Guidewire Path Research Articles

Analysis of recurrence factors after balloon compression for trigeminal neuralgia and the relationship between pear-shaped balloon and guidewire path

BackgroundPercutaneous balloon compression (PBC) is widely used to treat trigeminal neuralgia due to its significant efficacy and low treatment cost. However, there is considerable variation in postoperative pain recurrence among patients. Currently, the factors influencing pain recurrence after PBC are under discussion. This study aims to explore the impact of individual patient parameters and surgical parameters on postoperative pain recurrence following PBC. The goal is to provide clinicians with a reference for preoperative assessment of pain recurrence risk and to offer insights for effectively intervening in controllable influencing parameters. MethodsA analysis was conducted on 114 patients who underwent PBC in the Department of Neurosurgery at Hebei General Hospital. Univariate Kaplan-Meier analysis and multivariate Cox regression analysis were performed on the general and surgical data of the patients to identify factors potentially associated with postoperative pain recurrence. ResultsThe results of the multivariate Cox regression analysis showed that a history of hypertension, MRI indicating trigeminal nerve compression and a non-ideal pear-shaped balloon were statistically significant factors for pain recurrence after PBC. Additionally, the guidewire path during the procedure had a statistically significant impact on the rate of achieving a pear-shaped balloon (P<0.05). ConclusionA history of hypertension, MRI indicating trigeminal nerve compression and a non-ideal pear-shaped balloon shape are independent risk factors for pain recurrence after PBC. Additionally, to avoid pain recurrence due to an unfavorable balloon shape, it is recommended to use 3D-slicer for preoperative guidewire path simulation and 3D reconstruction of Meckel's cavity.

Percutaneous Atrial Septal Defect (ASD) closure technique in case of association with an azygos continuation of the inferior vena cava “case report”

Introduction: Atrial Septal Defect (ASD) is the most common congenital heart disease, accessible to percutaneous closure in 90% of cases. The closure procedure is performed usually under local anesthesia and TTE by femoral access. The association of OS-ASD with an azygos continuation of the inferior vena cava is very rare (&lt; 0.1/1000 births) making femoral access impossible. Only a few cases are mentioned in the literature, here we describe the procedure as faithfully as possible. Important clinical finding: We present a case of a 32-years-old female candidate for percutaneous closure of OS-ASD with right cavity dilatation who present during her procedure an unusual guidewire path suspecting an azygos continuation of the inferior vena cava, confirmed by CT angiography, making impossible the closure via the femoral approach. Therapeutic intervention: After being confronted with the categorical patient refusal of the surgery, we performed successfully the procedure; one month later; under general sedation by internal jugular approach. We finished with manual compression before extubating the patient. Outcomes: The follow-up was favorable at the cost of a hematoma at the puncture site and brachial plexus compression, which regressed after 3 days. Conclusion: We opted for general anesthesia and intubation to guide the procedure by TEE. We placed it in the aorta, which gave us good stability to continue successfully the procedure. We underestimated the risk of complication at the puncture site, which could have been avoided by using a vascular suture device or more prolonged compression. Main takeaway lesson: Percutaneous closure is the reference treatment for OS-ASD. In case of is associated with an azygos continuation of the inferior vena cava, the right internal jugular vein remains a reasonable approach; it requires discussion and rigorous preparation by the whole team. The management of the puncture site in this situation remains delicate and requires great concentration.

Surgical GAN: Towards real-time path planning for passive flexible tools in endovascular surgeries

Automatic surgical path planning of the passive flexible tool encounters a prohibitive challenge, typically in endovascular surgery (ES). The key problem is that unstructured surgical environment and tools’ unpredictable motion is hard to be explicitly modeled. We propose a generative adversarial networks (GAN)-based framework (defined as surgical GAN) towards automatic guidewire path planning in real time for ES. A novel GAN architecture is proposed by combining convolutional neural networks (CNN) and long short-term memory networks (LSTM), which extracts and fuses the spatial features in medical images and temporal features of historical tool path as the conditional information. It inputs the surgical state information and continuously outputs the local future path of the guidewire tip. A training dataset (3.5*105 samples) is collected under laboratory conditions with 10 surgeons. Effects of different CNN architectures and path planning length on network performance are investigated. User experiments, with the tasks delivering the guidewire tip inside a vascular model (endovascular evaluator) from the aortic arch into the left common carotid artery (LCCA), left subclavian artery (LSCA), or brachiocephalic trunk, are conducted with 10 novice surgeons in an operating room. The results shows significant improvement of a path planning accuracy with surgical GAN compared with baseline networks (from 46.2%–69.78%) and the non-rigid registration method (72.94%). Results of user experiments demonstrate an overall better task performance with the guidance of planned surgical path. Collectively, surgical GAN can achieve real-time path planning of the guidewire in simulated ES, and holds great potential for novice training and robotic ES autonomy.

An improved matrix-based endovascular guidewire position simulation using fusiform ternary tree.

In this paper, a new matrix-based method is proposed to real-time determine, the guidewire position inside an arterial system. The guidewire path is obtained by the optimal path method, particularly, the fusiform ternary tree method according to the principle of minimum output value of root node. An adaptive sampling strategy, and an optimization strategy based on the proximal end and distal end of the guidewire are proposed to change the guidewire position for obtaining an ideal guidewire path. Compared to the existing methods, the proposed method can achieve 74%, 64%, and 70% improvements in accuracy for phantoms 1, 2, and 3, respectively, investigated in this work.

An Improved Real-Time Endovascular Guidewire Position Simulation Using Activity on Edge Network

A novel network-based method to realistically simulate the guidewire position in the vascular system is presented in this paper. We can always obtain an ideal guidewire path by the shortest path algorithm, particularly, critical path algorithm based on the principle of maximum path length. Besides, we propose an adaptive sampling algorithm and optimizations based on two ends of the guidewire to adjust the guidewire position toward achieving an ideal simulation result. Compared with previous results, we can achieve 29%, 20% and 47% improvements in accuracy for three phantoms under the same conditions.

Computational Simulations to Predict Fenestrated Stent Graft Rotation on Deployment

The objective of this study was to use finite element simulations of fenestrated endovascular aneurysm repair to predict whether the stent graft would rotate on deployment, leading to fenestration misalignment and related complications, such as end-organ ischemia. After institutional research ethics approval, preoperative computed tomography scans and stent graft plans were collected for three patients who had undergone fenestrated endovascular aneurysm repair. The aortoiliac geometries were segmented from the common femoral artery to above the visceral vessels, and vessel centerlines were calculated. Geometries of the stent graft, based on the plans, as well as the guidewire and the delivery sheath were created. Realistic material properties, including frictional effects, were assigned for all materials, with the vessel wall properties being those of an elderly man taken from the literature. Using the finite element software LS-DYNA (Livermore Software Technology Corp, Livermore, Calif), vessel deformation in response to the guidewire was simulated by displacing the guidewire to follow the vessel centerline path and then removing this displacement, forcing the guidewire to try to straighten, until the deformations of the guidewire and the vessel wall reached equilibrium. The stent graft model was then compressed into a sheath that was delivered into position in the aorta by following the guidewire path. Once the device was in position, the sheath was removed, allowing the stent graft to expand and potentially rotate. Stent graft rotation was calculated as the angle between the positions of the graft before and after unsheathing. These calculated angles showed excellent agreement with the rotation measured clinically from the intraoperative imaging (7 degrees, 2 degrees, and 12 degrees computationally vs 5 degrees, 2 degrees, and 16 degrees clinically). A finite element model of stent graft delivery and deployment was developed to predict the amount of stent graft rotation that may occur clinically. Preliminary results show excellent agreement with the clinical data.

An improved real-time endovascular guidewire position simulation using shortest path algorithm.

In this study, we propose a new graph-theoretical method to simulate guidewire paths inside the carotid artery. The minimum energy guidewire path can be obtained by applying the shortest path algorithm, such as Dijkstra's algorithm for graphs, based on the principle of the minimal total energy. Compared to previous results, experiments of three phantoms were validated, revealing that the first and second phantoms overlap completely between simulated and real guidewires. In addition, 95% of the third phantom overlaps completely, and the remaining 5% closely coincides. The results demonstrate that our method achieves 87 and 80% improvements for the first and third phantoms under the same conditions, respectively. Furthermore, 91% improvements were obtained for the second phantom under the condition with reduced graph construction complexity.

Guidewire path determination for intravascular applications

Vascular diseases are among the major causes of death in developed countries and the treatment of those pathologies may require endovascular interventions, in which the physician utilizes guidewires and catheters through the vascular system to reach the injured vessel region. Several computational studies related to endovascular procedures are in constant development. Thus, predicting the guidewire path may be of great value for both physicians and researchers. However, attaining good accuracy and precision is still an important issue. We propose a method to simulate and predict the guidewire and catheter path inside a blood vessel based on equilibrium of a new set of forces, which leads, iteratively, to the minimum energy configuration. This technique was validated with phantoms using a ∅0.33 mm stainless steel guidewire and compared to other relevant methods in the literature. This method presented RMS error 0.30 mm and 0.97 mm, which represents less than 2% and 20% of the lumen diameter of the phantom, in 2D and 3D cases, respectively. The proposed technique presented better results than other methods from the literature, which were included in this work for comparison. Moreover, the algorithm presented low variation () due to the variation of the input parameters. Therefore, even for a wide range of different parameters configuration, similar results are presented for the proposed approach, which is an important feature and makes this technique easier to work with. Since this method is based on basic physics, it is simple, intuitive, easy to learn and easy to adapt.

Diagnosis and insertion of Hickman catheter for a patient with persistent left superior vena cava

A vascular access with good function for drug delivery is the basis of chemotherapy. If there is any congenital or acquired vascular abnormality, procedurally related and late complications such as vessel rupture, malposition, and dysfunction of the catheter with ensuing thrombosis may occur, especially when it is undiagnosed or ignored. We describe a case of implantable central venous catheter (CVC) malposition and subsequent insertion of a Hickman catheter for stem cell transplantation after the diagnosis of persistent left superior vena cava (PLSVC) by radiologic image studies. The case is about a 60-year-old male who suffered from mantle cell lymphoma. He complained of discomfort when chemotherapeutic drugs were delivered through an implanted subcutaneous port system. Malposition of the CVC with aberrant path venous catheter, which led to its migration to the right internal jugular vein (RIJV) was noted on the chest X-ray. In addition, results of ultrasound imaging revealed total occlusion of the RIJV, and a subsequent three-dimensional (3D) computed tomography (CT) reconstruction image revealed a PLSVC with an atretic right SVC. Ultrasound-guided venous puncture of the left internal jugular vein and intraoperative fluoroscopy for confirming the correct guide-wire path were used for successful insertion of Hickman catheter without any complication. When unexpected occurrence of migration or malposition of the long-term CVC is detected, early removal of the catheter is vital for preventing further complications. Proper and advanced image studies including ultrasound, contrast-enhanced venography, CT, and magnetic resonance imaging may be necessary for understanding the potential vascular abnormality and guiding the following treatment.

Guidewire Reproducibilty and Modeling

The number of minimally invasive vascular interventions is increasing, and the device most frequently used is a guidewire, along which devices are delivered to the intervention site. Procedural failure can occur due to improper guidewire and∕or device selection. To facilitate guidewire and device guidance, we investigated the reproducibility of guidewire paths in vessel phantoms. Several trained users repeatedly passed guidewires of different flexibility through the phantoms under pulsatile flow conditions. Afterwards, the 3D paths were reconstructed and compared. In addition, the 3D paths were calculated using graph representation techniques. Points in the vessel lumen in planes perpendicular to the vessel centerline were generated. All points in adjacent planes were joined generating a vector set in a graph representation in which the edge weights were functions of the angle between contiguous vectors. The optimal path through this weighted directed graph was then determined using a Dijkstra’s (shortest path) algorithm. The guidewire paths appear reproducible across users but not across materials. The average RMS difference of repeated placements was 0.17±0.02mm (plastic-coated guidewire), 0.73±0.55mm (steel guidewire) and 1.15±0.65mm (steel vs plastic-coated). For the guidewire modeling, the average RMS distance between the actual and simulated guidewire path was 0.7mm; computation time was 3s. For a given guidewire, these results indicate that the guidewire path is relatively reproducible in shape and position. The ability to predict the guidewire path inside vessels may facilitate calculation of vessel-branch access and force estimation.

Evaluation of guidewire path reproducibility

The number of minimally invasive vascular interventions is increasing. In these interventions, a variety of devices are directed to and placed at the site of intervention. The device used in almost all of these interventions is the guidewire, acting as a monorail for all devices which are delivered to the intervention site. However, even with the guidewire in place, clinicians still experience difficulties during the interventions. As a first step toward understanding these difficulties and facilitating guidewire and device guidance, we have investigated the reproducibility of the final paths of the guidewire in vessel phantom models on different factors: user, materials and geometry. Three vessel phantoms (vessel diameters approximately 4 mm) were constructed having tortuousity similar to the internal carotid artery from silicon tubing and encased in Sylgard elastomer. Several trained users repeatedly passed two guidewires of different flexibility through the phantoms under pulsatile flow conditions. After the guidewire had been placed, rotational c-arm image sequences were acquired (9 in. II mode, 0.185 mm pixel size), and the phantom and guidewire were reconstructed (512(3), 0.288 mm voxel size). The reconstructed volumes were aligned. The centerlines of the guidewire and the phantom vessel were then determined using region-growing techniques. Guidewire paths appear similar across users but not across materials. The average root mean square difference of the repeated placement was 0.17 +/- 0.02 mm (plastic-coated guidewire), 0.73 +/- 0.55 mm (steel guidewire) and 1.15 +/- 0.65 mm (steel versus plastic-coated). For a given guidewire, these results indicate that the guidewire path is relatively reproducible in shape and position.

Electronic exchange system. Part 2: Control

The structure and low-level control equipment of an electronic telephone-exchange system are described in Pt. 1 of the paper. Pt. 2 expands the control to the higher levels of register and unique common control and describes the operation of the whole system. The main problem and objective of the control system is to be economical for all sizes of exchange, for which purpose its cost must be approximately proportional to the size of exchange with only a small constant cost independent of size. To this end, advantage is taken of the low cost, concomitant with the use of t.d.m. (time-division multiplex) switches, of guide-wire path selection and distributed processors to reduce the cost of the unique common processor, the cost of which is minimised by a combination of wired and stored-program logic, the stored-program-logic part being remotely located and shared with other exchanges if an exchange is too small to support it alone.

Electronic crosspoints for switching analogue transmission circuits

Crosspoints are switches which interconnect line and trunk circuits in exchanges. The paper is concerned with switching analogue transmission circuits. Digital-circuit switching has much in common and is briefly mentioned. Exchange switches comprise assemblies of crosspoints. Electronic crosspoints are assembled by wiring which, compared with the mechanical assembly of metal-contact crosspoints, provides greater latitude in the construction, and greater economy in the number of crosspoints needed. The nature of electronic crosspoints compels the use of isolating transformers between the lines terminating at the exchanges and the trunks within the exchanges, which permits the trunks to have unbalanced transmission and also helps to economise on crosspoint costs. There are some transmission difficulties associated with 2-wire switching, but these are reduced by 4-wire switching which also provides opportunities for transmission improvements. The best use is made of the available bandwidth by time-division-multiplexing (t.d.m.) the transmission, whereby each crosspoint serves a multiplexed channel instead of one unmultiplexed channel. Other advantages of multiplexing include lower crosstalk, more signalling channels at practically no extra cost; and guide-wire path search and connection and multiplexed supervisories, both of which cost much less in t.d.m. form than in space-division form.