Edge-to-edge mitral repair: tension on the approximating suture and leaflet deformation during acute ischemic mitral regurgitation in the ovine heart.
(65/1172)
BACKGROUND: Edge-to-edge approximation of the mitral valve leaflets (Alfieri procedure) is a novel surgical treatment for patients with ischemic mitral regurgitation (IMR). Long-term durability may be limited if abnormal mitral leaflet stresses result from this procedure. The aim of the current study was to measure Alfieri stitch tension (F(A)) and to explore its geometric determinants in an ovine model of acute IMR as a reflection of the mitral leaflet stresses imposed by the procedure. METHODS AND RESULTS: Eight sheep were studied immediately after surgical placement of (1) a force transducer interposed between sutures approximating the central leaflet edges and (2) radiopaque markers around the mitral annulus and leaflet edges. Computer-aided analysis of videofluorograms was used to obtained 3D marker coordinates. Simultaneous measurements of F(A), septal-lateral annular dimension (L(S-L)), leaflet edge separation (L(SEP)), anterior (L(AL)) and posterior (L(PL)) leaflet length, and hemodynamic variables were obtained at baseline (CTL) and during acute IMR (circumflex artery occlusion). F(A) was significantly elevated throughout the cardiac cycle during IMR compared with CTL, with maximum F(A) in diastole (0.26+/-0.05 versus 0.46+/-0.08 N, CTL versus IMR; P<0.05). Multivariable analysis revealed L(S-L) as the single independent predictor of maximum F(A) (P<0.001). Positive linear correlations were shown between values of F(A) and L(AL) and L(PL) (dependent variables). CONCLUSIONS: These experimental data demonstrate higher F(A) during IMR and cyclic changes in F(A) closely paralleling changes in L(S-L), eg, being greatest in diastole when the annulus is largest. Increased F(A) during IMR is probably indicative of successful therapeutic intent, but higher diastolic leaflet stresses resulting from persistent or progressive mitral annular dilatation may adversely affect repair durability. This indirectly implies that concomitant mitral ring annuloplasty should be added to the Alfieri repair. (+info)
Electrophysiologic characteristics of paroxysmal and chronic atrial fibrillation in human right atrium.
(66/1172)
OBJECTIVES: The aim of the study was to analyze the electrophysiologic characteristics of paroxysmal (PAF) and chronic (CAF) atrial fibrillation (AF) in the human right atrium (RA). BACKGROUND: Differences that exist between PAF and CAF and the mechanisms of self-sustenance of these arrhythmias are incompletely understood. METHODS: A total of 53 patients with PAF (25 patients, mean age 59 +/- 6.1 years, 3 women) and CAF (28 patients, mean age 59 +/- 13 years, 7 women) underwent multisite mapping of the RA during ongoing AF using a 64-electrode basket catheter. Quantitative evaluation and three-dimensional activation patterns were performed using a computerized system. RESULTS: Patients with PAF, as compared with patients with CAF, had significantly longer AF cycle length, shorter time intervals with type III AF throughout the RA and a smaller number of endocardial breakthroughs (mean 51 +/- 19 vs. 104 +/- 40, p < 0.001). The majority of endocardial breakthrough points (88% in PAF patients and 98% in CAF patients) were located in the septal region and coincided anatomically with major interatrial connection routes. Coexistence of re-entrant and apparently focal activation determined maintenance of AF in the RA in PAF, whereas random re-entry was documented more frequently in patients with CAF. In patients with CAF, the duration of arrhythmia (in years) correlated strongly with the percentage of time during which type III AF was observed in the lateral wall of the RA (r = 0.71). CONCLUSIONS: Clinical PAF and CAF, as recorded in the RA, have, at least quantitatively, distinct electrophysiologic features and different mechanisms of maintenance. (+info)
Videourodynamic and sphincter motor unit potential analyses in Parkinson's disease and multiple system atrophy.
(67/1172)
OBJECTIVES: Urinary dysfunction is a prominent autonomic feature in Parkinson's disease (PD) and multiple system atrophy (MSA), which is not only troublesome but also a cause of morbidity in these disorders. Recent advances in investigative uroneurology offer a better insight into the underlying pathophysiology and appropriate management for urinary dysfunction. METHODS: twenty one patients with PD (15 men, six women, mean age 64 (49-76), mean disease duration 4 years (1-8 years), median Hoehn and Yahr grade 3 (1-4), all taking 300 mg/day of levodopa (100-500 mg)) and 15 with MSA (eight men, seven women, mean age 59 (48-72), mean disease duration 3 years (0.5-6 years)) were recruited. Videourodynamic and sphincter motor unit potential analyses in the patients with PD and MSA were carried out, looking for distinguishing hallmarks that might be useful in the differential diagnosis of these two diseases. RESULTS: Urinary symptoms were found in 72% of patients with PD and in 100% with MSA. Filling phase abnormalities in the videourodynamic study included detrusor hyperreflexia in 81% of patients with PD and 56% with MSA, and uninhibited external sphincter relaxation in 33% of patients with PD and 33% of those with MSA. However, open bladder neck at the start of filling was not seen in patients with PD but was present in 53% of those with MSA, suggestive of internal sphincter denervation. Sphincter motor unit potential analysis showed neurogenic motor unit potentials in 5% of patients with PD and in 93% of those with MSA, suggestive of external sphincter denervation. On voiding, detrusor-external sphincter dyssynergia was not seen in patients with PD but was present in 47% of those with MSA. Pressure-flow analysis showed that the Abrams-Griffiths number, a grading of urethral obstruction (outflow obstruction >40), in PD (40 in women and 43 in men) was larger than that in MSA (12 in women and 28 in men). Weak detrusor in PD (66% of women and 40% of men) was less common than that in MSA (71% of women and 63% of men). Postmicturition residuals >100 ml were absent in patients with PD but were present in 47% of patients with MSA. CONCLUSION: Patients with PD had less severe urinary dysfunction with little evidence of internal or external sphincter denervation, by contrast with the common findings in MSA. The findings of postmicturition residuals >100 ml, detrusor-external sphincter dyssynergia, open bladder neck at the start of bladder filling, and neurogenic sphincter motor unit potentials are highly suggestive of MSA. (+info)
Observation of the swallowing process by application of videofluoroscopy and real-time magnetic resonance imaging-consequences for retronasal aroma stimulation.
(68/1172)
The process of eating and drinking was observed in vivo by application of videofluoroscopy, a dynamic X-ray technique, as well as real-time magnetic resonance imaging. The study was aimed at elucidating the timing and performance of the physiological organs involved in mastication and swallowing, mainly the tongue, the pharynx and the soft palate (velum palatinum). It was shown for the first time that effective physiological barriers do exist during food consumption that are capable of retaining volatiles such as helium within the oral cavity. These barriers allow the access of odorants to the nasal cavity only at certain times during the eating process. Their effectiveness is related to the texture of the food as well as the amount of food material present in the oral cavity and, thereby, directly influences retronasal aroma perception. (+info)
Endovascular repair of aortic rupture due to trauma and aneurysm.
(69/1172)
OBJECTIVES: to report a single centre experience with endovascular repair of the ruptured descending thoracic and abdominal aorta. DESIGN: prospective non-randomised study in a university hospital. MATERIAL AND METHODS: between 1995 and 2000, endovascular treatment was utilised for 231 aortic repairs; in 37 cases (16%) endografting was conducted on an emergency basis for 21 ruptured infrarenal aortic aneurysms, 15 ruptured descending thoracic aortic lesions, and 1 ruptured thoracoabdominal aortic aneurysm. The feasibility of endovascular treatment and the prostheses' size were determined, based on preoperative spiral CT and intraoperative angiography, both obtained in each patient. RESULTS: endografting was successfully completed in 35 patients (95%). Primary conversion to open repair was necessary in 2 patients (5%). Postoperative 30-day mortality rate was 11% (4 deaths). No patient developed postoperative temporary or permanent paraplegia. In 2 patients (5%) primary endoleaks required overstenting and in 6 patients (16%) secondary surgical interventions were required. Mean follow-up was 19 months (1-70 months); three deaths occurred within three months postoperatively (1-year survival rate 81+/-6%). In one case, secondary conversion to open repair was necessary 14 months postoperatively. CONCLUSION: the feasibility of endoluminal repair of the ruptured aorta has been demonstrated. Endoluminal treatment may reduce morbidity and mortality, and may in time become the procedure of choice in certain centres. However, further follow-up is required to determine the long-term efficacy. (+info)
Decompression of multiple pneumatoceles in a premature infant by percutaneous catheter placement.
(70/1172)
Pneumatoceles due to acquired localized overinflation as a form of pulmonary interstitial emphysema are complications of advanced bronchopulmonary dysplasia. Different ventilation modes, selective bronchial intubation, balloon obstruction of the affected bronchus and steroids have been reported with success. Lobectomy has also been used. We present a premature infant with multiple large pneumatoceles causing respiratory compromise. In our case percutaneous decompression under fluoroscopy guidance resulted in a permanent cure. (+info)
Medical devices; exemptions from premarket notification; class II devices. Final rule.
(71/1172)
The Food and Drug Administration (FDA) is publishing a final rule exempting from the premarket notification requirements the fluoroscopic compression device, a manual compression device that allows a radiologist to press on the abdomen during a fluoroscopic procedure without exposing his or her hand to the x-ray beam. The device is classified as an accessory to the image-intensified fluoroscopic x-ray system. FDA received a petition requesting an exemption for the F-Spoon device, a type of fluoroscopic manual compression device. FDA is expanding the exemption for this type of generic device to include other fluoroscopic compression devices. FDA is publishing this order in accordance with the Food and Drug Administration Modernization Act of 1997 (FDAMA). (+info)
Long term safety of fluoroscopically guided selective salpingography and tubal catheterization.
(72/1172)
BACKGROUND: The irradiation of the ovaries of reproductive age women during fluoroscopically guided selective salpingography and tubal catheterization has raised concern about the safety of the procedure. In addition to the risk of cancer induction, which exists with the irradiation of all tissues, with the gonads, the induction of hereditary disorders is possible. The objective of this study was to estimate these risks and present them in a clinically meaningful way. METHODS: Retrospective analysis was undertaken of 366 consecutive cases of selective salpingography and tubal catheterization performed at the Birmingham Women's Hospital, UK. The radiation doses of different types of procedure were compared with the background annual radiation dose. The risks of cancer and genetic disorders induction were calculated using conversion coefficients published by the International Commission on Radiological Protection. RESULTS: The radiation dose women were exposed to during selective salpingography and tubal catheterization under fluoroscopic guidance was a fraction of the background annual radiation dose. The excess lifetime risks of cancer and hereditary disorders were in the order of four to 13 and two to six per million procedures respectively. CONCLUSIONS: The long term risks of selective salpingography and tubal catheterization under fluoroscopic guidance are low. (+info)