Wire Insertion Research Articles

Comparison of Three Different Approaches to Ultrasound Guided Internal Jugular Vein Cannulation: A Randomised Clinical Study

Introduction: The standard approaches to ultrasound-guided central line insertion by Short Axis (SAX) and Long Axis (LAX) have limitations. The Medial Oblique Axis (M-OAX) approach allows visualisation of the length of the needle in real-time along with both the artery and vein. Aim: To compare the three approaches for ultrasound-guided right Internal Jugular Vein (IJV) cannulation with respect to ease of access and complications. Materials and Methods: A total of 171 patients scheduled to undergo right IJV cannulation were divided equally into three groups-SAX (Group-1), LAX (Group-2), and M-OAX (Group-3). They were compared with respect to first pass success, Venous Access Time (VAT), guide wire insertion time, catheterisation time, and complications. Continuous variables were compared with Analysis of Variance (ANOVA) test. Categorical variables were analysed using the Chi-square test. The p-value <0.05 was considered significant. Results: First pass success was 55 (96.49%), 53(92.98%), and 54 (94.74%) in groups 1, 2, and 3, respectively. The VAT, guidewire insertion time, and catheterisation time were significantly lesser in Groups 1 and 3 compared to 2 (p<0.001). Two cases of carotid artery puncture were noted in Group-2, though statistically not significant (p>0.05). Conclusion: The medial oblique approach to IJV cannulation combines the advantages of both LAX and SAX and is a safer alternative with easier and faster venous access.

Abstract 17231: Importance of Intra Plaque Hemorrhage During Carotid Artery Revascularization

Introduction: The American Heart Association currently estimates that every 3 minutes a person dies from a stroke. Carotid artery stenosis, a major risk factor for new and recurrent strokes, can be treated with carotid artery revascularization. Vascular emboli released during this procedure are non-invasively detected by transcranial doppler (TCD) ultrasound as micro embolic signals (MES). In this study we aim to show the relationship between carotid plaque characteristics and MES rates that were detected by TCD-monitoring throughout the stages of the carotid artery revascularization procedures. Methods: Before elective carotid revascularization 30 patients (mean age 72±8 years; 16 males, 14 females) underwent 3-T MRI. After localization of the carotid bifurcation using phase contrast imaging, Time-of-Flight, 3D T1 weighting, transverse T1 and T2 weightings and proton density sequences were acquired. The different plaque components: lipid core, intraplaque hemorrhage, calcification and the characterization of the fibrous cap were assessed. While 20 patients underwent carotid endarterectomy (CEA), 10 patients had carotid artery stenting (CAS). CES was divided into 9 stages: 1- Pre-procedure, 2- Dissection, 3- IC clamp, 4- Shunt placement, 5- Shunt open, 6- Endarterectomy, 7- Clamped, 8- IC opened, 9- Post-procedure. Similarly, CAS was divided into 9 stages: 1- Pre-procedure, 2- Arch-carotid angiography, 3- Wire insertion, 4- Filter deployment, 5- Pre-dilation, 6- Stent deployment, 7- Post-dilation, 8- Final angiography, 9- Post-procedure. Patients were monitored continuously with TCD to detect pre-procedural, intra-procedural and post-procedural MES rates. Results: Intraplaque hemorrhage was observed in 18 patients (60%). Patients with intra plaque hemorrhage had more MES during carotid artery dissection/arch-carotid angiography (p=0.028) and IC clamping/wire insertion (p=0.009) compared to patients without intra plaque hemorrhage in the pre-procedural stage. Conclusions: Carotid plaques with intra plaque hemorrhage is associated with higher MES during carotid artery revascularization procedures.

Abstract 17178: Rates of Micro Embolic Signals at Different Stages of Carotid Artery Revascularization

Background: The American Heart Association currently estimates that over 160,000 people die every year due to new or recurrent strokes, many from carotid artery stenosis. This association has led to increased use of carotid revascularization procedures such as carotid endarterectomy (CEA) and carotid artery stenting (CAS). In this study we aim to describe the different rates of micro embolic signals (MES) at different stages of carotid artery revascularization. Methods: Before elective carotid revascularization 57 patients (mean age 72±8 years; 15 males, 21 females) underwent 3-T MRI. After localization of the carotid bifurcation using phase contrast imaging, Time-of-Flight, 3D T1 weighting, transverse T1 and T2 weightings and proton density sequences were acquired. The different plaque components: lipid core, intraplaque hemorrhage, calcification and the characterization of the fibrous cap were assessed. While 34 patients underwent CEA, 20 patients had CAS. CES was divided into 9 stages: 1- Pre-procedure, 2- Dissection, 3- IC clamp, 4- Shunt placement, 5- Shunt open, 6- Endarterectomy, 7- Clamped, 8- IC opened, 9- Post-procedure. Similarly, CAS was divided into 9 stages: 1- Pre-procedure, 2- Arch-carotid angiography, 3- Wire insertion, 4- Filter deployment, 5- Pre-dilation, 6- Stent deployment, 7- Post-dilation, 8- Final angiography, 9- Post-procedure. Patients were monitored continuously with transcranial doppler (TCD) to detect pre-procedural, intra-procedural and post-procedural MES rates. Results: MES was detected in 20 (87%) patients undergoing CAS compared to 18 (53%) patients undergoing CES during the IC Clamp/Wire Insertion stage (p=0.004). Greater mean micro embolic signals were also found in symptomatic patients undergoing CAS than in asymptomatic patients during arch-carotid angiography (10.8 vs 2.4, p= 0.022), post-dilation (3.1 vs 1.1, p=0.047), and post-procedure (4.8 vs 1.3, p=0.044). Conclusion: MES is increased during the wire insertion stage of CAS in addition to post-dilation and post-procedure stages. Also, the finding of increased MES during arch-carotid angiography suggests that less invasive alternatives to diagnostic angiography should be considered in symptomatic patients.

Rapid integration of screen-printed electrodes into thermoplastic organ-on-a-chip devices for real-time monitoring of trans-endothelial electrical resistance.

Trans-endothelial electrical resistance (TEER) is one of the most widely used indicators to quantify thebarrier integrity of endothelial layers. Over the last decade, the integration of TEER sensors into organ-on-a-chip (OOC) platforms has gained increasing interest for its efficient and effective measurement of TEERin OOCs. To date, microfabricated electrodes or direct insertion of wires has been used to integrate TEERsensors into OOCs, with each method having advantages and disadvantages. In this study, we developed aTEER-SPE chip consisting of carbon-based screen-printed electrodes (SPEs) embedded in a poly(methylmethacrylate) (PMMA)-based multi-layered microfluidic device with a porous poly(ethylene terephthalate)membrane in-between. As proof of concept, we demonstrated the successful cultures of hCMEC/D3 cellsand the formation of confluent monolayers in the TEER-SPE chip and obtained TEER measurements for 4days. Additionally, the TEER-SPE chip could detect changes in the barrier integrity due to shear stress oran inflammatory cytokine (i.e., tumor necrosis factor-α). The novel approach enables a low-cost and facilefabrication of carbon-based SPEs on PMMA substrates and the subsequent assembly of PMMA layers forrapid prototyping. Being cost-effective and cleanroom-free, our method lowers the existing logistical andtechnical barriers presenting itself as another step forward to the broader adoption of OOCs with TEERmeasurement capability.

Ultrasound Investigation of the Radial Nerve's Superficial Branch: Reducing the Risk of K-Wire Insertion Damage in Distal Radius Fractures.

Kirschner wire (K-wire) insertion during surgery for distal radius fractures carries a risk of damaging the radial nerve's superficial branch. In this prospective study, we investigated the relationship between the radial nerve's superficial branch and the radius using ultrasound to minimize risk. We collected data from 101 healthy volunteers (202 limbs; 51 men; mean age: 40.6 years). We ultrasonographically assessed the courses of the radial nerve's dorsal and superficial palmar branches at 0, 1, 2, and 3 cm proximal to the radial styloid process tip. The positional relationship between the radial nerve's superficial branch and the radius was determined by splitting the radius's ultrasound map into 4 sections (R1-R4) from the palmar side. The section containing the dorsal and palmar branch midpoints was determined for each height. In many limbs, the dorsal branch tended to wrap from the proximal palmar to the distal dorsal side at 1 to 2 cm proximal to the radial styloid process tip. In approximately 90% of limbs, the palmar branch ran along the radius's palmar side rather than the radial surface. A small incision enabling direct view may be the best approach for avoiding nerve damage when the superficial branch is less than or equal to 2 cm proximal to the tip of the radial styloid process. Inserting the K-wire from the dorsal side of the radius may be safer for more proximal locations. We recommend a preoperative ultrasound examination to determine the course of the superficial branches of the radial nerve in each patient.

Limb salvage and functional recovery in infected nonunion of the distal tibia treated with the Ilizarov techniques

IntroductionTreatment of infected nonunion of the distal juxta-articular tibia is a challenge due to a short distal fragment, deformity, thin soft-tissue envelope, and active infection. There is still no consensus on the approach that is able to maximally salvage the limb and ankle function. Material and methodsInfected juxta-articular nonunion of the distal tibia was managed with two Ilizarov techniques, monofocal compression (MC) used in 12 patients and bifocal compression-distraction (BCD) in 6 patients. The choice of the technique depended on the size of the postresection defect, ≥3 cm or ≤3 cm, respectively. The tactics of functional approach were careful debridement, insertion of wires in the distal fragment so that they do not penetrate the ankle joint, stable fixation, and temporary bridging of the ankle and forefoot. MSCT was used along with regular radiography to assess the union and regeneration. Ankle functions were evaluated with AOFAS ankle-hindfoot score system. ResultsBone consolidation, infection arrest and ankle function improvement were achieved in all patients. External fixation continued 221.7 ± 15.1 days for MC and 235 ± 25.8 days for BCD. Complications were wound divergence, wire-tract infection, premature consolidation of the fibula, and hypoplastic regeneration in one case. The mean functional AOFAS score after treatment was 90.7 ± 2.5 points in MC and 89.7 ± 1.3 in BCD patients. Residual limb discrepancy after MC ranged 0–4 cm. Bone shortening was compensated in BCD patients. ConclusionLimb-salvage and functional approach to the treatment of infected nonunion of the juxta-articular distal tibia with the Ilizarov techniques achieves good outcomes. It provides bone infection arrest, consolidation, defect compensation and significantly improves the ankle joint function.

Transfer Validity of Pediatric Supracondylar Humeral Fracture Pin Placement Practice on In-Theater Performance by Orthopedic Trainees Using an Augmented Reality Simulator: Protocol for a Pilot Interventional Cohort Study With a Retrospective Comparator Cohort.

Supracondylar humeral fractures (SCHF) are a common cause of orthopedic morbidity in pediatric populations across the world. The treatment of this fracture is likely one of the first procedures involving x-ray-guided wire insertion that trainee orthopedic surgeons will encounter in their career. Traditional surgical training methods of "see one, do one, teach one" are reliant on the presence of real-world cases and must be conducted within an operative environment. We have developed an augmented reality simulator that allows trainees to practice this procedure in a radiation-free environment at no extra risk to patients. This study aims to examine whether training on a simulator in addition to traditional surgical training improves the in-theater performance of trainees. This multicenter, interventional cohort study will involve orthopedic trainees from New Zealand in their first year of advanced training between 2019 and 2023. Advanced trainees with no simulator exposure who were in their first year in 2019-2021 will form the comparator cohort, while those in the years 2022-2023 will receive additional regular simulator training as the intervention cohort. The comparator cohort's performance in pediatric SCHF surgery will be retrospectively audited using routinely collected operative outcomes and parameters over a 6-month period. Data on the performance of the intervention cohorts will be collected in the same way over a comparable period. The data collected for both groups will be used to determine whether additional training with an augmented reality training shows improved real-world surgical outcomes compared to traditional surgical training. As of February 2022, a total of 8 retrospective comparator trainees have been recruited by email. The study is financially supported through an external grant from the Wishbone Orthopaedic Research Foundation of New Zealand (September 2021) and an internal research grant from the University of Otago (July 2021). This protocol has been approved by the University of Otago Health Ethics committee (reference HD21/087), and the study is due for completion in 2024. This protocol may assist other researchers conducting similar studies in the field. Australian New Zealand Clinical Trials Registry ACTRN12623000816651; https://tinyurl.com/mtdkecwb. DERR1-10.2196/38282.

Procedural Time and Outcomes of Chronic Total Occlusion Percutaneous Coronary Intervention

Chronic total occlusion (CTO) percutaneous coronary interventions (PCIs) can be lengthy procedures. We sought to investigate the effect of procedural time on CTO PCI outcomes. We examined the procedural time required for the various steps of CTO PCI in 6,442 CTO PCIs at 40 US and non-US centers between 2012 and 2022. The mean and median procedure times were 129 ± 76 and 112minutes, respectively, with no significant change over time. The median times from access to wire insertion, guidewire manipulation time, and post crossing were 20, 32, and 53minutes, respectively. Lesions crossed in <30minutes were less complex, as reflected by lower Japanese CTO score (1.89 ± 1.19, p <0.001) than lesions that were not successfully crossed (2.88 ± 1.22) and lesions that were crossed in ≥30minutes (2.85 ± 1.13). The likelihood of successful crossing if crossing was not achieved after 30, 90, and 180minutes were a 76.7%, 60.7%, and 42.7%, respectively. The parameters independently associated with ≥30minutes guidewire manipulation time in patients with a primary antegrade approach included left anterior descending target vessel, proximal cap ambiguity, blunt/no stump, occlusion length, previous failed attempt, medium/severe calcification, and medium/severe tortuosity. The mean duration of CTO PCI is approximately 2hours (∼20% of time for access to wire insertion, ∼30% wire manipulation time, and ∼50% postwiring time). Guidewire crossing time was shorter in less complex lesions and in cases without complications.

A multi-view interactive virtual-physical registration method for mixed reality based surgical navigation in pelvic and acetabular fracture fixation.

The treatment of pelvic and acetabular fractures remains technically demanding, and traditional surgical navigation systems suffer from the hand-eye mis-coordination. This paper describes a multi-view interactive virtual-physical registration method to enhance the surgeon's depth perception and a mixed reality (MR)-based surgical navigation system for pelvic and acetabular fracture fixation. First, the pelvic structure is reconstructed by segmentation in a preoperative CT scan, and an insertion path for the percutaneous LC-II screw is computed. A custom hand-held registration cube is used for virtual-physical registration. Three strategies are proposed to improve the surgeon's depth perception: vertices alignment, tremble compensation and multi-view averaging. During navigation, distance and angular deviation visual cues are updated to help the surgeon with the guide wire insertion. The methods have been integrated into an MR module in a surgical navigation system. Phantom experiments were conducted. Ablation experimental results demonstrated the effectiveness of each strategy in the virtual-physical registration method. The proposed method achieved the best accuracy in comparison with related works. For percutaneous guide wire placement, our system achieved a mean bony entry point error of 2.76 ± 1.31mm, a mean bony exit point error of 4.13 ± 1.74mm, and a mean angular deviation of 3.04 ± 1.22°. The proposed method can improve the virtual-physical fusion accuracy. The developed MR-based surgical navigation system has clinical application potential. Cadaver and clinical experiments will be conducted in future.

Finite Element Analysis of the Mechanical Strength of Phalangeal Osteosynthesis Using Kirschner Wires.

Background: Kirschner wire (K-wire) fixation is widely used to repair metacarpal and phalangeal fractures. In this study, we simulated K-wire osteosynthesis of a 3-dimensional (3D) phalangeal fracture model and investigated the fixation strength at various K-wire diameters and insertion angles to clarify the optimal K-wire fixation method for phalangeal fractures. Methods: The 3D phalangeal fracture models were created by using computed tomographic (CT) images of the proximal phalanx of the middle finger in five young healthy volunteers and five elderly osteoporotic patients. Two elongated cylinders representing K-wires were inserted according to various cross-pinning methods; the wire diameters were 1.0, 1.2, 1.5 and 1.8 mm, and the wire insertion angles (i.e. the angle between the fracture line and the K-wire) were 30°, 45° and 60°. The mechanical strength of the K-wire fixed fracture model was investigated by using finite element analysis (FEA). Results: The fixation strength increased with increasing wire diameter and insertion angle. Insertion of 1.8-mm wires at 60° achieved the strongest fixation force in this series. Fixation strength was generally stronger in the younger group than the elderly group. Dispersion of stress to cortical bone was a critical factor to increase fixation strength. Conclusions: We developed a 3D phalangeal fracture model into which we inserted K-wires; using FEA, we clarified the optimal crossed K-wire fixation method for phalangeal fractures. Level of Evidence: Level V (Therapeutic).

PROTOCOL FOR EXAMINING TRANSFER VALIDITY OF A SUPRACONDYLAR HUMERAL FRACTURE PINNING AUGMENTED REALITY SIMULATOR

Augmented reality simulators offer opportunities for practice of orthopaedic procedures outside of theatre environments. We developed an augmented reality simulator that allows trainees to practice pinning of paediatric supracondylar humeral fractures (SCHF) in a radiation-free environment at no extra risk to patients. The simulator is composed of a tangible child's elbow model, and simulated fluoroscopy on a tablet device. The treatment of these fractures is likely one of the first procedures involving X-ray guided wire insertion that trainee orthopaedic surgeons will encounter. This study aims to examine the extent of improvement simulator training provides to real-world operating theatre performance.This multi-centre study will involve four cohorts of New Zealand orthopaedic trainees in their SET1 year. Trainees with no simulator exposure in 2019 - 2021 will form the comparator cohort. Trainees in 2022 will receive additional, regular simulator training as the intervention cohort. The comparator cohort's performance in paediatric SCHF surgery will be retrospectively audited using routinely collected operative outcomes and parameters over a six-month period. The performance of the intervention cohorts will be collected in the same way over a comparable period. The data collected for both groups will be used to examine whether additional training with an augmented reality simulator shows improved real-world surgical outcomes compared to traditional surgical training. This protocol has been approved by the University of Otago Health Ethics committee, and the study is due for completion in 2024.This study is the first nation-wide transfer validity study of a surgical simulator in New Zealand. As of September 2022, all trainees in the intervention cohort have been recruited along with eight retrospective trainees via email. We present this protocol to maintain transparency of the prespecified research plans and ensure robust scientific methods. This protocol may also assist other researchers conducting similar studies within small populations.

Influence of Kirschner-Wire Insertion Angle on Construct Biomechanics following Tibial Tuberosity Osteotomy Fixation in Dogs.

The aim of this study was to evaluate the effect of Kirschner wire insertion angle on the biomechanical characteristics following tibial tuberosity osteotomy fixation in dogs. Twelve pairs of cadaveric tibia were harvested and randomly assigned to two treatment groups. Kirschner wires were placed either transversely (0 degrees) or placed caudodistally (30 degrees) with respect to the tibial tuberosity osteotomy. Each limb acted as its own respective control. Radiographic analysis allowed for the calculation of Kirschner wire insertion angle variance. Constructs were tested to monotonic failure while evaluating yield, peak, and failure forces, construct stiffness, and failure mode. Kirschner wire insertion angles were 1.1 ± 2.2 degrees and 30.5 ± 2.3 degrees, respectively, for 0-degree and 30-degree groups (p <0.0001). Yield (p = 0.0095), peak (p <0.024) and failure loads (p <0.030) were all significantly greater for Kirschner wires inserted at an angle of 0 degrees compared with 30 degrees. Construct stiffness did not differ regardless of insertion angle (p = 0.068). Failure mode did not differ (p = 0.87) with tibial tuberosity avulsion and Kirschner wire pull-out seen in the majority of constructs (67%). Kirschner wires placed transversely (0 degrees) for tibial tuberosity osteotomy fixation were biomechanically superior, increasing yield, peak, and failure forces by 1.6 times, 1.3 times, and 1.4 times, respectively, to those placed in a caudodistal (30 degrees) orientation. Kirschner wire insertion angle is an important consideration following tibial tuberosity osteotomy in dogs, with Kirschner wires placed at 0 degrees conferring increased resistance of the repair to construct deformation.

The preliminary outcomes of platelet-rich fibrin injection on pain perception following insertion of archwire: A randomized controlled clinical study

Objectives: This study aimed to determine the efficacy of platelet-rich fibrin (PRF) injection on orthodontic pain perception during the 1st week of the alignment and leveling process. Material and Methods: The study sample included 18 patients (11 females and 7 males). The patients were randomly divided into two groups, the PRF group (9 patients) and the control group (9 patients). The mean age of the sample members was 21.9 ± 2.5 and 20.8 ± 2.4 in the control and the PRF group, respectively. Conventional brackets were applied for both groups. PRF was injected into the six upper front teeth at a rate of 0.6 mm for each point before starting the primary wire insertion process. The pain parameters of each patient were evaluated for both groups during the 1st week of the alignment and leveling process by application of the Visual Analog Scale (VAS) at the durations of (2 h, 6 h, 1 day, 2 days, and 7 days) and all patients were followed up until the end of the alignment and leveling process. Results: PRF injection can reduce pain perception in orthodontic patients, overall (P &lt; 0.05), with an effect size of approx. 53 ± 0.13%. The biggest effect was observed 2 h after exposure (P &lt; 0.1) which showed a 50% reduction in pain in the PRF group. No significant effects were observed at later times (P &gt; 0.1). Conclusion: The present study concludes that PRF injection can be an effective alternative for decreasing pain perception levels; however, its efficacy needs to be leveraged immediately after the injection of PRF.

Electroanatomic visualization of coronary arteries: a case series to elicit safety, feasibility, and diagnostic value in complex ablation procedures.

The goal of this case series was to evaluate the feasibility, safety, and advantages of a wire-based approach for the live visualization of coronary arteries (CAs) in an electroanatomic mapping (EAM) system and to assess its diagnostic information. For this single-centre case series, we included procedures in which close proximity of a possible ablation site to any epicardial vessel was suspected. An uncoated-tip guidewire was introduced into the relevant CAs after exclusion of critical CA stenosis by coronary angiography. By connecting this wire to the EAM system using a clip and pin connection, mapping and live visualization of the wire tip is possible, as well as the assessment of the local electrograms within the respective CAs. Procedural wire insertion and intracoronary mapping was performed by EP specialists and was assisted to judge the relevance of CA disease by an interventional cardiologist. A total of nine procedures in nine patients were included in this case series, four ventricular tachycardia ablation procedures and five procedures for the ablation of premature ventricular contractions. The left CAs were mapped in eight cases and the right CA was mapped in one case. In two cases, epicardial mapping was combined with visualization of the right or left CAs. There were no complications attributed to coronary wiring and mapping in this case. We demonstrated the feasibility and safety of CA visualization and integration in an EAM. The live visualization of the CAs added valuable information without the need for preprocedural planning or the purchase of separate software. Electroanatomic visualization was achieved intraprocedurally in a safe and straightforward manner, adding critical diagnostic information without excessive costs or risks.

Caustic oesophageal stricture treated by instrumental dilatation: A review of 6 years of practice at the pediatric university hospital charles de gaulle of Ouagadougou.

Oesophageal stricture is one of the most important and redoubtable complications following caustic ingestions in children. Instrumental dilatation is usually considered the first line of treatment. This study aims to evaluate the outcomes of caustic stenosis treatment when using Lerut dilatators. This is a descriptive retrospective study from May 2014 to April 2020. All children under 15 years hospitalised in our department for caustic oesophageal stricture and had a gastrostomy and oesophageal dilatation with insertion of an endless wire were included. A total of 83 patients were included. The sex ratio was 2.2. The mean age was 4 years. The mean time from caustic ingestion to presentation was 90 days. Oesophageal stricture was mostly caused by caustic soda (n = 41) and potash (n = 15). We performed in total 469 dilatations and had only three oesophageal perforations. After a mean follow-up of 17 months, we had 60.2% good results (n = 50) and 7.2% (n = 6) failures. The mortality rate was 13.2% (n = 11). The results of the dilations by Lerut dilatators give encouraging results in our department. It is easy to perform and its complications remain rare. Mortality could be reduced by adequate nutritional support.

Experimental evaluation of the bone fragments fixation rigidity using standard transosseous elements and extracortical clamp device in the model of femoral lengthening over the intramedullary nail

Introdu ction. Fe mur lengthening over nail is an ef-fective method to reduce the rate of typical complica-tions of external fixation. However, the technical feature of the method is the tangential insertion of half-pins and wires and problems of nail jamming related with this. Ex-tracortical clamp device is one of the solutions to these problems. External fixation device used in this technique requires additional studies of fixation rigidity, including in the presence of the internal fixator. Aim: Compare ex- ternal fixation rigidity during femur lengthening over the nail using traditional half-pins and wires and extracorti-cal clamp device. Materials and m ethods. The fixation rigidity of 8 variants of the complete arrangement of the external fixation device in combination with an intra-medullary nail inserted both antegrade and retrograde were studied: 4 modules using only half-pins and wires and 4 modules with combination of half-pins, wires and extracortical clamp device. The studies were carried out using a biomechanical testing bench with the definition of longitudinal rigidity, angular and rotational stability. Results. Antegr ade modules had lower fixati on rigidi-ty, except for the longitudinal ones, compared to retro-grade modules. It can be associated with a technically more complex tangential insertion of half-pins in the proximal femur due to the nail in the canal. The retro-grade modules using extracortical clamp device had the highest fixation rigidity compared to other models in all series of experiment. The use of the extracortical clamp device increased the fixation rigidity of external fixation 1.5–2 times. Conclusion. The use of extracortical clamp device increases the fixation rigidity of bone fragments in combined osteosynthesis (external fixation device with intramedullary nail) and can be recommended for femur lengthening over the nail.

Atypical Autoerotic Death Due to Insertion of a Foreign Body into the Urethra and Rectum

Autoerotic death is an accidental death during sexual pleasure, usually caused by a device or equipment used to enhance pleasure. Autoerotic deaths can be classified as typical or atypical. Typical autoerotic deaths occur due to asphyxiation by mechanical compression, while atypical autoerotic deaths occur by means other than asphyxiation. Narcissism-associated accidental deaths during tube and wire insertion into the urethra and rectum are extremely rare. The victim, a man in his 40s, was found dead at his home. Several tools for masturbation and wires for urethral and rectal insertion were observed around the victim and many pornographic videos were also identified. Family accounts and medical records indicated that he masturbated often by inserting plastic tubes and wires into the urethra and rectum. Moreover, the victim had a history of surgeries to remove foreign objects from the urethra and rectum as well as a history of psychiatric treatment. The autopsy results revealed no specific findings indicative of the cause of death. In conclusion, the investigators determined the cause of death as an atypical autoerotic death based on the death scene investigation, autoerotic sexual behavior, personal history, and autopsy results.

Initial single-center experience using Fiber Optic RealShape guidance in complex endovascular aortic repair

ObjectiveIn the present study, we have described the technical success using Fiber Optic RealShape (FORS) endovascular guidance and its effects on the overall procedural time and radiation usage during complex endovascular aortic repair (EVAR). MethodsFenestrated and branched EVARs performed at a single center from 2017 to 2022 were prospectively studied. FORS-guided procedures were matched retrospectively 1:3 to non–FORS-guided procedures by the incorporated target arteries and body mass index. Technical success was defined as successful target vessel cannulation using FORS for the entirety of navigation (wire insertion to exchange for a stiff wire). The predictors of technical success were evaluated via logistic regression. The procedural times and radiation doses were compared between the matched cohorts using the Wilcoxon rank sum test. ResultsA total of 21 FORS-guided procedures were matched to 61 non–FORS-guided procedures. A total of 95 FORS cannulations were attempted (87 for the visceral target artery and 8 for the bifurcate gate). Technical success was achieved in 81 cannulations (85%); 15 (16%) were completed without the use of live fluoroscopy. The univariate predictors of FORS technical success included <50% target artery stenosis, <50% target artery calcification, and the target vessel attempted (P < .05 for each). FORS failures were attributed to device material properties in six cases, device failure in two cases, and the wire/catheter combination in six. The use of FORS guidance was associated with shorter median procedural and fluoroscopy times and a lower dose area product and air kerma (P ≤ .0001 for each). ConclusionsThe results from our initial experience with FORS during complex EVAR, including our learning curve, has shown promise, with acceptable technical success and reductions in procedural times and radiation usage.

Evaluation of intracoronary hemodynamics identifies perturbations in vorticity

Background and objective: Coronary artery disease (CAD) is highly prevalent and associated with adverse events. Challenges have emerged in the treatment of intermediate coronary artery stenoses. These lesions are often interrogated with fractional flow reserve (FFR) testing to determine if a stenosis is likely to be causative for ischemia in a cardiac territory. This invasive test requires insertion of a pressure wire into a coronary vessel. Recently computational fluid dynamics (CFD) has been used to noninvasively assess fractional flow reserve in vessels reconstructed from medical imaging data. However, many of these simulations are unable to provide additional information about intravascular hemodynamics, including velocity, endothelial shear stress (ESS), and vorticity. We hypothesized that vorticity, which has demonstrated utility in the assessment of ventricular and aortic diseases, would also be an important hemodynamic factor in CAD.Methods: Three-dimensional (3D), patient-specific coronary artery geometries that included all vessels &amp;gt;1 mm in diameter were created from angiography data obtained from 10 patients who underwent diagnostic angiography and FFR testing (n = 9). A massively parallel CFD solver (HARVEY) was used to calculate coronary hemodynamic parameters including pressure, velocity, ESS, and vorticity. These simulations were validated by comparing velocity flow fields from simulation to both velocities derived from in vitro particle image velocimetry and to invasively acquired pressure wire-based data from clinical testing.Results: There was strong agreement between findings from CFD simulations and particle image velocimetry experimental testing (p &amp;lt; 0.01). CFD-FFR was also highly correlated with invasively measured FFR (ρ = 0.77, p = 0.01) with an average error of 5.9 ± 0.1%. CFD-FFR also had a strong inverse correlation with the vorticity (ρ = -0.86, p = 0.001). Simulations to determine the effect of the coronary stenosis on intravascular hemodynamics demonstrated significant differences in velocity and vorticity (both p &amp;lt; 0.05). Further evaluation of an angiographically normal appearing non-FFR coronary vessel in patients with CAD also demonstrated differences in vorticity when compared with FFR vessels (p &amp;lt; 0.05).Conclusion: The use of highly accurate 3D CFD-derived intravascular hemodynamics provides additional information beyond pressure measurements that can be used to calculate FFR. Vorticity is one parameter that is modified by a coronary stenosis and appears to be abnormal in angiographically normal vessels in patients with CAD, highlighting a possible use-case in preventative screening for early coronary disease.

Preoperative and Intraoperative Considerations Using Intramedullary Nails for the Treatment of Tibial Shaft Fractures Below Total Knee Arthroplasty.

Periprosthetic tibial shaft fractures below total knee arthroplasty (TKA) are relatively rare, with an incidence of approximately 1%. However, as the rates of arthroplasty increase, orthopaedic surgeons are likely to see a corresponding increase in these types of fractures. Native tibial shaft fractures are routinely treated with either nails or plates, and the success of intramedullary nailing of tibial shaft fractures has been well described in the literature. In this article, we seek to describe a case series of tibial shaft fractures in patients with ipsilateral TKA treated with infrapatellar intramedullary nailing. We will focus on preoperative considerations including templating and measurement of the anterior cortical implant distance on the lateral radiograph to ensure space for safe nail passage. We will also discuss intraoperative technical tricks, including Kirschner wire insertion for sounding the start point, utilization of the curved awl, use of hand reamers, and rotation of the nail to bypass the implant. Using meticulous preoperative planning and technical intraoperative tricks, patients with tibial shaft fractures below TKA may be successfully treated with intramedullary nailing.