A technological revolution has occurred in laryngology rendering many time-honored surgical procedures obsolete. Significant advances in flexible endoscopes, laser delivery systems, and topical anesthesia have made it possible to perform surgery and many other office-based laryngeal procedures safely, with excellent results, patient acceptance, and cost savings. Unfortunately, reimbursement issues still create financial disincentives to the widespread proliferation of remarkable clinical advancements.
Perspective on New Technology in Laryngology
Since introduction of the rigid, distal-lighted esophagoscope by Chevalier Jackson over 100 years ago, the evolution of endoscopic surgery has generally paralleled advances in illumination, optics, and instrumentation. Until the 1960s, most otolaryngologic endoscopy (e.g., laryngoscopy, bronchoscopy, esophagoscopy) was performed with the patient awake using rigid instruments and the techniques described by Jackson.
In the 1960s, use of the operating microscope for laryngeal surgery spawned a new generation of endoscopic instrumentation, including wide-bore laryngoscopes, microlaryngeal instruments, optical telescopes, and the carbon-dioxide (CO2) laser with micro-manipulator. In addition, general anesthesia that allowed sharing of the airway (e.g., jet ventilation) became safer and more accepted. Most operative (rigid) laryngoscopy and bronchoscopy, as well as esophagoscopy for foreign body removal, were done in the operating room under general anesthesia.
When flexible fiberscopes became available in the 1970s, otolaryngologists began to examine the aerodigestive tract (especially the larynx) of awake, unsedated patients in the office. Diagnostic transnasal flexible laryngoscopy (TFL) was routinely performed with only topical nasal anesthesia. Until relatively recently, however, because the optics of TFL were not as good as those provided by the optical telescopic view, the per oral examination method remained popular despite the fact that laryngeal biomechanics could not be assessed.1
Introduced in 1999, the distal-chip camera for aerodigestive endoscopy created a new paradigm, and an instrument for transnasal esophagoscopy (TNE) was the first major advance.2,3 The TNE endoscope offered brilliant illumination and unsurpassed, high-resolution imaging with a working channel.4 The 2.0mm channel permitted air-insufflation, suction, and the introduction of small, flexible forceps, and laser fibers. Advances in techniques of anesthesia and laser technology (that allowed laser energy to be delivered through a flexible fiber) quickly followed. Since the external diameter of that endoscope was 5.1mm, most patients could easily tolerate having it passed transnasally. Soon after introduction of the TNE endoscope, a smaller, 4.1 mm external diameter, endoscope without a working channel became available for TFL.
In the last decade, the focus has been on the growth and development of “minimally invasive” (less invasive) methods for both diagnosis and treatment, particularly targeting expensive, high-prevalence diseases. In many cases, it has been the combination of technologies that has resulted in new applications.5-20 For the author, more than half of her laryngeal surgery is unsedated, office-based, laryngeal laser surgery (UOLS) using several different wavelength lasers alone or in combination.20 The advantages of UOLS are shown in Table 1 below. In addition to being cost-saving,21 UOLS is generally preferred by most patients to traditional surgery.22
|Table 1: Advantages of Minimally-Invasive Office-Based Laryngeal Laser Surgery|
|Unsedated: No IV or other medication|
|Patient requires no post-operative recovery|
|Only topical anesthesia (4% xylocaine spray)|
|Biopsies may be obtained for cytology or histology|
|Fewer complications (e.g., dental injury, airway)|
|Actual operating time is usually minimized|
|Many procedures are technically easier|
|Global time and cost savings|
|Increased patient satisfaction because of:|
|Safety (few complications)|
|Excellent (better) outcomes|
|Less lost time from work/family|
|Fewer out of pocket expenses|
It cannot be overemphasized that the emergence of UOLS as a viable technology was made possible by the confluence of three developments: (1) distal-chip quality imaging, (2) efficient anesthesia techniques for UOLS, and (3) development of several different wavelength lasers and fiber delivery systems.
Technique of Anesthesia for UOLS
Having a quick and effective anesthesia technique is one of the keys to successful UOLS. When we started out, we really didn’t know what to do. We were uncertain as to the minimum, let alone the optimum anesthesia that patients needed to comfortably tolerate such procedures. At first, we used the old techniques of Jackson that involved spraying the pharynx with a topical anesthetic, then insertion of xylocaine-soaked cotton balls on curved instruments into the piriform sinuses, followed by direct spraying of the endolarynx using TFL-guidance. This made the anesthesia procedure more difficult and time consuming than the surgery for both the doctor and the patient.
We also had patients breathe nebulized 4% xylocaine for 10-20 minutes, sometimes in combination with oral diazepam and/or topical throat spray. The nebulization method seemed to give variable levels of anesthesia; it worked well for some patients but not for others. The next alternative that we tried was performing bilateral superior laryngeal nerve blocks. When this worked really well, the patients coughed excessively because they tended to aspirate their own secretions; and when one or both injections didn’t find their mark, the patient complained of discomfort. Again, this technique seemed too complex and unpredictable for everyday application. Indeed, we tried many combinations of methods before settling on what has become for us the simplest and most predictably effective method. The author mentions all of the above suboptimal methods in the hope of helping new UOLS surgeons avoid our trial-and-error learning curve. What is the technique we now recommend?
First, we spray the nose with an ephedrine and pontocaine solution and then put a cotton or new-gauze pack in one side of the nose. The author being right handed, with the viewing monitor to her right, routinely uses the right side of the patient’s nose unless it is obstructed. The nasal packing is left in for 10-20 minutes; and sometimes the patient will note that his or her incisors feel numb. Adequate nasal anesthesia is important. Actually, when patients occasionally do complain about discomfort during UOLS, it is usually due to nasal pain. By the way, for TNE the above nasal anesthesia is all that is used for the vast majority of patients.
Second, the clinician should explain that the numbing process is quick and painless but that it is none-the-less unpleasant. We tell them that it is unnatural to have any liquid squirted into the larynx, because it will make them cough and sputter. This is assured as the right response, that is, the coughing and such disperses the anesthetic. Generally, three or four sprays of 4% xylocaine are needed. The standard TNE scope is 60 cm. long and the volume of the working channel is about 3.3 ml. That means if 5.0 ml of anesthetic is squirted through the TNE scope into the endolarynx approximately 1.7 ml of anesthetic will be delivered; the rest will be suctioned up.
The first squirt is delivered from above the palate; the second is aimed at the epiglottis and valleculae, and the third (and fourth) are squirted into the endolarynx. The author recommends having the patient phonate a sustained vowel and squirt at the end of the breath. That’s it, next the clinician can insert a laser fiber and go to work. It is worth noting that the posterior larynx is more difficult to anesthetize and that the patient will complain of discomfort about half of the time when having a vocal process granuloma removed.
Clinical Applications and Selection of Wavelength Laser for UOLS
For decades, the carbon-dioxide (CO2) laser was the workhorse in laryngology. It was used mostly in the operating room with a small spot size for excision of lesions such as papillomas, granulomas, polyps, and carcinomas. In recent years, the CO2 laser has been used sparingly for benign disease on the vocal fold striking zones due to potential scarring. Nevertheless, as a water-absorbing laser, it remains the gold standard for removal of most lesions not involving the free edge.
UOLS had its real origins with the pulsed-dye laser (PDL).5,9 At 585nm, it is primarily absorbed by hemoglobin. UOLS it has been shown to be safe and effective, especially for RRP (recurrent respiratory papillomas).12,18-20 A summary of the author’s approach to the laryngeal RRP patient is shown in Table 2. One of the chief advantages of the PDL wavelength is that both sides may be treated at the anterior commissure without significant risk of web formation. In addition, for certain lesions such as polypoid degeneration, it may be the wavelength laser of choice.20
|Table 2: Management of Laryngeal Recurrent Respiratory Papillomas (RRP)|
|First procedure in the OR for biopsies and complete examination|
|Follow-up UOLS in 6-8 weeks for residual RRPs (PDL allows aggressive treatment of bilateral anterior disease)|
|For bulky disease, CO2 or T:YAG, followed by PDL|
|Patient-directed PDL treatment intervals, usually for voice|
|Adjunctive medications generally not recommended|
A hollow-core CO2 laser fiber was introduced in 2004 and it has great potential application in the vaporization and/or excision of bulky lesions.20 The first UOLS case done was that of a woman with extensive and obstructing laryngotracheal papillomas that filled the airway to the carina.20 In that case, the PDL was insufficient to maintain the airway, and the CO2 laser delivered by UOLS was life saving. Later on, the CO2 laser was used first to remove bulk of the disease, and then the PDL was used after to treat residual epithelial disease.
Different wavelength lasers have different properties based upon their absorption. The Thulium:YAG laser is actually intermediate between the CO2 and the PDL in many ways. We have found it especially useful for the treatment of laryngotracheal amyloid.20 The KTP and the PDL lasers are quite similar in their tissue absorptive characteristics.
Contained within this issue of Current Opinion, there are reported the experiences and opinions of several authors using different wavelengths. These emerging technologies are all part of an evolutionary process; and as of this writing, there is no one best laser. The author’s current wavelength selections/applications are shown in Table 3.
|Table 3: Author’s Laser Wavelength Selection for Different Applications|
Table modified from: Koufman JA, Rees CJ, Frazier WD, Kilpatrick LA, Wright SC, Halum SL, Postma GN. Unsedated office-based laryngeal laser surgery: Review of 443 cases using three wavelengths. Otolaryngol Head Neck Surg 2007;137.
Current Limitations and Future Proliferation of UOLS
TNE and UOLS provide bone fide advances that simultaneously decrease morbidity and cost.4,20-22 In spite of the rather obvious advantages over traditional surgery for some, not all, applications, these technologies have not proliferated as rapidly as might have been expected. There appear to be two reasons for this. First, there has been some resistance from providers and payers who may have economic interests in maintaining status quo technology, networks and/or referral patterns. And in some cases the issue is lack of training.
Second, the principal barrier to proliferation is inadequate reimbursement. While marginal profitability can justify making a capital investment, sure economic loss is an overwhelming deterrent. In the face of such economic disincentives, advanced technology like TNE and UOLS will stagnate. Hopefully, those issues will be resolved soon as the potential cost savings to society are tremendous, measured in millions, perhaps billions of dollars.
The spectrum of laryngological office-based procedures has expanded dramatically in the last decade since the advent of the distal-chip camera and new laser technology. These procedures are well-tolerated by patients and at the same time minimize morbidity and are cost saving. In the next generation, each of the advances shown in Table 4 will continue to proliferate.
|Table 4: Spectrum of Laryngological Office-Based Procedures|
|Placement of TEP speaking valves|
|Panendoscopy for cancer screening|
|Unsedated office-based laryngeal laser surgery|
|Therapeutic vocal fold injection (e.g., augmentation, Botox)|
|Laryngeal, tracheal, and esophageal dilation|
|Diagnostics, e.g., electromyography, pH-testing, biopsy|
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2. Aviv JE, Takoudes TG, Ma G, Close LG. Office-based esophagoscopy: a preliminary report. Otolaryngol Head Neck Surg 2001: 125: 170-75.
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5. Franco RA Jr, Zeitels SM, Farinelli WA, Faquin W, Anderson RR. 585-nm pulsed dye laser treatment of glottal dysplasia. Ann Otol Rhinol Laryngol 2003: 112: 751-58. * Landmark report by leaders in the field
6. Hsiung MW, Kang BH, Su WF, Pai L, Wang HW. Clearing microvascular lesions of the true vocal fold with the KTP/532 laser. Ann Otol Rhinol Laryngol 2003: 112: 534-39.
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20. Koufman JA, Rees CJ, Frazier WD, Kilpatrick LA, Wright SC, Halum SL, Postma GN. Unsedated office-based laryngeal laser surgery: Review of 443 cases using three wavelengths. Otolaryngol Head Neck Surg 2007;137. * Huge series with minor complication rate of 0.9% and a discussion of applications of different wavelength lasers
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