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Results for “Device Removal”

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At least 289 records · Page 16Linked to original sources

PubMed1993

Percutaneous rotational thrombectomy reduces acute reocclusion in an animal model of acute coronary thrombosis.

This study was designed to compare acute reocclusion rates after treatment of acute coronary thrombosis with a percutaneous thrombectomy device or standard balloon angioplasty. Our group has previously reported on the rationale and development of a mechanical device for the treatment of intra-arterial thrombosis. This device removes fibrin from thrombus, allowing for dissolution of the cellular elements of the thrombus. Theoretically, thrombus removal (as opposed to displacement) might result in a lower rate of acute rethrombosis. The present study utilizes the device percutaneously in the coronary arteries of closed chest swine and compares recanalization and reocclusion rates with standard balloon angioplasty. Twenty-six animals with total thrombotic coronary occlusions were treated; 13 with each device. Reocclusion rates with the thrombectomy device were significantly reduced at 60 min and 120 min after recanalization (p < 0.02), and the mean time to reocclusion was prolonged by 45 min (p = 0.07). Technical problems included poor handling characteristics in early prototypes and stress fractures secondary to improper use. Changes in catheter design and operator protocols have largely eliminated these problems. We conclude that this study demonstrates the feasibility of percutaneous mechanical thrombectomy in the coronary arteries and that reocclusion rates after recanalization of thrombotic occlusions compare favorably to standard angioplasty.

Acute Disease↗

PubMedDate not supplied

Routine implantation of cardioverter/defibrillator devices in patients aged 75 years and older with prior myocardial infarction and left ventricular ejection fraction < 30: antagonist viewpoint.

The Multicenter Automatic Defibrillator Implantation Trial (MADIT II) investigators assert that their results justify the placement of artificial implantable defibrillator cardioverter devices in patients aged 75 years and older with prior myocardial infarction and left ventricular dysfunction (ejection fraction of 30 or less). The authors claim that the results of the trial do not justify this conclusion. The majority of patients were male (84%) and aged 64+/-10 years. Also, 2.8% of patients assigned to the defibrillator group and 1.5% had their device removed. Of the latter subgroup, nine patients (1.3%) received a heart transplant. Twelve had their artificial implantable defibrillator cardioverter device deactivated mostly because of terminal illness. Although the study results show a significant reduction in mortality over the control group (absolute reduction=5.6%), almost the same percentage required hospitalization because of manifestation of congestive heart failure (absolute value 5%; p=0.09). Also, 1.8% had lead problems, 0.7% had infections, and the benefits were only seen after the first year. Caution is needed before the results of this study are applied to a much older cohort comprised mainly of women in whom heart transplant is contraindicated and who have multiple health problems, including cognitive impairment. Artificial implantable cardioverter/defibrillator devices are expensive and this study's results need to be duplicated in other comparable cohorts.

Aged↗

PubMed1982

Laparoscopic removal of translocated intrauterine contraceptives devices.

Over a 6 year period, 67 women had a translocated intrauterine contraceptive device (IUCD) removed from the peritoneal cavity or uterovesical fold under general anaesthesia. In 40 patients removal of the IUCD at laparoscopy succeeded, whereas in 24 laparotomy proved necessary and three IUCD were removed per vaginam. Compared with the inert plastic device a larger proportion of copper-containing IUCD in the peritoneal cavity required laparotomy for removal, however, 44% could be removed by laparoscopy, the less traumatic procedure.

Female↗

PubMed2001

[Treatment of acute myocardial infarction with the x-sizer coronary thrombectomy device].

The abundant thrombi present in infarct-related arteries may impair the angiographic result of primary angioplasty in acute myocardial infarction. We describe the utilization of the thrombus-removal device X-Sizer before coronary stenting in 4 patients with acute myocardial infarction treated with primary angioplasty. The procedure was successful in all the cases and the patients were discharged without complications.

Aged↗

PubMed2026

An impact assessment of the European medical device regulations implementation - the current status quo.

BACKGROUND: This research aims to assess the current impact of the medical and in-vitro diagnostic devices regulations (MDR/IVDR) on the device industry in the EU, under the lens of postimplementation and the amending regulation, and in advance of the final transition to the IVDR/MDR in the future. RESEARCH DESIGN AND METHODS: A quantitative survey was administered to a diverse cohort of medical device enterprises, ranging from micro to large organizations. RESULTS: The survey indicates that the MDR/IVDR has harmed innovation, leading many manufacturers to seek initial device approval and launch elsewhere before in Europe. There is evidence that some manufacturers have rationalized their existing product portfolios and removed devices from the market as they stated they would in previous industry surveys. The MDR/IVDR has been shown to negatively impact manufacturers, with increased costs related to notified body (NB) fees, maintaining and updating documentation, recertification fees, and hiring additional staff. CONCLUSION: This study provides a current status of the effects of MDR/IVDR on manufacturers and finds that despite amending regulations and other interventions taken by the EU to mitigate regulatory burden, ensure product availability, and address stakeholder concerns, the EU is no longer the market of choice for new products.

Equipment and Supplies↗

PubMed1991

The prognostic value of extracellular matrix component concentrations in serum during treatment of adult respiratory distress syndrome with extracorporeal CO2 removal.

The time-dependent concentrations of hyaluronan, aminoterminal propeptide of type III procollagen, and laminin were determined in sera of 16 patients with severe adult respiratory distress syndrome during treatment with an extracorporeal CO2 removal device. Patients were classified according to lung parameters as responders (n = 10) and non-responders (n = 6) to extracorporeal CO2 removal. At the beginning of treatment strongly elevated serum concentrations of all studied extracellular matrix components were found. During the first 6-11 days of treatment the concentrations of aminoterminal propeptide of type III procollagen and hyaluronan increased further in non-responders but decreased in the majority of responders, while laminin decreased in both groups. No significant correlations were found between the serum concentrations of connective tissue components and the parameters of lung function. By non-parametric analysis of variance, significant differences between responders and non-responders according to treatment time could be established. By analysing the time course of the serum concentrations of hyaluronan and aminoterminal propeptide of type III procollagen, a total differentiation between responders and nonresponders was made possible by the trends of these analytes as early as three days after the start of treatment. The determination of aminoterminal propeptide of type III procollagen and hyaluronan in serum of patients with adult respiratory distress syndrome might therefore have prognostic significance in extracorporeal CO2 removal.

Adolescent↗

PubMed2001

Normal oxygenation and ventilation during snow burial by the exclusion of exhaled carbon dioxide.

OBJECTIVE: To confirm that the accumulation of exhaled carbon dioxide (CO2) is the principal cause of nonmechanical asphyxiation during avalanche burial by demonstrating that complete exclusion of exhaled CO2 during experimental snow burial results in normal oxygenation and ventilation utilizing the air within the snowpack. METHODS: In the experimental group, 8 healthy volunteers (mean age 32 years, range 19-44 years) were fully buried up to 90 minutes in compacted snow with a density ranging from 300 to 680 kg/ m3 at an elevation of 2385 m. The 6 men and 2 women breathed directly from the snow utilizing a device containing no air pocket around the inhalation intake, in addition to an extended exhalation tube running completely out of the snowpack to remove all exhaled CO2. Continuous physiologic monitoring included oxygen saturation, end-tidal CO2, inspired CO2, electrocardiogram, rectal core temperature, and respiratory rate. As controls, 5 of the 8 subjects repeated the study protocol breathing directly into a small, fist-sized air pocket with no CO2 removal device. RESULTS: In the experimental group, the mean burial time was 88 minutes, despite the absence of an air pocket. No significant changes occurred in any physiologic parameters in this group compared to baseline values. In contrast, the controls remained buried for a mean of 10 minutes (P = .003) and became significantly hypercapnic (P < .01) and hypoxic (P < .02). CONCLUSIONS: There is sufficient oxygen contained within a densified snowpack comparable to avalanche debris to sustain normal oxygenation and ventilation for at least 90 minutes during snow burial if exhaled CO2 is removed. The prolonged oxygenation observed during CO2 exclusion is irrespective of the presence of an air pocket.

Adult↗

PubMed1996

Effects of administering progesterone at selected intervals after insemination of synchronized heifers on pregnancy rates and resynchronization of returns to service.

In 3 separate trials at 2 locations, dairy heifers (n = 396) were treated with a Controlled Internal Drug Release (CIDR) progesterone device for 9 d. On Day 7 of CIDR treatment, all heifers were injected with PGF(2alpha). Synchronized estruses were detected using a tailpaint and chalk (TPC) scoring system. An animal's tailhead was painted at device insertion, and this strip was covered with a contrasting color of chalk at device removal. Over all trials, 85.1% of the heifers were detected in estrus and were inseminated at 48 or 72 hours after CIDR removal. These synchronized and inseminated heifers were divided into the following treatment groups: 1) untreated controls, receiving no further treatment (n = 138); 2) post-insemination progesterone supplementation with a new (n = 59) or used (n = 29) CIDR device for Days 1 to 8 or 2 to 9, respectively, following insemination; or 3) resynchronization of return to service with a used CIDR device for Days 17 to 22 after insemination (n = 112). The pregnancy rate to first insemination in the control and resynchronized groups (Groups 1 and 3) was 46.4%, but decreased to 18.2% with the post-insemination progesterone supplementation. Resynchronization of returns to service (estrus detected 1 to 4 d following removal of second CIDR) occurred in 58.9% of all nonpregnant heifers in Group 3. In summary, CIDR devices used in conjunction with PGF(2alpha) effectively synchronize estrus in dairy heifers. Progesterone supplementation within 2 d of first insemination for 7 d suppressed fertility. Used CIDR devices inserted for Days 17 to 22 after first insemination resynchronized heifers not pregnant to first insemination.

Journal Article↗

PubMed2006

Long-term stability and growth following unilateral mandibular distraction in growing children with craniofacial microsomia.

BACKGROUND: The purpose of this study was to evaluate long-term mandibular skeletal stability and growth following unilateral mandibular distraction in growing children. METHODS: This retrospective longitudinal study of 12 consecutive patients with unilateral craniofacial microsomia who underwent mandibular distraction had a range of 5 years of postdistraction follow-up; five patients were followed for 10 years. Records included clinical photographs, dental study models, lateral and posteroanterior cephalograms, and panoramic radiographs obtained before distraction, at the time of device removal, and 1, 5, and 10 years after distraction. The mean patient age at the time of distraction was 48 months. The device was activated an average of 21.7 mm at the rate of 1 mm per day. The mean latency period was 6.1 days, and the mean consolidation period was 60.6 days. Fifty-two parameters were examined at each of the five time intervals. RESULTS: On average, the ramal length (condylion to gonion) increased 13.04 mm in the distracted rami. At 1 year after distraction, this dimension decreased by 3.46 mm. At 5 and 10 years after distraction, the average condylion-gonion dimension increased by 3.83 and 4 mm, respectively, with an average growth rate of 0.87 mm per year; during the same period, the unaffected ramus grew 1.15 mm per year. CONCLUSIONS: The distraction technique does not eliminate the inherent growth potential of the affected mandibular side. Facial asymmetry is significantly improved after distraction, and despite mild relapse observed during the first year, surgical correction is stable in the later years of follow-up.

Cephalometry↗

PubMedDate not supplied

[Complications of intrauterine devices].

Abdominal migration of intrauterine devices is very rare. However, during the puerperium when the uterus is small and the uterine wall thin, the risk of perforation increases. A device removed by coelioscopy is described.

Adult↗

PubMed2005

Ultrafast integrated semiconductor optical modulator based on the plasma-dispersion effect.

We demonstrate integrated semiconductor optical devices with ultrafast temporal responses based on the plasma-dispersion effect. The geometry of the devices removes the dependence of the modulation time on the free-carrier dynamics. We present the theoretical analysis of the performance of such devices. We show that a silicon-based device with a free-carrier lifetime of 1.4 ns can be modulated on a time scale of only 20 ps. The ultrafast operation is verified experimentally.

Journal Article↗

PubMed1999

Investigation of a whole blood fluidized bed Taylor-Couette flow device for enzymatic heparin neutralization.

The use of clinical bioreactors will increase as more therapeutic proteins are being cloned, expressed, and produced at a reduced cost. The proposed use of an immobilized heparinase I reactor to make heparin anticoagulation a safer therapy is an example of how the specificity and high activity of an enzyme could be incorporated into a system to ultimately benefit a patient. However, the development of a safe and efficient bioreactor is important for the use of immobilized heparinase I and other therapeutic proteins designed for use in medical extracorporeal procedures. This study examined the possibility of using Taylor-Couette flow and "flow-induced" recirculation of the agarose beads as a way to fluidize agarose-bound heparinase in whole blood. Heparinase I was immobilized onto agarose beads via cyanogen bromide activation. A reactor based on Taylor-Couette flow was designed and modified with a tangential recirculation line. The reactor was tested for efficacy and safety in vitro in human blood. Visualization studies in water and 42% glycerol were used to determine the minimum rotation rate for efficient fluidization. The strategic placement of the recirculation line allowed recirculation of the agarose without the use of an external pump. The device removed 90% of the heparin activity within 2 min from 450 cc of human blood at a blood flow rate of 100 mL/min. Furthermore, the device maintained inlet and outlet clotting times of 269 +/- 10 and 235 +/- 6 s, respectively, demonstrating the potential for regional heparinization. Blood damage was a function of gel volume fraction and rotation rate of the inner cylinder. Hemolysis of the red cells is an important issue when Taylor vortices are combined with macroscopic solid particles such as agarose beads. A modified Taylor-Couette flow device was developed to treat whole blood and operational criteria were established to minimize hemolysis.

Bioreactors↗

PubMed2002

Rheolytic thrombectomy with Angiojet in thrombus-containing lesions.

The AngioJet thrombectomy device removes thrombus by creating a negative pressure and causing fragmentation of the thrombus. The objective was to study the safety and efficacy of this thrombectomy device during coronary interventions and to report the results of our experience. We studied 72 patients (mean age, 64.9 +/- 12.6 years; 79% males) who had an AngioJet procedure during coronary intervention; 33 (46%) had vein graft intervention. All patients had angiographic thrombus. Most patients presented either with unstable angina (54%) or acute myocardial infarction (32%) within 24 hr. The procedural success was high with AngioJet (93%). TIMI grade 3 flow was achieved in 79% of lesions treated with AngioJet. In-hospital mortality was 1.4%, death/Q-wave myocardial infarction was 4.2%, and the composite endpoint of death and Q-wave myocardial infarction/revascularization was 5.6% for patients undergoing AngioJet. Subgroup analysis of patients with vein graft intervention demonstrated high procedural success in those undergoing AngioJet (91%). At 1-year follow-up of the successful percutaneous interventions with AngioJet, the mortality, death/Q-myocardial infarction, and composite endpoint rates were 10%, 13.3%, and 35.5%, respectively. Long-term event-free survival was worse in vein graft interventions. The incidence of death, death/myocardial infarction, or composite endpoints at 1 year was 16%, 19%, and 46%, respectively. High procedural success can be achieved with the AngioJet thrombectomy device in lesions containing thrombus. It is effective in both native coronary arteries and vein graft interventions. However, the long-term outcome of patients with vein graft intervention was worse.

Aged↗

PubMed1994

Quantitative gas transfer of an intravascular oxygenator.

The intravascular oxygenator is a newly developed device for intracaval gas exchange in critically ill patients with respiratory failure. In an experimental ex vivo model, performance characteristics of the intravascular oxygenator/carbon dioxide removal device were studied. With a mean hemoglobin concentration of 6.2 +/- 1.9 g/dL (mean +/- standard deviation), total O2 transfer was 21.8 +/- 4.8 mL/min at a blood flow of 1 L/min, 37.0 +/- 12.6 mL/min at 2 L/min, at 2 L/min, and 47.5 +/- 16.7 mL/min at 3 L/min. Total CO2 transfer was 27.3 +/- 6.6 mL/min at a blood flow of 1 L/min, 38.6 +/- 8.9 mL/min at 2 L/min, and 40.4 +/- 9.3 mL/min at 3 L/min. In contrast to total gas transfer, O2/CO2 transfer rates (mL/L) diminished significantly with increasing blood flow. In addition, there was a negative correlation between O2 transfer rate and venous O2 partial pressure (r = -0.73; p < 0.0001), a positive correlation between CO2 transfer rate and venous CO2 partial pressure (r = 0.65; p < 0.0001), and a positive correlation between O2 and CO2 transfer rates and blood hemoglobin level (r = 0.57 [p < 0.01] and r = 0.70 [p < 0.01], respectively). These results demonstrate that the behavior of the intravascular hollow-fiber oxygenator is similar to that of the classic membrane oxygenator used for cardiopulmonary bypass: total gas transfer correlates directly with blood flow and venous CO2 partial pressure and indirectly with venous O2 partial pressure. The O2 and CO2 transfer rates increase significantly with increasing hemoglobin content of the blood.

Animals↗

PubMedDate not supplied

New access device for hemodialysis.

A new subcutaneous device (Dialock; Biolink Corp., Middleboro, MA) provides vascular access to patients who currently require hemodialysis (HD). The device consists of a port-like valve, implanted subcutaneously below the clavicle, which provides a linear flow passage to two catheters placed in the right atrium via the jugular vein. The valve is accessed percutaneously with needle-cannulas that functionally convert the device to twin catheters for connecting the patient to the HD lines. Interdialytic patency is maintained using a standard heparin lock. The device has been implanted in 10 outpatients under local anesthesia, with almost immediate use for HD (median, 3 days) and has functioned successfully for more than 6 months (mean +/- SD, 4.0 +/- 1.7; > 400 dialysis sessions). Blood flows over 300 ml/min were consistently achieved (average, 320 +/- 50) with venous and arterial pressures of 197 +/- 42 mmHg and -241 +/- 31 mmHg, respectively. After 40 patient-months, condition of the needle puncture sites remains satisfactory. Four systemic infections have occurred in three patients; all have resolved without the need for device removal. There have been no infections at the puncture sites. One patient whose heparin lock was not changed for 23 days (for reasons unrelated to the device) required fibrin sheath stripping of his catheters. Patient and nurse acceptance has been excellent. The device may offer substantial improvement over conventional devices for HD access.

Adult↗

PubMed1997

Distraction osteogenesis of costochondral neomandibles: a clinical experience.

Distraction osteogenesis quickly has become a mainstay in the treatment of craniofacial syndromes with mandibular hypoplasia. We report on a series of eight patients undergoing distraction osteogenesis of neomandibles constructed with costochondral grafts. The length of distraction, resting phase between distraction and device removal, and complication rate were significantly greater in the rib-graft distraction group when compared with our series of native mandibular distraction patients (n = 21 devices). Most complications were minor, including pintrack infection and hardware failure; however, major complications included fibrous union and facial nerve praxia. Secondary procedures have been able to be performed successfully on previously distracted rib grafts as well.

Adolescent↗

PubMed1990

[Backshifting of lower canines in occlusion regulation].

In 17 patients the lower canines were shifted back during treatment of prognathic malocclusion and cross-bites. Stable devices with retraction loops, rubber or spring traction were used. The duration of active treatment was about 3 months, on average. During the treatment gaps after the removed premolars were closed completely, although this is nearly impossible when removable devices are applied.

Cuspid↗

PubMed1988

[Evaluation from various viewpoints of the Lippes Loop, Multiload Cu 250 and Nova T].

In the present study, our experience at the family planning unit Ankara Military Hospital with intrauterine devices Lippes Loop, multiload Cu 250 and Nova T are presented. 595 women were included in the study between march 31, 1984 with a follow up of 12 months. Out of 595 women 547 (92%) reported no complaints at all. From the remaining 48 women 8 wished to have the device removed, 8 had spontaneous expulsions and in 31 IUD was removed for medical purposes.

Adult↗