The aim of this study was to evaluate the efficacy and the safety of endoscopic Nd-YAG laser treatment for early gastric cancer. Endoscopic Nd-YAG laser treatment was carried out in 20 patients; 12 with, early gastric cancers and 8 with borderline lesions.
In 11 patients with endoscopic diagnosis of early gastric cancer (type IIc 9, type IIa+IIc 1 and type IIc+III 1) and in 3 patients with borderline lesions trial treatment with Nd-YAG laser was carried out 2 to 14 days before gastrectomy. In 7 cases tumor cells were eradicated from the treated area, but in the other,7 cases (submucosal infiltration 3, muscle infiltration 2 and borderline lesion 2) residual tumor were observed in the periphery or deeper layers. On the other hand, in a patient with early gastric cancer (type IIa+IIc) and in 5 patients with borderline lesions Nd-YAG laser treatment was repeated 1 to 5 times as a curative treatment. Follow-up biopsies of the treated lesions confirmed loss of cancer and atypical cells.
Our results suggest that the endoscopic Nd-YAG laser treatment can be a curative method for cases of early gastric cancer limited to mucosa orinner layer of subnucosa without metastasis.

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Laser endscopy was applied to treat six cases of gastric cancer, a case of advanced gastric cancer and a case of early esophageal cancer. All cases ware males and two cases revealed type I, three cases type IIa, two cases type IIc and one case Borrmann III morphologically. Operation was not indicated in five cases because of associated diseases such as angina pactoris, liver cirrhosis, cardiac failure and postoperative status of malignancies. The mean age of five cases was 74 years old.
Laser irradiation was perfomed with the condition of 50 W/0.5 to 1 second from the distance of 1 cm in principle. This treatment was done for one to three days and the lesion was irradiated 14 to 120 times in each treatment. Three cases were successfully operated after laser therapy. Only the complication experienced was a perforation of the stomach due to direct irradiation to the ulcer although the patient was operated successfully. Five cases have been serially followed up for two to twelve months by the endoscopic biopsy and all have been still pathologically negative.
These data suggest that endoscopic YAG laser therapy could he applicable to those patients with early gastric and esophageal cancer who cannot tolerate surgical intervention.

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Microcirculation and intramucosal oxidative metabolism are visualized by optical analysis of intracapillary hemoglobin and oxygen metabolism in gastric mucosal tissue. Clinical application of this method has revealed that intracapillary hemoglobin concentration in corpus mucosa decreased significantly before appearance of acute gastric mucosal lesions. The decreased gastric blood volume in the ulcer margin at the healing stage of chronic gastric ulcer indicated an intractability of ulcer healing. The 2-dimensional display of the intracapillary hemoglobin conccentration using SIT tube and OSA 500 system could make the ischemic lesion clear. The color display also contributed to clear visualization of the ischemia and hypoxia of the mucosa. Thus, our function imaging could afford an effective method for detecting a microlesion, if combined with laser-fluorescence, -ab-sorption and -scattering. A laser Raman scattering using optical fiber during endoscopy was also presented and discussed with respect to analysis of molecular abnormality of the stomach, which will develop in future a new atraumatic, diagnostic method.

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Since a flexible delivery system was developed, it has been possible to treat bladder tumor with transurethral Nd YAG laser application. Herein, we report the results of the Nd-YAG laser irradiation on 72 tumors of 54 bladder tumor patients. Lumbar anesthesia was used in 46 cases and local anesthesia in 8 cases. 47 tumors were compleately resected with laser irradiation alone. Other 25 tumors were trated with electroresection or open surgery after laser irradiation. From our present clinical experience, we would like to make the following remarkes. 1) Transurethral Nd-YAG Laser surgery could be performed under local anesthesia. Accordingly it is indicated even for patients with severe complication. 2) Small tumor less than 1 cm is easily resected with laser irradiation, and tumor at the dome and the anterior wall could be eradiated. 3) Only a minimal or no bleeding occurred during the operation. 4) Bladder perforations were rare. 5) Obturator nerve reflex does not occur with laser irradiation, while it is often noted with electroresection. Thus, we believe that transurethral laser surgery could be reliable the for bladder tumor.

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In recent years, the Nd-YAG (Neodymium-yttrium aluminum garnet) laser has been successfully applied in neurosurgery for removal of hemorrhagic and hard brain tumors. The histological findings of rat brain tissue by Nd-YAG laser irradiation were investigated to elucidate the biological effect and the changes in chronic stage.
The first experiment was conducted on 12 rats. The fiber tip was fixed 2mm away from the dura mater. The brain was irradiated at the power of 60 watts for 1, 2 or 5 seconds. Half of the rats died on the spot.
The second experiment was conducted on 23 rats at the power of 60 watts for 1 second. Three rats were sacrificed immediately. Others awoke rapidly from anesthesia. Neither convulsive seizure or motor weakness was recognized. Four rats were sacrificed 48 hrs., 72 hrs., 1 week, 1 month and 2 months after the irradiation respectively.
In acute stage destructive changes were prevailing. Repair process followed to the invasion of polymorphonuclear leukocytes. Macrophages, fibroblasts and astrocytes etc. appeared. After 2 months a few cases disclosed small gliosis.

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Laser application has made a great contribution to neurosurgery. Advantages of Nd-YAG laser are highly coagulated ability and easy manipulation due to flexible beam fiber. Nd-YAG laser is suitable for 1) narrow operative field, 2) hemorrhagic tumors and 3) hard tumors.
During, the time period from December 1980 until October 1982, 77 patients have been operated on in our department of neurosurgery with the use of Nd-YAG laser. Histological changes of brain tumor after irradiation were investigated. Our series include 3 meningiomas and 2 mixed tumors. Laser injury cotained laser crater, carbonized layer, vesicular layer and edema layer. Beneath the carbonized layer nuclear changes were tremendous. These were pyknosis, fragmentation and karyolysis. Border between edema layer and normal part was not clear. Histological changes by Nd-YAG laser is due to acute thermal effect. In operative specimen this effect extended 6mm in depth and 10mm in the horizontal direction.

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The Nd: YAG laser has been applied in microneurosurgery and was found to be quite effective in the removal of hard and hemorrhagic tumors such as meningioma deep skull base tumors, or tumors in the deep ventricle. Another indication of the Nd: YAG laser is to open the thick sella floor in the transsphenoidal surgery. Comparing CO₂ laser, Nd: YAG laser caused short operation time and the latter was found to be quite easy to handle the laser quartz fiber.

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The cat's spinal dorsal column was irradiated with Ar of which power output was 500 mW and the spot size was 2mm in diameter. The somatosensory evoked potential was recorded. The conclusion can be summerized as follows;
(1) When the smaal demarcated area was made in the surface of the dorsal column with Ar laser irradiation, the early component of S. E. P. was disappeared. The histological examination shows the irradiated dorsal column was destroyed almost overall.
(2) By using the photosensitizing dye fluorescein i. v., the photoactivation effect of Ar laser was demonstrated in the spinal cord. The S. E. P. change and histological findings were the same as those of the experiment without using dye. So for evaluation of the photosensitizing agent in the spinal cord, the S. E. P. can be taken as the monitor of the Laser-Photo-Biological-Effect (L. P. B. h.).

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In 1973 Plog began his first experiment in laser therapy, mainly in the field of acupuncture and replaced the metal needle with the light beam. Based on Plog's report, the authors designed a laser system to stimulate the meridian points by intermittent irradiation of a pulsed beam through an optical fiber. The first prototype in Japan of a He-Ne laser acupuncture system was manufactured in 1978. Later the He-Ne laser was replaced with the YAG laser, which was divided optically into three beams to connect with three fibers.
Clinical application of YAG laser multi-acupuncture system proved that the laser therapy is effective to treat the muscle contraction headache, stiff neck, frozen shoulder, neuralgia, etc. Although some adverse effects were observed in the cases of vascular headache, the laser therapy could relieved the cluster headache.
One of mechanisms of the relief of pain is thought to be related to the relaxation of the muscles in an ischemic condition. The other possible neural mechanism is that impulses caused by laser stimulation has an inhibitory effect on the asending pathway of pain sensation. It seems likely laser acupuncture has also a humoral effect as Mester reported.

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Carcinoma of the maxillary sinus used to present poor prognosis. In 1963, Sato (1966) reported an epock-making technique in treating this difficult condition. His technique basically consisted of local chemotherapy via intra-arterial infusion, radiation and “necrotomy”. The term “necrotomy” implied daily procedures in which granulation, necrotic and fibrous tissues were mechanically removed via the window opened in the oral vestible. In our department, we have attempted his original method and various modifications since 1967. As for the treatments of carcinoma of the maxillary sinus, the best modalities appeared to be the following two combinations: (1) infusion, radiation and necrotomy followed by an eradicating surgery and (2) infusion, radiation and necrotomy associated with a mass reduction surgery. For the purpose of necrotomy or mass reduction, we adopted various method. The use of Nd-YAG laser has proved to be the best way of necrotomy or mass reduction for carcinoma of the maxillary sinus.

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Laser surgeries which employ CO₂ or Nd-YAG laser are very useful in treating head and neck cancers when correctly indicated. There are three major categories in the use of laser:(1) to treat cancers by the use of laser alone,(2) to use laser as one of the modalities in combination therapies, and (3) to use laser for palliation.
Tis and early Tl lesions are successively treated with the use of laser alone. These lesions are found most frequently in the oral cavity, oropharynx and larynx. Laser is used in varying combination therapies for cancers of the maxillary sinus, nasopharynx, oral cavity, oropharynx and larynx. For cancers of maxillary sinus and nasopharynx, laser is useful in executing necrotomy and mass reduction surgery. For advanced Tl and superficial T2 and T3 lesions of the oral cavity and oropharynx, laser is used for mass reduction surgery which is followed by radiotherapy and intra-arterial local chemotherapy. This modality minimizes postoperative functional disturbances. Basically the same procedure is applied to superficially located multifocal cancers of the larynx. For more advanced lesions, laser is not indicated.

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Since 1979, 308 patients have been treated by means of laser surgery at the otolaryngeal clinic of the Kobe University Hospital, Kobe City, Japan. The carbon dioxide surgical laser was predominantly used and sometimes Nd-YAG surgical laser was used.
Of the total of 308 patients, 149 cases were malignant, 26 cases were precancerous lesion, 53 cases were benign and 80 cases were other otolaryngeal diseases.
Satisfactory results were obtained in many cases by use of surgical laser as a single method of treatment or combined methods with other therapeutic methods.
But multidisciplinary treatment was required for more advanced cases of malignancy.
We used CO₂ surgical laser, Nd-YAG surgical laser, bipolar coagulator, cryosurgery, ultrasonic aspiration surgery, hyperthermia, radiotherapy, chemotherapy and immunotherapy in this multidisciplinary treatment.
These therapeutic methods have respectively advantages and disadvantages which are comprehended by us.
Satisfactory results were obtained for advanced cases of rnalignant tumor with proper use of these therapeutic methods in multidisciplinary treatment.
As a result, the extent of application of surgical laser was enlarged.

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A case is presented of an accidental macula burn caused by Q-switched Nd-YAG laser beam.
Massive vitreoretinal hemorrhage was observed at the posterior pole. Six month later a scar with pre-retinal membrane was observed in the macula.
The corrected visual acuity was 0.2.

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Trabeculo-trephining was performed utilizing CO₂ laser beam, which has several advantages to perforate the sclera.
1) Due to extremely narrow beam spread, very small spot size can be obtained (minimum 80μm in diameter).
2) Because of it's long wave length (10.6μm), the laser beam is well absorbed by the aqueous humor and vitreous. Therefor, damages to the lens crystallina and the retina can be avoided.
3) As the coagulation effect is obtained at the same time, no hemorrages are observed.
CO₂ laser unit with output range of 100mW-25W was used to make trephining in the trabeculum with a technique of trabeculectomy. To obtain perforation of the sclera, laser beam of 500um in diameter, l0W and 0.1 sec was used successfully.
In clinical study, 12 cases of glaucoma were selected to perform trabeculo-trephining at the limbus. None of them have after the surgery any complications of hemorrage and infection, and 10 of cases are still stayed under 20mmHg I. O. P. even 4 months after the surgery.

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Epidermal melanin disorders can occur as a result of melanin hyperproduction, hypoproduction, or non-production. When the melanin-producing melanocytes located in the epidermis produce too much melanin, hyperpigmentation results. Insufficient production of melanin results in hypopigmentation, and when melanin production stops completely, or when the melanocytes themselves disappear, depigmentation or vitiligo can occur as a result. I would like to introduce the various kinds of lasers with which we have been successful in controlling meianin disorders.

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During last three years, a trail of quantitative analysis of coloration of portwine stain was performed and a new method to classify portwine stain according to its optical nature was developed. Those of optical data were used as criteria of case selection before laser treatment and as fundamental materials to make proper judgement of result following laser treatment. A high speed spectrophotometric colorimeter (CMS-1200, Murakami) was used for this study. The optical data which we could acquire from CMS-1200 were including X. Y. Z.(Tristimulus value), x. y.(Chromaticity), L* (Metric lightness), a* b* (Metric chromaticity), C* (Metric chroma), H°(Metric hue angle), ΔE* (Color difference), R515 (Reflectance of P. S. to argon laser), d515 (Range of difference of reflectance between P. S. and normal skin), and so on.

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We have experienced to use the Nd-YAG laser since June, 1981. The Nd-YAG laser we have used was two types; Medilas YAG laser, MBB GrbH, West Germany and Molectron Model 8000, Molectron Co. Ltd., U. S. A. Laser beam delivered from these units was led by the quartz fiber covered with a polyvinyle tube and was emitted from the tip of this fiber.
We have chiefly used these laser units in the excision of vascular tumors, such as cavernous hemangiomas. For about one year, 10 cavernous hemangiomas of the head and neck have excised successfully with the Nd-YAG laser. By using this laser system, less blood loss during surgey has been obtained in all cases.
There was no differences between two type of laser units, but some differences in the cut surface arose out of the attachment adjacent to the quartz fiber.
Using scarpel as the attachment, the wound surface was covered with no carbonized layer and flat, and the coagulated layer was from 300 μm to 500 μm. So contact method with scalpel was thought to be slightly more available than non-contact method.
In this paper, we reported the management of cavernous hemangiomas with Nd-YAG laser.

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So far there has been many kinds of treatmant for hemangioma, bat none of them are satisfactory.
In this experiments, the author used newly devised Dye Laser which be to intermittent pulse beams and could produce beams of different kinds of wave length.
The author compared the Laser absorption of the hemangioma with that of the haemoglobin of the red blood cell and found both corelated considerably.
From upper comparison, the author chose beams of 610 nm and 575nm nave length and applied them to the hemangiomatous lesion and compared their effects to the tissue. It became clear that the beam of 577nm wave length was absorped far more selectively to the Itemangiomatous tissue than that of 610nm and the tissue damages were found mostly in the hemangiomatous area, lieving the surrounding normal tissue mostly unchanged.
As to the selective treatment of the lesion, there are the important factors, one is wave length and the other is the heat transmitting through the tissue.
From these points of view, Dye Laser seems to be more prosperous as to the selective effect than other continuous wave beams.

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Lasers is often radiated in the face and neck in the field of plastic surgery. YAG lasers must be used with great care because of its depth of radiation. Beneath the face and neck subcutaneously have the bones and brain, basic studies should be made to establish the conditions of safe radiation before clinical application of laser therapy.
The authors made experimental models which consisted of the superposition of either 1) soft bone and soft tissues or 2) bone and soft tissues (thickness: 7 to 8 mm for each) to study the thermal effects of lasers on them. This was on the assumption that lasers are used in areas where important organs, such as the brain, underlie the bone. Pig bones and livers were selected as bone and soft tissues. The laser device used was a Molectron Laser Coagulator Model 8000.
Based on these results, it is considered that even laser radiation direct on the bone has no thermal effects on the subosseous hepatic tissue if output is less than 60 W, if radiation time is shorter than 10 seconds, and if the radiation distance is less than 3 cm.

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A multispot photocoagulation system equipped with a fiber bundle scanner (FBS) is developed for the treatment of widely spread cutaneous lesion. The laser transmission system consists of multiple quartz fiber, the input ends of which are aligned and driven by a stepper motor across a high-power argon laser beam. The output ends are arranged in a hexagonal close-pack array from which the diverging laser beam successively irradiates different spots of a lesion without the use of a mechanical scan over the lesion. The output patterns from two bundles of graded index and step index fibers are analyzed experimentally.

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To treat the widely spreading cutaneous lesions, we propose a new laser transmission system, named Fiber Bundle Scanner (FBS), which produces a wide angle irradiation over the skin surface. In this section, the size of one irradiated hexagonal close-packed pattern (multispots) and the arrangement of these multispots were clinically investigated. When 5.0 watts power was used, the pulse duration was 0.14 seconds and the distance from the exit end of a fiber to the lesion was 35mm., the power density over the lesion was 400 mW/mm₂. In this condition, the size of a single spot was about 4mm. in diameter with a graded index type of quartz fiber of 0.4 mm.. The suitable size of one multispots was about 11 mm. in diameter with this FBS. To get uniformly irradiated result, the appropriate distance betweenthe centers of these multispots was 7 mm. at above these conditions.
Clinically, 71 cases with port wine stains were treated,by the FBS (graded index type). The progress reports of typically treated 3 cases were demonstrated.
Recently a new FBS using step index type fibers (SIF) was developed. The output laser spot from the SIF has a flat peak of of irradiance profile. Therefore, this scanner using SIF makes it easy and fast to irradiate the aimed lesion uniformly on the widely spreading lesions.

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Since 1980, we have developed the new ruby laser system for medical use, namely TMRL series, especially for the hyperpigmented skin lesions.
In 1981, kaleidoscope was introduced as an applicator instead of lens system which was fixed to the oscillator and this glass rod promised us the homogenous power distrubution and also the efficient irradiation with spuare exit surface.
In 1982, fiber-optic light guiding ruby laser system was developed for the first time in the world, and with this flexible manipulator, maneuverability has been so improved that the any site on the body surface can be irradiated.
With the most recent TMRL model, output power of 40 jule/cm² by 10×10mm square or 80 jule/cm² by 7×7mm square is availbale.
The authors will discuss about the clinical results obtained by using these TMRL series and also about the further problems.

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Autofluorescence of colonic polyps was endoscopically observed, which was excited by argon laser stimulation. When colonic polyps were stimulated by argon laser of 514.5nm wave-length, all of the polyps, regardless of the difference of their histological patterns, displayed autofluorescence, orange in color and slightly darken in tone than that of the normal colonic mucosa.
Especially in three cases of tubular adenoma with severe dysplasia (3/19), spotty or patchy and light orange colored autofluorescence was recognized brightly on the background of dark diffuse aurofluorescence. In adenomas with slight to moderate dysplasia, metaplastic polyp and inflammatory polyps, however, patchy and bright autofluorescence was not observed at all. Autofluorescence was cleary observed in colonic cancer in the previous study.
Although the biological mechanism of autofluorescence, generation is still unknown, it is quite interesting. That patchy autofluorescence was recognized in colonic adenoma with severe dysplasia, which is considered as high malignant potential and these findings were very suggestive of some relationship between colonic cancer and colonic adenoma with strong dysplasia.

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On this study we can take endoscopically the clear picture of the Argon laser induced fluorescence at the cancerous lesion of the stomach, the colon and the rectum by the ordinary method of taking a photograph of the lesion irradiated by the laser beam which was guided through the optical quartz fiber inserted into the biopsy-channel of the fiberscope. We don't need to use the image intensifier. The laser power at the tip of the optical quartz fiber is about 1 watt enough to take the clear picture of the fluorescence.
The same spot inside of the lesion may bring out the different color, when the Argon laser induced fluorescence is guided through the different sharp cut filters. Therefore, if we use only one sharp cut filter, we may give a wrong interpretation to such fluorescence. Then we must use different sharp cut filters alternatively.

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It is well recognized that fluorescence spctra of porphyrins vary with environments such as solvents, heating, pH and an absorption of light energy.
We studied the fluorescence spectra of hematoporphyrin (Hp), hematoporphyrin derivative (HpD) and protoporphyrin (Pp) in the various kind of conditions.
The fluorescence spectra of Hp, HpD and Pp in saline were so similar that an identification of porphyrins could not be made on the fluorometry. The fluorescence spectra of Hp in ethanol and in CCl₄ solution showed a red shift and an increase of number of peaks compared with Hp in saline. The addition of human serum to HpD solution rapidly produced a spectral change such as a red shift and a marked increase of intensity. The time course of a spectral change of HpD solution continuously illuminated by Argon laser showed a decrease of intensity and a change of the spectral shape. The fluorescence spectra of HpD in saline showed a red shift and a marked increase of intensity by heating of solution.

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FANFT induced transplantable rat urinary bladder cancer line (R9061) was used for this experiment. The cell suspension contain ng 2×10⁶ cells/ml was implanted into the bladder wall of a female Fisher rat.
In order to investigate photoradiation effect using the combination of Hematoporphyrin derivative (HpD) and Argon LASER, HpD of 2.5mg/kg dose was administered to each rat on the 5th day. Seventy two hours after administration of HpD, the rat exposed bladder received Argon LASER beam irradiation at a distance of 10cm from guartz tip to tumor. We could obsrve red fluorescence on the tumor by Argon irradiation. Results as shown would prove to be photoradiation effect with the combination of HpD and Argon LASER irradiation. M of the nontreated control group was 1.44g (n=4). M of the 60 sec. Argon irradiation without HpD was 0.988g( n=5). M of the 10 sec. Argon irradiation group with HpD was 0.49g (n=4) M of the 60 sec. Argon irradiation group with HpD was 0.62g (n=5). (M: average bladder weight)
There is a statistically significant difference between the nontreated control group and both the 10 sec. Argon group and the 60 sec. Argon group with HpD.(p<0.05)

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Effectiveness of photoradiation therapy for FANFT-induced transplantable tumor (R9061) and photosensitivity of HpD (Hematoporphyrin derivative) were studied, using intravesical instillation of HpD and Argon laser.
The average of rats bladder weight, which were intravesically administrated HpD (2.5mg/ml) 72 hours before radiation (10cm distance, 1W, 60 sec.), was 0.27±0.15g. The average of the bladder weight, administrated HpD just before radiation, was 0.25±0.08g. The control group (radiation only) was 0.27±0.132. There was no significant difference among these three groups.
The rats, had wood light after systemicadministration of HpD, showed severe edematous change in the skin. In the case of the. intravesical instillation of HpD, no skin lesion was demonstrated. It should be necessary to improve the way of administration of HpD to decrease its side effect.

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In an attempt to define the applicability of photoactivation therapy for cancer, the efficacy of therapy bad been studied using a tumor cell line (HeLa Ohio).
The light source were an argon laser (488, 514.5nm) and a krypton ion laser (647.1nm), Drugs tested were hematoporphyrin derivative (HpD) and Protoporphyrin disodium (PPNa) To investigate cytocidal ettects by laser irradiation with these drugs, the%⁵¹ Cr release was studied.
The %⁵¹ Cr release were less than 0.1% in laser irradiation only (60J/cm²), 49.2% in laser irradiation (at 514.5nm) with HpD (100μg/me) and 55.3%in laser irradiation (at 514.5nm) with PPNa (100μg/me)
The results revealed that laser irradiation only had no cytocidal ettect. while both of HpD d PPNa had intense cytocidal ettect.
Futhermore, these cytocidal ettects were strongly influenced by the changes of wave length
The most effective wavelength for laser irradiation with HpD or PPNa were 514.5nm.
These results showed that the photoactivation therapy with HpD may be more effective by the laser irradiation at 514.5nm, and from the intense cytocidal effects of laser irradiation with PPNa, PPNa may be effective as a new photosensitizer.

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Photochemical and photodynamical effects due to uptake of organic dyes incorporated with laser light irradiation on cultured cancer cells were studied. Cultured esophagus cancer cells (TE-2) were irradiated by Ar laser light after hematoporphyrin dihydrochloride (Hp. 2HCl) treatment. It was found that inactivation of these cells depends on Ar laser irradiated power and Hp. 2HCl concentration. Further more, we measured emission intensity at the wavelength 1.27um, of singlet molecular oxygen (¹O₂) generated from Hp.2HC1 in CC1₄ solution excited. by Ar laser light by means of the spectroscopic method. The measurement demonstrated that the emission intensity, that is, the concentration of ¹O₂ generated in this process, is approximately proportional to the Ar laser output power and the dye concentration. It was concluded that inactivation of cultured TE-2 cells shows certainly correlation with the concentration of ¹O₂ producted in laser-irradiated dyes.

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Rat hepatoma cell suspensions (JTC-16) containing various concentrations of HPD were irradiated with argon laser of 488nm and 514.5nm and dye laser of 630nm wave-length. Laser was irradiated with an energy of 5mW/cm₂ for 1, and 3 minutes, respectively. Morphological changes of cell structure were observed by a phase microscope immediately and 24 hours after irradiation. The results obtained were as follows.
1) Without addition of HPD, 3 minutes irradiation of laser with different wave-length did not damage cell structure at all.
2) With HPD concentration were 25,μg/ml, the cells were damaged even without any laser irradiation.
3) With low HPD concentration of 2.5μg/ml, the cell started degenerating with longer duration of laser irradiation.
4) The difference of wave length was negligible as to the cell damage.

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An attempt was made to evaluate a biological effect to the CNS and an antitumor effect in vivo and in vitro by argon laser photoirradiation associated with or without a fluorescein durg. The injury to the CNS was evaluated dose-dependently by exposure of the mice brains, and the photoactivated effect was evaluated by exposure of the spinal cords of the cats after cooperation of fluorescein. Retardation or temporary arrest in growth of a mouse fibrosarcoma (Fsa II) implanted subcutaneously in C3H mouse, was accomplished by exposure of the tumor to activating argon laser after cooperation of fluorescein. The photoirradiation therapy of argon laser proved lethal dose-dependently to the glioma cells in culture. The preliminary and basic study suggest a new method to the treatment of human gliomas by using an argon laser photoirradiation with fluorescein drug. However, a thermal effect to the CNS of the argon laser photoirradiation is very extensive, and further development and research are planned.

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Laser photoirradiation treatment using hematoporphyrin derivatives (HPD) has been successfully applied to treat breast cancer, bronchial cancer or other cacncers. However, there has been no report about its successful application in human giomas. We considered it mandatory to perform basic experiment before its application for human glioma.
Using rat T1 glioma inoculated subcuteneously, up-take of HPD was confirmed 24, 48, and 72 hours after intravenous injection of HPD.
Using HPD containing Ti cells cultured in vitro, laser irradiation of 630 nm, 50-400 mW and 15 minutes interval was shown to cause cell damage or cell death.
These data suggested that laser photoirradiation with HPD will be very effective for human gliomas. If some difficulties such as laser output wattages, penetration into tissues, price of laser machine, etc is overcome, this method of treatment will be one of the main therapeutic modalities for human gliomas.

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In this paper, we described the effectiveness of a laser photoradiation system involving intravenous administration of HpD and N₂ dye laser. For diagnosis, N₂ dye laser was used as a violet light sourse to excite of HpD, and the resulting fluorescence was observed through an image intensifier (Vara 8853). We obtained the following results. 1) Fluorescence was observed with image intensifier down to a concentration of 5 x 10^-3pg/dl in the laboratory model with use of HpD (5mg/d1) diluted solution. 2) Fluorescence was observed clearly both on the bared transplanted sarcoma in mice 48 hours and on the bared transplanted adenocarcinoma in mice 72 hours, and on the fresh resected specimens of stomack cancer 48 hours after intravenous H_pD (5mg/kg) administration. No fluorescence of tumor was observed through skin and non-cancerous epithelium. Indigocarmine solution used in dye spraying method did not disturbed the tumor fluorescence but blood and mucous lake disturbed.

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Argon-dye laser photoirradiation therapy following i. v. injection of hematoporphyrin derivative injection (HpD-PRT) is receiving increasing attention as a selective cancer-destroying method. We have applied HpD-PRT to treat cases of malignant head and neck tumors. The method consisted of irradiating the lesion with the laser beam transmitted via a quartz fiber 48 hours after i. v. injection of HpD. The standard light dosage was 200-500 mw/cm² for about 20 minutes. The cases were all male patients and consisted of 2 cases each of laryngeal cancer, meso pharyngeal cancer and cancer of the tongue.
Summary of Result:
1.The cancerous tissues showed extreme damaged in all the cases with no damage to normal tissues. 2.The edema immediately after the therapy was extreme so that it was found that a preliminary tracheotomy is necessary before treatment of lesions in the neighborhood of laryngeal region. 3.It is easy to apply the therapy to lesions in the oral cavity or in the soft pallate,but to lesions in the laryngeal region, where the morphological construction is so complicated, having many concave and convex surfaces and involving many reflex movements or storage of salive, it is not possible to obtain sufficient and homogeneous photoradiation of the total lesion with present instrumentation. 4.Deep-seated lesions are not controllable, but this therapy was found suitable for treatment of superficial lesions and cases of carcinoma in situ in the oral cavity, etc.

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Argon laser photo-chemotherapy with HpD has resulted in complete response in all of four patients with stomach and rectum carcinomas. At 72 hours after the administration of 2.5-3.0 mg/ Kg HpD intravenously, Argon laser beam with 0.4-1.5W, for 25- 50 min, was irradiated to the neoplastic lesions. Tumor regression was observed rapidly on the lesions with tissue necrosis within 24 hours after the treatment. The laser-induced ulceration was clearly demarcated from the surrounding normal mucosa. Complete disappearance of the tumor mass observed macro- and microscopically in a case with early rectal carcinoma. Invasive gastric cancers were also eradicated in three patients, but remained cancer cells were detected on repeated endoscopic biopsy. Since the present procedure give no influence to the immunological response of the body, a further laser treatment could be applied for total regression of neoplasm. Comparing with Nd: YAG laser treatment with a high energy, Argon laser photo-chemotherapy could be more effective as to tumor regression and less hazards. Because of applying the selective effect of HpD in the neoplastic cells, the procedure could be safely used in clinical medicine without surrounding normal mucosal damage.

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The effect of Nd-YAG-LASER: in liver surgery, especially in the treatment of hepatic tumor and injury, was investigated histopathologically in laboratory dogs and human clinical cases by means of laser scalpel. The device used was Molectron Model 8000 Nd-YAG-LASER. Hepatic substance affected by laser irradiation may be classified into 4 distinct layers according to the severity of histological change, i. e.
1) Vaporization layer 2) Coagulation necrosis layer 3) Acidophilic degeneration layer and VI) Edema layer.
Laser scalpel permits removal of tissue at low accumulated energy, hence causing lesser tissue damage. It ensures a shortening of the duration of operation with a consequent reduction of blood loss and is anticipated to have a wide range of application in surgical procedures.

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In the field of general surgery we have, since 1977, used the CO₂ laser scalpel (Medilaser-S) in more than 400 clinical cases and have conducted follow-up study in order to determine the effectiveness of the laser treatment.
In this paper we report on the results of our analysis of these cases and describe what we consider to be the indications for use of the CO₂ laser in general surgery, the laser output best suited to the particular form of surgery required, and the diseases for which use of the laser is recommended.

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The YAG laser equipment (Fujinon YAG laser coagulater, multi-purpose type), which is installed in the endoscopy room, has a quartz fiber extended 30 meters to the surgical theater, where the YAG laser was applied for surgical treatment with a surgical hand piece on the end of laser guide.
1. The laser beam was successfully applied on wedge resection of the pancreas directly invaded by the gastric cancer with minimal bleeding.
2. YAG laser was very effective in vaporization of small liver metastasis.
3. Operation of hemorroids by YAG laser; After operation, there were no edema nor pain. The patient had good healing and very short hospitalization.
4. The laser beam of 130,000 Joule was applied on the complete stricture due to the perirectal metastasis of the advanced gastric cancer through a proctoscope, and ileus was removed resulting in success of intake of meals without making artificial anus.
5. Treatment of the decubitus; The diffused YAG laser beam of very low power played the role of debridment, sterilization and promotion of the healing in 4 cases of the decubital ulcers.

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The selective proximal vagotomy for peptic ulcer has some difficulty in the operative technique and this operation has higher recurrence rate than conventional gastrectomy.
We attempted to block the vagus nerve through irradiation of the gastric serosa with carbon dioxide laser in order to simplify the operative technique and to make sure of the effect.
The carbon dioxide laser with the out put power of 30 watts as a deforcused beam with diameter of 10mm moved at speed of 10mm/sec. was the optimum condition for the degeneration of the subserosal vagus nerves. The vagus nerves were completely blocked on electrophysiological and histological studies and there were no regenerative findings one month after laser radiation.
The blocking of the vagus nerves on the gastric wall with laser prevented from duodenal ulcer induced by cysteamine in the rat.

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The 'no touch'isolation technique by Turnbull has been commonly approved in surgical removal of malignant disease of the colon. By Turnbull's isolation technique, micro-vascular dissemination in mural tissue or peritoneal dissemination at serosal invasion of the cancer cannot be prevented. We have developed more complete isolation technique by YAG laser.
Serosal isolation; Peritoneal isolation of the serosal invasion of cancer was performed by 20 W defocused YAG laser beam forming 300 μ of photocoagulated cancer-free necrotic tissue layer on the serosal surface. Transmural and mesenteric isolation; Transmural and mesenteric isolation were performed by continuously and slowly applying the diffused 40 W YAG laser beam around the cancer with forming all vessels obliteration. Both the mural and mesenteric dissemination were sealed by forming the photocoaglated transmural enclosure around the cancer.
The combination of serosal, transmural and mesenteric photocoagulation isolated the cancer completely.
This method could be applied in many kinds of surgical removal of cancers such as stomach cancer, pancreatic cancer, etc, which have more complex lymphovascular system than colonic cancer.

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Since our introduction of a Aloka's high-output carbon dioxide laser surgical unit to our surgical practice in the autumn of 1980, we have performed well over 300 operations at the Department of Surgery of the Tokyo Rosai Hospital in less than two years. Fourteen cases (4.7%) have been related to neoplastic or non-neoplastic diseases of the salivary gland and the thyroid. Namely, laser surgery has been applied to 5 cases of the salivary gland and 9 cases of the thyroid. This includes an incision, enucleation of the tumor, and partial or total extirpation of the gland. In some malignant diseases, the laser has been also utilized for an enbloc resection of metastatic lymphnodes.
An application of the carbon dioxide laser to this field of general surgery has shown definitive advantages over conventional surgical modalities in terms of excellent hemostasis as well as unique tumoricidal and bacteriocidal effects of the infrared laser beam. Healing of the carbon dioxide laser wound has been comparable to the electrosurgical wound. Current limitations and disadvantages of laser surgery will be also discussed.

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The effect of irradiation with low power laser on wound healing was studied. 80 guinea pigs were subjected to this experiment. Two open wounds, 1cm in diameter, were created on the back at the right and left side in each animals. The wound was limited to the skin (shallow wound) or excised as deep as the muscular layer (deep wound). Unilateral wound was irradiated with Argon laser (energy density 2 J/cm² or 6 J/cm²) every day or every other day till the wound completely healed. The contralateral wound was not irradiated. From this study the wound healing was accelerated by irradiation with Argon laser average 3 days faster than that of the non-irradiated wound.

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We have been performing endoscopic suergery, in which the Nd-YAG laser is irradiated under bronchofiber scopic observation, or the therapy by argon dye laser photoirradiation combined with the administration of hematoporphyrin derivative (HpD) on patients with lung cancer since 1980. After the laser photoirradiation, the exposed lung cancer cells show degeneration, necrosis and fibrosis. These changes were histopathologically compared using biopsy specimens obtained under bronchoscopic observation and opration specimens. The tissue specimens were examined primarily concerning chages in the bronchial wall according to the criteria for the evaluation of effects of the conservative treatment suggested by Oboshiand Shimosato (Grades 0 to IV).
The determination of the histopathological changes occurring in lung cancer following laser photoirradiation proved helpful to the improvement of the irradiation conditions and methods.

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Nd-YAG laser irradiation via the fiberoptic bronchoscope was performed in cases of tracheobronchial lesions to widen the airway in cases of stenosis of major airways by benign or malignant tumors, vaporization of small malignant lesions in inoperable cases or to coagulate bleeding lesions.
During 2 years and 7 months, 36 malignant and 14 benign cases were treated. To improve techniques of laser treatment, we studied effects on survival in malignant cases or the pathological effects on benign lesions.
Because of the nature of the malignant case, i.e. advanced cancer cases with severe dyspnea in which are confronted with a catastrophie outcome, it is impossible to make a comparison in terms of 6 month survival. However, it can be said that this modality can obtain relief and improvement in the quality of life in these cases and render theircancidates for other palliative modalities such as chemotherapy or radiotherapy. Nevertheless, it must be realized that this mode of treatment does not alter the natural history and systemic program of the disease.
In other words it appeares that this method has no effect on factors affecting survival apart from the episode of respiratory distress.
In benign cases in which active inflammation is not present, a single vaporization procedure is generally sufficient, but cases of active inflammation showed regrowth to the original conditions within one week to 3 months.
In conclusion, despite the ever increasing enthusiasm for laser applications in medicine, in cases involving the tracheabronchial tree, this particular method is indicated in only a small number of cases.
It is essential to comprehend the principle and effects of this method when selecting candidates, but in those few cases in which it is indicated it can be dramatically effective in relieving the symptoms of respiratory distress.

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The results of the treatment of tracheo-bronchial tumors had been unsatisfactory. In such cases, we have discussed our endoscopic surgical experience with treatment using YAG laser. In three cases, endoscopic surgery was employed using Olympus MYL-1 YAG laser which was accompanied by irradiation. Laser beam was guided through the biopsy channel in the bronchoscope, and cauterized the tumors serially. With these treatment, dyspnea and ventilation disturbance, which were caused by tracheo-bronchial obstruction, subsided.

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Tissue vaporization by an Nd-YAG laser via a teflon-clad quartz fiber inserted through the instrumentation channel of the fiberoptic bronchoscope was applied clinically in 1980. A total of 35 cases have been treated by this method. The purpose is to widen the airway in order to eliminate ventilatory disturbance or other pulmonary complications, therefore it can be indicated in certain cases of malignant or benign cases of airway stenosis. In one case of remarkable tracheal stenosis caused by adenoid cystic carcinoma this method totally eliminated ventilatory disturbance. While it can be dramatically effective in some cases of lung cancer, it must be remembered that it often does not achieve complete vaporization of all tumor cells. Therefore when applying this modality in the palliative treatment of ventilatory disturbance in cases of lung cancer, great cosideration must be devoted to the site and size of lesion, as well as the depth of invasion and how this method can best be combined with other therapeutic modalities.

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New CO₂ laser and laser microsurgical technique have been developed for the anastomosis on the small vessels (0.4-1.4mm diameter). The success of consistent and fast laser vascular anastomosis of the small vessels (96%) were basically required,
(1) short distant tissue penetrating specific CO₂ laser,
(2) optimal power density of the laser (1.5-2 joule/mm²),
(3) small focused beam (90-120μm dameter) and
(4) placement of laser beam on the well adapted vascular edge at the anastomose.
The laser irradiated patent arteries indicated less necrosis, scarring and faster healing than conventional suture arteries in the pathological studies. As a consequent, this technique could be highly expected to bring the good results on the clinical treatment of ischemia of the various organs. We have reported these technique detail and discussed about the results and complications.

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