Pulsed angiolytic laser treatment of ectasias and varices in singers

OBJECTIVES: 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. METHODS: 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. Results: All patients have resumed full vocal activities, and no patient has had a subsequent hemorrhage or vocal deterioration. CONCLUSIONS: 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.     

Office-based treatment of glottal dysplasia and papillomatosis with the 585-nm pulsed dye laser and local anesthesia

Treatment of glottal papillomatosis and dysplasia was mirror-guided and performed 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. Presently, the primary treatment goals, which are disease regression and voice restoration or maintenance, are tempered by the morbidity of general anesthesia and potential treatment-induced vocal deterioration. In fact, general anesthesia has been appropriately considered to be an acceptable source of morbidity for the promise of a precise procedure, which usually ensures airway safety and an optimal vocal outcome. However, patients with recurrent glottal papillomatosis and keratosis with dysplasia are typically monitored with various degrees of watchful waiting until there is a subjective judgment (on the part of the patient and surgeon) that the disease is more of a liability than is the procedure to treat it. Innovations in the 585-nm pulsed dye laser delivery system have allowed for its use in the clinic with local anesthesia through the working channel of a flexible fiberoptic laryngoscope. A prospective assessment was done on 51 patients in 82 cases of recurrent glottal papillomatosis (30) and dysplasia (52). All individuals had previously undergone microlaryngoscopic management with histopathologic evaluation. Five procedures could not be completed because of impaired exposure (2) or discomfort (3). Of those patients who could be treated, there was at least a 50% disease involution in 68 of 77 cases (88%) and 25% to 50% disease regression in the remaining 9 (12%). Patient self-assessment of the voice revealed that 34 of 77 were improved, 39 were unchanged, 4 were slightly worse, and none were substantially worse. These data confirm that diseased mucosa can be normalized without resection or substantial loss of vocal function. The putative mechanisms, which vary according to the fluence (energy) delivered by the laser, are photoangiolysis of sublesional microcirculation. denaturing of epithelial basement membrane linking proteins, and cellular destruction. Furthermore, this relatively safe, effective technique allowed for treatment of many patients (in a clinic setting) in whom classic surgery-related morbidity would have often delayed intervention.     

Effects of 532 nm pulsed-KTP laser parameters on vessel ablation in the avian chorioallantoic membrane: implications for vocal fold mucosa

OBJECTIVES: 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. STUDY DESIGN: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.     

532 nm pulsed potassium-titanyl-phosphate laser treatment of laryngeal papillomatosis under general anesthesia

OBJECTIVES: 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. STUDY DESIGN: A prospective pilot study was performed in 55 adult patients with laryngeal papillomatosis to determine disease response. METHODS: 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. RESULTS: 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. CONCLUSIONS: The 532 nm pulsed-KTP laser was effective for treating recurrent respiratory papillomatosis, which was similar to our experience as an office-based procedure.     

Office-based laryngeal laser surgery with the 532-nm pulsed-potassium-titanyl-phosphate laser

PURPOSE OF REVIEW: Office-based laryngeal laser surgery is a recent innovation. It is emerging as a reliable and practical method of treating a number of laryngeal lesions, which is increasingly popular in the US and abroad. The 532-nm pulsed-potassium-titanyl-phosphate laser has become our laser of choice in treating vocal-fold lesions and diseases for a number of transparent and practical reasons. RECENT FINDINGS: Fiber-based lasers and distal-chip flexible endoscopy have facilitated a new style of surgery. Epithelial diseases such as dysplasia and papillomatosis are well suited for this treatment. Although the initial angiolytic laser used in the larynx was a 585-nm pulsed-dye laser, the solid-state 532-nm pulsed-potassium-titanyl-phosphate laser has been demonstrated to be more effective clinically, more reliable structurally and less expensive. SUMMARY: Technologies to enhance laryngoscopic imaging and lasers, along with socioeconomic forces, should lead to increasing numbers of laryngeal procedures being done in the office with local anesthesia. The 532-nm pulsed-potassium-titanyl-phosphate laser has emerged thus far as the optimal technology for treating phonatory mucosa although further development is likely.     

Office-based laryngeal laser surgery with local anesthesia

PURPOSE OF REVIEW: Office-based laryngeal laser surgery was created recently and is emerging as a reliable and practical method of treating a number of laryngeal lesions. This style of minimally invasive surgery is becoming increasingly popular in the United States and abroad. RECENT FINDINGS: Fiber-based lasers and distal-chip flexible endoscopy have facilitated a new style of surgery. Epithelial diseases such as dysplasia and papillomatosis are well suited for treatment. Although the initial angiolytic laser used was a 585-nm pulsed-dye laser, the 532-nm pulsed-potassium-titanyl-phosphate laser has been demonstrated to be more effective. The 2013-nm Thulium laser shows promise as an office-based laser that simulates the properties of the carbon dioxide laser. SUMMARY: Evolving technologies to enhance laryngoscopic imaging and lasers along with socioeconomic forces should lead to increasing numbers of laryngeal procedures being performed in the office with local anesthesia.     

585-nm pulsed dye laser treatment of glottal papillomatosis

Treatment of recurrent respiratory papillomatosis of the glottis is often challenging. The surgeon and patient must cooperatively balance decisions regarding airway safety, effects of multiple general anesthesias, employment disturbance, and vocal dysfunction. A pilot study was done in 41 adult cases (23 patients; 78 vocal folds) without complication to evaluate the effectiveness of a 585-nm pulsed dye laser (PDL; 450-micros pulse width; fluence of 38 to 255 J/cm2; 1- to 2-mm spot size) in the treatment of this disorder. Thirty-seven of the 41 cases (90%) were bilateral disease. Twenty-six of the 41 cases (63%; including 20 cases with involvement of the anterior commissure) were treated by bilateral photocoagulation of the lesions' microcirculation without microflap resection of tissue. Clinical observation revealed that irradiated but unresected disease involuted without development of an anterior commissure web. In the initial 13 of the 41 cases (32%), PDL treatment was followed by cold instrument microflap resection. The PDL enhanced the epithelial excision by improving hemostasis and by creating an optimal dissection plane between the basement membrane and the underlying superficial lamina propria. The PDL at 585 nm was less effective in the management of exophytic lesions because of its limited depth of penetration (approximately 2 mm). In this initial trial, the PDL was a relatively safe and efficacious treatment for glottal recurrent respiratory papillomatosis. Since the lesions involute without complete resection of the diseased epithelium, the anterior commissure can be treated to minimize the number of procedures. To study patterns of recurrence will require longer follow-up.     

Efficacy of treating children with anterior commissure and true vocal fold respiratory papilloma with the 585-nm pulsed-dye laser

OBJECTIVE: To report preliminary results regarding the safety and efficacy of the 585-nm pulsed-dye laser (PDL) for the treatment of juvenile-onset recurrent respiratory papillomatosis (JORRP) in the pediatric population. DESIGN: Prospective longitudinal cohort study. SETTING: Two pediatric otolaryngology referral centers. PATIENTS: Twenty-three pediatric patients ranging in age from 6 months to 17 years. INTERVENTIONS: The 585-nm PDL was used for at least 1 treatment on each of these patients to treat JORRP of the true vocal folds or anterior commissure. MAIN OUTCOME MEASURES: Complications from the use of the 585-nm PDL in the treatment of JORRP. RESULTS: There was no evidence of anterior commissure webbing or true vocal fold scarring in this group of 23 patients followed up for 3 months to 1 year. CONCLUSIONS: The 585-nm PDL seems to be a safe instrument for treatment of JORRP. There is the potential that improved voice outcomes may be apparent when compared with traditional therapies because the vocal fold epithelium seems to be unharmed when treated with this method. Furthermore, the lack of epithelial damage incurred by the 585-nm PDL should enable more aggressive surgical excision of anterior commissure disease. Further prospective longitudinal studies examining voice outcomes are needed.     

Office pulsed dye laser treatment for benign laryngeal vascular polyps: a preliminary study

OBJECTIVES: The 585-nm pulsed dye laser (PDL) was recently deemed relatively safe and effective for treatment of laryngeal papilloma, dysplasia, and granuloma. We report on in-office PDL treatment of laryngeal vascular polyps. METHODS: Retrospective case results from 29 consecutive cases of laryngeal polyps were evaluated to determine the percent change in polyps after PDL treatment. Preoperative and postoperative measurements of polyp size, total power delivered to the site, and whether patients opted for postprocedure phonomicrosurgery were analyzed. RESULTS: After PDL treatment, the results varied from complete to partial resolution of the polyp. Four patients requested conventional phonomicrosurgery, and the rest had enough improvement to defer surgery. Almost 40% of patients with larger polyps desired operative intervention after laser treatment, whereas only 13% of those with small polyps opted for phonomicrosurgery. Thirty-eight percent (11 of 29) of the lesions had greater than 70% improvement after 1 or 2 laser treatments (average of 1.1 procedures). Smaller lesions responded better. Thirty-nine percent of small polyps resolved by greater than 70%, whereas only 20% of larger lesions improved by the same amount. There were no adverse events from the office procedure. CONCLUSIONS: In-office use of the PDL for treatment of vascular polyps may be a safe alternative to phonomicrosurgery. Small polyps seem to show a better response.     

A 585-nanometer pulsed dye laser treatment of laryngeal papillomas: Preliminary report

Objectives/Hypothesis: Standard management of recurrent respiratory papillomatosis (RRP) currently consists of CO₂ laser microsurgical ablation of papillomas. Because of the recurrent nature of this viral disease, patients are often faced with significant cumulative risk of soft tissue complications. As a minimally traumatic alternative to management of RRP, we have investigated the use of the 585-nm pulsed dye laser (PDL) to cause regression of papillomas by selective eradication of the tumor microvasculature. Study Design: Nonrandomized prospective pilot study. Methods: Patients with laryngeal papillomas were treated with the PDL at fluences of 6 J/cm ² (double pulses per irradiated site), 8 J/cm ² (single pulses), and 10 J/cm ² (single pulses), at noncritical areas within the larynx, using a specially designed micromanipulator. Lesions on the true cords were treated with the CO₂ laser, using standard methodology. Results: Clinical examination of three patients treated to date showed that PDL treatment appeared to produce complete regression of papillomas. Unlike the sites of lesions treated by the CO₂ laser, the epithelial surface at the PDL treatment sites was preserved intact. Conclusions: These preliminary results suggest the PDL may eradicate respiratory papillomas with minimal damage to normal laryngeal tissue. Further analysis of the ongoing study is required to demonstrate potential benefits of the technique.     

In-office laryngeal surgery with the 585-nm pulsed dye laser

PURPOSE OF REVIEW: To describe the current support in the literature for in-office surgery using the 585-nm pulsed dye laser. RECENT FINDINGS: There are substantial cost savings (US$5000) and patient comfort when in-office surgery is performed with the pulsed dye laser. The pulsed dye laser can be used in the office and operating room to activate aminolevulinic acid for photodynamic treatment of recalcitrant laryngeal keratosis, with long-term eradication of keratosis without the prolonged photosensitivity of previous photodynamic agents. The site of the cleavage plane created in the true vocal fold mucosa has now been elucidated. SUMMARY: The 585-nm pulsed dye laser allows safe, medically effective and cost-effective in-office surgery for a host of laryngeal lesions such as papillomatosis, keratosis, Reinke's edema, granulomas and other vascular lesions. The pulsed dye laser can activate aminolevulinic acid for laryngeal photodynamic therapy. Of the lasers currently in use it has the longest track record of safety and, to the satisfaction of many, continues in service at 23 centers around the world.     

Predicting clinical efficacy of photoangiolytic and cutting/ablating lasers using the chick chorioallantoic membrane model: implications for endoscopic voice surgery

Objectives/Hypothesis: The optimal balance between a laser's clinical efficacy and collateral thermal damage is the major determinant for selection of a particular laser in endolaryngeal surgery. The chick chorioallantoic membrane (CAM) simulates the microvasculature of the human vocal fold and is, therefore, useful for testing effects of laser settings, mode of delivery, active cooling, and wavelength. Such information is essential for optimizing the effectiveness of lasers in treating laryngeal pathology while preserving vocal function. Study Design and Methods: The thermal and coagulative effects of four lasers (585 nm PDL, 532 nm KTP, 2.01ìm Thulium, 10.6ìm CO₂) were quantified at selected (and clinically relevant) energy settings before and after tissue cooling using the CAM model. Measures included imaging real‐time vascular reactions in the CAM model (i.e., vessel coagulation and/or rupture), and post‐procedure histologic analysis of CAM tissue. In each experiment, laser energy was applied to the CAM in a controlled manner. Cooling was done using a dermatological cold‐air device, and temperatures were measured with a thermistor. Lasers tested included the photoangiolytic pulsed‐dye (PDL) and KTP, as well as the ablative/cutting CO₂ and thulium lasers. The vessel rupture/coagulation and thermal effects of various energy‐delivery parameters on the CAM, with and without cooling, were assessed. After removal of the CAM, specimens were stained as whole‐mounts, photographed at 4X magnification, and evaluated by two independent, blinded surgeon reviewers. The efficacy of increased pulse‐width (KTP laser) on treating larger vessels (>0.5 mm) and the effects of extravasated blood on photoangiolysis were also evaluated. Results: Photoangiolytic lasers: Vessel coagulation/rupture rates showed that the PDL caused more frequent vessel rupture than the KTP laser. For both lasers, cooling the CAM by ～20°C resulted in 30% ‐ 60% reduction in the thermal‐damage zone (P < .05). Cooling reduced the efficacy of coagulation with the PDL but not with the KTP laser. The clinically observed phenomenon that laser heating of extravasated blood increases thermal damage and decreases efficacy of coagulation was clearly evident in the CAM model. Ablative lasers: The thermal‐damage zone of the CO₂ laser (0.3 mm spot size) was not significantly different with or without cooling (0.32 mm² and 0.34 mm², respectively) (P = .30). However, when the spot size was defocused to 1 mm, the thermal‐damage zone was over 2× greater when the tissue was not cooled (0.74 mm² vs 0.35 mm²) (P < .002). The thermal‐damage zone of the Thulium laser was reduced by an average of 58% for the three power settings tested when the CAM was air‐cooled (P < .05). Conclusions: The CAM was an excellent model for studying the effects of photoangiolytic lasers, for which optimal pulse‐widths exist for vessel coagulation. Smaller vessels coagulated reliably at pulse widths >15 msec, and larger vessels required pulse widths >35 msec for optimal coagulation. Cooling the target tissue decreased the thermal‐damage zone created by photoangiolytic lasers. While cooling had no effect on the efficacy of coagulation with longer pulse widths (KTP), tissue cooling decreased the coagulation rate at shorter pulse widths (PDL). The thermal effects of cutting/ablating lasers can be reduced with cooling, but the CAM was not a good model with which to study coagulation/rupture rates in cutting/ablating lasers.     

Cost savings of unsedated office-based laser surgery for laryngeal papillomas

OBJECTIVES: Unsedated office-based laryngeal laser surgery (UOLS) is now an effective alternative to traditional operating room-based suspension microdirect laryngoscopy under general anesthesia. This procedure includes pulsed dye laser (PDL) treatment of recurrent respiratory papillomas, granulomas, leukoplakia, and polypoid degeneration. The objective of this study was to determine the magnitude of the cost savings derived by moving these types of procedures from the operating room to the office setting. METHODS: Retrospective cost-identification analysis was performed by comparing the billing records of patients who underwent surgical laser treatment for recurrent respiratory papillomatosis in the operating room to the costs and charges for patients who underwent similar procedures with the in-office PDL. RESULTS: In performing surgery with the PDL in the office, the average cost savings was more than $5,000 per case. Current reimbursement rates do not cover the cost of performing UOLS. CONCLUSIONS: The potential cost savings of UOLS are tremendous; however, at present significant financial disincentives prevent proliferation of this technology.     

Office-based 585 nm pulsed dye laser treatment for vocal polyps

Conclusions. Office-based 585 nm pulsed dye laser (PDL) surgery appeared to be safe and effective. It can be considered as a treatment option for office-based vocal polyp removal. Objectives. A 585 nm PDL has been introduced to photocoagulate vascular lesions of the superficial layer of the lamina propria in the vocal fold to treat laryngeal pathology including laryngeal papillomas, granulomas, leukoplakia, and Reinke's edema. This study investigated the efficacy and feasibility of PDL surgery for the treatment of vocal polyps, and evaluated the associated moribidity. Subjects and methods. Among 270 patients who underwent office-based PDL surgery under local anesthesia at the Yeson Voice Center, 75 patients with vocal polyps were evaluated. The mean follow-up period was 5.2 months (range 3–10 months). A retrospective analysis was performed on the postoperative perceptual and acoustic level and treatment outcome. Results. All patients who underwent PDL surgery had complete regression of their laryngeal lesion. The postoperative voice assessment including aerodynamic, acoustic, and perceptual parameters showed significant improvement. All patients tolerated the procedure without serious complications.     

Intratumoral hypericin and KTP laser therapy for transplanted squamous cell carcinoma

OBJECTIVES/HYPOTHESIS: To test intratumoral photodynamic therapy (IPDT) as a new treatment for squamous cell carcinoma in a preclinical tumor model. STUDY DESIGN AND METHODS: Human P3 squamous carcinoma cells were transplanted subcutaneously in athymic nude mice and allowed to grow into 300- to 500-mm3 tumors. Hypericin dye at 1 microg/gm of body weight was injected intratumorally (IT) or intravenously (IV). After 4 hours hypericin biodistribution was assessed in ethanol extracts from tissues by fluorescence spectroscopy. IPDT also was tested by KTP laser fiberoptic insertion in tumors 4 hours after IT dye injection compared to KTP532 laser therapy alone (532 nm, 1W, 40-60 J, 0.6-mm fiber). RESULTS: Hypericin concentration in tissues was as follows: (IT vs. IV) for tumors (3660 vs. 135 ng dye/gm tissue), lung (760 vs. 6345), liver (75 vs. 935), blood (65 vs. 480) compared to skin (465 vs. 110) or muscle (335 vs. 80) adjacent to the squamous cell tumors. Four hours after dye injection, the tumor exhibited bright orange fluorescence when excited by KTP 532-nm green laser light. The IPDT-treated tumors had a 3.32+/-0.32-mm radius of cell destruction when H&E-stained sections were examined compared with 2.5+/-0.38 mm for the laser only control group (n = 10, P = .003). CONCLUSIONS: This pilot study indicates laser IPDT with hypericin induces a significant increase in tumor necrosis compared with laser alone and may be useful as a less invasive adjuvant treatment for recurrent or inoperable human squamous cell cancers of the head and neck.     

Advantage and disadvantage of KTP-532 laser tonsillectomy compared with conventional method

Objective: The purpose of this prospective study is to define the advantages and disadvantages of KTP laser tonsillectomy compared with those of the conventional method. Methods: Eighteen adult patients (ten male and eight female, ranging in age from 14 to 44 years) underwent KTP-532 laser tonsillectomy on one side and standard dissection surgery on the other side under general anesthesia. Results: By KTP laser tonsillectomy, there was a reduction in intraoperative blood loss and average time for removing one tonsil. On the second day of tonsillectomy, subjective pain on the KTP laser surgery side was less than that on the conventional surgery side. By the days 5–8, however, this effect disappeared and many patients indicated the laser side was more painful. There was no postoperative bleeding after KTP laser tonsillectomy. Laser surgery appeared to lead to slow wound healing during the whole post-operative course with significant difference compared with the conventional method. Disadvantages of postoperative pain and the possibility of secondary infection due to slow wound healing could be prevented by application of antibiotics and an anodyne. Conclusion: Considering safety and reliability during surgery, KTP laser was considered useful for adult tonsillectomy.     

Effect of KTP laser on implants used in middle-ear surgery

The present study is intended to explore the effects of the KTP laser on various types of implant, used in middle-ear surgery. A laboratory study was undertaken to evaluate the interaction between the KTP laser (KTP-532 Orion Laser, Laserscope, UK) and individual middle-ear implants. A variety of middle-ear implants were used: a silicone sheet, Teflon, hydroxylapatite, ionomeric cement, gold and titanium prostheses as well as gelfoam. Following exposure to the laser, these implants were studied by direct inspection using an operating microscope. The KTP laser induced no detectable alteration in any of the implants when they were clean and dry. However, in the presence of fresh blood, under the influence of the energy of the absorbed laser, the silicone burnt and melted and the Teflon piston was vaporized. Likewise, a few tiny holes appeared on the surface of the ionomeric implant and then the prosthesis deformed. The hydroxylapatite implant broke into two pieces. However, no detectable alteration could be observed on gold or titanium pistons, even in the presence of blood. The authors conclude, that in the presence of blood, interaction between the KTP laser and both silicone and hydroxylapatite implants needs to be avoided. Teflon prostheses can be cautiously vaporized. Gold and titanium prostheses were unaffected by laser even in the presence of blood.     

Pulsed-dye laser and retinoic acid delay progression of oral squamous cell carcinoma: a murine model

OBJECTIVES/HYPOTHESIS: This study examined the role of the pulsed-dye laser (PDL) at 585 nm coupled with retinoic acid at therapeutic (5.0 mg/kg) and nontherapeutic (0.5 mg/kg) doses to delay the progression of cancer with a two-hit approach. The existing vasculature is selectively targeted by the laser, whereas retinoic acid inhibits future angiogenesis. STUDY DESIGN: Randomized, prospective study in a murine model. METHODS: Twenty-five athymic nude mice were inoculated with oral squamous cell cancers on six flank sites and randomly divided into five groups: 1) control subjects, 2) treatment with 0.5 mg/kg retinoic acid (RA 0.5), 3) treatment with 5.0 mg/kg retinoic acid (RA 5.0), 4) treatment with RA 0.5 + PDL, and 5) treatment with RA 5.0 + PDL. The PDL groups received irradiation after inoculation. The retinoic acid was administered daily. The tumors were counted and measured for 14 days. RESULTS: The control group developed visible tumors in 50% of the inoculation sites at 3 days compared with 3 days (RA 0.5) and 4 days (RA 5.0) for the retinoic acid groups and 9 days (RA 0.5 + PDL) and 10 days (RA 5.0 + PDL) for the laser treatment groups. There was no tumor growth until day 7 in the RA 5.0 + PDL group. The tumor volume was statistically different between the treatment groups. CONCLUSION: This study demonstrated the superiority of a single treatment with the PDL coupled with retinoic acid to delay the progression of cancer when compared with treatment with retinoic acid alone, thus introducing a novel strategy in cancer control.     

Combined endolaryngeal videoendoscopic surgery and photodynamic treatment of patients with recurrent laryngeal and tracheal papillomatosis

Two-stage combined treatment of chronic recurrent papillomatosis of the larynx and trachea has been designed and tested in P.A. Herzen Research Cancer Institute. Stage I of the treatment consisted in endolaryngeal videoendoscopic surgery with Nd:YAG-laser destruction, argon-plasma coagulation and electroresection of the papilloma; stage II - postoperative photodynamic therapy (PDT) to prevent recurrence. In 1995-2007 the treatment was given to 32 patients aged 10-66 years with recurrent papillomatosis of the airways with the disease history 5-58 years. In two thirds of the patients papillomatosis involved several parts of the larynx and trachea. Squamous cell papilloma was accompanied with dysplasia of the first-second degree in 10 (31%) patients, dysplasia of the third degree - in 4 (12,5%), cancer in situ - in 3 (9,4%) patients. Human papilloma virus (HPV) was detected by hybridization in situ in 96%. The course of the treatment resulted in a complete regression (CR) of papilloma in 25 of 32 (78%), partial regression in 7 patients. The recurrence-free interval averaged 32 months (maximal 7 years) in 14 of 25 patients with CR. HPV was eradicated in a group of patients with persistent clinical remission. A 6 to 19 month follow-up recorded papilloma recurrence in 11 patients. The recurrence-free period increased 2,5-fold. In patients with dysplasia of degree I-III and cancer in situ (n=17) CR of dysplasia and preinvasive cancer foci was achieved in 15 (88%) patients.