Randomized controlled trial of vacuum therapy for intermittent claudication.

OBJECTIVE: The "gold standard" treatment of intermittent claudication (IC) is supervised exercise therapy (SET). Intermittent vacuum therapy (IVT) has recently been promoted as an additional treatment of IC. During IVT, negative pressure and atmospheric pressure are alternatingly applied to the lower extremities, possibly resulting in improved circulation. The aim of this study was to determine a potential additional effect of IVT in IC patients undergoing a standardized SET program. METHODS: IC patients were recruited from three Dutch general hospitals between December 2015 and July 2017. They received a standardized SET program but were also randomly assigned to an intervention group receiving an IVT treatment (-50 mBar negative pressure) or a control group receiving a sham treatment (-5 mBar negative pressure). IVT was provided in a dedicated clinic during 12 sessions of 30 minutes during a 6-week period. The primary outcome measure was a change in maximal treadmill walking distance. Secondary outcome measures were a change in functional treadmill walking distance, 6-minute walk test, ambulatory ability, and quality of life. RESULTS: A total of 78 patients were randomized, of whom 70 were available for intention-to-treat analysis (control, n = 34; intervention, n = 36). At 6 and 12 weeks, increases in walking distance were of equal magnitude. Median (interquartile range) change in maximal treadmill walking distance during 12 weeks was +335 (205-756) meters in control patients and +250 (77-466) meters in intervention patients (P = .109), whereas functional treadmill walking distance increased +230 (135-480) meters and +188 (83-389) meters (P = .233), respectively. Mean ± standard deviation change in the 6-minute walk test was +36 ± 48 meters and +55 ± 63 meters (P = .823), respectively. Ambulatory ability and quality of life improved equally in both groups. CONCLUSIONS: IVT does not confer any additional beneficial effects in IC patients undergoing a standardized SET program.

Prolonged stance phase during walking in intermittent claudication.

BACKGROUND: Patients with intermittent claudication (IC) tend to walk slower and consume approximately 40% more oxygen during walking compared with healthy individuals. An unfavorable locomotion pattern has been suggested to explain this metabolic inefficiency. However, detailed knowledge of gait parameters in IC is lacking. METHODS: In a cross-sectional study, the gait pattern of newly diagnosed IC patients was compared with that of healthy controls. Spatiotemporal gait parameters such as step length and duration of stance phase were obtained by a photoelectric technique (OptoGait; Microgate, Bolzano, Italy). This system was previously found to have favorable concurrent validity and test-retest reliability characteristics. Parameters were determined during pain-free and painful treadmill walking at a comfortable self-determined walking pace. Each parameter was averaged on the basis of 80 steps. RESULTS: A total of 28 patients and 28 controls were examined. IC patients walked 1.2 km/h (-27%) slower than controls (P < .001), coinciding with a significantly shorter step length (-20%) and lower cadence (-11%). IC patients demonstrated a longer stance and double support phase, even before the onset of ischemic pain. Differences were also observed in segments of the stance phase, as a 14% shorter propulsion (P < .001) and 17% longer flat foot phase (P < .001) during painful walking were found. In considering the absolute duration of these stance phase segments, differences were found only for the flat foot time (Δ0.10 second; P < .001). CONCLUSIONS: Patients with IC demonstrate an altered gait pattern compared with healthy controls. The most prominent differences were a prolonged relative and absolute duration of the flat foot position during the stance phase. This adaptation may be intuitive as an augmented arterial blood flow into skeletal muscles is allowed during a prolonged relaxation phase. Therefore, not only the lack of propulsion but also a gain of relaxation may explain these gait alterations.

[Loeys-Dietz syndrome: aortic dissections and aneurysms]. / Loeys-Dietz-syndroom: aortadissecties en aneurysmata.

BACKGROUND: Loeys-Dietz syndrome is a connective tissue disorder accompanied by life-threatening vascular abnormalities such as aneurysms and dissections. Recognising the acute clinical picture is essential for rapid diagnosis and treatment. CASE DESCRIPTION: We describe three members of a family with a typical acute presentation of Loeys-Dietz syndrome, but without the characteristic physical abnormalities. A 40-year-old man presented with a type B aortic dissection and was treated with medication. Shortly afterwards he required emergency surgery for a ruptured aneurysm of the left common iliac artery. He subsequently developed a type A aortic dissection and progressive dilatation of his thoraco-abdominal aorta, for which surgical repair was performed. His sister and brother also presented with type B aortic dissections and both underwent surgery for thoraco-abdominal aortic aneurysms. They died at the age of 50 and 53 respectively. Clinical genetic investigation revealed a mutation of the type 2 receptor of the transforming growth factor beta (TGFß) gene. CONCLUSION: Loeys-Dietz syndrome is a rare hereditary condition accompanied by acute clinical symptoms. Physical characteristics of the syndrome may be absent. Timely recognition is essential for appropriate treatment and a good prognosis.

Median nerve neuropraxia by a large false brachial artery aneurysm.

Peripheral nerve compression is a rare complication of an iatrogenic false brachial artery aneurysm. We present a 72-year-old patient with median nerve compression due to a false brachial artery aneurysm after removal of an arterial catheter. Surgical exclusion of the false aneurysm was performed in order to release traction of the median nerve. At 3-month assessment, moderate hand recovery in function and sensibility was noted. In the case of neuropraxia of the upper extremity, following a history of hospital stay and arterial lining or catheterization, compression due to pseudoaneurysm should be considered a probable cause directly at presentation. Early recognition and treatment is essential to avoid permanent neurological deficit.

Preliminary intraobserver and interobserver variability in wall stress and rupture risk assessment of abdominal aortic aneurysms using a semiautomatic finite element model.

OBJECTIVE: We investigated the intraobserver and interobserver variability of using semiautomatic finite element analysis to calculate the von Mises stress and peak wall rupture risk (PWRR) in patients with an abdominal aortic aneurysm (AAA) in longitudinal studies. METHODS: Four independent observers made 3-dimensional (3D) reconstructions, with minimal manual adjustments, of small AAAs (<5.0 cm) in 17 patients and processed finite element analysis. We used semiautomatic diagnostic software with a finite element model (A4research, VASCOPS GmbH, Graz, Austria). The finite element method was used to calculate von Mises stress and PWRR, which are indicators for wall stress. The differences of each pair of measurements of von Mises stress and PWRR were plotted against their mean and the difference of the mean, according to Bland-Altman analysis. RESULTS: The intraobserver variability had an overall mean percentage difference of 6.86% ± 6.46% for the von Mises stress and 7.70% ± 6.26% for PWRR. The interobserver variability for the four observers showed an overall mean percentage difference of 7.09% ± 6.16% for the von Mises stress and 9.47% ± 8.18% for the PWRR measurement. No significant differences were found (P < .05), for the von Mises stress and PWRR for all observers. CONCLUSIONS: The von Mises stress and PWRR of small AAAs calculated in this semiautomatic finite element analysis program show good interobserver and intraobserver variability. It is suitable for clinical use to evaluate mechanical aortic wall characteristics and to compare it with other current methods such as maximum aortic diameter measurements.