Materials and methods
For both pediatric and adult populations,
medical
records were reviewed retrospectively of patients who had been treated
for RRP with operating room procedures,in the period from January 2018
to April 2021. The inclusion
criteria included patients with a diagnosis of RRP and at least 6 months
of follow-up. Each patient signed an informed consent form before
surgery. Patients were excluded if they did not fulfill these
requirements, or if they had received tracheostomy.
The following patient demographic
data were collected and analyzed: age, gender, smoking status, symptoms
at the first procedure, length of follow-up time, localization of the
papillomas, histological findings(evidence of dysplasia), number of
surgical procedures, the type and date of the surgical
treatment(Microdebrider, or CO2 laser or KTP laser), recurrence rate.
The treatment intervals were
calculated based upon these dates.
Anatomical Derkay severity scores
were captured for all patients preoperatively.
The survival curves were plotted
based on the recurrence events and follow-up time, through which we
could compare the recurrence trends of patients used three different
surgical modalities. According to Derkay et al, the aerodigestive tract
is divided into 25 subsites with each given a score if disease is
present (0 is no lesion, 1 is surface lesion, 2 is raised lesion, and 3
is bulk lesion).[11]
Treatment groups were stratified as
microdebrider, CO2 laser and KTP laser. We analyzed AO-RRP and JO-RRP
populations respectively, and we also combined the
pediatric and adult data for
comparison among three treatment modality groups.
The calculation of the interval of
treatment is started at 00:00 on the first day after surgery, and ended
at the time when the patient undergoes surgery again because of a
recurrence of the lesion. How to determine whether a patient is the
recurrent case or not? The surgeons
recorded photographs or videos of hard laryngoscopy or electronic fiber
laryngoscopy to compare preoperative and postoperative lesions. Criteria
for judging recurrence: papillary lesion reappear in the same or
adjacent parts of the previous operation, which is pathologically
confirmed as papillomas after surgery. When the interval between
surgeries is recorded, this case will be treated as a new case for
re-entry follow-up after surgery. Those who had not relapsed at the end
of the follow-up date were also counted separately as truncated data.
Statistics were performed using SPSS (IBM SPSS Statistics 26).
Continuous variables with a normal distribution were compared using a
2-tailed t-test and/or analysis of variance. Continuous variables
without a normal distribution were compared with Mann–Whitney test or
Kruskal–Wallis test. Categorical variables were compared with either
chi-squared test or Fisher’s exact.
The survival curve were plotted in
GraphPad Prism based on the recurrence events and follow-up time. A
value of P<0.05 was considered statistically significant.