Catheter-based renal sympathetic nerve denervation on hypertension management outcomes.

BACKGROUND: Renal sympathetic denervation (RSD) provides a minimally invasive interventional treatment modality for patients with resistant hypertension. However, the post-operative outcomes remain a key area of investigation since its earliest clinical trials. AIM: To evaluate patient outcomes after RSD intervention among peer-reviewed patient cases. METHODS: A systematic review of literature on MEDLINE, Google Scholar, and the Cochrane Database of Systematic Reviews for RSD case studies to assess post-operative hypertension readings and medical management. RESULTS: Among 51 RSD cases, the post-operative RSD patients report an apparent reduction with a mean number of 3.1 antihypertensive medications. The mean systolic arterial blood pressure 1 year following RSD was 136.0 mmHg (95%CI: 118.7-153.3). CONCLUSION: The apparent improvements in office systolic blood pressure after 12 month post-operative RSD can support the therapeutic potential of this intervention for blood pressure reduction. Additional studies which utilized a uniform methodology for blood pressure measurement can further support the findings of this systematic review.

Comparison of computed tomography imaging with intraprocedural contrast esophagram: implications for catheter ablation of atrial fibrillation.

BACKGROUND: Computed tomography (CT) has been used to localize the esophagus before radiofrequency ablation (RFA) of atrial fibrillation (AF). OBJECTIVE: The purpose of this study was to compare esophageal imaging by CT versus esophagram. METHODS: CT imaging of the left atrium was performed in 57 patients 1 week before RFA and was imported into the CARTO mapping system. The electrophysiologist created a virtual shell of the left atrium and pulmonary veins (PVs) that was merged with the CT image; however, the CT-defined location of the esophagus was not displayed. The patient was then given 10 mL of oral contrast. Using fluoroscopy, an electroanatomic catheter tagged the esophageal borders outlined by esophagram. The CT-defined esophagus was then imported, and the borders were tagged on the merged map. In this manner, the esophagus borders by esophagram versus those by CT were compared. RESULTS: The maximum diameter of the esophagus by esophagram versus CT was not different (16.3 +/- 3.4 vs. 16.5 +/- 3.1 mm; P = .7). The esophagus was near the left PVs in 34 (62%), center in 13 (24%), and near the right PVs in eight (15%) patients. There was concordance between CT and esophagram in 48 of 55 patients (87%; P = .2). Ye, in 21 (44%) of 48 patients with concordant location, the CT-defined esophageal borders were separated from the esophagram-defined borders by >or=50% of the esophagus diameter. CONCLUSIONS: Reliance on remotely acquired CT images does not ensure adequate intraprocedural localization of the esophagus or enhance recognition of esophageal motility.

Extraction of transvenous pacing and ICD leads.

The emergence of pacing and implantable cardioverter-defibrillator (ICD) systems, along with expanding indications of these devices (e.g., cardiac resynchronization therapy and sudden cardiac death prevention), increasing infection rates, and device recalls have created the need for removing and upgrading these systems due to various reasons. Removing the pulse generator of a system is generally uncomplicated. Chronically implanted transvenous leads, however, adhere to the venous endothelium and endocardial tissues over time due to fibrosis. Removal of such leads can be a significantly complex procedure requiring tools and techniques that free the lead at fibrotic binding sites. In this article, the state-of-the-art tools and techniques that provide a systematic approach to consistently and safely extract these devices will be reviewed.

Positron emission tomography with f18-fluorodeoxyglucose in the staging and preoperative evaluation of malignant pleural mesothelioma.

OBJECTIVES: The purpose of this study was to evaluate the utility of positron emission tomography with F18-fluorodeoxyglucose in the preoperative evaluation and staging of malignant mesothelioma in patients who were candidates for aggressive combined modality therapy. METHODS: Eighteen consecutive patients with biopsy-proven malignant mesothelioma underwent positron emission tomographic scanning. The results of positron emission tomographic imaging were compared with results obtained by computed tomography, mediastinoscopy, thoracoscopy, and pathologic examination of surgical specimens. All patients fasted and received an average of 14.5 +/- 2.7 mCi of F18-fluorodeoxyglucose for positron emission tomographic scanning. Attenuation-corrected whole-body and regional emission images of the chest and upper abdomen were acquired and formatted into transaxial, coronal, and sagittal images. RESULTS: All primary malignant mesotheliomas accumulated F18-fluorodeoxyglucose, and the mean standardized uptake value was 7. 6 (range, 3.33-14.85; n = 9). There were no false-negative results of positron emission tomography. Identification of occult extrathoracic metastases by positron emission tomography was the basis for excluding two patients from surgical therapy. There were two false-positive results of positron emission tomography: increased F18-fluorodeoxyglucose uptake in the contralateral chest that was negative by thoracoscopic biopsy (n = 1) and increased abdominal F18-fluorodeoxyglucose uptake after partial colectomy for diverticular disease (n = 1). CONCLUSIONS: Positron emission tomography can identify malignant pleural mesothelioma and appears to be a useful noninvasive staging modality for patients being considered for aggressive combined modality therapy.

Giant tumors of the chest: preoperative embolization and resection.

Giant tumors of the chest are rare. These tumors comprise a spectrum of disease from benign lesions to highly aggressive malignant tumors with cells of origin in the pleura, pulmonary parenchyma, blood vessels, thymus, and connective tissues. We report four cases of giant tumors of the thorax treated with preoperative arterial embolization followed by complete surgical resection. Their diagnostic and treatment courses, imaging, and pathology are described.

Giant solitary fibrous tumor of the pleura.

Solitary fibrous tumors of the pleura are rare. Approximately 600 cases have been described in the literature. We report a case of a young man with a giant solitary fibrous tumor of the pleura that filled his entire left hemithorax and anterior mediastinum and extended into the right side of his chest. The diagnostic modalities employed, the operation, and the postoperative management resulting in complete resection of the tumor and full lung reexpansion are described.

Physiological studies of whole-body hyperthermia of dogs.

Whole body hyperthermia to 42 degrees C was induced in five normal beagles, using a humidity- and temperature-controlled chamber. Core temperatures of 41.2-43.0 degrees C were achieved in 50 min and maintained for 60 min. Cardiopulmonary responses included marked tachypnea and tachycardia. Blood gases underwent progressive drops in both PO2 (mean, 117 torr) and PCO2 (mean, 22 torr), suggesting the possibility of the development of a diffusion barrier during heating. Increased anion gaps in the face of respiratory alkalosis indicated that a metabolic acidosis developed in the heated dogs. Transient but significant drops in serum potassium and phosphorus were also observed during hyperthermia. Other physiological data, including serum chemistries, complete blood count, colony-forming units, and urine electrolyte excretion, did not change significantly.

Technology advances for continuous compression milling pretreatment of lignocellulosics for enzymatic hydrolysis.

The feasibility of a continuous compression milling pretreatment process for the enzymatic hydrolysis of lignocellulosics has been demonstrated. Pretreatment efficiency was improved significantly by adjustment of feedstock moisture content prior to milling and/or increasing the roll pressure on the feedstock. Optimum moisture contents for newspaper (24%). corn stover (17%), popular (12-20%) were determined. Sugar Yields of 48% were obtained from air-dried newspaper after six passes through even-pressure rolls and the specific energy input was 0.21kW h/lb. The Effect of roll speed on enzymatic hydrolysis improvement was constant over a roll speed range of from 30-110 ft/min (65 rpm). Enzymatic hydrolysis results from commercial-scale pretreatment of moist newspaper processed at 6 tons/h/ correlated well with laboratory mill data while energy consumption was 26% less.

Effect of compression milling on cellulose structure and on enzymatic hydrolysis kinetics.

The changes in the cellulose structure by compression milling were studied and expressed in terms of crystallinity, accessibility, specific surface area, and degree of polymerization. The kinetic parameters, maximum reaction rate, and Michaelis constant were determined experimentally. Based on the experimental results a two-phase model, which is based on the degradation of cellulose by simultaneous actions of the cellulase complex on the crystalline and amorphous phases, is proposed. The relationships between cellulose accessibility and the kinetic parameters were compared with those predicted by the model. A good agreement was found, although the two-phase hypothesis is a simplification of the true state of order in cellulose.

Differential speed two roll mill pretreatment of cellulosic materials for enzymatic hydrolysis.

Differential speed two roll milling is an effective pretreatment for increasing the susceptibility of cellulose to enzymatic hydrolysis. Using mills with three, six, and ten in. diam rolls and processing times of 10 min or less results in the following percent increases in susceptibility over untreated controls: cotton, 1100; maple chips, 1600; white pine chips, 600; newspaper, 125. In comparison, ball milling of newspaper for 24 hr gives only a 62% increase. A further advantage of the roll mill is the increased wet density of the product permitting higher slurry concentrations during hydrolysis. Important parameters of mill effectiveness are roll clearance and processing time