Percutaneous Extraction of Cement Leakage After Vertebroplasty Under CT and Fluoroscopy Guidance: A New Technique

Purpose

We report a new minimally invasive technique of extraction of cement leakage following percutaneous vertebroplasty in adults.

Methods

Seven adult patients (five women, two men; mean age: 81?years) treated for vertebral compression fractures by percutaneous vertebroplasty had cement leakage into perivertebral soft tissues along the needle route. Immediately after vertebroplasty, the procedure of extraction was performed under computed tomography (CT) and fluoroscopy guidance: a Chiba needle was first inserted using the same route as the vertebroplasty until contact was obtained with the cement fragment. This needle was then used as a guide for an 11-gauge Trocar t’am (Thiebaud, France). After needle withdrawal, a 13-gauge endoscopy clamp was inserted through the cannula to extract the cement fragments. The whole procedure was performed under local anesthesia.

Results

In each patient, all cement fragments were withdrawn within 10?min, without complication.

Conclusions

This report suggests that this CT- and fluoroscopy-guided percutaneous technique of extraction could reduce the rate of cement leakage-related complications.     

Endovascular Retrieval of Intracaval Cement: A Fishing Net Technique

CardioVascular and Interventional Radiology - To describe a novel endovascular technique for intracaval cement retrieval after spinal surgery. We produced a replica of the intracaval cement...     

Retrograde Rotablator in Limb Salvage: A New Technique Using an Open Approach

Conventional vascular surgery and balloon angioplasty have poor results in severe and diffuse atherosclerotic disease of the infrapopliteal arteries. High-speed rotational atherectomy (Auth Rotablator) has not succeeded either, because of poor long-term patency and the non-reflow phenomenon. We report a case of limb salvage with long occlusion of the three infrapopliteal vessels. The anterior tibial artery was treated with retrograde Auth Rotablator atherectomy by an open approach through the pedal artery, resulting in full patency of the anterior tibial artery and healing of the skin lesions. The microparticulate debris from the ablation was drained out through the pedal arteriotomy, avoiding the complications associated with conventional antegrade high-speed rotational atherectomy.     

Safe Removal of an Encrusted Nephrostomy Tube Using a Vascular Sheath: A Technique Revisited

With the advent of interventional radiology and the decrease in mortality from chronic ailments, especially malignancy, percutaneous nephrostomy has become a commonly used safe technique for temporary relief of renal tract obstruction or for urinary diversion. However, these are associated with risks of infection, particularly septicaemia, colonisation, and blockage. Another significant complication is difficulty in removal due to encrustation. We describe a useful technique used in our department for the past few years and cite four cases of variable presentation and complexity for removal of an encrusted nephrostomy tube. No mention of this technique was found recent literature. An almost similar technique was described in the 1980s "Pollack and Banner (Radiology 145:203–205, 1982), Baron and McClennan (Radiology 141:824, 1981)". It is possible that experienced operators may have used this technique. We revisit it with pictographic representation, describing its use with currently available equipment, for benefit of operators who are not aware of this technique.     

Quantification of Nerve Viscosity Using Shear Wave Dispersion Imaging in Diabetic Rats: A Novel Technique for Evaluating Diabetic Neuropathy

ObjectiveViscoelasticity is an essential feature of nerves, although little is known about their viscous properties. The discovery of shear wave dispersion (SWD) imaging has presented a new approach for the non-invasive evaluation of tissue viscosity. The present study investigated the feasibility of using SWD imaging to evaluate diabetic neuropathy using the sciatic nerve in a diabetic rat model.Materials and MethodsThis study included 11 diabetic rats in the diabetic group and 12 healthy rats in the control group. Bilateral sciatic nerves were evaluated 3 months after treatment with streptozotocin. We measured the nerve cross-sectional area (CSA), nerve stiffness using shear wave elastography (SWE), and nerve viscosity using SWD imaging. The motor nerve conduction velocity (MNCV) was also measured. These four indicators and the histology of the sciatic nerves were then compared between the two groups. The performance of CSA, SWE, and SWD imaging in distinguishing the two groups was assessed using receiver operating characteristic (ROC) analysis.ResultsNerve CSA, stiffness, and viscosity in the diabetic group was significantly higher than those in the control group (all p < 0.05). The results also revealed a significantly lower MNCV in the diabetic group (p = 0.005). Additionally, the density of myelinated fibers was significantly lower in the diabetic group (p = 0.004). The average thickness of the myelin sheath was also lower in the diabetic group (p = 0.012). The area under the ROC curve for distinguishing the diabetic neuropathy group from the control group was 0.876 for SWD imaging, which was significantly greater than 0.677 for CSA (p = 0.030) and 0.705 for SWE (p = 0.035).ConclusionSciatic nerve viscosity measured using SWD imaging was significantly higher in diabetic rats. The viscosity measured using SWD imaging performed well in distinguishing the diabetic neuropathy group from the control group. Therefore, SWD imaging may be a promising method for the evaluation of diabetic neuropathy.     

脊髓再手术后并发切口脑脊液漏的防治附20例报告

目的：探讨脊髓再次手术后并发切口脑脊液漏的有效防治方法。方法：回顾性分析20例脊髓再次手术后并发脑脊液漏的临床资料。结果：经过加压包扎，加强漏口缝合，腰穿置管持续引流以及手术修补等治疗，切口漏均于3－15d停止。结论：术中严密缝合切口，术后出现脑脊液漏后采用加压包扎、漏口缝合，腰穿置管持续引流以及手术修补等措施是防治脑脊液漏的有效方法。     

A Novel Method of Island Blocking in Whole Abdominal Radiotherapy Using a Modified Electronic Tissue Compensation Technique

Traditionally, large fields requiring island blocking used external beam radiation therapy (EBRT) with Cerrobend blocks to limit dose to the critical structures. It is laborious to construct blocks and use them on a daily basis. We present a novel technique for island blocking using a modified electronic tissue compensation (MECOMP) technique. Five patients treated at our institution were selected for this study. The study compared two planning techniques: a novel MECOMP and a conventional EBRT technique. Conventional fields were defined using anterior-posterior and posterior-anterior (PA) fields. The kidneys were contoured and an aperture cut-out block was fitted to the OAR with a 1-cm margin (OAR_CTV) and placed in the PA field. A dynamic multileaf collimation (DMLC) plan with ECOMP was developed using identical beam and blocking strategy; this tissue compensation–based fluence map was modified to deliver a “zero” dose to the CTV_OAR from the PA field. There were no significant differences in the mean, maximum, and minimum doses to the right or left kidney between the two methods. The mean, maximum, and minimum doses to the peritoneal cavity were also not significantly different. The number of monitor units (MUs) required was increased using the MECOMP (273 vs. 1152, p < 0.01). The MECOMP is effectively able to deliver DMLC-based radiotherapy, even with island blocks present. This novel use of MECOMP for whole abdominal radiotherapy should substantially reduce the labor, daily treatment time, and treatment-related errors through the elimination of cerrobend blocks.     

A Novel Technique Using a Protection Filter During Fibrin Sheath Removal for Implanted Venous Access Device Dysfunction

With the increased use of implanted venous access devices (IVADs) for continuous long-term venous access, several techniques such as percutaneous endovascular fibrin sheath removal, have been described, to maintain catheter function. Most standard techniques do not capture the stripped fibrin sheath, which is subsequently released in the pulmonary circulation and may lead to symptomatic pulmonary embolism. The presented case describes an endovascular technique which includes stripping, capture, and removal of fibrin sheath using a novel filter device. A 64-year-old woman presented with IVAD dysfunction. Stripping was performed using a co-axial snare to the filter to capture the fibrin sheath. The captured fragment was subsequently removed for visual and pathological verification. No immediate complication was observed and the patient was discharged the day of the procedure.     

Block Regional Interpolation Scheme for k-Space (BRISK): A Rapid Cardiac Imaging Technique

We introduce an acquisition method, “block regional interpolation scheme for k-space” (BRISK), to reduce the acquisition time for cardiac imaging. The method exploits the high degree of correlation that exists between time-resolved cardiac images. For representative k-space data sets, Fourier analysis was applied along the cardiac phase dimension to reveal that different regions of k-space can be effectively sampled at different rates. A reduced sampling strategy was implemented, and unsampled points were generated by Fourier interpolation. Time savings of up to 75% are quite feasible and 25% BRISK scans compare well with 100% scans. Simulations and acquisitions using a normal volunteer and patients are presented.     

Use of Cutting Balloon in the Treatment of Urethral Stricture: A Novel Technique

The peripheral cutting balloon has been used to treat various nonvascular strictures as well as vascular stenosis. In this article, we describe for the first time the use of the cutting balloon in the treatment of patients with urethral stricture. Four patients with bulbar urethral stricture were included in the study. All strictures were successfully dilated with the cutting balloon, and patients were free of symptoms at 6-month follow-up. Cutting-balloon dilatation is a safe, easy-to-perform, and effective treatment for patients with tight urethral strictures.     

Echo-Time-Encoded Burst Imaging (EBI): A Novel Technique for Spectroscopic Imaging

A new technique for rapid spectroscopic imaging is presented. The proposed experiment enables a complete mapping of the two-dimensional reciprocal space k_x, k_o, and thus the acquisition of a 1D spectroscopic image in a single scan. The properties of the pulse sequence, based on the use of a burst of low flip angle pulses, are analyzed in the framework of linear response theory, and it is shown that chemical shift information may be introduced into the spatially encoded echoes. First experimental results are presented demonstrating that 32 x 32 proton spectroscopic images may be acquired within less than 1 min with a conventional imaging system.     

Successful Management with Glue Injection of Arterial Rupture Seen during Embolization of an Arteriovenous Malformation Using a Flow-Directed Catheter: A Case Report

We present a case in which an arterial rupture occurring during embolization of an arteriovenous malformation of the left occipital lobe with a flow-directed microcatheter, was successfully sealed with a small amount of glue. We navigated a 1.8-Fr Magic catheter through the posterior cerebral artery, and during superselective test injection, extravasation was observed at the parieto-occipital branch. The catheter was not removed and the perforation site was successfully sealed with a small amount of glue injected through the same catheter. Prompt recognition and closure of the perforation site is essential for good prognosis.     

Percutaneous Management of Accidentally Retained Foreign Bodies During Image-Guided Non-vascular Procedures: Novel Technique Using a Large-Bore Biopsy System

Objective

To describe a novel percutaneous image-guided technique using a large-bore biopsy system to retrieve foreign bodies (FBs) accidentally retained during non-vascular interventional procedures.

Materials and Methods

Between May 2013 and October 2015, five patients underwent percutaneous retrieval of five iatrogenic FBs, including a biopsy needle tip in the femoral head following osteoblastoma biopsy and radiofrequency ablation (RFA); a co-axial needle shaft within a giant desmoid tumour following cryoablation; and three post-vertebroplasty cement tails within paraspinal muscles. All FBs were retrieved immediately following original procedures under local or general anaesthesia, using combined computed tomography (CT) and fluoroscopic guidance. The basic technique involved positioning a 6G trocar sleeve around the FB long axis and co-axially advancing an 8G biopsy needle to retrieve the FB within the biopsy core. Retrospective chart review facilitated analysis of procedures, FBs, technical success, and complications.

Results

Mean FB size was 23 mm (range 8–74 mm). Four FBs were located within 10 mm of non-vascular significant anatomic structures. The basic technique was successful in 3 cases; 2 cases required technical modifications including using a stiff guide-wire to facilitate retrieval in the case of the post-cryoablation FB; and using the central mandrin of the 6G trocar to push a cement tract back into an augmented vertebra when initial retrieval failed. Overall technical success (FB retrieval or removal to non-hazardous location) was 100 %, with no complications.

Conclusion

Percutaneous image-guided retrieval of iatrogenic FBs using a large-bore biopsy system is a feasible, safe, effective, and versatile technique, with potential advantages over existing methods.

     

Enhanced Aneurysmal Flow Diversion Using a Dynamic Push-Pull Technique: An Experimental and Modeling Study

BACKGROUND AND PURPOSE:Neurovascular flow diverters are flexible, braided stent-meshes for intracranial aneurysm treatment. We applied the dynamic push-pull technique to manipulate the flow-diverter mesh density at the aneurysm orifice to maximize flow diversion. This study investigated the hemodynamic impact of the dynamic push-pull technique on patient-specific aneurysms by using the developed high-fidelity virtual-stenting computational modeling technique combined with computational fluid dynamics.MATERIALS AND METHODS:We deployed 2 Pipeline Embolization Devices into 2 identical sidewall anterior cerebral artery aneurysm phantoms by using the dynamic push-pull technique with different delivery-wire advancements. We then numerically simulated these deployment processes and validated the simulated mesh geometry. Computational fluid dynamics analysis was performed to evaluate detailed hemodynamic changes by deployed flow diverters in the sidewall aneurysm and a fusiform basilar trunk aneurysm (deployments implemented previously). Images of manipulated flow diverter mesh from sample clinical cases were also evaluated.RESULTS:The flow diverters deployed in silico accurately replicated in vitro geometries. Increased delivery wire advancement (21 versus 11 mm) by using a dynamic push-pull technique produced a higher mesh compaction at the aneurysm orifice (50% metal coverage versus 36%), which led to more effective aneurysmal inflow reduction (62% versus 50% in the sidewall aneurysm; 57% versus 36% in the fusiform aneurysm). The dynamic push-pull technique also caused relatively lower metal coverage along the parent vessel due to elongation of the flow diverter. High and low mesh compactions were also achieved for 2 real patients by using the dynamic push-pull technique.CONCLUSIONS:The described dynamic push-pull technique increases metal coverage of pure braided flow diverters over the aneurysm orifice, thereby enhancing the intended flow diversion, while reducing metal coverage along the parent vessel to prevent flow reduction in nearby perforators.

Used for intracranial aneurysm treatment, a neurovascular flow diverter (FD) is a braided stent-mesh device highly flexible in stretch and compression. A bench top study showed that an FD can form varied mesh densities through longitudinal compression,¹ consistent with our recent findings.² Meanwhile, there are concerns with using FDs in perforator-rich territories due to the likely occlusion of small vessel ostia. While increased mesh density at the aneurysm orifice may help aneurysmal flow reduction, it would be beneficial for the mesh density to be reducible in perforator-rich regions to preserve the perforators and branch vessels.We used the dynamic push-pull technique (DPPT) to effectively control the local FD mesh density. The concept of dynamic push-pull was originally introduced to keep the laser-cut stent at vessel centerline during its deployment.³ It was later extensively used in FD deployment to achieve complete opening and good wall apposition at highly curved locations.^4,5 Here, we further extended the technique, targeting flow control with the following objectives: 1) to adjust for the distal foreshortening of the FD, 2) to optimize the mesh density across the aneurysm neck to increase flow diversion, and 3) to decrease the mesh density to avoid occlusion of perforator ostia and branch vessels. The deployment technique involves individually varying the push and pull of the microcatheter and the delivery wire to control the FD mesh density and the positioning.To examine the DPPT in detail, we used in vitro testing and numerical modeling. Due to the limited resolution of current clinical angiography, it is still difficult to visualize and characterize the real-time FD deployment in patients. However, simulations of FD deployment and aneurysmal hemodynamics allow us to visualize, verify, and better understand the DPPT operation, which represents a significant advancement in intracranial aneurysm intervention.We have recently developed a finite-element-analysis workflow,⁶ referred to as the high-fidelity virtual stent-placement method. A follow-up study validated it through FD deployment in a fusiform phantom,² where DPPT was used on 2 FDs in 2 identical fusiform (basilar artery) aneurysm phantoms for differential mesh densities. We did not verify the posttreatment hemodynamic changes and did not investigate sidewall aneurysm morphology. In the current study, we further applied DPPT for the sidewall anterior cerebral artery aneurysm both experimentally and numerically. Computational fluid dynamics analyses were then performed in all 4 flow-diversion scenarios, including the sidewall and the previously deployed fusiform morphologies to evaluate the hemodynamic impact of DDPT on intra-aneurysmal flow.