Search PubMed⌕ Search

Biomedical subjects

J M Brunetaud

Publications and source records attributed to J M Brunetaud.

At least 37 records · Page 2Linked to original sources
PubMed1991

Peripheral laser angioplasty with sapphire tip.

UNLABELLED: To improve the result of peripheral laser recanalization (less perforation with wider tunnels of vaporization), we used the technique of sapphire laser angioplasty. A Nd:YAG laser with continuous emission was connected to a catheter with a 600 mum fiber and a sapphire probe to its extremity (1.8-3 mm in diameter). Treatment was performed on 127 patients with severe stenosis or occlusion of peripheral arteries (iliac, femoral, or popliteal arteries). Recanalization was obtained in 102 cases (80%) and was further embellished by balloon dilatation. The rate of success decreased proportionally with the length of occlusions (93% for 3 cm, 33% for 15 cm and more). Most failures were due to wall perforation or wall entry of the probe; passage of the sapphire tip was rarely blocked by the occlusion. At follow-up, 26.4% of arteries were reoccluded after 2 months. IN CONCLUSION: laser angioplasty with a sapphire tip can totally recanalize occluded arteries with low rate of failure and complications.

Adult↗
PubMed1991

[Development and evaluation of a laser catheter with tip fiberoptic for coronary angioplasty].

A fiber-optic tip catheter has been developed for treating coronary and peripheral atherosclerosis percutaneously. The catheter is coupled to an ionised Argon laser emitting at an optical power of 1 to 7 Watts. It is designed to follow a guide wire and to perform tissue ablation by a new concept combining the effects of central vaporisation and peripheral thermal remodelling of the obstructed artery. This mode of function should considerably reduce the risks of false route previously encountered with laser angioplasty. The optical and thermic properties of the catheter prototypes were determined by physical methods. These experiments showed that the temperature of the metallic component of the catheter tip did not exceed 30 degrees C at a continuous power of 6 laser Watts when the flush was functioning. It attained 400 degrees C in the absence of the flush. The performances of the catheter were then tested in a number of in vitro experiments. First of all, the catheter tip was placed perpendicularly to atheromatous cadaver aortae to study the effect of vaporisation with respect to the laser power. The threshold of vaporisation was 1 Watt (irradiance: 1100 Watts/cm2). The catheter was then introduced into plastic tubes obstructed by atheromatous plaques. This experiment demonstrated the mechanical solidity of the catheter and its flexibility in difficult operating conditions: diameter 2mm, 45 degrees angles, irregular calcified plaques. It also showed that the optimal safety-efficacy laser power was 3 laser Watts and that the exposure times varied with respect to the nature of the plaques tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1990

[Laser treatment of rectosigmoid villous tumors. Study of a series of 313 patients].

Endoscopic laser treatment is reported in 313 patients with benign rectosigmoid villous adenomas. Total tumor destruction was achieved in 92% of them, without any major complications. The circumferential extension of the tumor base was the only factor affecting this result. During the average 37-month follow-up period of the patients with total tumor destruction, 14% had a tumor recurrence. The recurrence rate after initial treatment was higher a) in patients treated for a recurrence after a previous non laser treatment, b) when the initial histology was low-grade dysplasia and c) when the tumor was located in the lower or middle rectum. Because treatment is long and difficult with a high cancer rate, laser treatment for patients with a circumferential villous adenoma should be limited to nonsurgical candidates. In the other cases, laser is well adapted to old and fragile patients, when transanal resection seems difficult or in case of recurrence after a previous non-laser treatment.

Actuarial Analysis↗
PubMed1990

[Blue rubber bleb nevus syndrome. 3 cases treated with a Nd:YAG laser and bipolar electrocoagulation].

This report concerns three patients with "blue rubber bleb nevus syndrome" presenting with recurrent digestive tract hemorrhage. Tuberous angiomas of the digestive tract associated with typical skin lesions as described by Bean led to diagnosis. Endoscopic coagulation with Nd:YAG laser and bipolar electrocoagulation "Bicap" of gastric and colonic angiomas was performed successfully without complication but did not avoid hemorrhagic recurrence originating from lesions located in the small bowel, as demonstrated during laparotomy in one case.

Adult↗
PubMed1989

Percutaneous coronary rotational angioplasty in humans: preliminary report.

Percutaneous coronary rotational angioplasty was attempted in 12 patients. The procedure was performed with a flexible rotating shaft with an abrasive tip, varying in diameter from 1.25 to 3.5 mm, tracking along a central guide wire. Among the 12 patients (mean age 58 years), 4 had a stenosis in the left anterior descending coronary artery and 8 a stenosis in the right coronary artery. After the guide wire crossed the stenosis, the abrasive tip was slowly advanced and several passes across the stenosis were made. The residual stenosis was measured with computerized automatic quantitative coronary angiography. Success was defined as a reduction of percent stenosis by greater than 20%. If residual stenosis remained significant (greater than 50%), the procedure was completed by balloon dilation. The device could not be inserted in 2 of the 12 patients. Five of the 10 patients underwent rotational angioplasty alone, and 5 had the procedure completed by balloon dilation. The stenosis was significantly enlarged from 0.56 +/- 0.31 mm to 1.26 +/- 0.28 mm. The outline of the vessel appeared smooth and regular. There were no complications related to the procedure and all patients were free of symptoms when discharged 2 to 3 days after the procedure. Thus, coronary rotational angioplasty is a simple and safe procedure allowing marked dilation of the narrowed segment. However, long-term follow-up is required for further evaluation.

Aged↗
PubMed1989

Parameters affecting laser palliation in patients with advanced digestive cancers.

Ninety-nine nonsurgical patients (group I) with esophagogastric cancer were referred to the laser center for palliation of dysphagia, and another 142 nonsurgical patients (group II) with a rectosigmoid cancer were referred for palliation of abnormal rectal discharge (125 patients) or occlusion (17 patients). The immediate success rate was 83% in group I and 90% in group II. Patients were retreated monthly. The average duration of palliation was 4.3 months +/- 0.5 (+/- standard error) in group I and 9.3 months +/- 0.95 in group II. Complication rate was 4% in group I and 3.4% in group II. Parameters affecting results were found only in group I. Factors that could negatively affect the immediate success rate included annular size of the tumor basis more than two thirds of the circumference, tumor localization at the upper third of the esophagus, and recurrence after a nonlaser treatment. The average duration of improvement after initial success was affected only by the circumferential extension.

Aged↗
PubMed1989

Comparative study of the "point-by-point technique" and the "scanning technique" for laser treatment of port-wine stain.

Photocoagulation using the argon laser has been proven to be an effective method for the treatment of port-wine stains (PWS). However, it is very difficult to reproduce the parameters of laser treatment. This leads to inaccurate energy dosages secondary to the difference in treatment patterns. The aim of this study was to compare the conventional point-by-point technique (PT) for PWS treatment against a new scanning technique (ST) using a device called "Hexascan" (PREIN & Partners, Ferney-Voltaire, France). A total of 249 patients (171 females and 78 males) using the argon laser have been studied in a retrospective study. Clinical results are presented. For each technique, blanching and hypertrophic scarring were examined. The results are classified into two groups: satisfactory and unsatisfactory. The clinical results show that the ST with the Hexascan is superior to the conventional PT. Scarring is drastically reduced because overdosage and overheating are avoided. Because of precisely controlled spot patterns, quality and homogeneity of blanching is improved. Treatment time can be reduced to 20% of that of the PT.

Adult↗
PubMed1989

Laser palliation for rectosigmoid cancers.

Lasers are now used in the rectum an colon for treatment of vascular telangiectasia [1], and benign and malignant sessile tumours [2,3]. This paper will describe the results of a 7 years experience with treatment of sessile rectosigmoid cancers.

Adult↗
PubMed1989

Endoscopic laser treatment for rectosigmoid villous adenoma: factors affecting the results.

Endoscopic laser treatment is reported in 264 patients with benign rectosigmoid villous adenomas revealed by biopsy. Patients include 100 who had contraindications to surgery, 60 who had a tumor recurrence after a nonlaser treatment, 101 for whom surgical resection appeared to be too drastic for a tumor found benign on biopsy, and 3 who refused surgery. Two types of lasers were used: the Nd:YAG and the argon laser. In some patients, both lasers were used. Treatment was completed in 226 patients. Total tumor destruction was attained in 92% of them, a carcinoma was detected in 7% on biopsy specimens obtained during laser treatment, and benign villous tissue persisted in 1%. During the average 25.9-mo follow-up period of the patients with total tumor destruction, 13% had a tumor recurrence. Treatment was well-tolerated with no major complications. The circumferential extension of the tumor base was the only factor affecting the duration of treatment, and the rate of complications. The recurrence rate after initial treatment was higher in patients treated for a recurrence after a previous nonlaser treatment than in patients treated only by laser (p = 0.04). It was also higher when the initial histology was low-grade dysplasia than if it was high-grade dysplasia (p = 0.017) and when the tumor was located in the lower or middle rectum as opposed to the upper rectum or sigmoid (p = 0.04). We estimated that the direct cost of laser treatments was 28%-40% of the surgery charges for lesions of identical size in our hospital and 31%-69% at UCLA Center for the Health Sciences. Because treatment is long and difficult and the cancer rate is high, endoscopic laser for patients with a circumferential villous adenoma should be limited to nonsurgical candidates. The risk of a fatal complication after surgery has to be balanced against the risk of undetected carcinoma in the other patients and the indication for endoscopic laser treatment should be discussed case by case.

Adenoma↗
PubMed1989

XeCl laser in biliary calculus fragmentation: fluence threshold and ablation products.

The in vitro action of a xenon-chlorine (XeCl) excimer laser on biliary calculi is reported: fluence threshold and rate for ablation process are given. An analysis of gaseous products evolved during irradiation of gallstones, performed through an infrared spectrophotometric technique is also reported. Based on the different results, we discuss the mechanism of destruction.

Bilirubin↗
PubMed1989

[The 1.320 micron Nd-YAG laser. Experimental study of a new wavelength adapted to neurosurgery].

The authors present a new laser wavelength for neurosurgery: the 1.32 micron Nd-YAG laser. Schematically, it combines the advantages of both the 1.06 micron Nd-YAG laser and the CO2 laser. As for nervous tissue it has the same physico-thermal properties as the CO2 laser: an important absorption and little thermal diffusion. Like the 1.06 Nd-YAG laser, the 1.32 Nd-YAG has very good maneuverability, because its beam is conducted through optical fibers. Experimental studies have been made on rats. They consisted of comparison between the thermal effects and the consequent histological lesions of three lasers: 1.32 micron Nd-YAG, 1.06 micron Nd-YAG, CO2. 145 impacts on the cortex of 45 rats have been studied. Each shot was registered with an infrared camera, measuring the cortex surface temperature around the impact. The signals were digitalized; they allowed us to obtain a numerical image and the profile of temperature for each shot, as well as the development of temperature of each point of the profile. These results have been correlated with the histological data. It appears that for equivalent efficient outputs, the cortical lesions, 8 days after the shots, were similar for the 1.32 Nd-YAG laser and the CO2 laser. For instance, the depth of the coagulation necrosis varied from 200 to 250 microns after CO2 laser impacts (P = 3W; t = 0 05s; Fluence = 5 Joules/cm2), and from 210 to 260 microns after 1.32 Nd-YAG laser impacts (P = 5-14W; t = 0.4s; F = 50-170 J/cm2).(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum Silicates↗
PubMed1989

[Treatment of superficial bladder tumors using the argon laser].

The authors report their experience of Argon laser in superficial bladder cancer (332 tumors in 106 patients). The advantages are: unneeded anesthesia, ambulatory treatment, absence of bleeding, no gaz, no obturator nerve stimulation, limited focal reaction and unlikely complications. The disadvantages are: duration of treatment, limited pathological material (with cold cup biopsy). The limitations are: size of the tumor (less than or equal to 1 cm) and a location in an area that can be reached perpendicularly. This kind of treatment does not seem to reduce the recurrence rate.

Argon↗
PubMed1988

Robotized scanning laser handpiece for the treatment of port wine stains and other angiodysplasias.

Port wine stains are currently treated by the argon laser with the "point-by-point" technique, or the "painting technique." In both cases, the quality of the results depends greatly on the dermatologist's experience. Furthermore, the first technique is slow, and the second is painful and requires anesthesia. Therefore, we have decided to design a robotized system with the following specifications: easy, fast, non-painful treatment giving a homogeneous and reproducible blanching. The system is made of a handpiece with the scanning mechanism and a control box with the microprocessor. The system is independent of the laser (no electrical connection) and has its own power meter. The deposit of energy was optimized in function of heat diffusion in the skin. Over a 12-month period, 123 patients were treated with the robotized handpiece. The treatment modalities and the results conformed to the above-mentioned specifications. Hypertrophic scars were not reported. Therefore, we think that this system will be an interesting tool for the laser treatment of port wine stains and other cutaneous angiodysplasias.

Adolescent↗
PubMed1988

[A new method of laser angioplasty by contact sapphire: preliminary results. Apropos of 20 cases].

We report our first 20 cases of peripheral laser angioplasty using an optic fibre with contact sapphire tip. The equipment included a teflon catheter on which was screwed a round sapphire 2.2 mm in diameter. A 600 microns optic fibre connected to a Nd-Yag laser instrument was introduced into the catheter and placed in contact with the sapphire. Twenty patients underwent recanalization of femoral or popliteal arteries occluded on a length of 5 to 45 cm. The sapphire-tipped catheter was introduced by the Seldinger technique up to the site of occlusion. The 15 watt laser emission was set at intervals of one second. Sixteen out of the 20 occluded arteries were recanalized. Among the 4 failures, 3 were due to perforation and 1 to intraparietal progression. Angioplasty was performed with laser alone in 3 cases and with laser completed by balloon catheter in 13 cases. The minimum diameter of the laser-induced channel was 2 mm and was significantly increased (3.8 mm) by complementary balloon dilatation. In the 3 patients who underwent laser angioplasty alone, no noticeable improvement in distal blood flow was demonstrated by doppler velocimetry, and reocclusion occurred either soon afterwards (n = 2) or later (n = 1). Midterm results were much better in patients who had had additional balloon dilatation: early (3rd day) or late (2 months) reocclusion took place in only 3 patients. In the remaining 10 patients, followed up for periods of 1 week to 18 months (mean: 6 months), clinical improvement and recanalization were maintained.

Angioplasty, Balloon↗