Use of Oral Sildenafil in Treatment of Pediatric Head and Neck Lymphatic Malformations

Background: Lymphatic malformation (LMs) is a low flow vascular malformation, with a morbidity rate of 1/2000 in neonates. Most of the LMs were found in the head and neck. Compared with the macrocrystic ones, the microcrystic LMs show stronger invasiveness and wider involved range, which leads to higher treatment difficulty and recurrence rate as well as a serious impact on patients´ health and quality of life. Aim: To evaluate the efficacy and safety of oral sildenafil in treatment of pediatric head and neck LMs. Methods: In total, 21 children diagnosed with LMs were given oral sildenafil and stopped at week 24. Therapeutic outcome was evaluated by comparing lesions' volume change with baseline. In addition, symptoms improvement and adverse effects were also recorded during the follow-up period. Results: Eight patients (38.0%) showed excellent improvement (>75%-100%), 1 patient (4.8%) had good (>50%-75%), 2 patients (9.6%) had fair (>25%-50%), 3 patients (14.3%) had minimal (0%-25%), and 7 patients (33.3%) had no improvement. The snoring or stridor completely disappeared in 2 subjects, although there was no apparent decrease in LMs size. Moreover, all 3 patients with macrocystic lesions displayed a positive response to sildenafil treatment, followed by mixed type (9/12, 75%). Only 2 out of 6 patients with microcystic lesions had minimal clearance. Only 4 patients showed transient mild diarrhea, there was no other adverse effect in this series. Conclusion: Our study showed that low-dose oral sildenafil citrate tablets are safe and effective to decrease the lesions volume in some LMs children, especially with macrocystic lesion or mixed type.