[Local curative treatment of superficial adenocarcinoma in Barrett's esophagus. First results of photodynamic therapy with a new photosensitizer]. / Traitement curatif local des adénocarcinomes superficiels sur endobrachyoesophage. Premiers résultats de thérapie photodynamique avec un nouveau photosensibilisateur.

Pre-cancerous lesions and mucosally confined superficial cancers can benefit from local therapy given with curative intent due to the absence of near metastatic lymph nodes. Photodynamic therapy (PDT) which acts by laser irradiation with an appropriate wave-length after administration of a photosensitiser retained preferentially by the cancerous tissue can destroy tumour cells selectively, but its efficiency depends upon the photosensitiser. The results presented concern 10 sites on Barrett's mucosa (BO). They consisted of either an association of intramucosal cancer (IMC) with high-grade dysplasia (HGD) or of high-grade dysplasia alone. The method consisted of intravenous injection of Temoporfin 0,15 mg/kg 4 days before irradiation of the lesion with a green laser light emitting 514 nm through a windowed diffuser. The light fluence was 75 J per cm2 and irradiation 100 mW per cm2. Irradiation time was 12,5 mn. Omeprazole was routinely prescribed after treatment at a dose of 40 mg daily. The follow-up protocol was 2 years with endoscopic surveillance at 2, 3, 6, 12, 18 and 24 months. Biopsies obligatory at 2 and 3 months were in fact carried out at all the other delays. Efficacy was judged on the absence of high-grade dysplasia or intra mucosal carcinoma on biopsies at treated sites. Undesirable side effects noted have been moderate for the most part. No stenosis appeared. Treatment has been 100% successful for the 10 lesion after 15 treatments with PDT. The follow up varies from 6-36 months and was more than 18 months for 6 lesions on 5 patients. Our series has demonstrated a great heterogeneity in lesions which were sometimes visible and highly localised, but more often invisible, multi-focal and diagnosable only by biopsy at different levels. In keeping with the literature and our experience, PDT has several advantages over the other locally curative therapies, mucosectomy and thermocoagulation. These are the possible treatments without general anaesthesia, selectively for cancer cells, an action on more extensive areas with eradication of non visible lesions. Temoporfin has contributed notably to the field of photodynamic therapy compared to previously used sensitisers. It is a pure, synthetic product which guarantees more reproducible results. Compared with Photofrin, Temoporfin has many advantages with smaller doses of drugs and less energy, better selectivity and rapid elimination which reduce the risk period for photosensitisation. The frequency of important undesirable side effects is diminished. Finally, it produces a consistent effect on the surface and in depth producing a complete reepithelialisation of the treated zones. Subject to validation of the method on a greater number of patients, the first results obtained on superficial cancer in Barrett's aesophagus allow us to propose green light Temoporfin PDT as an alternative first line therapy with curative intent.

Comparative study of the effects of argon and neodymium YAG laser beams on the normal fundic wall in the beagle dog.

A study was performed to compare the lesions induced by argon and neodymium YAG laser beams in the normal fundic wall of the same beagle dogs and to follow their healing over a 21-day period. The total energy per application was 21 joules for the argon laser and 53 joules for the neodymium YAG laser. Both laser beams were emitted from the same distance, directed at right angles to the tissue surface, and with the same flow rate of coaxial gas. Thirty-nine shots were performed with each type of laser. Differences between the two lasers were observed in the appearance of the impacts, the volume of tissue affected, and the rate of healing, but all the lesions healed without any perforation. The differences observed were probably due to differences between the two lasers in the radial distribution of luminous energy and its absorption and transformation within the tissue into heat. It was concluded, however, that under the experimental conditions chosen, both kinds of laser could be used to penetrate the mucosal and submucosal tissue without risk of damage either to the longitudinal or to the serosal layers of the fundic wall.

[Endoscopic treatment of oesophageal sténosis using Celestin prosthesis (author's transl)]. / Traitement endoscopique des sténoses oesophagiennes par prothèse de Célestin.

The Celestin pulsion tube introduced by endoscopy seems to constitute a satisfactory method of dealing with oesophageal strictures, both malignant and benign. The site and histology of the tumour, as well as the diameter of the remaining lumen are determined by an initial endoscopic examination. The Eder-Puestow guide wire, essential to safe dilatation and intubation, may be introduced in various ways depending upon the size, length and nature of the stenosis: it may be threaded through the lumen with a fiberoscope under radiological control, or after drilling with laser. Subsequent dilatation may be carried out with olive-shaped metal dialtors, stepped plastic dilators of laminaria, depending upon the degree of fibrosis and the risks of fissuration. A final diameter of 17 mm is advisable. The pulsion tube, with its soft anti-migration skirt, is positioned using an introducer mounted on a semi-rigid mandrin or sliding over a fiberoscope. Its position must be checked at three-monthly intervals. The authors have used this method in 115 patients, 24 of whom had benign lesions and 91 malignant lesions. Among the latter, 23 had been irradiated, 7 were post-anatomotic and 61 had never been treated. There were 5 cases of mediatinitis and one of haemorrhage. Eleven tight strictures, wich had resisted dilatation with metal olive yieled laminaria. The longest follow-ups are of 19 months for malignant stenose and 40 months for benign stenoses. The main indications are malignant stenoses, irrespective of whether they have been irradiated or not, and peptic stenoses in inopereable patients. The procedure restores normal oral feeding, thereby avoiding the need for gastrostomy or jejunostomy.