About RECURRENT RESPIRATORY PAPILLOMATOSIS (RRP)
Recurrent respiratory papillomatosis (RRP) is a typically a chronic disease characterized by proliferation of non-cancerous, wart-like growths in the airway. It is caused by infection of cells that line the airway with human papilloma virus (HPV). As the name implies, the disease tends to be recurrent in spite of treatment; this may have to due with HPV infecting cells that remain visibly normal around the periphery of the obviously papillomatous tissue as well as a selective immunodeficiency on the part of patients who suffer from the disease.
When RRP occurs in the voice box (larynx), it is called laryngeal papillomatosis, but it can also occur in the throat, mouth, esophagus, and anywhere else in the airway, including the lungs. When the vocal cords are involved, patients typically experience a raspy voice as a result of the disease impairing vocal cord closure and/or vibration. Symptoms of airway obstruction and/or swallowing difficulties can also result depending on disease volume and location.
Different examples of the vascular nature of papillomatosis, at various stages of growth in different patients, as visualized in the operating room.
The vascularity of the growth (papillomatosis) is perhaps the most important factor in determining the rapidity of its reappearance…Franklin Hooper, MD – 1882
Well over a century ago, laryngeal surgeons like Dr. Hooper realized that papillomatosis requires a robust local blood supply to grow. Two technologies today take advantage of this fact: the KTP laser and Avastin (bevacizumab), an anti- cancer drug that prevents new blood vessel growth. Avastin was only recently introduced into the field of laryngology (in an off-label manner) in the form of local injection of the drug directly into laryngeal tissues following surgical removal of papillomatosis (a non-cancerous disease). Preliminary studies demonstrate it to be safe for use in the vocal cords and to augment the effect of treating papilloma with the KTP laser alone.1,2,3
Surgical Treatment Of RECURRENT RESPIRATORY PAPILLOMATOSIS (RRP)
Microlaryngeal surgical excision is the mainstay of management for laryngeal papillomatosis. Because papilloma generally returns, repeated surgical treatments are usually the rule rather than the exception. Some patients with severe disease may require hundreds of surgeries over their lifetimes.
By definition, papillomatosis is a disease of the surface lining (epithelium) and does not invade deeper (as a cancer does). When it involves the vocal cords, proper surgery should not damage the vibratory layer that underlies the diseased epithelium but should attempt to removal as much of the disease as is safely possible.
In some senses, surgery for laryngeal papillomatosis involving the vocal cords is like mowing a lawn: the goal is to cut the grass as short as possible (since it will likely grow back), but without getting into the dirt.
Laryngeal papillomatosis treated by another surgeon, before and after microdebrider treatment, as visualized in the operating room. After treatment, the bulky airway disease has been removed, but a “carpet” of papilloma remains on both vocal cords. As is often the case, the surgeon has wisely erred on the side of removing too little papillomatosis, rather than removing too much and permanently damaging the vibratory layer of the vocal cords that exists just below the diseased epithelium.
Surgical management of papillomatosis involves either removal of diseased epithelium with the aid of lasers or “cold” instruments (named as such in contrast the heat that is generated by lasers). One of the more common cold instrument techniques involves using a microdebrider, which is a powered, small rotating blade that rapidly sucks papilloma into a chamber and then cleaves it. It is efficient at removing bulky disease but does not allow for precise removal of vocal cord papilloma at its interface with deeper, healthy tissues, in part because it results in bleeding that can impair visualization and because the device is generally too aggressive to safely operate with such a narrow margin of error at this location.
This is not to say that the microdebrider cannot be used to treat vocal cord papillomatosis, but rather that the result may not be as efficacious as other treatment modalities.
Examples of Laryngeal Papillomatosis – Before and After KTP Laser Treatment
Laryngeal papillomatosis before and after treatment with the KTP laser and localized Avastin (bevacizumab) injections.