Bulb Of Internal Jugular Vein Research Articles

CARD20: Investigating the Impact of Ventriculoatrial Shunts on Venous Hydrodynamics: A Computational Fluid Dynamics Analysis

Ventriculoatrial (VA) shunts are a common treatment option for patients suffering from hydrocephalus and requiring cerebrospinal fluid (CSF) drainage. However, the impact of this treatment on cardiac hydrodynamics has yet to be fully understood. To shed light on this issue, the present study employs computational fluid dynamics (CFD) simulations to evaluate the effects of VA catheters on venous hydrodynamics in hydrocephalus patients. The study focuses on five models of different sections of veins, including the Internal Jugular Vein (IJV), Right and Left Brachiocephalic Veins (RBV-LBV), and the Superior Vena Cava (SVC). The vein geometry was reconstructed from neck CT scans of a patient with mild hydrocephaly without a catheter. Blood flow simulations were performed using pressure-based transient laminar models solved with the Ansys Fluent Navier-Stokes solver. The analysis was conducted on two healthy cases with and without catheters, and three hydrocephalus cases with catheters, considering mild, moderate, and severe hypertension. The results show that pressure accumulation near the IJV bulb was observed in all cases, with maximum pressure in the severe hypertension case. A pressure of 3,050 Pa was reached over the catheter insertion site. The healthy case without the shunt showed velocities of up to 0.8 m/s, while in the severe hypertension case, velocities were less than 0.2 m/s in similar regions for the IJV, RBV, and LBV. Healthy streamlines showed some vortices throughout the IJV, which seemed to be minimized by the presence of the catheter in the other models. In conclusion, this study provides valuable information regarding the hydrodynamic alterations seen in patients with VA shunts. The observed pressure accumulation and decreased velocity can be associated with potential adverse effects such as thrombotic formation. These findings can be used to guide future treatment options and warrant further long-term study. The use of CFD simulations offers a non-invasive and efficient method to study the effects of VA shunts on cardiac hydrodynamics and can provide a deeper understanding of the complex interplay between cerebrospinal fluid drainage and venous hydrodynamics.

Jugular Foramen of Adult Human Skull and its Clinical Significance in Population of Eastern India: A Cross-sectional Study

Introduction: Jugular foramen is a complex irregular bony canal located at the base of the skull between the condylar part of occipital bone and petrous part of temporal bone. It allows passage of important nervous and vascular structures. These are ninth, tenth, eleventh cranial nerves, sigmoid sinus continued as the superior bulb of internal jugular vein and inferior petrosal sinus, meningeal branches of the ascending pharyngeal and occipital arteries. Jugular fossa has a septum and a dome. The dome lodges the superior bulb of internal jugular vein. The septum divides the foramen into two compartment, antero- medial and postero-lateral. There is a wide variation in shape, size and septation of jugular foramen in different regions of globe which have been studied by different authors in different periods of time. Many tumours may arise in this region causing compression of the vital structures passing through it. Surgery is the treatment of choice in these cases. Successful neuro surgeries involving this region require detailed knowledge about the anatomical variation of the jugular foramen. Aim: To study and compare the morphology of jugular foramen, its various dimensions, shape, size and septation which is related to the size of internal jugular vein. Materials and Methods: A cross-sectional descriptive study was carried out on 85 adult dry human skulls, collected from the Anatomy Department as well as from the first year Bachelor of Medicine and Bachelor of Surgery (MBBS) students of different Medical colleges of West Bengal from September 2020 to June 2021. Presence of septa were observed and anteroposterior (AP), mediolateral diameter (ML diameter) were measured by using vernier caliper. Then the area was calculated. Data collected were compiled in tabular form. They were analysed by using Statistical Package for Social Sciences (SPSS) statistics version 20.0 and paired t-test and chi-square tests were applied. Results: In the total 85 skulls studied, the area of jugular foramen was larger on right side in 91.76% and on left side in 8.24% of skull. The AP diameter was less than the ML diameter and areas in all cases. But both the diameters were significantly (p-value<0.001) larger on right side than the left. Complete septation was present in right side of 34 foramina and in left side of 17 foramina. Partial or incomplete septation was present on right side of 51 foramina and left side of 68 foramina. Conclusion: The study revealed variation in shape, size and septation in different skulls and also bilateral variation in same skull. It has immense value to radiologists, Ear Nose Throat (ENT) surgeons, neuro-surgeons and radiologists who deal with the diagnosis and management of space occupying lesions surrounding the jugular foramen.

Morphometric Study of Jugular Foramen and Jugular Fossa of Dried Adult Human Skulls and Its Clinical Significance

Abstract Introduction Jugular foramen is one of the most fascinating foramina of the human skull. It is a complex, irregular bony canal located between the occipital bone and petrous part of the temporal bone. Many important structures, like 9th, 10th, 11th cranial nerves, meningeal branch of occipital and ascending pharyngeal arteries, internal jugular vein, and inferior petrosal sinus, are passing through it. The jugular fossa has a septum and a dome. The septum divides the foramen into two compartments: anteromedial compartment (pars nervosa) and posterolateral compartment (pars vascularis). The dome contains superior bulb of internal jugular vein. The architecture of the foramen varies in size, shape, and laterality besides differences related to sex and race. The morphometric measurements of jugular foramen are very important for neurosurgeries and head and neck surgeries. Objectives The aim of the present study is to study the morphology of jugular foramen along with its dimensions, compartments, presence of partial or complete septa and dome. Materials and Methods A total number of 60 jugular foramina were examined from 30 adult dry human skulls of unknown age and sex from the Department of Anatomy, PSG Institute of Medical Sciences and Research, Coimbatore. Measurements were taken using Digital Vernier calipers. Results were analyzed statistically. Results The length, width, and surface area of jugular foramen of right side were measured and compared with the left side. Length and width of the jugular foramen was significantly higher on the right side. The presence of partial septum was found in 27 skulls (90%) on the right side and 29 skulls (99.7%) on the left side, respectively. Dome was present in 100% of the jugular foramina on the right side and 90% of the jugular foramina on the left side. Separate opening for inferior petrosal sinus was found in eight skulls (27%) on the right side and four skulls (13%) on the left side. Conclusion This study provides a clear understanding of anatomy of jugular foramen and supports the reported morphometric variations. The morphometric variations of jugular foramen in the parameters of the skull are probably due to ethnic and racial factors. Knowledge of these variations is important for neurosurgeons and radiologists who deal with space occupying lesions of the structures surrounding jugular foramen. This study may be helpful for ENT surgeons while performing middle ear surgeries.

Role of irradiation in combined treatment of head and neck paragangliomas at the Centre of Oncology in Krakow between 1970-2005.

Aim of the studyAim of the study is to evaluate the results of postoperative radiotherapy of paragangliomas, prognostic factors and causes of treatment failure.Material and methodsForty-four patients (39 females and 5 males) aged 20 to 74 years were treated for paraganglioma between 1970 and 2010 at the Centre of Oncology in Kraków. Patient survival probability was estimated with the Kaplan-Meier method. Log-rank tests and Cox proportional hazard model were used in univariate and multivariate analysis, respectively.ResultsThe most common locations of paragangliomas were the following: the ear, carotid body and internal jugular vein bulb. Forty (91%) out of them were benign and 4 – malignant. All patients underwent surgery followed by adjuvant radiotherapy. The delivered dose ranged from 50 to 72 Gy, the mean dose was 60 Gy. Five-year overall survival was 84%. Five-year relapse-free survival was 84%, either. The multivariate analysis has shown that the dose in an independent prognostic factor for the overall survival. The univariate analysis has shown significantly higher 5-year overall survival in patients who received a dose of 60 Gy or higher – 92% vs. 70% in patients who received a dose lower than 60 Gy.ConclusionsPostoperative radiotherapy with doses higher than 60 Gy in patients with paragangliomas is associated with longer overall survival.

Análise do comportamento do hemometabolismo cerebral durante endarterectomia carotídea com pinçamento transitório

Carotid endarterectomy with temporary clamping changes cerebral blood flow and cerebral metabolic oxygen demand ratio with consequent oligemic hypoxia or hemometabolic uncoupling. This study aimed at identifying changes in brain hemometabolism, evaluated through changes in oxyhemoglobin saturation in internal jugular vein bulb (SvjO2) during carotid endarterectomy with clamping, and at correlating these changes with potentially interfering factors, mainly end tidal CO2 pressure (P ET CO2) and cerebral perfusion pressure (CPP). Sixteen patients with unilateral carotid stenotic disease scheduled to carotid endarterectomy with carotid arterial clamping were enrolled in this study. Parameters including internal jugular bulb oxyhemoglobin saturation, stump pressure and end tidal CO2 pressure were measured at the following moments: M1 - pre-clamping; M2 - 3 minutes after clamping; M3 - pre-unclamping; M4 - post-unclamping). The comparison among SvjO2 (%, mean +/- SD) in all studied periods has shown differences between those recorded in moments M1 (52.25 +/- 7.87) and M2 (47.43 +/- 9.19). This initial decrease stabilized during temporary clamping, showing decrease in the comparison between M2 and M3 (46.56 +/- 9.25), without statistical significance (p = ns). At post-unclamping, M4 (47.68 +/- 9.12), SvjO2 was increased as compared to M2 and M3 clamping stages, however it was still lower than that of pre-clamping stage M1.(M4 x M1 - p < 0.04) This SvjO2 decrease was followed by significant cerebral perfusion pressure (stump pressure) decrease. Factors influencing this brain hemometabolic uncoupling trend were correlated to P ET CO2. The comparison between CPP and SvjO2 showed weak correlation devoid of statistical significance. In the conditions of our study, SvjO2 measurement is a fast and effective way of clinically monitoring changes in CBF/CMRO2 ratio. Temporary carotid clamping implies in a trend towards brain hemometabolic uncoupling and, as a consequence, to oligemic ischemia; cerebral perfusion pressure does not assesses brain hemometabolic status (CBF and CMRO2 ratio); hypocapnia, may lead to brain hemometabolic uncoupling; P ET CO2 monitoring is an innocuous and efficient way to indirectly monitor PaCO2 preventing inadvertent hypocapnia and its deleterious effects on CBF/CMRO2 ratio during temporary carotid clamping.

Cerebral blood flow in critically ill cardiac patients: effects of vasoactive drug therapy

The introduction of the thermodilution technique (TD) in measuring cardiac output (CO) and coronary sinus blood flow has suggested the application of the same technique into measuring CBF which has been validated by several methods using transcranial Doppler and Xenon inhalation clearance curves. The present work is intended to assess the effect of two vasoactive drugs on CBF in 20 critically ill patients (12 males, 8 females, mean age: 5.86 ± 9.46) all having CHF due to dilated cardiomyopathy. Following clinical examination all patients were subjected to haemodynamic evaluation including central venous line, arterial cannulation and jugular vein catheterization. The latter was performed using Baim coronary sinus catheter directed towards the right jugular vein under fluroscopic guidance up to the bulb of internal jugular vein. Jugular blood flow (JBF) was measured by constant infusion of ice cold (5%) dextrose solution and recorded digitally on a Baim coronary sinus computer. Haemodynamic measurements including CBF were made at rest and repeated following infusion of noradrenaline (NA) in incremental doses sufficient to raise BP by one third of the basal reading. An average of three readings were taken. NA was discontinued and after 20 min the same method was repeated after dobutamine infusion given in a dose of 10 μg/kg/min for 20 min. Compared to basic measurements, NA significantly reduced CBF by 22.4 ± 4.79% in 13 patients with simultaneous increase in CVR by 106.73 ± 29.0%, NA increased CBF by 40.46 ± 12.0% in seven patients with simultaneous decrease of CVR by 13.7 ± 6.2%. It also increased systemic vascular resistance by 24.9 ± 2.76%, P < 0.0001. On the other hand dobutamine has led to an increase in CBF by 56 ± 12% in 11 patients with simultaneous decrease in CVR by 22 ± 6.31%. It decreased the CBF by 38.1 ± 11.8% in four patients with simultaneous increase in CVR by 130.68 ± 70.01%, and a decrease SVR by 21 ± 5%, P < 0.0359. In conclusion, vasoactive drugs commonly used in critically ill cardiac patients have different effects on cerebral blood flow. Despite the beneficial effects obtained from using NA in increasing perfusion pressure and cardiac output, the adverse effects on CBF are an obvious limitation to its use as a monotherapy, compared to dobutamine which besides augmenting CO improves dramatically CBF.

Über die Kanalsysteme im Os temporale und deren Rechts-links-Unterschiede

The first part of the facial canal is the pars labyrinthica. Its means lateral length is in our material 2.63 mm on the right and 3.03 mm on the left side. The mean width of the pore on the fundus area was 1.3 mm on the right side and 1.07 mm on the left. The geniculate fossa had a mean length of 2.54 mm on the right and of 3.14 mm on the left side. The widths of different areas of the pars labyrinthica and fossa geniculata were also measured. The angle between the first and second parts of the Fallopian canal was estimated with different methods. The mean width of the tympanic part of the facial canal was found to be 1.79 mm on the right side and 1.67 mm on the left, the mean width of the mastoideal part was 1.8 mm on the right side and 1.7 mm on the left. Distances of the mastoideal part of the Fallopian canal to mastoideal cells, ear drum, sigmoid sinus and external surface of the temporal bone were also measured. Measurements of the sigmoid sinus, the bulb of internal jugular vein and the cavum musculi stapedii are included, too. The ranges found in our material are also given.