Laser arthroscopy of the temporomandibular joint

Laser surgery is very different than traditional surgery. The clinician must be familiar with the physical properties of the laser to use this instrument safely and properly. Various lasers are available for use in oral and maxillofacial surgery and dentistry, namely the carbon dioxide laser, the neodymium:yttrium-aluminum-garnet laser, and the holmium: yttrium-aluminum-garnet laser (Ho:YAG). Only the Ho:YAG laser has been used with effectiveness in temporomandibular joint arthroscopic surgery.     

Digital calcification in systemic sclerosis: effective treatment with good tissue preservation using the carbon dioxide laser

Tissue calcification of the fingers associated with limited systemic sclerosis is a common problem and is the source of considerable morbidity as it may be extremely tender and cause considerable functional disability. The current treatment of digital calcification is unsatisfactory. We evaluated the use of the carbon dioxide (CO2) laser in the management of this condition in six patients with the limited form of systemic sclerosis. A total of 21 areas of symptomatic digital calcification of the fingers were treated. Complete resolution of symptoms occurred in 12, moderate response with partial improvement was seen in five, little improvement was observed in two, and recurrence of calcinosis was found in two. The patient's average healing time was 6 weeks (range 4-10). The median duration of follow-up was 20 months (range 12-40). Postoperative infection was seen in two patients, and resolved completely in both with the use of topical and oral antibiotics. We found the CO2 laser a simple and effective treatment for most of the symptomatic lesions of digital calcification, and it may obviate the need for deforming surgery in many cases.     

Cell, tissue and organ culture as in vitro models to study the biology of squamous cell carcinomas of the head and neck

In vitro models are currently being used to study head and neck squamous cell carcinoma (HNSCC). Several hundred HNSCC cell lines have been established by various investigators and used to study a broad spectrum of questions related to head and neck cancer. The head and neck model with respect to multistage carcinogenesis is now complete. Several techniques exist for the culture of normal epithelial cells from the upper aerodigestive tract (UADT). The biology of these UADT cells (oral cavity, oropharynx, hypopharynx and larynx) is being studied. Successful culture of premalignant lesions (dysplastic mucosa, leukoplakia, erythroplakia) has resulted in establishment of a limited number of premalignant cell lines and cell cultures. HPV infection of normal oral epithelial cells for immortalization (approximately premalignant cells) coupled with transformation with carcinogens (malignant cells) has established an experimental model for progression. Two in vivo models for oral carcinogenesis, the 7,12 dimethylbenz(a)anthracene-induced hamster cheek pouch model and the 4-nitroquinoline-N-oxide rat oral model, have been established in culture. Thus, multistage carcinogenesis models have been established from both human tissues and animal models and include cultures of normal, premalignant and malignant cells. Culture techniques for growing dissociated primary tumor cells for short term experimental analysis are being used. The culture of normal or tumor tissue as organ/explant cultures allows for the maintenance of normal cell-cell and cell-matrix interaction, but limits experimentation since these cultures cannot be propagated. Several three dimensional model systems are being used to obtain this histological complexity but allow for experimentation. The ability to culture normal, premalignant and malignant cells coupled with the use of a variety of culture techniques, should allow for the continued growth and experimentation in head and neck cancer research.     

Noninvasive diagnosis of oral neoplasia based on fluorescence spectroscopy and native tissue autofluorescence

OBJECTIVE: To evaluate the clinical potential of fluorescence spectroscopy (a noninvasive technique for assessing the chemical and morphologic composition of tissue) for in vivo detection of oral cavity neoplasia. DESIGN: A fluorescence spectroscopy system recorded spectra from oral cavity sites in 8 healthy volunteers and in 15 patients with premalignant or malignant oral cavity lesions at 337-, 365-, and 410-nm excitation wavelengths in the emission range of 350 to 700 nm. Fluorescence peak intensities and spectral line shapes were compared and diagnostic algorithms were developed to distinguish normal sites from abnormal sites. SETTING: The head and neck cancer clinic at a tertiary referral center in Houston, Tex. RESULTS: Differences were found in spectra from normal, dysplastic, and malignant oral mucosa. The fluorescence intensity of normal mucosa was greater than that of abnormal areas. In addition, the ratio of red region (635-nm) to blue region (455-490-nm) intensities was greater in abnormal areas. Diagnostic discrimination was achieved when test site spectra were compared with spectra from a normal site in the same patient. One diagnostic algorithm based on spectra at 337 nm gave a sensitivity of 88% and a specificity of 100%. CONCLUSIONS: Consistent differences exist between the fluorescence spectra of abnormal and normal oral mucosa. Therefore, fluorescence spectroscopy has the potential to improve the noninvasive diagnosis of oral cavity neoplasia. Further studies will better define the role of this technique in the detection of premalignant and early oral cancer lesions.     

Laser blepharoplasty

Cosmetic eyelid surgery has benefited from the use of the carbon dioxide laser. The short pulsed laser cuts through tissue with limited surrounding thermal damage, resulting in incisions that heal with minimal scarring comparable to traditional cold steel methods. The laser provides excellent hemostasis, which shortens surgical time, and lessens postoperative bruising and swelling.     

Gorlin's syndrome: the role of the carbon dioxide laser in patient management

The treatment of multiple basal cell carcinomas in patients with Gorlin's syndrome presents a therapeutic challenge. The carbon dioxide laser presents a unique treatment option due to increased surgical speed, a bloodless operating field, reduced postoperative pain and discomfort, and acceptable scars. Six patients with Gorlin's syndrome have been treated with the carbon dioxide laser. Between 14 and 110 lesions were treated in one session under local anesthesia. Pre- and postlaser biopsies of the lesions confirm complete eradication of the tumors. Mean follow-up is 20 months. No local recurrence has been observed.     

Premalignant lesions of the vocal cords. A retrospective study of 62 cases treated with CO2 laser

A series of 62 patients treated by (repeated) CO2 laser excision and/or vaporization for premalignant lesions of the vocal cords was analysed retrospectively. Of the 54 patients available for follow-up (ranging from 1 to 15 years), five patients (9%) developed an invasive glottic carcinoma and needed radiotherapy. Only two patients (4%) needed extensive surgery (total laryngectomy). One patient (2%) died of a recurrent carcinoma despite radiotherapy and laryngectomy, and six patients (11%) died of a metachronic lung carcinoma. The therapeutic results of (repeated) laser therapy were comparable to those in other reports regarding radiotherapy or stripping. The subjective functional results were satisfactory and tended to improve along with refinement of laser surgery techniques. Follow-up of patients who once had a premalignant laryngeal lesion is mandatory ad vitam, regardless of the grade of the lesion. For the screening of lung cancer, there is still no consensus on a standard-of-care. The classical chest X-ray remains the most accessible and comfortable screening procedure.     

Instrumentation and techniques for carbon dioxide lasers in equine general surgery

The carbon dioxide laser has become an important surgical instrument in human and veterinary medicine. The unique properties of this laser make it the instrument of choice for precise incision, coagulation, and vaporization of tissue at the body surface with minimal morbidity to the patient. This article describes the instrumentation and techniques used to perform a variety of equine general surgical procedures with the carbon dioxide laser. The benefits of surgery using the carbon dioxide laser include precise dissection with minimal trauma to adjacent tissues, good hemostasis, and the ability of the laser beam's thermal properties to kill bacteria or tumor cells in the operative field.     

Circulating p53 antibodies as early markers of oral cancer: correlation with p53 alterations

p53 aberrations are early events in the pathogenesis of betel- and tobacco-related oral malignancies. Accumulation of p53 protein in oral lesions may elicit a humoral immune response against p53 protein in these patients. p53 antibodies (Abs) were analyzed in 183 sera obtained from patients with premalignant or malignant oral lesions and normal individuals by enzyme-linked immunoassay using recombinant p53 protein as antigen. These results were correlated with accumulation of p53 protein in patients' matched oral tissue specimens. Circulating p53 Abs were observed in 24 of 70 (34%) cancer patients and 15 of 50 (30%) patients with premalignant oral lesions. p53 Abs showed a significant association with increase in tumor size and dedifferentiation of tumors, factors indicative of poor prognosis. Expression of p53 protein was analyzed in 43 matched oral lesions (18 premalignant and 25 malignant cases). All the p53-seropositive patients (7 leukoplakia and 11 squamous cell carcinoma) showed elevated levels of p53 protein in matched oral lesions. However, the total number of patients seropositive for p53 Abs was lesser than that of patients exhibiting p53 protein accumulation in oral lesions. Four of the 63 normal healthy individuals who were heavy consumers of tobacco (smoking/chewing) and betel were found to be positive for p53 Abs. Detection of circulating p53 Abs in patients with premalignant oral lesions suggests that humoral immune response against p53 protein is an early event in oral oncogenesis and may be a surrogate marker for both p53 alteration and preclinical cancer.     

Types of medical lasers

The knowledge about different types of lasers and their potential use in medicine is presented. A very rapid development of laser technology in the world imposes a need for up-to-date information about the characteristics of different laser instruments. Without this kind of information it would be difficult to keep in touch with the latest developments in the world's technology. Different types of lasers have different indication range in the medical practice. An inquiry into the fundamental principles of lasers physics is an important prerequisite for successful application of this technology in medicine. Laser as a surgical knife has shown certain advantages over scalpel, electrocautery and cryosurgery, as the laser surgery is a noncontact method, bloodless, precise, with better visualization, minimal postoperative edema, painless healing, without complications. Although laser cannot entirely replace conventional surgical instruments, it is still the instrument of choice for treatment of numerous pathological conditions. The carbon dioxide laser is a highly precise, bloodless light scalpel used for incising and excising tissues and sealing small blood vessels. The infrared beam at 10,600 nm wavelength is absorbed by water and tissue destruction is due to the instantaneous vaporization at relatively low temperature of 100 degrees C. The beam seals blood vessels of up to 0.5 mm in diameter and if the beam is defocused, larger vessels may be controlled. The beam also seals lymphatics, possibly reducing the spread of tumour cells by this route, and seals nerve endings: there is no incidence of neuroma formation. Carbon dioxide laser has shown a great efficiency in otorhinolaryngology, in maxillo-facial surgery and plastic surgery, in urology and gynecology. Provides true "no touch" surgery, and is used increasingly in neurosurgery for the precise atraumatic removal of tissue and for creation of precise lesions for the control of pain. The carbon dioxide laser beam cannot, at present, be transmitted via a flexible fibre, although a number of fibres are being investigated. Delivery of laser energy to microscope, colposcope or handpiece is via an articulated arm which is a hollow tube with mirrors at the articulations. The argon laser produces blue-green coherent light at a number of wavelengts but 80% of the energy is at wavelengths of 488 and 514 nm. This laser was first used in ophtalmology to treat diabetic retinopathy through, and without damage to, the clear anterior parts of the eye. The argon laser is used for blood vessel coagulation but can be used to perform slow, thermal tissue destruction at higher power levels. Argon laser is most commonly used in ophthalmology for otological micro-surgery, particularly in the treatment of otosclerosis and tympanosclerosis. Very good results have been achieved in the argon laser treatment of gastrointestinal bleeding ulcers, vascular lesions and polyps. Dermatology is another field where argon laser has shown great efficiency: hemangyomas, telangiectasias, tattoos, small benign and malignant tumours are amenable to argon laser treatment. In neurosurgery it is used to control both normal and abnormal blood vessels but at present much work on treatment of arteriovenous malformations and aneurysms is experimental. Both the argon laser energy can be transmitted via flexible fibre optic delivery system which can then be attached to an operating microscope, slit lamp, endoscope delivery fibre or handpiece. The Neodymium-YAG laser is used both for tissue destruction with good haemostasis and for the control of normal and abnormal blood vessels. This laser produces infrared coherent light at 1060 nm wavelength, which is deeply absorbed in the tissues without colour or tissue specificity. Neodymium-YAG laser is mostly used in tracheobronchial, gastrointestinal and urologic pathology in the treatment of stenoses, granulomas, benign tumours, and for reduction of malignant tumours. (ABSTRACT TRUN     

Carbon dioxide laser vaporization for genital wart

The purpose of this study was to evaluate the effectiveness of carbon dioxide laser vaporization in the treatment of coalescent condyloma acuminata of the female lower genital tract. Between July 1990 and September 1992, 24 cases were enrolled in the study. There were 13 pregnant patients and 11 nonpregnant patients. We performed the procedure under colposcopic guidance on an out-patient basis. Carbon dioxide laser vaporization was carried out in continuity to an appropriate tissue depth with carbon dioxide brushing 1 cm around the lesion. Of these 24 cases, biopsy proven 2 residual lesions and 1 recurrence were documented at the 2nd week and the 2nd month postoperative, respectively. We found low rate of intraoperative and postoperative morbidity or complication, with mild to moderate vulvar pain in the patients and no gross scarring. It is concluded that carbon dioxide laser is effective for eradicating extensive condylomata in the female lower genital tract with low intraoperative and postoperative morbidity on an out-patient basis.     

Clinical applications of the CO2 laser in neoplastic lesions of the aerodigestive tract

The use of the CO2 laser in otolaryngologic microsurgery offers the opportunity to reduce morbidity and deformity, and to decrease hospitalization time associated with resection of neoplasms of the oral cavity, pharynx, and larynx. We used the CO2 laser to resect a variety of lesions in 14 patients. Laser resection was the primary mode of therapy, in combination with irradiation and chemotherapy. Local control of the neoplasms was achieved with a number of advantages over established modes of therapy. The CO2 laser continues to show promise as a means of primary control in head and neck neoplasms, with a minimum of morbidity and deformity.     

Correlation between dietary vitamin A consumption and onset of precancerous lesions in the oral cavity

The efficacy of vitamin A in the prevention of oral cavity cancer has been studied during the last years due to the interest for a possible application of new drugs in the treatment of second primary tumours and multiple neoplasms. Fifty patients with oral precancerous lesions treated at the "Centre for prevention of oral cavity cancer" of the "Regina Elena" Institute in Rome, have been subjected to a rigorous questionnaire about their use of vitamin A in the diet. Moreover a standard sample of fifty healthy people without oral cavity lesions.     

Transoral laser surgery of supraglottic cancer: follow-up of 141 patients

OBJECTIVE: To determine the role of transoral laser resection of supraglottic carcinomas. DESIGN: Retrospective unicenter study of the oncologic results of transoral carbon dioxide laser microsurgery for supraglottic carcinomas performed between February 1979 and December 1993. Median follow-up was 37 months. SETTING: University hospital academic tertiary referral center. PATIENTS: We reviewed the medical records of 141 patients (a consecutive sample of 131 men and 10 women; mean age, 60 years) with histologically proven supraglottic carcinomas undergoing transoral laser surgery, possibly in combination with neck dissection or radiotherapy. Stage distribution of patients was as follows: stage I, 23.4%; stage II, 25.5%; stage III, 16.3%; and stage IV, 34.8% (according to the Union Internationale Contre le Cancer staging system). MAIN OUTCOME MEASURES: Recurrence-free survival rates and local and regional recurrence rates. RESULTS: Five-year recurrence-free survival rates were as follows: the whole case load, 65.7%; stage I, 85.0%; stage II, 62.6%; stage III, 74.2%; and stage IV, 45.3%, according to the Union Internationale Contre le Cancer staging system. The local and regional recurrence rates were 16.3% and 9.9%, respectively. CONCLUSIONS: The oncologic results of transoral carbon dioxide laser surgery are satisfying if clean surgical margins (R0 resection) can be reached. In patients in whom tumor-free margins are not achieved (R1 and R2 resection) and transoral revision is not possible, transcervical procedures (partial or total laryngectomy) should be performed. The indication for transoral supraglottic laryngectomy in T3 lesions should be considered with restraint.     

Treatment of resistant forms and recurrence of Hodgkin''s disease]

BACKGROUND: Vascular anomalies (hemangiomas and vascular malformations) are frequently located in the oral cavity. They can be treated by cool steel surgery, cryotherapy, laser therapy, embolization, and sclerosis. The choice of treatment should depend on the type of vascular anomaly, its site, the general condition of the patient, and the doctor's experience. OBJECTIVE: The objective of this article is to assess the usefulness, indications, and advantages of transfixion technique in the treatment of oral vascular lesions. METHODS: We present seven patients with various vascular anomalies in the oral cavity that were treated using transfixion technique. This procedure is performed with local infiltration anesthesia and it consists of interlacing a polyglycolic acid suture a number of times in an upward direction until the vascular anomaly becomes bloodless. RESULTS: In all seven patients we completely eliminated the vascular lesion without significant long-term complications. We detected a transitory retractil scar in only one patient and edema in the postoperative period in another one. CONCLUSIONS: Treatment of vascular anomalies of the oral cavity by transfixion technique is an effective, simple method that does not cause major complications and is low in cost.     

Combination carbon dioxide laser vermilionectomy and wedge excision of the lip

Dermatologic surgeons are very familiar with the use of the carbon dioxide (CO2) laser for treating actinic cheilitis. When squamous cell carcinoma is proven or suspected in the affected lip, then combined CO2 laser vermilionectomy and wedge excision as a one stage procedure has significant advantages for the patient.     

Laser skin resurfacing with the Q-switched Nd:YAG laser

BACKGROUND: Recent studies have shown that char-free pulsed carbon dioxide lasers are useful in the treatment of rhytids. Other infrared lasers have also been observed to induce changes in the skin. OBJECTIVE: In this pilot study, we evaluated the rhytid resurfacing capability of the Q-switched neodymium:yttrium-aluminum-garden (QS Nd:YAG) laser at 1064 nm as compared with char-free carbon dioxide lasers at 10,600 nm. METHODS: Three lasers were used in the study: The QS Nd:YAG laser, the SilkTouch carbon dioxide laser, and the UltraPulse carbon dioxide laser. Eleven subjects were treated in either the periorbital or perioral region with the QS Nd:YAG laser on one side of the face, and both of the char-free pulsed carbon dioxide lasers on the other side. The subjects were evaluated at posttreatment days 7, 30, 60, and 90 for improvement of rhytids, healing, pigmentary changes, and erythema. RESULTS: All 11 patients treated with the char-free carbon dioxide lasers improved. Nine of 11 patients treated with the QS Nd:YAG laser were improved. Healing (complete reepithelialization) was noted to occur 3-6 days earlier in sites treated with the QS Nd:YAG than in sites treated with char-free carbon dioxide lasers. Pigmentary changes were not observed in any treatment site. Erythema was observed at 1 month after treatment in all areas treated with the char-free carbon dioxide lasers, but only three patients treated with the QS Nd:YAG exhibited erythema. These were the same three QS Nd:YAG-treated patients whose clinical improvement was comparable with that of the char-free carbon dioxide lasers. CONCLUSION: The Q-switched Nd:YAG laser may play a role in the treatment of rhytids.     

When life is ending, there is the right to death with dignity

BACKGROUND: This report summarizes an institutional review board-approved 6-month study with the NovaPulse carbon dioxide (CO2) laser utilizing the NovaScan handpiece in facial skin resurfacing applications. OBJECTIVE: This study comprised the initial clinical evaluation (pre-FDA approval) of this device. METHODS: A total of 54 patients underwent 56 laser procedures: 36 full face and 20 regional procedures. RESULTS: Following healing, there was a 91% satisfaction rate. The mean laser-on times were: full face, 27 min; perioral, 7 min; periorbital, 3 min; glabellar, 2.5 min; scar, 5 min; and epidermal lesions, 6 min. CONCLUSIONS: The NovaScan CO2 laser handpiece is a safe tool for skin resurfacing. In its initial use over a 6-month period there were no device-related complications.     

Photodynamic therapy for premalignant lesions in DMBA-treated hamsters: a preliminary study

PURPOSE: Photodynamic therapy (PDT) involves the selective destruction of neoplastic cells through the activation of a photosensitizer by light. We have previously shown that the photosensitizer Photofrin (porfimer sodium) is selectively accumulated in transformed lesions destined to become malignant, but not yet definable histologically as precancers. The aim of this investigation was to determine if this premalignant tissue could be selectively destroyed by systemically administered Photofrin activated by 630 nm red light via an argon dye laser. MATERIALS AND METHODS: The carcinogenic model used was the DMBA (9, 10 dimethyl 1,2 benzanthracene)-treated hamster cheek pouch. The animals were treated with 0.5% DMBA in acetone thrice weekly for 6 weeks (experiment I, premalignant lesions), or 12 weeks (experiment II, malignant lesions). Ten animals were in experiment I; nine animals were in experiment II. These were divided into experimental and control subgroups. The 6-week experimental group received PDT and CO2 laser incision into the DMBA-treated area. The CO2 laser was used as a promoter of neoplasia in a field that had already undergone initiation from the DMBA treatment. The control groups received either CO2 laser incision alone into the DMBA-treated field or CO2 laser incision and argon pumped dye laser treatment (without Photofrin). The 12-week experimental group received PDT after CO2 laser excision of tumors. The controls received CO2 excision alone, or CO2 excision combined with postoperative hyperthermia. RESULTS: One hundred percent (three of three) of cheeks in experiment I receiving PDT developed necrosis of the treated area within 24 to 48 hours, but 0% (0 of three) subsequently developed tumors. No necrosis was seen in control cheeks receiving Photofrin without irradiation (0 of four) or irradiation without Photofrin (0 of six), and 56% (five of nine) of cheeks exposed to identical carcinogenic stimulus, without PDT, developed tumors (n = 9). In experiment II, 0% (0 of six) of cheeks receiving postoperative PDT developed tumor recurrence. In experiment II controls, 50% (three of six) of cheeks that underwent excision and hyperthermia developed tumor recurrence. In cheeks treated only with CO2 laser excision of tumors, a recurrence rate of 67% (four of six) was noted. These results were found to be statistically significant by the Student t-test on the binomial distribution (P < .01). One animal was treated with DMBA for 6 weeks, administered Photofrin, and the right cheek was irradiated and the animal was left for 30 weeks. The irradiated cheek epithelium necrosed but no cancer developed, whereas the positive control cheek developed a large cancer. CONCLUSION: These results suggest that photodynamic therapy possesses significant potential in elimination of premalignant tissue. This could be beneficial in treating potentially premalignant lesions such as oral leukoplakia, and useful as adjunctive therapy in removal of areas of field cancerization adjacent to surgical sites.     

Comparison of carbon dioxide and normal saline for uterine distension in outpatient hysteroscopy

OBJECTIVE: To evaluate patient acceptance and the clinical feasibility of carbon dioxide compared with normal saline for uterine distension in outpatient hysteroscopy. DESIGN: Prospective, randomized clinical trial. SETTING: Outpatient hysteroscopy clinic in a university hospital. PATIENTS: One hundred fifty-seven patients undergoing outpatient hysteroscopy. INTERVENTIONS: Outpatient hysteroscopy was performed with carbon dioxide or normal saline with endometrial biopsy when indicated. MAIN OUTCOME MEASURES: Need for local anesthesia, cervical dilatation, view of uterine cavity, need to change from carbon dioxide to normal saline distension, procedure time, patient discomfort (lower abdominal pain, shoulder tip pain, nausea) and complications. RESULTS: Carbon dioxide was used for uterine distension in 79 women and normal saline was used in 78. Cervical dilatation was required more often with carbon dioxide hysteroscopy, although there was no increased requirement for local anesthesia. Hysteroscopic vision was similar between the two media, but eight carbon dioxide cases had to be converted to liquid distension. Procedure times were significantly longer for carbon dioxide hysteroscopy as was the occurrence of bubbles during the procedure. Lower abdominal pain and shoulder tip pain were significantly worse with carbon dioxide distension. Although the incidence of nausea and vomiting was higher with the use of carbon dioxide, the differences did not achieve statistical significance. CONCLUSION: The use of normal saline for uterine distension had no adverse affects on the hysteroscopic view. It provided a shorter operating time and was well accepted by patients. Because of its easy availability and low cost, normal saline is an excellent alternative to carbon dioxide in women undergoing outpatient hysteroscopy.