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Tissue Ablation (tissue + ablation)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Effectiveness of Multilevel (Tongue and Palate) Radiofrequency Tissue Ablation for Patients with Obstructive Sleep Apnea Syndrome,

THE LARYNGOSCOPE, Issue 12 2004
David L. Steward MD
Abstract Objectives: The primary objective is to determine the effectiveness of multilevel (tongue base and palate) temperature controlled radiofrequency tissue ablation (TCRFTA) for patients with obstructive sleep apnea syndrome (OSAS). The secondary objective is to compare multilevel TCRFTA to nasal continuous positive airway pressure (CPAP). Study Design and Methods: The study is a controlled case series of one investigator's experience with multilevel TCRFTA for patients with OSAS. Twenty-two subjects with mild to severe OSAS, without tonsil hypertrophy, completed multilevel TCRFTA (mean 4.8 tongue base and 1.8 palate treatment sessions) and had both pre- and posttreatment polysomnography. Primary outcomes included change from baseline in apnea/hypopnea index (AHI), daytime somnolence, and reaction time testing measured 2 to 3 months after TCRFTA. Secondary outcomes included change in other respiratory parameters, OSAS related quality of life, and upper airway size. Comparison of 18 patients treated with TCRFTA for mild to moderate OSAS (AHI > 5 and , 40) is made with 11 matched patients treated with nasal CPAP for mild to moderate OSAS. Results: Multilevel TCRFTA significantly improved AHI (P = .001), apnea index (P = .02), as well as respiratory and total arousal indices (P = .0002 and P = .01). Significant improvement with moderate or large treatment effect sizes were noted for OSAS related quality of life (P = .01) and daytime somnolence (P = .0001), with a trend toward significant improvement in reaction time testing (P = .06), with mean posttreatment normalization of all three outcome measures. Fifty-nine percent of subjects demonstrated at least a 50% reduction in AHI to less than 20. The targeted upper airway, measured in the supine position, demonstrated a trend toward significant improvement in mean cross sectional area (P = .05) and volume (P = .10). Side effects of TCRFTA were infrequent, mild, and self-limited. No significant correlation between pretreatment parameters and outcome improvement was noted. Nasal CPAP resulted in significant improvement in AHI (P = .0004) to near normal levels, with an associated improvement in OSAS related quality of life (P = .02) and a trend toward significant improvement in daytime somnolence (P = .06). Reaction time testing demonstrated no significant improvement (P = .75). No significant differences were seen for change in AHI, OSAS related quality of life, daytime somnolence, or reaction time testing between multilevel TCRFTA and CPAP. Conclusion: Multilevel (tongue base and palate) TCRFTA is a low-morbidity, office-based procedure performed with local anesthesia and is an effective treatment option for patients with OSAS. On average, abnormalities in daytime somnolence, quality of life, and reaction time testing demonstrated improvement from baseline and were normalized after treatment. Polysomnographic respiratory parameters also demonstrated significant improvement with multilevel TCRFTA. [source]

Irreversible electroporation of the pancreas in swine: a pilot study

HPB, Issue 5 2010
Kevin P. Charpentier
Abstract Background:, Irreversible electroporation (IRE) is a novel, non-thermal method of tissue ablation using short pulses of high-voltage DC current to ablate tissue. Methods:, Irreversible electroporation of the pancreas was performed in four domestic female swine using two monopolar probes spaced 9,15 mm apart. Ninety pulses of 1500 V/cm were delivered for each ablation. Results:, All animals survived for their designated times of 2 h (n= 1), 2 days (n= 1) and 14 days (n= 2), respectively. No procedure-related complications occurred. Three animals in which probes had been spaced at intervals of 10 ± 1 mm showed evidence of irreversible ablation, with ablation height ranging from <10 mm to 21 mm and ablation width ranging from <10 mm to 16 mm by gross appearance and triphenyltetrazolium chloride (TTC) staining. The only animal in which probes had been spaced at intervals of 15 mm did not show evidence of irreversible ablation at 2 weeks. This may be secondary to the wider probe spacing and relatively low voltage, which results in a mostly reversible form of electroporation without cell death. Conclusions:, Irreversible electroporation appears to be a safe method for pancreas tissue ablation. Staining with TTC can predict the zone of IRE ablation within 2 h of treatment. [source]

Catheter Ablation of Long-Lasting Persistent Atrial Fibrillation: Critical Structures for Termination

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 11 2005
MICHEL HAÏSSAGUERRE M.D.
Background: The relative contributions of different atrial regions to the maintenance of persistent atrial fibrillation (AF) are not known. Methods: Sixty patients (53 ± 9 years) undergoing catheter ablation of persistent AF (17 ± 27 months) were studied. Ablation was performed in a randomized sequence at different left atrial (LA) regions and comprised isolation of the pulmonary veins (PV), isolation of other thoracic veins, and atrial tissue ablation targeting all regions with rapid or heterogeneous activation or guided by activation mapping. Finally, linear ablation at the roof and mitral isthmus was performed if sinus rhythm was not restored after addressing the above-mentioned areas. The impact of ablation was evaluated by the effect on the fibrillatory cycle length in the coronary sinus and appendages at each step. Activation mapping and entrainment maneuvers were used to define the mechanisms and locations of intermediate focal or macroreentrant atrial tachycardias. Results: AF terminated in 52 patients (87%), directly to sinus rhythm in 7 or via the ablation of 1,6 intermediate atrial tachycardias (total 87) in 45 patients. This conversion was preceded by prolongation of fibrillatory cycle length by 39 ± 9 msec, with the greatest magnitude occurring during ablation at the anterior LA, coronary sinus and PV-LA junction. Thirty-eight atrial tachycardias were focal (originating dominantly from these same sites), while 49 were macroreentrant (involving the mitral or cavotricuspid isthmus or LA roof). Patients without AF termination displayed shorter fibrillatory cycles at baseline: 130 ± 14 vs 156 ± 23 msec; P = 0.002. Conclusion: Termination of persistent AF can be achieved in 87% of patients by catheter ablation. Ablation of the structures annexed to the left atrium,the left atrial appendage, coronary sinus, and PVs,have the greatest impact on the prolongation of AF cycle length, the conversion of AF to atrial tachycardia, and the termination of focal atrial tachycardias. [source]

Ex vivo histological characterization of a novel ablative fractional resurfacing device,

LASERS IN SURGERY AND MEDICINE, Issue 2 2007
Basil M. Hantash MD
Abstract Background and Objectives We introduce a novel CO2 laser device that utilizes ablative fractional resurfacing for deep dermal tissue removal and characterize the resultant thermal effects in skin. Study Design/Materials and Methods A prototype 30 W, 10.6 µm CO2 laser was focused to a 1/e2 spot size of 120 µm and pulse duration up to 0.7 milliseconds to achieve a microarray pattern in ex vivo human skin. Lesion depth and width were assessed histologically using either hematoxylin & eosin (H&E) or lactate dehyrdogenase (LDH) stain. Pulse energies were varied to determine their effect on lesion dimensions. Results Microarrays of ablative and thermal injury were created in fresh ex vivo human skin irradiated with the prototype CO2 laser device. Zones of tissue ablation were surrounded by areas of tissue coagulation spanning the epidermis and part of the dermis. A thin condensed lining on the interior wall of the lesion cavity was observed consistent with eschar formation. At 23.3 mJ, the lesion width was approximately 350 µm and depth 1 mm. In this configuration, the cavities were spaced approximately 500 µm apart and interlesional epidermis and dermis demonstrated viable tissue by LDH staining. Conclusion A novel prototype ablative CO2 laser device operating in a fractional mode was developed and its resultant thermal effects in human abdominal tissue were characterized. We discovered that controlled microarray patterns could be deposited in skin with variable depths of dermal tissue ablation depending on the treatment pulse energy. This is the first report to characterize the successful use of ablative fractional resurfacing as a potential approach to dermatological treatment. Lasers Surg. Med. 39:87,95, 2007. © 2007 Wiley-Liss, Inc. [source]

Comparison of germanium oxide fibers with silica and sapphire fiber tips for transmission of erbium: YAG laser radiation

LASERS IN SURGERY AND MEDICINE, Issue 8 2006
Travis J. Polletto BS
Abstract Background and Objectives Endoscopic applications of the Erbium:YAG laser have been limited due to the lack of a suitable optical fiber delivery system. The purpose of this study was to compare the transmission of Er:YAG laser radiation through germanium oxide trunk fibers with silica and sapphire fiber tips for potential use in contact tissue ablation during endoscopy. Study Design/Materials and Methods Er:YAG laser radiation with a wavelength of 2.94 µm, pulse length of 300 microseconds, pulse energies from 5 to 1,360 mJ, coupled into pulse repetition rates of 3,10 Hz, was through 1-m-long germanium oxide fibers with either 1-cm-long, 550-µm-diameter silica or sapphire tips. Results Transmission through the germanium oxide/sapphire fibers measured 65±5% compared with 55±4% for the germanium oxide/silica fibers (P<0.05). The damage threshold for the hybrid fibers averaged 309± 44 mJ and 126±43 mJ, respectively (n,=,7 fibers each) (P<0.05). The highest pulse energies transmitted through the fibers were 700 mJ and 220 mJ, respectively. Conclusions Improved index-matching of the trunk fiber and fiber tip at 2.94 µm resulted in higher transmission and damage thresholds for the germanium oxide/sapphire fibers. The germanium oxide/sapphire fiber may represent a promising mid-infrared optical fiber delivery system for use in endoscopic applications of the Er:YAG laser requiring a flexible, biocompatible, and robust fiber delivery system for contact tissue ablation. Lasers Surg. Med. 38:787,791, 2006. © 2006 Wiley-Liss, Inc. [source]

Hybrid germanium/silica optical fibers for endoscopic delivery of erbium:YAG laser radiation

LASERS IN SURGERY AND MEDICINE, Issue 1 2004
Charles A. Chaney MS
Abstract Background and Objectives Endoscopic applications of the erbium (Er):YAG laser have been limited due to the lack of an optical fiber delivery system that is robust, flexible, and biocompatible. This study reports the testing of a hybrid germanium/silica fiber capable of delivering Er:YAG laser radiation through a flexible endoscope. Study Design/Materials and Methods Hybrid optical fibers were assembled from 1-cm length, 550-,m core, silica fiber tips attached to either 350- or 425-,m germanium oxide "trunk" fibers. Er:YAG laser radiation (,,=,2.94 ,m) with laser pulse lengths of 70 and 220 microseconds, pulse repetition rates of 3,10 Hz, and laser output energies of up to 300 mJ was delivered through the fibers for testing. Results Maximum fiber output energies measured 180±30 and 82±20 mJ (n,=,10) under straight and tight bending configurations, respectively, before fiber interface damage occurred. By comparison, the damage threshold for the germanium fibers without silica tips during contact soft tissue ablation was only 9 mJ (n,=,3). Studies using the hybrid fibers for lithotripsy also resulted in fiber damage thresholds (55,114 mJ) above the stone ablation threshold (15,23 mJ). Conclusions Hybrid germanium/silica fibers represent a robust, flexible, and biocompatible method of delivering Er:YAG laser radiation during contact soft tissue ablation. However, significant improvement in the hybrid fibers will be necessary before they can be used for efficient Er:YAG laser lithotripsy. Lasers Surg. Med. 34:5,11, 2004. © 2004 Wiley-Liss, Inc. [source]

Effectiveness of Multilevel (Tongue and Palate) Radiofrequency Tissue Ablation for Patients with Obstructive Sleep Apnea Syndrome,

Hot and cold technologies for tissue ablation in urology

BJU INTERNATIONAL, Issue 6 2006
Jennifer M. Burr
Increasingly, technology plays an important role in urology, and with this greater use comes the expected increase in regulation. Authors from the UK present a review of the physical properties of ablative technologies, evaluating efficacy and safety, and summarising guidance issued by the National Institute of Health and Clinical Excellence (NICE) where available. There are also reviews from the UK on haematuria, and on the pathology of bladder cancer from an international group of European authors. [source]

Use of electrolysis as an adjunct to liver resection

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 8 2002
B. G. Fosh
Background: Patients with hepatic metastases are potentially curable if all the diseased tissue can be resected. Unfortunately, only 10,20 per cent of patients are suitable for curative resection. Electrolysis is a novel non-thermal method of tissue ablation. When used in conjunction with surgery it may increase the number of resectable liver tumours with curative treatment. Methods: All patients had been deemed inoperable using currently accepted criteria. Nine patients with hepatic deposits from colorectal carcinoma underwent combined surgical resection and electrolytic ablation of metastases. Results: The treatment was associated with minimal morbidity. Within the electrolytically treated area seven patients had no radiological evidence of recurrence at a median follow-up of 9 (range 6,43) months; local recurrence was detected in two patients. Six of the nine patients had metastases elsewhere in the liver with four having extrahepatic metastases. Three patients remain tumour free. Three patients died. The median survival was 17 (range 9,24) months from the time of treatment. Discussion: Electrolysis with resection may confer a disease-free and overall survival benefit. The small size of this initial study precludes statistical analysis, but preliminary results are encouraging. © 2002 British Journal of Surgery Society Ltd [source]

Adenocarcinoma complicating restorative proctocolectomy for ulcerative colitis with mucosectomy performed by Cavitron Ultrasonic Surgical Aspirator®

COLORECTAL DISEASE, Issue 4 2009
B. C. Branco
Abstract This is a report of adenocarcinoma arising in an ileal pouch after restorative proctocolectomy (RPC) with rectal mucosal stripping performed by Cavitron Ultrasonic Surgical Aspirator (CUSA®) for ulcerative colitis. The CUSA® was introduced to simplify and optimize ileal pouch,anal anastomosis with mucosectomy and has been shown to shorten the operative time and reduce blood loss. Its use however, may increase the number of pathology specimens made uninterpretable on account of tissue ablation. In the present case, even though preoperative colonoscopy had clearly shown dysplasia, the surgical pathology report could not detect any neoplasia in the specimen; hence, the patient was not surveyed for pouch cancer. Six years later, the patient presented with intestinal obstruction caused by cancer. While protocols for universal pouch surveillance remain somewhat controversial, we conclude on the basis of this case and a review of the literature that in RPC with mucosectomy performed by CUSA®, pouch cancer surveillance is particularly important because remnants of rectal epithelium may have been left behind and tissue ablation may have made the surgical pathology report uninterpretable. [source]