Intravascular sonotherapy for treatment of in-stent restenosis

Intravascular sonotherapy has been introduced as a potential alternative to brachytherapy for prophylactic and therapeutic application in patients after coronary stent placement. Sonotherapy represents a non-ablative, non-thermal form of therapeutic ultrasound. The ultrasound catheter with diameter between 4 and 5 French carries up to 6 electronic elements operating currently at a frequency of 1.0 to 1.4 MHz. Animal studies have proven the efficacy of intravascular sonotherapy with respect to a reduction of neointimal ingrowth after stent placement. A first multicenter observational study in humans has documented that its application is safe and yields favorable results after coronary stenting, also in complex patient and lesion characteristics. This technique is currently under investigation in large prospective, multicenter, randomized studies performed in patients with de novo stenting or documented in-stent restenosis.     

No association between high-altitude tolerance and the ACE I/D gene polymorphism

PURPOSE: The absence (deletion allele [D]) of a 287 base-pair fragment in the ACE gene is associated with higher ACE tissue activity than its presence (insertion allele [I]) and, as such, may enhance vasoconstriction and fluid retention through increased levels of angiotensin II and aldosterone. Because fluid retention is found in acute mountain sickness (AMS) and exaggerated pulmonary hypertension is essential in the pathophysiology of high-altitude pulmonary edema (HAPE), we hypothesized that the DD genotype is associated with increased susceptibility to these illnesses. METHODS: ACE genotype was thus determined in 83 mountaineers staying over night at 4559 m and related to AMS symptoms. Genotype was similarly determined in 76 mountaineers who had participated in previous studies at 4559 m; 38 of the latter group had a history of HAPE, and 25 had developed HAPE again during these studies. RESULTS: The allele frequency was in Hardy-Weinberg equilibrium in both investigations. Neither the history nor the observed episodes of HAPE nor the prevalence of AMS defined as an AMS-C score >/= 0.70 (environmental symptom questionnaire) in the first study or in both studies taken together were significantly different between the genotypes DD, ID, and II. CONCLUSION: We conclude that I/D-ACE gene polymorphism has no important effect on susceptibility to AMS or HAPE.     

Physical performance responses during 72 h of military operational stress

PURPOSE: To characterize the impact of prolonged work, underfeeding, and sleep deprivation (i.e., sustained operations; SUSOPS) on physical and occupational related performance during military operational stress. METHODS: Ten male soldiers were tested on days 1 (D1), 3 (D3), and 4 (D4) of a control and an experimental week that included prolonged physical work (total daily energy expenditure approximately 4,500 kcal x d(-1)), underfeeding (approximately 1,600 kcal x d(-1)), and sleep deprivation (approximately 2 h x d(-1)). Body composition was measured with dual-energy x-ray absorptiometry (DEXA). Ballistic power was assessed by 30 repetitive squat jumps and bench-press throws. Military-relevant occupational performance was evaluated with a 10-min box lift, obstacle course, grenade throw, rifle marksmanship, and a 25-min wall-build task. RESULTS: Fat-free mass (-2.3%) and fat mass (-7.3%) declined (P 相似文献   

Traumatic injuries: role of imaging in the management of the polytrauma victim (conservative expectation)

Abdominal US and CT play an important role in the initial management of blunt trauma in adults. Ultrasound is an excellent method for detection of free intra-abdominal fluid. It is the modality of choice for initial screening and enables selection of hemodynamically unstable trauma victims with severe hemoperitoneum for immediate surgery. However, even in experienced hands, US is not sufficient to rule out organ injuries reliably. Computed tomography, and particularly multislice CT (MSCT), has several major advantages over US and is currently unsurpassed for the detection of blunt visceral injuries in the abdomen. Computed tomography has a high sensitivity for the detection of parenchymal splenic and hepatic injuries. Injuries of the gastrointestinal tract may be detected with good sensitivity provided that adequate examination technique and careful diagnostic interpretation are combined. The value of CT-based injury-grading systems for predicting the outcome of conservative treatment remains unproven; however, demonstration of direct vascular injuries with CT, e.g., the intrasplenic "contrast blush" sign, may indicate a high likelihood that conservative treatment will fail, thus warranting angiographic embolization or surgery. Monitoring of conservatively treated trauma victims by means of repeat CT studies enables early detection of a variety of delayed, clinically silent complications of trauma, e.g., posttraumatic biloma or bowel devascularization. Catheter angiography may be reserved to selected cases with vascular injuries proven on CT.     

Aneurysmal re-rupture during selective cerebral angiography

Two cases of aneurysmal re-rupture during intracranial angiography are presented. This event is accompanied by disastrous consequences with regard to the clinical condition of the patient, as is evident from the cases presented as well as from the literature. Acute alterations of intraluminal pressure as well as a time interval of less than 6 h seems to increase the risk of re-bleeding during angiography. The introduction of and the growing experience with CT and MR angiography may in the near future provide sufficient diagnostic information for surgical planning and thus help to overcome the risk of aneurysmal re-rupture during intra-arterial angiography.     

Peripheral arterial balloon angioplasty: effect of short versus long balloon inflation times on the morphologic results

PURPOSE: To evaluate the effect of different balloon inflation times on angiographic results in peripheral angioplasty. MATERIALS AND METHODS: Seventy-four infrainguinal arteriosclerotic lesions were randomized prospectively to undergo balloon dilation for 30 seconds (group I) or 180 seconds (group II). Each group consisted of 37 patients. Postinterventional angiograms were evaluated by two blinded readers. Dissections were graded as follows: 1 = no dissection; 2 = minor flap; 3 = extensive dissection membrane, not flow limiting; or 4 = flow-limiting flap. The rate of major-grade dissections (grades 3 and 4), residual stenosis (>30%), and further interventions were compared with the two-tailed chi(2) test. RESULTS: In group I, major dissections were noted in 16 patients (43%) compared with five patients (14%) in group II (P =.009). Residual stenoses were found in 12 patients (32%) in group I compared with five patients (14%) in group II (P =.096). The rate of additional interventions was significantly higher in group I than in group II (20 of 37 vs nine of 37; P =.017). CONCLUSION: A prolonged inflation time of 180 seconds improves the immediate angioplasty result of infrainguinal lesions compared to a short dilation strategy. Significantly fewer major dissections and a modest reduction of residual stenoses are observed. The requirement of costly and time-consuming further interventions is significantly reduced.     

Two Fatal Complications after Parallel Tracheal-Esophageal Stenting

Two patients with malignant obstructions of both the trachea and esophagus underwent parallel stent placement with Gianturco-R?sch Z (GRZ) stents for palliation of symptoms. Fatal hemorrhage occurred in both patients 2 and 3 weeks after stent placement respectively. An autopsy performed on one of these patients demonstrated esophageal tissue necrosis and erosion with perforation of both the tracheal and esophageal walls at sites where the stent struts were in direct opposition, leading to bleeding from the esophageal venous plexus. GRZ stents have been successful in the treatment of both solitary tracheal and esophageal stenoses. However, parallel tracheal-esophageal stenting with GRZ stents places patients at high risk for complications due to the high radial force exerted by this particular stent and the minimal amount of intervening tissue between the two structures.     

Tetrofosmin imaging in the detection of myocardial viability in patients with previous myocardial infarction: comparison with sestamibi and tl-201 scintigraphy

BACKGROUND: Technetium 99m tetrofosmin has been introduced as a myocardial perfusion agent, providing similar results to those of thallium 201 and sestamibi in the identification of patients with coronary artery disease. No data are available comparing tetrofosmin and sestamibi imaging in the identification of reversible left ventricular (LV) dysfunction in the same patients. This study compared the results of tetrofosmin, thallium, and sestamibi single photon emission computed tomography at rest in detection of myocardial viability in patients with previous myocardial infarction. METHODS AND RESULTS: Seventeen patients with previous myocardial infarction who were undergoing coronary revascularization were studied. Echocardiography was performed at baseline and 3 months after revascularization to evaluate recovery of LV function. The optimal threshold cutoffs to separate reversible from irreversible dysfunction, as determined by receiver operating characteristic analysis, were 55% of peak activity for both tetrofosmin and sestamibi and 60% for thallium. In all asynergic segments (n = 77) analyzed, tetrofosmin uptake correlated with both sestamibi (r = 0.90, P <.0001) and thallium (r = 0.85, P <.0001) activity. The sensitivity and specificity for reversible dysfunction were, respectively, 70% and 70% for tetrofosmin, 70% and 66% for sestamibi, and 60% and 68% for thallium imaging (all P = not significant). The areas under the receiver operating characteristic curves constructed for tetrofosmin, thallium, and sestamibi activity were 0.74 +/- 0.06 (mean +/- SD), 0.75 +/- 0.06, and 0.74 +/- 0.06, respectively (all P = not significant). Concordance for detecting myocardial viability between tetrofosmin and thallium imaging was found in 67 regions (87%) (kappa = 0.74), and concordance between tetrofosmin and sestamibi imaging was found in 69 regions (90%) (kappa = 0.79). CONCLUSIONS: The diagnostic performance of quantitative rest tetrofosmin single photon emission computed tomography in predicting functional recovery after revascularization is comparable to that of both thallium and sestamibi scintigraphy in patients with myocardial infarction and chronic LV dysfunction.