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Use of hyperbaric oxygen
LETTERS TO THE EDITOR J Oral Maxillofac 42:697,
Surg
1964
USE OF HYPERBARIC OXYGEN read Doctor Kagan’s letter on the use of hyperbaric oxygen for treatment of osteoradionecrosis, and Doctor Marx’s reply (J Oral Maxillofac Surg 42:141, 1984), with great interest. One can hardly dispute any of Marx’s statements. Nevertheless, he failed to respond to the central issue raised by Kagan: Can one make valid scientific inferences, based upon uncontrolled clinical trials, when numerous potentially powerful variables coexist with the mode of therapy being tested? Although hyperbaric oxygen (HBO) therapy may represent an important advance in the treatment of several disorders, there are relevant points that have not been made strongly enough in the pages of the Jo&ml to prevent misunderstanding by some of the readership. HBO is currently accepted as being useful in the treatment of 12 disorders; three of these disorders are of interest to the oral and maxillofacial surgeon. Randomized, placebocontrolled, double-blinded clinical trials of HBO have not yet been published for any of these three disorders. Marx’s work has clearly demonstrated a correlation between the use of HBO as an adjunct to local surgical therapy and resolution of osteoradionecrosis of the jaws. However, there are hazards drawing conclusions based primarily on correlation. Correlation can be useful in suggesting modes of treatment and in directing clinical research. However, correlation is not cause. We take a risk in accepting such conclusions as scientifically valid. Hyperbaric oxygen therapy is becoming increasingly available in the community. The “high-technology” aspect of the treatment appeals to doctors and patients alike. Some of our colleagues, ignorant of the indications for HBO therapy and anxious to find cures for difficult problems, refer patients for this treatment who are clearly inappropriate (for example, those who have acute osteomyelitis, failing osteotomies, or infected bone grafts). Others, ignorant of the scientific basis for the use of HBO, refer patients who have chronic osteomyelitis or osteoradionecrosis in the mistaken belief that it can spare them surgical debridement of necrotic bone. I believe that I have achieved excellent results treating osteoradionecrosis with the very same therapies that Marx uses, but without HBO. I have also had excellent results performing bone grafts on irradiated patients without using HBO. While Marx’ results are to be commended, only randomized clinical trials will demonstrate conclusively whether or not HBO is supertluous in the presence of meticulous surgical care. Until such trials have been carried out, we must accept the fact that even the most careful clinical observations are subject to bias, and that another’s clinical correlations are equally valid as one’s own. HARRY C. SCHWARTZ Los Angeles, California To the Editor:-1
697
The author replies:I would like to reinforce Dr. Schwartz’s point that there are currently only three indications for the use of HBO in oral and maxillofacial surgery that are accepted by the Hyperbaric Oxygen Committee of the Undersea Medical Society, of which I and Dr. Elgene Mainous are members from our profession. These are the treatment of osteoradionecrosis, the surgical reconstruction of tissues that have received large doses of radiation, and the management of chronic refractory osteomyelitis. The use of HBO in cases for other maxillofacial indications is strictly experimental and has no known scientific basis. Clearly, the use of HBO to salvage infected bone grafts and failing osteotomies and to treat acute osteomyelitis and even alveolar osteitis is mistaken and can at best be called over-enthusiastic. I would join Dr. Schwartz, and can speak for the Undersea Medical Society, in condemning such abuse as potentially harmful to patients and to the medical and dental professions. Research on the clinical usefulness of hyperbaric oxygen therapy in the field of oral and maxillofacial surgery is still in its infancy. To date, our six years of research have documented HBO-induced tissue angiogenesis, stimulation of collagen synthesis, and T-cell and neutrophil enhancement. Studies controlled by the use of a standardized technique and one surgeon have also shown statistically greater success in the treatment of osteoradionecrosis, chronic refractory osteomyelitis of the jaws, and the grafting of bone in irradiated patients with the use of HBO than when the same technique was used without HBO. Although such findings form a strong scientific basis for use of HBO in these three conditions, this has not yet been tested by placebo-controlled prospective studies. Such studies are underway but not yet completed. However, we have recently accom&ished the first prospective randomized trial concerning use of HBO for irradiated patients. This data, which was presented at a symposium during the September 1984 AAOMS meeting in New York, documented a statistically signiticant prevention of osteoradionecrosis after tooth removal when HBO was used before tooth removal. In conclusion, I would point out that the determination of scientific validity is made by the readers of refereed scientific journals such as this one, and is based on the evaluation of submitted research. We have submitted our preliminary data and plan to submit much more comprehensive data soon (both pro and con for the use of HBO). I invite Dr. Schwartz to present his research. Our profession needs more contributions in this important area.
ROBERT E. MARX Miami, Florida
Surg
1964
USE OF HYPERBARIC OXYGEN read Doctor Kagan’s letter on the use of hyperbaric oxygen for treatment of osteoradionecrosis, and Doctor Marx’s reply (J Oral Maxillofac Surg 42:141, 1984), with great interest. One can hardly dispute any of Marx’s statements. Nevertheless, he failed to respond to the central issue raised by Kagan: Can one make valid scientific inferences, based upon uncontrolled clinical trials, when numerous potentially powerful variables coexist with the mode of therapy being tested? Although hyperbaric oxygen (HBO) therapy may represent an important advance in the treatment of several disorders, there are relevant points that have not been made strongly enough in the pages of the Jo&ml to prevent misunderstanding by some of the readership. HBO is currently accepted as being useful in the treatment of 12 disorders; three of these disorders are of interest to the oral and maxillofacial surgeon. Randomized, placebocontrolled, double-blinded clinical trials of HBO have not yet been published for any of these three disorders. Marx’s work has clearly demonstrated a correlation between the use of HBO as an adjunct to local surgical therapy and resolution of osteoradionecrosis of the jaws. However, there are hazards drawing conclusions based primarily on correlation. Correlation can be useful in suggesting modes of treatment and in directing clinical research. However, correlation is not cause. We take a risk in accepting such conclusions as scientifically valid. Hyperbaric oxygen therapy is becoming increasingly available in the community. The “high-technology” aspect of the treatment appeals to doctors and patients alike. Some of our colleagues, ignorant of the indications for HBO therapy and anxious to find cures for difficult problems, refer patients for this treatment who are clearly inappropriate (for example, those who have acute osteomyelitis, failing osteotomies, or infected bone grafts). Others, ignorant of the scientific basis for the use of HBO, refer patients who have chronic osteomyelitis or osteoradionecrosis in the mistaken belief that it can spare them surgical debridement of necrotic bone. I believe that I have achieved excellent results treating osteoradionecrosis with the very same therapies that Marx uses, but without HBO. I have also had excellent results performing bone grafts on irradiated patients without using HBO. While Marx’ results are to be commended, only randomized clinical trials will demonstrate conclusively whether or not HBO is supertluous in the presence of meticulous surgical care. Until such trials have been carried out, we must accept the fact that even the most careful clinical observations are subject to bias, and that another’s clinical correlations are equally valid as one’s own. HARRY C. SCHWARTZ Los Angeles, California To the Editor:-1
697
The author replies:I would like to reinforce Dr. Schwartz’s point that there are currently only three indications for the use of HBO in oral and maxillofacial surgery that are accepted by the Hyperbaric Oxygen Committee of the Undersea Medical Society, of which I and Dr. Elgene Mainous are members from our profession. These are the treatment of osteoradionecrosis, the surgical reconstruction of tissues that have received large doses of radiation, and the management of chronic refractory osteomyelitis. The use of HBO in cases for other maxillofacial indications is strictly experimental and has no known scientific basis. Clearly, the use of HBO to salvage infected bone grafts and failing osteotomies and to treat acute osteomyelitis and even alveolar osteitis is mistaken and can at best be called over-enthusiastic. I would join Dr. Schwartz, and can speak for the Undersea Medical Society, in condemning such abuse as potentially harmful to patients and to the medical and dental professions. Research on the clinical usefulness of hyperbaric oxygen therapy in the field of oral and maxillofacial surgery is still in its infancy. To date, our six years of research have documented HBO-induced tissue angiogenesis, stimulation of collagen synthesis, and T-cell and neutrophil enhancement. Studies controlled by the use of a standardized technique and one surgeon have also shown statistically greater success in the treatment of osteoradionecrosis, chronic refractory osteomyelitis of the jaws, and the grafting of bone in irradiated patients with the use of HBO than when the same technique was used without HBO. Although such findings form a strong scientific basis for use of HBO in these three conditions, this has not yet been tested by placebo-controlled prospective studies. Such studies are underway but not yet completed. However, we have recently accom&ished the first prospective randomized trial concerning use of HBO for irradiated patients. This data, which was presented at a symposium during the September 1984 AAOMS meeting in New York, documented a statistically signiticant prevention of osteoradionecrosis after tooth removal when HBO was used before tooth removal. In conclusion, I would point out that the determination of scientific validity is made by the readers of refereed scientific journals such as this one, and is based on the evaluation of submitted research. We have submitted our preliminary data and plan to submit much more comprehensive data soon (both pro and con for the use of HBO). I invite Dr. Schwartz to present his research. Our profession needs more contributions in this important area.
ROBERT E. MARX Miami, Florida