RESULTS
Patient profiles
Table 1 shows patient profiles before and after propensity score
matching. A total of 175 patients with 33 patients in ADM group were
enrolled in this study. Before propensity score-matching, the ADM group
contained lower age, size of tumor, and volume of specimen, than those
in the Control group. Moreover, the type of parotidectomy in the Control
group were significantly difference than the type in the ADM group
(P = 0.008). As a result, the rate of male and hypertension in
both groups was similar (P = 0.447, P =0.902). After
propensity score-matching, both groups were well matched in all
parameters. 30 patients each were allocated to the ADM group and the
Control group. Pleomorphic adenomas and Warthin’s tumors were the most
frequent histological type in two groups. 25 patients (83%) or 23
patients (77%) underwent partial superficial parotidectomy, followed by
superficial parotidectomy (4 patients in ADM group and 6 patients in
Control group).
Complications
Overall complication rates are shown in Table 2. ADM group were
associated with a total of 5 complications (17%), whereas Control group
were associated with a total of 13 complications (43%)
(P =0.024).
Postoperative facial function was graded on the House-Brackmann scale in
all patients. 3 patients (10%) in the ADM group and 4 patients (13%)
in the Control group had facial
palsy, with initially founded on the first day after operation. The
postoperative facial palsy did not get statistical significance between
two groups. All patients except the two Nerve Schwannoma patients fully
regained normal facial function within 6 months. The two Nerve
Schwannoma patients in either group developed permanent facial palsy
with grade IV.
1 patient (3%) in the ADM group and 6 patients (20%) in the Control
group developed a sialocele or salivary fistula. No significant
difference was achieved between the two groups (P =0.108).
1(3%) patient in the ADM group
and 9(30%) patients in the Control group experienced sweating over the
preauricular regions 6 months after the operation. There was
statistically significant difference between the two groups in
subjective Frey syndrome (FS) (P =0.015).
The most common complication was sensory deficit in both groups.
Numbness in the infra-auricular region occurred in 4 patients (13%) in
the ADM group and in 7 patients (23%) in the Control group
(P =0.317). 9 of the 11 patients with sensory deficit recovered
sensation within 6 months after the operation.
None of the patients in the ADM group experienced complications at the
donor site. No patient in either group had tumor recurrence and seromas
during the follow-up period.
Postoperative drainage
The postoperative drainage in the
ADM group was 59.7+ 26.0 mL, whereas the postoperative drainage in
the Control group was 110.0+ 78.7mL. Postoperative drainage was
significantly decreased in the ADM group compared with the Control group
(Fig. 2A) (P =0.002). The postoperative drainage time in the ADM
group was 3.6+ 0.8 days, whereas the postoperative drainage time
in the Control group was 4.7+ 1.7days. Postoperative drainage time
was significantly lower in the ADM group compared with the Control group
(Fig. 2B) (P =0.001).
Expect the sialocele or salivary fistula patients, the postoperative
drainage in the ADM group (29 patients) was 58.3+ 25.3 mL, whereas
the postoperative drainage in the Control group (24 patients) was
95.3+ 72.6mL. Postoperative drainage was also significantly
decreased in the ADM group compared with the Control group
(P =0.013). The postoperative drainage time in the ADM group was
3.6+ 0.8 days, whereas the postoperative drainage time in the
Control group was 4.5+ 1.6days. Postoperative drainage time was
also significantly lower in the ADM group compared with the Control
group (P =0.010).
Subjective aesthetic score
Patients in the ADM group had a subjective aesthetic score of
6.1+ 1.7 compared with 5.2+ 1.7 in the Control group (Fig.
3). The subjective aesthetic score
for patients in the ADM group was higher than those in the Control group
(P =0.040).