Thirty-eight patients (16 male, 22 female) underwent fronto-facial distraction during the study period and met all inclusion criteria. Fifteen patients were included in the FOA- group and 23 patients were included in the FOA+ group. Across groups, there were no significant differences in sex, age at surgery, prior VP shunting, Chiari decompressions, tracheostomies, or procedure types (monobloc, bipartition, multi-level midface osteotomy). There was a trend towards a higher prevalence of Apert syndrome in the FOA- cohort and Crouzon syndrome in the FOA+ cohort (p = 0.055, Table 2).
Table 2: Demographic information and surgical histories across the FOA- group and FOA+ group.
|
FOA-
|
FOA+
|
p
|
N
|
15
|
23
|
|
Sex
|
|
|
0.970
|
Male
|
6
|
10
|
|
Female
|
9
|
13
|
|
Diagnosis
|
|
|
0.055
|
Apert
|
3
|
12
|
|
Crouzon
|
9
|
4
|
|
Pfeiffer
|
2
|
5
|
|
Other
|
1
|
2
|
|
Age at Surgery in years,
median (IQR)
|
5.9 (5.1-7.4)
|
5.9 (5.5-9.3)
|
0.339
|
Comorbidities
|
|
|
|
VP Shunt
|
2
|
8
|
0.389
|
Chiari Decompression
|
1
|
7
|
0.434
|
Tracheostomy
|
0
|
4
|
0.376
|
Procedure
|
|
|
0.970
|
Monobloc
|
11
|
19
|
|
Monobloc Bipartition
|
2
|
2
|
|
Multipiece Osteotomy
|
2
|
2
|
|
Operative time was similar for the FOA- group (307 ± 61 minutes) and the FOA+ group (343 ± 64 minutes, p = 0.128), as was anesthesia time (FOA-: 439 ± 80 minutes; FOA+: 439 ± 60 minutes, p = 0.893). Compared to the FOA- group, the FOA+ group had more dural tears (65% vs 20%, p = 0.006), longer total lengths of stay (9.6 ± 9 days vs 6.8 ± 3.8 days, p = 0.037), and longer PICU stays (6.7 ± 7.0 days vs 4.3 ± 4.9, p = 0.031, Table 3). Estimated blood loss did not vary between groups (FOA-: 43 ± 37mL/kg; FOA+: 58 ± 34mL/kg, p = 0.073), nor did volume of transfused blood products (FOA-: 55 ± 30mL/kg; FOA+: 76 ± 53mL/kg, p = 0.129), though it is possible that we were underpowered to assess blood loss.
Table 3: Perioperative characteristics of the FOA- and FOA+ groups, reported as median and IQR (Q1-Q3). P-values for continuous measures are derived from the Mann-Whitney test. P-values for nominal measures are derived from the chi-square test. Significance (α < 0.05) bolded.
|
FOA- (%)
|
FOA+ (%)
|
p
|
N
|
15
|
23
|
|
Distractor Type
|
|
|
0.142
|
Halo
|
13 (87)
|
15 (68)
|
|
Buried
|
2 (15)
|
8 (32)
|
|
Age at Surgery, yrs
|
|
|
0.339
|
Median
|
5.9
|
5.9
|
|
IQR
|
5.1-7.4
|
5.5-9.3
|
|
Weight, kg
|
|
|
0.483
|
Median
|
20
|
21
|
|
IQR
|
19-21
|
18-25
|
|
Operative Time, min
|
|
|
0.128
|
Median
|
295
|
332
|
|
IQR
|
258-364
|
298-390
|
|
Anesthesia Time, min
|
|
|
0.893
|
Median
|
444
|
430
|
|
IQR
|
376-480
|
395-481
|
|
EBL mL/kg
|
|
|
0.073
|
Median
|
35
|
52
|
|
IQR
|
22-48
|
35-72
|
|
Transfusion mL/kg
|
|
|
0.129
|
Median
|
54
|
75
|
|
IQR
|
36-68
|
53-90
|
|
Fluids/kg
|
|
|
0.095
|
Median
|
55
|
84
|
|
IQR
|
43-89
|
60-154
|
|
|
|
|
|
Dural Tear
|
3 (20)
|
15 (65)
|
0.006
|
|
|
|
|
Length of Hospital Stay, d
|
|
|
0.037
|
Median
|
6
|
7
|
|
IQR
|
5-6
|
6-10
|
|
Length of PICU Stay, d
|
|
|
0.031
|
Median
|
3
|
4
|
|
IQR
|
2-5
|
4-7
|
|
Time with Distractors, d
|
|
|
0.104
|
Median
|
91
|
104
|
|
IQR
|
85-104
|
88-134
|
|
There were no deaths in either group. Four patients (27%) in the FOA- group had complications, compared to 14 (61%) in the FOA+ group (p = 0.039, Table 4). There was no difference in the incidence of minor complications between groups (p > 0.999), but the incidence of major complications was higher in the FOA+ group (48% vs. 13%, p = 0.028). There were no cases of postoperative CSF leak in the FOA- groups and four cases in the FOA+ group (p = 0.139). Complications in the FOA+ group were more often Clavien-Dindo IIIa or higher, however the distribution of complications across cohorts was not significant (p = 0.260, Table 4, Figure 1). The complications of grade IIIa or higher consisted of 4 frontal/temporal abscesses, 3 distractor pin site infections without frank purulence, 2 lumbar drain placements for persistent CSF leak, 2 distractor dislodgements, and 2 ascending infections attributed to nasofrontal fistulas.
Table 4: Complications between study groups. Major complications defined as Clavien-Dindo IIIa or above, whereas minor complication were Clavien-Dindo I and II. Minor complication broken down by seroma and surface infection. Major complications broken down by deep infection and hardware failure necessitating reoperation. Significance (α < 0.05) bolded.
|
FOA- (%)
|
FOA+ (%)
|
p
|
N
|
15
|
23
|
|
Minor Complications (I-II)
|
2 (13)
|
3 (13)
|
|
Surface Infection/Cellulitis
|
1 (7)
|
3 (13)
|
0.280
|
Seroma
|
1 (7)
|
0 (0)
|
0.395
|
Major Complications (IIIa+)
|
|
|
|
Reoperation
|
2 (13)
|
11 (48)
|
0.053
|
Deep Infection
|
2 (13)
|
9 (39)
|
0.087
|
Hardware Malfunction
|
0 (0)
|
2 (9)
|
0.791
|
Patients with Major Complication
|
2 (13)
|
11 (52)
|
0.028
|
Patients with Any Complication
|
4 (27)
|
14 (61)
|
0.039
|
Clavien-Dindo score
|
|
|
0.260
|
I
|
1 (7)
|
0 (0)
|
|
II
|
1 (7)
|
3 (17)
|
|
IIIa
|
0 (0)
|
0 (0)
|
|
IIIb
|
2 (13)
|
10 (39)
|
|
IVa
|
0 (0)
|
1 (4)
|
|
IVb
|
0 (0)
|
0 (0)
|
|
V
|
0 (0)
|
0 (0)
|
|
To assess changes in complication rates over time, cases were divided into two groups (early 2000-2011, n = 14 vs. late 2012-2022, n = 24). There was no difference in major (p = 0.898) or minor (p = 0.067) complication rate across periods (Figure 2).
There was a trend towards patients over the age of 8 at surgery having more major complications compared to those under 8 (54% vs 24%, p = 0.066). 2 of 4 patients with a preoperative tracheostomy experienced deep infections necessitating reoperation and one other patient developed a CSF leak which was managed nonoperatively.
Multivariate logistic regression found that history of FOA was the sole independent predictor associated with major complications (OR 6.0, 95% CI 1.1-32.6, p = 0.040) and intraoperative dural injury (OR 6.5, 95% CI 1.4-30.9, p = 0.018). Multivariate linear regression was used to identify variables associated with length of stay and operative time. Tracheostomy (p < 0.001), increasing anesthesia time (p = 0.031), and age at surgery (p = 0.002), were associated with longer length of hospital stay. Predictors of prolonged surgical time were early (2000-2011) time period (p = 0.024), a diagnosis of Apert syndrome (p = 0.022), and male sex (p = 0.021, Table 5).
Table 5: Multivariate Regression predicting major complications, dural tears, length of stay, and operative time. Logistic regression models presented with odds ratios and 95% confidence intervals, and linear models presented with linear estimates and standard errors. Significance (α < 0.05) bolded.
Logistic Models
|
Predictor
|
OR
|
95% CI
|
p
|
(1) Major Complications
|
|
|
|
|
|
Prior FOA
|
6.0
|
1.1-32.6
|
0.040
|
(2) Dural Tears
|
|
|
|
|
|
Prior FOA
|
6.5
|
1.4-30.9
|
0.018
|
|
Shunt
|
2.6
|
0.5-14.2
|
0.260
|
|
|
|
|
|
Linear Models
|
Predictor
|
Estimate
|
Standard Error
|
p
|
(1) Length of Stay
|
|
|
|
|
|
Age at Surgery
|
1.15
|
0.34
|
0.002
|
|
Anesthesia time, min
|
0.03
|
0.01
|
0.031
|
|
Tracheostomy
|
11.3
|
2.94
|
< 0.001
|
(2) Operative Time
|
|
|
|
|
|
Time Period
|
|
|
|
|
2000-2011
|
Ref
|
-
|
|
|
2012-Present
|
-44.08
|
18.61
|
0.024
|
|
Diagnosis
|
|
|
|
|
Pfeiffer
|
Ref
|
-
|
|
|
Apert
|
60.56
|
25.10
|
0.022
|
|
Crouzon
|
39.44
|
24.99
|
0.124
|
|
Other
|
-31.25
|
36.52
|
0.399
|
|
Male Sex
|
46.09
|
18.94
|
0.021
|