Anatomical Variability Research Articles

Sex-specific difference in agonistic sounds depends on size of sonic organs in fishes: Testing the hypothesis in the croaking gourami (Labyrinth fishes).

In most vocal fish species, females possess smaller sound-generating organs and vocalize less than males. In certain cases females lack sonic organs, in others differences between sexes are unknown. This study analyzes in detail the relationship between sexual dimorphism of sonic organs and the characteristics of agonistic behavior and of sounds recorded under the same behavioral conditions in a vocal fish species, the croaking gourami Trichopsis vittata. During agonistic contests both sexes stretch and pluck two enhanced (sonic) tendons when beating pectoral fins alternately, resulting in a series of double-pulsed bursts, termed croaking sound. The following anatomical, behavioral, and acoustic variables were analyzed: diameter of enhanced tendons in each specimen, duration of same-sex dyadic contests, number and duration of lateral display bouts and of sounds, number of single- and double-pulsed bursts, burst period, peak-to-peak amplitudes of pulses, dominant frequency and sound pressure level (SPLrms). Female sonic tendons were approximately one-fifth smaller than male's of the same size. Six out of seven behavioral variables did not differ between sexes. Sound characteristics were similar in both sexes except for SPLs, which were on average 5 dB lower in females. The degree of sexual dimorphisms in sonic organs may explain differences in sound characteristics. Sounds differ only in one sound characteristic (SPLrms) in T.vittata, in contrast with the congeneric Trichopsispumila which possesses a more pronounced sexual dimorphism in sonic organs and in which agonistic sounds differ in all sound properties between sexes.

The rule of five: A novel anatomical landmark for approaching cavernous sinus content.

The main objective of this study is to enhance neurosurgeons' anatomical knowledge by providing specific anatomical references of the cavernous sinus (CS). However, it is essential to clarify that our study does not seek to establish an absolute intraoperative rule due to the inherent anatomical variability that must be considered. Fifty-three cadaveric specimens were procured from the Forensic Institute (Bogotá) and subjected to dissection through an extradural approach. The measurements were taken in two distinct phases. The first phase involved the measurement of various anatomical structures in 25 specimens with respect to the anterior and posterior clinoids. The second phase, which was conducted 5 years later, involved the measurement of the distance between the foramen rotundum and the foramen ovale in 28 specimens using the L&W tools microcaliper. In 25 specimens, a perpendicular imaginary line was drawn from the lateral tip of the anterior clinoid to the floor of the medial fossa. This facilitated access to the Parkinson's triangle, which is located between the IV cranial nerve and the ophthalmic V1 nerve, revealing a constant distance of 5 mm between the lateral tip of the anterior clinoid and the IV cranial nerve. Furthermore, in 28 specimens, the mean distance from the foramen rotundum to the foramen ovale was found to be 1.3 cm bilaterally. The rule of five is a valuable tool for comprehensively understanding the anatomy of the CS, providing a reference point for the different normal anatomical structures within the CS.

Factors affecting the primary patency of native arteriovenous fistulas after ultrasound-guided percutaneous transluminal angioplasty

Objective By analyzing the clinical history, laboratory test indexes, and intraoperative ultrasound imaging data of patients receiving ultrasound-guided percutaneous transluminal angioplasty (UG-PTA) for the first time, the application value of UG-PTA in the treatment of peripheral stenosis of autogenous arteriovenous fistula (AVF) and the related factors affecting postoperative patency were investigated. Methods A total of 381 patients with dysfunction of radio-cephalic AVF were treated with UG-PTA from June 2017 to September 2019. According to the inclusion and exclusion criteria, 199 patients were included in this study. Baseline characteristics of patients, including demographic, clinical, and laboratory data, were collected. Kaplan–Meier’s survival curve was used to demonstrate the cumulative primary patency rate of UG-PTA. Univariate and multivariate Cox regression analysis was performed on clinical, anatomic, biochemical, and medication variables to identify the predictors of postintervention primary patency. Results The early technical success rate of UG-PTA was 98.4% (375/381). One hundred and ninety-nine patients, with an average age of 52.9 years, were analyzed, 97 of whom were males (48.7%). The median follow-up duration was 21 months. No major complication was observed. Postintervention primary patency rates were 87.7%, 75.8%, and 60.0% at 6, 12, and 24 months, respectively. A previously failed AVF (HR, 1.935, 95% CI 1.071–3.494; p = .029) and an increased level of parathyroid hormone (HR per 100 pg/mL increase, 1.105; 95% CI 1.014–1.203; p = .004) were identified as independent negative predictors of primary patency of UG-PTA. Conclusions UG-PTA is a safe and effective method for the treatment of peripheral stenosis of AVF. Previously failed AVF and elevated parathyroid hormone levels are associated with lower primary patency rate.

Factors affecting the maxillary and mandibular incisors’ buccolingual inclinations and buccal and lingual cortical plate heights

IntroductionOrthodontics is closely related to periodontics. The buccolingual inclination (BLI) of the incisors and deficiencies in their buccal (BHd) and lingual (LHd) cortical plate heights may affect orthodontic outcomes. Identifying risk factors that can compromise buccal or lingual bone heights may have clinical value. The literature on BLI/BHd/LHd is not only scarce but also limited to one jaw. We aimed to examine, for the first time, factors affecting BLI/BHd/LHd not evaluated before as well as other factors with scarce literature about them.MethodsIn this two-phase epidemiological and analytical study, inclinations and cortical heights of 248 incisors (bilateral centrals and laterals) were evaluated blindly on 62 randomly selected high-resolution pretreatment cone-beam computed tomography volumes (30 maxillae [13 men, 17 women], 32 mandibles [13 men, 19 women]). The sample was balanced in terms of sexes, jaws, and ages. The BLI/BHd/LHd of bilateral incisors were measured (intraobserver agreement > 95%). The effects of jaws, sexes, age, sides, and incisor types on each of the anatomical variables (BLI/BHd/LHd) were analyzed using a Mixed-Model Multiple Linear Regression analysis. Correlations among continuous variables were assessed using a Pearson coefficient (α = 0.05).ResultsFor the maxillary centrals, BLI, BHd, and LHd were 106.79 ± 5.06, 1.94 ± 0.95, and 1.50 ± 0.76, respectively. These parameters were ‘110.56 ± 5.97, 1.81 ± 0.83, 1.23 ± 0.69’ for the maxillary laterals; ‘97.64 ± 8.26, 2.98 ± 1.48, 3.46 ± 1.45’ for the mandibular centrals; and ‘95.98 ± 6.80, 3.29 ± 1.72, and 2.73 ± 1.15’ for the mandibular laterals. BLI was greater in the maxilla compared to the mandible and in the lateral incisors compared to centrals (P < 0.05). BHd was greater (more deficient) in the mandible (P = 0.000). Age, sex, or side were not associated with BLI (P > 0.05). Age, sex, side, or incisor types were not associated with BHd (P > 0.05). LHd was greater in the mandible, older individuals, and centrals (P < 0.05). There were some significant but weak correlations between BLI with BHd and especially LHd (P < 0.05).ConclusionIn the maxilla, but not in the mandible, incisors’ BLI may determine LHd. Maxillary incisors may have greater BLIs as well as greater buccal and lingual alveolar bone heights compared to mandibular incisors. BLI might be greater in the laterals compared to the centrals in both jaws combined.

Anatomical Variations of the External Branch of the Superior Laryngeal Nerve and its Correlations with the Superior Thyroid Artery and the Upper Pole of the Thyroid Gland: A Review of the Literature

Injury to the external branch of the superior laryngeal nerve (EBSLN) following thyroid or parathyroid surgery often results in devastating voice changes especially noticed by patients who use their voice professionally. The external branch arises from the vagus nerve which provides the motor supply to the cricothyroid muscle, an exclusive tensor of the vocal cords. The course of the EBSLN is subject to great anatomic variability. Damage to the nerve occurs during improper ligation of superior thyroid vessels close to the upper pole of thyroid gland in up to 58% of patients undergoing thyroid surgery. Thus, a thorough knowledge of the anatomy of the EBSLN and its variations, is essential requirement to minimize iatrogenic complications during surgery of the neck. Additionally, nerve monitoring methods have been developed to facilitate the localisation of the nerve, decreasing the possibility of nerve injury during thyroid surgery. The aim of this study is to analyze and review the anatomical variations of the EBSLN and its correlations with the superior thyroid artery and the upper pole of the thyroid gland. The literature search was performed during the period from February 1992 through November 2021. The position of the EBSLN was classified according to the Cernea and Kierner classification. Based on this classification, type 2a variant of EBSLN was the commonest followed by type 1. In addition, neuromonitoring allowed a higher identification rate than the visual identification.

Anatomic characteristics of branches related to the vegetative growth of coffee tree (Coffea arabica L., Rubiaceae) under nutritional variation

Although the anatomical tracts of the stem are used to assess the vegetative vigor of different crops, little is known about which characteristics of the vascular system contribute to the growth of coffee plants or how these characteristics are influenced by variations in macronutrients. The study objective was to understand how the growth, anatomical characteristics of the stem, and yield of coffee plants were modified by nutritional variation and which anatomical variables most contribute to growth and/or yield of the coffee plants. Growth, yield, and characteristics of the vascular system of orthotropic and plagiotropic branches of coffee plants, subjected to different percentages of NPK delivered by standard fertilization for coffee plants, had been evaluated. All the evaluated characteristics best fit the quadratic regression model. Growth, morphology, anatomy, and yield were promoted to some extent by NPK fertilization. Orthotropic branches had larger vessel diameters and ray frequencies, whereas in plagiotropic branches, vessels were more numerous. The pith area and the frequency of the rays were correlated with the height of the plant, which in turn was correlated with yield. Plant height, anatomy, and yield were modified by the fertilization. The best NPK range for plant height and yield was 100–130% of the standard. The anatomical variables most correlated with plant height were the pith area of the plagiotropic branch and the ray frequency of the orthotropic branch.

The Superior Cerebellar Artery: Variability and Clinical Significance.

The superior cerebellar artery (SCA) arises from the distal part of the basilar artery and passes by the oculomotor, trochlear, and trigeminal nerves. SCA is known to play a crucial role in the development of trigeminal neuralgia. However, due to its anatomical variability, it may also trigger other neurovascular compression (NVC), including hemifacial spasm, oculomotor nerve palsy, and ocular neuromyotonia. Additionally, it may be associated with ischemic syndromes and aneurysm development, highlighting its clinical significance. The most common anatomical variations of the SCA include duplication, a single vessel origin from the posterior cerebral artery (PCA), and a common trunk with PCA. Rarely observed variants include bifurcation and origin from the internal carotid artery. Certain anatomical variants such as early bifurcation and caudal course of duplicated SCA trunk may increase the risk of NVC. In this narrative review, we aimed to examine the impact of the anatomical variations of SCA on the NVCs based on papers published in Pubmed, Scopus, and Web of Science databases with a snowballing approach. Our review emphasizes the importance of a thorough understanding of the anatomical variability of SCA to optimize the management of patients with NVCs associated with this artery.

Evaluating the influence of the mandibular canal trajectory on the duration of postoperative paraesthesia in patients undergoing inferior alveolar nerve lateralisation: a prospective cohort study

This prospective cohort study aims to evaluate the influence of the mandibular canal trajectory on the duration of postoperative paraesthesia in patients undergoing inferior alveolar nerve lateralisation (IANL). Twenty patients received a total of 50 dental implants, and their postoperative paraesthesia duration, implant success rate, and anatomical variables were assessed. All patients experienced temporary neurosensory disturbances postoperatively during the first week, but none reported permanent issues at the 12-month follow up. The median paraesthesia duration was 120 days, and no significant differences were detected between genders, anaesthesia types, or patient satisfaction. No significant association was found between the mandibular canal trajectory and postoperative paraesthesia duration. The implant success rate was 100%, with all implants integrating successfully. Our findings suggest that IANL is a safe and effective method for dental implant placement in atrophic mandibles.

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

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

Anatomic Variability of the Accessory Nerve: Implications for Dissection of Level IIB.

During neck dissection, level IIB lymphadenectomy necessitates manipulation of the spinal accessory nerve that might be avoided and might cause postoperative disability. Current literature does not describe the effect of variation in the spinal accessory nerve in the upper neck. We sought to measure the effect of the dimensions of level IIB on nodal yield in level IIB and on patient reported neck symptoms. We measured the boundaries of level IIB of 150 patients undergoing neck dissection. Level II was dissected and separated into levels IIA and IIB intraoperatively. Patient-reported symptoms were assessed in 50 patients using the Neck Dissection Impairment Inventory. We computed descriptive statistics, and sought to identify correlation with the number and proportion of level IIB nodes and the number of metastatic nodes. Level IIB dimensions were analyzed as predictors of postoperative symptoms. We measured 184 sides, with 37.7% of level II nodes found in level IIB. Mean accessory nerve length across level II was 2.5 cm. Every additional 1 cm in accessory nerve length was associated with two more level IIB nodes. At all accessory nerve lengths, meaningful numbers of nodes were present in level IIB. Accessory nerve length and other factors did not correlate with NDII scores. Longer lengths of accessory nerve across level IIB correlated with greater nodal yield. However, data did not point to an accessory nerve length cutoff below which level IIB dissection could be avoided. In addition, the dimensions of level IIB did not correlate with postoperative neck symptoms. 2 Laryngoscope, 134:154-159, 2024.

A microcomputed tomographic analysis of the morphological variabilities and incidence of extra canals in mandibular first molar teeth in an Egyptian subpopulation

A well-protected microbial habitat may be present in the root and canal morphology, which is varied and complicated. Before initiating effective root canal treatment, a detailed knowledge of the root and canal anatomical variances in each tooth is a must. This study aimed to investigate the root canal configuration, apical constriction anatomy, location of the apical foramen, dentine thickness, and prevalence of accessory canals in mandibular molar teeth in an Egyptian subpopulation using micro-computed tomography (microCT). A total of 96 mandibular first molars were scanned using microCT, and 3D reconstruction was performed using Mimics software. The root canal configurations of each of the mesial and distal root were classified with two different classification systems. The prevalence and dentin thickness around middle mesial and middle distal canals were investigated. The number, location and anatomy of major apical foramina and the apical constriction anatomy analysed. The number and location of accessory canals were identified. Our findings showed that two separate canals (15%) and one single canal (65%) were the most common configuration in the mesial and distal roots, respectively. More than half of the mesial roots had complex canal configurations and 51% had middle mesial canals. The single apical constriction anatomy was the most common for both canals followed by the parallel anatomy. Disto-lingual and distal locations of the apical foramen are the most common location for both roots. Mandibular molars in Egyptians show a wide range of variations in root canal anatomy with high prevalence of middle mesial canals. Clinicians should be aware of such anatomical variations for successful root canal treatment procedures. A specific access refinement protocol and appropriate shaping parameters should be designated for each case to fulfil the mechanical and biological objectives of root canal treatment without compromising the longevity of treated teeth.

Cardiac Resynchronization in the Acute Phase of Decompensated Heart Failure in a Young Patient with Systemic Sclerosis

Abstract Cardiac resynchronization therapy is an essential tool for treating patients with heart failure in different types of dilatative cardiomyopathy with bundle branch block. This technique is wildly used with significant benefits in terms of quality of life and effort tolerability along with optimized medical therapy. In spite of its benefits, several factors may influence its efficacy such as etiology, lead position, or device settings. In some cases, the anatomical variance of the coronary sinus could create technical difficulties for advancing the left ventricular lead. This case report describes a female patient presenting with decompensated heart failure, known with complicated sclerosis multiplex and a fibrous tissue in the coronary sinus, which created a critical obstruction leading to impossibility to advance the left ventricular lead. This case underlines the importance of appropriate imaging investigation for optimal interventional approach in these difficult cases.

Centerline depth world for left atrial appendage orifice localization using reinforcement learning.

Left atrial appendage (LAA) occlusion (LAAO) is a minimally invasive implant-based method to prevent cardiovascular stroke in patients with non-valvular atrial fibrillation. Assessing the LAA orifice in preoperative CT angiography plays a crucial role in choosing an appropriate LAAO implant size and a proper C-arm angulation. However, accurate orifice localization is hard because of the high anatomic variation of LAA, and unclear position and orientation of the orifice in available CT views. With the major research focus being on LAA segmentation, the only existing computational method for orifice localization utilized a rule-based decision. Nonetheless, using such a fixed rule may yield high localization error due to the varied anatomy of LAA. While deep learning-based models usually show improvements under such variation, learning an effective localization model is difficult because of the tiny orifice structure compared to the vast search space of CT volume. In this paper, we propose a centerline depth-based reinforcement learning (RL) world for effective orifice localization in a small search space. In our scheme, an RL agent observes the centerline-to-surface distance and navigates through the LAA centerline to localize the orifice. Thus, the search space is significantly reduced facilitating improved localization. The proposed formulation could result in high localization accuracy compared to the expert annotations. Moreover, the localization process takes about 7.3s which is 18 times more efficient than the existing method. Therefore, this can be a useful aid to physicians during the preprocedural planning of LAAO.

Root and canal anatomy of mandibular first molars using micro-computed tomography: a systematic review

BackgroundA thorough understanding of root and canal anatomy is crucial for successful root canal treatment outcomes. This systematic review aims to explore the published micro-CT studies investigated the anatomy of root and canal system in permanent mandibular first molars.MethodAn electronic search was performed on Web of science, PubMed, and Scopus. Micro-CT journal studies investigated the root and canal anatomy of permanent double-rooted mandibular first molars were included. Data on study characteristics, objectives of interest, specifications of the studies, and micro-CT specifications were extracted. Risk of bias assessment (ROB) of the included studies was performed using Anatomical Quality Assessment (AQUA) tool. The extracted data were presented in tables and figures to present and synthesise the results. A meta-analysis was performed for the studies related to the prevalence of Vertucci's canal configurations, middle mesial canal (MMC) configurations, and Fan's isthmus types.ResultsAmongst 1358 identified studies, thirty met the inclusion criteria. In terms of the objectives, the selected studies showed high anatomical variability in mandibular first molars. Twenty-two (73%), 25 (83%), and 12 (40%) of the studies reported the population/ethnicity, micro-CT specifications, and ethical approval, respectively. 28 (93%) studies did not disclose the method of sample size estimation. In only 6 (20%) of the studies, the authors had calibrated the assessment approaches. Mostly, a potential ROB was reported in domain 1 (objective(s) and subject characteristics) and domain 3 (methodology characterization). Whilst, low risk was reported in domains 2 (study design), 4 (descriptive anatomy), and 5 (reporting of results). The overall ROB was reported to be ''moderate'' in the vast majority of the studies (27/30). Meta-analysis results showed high levels of heterogeneity among the studies related to MMCs (I2 = 86%) and Fan's isthmus (I2 = 87%). As for the root canal configuration, pooled prevalence showed that Vertucci type IV and type I were the most prevalent in mesial and distal root canals, respectively.ConclusionBased on moderate risk of bias level of evidence, micro-CT studies have shown wide range of qualitative and quantitative data presentations of the roots and canals in mandibular first molars.Protocol and registration.The protocol of this systematic review was prospectively registered in the Open Science Framework database (https://osf.io) on 2022–06-20 with the registration number 10.17605/OSF.IO/EZP7K.

Individual-typological assessment of the body fat component of the examined children and youth

Background. Individual anatomical variability in the human body shape can be characterized by its proportions, which serve as the main components of assessing the type of human constitution.&#x0D; Aim. Establish individual typological features of the age-related changes in the fat component of the examined children, adolescents and youth.&#x0D; Material and methods. 409 residents of the Smolensk region aged 420 years were examined: 212 males and 197 females. The cohort was divided according to the International Age Periodization 1965. Studies of the longitudinal-transverse type lasted for 10 years (20102020). The research methods included anthropometry, somatodiagnostics, determination of the biological development variant. To determine the fat component, the thickness of the skin-fat folds was measured, the calculation was made according to the formulas of Ya. Mateyko. The analyzed data had a normal distribution (ShapiroWilk test). The hypothesis of statistical significance of differences was tested using Student's t-test.&#x0D; Results. Assessment of age-related changes in the body fat component of the subjects showed its continuous increase from 4 to 20 years. In female subjects it was higher, the significance of differences was established from the age of 12 (p 0.05). The fat component had a high and moderate degree of correlation with body height and weight (r=0.5330.753 and r=0.5300.833), skin-fat folds (r=0.5010.941) and body circumference (r=0.5030.790). Significant differences were established between the extreme variants of biological development (isochronic approach) (t=2.3052.604; р 0.05). In the examined males, the difference was 1012%, females 2530%. Somatotypological assessment (isosome approach) showed significant differences (t=3.4626.781; p 0.001) in the severity of fat mass in the subjects of both sexes of macrosomal and microsomal types.&#x0D; Conclusion. The conducted studies have confirmed the presence of high individualization of the fat components growth processes of male and female subjects of various somatic types and biological development variants.

Evaluation of predictive models of aneurysm focal growth and bleb development using machine learning techniques

BackgroundThe presence of blebs increases the rupture risk of intracranial aneurysms (IAs).ObjectiveTo evaluate whether cross-sectional bleb formation models can identify aneurysms with focalized enlargement in longitudinal series.MethodsHemodynamic, geometric, and anatomical...

Usefulness of parahisian pacing for risk prediction of pacemaker implantation after TAVI

Abstract Funding Acknowledgements Type of funding sources: None. Background Conduction disturbances determining pacemaker implantation are a significant concern in patients undergoing Transcatheter Aortic Valve Implantation (TAVI), a procedure that is nowadays spreading even in the low-risk population. OBJECTIVE The aim of the study was to evaluate the role of the parahisian pacing, a method to directly identify the conduction system anatomical variability, in predicting the iatrogenic damage risk conditioning pacemaker implantation after TAVI. Methods Between October 2021 and November 2022 we prospectively collected clinical features, ECG, procedural and imaging data (cardiac CT and echocardiography) of every patient who underwent electrophysiological study for pre-existing or worsening conduction disorders within 48 hours after TAVI procedures in our centre. After having recorded the HV interval, parahisian stimulation at decreasing energy output was performed (CL 600 ms, 25V to 0.5V x 2 ms) with definition of the loss of capture pattern related to the three anatomical variations of His bundle described by Kawashima (1). Fisher’s exact test was used for statistical analysis; p-value &amp;lt;0.05 was considered statistically significant. Results Out of 110 TAVI performed, a total of 31 patients with conduction disorders have been studied. Patients who developed permanent 3rd degree AV block after the procedure were excluded. Mean age was 82.6±4.4 years; 21 patients (67.7%) were males. 11 patients (35.5%) had a pre-existing conduction disorder worsened after TAVI, 13 patients (41.9%) developed newly-onset LBBB; 8 (25.8%) also developed 1st degree AV block. The total number of patients who underwent PM implantation was 16 (51.6%). The anatomical variables (membranous septum &amp;lt;3mm and/or septal cusps calcifications) and type of valve implanted were not significantly associated with PM implantation (p = NS). An HV interval &amp;lt;70 ms was registered in 20 (64.5%) patients (Fig. 1); 7 of them underwent PM implantation as they developed paroxysmal 3rd degree AV block. These 7 patients all had type 2 or type 3 pattern during parahisian stimulation. None of the patients undergoing PM implantation presented a type 1 pattern during parahisian stimulation. A significant protective value (p = 0.02) for PM implantation in patients with type 1 pattern was observed (Fig. 2). Conclusions Parahisian stimulation can be a useful tool to define the conduction system anatomical variability. It can also be helpful to predict the conduction system damage risk during TAVI, conditioning PM implantation. Our data need to be confirmed in a larger population.

Voltage and propagation mapping: new tools to improve successful ablation of atrioventricular nodal reentry tachycardia

Abstract Funding Acknowledgements Type of funding sources: None. Background Ablation of atrioventricular nodal reentry tachycardia (AVNRT) has become the treatment of choice for AVNRT due to high success and low complication rate. A 3-D reconstruction of the atrial endocardial anatomy created by mapping system is useful because anatomic variances or unusual slow pathway locations may affect the effectiveness of classical anatomical approach. Voltage mapping is useful to identify a low voltage area in the Koch triangle (KT) called low-voltage-bridge (LVB); propagation mapping identifies the collision point (CP) of atrial wavefront convergence. These technique may be helpful to improve the localization of the slow pathway. Purpose Our purpose is to conduct a prospective study to evaluate the relationship of the propagation map to voltage mapping and successful site of ablation; moreover we would identify a cut-off value of LVB able to standardized the procedure. Methods Voltage maps of KT (at least 150 points) were obtained through the ablation catheter. Voltage values were adjusted until LVB was observed and classified in two types (Pic 1): Type I is a clear, large area; Type II is a narrow corridor or small areas. The collision point is the area in which the atrial wavefront during sinus rhythm collided on the propagation map indicating the area of slow pathway conduction. Ablation site was selected by LVB position or collision point, confirmed on anatomic position or AV ratio. Ablation of the slow pathway was performed using radio-frequency (RF) or cryotherapy. Results Eighteen consecutive patients were included; one patient was excluded because of inadequate voltage map. Ten patients were female. The median age was 51. In all patients inducible typical AVNRT was present. In 8 patients RF energy was used. Mean procedure time was 109 minutes; mean fluoroscopy time was 3,4 seconds (zero-fluoro procedure in 13 patients). Procedure success (no inducible AVNRT and no more than a single AV node echo beat) was achieved in all patient. No procedural complications were observed. No recurrence at 1 year follow up. The LVB was present in all patients; 9 patients had a type 1 LVB. Voltage map was created adjusting voltage high and low ranges in order to visualize LVB. Limited of LVB visualization is the leak of standard range of value for map creation. Post procedural evaluation identified standard cut-off of 0.3-1mv useful for LVB identification (only one patient had lower voltage range). The collision point was present in all patients. A correlation between LVB and CP was observed in 17/18 patients (Pic 2). In 16 patients successful ablation site was within 5mm of the wave collision. Conclusion In our prospective study, we found correlation between LVB and CP and the site of effective slow pathway ablation in most patients, and we identified a voltage range useful for standardized LVB identification during voltage mapping. Moreover, these techniques are useful to identify ablation site and minimize radiation exposure.

The novel left atrial anterior 'seatbelt' line reduces sustained atrial arrhythmia by 72% compared to pulmonary vein isolation alone in a cohort of 400 virtual atria models

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No.860974. Background The success-rate of pulmonary vein isolation (PVI) is modest in persistent atrial fibrillation (AF), but additional empirical ablation, such as posterior wall isolation (PWI), has not been shown to reduce the rate of AF recurrence. The "seatbelt", an anterior linear ablation lesion connecting the right superior pulmonary vein to the mitral annulus, is a novel substrate modification approach that is yet to be tested in a large-scale randomised clinical trial. Purpose To use in-silico trials with human-based modelling and simulation to compare the efficacy of (i) PVI alone, (ii) PVI and PWI (PVI+PWI), or (iii) PVI and seatbelt (PVI+SB) for the prevention of atrial arrhythmia in large populations of virtual patient models. Methods AF was simulated in a cohort of 400 virtual atrial models with anatomical and electrophysiological variability, with AF persisting for &amp;gt;7 seconds defined as sustained. Models which sustained AF were each independently subjected to all three ablation approaches before repeating the AF induction protocol. Results Three hundred forty-four (86%) atrial models developed sustained AF at baseline. After applying the ablation lesions, substantially fewer models sustained atrial arrhythmias in the PVI+SB group (50 [14%] vs. 134 [39%] with PVI+PWI vs. 172 [50%] with PVI). PVI+SB was more effective than PVI and PVI+PWI in preventing both AF and atrial flutter (i.e., presence of a single rotor), since PVI and PVI+PWI led to the formation of anatomical re-entries around the rings of the pulmonary veins and the posterior wall of the left atrium, respectively (Figure). Therefore, PVI+SB restricted atrial flutter mainly to the right atrium (either anatomical, around the inferior cava vein, or functional, meandering throughout the venous portion of the right atrium, Figure). Importantly, in all three ablation strategies, the likelihood of AF recurrence was directly proportional to the surface area of the right atrium (AF probability increased 0.95%/cm², 0.88%/cm² and 0.56%/cm² after PVI+SB, PVI+PWI and PVI, respectively). The role of the right atrial size was less accentuated for PVI alone, since after the ablation the entire left atrial body was still available for rotor anchoring. Moreover, an enlarged left atrium enabled the appearance of micro-re-entries in the anterior and inferior wall of the left atrium, even after applying floor and roof lines. One atrial model additionally presented a rotor in the posterior wall of the left atrium after completely isolating it from the left atrial body. Conclusion(s) In a cohort of 400 virtual atrial models, PVI+SB reduced sustained atrial arrhythmias by 72% compared to PVI alone and by 64% to PVI+PWI, but AF could still originate in an enlarged right atrium.

TOPOGRAPHIC AND ANATOMICAL RELATIONSHIPS OF INTRAMUSCULAR ARTERIES AND NERVES IN THE SHOULDER REGION OF HUMAN FETUSES

In modern surgical practice, there is a growing need to improve techniques of operative interventions. Despite advancements in diagnosis and treatment, combined shoulder injuries remain a pressing problem. In the past, surgical intervention for combined trauma primarily focused on saving the patient's life. However, today it is essential not only to preserve life but also to restore the function of the injured structures. Humerus fractures are observed in 27.9% of polytrauma cases, significantly complicating urgent diagnostic and treatment procedures and worsening the patient's condition. A comprehensive study of the topographical and anatomical relationships of intramuscular arteries and nerves at the shoulder level can facilitate the selection of optimal surgical approaches, prevent iatrogenic damage, and contribute to the patient's rapid rehabilitation.&#x0D; The objective of this study was to identify the distribution patterns of arteries and nerves at different levels of the shoulder in human foetuses.&#x0D; Materials and Methods. The study involved the examination of upper limb preparations from 48 human foetuses, ranging from 81.0 to 370.0 mm in parietal-caudal length without external signs of anatomical deviations or anomalies in the development of the skeletal and muscular structures of the upper limbs. Macromicroscopic dissection, vessel injection, and morphometry techniques were employed.&#x0D; Results and Discussion. In human foetuses, the upper and middle thirds of the shoulder were found to have the highest concentration of intramuscular arteries and nerves. The entry points of arteries and nerves, their topography and branching patterns within the shoulder muscles did not always align. Arterial branches generally entered the muscles at slightly more distal locations than the nerve trunks, following the shortest path to reach the muscles.&#x0D; The levels at which arteries and nerves start branching to supply and innervate the muscles of the anterior and posterior shoulder groups, vary in human foetuses. This variation depends on the individual anatomical variability of the major vascular and nerve trunks.&#x0D; Conclusion: The levels of arterial and nerve abduction are related to the topographic and anatomical features of a particular shoulder muscle. Considering the topography of intramuscular arteries and nerves, it is advisable to perform incisions along the direction of muscle bundles, particularly near the lower border of the neurovascular unit of the brachial biceps. This approach can offer higher clinical and surgical effectiveness.