Monday, July 11, 2011

Laser Treatment of Stretch Marks – an Article Review

Stretch marks (striae distensae) are common.  They represent linear dermal scars accompanied by epidermal atrophy.  Stretch marks aren’t a significant medical problem, but can be a source of significant emotional distress.

There are many treatments available, ranging from therapy applied to the skin, laser therapy, and even more invasive surgical methods. Unfortunately, stretch marks remain a tricky problem to target, in which no established treatment exists.

A recent article in the  May issue of the Aesthetic Surgery Journal (full reference below) discusses the use of fractional nonablative laser treatment for stretch marks.

Dr. Francesca de Angelis and colleagues conducted a clinical study involving 51 patients with striae, three male and 48 female,  who were treated between May 2007 to May 2008.  Several patients had striae on multiple areas of the body so a total of 79 striae locations were treated.  

Patient ages ranged from 13 to 56 years (mean, 33 years). Fitzpatrick skin type ranged from II to IV. The duration of striae ranged from one to 40 years, with an average duration of 12 years. The striae formed as a result of pubertal growth (41%, n = 21), pregnancy (31%, n = 16), weight change (20%, n = 10), muscular atrophy (2%, n = one ), or unknown causes (6%, n = three).

Anatomical locations for treatment included the hips, breasts, abdomen, flanks, knees, buttocks, arms, thighs, and shoulders, with the majority of treatments occurring on the first three sites.

The stated objective of this study was to determine whether the 1540-nm Er:Glass laser could safely and effectively improve the appearance of both striae rubra and alba while minimizing the risk of PIH.

The laser used in this study, the fractional nonablative 1540-nm erbium:glass (Er:Glass) laser (Lux1540; Palomar Medical Technologies, Inc., Burlington, Massachusetts), is currently the only fractional laser approved by the US Food and Drug Administration to treat striae.

Treatment parameters included two to three passes with the 1540-nm laser, with energy settings from 35 to 55 mJ/mb with the 10-mm optical tip or 12 to 14 mJ/mb with the 15-mm optical tip. Two to four total treatments were performed at four- to six-week intervals.

Patients were given a pretreatment regimen which consisted of applying a compound of 1% hydrocortisone, 4% hydroquinone cream, and 3% vitamin C to their striae for 30 days prior to treatment.

After treatment, patients were instructed to apply moisturizing cream multiple times per day to maintain hydration of the skin and to help reduce erythema. All patients were also instructed to apply the same pretreatment topical compound to their treated striae every day for three to six months after their final treatment.

Both nonblinded and blinded reviewers evaluated the percent improvement after treatment on a 0% to 100% quartile scale.

Skin reactions were assessed by the treating physician and recorded at multiple time points, and histology was conducted with hemotoxylin and eosin as well as Orcein-Giemsa staining.

The researchers report

H&E staining of pretreatment tissue samples revealed an atrophied epidermis and flattened rete ridges within the papillary dermis. No intact collagen fibers were identifiable in the striae before treatment, and the degenerated appearance of the fibers resulted in uneven staining as well as indistinct borders.

In contrast, following three 1540-nm treatments with the 10-mm tip at 40 mJ and 10-ms pulse width, significant neocollagenesis was observed. Elastic fibers in the reticular dermis appeared sparse and fragmented prior to the 1540-nm treatment.

One month after the third treatment, elastic fibers were uniformly increased in number throughout the reticular dermis.

My biggest problem with this study is how do the researchers know the laser was the source of improvement rather than their pre- and post-treatment topical skin care.  Why not do a comparison of areas treated with the topicals verse the topicals and laser? 

The photos included did show some improvement, but …. (photo source, the article)

 

 

 

 

REFERENCE

Fractional Nonablative 1540-nm Laser Treatment of Striae Distensae in Fitzpatrick Skin Types II to IV: Clinical and Histological Results;  F de Angelis, L Kolesnikova, F Renato, G Liguori; Aesthetic Surgery Journal May 2011 31: 411-419, doi:10.1177/1090820X11402493

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