–facial trunk

Purpose  We quantified variations of the lingual artery origin, measured the lingual artery origin distance from clinical relevant landmarks and compared the lingual artery diameters with normal and variable origin. Methods  Forty-two formalin fixed male cadavers were bilaterally evaluated. Measurements were performed with the aid of an electronic digital caliper. Results  The origin distances from the common carotid artery bifurcation was 1.05 ± 0.11 and 1.02 ± 0.11 cm for the right and left lingual arteries respectively with no differences compared to the lingual–facial trunks. The diameters of the lingual arteries were 0.25 ± 0.01 and 0.26 ± 0.01 cm for the right and left sides, respectively, while the lingual–facial trunks showed diameters of 0.21 ± 0.02 and 0.24 ± 0.02 cm for the right and left sides, respectively. Conclusions  The present study adds information on the lingual artery diameter and its anatomical relation to clinically useful landmarks.     

High bifurcation of abdominal aorta upon horseshoe kidney at the level of upper L2 vertebral body: a rare case report

A high-positioned bifurcation of abdominal aorta upon a horseshoe kidney at the level of upper L2 vertebral body was detected during contrast enhanced abdominal computed tomography scan. The isthmus was clamped between the two elevated and extended common iliac arteries. The right renal artery arose from right common iliac artery supplying the superior and medium segments of right kidney. The left renal artery originated from right common iliac artery and branched off into three main arteries supplying the medium segment of right kidney, the inferior segment of right kidney and the lower half part of left kidney, respectively. The left accessory renal artery arose from abdominal aorta supplying the upper half part of left kidney. The inferior mesenteric artery arose from right common iliac artery. Lumbarization anomaly, scoliolosis, asymmetric pelvis and serious hydronephrosis of left kidney were also found. We describe this rare case of variations and discuss the possible embryonic development mechanism.     

腹主动脉杈处的形态观察及力学分析

对87例尸体腹主动脉权的形态进行标定,拍照,通过MYPAD-A_3 K_(510)数字化仪及IBM PC/XT计算机进行参数统计、分析。结果为:①左、右髂总动脉口径无性别、年龄差异;③腹主——髂总动脉分权角左侧大于右侧;③左、右支分支角与相应侧腹主——髂总动脉密切圆半径呈负相关。本文从流体力学角度阐明血管形态与流体间关系,并探讨腹主动脉瘤形成的力学机理。     

An extremely rare bifurcation pattern of the caudal abdominal aorta: case report demonstrated by angiography

An extremely rare bifurcation pattern at the caudal abdominal aorta was encountered on the pelvic angiography and MR angiography of a male patient. Instead of dividing into two common iliac arteries, the caudal abdominal aorta first gave the right external iliac artery at the level of the last lumbar arteries, then bifurcated into a right internal iliac artery and a left common iliac artery. The median sacral artery originated at this anomalous bifurcation. This high origin of the right external iliac artery and separate branching of these right iliac vessels from the abdominal aorta are important during the interventions in the region. We present the angiography findings and discuss the embryological origin of this unusual and unreported congenital anomaly.     

Ectopic kidney with varied vasculature: demonstrated by CT angiography

An ectopic kidney was found incidentally in a 20-year-old male patient during the abdominopelvic CT angiography. It was situated on the right side at the abdominopelvic junction, partly in the abdomen at the level of the intervertebral disc between L3 and L4 superiorly and partly in the greater pelvis at the level of the promontorium and close to the inferior border of the sacroiliac joints. It was supplied by two arteries which were nearly in the same caliber, and each of which branched from the common iliac arteries both close to the aortic bifurcation. There were two renal veins. The larger one which was emerging from the lateral part of the ectopic kidney was draining into the inferior vena cava. The smaller one which was the only hilar vessel of the ectopic kidney was draining into the left common iliac vein. The orthotopic left kidney was also supplied by two arteries from the abdominal aorta. Ectopic kidneys pose a problem for any planned surgical intervention given their anomalous blood supply. Ectopic position and varied vasculature can predispose to iatrogenic trauma during interventional radiological and laparoscopic procedures, and emergency operations.     

The anatomical relationship of the aortic bifurcation to the lumbar vertebrae: a MRI study

The objective of this study was to determine the level of the aortic bifurcation in relation to the lumbar spine by MRI and the effect of lumbosacral anomalies on the aortic bifurcation. A prospective study of 441 patients was performed. Sagittal MR images of the entire spine were obtained along with the standard protocol for imaging of the lumbar spine. The vertebrae were counted caudally from C2 instead of cranially from the presumed L5 vertebra. The aortic bifurcation in relation to the lumbar vertebrae was determined. The aorta bifurcated at the L4 vertebral body in 67% of cases. In patients with sacralization of L5 the aortic bifurcation was at the L3 vertebral body in 59%. In those patients with lumbarization of S1 the aorta bifurcated at the level of the L4 vertebral body in 40% and at the L4/5 disc space in 33%. There was no demographic variation of the aortic bifurcation in relation to age or sex. The aorta bifurcated at L4 in two-thirds of cases and was variably located in the remaining third. The stability of this as a landmark is disturbed by the significant high incidence of lumbosacral transitional segments.     

Clinical anatomy study of autonomic nerve with respective to the anterior approach lumbar surgery

Introduction  Male genital dysfunction was recognized as a complication following anterior approach lumbar surgery. Disruption of efferent sympathetic pathways such as the abdominal aortic plexus (AAP) and superior hypogastric plexus (SHP) which lied pre-abdominal aorta and iliac artery had been thought as the main reason. Though there were some clinical reports of retrograde ejaculation, the applied anatomic study of the autonomic nerve anterior to the lumbar was little. The purpose was to find out a lumbar surgery approach which was ejaculation preservation through the detailed study of the anatomy and histology observation of the autonomic nerve anterior to the lumbar vertebrae. Methods  The lumbar region of ten male cadavers was dissected and analyzed. We investigated the relationship between the peritoneum and abdominal aorta, iliac artery and sacral promontory fascia, as well as the trend and distribution of the autonomic nerve and SHP anterior to the L5-S1. We also observed the distribution of autonomic nerve at retroperitoneum through hematoxylin and eosin (HE)-stained tissues pre-aorta, para-aorta, and pre-vertebrae sacrales. Results  Superior hypogastric plexus, which deviated to left, located in a triangle formed by the common iliac arteries and its bilateral branches, its truck sited anterior to the lumbarsacral space in seven cases (70%), and anterior to sacrum in three cases (30%); at the aortic bifurcation, SHP strided over left iliac artery from left-hand side, then located in front of sacrum in four cases (40%), and sifted to the left at the lumbar sacral promontory in six cases (60%); from both anatomic and histological view, the autonomic nerve plexus lying in an fascia layer of retroperitoneum. Conclusion  At the anterior approach lumbar surgery of trans-peritoneum, we should choose the right-hand side incision; the SHP should be pushed aside carefully from right to left along intervertebral disc. The accurate surgical plane was at the deeper layer of autonomical nerve fascia; we also could lift the complete autonomical nerve layer which lies behind the aorta and lumbar sacral promontory, so that the autonomic nerve could be preserved.     

Emergence and distribution of the ilioinguinal nerve in the inguinal region: applications to the ilioinguinal anaesthetic block (about 100 dissections)

The variations in the emergence and distribution of the ilioinguinal nerve are the cause of the failures of the ilioinguinal block and the difficulties at interpreting the ilioinguinal nerve syndrome. In order to identify its variations and set reliable anatomical landmarks for performing the ilioinguinal block, we dissected 100 inguinal regions of 51 adult corpses. The nerve was absent in seven cases and double in one case. The ilioinguinal nerve emerged from the internal oblique muscle, passing at 1 ± 0.8 cm of the inguinal ligament and 3.33 ± 2 cm of the ventral cranial iliac spine. It appeared behind the inguinal ligament and/or the ventral cranial iliac spine in 19 cases and presented a common trunk with the iliohypogastric nerve in 13 cases. In 47 cases, the nerve appeared in the form of a single trunk. Sixteen modes of division and eight types of predominantly anterior scrotal topographic distribution could be noted. These results show the high variability of the emergence and the sensory distribution of the ilioinguinal nerve. They enable us to propose techniques for ilioinguinal block performance using more accurate anatomical landmarks formed by the inguinal ligament and the ventral cranial iliac spine and a better diagnostic approach of ilioinguinal neuropathies.     

Flow changes in the aorta associated with the deployment of a AAA stent graft

The purpose of this study was to investigate the hemodynamic implications of a proximal shift in the aortic bifurcation that results from abdominal aortic aneurysm (AAA) stent graft deployment. A flow model was constructed in which an anatomically accurate model of the aorta was subjected to physiologic pulsatile flow. The model included the celiac, superior mesenteric, left and right renal arteries. The aortic bifurcation, leading to the right and left iliac arteries was included, as well as the lumbar curvature. Flow simulations were performed under resting and mild exercise conditions with and without a Cordis AAA stent graft deployed. Flow patterns were visualized with dye injection and recorded onto video. The flow rates through the iliac and renal arteries were continuously monitored using ultrasonic flowmeters. Flow visualization revealed that flow disturbances at the level of the renal arteries were slightly increased with the deployment of the stent graft. The orientation of the endolegs within the aorta had no perceptible effect on these disturbances. Under mild exercise conditions, very little flow disturbance was observed. In conclusion, there are slight changes in flow disturbance near the renal arteries due to stent graft deployment, but these changes would not be expected to have significant clinical implications.     

Revisiting thoracic surface anatomy in an adult population: A computed tomography evaluation of vertebral level

To compare key thoracic anatomical surface landmarks between healthy and patient adult populations using Computed Tomography (CT). Sixteen slice CT images of 250 age and gender matched healthy individuals and 99 patients with lung parenchymal disease were analyzed to determine the relationship of 17 thoracic structures and their vertebral levels using a 32‐bit Radiant DICOM viewer. The structures studied were: aortic hiatus, azygos vein, brachiocephalic artery, gastroesophageal junction (GEJ), left and right common carotid arteries, left and right subclavian arteries, pulmonary trunk bifurcation, superior vena cava junction with the right atrium, carina, cardiac apex, manubriosternal junction, xiphisternal joint, inferior vena cava (IVC) crossing the diaphragm, aortic arch and junction of brachiocephalic veins. The surface anatomy of all structures varied among individuals with no significant effect of age. Binary logistic regression analysis showed a significant association between individual health status and vertebral level for brachiocephalic artery (P = 0.049), GEJ (P = 0.020), right common carotid (P = 0.009) and subclavian arteries (P = 0.009), pulmonary trunk bifurcation (P = 0.049), carina (P = 0.004), and IVC crossing the diaphragm (P = 0.025). These observations differ from those reported in a healthy white Caucasian population and from the vertebral levels of the IVC, esophagus, and aorta crossing the diaphragm in an Iranian population. The differences observed in this study provide insight into the effect of lung pathology on specific thoracic structures and their vertebral levels. Further studies are needed to determine whether these are general changes or pathology‐specific. Clin. Anat. 30:227–236, 2017. © 2017 Wiley Periodicals, Inc.     

Anterior retroperitoneal rami: Until now unnamed direct branches of the abdominal aorta

The aim of the study was to gain a thorough knowledge of the topography and distribution of until now officially unnamed minute direct branches from abdominal aorta, stemming from its ventral and lateral aspects, supplying surrounding tissue, and to comprise it to the existing studies. The study was performed in fixed cadaverous material collected from India ink injections of abdominal aorta samples with large surrounding retroperitoneal tissue. The 25 samples were dissected under magnifying binocular glass, followed by graphic reconstruction; statistical analysis, and the study was preceded with detailed review of branches from abdominal aorta. For systematization of the segmental anatomy of the abdominal aorta and infrarenal segment of inferior vena cava, we defined three levels in this area. The retroperitoneal branches were most frequently situated simultaneously within all three predefined levels according to renal and inferior mesenteric arteries origin. There were 18% of retroperitoneal branches within Level 1, 39% within Level 2 and 43% within Level 3. They were branches not only from the abdominal aorta, but also from the testicular/ovarian artery, common iliac artery and in one case from the right accessory renal artery. Paired arrangement was recorded mainly cranially to the origin of inferior mesenteric artery, unpaired branches were more frequently found caudally. In conclusion, due to the terminological disunity of these arteries in the clinical literature and total absence in the anatomical literature, we propose to denominate them as anterior retroperitoneal branches of abdominal aorta (rami retroperitoneales anteriores aortae abdominalis). Clin. Anat. 27:894–899, 2014. © 2014 Wiley Periodicals, Inc.     

Anatomical significance in aortoiliac occlusive disease

Aortoiliac occlusive disease is a subset of peripheral arterial disease involving an atheromatous occlusion of the infrarenal aorta, common iliac arteries, or both. The disease, as it is known today, was described by the French surgeon René Leriche as a thrombotic occlusion of the end of the aorta. Leriche successfully linked the anatomic location of the occlusion with a unique triad of symptoms, including claudication, impotence, and decreased peripheral pulses. The anatomical location of the atheromatous lesions also has a direct influence on classification of the disease, as well as choice of treatment modality. Considering its impact on diagnosis and treatment, we aimed to provide a detailed understanding of the anatomical structures involved in aortoiliac occlusive disease. Familiarity with these structures will aid the physician in interpretation of radiologic images and surgical planning. Clin. Anat. 27:1264–1274, 2014. © 2014 Wiley Periodicals, Inc.     

Correlation of CT aortography measurements of infrarenal aortic aneurysms and body mass index in preprocedural evaluation for endovascular repair

The aim of this study is to analyze the morphological differences of infrarenal aortic aneurysms and common iliac arteries that are important for endovascular management between patients of different body mass index using 64 slice multidetector row CT aortography. This was a multicenter study of 100 patients (50 Europeans and 50 Japanese). All patients had risk factors, manifest symptoms, and ultrasound verified aneurysmal dilation of the infrarenal aorta. All examinations were performed on the same CT platform using the same post-processing protocols. Due to the heterogeneity of the population, several statistical models were used. Significant differences were found in morphological parameters of infrarenal aorta in relation to BMI. In over one out of three patients with BMI less than 23, endovascular treatment is contraindicated due to the dimensions of the aneurysmal neck. Relative to BMI value, differences were found in transverse diameters of the medium part of the aneurysm and in the length of common iliac arteries. CT aortography performed on a 64 slice multidetector row CT platform provides precise and numerous data for the analysis of anatomical and pathological differences of infrarenal aortic aneurysms that are of crucial importance for the planning of treatment and the analysis of the differences relating to body habitus.     

Anatomical variations in branching pattern of arcus aorta: 64-slice CTA appearance

Purpose

To review the 64-slice CTA (computed tomography angiography) appearance of anatomical variations in branching pattern of the arcus aorta, and to determine their prevalence in 1001 cases.

Materials and methods

1001 cases that underwent carotid CTA (performed by a 64-slice scanner) were included in the study.

Results

Seven types of aortic arch were found. In 853 cases (853/1001, 85.2 %) classical branching pattern of arcus aorta (three branches; TB, LCC, LS) was observed. Variations were present in 147 cases (147/1001, 14.7 %). One case (1/1001, 0.1 %) had right aortic arch. The most frequent variation was origination of LCC from TB (arch with 2 branches, TB with LCC and LS) which was observed in 78 cases (78/1001, 7.8 %). Origination of LV directly from the aortic arch (four branches; TB, LCC, LV, LS or TB, LCC, LS, LV) was observed in 51 cases (51/1001, 5.1 %). In two cases (2/1001, 0.2 %) truncus bicaroticus (3 branches; RS, common trunk for carotids, LS) was present. In seven cases (7/1001, 0.7 %) aortic arch had four branches in the order of RCC, RS, LCC and LS. In one case (1/1001, 0.1 %) left truncus brachiocephalicus (three branches; RS, RCC, LTB) was present. Seven cases (7/1001, 0.7 %) had aberrant RS (RCC, LCC, LS, RS).

Conclusion

Variations in branching pattern of arcus aorta are not rare and being aware of them before surgical and interventional procedures of this region is important. CTA can depict the anatomical features of the aortic arch and is valuable as a road map.     

Tubular stenosis of the aorta with aortic fibromuscular dysplasia.

The autopsy findings in a 2-year-old girl with severe hypertension resulting from stenosis of the lower part of the thoracic and the abdominal aorta were reviewed. The lower portion of the thoracic aorta and the abdominal aorta showed uniform narrowing down to the level of the bifurcation of iliac arteries. Histologically, the aortic wall of the stenotic site showed irregular proliferation of smooth muscle cells and collagen fibers. The elastic fibers had disappeared from outside the media. No intimal thickening and inflammatory cell infiltration were observed. These histologic changes of the aortic media in this case are apparently similar to fibromuscular dysplasia (medial hyperplasia).     

The anatomy of the infrarenal lumbar splanchnic nerves in human cadavers: implications for retroperitoneal nerve‐sparing surgery

Injury to the nerves of the aortic‐ and superior hypogastric plexuses during retroperitoneal surgery often results in significant post‐operative complications, including retrograde ejaculation and/or loss of seminal emission in males. Although previous characterizations of these plexuses have done well to provide a basis for understanding the typical anatomy, additional research into the common variations of these plexuses could further optimize nerve‐sparing techniques for retroperitoneal surgery. To achieve this, the present study aimed to document the prevalence and positional variability of the infrarenal lumbar splanchnic nerves (LSNs) through gross dissection of 26 human cadavers. In almost all cases, two LSNs were observed joining each side of the aortic plexus, with 48% (left) and 33% (right) of specimens also exhibiting a third joining inferior to the left renal vein. As expected, the position of the LSNs varied greatly between specimens. That said, the vast majority (98%) of LSNs joining the aortic plexus were found to originate from the lumbar sympathetic trunk above the level of the inferior mesenteric artery. It was also found that, within specimens, adjacent LSNs often coursed in parallel. In addition to these nerves, 85% of specimens also demonstrated retroaortic LSN(s) that were angled more inferior compared with the other LSNs (P < 0.05), and exhibited a unique course between the aorta/common iliac arteries and the left common iliac vein before joining the superior hypogastric plexus below the aortic bifurcation. These findings may have significant implications for surgeons attempting nerve‐sparing procedures of the sympathetic nerves in the infrarenal retroperitoneum such as retroperitoneal lymphadenectomies. We anticipate that the collective findings of the current study will help improve such retroperitoneal nerve‐sparing surgical procedures, which may assist in preserving male ejaculatory function post‐operatively.