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Visceral artery aneurysms (VAA) and pseudoaneurysms (VAPA) can be life-threatening conditions with high incidence of rupture and hemorrhage. Greater availability and increased use of advanced imaging technology has led to the increased incidental detection of asymptomatic visceral aneurysms. In addition, increased percutaneous endovascular interventions have raised the incidence of iatrogenic pseudoaneurysms. Due to this, both VAA and VAPA have become an increasingly frequent diagnosis confronting the vascular surgeon. Over the past decade, there has been steady increase in the utilization of minimally invasive, non-operative interventions, for vascular occlusive and aneurysmal disease. All VAA and VAPA can technically be fixed by endovascular techniques but that does not mean they should. These catheter-based techniques constitute an excellent approach in the elective setting, particularly in patients who are poor surgical candidates due to their comorbidities or who present a hostile abdomen. However, in the emergent setting it may carry a higher morbidity and mortality. We review the literature about open and endovascular approach for the treatment of VAA and VAPA both in the elective and emergent setting.

Fundamentals of randomized clinical trials in wound care: reporting standards

In wound care research, available high-level evidence according to the evidence pyramid is rare, and is threatened by a poor study design and reporting. Without comprehensive and transparent reporting, readers will not be able to assess the strengths and limitations of the research performed. Randomized clinical trials (RCTs) are universally acknowledged as the study design of choice for comparing treatment effects. To give high-level evidence the appreciation it deserves in wound care, we propose a step-by-step reporting standard for comprehensive and transparent reporting of RCTs in wound care. Critical reporting issues (e.g., wound care terminology, blinding, predefined outcome measures, and a priori sample size calculation) and wound-specific barriers (e.g., large diversity of etiologies and comorbidities of patients with wounds) that may prevent uniform implementation of reporting standards in wound care research are addressed in this article. The proposed reporting standards can be used as guidance for authors who write their RCT, as well as for peer reviewers of journals. Endorsement and application of these reporting standards may help achieve a higher standard of evidence and allow meta-analysis of reported wound care data. The ultimate goal is to help wound care professionals make better decisions for their patients in clinical practice.

A Giant Superior Mesenteric Artery Aneurysm Mimicking an Abdominal Aortic Aneurysm

Superior mesenteric artery aneurysms are a rare clinical finding but can present with a wide range of symptoms. They are associated with a high risk of rupture, as well as high morbidity and mortality. We present a case of a 38-year-old female who presented with acute abdominal pain and a pulsatile palpable mass in the right epigastric region without other signs or symptoms.

Omental vein catheter thrombolysis for acute porto-mesenteric vein thrombosis

Mesenteric venous thrombosis (MVT) is an uncommon clinical condition with potential high morbidity. We report here a patient who presented with acute-onset MVT and bowel infarction, which was successfully ameliorated with intramesenteric vein thrombolytic therapy.

Application of Porter’s Five Forces Model and generic strategies for vascular surgery: should be stuck in the middle?

There are many stakeholders in the vascular marketplace from clinicians to hospitals, third party payers, medical device manufacturers and the government. Economic stress, threats of policy reform and changing health-care delivery are adding to the challenges faced by vascular surgeons. Use of Porter's Five Forces analysis to identify the sources of competition, the strength and likelihood of that competition existing, and barriers to competition that affect vascular surgery will help our specialty understand both the strength of our current competition and the strength of a position that our specialty will need to move to. By understanding the nature of the Porter's Five Forces as it applies to vascular surgery, and by appreciating their relative importance, our society would be in a stronger position to defend itself against threats and perhaps influence the forces with a long-term strategy. Porter's generic strategies attempt to create effective links for business with customers and suppliers and create barriers to new entrants and substitute products. It brings an initial perspective that is convenient to adapt to vascular surgery in order to reveal opportunities.Vascular surgery is uniquely situated to pursue both a differentiation and high value leadership strategy.

Contemporary evaluation and management of the diabetic foot

Foot problems in patients with diabetes remain a major public health issue and are the commonest reason for hospitalization of patients with diabetes with prevalence as high as 25%. Ulcers are breaks in the dermal barrier with subsequent erosion of underlying subcutaneous tissue that may extend to muscle and bone, and superimposed infection is a frequent and costly complication. The pathophysiology of diabetic foot disease is multifactorial and includes neuropathy, infection, ischemia, and abnormal foot structure and biomechanics. Early recognition of the etiology of these foot lesions is essential for good functional outcome. Managing the diabetic foot is a complex clinical problem requiring a multidisciplinary collaboration of health care workers to achieve limb salvage. Adequate off-loading, frequent debridement, moist wound care, treatment of infection, and revascularization of ischemic limbs are the mainstays of therapy. Even when properly managed, some of the foot ulcers do not heal and are arrested in a state of chronic inflammation. These wounds can frequently benefit from various adjuvants, such as aggressive debridement, growth factors, bioactive skin equivalents, and negative pressure wound therapy. While these, increasingly expensive, therapies have shown promising results in clinical trials, the results have yet to be translated into widespread clinical practice leaving a huge scope for further research in this field.

Cyclic strain delays the expression of tissue factor induced by thrombin in human umbilical vein endothelial cells

Most studies of tissue factor (TF) expression in endothelial cells (EC) are performed under stationary culture conditions. The purpose of this study was to determine the influence of mechanical stimuli such as cyclic strain (CS) on the expression of TF in EC exposed to thrombin (Thr). Human umbilical vein endothelial cells (HUVEC) were exposed to 4 U·mL(-1) Thr in the presence or absence of 10% average CS at 60 cycles·min(-1) and then TF expression was measured. TF messenger RNA (mRNA) expression peaked at 2 hours in HUVEC exposed to Thr, but at 4 hours in HUVEC exposed to both Thr + CS. TF expression was inhibited by p38 and extracellular signal-regulated protein kinase (ERK) inhibitors. For both Thr or Thr + CS stimuli, p38 and ERK activity peaked at 5 minutes (p < 0.05). Nuclear factor-kappa B levels remained high in the Thr group but not in the Thr + CS group, while Egr-1 levels were elevated in the Thr + CS group. We demonstrated CS-delayed, Thr-induced TF mRNA expression in HUVEC, which may be modulated by p38 and ERK inhibitors.

The use of retrievable inferior vena cava filters in the trauma population

OBJECTIVE

To determine if the use of retrievable filters resulted in an increase in the placement of inferior vena cava (IVC) filters in trauma patients.

DESIGN

All patients who underwent IVC filter placement at Yale-New Haven Hospital, New Haven, Connecticut, USA between the years 1999 and 2004.

SETTING

Academic, level 1 trauma centre.

PATIENTS

Included in the present study were 202 trauma patients and 676 nontrauma patients.

INTERVENTION

IVC filter placement.

MAIN OUTCOME MEASURE

Demographics, indications, complication rates and type of IVC filters placed in trauma patients versus nontrauma patients were evaluated.

RESULTS

The present study determined 45.4% (n=92) of trauma patients undergoing IVC filter placement were younger than 40 years of age, compared with 7.8% (n=53) of nontrauma patients. The most common indication for IVC filter placement in trauma patients was prophylaxis (n=162, 80.2%), while in the nontrauma patients only 11.4% (n=77) of patients underwent prophylactic filter placement. The number of retrievable filters used in trauma patients increased from 46.7% in 2001, the year they became available, to 78.9% in 2004. The use of retrievable filters similarly increased in the nontrauma population from 35.9% in 2001 to 78.3% in 2004. Approximately 24% of the patients that underwent IVC filter placement at Yale-New Haven Hospital were categorized as trauma patients. The complication rate for this time period was 0.5% (n=1) in the trauma population versus 3.7% (n=26) in the nontrauma population.

CONCLUSION

The overall number of IVC filters placed in trauma patients did not dramatically increase with the introduction of retrievable filters, suggesting that the indications for the use of IVC filters have not changed.

Lower extremity limb salvage with cryoplasty: a single-center cohort study

Endovascular techniques have been playing an increasing role in managing lower extremity chronic critical limb ischemia (CLI) in patients considered poor or non-candidates for surgical revascularization secondary to co-morbidities such as coronary artery disease, uncontrolled hypertension, diabetes mellitus or inadequate conduit. This study reviews our recent clinical experience in the treatment of peripheral artery disease solely using cryoplasty. A retrospective cohort study was performed. The cohort consisted of 88 patients who underwent lower extremity revascularization utilizing cryoplasty between December 2003 and August 2007. Indications for intervention included poor wound healing after forefoot amputation or persistent ulceration of the foot, disabling claudication and rest pain. Kaplan–Meier analysis was performed to assess salvage rates. One hundred twenty-six lesions were treated in 88 patients. Technical success rate was 97%. Limb salvage rates were 75 and 63% for patients with critical limbs ischemia after one and three years, respectively. A history of smoking was associated with a threefold increased risk of limb loss. In conclusion, endovascular management of lower extremity lesions with cryoplasty is an emerging and viable paradigm in the treatment of CLI in an attempt to preserve limbs and avoid major amputations.

Cardiovascular disease: the new epidemic in sub-Saharan Africa

Sub-Saharan Africa (SSA) is now facing a double burden of disease where patients are suffering from non-communicable diseases such as coronary heart disease, along with the burden of the current human immunodeficiency virus (HIV) epidemic. Due to this double burden, cardiovascular disease (CVD) prevention and treatment has been overlooked, allowing the rates to continue to rise unchecked. A series of searches were conducted using PubMed as the primary database. From these searches, journal articles were compiled that related to diabetes, obesity and smoking rates in SSA. Also, the prevalence of CVD in the USA was reviewed. Although the USA has higher rates of CVD now, the rates were on the decline compared with SSA. Due to 'Westernization' of SSA, the rates of CVD risk factors, such as diabetes, are expected to increase by 50%. Because of this, 80% of CVD deaths worldwide took place in developing countries like those in SSA. Although HIV/acquired immunodeficiency syndrome (AIDS) is the current epidemic in SSA, CVD disease poses a threat as the new epidemic because of the increasing rates of these CVD risk factors. Without combating this disease now, SSA is facing an epidemiological shift from AIDS to CVD being the leading cause of death.

Traumatic innominate artery pseudoaneurysm in the setting of a bovine arch

Blunt traumatic injury of the innominate artery occurs infrequently but is commonly lethal. Bovine aortic arch anatomy is a predisposition to this injury. Clinical findings, chest X-ray, and computerized tomography may suggest the diagnosis, and it may be confirmed with angiography. Both interposition and bypass grafting are operative repair methods of choice. EEG monitoring confirms cerebral perfusion, thereby allowing the deferment of shunts and cardiovascular bypass with hypothermic arrest. We report a case of traumatic innominate artery pseudoaneurysm in the setting of "bovine aortic arch" anatomy, together with multiple associated injuries, including descending aorta transection. We also review the current literature on the topic.

Varying effects of hemodynamic forces on tissue factor RNA expression in human endothelial cells

BACKGROUND

Atherosclerotic lesions predominantly localize in areas exposed to distinct hemodynamic conditions. In such lesions, tissue factor (TF) is over-expressed. Therefore, we hypothesized that varying types of mechanical forces may induce different effects on TF expression in endothelial cell, and may also influence the effects of chemical stimuli.

MATERIALS AND METHODS

TF RNA expression in human umbilical vein endothelial cells (HUVEC) exposed to mechanical stress in the presence or absence of chemical stimulation with thrombin (Th) was determined. The forces examined were: steady unidirectional laminar flow (LF), pulsatile unidirectional laminar flow (PF), constant oscillatory flow (OF), pulsatile to-fro flow (TFF), and cyclic strain (CS).

RESULTS

Mechanical stimulation of HUVEC with LF for 2 h induced an 8.7 ± 0.7-fold increase in TF RNA expression, while PF induced 4.7 ± 0.9 and TFF induced 8.6 ± 1.7-fold, respectively. These responses were significantly higher than static controls. Exposure to OF or CS did not result in any significant increase, whereas chemical stimulation with Th led to significant TF expression (4.9 ± 0.3-fold). The combination of mechanical-chemical stimuli induced significantly higher TF expression than mechanical stresses alone, and this effect was synergistic. Combination of LF+Th for 2 h induced significantly increased TF expression (16.6 ± 1.7-fold), as did PF+Th (14.8 ± 2.4) and TFF+Th (17.4 ± 1.0). Furthermore, after 6 h exposure, only TFF demonstrated significantly higher TF expression both with and without Th.

CONCLUSIONS

While uniform laminar flow resulted in transient TF expression, disturbed flow induced sustained amplification of TF expression. Further investigation is needed to elucidate the mechanism of localized atherosclerosis in areas exposed to disturbed flow.

Endograft collapse after thoracic endovascular aortic repair

PURPOSE

To provide insight into the causes, timing, and optimal management of endograft collapse after thoracic endovascular aortic repair (TEVAR).

METHODS

A comprehensive review was conducted of all published cases of endograft collapse after TEVAR identified using Medline, Cochrane Library Central, and EMBASE. In total, 32 articles describing 60 patients (45 men; mean age 40.6 ± 17.2 years, range 17-78) with endograft collapse were included. All data were extracted from the articles and systematically entered into a database for meta-analysis.

RESULTS

In the 60 cases of endograft collapse, TEVAR had most commonly been applied to repair traumatic thoracic aortic injuries (39, 65%), followed by acute and chronic type B aortic dissections (9, 15%). The median time interval between TEVAR and diagnosis of endograft collapse was 15 days (range 1 day to 79 months). On average, the collapsed endografts were oversized by 26.7% ± 12.0% (range 8.3%-60.0%). Excessive oversizing was reported as the primary cause of endograft collapse in 20%, and a small radius of curvature of the aortic arch was responsible for 48% of the cases. The 30-day mortality was 8.3%, and the freedom from procedure-related death at 3 years after diagnosis of stent-graft collapse was 83.1% for asymptomatic patients compared with 72.7% for patients who had symptoms at diagnosis (p=0.029).

CONCLUSION

Endograft collapse typically occurs shortly after TEVAR, most frequently after endovascular repair of traumatic aortic injury. A high level of suspicion for endograft collapse in the first month after TEVAR, as well as further improvement of current endovascular devices, may be required to improve the long-term outcomes of patients after TEVAR.

Laminar shear, but not orbital shear, has a synergistic effect with thrombin stimulation on tissue factor expression in human umbilical vein endothelial cells

INTRODUCTION

High levels of tissue factor (TF) have been associated with atherosclerotic plaques. The specific pathways linked to TF expression in endothelial cells (ECs) have not been well defined. This study compared TF expression in human umbilical vein ECs (HUVECs) exposed to laminar shear stress (LSS) using a parallel flow chamber and to orbital shear stress (OSS) using an orbital shaker. We also compared the effects of thrombin (TH) stimulation of ECs exposed to different shear forces on the expression of TF and investigated the role that second messengers, p38 and extracellular signal-regulated kinase 1 and 2 (ERK1/2), had in the EC response.

METHODS

HUVECs were subjected to 2, 4, or 6 hours of LSS or OSS in the presence or absence of 4 U/mL of TH. Western blot analysis of ERK1/2 and p38 activation and polymerase chain reaction analysis of TF in the presence of inhibitors to these second messengers was performed in HUVECs subjected to OSS or LSS in the presence or absence of TH.

RESULTS

TF expression was increased and peaked at 2 hours in all HUVECs exposed to LSS or TH. Stimulation of static HUVECs with TH resulted in an increase in TF expression of 5.68 ± 1.58-, 3.80 ± 1.21-, and 2.54 ± 0.38-fold at 2, 4, and 6 hours, respectively (n = 6 experiments). In the absence of TH, HUVECs exposed to LSS demonstrated a 9.51 ± 0.62-, 7.31 ± 1.43-, and 4.39 ± 1.32-fold increase in TF expression at 2, 4, and 6 hours, respectively (n = 6 experiments). TF was increased significantly more when exposed to LSS in the presence of TH (18.85 ± 1.43-, 15.05 ± 0.95-, and 8.91 ± 1.06-fold increases at 2, 4, and 6 hours, respectively [n = 6 experiments], P < .01). Between-group analysis showed a significant difference between groups (P < .001). OSS did not significantly increase TF expression in the presence or absence of TH. ERK1/2 and p38 activation was increased in LSS and LSS + TH but not in OSS or OSS + TH (n = 3 experiments).

CONCLUSION

LSS and TH independently increased TF expression, but OSS did not. LSS + TH stimulation showed a synergistic effect, which suggests that these mechanical and chemical stimuli work through different pathways or that an intracellular interaction between TH and LSS may be present that does not occur in OSS.

Pulsatile to-fro flow induces greater and sustained expression of tissue factor RNA in HUVEC than unidirectional laminar flow

Tissue factor (TF) is expressed in atherosclerotic lesions. Since mechanical forces influence endothelial cell (EC) function and are thought to account for the unique distribution of atherosclerosis in areas exposed to disturbed flow, we hypothesized that disturbed to-fro flow (TFF) and unidirectional pulsatile forward flow (PFF) would have different effects on TF expression in EC. TF RNA expression in HUVEC exposed to mechanical stress in the presence or absence of chemical stimulation with thrombin was determined. TFF induced a significantly higher TF expression than PFF that was sustained for 8 h. Combination of mechanical and chemical stimuli induced significantly higher TF expression than only mechanical stresses, and this effect was synergistic in both TFF and PFF. The MAPK p38 inhibitor SB-203580 significantly inhibited TF expression induced by mechanical and chemical stimulations, but the MEK inhibitor PD-98059 did not inhibit TF induced by TFF. Immunoblotting revealed that ERK1/2 phosphorylation induced by TFF was sustained for 120 min, whereas that induced by PFF was not. We conclude that disturbed flow induced greater and sustained amplification of TF expression, and this synergistic effect may be regulated by p38 MAPK and ERK1/2. These results provide added insight into the mechanism of atherosclerosis in areas of disturbed flow.

Thrombospondin 1, Fibronectin, and Vitronectin are Differentially Dependent Upon RAS, ERK1/2, and p38 for Induction of Vascular Smooth Muscle Cell Chemotaxis

Background: Thrombospondin 1 (TSP-1), fibronectin (Fn), and vitronectin (Vn) promote vascular smooth muscle cell (VSMC) chemotaxis through a variety of second messenger systems, including Ras, ERK1/2, and p38. Hypothesis: Ras, ERK1/2, and p38 differentially affect TSP-1-, Fn-, and Vn-induced VSMC chemotaxis. Methods: Bovine VSMCs were transfected with Ras N17 or treated with the following inhibitors: a farnesyl protein transferase (FPT) inhibitor, PD098059 (ERK1/2 inhibitor), or SB202190 (p38 inhibitor). Thrombospondin 1, Fn, and Vn were used as chemoattractants. Results were analyzed by analysis of variance (ANOVA) with post hoc testing (P < .05). Results: Ras N17 transfection or FPT inhibitor treatment inhibited TSP-1-, Fn-, and Vn-induced chemotaxis. PD098059 or SB202190 resulted in more inhibition of VSMC migration to TSP-1 than to Fn or Vn. Conclusions: Ras appears equally relevant in the signal transduction pathways of TSP-1-, Fn-, and Vn-induced VSMC chemotaxis. Thrombospondin 1-induced migration is more dependent upon ERK1/2 and p38 than Fn- or Vn-included migration.

The role of interdisciplinary team approach in the management of the diabetic foot: a joint statement from the Society for Vascular Surgery and the American Podiatric Medical Association

The Society for Vascular Surgery (SVS) and the American Podiatric Medical Association (APMA) recognize the beneficial impact of a multidisciplinary team approach on the care of patients with critical limb ischemia, especially in the diabetic population. As a first step in identifying clinical issues and questions important to both memberships, and to work together to find solutions that will benefit the shared patient, the two organizations appointed a representative group to write a joint statement on the importance of multidisciplinary team approach to the care of the diabetic foot.