Evaluation of an augmented reality navigational guidance platform for percutaneous procedures in a cadaver model.

Purpose: The objective of this study is to review the accuracy of an augmented reality navigational guidance system designed to facilitate improved visualization, guidance, and accuracy during percutaneous needle-based procedures including biopsies and ablations. Approach: Using the HoloLens 2, the system registers and projects 3D CT-based models of segmented anatomy along with live ultrasound, fused with electromagnetically tracked instruments including ultrasound probes and needles, giving the operator comprehensive stereoscopic visualization for intraoperative planning and navigation during procedures.Tracked needles were guided to targets implanted in a cadaveric model using the system. Image fusion registration error, the multimodality error measured as the post-registration distance between a corresponding point measured in the stereoscopic CT and tracked ultrasound coordinate systems, and target registration error, the Euclidean distance between needle tip and target after needle placement, were measured as registration and targeting accuracy metrics. A t-distribution was used for statistical analysis. Results: Three operators performed 36 total needle passes, 18 to measure image fusion registration error and 18 to measure target registration error on four targets. The average depth of each needle pass was 8.4 cm from skin to target center. Mean IFRE was 4.4 mm (H0: µ=5 mm, P<0.05). Mean TRE was 2.3 mm (H0: µ=5 mm, P<0.00001). Conclusions: The study demonstrated high registration and targeting accuracy of this AR navigational guidance system in percutaneous, needle-based procedures. This suggests the ability to facilitate improved clinical performance in percutaneous procedures such as ablations and biopsies.

Outcome Comparison of Drug-Resistant Trigeminal Neuralgia Surgical Treatments-An Umbrella Review of Meta-Analyses and Systematic Reviews.

Medical treatment for trigeminal neuralgia (TN) is not always a feasible option due to a lack of full response or adverse effects. Open surgery or percutaneous procedures are advocated in these cases. Several articles have compared the results among different techniques. Nevertheless, the findings of these studies are heterogeneous. Umbrella reviews are studies sitting at the peak of the evidence pyramid. With this umbrella review, we provided a systematic review of the outcomes of the surgical procedures used for TN treatment. Only systematic reviews and meta-analyses were included following the PRISMA guidelines. Ten articles were enrolled for qualitative and quantitative assessment. Level of evidence was quantified using a specific tool (AMSTAR-2). Results were heterogenous in terms of outcome and measurements. Microvascular decompression (MVD) appeared to be the most effective procedure both in the short-term (pain relief in 85-96.6% of cases) and long-term follow-up (pain relief in 64-79% of cases), although showed the highest rate of complications. The results of percutaneous techniques were similar but radiosurgery showed the highest variation in term of pain relief and a higher rate of delayed responses. The use of the AMSTAR-2 tool to quantify the evidence level scored three studies as critically low and seven studies as low-level, revealing a lack of good quality studies on this topic. Our umbrella review evidenced the need of well-designed comparative studies and the utilization of validated scales in order to provide more homogenous data for pooled-analyses and meta-analyses in the field of TN surgical treatment.

Experimental study of mosquito-inspired needle to minimize insertion force and tissue deformation.

The aim of this work is to propose a mosquito-inspired (bioinspired) design of a surgical needle that can decrease the insertion force and the tissue deformation, which are the main causes of target inaccuracy during percutaneous procedures. The bioinspired needle was developed by mimicking the geometrical shapes of mosquito proboscis. Needle prototypes were manufactured and tested to determine optimized needle shapes and geometries. Needle insertion tests on a tissue-mimicking polyvinylchloride (PVC) gel were then performed to emulate the mosquito-proboscis stinging dynamics by applying vibration and insertion velocity during the insertion. An insertion test setup equipped with a sensing system was constructed to measure the insertion force and to assess the deformation of the tissue. It was discovered that using the proposed bioinspired design, the needle insertion force was decreased by 60% and the tissue deformation was reduced by 48%. This finding is significant for improving needle-based medical procedures.

A survey of catheter tracking concepts and methodologies.

Catheter tracking has become an integral part of interventional radiology. Over the last decades, researchers have significantly contributed to theoretical and technical catheter tracking solutions. However, most of the published work thus far focuses on a single application or a single tracking technology. This paper provides an exhaustive review of the state-of-the-art for catheter tracking in general by analyzing significant contributions in this field. We first present a historical overview that led to catheter tracking and continue with a survey of leading tracking technologies. These include image-based tracking, active and passive tracking, electromagnetic tracking, fiber optic shape sensing, bioelectric navigation, robotic tracking solutions, and hybrid tracking. As for imaging modalities, the focus is on x-ray based modalities, ultrasound, and magnetic resonance imaging. Finally, we review each tracking technology with respect to the imaging modality and establish the relation between the two and the underlying anatomy of interest.

Combined MitraClip and Left Atrial Appendage Occlusion: Is It Still a Utopia?

Atrial fibrillation (AF) is the most common cardiac arrhythmia, affecting 32 million individuals worldwide, particularly the elderly. It is the main cause of ischemic strokes. Oral anticoagulation (OAC) is the gold standard strategy for stroke prevention. Still, there is a not negligible share of patients who have contraindications to this therapy, more frequently due to an increased risk of bleeding. AF is often associated with moderate-severe mitral regurgitation (MR), the second most frequent valvular disease in elderly patients. Data from the literature reported that more than half of patients with severe mitral regurgitation are not suitable candidates for cardiac surgery. Given the progressive aging of the population and the simultaneous increase in the number of patients with comorbidities, the advent of new therapeutic strategies, such as the combined approach of Left Atrial Appendage Occlusion (LAAO) and MitraClip procedure, is acquiring great interest. At present, the category of patients who may benefit from combined percutaneous therapies and the long-term risks and benefits might not have been identified. Despite the efforts of researchers, the correct selection of patients is a very important clinical need that has not yet been met to avoid committing human and financial resources to interventions that may be unnecessary. It is conceivable that the most modern and recent innovations in cardiovascular imaging, particularly three-dimensional echocardiography and new methods of volume imaging, could improve our ability to select patients appropriately. Since data in the literature are scarce, future studies will be needed to evaluate the efficacy and safety of combined MitraClip and LAA occlusion.

Incidence of repeat procedures and healthcare utilization following surgery, radiosurgery, and percutaneous procedures in elderly patients with trigeminal neuralgia.

OBJECTIVE: Management of trigeminal neuralgia (TN) in elderly patients poses significant challenges. The impact of different treatment modalities (surgery, radiosurgery [RS], and percutaneous techniques [PTs]) on healthcare utilization is not well defined in the management of TN in elderly patients. The aim of this study was to compare the long-term healthcare utilization metrics of different interventions in the management of elderly patients with TN. METHODS: The MarketScan database was queried using the International Classification of Diseases, Ninth Revision and Current Procedural Terminology, from 2000 to 2016. TN patients ≥ 65 years of age managed using surgery, RS, and PTs with at least 5 years of follow-up after the index procedure were included. Outcomes analyzed were hospital admissions, outpatient services, and medication refills. RESULTS: Of 993 patients, 43% (n = 430) underwent RS, 44% (n = 432) had PTs, and only 13% (n = 131) underwent surgery for TN. Overall, the median age of patients was 74 years old, 64% were females, 90% had Medicare insurance, and 17% had an Elixhauser index ≥ 3. Patients in the surgery group were younger (median age 71 years) with a higher comorbidity index (≥ 3; 24%) compared with patients undergoing RS and PTs (13% and 17%, respectively). At 1, 2, and 5 years after the index procedure, 41%, 48%, and 57% of patients in the PT cohort underwent any repeat procedure compared with 11%, 18%, and 29% for the RS cohort, and 6%, 9%, and 11% for the surgical cohort, respectively. Also, patients in the PT cohort incurred 1.8, 1.9, and 2.0 times the combined payment at 1, 2, and 5 years, respectively, compared with the surgery cohort. Similarly, patients who underwent RS for TN incurred 1.4, 1.5, and 1.5 times the combined payment at 1, 2, and 5 years, respectively, compared with the surgery cohort. At 5 years after the index procedure, combined payments for the PT cohort were $79,753 (IQR $46,013, $144,064) compared with $61,016 (IQR $27,114, $117,097) for the RS cohort and $41,074 (IQR $25,392, $87,952) for the surgery cohort (p < 0.0001). CONCLUSIONS: PTs followed by RS were the common procedures used in the majority of elderly patients with TN. However, surgery for TN resulted in durable control with the least need for reoperations up to 5 years after the index procedure, followed by RS and PTs. PTs for TN resulted in the highest utilization of healthcare resources and need for reoperations at all time points. These findings should be considered in clinical decision-making when selecting appropriate treatment modalities in elderly patients with TN.

Augmented reality-based autostereoscopic surgical visualization system for telesurgery.

PURPOSE: The visualization of remote surgical scenes is the key to realizing the remote operation of surgical robots. However, current non-endoscopic surgical robot systems lack an effective visualization tool to offer sufficient surgical scene information and depth perception. METHODS: We propose a novel autostereoscopic surgical visualization system integrating 3D intraoperative scene reconstruction, autostereoscopic 3D display, and augmented reality-based image fusion. The preoperative organ structure and the intraoperative surface point cloud are obtained from medical imaging and the RGB-D camera, respectively, and aligned by an automatic marker-free intraoperative registration algorithm. After registration, preoperative meshes with precalculated illumination and intraoperative textured point cloud are blended in real time. Finally, the fused image is shown on a 3D autostereoscopic display device to achieve depth perception. RESULTS: A prototype of the autostereoscopic surgical visualization system was built. The system had a horizontal image resolution of 1.31 mm, a vertical image resolution of 0.82 mm, an average rendering rate of 33.1 FPS, an average registration rate of 20.5 FPS, and average registration errors of approximately 3 mm. A telesurgical robot prototype based on 3D autostereoscopic display was built. The quantitative evaluation experiments showed that our system achieved similar operational accuracy (1.79 ± 0.87 mm) as the conventional system (1.95 ± 0.71 mm), while having advantages in terms of completion time (with 34.11% reduction) and path length (with 35.87% reduction). Post-experimental questionnaires indicated that the system was user-friendly for novices and experts. CONCLUSION: We propose a 3D surgical visualization system with augmented instruction and depth perception for telesurgery. The qualitative and quantitative evaluation results illustrate the accuracy and efficiency of the proposed system. Therefore, it shows great prospects in robotic surgery and telesurgery.

Percutaneous Versus Surgical Interventions for Hepatic Cystic Echinococcosis: A Systematic Review and Meta-Analysis.

PURPOSE: This systematic review and meta-analysis summarises the current literature on invasive treatment options of cystic hepatic echinococcosis (CE), comparing percutaneous radiological interventions to surgery, still the cornerstone of treatment in many countries. METHODS: A literature search was conducted in Medline and EMBASE databases (PROSPERO registration number: CRD42019126150). The primary outcome was recurrence of cysts after treatment. Secondary outcomes were complications, duration of hospitalisation, mortality and treatment conversion. RESULTS: The number of eligible prospective studies, in particular RCTs, was limited. In the four included studies, only conventional surgery is compared directly to percutaneous techniques. From the available data, in terms of recurrence, percutaneous treatment of hydatid cysts is non-inferior to open surgery. With regard to complications and length of hospital stay, outcomes favour percutaneous therapy. CONCLUSION: Although evidence from prospective research is small, percutaneous treatment in CE is an effective, safe and less invasive alternative to surgery.

The unfinished saga of invasive procedures for secondary mitral regurgitation.

Secondary mitral regurgitation (MR) is a common valvular heart disease. Its prognostic burden in patients suffering from idiopathic or ischemic cardiomyopathy (ICM) with left ventricular (LV) dysfunction/dilation has been clearly demonstrated. Severe secondary MR is associated with an increased mortality and frequent heart failure hospitalizations. Although guideline-directed medical therapy (GDMT) is the cornerstone of the management of secondary MR, a certain proportion of patients remain symptomatic. For these patients, several surgical techniques have been progressively developed during the last few decades (replacement, repair, sub-valvular apparatus interventions and other ventricular approaches). In the absence of evidence-based medicine, the benefits of these surgical procedures remains controversial, leading to a low level of recommendation in the guidelines. One way to anticipate the future is to look to the past. Recent prospective randomized trials evaluated surgical and percutaneous techniques and led to a better understanding of how best to treat this disease. In this article, we aim to describe the saga of the surgical and percutaneous treatments for secondary MR throughout the previous decades.

Terminology and Legislation referring to Percutaneous Facet Procedures to Treat Low Back Pain in Brazil ­ Current Status

Incongruities in the terminology and in the Brazilian legislation about percutaneous facet procedures (PFPs) for the treatment of chronic lower back pain are frequently the subject of litigations between health professionals and supplementary healthcare providers. The Brazilian Hierarchical Classification of Medical Procedures (CBHPM, in the Portuguese acronym) describes four types of PFPs, while the Brazilian Unified Supplementary Health Terminology (TUSS, in the Portuguese acronym) describes five distinct lumbar PFPs, which correlate with the ones described on the List of Procedures and Events in Health, created by the Brazilian National Agency of Supplementary Health (ANS, in the Portuguese acronym). In the present paper, we review the terminology of the procedures, proposing the unification of the terminology and the abolition of redundancies in the tables. Finally, we developed a single terminology proposal for the PFPs based on their complexity and objectives to be used for the treatment of lower back pain.

GantryMate: A Modular MR-Compatible Assistance System for MR-Guided Needle Interventions.

Percutaneous minimally invasive interventions are difficult to perform in closed-bore high-field magnetic resonance systems owing to the limited space between magnet and patient. To enable magnetic resonance-guided needle interventions, we combine a small, patient-mounted assistance system with a real-time instrument tracking sequence based on a phase-only cross-correlation algorithm for marker detection. The assistance system uses 2 movable plates to align an external passive marker with the anatomical target structure. The targeting accuracy is measured in phantom experiments, yielding a precision of 1.7 ± 1.0 mm for target depths up to 38 ± 13 mm. In in vivo experiments, the possibility to track and target static and moving structures is demonstrated.

Development of a shoulder-mounted robot for MRI-guided needle placement: phantom study.

PURPOSE: This paper presents new quantitative data on a signal-to-noise ratio (SNR) study, distortion study, and targeting accuracy phantom study for our patient-mounted robot (called Arthrobot). Arthrobot was developed as an MRI-guided needle placement device for diagnostic and interventional procedures such as arthrography. METHODS: We present the robot design and inverse kinematics. Quantitative assessment results for SNR and distortion study are also reported. A respiratory motion study was conducted to evaluate the shoulder mounting method. A phantom study was conducted to investigate end-to-end targeting accuracy. Combined error considering targeting accuracy, respiratory motion, and structure deformation is also reported. RESULTS: The SNR study showed that the SNR changes only 2% when the unpowered robot was placed on top of a standard water phantom. The distortion study showed that the maximum distortion from the ground truth was 2.57%. The average error associated with respiratory motion was 1.32 mm with standard deviation of 1.38 mm. Results of gel phantom targeting studies indicate average needle placement error of 1.64 mm, with a standard deviation of 0.90 mm. CONCLUSIONS: Noise and distortion of the MR images were not significant, and image quality in the presence of the robot was satisfactory for MRI-guided targeting. Combined average total error, adding mounting stability errors and structure deformation errors to targeting error, is estimated to be 3.4 mm with a standard deviation of 1.65 mm. In clinical practice, needle placement accuracy under 5 mm is considered sufficient for successful joint injection during shoulder arthrography. Therefore, for the intended clinical procedure, these results indicate that Arthrobot has sufficient positioning accuracy.

The Radial Artery for Percutaneous Coronary Procedures or Surgery?

This article summarizes the current research on the benefits of using the transradial approach for percutaneous procedures and the radial artery as a conduit for coronary artery bypass surgery. Based on the available evidence, the authors provide recommendations for the use of the radial artery in patients undergoing percutaneous or surgical coronary procedures.

[Transesophageal echocardiography in adults - guidelines of the Working Group on Echocardiography of the Polish Cardiac Society]. / Transesophageal echocardiography in adults ­ guidelines of the Working Group on Echocardiography of the Polish Cardiac Society.

This document presents current Polish guidelines on the clinical use of transesophageal echocardiography, including guidance of percutaneous procedures and intraoperative echocardiography, in adult patients. The authors present recommendations regarding indications and contraindications, staff and equipment requirements, patient preparation and information, examination protocol, reporting and reimbursement.

Abducent nerve palsy after microballoon compression of the trigeminal ganglion: Case report.

BACKGROUND: Trigeminal neuralgia (TN) is the most common type of facial neuralgia with incidence of 26.8/100,000 person year. In general, this scenario is characterized by a lancinating, unilateral, paroxysmal pain in the area of the fifth cranial nerve. Several treatment methods, including the injection of ethyl alcohol or butyl alcohol into the ganglion, the glycerol injection into the trigeminal cistern, peripheral nerve divisions, the radiofrequency thermocoagulation of the preganglionic fibers, and radiosurgery has been used for TN. CASE DESCRIPTION: A case of a 74-year-old woman patient who undergone a treatment of TN through a compression of Meckel cave and developed a transient abducent palsy is presented. Complication regarding to a palsy of abducent nerve is discussed as well as the analysis of presumable evolving physiopathology. A critical review of literature was performed. CONCLUSIONS: Among the procedures, we mean that percutaneous microballoon compression (PMC) is the best choice for elderly frail patients, because it had a very low associated mortality-morbidity rate and does not damage permanent the Gasserian ganglion.

An experimental animal model for percutaneous procedures used in trigeminal neuralgia.

OBJECT: This study describes an experimental rabbit model that allows the reproduction of percutaneous operations that are used in patients with trigeminal neuralgia (TN). Attention was given to an exact anatomical description of the rabbit's middle cranial fossa as well as the establishment of conditions for a successful procedure. METHODS: Morphometric measurements were taken from 20 rabbit skulls and CT scans. The anatomy of the trigeminal nerve, as well as its surrounding structures, was assessed by bilateral dissection of 13 New Zealand white rabbits (NWR). An ideal approach of placing a needle through the foramen ovale to reach the TG was sought. Validation of correct placement was realized by fluoroscopy and confirmed by dissection. RESULTS: Precise instructions for successful reproduction of percutaneous procedures in NWR were described. According to morphological measurements, for balloon compression of the trigeminal ganglion (TG) the maximal diameter of an introducing cannula is 1.85 mm. The diameter of an empty balloon catheter should not exceed 1.19 mm, and the length of the inflatable part of the balloon can range up to 4 mm. For thermocoagulation the needle electrodes must not exceed an external diameter of 1.39, mm and the length of the non-insolated tip can range up to 4 mm. Glycerol rhizolysis can be achieved because the trigeminal cistern in the NWR is a closed space that allows a long dwelling time (>10 min) of the contrast agent. CONCLUSIONS: An experimental NWR model intended for the reproduction of percutaneous procedures on the TG has been meticulously described. This provides a tool that enables further standardized animal research in the field of surgical treatment of TN.

Vascular complications post-transcatheter aortic valve procedures.

Transcatheter aortic valve replacement (TAVR) has rapidly emerged as the standard of care for severe symptomatic aortic stenosis in patients whose comorbidities put them at prohibitive risk for surgical aortic valve replacement (SAVR). Several trials have demonstrated superior outcomes with TAVR compared to medical management alone. TAVR has also shown favorable outcomes in patients at high risk for SAVR. TAVR can be associated with significant vascular complications, which adversely impact outcomes, and operators should be cognizant of their early recognition and appropriate management. In this article, we review the major vascular complications associated with TAVR, along with optimal prevention and management strategies.

Numerical model of a valvuloplasty balloon: in vitro validation in a rapid-prototyped phantom.

BACKGROUND: Patient-specific simulations can provide insight into the mechanics of cardiovascular procedures. Amongst cardiovascular devices, non-compliant balloons are used in several minimally invasive procedures, such as balloon aortic valvuloplasty. Although these balloons are often included in the computer simulations of these procedures, validation of the balloon behaviour is often lacking. We therefore aim to create and validate a computational model of a valvuloplasty balloon. METHODS: A finite element (FE) model of a valvuloplasty balloon (Edwards 9350BC23) was designed, including balloon geometry and material properties from tensile testing. Young's Modulus and distensibility of different rapid prototyping (RP) rubber-like materials were evaluated to identify the most suitable compound to reproduce the mechanical properties of calcified arteries in which such balloons are likely to be employed clinically. A cylindrical, simplified implantation site was 3D printed using the selected material and the balloon was inflated inside it. The FE model of balloon inflation alone and its interaction with the cylinder were validated by comparison with experimental Pressure-Volume (P-V) and diameter-Volume (d-V) curves. RESULTS: Root mean square errors (RMSE) of pressure and diameter were RMSE P = 161.98 mmHg (3.8 % of the maximum pressure) and RMSE d = 0.12 mm (<0.5 mm, within the acquisition system resolution) for the balloon alone, and RMSE P = 94.87 mmHg (1.9 % of the maximum pressure) and RMSE d = 0.49 mm for the balloon inflated inside the simplified implantation site, respectively. CONCLUSIONS: This validated computational model could be used to virtually simulate more realistic valvuloplasty interventions.

More nerve root injuries occur with minimally invasive lumbar surgery, especially extreme lateral interbody fusion: A review.

BACKGROUND: In the lumbar spine, do more nerve root injuries occur utilizing minimally invasive surgery (MIS) techniques versus open lumbar procedures? To answer this question, we compared the frequency of nerve root injuries for multiple open versus MIS operations including diskectomy, laminectomy with/without fusion addressing degenerative disc disease, stenosis, and/or degenerative spondylolisthesis. METHODS: Several of Desai et al. large Spine Patient Outcomes Research Trial studies showed the frequency for nerve root injury following an open diskectomy ranged from 0.13% to 0.25%, for open laminectomy/stenosis with/without fusion it was 0%, and for open laminectomy/stenosis/degenerative spondylolisthesis with/without fusion it was 2%. RESULTS: Alternatively, one study compared the incidence of root injuries utilizing MIS transforaminal lumbar interbody fusion (TLIF) versus posterior lumbar interbody fusion (PLIF) techniques; 7.8% of PLIF versus 2% of TLIF patients sustained root injuries. Furthermore, even higher frequencies of radiculitis and nerve root injuries occurred during anterior lumbar interbody fusions (ALIFs) versus extreme lateral interbody fusions (XLIFs). These high frequencies were far from acceptable; 15.8% following ALIF experienced postoperative radiculitis, while 23.8% undergoing XLIF sustained root/plexus deficits. CONCLUSIONS: This review indicates that MIS (TLIF/PLIF/ALIF/XLIF) lumbar surgery resulted in a higher incidence of root injuries, radiculitis, or plexopathy versus open lumbar surgical techniques. Furthermore, even a cursory look at the XLIF data demonstrated the greater danger posed to neural tissue by this newest addition to the MIS lumbar surgical armamentariu. The latter should prompt us as spine surgeons to question why the XLIF procedure is still being offered to our patients?