Dermatology Online Journal

Patient perceptions of 595 nm pulsed dye laser through glass compression in the treatment of thick port wine stains and superficial venous malformations
Marvin H Klapman MD¹, Valentina B Sosa MD¹, Gail F Mattson-Gates MD², Cynthia N Baker MD³, Victor L Ong PA¹, Janis F Yao MS⁴
Dermatology Online Journal 14 (8): 1

1. Department of Dermatology, Kaiser Permanente Los Angeles Medical Center
2. Department of Plastic Surgery, Kaiser Permanente Orange County
3. Department of Pediatrics, Kaiser Permanente Los Angeles Medical Center
4. Department of Research and Evaluation, Southern California Kaiser Permanente
marvin.h.klapman@kp.org

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Abstract

In treating thickened port wine stains and superficial venous malformations with the 595 nm pulse dye laser, we have sometimes compressed the lesion with a glass slide to enable the laser beam to penetrate more deeply. In order to evaluate the patients' perception of this modality, 54 subjects were treated with glass compression using ice applications to cool the skin surface and without glass compression using a cryospray to cool the surface. The subjects were asked to rate the difference in 2 questionnaires after the first and second treatments as to effectiveness, pain of procedure, and overall preference. Of those subjects who perceived a difference between modalities, a significant number perceived treatments with glass compression to be more effective than without (p=0.0002 and p=0.0006), but more painful (p<0.0001). There was no significant difference in overall preference. Blistering occurred in 5 subjects when the glass slide was left on the skin more than 1 minute between ice applications.

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Introduction

We have been using the 595 nm pulsed dye laser with a long pulse duration of 30 milliseconds at the Kaiser-Permanente Los Angeles Medical Center for treating thick port wine stains and superficial venous malformations. At times we compress the skin with a glass slide to allow the laser to penetrate more deeply. The laser has a cryospray that cools the skin surface as the laser beam passes through it, protecting the epidermis and lessening pain. However, the glass slide blocks the cryospray, so we apply ice cubes in those cases. The purpose of this study was to determine the patients' perceptions of this modality as to effectiveness and comfort of treatment. We also assessed the patients' overall opinion as to whether the benefit outweighed any increased discomfort associated with it.

Methods

After obtaining approval from our Institutional Review Board, we recruited 54 subjects for treatment with a 595 nm pulsed dye laser set at parameters of 7.5 to 18 joules/cm² fluency, 30 milliseconds pulse duration, and 5, 7, 10, or 10x3 mm spot size. Half of a selected area was treated with glass compression and the other half without glass compression. The same parameters were used for both halves. Two laser treatments spaced at least 2 months apart were included in the study. Each subject filled out a questionnaire comparing effectiveness, pain, and overall preference for each modality at the time of the second treatment and again approximately 2 months later. The results were analyzed using McNemar's test.

Results

Of the 54 subjects recruited, 39 answered at least part of the first questionnaire, and 30 answered at least part of the second questionnaire. A summary of the answers is presented in the Table. Five subjects experienced blisters at the site of treatment through glass compression when the treatment was continued for more than a minute without removing the glass slide and applying ice.

Discussion

Previous studies

Previous studies have demonstrated that a laser beam can pass through glass [1] and that effectiveness in treating vascular lesions can be enhanced by compression with clear plastic [2] or ice cubes [3]. None of the previous studies explored the perception of patients to the modality of firing a laser beam through glass compression in the treatment of thick port wine stains or superficial venous malformations.

Our study

In our study, approximately 1/3 to 1/2 of the subjects did not perceive any difference with or without glass compression. However, among those who did perceive a difference, a significant number perceived glass compression to be more effective but also more painful. As for overall preference, there was no significant difference. Apparently the increased pain balanced the benefit. Five subjects experienced blistering when the glass slide was left on the skin more than 1 minute between ice applications.

Conclusion

In conclusion, pulsed dye laser through glass compression might be indicated in selected cases of thick port wine stains and superficial venous malformations. The patient should be informed that the procedure can be painful and that blistering may occur. The glass should be lifted up and ice re-applied at least once every minute to avoid blistering.

The authors would like to acknowledge Keith Terasaki, MD, Mark D Rayman, MD, and Tina L Hardly MD (Department of Medical Imaging, Kaiser Permanente Los Angeles Medical Center) for their participation in the clinical care of the subjects.

References

1. Chen C, Diven DG, Lockhart S, Bell B Laser transmission through transparent membranes used in cutaneous laser treatment. J Am Acad Dermatol. 2001 Dec;45(6):919-23. PubMed

2. Boffa MJ. Pulsed dye laser treatment of thick/raised vascular lesions using compression with clear plastic. J Am Acad Dermatol 2003 Nov;49(5):879-81. PubMed

3. Werner JA, Lippert BM, Godberson GS, Rudert H. Treatment of hemangioma with the neodymium:yttrium-aluminum-garnet laser (Nd:YAG laser). Laryngorhinootologie. 1992 Aug;71(8):388-95. German. PubMed

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