Key points:
  1. CO2 and KTP laser were developed to treat LP, but the differences in their outcomes have not been systematically summarized.
  2. This review was conducted through three databases involving 283 related studies, and 15 of them met the inclusion criteria.
  3. KTP laser might result in a superior outcome and lower postoperative complication rate than CO2 laser for LP.
  4. HPV positive rate, remission rate, and clearance rate for LP are suggested to be reported in future studies.
  5. High-quality randomized controlled studies are needed to further evaluate the benefits of the two surgical techniques.
Introduction
Laryngeal papillomatosis (LP) is a benign tumor that can involve the whole respiratory tract and upper digestive tract1. It is also termed as recurrent respiratory papillomatosis(RRP) due to its high recurrence rate postoperatively and multiple surgeries are frequently required2. In general, LP can be divided into juvenile-onset and adult-onset LP3. The reported incidence rate is 0.17 and 0.54 per 100 000 people for juvenile-onset and adult-onset LP, respectively4. Its morphological characteristics appeared with many abnormal exophytic projections, one of which is composed of a center of connective tissue covered with squamous epithelium5,6. Although benign, LP is chronic and can significantly influence on life style due to requiring multiple operations and significant financial impact, scarring, airway obstruction, hoarseness, and rare but the potential for malignant transformation4,7,8.
Currently, no definite treatment modality for LP is yet available, clinical management of LP is mainly rely on repeated careful surgical resections with preservation of non-infected tissue9,10. Besides, the treatment for LP in clinical is still frustrating on account of unpredictable outcomes, the tendency for recurrence, and intractable complicates11,12. Effective prevention of complicates is one of the main targets for treatments, which could be the important criteria for evaluating treatment methods2,3,13. Surgical excision in the operating room under general anesthesia is the traditional management method1,14,15. Powered by advanced technology, a direct laryngoscopic approach started in the 20thcentury16,17. Afterwards, with the development of the carbon dioxide (CO2) laser in the 1960s, it quickly became popular in laryngology but multiple complications, such as thermal injury, significantly limited its applications1,18,19. Subsequently, the 585-nm pulsed dye laser (PDL) was first introduced in 2001 to manage PL with a fiber delivery system of absorbable energy20,21. However, bleeding caused by PDL and its extremely short pulse width blocked the further application of this technology2,22,23. Furthermore, adjuvant antiviral drugs have been administrated and studied for increasing therapeutic effects in recent years, but their therapeutic effects have not been confirmed24–26.
In the past thirty years, photoangiolytic laser-the 532-nm potassium titanyl phosphate laser (KTP), has been widely applied in office-based laryngeal surgical procedures27–29. Many studies have been reported successful treatment of multiple vocal diseases, such as papilloma, varix, polyp, Reinke edema, vocal process granuloma, ectasia, and glottal dysplasia29. The angiolytic properties of KTP shrink lesions through photothermolysis and the laser energy can be absorbed by hemoglobin10,30,31. With those advantages, KTP laser seems to be the promising modality of LP treatment. However, in China(and neighboring countries), the CO2 laser is being used as the first-choice modality for LP applied by most hospitals. To date, there was no consensus or comparison study on which laser is better for LP therapy.
This review aims to evaluate and compare the cure, complications, and recurrence rates of CO2 and KTP lasers for LP. We hypothesized that KTP laser could yield comparatively better outcomes than CO2 laser for LP.
Method
The study was performed according to PRISMA32 and the check list was presented in Appendix S1.