Distribution Of Branches Research Articles

Automatic annotation of liver computed tomography images based on a vessel‐skeletonization method

AbstractAnatomical analysis of liver region is an essential and key step for liver‐related disease diagnosis and treatment. One of the challenging issues is to annotate the functional regions of liver automatically or semi‐ automatically by analyzing Computed Tomography (CT) images. The present study developed a complete liver annotation system with an improved vessel‐skeletonization method is proposed for CT images. In the first step, an automatic level set method and a customized region‐growing method are applied to extract the liver region including vessels and tumors. Next, a modified iterative thinning method is developed to obtain the geometric structure of liver vessels and mark a vessel skeleton. The three‐dimensional information is transformed into a tree data structure for storage. Based on the branch distribution of portal vein skeleton, a model‐based method with a modified nearest neighbor segment approximation (NNSA) algorithm is adopted for the functional liver anatomy. Three experiments involving five 64‐row liver CT datasets are performed. The accuracies of segmentation and annotation results were validated by an experienced doctor. Compared with different methods, our proposed vessel skeletonization method can simultaneously preserve the connectivity of the vasculature topology and generate the skeleton in a shorter time. Furthermore, our proposed annotation system can provide both visual and measurable information of livers. These experimental results demonstrate the usefulness and effectiveness of our proposed method. Our liver annotation system is helpful to evaluate the function of liver system and support diagnosis of liver disease.

The angiographic anatomy of the inferior mesenteric artery in elder

Objective: To examine the characteristics of the digital subtraction angiography of inferior mesenteric artery (IMA) in elderly Chinese patients over 65 years old. Methods: Totally 64 cases who underwent angiography of IMA were selected from the Department of General Surgery, Xuanwu Hospital of Capital Medical University, including 42 males and 22 females, aging (70.9±5.1) years (range: 60 to 88 years). The origin, diameter and trunk length of IMA were analyzed. The distribution of IMA branching and the relationship between LCA and IMV at the level of IMA opening position were revealed. Also, the range of IMA perfusion, Riolan arch and IMA occlusion were observed. Results: All 64 patients underwent IMA angiography successfully. The diameter of IMA was (3.2±0.5) mm (range: 2.6 to 4.4 mm), and the trunk length was (3.8±1.0) cm (range: 1.1 to 7.0 mm). According to IMA classification standard, there were 26 patients with type Ⅰ (40.6%), 24 patients with type Ⅱ (37.5%), 12 patients with type Ⅲ (18.8%), 2 patients with type Ⅳ(3.1%). The horizontal distance between IMV and LCA was less than 0.5 cm in 58 cases (90.6%) and more than 0.5 cm in 6 cases (9.4%). IMA perfusion was interrupted at the splenic flexure in elderly patients in 14 cases (21.9%), including 11 cases terminated at splenic flexure and 3 cases terminated at descending colon. Riolan arch was found in only 4 of 64 patients (6.2%). Two patients (3.1%) had IMA or its branch occlusion, the arterial perfusion were compensated by Drummond arch without Riolan arch. Conclusions: The anatomy of IMA should be taken attention seriously in laparoscopic left-colorectal cancer radical resection. IMA shape, type, blood supply range and the relationship between LCA and IMV could be considered by the angiography or other examination, which can help to determine the ligation position of blood vessels, which could optimize the operation strategy.

Suprascapular nerve block - do it yourself

Background:Suprascapular nerve (SSN) block using bone reference points (BARO) is a technique that in principle is accessible to practitioners without experience in locoregional anesthesia or ultrasound guidance. The primary objective was to validate the feasibility of SSN BARO by an orthopedic surgeon. The secondary objective was to provide a description of the path of the sensory branches from the SSN to the shoulder.Methods:A BARO was performed on 15 cadaveric shoulders by an intern in orthopedic surgery. Ten ml of methylene blue and 0.75% ropivocaine were injected around the SSN. 2.5ml of a red latex solution were also injected to identify the injection site. The distribution of the sensory branches of the NSS was also described.Results:The average distance between the SSN and the injection site was 1.5cm (0-4.5cm). The most frequent injection site was the proximal third of the scapular neck. Fifteen SSNs were marked upstream of the origin of the sensory branches. The 15 SSN produced 3 sensory branches that innervate the posterior glenohumeral capsule, the subacromial bursa, and the coracoclavicular and acromioclavicular ligaments.Conclusion:SSN BARO by an orthopedic surgeon is a simple, reliable, and accurate technique. Injection near the suprascapular notch is recommended to mark the SSN upstream of its three sensory branches.

INNERVATION OF THE MEDIAN NERVE MOTOR BRANCHES IN THE FOREARM AND ITS CLINICAL SIGNIFICANCE.

ABSTRACTObjective: To analyse the anatomical variations of the median nerve motor branches in the elbow region.Methods: Twenty upper limbs of 10 adult male cadavers were prepared by intra-arterial injection of a solution of 10% glycerol and formaldehyde. All cadavers belonged to the institution anatomy laboratory. Results: We found a great variability within the distribution of median nerve branches leading to forearm muscles. Only three limbs (14%) presented the normal standard of innervation described in anatomy treatises. The pronator teres muscle (PTM), flexor carpi radialis (FCR), palmaris longus (PL), and the flexor digitorum superficialis (FDS) received exclusive innervation from the median nerve in all forearms. The anterior interosseous nerve (AIN) also originated from the median nerve in all dissected limbs. Conclusion: A thorough understanding of the anatomy of the median nerve branches is important for performing surgeries such as: approach to the proximal third of the forearm, alleviation of pronator teres and anterior interosseous nerve compression syndromes, and distal nerve transfers. It also enables a better understanding the recovery of muscle function after a nerve injury. Level of Evidence IV, Case series.

Clinical and Radiological Profile of Trigeminal Neuralgia- A Retrospective Study

Introduction: Trigeminal neuralgia is described as severe, stabbing unilateral pain along the distribution of trigeminal nerve branches. The three subtypes include- Classical, secondary and idiopathic. Aim: To study the clinical profile, presentation and radiological imaging features in trigeminal neuralgia patients. Materials and Methods: This cross-sectional study included outpatient medical records of 60 trigeminal neuralgia patients between June 2015 to June 2020 (five years) in a Tertiary care Medical College Hospital. Various parameters studied were: (a) Age; (b) Gender; (c) Dental treatment; (d) Pain severity; (e) Trigger factors; (f) Side and branch involved; (g) Sensory abnormalities; (h) MRI. Data was entered in Microsoft excel and analysed using SPSS statistical software 20.0. Chi-square test was used for categorical variables. Results: Among the 60 patients studied, the common demographic and clinical features were as follows: 34 were females (56.7%); 36 with right side presentation (60%); 25 had maxillary nerve division distribution (41.7%); 57 patients experienced shock/lancinating pain (95%); and 40 had numeric pain severity scale of 4-6 (66.7%). Classical Trigeminal Neuralgia was the most common subtype seen in 31 patients (51.7%). Involvement of dual divisions (maxillary and mandibular), absence of trigger factors and presence of hypoesthesia were more suggestive of Secondary Trigeminal Neuralgia (p<0.05). Based on MRI imaging, 31 (51.7%) showed neurovascular compression with atrophy or displacement of trigeminal nerve root. Only 5 (8.4%) had secondary causes (schwannoma, meningioma, demyelination, infarct). Conclusion: The key clinical features of trigeminal neuralgia include female preponderance, right side presentation, maxillary nerve division distribution, shock/lancinating pain with touch and breeze as common trigger factors. As some of them had a previous dental treatment or procedure, dentists need to be aware of this entity. Certain clinical features would help to differentiate the secondary from classic and idiopathic neuralgia subtype.

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THE CONCEPT OF AGRICULTURAL DIVISION INTO DISTRICTS WITH DEFINITION OF ZONE SPECIALIZATION OF AGRICULTURAL PRODUCTION RА In Agrarian sector of Armenia the issue of the territorial organization of an economy should be discussed on the basis of the concept about division into districts. Hence in the current contribution special attention is given to discussion and estimation of the approaches, referring such concepts, as "specialization", "territorial administration", "adaptive-landscape approach", "vertically - landscape zones". Moreover on the basis of territorially - branch division of labor there is a necessity more proved placing and natural deepening of specialization of manufacture of an agricultural zone. In this context during the Soviet period of development of Agrarian sector under different schemes nature - agricultural division into districts the agro-industrial estimation of all territory of the republic has been given. During this period as system-design units have been accepted uniformity of vertical landscape zones and law of transitions. However in Agrarian activity, in connection with high level of state intervention, the principle of the proved distribution of branches and sub-sectors which corresponded to agricultural zones of the republic was broken. In a market economy, the absolutization of land ownership began to interfere with this. For changing the situation it is necessary to develop corresponding territorial Agrarian policy.

Structural and functional characteristics of clustered amylopectin produced by glycogen branching enzymes having different branching properties

Three bacterial glycogen branching enzymes (GBEs) having different branching characteristics were used to produce clustered amylopectin (CAP), and structure and functional properties of CAPs were intensively analyzed. Branch distributions of three CAPs varied from very short (DPn = 6.65) to medium (DPn = 14.1). Branch distribution showed profound correlation with hydrodynamic diameter, water solubility, digestibility, and effects on mice gut-microbiota. All the CAPs showed nearly no viscosity and retrogradation. The very short-branch CAP exhibited more than 100-fold water-solubility, 3.5-fold lower α-amylase catalytic efficiency, and 27% lower digestibility in small intestine-mimicking condition than amylopectin. Intriguingly, medium branch CAP had 1.8-fold larger hydrodynamic diameter than the very short one. Mice gut-microbiota composition statistically varied after 12-day feeding of the CAPs, but only the medium chain CAP brought clear positive changes on the gut-microbiota. Consequently, slowly digestible starch was successfully synthesized by the single GBE, but the CAP structure affects in vivo functions in complicated manner.

Spatial Anisotropy Assessment of the Forest Vegetation Heterogeneity at Different Azimuth Angles of Radar Polarimetric Sensing

The results of studies to assess the texture of L- and C-band radar polarimetric images from SIR-C and ALOS PALSAR-1 satellites for analyzing forest-vegetation characteristics using different signatures are summarized. A fractal polarization signature is proposed for the study; this signature makes it possible to estimate the spatial anisotropy of forest-vegetation heterogeneities at different azimuthal angles of radar sensing. In addition, the signature of lacunarity is suggested as a tool for the qualitative assessment of the angular distribution of tree branches. The heterogeneities of forest vegetation at the test site near Lake Baikal are estimated based on the results of an analysis of the fractal dimension and lacunarity at different states of the polarization ellipse.

Polymerization Kinetics and Microstructure of Ethylene/1‐Hexene Copolymers Made with Dual Metallocenes

AbstractMathematical models are developed to describe the polymerization of ethylene and 1‐hexene with a constrained geometry catalyst (CGC‐Ti) and with bis(cyclopentadienyl)‐zirconium (IV) dichloride (Cp2ZrCl2). Particle swarm optimization is used to fit these models to homo‐ and copolymerization data. The models are also used to describe copolymerizations with mixtures of CGC‐Ti and Cp2ZrCl2 to make copolymers with inverse short chain branching distribution. Copolymer molecular weight and short chain branch distributions, as well as polymerization rates with the dual metallocene system, are measured to test whether they agreed with model predictions. The results show that the two metallocenes do not interact strongly when used as a mixture to make ethylene/1‐hexene copolymers.

Dominant Effects of Short-Chain Branching on the Initial Stage of Nucleation and Formation of Tie Chains for Bimodal Polyethylene as Revealed by Molecular Dynamics Simulation.

The molecular mechanism of short-chain branching (SCB), especially the effects of methylene sequence length (MSL) and short-chain branching distribution (SCBD) on the initial stage of nucleation, the crystallization process, and particularly the tie chain formation process of bimodal polyethylene (BPE), were explored using molecular dynamics simulation. This work constructed two kinds of BPE models in accordance with commercial BPE pipe resins: SCB incorporated in the long chain or in the short chains. The initial stage of nucleation was determined by the MSL of the system, as the critical MSL for a branched chain to nucleate is about 60 CH2. SCB incorporated in the long chain led to a delay of the initial stage of nucleation relative to the case of SCB incorporated in the short chains. The increase of branch length could accelerate the delay to nucleation. The location of short chain relative to the long chain depended on the MSL of the short chain. As the MSL of the system decreased, the crystallinity decreased, while the tie chains concentration increased. The tie chains concentration of the BPE model with branches incorporated in the long chain was higher than that with branches incorporated in the short chain.

MULTIPLE AGENT MANAGEMENT BY DISTRIBUTION ELECTRIC NETWORKS OPTIMAL DISPATCH

Solving the problem of management intellectualization is complicated by the large dimensionality and branching distribution network, low monitoring of its regime and limited set of adaptive management measures. Introduction the SmartGrid concept in modern distribution power networks makes it unnecessary to solve the problem of adaptation the topology of the working scheme to the electricity transmission mode current conditions in real time. The paper substantiates the special urgency of the problem of closing closed circuits in modern heterogeneous electrical networks, which are maintained by operators of electric networks of different hierarchical levels. Known methods of optimization disconnection of electrical networks provide a centralized approach to the relevant control systems that practically impossible to implement optimal commutation switching in real time. Therefore, it is expedient to use a decentralized approach, based on the principles of multi-agent management of the distribution grid. Obviously, operative optimization of the places of unplugging of distributive electric networks will cause the improvement of the quality of electric energy by voltage deviation. This situation has fallen to the basis of the developed mathematical apparatus supporting decisions by the multi-agent system of operational reconfiguration of distribution electrical networks. The proposed approach to the formation of a multi-agent control system for the configuration of distribution electrical networks is illustrated in the scheme of heterogeneous electrical networks 110-750 kV of the Southern power grid of UPS Ukraine. It is stated that the opening of circuits 110 (150) kV will result in decrease of active power losses by 9.5%, and energy losses during the year is approximately 8%. The operational adaptation of the working circuit of distribution networks further reduces energy losses by 3-5% during the year.

Analysis of Chinese Patent Technology in Ship and Marine Engineering Equipment Industry

Based on the current situation of China’s shipbuilding and marine engineering equipment industry, this paper divides the shipbuilding industry into three categories: general-purpose shipbuilding industry, special-purpose shipbuilding industry and marine engineering equipment industry. Patsnap patent search platform is used to analyze the patent trend, distribution of key technology branches and key applicants of the three types of shipbuilding industry in China. According to the analysis results, the corresponding policy strategies are put forward to provide reference for enterprises to accurately grasp the future direction of development and avoid patent risks.

Application effects of enhanced computed tomography and three-dimensional reconstruction technology in reconstruction of pediatric post-burn scars with expanded flaps

Objective: To explore the application effects of enhanced computed tomography (CT) and three-dimensional reconstruction technology in the reconstruction of pediatric post-burn scars with expanded flaps. Methods: From May 2016 to March 2019, 19 children with hypertrophic scars after thermal injuries were admitted to our unit, including 10 boys and 9 girls, aged from 4 years and 5 months to 15 years and 11 months. The area of scars ranged from 5 cm×4 cm to 23 cm×9 cm. One or more skin and soft tissue expanders with suitable volume and shape were implanted into the normal skin area around scar of children. Three to six months later, enhanced CT and three-dimensional reconstruction were performed before the second stage operation to obtain three-dimensional images of the vascular branches in the donor site for expanded flaps to be cut, so as to determine the course and distribution of the vascular branches and guide the design of expanded flaps. According to the design scheme, the resection of scar, removal of expanders, and excision and transfer of flaps were performed to repair the wounds after scar resection. The area of flaps ranged from 6 cm×4 cm to 25 cm×10 cm. The donor site was closed directly. The number of flaps was counted. The anatomical structure, vascular distribution, and adverse reactions during enhanced CT and three-dimensional reconstruction of site for expanded flaps to be cut, the survival of expanded flaps and the follow-up after the second-stage operation were observed. Results: A total of 48 expanded flaps were designed and excised in 19 children. The anatomical structure of the site for expanded flaps to be cut and the adjacent spatial position relationship were visually observed through the three-dimensional reconstruction after enhanced CT, and no adverse reactions were observed. Arterial branch blood supply or venous return was observed in 29 sites for expanded flaps to be cut. All the expanded flaps survived well without blood supply disorder after the second stage operation. The children were followed up for 6 months to 1 year and 6 months after the second stage operation. The appearance of the flaps was natural, and the color and thickness of the flaps were similar to those of the surrounding normal skin, except for one child with obvious linear scar. Conclusions: Enhanced CT and three-dimensional reconstruction can assist the vascular assessment of the expended flaps, which is helpful for rational design of the flap excision and transfer protocol to improve the survival rate of flaps. Thus, it has certain clinical application value in the reconstruction of post-burn scar in children with expanded flaps.

Correlation between isothermal crystallization properties and slow crack growth resistance of polyethylene pipe materials

In this study, three PE100 polyethylene materials with fairly different short chain branch distributions were used to characterize the relation between thermal properties and creep test failure time. The samples were thermally characterized using isothermal and non-isothermal differential scanning calorimetry (DSC). The three resins showed different behavior after fitting on the Avrami equation. N-100J2 sample, in which short chain branches (SCBs) are located on longer molecule chains, has a lower chain mobility and higher crystallization time, while N-100J1 has the opposite crystallization properties. Also, these samples had different Avrami index, n. Microstructural evaluation of these samples revealed that the Avrami index had a direct relationship with the morphology of samples and the higher n correlates to formation of more spherulite structures. The creep test result showed that the sample with a lower crystallization rate and lower Avrami index was more resistant against slow crack growth (SCG) because of its crystalline morphology with the obstacles in crack growth. There is a meaningful relationship between lamellae arrangement and failure time; when a crystalline segment in resin has more spherulite structures, higher Avrami index, the boundary of these spherulites may act as weak regions in front of crack and consequently lead to easier crack growth in such material.

Trigeminal-Targeted Treatments in Migraine: Is 60% the Magic Number?

Trigeminal-targeted treatments (TTTs), the most specific and selective therapeutic migraine approach to date, are effective in approximately 60% of patients regardless of treatment type or mechanism, at least if used alone. Sixty percent is also the proportion of migraineurs who develop migraine-like episodes following experimental intravenous administration of trigeminal neuropeptides and roughly 60% is the percentage of patients with a unilateral migraine tracing the area of cutaneous distribution of the trigeminal ophthalmic branch. Hence, mechanisms other than the trigeminovascular activation are probably involved in the 40% of migraineurs who do not respond to TTTs. A closer cooperation between clinical and basic neuroscientists is needed to explore migraine models because only a careful appraisal of migraine endophenotypes may help to unravel their underlying multifaceted pathophysiological machinery.

The evolution mechanism of different forms of bursting oscillations in non-smooth dynamical systems

The dynamics of the systems with non-smoothness and the coupling of multiple scales have become the key subject because of their wide applications in science and engineering problems. The main purpose of the manuscript is to investigate the complicated dynamics in non-smooth systems caused by the coupling of two scales in frequency domain. Based on a common model of the boost converter controlled by a SMC-Washout as an example, By introducing a periodically changed electric power source and taking suitable parameter values, a piecewise non-smooth Filippov system with two scales in frequency domain is established. For the case when the exciting frequency is far less than the natural frequency, the whole exciting term can be regarded as a slow-varying parameter. Upon the analysis of the two subsystems located in two regions divided by the non-smooth boundary, the evolution of the equilibrium branches as well as the bifurcations with the variation of the slow-varying parameter are derived. Two typical cases corresponding to different distribution of the equilibrium branches as well as the bifurcations with the variation of the slow-varying parameter are taken into consideration, in which different types of bursting oscillations can be observed. By introducing the concept of the transformed phase portrait, the associated bifurcation mechanism of the bursting oscillations is presented. It is found that, the equilibrium branches and the related bifurcations may change with the variation of parameters, which may not only affect the quiescent states and the spiking states, but also influence the bifurcations between the two states, leading to different forms of bursting oscillations. It is pointed out that, when the trajectory of system jumps between different stable equilibrium branches of the two subsystems located in two associated regions, the types of point/point bursting oscillations may be obtained, while with the variation of the parameters, when the stable limit cycles involves the attractors, the types of point/cycle bursting oscillations may appear.

The applied anatomy of posterior tibial artery cutaneous branches-chain flap

Objective To provide anatomy information for harvesting the posterior tibial artery cutaneous branches-chain flaps. Methods The research was performed from January, 2017 to January, 2018. Anatomic observation on 10 legs from fresh human cadaver were performed. The location of cutaneous branches of the posterior tibial artery was observed and its diameter and length was measured. Five legs were prepared to investigate the cutaneous branches of posterior tibial artery. The anastomosis of cutaneous branches of posterior tibial artery was observed by PVA-bismuth oxide perfusion for molybdenum target X-ray arteriography in 5 perfused legs. The cutaneous branches with diameter over 0.2 mm in 10 legs of latex perfusion microdissection were included in the statistical analysis. The data were clustered and analyzed to find the location of distant and near cutaneous branches, which was called the gathering point of cutaneous branch vascular plexus. Secondly, the measured data of distal and near segments containing cutaneous branches were compared by t-test. Then the distribution of cutaneous branches of posterior tibial artery on the tibiofibular side was compared by Chi-square test. It was considered to be significant if P value was under 0.05. Results ①There were 4.3 cutaneous branches raised from the posterior tibial artery. There was no significant difference on the tibial and ribula side distribution of the cutaneous branches from the posterior tibial artery(P>0.05). ②The distal cutaneous branch clusters was located at about 1/5 of the distal leg and there were 3.6 cutaneous branches raised from the posterior tibial artery. While the proximal clusters was located at 1/3 of the proximal leg and there were 0.7 cutaneous branches raised from the posterior tibial artery. There were no significant differences in the diameters (P=0.28) and pedicle length (P=0.14) between distal and proximal cutaneous branches. ③ There were the large cutaneous perforators (≥1.0) mm from the posterior tibial artery at (6.37±1.22) cm proximal to the medial malleolus. The diameter and pedicle length of the distal perforators were (1.11±0.09) mm and (6.53±1.51) mm respectively. ④ The vascular chains parallel to the posterior tibial artery were formed via anastomosis of the adjacent cutaneous perforators. Conclusion The cutaneous expenditure of posterior tibial artery is constant, with a certain pedicle length and diameter. There are 2 relatively dense vascular plexus of cutaneous branches. The proximal and distal vascular flaps can be designed with these 2 vascular dense points as rotation points. Key words: Posterior tibial artery; Cutaneous branches-chain flap; Shank; Applied anatomy

Polyolefins Formed by Chain Walking Catalysis-A Matter of Branching Density Only?

Recently developed chain walking (CW) catalysis is an elegant approach to produce materials with controllable structure and properties. However, there is still a lack in understanding of how the reaction mechanism influences the macromolecular structures. In this study, a series of dendritic polyethylenes (PE) synthesized by Pd-α-diimine-complex through CW catalysis (CWPE) is investigated by means of theory and experiment. Thereby, the exceptional ability of in situ tailoring polymer structure by varying synthesis parameters was exploited to tune the branching architecture, which allowed us to establish a precise relationship between synthesis, structure, and solution properties. The systematically produced polymers were characterized by state-of-the-art multidetector separation and neutron scattering experiments as well as atomic force microscopy to access molecular properties of CWPE. On a global scale, the CWPE appear in a worm-like conformation independently on the synthesis conditions. However, severe differences in their contraction factors suggested that CWPE differ substantially in topology. These observations were verified by NMR studies that showed that CWPE possess a constant total number of branches but varying branching distribution. Small angle neutron scattering experiments gave access to structural characteristics from global to segmental scale and revealed the unique heterogeneity of CWPE, which is predominantly based on differences in their dendritic side chains. The experimental data were compared to theoretical CW structures modeled with different reaction-to-walking probabilities. Simple theoretical arguments predict a crossover from dendritic to linear topologies yielding a structural range from purely linear to dendritic chain growth. Yet, comparison of theoretical and empirical scattering curves gave the first evidence that a transition state to worm-like topologies is actually experimentally accessible. This crossover regime is characterized by linear global features and dendritic local substructures contrary to randomly hyperbranched systems. Instead, the obtained CWPE systems have characteristics of disordered dendritic bottle brushes and can be adjusted by the walking rate/reaction probability of the catalyst.

Ultrasound-Guided Proximal and Distal Suprascapular Nerve Blocks: A Comparative Cadaveric Study.

The primary aim of our study was to evaluate and compare the accuracy of ultrasound (US)-guided distal suprascapular nerve (dSSN) and proximal SSN (pSSN) blocks. Secondary aims were to compare the phrenic nerve involvement between groups and to describe the anatomical features of the sensory branches of the dSSN. pSSN and dSSN blocks were performed in 14 cadavers (28 shoulders). Ten mL of 0.2% ropivacaine colored with methylene blue was injected under US guidance. Accuracy was determined using SSN staining and the distance between predefined anatomical landmarks and the targeted SSN. The phrenic nerve (PN) was judged to be colored or not. The distribution of the sensory branches that originate from the 14 dSSNs is described. Quantitative data are expressed as median (range). The pSSN was dyed more frequently than the dSSN (13 vs 11, P = 0.59). The targeted SSN was close to the suprascapular notch (1.3 [0-5.2] cm) and the origin of the SSN (1.4 [0.2-4.5] cm) for dSSN and pSSN blocks, respectively (P = 0.62). For dSSN blocks, the most frequent injection site was the supraspinous fossa. Three PNs were marked in pSSN blocks, compared with none in dSSN blocks (P = 0.22). Three sensory branches were identified for all 14 dSSNs: the medial subacromial branch, the lateral subacromial branch, and the posterior glenohumeral branch. US-guided pSSN and dSSN blocks can be realized with accuracy. A distal approach to the SSN could be an alternative to interscalene brachial plexus block for the management of postoperative pain after shoulder surgery in high-respiratory risk patients.

Anatomical course of the lateral femoral cutaneous nerve with special reference to the direct anterior approach to total hip arthroplasty

Objectives: To document the anatomical variation of the lateral femoral cutaneous nerve (LFCN) at the proximal aspect of the thigh and to determine its susceptibility to injury during total hip arthroplasty via a direct anterior approach (DAA).Methods: We obtained 64 thighs from formalin-preserved cadavers of 45 Japanese individuals. LFCN was identified at the level of the inguinal ligament. All nerve branches of the LFCN were carefully traced distally in the subcutaneous tissue. The branching pattern and distribution at the proximal aspect of the thigh were described. A safe zone to avoid LFCN injury in DAA was estimated for the skin incision.Results: The branching pattern of LFCN was highly varied. There were 37% of the anterior type, characterized by a thicker anterior branch, which coursed along the medial border of the tensor fascia lata (TFL) muscle with thinner branches. There were 63% of the posterior type, characterized by posterior branches thicker than or equal to the anterior branch. In 27 of 64 thighs (42%), the LFCN crossed the skin incision along the midline of the TFL muscle.Conclusion: LFCN showed anatomical variation of anterior and posterior branches and 42% were in danger of injury during DAA.