Residual Popliteal Aneurysm Perfusion Leading to Embolic Complications: A Case Report.

Introduction: Surgical management of popliteal artery aneurysms has been described for half a century. Long term development of the excluded aneurysm sac in the popliteal segment however remains widely unknown, with only a few small series describing outcomes. Residual aneurysm perfusion has the potential to lead to serious complications. Report: A 63 year old man presents with skin and soft tissue necrosis of the right calf two years after proximal and distal aneurysm ligation and great saphenous vein bypass for a popliteal artery aneurysm. Computed tomography and magnetic resonance angiography show perfusion of the excluded aneurysm as well as extensive necrosis of the gastrocnemius muscle. Direct angiography of the aneurysm demonstrated retrograde aneurysm perfusion due to insufficient distal ligation with recurrent micro-embolisation to the calf via geniculate arteries. Coiling of the geniculate arteries was performed, plugging the connection to the tibiofibular trunk and embolisation of the aneurysm sac. After the intervention, no flow was seen in the aneurysm sac and the patient made full recovery. Discussion: Residual aneurysm sac perfusion can lead to complications long after successful aneurysm exclusion. Follow-up after surgery of popliteal aneurysms should include observation of the excluded aneurysm sac with control of residual blood flow. For persistent sac perfusion, aneurysm enlargement or symptoms, further treatment should be considered. Surgical aspects such as complete transection of the artery after aneurysm ligation or end to end anastomosis of the bypass may be considered, to prevent such complications.

Transfemoral hepatic vein catheterization reduces procedure time in double vein embolization.

BACKGROUND: Double vein embolization with simultaneous embolization of the portal and hepatic vein aims to grow the future liver remnant in preparation for major hepatectomy. Transvenous hepatic vein embolization is usually done via a transjugular access. The purpose of this study is to describe the transfemoral approach as an alternative option and to discuss potential advantages. RESULTS: Twenty-three patients undergoing hepatic vein embolization via a transjugular (n = 10) or transfemoral access (n = 13) were evaluated retrospectively. In all cases the portal vein embolization was done first. All procedures were technically successful. There were no peri-interventional complications. Only two patients were not able to proceed to surgery. Standardized future liver remnant hypertrophy was non-inferior with the transfemoral approach compared to the transjugular route. Procedure time was significantly shorter in the transfemoral access group (40 ± 13 min) compared to the transjugular group (67 ± 13 min, p < 0.001). CONCLUSION: Transfemoral hepatic vein embolization is feasible, safe, and faster due to easier catheterization, improved stability, and simpler patient preparation. These findings will need to be validated in larger studies.

Liver regeneration after portal and hepatic vein embolization improves overall survival compared with portal vein embolization alone: mid-term survival analysis of the multicentre DRAGON 0 cohort.

BACKGROUND: The purpose of this study was to compare 3-year overall survival after simultaneous portal (PVE) and hepatic vein (HVE) embolization versus PVE alone in patients undergoing liver resection for primary and secondary cancers of the liver. METHODS: In this multicentre retrospective study, all DRAGON 0 centres provided 3-year follow-up data for all patients who had PVE/HVE or PVE, and were included in DRAGON 0 between 2016 and 2019. Kaplan-Meier analysis was undertaken to assess 3-year overall and recurrence/progression-free survival. Factors affecting survival were evaluated using univariable and multivariable Cox regression analyses. RESULTS: In total, 199 patients were included from 7 centres, of whom 39 underwent PVE/HVE and 160 PVE alone. Groups differed in median age (P = 0.008). As reported previously, PVE/HVE resulted in a significantly higher resection rate than PVE alone (92 versus 68%; P = 0.007). Three-year overall survival was significantly higher in the PVE/HVE group (median survival not reached after 36 months versus 20 months after PVE; P = 0.004). Univariable and multivariable analyses identified PVE/HVE as an independent predictor of survival (univariable HR 0.46, 95% c.i. 0.27 to 0.76; P = 0.003). CONCLUSION: Overall survival after PVE/HVE is substantially longer than that after PVE alone in patients with primary and secondary liver tumours.

Safety of Percutaneous Transmesenteric and Transsplenic Access for Portosystemic Shunt Creation in Patients with Portal Vein Obstruction: Single-Center Experience and Review of Literature.

PURPOSE: To evaluate the safety of ultrasound-guided percutaneous mesenteric vein access compared to transsplenic portal vein access for portosystemic shunt placement in patients with portal vein obstruction. MATERIALS AND METHODS: Eight patients underwent portosystemic shunt creation through either a transsplenic (n = 4) or transmesenteric (n = 4) approach. The superior or inferior mesenteric vein was percutaneously accessed under ultrasound guidance using a 21G needle and a 4F sheath. Hemostasis at the mesenteric access site was achieved with manual compression. For transsplenic access, sheath sizes between 6 and 8F were used and tract embolization with gelfoam was performed. RESULTS: Portosystemic shunt placement was successful in all patients. While there were no bleeding complications with transmesenteric access, hemorrhagic shock requiring splenic artery embolization occurred in one patient in which the transsplenic approach was used. CONCLUSION: Ultrasound-guided mesenteric vein access seems feasible and a valid alternative to the transsplenic access in case of portal vein obstruction. Level of Evidence Level 4, case series.

Postinterventional Patient Comfort After Uterine Artery Embolization and Superior Hypogastric Nerve Block.

PURPOSE: To evaluate the duration and effect of superior hypogastric nerve block (SHNB) with ropivacaine and clonidine on postinterventional pain levels and opioid requirements in patients undergoing uterine artery embolization. MATERIALS AND METHODS: Postinterventional pain levels (numeric rating scale, NRS 0-10) and opioid doses were retrospectively analyzed in 53 patients undergoing transfemoral uterine artery embolization and intraprocedural superior hypogastric nerve block during 24 h. A mixture of 150 mg of ropivacaine and 150 µg of clonidine was used for the block. RESULTS: Postinterventional pain averaged between 1.4 and 2.0 during the first 9 h, after which a small but significant increase was observed (NRS 1.7 ± 1.6 vs. NRS 2.6 ± 2.2, p < 0.001). 70% of patients did not exceed a tolerable pain threshold of NRS 4 during the first 9 h after the intervention. Thirty-three patients (62%) did not require any opioid medication. Mean iv morphine dose was 3.1 ± 4.7 mg, whereas 71% of opioid doses were administered after 9 h. CONCLUSION: Superior hypogastric nerve block using a mixture of ropivacaine and clonidine provides good pain relief for 9 h after uterine artery embolization requiring only very low amounts of additional opioids.

Resectability of bilobar liver tumours after simultaneous portal and hepatic vein embolization versus portal vein embolization alone: meta-analysis.

BACKGROUND: Many patients with bi-lobar liver tumours are not eligible for liver resection due to an insufficient future liver remnant (FLR). To reduce the risk of posthepatectomy liver failure and the primary cause of death, regenerative procedures intent to increase the FLR before surgery. The aim of this systematic review is to provide an overview of the available literature and outcomes on the effectiveness of simultaneous portal and hepatic vein embolization (PVE/HVE) versus portal vein embolization (PVE) alone. METHODS: A systematic literature search was conducted in PubMed, Web of Science, and Embase up to September 2022. The primary outcome was resectability and the secondary outcome was the FLR volume increase. RESULTS: Eight studies comparing PVE/HVE with PVE and six retrospective PVE/HVE case series were included. Pooled resectability within the comparative studies was 75 per cent in the PVE group (n = 252) versus 87 per cent in the PVE/HVE group (n = 166, OR 1.92 (95% c.i., 1.13-3.25)) favouring PVE/HVE (P = 0.015). After PVE, FLR hypertrophy between 12 per cent and 48 per cent (after a median of 21-30 days) was observed, whereas growth between 36 per cent and 67 per cent was reported after PVE/HVE (after a median of 17-31 days). In the comparative studies, 90-day primary cause of death was similar between groups (2.5 per cent after PVE versus 2.2 per cent after PVE/HVE), but a higher 90-day primary cause of death was reported in single-arm PVE/HVE cohort studies (6.9 per cent, 12 of 175 patients). CONCLUSION: Based on moderate/weak evidence, PVE/HVE seems to increase resectability of bi-lobar liver tumours with a comparable safety profile. Additionally, PVE/HVE resulted in faster and more pronounced hypertrophy compared with PVE alone.

Transarterial Radioembolization to Impact Liver Volumetry: When and How.

Inadequate volume of the future liver remnant (FLR) renders many patients with liver malignancies not amenable to surgical resection. Depending on the health of the liver and the patient in general, an FLR of 25-40% is required to avoid acute post-hepatectomy liver failure. Transarterial radioembolization (TARE) of a diseased liver lobe leads to atrophy of the embolized lobe and compensatory hypertrophy of the contralateral lobe. Although the absolute degree of FLR hypertrophy seems to be comparable to portal vein embolization, the kinetic of hypertrophy is much slower after radioembolization. However, TARE has the unique advantages of simultaneously offering local tumor control, possibly downstaging disease, and providing biological test of time. Progressions in technique and personalized dosimetry allow for more predictable ablative treatment of liver malignancies and preparation for major liver surgery. This article provides an overview of the existing literature, discusses the evidence, and considers possible criteria for patient selection.

High-Resolution 3D versus Standard-Resolution 2D T2-Weighted Turbo Spin Echo MRI for the Assessment of Lumbar Nerve Root Compromise.

Radiculopathy can be caused by nerve root irritation and nerve root compression at the level of the lateral recess or at the level of the intervertebral foramen. T2-weighted (T2w) MRI is considered essential to evaluate the nerve root and its course, starting at the lateral recess through the intervertebral foramen to the extraforaminal space. With the introduction of novel MRI acceleration techniques such as compressed SENSE, standard-resolution 2D T2w turbo spin echo (TSE) sequences with a slice-thickness of 3-4 mm can be replaced with high-resolution isotropic 3D T2w TSE sequences with sub-millimeter resolution without prolonging scan time. With high-resolution 3D MRI, the course of the nerve root can be visualized more precisely due to a detailed depiction of the anatomical situation and less partial volume effects, potentially allowing for a better detection of nerve root compromise. In this intra-individual comparison study, 55 patients with symptomatic unilateral singular nerve root radiculopathy underwent MRI with both 2D standard- and 3D high-resolution T2w TSE MRI sequences. Two readers graded the degree of lumbar lateral recess stenosis and lumbar foraminal stenosis twice on both image sets using previously validated grading systems in an effort to quantify the inter-readout and inter-sequence agreement of scores. Inter-readout agreement was high for both grading systems and for 2D and 3D imaging (Kappa = 0.823-0.945). Inter-sequence agreement was moderate for both lumbar lateral recess stenosis (Kappa = 0.55-0.577) and lumbar foraminal stenosis (Kappa = 0.543-0.572). The percentage of high degree stenosis with nerve root deformity increased from 16.4%/9.8% to 41.8-43.6%/34.1% from 2D to 3D images for lateral recess stenosis/foraminal stenosis, respectively. Therefore, we show that while inter-readout agreement of grading systems is high for both standard- and high-resolution imaging, the latter outperforms standard-resolution imaging for the visualization of lumbar nerve root compromise.

Impact of Acoustic Noise Reduction on Patient Experience in Routine Clinical Magnetic Resonance Imaging.

OBJECTIVES: Acoustic noise emission from MRI scanners is considered a major factor of patient discomfort during routine MRI examinations. We prospectively evaluated the impact of acoustic noise reduction using software implementations in routine clinical MRI on subjective patient experience and image quality. METHODS: Two-hundred consecutive patients undergoing one of four MRI examinations (brain, lumbar spine, shoulder, and knee) at a single center were prospectively randomized into two groups at a 1 to 1 ratio: standard MRI examination and MRI examination with acoustic noise reduction. After the examination, patients were asked to complete a questionnaire aimed at defining their subjective experience (primary endpoint). Two readers assessed subjective image quality of all patient studies in consensus (secondary endpoint). Nonparametric tests and logistic regression models were used for statistical analysis. RESULTS: Hundred-seventy-four patients were included in the final study. Patients in the intervention group felt less discomforted by the acoustic noise (p = 0.01) and reported increased audibility of music through the headphones (p = 0.03). No significant difference in subjective image quality was found. CONCLUSION: Our study indicates that the effects of acoustic noise reduction in routine clinical MRI can be translated into reduced patient discomfort from acoustic noise and improved audibility of music. Acoustic noise reduction thus significantly contributes to increased patient comfort during MRI examinations.

Contrast-Enhanced T1-Weighted Head and Neck MRI: Prospective Intraindividual Image Quality Comparison of Spiral GRE, Cartesian GRE, and Cartesian TSE Sequences.

BACKGROUND. Sequences with noncartesian k-space sampling may improve image quality of head and neck MRI. OBJECTIVE. The purpose of this study was to compare intraindividually the image quality of a spiral gradient-recalled echo (GRE) sequence and conventional cartesian GRE and cartesian turbo spin-echo (TSE) sequences for contrast-enhanced T1-weighted head and neck MRI. METHODS. This prospective study included patients referred for contrast-enhanced head and neck MRI from August 2020 to May 2021. Patients underwent 1.5-T MRI including contrast-enhanced spiral GRE (2 minutes 28 seconds), cartesian GRE (4 minutes 27 seconds), and cartesian TSE (3 minutes 41 seconds) sequences, acquired in rotating order across patients. Three radiologists independently assessed image quality measures, including conspicuity of prespecified lesions, using 5-point Likert scales. One reader measured maximal extent of dental material artifact and contrast-to-noise ratio (CNR). RESULTS. Thirty-one patients (13 men, 18 women; mean age, 63.8 years) were enrolled. Nineteen patients had a focal lesion; 22 had dental material. Interreader agreement for image quality measures was substantial to excellent (Krippendorff alpha, 0.681-1.000). Scores for overall image quality (whole head and neck, neck only, and head only), pulsation artifact, muscular contour delineation, vessel contour delineation, motion artifact, and differentiation between mucosa and pharyngeal muscles were significantly better for spiral GRE than for cartesian GRE and cartesian TSE for all readers (p < .05). Scores for lesion conspicuity (whole head and neck, neck only, and head only), quality of fat suppression, flow artifact, and foldover artifact were not significantly different between spiral GRE and the cartesian sequences for any reader (p > .05). Dental material artifact scores were significantly worse for spiral GRE than the other sequences for all readers (p < .05). The mean maximum extent of dental material artifact was 39.6 ± 25.5 (SD) mm for spiral GRE, 35.6 ± 24.3 mm for cartesian GRE, and 29.6 ± 21.4 mm for cartesian TSE; the mean CNR was 221.1 ± 94.5 for spiral GRE, 151.8 ± 85.7 for cartesian GRE, and 153.0 ± 63.2 for cartesian TSE (p < .001 between spiral GRE and other sequences for both measures). CONCLUSION. Three-dimensional spiral GRE improves subjective image quality and CNR of head and neck MRI with shorter scan time versus cartesian sequences, though it exhibits larger dental material artifact. CLINICAL IMPACT. A spiral sequence may help overcome certain challenges of conventional cartesian sequences for head and neck MRI.

Spiral 3D time-of-flight MR angiography for rapid non-contrast carotid artery imaging: Clinical feasibility and protocol optimization.

PURPOSE: To assess the clinical feasibility of spiral 3D Time-Of-Flight (TOF) MR Angiography (MRA) sequence variants for rapid non-contrast carotid artery imaging. METHODS: Nine different 3D TOF MRA sequences were acquired in nine healthy volunteers on a standard clinical 1.5 T scanner. Three cartesian sequences (fully sampled (10:15 min), accelerated with SENSE (05:08 min), accelerated with Compressed SENSE (03:32 min)) and six different spiral sequences were acquired (spiral acquisition windows ranging from 10 to 5 ms (01:32 min-03:05 min)). Three readers graded the images qualitatively in terms of overall image quality, vessel sharpness, inhomogeneous intraluminal signal, background noise, visualization of large and small vessels and overall impression of the number of visible vessels. Cross-sectional areas of the vessel lumen were measured and vessel sharpness was quantified. RESULTS: The SENSE and Compressed SENSE accelerated cartesian sequences and the Spiral 6 ms and 5 ms sequences were deemed comparable to the fully sampled cartesian sequence in most qualitative categories (p > 0.05) based on exact binomial tests. The Spiral 6 ms and 5 ms sequences achieved a scan time reduction of 75.3% and 69.9% respectively compared to the fully sampled cartesian sequence. The spiral sequences (generally) exhibited improved subjective vessel sharpness (p < 0.01-p = 0.13) but increased background noise (p = 0.03-p = 0.25). Cross-sectional area measurements were similar between all sequences (Krippendorff's alpha: 0.955-0.982). Quantitative vessel sharpness was increased for all spiral sequences compared to all cartesian sequences (p = 0.004). CONCLUSIONS: Spiral 3D TOF MRA sequences with a spiral acquisition window of 5 ms or 6 ms may be used for accurate, rapid, clinical non-contrast carotid artery imaging.

Single shot zonal oblique multislice SE-EPI diffusion-weighted imaging with low to ultra-high b-values for the differentiation of benign and malignant vertebral spinal fractures.

PURPOSE: To investigate the diagnostic yield of low to ultra-high b-values for the differentiation of benign from malignant vertebral fractures using a state-of-the-art single-shot zonal-oblique-multislice spin-echo echo-planar diffusion-weighted imaging sequence (SShot ZOOM SE-EPI DWI). MATERIALS AND METHODS: 66 patients (34 malignant, 32 benign) were examined on 1.5 T MR scanners. ADC maps were generated from b-values of 0,400; 0,1000 and 0,2000s/mm2. ROIs were placed into the fracture of interest on ADC maps and trace images and into adjacent normal vertebral bodies on trace images. The ADC of fractures and the Signal-Intensity-Ratio (SIR) of fractures relative to normal vertebral bodies on trace images were considered quantitative metrics. The appearance of the fracture of interest was graded qualitatively as iso-, hypo-, or hyperintense relative to normal vertebrae. RESULTS: ADC achieved an area under the curve (AUC) of 0.785/0.698/0.592 for b = 0,400/0,1000/0,2000s/mm2 ADC maps respectively. SIR achieved an AUC of 0.841/0.919/0.917 for b = 400/1000/2000s/mm2 trace images respectively. In qualitative analyses, only b = 2000s/mm2 trace images were diagnostically valuable (sensitivity:1, specificity:0.794). Machine learning models incorporating all qualitative and quantitative metrics achieved an AUC of 0.95/0.98/0.98 for b-values of 400/1000/2000s/mm2 respectively. The model incorporating only qualitative metrics from b = 2000s/mm2 achieved an AUC of 0.97. CONCLUSION: By using quantitative and qualitative metrics from SShot ZOOM SE-EPI DWI, benign and malignant vertebral fractures can be differentiated with high diagnostic accuracy. Importantly qualitative analysis of ultra-high b-value images may suffice for differentiation as well.

One Year Outcomes of the VIVO-EU Study of Treatment of Symptomatic Iliofemoral Outflow Obstruction with the Zilver Vena Venous Self-Expanding Stent.

OBJECTIVE: To evaluate the performance of the Zilver® Vena™ Venous Stent in the treatment of patients with symptomatic iliofemoral outflow obstruction. METHODS: Between August 2012 and January 2015, 35 patients (mean age of 45.1 ± 15.5 years; 77.1% female) with symptomatic iliofemoral venous outflow obstruction were treated with the Zilver Vena Venous Stent (Cook Ireland, Ltd.) as part of this prospective, single arm, multicenter study. Study assessments included procedural success, major adverse events (MAEs), freedom from occlusion and qualitative patency at 6 and 12 month post-procedure, clinical symptoms of venous insufficiency, and reintervention with the treated venous segment. RESULTS: The rate of freedom from occlusion at 6 month and 12 month was 88.2%. The rate of qualitative patency was 88.2% at 6 month and 85.2% at 12 month. Three MAEs were reported: one symptomatic pulmonary embolism and two clinically-driven reinterventions. Following stenting, clinical symptoms of venous insufficiency improved significantly from baseline at each follow-up, as measured by VDS (p < 0.0001), CEAP "C" (p ≤ 0.0001), VCSS (p < 0.0001), and CIVIQ (p < 0.0001). CONCLUSION: Clinical results with the Zilver Vena Venous Stent were favorable through 12 month, with high patency rates, reduction of venous insufficiency symptoms, and low morbidity.

Consensus Guidelines for the Definition of Time-to-Event End Points in Image-guided Tumor Ablation: Results of the SIO and DATECAN Initiative.

There is currently no consensus regarding preferred clinical outcome measures following image-guided tumor ablation or clear definitions of oncologic end points. This consensus document proposes standardized definitions for a broad range of oncologic outcome measures with recommendations on how to uniformly document, analyze, and report outcomes. The initiative was coordinated by the Society of Interventional Oncology in collaboration with the Definition for the Assessment of Time-to-Event End Points in Cancer Trials, or DATECAN, group. According to predefined criteria, based on experience with clinical trials, an international panel of 62 experts convened. Recommendations were developed using the validated three-step modified Delphi consensus method. Consensus was reached on when to assess outcomes per patient, per session, or per tumor; on starting and ending time and survival time definitions; and on time-to-event end points. Although no consensus was reached on the preferred classification system to report complications, quality of life, and health economics issues, the panel did agree on using the most recent version of a validated patient-reported outcome questionnaire. This article provides a framework of key opinion leader recommendations with the intent to facilitate a clear interpretation of results and standardize worldwide communication. Widespread adoption will improve reproducibility, allow for accurate comparisons, and avoid misinterpretations in the field of interventional oncology research. Published under a CC BY 4.0 license. Online supplemental material is available for this article. See also the editorial by Liddell in this issue.

Introduction and reproducibility of an updated practical grading system for lumbar foraminal stenosis based on high-resolution MR imaging.

In this paper we sought to develop and assess the reproducibility of an updated 6-point grading system for lumbar foraminal stenosis based on the widely used Lee classification that more accurately describes lumbar foraminal stenosis as seen on high-resolution MRI. Grade A indicates absence of foraminal stenosis. Grades B, C, D and E indicate presence of foraminal stenosis with contact of the nerve root with surrounding anatomical structures (on one, two, three or four sides for B, C, D and E respectively) yet without morphological change of the nerve root. To each grade, a number code indicating the location of contact between the nerve root and surrounding anatomical structure(s) is appended. 1, 2, 3 and 4 indicate contact of the nerve root at superior, posterior, inferior and anterior position of the borders of the lumbar foramen. Grade F indicates presence of foraminal stenosis with morphological change of the nerve root. Three readers graded the lumbar foramina of 101 consecutive patients using high-resolution T2w (and T1w) MR images with a spatial resolution of beyond 0.5 mm3. Interreader agreement was excellent (Cohen's Kappa = 0.866-1). Importantly, 30.6%/31.6%/32.2% (reader 1/reader 2/ reader 3) of foramina were assigned grades that did not appear in the original Lee grading system (grades B and D). The readers found no foramen that could not be described accurately with the updated grading system. Thus, an updated 6-point grading system for lumbar foraminal stenosis is reproducible and comprehensively describes lumbar foraminal stenosis as seen on high-resolution MRI.

Combined simultaneous embolization of the portal vein and hepatic vein (double vein embolization) - a technical note about embolization sequence.

BACKGROUND: Simultaneous portal vein embolization (PVE) and hepatic vein embolization (HVE) has been shown to be feasible, safe and lead to a faster growth of future liver remnant (FLR) than PVE alone. The objective of this study is to highlight different technical aspects as well as importance of embolization order. MATERIALS AND METHODS: Seven patients were treated with simultaneous PVE and HVE. In three cases, HVE was performed first followed by PVE and in four cases the other way around. Portal vein branches were embolized using Glubran-Lipiodol mixture in all cases. Hepatic veins were embolized using Amplatzer II plugs sized 8-20 mm. Specific consideration was given to depth of glue penetration in the portal vein defined by visible branch order on the treated side. RESULTS: Six of seven patients were discharged home the same day. One patient with infected tumor necrosis died of liver failure 40 days later, otherwise there were no periprocedural clinical complications. Median glue penetration was to the 5th order (4th - 5th) when PVE was performed first and 3rd order (2nd - 4th) when PVE was performed after HVE. In one PVE first case, glue spillage was seen due to marked reduced flow in the right portal vein. There was sufficient FLR growth for subsequent surgical resection in the remaining six patients. CONCLUSION: PVE should be performed prior to HVE because the reduced flow in the portal vein after HVE leads to less deep glue penetration with presumably increased risk of contralateral spillage.