Port wine stain treatment with a dual-wavelength Nd:Yag laser and cryogen spray cooling: a pilot study

BACKGROUND AND OBJECTIVES: We report on a pilot study of port wine stain (PWS) treatment with a prototype Nd:YAG/KTP laser system, emitting simultaneously at 1,064 and 532 nm, and equipped with a cryogen spray cooling (CSC) device. STUDY DESIGN/PATIENTS AND METHODS: On 10 patients (4-36 years old, mean: 16.2 years) with skin types II-III, therapeutic efficacy of the dual-wavelength laser (KTP+) was compared with a standard KTP laser (532 nm only) at the same pulse duration (25 millisecond), spot diameter (3 mm), and CSC parameters. The fluences were selected in order to obtain the same immediate response with both laser systems. Blanching of each test segment was assessed 8 weeks post treatment by an independent evaluator and by the subjects, and graded on a 1-4 scale. RESULTS: Significant blanching of PWS was noted 8 weeks after a single therapeutic session with the KTP+ laser (mean: 532 nm radiant exposure: 8.2 J/cm(2)), very similar to that observed with KTP at 12.4 J/cm(2). The evaluator noticed a slight brownish coloration in areas treated with the KTP+ laser. Isolated beam-sized atrophic scars were present in two patients where KTP+ (9 and 10 J/cm(2)) and KTP (14 J/cm(2)) lasers were used. CONCLUSIONS: The addition of 1,064 nm radiation allowed a significant reduction of 532 nm radiant exposure with no loss of efficacy in PWS treatment.     

A Split-Face Comparison Study of Pulsed 532-nm KTP Laser and 595-nm Pulsed Dye Laser in the Treatment of Facial Telangiectasias and Diffuse Telangiectatic Facial Erythema

BACKGROUND AND OBJECTIVES: Pulsed 595 nm and 532 nm lasers can effectively diminish or eliminate facial telangiectasia. We performed a split-face, single-blind, controlled, comparison study in an effort to determine their individual and comparative efficacy. STUDY DESIGN/MATERIALS AND METHODS: Fifteen patients were treated using a 595-nm PDL on one side of the face and a pulsed 532-nm potassium-titanyl-phosphate (KTP) laser on the other. Each subject was evaluated at 3 weeks after three treatments. RESULTS: Both devices improved telangiectasia. The 532-nm device, however, was at least as effective or more effective than the 595-nm laser in all subjects. On average, the KTP laser achieved 62% clearing after the first treatment and 85% clearing 3 weeks after the third treatment, compared to 49% and 75% for the PDL, respectively. Seventy-nine percent of KTP laser-treated patients continued to have swelling for greater than 1 day versus 71% of PDL-treated patients. Of those patients who noted persistent erythema for at least 1 day after treatment, 58% noted more erythema on the KTP laser-treated side compared to 8% on the PDL-treated side. CONCLUSIONS: Both the 595-nm and the 532-nm pulsed lasers are highly effective in the treatment of facial telangiectasia and redness. The 532-nm KTP laser appears to be more effective but causes more swelling and erythema.     

Treatment of spider leg veins with the KTP (532 nm) laser--a prospective study

BACKGROUND AND OBJECTIVES: Spider leg veins are telangiectasias located intracutaneously. This condition poses a cosmetic problem. STUDY DESIGN/PATIENTS AND METHODS: The purpose of this study was to determine what influence the KTP (532 nm) laser has on spider leg veins dependent on the vascular diameter and to what extent the skin has been affected. Seventy female patients were treated in three laser sessions. Analysis was done 30 weeks after the last laser treatment session. RESULTS: Fifty-six patients completed the study. In group 1 (vascular diameter < or = 0.6 mm), spider leg veins were no longer visible in 33%; in 40%, a decrease in vascular diameter could be observed; in 27%, no change in size occurred. In group 2 (vascular diameter 0.7-1.0 mm), laser-treated spider leg veins were visible in all patients. Hyperpigmentation occurred in 13 patients. CONCLUSIONS: The KTP (532 nm) laser is an effective for treating spider leg veins having a vascular diameter under 0.7 mm.     

Clinical evaluation of enhanced nonablative skin rejuvenation using a combination of a 532 and a 1,064 nm laser

BACKGROUND AND OBJECTIVES: Improvements in the physical signs of photoaging can be achieved by non-invasive laser resurfacing procedures. To evaluate the effectiveness and safety of the Nd:YAG 1,064 nm and KTP 532 nm lasers for non-invasive skin rejuvenation. STUDY DESIGN/PATIENTS AND METHODS: Subjects requesting non-invasive skin rejuvenation underwent two treatments with the 532 nm laser to one side of the face and with both lasers to the other side, followed by three treatments with the 1,064 nm laser to both sides. Skin characteristics were evaluated before, during, and up to 4 months after treatment. RESULTS: A >25% improvement in overall skin condition was observed for >30% of subjects at the 1 month follow-up and >40% of subjects at the 4 month follow-up. The greatest improvements were observed for visual dryness, roughness, and uneven pigmentation. No adverse events were reported. There was a trend for greater improvement in patients who received more 1,064 nm treatments but this was not statistically significant. CONCLUSIONS: The 532 nm KTP and 1,064 nm Nd: YAG lasers can be effectively and safely used for non-invasive skin rejuvenation.     

Limited lung resection using the potassium-titanyl-phosphate laser

BACKGROUND AND OBJECTIVES: Recently, the use of the potassium-titanyl-phosphate (KTP) laser with a wavelength of 532 nm, which is half the wavelength of the neodymium:yttrium-aluminum-garnet (Nd:YAG) laser, has been expanding in many fields, since this laser offers hemostasis and vaporization with minimal coagulation of the underlying structures. The purpose of this study was to determine the usefulness of the KTP laser in limited lung resection done for pulmonary nodular lesions. STUDY DESIGN/PATIENTS AND METHODS: We used the KTP laser to manage 10 partial resections (Group 1) and 16 segmentectomies (Group 2). The variables that were used to compare the two methods of resection included intra-operative blood loss, mean drainage time, and post-operative morbidity. RESULTS: The mean intra-operative blood loss was smaller in Group 1 (152.8 +/- 65.0 cc, P = 0.002) than in Group 2 (341.9 +/- 178.6 cc). Mean drainage time was shorter in Group 1 (1.8 +/- 1.0 days, P = 0.0141) than in Group 2 (3.6 +/- 2.9 days). The results of both groups with respect to hemostatic and healing effects were satisfactory. On histopathologic evaluation, the KTP laser-irradiated field tissue alteration consisted of two layers with a depth up to 2 mm. CONCLUSIONS: The results of this study suggest that the KTP laser has the potential to become a useful and reliable tool for limited lung resection.     

Analysis of shade, temperature and hydrogen peroxide concentration during dental bleaching: in vitro study with the KTP and diode lasers

Many dental bleaching techniques are now available, several of them using a laser source. However, the literature on the exact role of coherent light in the biochemical reaction of the whitening process is very discordant. The aims of this in vitro study were: (1) to compare two different laser sources, a KTP laser with a wavelength of 532 nm and a diode laser with a wavelength of 808 nm, during dental bleaching, and (2) to investigate the relationships among changes in gel temperature, tooth shade and hydrogen peroxide (HP) concentration during laser irradiation. Altogether, 116 bovine teeth were bleached using a 30% HP gel, some of them with gel only and others with gel plus one of the two lasers (532 or 808 nm) at two different powers (2 and 4 W). The KTP laser produced a significant shade variation with a minimal temperature increase. The diode laser led to a higher temperature increase with a greater reduction in HP concentration, but the change in shade was only statistically significant with a power of 4 W. At a power of 2 W, the KTP laser caused a greater change in shade than the diode laser. No significant correlations were found among temperature, HP concentration and shade variation. The KTP laser appears to provide better results with less dangerous thermal increases than the diode laser. This might call into question most of the literature affirming that the action of laser bleaching is by increasing the gel temperature and, consequently, the speed of the redox reaction. Further study is required to investigate the correlations between the parameters investigated and efficacy of the bleaching process.     

Enhancement of tissue lesion depth by dual wavelength irradiation with the Nd-YAG/KTP laser: Perspectives for laser prostatectomy

The Nd-YAG/KTP laser coagulates and vaporizes prostate tissue. The objective of this study was to investigate the combined effects of both wavelengths and to determine the irradiation parameters allowing the largest lesion volume. Chicken breast tissue was irradiated ex vivo. Consecutive 1064 and 532 nm Nd-YAG/KTP laser irradiations were performed for different combinations (30 W/10 W, 20 W/20 W, 10 W/30 W) with variable total fluence (1200 J, 2400 J, 3600 J) and compared to isofluent single wavelengths at 40 W irradiation. The depths, diameters and volumes of the total lesion as well as the vaporization effects of the 532 nm wavelength on normal and on priorly coagulated tissue were analysed. Maximum total lesion depths (p< 0.001) were found under combined Nd-YAG/KTP (20 W/20 W) irradiation conditions. Ablation efficacy of the 532 nm wavelength was reduced after prior 1064 nm irradiation, but crater depths were increased. Dual wavelength irradiation with the Nd-YAG/KTP laser induces a specific denaturation process. This may represent a new approach to increase the depth of coagulation necrosis, and thus the treated volume, thereby improving long-term results.     

Der Diodenlaser

INTRODUCTION AND OBJECTIVES: Laser therapy of symptomatic benign prostatic hyperplasia (BPH) remains a challenge for most urologic surgeons. The main goal of laser surgery is to achieve a marked volume reduction and to decrease bladder outlet obstruction and lower urinary tract symptoms with minimal morbidity. Laser therapy encompasses a variety of techniques using different laser wavelengths, application systems, and surgical techniques to achieve contrasting tissue effects. In an in vitro animal model we compared the vaporization and coagulation effects of the potassium-titanyl-phosphate (KTP) laser, holmium:yttrium-aluminum-garnet (Ho:YAG) laser, and diode laser (980 nm). MATERIAL AND METHODS: In an in vitro model using isolated perfused porcine kidneys we investigated the vaporization, the coagulation effect, and the bleeding rate of the KTP, Ho:YAG, and diode lasers on five porcine kidneys each. The application of each laser type was standardized. The area of laser application was 1 cm x 1 cm. The KTP group received an application with 80 W, the Ho:YAG group an application with 10-30 W, and the diode group an application with 30, 60, and 100 W. Hemostasis was measured semiquantitatively. Ablation and coagulation were investigated macro- and microscopically. RESULTS: Concerning the ablation capacity, the diode laser is most effective (more than fivefold) compared to the KTP and Ho:YAG lasers but demonstrated a rather large coagulation zone of up to tenfold in comparison to the KTP and Ho:YAG lasers. Semiquantitatively, in terms of bleeding rate, all lasers were equivalent in this ex vivo model. CONCLUSIONS: Our very early and limited experience indicates that KTP (80 W) and Ho:YAG (30 W) laser application are equivalent in terms of tissue ablation capacity and coagulation in an experimental setting. The diode laser at 980 nm is superior in terms of ablation capacity but has a large coagulation zone. Concerning the bleeding rate all tested lasers are equivalent in this ex vivo model.     

Nonablative Phototherapy for Acne Vulgaris Using the KTP 532 nm Laser

BACKGROUND: Acne vulgaris is an acute inflammatory disease of the pilosebaceous units. The bastion of treatment for acne vulgaris has been the use of topical and systemic therapies. Despite many modalities available for treatment, there exists an imperative need for effective noninvasive treatments that reduce the risks of medication side effects. OBJECTIVE: To study the safety and efficacy of the potassium titanyl phosphate (KTP) 532 nm pulsed laser for the treatment of acne vulgaris. METHODS: Twenty-six subjects, clinically evaluated with moderate facial acne, were enrolled in this single-center prospective trial. The entire facial area for each subject was divided in half and randomly designated as either a treatment or a control side. Each subject was treated with four laser exposures using a KTP 532 nm laser with continuous contact cooling. The results were assessed at 1 and 4 weeks post-final treatment. Primary outcome measures were Micha?lsson acne severity score and adverse treatment effects. Secondary outcome measures included subjective evaluations from the investigator and patients assessing their overall percent satisfaction. RESULTS: Primary outcome analysis in the Micha?lsson acne severity score demonstrated a mean 34.9% (p = .011) and 20.7% (p = .25) reduction at the 1-week and 4-week post-final treatments, respectively. Subjective investigator evaluations of overall percent satisfaction indicated that all patients demonstrated a minimum 50% overall satisfaction in treatment outcomes at the 4-week follow-up period. No side effects were encountered. CONCLUSION: Use of the KTP 532 nm laser for the treatment and management of acne vulgaris is both safe and effective, with positive results enduring up to 4 weeks post-treatment.     

Improved photochemotherapy of malignant cells with daunomycin and the KTP laser

Laser photochemotherapy of malignancies may become an effective palliative treatment for advanced had and neck cancer using light-sensitive, chemotherapeutic drugs activated in tumors via interstitial laser fiberoptics. Previously, it was reported that cultured human P3 squamous cells incubated 2 hours with daunomycin (Dn) exhibited tenfold enhanced cytotoxicity after exposure to argon laser light at 514 nm. This short-term uptake leads to drug localization in cytoplasmic and membrane sites prior to nuclear accumulation and daunomycin topoisomerase inhibition. In the current study phototoxicity of Dn-sensitized human cancer cells was tested using broad-spectrum white light compared to monochromatic green-wavelength light. Drug uptake and laser energy levels were optimized for maximum synergy. To test light-enhanced chemotherapy in vitro, the kinetics of cell uptake and toxicity of daunomycin was measured at 1, 2, and 5 μg/ml in three human tumor cell lines: P3 squamous-cell carcinoma, M26 melanoma, and TE671 fibrosarcoma. After 2 hr Dn uptake, all cell lines were tested for phototherapy response by exposure to 300- to 900-nm visible light from a xenon lamp or monochromatic 532-nm green light from a KTP laser. When the KTP laser output was varied from 0 to 120 Joules in Dn-sensitized tumor cells, a linear phototherapy response was seen with energy as low as 12 J inducing drug phototoxicity. These results provide evidence that daunomycin cytotoxicity is enhanced when exposed to 532-nm laser illumination in the three tumor types tested and confirm that the response is related to both energy level and drug dose. Lasers Surg. Med. 23:33–39, 1998. © 1998 Wiley-Liss, Inc.     

Q-switched double frequency Nd:YAG 532-nm nanosecond laser vs. double frequency Nd:YAG 532-nm picosecond laser for the treatment of solar lentigines in Asians

Solar lentigines are common pigmentary lesions. Q-switched lasers are effective treatment options but postinflammatory hyperpigmentation (PIH) is common in darker skin. The objective of the study is to compare the efficacy and safety in solar lentigines of Asian skin treated by Q-switched potassium titanyl phosphate (KTP) 532-nm nanosecond laser vs. KTP 532-nm picosecond laser for the treatment of solar lentigines in Asians. Thirty patients with at least 2 solar lentigines on the upper extremities were enrolled. A total of 30 paired lentiginous lesions were randomly treated with a single treatment of either Q-switched KTP 532-nm nanosecond laser vs. KTP 532-nm picosecond laser. In terms of efficacy, mean luminance score was evaluated at baseline, at 6th, and 12th week. Degree of pigment clearance was assessed by a blinded physician and the patients. Satisfaction score was rated by patients using visual analogue scale. Adverse events were also recorded. Twenty-eight patients completed the study. Both lasers showed significant improvement in mean luminance score from baseline (p?<?0.05). Likewise, there was no significant difference in pigment clearance between two lasers either assessed by physician or patients. However, patients’ satisfaction score was significantly higher with the picosecond laser (p?=?0.014). Adverse events and pain were not different between groups. Q-switched KTP 532-nm nanosecond laser and KTP 532-nm picosecond laser are safe and effective for treating solar lentigines in Asians. Based on cost-effectiveness, Q-switched KTP 532-nm nanosecond laser remains the main treatment while KTP 532-nm picosecond laser can be considered as a treatment option.     

Preliminary investigation of KTP/532 laser light in the treatment of hemangiomas and tattoos

Preliminary investigation of a frequency-doubled YAG laser (KTP 532 nm) manufactured by Laserscope of Santa Clara was undertaken. Twenty-five patients with either port wine hemangiomas or decorative tattoos were treated with a 532-nm light and the results compared to argon laser at identical power settings. Clinical and histological results were identical between the two lasers.     

Treatment of Leg Telangiectases with a 532 nm KTP Laser in Multipulse Mode

BACKGROUND: The multiple mode emission emphasizes the efficacy of the KTP laser. OBJECTIVE: To evaluate the efficacy of a 532 nm KTP laser emitting in multipulse mode for the treatment of superficial 0.5-1 mm leg telangiectases. METHODS: A 532 nm KTP laser was used in a nonuniform pulse sequence or multipulse mode emission (three stacked pulses of 100 msec, 30 msec, 30 msec, and a delay between pulses of 250 msec), a fluence of 60 J/cm2, and a 0.75 mm collimated spot. No cooling was used. Fourteen female patients (average age 46 years, range 27-57 years), phototypes I-IV were examined with Doppler ultrasound to ensure their big veins were competent. A topography of the telangiectatic network was reported on a tracing plastic frame before each session and 6 weeks after the last one. These frames were digitized and the number of vessels (before and 6 weeks after each session) was determined using imaging software. Side effects, pain, and patient satisfaction were noted. RESULTS: Moderate pain, immediate erythema and edema, sometimes light scabbing, temporary hypopigmentation rarely, and no matting were observed. After one treatment, vessel clearing was 53% (P <.001). It increased to 78% (P <.001) 6 weeks after two treatments, to 85% (P <.05) 6 weeks after three treatments, and to 93% (NS) 6 weeks after four treatments. CONCLUSION: This nonuniform pulse sequence or multipulse mode emission emphasizes the efficacy of the KTP laser in this study. It provides a safe and effective treatment that achieved an important reduction of red leg veins telangiectases from 0.5 to 1 mm in diameter, with very few side effects.     

NIR laser tissue welding of in vitro porcine cornea and sclera tissue

BACKGROUND AND OBJECTIVE: The objective of this study was to test the hypothesis that an near infrared (NIR) laser system (1,455 nm) in combination with a motorized translational stage to control the position and speed of the laser beam and a shutter to control the laser exposure to the tissue being welded could be used to successfully weld ocular tissues. STUDY DESIGN/MATERIALS AND METHODS: Seventy-five porcine corneas and 23 porcine scleral tissues were welded in vitro in this study. The welded tissues were examined using histopathology and tensile strength analysis. Eight different welding conditions were analyzed for porcine cornea and one for sclera tissues. The tensile strength of the welded groups was compared to a sutured cornea control group. RESULTS: The NIR laser welding system provides strong, full thickness welds and does not require the use of extrinsic dyes, chromophores, or solders. Mean weld strengths of 0.15-0.45 kg/cm(2) were obtained for the cornea and 1.01 kg/cm(2) for sclera welds. The native H(2)O in the ocular tissue serves as an absorber of the 1,455 nm radiation and helps to induce the welds. CONCLUSIONS: We conclude that an NIR laser system using an optimal laser radiation wavelength of 1,455 nm can effectively weld cornea and sclera tissue and that this laser tissue welding (LTW) methodology typically causes minimal disruption of tissue, and thus, avoids opacities and irregularities in the tissue which may result in decreased visual acuity. The optimization of a laser welding system that leads to a strong full thickness tissue bond without tissue destruction, an instant seal that promotes wound healing, and the absence of a continued presence of a foreign substance like a suture, is of considerable importance to the ophthalmology medical community. This need is especially apparent with respect to corneal transplantation and fixing the position of corneal flaps in Laser-Assisted In Situ Keratomileusis (LASIK), a laser procedure used to permanently change the shape of the cornea.     

"Hot" KTP-laser treatment of facial angiofibromata

BACKGROUND AND OBJECTIVE: Treatment of facial angiofibromata (AF) relied largely upon cutaneous resurfacing. While effective, resurfacing affects large areas with attendant risks of dyspigmentation, infection, and scarring. We investigated the pulsed KTP (532 nm) laser energy for its high absorption by melanin and hemoglobin as a photothermal destructive method for treating AF. STUDY DESIGN/MATERIALS AND METHODS: In five patients (Fitzpatrick phototypes II-;VI), AF were treated with the KTP laser (10 ms, 20 J/cm(2), 2 mm beam) using stacked pulses (2-3.3 Hz) or passes. No cooling device was employed. Each pulse evoked puffs of steam and caused progressive flattening of AF. Normal intervening skin was strictly avoided. Patients underwent one to five sessions in which as many as 100 lesions were treated. RESULTS: Individual lesions responded with complete flattening in one or two treatments. While this effect has persisted for 18-;24 months, slow recrudescence is expected. Transient hypopigmentation and hyperpigmentation were localized to treated skin. No scarring, infection, or other adverse events were observed. Patient satisfaction with this method was high due to rapid healing time ( < 10 days), minimal pain, ease of wound care, and efficacy. CONCLUSIONS: "Hot" KTP laser is an effective and safe method of treatment for facial AF. Limiting treatment only to lesional skin allowed rapid healing and very limited adverse effects despite the increased non-specific thermal damage caused by high fluence, long pulse duration, and an absence of superficial tissue cooling.     

Laser myringoplasty for tympanic membrane atelectasis

OBJECTIVE: To review our experience with laser myringoplasty using a potassium-titanyl-phosphate (KTP) laser for pars tensa atelectasis. STUDY DESIGN: Retrospective review. METHODS: A pulsed diode KTP laser (532 nm) was used to tighten the tympanic membrane after lysis of middle ear adhesions through a myringotomy. A tympanostomy tube was then placed. Operative reports and clinic notes were reviewed. RESULTS: We reviewed 34 procedures performed on 31 ears in 29 patients. The average time of follow-up was 10.5 months with a range of 1 to 30 months. Seventeen of 34 tubes (50%) extruded during the follow-up period. Eleven cases had follow-up with the tube extruded and TM intact. Two (18%) of those had progression of atelectasis. Two (6%) cases had operative perforations and both healed spontaneously. CONCLUSION: Laser myringoplasty using a KTP laser for pars tensa atelectasis appears to be beneficial in selected patients. Patients should be followed closely for early tube extrusion and recurrent disease.     

Treatment of superficial cutaneous vascular lesions: experience with the KTP 532 nm laser

Whilst most facial telangiectasias respond well to short-pulse-duration pulsed dye laser therapy, studies have shown that for the treatment of larger vessels these short-duration pulses are sub-optimal. Long-pulse frequency-doubled neodymium:YAG lasers have been introduced with pulse durations ranging from 1–50 ms and treatment beam diameters of up to 4 mm. We report the results of KTP/532 nm laser treatment for superficial vascular skin lesions. The aim was to determine the efficacy of the KTP/532 nm laser in the treatment of superficial cutaneous vascular lesions at a regional dermatology centre in a 2 year retrospective analysis. Patients were referred from general dermatology clinics to a purpose-built laser facility. A test dose was performed at the initial consultation and thereafter patients were reviewed and treated at 6 week intervals. Outcome was graded into five classifications by the patient and operator independently based on photographic records: clear, marked improvement, partial response, poor response, and no change or worsening. Over the 2 year period, 204 patients with 246 diagnoses were treated [156 female; median age 41 (range 1–74) years; Fitzpatrick skin types I–III]. Equal numbers of spider angioma (102) and facial telangiectasia (102) were treated. Of those patients who completed treatment and follow up, 57/58 (98%) of spider angiomas and 44/49 (90%) of facial telangiectasia markedly improved or cleared. Satisfactory treatment outcomes, with one clearance and two partial responses, occurred in three of five patients with port-wine stain. Few patients experienced adverse effects: two declined further treatment due to pain, and a small area of minimal superficial scarring developed in one case. Two patients developed mild persistent post-inflammatory hyperpigmentation, and one subject experienced an episode of acute facial erythema, swelling and blistering after one treatment. The KTP/532 nm frequency-doubled neodymium:YAG laser is a safe and effective treatment for common superficial cutaneous vascular lesions in patients with Fitzpatrick skin types I–III.     

A comparison of the KTP/532-laser tonsillectomy vs. traditional dissection/snare tonsillectomy

This study compared tonsillectomy by potassium-titanyl-phosphate (KTP/532) laser with tonsillectomy by traditional dissection and snare. Eighty-three consecutive patients who were candidates for a tonsillectomy were randomly assigned to one of four groups in a prospective study. The four treatments were bilateral traditional dissection/snare tonsillectomy, bilateral KTP/532-laser tonsillectomy, left laser tonsillectomy and right dissection/snare tonsillectomy, and left dissection/snare tonsillectomy and right laser tonsillectomy. Intraoperative comparisons were made between the two methods with regard to blood loss and operating time. Postoperatively bleeding and healing time were also recorded. A questionnaire answered on a daily basis assessed the patient's pain. Disadvantages of the KTP/532 tonsillectomy included increased cost, increased total operating time as a result of increased setup time and laser malfunctions, delayed healing, and no statistically significant improvement in level of pain. The sole advantage associated with the KTP/532 laser tonsillectomy was decreased blood loss, which may be significant for patients with a coagulopathy.     

Photoselective vaporization of the prostate: initial experience with a new 80 W KTP laser for the treatment of benign prostatic hyperplasia

PURPOSE: To study the safety and efficacy of a new high-power potassium-titanyl-phosphate laser (KTP/532; Niagara PV trade mark laser system; Laserscope, San Jose, CA) for transurethral photoselective vaporization of benign obstructive prostate tissue. PATIENTS AND METHODS: The KTP/532 laser energy at 80 W was delivered by a 6F side-firing fiber through a 23F continuous-flow cystoscope. Photoselective vaporization of the prostate (PVP) using sterile water irrigation was performed under spinal anesthesia on an outpatient basis in 10 patients with a preoperative mean prostate volume of 41.37 +/- 18.5 cc (range 24-76.3 cc). The mean lasing time was 19.8 +/- 4.9 minutes. RESULTS: Two patients experienced 1 to 7 days of mild dysuria, and one who was taking warfarin had mild transient hematuria, but none had urinary retention or other complications. The mean catheterization time was 17.2 +/- 9.6 hours (range 0-28 hours). At 1 year, the outcomes, which had showed significant improvement sustained throughout the follow-up, were as follows: mean American Urological Association Symptom Score decreased from 23.2 +/- 4.7 to 2.6 +/- 0.5 (88.8%), the mean quality of life score improved from 4.3 +/- 0.7 to 0.4 +/- 0.5 (90.7%), the mean peak urinary flow rate increased from 10.3 +/- 1.4 mL/sec to 30.7 +/- 5.8 mL/sec (198.1%), and the mean postvoiding residual volume decreased from 137.6 +/- 112.2 mL to 3.0 +/- 4.8 mL (97.8%). The mean prostate volume decreased by 27%. CONCLUSIONS: This pilot study indicates that PVP with the new 80 W KTP/532 laser is a simple, safe, and efficacious outpatient procedure for the treatment of obstructive BPH.     

Endoscopic laser sinus surgery using KTP/532 laser

KTP/532 lasers have been used in a variety of medical applications since 1986. The authors have explored this relatively new wavelength in Japan in the field of rhinology, and report new aspects of KTP/532 laser application in endoscopic sinus surgery on the basis of confirmatory and subjective methods. Eighty patients with chronic sinusitis and mucoceles received KTP/532 laser endoscopic sinus surgery. The KTP/532 laser demonstrated excellent results showing reduction of post-operative polyps and granulation tissues around the enlarged maxillary sinus ostium. In addition, patients with chronic sinusitis demonstrated enhanced healing of the polypoid degeneration of the maxillary sinus. However, no significant improvement in the post-operative care was observed in the enlarged opening of mucoceles. It is concluded that the KTP/532 laser is a promising tool for endoscopic sinus surgery.