- Email: [email protected]
Tissue-damaging effects of ultrasound
Tissue-damaging effects of ultrasound Ft. WITTENZELLNER Professor Wittenzellners’ hitherto unpublished work was completed in January 1951 and is now presented as an item of historical and current interest. It contains some of the first studies on the effects of ultrasonic irradiation applied to body tissues, a subject now of popular interest in medical ultrasonics.
Over 25 years ago I submitted to the University of Munich my M.D. thesis on the ‘driving-in’ effects of ultrasonics into the skin. The results of this work, rated ‘summa cum laude’, were mainly based on self-experimentation. In addition to electronic measurements on fresh human skin specimens (surgical preparations), over 1 000 experiments on living human skin were carried out whereby special attention was given to the possibility of driving in pharmacological substances directly into the skin by means of ultrasound. The skin, partly untreated, partly prepared by various methods (ungreased, rubbed or even rouhgened), received ultrasonic irradiation at various power levels (5 30 W) in the frequency range (20 - 800 kHz); the temperature of the cooling water and the coupling fluid (watersoluble and liquid-soluble substances) varied between 15 and 45°C. Histamine and adrenaline solutions, Forapinemulsions, bee-poison solutions, salicylic acid and chloroform were used for coupling. In each case, the most effective frequencies and power could be determined by the reaction of the skin. Both thighs were irradiated for a total of 40 h, whereby all clinical symptoms, both acute and chronical, ranging from fatigue, uneasiness, sweating attacks through moderate diuresis to stenocardiac complaints were observed and recorded. Based on these experiments, the ‘driving-in’ effect of ultrasonic waves, assumed in previous publications, has been rejected, and a mechanical damaging of the skin caused by ultrasound through a sort of loosening of its texture was assumed. Histologic studies of skin, part irradiated with ultrasound of 1.33 W cmm2 at 800 kHz for 25 min showed an acute, cellular-serial inflamation, and damage (appearance of blister) to the stratified flat epithelium. Considerable loosening of the cutaneous and subcutaneous connective tissue, high-grade pigmentation of the basal layers, intense accumulation of the white cells in the capillaries of the papillae (leucostase), further, exudation of leucocytes and Prof. Dr. Rudolf Wittenzellner is at Gesellschaft fur Strahlen - und Umweltforschung GmbH Ingolstadter Landstrasse 1, 8042 Neuherberg bei, Munchen FDR. Paper received 20 May 1976.
ULTRASONICS.
NOVEMBER
1976
Fig. 1 Appearance of blister, loosening of the cutaneous and subcutaneous connective tissue, high-grade pigmentation of the basal layers, leucostase, further mobilisation of histiocytic cells in the surroundings of capillaries observed in preparation of skin exposed to ultrasound of 1.33 W cm-’ at 800 kHz for 25 min
lymphocytes, mobilisation of histiocytic cells in the surroundings of capillaries heavily crowded with leucocytes, of papillae and of the cutaneous tissue was also noted, see Fig. 1 Skin pieces exposed to ultrasound for a total time duration of more than 14 h during a period of 7.5 months were excised; a minor chronic-inflammatory irritation was histologically found at that time. (Fig. 2).
281
Fig. 2 Preparation of skin exposed to large doses of ultrasound over a period of 7.5 months shows minor chronic-inflammatory irritation
Fig. 4 Normal
Regular stratification and hornification of the flat epithelium. melanin pigmentation in the basal epidermis. Inconspicuous vessels in the subepithelal ‘tissue (magnification x310)
For those who today use ultrasound both in diagnostics and therapy it may be of interest to know whether any clinically or histologically seizable symptoms were found after the self-experiments carried out 25 years ago, that exceeded all therapeutic and diagnostic limits. 1.
Fig. 3 Normal stratified (magnification xl 25)
flat epithelium
with regular hornification
Increased keratosis, augmented pigmentation as well as minor loosening of the cutaneous and subcutaneous connective tissue could be detected on the insonified skin. Massage of the connective tissue after Leube-Dicke showed decreased redness of the skin and caused shooting pain. The ultraviolet erythematous threshold of the insonified skin was significantly elevated. The bone structure of the left thigh showed no radiological anomalies. Ultrasound is currently used to a relatively small extent in medical therapy. It has found extensive application in diagnostics, however. Present-day sonography provides us with reliable diagnostic results without annoyance and noticeable risks to the patient and at reasonable expenditure. Repetition of the examination as well as frequent controls are practically free from problems.
282
Clinically, no remainder traits can be found.
2. The macroscopic view shows that the skin on both thighs is neither edematously swollen nor sensible to temperature or touching; hairiness, pigmentation and hornification are normal, merely the superficial vein pattern is intensified; the ultraviolet erythematous threshold is normal. 3. Histological examination of a skin area that 25 years ago received ultrasonic irradiation of various frequencies and power for at least 7 h shows no significant findings. (Figs. 3 and 4). 4. The soft tissues in the insonified region of the thighs show no anomalies (for example no signs of calcification). 5. The x-ray picture of the bone structure of the thighs is normal. Although no generally valid conclusions can be drawn from just one single case, one can state that the after-effects of ultrasonic irradiation certainly are restricted if even 25 years after the irradiations, far exceeding usual limits, no significant traits of anomalies can be seen. Acknowledgements The evaluation of the skin specimens was kindly undertaken by Profs Gloggengiesser (1950-51) and Gossner (1976) respectively, in Munich.
ULTRASONICS.
NOVEMBER
1976
Over 25 years ago I submitted to the University of Munich my M.D. thesis on the ‘driving-in’ effects of ultrasonics into the skin. The results of this work, rated ‘summa cum laude’, were mainly based on self-experimentation. In addition to electronic measurements on fresh human skin specimens (surgical preparations), over 1 000 experiments on living human skin were carried out whereby special attention was given to the possibility of driving in pharmacological substances directly into the skin by means of ultrasound. The skin, partly untreated, partly prepared by various methods (ungreased, rubbed or even rouhgened), received ultrasonic irradiation at various power levels (5 30 W) in the frequency range (20 - 800 kHz); the temperature of the cooling water and the coupling fluid (watersoluble and liquid-soluble substances) varied between 15 and 45°C. Histamine and adrenaline solutions, Forapinemulsions, bee-poison solutions, salicylic acid and chloroform were used for coupling. In each case, the most effective frequencies and power could be determined by the reaction of the skin. Both thighs were irradiated for a total of 40 h, whereby all clinical symptoms, both acute and chronical, ranging from fatigue, uneasiness, sweating attacks through moderate diuresis to stenocardiac complaints were observed and recorded. Based on these experiments, the ‘driving-in’ effect of ultrasonic waves, assumed in previous publications, has been rejected, and a mechanical damaging of the skin caused by ultrasound through a sort of loosening of its texture was assumed. Histologic studies of skin, part irradiated with ultrasound of 1.33 W cmm2 at 800 kHz for 25 min showed an acute, cellular-serial inflamation, and damage (appearance of blister) to the stratified flat epithelium. Considerable loosening of the cutaneous and subcutaneous connective tissue, high-grade pigmentation of the basal layers, intense accumulation of the white cells in the capillaries of the papillae (leucostase), further, exudation of leucocytes and Prof. Dr. Rudolf Wittenzellner is at Gesellschaft fur Strahlen - und Umweltforschung GmbH Ingolstadter Landstrasse 1, 8042 Neuherberg bei, Munchen FDR. Paper received 20 May 1976.
ULTRASONICS.
NOVEMBER
1976
Fig. 1 Appearance of blister, loosening of the cutaneous and subcutaneous connective tissue, high-grade pigmentation of the basal layers, leucostase, further mobilisation of histiocytic cells in the surroundings of capillaries observed in preparation of skin exposed to ultrasound of 1.33 W cm-’ at 800 kHz for 25 min
lymphocytes, mobilisation of histiocytic cells in the surroundings of capillaries heavily crowded with leucocytes, of papillae and of the cutaneous tissue was also noted, see Fig. 1 Skin pieces exposed to ultrasound for a total time duration of more than 14 h during a period of 7.5 months were excised; a minor chronic-inflammatory irritation was histologically found at that time. (Fig. 2).
281
Fig. 2 Preparation of skin exposed to large doses of ultrasound over a period of 7.5 months shows minor chronic-inflammatory irritation
Fig. 4 Normal
Regular stratification and hornification of the flat epithelium. melanin pigmentation in the basal epidermis. Inconspicuous vessels in the subepithelal ‘tissue (magnification x310)
For those who today use ultrasound both in diagnostics and therapy it may be of interest to know whether any clinically or histologically seizable symptoms were found after the self-experiments carried out 25 years ago, that exceeded all therapeutic and diagnostic limits. 1.
Fig. 3 Normal stratified (magnification xl 25)
flat epithelium
with regular hornification
Increased keratosis, augmented pigmentation as well as minor loosening of the cutaneous and subcutaneous connective tissue could be detected on the insonified skin. Massage of the connective tissue after Leube-Dicke showed decreased redness of the skin and caused shooting pain. The ultraviolet erythematous threshold of the insonified skin was significantly elevated. The bone structure of the left thigh showed no radiological anomalies. Ultrasound is currently used to a relatively small extent in medical therapy. It has found extensive application in diagnostics, however. Present-day sonography provides us with reliable diagnostic results without annoyance and noticeable risks to the patient and at reasonable expenditure. Repetition of the examination as well as frequent controls are practically free from problems.
282
Clinically, no remainder traits can be found.
2. The macroscopic view shows that the skin on both thighs is neither edematously swollen nor sensible to temperature or touching; hairiness, pigmentation and hornification are normal, merely the superficial vein pattern is intensified; the ultraviolet erythematous threshold is normal. 3. Histological examination of a skin area that 25 years ago received ultrasonic irradiation of various frequencies and power for at least 7 h shows no significant findings. (Figs. 3 and 4). 4. The soft tissues in the insonified region of the thighs show no anomalies (for example no signs of calcification). 5. The x-ray picture of the bone structure of the thighs is normal. Although no generally valid conclusions can be drawn from just one single case, one can state that the after-effects of ultrasonic irradiation certainly are restricted if even 25 years after the irradiations, far exceeding usual limits, no significant traits of anomalies can be seen. Acknowledgements The evaluation of the skin specimens was kindly undertaken by Profs Gloggengiesser (1950-51) and Gossner (1976) respectively, in Munich.
ULTRASONICS.
NOVEMBER
1976