Duplex Imaging Research Articles

Clinical study on management of venous ulcer

Background: Venous ulcer is the most common ulcer affecting the lower limbs, usually associated with varicose veins. They are diagnosed by their location, morphology, skin changes, and association with venous insufficiency. They are complicated with local scarring, ankylosis of ankle joint, and occasionally malignancy. Diagnosis is confirmed by venous duplex imaging. They significantly reduce quality of life due to pain, and reduced mobility leading to loss of income and social isolation. Cost estimates put them at upwards of 2% of national resources. Recurrence is high with conservative treatment. Surgery addressing venous valvular insufficiency plays a major role. Objectives of current study was to assess the role of conservative treatment and surgical management of venous ulcers.Methods: A cross-sectional study of 80 patients in the period 2019 -2020 at a tertiary care center.Results: 84% of the patients were male with maximum patients in the 6th decade. 67% were overweight. Conservative treatment was done in 22% of cases and surgery for 78%. Flush ligation and venous stripping with perforator ligation was the most common surgery done. 89% of the patients achieved healing by the end of 3 months, and 7% by the end of 6 months. Wound healing time in surgical vs conservatively was 8.3 and 10.4 weeks respectively.Conclusions: Correction of underlying venous insufficiency is the main stay of the treatment. Surgery gives best results with long term benefits.

A robust dual-channel fluorescence-enhanced probe for duplex imaging of endogenous HClO/ClO- in living cells and in zebrafish

A unique fluorescent probe, MCB, for HClO/ClO- was rationally constructed by integrating methylene blue, 7-hydroxycoumarin, and two HClO-specific reacting moieties into a single molecular structure. Distinct from other published cases, MCB displayed remarkable dual-channel fluorescence enhancement, peaked at 464 and 700 nm respectively, which simultaneously provided two crosstalk-free fluorescence channels, blue and NIR channels, for mutual corroboration, and hence improving the reliability of the detection results. More importantly, MCB exhibited excellent sensing properties for HClO/ClO-, such as fast response (within 90 s), high sensitivity (LOD as low as 3.9 nM based on blue fluorescence channel), and sufficient selectivity. Significantly, MCB was successfully utilized for dual-channel imaging of HClO/ClO-in living cells and zebrafish, thereby holding the potential for research that focused on elucidating the biological roles of HClO/ClO-.

Engineering Molecular Probes for In Vivo Near-Infrared Fluorescence/Photoacoustic Duplex Imaging of Human Neutrophil Elastase.

Early detection of human neutrophil elastase (HNE), the potential biomarker of lung cancer, is crucial for the accurate diagnosis and evaluation of lung cancer. Currently, little progress of HNE-activated probes has been made for in vivo imaging. Herein, assisted by probe-active pocket match engineering, we synthesized a series of near-infrared fluorescence (NIRF) and photoacoustic (PA) duplex imaging probes by conjugating diverse fluorinated amide chains onto hemi-cyanine. Finally, we identified that probe 2 (denoted as LET-8), with the pentafluoroethyl group, is a superior probe to detect HNE with the best selectivity as well as good response ability and thus successfully realized NIRF/PA duplex imaging of HNE activity both in vitro and in vivo.

Management of Arterio-Venous Fistula Side Branches During Maturation: Ligation or Coil Embolization

Failure of maturation of arteriovenous fistulae (AVF) remains an ongoing concern for dialysis access. One etiology is the presence of side branches that divert flow from the main AVF channel. This study aims to evaluate the outcomes of endovascular and open surgical interventions for AVF side branches in the setting of maturation failure. A retrospective review of all patients within a 10-year period with primary radio cephalic and brachiocephalic AVF was undertaken, and 380 cases of maturation failure related to branch diversion were selected for the study. Fifty-four percent and 48% of the AVF in the ENDO and OPEN groups respectively have concomitant stenosis further along in the flow path that required intervention by balloon angioplasty at the same time as a side branch intervention. All patients underwent duplex imaging or a fistulogram before intervention. Indications were low flow (<600 mL/min) or failure to increase in size (<6 mm diameter) in all cases. Interventions were divided into endovascular (coil embolization; ENDO) and surgical (branch ligation; OPEN) interventions. Outcomes of maturation (successful progression to hemodialysis (HD)), re-intervention, and functional dialysis (continuous HD for three consecutive months) were examined. From January 2008 to December 2018, 187 patients (49^ of all cases with side branches; 65% female, age of 57 ± 18 years; mean ± SD) with poorly maturing radiocephalic (70%) and brachiocephalic AVF (30%) underwent intervention due to the presence of accessory venous branches only. Indications were failure to mature in 54% and low flow in 46%. The average time to intervention due to failure to mature was 5 ± 4 weeks (mean ± SD) after primary access placement. Eighty-one had coil embolization and 106 had open branch ligation. Technical success was 90% in ENDO and 100% in OPEN. Technical ENDO failures had a secondary open branch ligation but were considered failures for analysis. Repeat interventions by balloon-assisted maturation were required in 45% of all the cases with no difference between ENDO and OPEN. Recannulation of the ENDO branches occurred in 10% of the cases requiring repeat intervention. Sixty one percent of isolated endovascular (n=49) and 64% of isolated open (n=68) matured to successful cannulation (P=0.84). Median functional dialysis durations remained equivalent between ENDO (2.6 years) and OPEN (2.8 years) groups (P=0.12). There is an improved maturation rate following the ENDO group compared to OPEN interventions while both ENDO and OPEN modalities demonstrated similar long-term functionality.

Photoregulated plasmon enhanced controllable hydrogen sulfide delivery for photothermal augmented gas therapy

Gas therapy has emerged as a promising “green” treatment modality for malignant cancer, however, the targeted delivery of gas donors as well as the controlled gas release remain a formidable challenge. Herein, self-assembled gold nanovesicles (GVs) loaded with ammonium sulfide ((NH4)2S) (denoted as GV-(NH4)2S) were developed as theranostic nanoplatform for near-infrared (NIR)-activated in-situ hydrogen sulfide (H2S) generation, controllable gas delivery, and combined photothermal/gas therapy of cancer. GVs had the following features, (1) large hollow cavity, offering high encapsulation efficiency of (NH4)2S (∼95%), (2) strong plasmon coupling effect, promoting high photothermal effect under NIR laser irradiation. Upon laser irradiation, GVs were ruptured, thus allowing the simultaneous release and decomposition of (NH4)2S to generate H2S. The generated H2S induced significant mitochondrial damage and thus reduced adenosine triphosphate (ATP) energy level. Consequently, upon integration, GV-(NH4)2S triggered substantial tumor cell killing in vitro and complete 4T1 tumor ablation in vivo, with negligible tumor recurrence and systemic side effects, under the guidance of photoacoustic (PA)/photothermal duplex imaging. This work highlighted the great promise of GVs as a versatile nanocarrier for spatio-temporally controlled and on-demand delivery of gaseous messengers to achieve precision cancer theranostics.

Prevalence and Predictors of Cerebral Microangiopathy Determined by Pulsatility Index in an Asymptomatic Population From the ILERVAS Project.

Background: Little is known about the prevalence of cerebral microangiopathy (CM), which is related to cognitive impairment, in an asymptomatic population. Pulsatility index (PI) is an easily measurable parameter of cerebral vascular resistance in transcranial duplex of the middle cerebral artery (MCA) study. We aimed to determine the prevalence of CM measured by PI of MCA in low to moderate vascular risk subjects.Methods: We included 3,721 subjects between 45 and 70 years without previous history of vascular disease or diabetes mellitus and with at least one other vascular risk factor from the cross-sectional study ILERVAS (Lleida, Spain). Patients underwent transcranial duplex to determine MCA-PI. Possible CM was defined by MCA-PI >1.1. Carotid and femoral arteries ultrasound registration was done to determine the presence, the number, and the area of atheromatous plaques. Body mass index (BMI), pulse pressure (PP) and laboratory data were also recorded.Results: 439 (11.8%) subjects were excluded due to the low quality of transcranial duplex images. Median age was 57 [IQR 52, 62] years. Possible CM was found in 424 (12.9%) subjects. CM patients had higher prevalence of plaques than non-CM (77.4 vs. 66.4%, p < 0.001). PI showed a positive linear correlation with the number of territories with plaques (r = 0.130, p < 0.001), and the total plaque area (r = 0.082, p < 0.001). The predictors of possible CM were the age, male gender, and PP.Conclusions: In low-to-moderate vascular risk asymptomatic population, the proportion of abnormal brain microvascular bed determined by MCA-PI is not negligible. The planned 10-year follow-up will describe the clinical relevance of these findings.

Development of a Duplex Ultrasound Protocol for Baseline and Follow-Up Imaging of a Branched Aortic Endoprosthesis

Branched endoprostheses for endovascular repair of pararenal and thoracoabdominal aortic aneurysms are undergoing evaluation in prospective clinical trials. Duplex ultrasound has been a cornerstone of surveillance for vascular reconstructions. This paper describes the development and deployment of a standardized duplex imaging protocol to evaluate individuals who have undergone endovascular repair of their thoracoabdominal aortic aneurysm. Ultrasound imaging is performed after an 8 to 12 hour fast to minimize the presence of bowel gas and allow for optimal imaging of abdominal vascular structures. Doppler measurements of peak systolic and end diastolic velocity are made at specific arterial segments in the aorta and the celiac, superior mesenteric, and renal arteries. Resistive indices are also recorded in the segmental and arcuate arteries of both kidneys. Pulsed-wave Doppler is used to record spectral Doppler data and color Doppler is used to image all arterial segments and ensure proper placement of the Doppler sample volume and ensure correct angle of interrogation. Implementation of a standardized duplex ultrasound imaging protocol can be used to image and follow individuals who have received the Thoracoabdominal Branch Endoprosthesis (TAMBE) device and branched endovascular aneurysm repair (BEVAR). Ultrasound may provide complementary findings and may add information to the computed tomography angiography imaging for following these individuals.

Hierarchical Fluorescence Imaging Strategy for Assessment of the Sialylation Level of Lipid Rafts on the Cell Membrane.

Glycosylation is one of the most ubiquitous and complicated modifications of proteins and lipids. The revelation of glycosylation-mediated regulation mechanisms of biological processes relies critically on the tools that can reflect the spatial heterogeneity of cell surface glycans, for example, distinguishing glycans exhibited in lipid raft or nonraft domains. To achieve simultaneous visualization of raft and raft-harbored glycans on the cell surface, we combine specific raft recognition, glycan chemoselective labeling, and DNA dynamic hybridization techniques to develop a hierarchical fluorescence imaging strategy using N-acetyl-neuraminic acid (Sia) as the model sugar. We fabricate a raft probe and Sia probe for rafts and Sia, respectively. After specifically anchoring the two probes on the cell surface, the raft probe can be cyclically utilized to turn on the fluorescence of the Sia probe, only residing in rafts, via a proximity cascade DNA reaction. The duplex imaging capability for spatially relevant levels of biological structures enables the revelation of the reason for raft-confined Sia variation in different biological processes. Thus, this work provides an elegant and powerful tool for interrogation of the glycan regulation mechanisms on raft composition, organization, and functions and also contributes to the development of raft-carried glycoconjugate-based theranostic techniques.

Direct oral anticoagulants decrease treatment failure for acute lower extremity deep venous thrombosis.

Optimal medical therapy for acute lower extremity deep venous thrombosis (DVT) remains an enigma. While clinical trials demonstrate non-inferiority with an oral anti-Xa inhibitor, or direct oral anticoagulant (DOAC), versus combined low-molecular weight heparin (LMWH) and oral vitamin K antagonist (VKA), the most effective regimen remains to be determined. This study is a single-center retrospective cohort study from October 2014 to December 2015 of patients with a diagnosis of acute DVT and subsequent serial lower extremity venous duplex. Demographics, medical history, medications, serial ultrasound findings, as well as the primary anticoagulant used for treatment were collected and analyzed by two independent data extractors. Treatment failure was defined as any new DVT or progression of an existing DVT within 3months of diagnosis of the index clot. Risk factors for treatment failure were assessed using standard odds ratios and Fischer's exact test. Among 496 patients with an acute lower extremity DVT, 54% (n = 266) were men, mean age was 61years, 35% (n = 174) involved the popliteal or more proximal segments, and 442 had documentation of the primary treatment for DVT: 20% (n = 90) received nothing; 20% (n = 92) received an oral VKA; 34% (n = 149) received a DOAC; 20% (n = 90) received LMWH; and 5% (n = 21) received another class of anticoagulant. Within 3months, 21% (n=89 out of 427) had treatment failure defined as any new DVT or progression of prior DVT. Patients treated with a DOAC were less likely to experience treatment failure when compared with any other treatment (odds ratio 0.43; 95% confidence intervals [0.23, 0.79]; p = 0.0069) and when compared with traditional oral VKA (OR 0.44; 95% CI [0.21, 0.92]; p = 0.029). None of prior history of DVT, pulmonary embolism, thrombophilia, renal insufficiency, hepatic insufficiency, cancer, or antiplatelet therapy correlated with treatment failure. Treatment outcome did not correlate with being on any anticoagulation versus none (p = 0.74), nor did it correlate with the duration of treatment (<3months versus ≥3months) (p = 0.42). Proximal and distal DVTs showed no difference in treatment failure (19% versus 22%, respectively; p = 0.43). In summary, the use of a DOAC for acute lower extremity DVT yielded better overall outcomes and fewer treatment failures at 3months as compared to traditional oral VKA therapy based on serial duplex imaging.

Dialysis-associated steal syndromes.

The aim of this article is to review contemporary concepts in the genesis of dialysis access steal syndrome (DASS) and its current management. An electronic search of literature from 1960 to 2020 in PubMed and the Cochrane library was conducted and practice guidelines were examined. Search terms included dialysis, steal, ischemia, access and ESRD. Clinical presentation, pathophysiology, risk factors, diagnostic techniques and management outcomes of extremity ischemia following dialysis access creation were reviewed. Symptomatic steal occurs in 4-10% of patietns after creation of hemodialysis access creation. Risk factos include brachial based fistula, diabetes, female sex, coronary heart disease, cerebrovascular disease, tobacco use, age more than 60 and hypertension. Diagnosis is mainly clinical and can be aided by non invasive testing. Correction o finflow stenosis, Distal revasulatisation with interval ligation, revision using distal inflow or other techniques are useful for fistula preservation. Dialysis-associated steal syndromes have a complex haemodynamic causation. Clinical presentation is diagnostic; however when the diagnosis is uncertain adjunctive non-invasive perfusion tests, duplex and other imaging amy be required. Management is guided by anatomic, patient and disease-related considerations.

COLOR DUPLEX VERSUS CT ANGIOGRAPHY IN ASSESSMENT OF INFRA POPLITEAL ARTERIAL CIRCULATION IN DIABETIC PATIENTS: A COMPARATIVE STUDY

Background: Peripheral vascular disease is narrowing or occlusion of arteries mostly due to atherosclerosis which is very common in patients with diabetes mellitus (DM). Objective: To compare lower limb arterial diseases using Color duplex and multi-detector CT angiography (MDCTA) and to find the better non-invasive modality of choice. Patients and Methods: Thirty diabetic patients of lower limb peripheral arterial disease underwent Color duplex and multi-detector CT angiography (MDCTA). Infra popliteal arterial system, divided into anatomic segments and luminal narrowing, were compared using color duplex and axial images of arterial phase of CT angiography. Using statistical methods, sensitivity, specificity and accuracy of color duplex and CT angiography were determined. Results: One hundred and fifty six arterial segments were studied with CT angiography and color duplex. Out of the total 156 vessel segments, color duplex was able to detect 140 (89.7 %) diseased segments, while MDCTA which was able to detect 114 (73 %) diseased segments. Color duplex was able to pick up grade 1 lesions better than MDCT angiography with sensitivity 91.6%. Grade 2 and grade 3 were better picked up by MDCT angiography with color duplex sensitivity of 80% and 76 % for grade 2 and grade 3 respectively. The two modalities showed comparable results for grade 4 lesions with sensitivity of 85.7 %. Significant statistical agreement existed between color duplex and CT angiography with moderate total agreement (Weighted kappa estimation (Kw) = 0.64) for grade 1 lesions, fair total agreement (Kw= 0.39) for grade 2 lesions, good total agreement (Kw = 0.75) for grade 3 and very good agreement (Kw= 0.88) for grade 4 lesions. Conclusion: Color duplex is a safe, inexpensive, non-invasive, easily available diagnostic tool with high diagnostic accuracy in the investigation of peripheral arterial disease PAD among patients with diabetes mellitus DM. Color duplex is better than CT angiography in the diagnosis of Grade 1 and 2 lesions. CT angiography is more accurate in assessing grade 3 and grade 4 stenosis. Color duplex remains the only available diagnostic tool in diabetic patients with contraindications for contrast media administration.

Use of Inner Branches During Physician-Modified Endografting for Complex Abdominal and Thoracoabdominal Aortic Aneurysms

Endovascular repair of complex abdominal and thoracoabdominal aortic aneurysms have been performed widely in an increasing number of centers, utilizing custom-manufactured or physician-modified stent grafts containing fenestrations and side-arm branches for visceral and renal artery incorporation. Alternatively, inner branch configurations may be useful in complex anatomy, where application of fenestrations or side-arm branches can be challenging. Our study aims to evaluate the incidence of target vessel instability when incorporated with inner branch configurations, and report clinical outcomes of patients who underwent fenestrated/branched endovascular aortic repairs (F-BEVAR) containing one or more inner branches. We reviewed patients who underwent F-BEVAR with at least one inner branch configuration for complex abdominal or thoracoabdominal aortic aneurysms at Keck Hospital of University of Southern California from 2014 to 2020. Endpoints were mortality, major adverse events (MAE), technical success, and target vessel instability. Target vessel instability was assessed using follow-up computed tomography (CT) and duplex imaging. Out of the 175 patients who underwent F-BEVAR for complex abdominal and TAAA during the study period, 17 patients had at least one inner branch configuration. All were deemed high-risk for open repair with multiple cardiovascular and/or pulmonary comorbidities. Eight (47%) patients had extent I, II, III thoracoabdominal aortic aneurysms, and 10 (59%) had prior aortic repairs. A total of 68 target vessels were incorporated (mean=4 vessels/patient, range=1~6), of which 40% were inner branch configurations, most commonly for renal arteries. Technical success was 94.1%. There was one perioperative mortality due to massive myocardial infarction, as well as one patient who needed temporary hemodialysis. No device-related mortalities were observed. At 30 days, primary inner branch patency was 100% with no target vessel instability or reintervention. At mean follow-up of 5.8 months, the overall survival was 94% with one patient who expired from unknown cause. Overall primary inner branch patency was 96.3%, due to occlusion of a long lumbar artery branch with no clinical sequelae. Inner branch configurations can provide a safe alternative technique of branch incorporation during complex endovascular aortic repair.

Abstract No. 513 Endovascular interventions safely and effectively maintain long-term patency in patients with arterial complications of liver transplantation

To investigate the long-term safety and efficacy of endovascular interventions at treating transplant hepatic artery stenosis and thrombosis An IRB-approved, retrospective single-center cohort study was conducted on patients who underwent liver transplantation surgery from 1986 to 2020. Of the 1984 liver transplant patient records reviewed, 29 contained diagnoses of transplant hepatic artery stenosis (HAS) or thrombosis (HAT) necessitating a total of 50 endovascular interventions between 2005 and 2020. Median follow-up time from the initial intervention was 644 days (range, 5–4782 days) with follow-up time exceeding 2500 days in 11 cases. Complications were considered clinically significant if the Common Terminology Criteria for Adverse Events grade was 2 or greater. Two-sided, Wilcoxon signed-rank tests were performed to compare pre- and post-procedural duplex imaging measurements of resistive index and peak systolic velocity; P values less than 0.05 were considered statistically significant. Kaplan-Meier analyses were used to evaluate the primary patency and primary-assisted patency rates of the interventions. 94% (47/50) of interventions were performed for HAS, and 6% (3/50) were performed for HAT. Primary technical success was achieved in 92% (46/50) of cases. Clinically significant peri-procedural complications occurred in 6% (3/50) of cases. Pre- and post-procedural duplex imaging demonstrated improvements in both resistive index (mean difference, 0.10; P < 0.05) and peak systolic velocity (mean difference, -128 cm/s; P < 0.01). The primary patency rate of initial interventions was 90%, 63%, and 55% at 1, 6, and 12 months, respectively. The primary-assisted patency rate was maintained at 97% through 10 years of follow-up. Endovascular interventions used to treat transplant HAS and HAT demonstrate safety and efficacy on long-term follow-up. Although one-year primary patency is modest, additional interventions can be performed to maintain primary-assisted patency for a durable long-term result.

Advances in ultrasound imaging: Passive cavitation imaging/mapping

Ultrasound-induced cavitation has been demonstrated to induce numerous bioeffects, including tissue ablation and drug delivery. Different types of cavitation activity (e.g., inertial or stable) nucleate different bioeffects and are associated with distinct regimes of ultrasonic emissions. Thus decades of research have investigated the emission-bioeffect relationship. Since 2008, beamforming of cavitation emissions has been performed to provide images of cavitation activity. This enables the spatio-temporal localization, characterization, and quantification of cavitation activity, which has been shown to have utility in both image-guidance of therapies and basic science studies. The goal of this tutorial is to familiarize participants with the principles and implementation techniques for array-based passive cavitation monitoring. We will begin with a review the fundamentals of time-domain and frequency-domain beamforming, including an opportunity to form images during the tutorial using data and MATLAB code provided by the speakers. Next, we will discuss steps to correct for propagation path and hardware-specific effects in order to provide improved cavitation dose estimates. Display considerations and B-mode duplex imaging topics will follow. Finally, common hardware configurations, including benefits and limitations, will be covered to provide guidance for individuals considering a setup in their laboratory.

The role of combined computed tomographic angiography and digital subtraction angiography in the management of cervico-facial vascular lesions

BackgroundCervicofacial vascular lesions are one of the most challenging diseases managed by intervention radiologists and specialized surgeons. These lesions were diagnosed to be vascular in origin by other imaging techniques such as Duplex and/or magnetic resonance imaging (MRI). All patients underwent computed tomographic angiography (CTA) to confirm the diagnosis as well as to decide the most effective choice of management based on multidisciplinary team (MDT). Then, Digital subtraction angiography (DSA) was done as it is offering an accurate vascular map for the vascular lesions which is inevitable for successful super-selective endovascular embolization which can be done at same sitting. Small cases of arteriovenous malformations (AVMs) were sufficiently managed by only embolization, whereas cases of adequately embolized large AVMs as well as juvenile nasopharyngeal angiofibroma (JNA) cases were followed by surgery with the advantage of less blood loss and decreasing operation time as well as complications. This prospective study was done to highlight the role of combined CTA and DSA in cervicofacial vascular lesion management.ResultsTwenty patients were included in our study: 16 patients were males, and 4 were females; 17 of them were under 40 years, and three were above 40 years. Preoperative embolization was done in 12 patients, which were all the cases of JNAs and large AVMs. Four patients were managed by only embolization as a definitive treatment. Complete technical success rate was about 94%, while only 6% (single case) of the partial technical success rate which was due to a very small accessory feeder that could not be catheterized even with repeated trials.ConclusionsCombined CTA and DSA is the cornerstone for managing vascular lesions in the cervicofacial region, which necessitates a MDT to decide the most beneficial and least complicated way for management.

A Review of Current Noninvasive Imaging Surveillance Practices for Deep Venous Arterialization Procedures

Venous arterialization is an increasingly common procedure performed in patients with critical limb-threatening ischemia (CLTI) where there are no open or percutaneous revascularization options. This study aims to review the imaging follow-up for venous arterialization described in the literature. A systematic review was performed on venous arterialization studies for CLTI using the PRISMA methodology. A literature search was performed on 5 databases from inception. We included all original studies, case reports, and reviews regarding venous arterialization for all pathologies. We excluded free standing abstracts, animal studies, other than lower extremity, and foreign language studies. Our search strategy yielded 23 studies that met inclusion criteria, with 16 studies reporting a specific value from at least one surveillance imaging methodology. Most studies used Duplex imaging (16 studies) and TCPo2 (9 studies). Only 9 studies provided any detail regarding the Duplex findings. One study used focal peak systolic velocity (PSV) gradient (PSV at the lesion in the graft divided by PSV in a proximal segment of the graft) above 2.5 as an indicator for flow-inhibiting venous valves or stenosis in the graft. Another study reported a turbulent flow pattern in the graft, elevating peak velocities to 100 to 200 cm/s throughout the bypass. Four studies reported flow volume measurement through the bypass or in pedal vein ranging from 40 to 437 mL/min. Seven studies reported a mean increase of 18.7 mmHg in TCPo2. Eighty-two percent of patients saw an improvement of TCPo2 in 2 studies. To date, no criteria have been identified that are predictive of the success or failure of deep vein arterialization. Venous arterialization is an increasingly common procedure in the “no-option” diabetic patient. Duplex imaging with TCPo2 offers the most appropriate means of surveillance; however, the literature is sparse with no guidance on normal or critical values.

Relationship between internal carotid artery stenosis grade and optic nerve sheath diameter measured by transorbital ultrasonography.

To assess the consequence of the presence, grade, and asymmetry of carotid artery stenoses on the optic nerve sheath diameter (ONSD) measured by ultrasonography. ONSD was measured with B-mode ultrasonography in 129 patients referred for duplex and color Doppler imaging of the carotid arteries. Internal carotid artery stenosis was graded on the basis of peak systolic flow velocity. The mean ONSD was 3.04 ± 0.38 mm in the patients without or with <50% internal carotid artery stenosis and 2.46 ± 0.35 mm in those with >70% stenosis. There was an average difference of 0.58 mm between the ONSD of the patients with <50% and the patients with >70% stenosis. ONSD is lower in patients with carotid artery stenosis. Carotid arteries should be investigated, especially in patients with cardiovascular risk factors or diseases, before interpreting ONSD values.

Carotid Web Is an Under-recognized and Devastating Cause of Ischemic Stroke

Carotid web is a rare form of fibromuscular dysplasia that can result in embolic stroke. Misdiagnosis is common and can lead to catastrophic neurologic events. Reports in the literature are scarce, and management remains controversial. Carotid web was defined as single, shelf-like, linear projection in the carotid bulb causing a characteristic filling defect on computed tomography angiography (CTA) or angiography (Fig). Cases at a single institution with a high-volume stroke center were identified retrospectively. Between 2016 and 2020, a total of 38 webs were identified in 32 patients; 22 (69%) were women. Average age was 48 years; 23 (72%) were African American. Symptomatic patients (26/32; 81%) initially presented with stroke (23/26; 88%) or transient ischemic attack (3/26; 12%). Webs were found incidentally in 6 of 32 patients (19%). Notably, the degree of stenosis was less than 50% in all patients, none were diagnosed with carotid ultrasound examination, and 16 of the 26 (62%) symptomatic webs were missed on initial CTA or cerebral angiography. Web-associated thrombus was observed radiographically or grossly upon carotid exploration in 13 of 26 (50%) symptomatic patients (Fig). Seven patients (27%) had a history of cryptogenic stroke and presented with ipsilateral recurrence at an average interval of 28 months. All seven were on dual antiplatelet and statin therapy prior to recurrence; four were left with permanent deficits. Definitive treatment in symptomatic patients was with transfemoral stenting in 19 of 25 (76%) or endarterectomy in 6 of 25 (24%). After an average follow-up of 19 months, there has been no reported stroke or mortality following intervention. Six patients with asymptomatic webs have been managed with antiplatelet and statin therapy for an average of 20 months. As the largest experience reported to date, our series demonstrates that carotid web is often missed on carotid duplex imaging, CTA, and cerebral angiography, and that devastating neurologic events occur if treatment is delayed after initial, web-related stroke. Symptomatic patients warrant aggressive intervention, as recurrent stroke occurred in all who were managed with medical therapy alone after initial ipsilateral stroke. A high index of suspicion and rigorous review of imaging are essential for accurate diagnosis, especially in younger, African American women who present with cryptogenic stroke and minimal carotid stenosis.

Hybrid Approach with Angiography and Limited Open Exposure to Treat Type Ia Endoleaks after Endovascular Aortic Aneurysm Repair

Type Ia endoleaks after endovascular aortic repair (EVAR) almost always mandate secondary percutaneous reinterventions. Several patients, however, will require conversion to open surgical repair with complete graft explant, which is associated with significant morbidity and mortality. We herein present 3 cases of hybrid surgical repair for type Ia endoleaks, using a limited open exposure for proximal stent graft edge revision to achieve graft preservation and effective aneurysm sac exclusion. Angiography was used to confirm type Ia endoleak in 3 patients (2 males) who had previous EVAR between October 2017 and October 2019. Time to the endoleak after the index EVAR was immediate in 1 patient during repair of a ruptured aneurysm, 2 months in 1 patient and 2 years in 1 patient. The aorta was exposed through a limited transabdominal (n = 1) or retroperitoneal (n = 2) approach and circumferential aortic control was achieved below the renal arteries. A row of interrupted horizontal mattress sutures of 3-0 polypropylene reinforced with Teflon pledgets was placed along the aortic neck circumference. Multi-planar angiography was then repeated to verify the absence of sac filling and successful type Ia endoleak exclusion. Follow-up abdominal duplex was obtained for all 3 patients after discharge to monitor the stent graft and confirm endoleak resolution. Furthermore, there were no instances of acute renal failure. In the period of review, 77 patients underwent EVAR. In the 3 patients described, we were able to achieve complete aneurysm sac exclusion and stent graft preservation in all cases. Follow-up imaging was available on 2 patients at 4-6 weeks after surgery demonstrating sustained exclusion of the endoleak. Two patients died during follow-up: one from a myocardial infarction 7 weeks after surgery and one from metastatic lung cancer at 8 months after surgery. Follow up duplex imaging at one year on the single survivor demonstrated sac shrinkage and absence of endoleak. Type Ia endoleaks represent a significant source of morbidity and mortality after EVAR and typically require repair to avoid aneurysm rupture. Our use of limited proximal revision without explant provides an alternative approach to resolve the endoleaks while reducing the magnitude of physiological stress when compared to an open explant. It represents a feasible option for high-risk patients.

The Feasibility of a Novel Index From a Wireless Doppler Ultrasound Patch to Detect Decreasing Cardiac Output in Healthy Volunteers.

ABSTRACTIntroductionEarly hemorrhage is often missed by traditional vital signs because of physiological reserve, especially in the young and healthy. We have developed a novel, wearable, wireless Doppler ultrasound patch that tracks real-time blood velocity in the common carotid artery.Materials and MethodsWe studied eight healthy volunteers who decreased their cardiac output using a standardized Valsalva maneuver. In all eight, we simultaneously monitored the velocity time integral (VTI) of the common carotid artery (using the ultrasound patch) as well as the descending aorta (using a traditional pulsed wave duplex imaging system); the descending aortic VTI was used as a surrogate for left ventricular stroke volume (SV). Additionally, in a subset of four, we simultaneously measured SV using a noninvasive pulse contour analysis device.ResultsFrom baseline to peak effect of Valsalva, there was a statistically significant fall in descending aortic and common carotid VTI of 37% (P = 0.0005) and 23% (P < 0.0001), respectively. Both values returned to baseline on recovery. Additionally, a novel index from the carotid ultrasound patch (i.e., the heart rate divided by the carotid artery VTI) detected a 10% fall in aortic VTI with high sensitivity and specificity (100% and 100%, respectively); this novel index also accurately detected a 10% decrease in SV as measured by the noninvasive SV monitor. The mean arterial pressure, measured by the noninvasive pulse contour device, did not correctly detect the fall in SV.ConclusionIn summary, a novel index from a wireless Doppler ultrasound patch may be more sensitive and specific for detecting decreased cardiac output than standard vital signs in healthy volunteers.