bwus_DSU_29012 80..84 Single-Pass Carbon Dioxide Versus Multiple-Pass Er:YAG Laser Skin Resurfacing: A Comparison of Postoperative Wound Healing and Side-Effect Rates ELIZABETH L. TANZI, MD, AND TINA S. ALSTER, MD Washington Institute of Dermatologic Laser Surgery, Washington, DC BACKGROUND. Ablative laser skin resurfacing with carbon dioxide (CO2) and erbium:yttrium-aluminum-garnet (Er:YAG) lasers has been popularized in recent years and their side effects individually reported. No prior study, however, has directly compared the relative healing times and complications rates between the two different systems. OBJECTIVE. To evaluate and compare postoperative wound healing and short- and long-term side effects of single-pass CO2 and multiple-pass, long-pulsed Er:YAG laser skin resurfacing for the treatment of facial photodamage and atrophic scars. METHODS. A retrospective chart review and analysis of sequential clinical photographs were performed in 100 con- secutive patients who underwent laser skin resurfacing with single-pass CO2 (Ultrapulse 5000; Coherent, Palo Alto, CA, N 5 50) or multiple-pass, long-pulsed Er:YAG laser resurfacing (Contour; Sciton, Palo Alto, CA, N 5 50). All laser procedures were performed by a single operator for the amelioration of facial rhytides or atrophic scars. The rate of re-epithelialization, duration of erythema, and presence of complications were tabulated. RESULTS. The average time to re-epithelialization was 5.5 days with single-pass CO2 and 5.1 days with long-pulsed Er:YAG laser resurfacing. Postoperative erythema was observed in all patients, lasting an average of 4.5 weeks after single-pass CO2 laser treatment and 3.6 weeks after long-pulsed Er:YAG laser treatment. Hyperpigmentation was seen in 46% of the patients treated with single-pass CO2 and 42% of the patients treated with the long-pulsed Er:YAG laser (average duration of 12.7 and 11.4 weeks, respectively). No incidences of hypopigmenta- tion or scarring were observed. CONCLUSION. Skin resurfacing with single-pass CO2 or multi- ple-pass long-pulsed Er:YAG laser techniques yielded comparable postoperative healing times and complication profiles. E.L. TANZI, MD, AND T.S. ALSTER, MD HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS. LASER SKIN resurfacing is an effective treatment option for many patients with cutaneous photodam- age, wrinkles, and acne scarring.1–4 Based on the principles of selective photothermolysis,5 ablative resurfacing lasers target and effectively vaporize water-containing tissue. Collagen shrinkage and re- modeling are initiated by controlled thermal injury to the dermis.6–8 Several laser systems are currently available for cutaneous laser resurfacing, including high-energy pulsed and scanned carbon dioxide (CO2) and erbium:yttrium-aluminum-garnet (Er:YAG) lasers. Although excellent improvement of photodamaged skin, rhytides, and atrophic scars can be achieved after multiple pass treatment technique with these laser systems,1,3,9–15 an extended recovery period and, in some cases of CO2 laser resurfacing, prolonged erythema have diminished the enthusiasm for multi- pass CO2 procedures. 16,17 Moreover, delayed-onset permanent hypopigmentation has been shown to occur in upward 20% of those treated with multiple- pass CO2 laser skin resurfacing. 17,18 In response to these disadvantages, refinements in the CO2 surgical technique and Er:YAG laser technology have been developed. In 1997, a minimally traumatic single-pass CO2 laser resurfacing procedure was described that resulted in faster re-epithelialization and an improved side- effect profile than typically observed after use of the multiple-pass technique.19 After application of the CO2 laser scans, partially desiccated skin is left intact (rather than removed as is typical with multi- pass procedures) to serve as a biologic wound dressing. Additional passes with the CO2 laser may be per- formed focally in areas of more extensive involvement to limit unnecessary thermal and mechanical trauma to less involved skin. Subsequent reports have sub- stantiated the improved side-effect profile of this less aggressive procedure.20,21 r 2003 by the American Society for Dermatologic Surgery, Inc. � Published by Blackwell Publishing, Inc. ISSN: 1076-0512/02/$15.00/0 � Dermatol Surg 2003;29:80–84 Address correspondence and reprint requests to: Tina S. Alster, MD, Washington Institute of Dermatologic Laser Surgery, 2311 M Street, N.W., Suite 200, Washington, DC, 20037, or e-mail: talster@skin laser.com. In addition to the development of minimally traumatic CO2 laser techniques, the search for alter- native methods of cutaneous resurfacing led to the development of the Er:YAG laser. At a wavelength of 2940 nm, the Er:YAG laser corresponds to the peak absorption coefficient of water and is absorbed 12 to 18 times more efficiently by cutaneous water-contain- ing tissue than is the 10,600-nm wavelength of the CO2 laser. 22 At a fluence of 5 J/cm2, a typical short- pulsed (250 ms) Er:YAG laser reliably ablates 10 to 20 mm of tissue per pass, producing a residual zone of thermal injury not exceeding 15 mm.4,23 In contrast, CO2 laser skin resurfacing produces 20 to 60 mm of tissue ablation and up to 150 mm of residual thermal injury per pass. As a result of the minimal thermal injury induced by short-pulsed Er:YAG laser resurfa- cing, faster re-epithelialization and an improved side effect profile are effected (as compared with CO2 laser skin resurfacing).24–26 On the other hand, minimal thermal injury in the dermis provides insufficient vas- cular coagulation (resulting in poor intraoperative hemo- stasis) and reduced collagen contraction and remodeling (resulting in less impressive clinical results).4,23 To address the limitations associated with short- pulsed Er:YAG laser skin resurfacing, modulated (variable-pulsed) Er:YAG laser systems have been developed to improve intraoperative hemostasis and induce collagen remodeling. Modulated Er:YAG laser systems allow precise control of ablation while increas- ing the ability to induce collagen formation and achieve hemostasis through increased thermal injury.18 Although the previously described single-pass CO2 and modulated Er:YAG laser skin resurfacing techni- ques for facial photodamage, rhytides, and atrophic scarring have gained popularity among cutaneous laser surgeons, long-term studies comparing their relative side effects and complications have not been per- formed. Therefore, the objective of this study was to evaluate and compare postoperative wound healing and side-effect profiles of these two techniques for the treatment of photodamage and atrophic scarring. Methods A retrospective chart review and analysis of digital photography was performed in 50 consecutive patients (49 females and 1 male; mean age, 51; skin phototypes I–V) who received single-pass CO2 laser resurfacing (Ultrapulse 5000; Lumenis Laser Corp., Santa Clara, CA) and 50 consecutive patients (47 females and 3 males; mean age, 47; skin phototypes I–V) who received multiple-pass, long-pulsed Er:YAG laser (Contour; Sciton Laser Corp., Palo Alto, CA) resurfa- cing (Table 1). All laser procedures were performed by a single surgeon (T.S.A.) over a 2-year period for the indication of photodamage, rhytides, or atrophic scarring on the face. Anesthesia was obtained with regional nerve blocks using 1% lidocaine with 1:200,000 epinephr- ine. For full-face procedures, intravenous anesthesia was administered by a certified nurse anesthetist using a combination of propofol, midazolam, fentanyl, and ketamine. The CO2 laser was calibrated to 300-mJ energy and 60-W power through an 8-mm square scanning handpiece, and the entire face was treated with adjacent nonoverlapping laser scans in a single laser pass at CPG density 5. The 3-mm collimated hand- piece was used at 300- to 500-mJ energy and 5- to 7-W power to refine treatment edges. Partially desiccated tissue remained intact to serve as a biologic wound dressing. Er:YAG laser resurfacing was performed in dual mode (sequential ablation/coagulation) after being calibrated to 90-mm ablation (22.5 J/cm2) with 50% spot overlap and 50-mm coagulation. A square scanning handpiece was used to vaporize the epidermis in a single pass over the entire face. An additional one to two regional passes were delivered to the involved areas using identical laser settings. Laser scans were placed in an adjacent nonoverlapping manner, care- fully removing all partially desiccated skin with saline- soaked gauze between each laser pass. The partially desiccated tissue remaining from the final laser pass was left intact as a biologic wound dressing. The laser- irradiated skin showed a clean, pale pink hue with minimal to no bleeding. Immediately after laser treatment, Aquaphor oint- ment (Beirsdorf Inc., Wilton, CT) was applied to the irradiated skin. Each patient was instructed to perform gentle facial rinses with dilute acetic acid soaks several times daily, followed by an application of ointment Table 1. Patient Characteristics Procedure Female Male Mean Age (Year) SPT I SPT II SPT III SPT IV SPT V One pass 49 1 51 13 26 6 4 1 CO2 Multipass Er:YAG 47 3 47 20 16 7 5 2 Abbreviation: SPT, skin phototype. Dermatol Surg 29:1:January 2003 TANZI AND ALSTER: SINGLE-PASS CO2 VERSUS MULTIPLE-PASS ER:YAG SKIN RESURFACING 81 and a cooling masque (SkinVestment Inc., Washington, DC). A 10-day course of prophylactic antiviral treatment (valacyclovir 500 mg twice daily) was initiated on the morning of surgery. Patients were followed closely during the first postoperative week, during which time any residual coagulated debris was gently removed with cool water and dilute acetic acid compresses. All patients were able to apply camouflage make-up within 7 to 10 days postoperatively. Patients were formally evaluated by a physician on postoperative days 3 through 7, and at 1, 3, 6, and 12 months after the procedure. If prolonged erythema or hyperpigmentation was noted, the patient was eval- uated every 2 weeks until complete resolution. The incidence, severity, and duration of side effects and complications were recorded at each postoperative patient visit. Patient satisfaction surveys (poor, fair, good, or excellent results) were obtained 12 months after the procedure. Results The average time to re-epithelialization was 5.5 days (range, 5–7 days) with single-pass CO2 and 5.1 days (range, 5–8 days) with long-pulsed Er:YAG laser resurfacing (Table 2). Postoperative erythema was observed in all patients, lasting an average of 4.5 weeks (range, 3–12 weeks) after single-pass CO2 laser treatment and 3.6 weeks (range, 3–14 weeks) after long-pulsed Er:YAG laser treatment. Hyperpigmentation was seen in 46% of patients treated with single-pass CO2 and 42% of patients treated with the long-pulsed Er:YAG laser (average duration of 12.7 and 11.4 weeks, respec- tively) (Figures 1A,B and 2A,B). The majority of patients experiencing postinflammatory hyperpigmen- tation had darker skin tones (skin phototypes III–V); however, nearly 40% of patients with skin phototype II also hyperpigmented. Mild acne occurred in 12 patients (5 after CO2 and 7 after Er:YAG) during the first postoperative week, presumably because of the use of occlusive ointment. All cases of acne responded without recurrence to oral minocycline (75 mg twice daily for 1 week). Seven patients (three after CO2 and four after Er:YAG) developed transient milia requiring no intervention. Dermatitis was noted in five patients (one after CO2 and four after Er:YAG) and responded to mild topical corticosteroid cream. No cases of herpetic or fungal infections were encountered; however, nine patients (four after CO2 and five after Er:YAG) experienced localized superficial bacterial infections that fully resolved with oral ciprofloxacin (500 mg twice daily for 5 days). No hypopigmentation or hypertrophic scarring was observed in any study patient throughout the 12-month study period. Patient satisfaction surveys revealed good to excellent ratings in 85% of the patients after Er:YAG laser skin resurfacing and in 87% of the patients after single-pass CO2 laser treatment. Discussion Although the demand for ablative laser skin resurfa- cing procedures has been in recent decline because of Table 2. Postoperative Healing Time and Side Effect/Complication Rates Procedure N Reepithelialization Time (Average Duration in Days) Erythema (Average Duration in Weeks) Hyperpigmentation (Incidence; Average Duration in Weeks) Hypopigmentation Acne Milia Dermatitis Infection Scar One-pass CO2 50 5.5 4.5 23 (46%; 12.7) 0 5 (10%) 3 (6%) 1 (2%) 4 (8%) 0 Multipass Er:YAG 50 5.1 3.6 21 (42%; 11.4) 0 7 (14%) 4 (8%) 4 (8%) 5 (10%) 0 Figure 1. (A) Hyperpigmentation seen 4 weeks after single-pass CO2 laser treatment in a patient with skin phototype III. (B) Hyperpigmenta- tion resolved 13 weeks postoperatively. Figure 2. (A) Hyperpigmentation observed 3 weeks after multipass Er:YAG laser resurfacing (skin phototype III). (B) Complete normal- ization of skin pigmentation 11 weeks postoperatively. 82 TANZI AND ALSTER: SINGLE-PASS CO2 VERSUS MULTIPLE-PASS ER:YAG SKIN RESURFACING Dermatol Surg 29:1:January 2003 the development of nonablative laser technology and concerns regarding postoperative morbidity, few mod- alities can rival the impressive clinical results that ablative lasers can achieve.6,26 Less invasive CO2 laser resurfacing techniques and Er:YAG laser technology have been developed to reduce the postoperative morbidity associated with traditional multiple-pass CO2 laser resurfacing. Although these techniques have gained widespread acceptance among cutaneous laser surgeons, studies comparing their long-term side effects and complications are limited. Ruiz-Esparza and Gomez20 evaluated 15 patients after one-pass CO2 laser skin resurfacing for a follow- up period of 18 months. All patients were re- epithelialized by 7 days, and continued clinical improvement of rhytides was observed throughout the length of the study. No cases of scarring or persistent dyspigmentation were reported. Ross et al.27 evaluated 13 patients over a 6-month period following single-pass CO2 laser resurfacing on one side of the face and multiple-pass, short-pulsed Er:YAG laser resurfacing on the contralateral side. Their histologic results demonstrated that when CO2 and Er:YAG lasers produce equal levels of thermal destruction, equivalent healing and clinical improvement are effected. Delayed-onset permanent hypopigmentation—a serious complication that has been observed several months after multiple-pass CO2 laser skin resurfa- cing—has not yet been seen following single-pass treatment. Although no incidences of hypopigmenta- tion occurred in this study population at the 1-year follow-up evaluation, the frequency of hypopigmenta- tion following modulated Er:YAG laser skin resurfa- cing remains unknown. To date, only three cases of hypopigmentation following modulated Er:YAG laser skin resurfacing have been reported.18,28,29 Because it is possible for hypopigmentation to present several years postoperatively, additional studies are necessary to assess its true incidence after either single-pass CO2 or modulated Er:YAG laser skin resurfacing. Conclusion Single-pass CO2 laser resurfacing has a comparable postoperative period and complication profile to that of multiple-pass, long-pulsed Er:YAG laser resurfa- cing, even in patients with dark skin tones. Thus, the CO2 laser can still be employed when invasive skin resurfacing is indicated, effecting relatively few side effects and complications (compared with multipass CO2 procedures). Reliable comparisons of clinical improvement between modalities in a retrospective review are tenuous at best as digital photography was not standardized for all of the patients studied. As such, a comparison of clinical improvement between the two systems was not reported herein. The high degree of patient satisfaction reported after treatment with each of the two systems, however, indicates an equivocal clinical effect. Clearly, additional long-term comparison studies between one-pass CO2 and modu- lated Er:YAG laser skin resurfacing are warranted to delineate fully the advantages and disadvantages of each technique. Continued research and advances in ablative technology should further enhance the ability to achieve minimal-risk wrinkle or scar effacement. References 1. Alster TS, Garg S. Treatment of facial rhytides with a high-energy pulsed CO2 laser. Plast Reconstr Surg 1996;98:791–4. 2. Alster TS, Kauvar ANB, Geronemus RG. Histology of high-energy pulsed CO2 laser resurfacing. Semin Cutan Med Surg 1996;15: 189–93. 3. Fitzpatrick RE. Maximizing benefits and minimizing risk with CO2 laser resurfacing. Dermatol Clin 2002;20:77–86. 4. Sapijaszko MJA, Zachary CB. Er: YAG laser skin resurfacing. Dermatol Clin 2002;20:87–96. 5. Anderson RR, Parrish JA. Selective photothermolysis. precise microsurgery by selective absorption of pulsed radiation. Science 1983;220:524–7. 6. Alster TS. Cutaneous resurfacing with CO2 and erbium:YAG: lasers: preoperative, intraoperative, and post-operative considerations. Plast Reconstr Surg 1999;103:619–32. 7. Ross EV, McKinlay JR, Anderson RR. Why does carbon dioxide resurfacing work? A review. Arch Dermatol 1999;135:444–54. 8. Smith KS, Skelton HG, Graham JS, et al. Depth of morphologic skin damage and viability after one, two and three passes of a high- energy, short-pulse CO2 laser (TruPulse) in pig skin. Dermatol Surg 1997;37:204–10. 9. Alster TS, Nanni CA, Williams CM. Comparison of four carbon dioxide resurfacing lasers: a clinical and histopathologic evaluation. Dermatol Surg 1999;25:153–9. 10. Apfelberg DB. Ultrapulse carbon dioxide laser with CPG scanner for full-face resurfacing of rhytides, photoaging, and acne scars. Plast Reconstr Surg 1997;99:1817–25. 11. Fitzpatrick Re Goldman MP, Satur NM, et al. Pulsed carbon dioxide laser resurfacing of photoaged facial skin. Arch Dermatol 1996;132:395–402. 12. Alster TS, West TB. Resurfacing atrophic facial scars with a high- energy, pulsed carbon dioxide laser. Dermatol Surg 1996;22:151–5. 13. Waldorf HA, Kauvar ANB, Geronemus RG. Skin resurfacing of fine to deep rhytides using a char-free carbon dioxide laser in 47 patients. Dermatol Surg 1995;21:940–6. 14. Weinstein C, Alster TS Skin resurfacing with high-energy, pulsed carbon dioxide lasers. In: Alster TS, Apfelberg DB, eds. Cosmetic Laser Surgery. New York: John Wiley & Sons, 1996:9–28. 15. Tanzi EL, Alster TS. Treatment of atrophic facial scars with a dual- mode erbium: YAG laser. Dermatol Surg 2002;28:551–5. 16. Nanni CA, Alster TS. Complications of CO2 laser resurfacing: an evaluation of 500 patients. Dermatol Surg 1998;24:315–20. 17. Bernstein LJ, Kauvar ANB, Grossman MC, et al. The short and long term side effects of carbon dioxide laser resurfacing. Dermatol Surg 1997;23:519–25. 18. Zachary CB. Modulating the Er: YAG laser. Lasers Surg Med 2002;26:223–6. 19. David L, Ruiz-Esparza J. Fast healing after laser skin resurfacing: the minimal mechanical trauma technique. Dermatol Surg 1997;23:359–61. 20. Ruiz-Esparza J, Gomez JMB. Long-term effects of one general pass laser resurfacing: a look at dermal tightening and skin quality. Dermatol Surg 1999;25:169–74. 21. Khosh MM, Larrabee WF, Smoller B. Safety and efficacy of high fluence CO2 laser skin resurfacing with a single pass. J Cutan Laser Ther 1999;1:37–40. Dermatol Surg 29:1:January 2003 TANZI AND ALSTER: SINGLE-PASS CO2 VERSUS MULTIPLE-PASS ER:YAG SKIN RESURFACING 83 22. Walsh JT, Flotte TJ, Deutsch TF. Er:YAG laser ablation of tissue: effect of pulse duration and tissue type on thermal damage. Lasers Surg Med 1989;9:314–26. 23. Alster TS. Clinical and histological evaluation of six erbium: YAG lasers for cutaneous resurfacing. Laser Surg Med 1999;24: 87–92. 24. Bass LS. Erbium:YAG laser skin resurfacing: preliminary clinical evaluation. Ann Plast Surg 1998;40:328–34. 25. Khatri KA, Ross V, Grevelink JM, et al. Comparison of erbium: YAG and carbon dioxide lasers in resurfacing of facial rhytides. Arch Dermatol 1999;135:391–7. 26. Tanzi EL, Alster TS Side effects and complications of variable- pulsed erbium:YAG laser skin resurfacing: extended experience with 50 patients. Plast Reconstr Surg, in press. 27. Alster TS, Lupton JR. Update of dermatologic laser surgery: new trends for 2002. Cosmet Dermatol 2002;15:33–6. 28. Ross VE, Miller C, Meehan K, et al. One-pass CO2 versus multiple- pass Er:YAG laser resurfacing in the treatment of rhytides: a comparison side-by-side study of pulsed CO2 and Er:YAG lasers. Dermatol Surg 2001;27:709–15. 29. Jeong JT, Kye YC. Resurfacing of pitted facial acne scars with a long-pulsed Er: YAG laser. Dermatol Surg 2001;27:107–10. 84 TANZI AND ALSTER: SINGLE-PASS CO2 VERSUS MULTIPLE-PASS ER:YAG SKIN RESURFACING Dermatol Surg 29:1:January 2003