Recently, access to the coronary arteries became available to laser angioplasty based upon a new concept which utilizes a pulsed laser source and multifiber,“over-the-wire”guided catheters. The aim of this study was to evaluate the early results and the side effects of coronary angioplasty using a Holmium-YAG or an excimer laser. Forty-two consecutive patients were treated with the Holmium-YAG laser (group I) and 61 consecutive patients were treated with the excimer laser (group II). The procedural success rate was 98%and 87%for group I and II, respectively. It was similar in calcified and in non-calcified lesions and in total occlusions and stenoses. Dissection occurred more frequently in group II than in group I patients. In selected cases, coronary angioscopy was performed to elucidate the mechanism of these complications. The characteristics of angioscopic findings after excimer laser angioplasty consisted of flaps, fractures of plaques and abundant tissue remnants. These results indicate that 1) the procedural success rate using either laser is high, 2) Ex has a higher rate of dissections, and 3) Tissue remnants, mural thrombi or flaps may explain the complications after laser angioplasty.

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Argon laser angioplasty was performed in 86 patients with peripheral arterial disease. Initial clinical success was achieved in 79 (79%) of all 101 lesions.%stenosis of the lesion on arteriogram was signigficantly decreased from 92.2±10.7 preoperatively to 19.1±19.8 (p<0.01), and ankle pressure index was remarkably improved from 0.50±0.18 to 0.85±0.20 (p<0.01). there were no complications required emergency operation. At the follow-up of 81 months, the cumulative patency rate was 76%in 74 cases with initial clinical success. These results suggested that laser angioplasty might be a useful treatment for the patients with arterial occlusive diseases and improve the long-term patency rate compared with conventional balloon angioplasty.
Besides, angioscopic inspections were performed in the 24 patients who underwent laser angioplasty. Useful images could be obtained in 20 (83%) of 24 observations, and the successful rates of angioscopic observation were influenced by the diameter and the degree of kinking of each vessel. Angioscopy was useful not only for a diagnostic tool to inspect vascular atherosclerotic changes but also for a guide of laser recanalization.

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Angioscopy is a new diagnostic tool that permit non-operative imaging of intravascular structure. However, the efficacy of angioscopy has not be defined. Therefore, we investigated the strength and weakness of angioscopy for the diagnosis of intraluminal changes, compared with intravascular ultrasound. We also evaluated the efficacy of angioscopy during laser angioplasty and thrombolytic therapy. Finally, we evaluated whether coronary angioscopy can predict adverse outcomes such as sudden death, or acute myocardial infarction. I. The strength and weakness of angioscopy: Both angioscopy and intravascular ultrasound were performed using 27 postmortem human arterial segment. Angioscopy was much more sensitive in detecting thrombus, complex atheroma, and yellow atheroma than intravascular ultrasound. II. The efficacy of angioscopy during intervention: (1) Laser angioplasty. Using the torc control and the angulation mechanism of the angioscopic catheter, all target lesions were placed to the good position for laser irradiation. Nine out of 11 laser angioplasty were succeeded without perforation. (2) Thrombolytic therapy. Angioscopy could define the character of coronary thrombi (e. q. red thrombi, white thrombi) and angioscopy revealed the efficacy of thrombolytic therapy depended on the character of thrombi. White thrombi were more resistant to thrombolytic therapy than red thrombi. III. The prediction of adverse outcomes: Lesion morphology was classified into 4 patterns by angioscopy. The presence of massive hemorrhage or thrombus is associated with a high proportion of adverse outcomes. Conclusions: Angioscopy is useful for vascular interventions and the prediction of coronary adverse outcomes.

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The newly developed coating type ceramic tip has been already used clinically to treat lesions of G. I. tract. Asessing the efficacy and safety of this of type ceramic tip for clinical application of Laser angioplasty, in vitro basic quantitative study was performed using specimens of human common iliac artery. The volume of laser ablation was measured on each energy of Nd: YAG 1.32μm laser irradiation using two types of ceramic tip (coating type ceramic tip and non-coated usual tips). The quantitative data were analyzed to determine the significance of two types tip. A definite difference in volume of laser ablation was cleary demonstrated. The volume of laser ablation irradiated by coating type tip was larger than non-coating usual type tip. As the laser energy incresed, the volume of ablation increased. Using coatig type ceramic tip at over 30J, volume of laser ablation increased sharply and 60J laser perforated the iliac artery.

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The experimental study of partial isolation with Nd: YAG Laser was performed. After the right lateral thoracotomy in five dogs, temporal pacing wires were sutured on the free wall of right atrium and right ventricular myocardium. Under overdrive pacing of atrium or ventricle, Nd: YAG laser was delivered continuously on the epicardial surface around pacing wires with cooling on the lased surface with cold saline. The lasing energy was 25J, and 1~2ml per minute cold saline was splashed on the lased surface from side-holes of laser fiber. We used a pen-held type laser probe with the contact tip positioned at the top of 600μquartz fiber. The diameter of the tip was 2.2mm. The pacing sites of myocardium were easily isolated from surrounding myocardium without perforation and charring. The microscopic view of lased myocardium showed well-demarcated and transmural necrosis, which area was larger than that of necrosis made by non-contact lasing because of scattering in tissue. We concluded that laser ablation might be applied to maze procedure for a new method of atrial isolation.

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we experimentally and clinically assessed the accumulation of doxycycline in arteriosclerotic lesions by fluorescence microscopy and fluorescence spectrum analysis.
In the experimental study using spectral analysis, we observed autofluorescence of the media the intimal thickening was less than 100 μm and its peak at 540 nm. we also observed mixed fluorescence spectral patten of doxycycline fluorescence peak at 560nm and media autofluorescence of 540nm peak.
In contrast, when intimal thickening was 100 μm or more, we observed only doxycycline fluorescence peak at 560nm.
In the clinical study, doxycycline fluorescence (peak at 560nm) was observed at sites of coronary artery stenosis, and the intensity of this fluorescence was significantly higher than at normal sites.
Sinece yellowish-green doxycycline fluorescence was observed by fluorescence microscopy of DCA tissue obtained from angina patients treated with thin agent, doxycycline obviously accumulates in the arteriosclerotic lesions of human coronary arteries in vivo.
This method appears capable of being applied to intraoperative monitoring of the PTLCA, DCA, etc, as well as to PDT.

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A new photosensitiser, NPe6, is known to accumulate selectively in atherosclerotic plaques. At six hours after administration of NPe6, atherosclerotic tissue was recognized by detecting the specific fluorescence spectrum of the photosensitiser using a spectrophotometer. We reported that atheromas were diagnosed both angioscopically and laparoscopically. In this study, we demonstrated specific detection of the fluorescence of NPe6 emitted from the atherosclerotic coronary arteries using an epifluorescence stereoscope sysytem.

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A new photosensitizer, PH-1126, was administered intravenously into the ear vein of cholesterol-fed atherosclerotic rabbits at a dose of 1mg/kg of body weight. At 24 hours after PH-1126 administration, the atherosclerotic lesions of the abdominal aorta was irradiated by krypton ion laser at 647nm of wavelength with 100J/cm². The abdominal aorta irradiated by laser beam was excised for histological analysis using, the scanning electron microscopy and transmission electron microscopy.
In the atherosclerotic plaque irradiated by krypton ion laser, migratory cells were observed and some of these cells were migrated into the lumen of the vessel. These findings suggested that these migratory cells from atherosclerotic plaque were foam cells destroied by photodynamic therapy.

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As a part of our research on the application of pheophorbide-a using photodynamic therapy (PDT), we assessed the accumulation of this agent in arteriosclerotic lesions and analyzed its fluorescence spectrum. After inducing arteriosclerosis in the abdominal aortae of Japanese white rabbits, we administered them pheophorbide-a (20 mg/kg) via the jugular vein and sacrificed them for autopsy after 1, 6, 24, and 48 hours later. Red fluorescence of pheophorbide-a was obsereved in the thickened intima by fluorescence microscopy, and spectral analysis revealed a fluorescence spectrum peak at 680nm. This fluorescence intensity peak at 6 hours after administration tend to diminish. Pheophorbide-a shows accumulation in thickened intima, and it appears that diagnosis of the atherosclerosis using pheophorbide-a by fluorescence spectrum analysis will be able to apply this agent for PDT in the future.

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We developed a new laser-hot-balloon angioplasty system to overcome restenosis problem after balloon angioplasty. We developed a new laser-hot-balloon angioplasty system to overcome restenosis problem after balloon angioplasty. We have developed the laser-hot-balloon catheter which realized short heating duration to improve poor clinical patency using conventional hot balloon catheter. Acute and chronic animal experiments of our laser-hot-balloon angioplasty revealed that ristricted heating zone within vascular wall thickness due to short heating duration made effective results to solve abrupt reclosure and chronic restenosis. However,since an irrigation of contrast medium which was heated by laser radiation was maintained by hand,operation,a lack of temparature reproducibility and breaking down of heat generation structure were observed due to fluctuation of the rate. TO stabilize irrigation rate to solve these problems, we constracted the automatic irrigation system. This system consisted a specially made constant injector,inlet and outlet pressure monitors, and computer controlled variable valve. The typical flow rate was set to 0.04ml/sec. The typical balloon pressure was controlled 3 atm. The flow rate of contrast medium was completely stabilized. The reproducibility of balloon temparature and breaking down rate were drastically improved. We think that our laser-hot-balloon system with the automatic irrigation system would be the practical angioplasty system for stenotic desease.

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The catheter combined with endoscope and intravascular ultrasound for laser mitral commissurotomy was develped. The catheter had a lumen for laser fiber and had the function of vending. This newly developed catheter was named the L-PTMC2. The diameter of endoscope was 2.3mm and the diameter of intravascular ultrasound was 2.4mm. Therefore the cutting area of this catheter could be decreased from the old type. With this catheter animal experiment was performed using the mongrel dogs. After the left thoracotomy, the L-PTMC2 was inserted from the left atrium. Scanning with the intravascular ultrasound, the laser-tip was approached to the commissure. Comfirming that the laser tip was touched to the commissure with the endoscope, the laser ablation to was performed. In conclusion, this catheter considered to have an ability in clinical application.

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Purpose: To elucidate the good indication of percutaneous transluminal laser angioplasty (PTLA) for arteriosclerosis obliterans (ASO) from the outcome of PTLA. PTLA was carried out using 1064nm continuous wave Nd: YAG laser. In most cases a ceramic tip laser probe was used for contact method for laser irradiation. Twenty to 25 Watts were used and the time of lasing varied for 1 to 2 seconds. Lasing was repeated until a hole was created in the obstructive lesions. The diameter of a hole was about the diameter of the probe, which was 1.8mm. Additional balloon dilatation was done after lasing. During the period of March, 1985 through March 1993, 134 lesions in 77 patients with peripheral ASO were treated by PTLA. Initial success rate was 90.0%during the first 6 years, and 87.3%during the whole 8 years. The cumulative patency rate of total lesions was 89.7%at the end of 6 years, and 67.7%at the end of 8 years. However, those lesions, less than 10cm in length, revealed a good cumulative patency rate, which was more than 80%. The 8-year-cumulative patency rate of the iliac lesions was about 80%. There was no major complication. Dissection of arterial wall was noted in 19.4%of cases. This was caused by balloon dilatation and not by lasing. Distal embolization was noted in 7.5%of cases, but the occurrence of the complication markedly decreased after the application of aspiration of sludge before penetrating the final segment (1cm) of the occlusion. No perforation of the artery was noted. PTLA is especially indicated to peripheral occlusive arterial disease, less than 10cm in length. PTLA expanded the indication of percutaneous treatment of ASO, since lesions, in which PTA failed, could be treated successfully.

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We successfully developed a new hot-balloon catheter system with Nd: YAG laser (laser hot-balloon catheter; LHC) which was able to heat in short duration to minimize heat injury to the surroundings of a vessel. The uniform temperature distribution throughout the balloon was attained by the irrigation of the heated contrast medium. In vitro experiments demonstrated the efficacy of new angioplasty using the LHC.

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The optical laser setting for successful hemostatic transection of vessels using Laser Bipolar Dissector (LBD) and the important factor in closure and the healing process of the vessel stump were examined in abdominal aortas, mesenteric arteries and femoral arteries of rabbits (n=40). Interluminal bursting pressures (BP) were measured. The cutting edges were harvested at one week (n=4), at 2, 3 and 4 weeks (n=4) and 6 months (n=4), and evaluated by light microscopy. Histopathological examinations were carried out by HE and EVG stainings.
The BP immediately after transection at laser power of 10 (n=5) and 13W (n=5) was above 346mmHg, and that of 15W (n=5) and 20W (n=5) was 280mmHg, 208mmHg respectively. The transected sites of vessels revealed well-apposed tissue welding of vascular wall. The welding of internal elastic lamina without fragmentation is histologically most important for closure of the vessel stump. An increase in the laser power from 10 to 20W resulted in increased severity of histopathological deterioration of tissue connectivity (n=10, p<0.01) and in decreased bursting strength (n=5, p<0.01). Laser power of 10 to 13W was the most suitable for hemostatic dissection of large vessels. In the healing process, cartilaginous foci (n=4) were observed in the vascular cutting edges at 4 weeks after LBD dissection, and osseous foci (n=3) were observed at 6 months.
These observations may suggest that use of the LBD for vascular transection results in excellent tissue welding of vascular stumps in 2 to 3mm diameter arteries and that the the vascular stump is repaired with the strengest tissue material.

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Percutaneous laser disc decompression (PLDD) is a very safe, simple, effective and epochmaking treatment of lumbar disc herniation. We have performed 144 procedures of the disc decompression in 105 patients with successful results in 70%, three months after the PLDD, according to the“Low Back Pain Score”of the Japanese Orthopardic Association.
The resuts were followings: 72 patients had refief of the pain immidiatery after the procedure. MRI findings at three months after the PLDD schowed moderte decrease of the disc herniation. While three patients required PLDD more than two times. Four patients required subsequent open laminectomy. We have no complications in our series. The average duration of this surgical treatment was only 11 minutes.

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Last year, we proposed the new method of neurotomy by using laser. However, there appeared sometimes the problem that the power density at the tip of the optical fiber was high enough to carbonize the tissue around the tip of the optical fiber when the laser power was high enough to be obtained the total thermal degeneration of nerve fiber. In this study, in order to improve these problem, we examined the kind of laser and the combination of dye and laser. We selected argon laser that has a good absorption in tissue. And we selected indocyanine green (ICG), which has a good absorption in infrared area, to combine with infrared semiconductor laser. By using rabbits, the reaction of nerve fiber with argon laser and that with the combination of ICG and semiconductor laser were investigated pathologically. When using argon laser, the thermal degeneration in nerve fiber was observed with more than 200mW of laser power. However, the carbonization around the tip of optical fiber tended to be occurred. When using the combination of ICG and semiconductor laser, the thermal degeneration in nerve fiber was also observed with more than 200mW of laser power. In this method, the area in which dye was applied was heated up selectively, so it was considered to be useful method to realize the neurotomy by using laser.

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In the present study, we examined the clinical effects of irradiation of linear polarized light therapy in our out-patients.
The most of the acute patients subjectively noticed the improvement of their symptoms immediately after onset of the therapy.
Furthermore we speculated that the long-term irradiation therapy can be more effective than short-term therapy in the chronic patients.
We conclude that the linear polarized light therapy is useful and non-invasive therapy.

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Nd: YAG laser has high penetrating rate to the tissue, and it is possible to vaporize the tissue, efficiently. Taking advantages of these characters of the Nd: YAG laser, we carried out transurethral laser surgery for benign prostatic hyperplasia by method of contact irradiation in 57 cases between April 1993 and August 1994. Forty-nine cases of them were without other adjuvant therapies.
Patients' age ranged 53-85 years old (ave. 69). The results of preoperative examinations were as follows: AUA-Prostate Symptom Score (AUA-PSS) was 15-32 points (ave. 21), maximum flow rate (Qmax) 0.4-14.4 ml/sec(ave. 6.25), and average flow rate 0.4-9.8ml/sec. (ave. 3.7).
In all cases, the prostatic tissue was evaporated by contact irradiation method at over 50 watts output. No bleeding was found during and after the operation. Total amount of irradiation was 1700-117030 joules (ave. 26235), operation time 15-105 minutes (ave. 46.6). The results of postoperative examinations were as follows: AUA-PSS of 4-26points (ave. 11), maximum flow rate(Qmax) 2.9-29ml/sec. and average flow rate 1.8-18.4ml/sec. (ave. 9.0).
There were 18 cases with transitory urinary retention when catheters were removed 3-5days after the operation. Acute epididymitis was found in 3 cases. Now we are researching the long term results of 1 year follow up, postopeatively.

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Since 1992, we have performed the VLAP using right angle laser derivery system (Urolase) for the patients of BPH with significant underlying non-urological diseases such as cardiovascular disease, malignant disease, DM and pulmonary disease. Sufficient clinical outcome has obtained without major complication after a short term and a long term observation. In this study, we discuss the clinical advantages and safety in comparison with TUR-P through the analysis of the clinical courses of the VLAP for the patients treated with anticoagulant agents such as warfarin. In our series of 40 cases, 8 patients were treated with anticoagulant for the reason of cardiovascular disease. During the procedure and after the operation, no significant complications were encountered except for a transient postoperative bleeding.
And 8 cases with anticoagulant therapy underwent TUR-P were also analyzed as a comparison. The time of the procedure and the volume of the blood loss were significantly reduced by VLAP. The hemostatic nature of YAG laser energy seems to result in a technical improvement on conventional TUR-P for the patients under anticoagulant therapy.

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Basic studies of transurethral balloon laser therapy (TUBAL) using dog's prostates showed that three treatments, namely hyperthermia (TUBAL-H), thermotherapy (TUBAL-T) and prostatectomy, can be performed for prostatic diseases. TUBAL-H was performed for chronic non-bacterial prostatitis in 5 patients who failed to respond conventional treatments. Complete improvement of symptoms was observed in one patient, partial improvement in three, and no improvement in one. TUBAL-T was performed in 15 patients with benign prostatic hypertrophy. AUA symptoms score was significantly improved at three months compared with that before treatment. Subjective findings were not significantly observed to be improved.

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From August 1992 to September 1994, we conducted Visual Laser Ablation of the Prostate (VLAP) with Urolase on 103 patients. At present, 79 patients had been subjected to through workups for more than 3 months. Average operation time time and total laser energy were 17.8 and 29614 jules, respectively. Totally, AUA symptom scores decreased from 22.5 to 7.9, 8.5 and 9.0 at 3, 6 and 12 months postoperatively, respectively (p0.0001). Peak urinary flow rate (PFR) increased from 8.1ml/sec to 16.0, 15.1 and 13.5ml/sec (p0.0001). Recidural urine volume decreased from 75ml to 34 (p0.0001), 35 (p0.0006) and 42ml (p0.01). Sonographically measured volume of the prostate gland decreased fron 31.7 to 24.5, 27.0 and 27.0cc (p0.0001). Sixty-three of 79 (79.9%) patients, 43 of 60 (71.7%) and 27 of 38 (71.0%) showed as successful cases at 3, 6 and 12 months follow up.
We found VLAP to be a cost-effective and less morbid alterative to traditional transurethral resection of the prostate.

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To clearly observe the upper urinary tract with a thin flexible endoscope, we developed a novel real-time image processing system. The dark cladding portion in an image guide was electrically painted out by the light which was emitted from each core pixels to obtain bright image. Thirty patients were examined using a thin flexible endoscope with this system at retrograde pyelography or puncture of a renal or prostatic cyst. The endoscope which was 0.75mm in diameter had 3,000 pixels of image fiber. The objectives were clearly seen without the dilation of the ureteral orifice. Finer and more colorful image could be obtained with this system. However, visualization was not clear in 4 patients because of poor manipulation capability at the endoscope tip. There were no complications, such as perforation of the ureter. We concluded that a thin endoscope with the real-time processing system would be useful for the diagnosis or treatment of the upper urinary tract or a cystic disease.

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To develop a new transperineal laser prostatectomy through a biopsy needle, we evaluated the efficacy of pulsed Ho: YAG laser irradiation for the canine prostate. The Ho: YAG laser may induce stress-wave to destroy the small vessels in the prostate. Seventeen mongrel dogs were used. After a lower midline abdominal incision, the prostate was punctured with a 18G biopsy needle in parallel to the urethra. Two prostates were punctured without the irradiation as a control. One of the 15 treated prostates was removed immediately after high fluence irradiation (500J/cm²) in left lobe and low (150J/cm²) in right lobe. In 12 of 15 dogs, each lobe of the prostate was irradiated with high fluence. In 2 of 15 dogs, each lobe of the prostate was irradiated with low fluence. The treated prostates were removed immediately, 1 week, 1 month and 2 months after the irradiation. The high fluence irradiation resulted in the sufficient volume reduction (40%) and the huge cavities were created I month later. The low fluence irradiation showed only the inflammatory reaction. The histological examination showed that the hemorrhage and subsequent histological changes may be caused by the laser induced stress-wave rather than by thermal effect. Our results suggest that transperineal irradiation with pulsed Ho: YAG laser can be useful in the treatment of prostatic obstruction.

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Between April 1993 and May 1994, 66 patients with benign prostatic hyperplasia (BPH) were treated with transurethral balloon laser thermotherapy. No significant difference was observed in the prostatic volume between the baseline and the volume at one month after treatment. However, at 3 months and at 6 months, there was clearly a significant reduction in prostatic volume compared to the baseline (p<0.0001). The mean reduction rates of the prostatic volume were 12% at 3 months and 16% at 6 months respectively. The degenerative necrosis of the prostatic tissue was clearly observed at 2 weeks after treatment, using light and electron microscopy. The serum prostatic-specific antigen increased to a level 4 times that of the baseline on the 7th day. Noradrenaline-induced peristaltic pressure elevations of the prostatic urethra were significantly inhibited 3 and 6 months after treatment. The prostatic volume reduction and the inhibition in responsiveness to noradrenaline in the prostatic urethra may play a role in a reduction of urethral resistance in BPH.

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Interested in the anti-inflammatory effect of LPL, we conducted a study to investigate the efficacy of LPL for the treatment pf urinary disturbance of prostatic hypertrophy.
Objects were 30 PH patients (53-87 years old, all male), who had urinary disturbance.
A group received the LPL therapy of 10mW laser and B group was treated by 1mW laser. The irradiation time was 30~60 seconds/point, 6 points/patients, 3~4 minutes in total and repeated for 7 days continuously.
The efficacy of LPL was checked by a questionnaire about the level of urinary disturbance.
As a result of analysis of questionnaire, we found the possible efficacy of LPL for PH patients, especially 1mW laser more effective than 10mW laser.

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Ten patients with benign prostatic hyperplasia and one patient with prostatic cancer (stage D2) were treated with the Nd: YAG laser using Urolase right angle laser fiber. Their conditions were compared preoperatively and 3 months postoperatively. Symptom scores (IPSS) decreased from an average 23 to 5. There was a marked increase in peak urinary flowrate from 7 to 18 ml/s and in average urinary flowrate from 3 to 10 ml/s. Secondary, the depth and volume of the implanted Seminoma tissue ablation for single, continuous laser applications with the Urolase right angle fiber were measured at 40 and 60 watts from 30 to 120 seconds. The mean depth penetration (mm) and volume ablation (ml) at 60 watts, 60 seconds was greater than that observed at 40 watts, 90 seconds, and we found that the volume ablation had the relationship of irradiation times after popcorn phenomenon. These basic data and clinical experience might help guide the development new and improved laser treatment of benign prostatic hyperplasia.

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New contact delivery surgical instruments employing Nd; YAG laser are the flexible probe which “side-fires”the laser beam at 90 degrees to the optical fibre, the ceramic-tipped laser scalpel, and the laser bipolar dissecting forcep. Useful in Urology and other surgical diciplines, these instruments add a completely new dimension to many commonly performed operative procedures benefiting both the patient and the health insurer, be they a private company or goverment.
Contact mode Nd; YAG visual incision in urethral stricture and bladder neck with“side-fire”offers the same surgical effect as visual cold-knife urethrotomy and electro-cautery bladder neck incision but with the advantage of day only surgery as there is less pain and no bleeding. Fourteen such treated patients at three months follow-up resulted in only 3 nights of hospital bed occupancy compared with an estimated 40 to 50 hospital bed occupancy nights for conventional non-laser mehods.
The ceramic tipped instruments offer to the surgeon such precision and haemostasis that for high blood loss operations such as partial nephrectomy (2), radical cystectomy (2), or radical prostatectomy (2), in 6 patients so far treated, no blood transfusion has been required, and hospital stay has been apprectiably shorter.
This technology appropiately advances surgery into the 21st century where it is believed through this type of change there will be a steady trend to short stay surgery.

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Endoscopic laser cystolithotripsy was performed in 5 patients with bladder stones. The average stone size was 26×18mm, and the average time for laser lithotripsy was 46 minutes. The stone composition was uric acid in 3, calcium phosphate in 2 and calcium oxalate in 1 patient.
Lithotripsy with the holmium YAG laser was successful in all cases. There were no complications during the procedure. In conclusion, we confirm the holmium YAG laser is effective and safe for cystolithotripsy.

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Histopathological changes of the prostatic smooth muscle cells following transurethral balloon laser thermotherapy (TUBAL-T) were studied under light and electron microscopy. Transperineal needle biopsy of the prostate was carried out in six patients with symptomatic benign prostatic hyperplasia immediately, 3 days, 2 weeks and 4 weeks after TUBAL-T. Immediately after treatment, edematous changes occured in the prostatic stroma. Two-four weeks after treatment, prominent degenerative necrosis of the prostatic smooth muscle cells were clearly observed. Immunoenzymatic stains of desmin and heat shock protein (HSP) were performed. Two weeks after treatment, the prostatic smooth muscle cells showed a weak stain of desmin. A generation of HSP was observed in the prostatic smooth muscle cells 90 minutes after treatment. These findings indicate that TUBAL-T causes degenerative necrosis of the prostatic smooth muscle cells.

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In cases of nevus spilus, in which the recurrence rate is high following treatment with long pulses of 2msec. alone, the recurrence rate was minimized by additional treatment using short pulses. The high effectiveness of this treatment method has been proven, particularly in cases of late nevus spilus or so-called Becker's nevus. This additional treatment permits cells with the ability to produce melanin relatively deep in the skin to be destroyed, resulting in further improvements in treatment effectiveness. Furthermore, treatment effectiveness was improved by additional laser treatment using short pulses at 10J/cm² within 3 weeks after the first treatment. However, particularly in cases of congenital nevus spilus of youg patients under 20 years of age, favorable results cannot be obtained and the recurrence rate is still high. We must strive to overcome this problem.

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Light and electron microscopic findings of benign cutaneous pigmented lesions irradiated with several types of laser were reported, and their cause of clinical limitation were discussed. In port-wine stain, hyperpigmentation of epidermis, extensively dilated vessels, small amount of red blood cells in the vessels and deeply located vessels were considered to be main causes which the effects of dye laser fade away. Epidermal melanin pigmentation was removed with laser treatment, but the amount of the pigment in the repaired epidermis seems controlled genetically. Dermal melanocytes in nevus of Ota showed destruction with melanosomes disruption by Q-switched ruby and alexandrite laser irradiation, but long term follow up study is not made yet.

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Dye laser is a main treatment modality without operation to hemangioma simplex. We have used a dye laser device with 585nm wavelength and 4.5×10^-4 second irradiation time to this disease. Our schedule of the treatment using dye laser is as follows:test irradiation with various energy density is done to a small portion at first. Two or 3 months after that, treatment is actually begun with appropriate energy density. The results are that enough effect was obtained in the field of face and neck, but the effectiveness is unstable in that of limbs. Dye laser is much more effective to hemangioma simplex than the results of argon laser which had been used to this disease, however, this device should be improved to get higer efficiency. A dye laser device with 510nm wavelength and 3×10^-7second irradiation time was developed for treatment of brown pigmented spot,for example nevus spilus, senile pigmentation and pigmentation after trauma. We expect that dye laser will contribute further to superficial skin diseases as treatment modality without operation.

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In the treatment of pigmented region, we used the combined therapy which was consisting of a preparatory treatment and Q-SWRL irradiation. The former, i. e. epithelial peeling or mass reduction, was performed with the object of exasparation of permeability of Q-SWRL.
In the treatments of nevus Ohta and nevus cell nevus, the combinedtherapy was more effective than the Q-SWRL irradiation without the preparatory treatment. In the treatment of nevus spilus however, the effect of the combined therapy was not stable.

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Serious and moderate AD patients were treated for 2-14 months using LPL instruments( FLAT10, 780nm, 10mW, by Fuji Electric). Subjects were 14 male and female patients aged 1~18 years old. They had been treated by DSCG, anti-histamine internal use, mild-strong steroid application and removal of egg and soy oil intake. Conventional treatments were continued while being treated by LPL therapy, the improvement of itch and efflorescence was observed in all cases. The itch decreased by 1-5 times irradiation of LPL. The efflorescence dried up after 3-6 times irradiation of LPL and the flare started to decrease. Although the efflorescence did notdisappear completely, it was admitted to improve in the long term observation.
Taking up 61 mild and serious AD patients as subjects, we studied if the itch would be depressed during night and until following morning by the irradiation of LPL at eczema parts. Marked effect was 12 out of 61 cases, the effective cases of the itch depression were 39 accouting for 83.6%. The LPL therapy is concluded to be very effective for the treatment of AD. The erythema and the wheal induced by histamine (10mg/ml) and mite antigen (1/100w/v) were not suppressed by the irradiation of LPL. As far as we cheched the immunological effects of LPL, the number of mast cells in the nasal smear of allergic rhinitis decreased after the irradiation of LPL.

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One hundred twelve patients with skin ulcer were treated by He - Ne laser of 8mW for 5 10min and Diod laser of 100mW for 2-3min. Irradiation of Diod was limitted to the lesion within lOmm in diameter. Treatment was performed fourth a week dy scanning over the each raw surface. Skin ulcers we chose were superficial dermal trauma (SDT), postoperative deep dermal defects (DDD) those had been remained after excision of epidermoid cysts, superficial dermal burn (SDB), deep dermal burn (DDB) and deep burn (DB). Period of dates for epithelization of irradiated ulcers became shorter than non-irradiated lesion shown as below(mean±S. E.); SDT: 10.0±1.7; DDD:9.9±0.6; SDB: 8.4±0.7; DDB:14.9±1.4; DB: 50.3±7.2. Scar formation, which was elastic soft, was recognized only in DB and a few cases of DDD. These findings indicate that the low - energy lasers accelerate epithelization from epidermal appendages as well as from the edge of raw skin surface with increasing granulation tissue. And also laser irradiation might affect the stability of scar formation.

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We studied the effectiveness of the Q-switched alexandrite laser (QAL). PLTL-1 (755nm, 100ns), Candela Corporation, by treating 78 cases of Ota's nevus.
The results of the total 78 cases were excellent in 10 cases (13%), good in 59 cases (75%), fair in 6 cases (8%), poor in 3 cases (4%). Satisfactory results (excellent or good) were achieved in 88%of total cases. Those treated once or twice showed the less satisfactory results as fair and poor, while those treated more than three times showed the satisfactory results. No side effects, such as scar formation, abnormal hyper or hypopigmentation, was noted on any cases.
From these findings, it appeared that the QAL was highly effective and safe in the treatment of Ota's nevus and repeated multiple treatments to the same site at regular intervals could attain high efficacy. QAL had less machine troubles than QRL.
Therefore, maintenance and running costs of QAL were cheaper than those of QRL.

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Ot's nevus with 120 cases were irradiated by using YAG Laser, of which 280 lesions were treated for one time irradiation, in addition 36 cases were irradated with two times, so totally 316 lesions were treated.
As the evaluation for the irradiation after studying histopathological finding of view was performd.
Superficial type of melanocyte was more effective than the deeper one from our study.
Electron microscopic finding showed destruction of membrane of melanocyte as well as black granulae in the membrane.

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There are relatively many patients among men and women who worry about their facial redness. We began to use the Dye Laser system (Candela SPTL-1) in MAY 1991. We examined the results of the microvascular dilation of the face, especially dorsum of the nose and the cheek.
Total numbers of patients were 16 (10 males, 6 females). Range in age was from 12 to 56y/o, and 34y/o in average. Affected areas were 4 noses and 6 cheeks in male and 1 nose and 6 cheeks in female. Laser irradiation was performed with 7j and 450 microsecond pulse width.
For the treatment of the big vertical vessel of the dorsum of the nose, depilation machine (IME HR-5000) was additionally applied. After irradiation, 2 weeks sterilization and ointment application and 3 monthes sun screening was recommended. For sedation for irradiation, we applied anesthesia using Iontophoreser (UI-4020, B. S. Medical) from May, 1991.
We think the combined therapy for microvascular dilation was very effective, especially nasal microvascular dilation.

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With the progress of the laser technique, laser has been applied for many kinds of clinical treatments.
The carbon dioxide (CO₂) laser and the neodymium yttrium aluminum garnet (Nd: YAG) laser have been used in plastic surgery. We treated a 12-year-old girl with pudendal hemangioma using Nd: YAG laser (SLT CO. CL-50 1.064μm, continuous wave). She had massive anal bleeding at the age of three. She was diagnosed giant pelvic hemangioma which involved rectum, sigmoid colon, uterus, vagina, and bladder. At the age of four, ligation of left internal iliac artery, resection of rectosigmoid colon, and endorectal pull-though operation were performed. After the surgery, the anal bleeding was eliminated. But when she was 10 years old, swelling of a left large pudendal lip and a clitoris gradually became remarkable.
As embolization was not available because of small feeding arteries of the hemangioma and irradiation (total 30 Gy) was not effective, the hemangioma was resected using Nd: YAG laser with minimal bleeding during surgery. She did not complain severe postoperative pain without analgesics. Nd: YAG laser has significant benefits of minimal blood loss and minimal postoperative pain.

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We have down treatment of portwine stain with the argon laser and the pulsed dye laser for 15 years.
Specially, in this paper we report data concerning anatomical differences of portwine stain in response to treatment with the pulsed dye laser, and state about 10 years elapsed state of argon laser treated portwine stain.
Portwine stains of the head and neck demonstrate difference in response to treatment with dye laser according to their anatomical location.
Centrofacial lesion and lesions involving dermatome V₂ respond less favorable than lesions located else where on the head and neck. Midline lesion respond very favorably.
10 years after argon laser therapy is supposed to give good influence to effect of performed argon laser therapy for port wine stain.

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Diseases of the blood vessel anomaly group can now be treated by a number of lasers, including the pulsed dye laser. Blood vessels have a variety of diameters, which will in turn affect the result of laser haemocoagulation. We have designed a computer simulation which can calculate the temperature rise in target vessels dependent on the diameter of the vessel. Seven simulations have been carried out, based on the following parameters: exposure time, 400 usec; energy density, 5J/cm²; and the inner diameter of the blood vessels ranging from 10um-640um. For vessels of 10um in diameter, the maximum temperature rise was 2.36°K. For vessels of 640um in diameter, the maximum rise was 18.3°K. We also calculated the time for the temperature to fall by half (temperature half fall time). It was 0.92ms and 225ms for 10um and 640um vessels, respectively. From these data it is easy to infer that the greater efficacy of the dye laser in the treatment of smaller diameter vessels compared to those of a larger diameter is the low temperature rise and shorter duration in the smaller diameter vessels.

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We used LLLT with the object of the photo-bio-activation effects, and HLLT of the prevention of recurrence and exasperation of permeability of the laser. As to LLLT, (1) the scanning irradiation of the laser by use of free hand was applied to the scar, and (2) the spot irradiation of the defocus beam of the laser from a distance of about 10 cm was applied to melasma and nevus spilus. As to HLLT, (3) the laser abrasion was performed to nevus cell nevus as a pre-treatment of the combined therapy, and the laser vaporization and the supplemental laser vaporization after the CO₂ laser reduction were performed for the cases in which the reduction was necessary. LLLT is application for children since the treatment is not painful though sometimes needs long duration. There are also many application of LLLT because of no disturbance in daily life after the laser irradiation. There is no scar formation after HLLT because of its simultaneous LLLT effects. Wider application area is possible by use of the combined therapy.

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The Frequency Doubled Q-Switched Nd:YAG Laser system with a pulse duration of 10 ns and a dual wavelength of 1064 nm and 532 nm has been demonstrated to successfully remove tattoos and epidermal pigmented lesions. Additionally, the author has used this laser system to treat dermal melanocytosis. Dermal melanocytosis, such as nevus of Ota and aberrant or persistant Mongolian spot, is more common in Asian people. Conventional treatments for these lesions, including cryosurgery with dry ice or liquid nitrogen, dermabrasion, excision or skin grafting, have limited success or undesirable side effects such as hyper or hypopigmentation and scarring. The author has used a 1064 nm wavelength Q-switched Nd:YAG laser for two years to treat nevus of Ota and aberrant Mongolian spot on both adults and children. Clearing or significant lightening with no scarring or permanent hypo or hyperpigmentation was seen in all cases. The author suggests that the Q-switched Nd:YAG laser is both safe and effective for treatment of dermal melanocytosis. Regarding treatment of epidermal pigmented lesions it is important to tell if the pigmentation seen after laser irradiation of Asian skin using a wavelength of 532 nm is postinflammatory pigmentation or whether it is due to incomplete clearance or a recurrence of the lesion.

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Partial labyrinthectomy with argon laser was carried out on three patients with delayed endolymphatic hydrops. The complaints of the patients were series of dizzy spells and/or long-lasting positional vertigo.
The macula utriculi was irradiated with argon laser through the stapedectomized oval window. Singular neurectomy was also done.
After surgery, the patien's symptom disappeared or impproved.
Hearing was preserved in one patient. Unfortunately another patient lost hearing in 3 month. The other patient was already deaf before the operation.
Balance was improved within one week postoperatively. Caloric responce was observed in two patients.

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We know that in nasal allergy, the histamine is one of chemical mediators from mast cell and its release is inactivated by the hyperthermia. And it is said that mucosal edema because of the high permeability in vessel's wall and the failure of the local circulation is improved with the hyperthermia. On account of these fact, we tried to apply the Balloon-Laser-Hyperthermia (BL-hyperthermia) to allergic rhinitis to obtain more direct and constant effect of the hyperthermia on the nasal mucosa.
The subjects of this therapy were performed BL-hyperthermia more than 3 times and were not done the other therapy. The number of subjects was 16. We evaluated the subjective symptoms and the objective findings.
We used the device for BL-hyperthermia manufactured by corporation with SLT. Japan. We can know the temperature of the nasal cavity with the thermosensor connecting to the thermocontroller. The temperature on the thermosensor was nearly 43°C as the set temperature. This hyperthermia was done for 10min by a nasal cavity.
As to the subjective symptoms, the 9 cases (56%) were improved. As to the objective findings, the result was same. In both of them, the 5 cases were improved. They were severe or middle cases with nasal allergy.

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Since 1982, we have performed the CO₂ LASER turbinectomy for 1500 patients with perennial nasal allergy. We initially reported its methods and the short-term efficacy in 1986. The long-term efficacy and its mechanism will be discussed. Improvement was noted in 78% of the patients one month after laser surgery, and in 76% two years later. The longterm (2 years after the surgery) efficacy for nasal blockage, sneezing and nasal discharge are 72%, 70% and 67%, respectively. Laser surgery was more effective in younger than in older patients. Revepolization was performed in patients whose nasal symptoms had been alleviated after the initial laser surgery, resulting being of in 85% one month after the surgery in 78% 2 years after the surgery and in 64% 3 years after the revaporization.
The long-term management of nasal symptoms can be possible by the revaporization with minimum cost and minimum time consuming. These results of the prolong effect of laser surgery for perennial nasal allergy were supported by the histological appearance of nasal mucosa: a layer of abundant fibrous tissue was evident even 5 years after CO₂ LASER surgery. Also decreased content of ECP and decreased regional blood suggest that laser surgery eliminates the surface of nasal mucosa which is a site of allergic reaction.

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The newly developed holmium: YAG (Ho: YAG) laser was applied to endoscopic endonasal sinus surgery in the viewpoint of a characteristic property of efficient ablation to bone tissues. We applied Ho: YAG laser to inferior turbinectomy (5 cases), marsupialization of paranasal sinus mucoceles (10 cases), and dacryocystorhinostomy (2 cases), which led to successful and satisfactory results. The present results revealed that Ho: YAG laser is useful tool for bone ablation in endoscopi sinus surgery.

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An in vivo study was performed to examine the application of laser beam for the fragmentation of salivery stones. In accordance with the absorption and reflection spectra of section of salivary stones, optimal fragmentation was achived using a pulsed dye laser with pulus windth of 1.4 gm and a weave-length of 504nm. Further studies on the particles size were conducted and a new“sialioendoscope”technique was developed. 6 patients suffering from a sialolithiasis of the submadibular gland were treated.
Under continuous endoscopic monitoring a laser-induced shock wave lithotripsy was performed. In 1 case complete fragmentation and removal of the salivary stones was achived and in another case 50-70% fragmentation was performed and saliva passaging was recovered. This approch to laser lithotripsy of salivary stones with endoscopic monitoring represents a novel method that permits treatment on an outpatients basis under local anesthesia, with little inconvenience to the patient.

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It is difficult to perform operation for epiglottic diseases by conventional surgical method under microlaryngosopy. Bleeding can not be controlled and sometimes visual field is obstructed by blood. However most of epiglottic diseases can be operated without bleeding by using CO₂ laser. We can get enough visual field under laser surgery. In some cases, for example, malignant tumor and big epiglottic cyst, we need not only CO₂ laser but also bipolar coagulator to sotp bleeding from branches of upper laryngeal artery as same as in cases of tong cancer special laryngoscope. Epiglottic or vallecular cyst can be perfectly removed by this method and epiglottectomy also casily performed under microlaryngo-surgery.

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Nine cases with laryngeal stenosis were treated by endolaryngeal CO₂ laser surgery in our clinic The causes of laryngeal stenosis were included into four cases of bilateral vocal paralysis, three cases of laryngeal wed and two cases of scar formation after laryngofissure for laryngeal papilloma. All cases were performed under general anes thesia
1) Glottal openning for bilateral vocal paralysis was applied to cut off techinique of the vocul fold and resection of the arytenoid cartilage in one side to remain the vocal function after operation.
2) One of three web cases, we have to use the laryngeal stent to prevent the vocal readhesion.

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