Comparison of human cadaver and blue phantom for teaching ultrasound-guided regional anesthesia to novice postgraduate students of anesthesiology: A randomized controlled trial.

Background and Aims: Simulation is increasingly used in medical teaching. Various studies have evaluated different simulation models for training of regional anesthesia (RA). We compared the use of human cadaver and blue phantom models for training of regional anesthesia to novice postgraduate students of anesthesiology. Material and Methods: Fifty students were taught knobology of the ultrasonography (USG) machine. They were divided into two equal groups by computer-generated random number table, and the groups assigned were kept in sealed envelopes. In group BP, students were trained on a blue phantom model, and in group HC, students were trained on human cadaver. After training, a didactic video of sonoanatomy of the supraclavicular block was shown to all participants. The block performance was then judged on patients requiring supraclavicular block. The primary objective of the study was to compare the block performance time, and secondary objectives were the quality of image acquired, orientation of transducer to the target, identification of ultrasound artifacts, errors committed, complications, and success rate. Results: The mean block performance time was shorter in group HC compared to group BP (451.96 ± 50.25 and 526.48 ± 43.486 s, respectively; P < 0.001). The image quality score, transducer orientation to the target, and identification of USG artifacts were better in group HC compared to group BP, with lesser number of needle passes. Conclusion: Cadaver-based training produced better results compared to blue phantom simulator model for teaching of ultrasound-guided RA to novice postgraduate trainees of anesthesiology.

Dependability of Electrode to Modiolus Distance in Patients Specific Electrode Selection: A Cadaveric Model Study.

OBJECTIVE: This study aims to discern the disparities in the electrode-to-modiolus distance (EMD) between cochleostomy and round window approaches when performed sequentially in the same temporal bone. Additionally, the study seeks to identify the cochlear metrics that contribute to these differences. METHODOLOGY: A cross-sectional study was conducted, involving the sequential insertion of a 12-electrode array through both round window and cochleostomy approaches in cadaveric temporal bones. Postimplantation high-resolution CT scans were employed to calculate various parameters. RESULTS: A total of 12 temporal bones were included in the imaging analysis, revealing a mean cochlear duct length of 32.892 mm. The EMD demonstrated a gradual increase from electrode 1 (C1) in the apex (1.9 ± 0.07 mm; n = 24) to electrode 12 (C12) in the basal turn (4.6 ± 0.24 mm; n = 12; p < 0.01). Significantly higher EMD values were observed in the cochleostomy group. Correlation analysis indicated a strong positive correlation between EMD and cochlear perimeter (CP) (rs = 0.64; n = 12; p = 0.03) and a strong negative correlation with the depth of insertion (DOI) in both the middle and basal turns (rs = - 0.78; n = 20; p < 0.01). Additionally, EMD showed a strong negative correlation with the DOI-CP ratio (rs = -0.81; n = 12; p < 0.01). CONCLUSION: The cochleostomy group exhibited a significantly higher EMD compared with the round window group. The strong negative correlation between EMD and DOI-CP ratio suggests that in larger cochleae with shallower insertions, EMD is greater than in smaller cochleae with deeper insertions. LEVEL OF EVIDENCE: N/A Laryngoscope, 2024.

Morphometric Comparison of Endoscopic Endonasal Transpterygoid and Precaruncular Contralateral Medial Transorbital Approaches to Sphenoid Sinus Lateral Recess.

BACKGROUND AND OBJECTIVES: The endoscopic endonasal transpterygoid approach (TPA), minimally invasive compared with the sublabial transmaxillary and transcranial approaches, still accounts for morbidity in benign lateral recess of sphenoid sinus (LRSS) pathologies. Others have suggested an alternative route to the LRSS, the endoscopic contralateral medial transorbital approach (cMTO). However, no quantitative evidence exists to support the clinical application of this approach. This cadaveric study, in a controlled laboratory setting, provides a morphometric comparison of the TPA and cMTO for accessing the LRSS. The study also details the anatomy and technical nuances for optimizing the cMTO corridor. METHODS: Ten fresh preinjected human cadaveric specimens (20 sides) were dissected with neuronavigation, completing endoscopic cMTO and TPA on each side. Four parameters-working distance to lateral recess, surgical exposure area, angle of attack (AoA), and surgical freedom-were measured for each approach. Relevant osteological measurements in 10 dried human skulls were recorded. RESULTS: The mean distance from the superior margin of the lacrimal sac impression to the inferior margin of the trochlear fossa was 10.29 ± 1.13 mm, and that from the anterior ethmoidal artery foramina to the posterior lacrimal crest was 9.63 ± 1.23 mm. The mean exposure area around the LRSS was significantly higher in TPA (614.09 ± 40.38 mm2) than in cMTO (391.19 ± 59.01 mm2, P = .001). The mean AoA was 9.83° and 10.24° in the cMTO and TPA, respectively, in the craniocaudal direction (P = .529). In the horizontal plane, it was 9.29° and 10.76° (P = .012). There was no significant difference in surgical freedom between the cMTO and TPA (804.61 and 806.05 mm3, respectively; P = .993). CONCLUSION: Although comparatively limited exposure area, the cMTO approach has a similar AoA and surgical freedom as TPA and offers better visualization and ergonomic advantages. cMTO provides a feasible, less morbid, multiport technique for benign sphenoid sinus lateral recess pathologies.

Comparison of depth of electrode insertion between cochleostomy and round window approach: a cadaveric study.

INTRODUCTION: Round window approach and cochleostomy approach can have different depth of electrode insertion during cochlear implantation which itself can alter the audiological outcomes in cochlear implant. OBJECTIVE: The current study was conducted to determine the difference in the depth of electrode insertion via cochleostomy and round widow approach when done serially in same temporal bone. METHODOLOGY: This is a cross-sectional study conducted in the Department of Otorhinolaryngology in conjunction with Department of Anatomy and Department of Diagnostic and Interventional Radiology over a period of 1 year. 12-electrode array insertion was performed via either approach (cochleostomy or round window) in the cadaveric temporal bone. HRCT temporal bone scan of the implanted temporal bone was done and depth of insertion and various cochlear parameters were calculated. RESULT: A total of 12 temporal bones were included for imaging analysis. The mean cochlear duct length was 32.892 mm; the alpha and beta angles were 58.175° and 8.350°, respectively. The mean angular depth of electrode insertion via round window was found to be 325.2° (SD = 150.5842) and via cochleostomy 327.350 (SD = 112.79) degree and the mean linear depth of electrode insertion via round window was found to be 18.80 (SD = 4.4962) mm via cochleostomy 19.650 (SD = 3.8087) mm, which was calculated using OTOPLAN 1.5.0 software. There was a statically significant difference in linear depth of insertion between round window and cochleostomy. Although the angular depth of insertion was higher in CS group, there was no statistically significant difference with round window type of insertion. CONCLUSION: The depth of electrode insertion is one of the parameters that influences the hearing outcome. Linear depth of electrode insertion was found to be more in case of cochleostomy compared to round window approach (p = 0.075) and difference in case of angular depth of electrode insertion existed but not significant (p = 0.529).

Can ultrasound-guided radiofrequency ablation of genicular nerves of the knee, be performed without locating corresponding arterial pulsations-a cadaveric study.

INTRODUCTION: Given the rising prevalence of knee osteoarthritis, radiofrequency ablation of genicular nerves (RFA) has emerged as a promising treatment option for knee pain. The knee has an extremely complex and variable innervation with nearly 13 genicular nerves described. The frequently ablated genicular nerves are the superomedial (SMGN), the superolateral (SLGN), and the inferomedial (IMGN) genicular nerves. Conventionally, under ultrasound guidance, these nerves are ablated near the corresponding arterial pulsations, but due to the rich vascular anastomosis around the knee joint, identifying the arteries corresponding to these constant genicular nerves can be tedious unless guided by some bony landmarks. In this study, we have evaluated whether it is possible to accurately target these three genicular nerves by just locating bony landmarks under ultrasound in human cadaveric knee specimens. METHODS: Fifteen formalin-fixed cadaveric knee specimens were studied. SMGN was targeted 1 cm anterior to the adductor tubercle in the axial view. For SLGN, in the coronal view, the junction of the lateral femoral condyle and shaft was identified, and at the same level in the axial view, the crest between the lateral and posterior femoral cortex was targeted. For IMGN in the coronal view, the midpoint between the most prominent part of the medial tibial condyle and the insertion of the deep fibers of the medial collateral ligament was marked. The medial end of the medial tibial cortex was then targeted at the same level in the axial view. The needle was inserted from anterior to posterior, with an in-plane approach for all nerves. Eosin, 2% W/V, in 0.1 ml was injected. Microdissection was done while keeping the needle in situ. Staining of the nerve was considered a positive outcome, and the percentage was calculated. The nerve-to-needle distance was measured, and the mean with an interquartile range was calculated. RESULT: The accuracies of ultrasound-guided bony landmarks of SMGN, SLGN, and IMGN were 100% in terms of staining, with average nerve-to-needle distances of 1.67, 3.2, and 1.8 mm respectively. CONCLUSION: It is with 100% accuracy, that we can perform RFA of SMGN, SLGN, and IMGN under ultrasound guidance, by locating the aforementioned bony landmarks.

Systematic Review of Morphometric Analysis of Anterior Cerebral Artery (ACA) Emphasizing on Its Clinical Implications.

Thorough data of morphometric measurements of arteries forming Circle of Willis (CW) is crucial for radiological and neurosurgical interventions. This systematic review has been conducted with the objective to find an effective range of length and diameter of anterior cerebral artery (ACA) and to observe whether there is any change in the length and diameter of ACA depending on age or sex. Articles based on length and diameter of ACA via any mode of study like cadaveric or radiological were considered in this systematic review. A comprehensive literature search using databases Cochrane Library, PubMed, and Scopus for relevant articles was done. Research papers which answered the focused questions were selected for data analysis. It was observed that the range of length and diameter of ACA were 8.1 mm-21 mm and 0.5 Å-3.4 mm, respectively. In majority of the studies, length and diameter of ACA were more in the younger age group (>40 years); and the length of ACA was more in females whereas the diameter of ACA was more in males. These data will be applicable for better construction and decipherment of angiographic images. This will help in the proper and guided treatment of intracranial pathologies.

Forensic tool for sex prediction- hand dimensions.

Background: Determination of sex from mutilated body fragments can perform vital role for identification of departed soul. Forensic authority pacts with human identification from the hand measurements which is of prodigious assessment during tragedies, terror attacks and in criminality. Objective: Present study explored the analytical role of the anthropometric measurements of hand dimensions, find demarking points for male and female, check percentage exactitude of sex determination in Western Indian population. Methods: The study was piloted on a sample of 504 individuals. All the measurements were taken by standard procedure. Discriminant analysis and demarking points were created for all hand measurements. Results: Males have a significantly higher values of all measurements than females. The left-hand length measurement unveiled a noteworthy sexual dimorphism index (110.80). The higher value of the demarking point labelled as males. The best sexually dimorphic hand dimensions showed the utmost precision left hand length (95% in the male), followed by right hand length (76.1%). Conclusion: All hand measurements like length, breadth and index are displaying sexual dimorphism, hence they can be used for determination of sex when isolated hand is found.

Morphometric Analysis of parameters of Internal Carotid Artery-Potential Clinical Implications.

BACKGROUND: The study in consideration aimed to do morphometry of internal carotid artery (ICA) and substantiate any differences significant in relation to sex and age on digital subtraction angiography (DSA) imaging. OBJECTIVES: Our study aims to ascertain morphometric parameters of ICA through DSA evaluation and to build a normative data which is accurate enough for the neurovascular procedures to be performed. The study will also carry out correlation of morphometry of intracerebral blood vessels with sex, age, and side-related dimorphism. MATERIAL AND METHODS: Our study, cross-sectional in design was done on 70 patients (>20 years). Diameter of different segments of ICA were measured after imaging was done on DSA using a Philips biplane system clarity (Allura FD20/20). Statistical analysis was done. RESULT AND CONCLUSION: In males, mean diameter of petrous, cavernous, supraclinoid, and choroidal segments of ICA were more when compared to females. Statistically significant differences were found in supraclinoid segment of ICA between males and females. The mean diameter of supraclinoid and choroidal segments of ICA showed a decreasing trend from younger to older age groups. The difference in the mean diameter of petrous segment of ICA with increasing age was statistically significant. The results of our study show that differences were statistically significant in supraclinoid segment of ICA in males and females. Neurosurgeons in order to be confident in tackling the various emergencies in this region need to have in-depth knowledge of morphometery of cerebral arterial circle.

Design and experimental investigations on six-stroke SI engine using acetylene with water injection.

In the present study, a four-stroke cycle gasoline engine is redesigned and converted into a six-stroke cycle engine and experimental study has been conducted using gasoline and acetylene as fuel with water injection at the end of the recompression stroke. Acetylene has been used as an alternative fuel along with gasoline and performance of the six-stroke spark ignition (SI) engine with these two fuels has been studied separately and compared. Brake power and thermal efficiency are found to be 5.18 and 1.55% higher with acetylene as compared to gasoline in the six-stroke engine. However, thermal efficiency is found to be 45% higher with acetylene in the six-stroke engine as compared to four-stroke SI engine. The CO and HC emissions were found to be reduced by 13.33 and 0.67% respectively with acetylene as compared to gasoline due to better combustion of acetylene. The NOx emission was reduced by 5.65% with acetylene due to lower peak temperature by water injection. The experimental results showed better engine performance and emissions with acetylene as fuel in the six-stroke engine.

Properties and effects of organic additives on performance and emission characteristics of diesel engine: a comprehensive review.

Fast depletion of conventional automobile fuels and environmental pollution due to exhaust emission are the issues of great importance. Improvement in engine performance and emission control is quite difficult to handle simultaneously. The fuel properties can be improved substantially by incorporation of additives in different proportions to get better emission standard without deteriorating the engine performance. The aim of current study is to review/summarize the effects of various organic additives on the engine performance (i.e., brake thermal efficiency, brake specific fuel consumption, volumetric efficiency, etc.) and emissions (i.e., carbon dioxide, carbon monoxide, nitrogen oxides, hydrocarbons, particulate matter, and other harmful compounds). The physico-chemical and combustion properties (i.e., density, latent heat, dynamic viscosity, flash point, boiling point, cetane number, oxygen content, lower heating value, auto-ignition temperature, etc.) of various additives were also discussed to check the suitability of additives with diesel. Finally, limitations and opportunities using organic additives with respect to engine performance and combustion were discussed to guide future research and improvement in this field.

Experimental investigation of performance and emissions of a VCR diesel engine fuelled with n-butanol diesel blends under varying engine parameters.

The continuous rise in the cost of fossil fuels as well as in environmental pollution has attracted research in the area of clean alternative fuels for improving the performance and emissions of internal combustion (IC) engines. In the present work, n-butanol is treated as a bio-fuel and investigations have been made to evaluate the feasibility of replacing diesel with a suitable n-butanol-diesel blend. In the current research, an experimental investigation was carried out on a variable compression ratio CI engine with n-butanol-diesel blends (10-25% by volume) to determine the optimum blending ratio and optimum operating parameters of the engine for reduced emissions. The best results of performance and emissions were observed for 20% n-butanol-diesel blend (B20) at a higher compression ratio as compared to diesel while keeping the other parameters unchanged. The observed deterioration in engine performance was within tolerable limits. The reductions in smoke, nitrogen oxides (NO x ), and carbon monoxide (CO) were observed up to 56.52, 17.19, and 30.43%, respectively, for B20 in comparison to diesel at rated power. However, carbon dioxide (CO2) and hydrocarbons (HC) were found to be higher by 17.58 and 15.78%, respectively, for B20. It is concluded that n-butanol-diesel blend would be a potential fuel to control emissions from diesel engines. Graphical abstract ᅟ.

Unilateral intercordal neural communication coexistent with variant branching pattern of posterior cord of brachial plexus.

Variant branching pattern of the cords of brachial plexus coupled with erroneous communications has been an area of concern for surgeons opting to explore this region. Anaesthetic blocks and surgical approaches are the highlights of these interventions, where a keen familiarization of the anatomy of this region is mandatory. The present case description reports a unilateral variant branching pattern of the posterior cord coexistent with a neural communication between lateral and medial cords in an adult male cadaver. This intercordal neural communication between lateral and medial cords was oriented obliquely and measured 2.2 cm in length. Furthermore, the posterior cord revealed a variant branching pattern. It branched into three upper subscapular nerves and a common trunk for the thoracodorsal and lower subscapular nerves. The lowest of the three upper subscapular nerves gave a communicating twig to the thoracodorsal nerve. Inspite of uncountable reports on variations ofbrachial plexus, descriptions regarding anomalous branching patterns hold enormous clinical significance for the radiologists, anesthetists and surgeons, besides being of academic interest for the anatomists.