Search results for "ABLATION"
showing 10 items of 322 documents
Mass spectroscopic analysis of excimer laser ablated material from human corneal tissue.
1988
The clinical feasibility of photorefractive keratectomy depends on the surface structure of the ablated cornea. Two factors that influence the remodeled surface are the homogeneity of the energy distribution and the properties of the laser source (energy and wavelength). Currently, the homogeneity of the beam is difficult to control. The second factor, laser source properties, was the focus of this study. We investigated the effect of laser wavelength and energy by analyzing the reaction products of photoablation. We monitored the fragments produced by UV-laser ablation of human corneas using mass spectroscopy in the range of 0 to 100 atomic mass units. At 248 nm (KrF), average photon energ…
Randomized study comparing two tongue base surgeries for moderate to severe obstructive sleep apnea syndrome
2009
To compare the effectiveness and morbidity of the tongue base radiofrequency and tongue base suspension techniques combined with uvulopalatopharyngoplasty for moderate to severe obstructive sleep apnea.Prospective and randomized surgical trial at a university hospital.In total, 57 patients received either tongue base radiofrequency reduction (n = 29) or tongue base suspension (n = 28). Apnea-hypopnea index, lowest oxygen saturation (polysomnography), Epworth score, and side effects were assessed. Success was defined as aor =50 percent reduction and final apneahypopnea index15/h, and an Epworth score11.The success rates of the two procedures were 57.1 percent and 51.7 percent, respectively (…
Direct Objective Quantification of Corneal Haze after Excimer Laser Photorefractive Keratectomy for High Myopia
1996
Purpose: The purpose of the study is to measure regional distribution differences in corneal haze after excimer laser photorefractive keratectomy for high myopia. Methods: The authors developed computerized gradient edge detectors with which were analyzed digitized anterior slit-lamp photographs of 40 eyes, an average of 21.0 plus or minus 14.5 weeks after photorefractive keratectomy for high myopia (−6 to −22 diopters). A treated area and an adjacent untreated area on the anterior corneal surface, each containing six regions, were quantified, and the difference was correlated with various parameters. Results: Mean differences between scarred and clear areas for haze grade 0.5, 1.0, 2.0, 3.…
Excimer laser photorefractive keratectomy for high myopia
1995
Abstract One hundred and thirty-three eyes of 103 patients had photorefractive keratectomy with a slit scan mode excimer laser for myopia ranging from −6.00 to −22.00 diopters (D). The epithelium was removed with 20% ethanol, and the ablation was done with a tapered profile surrounding the optical zone. Patients were divided into two groups based on preoperative myopia: Group A, −6.00 D to −12.00 D (88 eyes); Group B, −12.50 D to −22.00 D (45 eyes). In Group A, mean preoperative refraction was −9.59 ± 1.79 D. Mean postoperative refraction was −0.29 ± 1.47 D at one month, −0.85 ± 1.68 D at three months, −1.17 ± 2.04 D at six months, and −0.56 ± 0.74 D at one year. Anterior stromal haze was g…
High frequency rotational ablation: an alternative in treating coronary artery stenoses and occlusions.
1993
OBJECTIVE--To prove the safety and effectiveness of high frequency rotational ablation of coronary artery stenoses and occlusion in humans. SUBJECTS--106 patients with symptoms (91 men, 15 women) who had 67 significant stenoses, mainly types B and C, and 46-chronic occlusions. MAIN OUTCOME MEASURES--Mean change in diameter stenosis after rotational angioplasty alone and in combination with percutaneous transluminal coronary angioplasty immediately after treatment and 24 hours and six months later; restenosis rates at six months; complication of treatment. RESULTS--Rotational ablation could not be used in five stenoses and 16 chronic occlusions because of inability to reach or cross the lesi…
Five-year follow-up after catheter ablation of persistent atrial fibrillation using the stepwise approach and prognostic factors for success.
2015
Background— In the meantime, catheter ablation is widely used for the treatment of persistent atrial fibrillation (AF). There is a paucity of data about long-term outcomes. This study evaluates (1) 5-year single and multiple procedure success and (2) prognostic factors for arrhythmia recurrences after catheter ablation of persistent AF using the stepwise approach aiming at AF termination. Methods and Results— A total of 549 patients with persistent AF underwent de novo catheter ablation using the stepwise approach (2007–2009). A total of 493 patients were included (Holter ECGs ≥every 6 months). Mean follow-up was 59±16 months with 2.1±1.1 procedures per patient. Single and multiple procedu…
Radiofrequency tissue volume reduction for treatment of auricle keloids
2010
Objectives/Hypothesis: Keloids are often refractive to treatment, and recurrences occur quite frequently. Radiofrequency tissue volume reduction (RFTVR) is a surgical technology that induces extensive fibrosis at the target tissues. Methods: We applied RFTVR in 14 patients (19 auricles, 5 patients treated bilaterally; 9 female, 5 male; range, 10–66 years) with keloids of the auricle. Keloids were located at the earlobe in 4 patients (5 auricles), helix in 9 patients (12 auricles), and at both earlobe and helix in 1 patient (2 auricles). In 6 patients (8 auricles) RFTVR was the sole treatment modality applied, and in 7 patients (10 auricles) intralesional steroid injection was also performed…
Evaluation of posttreatment response of hepatocellular carcinoma: comparison of ultrasonography with second-generation ultrasound contrast agent and …
2010
We evaluated the ability of one-month follow-up contrast-enhanced ultrasound (CEUS) with second-generation contrast agent in monitoring radio frequency ablation (RFA) and transcatheter arterial chemoembolization (TACE) treatments of hepatocellular carcinoma (HCC). One-hundred forty-eight HCCs were studied using CEUS: 110 nodules were treated with RFA [41/110 RFA were performed using a pretreatment and an immediate postablation evaluation using CEUS (group 1); 69/110 using only US guidance (group 2)] and 38 nodules treated with TACE. For statistical analysis, McNemar test was used. Overall complete response was observed in 107/148 nodules (92/110 treated with RFA and 15/38 with TACE). A bett…
Radiofrequency ablation as first-line treatment in patients with early colorectal liver metastases amenable to surgery.
2010
Aiming at avoidance of futile surgery, we have tested whether radiofrequency ablation (RFA) may be used as first-line treatment in patients with colorectal metastases (CRLM) occurring within the first year after colorectal surgery.Surgical resection is the standard treatment in patients with CRLM. Major retrospective analyses have identified the interval between colorectal surgery and the occurrence of CRLM to be of prognostic importance. So far, it is unknown whether survival of the respective patients is hampered if RFA is used as first-line treatment.According to a clinical pathway, we have treated patients with CRLM detected within the first year after colorectal surgery preferentially …
Cryotherapy for liver metastases
2000
Cryotherapy is undergoing a renaissance in the treatment of nonresectable liver tumors. In a prospective case control study we assessed the morbidity, mortality, and efficacy of hepatic cryotherapy for liver metastases. Between January 1996 and September 1999 a total of 54 cryosurgical procedures were performed on 49 patients (median age 66 years, 21 women) with liver metastases. Patient, tumor, and operative details were recorded prospectively. Liver metastases originated from colorectal cancer (n=37), gastric cancer (n=3), renal cell carcinoma (n=2), and other primaries (n=7). Median follow-up was 13 months (1-32). The median number of liver metastases was 3 (range 1-10) with a median dia…