Prevalence and Characteristics of Patients with Median Arcuate Ligament Syndrome in a Cohort Diagnosed with Celiac Artery Compression

BACKGROUND

Median arcuate ligament syndrome (MALS) is a frequent differential diagnosis in patients with postprandial abdominal symptoms, but diagnosis remains challenging. The aim of this study was to identify characteristics of patients who had MALS compared with non-MALS patients among a cohort of patients diagnosed with celiac artery compression (CAC).

STUDY DESIGN

An IRB-approved retrospective chart review (2000 to 2021) of patients at our institution with a discharge diagnosis of CAC was performed. Medical record review for clinical symptoms and findings consistent with MALS was performed.

RESULTS

Two hundred ninety-three patients with a diagnosis of CAC were identified; 59.7% were women, and average age was 63.9 ± 20.2 years. Sixty-nine (23.5%) patients with CAC had MALS. There were no significant differences in sex or race between MALS and non-MALS patients, but MALS patients were younger (55.7 vs 68.1, p < 0.001). There was no significant difference in gastrointestinal comorbidities between the 2 groups. Patients with MALS were less likely to have diabetes (12.5% vs 26.9%), renal disease (4.6% vs 8.2%), hypertension (41.5% vs 70.3%), mesenteric atherosclerotic disease (14% vs 61.9%), and peripheral artery disease (15.0% vs 39.7%).

CONCLUSIONS

We demonstrate a novel observation that MALS patients tend to have fewer atherosclerotic characteristics than non-MALS patients with CAC. Patients in our study with MALS were more likely to be younger, women, and presenting with epigastric pain. MALS patients had a significantly lower incidence of diabetes, hypertension, renal disease, mesenteric artery disease, and peripheral arterial disease compared with the non-MALS group. An important clinically relevant feature of MALS patients may be their lack of atherosclerotic phenotype compared with non- MALS patients with CAC.

Utility of Hook Sign in the Diagnosis of Median Arcuate Ligament Syndrome

OBJECTIVE

Median arcuate ligament syndrome (MALS) is a clinical syndrome caused by compression of the celiac artery by the median arcuate ligament (MAL) that often manifests with non-specific abdominal pain. Identification of this syndrome is often dependent on imaging of compression and upward bending of the celiac artery by lateral CTA, the so-called "hook sign." The purpose of this study was to assess the relationship of radiologic characteristicss of the celiac artery to clinically relevant MALS.

DESIGN

Single-center retrospective study METHODS: An IRB-approved retrospective chart review from 2000-2021 of 293 patients at a tertiary academic center diagnosed with celiac artery compression (CAC) was performed. Patient demographics and symptoms of 69 patients who were diagnosed with symptomatic MALS were compared to 224 patients without MALS (but with CAC) per electronic medical record review. CTA images were reviewed and the fold angle (FA) was measured. The presence of a hook sign (defined as a visual fold angle < 135 degrees) was recorded as well as stenosis (defined as >50% of luminal narrowing on imaging). Wilcoxon rank sum test and Chi-squared were utilized for comparative analysis. Logistic model was run to relate the presence of MALS with comorbidities and radiographic findings.

RESULTS

Imaging was available in 59 patients (25 males, 34 females) and 157 patients (60 males, 97 females) with and without MALS respectively. Patients with MALS were more likely to have a more severe FA (120.7 ± 33.6 vs. 134.8 ± 27.9, P = 0.002). Males with MALS were also more likely to have a more severe FA compared with males without MALS (111.1 ± 33.7 vs. 130.4 ± 30.4, P = 0.015). In patients with BMI > 25, MALS patients also had narrower FA compared with patients without MALS (112.6 ± 30.5 vs. 131.7 ± 30.3, P = 0.001). The FA was negatively correlated with BMI in patients with CAC . The hook sign and stenosis were associated with diagnosis of MALS (59.3% vs. 28.7%, P < 0.001, and 75.7% vs. 45.2%, P < 0.001, respectively). In logistic regression, pain, stenosis and a narrow FA were statistically significant predictors of the presence of MALS.

CONCLUSIONS

The upward deflection of the celiac artery in patients with MALS is more severe compared with patients without MALS. Consistent with prior literature, this bending of the celiac artery is negatively correlated with BMI in patients with and without MALS. When demographic variables and comorbidities are considered, a narrow FA is a statistically significant predictor of MALS. Regardless of MALS diagnosis, a hook sign was associated with narrower FA. While demographics and imaging findings may inform MALS diagnosis, clinicians should not rely on a visual assessment of a hook sign but should quantitatively measure the anatomic bending angle of the celiac artery to assist with the diagnosis and understand the outcomes.

Factors associated with successful median arcuate ligament release in an international, multi-institutional cohort

OBJECTIVE

Prior research on median arcuate ligament syndrome has been limited to institutional case series, making the optimal approach to median arcuate ligament release (MALR) and resulting outcomes unclear. In the present study, we compared the outcomes of different approaches to MALR and determined the predictors of long-term treatment failure.

METHODS

The Vascular Low Frequency Disease Consortium is an international, multi-institutional research consortium. Data on open, laparoscopic, and robotic MALR performed from 2000 to 2020 were gathered. The primary outcome was treatment failure, defined as no improvement in median arcuate ligament syndrome symptoms after MALR or symptom recurrence between MALR and the last clinical follow-up.

RESULTS

For 516 patients treated at 24 institutions, open, laparoscopic, and robotic MALR had been performed in 227 (44.0%), 235 (45.5%), and 54 (10.5%) patients, respectively. Perioperative complications (ileus, cardiac, and wound complications; readmissions; unplanned procedures) occurred in 19.2% (open, 30.0%; laparoscopic, 8.9%; robotic, 18.5%; P < .001). The median follow-up was 1.59 years (interquartile range, 0.38-4.35 years). For the 488 patients with follow-up data available, 287 (58.8%) had had full relief, 119 (24.4%) had had partial relief, and 82 (16.8%) had derived no benefit from MALR. The 1- and 3-year freedom from treatment failure for the overall cohort was 63.8% (95% confidence interval [CI], 59.0%-68.3%) and 51.9% (95% CI, 46.1%-57.3%), respectively. The factors associated with an increased hazard of treatment failure on multivariable analysis included robotic MALR (hazard ratio [HR], 1.73; 95% CI, 1.16-2.59; P = .007), a history of gastroparesis (HR, 1.83; 95% CI, 1.09-3.09; P = .023), abdominal cancer (HR, 10.3; 95% CI, 3.06-34.6; P < .001), dysphagia and/or odynophagia (HR, 2.44; 95% CI, 1.27-4.69; P = .008), no relief from a celiac plexus block (HR, 2.18; 95% CI, 1.00-4.72; P = .049), and an increasing number of preoperative pain locations (HR, 1.12 per location; 95% CI, 1.00-1.25; P = .042). The factors associated with a lower hazard included increasing age (HR, 0.99 per increasing year; 95% CI, 0.98-1.0; P = .012) and an increasing number of preoperative diagnostic gastrointestinal studies (HR, 0.84 per study; 95% CI, 0.74-0.96; P = .012) Open and laparoscopic MALR resulted in similar long-term freedom from treatment failure. No radiographic parameters were associated with differences in treatment failure.

CONCLUSIONS

No difference was found in long-term failure after open vs laparoscopic MALR; however, open release was associated with higher perioperative morbidity. These results support the use of a preoperative celiac plexus block to aid in patient selection. Operative candidates for MALR should be counseled regarding the factors associated with treatment failure and the relatively high overall rate of treatment failure.

Hyperspectral imaging in systemic sclerosis-associated Raynaud phenomenon

BACKGROUND/PURPOSE

Lack of robust, feasible, and quantitative outcomes impedes Raynaud phenomenon (RP) clinical trials in systemic sclerosis (SSc) patients. Hyperspectral imaging (HSI) non-invasively measures oxygenated and deoxygenated hemoglobin (oxyHb and deoxyHb) concentrations and oxygen saturation (O2 sat) in the skin and depicts data as oxygenation heatmaps. This study explored the potential role of HSI in quantifying SSc-RP disease severity and activity.

METHODS

Patients with SSc-RP (n = 13) and healthy control participants (HC; n = 12) were prospectively recruited in the clinic setting. Using a hand-held camera, bilateral hand HSI (HyperMed™, Waltham, MA) was performed in a temperature-controlled room (22 °C). OxyHb, deoxyHb, and O2 sat values were calculated for 78-mm2 regions of interest for the ventral fingertips and palm (for normalization). Subjects underwent a cold provocation challenge (gloved hand submersion in 15 °C water bath for 1 min), and repeated HSI was performed at 0, 10, and 20 min. Patients completed two patient-reported outcome (PRO) instruments: the Raynaud Condition Score (RCS) and the Cochin Hand Function Scale (CHFS) for symptom burden assessment. Statistical analyses were performed using the Mann-Whitney U test and a mixed effects model (Stata, College Station, TX).

RESULTS

Ninety-two percent of participants were women in their 40s. For SSc-RP patients, 69% had limited cutaneous SSc, the mean ± SD SSc duration was 11 ± 5 years, and 38% had prior digital ulcers-none currently. Baseline deoxyHb was higher, and O2 sat was lower, in SSc patients versus HC (p < 0.05). SSc patients had a greater decline in oxyHb and O2 sat from baseline to time 0 (after cold challenge) with distinct rewarming oxyHb, O2 sat, and deoxyHb trajectories versus HCs (p < 0.01). There were no significant correlations between oxyHb, deoxyHb, and O2 sat level changes following cold challenge and RCS or CHFS scores.

CONCLUSION

Hyperspectral imaging is a feasible approach for SSc-RP quantification in the clinic setting. The RCS and CHFS values did not correlate with HSI parameters. Our data suggest that HSI technology for the assessment of SSc-RP at baseline and in response to cold provocation is a potential quantitative measure for SSc-RP severity and activity, though longitudinal studies that assess sensitivity to change are needed.

Heterogeneity in the guidelines for the management of diabetic foot disease in the Caribbean

The prevalence of diabetes mellitus, diabetic foot (DF) disease and, as a result, lower extremity amputation rates remain high in the Caribbean. This study was undertaken to determine whether Caribbean countries have designated individuals that monitor DF disease and whether there are DF protocols consistent with the International Working Group on the Diabetic Foot (IWGDF) guidance documents. Relevant DF health care personnel(s) from the CARICOM and Dutch Caribbean countries were called or sent questionnaires regarding the presence of structured programs to monitor and manage DF problems in the population. All 25 countries (100%) responded. 81% of respondents could not identify any Ministry, Hospital or individual initiatives that monitored the DF. Only 9 (36%) countries had any guidelines in place. Only 3 countries with guidelines in place utilized IWGDF guidelines. Only 6 (24%) countries had podiatrists and 10 (40%) had vascular surgery availability. 7 (28%) countries had the components for a multidisciplinary team. The presence or the appointment of a designated individual and/or a multidisciplinary approach within the countries for DF disease was absent in the majority of respondent countries. Only a minority of countries implemented DF guidelines or had expertise available to organize a DF multidisciplinary team. Vascular surgery and podiatric care were noticeably deficient. These may be critical factors in the variability and reduced success in implementation of strategies for managing DF problems and subsequent amputations amongst these Caribbean countries.

Popliteal Artery Occlusion with Collateral Blood Flow in a Reducible Knee Dislocation During Pregnancy: A Case Report

CASE

A 29-year-old healthy woman, 19 weeks pregnant, sustained a right posterolateral knee dislocation with multiligamentous injury and a complete occlusive injury to the right popliteal artery yet had adequate distal perfusion. She declined operative management for both the knee dislocation and the arterial injury, and successful collaboration between obstetrical, vascular, and orthopaedic surgical services resulted in limb preservation and restoration of function.

CONCLUSION

This is a unique case of traumatic complete popliteal artery occlusion with adequate collateral arterial perfusion after a reducible posterolateral knee dislocation in a pregnant patient that resulted in limb preservation with nonoperative management.

Prognostic Value of Radiotracer-Based Perfusion Imaging in Critical Limb Ischemia Patients Undergoing Lower Extremity Revascularization

OBJECTIVES

The purpose of this study was to evaluate the prognostic value of single-photon emission computed tomography (SPECT)/computed tomography (CT) imaging of angiosome foot perfusion for predicting amputation outcomes in patients with critical limb ischemia (CLI) and diabetes mellitus (DM).

BACKGROUND

Radiotracer imaging can assess microvascular foot perfusion and identify regional perfusion abnormalities in patients with critical limb ischemia CLI and DM, but the relationship between perfusion response to revascularization and subsequent clinical outcomes has not been evaluated.

METHODS

Patients with CLI, DM, and nonhealing foot ulcers (n = 25) were prospectively enrolled for SPECT/CT perfusion imaging of the feet before and after revascularization. CT images were used to segment angiosomes (i.e., 3-dimensional vascular territories) of the foot. Relative changes in radiotracer uptake after revascularization were evaluated within the ulcerated angiosome. Incidence of amputation was assessed at 3 and 12 months after revascularization.

RESULTS

SPECT/CT detected a significantly lower microvascular perfusion response for patients who underwent amputation compared with those who remained amputation free at 3 (p = 0.01) and 12 (p = 0.01) months after revascularization. The cutoff percent change in perfusion for predicting amputation at 3 months was 7.55%, and 11.56% at 12 months. The area under the curve based on the amputation outcome was 0.799 at 3 months and 0.833 at 12 months. The probability of amputation-free survival was significantly higher at 3 (p = 0.002) and 12 months (p = 0.03) for high-perfusion responders than low-perfusion responders to revascularization.

CONCLUSIONS

SPECT/CT imaging detects regional perfusion responses to lower extremity revascularization and provides prognostic value in patients with CLI (Radiotracer-Based Perfusion Imaging of Patients With Peripheral Arterial Disease; NCT03622359).

The Role of Lower Extremity Amputation in Chronic Limb-Threatening Ischemia

Chronic limb-threatening ischemia (CLTI) is a severe form of peripheral artery disease associated with high rates of limb loss. The primary goal of treatment in CLTI is limb salvage via revascularization. Multidisciplinary teams provide improved care for those with CLTI and lead to improved limb salvage rates. Not all patients are candidates for revascularization, and a subset will require major amputation. This article highlights the role of amputations in the management of CLTI, and describes the patients who should be offered primary amputation.

Radiotracer Imaging Allows for Noninvasive Detection and Quantification of Abnormalities in Angiosome Foot Perfusion in Diabetic Patients With Critical Limb Ischemia and Nonhealing Wounds

Background:

Single photon emission computed tomography (SPECT)/computed tomography (CT) imaging allows for assessment of skeletal muscle microvascular perfusion but has not been quantitatively assessed in angiosomes, or 3-dimensional vascular territories, of the foot. This study assessed and compared resting angiosome foot perfusion between healthy subjects and diabetic patients with critical limb ischemia (CLI). Additionally, the relationship between SPECT/CT imaging and the ankle–brachial index—a standard tool for evaluating peripheral artery disease—was assessed.

Methods and Results:

Healthy subjects (n=9) and diabetic patients with CLI and nonhealing ulcers (n=42) underwent SPECT/CT perfusion imaging of the feet. CT images were segmented into angiosomes for quantification of relative radiotracer uptake, expressed as standardized uptake values. Standardized uptake values were assessed in ulcerated angiosomes of patients with CLI and compared with whole-foot standardized uptake values in healthy subjects. Serial SPECT/CT imaging was performed to assess uptake kinetics of technetium-99m-tetrofosmin. The relationship between angiosome perfusion and ankle–brachial index was assessed via correlational analysis. Resting perfusion was significantly lower in CLI versus healthy subjects (P=0.0007). Intraclass correlation coefficients of 0.95 (healthy) and 0.93 (CLI) demonstrated excellent agreement between serial perfusion measurements. Correlational analysis, including healthy and CLI subjects, demonstrated a significant relationship between ankle–brachial index and SPECT/CT (P=0.01); however, this relationship was not significant for diabetic CLI patients only (P=0.2).

Conclusions:

SPECT/CT imaging assesses regional foot perfusion and detects abnormalities in microvascular perfusion that may be undetectable by conventional ankle–brachial index in patients with diabetes mellitus. SPECT/CT may provide a novel approach for evaluating responses to targeted therapies.

Management of Asymptomatic Popliteal Artery Aneurysms

Popliteal artery aneurysms (PAAs) are the most common peripheral artery aneurysms. They are frequently symptomatic and are associated with high rates of morbidity and limb loss. PAA can be treated by open or endovascular means, although there are no specified recommendations guiding treatment choice. This article delineates many of the differences between open and endovascular repair of asymptomatic PAA, and highlights several key articles comparing open and endovascular repair to guide decision making. Proper diagnosis and choice of repair can lead to good outcomes in the treatment of asymptomatic PAA.

Acute Limb Ischemia in an 8-Year-Old Patient: A Case Report

We report the case of an 8-year-old patient with a history of nephrotic syndrome, who presented to the emergency department with right foot pain. The patient's mother described intermittent pain that woke her son from sleep and was accompanied by the foot turning purple and becoming cold to touch. Physical examination revealed capillary refill of over 10 seconds in the right and less than 2 seconds in the left foot. Ankle-brachial indices (ABIs) were 0.0 on the right and 0.96 on the left. The patient was admitted and started on therapeutic intravenous heparin. After consultation with his parents, right lower extremity angiography and thrombolysis was performed over 2 days. He subsequently underwent fasciotomy and amputation of the tip of all 5 toes. Eighteen months later, there is no leg length discrepancy, he is walking with foot inserts and has normal ABIs bilaterally.

Popliteal Artery Entrapment Syndrome: Bilateral Lower Extremity Involvement

Popliteal artery entrapment syndrome is a condition in which compression of the popliteal neurovascular structures results in symptoms of lower extremity claudication by way of a constricting anatomic structure or a hypertrophied surrounding musculature. This diagnosis is often missed or misdiagnosed because popliteal artery entrapment syndrome has a presentation similar to that of exertional compartment syndrome. Popliteal artery entrapment syndrome may result in persistent disability or unnecessary morbidity or prevent athletes' return to sport. A female collegiate athlete presented with bilateral popliteal artery entrapment syndrome. She had successful surgical treatment and returned to a high level of sport. This article describes popliteal artery entrapment syndrome, emphasizes the importance of a thorough history and physical examination to elucidate the diagnosis, and provides information that may lead to the identification of individuals who will benefit from surgical intervention. [Orthopedics. 2018; 41(2):e295-e298.].

Improved mortality in treatment of patients with endovascular interventions for chronic mesenteric ischemia

OBJECTIVE

Chronic mesenteric ischemia (CMI) continues to be a devastating diagnosis. There is a national trend toward increased use of endovascular procedures with improved survival for the treatment of these patients. Our aim was to evaluate whether this trend has changed CMI patients' length of hospitalization and health care cost.

METHODS

We identified all patients admitted for CMI from the National Inpatient Sample (NIS) from 2000 to 2014. Our primary end points included length of hospital stay (LOS) and cost of hospitalization (COH). Our secondary end points included mortality assessment of the CMI hospitalization.

RESULTS

There were 15,475 patients admitted for CMI. The mean age of patients was 71 years, and 4022 (26.0%) were male. There were 10,920 (70.6%) patients treated endovascularly (ENDO) and 4555 (29.4%) patients treated in an open fashion (OPEN). Although a higher proportion of patients in the ENDO (43.3%) group vs OPEN (33.1%) had a Charlson Comorbidity Index score of ≥2 (P < .0001), they had a lower mortality rate (2.4% vs 8.7%; P < .0001), lower mean LOS (6.3 vs 14.0 days; P < .0001), and lower COH ($21,686 vs $42,974; P < .0001). After adjusting for clinical and hospital factors, OPEN continued to demonstrate higher mortality than ENDO (odds ratio, 7.2; 95% confidence interval, 4.9-10.6; P < .0001), longer LOS (mean, +9.7 days; P < .0001), and higher COH (mean, +$25,834; P < .0001).

CONCLUSIONS

The rate of ENDO continues to rise nationally in the treatment of CMI patients. After adjusting for clinical and hospital factors, patients in the ENDO group tend to have lower in-hospital mortality of 2.4% and lower LOS by 10 days, and they incur a cost saving of >$25,000 compared with patients in the OPEN group. ENDO should be considered first line of therapy for patients with CMI.

Shear Stress Induces Change in Extracellular Signal-Regulated Kinase 5 Levels with Sustained Activation under Disturbed and Continuous Laminar Flow

Extracellular signal-regulated kinase 5 (ERK5) has been reported to regulate endothelial integrity and protect from vascular dysfunction under laminar flow. Previously reported research indicates that under laminar flow ERK5 is activated with production of atheroprotective molecules. However, the characterization of ERK5 activation and levels under different flow patterns has not been investigated. Confluent HUVECs were serum-starved then seeded on glass slides. HUVECs incubated in 1% FBS were exposed to continuous laminar flow (CLF), to-and-fro flow (TFF), or pulsatile forward flow (PFF) in a parallel plate flow chamber. At the end of experimentation, cell lysates were immunoblotted with antibodies to phospho-ERK5 and total ERK5. ERK5 activation was assessed by the levels of phosphorylated ERK5. The densitometric mean ± SEM is calculated and analyzed by ANOVA. p < 0.05 is considered significant. Levels of ERK5 decreased with all flow conditions with the largest decrease in TFF flow condition. TFF and CLF exhibited sustained ERK5 phosphorylation in HUVECs stimulated for up to 4 hours. PFF had transient phosphorylation of ERK5 at 2 hours, which then became undetectable at 4 hours of exposure to flow. Also, TFF and CLF both showed decreased levels at 4 hours, suggesting a decrease in activation for these flow conditions. Exposure of HUVEC to different types of shear stress results in varying patterns of activation of ERK5. Activation of ERK5 with TFF suggests a role in the pathogenesis of atherosclerosis and vascular remodeling under disturbed flow conditions.

Abdominal aortic aneurysm in association with a congenital pelvic horseshoe kidney: sentinel report and technical consideration

A case of an abdominal aortic aneurysm in the presence of a congenital pelvic horseshoe kidney is described and the technical approach discussed. Renal function was preserved by ‘double clamping’ during the proximal anastomosis and infusing cold crystalloid into cannulated renal arteries originating from the aneurysm sac.

Efficacy of Dextran Solutions in Vascular Surgery

The purpose of this paper is to discuss the role and efficacy of dextran in vascular procedures using evidence-based data from the review of surgical literature. A MEDLINE search using “dextran,” “vascular surgery,” and “antiplatelet therapy” as keywords was performed for English-language articles. Further references were obtained through cross-referencing the bibliography cited in each work. Dextran is commonly used in carotid endarterectomy (CEA) patients where the embolic rate is reduced by 46%, resulting in fewer procedure-related strokes. As a prophylactic agent against thrombosis, multiple randomized studies have reported its benefit over other antithrombotic medications. Dextran is also particularly useful in “difficult” infragenicular lower extremity bypasses where artificial grafts (such as polytetrafluoroethylene [PTFE] or umbilical vein) are used in the setting of poor outflow vessels, or those with composite grafts and small-caliber venous conduits. Distal bypasses with adjunctive procedures (eg, arteriovenous fistula or anastomotic cuffs) also have a better outcome with the addition of dextran. Dextran has numerous important implications in vascular surgery, in particular with CEA patients or “difficult” infragenicular bypasses. Its effectiveness with endovascular stents remains unknown.

Predictors for the Healing of Transmetatarsal Amputations: Retrospective Study of 91 Amputations

This retrospective study reviewed 80 consecutive patients (mean age 62 years; range 21–91 years) who underwent 91 transmetatarsal amputations (TMAs) between 1995 and 2003. The mean follow-up was 12 ± 1.36 months. Sixty-two TMAs healed initially (group 1), whereas 29 TMAs did not heal by 3 months (group 2). At the final examination, in groups 1 and 2, 63 of 91 (69%) limbs were healed. Of the 28 limbs that did not heal, 25 of 28 (89%) required further proximal amputation. Initial healing correlated significantly with the ability to ambulate ( p < .0001) and overall limb salvage ( p < .0001). In group 1, 20 of 27 (74%) limbs that were revascularized healed ( p = .0336). Nonhealing amputations were associated with end-stage renal disease (13 of 19; 68%) ( p = .0209) and leukocytosis (13 of 19; 68%) ( p = .0052).

Abstract 325: Non-Invasive Volumetric Assessment of Angiosome Perfusion in Diabetic Patients With Critical Limb Ischemia and Non-Healing Ulcers Using Radiotracer Imaging

Introduction: Impaired lower extremity perfusion is a hallmark of peripheral vascular disease (PVD) and is particularly problematic in diabetic patients, who suffer from high rates of PVD, ulceration, and lower extremity amputation. The ability to non-invasively detect deficits in microvascular perfusion within vascular territories, or angiosomes, of the feet may provide information related to tissue viability, assist with classification of diabetic wounds, and guide future therapeutic interventions. In this study, we sought to quantify volumetric microvascular perfusion within specific angiosomes containing non-healing foot ulcers in diabetic patients with critical limb ischemia.

Methods: Twenty-eight diabetic patients (mean age, 68 ± 13 yrs) with non-healing ulcers underwent SPECT/CT imaging of the feet following a resting injection of 99m Tc-tetrofosmin (dose, 550.6 ± 37 Mbq). CT images were segmented into five angiosomes and used for quantifying relative radiotracer uptake (Fig. 1A), expressed as standardized uptake values (SUVs). SUVs were assessed for each patient in the angiosome containing the non-healing ulcers, which were rated using the Wagner Grade Classification.

Results: SPECT/CT imaging allowed for visualization of resting perfusion deficits in ulcer sites (Fig. 1B) and quantitative image analysis revealed variability in angiosome perfusion based on Wagner Grade of ulcers. Angiosomes containing Wagner Grade IV ulcers exhibited significantly lower SUVs when compared to SUVs of angiosomes containing Wagner Grade I, II, and III ulcers (Fig. 1C).

Conclusions: SPECT/CT imaging provides a useful non-invasive tool for evaluating a wide clinical spectrum of ulcers within associated angiosomes of the foot and can be performed without requiring pharmacological or exercise stress. Future application of SPECT/CT imaging may provide additional value for detection and targeting of ischemic tissue for therapeutic interventions.

Abstract 297: SPECT/CT Imaging of Regional Foot Perfusion Provides a Quantitative Index for Evaluation of Targeted Revascularization in the Diabetic Foot

Introduction: No standard quantitative imaging approach exists to evaluate volumetric changes in tissue perfusion in the lower extremities following medical treatment. In this study, we develop and apply a three-dimensional model of the foot for evaluation of regional changes in perfusion following revascularization in diabetic patients with non-healing foot ulcers. We hypothesize that SPECT/CT imaging will permit quantification of regional improvements in tissue perfusion in territories of the foot that contain non-healing ulcers, allowing for quantitative evaluation of revascularization procedures.

Methods: Resting 99m Tc-tetrofosmin (dose 554.0 ± 26.6 MBq) SPECT/CT was performed on diabetic patients (n=5; 64 ± 15 yrs) before and 1-3 days after lower extremity angioplasty and/or stenting. The CT attenuation scans were used to define five regions of interest (ROIs) in the foot and for quantification of relative changes in regional perfusion with 99m Tc-tetrofosmin SPECT (Fig. 1A). Radiotracer uptake for each ROI was normalized to injected dose and ROI volume, and expressed as a percent change from baseline value.

Results: SPECT/CT imaging demonstrated quantitative improvements in regional tissue perfusion in ROIs containing non-healing ulcers for 4 out of 5 patients following revascularization (Fig. 1B). The single patient demonstrating a negative response (11.7% decrease in perfusion) underwent eventual amputation.

Conclusions: Early changes in tissue perfusion following revascularization can be non-invasively evaluated in specific vascular territories of the foot using SPECT/CT imaging and may be associated with wound healing and limb salvage outcomes.

Economic development and diabetes prevalence in MENA countries: Egypt and Saudi Arabia comparison

Diabetes is increasing in epidemic proportions globally, exhibiting the most striking increase in third world countries with emerging economies. This phenomena is particularly evident in the Middle East and North Africa (MENA) region, which has the highest prevalence of diabetes in adults. The most concerning indirect cost of diabetes is the missed work by the adult population coupled with the economic burden of loss of productivity. The major drivers of this epidemic are the demographic changes with increased life expectancy and lifestyle changes due to rapid urbanization and industrialization. Our focus is to compare MENA region countries, particularly Egypt and Saudi Arabia, in terms of their economic development, labor force diversity and the prevalence of diabetes.

Contemporary assessment of foot perfusion in patients with critical limb ischemia

Significant progress in limb salvage for patients with peripheral arterial disease and critical limb ischemia has occurred in the past 2 decades. Improved patient outcomes have resulted from increased knowledge and understanding of the disease processes, as well as efforts to improve revascularization techniques and enhance patient care after open and endovascular procedures. An imaging modality that is noninvasive, fast, and safe would be a useful tool for clinicians in assessing lower-extremity perfusion when planning interventions. Among the current and emerging regional perfusion imaging modalities are transcutaneous oxygen monitoring, hyperspectral imaging, indocyanine green dye-based fluorescent angiography, nuclear diagnostic imaging, and laser Doppler. These tests endeavor to delineate regional foot perfusion to guide directed revascularization therapy in patients with critical limb ischemia and foot ulceration.

New advances in limb salvage

Critical limb ischemia (CLI) is an already significant and growing epidemiologic problem with substantial implications for patient mortality, quality of life, and healthcare costs. Considerable progress has been made in its treatment and prevention; however, poor outcomes, especially with regard to limb loss, warrant further development of treatment options. This article will examine new advances being made in the area of limb salvage for this morbid disease. Open surgical techniques and materials such as distal vein patches and heparin-bonded PTFE will be discussed. Additionally, new developments in endovascular therapies with particular regard to infrapopliteal interventions and drug-eluting stents will be reviewed. Beyond the simple techniques and materials, there is a growing movement in the world of vascular surgery to examine surgical and endovascular interventions with regard to angiosome-oriented revascularization of ulceration and gangrene. This paradigm has the potential to change prioritization and planning of both types of therapies as further research into this concept develops.

Characterization of extracellular signal-regulated kinase 5 levels in human umbilical vein endothelial cells exposed to disturbed and uniform flow

Extracellular signal-regulated kinase 5 (ERK5) has been reported to regulate endothelial cell integrity and protect from vascular dysfunction under continuous laminar flow. However, the effect of flow on ERK5 levels has not been determined. Confluent human umbilical vein endothelial cells (HUVECs) were seeded on fibronectin coated glass slides and serum starved for 2 hours with 1% fetal bovine serum (FBS). HUVECs were then exposed to to and fro flow (TFF), pulsatile forward flow (PFF), or continuous laminar flow (CLF) in a parallel plate flow chamber for up to 2 hours. At the end of experiment, cell lysates were prepared and immunoblotted with antibodies to total ERK5. Both CLF and TFF exhibited a decrease in ERK5 after levels after 2-hour exposure. However, the level of ERK5 for PFF remained the same. Disturbed, but not uniform pulsatile, flow decreases ERK5 levels in HUVECs.

Effect of pulsatile and continuous flow on yes-associated protein

Yes-associated protein (YAP) is a mechanosignaling protein that relays mechanical information to the nucleus by changing its level of phosphorylation. We hypothesize that different flow patterns show differential effect on phosphorylated YAP (pYAP) (S127) and total YAP and could be responsible for flow dependent localization of atherosclerosis. Confluent human umbilical vein endothelial cells (HUVECs) seeded on fibronectin-coated glass slides were exposed to continuous forward flow (CFF) and pulsatile forward flow (PFF) using a parallel plate flow chamber system for 30 minutes. Cell lysates were prepared and immunoblotted to detect the levels of phosphorylated YAP and total YAP. HUVECs exposed to both PFF and CFF showed a mild decrease in the levels of both pYAP (S127) and total YAP. While the levels of pYAP (S127) decreased to 87.85 and 85.21% of static control with PFF and CFF, respectively, the levels of total YAP significantly decreased to 91.31 and 92.27% of static control. No significant difference was seen between CFF and PFF on their effect on pYAP (S127), but both conditions resulted in a significant decrease in total YAP at 30 minutes. The results of this experiment show that the possible effect of different types of flow on YAP is not induced before 30 minutes. Experiments exposing endothelial cells to various types of flow for longer duration of time could help to elucidate the role of YAP in the pathogenesis of atherosclerosis.

Open repair, endovascular repair, and conservative management of true splenic artery aneurysms

OBJECTIVE

True splenic artery aneurysms (SAAs) are a rare but potentially fatal pathology. For many years, open repair (OPEN) and conservative management (CONS) were the treatments of choice, but throughout the last decade endovascular repair (EV) has become increasingly used. The purpose of the present study was to perform a systematic review and meta-analysis evaluating the outcomes of the three major treatment modalities (OPEN, EV, and CONS) for the management of SAAs.

METHODS

A systematic review of all studies describing the outcomes of SAAs treated with OPEN, EV, or CONS was performed using seven large medical databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to ensure a high-quality review. All articles were subject to critical appraisal for relevance, validity, and availability of data regarding characteristics and outcomes. All data were systematically pooled, and meta-analyses were performed on several outcomes, including early and late mortality, complications, and number of reinterventions.

RESULTS

Original data of 1321 patients with true SAAs were identified in 47 articles. OPEN contained 511 patients (38.7%) in 31 articles, followed by 425 patients (32.2%) in CONS in 16 articles and 385 patients (29.1%) in EV in 33 articles. The CONS group had fewer symptomatic patients (9.5% vs 28.7% in OPEN and 28.8% in EV; P < .001) and fewer ruptured aneurysms (0.2% vs 18.4% in OPEN and 8.8% in EV; P < .001), but no significant differences were found in existing comorbidities. CONS patients were usually older and had smaller-sized aneurysms than patients in the OPEN and EV groups. The only identified difference in baseline characteristics between OPEN and EV was the number of ruptured aneurysms (18.4% vs 8.8%; P < .001). OPEN had a higher 30-day mortality than EV (5.1% vs 0.6%; P < .001), whereas minor complications occurred in a larger number of the EV patients. EV required more reinterventions per year (3.2%) compared with OPEN (0.5%) and CONS (1.2%; P < .001). The late mortality rate was higher in patients treated with CONS (4.9% vs 2.1% in OPEN and 1.4% in EV; P = .04).

CONCLUSIONS

EV of SAA has better short-term results compared with OPEN, including significantly lower perioperative mortality. OPEN is associated with fewer late complications and fewer reinterventions during follow-up. Patients treated with CONS showed a higher late mortality rate. Ruptured SAAs are predictors of a significantly higher perioperative mortality compared with nonruptured SAAs in the OPEN and EV groups.

Open repair, endovascular repair, and conservative management of true splenic artery aneurysms

OBJECTIVE

True splenic artery aneurysms (SAAs) are a rare but potentially fatal pathology. For many years, open repair (OPEN) and conservative management (CONS) were the treatments of choice, but throughout the last decade endovascular repair (EV) has become increasingly used. The purpose of the present study was to perform a systematic review and meta-analysis evaluating the outcomes of the three major treatment modalities (OPEN, EV, and CONS) for the management of SAAs.

METHODS

A systematic review of all studies describing the outcomes of SAAs treated with OPEN, EV, or CONS was performed using seven large medical databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to ensure a high-quality review. All articles were subject to critical appraisal for relevance, validity, and availability of data regarding characteristics and outcomes. All data were systematically pooled, and meta-analyses were performed on several outcomes, including early and late mortality, complications, and number of reinterventions.

RESULTS

Original data of 1321 patients with true SAAs were identified in 47 articles. OPEN contained 511 patients (38.7%) in 31 articles, followed by 425 patients (32.2%) in CONS in 16 articles and 385 patients (29.1%) in EV in 33 articles. The CONS group had fewer symptomatic patients (9.5% vs 28.7% in OPEN and 28.8% in EV; P < .001) and fewer ruptured aneurysms (0.2% vs 18.4% in OPEN and 8.8% in EV; P < .001), but no significant differences were found in existing comorbidities. CONS patients were usually older and had smaller-sized aneurysms than patients in the OPEN and EV groups. The only identified difference in baseline characteristics between OPEN and EV was the number of ruptured aneurysms (18.4% vs 8.8%; P < .001). OPEN had a higher 30-day mortality than EV (5.1% vs 0.6%; P < .001), whereas minor complications occurred in a larger number of the EV patients. EV required more reinterventions per year (3.2%) compared with OPEN (0.5%) and CONS (1.2%; P < .001). The late mortality rate was higher in patients treated with CONS (4.9% vs 2.1% in OPEN and 1.4% in EV; P = .04).

CONCLUSIONS

EV of SAA has better short-term results compared with OPEN, including significantly lower perioperative mortality. OPEN is associated with fewer late complications and fewer reinterventions during follow-up. Patients treated with CONS showed a higher late mortality rate. Ruptured SAAs are predictors of a significantly higher perioperative mortality compared with nonruptured SAAs in the OPEN and EV groups.

African Trypanosome-Induced Blood-Brain Barrier Dysfunction under Shear Stress May Not Require ERK Activation

African trypanosomes are tsetse fly transmitted protozoan parasites responsible for human African trypanosomiasis, a disease characterized by a plethora of neurological symptoms and death. How the parasites under microvascular shear stress (SS) flow conditions in the brain cross the blood-brain barrier (BBB) is not known. In vitro studies using static models comprised of human brain microvascular endothelial cells (BMEC) show that BBB activation and crossing by trypanosomes requires the orchestration of parasite cysteine proteases and host calcium-mediated cell signaling. Here, we examine BMEC barrier function and the activation of extracellular signal-regulated kinase (ERK)1/2 and ERK5, mitogen-activated protein kinase family regulators of microvascular permeability, under static and laminar SS flow and in the context of trypanosome infection. Confluent human BMEC were cultured in electric cell-substrate impedance sensing (ECIS) and parallel-plate glass slide chambers. The human BMEC were exposed to 2 or 14 dyn/cm(2) SS in the presence or absence of trypanosomes. Real-time changes in transendothelial electrical resistance (TEER) were monitored and phosphorylation of ERK1/2 and ERK5 analyzed by immunoblot assay. After reaching confluence under static conditions human BMEC TEER was found to rapidly increase when exposed to 2 dyn/cm(2) SS, a condition that mimics SS in brain postcapillary venules. Addition of African trypanosomes caused a rapid drop in human BMEC TEER. Increasing SS to 14 dyn/cm(2), a condition mimicking SS in brain capillaries, led to a transient increase in TEER in both control and infected human BMEC. However, no differences in ERK1/2 and ERK5 activation were found under any condition tested. African trypanosomiasis alters BBB permeability under low shear conditions through an ERK1/2 and ERK5 independent pathway.

Subclavian aneurysm presenting with massive hemoptysis: a case report and review of the literature

We present a case of a 70-year-old male with a past medical history of coronary artery bypass grafting and end stage renal disease who presented with massive hemoptysis. He had a history of methicillin-resistant Staphylococcus aureus endocarditis, with infection and removal of endocardial pacing leads. His work-up revealed a 2.9-cm proximal left subclavian artery aneurysm. Bronchoscopy confirmed bright red blood in the left upper lobe bronchus and coronary angiography confirmed a patent left internal mammary artery (LIMA) to left anterior descending bypass. Because of the consideration of maintaining coronary perfusion via the LIMA while excluding the subclavian aneurysm, he underwent a left carotid to left axillary artery bypass graft followed by deployment of an Amplatzer II vascular plug just distal to the aneurysm. A thoracic endograft was then deployed to exclude the origin of the subclavian. A review of the literature reveals hemoptysis as a rare presentation of a subclavian aneurysm. We discuss approaches to this challenging clinical problem, ranging from open repair to hybrid approaches.

New modalities in the chronic ischemic diabetic foot management

The diabetic population is increasing worldwide at a staggering rate. Diabetic foot ulcers are a major contributor to nontraumatic lower limb amputations and peripheral arterial disease is one of main contributing pathophysiologic causes of diabetic ulcers. The dire need to reduce complication and wound healing recovery period of the chronic ischemic diabetic foot (CIDF) is indispensable to limb salvage and improvement of quality of life of patients with CIDF. This article discusses newer modalities that have been proposed to improve CIDF efficiently, safely, and effectively either alone or as adjuvants to conventional therapy.

Diabetes mellitus and peripheral vascular disease: diagnosis and management

Diabetes mellitus and peripheral artery disease are prevalent diseases throughout the world and often present simultaneously in the same patient, which has direct implications for their diagnosis and management. Refinements of existing and development of new diagnostic and treatment modalities are changing the management of these diseases. This article reviews the significant pathologic basis, history, and physical examination findings with respect to each disease and their presentation together. Advantages and disadvantages of different diagnostic modalities, including noninvasive studies and imaging technologies, are discussed. General medical management principles and indications, techniques, and efficacy of surgical and endovascular interventions are reviewed.

Prosthetic options available for the diabetic lower limb amputee

Although the rate of lower limb amputation in patients with diabetes is decreasing, amputation still remains a major complication of diabetes. Prosthetics have been long used to help amputees ambulate. The last decade has seen many advances in prostheses with the enhanced understanding of the mechanics of ambulation and improved use of technology. This review describes the different types of prosthetic options available for below knee, ankle, and foot amputees, emphasizing the latest advances in prosthetic design.