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Primary arterial neoplasms are rare lesions which have been most frequently associated with local or constitutional symptomatology, and with distal embolization. Perirenal aortic disruption with pseudoaneurysm formation due to an intimal sarcoma adjacent to a previously placed prosthetic graft is reported in a 66-year-old man. This case supports the premise that the presence of a vascular prosthesis might result in the induction of an arterial wall malignancy. This should be considered when an intraluminal mass is identified in the absence of other arterial pathology. Although the prognosis of these tumors is poor, their preoperative recognition may enhance treatment outcomes. [ABSTRACT FROM AUTHOR]

We aimed to examine the association between weight loss, dietary patterns, diabetes, and glycemic control among Qatari adults with a history of bariatric surgery (BS). Data from 1893 adults from the Qatar Biobank study were analyzed. Diabetes was defined by blood glucose, HbA1c, and medical history, with poor glycemic control defined as HbA1c ≥ 7.0%. The dietary patterns were derived from a Food Frequency Questionnaire using factor analysis. The participants' mean age was 38.8 years, with a mean weight loss of 23.4% and a 6.1% prevalence of poor glycemic control. Weight loss was inversely associated with diabetes and poor glycemic control. The traditional dietary pattern (high intake of Biryani, chicken, meat, fish dishes, zaatar fatayer, croissant, lasagna, and Arabic bread) was inversely associated with diabetes prevalence, with an OR of 0.61 (95%CI, 0.41-0.99) when comparing extreme quartiles. No significant associations were found between prudent or sweet dietary patterns and diabetes. Among the individuals with known diabetes, the prevalence of remission was 33.4%, with an OR for remission of 5.94 (95%CI, 1.89-18.69) for the extreme quartiles of weight loss. In conclusion, weight loss and traditional dietary patterns are inversely associated with diabetes and glycemic control among adults with a history of BS, with weight loss being the main determinant.

The question of whether economic recessions increase or decrease the earnings gap between the working and upper-middle class is debated. We study this issue and examine the Great Recession period using two different analytical strategies: three-level multilevel models and multivariate analysis over time. Based on EU Statistics on Income and Living Conditions (EU-SILC) data in 23 countries from 2004 to 2017, our results under both analytical strategies provide robust evidence that, by and large, the Great Recession widened the earnings gap between the working and upper-middle class. The effect magnitude is sizable; an increase of 5 percentage points in the unemployment rate is associated with an increase in the class earnings gap of approximately 0.10 log points., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Author. Published by Elsevier Inc. All rights reserved.)

Introduction: COVID-19 has imposed many shared limitations on medical and health education. Just like other health professions programs at most institutions, the Qatar University health cluster (QU Health) applied a containment approach and shifted all learning online, and onsite training was replaced by virtual internships (VIs) during the first wave of the pandemic. Our study aims to explore the challenges of virtual internships during the COVID-19 pandemic and their influence on the professional identity (PI) of the health cluster students from the College of Medicine, the College of Health Sciences, and the College of Pharmacy at Qatar University., Methods: A qualitative approach was employed. In total, eight focus groups with students ( N = 43) and 14 semi-structured interviews with clinical instructors from all the health cluster colleges were conducted. Transcripts were analyzed following the inductive approach., Results: The major challenges reported by students were mainly related to the lack of the required skills for navigating the VI, professional and social stressors, the nature of VIs and the quality of learning, technical and environmental issues, and the development of students' professional identity in an alternative internship environment. The challenges relating to the development of professional identity included: limited clinical (practical) experience, a lack of experience in fighting a pandemic, a lack of communication and feedback, and a lack of confidence in meeting the internship's goals. A model was constructed to represent these findings., Discussion: The findings are important in identifying the inevitable barriers to virtual learning for health professions students and provide a better understanding of how such challenges and different experiences would be affecting the development of their PI. Hence, students, instructors, and policymakers alike should strive to minimize these barriers. Since physical interactions and patient contact are indispensable components of clinical teaching, these extraordinary times demand innovations involving technology and simulation-based teaching. There is a need for more studies that are focused on determining and measuring the short- and long-term effects of the VI on students' PI development., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Bawadi, Shami, El-Awaisi, Al-Moslih, Abdul Rahim, Du, Moawad and Al-Jayyousi.)

In efforts to contain the COVID-19 pandemic, health colleges at Qatar University shifted their clinical training to virtual internships (VI) and project-based learning (PBL). The shift was new to students and faculty alike, and a major change that posed many challenges. This study aimed to explore the experience of changing to VIs during the pandemic from both the clinical instructors' and health sciences students' perspectives. A qualitative study was conducted based on the framework of readiness to change. It involved focus group discussions with students from the departments of Public Health and Human Nutrition and in-depth interviews with clinical instructors using appropriate online platforms. A total of 4 focus groups with 20 students and 4 interviews with instructors were conducted. Transcripts were analyzed following the inductive-deductive approach. The major themes that emerged from the analysis described students' and clinical instructors' perceptions of the necessity and efficiency of the switch to VI; the design of the VI and the extent of the clinical/field experience and skills that it offered; confidence in the ability to succeed in this type of internship and confidence about reaching expected goals; academic and moral support from clinical faculty and coordinators and the communication process with faculty and preceptors; and finally, the benefits gained and how employers would view this type of internship. Health sciences students' readiness for VI was generally low. Several student and faculty needs have to be addressed, specifically regarding the design of the program and the level of preceptors' communication with students. The findings would direct health programs, clinical instructors, and preceptors to better understand students' needs and efficiently plan for virtual internships during not only emergencies but also whenever there is a need to deliver online experiential learning courses., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Bawadi, Abdul Rahim, Moawad, Shami, Du, El-Awaisi, Al-Moslih, Diab and Al-Jayyousi.)

Polycystic ovary syndrome (PCOS) is an endocrinopathy that is common among women of reproductive age. It is a heterogeneous disorder with an unknown etiology. Different strategies have been proposed for the treatment of PCOS. Recent studies recommend supplementation with specific minerals for treating various PCOS phenotypes. We searched PubMed, Google Scholar, and SCOPUS databases by using search terms combining PCOS with the supplementation of magnesium, zinc, selenium, or chromium. This review presents a narrative concerning the association between PCOS and magnesium, zinc, selenium, and chromium supplementation. We review findings from various randomized controlled trials and meta-analyses conducted in women of childbearing age with PCOS. Recent reports highlight the beneficial effect of minerals on the clinical and metabolic symptoms of PCOS. Further studies are required to establish the appropriate dosage level of these minerals for ameliorating the pathologies associated with PCOS because of the potential health risks linked with higher doses.

The association between nuts intake and cognitive function is inconclusive. We aimed to investigate the association between habitual nuts consumption and cognition among Qatari adults. Data from 1000 participants aged >20 years who attended Qatar Biobank (QBB) were used. Nuts consumption was assessed by a food frequency questionnaire (FFQ). Blood samples were measured for magnesium, lipids and glucose. Mean reaction time (MRT) was used as an indicator of cognitive function. Linear regression was used to assess the association. A total of 21.1% of the participants reported consuming nuts ≥4-6 times/week (high consumption) while 40.2% reported consuming ≤1 time/month (low consumption). The mean MRT was 715.6 milliseconds (SD 204.1). An inverse association was found between nuts consumption and MRT. Compared to those with a low consumption, high consumption of nuts had a regression coefficient of -36.9 (95% CI -68.1 to -5.8) after adjusting for sociodemographic and lifestyle factors. The inverse association between nuts and MRT was mainly seen among those >50 years. There was an interaction between nuts consumption and hypertension. The association between nuts consumption and MRT was not mediated by hypertension, diabetes, or serum magnesium. Habitual higher consumption of nuts is positively associated with cognitive function, especially among old adults.

Co-existence of iron deficiency and obesity in adults has been reported in many countries. However, little is known on the association between obesity and iron deficiency in Qatar. This study aimed to investigate the link between abdominal obesity indices and iron status among adults in Qatar. A random sample of 1000 healthy Qatari adults, aged 20-50 years, was obtained from Qatar Biobank study. Body weight, waist circumference, dual x-ray absorptiometry (DXA) parameters and iron status indicators were measured using standard techniques. Multiple regression analysis was used to examine the associations. The prevalence of iron deficiency and anaemia were 35.4 and 25%, respectively. Of the participants with a large waist circumference, 31.7% had anaemia. Ferritin significantly increased with the increase in the android fat to gynoid fat ratio and visceral fat in both genders. Serum iron and transferring saturation decreased significantly with the increase in waist circumference in women. In both genders, C-reactive protein increased with the increase in all obesity indices. Standardized values of waist circumference, android fat, gynoid fat ratio and visceral fat were significantly associated with log transformed ferritin in men and women. Waist circumference was inversely related to serum iron (β:-0.95, 95% CI:-1.50,-0.39) and transferrin saturation (β:-1.45, 95%CI:-2.46, -0.43) in women. In men, waist circumference was positively associated with haemoglobin level (β: 0.16, 95% CI:0.04, 0.29). Central obesity coexists with anaemia among the study population. Elevated central obesity indices were associated with an increase in ferritin concentration. The increased ferritin concentration may be attributed to the increase in inflammatory status as a result of an increase in c-reactive protein concentration associated with central obesity., Competing Interests: The authors have declared that no competing interests exist.

Background: Diabetes is a highly prevalent chronic disease that is associated with major complications. Findings regarding risk of depression among patients with diabetes are controversial. This study aimed to determine the prevalence and determinants of depressive symptoms among Qatari patients with type 2 diabetes. Methods: This cross-sectional study was based on Qatar Biobank (QBB) data of 2448 Qatari adults with diabetes aged 21-60 years old. Data regarding age, gender, education, income, body mass index (BMI), medication use, glycated hemoglobin (HbA1c) were retrieved. Patients' responses to the Patient Health Questionnaire-9 (PHQ-9) were also obtained. Data analyses was performed using STATA 16, and statistical significance was considered at a p -value of <0.05. Results: Of the 2448 participants, 15.4% ( n = 378) had self-reported depressive symptoms. Depressive symptoms were frequent among females (69.6%), smokers (15.9%), and participants with a higher level of education (47.1%). Average age of participants who reported depressive symptoms was significantly less that among participants without depressive symptoms (44.8 vs. 52.9 years). Qatari women with diabetes seem to be at higher risk of depression when compared to men (OR = 1.819, 95% CI: 1.42-2.33); The odds of reporting depressive symptoms were 35% higher among patients with more advanced educational qualifications (OR = 1.351, 95% CI: 1.00, 1.82). Smokers were twice as likely to report depressive symptoms as their non-smoking counterparts. There was no significant relationship between depression and poor glycemic control, physical activity, BMI, or insulin use. Conclusions: In summary, the study results suggest that several sociodemographic factors, such as age, gender, and level of education were associated with the risk of depressive symptoms among Qataris with diabetes.

Along with the issues of inflated social and financial burden associated with autism spectrum disorder (ASD), specific treatment for this disorder has also not been developed. Having a thorough look at previous trials done to treat autism, we find that nutrition intervention had been used frequently as a complementary form of therapy. Indeed, an early diagnosis of nutrition deficiency and metabolic disorders done concomitantly with accurate therapeutic interventions can be a cornerstone for improving cognitive and behavioral aptitudes of people with autism. Several studies have showed that increasing the intake of specific nutrients can reduce the symptoms and comorbidities associated with autism. Consequently, nutrition intervention and appropriate supplementation can be crucial in managing and treating autism. This paper will discuss recent literature on the significance of metabolic aspects in autistic disorder and highlight the influence of nutrition intervention on the symptoms of autism.

Background: This study investigated employers' perspectives on the impact of a supervised practice program (SPP), guided by international accreditation standards on the skill development and potential employability of dietetics students., Main Body: This study was based on qualitative research. Fifteen potential employers, who also served as SPP preceptors, participated in this study. Participants were interviewed using semi-structured questionnaire. All interviews were conducted face-to-face by a trained interviewer. Participates were invited to discuss their own experiences in the current SPP, their perceptions of the impact of SPP on skills and attributes of graduates, and their overall ideas of how SPP may contribute to the employability of graduates. This study found that the SPP program guided by international accreditation standards shaped the duties and responsibilities of preceptors/supervisors and promoted a beneficial relationship between preceptors and SPP students. The benefits to graduates include bridging the gap between classroom didactic knowledge and practice; improving workplace self-confidence; developing competencies such as critical-thinking, communication, interviewing, and counselling skills in various multidisciplinary and multicultural settings. In addition, the preceptors suggested that accreditation-guided SPP contributes to the employability of graduates. Also, they opined that it reduced the need for orientation and shortened the probation time because students were familiar with the work environment and work flow. This lead to the improved preparedness for work., Conclusion: SPP based on set of competencies guided by international accreditation standards provides an up-to-date curriculum, improves the quality of the nutrition and dietetics services, and increases the potential employability of the graduates.

Background and Aim: Tetrahydrobiopterin (BH 4 ) is an essential co-factor that regulates nitric oxide (NO) and reactive oxygen species (ROS) production by nitric oxide synthases (NOS). In this study, we evaluated the effects of sepsis on BH 4 level and redox status in the brain by using the rat model of sepsis-induced by cecal ligation and puncture (CLP) and examined whether BH 4 and/or acetyl-L-carnitine (ALC) could prevent the neuronal apoptosis and neurological changes induced by sepsis., Material and Method: Male albino rats were randomly and blindly divided into 8 groups: sham, sham + BH 4 , sham + ALC, sham +BH 4 + ALC, CLP, CLP + BH 4 , CLP + ALC, and CLP+BH 4 + ALC. We measured neurological indicators, brain levels of BH 4 , guanosine triphosphate cyclohydrolase (GTPCH), sepiapterin reductase (SR) and dihydropteridine reductase (DHPR) genes expression (Essential enzymes in BH 4 biosynthesis and recycling pathways). We investigated also brain redox status and both endothelial and inducible NOS expressions., Results: Brain of septic rats demonstrated a reduced BH 4 bioavailability, downregulation of BH 4 synthetic enzymes, increased production of hydrogen peroxide and impaired antioxidant enzymes activities. Treatments with BH 4 and/or ALC increased BH 4 level, upregulated BH 4 synthetic enzymes expressions, and attenuated oxidative-induced neuronal apoptosis., Conclusion: Our results suggest that BH 4 and/or ALC might protect the brain against oxidative stress induced neuronal apoptosis by restoring bioavailability of BH 4 and upregulating of BH 4 synthetic enzymes in the brain during sepsis., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Visceral ischemic syndromes are rare but catastrophic disorders. In acute presentations, treatment modalities include thrombolytic therapy, open surgical revascularization and percutaneous endovascular therapy. Endovascular therapy has become the most commonly utilized treatment option for chronic mesenteric ischemia and should be considered the first line of therapy for patients with anatomically suitable lesions or excessive open surgical risk. Open surgical revascularization has been associated with outstanding long-term outcomes. The various surgical and endovascular techniques and their associated outcomes for the treatment of mesenteric ischemic syndromes are reviewed in detail.

Unlabelled: Sepsis is associated with neuronal damage and cognitive impairment, with the participation of pro-inflammatory cytokines and oxidative-nitrous stress. It is known that activated microglia plays a vital role in neuro-inflammation and neuro-degeneration. Thus, the objective of this study was to evaluate therapeutic roles of two microglia regulating agents, JWH-133 and Eserine, on the neuroinflammatory associated brain dysfunctions. To achieve our aim, we used control rats or submitted rats to lipopolysaccharide (LPS) challenge. 30 min after LPS challenge, the animals received either saline, Eserine, JWH-133 or Eserine+JWH-133. After 24h, animals were submitted to the habituation to T maze, Rotarod and activity cage tests. The rats were killed after and were evaluated for central and peripheral inflammatory and oxidative parameters. We observed that the use of Eserine, JWH-133 or Eserine + JWH-133 reverted the increases in the inflammatory markers [interleukin 6 (IL6), vascular cell adhesion molecule 1(VCAM-1) and Eselectin] and oxidative-nitrous stress MDM, and that the anti-inflammatory, antioxidant properties of both JWH-133 and Eserine successfully improve the LPS induced brain dysfunction., Conclusions: The results observed in this study reinforce the role of microglia activation regulating agents, in particular, JWH-133 and Eserine, in the brain dysfunction associated with endotoxemia., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The outcome of carotid artery occlusion was studied through the retrospective identification of 115 affected patients. The majority were white (77%) males (61%) with multiple atherogenic risk factors and suffering ipsilateral stroke (57%). Those patients presenting with stroke were not distinguished by demographic features, risk factors, lipid profile, medical regimen, or subsequent mortality when compared with those without. Overall, 36 patients (31%) required contralateral carotid endarterectomy (CEA), with one (2.8%) perioperative stroke, whereas 4 (3%) underwent ipsilateral external CEA without incident. With 81% follow-up (mean 3.9 years), the overall mortality of the group was 46%; the annualized risk of ipsilateral stroke was 1.6%. This study documents a significant risk of stroke and contralateral occlusive disease with ipsilateral carotid artery occlusion, which cannot be reliably predicted by clinical criteria. Duplex surveillance is valuable, but flow velocity measurements alone may be misleading. Surgical endarterectomy can be performed with an acceptable rate of perioperative stroke.

The superiority of autologous venous conduit for infrainguinal arterial bypass has been well documented, especially when the bypass extends below the knee or to the tibial arteries. Nevertheless, when adequate autologous vein is not available, prosthetic bypasses (eg, polytetrafluoroethylene [PTFE] or Dacron) are often used in limb-salvage situations. The inferior long-term patency of these infrainguinal prosthetic bypasses has been documented by a number of studies. One such study reported a prospective multicenter randomized trial with only a 12% primary patency for infrapopliteal prosthetic bypasses after 4 years. Another study reported a similar experience with infragenicular bypasses with PTFE for limb salvage even for above-knee (27%, 5 year) and below-knee (25%, 5 year) femoral-popliteal bypasses. The reported PTFE graft patency was consistently inferior to that achieved with autologous vein for limb salvage. Dacron grafts appear to have similar patency rates to PTFE. In an attempt to improve prosthetic graft patency, a number of surgical and medical adjuncts have been developed. In this review, the authors discuss these adjuncts and their impact on infrainguinal prosthetic graft patency.

This study examined the efficiency of adenoviral-mediated gene transfer in experimental vein grafts and cultured human saphenous vein under physiologic conditions using clinically relevant exposure times, pressures, and viral concentrations. The external jugular veins of 25 male New Zealand White rabbits were exposed to 0.5 mL of replication-deficient adenovirus vectors encoding beta-galactosidase (AdlacZ), control adenovirus (AdBg/II), or vehicle at pressures ranging from 0 to 120 mmHg for 10 min. Veins were excised and grafted into the carotid circulation. After 5 days, the vessels were reexposed, excised, and stained with X-gal chromagen for beta-galactosidase (beta-gal) activity. Gene transfer was also performed in 13 segments of human saphenous vein discarded at the time of bypass grafting. The veins were cultured for 0-21 days and assayed for beta-gal activity as above. Rabbit vein grafts exposed to high-pressure AdlacZ transfection showed significant transgene expression in 100% of grafts (39 +/- 2% positive cells/hpf) while only 60% of those transfected at low pressure expressed beta-gal (9 +/- 3% positive cells/hpf). All human veins exposed to AdlacZ expressed beta-gal to a variable degree (range 10-50% positive cells/hpf). No control grafts or veins expressed the transgene. Efficient adenoviral-mediated gene transfer in experimental vein grafts and human saphenous vein segments can be achieved using clinically feasible parameters of exposure time, pressure, and viral concentration.

Introduction: Conduit size and quality are major determinants of the long-term success of infrainguinal autologous vein grafting. However, accurate measurement of the internal diameter of vein grafts is difficult given their variable wall thickness and taper. The purpose of this study was to define the "effective" internal diameter of a vein graft according to its hemodynamic properties and to determine its significance for graft patency., Methods: Sixty infrainguinal bypass grafts performed on 57 patients were evaluated intraoperatively. Proximal and distal graft pressure and blood flow (Q(meas)) were measured with fluid-filled catheter transduction and ultrasonic transit-time flowimetry, respectively, after unclamping. Waveforms were recorded digitally at 200 Hz under baseline conditions and after stimulation with 60 mg of papaverine. According to Fourier transformation of the measured pressure gradient (DeltaP), the Womersley solution for fluid flow in a straight rigid tube was used to calculate theoretical flow waveforms (Q(calc)) for a range of graft diameters. The theoretical waveforms were then compared with the measured flow waveforms and the best-fit diameter chosen as the "effective hemodynamic diameter" (EHD). Only grafts in which the correlation coefficient of Q(calc) versus Q(meas) was more than 0.90 were accepted (n = 47) to assure validity of the hemodynamic model. After a mean follow-up of 12.5 months (range, 0.1-43.9 months), patency was determined by the life table method. Hemodynamic and clinical variables were tabulated, and their effect on patency determined the use of univariate and multivariate Cox regression., Results: Mean EHD was 4.1 +/- 0.1 mm with a range of 2.5 to 5.7 mm. Administration of papaverine caused profound changes in DeltaP (+78% +/- 17%) and Q(meas) (+71% +/- 12%) as expected, but had no effect on EHD (+0.05% +/- 0.1%). Univariate regression identified five variables associated with decreased secondary patency (P <.10): low EHD, conduit source other than the greater saphenous vein, high baseline DeltaP(mean), female sex, and redo operation. Of these, only low EHD was significant after multivariate analysis (P =.03). Patency of small diameter grafts (EHD < 3.6 mm; n = 11) was compared with patency of larger grafts (EHD > 3.6 mm; n = 36) to test a frequently espoused clinical guideline. Grafts with an EHD less than 3.6 mm exhibited significantly lower secondary patency compared with larger grafts (P =.0001). The positive and negative predictive values for an EHD less than 3.6 mm for secondary graft failure for grafts with at least 1 year follow-up were 86% and 88%, respectively., Conclusion: An EHD is a unique parameter that quantifies conduit size and has a significant impact on vein graft patency. An EHD less than 3.6 mm portends graft failure.

Purpose: Inappropriate or excessive vascular smooth muscle cell proliferation leads to the development of occlusive lesions in up to 50% of vein grafts. The purpose of this study was to test the hypothesis that induced overexpression of a cytostatic nonphosphorylatable form of the retinoblastoma protein (DeltaRb) would attenuate neointimal thickening in experimental vein grafts., Methods: A replication-deficient adenovirus vector that encoded a nonphosphorylatable, constitutively active form of DeltaRb was constructed (AdDeltaRb) and contained an NH2-terminal epitope tag from the influenza hemagglutinin molecule (HA). Forty-eight male New Zealand white rabbits underwent surgical exposure of the external jugular vein for transfection with either 3 x 10(10) plaque-forming units/mL AdDeltaRb (n = 16), 3 x 10(10) plaque-forming units/mL control adenovirus (AdBglII, n = 15), or vehicle (n = 17) for 10 minutes at 120 mm Hg. After vector exposure, the vein was excised and interposed end-to-end into the carotid circulation. After 5 days, 12 grafts (four from each group) were excised and assayed for genomic DeltaRb DNA with the polymerase chain reaction or for hemagglutinin molecule expression and localization with immunohistochemistry. The remainder of the grafts (n = 36) were perfusion-fixed after 4 weeks, and 5 microm sections prepared for digital planimetric analysis., Results: Polymerase chain reaction results identified the DeltaRb gene only in the grafts that were transfected with AdDeltaRb. Immunohistochemical analysis results revealed transgene expression in most of the endothelial cells and in many of the smooth muscle cells. After 4 weeks, the grafts that were exposed to AdDeltaRb exhibited a 22% reduction in neointimal thickness (vehicle, 77 +/- 7 microm; AdBglII, 75 +/- 5 microm; AdDeltaRb, 60 +/- 5 microm; P =.05), and medial thickness, luminal diameter, and other parameters were unchanged (medial thickness: vehicle, 72 +/- 10 microm; AdBglII, 85 +/- 7 microm; AdDeltaRb, 69 +/- 9 microm; P = NS; luminal diameter: vehicle, 4.5 +/- 0.2 mm; AdBglII, 4.4 +/- 0.2 mm; AdDeltaRb, 4.7 +/- 0.1 mm; P = NS)., Conclusion: With this delivery system, adenoviral-mediated gene transfer is highly efficient and induced overexpression of DeltaRb leads to a reduction in vein graft neointimal thickening.

Background: Although recognition of chronic mesenteric ischemia has increased in recent years, this disorder has continued to present diagnostic and therapeutic challenges., Objective: To examine the modern results of surgical revascularization for chronic mesenteric ischemia., Design: Retrospective review., Setting: University medical center., Patients: The management of 24 consecutive patients (mean +/- SEM age, 58 +/- 3 years; 5 men, 19 women) who were undergoing surgical treatment of chronic mesenteric ischemia between 1986 and 1996 was reviewed., Intervention: Surgical mesenteric revascularization., Main Outcome Measures: Postoperative course, long-term graft patency rate, and long-term symptom-free survival rate., Results: The most frequent presenting symptoms were postprandial abdominal pain (18 patients [75%]) and weight loss (14 patients [58%]). Less specific complaints included nausea and vomiting (8 patients [33%]), diarrhea (7 patients [29%]), and constipation (4 patients [17%]). Atherosclerotic risk factors were common, including tobacco use (20 patients [83%]), coronary artery disease (10 patients [42%]), and hypertension (10 patients [42%]). The cause was identified as atherosclerosis in 21 patients, median arcuate ligament compression in 2 patients who were monozygotic twins, and Takayasu arteritis in 1 patient. Lesions were localized to all 3 major visceral vessels (celiac artery, superior mesenteric artery [SMA], and inferior mesenteric artery) in 8 patients, celiac artery and SMA in 13, SMA alone in 2, and SMA and inferior mesenteric artery in 1. Seventeen patients underwent antegrade reconstructions from the supraceliac aorta to the SMA and/or celiac artery; 7 patients underwent revascularization by use of a retrograde bypass that originated from the infrarenal aorta or a prosthetic graft. There were no perioperative deaths although 1 patient died in the hospital 6 weeks after early graft failure and sepsis (overall in-hospital mortality, 4%). Follow-up ranged from 3 months to 10 years (median, 2.4 years). The mean +/- SEM 5-year primary graft patency rate, as objectively documented by use of contrast angiography or duplex scanning in 19 of 24 patients, was 78% +/- 11%. Primary failure was documented in 3 patients (at 3 weeks, 5 months, and 7 months). Two patients required a thrombectomy; 1 of these patients subsequently died of an intestinal infarction. The mean +/- SEM 5-year survival rate by use of life-table analysis was 71% +/- 11%. No patient with a patent graft experienced a symptomatic recurrence., Conclusions: Chronic mesenteric ischemia is usually a manifestation of advanced systemic atherosclerosis. Symptoms almost always reflect midgut ischemia in the distribution of the SMA. An antegrade bypass from the supraceliac aorta can be performed with acceptable operative morbidity and is currently the preferred reconstructive technique. Surgical revascularization affords long-term symptom-free survival in a majority of patients with chronic mesenteric ischemia.

Owing to a heightened awareness of the disease as well as improved diagnostic tests, chronic mesenteric ischemia is now recognized as a more common cause of abdominal pain. The classic symptoms of postprandial abdominal pain with weight loss are evident in the majority of proven cases; most patients also have other evidence of advanced atherosclerotic vascular disease. Several new diagnostic techniques are being developed and tested, most notably color duplex imaging, although angiography still remains the diagnostic gold standard. It is hoped that better noninvasive testing may eventually eliminate the need for angiography, as well as lead to a more expedient diagnosis of chronic mesenteric ischemia.

Atherosclerosis is a degenerative process characterized by endothelial cell dysfunction, inflammatory cell adhesion and infiltration, and the accumulation of cellular and matrix elements leading to the formation of fibrocellular plaques. In the end stages, advanced occlusive plaques limit blood flow and oxygen delivery resulting in the well-known ischemic syndromes of the coronary, skeletal muscle, mesenteric, and cerebrovascular circulation. Moreover, sudden critical ischemic events may be precipitated by plaque disturbance, rupture, hemorrhage, and/or thrombosis. Traditional pharmacologic approaches have been effective in reducing serum cholesterol and controlling thrombosis but, in the main, have had little impact on the treatment of advanced lesions. The purpose of this review is to examine the current status of gene therapy for vascular proliferation, aberrant endothelial function, thrombosis, peripheral ischemia, and modification of the blood/biomaterial interface.

The purpose of this investigation was to measure vascular input impedance in infrainguinal vein grafts and assess the importance of clinical and hemodynamic parameters in predicting graft patency. Fifty-seven patients undergoing infrainguinal vein bypass grafting for limb salvage (n = 40) or claudication (n = 17) were prospectively studied. At the time of revascularization, simultaneously acquired intraluminal pressure and blood flow waveforms were digitized at 200 Hz and subjected to Fourier transformation in near real-time. Input impedance was calculated at baseline (immediately after unclamping) and after stimulation with either papaverine or completion arteriography. Resistance (Rin) was calculated as mean pressure divided by mean blood flow (Q). Characteristic impedance (Z0) was calculated as the mean of harmonics 3-10. Intraoperative data acquisition required approximately 5 min, utilized the completion angiography cannula already in place, and was uncomplicated in all patients. Stimulation with either papaverine or arteriography resulted in increased Q (72 +/- 7 to 146 +/- 11 ml/min, p < 0.001), decreased Rin (126 +/- 13 to 52 +/- 4 x 10(3) dyne.s.cm-5, p < 0.001), and slightly decreased Z0 (18 +/- 2 to 15 +/- 1, p = 0.002). After a mean follow-up of 20 months, the 2-year primary patency, secondary patency, limb salvage, and survival rates were 61 +/- 8%, 74 +/- 7%, 76 +/- 6%, and 86 +/- 6%, respectively. Primary patency was not associated with any of the clinical variables studied including age, sex, smoking history, history of previous vascular surgery, hypertension, coronary artery disease, diabetes mellitus, creatinine, indication for revascularization (claudication versus limb salvage), anesthesia (general versus regional), or level of distal anastomosis (popliteal versus infrapopliteal). Furthermore, there was no association between primary patency and baseline Q, baseline Rin, or stimulated Z0. However, using univariate analysis, patency was positively associated with decreased stimulated Rin (p = 0.002), elevated stimulated Q (p = 0.006), and decreased baseline Z0 (p = 0.02). Multiple regression analysis identified stimulated Rin as the only independent predictor of primary patency (p = 0.002). Stimulated Rin > or = 50 x 10(3) dyne.s.cm-5 was 71% sensitive and 65% specific for graft failure. It is concluded that 1) vascular input impedance can be simply and reliably measured in the operating room, and 2) elevated stimulated Rin is an independent predictor of primary patency.