Pulsed KTP Laser Research Articles

Surgical Outcome of Potassium-Titanyl-Phosphate (KTP) Laser Photocoagulation for Vocal Fold Vascular Lesions

IntroductionLaser technology is used in microscopic direct laryngeal surgery for a variety of indications. Lasers are categorized broadly as photoangiolytic or cutting/ablating lasers, based on the chromophores that absorb their energy. Photoangiolytic lasers such as the 532 nm Potassium-Titanyl-Phosphate (KTP) laser are absorbed selectively by the chromophore hemoglobin, facilitating controlled intravascular coagulation, with preservation of the overlying epithelium and adjacent tissue. Efficacy of the KTP laser has been demonstrated for incision, coagulation, and ablation in vocal fold (VF) surgery. ObjectiveThe purpose of the present study was to examine surgical outcomes following KTP laser photocoagulation for the management of VF vascular lesions. MethodsAdult patients with sufficient data who had undergone KTP laser photocoagulation in the operating room for the treatment of VF vascular lesions were included in this retrospective study. Strobovideolaryngoscopy (SVL) video footage from all preoperative visits and all available postoperative visits was compiled and de-identified. Patients were followed up at days 1-7, 8-14, 30-60, and greater than 60 days after surgery. Three blinded physician evaluators reviewed and evaluated the SVL footage independently for postoperative outcome parameters. Postoperative SVL video footage was evaluated on a 5-point scale for surgical success (surgical objective score; 1 = failure and 5 = complete success). The average surgical objective score was 4.36, 4.04, 4.25, and 4.46 (out of 5) at postoperative visits 1-4, respectively. ResultsThere were 60 cases (19 male and 41 female) included in the retrospective cohort. The average age was 42.42 ± 15.51 (range = 18-74). Fifty-one-point six seven percent of subjects were professional voice users (singers, teachers, public speakers, and others). All subjects were diagnosed preoperatively with VF vascular malformations and had undergone pulsed KTP laser photocoagulation. There were 40 bilateral cases and 20 unilateral cases, for a total of 100 VFs included in the study. Vascular malformation recurrence was identified in 3.00% and 10.00% of subjects at the third and fourth postoperative visits, retrospectively. The formation of new vascular malformations was identified in 0.00%, 1.00%, 6.00%, and 7.00% of subjects at postoperative visits 1-4, respectively. ConclusionKTP laser photocoagulation is highly effective for the management of vocal fold vascular lesions. Presence of hemorrhage or edema does not affect the long-term surgical outcome. In relatively few cases, vascular lesion recurrence or formation of new vascular lesions may occur.

Treatment Outcomes of In-Office KTP Ablation of Vocal Fold Granulomas.

To determine the effectiveness of in-office potassium-titanyl-phosphate (KTP) treatment of vocal fold granulomas and identify any predictors of complete lesion resolution. A retrospective review of patients who underwent in-office KTP ablation of vocal fold granulomas between 2007 and 2016 was performed. Medical records were reviewed for use of acid suppression medication, prior surgical treatment, voice therapy, laser settings, number of treatments, follow-up time, and Voice Handicap Index-10 (VHI-10) scores. Twenty-six patients underwent a total of 43 laser treatments. Eighty percent of patients were previously on acid suppression medication, and 42.3% had failed previous endoscopic treatments. Patients underwent a mean number of 1.65 ± 1.16 in-office treatments with decrease in size in 96.2% of cases. The VHI-10 was not significantly affected. Complete resolution occurred in 73.1% of cases with follow-up time ranging from 1 to 86 months (median = 9.5 months). No recurrences occurred in patients with complete resolution. Other than undergoing a single KTP treatment, no variable was found to be predictive of complete lesion resolution. Granuloma etiology was not predictive of lesion resolution but did correlate with symptom improvement. In-office pulsed KTP laser is an effective treatment option for vocal fold granulomas as the lesion resolves in the majority of cases.

Ultrapulse carbon dioxide laser ablation of xanthelasma palpebrarum: A case series

Context:Xanthelasma palpebrarum is the most common form of xanthomas. Albeit a benign entity, it is cosmetically disturbing and a frequently recurring dermatologic referral. Although the classical treatment option remains surgical excision, alternatively, chemical cauterization, cryosurgery and electrofulguration have all been tried in the past with mixed results. The use of laser systems such as carbon dioxide laser, Erb:YAG laser, Q-switched Nd:YAG laser, diode laser, pulsed dye laser and KTP laser have become popular in the treatment of these lesions. Recent literature suggests minimal pigmentary changes and scarring with the use of ultrapulse carbon dioxide laser treatment of these lesions.Aim:To study and evaluate the effectiveness of ultrapulse carbon dioxide laser ablation for treatment of xanthelasma palpebrarum.Materials and Methods:10 patients presenting with bilateral xanthelasma palpebrarum, new and with recurrence were studied for results after a single treatment with ultrapulse carbon dioxide laser (10,600 nm; 100-200 Hz; 200-400 μsec). The follow-up time was 9 months.Results:All lesions were treatable with a single-laser treatment session. Two patients (20%) developed recurrence during the follow-up period. Side effects included post inflammatory hyperpigmentation in two patients (20%), but no visible scarring was observed.Conclusions:The ultrapulse carbon dioxide laser is an effective and safe therapeutic alternative in treatment of xanthelasma palpebrarum.

KTP Laser on Microleakage of Compomer Restorations in Class V Restorations

To evaluate the effects of pulsed KTP (potassium-titanyl-phosphate) laser on decrease of dentinal microleakage of compomer restorations in primary teeth. Twenty four primary molars were selected for the study After Class V cavity preparations in buccal and lingual surfaces, teeth were divided into three groups: Group 1: Control, Group 2: 1 WKTP laser Group 3: 1.5 WKTP laser. Then cavities were restored with compomer and teeth were thermocycled to 500 cycles, isolated and immersed in 0.5% basic fuchsin for 24 hours. Teeth were rinsed, dried, and sectioned, and microleakage was assessed by dye penetration at the occlusal and gingival surface of the teeth with stereomicroscope (40X). The data were analyzed with Kruskal-Wallis, Mann-Whitney U and Wilcoxon tests. When the scores of microleakage at the gingival margins of the groups were compared, the differences among the groups were found to be statistically significant (p<0.05). At the occlusal margins of the groups, there were no statistical differences (p>0.05). Comparing the gingival and the occlusal margins in the each group, statistically significant differences existed in the Groups 1 and 3 (p<0.05). KTP laser is able to seal dentinal tubules and consequently reduce microleakage towards pulp in primary teeth.

Supraglottic Stenosis: Etiology and Treatment of a Rare Condition

Although laryngotracheal stenosis is well described in the literature, the vast majority of cases are of stenosis at either the subglottic or glottic level. Supraglottic stenosis is an unusual subset of laryngotracheal stenosis that has distinctly different causes, symptoms, and treatment options. A retrospective chart review was conducted on all adult patients at our institution with a diagnosis of supraglottic stenosis. Clinical records, videolaryngoscopic examinations, and operative and clinic procedure records were reviewed. All patients had a minimum follow-up of 12 months. Eight patients with supraglottic stenosis were identified. Five (62.5%) had a history of radiation therapy, and the remaining 3 cases were associated with autoimmune disorders. Our data revealed a frequent association with dysphagia (7 of 8 cases, or 87.5%), including 2 patients with complete pharyngoesophageal stricture and 3 who required a percutaneous gastrostomy tube. All of the patients required more than 1 surgical intervention because of symptomatic recurrent airway stenosis. Three patients underwent successful endoscopic treatment with a carbon dioxide laser in the operating room. One of these patients and 5 additional patients were successfully managed with pulsed KTP laser treatment in the clinic setting without complications. We observed 2 cases of acute intraoperative supraglottic edema in the setting of suspension laryngoscopy and jet ventilation, 1 of which necessitated emergent tracheostomy. Supraglottic stenosis is a rare condition that is often associated with external-beam radiation or autoimmune disorders. All of the patients in our series experienced some degree of symptomatic airway obstruction that required management. The majority also had coexisting dysphagia, often associated with pharyngeal or esophageal stricture. Despite the favorable response to endoscopic treatment, all patients eventually required additional procedures because of symptomatic recurrence of their stenosis. Although endoscopic surgical treatment with a carbon dioxide laser in the operating room setting is a viable option, office-based treatment with a pulsed KTP laser appears to be an effective and potentially safer alternative.

Effect of the 532nm pulsed KTP laser in the treatment of Reinke's edema

To evaluate the effect and safety of the 532nm Pulsed Potassium-Titanyl-Phosphate (KTP) laser in the office-based treatment of patients with Reinke's edema using objective and subjective scaled outcome measures. Case Series. Tertiary hospital center. Seven adult females undergoing in-office KTP laser treatment for Reinke's edema. Participants were studied pre- and posttreatment. Vocal function was evaluated by objective aerodynamic and acoustic analysis. Subjective changes were evaluated using the GRBAS scale, Voice Handicap Index, and videostroboscopy. Histologic effects of the laser were investigated by comparing one patient treated with laser one year prior to excision, one treated with laser just prior to excision, and one control patient who underwent excision without prior laser treatment. At an average postoperative follow up of 17.8 weeks (range 5-78), maximum phonation time trended toward improvement. The median VHI score decreased from 37 to 26 (p=0.150). There was a reduction in each component of the GRBAS scoring and the median fundamental frequency increased from 162 to 186 (p=0.625). Stroboscopic findings demonstrated an intact posttreatment mucosal wave. Histologic comparison of the tissue effects of laser in three patients demonstrated changes in vocal fold vascularity but no acute or long-term damage to the overlying epithelium. Objective and subjective scaled measures suggest that treatment of Reinke's edema in the office with a 532nm KTP laser may result in improved voice. It appears safe with histologic preservation of the vocal fold vibratory epithelium and persistence of mucosal wave.

Local Injection of Bevacizumab (Avastin) and Angiolytic KTP Laser Treatment of Recurrent Respiratory Papillomatosis of the Vocal Folds: A Prospective Study

Photoangiolytic laser treatment of recurrent respiratory papillomatosis (RRP) is effective, but does not reliably prevent recurrence. Therefore, sublesional injections of the antiangiogenic agent bevacizumab (Avastin) were given to assess the adjunctive effect on disease recurrence. Since bevacizumab is a new therapeutic modality for RRP, there were also primary safety objectives to determine whether there was a pegative impact on the voice and whether there were local or systemic complications. A prospective open-label investigation was conducted in 20 adult patients with bilateral vocal fold RRP. The patients underwent planned 532-nm pulsed KTP laser photoangiolysis of bilateral glottal disease 4 times with an approximately 6-week interval between procedures. At each planned laser procedure, the vocal fold that on initial presentation had a greater volume of disease also underwent 4 serial sublesional bevacizumab injections (7.5 to 12.5 mg in 0.3 to 0.5 mL). A sham injection with saline solution was administered to the other vocal fold as a control. Disease resolution was compared between subjects' vocal folds, and objective measures of vocal function (acoustic, aerodynamic), as well as patients' self-assessments of vocal function (Voice-Related Quality of Life survey), were obtained. All 20 patients completed the study, and there were no local or systemic complications. After 4 injections, 3 of the 20 patients had no discernible disease in either vocal fold. Of the remaining 17 subjects, 16 had less disease in the bevacizumab-treated vocal fold despite starting with more disease. Only 1 of the 17 had more disease in the bevacizumab-treated vocal fold after 4 injections. Moreover, 7 of the 20 patients (35%) did not require a laser procedure in the vocal fold that had received 4 bevacizumab injections, as compared with 3 of the 20 vocal folds (15%) that were treated with laser alone. All of the vocal function measures displayed statistically significant posttreatment improvements, except for average fundamental frequency in the 3 female patients, in whom it fell below the normal range. This prospective investigation provided evidence that bevacizumab injections enhanced KTP laser treatment of glottal papillomatosis without systemic or local complications. Coupling the antiangiogenesis agent bevacizumab with KTP laser photoangiolysis is conceptually synergistic and scientifically promising since the mechanisms of action are complementary.

Pulsed potassium‐titanyl‐phosphate laser photoangiolytic treatment of mucosal squamous cell carcinoma in the hamster cheek pouch

Early glottic cancer has been involuted by treatment with the 532 nm pulsed potassium-titanyl-phosphate (KTP) laser in initial clinical studies. Selective photoangiolysis of the sublesional circulation that allows for relative sparing of surrounding tissue is the presumed mechanism. No prior controlled animal-model study has analyzed the ability of selective coagulation of lesional microvasculature coagulation with the KTP laser to involute malignant lesions. This study tests the efficacy of photoangiolysis with the KTP laser in treating squamous cell carcinoma in an established animal model. In vivo. Malignant lesions were induced unilaterally in the cheek pouches of 21 hamsters by applying 9,10-dimethyl-1,2-benzanthrancene. The contralateral cheek pouch served as a control. Weekly lesion photodocumentation and pulsed KTP laser (30 W, 15 msec pulse width, 2 pulses/sec) treatments were done. The endpoint of each treatment was a uniform white-blanching of the lesion. Hamsters were sacrificed 1 week after the last treatment and cheek pouches were analyzed histologically. Carcinoma was confirmed in 19 hamsters, and lesions that were initially <2 mm were more effectively treated than lesions that were >2 mm (P = .0004). Every lesion (10/10) that initially measured <2 mm resolved completely after laser treatment with minimal scarring noted at the treatment site based on histology. Lesions measuring between 2 and 5 mm resolved 33% of the time (2/6), and none (0/3) of the lesions >5 mm resolved after completion of the treatment period. Pulsed KTP laser photoangiolysis can effectively involute small malignant lesions, but may be less effective at involuting larger (>2 mm) lesions.

Cooling the “Oven”: A Temperature Study of Air and Glottal Tissue during Laser Surgery in an Ex Vivo Calf Larynx Model

Endoscopic microlaryngeal laser surgery performed with general anesthesia through a laryngoscope speculum generates heat that accumulates at the distal lumen, creating an "oven" effect and potentially causing bystander thermal damage to nontarget tissue such as the contralateral vocal fold. We report the effects of cooling on air and tissue temperatures that occurred during simulated laryngeal laser surgery with KTP and thulium lasers in an ex vivo calf model. Ten fresh excised calf larynges were studied at room temperature. Laser energy was applied to one vocal fold for 2 minutes, with or without cooling, while temperatures were monitored with sensors placed within the glottal lumen or inserted superficially into the contralateral vocal fold. A pulsed KTP laser (525 mJ) was used for 5 larynges, and a thulium laser (7 W, continuous) was used for the other 5 larynges. Heating was slightly greater for the KTP laser than for the thulium laser with use of these parameters. The lumen temperatures for both lasers increased an average of 13.2 degrees C without cooling, but only 6.7 degrees C with cooling (p < 0.05). The contralateral vocal fold (subepithelial space) temperature increased an average of 6.8 degrees C without cooling, but only 4.2 degrees C with cooling (p > 0.05). Cooling with room-temperature air during laryngeal laser surgery reduces luminal air and contralateral vocal fold temperatures. This effect is believed to be due to elimination of the plume of steam and smoke that significantly heats surrounding structures.

Microlaryngoscopic and Office-Based Injection of Bevacizumab (Avastin) to Enhance 532-nm Pulsed KTP Laser Treatment of Glottal Papillomatosis

Photoangiolytic lasers effectively treat glottal papillomatosis, but do not reliably prevent recurrence. Therefore, sublesional injections of the antiangiogenic agent bevacizumab (Avastin) were given to assess the effect on disease recurrence and phonatory function. A retrospective investigation was done in a pilot group of 10 adult patients with bilateral glottal papillomatosis who had prior angiolytic laser treatment with established patterns of recurrence. The patients underwent 5 bevacizumab injections (5 to 10 mg) into the diseased vocal folds along with 532-nm pulsed KTP laser photoangiolysis treatments 4 to 6 weeks apart. Their disease resolution was compared to findings from prior laser treatment alone, and objective measures of vocal function (acoustic, aerodynamic, Voice-Related Quality of Life survey) were obtained. All 10 patients had a greater than 90% reduction in recurrence. Four of the 10 had resolution. Four of the 10 have limited recurrent or persistent disease, receive injections of bevacizumab at 8- to 12-week intervals, and have not required laser treatment. Two of the 10 have ongoing periodic office-based KTP laser treatment along with bevacizumab injections. No patient has required microlaryngeal surgery with general anesthesia, and all 10 have had substantial improvement in vocal function. This pilot investigation provides preliminary evidence that bevacizumab injections enhance photoangiolytic laser treatment of glottal papillomatosis while enhancing phonatory function. Coupling an antiangiogenesis agent with pulsed KTP laser photoangiolysis is conceptually promising, since the mechanisms of action are complementary.

Laryngeal Laser Surgery for Recurrent Respiratory Papillomatosis, Cancer and Dysplasia: Operating Room and Office

AbstractSince their introduction in laryngology over 30 years ago, lasers have facilitated critically-important innovations that have now evolved into office-based surgery. Recent advances include the application of angiolytic lasers that treat vocal fold lesions by ablating vasculature and the use of the thulium laser as a more efficient and versatile tissue dissector. In our experience, the 532nm pulsed KTP laser has emerged thus far as the optimal angiolytic laser to treat vocal-fold lesions both in the operating room and in the clinic setting. Despite the fact that the skill-sets to adopt office-based laser treatment are an easy transition for most laryngological surgeons, the primary impediment to widespread adoption is the cost of the technology. Furthermore, critical development of these new lasers will occur with broader use of these lasers in other surgical disciplines, which should diminish costs for all surgeons and thereby promote better outcomes for individuals with voice disorders.

Photoangiolytic Laser Treatment of Early Glottic Cancer: A New Management Strategy

The 532 nm pulsed KTP (potassium titanyl phosphate) laser and the 585 nm pulsed dye laser (PDL) are photoangiolytic lasers that have been demonstrated to be effective for managing vocal fold dysplasia. The putative mechanism of action is selective photoangiolysis of the sublesional microcirculation. On the basis of this experience, early glottic cancers were treated by selectively targeting the intralesional and sublesional microvasculature. This approach was derived from Folkman's concepts of neoplastic growth resulting from tumor angiogenesis. Staged microlaryngeal treatment was adopted, because it facilitated optimal functional results, and was considered safe, because early glottic cancer rarely metastasizes. Furthermore, intercurrent disease during conventional incremental radiotherapy is typical in treating early glottic cancer. A pilot group of 22 patients with early glottic cancer (13 T1, 9 T2) were treated with a fiber-based angiolytic laser. Eleven of the 22 had unilateral disease and were entirely treated by laser photoangiolysis as a sole modality. Eleven of the 22 had bilateral disease; 5 of the 11 were treated entirely (bilaterally) by laser photoangiolysis, and 6 of the 11 only underwent laser treatment of the less involved vocal fold, with conventional resection being done on the dominant side of the cancer. The initial 8 of the 22 were treated with the PDL, and the latter 14 of the 22 were treated with the pulsed KTP laser. No patient has cancer presently, and none have undergone posttreatment radiotherapy or open surgery. The mean follow-up is 27 months, 13 of the 22 patients have at least 2 years of follow-up, and the first patient was treated just over 5 years ago. Objective measures of vocal function revealed that photoangiolytic treatment of early glottic cancer resulted in significant postoperative improvements despite the fact that half of the patients had bilateral disease. Angiolytic lasers effectively involuted early glottic cancer, with microsurgically directed nonionizing radiation of the dense neoplastic blood supply resulting in complete tumor regression. This approach is conceptually attractive, because it is repeatable, it preserves all conventional cancer treatment options, and it results in excellent vocal function by improving phonatory mucosal wave vibration. Observations from this investigation suggest that this new and novel cancer treatment strategy is effective; however, larger patient cohorts, longer follow-up, and multi-institutional confirmation will be necessary to establish incontrovertible oncological efficacy.

Photoangiolytic Laser Treatment of Early Glottic Cancer: A New Management Strategy

The 532 nm pulsed KTP (potassium titanyl phosphate) laser and the 585 nm pulsed dye laser (PDL) are photoangiolytic lasers that have been demonstrated to be effective for managing vocal fold dysplasia. The putative mechanism of action is selective photoangiolysis of the sublesional microcirculation. On the basis of this experience, early glottic cancers were treated by selectively targeting the intralesional and sublesional microvasculature. This approach was derived from Folkman's concepts of neoplastic growth resulting from tumor angiogenesis. Staged microlaryngeal treatment was adopted, because it facilitated optimal functional results, and was considered safe, because early glottic cancer rarely metastasizes. Furthermore, intercurrent disease during conventional incremental radiotherapy is typical in treating early glottic cancer. A pilot group of 22 patients with early glottic cancer (13 T1, 9 T2) were treated with a fiber-based angiolytic laser. Eleven of the 22 had unilateral disease and were entirely treated by laser photoangiolysis as a sole modality. Eleven of the 22 had bilateral disease; 5 of the 11 were treated entirely (bilaterally) by laser photoangiolysis, and 6 of the 11 only underwent laser treatment of the less involved vocal fold, with conventional resection being done on the dominant side of the cancer. The initial 8 of the 22 were treated with the PDL, and the latter 14 of the 22 were treated with the pulsed KTP laser. No patient has cancer presently, and none have undergone posttreatment radiotherapy or open surgery. The mean follow-up is 27 months, 13 of the 22 patients have at least 2 years of follow-up, and the first patient was treated just over 5 years ago. Objective measures of vocal function revealed that photoangiolytic treatment of early glottic cancer resulted in significant postoperative improvements despite the fact that half of the patients had bilateral disease. Angiolytic lasers effectively involuted early glottic cancer, with microsurgically directed nonionizing radiation of the dense neoplastic blood supply resulting in complete tumor regression. This approach is conceptually attractive, because it is repeatable, it preserves all conventional cancer treatment options, and it results in excellent vocal function by improving phonatory mucosal wave vibration. Observations from this investigation suggest that this new and novel cancer treatment strategy is effective; however, larger patient cohorts, longer follow-up, and multi-institutional confirmation will be necessary to establish incontrovertible oncological efficacy.

Laser myringoplasty for tympanic membrane atelectasis

To review our experience with laser myringoplasty using a potassium-titanyl-phosphate (KTP) laser for pars tensa atelectasis. Retrospective review. 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. 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. 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.

MP-01.26 (podium): Use of pulsed KTP laser coagulation of submucosal telangiectatic vessels in patients with radiation cystitis

MP-01.26 (podium): Use of pulsed KTP laser coagulation of submucosal telangiectatic vessels in patients with radiation cystitis

532 nm Pulsed Potassium‐Titanyl‐Phosphate Laser Treatment of Laryngeal Papillomatosis under General Anesthesia

Angiolytic lasers have been shown to be an effective treatment strategy for laryngeal papillomatosis. These lasers precisely target hemoglobin within the microcirculation of papillary lesions. We have previously demonstrated the advantages of the fiber-based pulsed 532-nm potassium-titanyl-phosphate (KTP) laser in an office setting (with local anesthesia). This investigation provides the first report of the pulsed-KTP laser during microlaryngoscopy under general anesthesia. A prospective pilot study was performed in 55 adult patients with laryngeal papillomatosis to determine disease response. During suspension microlaryngoscopy, a solid-state 532 nm pulsed-KTP laser was used (15 ms pulse width, 5.25-7.5 J/pulse maximum output, 2 Hz repetition rate, 0.4 mm fiber, approximately 20-80 J/cm2 fluence) to treat laryngeal papillomatosis. All patients underwent postoperative videolaryngoscopy to assess disease regression based on a previously used rating scale. Thirty-seven patients underwent 55 procedures during the 18-month study period. Near-term follow-up with an early postoperative evaluation was available in 23 patients (35 procedures). Fourteen patients (20 procedures) were geographically distant and only returned after developing symptoms with significant disease recurrence. Of the 35 procedures in which near-term follow-up was available, 90% or greater disease regression was achieved in 28 of 35 (80%), 75% to 89% disease regression was achieved in 4 of 35 (11%), and 50% to 74% disease regression in 3 of 35 (9%). Anterior-commissure disease was present in 51 of 55 (93%) cases, and no new webbing/synechia occurred. All patients reported that their vocal function improved after treatment. The 532 nm pulsed-KTP laser was effective for treating recurrent respiratory papillomatosis, which was similar to our experience as an office-based procedure.

Effects of 532 nm Pulsed‐KTP Laser Parameters on Vessel Ablation in the Avian Chorioallantoic Membrane: Implications for Vocal Fold Mucosa

Selective vascular ablation (photoangiolysis) using pulsed lasers that target hemoglobin is an effective treatment strategy for many vocal fold lesions. However, vessel rupture with extravasation of blood reduces selectivity for vessels, which is frequently observed with the 0.45-ms, 585-nm pulsed dye laser. Previous studies have shown that vessel rupture is the result of vaporization of blood, an event that varies with laser pulse width and pulse fluence (energy per unit area). Clinical observations using a 532-nm wavelength pulsed potassium-titanyl-phosphate (KTP) laser revealed less laser-induced hemorrhage than the pulsed dye laser. This study investigated settings for the pulsed KTP laser to achieve selective vessel destruction without rupture using the avian chorioallantoic membrane under conditions similar to flexible laryngoscopic delivery of the laser in clinical practice. The chick chorioallantoic membrane offers convenient access to many small blood vessels similar in size to those targeted in human vocal fold. Using a 532-nm pulsed KTP laser, pulse width, pulse energy, and working distance from the optical delivery fiber were varied to assess influence on the ability to achieve vessel coagulation without vessel wall rupture. Third-order vessels (n = 135) were irradiated: Energy (471-550 mJ), pulse width (10, 15, 30 ms), and fiber-to-tissue distance (1 mm, 3 mm) were varied systematically. Selective vessel destruction without vessel wall rupture was more often achieved by increasing pulse width, increasing the fiber-to-tissue distance, and decreasing energy. Vessel destruction without rupture was consistently achieved using 15- or 30-ms pulses with a fiber-to-tissue distance of 3 mm (pulse fluence of 13-16 J/cm). This study substantiates our clinical observation that a 532-nm pulsed KTP laser was effective for ablating microcirculation while minimizing vessel wall rupture and hemorrhage.

Office-Based 532-nm Pulsed KTP Laser Treatment of Glottal Papillomatosis and Dysplasia

Treatment of glottal papillomatosis and dysplasia was mirror-guided and done in surgeons' offices in the 19th century. It migrated to the operating room in the 20th century to accommodate direct laryngoscopic surgery, which required assistants to administer anesthesia and procedural support. The primary treatment goals, which are disease regression and voice restoration and/or maintenance, are tempered by the morbidity of general anesthesia and potential treatment-induced vocal deterioration. To obviate general anesthesia, office-based laser laryngeal surgery was first done in 2001 with the 585-nm pulsed dye laser (PDL), because it employs a fiber delivery system and its energy is selectively absorbed by oxyhemoglobin. Since then, this new angiolytic laser treatment paradigm has become a mainstay of management for many surgeons; however, there are a number of shortcomings of the PDL. To further develop this concept and address the limitations of the PDL, we used a 532-nm pulsed potassium titanyl phosphate (KTP) laser. A prospective assessment was performed on 48 patients in 72 cases of recurrent glottal dysplasia (36) or papillomatosis (36). All individuals had previously undergone microlaryngoscopic management with histopathologic evaluation. Two dysplasia patients did not tolerate the procedure. Of the treatable dysplasia cases, there was follow-up in 29 of 34. Disease regression was at least 75% in 18 of 29 cases (62%), 50% to 75% in 7 of 29 (24%), and 25% to 50% in the remaining 4 of 29 (14%). Papilloma patients returned for treatment when symptoms recurred, so disease regression could not be assessed accurately. Similar to data obtained with the PDL, these data confirmed that dysplastic mucosa could normalize without resection. Our observations revealed that the 532-nm pulsed KTP laser provided enhanced performance over the PDL laser in a number of ways. The ability to use smaller glass fibers precluded mechanical trauma to the channels of the flexible laryngoscopes and allowed for improved suctioning of secretions. Oxyhemoglobin absorbs energy better at 532 nm than at 585 nm, and the KTP laser can be delivered through a longer pulse width. These factors provide enhanced hemostasis and improved intralesional energy absorbance. Finally, unlike the PDL, the KTP laser is a solid-state laser and is not prone to mechanical failure.

Pulsed Angiolytic Laser Treatment of Ectasias and Varices in Singers

Varices and ectasias in singers are typically the result of phonotraumatic shearing stresses and/or collision forces on the microcirculation within the superficial lamina propria. These lesions can be debilitating in performing vocalists because of the effect of recurrent hemorrhage and/or as a contributing factor to the morbidity of other mass lesions such as polyps, nodules, and cysts. Phonomicrosurgical treatment of performers is understandably approached with great trepidation, as the vocal liability of surgically disturbing the superficial lamina propria and epithelium must be balanced with the inherent detrimental vocal effect(s) of the lesion(s). Pulsed angiolytic lasers that emit radiation at high absorbance peaks of oxyhemoglobin were examined to determine whether they were an efficacious treatment approach for ectasias and varices based on these lasers' mechanisms of action and prior experience in phonomicrosurgery. A prospective trial was done in 39 patients (40 procedures in 54 vocal folds) without complication to evaluate the effectiveness of a 585-nm pulsed dye laser (PDL; 25 cases) and a 532-nm pulsed KTP laser (15 cases) in a noncontact mode to treat 65 varices and 43 ectasias. Twenty-nine of 39 patients had varices and ectasias associated with other phonotraumatic mass lesions that required resection. All patients have resumed full vocal activities, and no patient has had a subsequent hemorrhage or vocal deterioration. Both the 585-nm PDL and the 532-nm pulsed KTP laser were found to be efficacious and relatively safe treatment modalities for vascular abnormalities of the vocal folds in singers. Noncontact selective photoangiolysis of the aberrant vessels prevented future bleeding without substantial photothermal trauma to the overlying epithelium and surrounding delicate superficial lamina propria, thereby allowing for optimal postoperative mucosal pliability and glottal sound production. However, the pulsed KTP laser was substantially easier to use because of its enhanced hemostasis due to its longer pulse width. Vessel wall rupture was commonplace during use of the 585-nm PDL, but rarely occurred during photoangiolysis with the 532-nm pulsed KTP laser.

Our approach to non-ablative treatment of photoaging

Many laser, light and energy emitting devices are utilized for skin rejuvenation. The clinical approach to multiple problems of photoaging are discussed and an algorithm for approach by problem is presented. Clinical use of various modalities such as LED photomodulation, intense pulsed light, pulsed dye laser, KTP laser, radiofrequency and fractional resurfacing are presented with successful parameters, developed over several years, utilized on a daily basis in a busy cosmetic dermatology clinic. Significant improvement in the appearance of signs and symptoms of photoaging, including telangiectasias, mottled pigmentation, irregular surface texture, wrinkling and skin sagging can achieved by relatively non-invasive means.