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Goal: In this study, we investigated the feasibility of predicting the performance of a specific guidewire in terms of its ability to cover a lesion cap surface and apply force to the lesion for a given patient's vessel anatomy. The aim of this research was to provide information that could be used to plan occlusion crossings and peripheral revascularization procedures preoperatively in a way that reduces the risk of potential intraoperative complications and increases the likelihood of success. Methods: We used finite element (FE) analysis to simulate the interaction between the guidewire and a model of a tortuous vessel, and we used this simulation to predict the reachable workspace and deliverable forces of the device for various entry positions and angles. We then validated these predictions through experiments in which we advanced a guidewire through an identical vessel phantom using a robotic manipulator. Conclusions: Our findings suggest that it may be possible to predict the performance of a guidewire and forecast the likelihood of success or failure for a given vessel anatomy and lesion morphology, which could enable improved planning and device selection.

The use of catheters and guide-wires in minimally invasive therapeutic approaches is an important part of clinical practice. In the neurovascular field, the unique nature of cerebral blood vessels necessitates very thin-walled and flexible catheters. The blood vessels in question are highly branched and at the same time can be less than one millimetre in diameter. This results in high demands on micro-catheters and guide-wires for successful endovascular therapy. The interaction of these surgical tools and the vessel wall is of especial interest. Depending on the catheter stiffness, this interaction can be friction, punctual collision or straightening. The work aims to design and implement a test setup for evaluation of these interactions with the vessel wall. For this purpose, a standardized vessel course with representative characteristics is necessary. Furthermore, by implementing suitable measuring equipment, an endovascular intervention can be simulated.

Background: Glaucoma is a progressive optic neuropathy and it is the main cause of irreversible blindness worldwide. Intraocular pressure (IOP) is the only modifiable one and trabeculectomy is commonly considered the surgical "gold standard" to decrease IOP. In particular cases, other kind of surgeries, as the Ahmed Glaucoma Valve (AGV) implant, are a reliable alternative. Usually, the silicone tube of AGV surgery is inserted into the anterior chamber. Sometimes it is necessary to place the AGV silicone tube in the ciliary sulcus, especially in cases of endothelial decompensation. This surgical procedure is not always easy to perform., Case Presentation: This article describes and presents a technique for inserting the AGV tube into the posterior chamber using a guide-wire, in a total of 12 cases are reported. This procedure has been mostly applied in a group of pseudophakic patients who need AGV placement to control elevated IOP. In exceptional situations, this procedure was applied in pseudophakic patients previously with AGV tube implanted in the anterior chamber and with loss of endothelial cells or in phakic patients with previously implanted AGV anterior chamber tube, simultaneously to cataract surgery., Conclusion: The purpose of these cases presentations attended at our service is to demonstrate the passage of the AGV silicone tube was performed with the aid of a guide wire., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. This procedure was presented in the surgical videos section at the 65° Congresso Português de Oftalmologia.

The use of exclusive guide-wire cannulation (e-GW) instead of contrast injection reduces post-ERCP pancreatitis (PEP) and pre-cutting and increases cannulation rate. Herein, we intend to compare e-GW with the hybrid technique (GW-C and/or contrast injection). Prospective single-center randomized comparative study, which included all patients referred to ERCP to our unit. Patients with non-naïve papilla; previous ERCP; direct infundibulotomy, ampullectomy, Billroth II gastrectomy or pancreatic sphincterotomy and patients lost to follow up were excluded. 727 consecutive patients were assessed. Of these, 588 naïve papilla patients were included and randomized to receive e-GW (n = 299) or GW-C (n = 289) for selective biliary cannulation. The mean age was 60.3 years and 60.5% were women. PEP occurred in 15(5%) cases in e-GW group and 9(3.1%) in the GW-C group (p = 0.29). Time to reach deep cannulation was faster in the latter group (75% < 5 min vs. 50.2% < 5 min, p<0.001). > 10 min until cannulation was observed in 21% vs. 10% of the ERCPs (groups e-GW and GW-C, respectively, p < 0.001). Total ERCP time was also shorter in the GW-C group (12 vs. 10 min; p < 0.001). Pre-cut (23.8 vs.11.8%, p < 0.001) and pancreatic sphincterotomy as a pre-cut technique (15.8 vs. 5.6%, p < 0.001) were used more frequently in the e-GW group. Compared to exclusive G-W- assisted biliary cannulation, the hybrid technique did not significantly reduce the PEP rate, however it promoted faster cannulation and, consequently, reduced the total procedure time and the use of pre-cut techniques. [ABSTRACT FROM AUTHOR]

Background and Aims: Fracture and retention of a guidewire after cardiac resynchronization therapy device implantation has not been reported in the literature so far, although it is an uncommon but known complication during cardiac interventions like percutaneous coronary interventions and other cardiac catheterization procedures. Methods: A 53 years old female patient presented with severe pain over the left arm and shoulder for a period of 1 to 2 days. The patient had a history of dilated cardiomyopathy with severe left ventricular dysfunction and underwent cardiac resynchronization therapy device implant 3 years back with subsequent lead replacement 6 months back due to lead dysfunction. On evaluation, a coronary guidewire which might have fractured and been retained inadvertently during previous surgical procedure, was discovered in her deltoid muscle. Her symptoms were attributed to the guide wire which may have been aggravated by the movements of her arm. Emergency surgical exploration was done and the guidewire was removed. Results and Conclusion: We are reporting a case of unlikely and unusual delayed presentation of retained intervention guide‐wire post cardiac resynchronization therapy, which was retrieved from the left deltoid muscle. [ABSTRACT FROM AUTHOR]

Background Hip fractures contribute to a significant clinical burden globally with over 1.6 million cases per annum and up to 30% mortality rate within the first year. Insertion of a dynamic hip screw (DHS) is a frequently performed procedure to treat extracapsular neck of femur fractures. Poorly performed DHS fixation of extracapsular neck of femur fractures can result in poor mobilisation, chronic pain, and increased cut-out rate requiring revision surgery. A realistic, affordable, and portable fluoroscopic simulation system can improve performance metrics in trainees, including the tip-apex distance (the only clinically validated outcome), and improve outcomes. Method We developed a digital fluoroscopic imaging simulator using orthogonal cameras to track coloured markers attached to the guide-wire which created a virtual overlay on fluoroscopic images of the hip. To test the accuracy with which the augmented reality system could track a guide-wire, a standard workshop femur was used to calibrate the system with a positional marker fixed to indicate the apex; this allowed for comparison between guide-wire tip-apex distance (TAD) calculated by the system to be compared to that physically measured. Tests were undertaken to determine: (1) how well the apex could be targeted; (2) the accuracy of the calculated TAD. (3) The number of iterations through the algorithm giving the optimal accuracy–time relationship. Results The calculated TAD was found to have an average root mean square error of 4.2 mm. The accuracy of the algorithm was shown to increase with the number of iterations up to 20 beyond which the error asymptotically converged to an error of 2 mm. Conclusion This work demonstrates a novel augmented reality simulation of guide-wire insertion in DHS surgery. To our knowledge this has not been previously achieved. In contrast to virtual reality, augmented reality is able to simulate fluoroscopy while allowing the trainee to interact with real instrumentation and performing the procedure on workshop bone models. [ABSTRACT FROM AUTHOR]

Goal: In this study, we investigated the feasibility of predicting the performance of a specific guidewire in terms of its ability to cover a lesion cap surface and apply force to the lesion for a given patient's vessel anatomy. The aim of this research was to provide information that could be used to plan occlusion crossings and peripheral revascularization procedures preoperatively in a way that reduces the risk of potential intraoperative complications and increases the likelihood of success. Methods: We used finite element (FE) analysis to simulate the interaction between the guidewire and a model of a tortuous vessel, and we used this simulation to predict the reachable workspace and deliverable forces of the device for various entry positions and angles. We then validated these predictions through experiments in which we advanced a guidewire through an identical vessel phantom using a robotic manipulator. Conclusions: Our findings suggest that it may be possible to predict the performance of a guidewire and forecast the likelihood of success or failure for a given vessel anatomy and lesion morphology, which could enable improved planning and device selection.

Abstract: The placement of guide-wires and catheters to gain access to the upper urinary tract can induce undesirable stresses on tissues. Previous studies have characterized the performance of wires and catheters by evaluating their physical properties such as stiffness and friction coefficient. However, the results of these studies do not directly quantify the wire''s effects on tissues. Furthermore, the individual physical properties of wires and catheters investigated in previous studies cannot be simply summed up to characterize the behavior of an entire wire/catheter ensemble. This paper presents an objective method for testing guide-wires and catheters that estimates the forces applied by these instruments to anatomical structures during urological procedures. Our model utilizes a computer-controlled test stand that simulates a urological environment by including a tortuous path and a stone obstruction. Experimental results using this model show significant promise in reflecting the performance of guide-wires and catheters measuring the stress exerted upon relevant anatomical structures. Furthermore, due to the modularity of the approach, the model can be easily reconfigured to simulate environments relevant to other medical fields. [Copyright &y& Elsevier]

Background. Lymphocoeles post renal transplantation can be difficult to see laparoscopically. The objective of this study was to report a new technique of catheter or guide‐wire placement for the guidance of laparoscopic marsupialization of symptomatic post renal transplant lymphocoeles, refractory to conservative therapy. [ABSTRACT FROM PUBLISHER]

Background: The use of exclusive guide-wire cannulation (e-GW) instead of contrast injection reduces post-ERCP pancreatitis (PEP) and pre-cutting and increases cannulation rate. Herein, we intend to compare e-GW with the hybrid technique (GW-C and/or contrast injection)., Methods: Prospective single-center randomized comparative study, which included all patients referred to ERCP to our unit. Patients with non-naïve papilla; previous ERCP; direct infundibulotomy, ampullectomy, Billroth II gastrectomy or pancreatic sphincterotomy and patients lost to follow up were excluded., Results: 727 consecutive patients were assessed. Of these, 588 naïve papilla patients were included and randomized to receive e-GW (n = 299) or GW-C (n = 289) for selective biliary cannulation. The mean age was 60.3 years and 60.5% were women. PEP occurred in 15(5%) cases in e-GW group and 9(3.1%) in the GW-C group (p = 0.29). Time to reach deep cannulation was faster in the latter group (75% < 5 min vs. 50.2% < 5 min, p<0.001). > 10 min until cannulation was observed in 21% vs. 10% of the ERCPs (groups e-GW and GW-C, respectively, p < 0.001). Total ERCP time was also shorter in the GW-C group (12 vs. 10 min; p < 0.001). Pre-cut (23.8 vs.11.8%, p < 0.001) and pancreatic sphincterotomy as a pre-cut technique (15.8 vs. 5.6%, p < 0.001) were used more frequently in the e-GW group., Conclusions: Compared to exclusive G-W- assisted biliary cannulation, the hybrid technique did not significantly reduce the PEP rate, however it promoted faster cannulation and, consequently, reduced the total procedure time and the use of pre-cut techniques., (Copyright © 2020 IAP and EPC. Published by Elsevier B.V. All rights reserved.)