Threatening Inferior Limb Ischemia: When to Consider Fasciotomy and What Principles to Apply?

Inferior limb compartmental syndrome (CS) gathers a constellation of symptoms that traditionally refers to pathologically increased intramuscular and surrounding tissue pressure generally contained in nonexpansile leg spaces. It associates oftentimes reperfusion or traumatic injury. Intrinsic rigidity of these leg and foot closed compartments may enhance critical pressure risings with deleterious effects on specific vascular and nervous supply, with two main presentations: acute versus chronic display. For these situations, early fasciotomy plays the major role of releasing specific compartment hypertension and prevents deleterious tissue necrosis. Intervention is effective only if required upon precise indications (measured tissue pressure within 20 to 30 mm Hg of systemic diastolic pressure) and performed correctly in a timely fashioned approach. Any failure or delay in recognizing CS inevitably leads to adverse outcomes and jeopardy for secondary limb loss. When judiciously applied during or soon after limb-salvage revascularization technically successful fasciotomy may represent a major contributor in limb preservation. It accounts for a well-defined therapeutic proceeding available for any conscientious and well-briefed interventionist.

Vascular Tissue Engineering: Recent Advances in Small Diameter Blood Vessel Regeneration

Cardiovascular diseases are the leading cause of mortality around the globe. The development of a functional and appropriate substitute for small diameter blood vessel replacement is still a challenge to overcome the main drawbacks of autografts and the inadequate performances of synthetic prostheses made of polyethylene terephthalate (PET, Dacron) and expanded polytetrafluoroethylene (ePTFE, Goretex). Therefore, vascular tissue engineering has become a promising approach for small diameter blood vessel regeneration as demonstrated by the increasing interest dedicated to this field. This review is focused on the most relevant and recent studies concerning vascular tissue engineering for small diameter blood vessel applications. Specifically, the present work reviews research on the development of tissue-engineered vascular grafts made of decellularized matrices and natural and/or biodegradable synthetic polymers and their realization without scaffold.

Postoperative Tachyarrhythmias: On-Pump versus Off-Pump Coronary Artery Bypass Grafting

Objective. Tachyarrhythmias, after coronary artery bypass graft (CABG) surgery, develop in 11%–40% of patients. Surgery technique (on-pump or off-pump) might affect incidence of post-CABG tachyarrhythmias. Methods. The study included 60 patients undergoing CABG (≥2 grafts) with left ventricle ejection fraction (LV EF) >40%. Patients were divided into two groups equally: group A (on-pump) and group B (off-pump). Patients were subjected to electrocardiographic monitoring (7 days postoperatively), transthoracic echocardiography, with recording of surgical details and complications. Results. Data collected between December 2012 and May 2013 showed no significant difference between two groups regarding incidence of postoperative tachyarrhythmias with statistically significant higher incidence of supraventricular tachycardia in group B (P<0.05) and a trend towards higher incidence of atrial fibrillation in group A. Patients who developed postoperative tachyarrhythmias in group A showed higher prevalence of family history of coronary artery disease and higher incidence of postoperative chest infections (P<0.05), while those in group B showed higher mean LV EF (pre- and postoperatively) (P<0.05). Data were statistically described in terms of mean ± standard deviation. Comparison of numerical and categorical variables was done using Student’s t- and Chi-square tests, respectively. Conclusion. Adopting off-pump CABG technique is not associated with less incidence of post-operative tachyarrhythmias, as compared to on-pump technique.

Lipid Lowering Therapy with Combination of Niacin and Statin in Women: Age-Related Endothelial Effects

Background. Many women remain at risk for cardiac events despite treatment to reduce low-density lipoprotein cholesterol (LDL-C). We hypothesized that for postmenopausal women treated with niacin in addition to statin vascular function will improve. Methods. We conducted a randomized, double-blind, placebo-controlled trial of 16 weeks of niacin (N) versus placebo (PL) in 43 women (mean age, 67±9 years) previously on statin therapy. Study outcomes included lipoprotein levels, vascular inflammation assessed by high sensitivity C-reactive protein (hsCRP), interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), and endothelial function, assessed as brachial artery flow mediated dilation (FMD). Results. The N group significantly increased HDL-C and decreased LDL-C cholesterol relative to PL (both P<0.01). FMD improved in both groups (P=0.02) irrespective of niacin (P=0.21). Age influenced change in FMD (P=0.01) such that improved FMD (before to after) with lipid lowering therapy was greater with older age (P=0.03 Pearson correlation = 0.34), independent of treatment group. Conclusions. Lipid lowering therapy with combination of niacin and statin does not improve inflammation or endothelial function compared to statin alone. However, older women demonstrate relatively greater endothelial benefit of lipid lowering therapy over 4 months. This trial is registered with Clinicaltrials.gov NCT00590629.

Tumour Thrombi in the Suprahepatic Inferior Vena Cava: The Cardiothoracic Surgeons’ View

Background. Retroperitoneal tumours propagate intrathoracic caval tumour thrombi (ICTT) of which we consider two subgroups: ICTT-III (extracardiac) and ICTT-IV (intracardiac). Methods. Case series review. Results. 29 series with 784 patients, 453 with extracardiac and 331 with intracardiac ICTT. Average age was 59 years. 98% of the tumours were RCC, 1% adrenal and Wilms’ tumours, and 1% transitional cell carcinomas. The prevalent incision was rooftop with or without sternotomy. Mortality was 10% (5% for ICTT-III, 15% for ICTT-IV). Morbidity was 56% (36% for ICTT-III, 64% for ICTT-IV) and reoperation for bleeding was the commonest complication (14%). Mean Blood loss was 2.6 litres for ICTT-III and 3.7 litres for ICTT-IV. Mean blood product use was 2.4 litres for ICTT-III and 3.5 litres for ICTT-IV. Operative and anaesthetic times exceeded 5 hours. Hospital stay averaged 13 days. Variations in perioperative care included preoperative embolisation, perioperative transoesophageal echo, surgical incisions, and extracorporeal circulation. Brief Summary. Surgery for ICTT has high transfusion, operating/anaesthetic time, and in-hospital stay requirements, and intracardiac ICTT also attract higher risk. Preoperative tumour embolisation is controversial. The cardiothoracic team offers proactive optimisation of blood loss and preemptive management of intracardiac thrombus impaction: we should always be involved in the management the ICTT.

Repeatability of Peripheral Artery Tonometry in Female Subjects

Background. Peripheral arterial tonometry (PAT) is a novel, non-invasive and operator-independent method for simultaneous assessment of endothelial function and arterial stiffness. We examined the repeatability of PAT in females and the influence of the estrous cycle. Methods. In 14 healthy female and five healthy male control subjects, PAT was performed on three separate occasions with 10 days between visits. Reactive hyperemia index (RHI), a measure of endothelial function, and peripheral augmentation index (AIx), a measure of arterial stiffness, were determined with the EndoPAT-2000 system. Intraclass correlation coefficient (ICC) was calculated as a measure of repeatability. Results. In both female and male groups, RHI and AIx did not differ between the three measurements (all n.s. by 1-way ANOVA). In females, reanalyzing the data after taking phase of estrous cycle into account had no effect on the results. Repeatability for RHI and AIx in females (ICC for RHI = 0.43, ICC for AIx = 0.78) was similar to that in male subjects (ICC for RHI = 0.42, ICC for AIx = 0.63). Conclusions. PAT measurements were not affected by the estrous cycle in females, and repeatability was comparable to that in males. This should facilitate inclusion of female subjects into vascular function studies using PAT.

The Use of Computed Tomography of Pulmonary Angiogram in a District Hospital

Background. Computed tomography of pulmonary angiogram (CTPA) is a widely used investigation in patients with suspected pulmonary embolism (PE). It is not without adverse effects either through contrast injection or radiation exposure. International guidelines suggest that patients with a low/intermediate clinical probability and negative D-dimer do not require CTPA to exclude PE. Method. A retrospective audit of 100 consecutive CTPA scans was performed at a district general hospital from January to May 2012 to assess adherence to the current guidelines for diagnosis of acute PE and utilisation of CTPA. Result. Of the total 88 CTPA scans that were included in the study, 14% were positive for PE. At least 6%, potentially up to 30% of all the scans, could have been avoided by adherence to current guidelines, thereby improving the positive yield to as high as 19%. Clinical probability scores were documented in only 3%. Orthopaedics requested 3% of all scans and the Assessment Treatment and Rehabilitation (ATR) unit had the highest number of CTPA requests per 100 departmental inpatient admissions. Conclusion. Adherence to the current guidelines can reduce the number of CTPA scans required and may reduce cost, contrast exposure, and radiation burden.

Targeted Drug Delivery to Endothelial Adhesion Molecules

Endothelial cells represent important targets for therapeutic and diagnostic interventions in many cardiovascular, pulmonary, neurological, inflammatory, and metabolic diseases. Targeted delivery of drugs (especially potent and labile biotherapeutics that require specific subcellular addressing) and imaging probes to endothelium holds promise to improve management of these maladies. In order to achieve this goal, drug cargoes or their carriers including liposomes and polymeric nanoparticles are chemically conjugated or fused using recombinant techniques with affinity ligands of endothelial surface molecules. Cell adhesion molecules, constitutively expressed on the endothelial surface and exposed on the surface of pathologically altered endothelium—selectins, VCAM-1, PECAM-1, and ICAM-1—represent good determinants for such a delivery. In particular, PECAM-1 and ICAM-1 meet criteria of accessibility, safety, and relevance to the (patho)physiological context of treatment of inflammation, ischemia, and thrombosis and offer a unique combination of targeting options including surface anchoring as well as intra- and transcellular targeting, modulated by parameters of the design of drug delivery system and local biological factors including flow and endothelial phenotype. This review includes analysis of these factors and examples of targeting selected classes of therapeutics showing promising results in animal studies, supporting translational potential of these interventions.

Suppression of Receptor for Advanced Glycation End Products Improves Angiogenic Responses to Ischemia in Diabetic Mouse Hindlimb Ischemia Model

Background. The role of the receptor for advanced glycation end products (RAGE) for the impaired angiogenic response in diabetic patients is not well known. We investigated the impact of RAGE suppression by soluble RAGE (sRAGE) on the angiogenic response in a diabetic hindlimb ischemia mouse model. Materials and Methods. Hindlimb ischemia model was prepared by ligation of femoral artery in diabetic and nondiabetic mice. Ischemia-induced angiogenic response was evaluated by laser-Doppler perfusion imaging, muscle capillary density, and protein expression of vascular endothelial growth factor (VEGF) and high-mobility group box (HMGB)-1. Results. Diabetic mice showed attenuated recovery of ischemic limb perfusion on laser-Doppler perfusion imaging compared with nondiabetic mice. The treatment with sRAGE significantly improved blood flow in the ischemic limbs of diabetic mice. The expression levels of VEGF and HMGB-1 in the limb muscle tissues of diabetic mice were lower than in those of nondiabetic mice. The treatment with sRAGE significantly increased the VEGF and HMGB-1 protein expression in the ischemic limb muscle tissues in the diabetic mice. Conclusion. The suppression of RAGE by sRAGE administration improved angiogenic response to ischemia in diabetic mice and was associated with increased HMGB-1 and VEGF levels in muscle tissues.

Bronchial and Nonbronchial Systemic Artery Embolization in Management of Hemoptysis: Experience with 348 Patients

Background. We aimed to report our experience with bronchial artery embolization (BAE) in the management of moderate recurrent and/or life-threatening hemoptysis. Methods. We evaluated the demographics, clinical presentation, radiographic studies, short- and long-term efficacy, and complications in patients Who underwent BAE, at a tertiary university hospital, from 2003 to 2012. Results. Three hundred forty-one patients underwent BAE for the management of moderate recurrent or life-threatening hemoptysis. Pulmonary TB and bronchiectasis were the most common etiologies for hemoptysis in our locality. The most common angiographic signs for hemoptysis were hypervascularity and systemic-pulmonary artery shunt. BAE was successful in controlling hemoptysis immediately in 95% of patients and at 1 month in 90% of patients. Recurrence of hemoptysis was observed in 9.6% of patients, and reembolization was indicated in 85% of those cases. Complications of BAE were self-limited acute and subacute complications, while chronic complications were not recorded during this study. Conclusions. TB and bronchiectasis are the commonest etiologies for moderate recurrent or life-threatening hemoptysis in our locality. Hypervascular lesions from the bronchial arteries and nonbronchial systemic arteries represented the major vascular abnormalities. Bronchial and nonbronchial systemic artery embolizations were effective to control both acute and chronic hemoptyses, with no serious complications.