The Semmes Weinstein monofilament examination as a screening tool for diabetic peripheral neuropathy

ObjectiveThe purpose of this systematic review is to evaluate current evidence in the literature on the efficacy of Semmes Weinstein monofilament examination (SWME) in diagnosing diabetic peripheral neuropathy (DPN).MethodsThe PubMed database was searched through August 2008 for articles pertaining to DPN and SWME with no language or publication date restrictions. Studies with original data comparing the diagnostic value of SWME with that of one or more other modalities for DPN in patients with diabetes mellitus were analyzed. Data were extracted by two independent investigators. Diagnostic values were calculated after classifying data by reference test, SWME methodology, and diagnostic threshold.ResultsOf the 764 studies identified, 30 articles were selected, involving 8365 patients. There was great variation in both the reference test and the methodology of SWME. However, current literature suggests that nerve conduction study (NCS) is the gold standard for diagnosing DPN. Four studies were identified which directly compared SWME with NCS and encompassed 1065 patients with, and 52 patients without diabetes mellitus. SWME had a sensitivity ranging from 57% (95% confidence interval [CI], 44% to 68%) to 93% (95% CI, 77% to 99%), specificity ranging from 75% (95% CI, 64% to 84%) to 100% (95% CI, 63% to 100%), positive predictive value (PPV) ranging from 84% (95% CI, 74% to 90%) to 100% (95% CI, 87% to 100%), and negative predictive value (NPV) ranging from 36% (95% CI, 29% to 43%) to 94% (95% CI, 91% to 96%).ConclusionsThere is great variation in the current literature regarding the diagnostic value of SWME as a result of different methodologies. To maximize the diagnostic value of SWME, a three site test involving the plantar aspects of the great toe, the third metatarsal, and the fifth metatarsals should be used. Screening is vital in identifying DPN early, enabling earlier intervention and management to reduce the risk of ulceration and lower extremity amputation

Shear stress-stimulated endothelial cells induce smooth muscle cell chemotaxis via platelet-derived growth factor-BB and interleukin-1α

ObjectiveVascular smooth muscle cell (SMC) migration is critical to the development of atherosclerosis and neointimal hyperplasia. Hemodynamic forces such as shear stress and cyclic strain stimulate endothelial cell signal-transduction pathways, resulting in the secretion of several factors, including SMC chemoattractants such as platelet-derived growth factor (PDGF). We hypothesized that mechanical forces stimulate endothelial cells to secrete SMC chemoattractants to induce migration via the mitogen-activated protein kinase (MAPK) pathway.MethodsBovine aortic endothelial cells were exposed to shear stress, cyclic strain, or static conditions for 16 hours. The resulting conditioned medium was used as a SMC chemoattractant in a Boyden chamber. Activation of SMC extracellular signal-regulated protein kinase 1/2 (ERK1/2) was assessed by Western blot analysis. Pathways were inhibited with anti-PDGF-BB or anti-interleukin-1α (IL-1α) antibodies, or the ERK1/2 upstream pathway inhibitor PD98059.ResultsConditioned medium from endothelial cells exposed to shear stress corresponding to arterial levels of shear stress stimulated SMC migration but lower levels of shear stress or cyclic strain did not. Both PDGF-BB and IL-1α were secreted into the conditioned medium by endothelial cells stimulated with shear stress. Both PDGF-BB and IL-1α stimulated SMC chemotaxis but were not synergistic, and both stimulated SMC ERK1/2 phosphorylation. Inhibition of PDGF-BB or IL-1α inhibited SMC chemotaxis and ERK1/2 phosphorylation.ConclusionShear stress stimulates endothelial cells to secrete several SMC chemoattractants, including PDGF-BB and IL-1α; both PDGF-BB and IL-1α stimulate SMC chemotaxis via the ERK1/2 signal-transduction pathway. These results suggest that the response to vascular injury may have a common pathway amenable to pharmacologic manipulation.Clinical relevanceOne difficulty in the pharmacologic treatment of atherosclerosis or neointimal hyperplasia leading to restenosis is the multiplicity of activated pathways and thus potential treatment targets. This study demonstrates that shear stress, a hemodynamic force that may be a biologically relevant stimulus to induce vascular pathology, stimulates endothelial cells to secrete PDGF-BB and IL-1α. Both of these mediators stimulate the SMC ERK1/2 pathway to induce migration, a critical event in the pathogenesis of atherosclerosis and neointimal hyperplasia. Therefore, this study suggests a relevant common target pathway in SMC that is amenable to manipulation for clinical treatment

Meta-analysis of open versus endovascular repair for ruptured descending thoracic aortic aneurysm

IntroductionRuptured descending thoracic aortic aneurysm (rDTAA) is associated with high mortality rates. Data supporting endovascular thoracic aortic aneurysm repair (TEVAR) to reduce mortality compared with open repair are limited to small series. We investigated published reports for contemporary outcomes of open and endovascular repair of rDTAA.MethodsWe systematically reviewed all studies describing the outcomes of rDTAA treated with open repair or TEVAR since 1995 using MEDLINE, Cochrane Library CENTRAL, and Excerpta Medica Database (EMBASE) databases. Case reports or studies published before 1995 were excluded. All articles were critically appraised for relevance, validity, and availability of data regarding treatment outcomes. All data were systematically pooled, and meta-analyses were performed to investigate 30-day mortality, myocardial infarction, stroke, and paraplegia rates after both types of repair.ResultsOriginal data of 224 patients (70% male) with rDTAA were identified: 143 (64%) were treated with TEVAR and 81 (36%) with open repair. Mean age was 70 ± 5.6 years. The 30-day mortality was 19% for patients treated with TEVAR for rDTAA compared 33% for patients treated with open repair, which was significant (odds ratio [OR], 2.15, P = .016). The 30-day occurrence rates of myocardial infarction (11.1% vs 3.5%; OR, 3.70, P < .05), stroke (10.2% vs 4.1%; OR, 2.67; P = .117), and paraplegia (5.5% vs 3.1%; OR, 1.83; P = .405) were increased after open repair vs TEVAR, but this failed to reach statistical significance for stroke and paraplegia. Five additional patients in the TEVAR group died of aneurysm-related causes after 30 days, during a median follow-up of 17 ± 10 months. Follow-up data after open repair were insufficient. The estimated aneurysm-related survival at 3 years after TEVAR was 70.6%.ConclusionEndovascular repair of rDTAA is associated with a significantly lower 30-day mortality rate compared with open surgical repair. TEVAR was associated with a considerable number of aneurysm-related deaths during follow-up

4. Ruptured Abdominal Aortic Aneurysm

A 70-year-old white male presents to the emergency department with sudden onset of severe back pain. The pain is described as severe and constant without alleviating or aggravating symptoms. He has never had pain like this before. He denies chest pain, shortness of breath, or loss of consciousness. He denies any history of an abdominal aortic aneurysm. His past medical history is significant for hypertension, and chronic obstructive pulmonary disease that requires home oxygen therapy. He had bilateral inguinal herniorrhaphy some years ago, but has never had a laparotomy. His vital signs yielded a pulse at 90 bpm and a blood pressure of 110/60 mm Hg. He is appropriately conversant and appears older than his stated age. He was without abdominal tenderness or masses and no bruits were heard; however, his belly was slightly obese and the examination was difficult. He has bilaterally palpable lower extremity pulses. Question 1 What symptoms are considered the classic presenting triad for ruptured AAA? A. Abdominal/back pain, shortness of breath, and a pulsatile mass. B. Abdominal/back pain, syncope, and a pulsatile mass. C. Abdominal/back pain, nausea, and syncope. D. Abdominal/back pain, chest pain, and hematochezia. The patient remained stable while the emergency department staff obtained laboratory results and cross-matched blood, and performed an electrocardiogram (ECG)