Posterior Process Research Articles

Prevalence of Asymptomatic Bone Marrow Edema in the Talus in Professional Ballet Dancers: Preliminary Data from 2-Year Prospective Study

Category:Ankle; SportsIntroduction/Purpose:Bone marrow edema (BME) appears as increased interstitial fluid accumulation within the bone marrow on magnetic resonance images (MRI). Asymptomatic BME has been found incidentally and described in competitive athletes, long- distance runners, and patients with altered biomechanics where the true etiology remains unclear. The natural history and clinical implications of asymptomatic BME in the elite and actively-competing athlete is not well characterized. Moreover, there is debate on how to manage and counsel patients on these findings in a high-risk bone such as the talus. This study presents early data from a prospective enrollment study of professional ballet dancers characterizing the prevalence of asymptomatic BME in the talus.Methods:Fourteen (14) professional ballet dancers enrolled in the 2-year prospective, IRB-approved study after informed consent was obtained. Exclusion criteria included: subjects reporting foot and ankle pain or disability on initial preseason evaluation, foot and ankle surgery or injury within the last year prior to evaluation, and any contraindications for MRI. Subjects underwent a physical examination and completed Foot and Ankle Ability Measure (FAAM) and Foot and Ankle Disability Index scores (FADI). Bilateral foot and ankle MRIs without contrast were completed upon study enrollment and interpreted by a blinded, fellowship-trained musculoskeletal radiologist.Results:Of 14 professional ballet dancers enrolled in the study, 6 were female, 8 were male, and the mean age was 24.4 years. All dancers reported no pain or disability in their feet and ankles at the time of evaluation and had physical exam findings unremarkable for performance-limiting pathology. Of the 14 dancers, 64% (9) had MRI evidence of talar BME. 6 subjects had bilateral talar BME and 3 had unilateral findings. 53% (8) had BME localized to the posterior process of the talus, 13% (2) localized in the talar body, 13% (2) localized to the talar head and neck, and 20% (3) subjects had pan-talar BME. All subjects had BME seen only on T2 sequences with one patient demonstrating bilateral pan-talar BME on both T1 and T2 sequences. There was no significant correlation using Welch’s unequal variances t-test (α = 0.05) between talar BME and either FADI or FAAM scores.Conclusion:These findings demonstrate a high prevalence (64%) of talar bone marrow edema in asymptomatic professional ballet dancers with benign physical exams and normal functional scores. Yet, the long-term clinical significance of these findings are unknown.

Arthroscopic treatment for posteromedial talar process fracture (Cedell fracture): a case report

Fracture of the posteromedial talar process (Cedell fracture) is a rare injury and is easily misdiagnosed as a simple ankle sprain. Suspicion should be heightened if specific mechanisms of injury are present, and, in these cases, a CT scan should be performed. Significant ankle pain and disability can result if these injuries are not identified and treated properly. Few cases have been described in the literature, and the efficacy of surgical techniques and approaches for fractures of the posterior talar process remains controversial. We report a 56-year-old man with an acute posteromedial talar fracture treated arthroscopically. This approach provides good access to the posterior ankle compartment, subtalar joint, and extraarticular structures, which may allow fracture reduction and fixation under arthroscopic visualization. Level of Evidence V; Therapeutic Studies; Expert Opinion.

Supervised Machine Learning for Predicting Length of Stay After Lumbar Arthrodesis: A Comprehensive Artificial Intelligence Approach.

Few studies have evaluated the utility of machine learning techniques to predict and classify outcomes, such as length of stay (LOS), for lumbar fusion patients. Six supervised machine learning algorithms may be able to predict and classify whether a patient will experience a short or long hospital LOS after lumbar fusion surgery with a high degree of accuracy. Data were obtained from the National Surgical Quality Improvement Program between 2009 and 2018. Demographic and comorbidity information was collected for patients who underwent anterior, anterolateral, or lateral transverse process technique arthrodesis procedure; anterior lumbar interbody fusion (ALIF); posterior, posterolateral, or lateral transverse process technique arthrodesis procedure; posterior lumbar interbody fusion/transforaminal lumbar interbody fusion (PLIF/TLIF); and posterior fusion procedure posterior spine fusion (PSF). Machine learning algorithmic analyses were done with the scikit-learn package in Python on a high-performance computing cluster. In the total sample, 85% of patients were used for training the models, whereas the remaining patients were used for testing the models. C-statistic area under the curve and prediction accuracy (PA) were calculated for each of the models to determine their accuracy in correctly classifying the test cases. In total, 12,915 ALIF patients, 27,212 PLIF/TLIF patients, and 23,406 PSF patients were included in the algorithmic analyses. The patient factors most strongly associated with LOS were sex, ethnicity, dialysis, and disseminated cancer. The machine learning algorithms yielded area under the curve values of between 0.673 and 0.752 (PA: 69.6% to 80.1%) for ALIF, 0.673 and 0.729 (PA: 66.0% to 81.3%) for PLIF/TLIF, and 0.698 and 0.749 (PA: 69.9% to 80.4%) for PSF. Machine learning classification algorithms were able to accurately predict long LOS for ALIF, PLIF/TLIF, and PSF patients. Supervised machine learning algorithms may be useful in clinical and administrative settings. These data may additionally help inform predictive analytic models and assist in setting patient expectations. Diagnostic study, retrospective cohort study.

Extensive pneumatisation of the sphenoid bone: anatomical investigation of the recesses of the sphenoid sinuses and their clinical importance.

There is a great variance between the extents of pneumatisation of the sphenoid sinuses that can reach beyond the body of the sphenoid bone. The purpose of this study was to find the prevalence of the recesses of the sphenoid sinuses in Polish adult population. Two hundred ninety-six computed tomography (CT) scans of patients who did not present any pathology in the sphenoid sinuses were evaluated in this retrospective analysis. Spiral CT scanner (Siemens Somatom Sensation 16) was used to glean the medical images. Standard scan procedure was applied, with Siemens CARE Dose 4D option enabled. No contrast medium was administered. In the majority of the patients (93.92%), the pneumatisation of the sphenoid sinuses expanded beyond the body of the sphenoid bone; hence, there were recesses of the sinuses present. The most common variant was the presence of two recesses - 12.84% of cases. The prevalence of all the 17 recesses was only 0.34%. Amongst the uneven recesses present, the sphenoidal rostrum's recess (61.15% of the patients) and the inferior clinoid recess (56.42%) were the most common. Amongst the even recesses present, the lateral recess was prevalent in the majority (65.88%), whereas the posterior clinoid process' recess was the least common (9.8%). Presence of the recesses might facilitate access to the cranial fossae; hence, comprehensive evaluation of the sphenoid sinuses is of immense importance in order to avoid unnecessary drills through the hard bone, which could potentially damage the nearby neurovascular structures.

Radiological study of Os trigonum and its clinical significance

Background: Os trigonum (OST) is commonly located on the posterior aspect of the talus. It occurs as a result of secondary ossification center failing to fuse with the lateral tubercle of the posterior process of the talus; its incidence varies between 2 and 25%, and is more often bilateral. It occurs as an intra-articular Os, which is most often securely rooted to the lateral tubercle of the talus by a fibrocartilaginous synchondrosis. Aims and Objective: To determine the incidence, morphology, and distribution of Os Trigonum (OST). Materials and Methods: Retrospective 500 lateral foot radiographs view were studied to determine the incidence, morphology, and distribution of OST. Results: Incidence of OST in the present study was 6.6%, with predominantly round or ovoid in shape. OST was located on the posterolateral aspect of the talus. Conclusion: OST can be one of the causative factor responsible for Flexor hallucis longus tendonitis, OST syndrome, which occur in plantarflexion of the ankle, leading to compression of the OST between the distal tibia and the calcaneus. Hence, knowledge regarding the incidence, morphology, and distribution of OST is important for the radiologist, orthopedic surgeons to arrive at a correct diagnosis, which aids in the management of cases presenting with complaints of posterior ankle pain.

Multi-objective Bayesian optimization of ferroelectric materials with interfacial control for memory and energy storage applications

Optimization of materials’ performance for specific applications often requires balancing multiple aspects of materials’ functionality. Even for the cases where a generative physical model of material behavior is known and reliable, this often requires search over multidimensional function space to identify low-dimensional manifold corresponding to the required Pareto front. Here, we introduce the multi-objective Bayesian optimization (MOBO) workflow for the ferroelectric/antiferroelectric performance optimization for memory and energy storage applications based on the numerical solution of the Ginzburg–Landau equation with electrochemical or semiconducting boundary conditions. MOBO is a low computational cost optimization tool for expensive multi-objective functions, where we update posterior surrogate Gaussian process models from prior evaluations and then select future evaluations from maximizing an acquisition function. Using the parameters for a prototype bulk antiferroelectric (PbZrO3), we first develop a physics-driven decision tree of target functions from the loop structures. We further develop a physics-driven MOBO architecture to explore multidimensional parameter space and build Pareto-frontiers by maximizing two target functions jointly—energy storage and loss. This approach allows for rapid initial materials and device parameter selection for a given application and can be further expanded toward the active experiment setting. The associated notebooks provide both the tutorial on MOBO and allow us to reproduce the reported analyses and apply them to other systems (https://github.com/arpanbiswas52/MOBO_AFI_Supplements).

Endoscopic Endonasal Surgical Strategy for Skull Base Chordomas Based on Tumor Growth Directions: Surgical Outcomes of 167 Patients During 3 Years.

BackgroundSkull base chordomas (SBCs) are rare malignant bone tumors with dismal long-term local control. Endoscopic endonasal surgeries (EESs) are increasingly adopted to resect SBCs recently. Gross total resection (GTR) favors good outcomes. However, the SBCs often invade the skull base extensively and hide behind vital neurovascular structures; the tumors were challenging to remove entirely. To improve the GTR, we established a surgical strategy for EES according to the tumor growth directions.MethodsA total of 112 patients with SBCs from 2018 to 2019 were classified into the derivation group. We retrospectively analyzed their radiologic images and operation videos to find the accurate tumor locations. By doing so, we confirmed the tumor growth directions and established a surgical strategy. Fifty-five patients who were operated on in 2020 were regarded as the validation group, and we performed their operations following the surgical strategy to verify its value.ResultsIn the derivation group, 78.6% of SBCs invade the dorsum sellae and posterior clinoid process region. 62.5% and 69.6% of tumors extend to the left and right posterior spaces of cavernous ICA, respectively. 59.8% and 61.6% of tumors extend to the left and right posterior spaces of paraclival and lacerum ICA (pc-la ICA), respectively. 30.4% and 28.6% of tumors extended along the left and right petroclival fissures that extend toward the jugular foramen, respectively. 30.4% of tumors involved the foramen magnum and craniocervical junction region. The GTR was achieved in 60.8% of patients with primary SBCs in the derivation group. Based on the tumors’ growth pattern, pituitary transposition and posterior clinoidectomy techniques were adopted to resect tumors that hid behind cavernous ICA. Paraclival ICA transposition was used when the tumor invaded the posterior spaces of pc-la ICA. Lacerum fibrocartilage resection and eustachian tube transposition may be warranted to resect the tumors that extended to the jugular foramen. GTR was achieved in 75.0% of patients with primary SBCs in the validation group.ConclusionBesides the midline clival region, the SBCs frequently grow into the eight spaces mentioned above. The surgical strategy based on the growth pattern contributes to increasing the GTR rate.

A feature-based statistical shape model for geometric analysis of the human talus and development of universal talar prostheses.

Statistical data pertaining to anatomic variations of the human talus contain valuable information for advances in biological anthropology, diagnosis of the talar pathologies, and designing talar prostheses. A statistical shape model (SSM) can be a powerful data analysis tool for the anatomic variations of the talus. The main concern in constructing an SSM for the talus is establishing the true geometric correspondence between the talar geometries. The true correspondence complies with biological and/or mathematical homologies on the talar surfaces. In this study, we proposed a semi-automatic approach to establish a dense correspondence between talar surfaces discretized by triangular meshes. Through our approach, homologous salient surface features in the form of crest lines were detected on 49 talar surfaces. Then, the point-wise correspondence information of the crest lines was recruited to create posterior Gaussian process morphable models that non-rigidly registered the talar meshes and consequently established inter-mesh dense correspondence. The resultant correspondence perceptually represented the true correspondence as per our visual assessments. Having established the correspondence, we computed the mean shape using full generalized Procrustes analysis and constructed an SSM by means of principal component analysis. Anatomical variations and the mean shape of the talus were predicted by the SSM. As a clinically related application, we considered the mean shape and investigated the feasibility of designing universal talar prostheses. Our results suggest that the mean shape of (the shapes of) tali can be used as a scalable shape template for designing universal talar prostheses.

A new species of the genus Raphiglossa S.S. Saunders, 1850 (Hymenoptera: Vespidae: Eumeninae sensu lato) from Turkmenistan

Raphiglossa rasnitsyni Fateryga, sp. n. is described from Turkmenistan. The new species resembles R. eumenoides S.S. Saunders, 1850 in its body size and proportions of the metasomal tergum 1 but strongly differs from it by having a narrow propodeal concavity which is less wide than the metasomal tergum 1 at base, anterior margin of clypeus deeply emarginated and with a single tooth at center in the female, and male genitalia with reduced parameral spine (gonostylus), digitus lacking posterior process, and robust aedeagus broadened (in lateral view) towards the apex and curved dorsally.

Putative poison gland in the thorny catfish Acanthodoras spinosissimus (Siluriformes: Doradidae)

ABSTRACT Acanthodoras is the only genus of catfish known to secrete a conspicuous and abundant milky-looking substance through an axillary pore located just below the base of the posterior cleithral process. Despite this remarkable feature, there is no published information on the anatomical structures that produce the secretion and its possible biological/ecological functions. Dissection and histological analysis of preserved specimens of A. spinosissimus revealed the presence of a saccular axillary gland with large, binuclear secretory cells, similar to those found in other poisonous catfish. Secretory cells near the lumen appear to lose nuclei and become filled with secretory products, possibly with proteinaceous elements, as indicated by their eosinophilic appearance. As far as we know, the saccular morphology of the gland appears to constitute a unique characteristic of Acanthodoras among Doradidae catfishes. Further studies are necessary to determine the chemical composition of the secretion, as well as its possible uses by the catfish in its natural environment.

Fracture of the Posteromedial Tubercle of the Talus: Surgical Approach With Case Examples

Ten to 21% of talus fractures involve the posteromedial tubercle. A search query of the institutional database was performed for all adult patients that sustained talar fractures over an 8-year period. Fifteen of these patients had isolated fractures of the posteromedial tubercle. Seventy-three percent of the patients had an associated subtalar dislocation; in all of these, the fracture of the posteromedial tubercle was comminuted. Plain radiographs have been shown to lack sensitivity in detecting posterior process fractures, which includes posteromedial and posterolateral tubercles. In this group, 86% had initial plain radiographs that missed the fracture. This paper reviews the posteromedial tubercle fractures and fracture patterns to illustrate surgical strategies and approaches for open reduction and internal fixation. Exposures are described for access to the posteromedial tubercle and strategies for distraction and reduction are described. Level of Evidence: Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Minimally Invasive Subfrontal Approach: How to Make it Safe and Effective from the Olfactory Groove to the Mesial Temporal Lobe.

Different surgical approaches have been developed to manage lesions of the anterior and middle skull base areas. Frontal, pterional, bifrontal, and fronto-orbito-zygomatic approaches are traditionally used to reach these regions. With advancements in the neurosurgical field, skull opening should be simple and as minimally invasive as possible, tailored on the surgical corridor to the target. The supraorbital approach and the "keyhole" concept have been introduced and popularized by Axel Perneczky starting from 1998 and are now considered a part of everyday practice. The extended possibilities of this surgical route, considering the reachable targets and surgical limits, are described and systematically analyzed, including a description of the salient surgical anatomy, presenting different illustrative cases. Different illustrative cases are presented and discussed to underline the potentials and limits of the minimally invasive subfrontal approach (MISFA) and the possibilities to tailoring the craniotomy on the basis of the targets: extra-axial lesions with different localizations (anterior roof of the orbit, olfactory groove, tuberculum sellae, medial third of the sphenoid wing, anterior and posterior clinoid process), deeper intra-axial lesions (gyrus rectus, medial temporal lobe-uncus-amygdala-anterior hippocampus), and vascular lesions (anterior communicating aneurysm). Each case has been preoperatively planned considering the anatomical and radiologic features and using virtual simulation software to tailor the best possible corridor to reach the surgical target. The MISFA is a safe multicorridor approach that can be used efficiently to manage lesions of the anterior and middle skull base areas with extremely low approach-related morbidity.

A Multi-Objective Bayesian Optimization Approach Using the Weighted Tchebycheff Method

Abstract Bayesian optimization (BO) is a low-cost global optimization tool for expensive black-box objective functions, where we learn from prior evaluated designs, update a posterior surrogate Gaussian process model, and select new designs for future evaluation using an acquisition function. This research focuses upon developing a BO model with multiple black-box objective functions. In the standard multi-objective (MO) optimization problem, the weighted Tchebycheff method is efficiently used to find both convex and non-convex Pareto frontiers. This approach requires knowledge of utopia values before we start optimization. However, in the BO framework, since the functions are expensive to evaluate, it is very expensive to obtain the utopia values as a prior knowledge. Therefore, in this paper, we develop a MO-BO framework where we calibrate with multiple linear regression (MLR) models to estimate the utopia value for each objective as a function of design input variables; the models are updated iteratively with sampled training data from the proposed MO-BO. These iteratively estimated mean utopia values are used to formulate the weighted Tchebycheff MO acquisition function. The proposed approach is implemented in two numerical test examples and one engineering design problem of optimizing thin tube geometries under constant loading of temperature and pressure, with minimizing the risk of creep-fatigue failure and design cost, along with risk-based and manufacturing constraints. Finally, the model accuracy with frequentist, Bayesian and without MLR-based calibration are compared to true Pareto solutions.

B-PO02-135 LEFT VENTRICLE POSTERIOR SUPERIOR PROCESS ECTOPY: RISK OF AV NODE BLOCK DURING ABLATION

Premature ventricular contractions (PVC) originating from the highest portion of the inferior left ventricular (LV) septum are infrequent and challenging to treat with catheter ablation (CA). The incidence and CA risks are ill-defined. We sought to determine the incidence of PVC originating from the posterior superior process (PSP) at our institution. We reviewed our records retrospectively between 1/2018 and 10/2020 for all PVC ablations. We selected all patients who underwent PVC ablation from the PSP region. 370 patients underwent PVC were identified from institutional ventricular tachycardia database. Of the total cohort, four patients (1%) had PVCs ablated from the PSP region. Three of four were male, normal LVEF average 51% and only one had myocardial scarring on imaging studies. Despite different PVC morphologies, EKG had common characteristics including monophasic R in lead I, rS in lead II and slow downsloping QS in aVR (the “RI-rSII-QSaVR” triad). Acutely successful ablation was performed in all four cases. In all but one case, RF ablation at the earliest mapping site was associated with either transient delay in AV conduction or accelerated junctional rhythm. In 6 months follow up, none of the patients had arrhythmia recurrence. Prolonged monitoring in two patients indicated high degree AV block at sleep but none meet the criteria for pacing. PVCs originating from the PSP are rare, occurring in about 1% of referred patients. Even when approached from the left side, attention to proximity to the compact AV node is warranted when ablating in the PSP region. Despite these concerns, success of ablation is high.

Comparative anatomy of the middle ear in some lizard species with comments on the evolutionary changes within Squamata.

The skeleton of the middle ear of lizards is composed of three anatomical elements: columella, extracolumella, and tympanic membrane, with some exceptions that show modifications of this anatomy. The main function of the middle ear is transforming sound waves into vibrations and transmitting these to the inner ear. Most middle ear studies mainly focus on its functional aspects, while few describe the anatomy in detail. In lizards, the morphology of the columella is highly conservative, while the extracolumella shows variation in its presence/absence, size, and the number of processes present on the structure. In this work, we used diaphanized and double-stained specimens of 38 species of lizards belonging to 24 genera to study the middle ear’s morphology in a comparative framework. Results presented here indicate more variation in the morphology of the extracolumella than previously known. This variation in the extracolumella is found mainly in the pars superior and anterior processes, while the pars inferior and the posterior process are more constant in morphology. We also provide new information about the shape of gekkotan extracolumella, including traits that are diagnostic for the iguanid and gekkonid middle ear types. The data collected in this study were combined with information from published descriptive works. The new data included here refers to the length of the columella relative to the extracolumella central axis length, the general structure of the extracolumella, and the presence of the internal process. These characters were included in ancestral reconstruction analysis using Bayesian and parsimony approaches. The results indicate high levels of homoplasy in the variation of the columella-extracolumella ratio, providing a better understanding of the ratio variation among lizards. Additionally, the presence of four processes in the extracolumella is the ancestral state for Gekkota, Pleurodonta, and Xantusiidae, and the absence of the internal processes is the ancestral state for Gekkota, Gymnophthalmidae, and Scincidae; despite the fact that these groups convergently develop these character states, they could be used in combination with other characters to diagnose these clades. The posterior extension in the pars superior and an anterior process with some small and sharp projections is also a diagnostic trait for Gekkota. A more accurate description of each process of the extracolumella and its variation needs to be evaluated in a comprehensive analysis, including a greater number of species. Although the number of taxa sampled in this study is small considering the vast diversity of lizards, the results provide an overall idea of the amount of variation of the middle ear while helping to infer the evolutionary history of the lizard middle ear.

Coordination of similar days and multi-objective posterior process to predict energy of transmission substation

Purpose This paper aims to present a hybrid model to mid-term forecast the load of transmission substations based on the knowledge of expert site and multi-objective posterior framework. The main important challenges in load forecasting are the different behavior of load in specific days. Regular days, holidays and special holidays, days after a holidays and days of load shifting are characterized by abnormal load profiles. The knowledge of these days is verified by expert operators in regional dispatching centers. Design/methodology/approach In this paper, a hybrid model for power prediction of transmission substations based on the combination of similar day selection and multi-objective posterior technique has been proposed. In the first step, the important data for prediction is provided. Posterior method is used in the second step for prediction that it is based on kernel functions. A multi-objective optimization has been formulated with three type of output accuracy measurement function that it is solved by non-dominated sorting genetic technique II (NSGT-II) method. TOPSIS way is used to find the best point of Pareto. Findings The presented method has been tested in four scenarios for three different transmission stations, and the test results have been compared. The presented results indicate that the presentation method has better results and is robust to different load characteristics, which can be used for better forecasting of different stations for better planning of repairs and network operation. Originality/value The main contributions of this paper can be categorized as follows: A hybrid model based on similar days selection and multi-objective framework posterior is presented. Similar day selection is done by expert site that the day type and days with scheduled repair are considered. Hyperparameters of posterior process are found by NSGT-II based on TOPSIS method.

Commentary: Management of an Uncommon Complication: Anterior Choroidal Artery Occlusion by Posterior Clinoid Process Detected Through Intraoperative Monitoring After Clipping of Paraclinoid Aneurysm: 2-Dimensional Operative Video.

Correspondence: Anas Abdallah, Assoc Prof Dr (MD), Department of Neurosurgery, Private Aile Hospital, Talatpaşa Bulvarı, Begonya Sk, No: 7-9, Istanbul 34590, Turkey. Email: [email protected]

Functional Morphology of the Flight Apparatus of Ephemera vulgata (Ephemeroptera: Ephemeridae) and Implications for the Evolution of Flight in Insects

Abstract The mesothoracic flight apparatus of preserved and freshly killed specimens of Ephemera vulgata is examined in detail by means of functional morphological examinations. The basic drive mechanism of the forewing of Ephemera vulgata constitutes a four-bar kinematic chain, which encompasses the whole mesothorax. Based on this reassessment, the operating principles of the different subsystems of the flight apparatus of the mayfly were newly analysed. As in the Neoptera, the indirect dorsolongitudinal downstroke and dorsoventral upstroke muscles rotate the wing around an axis which runs through the main wing joint of the fulcrum. In contrast to the Neoptera, the wing is driven via the posterior notal wing process and fourth axillary. A strong direct subalar muscle is able to move the subalare (together with the pleural ridge) inwards and to affect the wingstroke via a bistable click mechanism in this unusual way. The axillary sclerites, two frontal first axillaries and one caudal fourth axillary, permit the radioanal plate to rotate forward–backward on the fulcrum. This motion system, which is superimposed on the kinematic chain mechanism, permits alterations of the wingstroke plane. A short muscle of the radioanal plate allows adjusting the passive pronation of the wing during the downstroke and achieving an increase of the aerodynamical angle of attack. The step-by-step derivability of basal flight mechanisms of the main groups of Pterygota indicates a paranotal origin of the wings. The possibility that the Ephemeroptera and Neoptera constitute sister groups is discussed.

SURGICAL OUTCOME OF THE SUPERIOR MESENTERIC ARTERY FIRST TECHNIQUE COMBINING POSTERIOR AND UNCINATE PROCESS APPROACH TO PANCREATICODUODENECTOMY FOR THE PANCREATIC HEAD AND THE PERIAMPULLARY CANCER

Background: Pancreaticoduodenectomy is the only curative treatment for periampullary and head of pancreas cancers. Various approaches have been described as the superior mesen­teric artery (SMA) first technique. This study aimed to report the surgical outcome of the SMA first technique combining posterior and uncinate process approach to pancreaticoduo­denectomy. Methods: This retrospective study was done at the Department of Surgical Oncology at BP Koirala Memorial Cancer Hospital. The data was collected from January 2015 to September 2020. All the patients underwent pancreaticoduodenectomy for pancreatic head cancer and periampullary can­cer with the technique combining posterior and uncinate process approaches. Results: A total of 85 patients underwent pancreaticoduodenectomy with 42.4% male and 57.6% female. Fifty-nine (69.4%) cases were classified as resectable and 26 (30.6%) as borderline re­sectable. The median operative time was 300 minutes. The median intraoperative blood loss was 391ml. Intra-operative blood transfusion was done in 8.5%. The median total number of dissected lymph nodes was 13. The postoperative pancreatic fistula was seen in 8 patients while 4 patients had a post-pancreatectomy hemorrhage. Delayed gastric emptying was seen in 12 patients. There were overall 8 (9.4%) in-hospital mortality. R0 resection was achieved in 84 patients (98.82%). Conclusions: The combined posterior and uncinate process approach SMA first technique for pan­creaticoduodenectomy is a safe and standard technique. It decreases intraoperative blood loss, to­tal operative time, and increases R0 resection compared to posterior or uncinate process approach only. It plays a key role in lowering the postoperative complication rate.

Representación gráfica del aporte vascular intraóseo y extraóseo del astrágalo. Anatomía ilustrada

BackgroundThe vascular anatomy of the talus attracts intense research being not always easy to understand.The high intraosseous variability together with the anatomical characteristics makes some areas of the talus more prone to vascular compromise.The aim of this study is to describe the vascularization of the talus, both intraosseous and extraosseous. Material and methodsFrom the literature reviewed, we have developed a graphic scheme that allows easy observation of the irrigation distribution. To this end, nineteen anatomical dissections of human cadaveric feet have been carried out. Fifteen fresh-frozen slices have been cut in different planes and prepared using the modified Spalteholz technique and latex injection with blue and black ink to visualize the vascular network. In addition, the study has been complemented with a comprehensive literature review on this subject. ResultsThe findings allowed us to conclude that the posterior tibial artery provides the most important blood supply to the neck and body of the talus through the tarsal canal artery and the deltoid branch.The anterior tibial artery splits in the dorsal pedis artery, for the head and neck, and the lateral tarsal artery which throughout anastomoses breeds the tarsal sinus artery. The perforating peroneal artery branches out from the peroneal artery, creating an intraosseous anastomosis for the body and the posterior process. ConclusionThe results obtained have contributed to develop a graphical representation that we present in this study, which allows a simple understanding of the intraosseus and extraosseus vascularization of the talus.