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Upper airway outcomes following midface distraction osteogenesis: A systematic review
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Journal of Plastic, Reconstructive & Aesthetic Surgery (2014) xx, 1e9
REVIEW
Upper airway outcomes following midface distraction osteogenesis: A systematic review B.A. Taylor a, M. Brace a,*, P. Hong a,b a IWK Health Centre, Dalhousie Pediatric Craniofacial Group, Department of Surgery, Dalhousie University, Halifax, Nova Scotia, Canada b School of Human Communication Disorders, Dalhousie University, Halifax, Nova Scotia, Canada
Received 16 May 2013; accepted 5 February 2014
KEYWORDS Distraction osteogenesis; Le Fort III osteotomy; Upper airway obstruction; Functional outcomes
Summary The objective of this paper is to systematically review the airway outcomes following distraction osteogenesis of midface with the goal of (1) deriving clinically oriented insights and (2) identifying gaps in knowledge to stimulate future research. Medline, EMBASE and Cochrane databases were searched and studies were included if subjects of any age had midface retrusion/hypoplasia and underwent midface distraction osteogenesis. Outcome measures of interest were any respiratory or airway associated measures, and reports of adverse events. A total of 368 abstracts were generated from the literature searches; 16 studies met the criteria for data extraction and analysis. All 16 studies were observational. Generally, midface distraction osteogenesis was reported to improve respiratory status and was well tolerated. Specifically, favorable outcomes in cephalometry (9 studies), polysomnography (9 studies), and decannulation rates (8 studies) were reported. In conclusion, upper airway status was improved in most patients who underwent midface distraction osteogenesis, yet long-term results and consistent objective measures are lacking. Studies reviewed were retrospective case series and details regarding patients who did not improve were deficient. A standardized prospective multicenter cohort trial with long-term patient follow up is required. ª 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
* Corresponding author. IWK Health Centre, 5850/5980 University Avenue, PO Box 9700, Halifax, Nova Scotia B3K 6R8, Canada. Tel.: þ1 (902) 470 0841; fax: þ1 (902) 470 8041. E-mail address: [email protected] (M. Brace). http://dx.doi.org/10.1016/j.bjps.2014.02.013 1748-6815/ª 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Taylor BA, et al., Upper airway outcomes following midface distraction osteogenesis: A systematic review, Journal of Plastic, Reconstructive & Aesthetic Surgery (2014), http://dx.doi.org/10.1016/j.bjps.2014.02.013
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Introduction Distraction osteogenesis (DO) was initially described by Codvilla in the early 20th century1 and subsequently popularized by Ilizarov in the 1940s.2,3 Yet, it was not until the 1970s that DO was applied to the craniofacial skeleton, first in a canine model.4 Few years later, McCarthy and colleagues described clinical results of DO for patients with congenital mandibular deformities.5 Since then DO of the craniofacial skeleton has become widely accepted and practiced in many craniofacial centres.6 Upper airway obstruction and obstructive sleep apnea (OSA) is very common in patients with craniofacial disorders and the management of these problems requires a multidisciplinary approach.6 The specific cause of airway compromise may be multifactorial but for those patients with midface retrusion, there can be narrowing of the pharyngeal airways, resulting in obstruction when postural muscles relax during sleep.7 Midface DO is a relatively new surgical procedure typically performed to relieve the upper airway obstruction at the level of the nasopharynx and velopharynx. Conceptually, this procedure would increase the restricted airway space, thereby reducing the obstructive respiratory problems and obstructive sleep apnea (OSA).8 Other indications include exorbitism, malocclusion and cosmetic concerns, but these are considered secondary to upper airway obstruction and OSA. Functional outcomes in DO have been reported mostly in cases that involve the mandible. Specifically, DO of the mandible has been shown to improve upper airway obstruction,6,9 feeding,10 and health-related quality of life.11 However, much less has been reported in regards to functional outcomes post-midface DO. The purpose of this systematic review was to consider original articles reporting on upper airway changes in patients following midface DO. These studies evaluate the airway through a number of different measures including polysomnography, decannulation rates, imaging analysis, and subjective changes. This review aims to aid clinicians and patients considering midface DO by providing a comprehensive appraisal of airway outcomes as reported currently in the literature.
Methods The authors formulated the research question for this study using the Population, Intervention, Comparison, and Outcome (PICO) research question guideline: Populationindividuals with midface hypoplasia/retrusion; Intervention-LeFort II or LeFort III osteotomy with DO; Comparison-pre- and post-operative airway status; and Outcomes-subjective and objective respiratory clinical observations, polysomnography, decannulation rates, and imaging analysis.
B.A. Taylor et al. which included these terms: “Distraction Osteogenesis”, “Airway”, “Airway Obstruction”, “Obstructive Sleep Apnea”, “Breathing” and “Respiration” (Figure 1). All titles and abstracts resulting from the aforementioned search strategy were obtained.
Inclusion/exclusion criteria Studies that included upper airway outcomes in subjects with midface hypoplasia/retrusion who underwent midface DO were included in the review. Patients who underwent facial bipartitions were also included. Both external and internal distractor devices were accepted. Studies that involved trials of novel osteotomies or other surgical techniques were excluded. LeFort I and maxillary advancements in patients with cleft lip and palate were also excluded. Finally, studies with duplicate patients were excluded. Studies were required to meet Oxford Center for Evidence Based Medicine Level 4 or above.12 This included case series, case-control studies, cohort studies, and randomized control trials. Inclusion criteria also included studies with any subjective and/or objective airway outcomes. Only articles in English language were included. A list of titles and abstracts was generated from articles meeting the aforementioned criteria. Two of the authors independently screened the list, selecting pertinent articles for further review, involving the third author when there were conflicts. Full texts were obtained and further evaluated against inclusion criteria. This included hand searching of the references of individual full reviewed articles.
Data extraction and analysis Data were extracted from the studies meeting criteria for inclusion. The following data were extracted: study design, number of subjects, subject demographics (age, gender, syndromes) description of intervention, and outcome measures. For quantitative outcome measures, mean values, standard deviations, confidence intervals, and/or P values were recorded; data were synthesized into tables when methodologies were similar enough to allow it. The authors assessed the quality of the studies with the use of a Quality Assessment Score out of 7 possible points comprised of the following characteristics: 1) inclusion/ exclusion criteria clearly stated (yes Z 1, no Z 0); 2) assessment method validated (yes Z 1, no Z 0); 3) appropriate comparison group (intra-subject Z 1, no Z 0); 4) observers blinded to condition/treatment (yes Z 1, no Z 0); 5) adequate sample size/power analysis (yes Z 1, no Z 0); 6) well-defined, consecutive sample (yes Z 1, no Z 0); and 7) less than 5% lost to follow-up (yes Z 1, no or not provided Z 0).
Results
Literature search strategy Study selection The following databases were searched: EMBASE (1974 to August 26, 2013), MEDLINE (1966 to August 26, 2013), and Cochrane library using a comprehensive search strategy,
A total of 368 titles/abstracts were recovered from the comprehensive search of the online databases. After
Please cite this article in press as: Taylor BA, et al., Upper airway outcomes following midface distraction osteogenesis: A systematic review, Journal of Plastic, Reconstructive & Aesthetic Surgery (2014), http://dx.doi.org/10.1016/j.bjps.2014.02.013
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Upper airway outcomes following midface distraction osteogenesis
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MEDLINE/PubMed Run August 26, 2013 Search Strategy: "osteogenesis, distraction"[MeSH Terms] OR ("osteogenesis"[tiab] AND "distraction"[tiab]) OR "distraction osteogenesis"[tiab] OR ("distraction"[tiab] AND "osteogenesis"[tiab]) Airway*[tiab] OR ("Airway Resistance"[Mesh]) OR "obstructive sleep apnoea"[All Fields] OR "sleep apnea, obstructive"[MeSH Terms] OR ("sleep"[All Fields] AND "apnea"[All Fields] AND "obstructive"[All Fields]) OR "obstructive sleep apnea"[All Fields] OR ("obstructive"[All Fields] AND "sleep"[All Fields] AND "apnea"[All Fields]) OR (airway complications[tiab]) OR (airway obstruction[tiab]) OR ("Airway Obstruction"[MeSH]) OR (breathing[MeSH]) OR (breathe[tiab]) OR (respiration[tiab]) OR (resp[tiab]) #1 AND #2 EMBASE Run September 26, 2012 Search Strategy: 1. exp "distraction osteogenesis" OR (exp "osteogenesis" AND "distraction") 2. exp "airway resistance" OR "exp airway obstruction" OR (exp "airway" AND exp "obstruction") OR exp "airway" OR (exp "airway" AND "complications") OR exp "sleep apnea syndrome" OR ("obstructive" AND exp "sleep" AND exp "apnea") OR exp “breathing” OR exp “breathe” OR “resp” OR exp “respiration”. 3. #1 AND #2 Cochrane Library Run September 26, 2012 Search Strategy: 1. MeSH descriptor: [Osteogenesis, Distraction] explode all trees OR ("osteogenesis" and "distraction") OR "distraction osteogenesis" 2. "airway" OR "obstruction" OR "airway obstruction" OR "airway resistance" OR "apnea" OR "sleep" OR "sleep apnea" OR "obstructive" OR ("obstructive" AND "sleep" AND "apnea") OR “breathing” OR “breathe” OR “resp” OR “respiration” 3. #1 AND #2 Figure 1
Details of search terms used in the systematic literature review.
screening, 23 met criteria for full article review. The remaining abstracts were rejected mainly because they did not include airway outcomes in their analyses. Full article review yielded 16 studies meeting inclusion criteria.13e26 A flow diagram adopted from Moher et al.29 depicts search, screening and exclusion processes (Figure 2).
Study characteristics Data extraction and analysis were performed as outlined above. All articles reported subjective outcomes, which were mostly based on caregiver observation of snoring and/or apneic episodes. Objective airway outcomes were described as follows: cephalometry in 9 studies,13,14,16,17,19e22,25 polysomnography in 9 studies,13,14,16,19e23,27 quantitative computed tomography in 7 studies,18e21,23,25e27 and decannulation rates in 9 studies.13e16,20,24,26e28 There were 210 patients who underwent midface DO procedures. Subcranial Le Fort III osteotomy with application of external distractor device was the most common procedure, followed by monobloc DO with external device. Subjects ranged in age from 4 months to 23.2 years and all patients had syndromic craniosynostosis with midface retrusion/hypoplasia. All studies encountered were case series. Study characteristics, along with individual study Quality Assessment Scores, are summarized in Table 1.
Polysomnographic outcomes Pre- and post-operative polysomnography was reported in 67 patients, and most demonstrated improvements postmidface DO. However, raw data was not available in most studies (only mean data) and some studies reported patients with no improvements.23 Furthermore, although apnea-hypopnea index (respiratory distress index) was reported in 7 of 9 studies, the exact definition of apnea or hypopnea was not mentioned. Time of follow-up also varied (2 studies) or was not reported. Polysomnographic outcomes are summarized in Table 2.
Cephalometric outcomes Cephalometric outcomes (Table 3) were reported in 135 patients. The images were compared pre- and postoperatively and measured from a number of standard and non-standard reference points. Commonly, Point A measurements (the most posterior point on the maxilla below the level of the anterior nasal spine), which were reported in 5 studies (78 patients), demonstrated a mean increase of 16.49 mm, following midface DO procedures. The upper incisal edge was also a common point of reference and was measured in 4 studies. The mean increase in distance of this measurement was calculated to be 18.47 mm. Finally, the
Please cite this article in press as: Taylor BA, et al., Upper airway outcomes following midface distraction osteogenesis: A systematic review, Journal of Plastic, Reconstructive & Aesthetic Surgery (2014), http://dx.doi.org/10.1016/j.bjps.2014.02.013
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B.A. Taylor et al.
Records identified through database searching (n = 360)
Screening
Identification
4
Additional records identified by hand searching bibliographies (n = 8)
Abstracts screened (n = 368)
Eligibility
Full-text articles assessed for eligibility (n = 23)
Records excluded (n = 345)
Studies excluded, with reasons (n = 7) Non-LeFort III (1) No distraction (1) Combined procedures (3) No outcomes (2)
Included
Studies with airway outcomes (n = 16)
Figure 2
Flow diagram of article selection process.
SNA angle, which describes the angular vector between the sella, nasion, and Point A, was reported in 6 studies totaling 120 patients. The mean increase in the SNA angle was 18 . Volumetric analysis based on cephalometric data was quantitatively reported in 4 studies. Ko et al. reported an increase in mean upper airway volume of 16.64 cm3 (85%),25 and Xu et al. reported an increase of 9.13 mL (64.30%) postoperatively.19 Nout et al. reported an increase in mean upper airway volume by 37.4 20.7%21 and an increase in mean upper airway volume by 29.26%.27
Computed tomography Seven studies used computed tomography (CT) images for post-midface DO analysis.18e21,23,25e27 Three studies used reconstructed sagittal CT images to report standard cephalometric measurements,23,26 while 5 studies used 3dimensional reconstructions and volumetric analysis using computer software programs.19e21,25,27 All studies reported an increase in upper airway volume at the level of the nasopharynx and/or velopharynx.
Decannulation rates and other clinical outcomes Post-operative decannulation rates were included in 9 articles (Table 4). Of the 38 patients who had a tracheostomy, 25 (65.7%) were safely decannulated after undergoing midface DO. All patients remained decannulated at least until the time of study completion. Reported follow-up
times ranged from 6 months to lifetime, however, 2e5 years was the most common time frame. Subjective outcomes, including respiratory distress, nighttime snoring or apneic episodes were mentioned in all studies. Mostly, data was gathered through parent and clinician report of respiratory features observed during the pre- and post-operative period. Positive results were reported in most cases.
Adverse outcomes All articles meeting criteria for the systematic review were screened for adverse outcomes. No significant intraoperative complications were reported. Post-operative complications were divided into severe and non-severe categories. Severe complications included meningitis (2 patients), cerebrospinal fluid leak (13 patients), unplanned tracheostomy (3 patients), and superficial abscesses requiring incision and drainage (3 patients). One death was reported 9 months post-operatively which occurred immediately following a tracheal reconstruction procedure, and was seemingly unrelated to the original craniofacial procedure. Non-severe complications were mostly transient and included local wound/pin-site infections (16 patients), asymmetric/incomplete advancements (10 patients), external frame slip/device dissemblance (7 patients), transient trismus (8 patients), and transient velopharyngeal insufficiency/hypernasality (6 patients). Other rare adverse
Please cite this article in press as: Taylor BA, et al., Upper airway outcomes following midface distraction osteogenesis: A systematic review, Journal of Plastic, Reconstructive & Aesthetic Surgery (2014), http://dx.doi.org/10.1016/j.bjps.2014.02.013
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Upper airway outcomes following midface distraction osteogenesis Table 1
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Characteristics of studies included in the systematic review.
Study
Country
Quality score
Study design
N
Patient characteristics
Objective outcomes
Fearon, 200514
United States
5
Case series
41
Cephalometry Polysomnography Decannulation
Cedars, 199913
United States
4
Case series
14
Ettinger, 201123
United States
4
Case series
12
Nelson, 200816
United States
3
Case series
18
Xu, 200919
China
3
Case series
11
Mathijssen, 200615
France
4
Case series
17
Bradley, 200817
United States
4
Case series
13
Ponniah, 200818
United States
4
Case series
10
Flores, 200920
United States
4
Case series
20
Age: mean 8 years, range 3e16 years Sex: unspecified Indications: craniofacial dysostosis with midface retrusion Intervention: subcranial Le Fort III osteotomies, external distractors Age: range 4 years and 1-month-12 years and 8 months Sex: unspecified Indications: craniofacial dysostosis, midfacial cleft Intervention: subcranial Le Fort III osteotomies, internal distractors Age: mean 8.6 years, range 4.6e17.8 years Sex: unspecified Indications: syndromic midface hypoplasia and sleep apnea Intervention: subcranial Le Fort III osteotomies, external distractors Age: mean 10.4 years, range 2.7e17.4 years Sex: 11 males; 7 females Indications: syndromic bilateral coronal synostosis with midface hypoplasia Intervention: subcranial Le Fort III osteotomies, internal and external distractors Age: mean 10.2 years, range 5e16 years Sex: unspecified Indications: syndromic craniosynostosis with midface retrusion Intervention: Le Fort III osteotomies, external distractors (5 had monobloc procedure) Age: mean 6 years, range 4 monthse18 years Sex: unspecified Indications: faciocraniosynostosis and associated midface retrusion Intervention: Le Fort III osteotomies, external distractors Age: mean 8.6 years, range 5e15 years Sex: unspecified Indications: syndromic craniosynostosis Intervention: combined facial bipartition and monobloc distraction Age: mean 9 years, range 4 monthse15 years Sex: unspecified Indications: syndromic craniosynostosis Intervention: 3 monobloc, 7 facial bipartition Age: mean 5.7 years, range 3e12 years Sex: 10 males; 10 females Indications: syndromic craniosynostosis with midface hypoplasia Intervention: subcranial Le Fort III osteotomies; external distractors
Cephalometry Polysomnography Decannulation
Polysomnography Quantitative computed tomography
Decannulation Cephalometry Polysomnography
Polysomnography Quantitative computed tomography (volumetric assessment)
Decannulation
Cephalometry
Quantitative computed tomography
Cephalometry Decannulation Polysomnography Quantitative computed tomography (volumetric analysis) (continued on next page)
Please cite this article in press as: Taylor BA, et al., Upper airway outcomes following midface distraction osteogenesis: A systematic review, Journal of Plastic, Reconstructive & Aesthetic Surgery (2014), http://dx.doi.org/10.1016/j.bjps.2014.02.013
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B.A. Taylor et al. Table 1 (continued ) Study
Country
Quality score
Study design
N
Patient characteristics
Objective outcomes
Nout, 201021
United States
4
Case Series
19
Computed tomography Cephalometry Polysomnography
Mitsukawa, 201022
Japan
3
Case series
5
Meling, 200424
Norway
3
Case series
4
Ko, 201225
Taiwan
3
Case series
5
Ahmad, 201226
United Kingdom
4
Case series
12
Nout, 201227
United States
4
Case Series
10
Cohen, 199928
United States
1
Case Series
5
Age: mean 14.6 years Sex: 9 males, 10 females Indications: syndromic craniosynostosis Intervention: LeFort III distraction osteogenesis (18); LeFort II osteotomy (1) Age: mean 18.4 months, range 7 months-2 years Sex: 2 males; 3 females Indications: syndromic craniosynostosis with obstructive respiratory disorders Intervention: Le Fort III osteotomy; transfacial pinning system (3 had frontoorbital distraction simultaneously) Age: range 17 months-15 years Sex: 2 males; 2 females Indications: syndromic craniosynostosis with midface retrusion and severe respiratory obstruction or exophthalmos Intervention: monobloc distraction; internal distractors Age: mean 9.4 years, range 4.8e18.4 years Sex: 3 males; 2 females Indications: syndromic craniosynostosis with midface retrusion Intervention: monobloc distraction; external distractors Age: mean 18 months, range 4e30 months Sex: unspecified Indications: syndromic craniosynostosis with multiple functional problems Intervention: monobloc distraction; external distractors Age: mean 12.9 years, range 1.5e23.2 years Sex: unspecified Indications: syndromic craniosynostosis Intervention: 9 LeFort III osteotomies (5 had Monobloc procedure), 1 LeFort I Age: range 9 months- 5 years Sex: 1 male, 4 females Indications: syndromic craniosynostosis with multiple functional problems Intervention: Monobloc (3), monobloc with facial bipartition (2)
outcomes included scarring, corneal abrasion, poor pain control, hyperacusis, maxillary sinusitis, transient enophthalmos, and temporalis wasting (13 patients).
Discussion Results of midface DO procedures encountered in this review indicate that most patients had subjective improvements in symptoms of respiratory distress, nighttime snoring and apneic episodes. However, most studies relied
Polysomnography Cephalometry
Decannulation
Cephalometry Quantitative computed tomography
Computed tomography Decannulation Polysomnography
Quantitative computed tomography (volumetric analysis) Decannulation Polysomnography Decannulation
on subjective parental reporting of respiratory and sleeprelated symptoms, introducing a significant potential bias. There was no standardized duration of observation, which may affect reported outcomes since relapse has been reported in the past. Polysomnographic results were compared pre- and postoperatively in 9 studies. Overall, improvements or normalization of sleep apnea was reported in most patients. However, the specific timing of post-operative polysomnography was only available in 2 studies, which varied between 6 and 18 months. Therefore, we cannot comment
Please cite this article in press as: Taylor BA, et al., Upper airway outcomes following midface distraction osteogenesis: A systematic review, Journal of Plastic, Reconstructive & Aesthetic Surgery (2014), http://dx.doi.org/10.1016/j.bjps.2014.02.013
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Upper airway outcomes following midface distraction osteogenesis Table 2
Polysomnographic outcomes.
Study
N
Polysomnographic outcomes
Fearon14
12
Mean respiratory disturbance index Preoperative: 23.45 Postoperative: 10.99 P Z 0.004 Mean minimum oxygen saturation 80.39% 89.00% P Z 0.006 2 tracheostomy patients had “substantial falls” in their oxygen saturations when capped 3 had initial improvement in their end-tidal CO2 levels; 2 had partial return of OSA on testing at 2.5 years but remained off BiPAP Mean apnea hypopnea index Preoperative: 20.7 (range, 5.7e51.3) Postoperative: 9.5 (range, 2.1e22.7) 8 had improved apnea hypopnea index 4 no improvement or worsened apnea hypopnea index Mean respiratory distress index Preoperative: 33.4 37.57 (range, 1.8e109.2) Postoperative: 12.6 26.32 (range, 0.00e72.0) P < 0.05 Mean apnea hypopnea index Preoperative: 30 and 14.4 Postoperative: 4.4 and 1.1, respectively
Cedars et al.13
Ettinger et al.23
5
12
Nelson et al.16
18
Xu et al.19
2
Improved average and lowest O2 levels Flores et al.20
3
Nout et al.21
4
Mitsukawa et al.22
2
Nout et al.27
10
Preoperative: 3 severe apnea (respiratory distress index>10) Postoperative: 2 moderate apnea (respiratory distress index 5e10) and 1 mild apnea (respiratory distress index 2e5) Post-operative polysomnography showed significant improvement in OSA in 4/4 patients One of which had complete resolution of symptoms while 3 retained mild residual OSA Mean apnea hypopnea index Preoperative: 23.6 and 17.7 Postoperative: 1.7 and 0.8, respectively Mean apnea hypopnea index Preoperative: 38 (range 8e66) Postoperative: 6.42 (range 0.5e26) Oxygen desaturation index Preoperative: 21.91 (range 1.5e56) Postoperative: 5.84 (range 0e8.5) (continued on next page)
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Table 2 (continued ) Study
N
Polysomnographic outcomes Post-operative polysomnography showed improvement of OSA in 6/10 patients Two had complete resolution of symptoms while 4 remained symptomatic to a lesser extent
OSA: obstructive sleep apnea; BiPAP: bi-level positive airway pressure.
on the persistence of these positive results as no long-term data is available. Also, the definition of apnea and hypopnea was not available in most studies. This is especially important to define in pediatric sleep studies, since
Table 3 Study
Cephalometric outcomes. N Cephalometric outcomes (means)
41 SNA angle increased from 70 to 87 Point A advanced 17 mm Upper incisal edge advanced 18 mm 6 Early postoperative (1 week to 4 months) Cedars Point A advanced 14 mm (9e19.5 mm) et al.13 Orbitale advanced 15 mm (12e20.5 mm) Late postoperative (12 to 25 months) Point A advanced 0.5 mm (0e2 mm) Orbitale retruded 1 mm (3.5e0.5 mm) 18 Midface advanced (incisal edge) Nelson 20.5 7.4 mm (range, 10e30 mm) et al.16 13 Midface horizontal advancement Bradley (mean): 14 1 mm et al.17 Maxillary horizontal advancement (mean) 13 1 mm Xu et al.19 11 Midface advanced 20.27 8.04 mm Point A-nasion-point B (ANB) angle increased from 3.47 3.60 to 7.16 3.41 Flores 20 Point A advanced 16.2 mm (range, et al.20 6.2e26.1 mm; SD, 5.64) Velar angle increased from 121 to 148 , P < 0.001 Nasopharyngeal space increased from 3.9 to 13.0 mm, P < 0.001 Velopharyngeal space increased from 2.0 to 5.9 mm, P < 0.01 19 Horizontal advancement (point A) Nout 13.2 4.7 mm et al.21 Vertical advancement (Sella) 6.7 4.6 mm SNA angle 12.4 5.4 Mitsukawa 2 Area of upper face (cm2) et al.22 Patient 1: 15.8 to 24.6 (43% increase) Patient 2: 24.1 to 35.8 (48.5% increase) Ko et al.25 5 Supraorbital region advanced 15.3 mm Orbitale advanced 17.7 mm Anterial nasal spine advanced 22.1 mm Point A advanced 23.1 mm Fearon
14
Abbreviations: SNA, sella-nasion-subspinale; SD, standard deviation.
Please cite this article in press as: Taylor BA, et al., Upper airway outcomes following midface distraction osteogenesis: A systematic review, Journal of Plastic, Reconstructive & Aesthetic Surgery (2014), http://dx.doi.org/10.1016/j.bjps.2014.02.013
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B.A. Taylor et al. Table 4
Decannulation rates and other clinical outcomes.
Study
N 14
Fearon Cedars et al.13 Meling et al.24
3 2 4
Nelson et al.16
18
Mathijssen et al.15
17
Flores et al.20
10
Ahmad et al.26 Nout et al.27 Cohen et al.28
9 3 2
Clinical outcomes 2 of 3 decannulated 1 of 2 decannulated 3 of 4 decannulated All 4 had cessation of preoperative respiratory problems and improved sleep quality 5 of 6 decannulated 6 of 9 no longer required continuous or bilevel positive airway pressure 4 of 7 decannulated 1 with mild and 1 with severe respiratory impairments improved postoperatively 1 of 2 decannulated 9 of 10 patients with significant airway compromise improved 6 of 9 decannulated 1 of 3 decannulated 2 of 2 decannulated
controversy still exists regarding what should be considered “normal sleep” in children.30 Finally, there were no studies that assessed daytime features related to OSA. Regarding the actual polysomnography testing, lack of descriptive details was noted in all but 1 study. For instance, there was no mention of who scored the sleep study results (e.g. certified sleep specialist) and whether the tests were conducted in an accredited sleep lab. Future studies of midface DO procedures would benefit from standardization of follow-up times, polysomnography procedures and clearly defined definitions of apnea and hypopnea to permit direct comparisons between studies. Post-operative decannulation was successful in 65.7% of patients who required a tracheostomy. Decision to decannulate was based on post-operative improvements or normalization of polysomnography with a capped tracheostomy in 5 studies. The remaining articles did not describe how the decision to decannulate was made. The most common follow-up time was between 2 and 5 years postoperatively, and no studies described delayed failures requiring repeat tracheostomies. However, it is difficult to comment on the possibility of late post-operative failures, due to limited longitudinal follow-up times in some studies. Imaging analysis typically involved cephalometry, with few studies reporting 3-dimensional volumetric outcomes with CT images. Although similar, each study used a unique method of measurement, preventing direct comparison of the results. Thus, it is difficult to reliably condense the results produced by the various imaging modalities used. Overall, there was an increase in cephalometric and CT volumetric dimensions in all reviewed studies. Yet, the timing of post-operative imaging was not uniform and was
unspecified in some studies. Future studies would benefit from the use of standardized measurements and timing of post-operative imaging.
Conclusion Midface DO is an important tool in the armamentarium of the craniofacial reconstructive surgeon but long-term outcome is lacking regarding the success and complication rates for these procedures. Most studies included in this review reported improved airway and respiratory status in patients post-midface DO, based on polysomnography, cephalometry, decannulation rates, and imaging studies. Yet, majority of the studies were small case series, which inherently lacked statistical validity. Unfortunately, the lack of standardization of protocols, follow-up, and outcome measures makes comparisons between studies impossible. Further, in cases where patients did not improve, details were lacking. A prospective multicenter cohort trial with standardized distraction protocols, clearly defined and consistent outcome measures is required to fully elucidate the long-term outcomes of midface DO. Of particular promise is objective quantitative measure, such as volumetric analysis by 3-dimensional CT. This modality offers precise documentation of airway changes and may be standardized between centres, making it an important emerging tool for midface DO patient follow-up.
Funding None.
Conflicts of interest None.
References 1. Codvilla A. On the means of lengthening in the lower limbs, the muscles and tissues which are shortened through deformity. Am J Orthop Surg 1905;2:353e69. 2. Ilizarov GA. Basic principles of transosseous compression and distraction osteosynthesis. Orthop Traumatol Protez 1971;32: 7e9. 3. Ilizarov GA. The principles of the Ilizarov method. Bull Hosp Jt Dis Orthop Inst 1988;48:1e12. 4. Snyder CC, Levine GA, Swanson HM, Browne EZ. Mandibular lengthening by gradual distraction: preliminary report. Plast Reconstr Surg 1973;51:506e8. 5. McCarthy JG, Schrieber J, Karp N, Thorne CH, Grayson BH. Lengthening of the human mandible by gradual distraction. Plast Reconstr Surg 1992;89:1e12. 6. Hong P. A clinical narrative review of mandibular distraction osteogenesis in neonates with Pierre Robin sequence. Int J Pediatr Otorhinolaryngol 2011;75:985e91. 7. Swibel Rosenthal LH, Caballero N, Drake AF. Otolaryngologic manifestations of craniofacial syndromes. Otolaryngol Clin North Am 2012;45:557e77. 8. Hopper RA. New trends in cranio-orbital and midface distraction for craniofacial dysostosis. Curr Opin Otolaryngol Head Neck Surg 2012;20:298e303.
Please cite this article in press as: Taylor BA, et al., Upper airway outcomes following midface distraction osteogenesis: A systematic review, Journal of Plastic, Reconstructive & Aesthetic Surgery (2014), http://dx.doi.org/10.1016/j.bjps.2014.02.013
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Upper airway outcomes following midface distraction osteogenesis 9. Ow AT, Cheung LK. Meta-analysis of mandibular distraction osteogenesis: clinical applications and functional outcomes. Plast Reconstr Surg 2008;121:54ee69e. 10. Hong P, Brake MK, Cavanagh JP, Bezuhly M, Magit AE. Feeding and mandibular distraction osteogenesis in children with Pierre Robin sequence: a case series of functional outcomes. Int J Pediatr Otorhinolaryngol 2012;76:414e8. 11. Hong P, McNeil M, Kearns DB, Magit AE. Mandibular distraction osteogenesis in children with Pierre Robin sequence: impact on health-related quality of life. Int J Pediatr Otorhinolaryngol 2012;76:1159e63. 12. OCEBM Levels of Evidence Working Group. The oxford levels of evidence http://www.cebm.net/mod_product/design/files/ CEBM-Levels-of-Evidence-2.1.pdf; 2011 [accessed 26.10.12]. 13. Cedars MG, Linck DL, Chin M, Toth BA. Advancement of the midface using distraction techniques. Plast Reconstr Surg 1999;103:429e41. 14. Fearon JA. Halo distraction of the Le Fort III in syndromic craniosynostosis: a long-term assessment. Plast Recontr Surg 2005;115:1524e36. 15. Mathijssen I, Arnaud E, Marchac D, et al. Respiratory outcome of mid-face advancement with distraction: a comparison between Le Fort III and frontofacial monobloc. J Craniofac Surg 2006;17:880e2. 16. Nelson TE, Mulliken JB, Padwa BL. Effect of midfacial distraction on the obstructed airway in patients with syndromic bilateral coronal synostosis. J Oral Maxillofac Surg 2008;66:2318e21. 17. Bradley JP, Levitt A, Nguyen J, et al. Roman arch, keystone fixation for facial bipartition with monobloc distraction. Plast Reconstr Surg 2009;122:1514e23. 18. Ponniah AJT, Witherow H, Richards R, Evans R, Hayward R, Dunaway D. Three-dimensional image analysis of facial skeletal changes after monobloc and bipartition distraction. Plast Reconstr Surg 2008;122:225e31. 19. Xu H, Yy Z, Mu X. The assessment of midface distraction osteogenesis in treatment of upper airway obstruction. J Craniofac Surg 2009;20:1876e81. 20. Flores RL, Shetye PR, Zeitler D, et al. Airway changes following Le Fort III distraction osteogenesis for syndromic
21.
22.
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25.
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27.
28.
29.
30.
9 craniosynostosis: a clinical and cephalometric study. Plast Reconstr Surg 2009;124:590e601. Nout E, Bouw FP, Veenland JF, et al. Three-dimensional airway changes after LeFort III advancement in syndromic craniosynostosis patients. Plast Reconstr Surg 2010;126:564e71. Mitsukawa N, Satoh K. Midfacial distraction using a transfacial pinning technique for syndromic craniosynostosis with obstructive respiratory disorders. J Plast Reconstr Aesthet Surg 2010;63:1990e4. Ettinger RE, Hopper RA, Sandercoe G, et al. Quantitative computed tomographic scan and polysomnographic analysis of patients with syndromic midface hypoplasia before and after Le Fort III distraction advancement. Plast Reconstr Surg 2011; 127:1612e9. Meling TR, Due-Tønnessen BJ, Høgevold HE, Skjelbred P, Arctander K. Monobloc distraction osteoegenesis in pediatric patients with severe syndromal craniosynostosis. J Craniofac Surg 2004;15:990e1000. Ko EW-C, Chen PK-T, Tai IC-H, Huang CS. Fronto-facial monobloc distraction in syndromic craniosynostosis. Threedimensional evaluation of treatment outcome and facial growth. Int J Oral Maxillofac Surg 2012;41:20e7. Ahmad F, Cobb ARM, Mills C, Jones BM, Hayward RD, Dunaway DJ. Frontofacial monobloc distraction in the very young: a review of 12 consecutive cases. Plast Reconstr Surg 2012;129:488ee97e. Nout E, Bannink N, Koudstaal MJ, et al. Upper airway changes in syndromic craniosynostosis patients following midface or monobloc advancement: correlation between volume changes and respiratory outcome. J Craniomaxillofac Surg 2012;40: 209e14. Cohen SR, Boydston W, Hudgins R, Burstein FD. Monobloc and facial biparpartition distraction with internal devices. J Craniofac Surg 1999;10:244e51. Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group. Preferred reporting items for systematic reviews and metaanalyses: the PRISMA statement. PLoS Med 2009;6:e1000097. Hara Y, Noda A, Miyata S, et al. Comparison of oxygen desaturation patterns in children and adults with sleep-disordered breathing. Am J Otolaryngol 2013;34(5):537e40.
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Journal of Plastic, Reconstructive & Aesthetic Surgery (2014) xx, 1e9
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Upper airway outcomes following midface distraction osteogenesis: A systematic review B.A. Taylor a, M. Brace a,*, P. Hong a,b a IWK Health Centre, Dalhousie Pediatric Craniofacial Group, Department of Surgery, Dalhousie University, Halifax, Nova Scotia, Canada b School of Human Communication Disorders, Dalhousie University, Halifax, Nova Scotia, Canada
Received 16 May 2013; accepted 5 February 2014
KEYWORDS Distraction osteogenesis; Le Fort III osteotomy; Upper airway obstruction; Functional outcomes
Summary The objective of this paper is to systematically review the airway outcomes following distraction osteogenesis of midface with the goal of (1) deriving clinically oriented insights and (2) identifying gaps in knowledge to stimulate future research. Medline, EMBASE and Cochrane databases were searched and studies were included if subjects of any age had midface retrusion/hypoplasia and underwent midface distraction osteogenesis. Outcome measures of interest were any respiratory or airway associated measures, and reports of adverse events. A total of 368 abstracts were generated from the literature searches; 16 studies met the criteria for data extraction and analysis. All 16 studies were observational. Generally, midface distraction osteogenesis was reported to improve respiratory status and was well tolerated. Specifically, favorable outcomes in cephalometry (9 studies), polysomnography (9 studies), and decannulation rates (8 studies) were reported. In conclusion, upper airway status was improved in most patients who underwent midface distraction osteogenesis, yet long-term results and consistent objective measures are lacking. Studies reviewed were retrospective case series and details regarding patients who did not improve were deficient. A standardized prospective multicenter cohort trial with long-term patient follow up is required. ª 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
* Corresponding author. IWK Health Centre, 5850/5980 University Avenue, PO Box 9700, Halifax, Nova Scotia B3K 6R8, Canada. Tel.: þ1 (902) 470 0841; fax: þ1 (902) 470 8041. E-mail address: [email protected] (M. Brace). http://dx.doi.org/10.1016/j.bjps.2014.02.013 1748-6815/ª 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
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Introduction Distraction osteogenesis (DO) was initially described by Codvilla in the early 20th century1 and subsequently popularized by Ilizarov in the 1940s.2,3 Yet, it was not until the 1970s that DO was applied to the craniofacial skeleton, first in a canine model.4 Few years later, McCarthy and colleagues described clinical results of DO for patients with congenital mandibular deformities.5 Since then DO of the craniofacial skeleton has become widely accepted and practiced in many craniofacial centres.6 Upper airway obstruction and obstructive sleep apnea (OSA) is very common in patients with craniofacial disorders and the management of these problems requires a multidisciplinary approach.6 The specific cause of airway compromise may be multifactorial but for those patients with midface retrusion, there can be narrowing of the pharyngeal airways, resulting in obstruction when postural muscles relax during sleep.7 Midface DO is a relatively new surgical procedure typically performed to relieve the upper airway obstruction at the level of the nasopharynx and velopharynx. Conceptually, this procedure would increase the restricted airway space, thereby reducing the obstructive respiratory problems and obstructive sleep apnea (OSA).8 Other indications include exorbitism, malocclusion and cosmetic concerns, but these are considered secondary to upper airway obstruction and OSA. Functional outcomes in DO have been reported mostly in cases that involve the mandible. Specifically, DO of the mandible has been shown to improve upper airway obstruction,6,9 feeding,10 and health-related quality of life.11 However, much less has been reported in regards to functional outcomes post-midface DO. The purpose of this systematic review was to consider original articles reporting on upper airway changes in patients following midface DO. These studies evaluate the airway through a number of different measures including polysomnography, decannulation rates, imaging analysis, and subjective changes. This review aims to aid clinicians and patients considering midface DO by providing a comprehensive appraisal of airway outcomes as reported currently in the literature.
Methods The authors formulated the research question for this study using the Population, Intervention, Comparison, and Outcome (PICO) research question guideline: Populationindividuals with midface hypoplasia/retrusion; Intervention-LeFort II or LeFort III osteotomy with DO; Comparison-pre- and post-operative airway status; and Outcomes-subjective and objective respiratory clinical observations, polysomnography, decannulation rates, and imaging analysis.
B.A. Taylor et al. which included these terms: “Distraction Osteogenesis”, “Airway”, “Airway Obstruction”, “Obstructive Sleep Apnea”, “Breathing” and “Respiration” (Figure 1). All titles and abstracts resulting from the aforementioned search strategy were obtained.
Inclusion/exclusion criteria Studies that included upper airway outcomes in subjects with midface hypoplasia/retrusion who underwent midface DO were included in the review. Patients who underwent facial bipartitions were also included. Both external and internal distractor devices were accepted. Studies that involved trials of novel osteotomies or other surgical techniques were excluded. LeFort I and maxillary advancements in patients with cleft lip and palate were also excluded. Finally, studies with duplicate patients were excluded. Studies were required to meet Oxford Center for Evidence Based Medicine Level 4 or above.12 This included case series, case-control studies, cohort studies, and randomized control trials. Inclusion criteria also included studies with any subjective and/or objective airway outcomes. Only articles in English language were included. A list of titles and abstracts was generated from articles meeting the aforementioned criteria. Two of the authors independently screened the list, selecting pertinent articles for further review, involving the third author when there were conflicts. Full texts were obtained and further evaluated against inclusion criteria. This included hand searching of the references of individual full reviewed articles.
Data extraction and analysis Data were extracted from the studies meeting criteria for inclusion. The following data were extracted: study design, number of subjects, subject demographics (age, gender, syndromes) description of intervention, and outcome measures. For quantitative outcome measures, mean values, standard deviations, confidence intervals, and/or P values were recorded; data were synthesized into tables when methodologies were similar enough to allow it. The authors assessed the quality of the studies with the use of a Quality Assessment Score out of 7 possible points comprised of the following characteristics: 1) inclusion/ exclusion criteria clearly stated (yes Z 1, no Z 0); 2) assessment method validated (yes Z 1, no Z 0); 3) appropriate comparison group (intra-subject Z 1, no Z 0); 4) observers blinded to condition/treatment (yes Z 1, no Z 0); 5) adequate sample size/power analysis (yes Z 1, no Z 0); 6) well-defined, consecutive sample (yes Z 1, no Z 0); and 7) less than 5% lost to follow-up (yes Z 1, no or not provided Z 0).
Results
Literature search strategy Study selection The following databases were searched: EMBASE (1974 to August 26, 2013), MEDLINE (1966 to August 26, 2013), and Cochrane library using a comprehensive search strategy,
A total of 368 titles/abstracts were recovered from the comprehensive search of the online databases. After
Please cite this article in press as: Taylor BA, et al., Upper airway outcomes following midface distraction osteogenesis: A systematic review, Journal of Plastic, Reconstructive & Aesthetic Surgery (2014), http://dx.doi.org/10.1016/j.bjps.2014.02.013
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Upper airway outcomes following midface distraction osteogenesis
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MEDLINE/PubMed Run August 26, 2013 Search Strategy: "osteogenesis, distraction"[MeSH Terms] OR ("osteogenesis"[tiab] AND "distraction"[tiab]) OR "distraction osteogenesis"[tiab] OR ("distraction"[tiab] AND "osteogenesis"[tiab]) Airway*[tiab] OR ("Airway Resistance"[Mesh]) OR "obstructive sleep apnoea"[All Fields] OR "sleep apnea, obstructive"[MeSH Terms] OR ("sleep"[All Fields] AND "apnea"[All Fields] AND "obstructive"[All Fields]) OR "obstructive sleep apnea"[All Fields] OR ("obstructive"[All Fields] AND "sleep"[All Fields] AND "apnea"[All Fields]) OR (airway complications[tiab]) OR (airway obstruction[tiab]) OR ("Airway Obstruction"[MeSH]) OR (breathing[MeSH]) OR (breathe[tiab]) OR (respiration[tiab]) OR (resp[tiab]) #1 AND #2 EMBASE Run September 26, 2012 Search Strategy: 1. exp "distraction osteogenesis" OR (exp "osteogenesis" AND "distraction") 2. exp "airway resistance" OR "exp airway obstruction" OR (exp "airway" AND exp "obstruction") OR exp "airway" OR (exp "airway" AND "complications") OR exp "sleep apnea syndrome" OR ("obstructive" AND exp "sleep" AND exp "apnea") OR exp “breathing” OR exp “breathe” OR “resp” OR exp “respiration”. 3. #1 AND #2 Cochrane Library Run September 26, 2012 Search Strategy: 1. MeSH descriptor: [Osteogenesis, Distraction] explode all trees OR ("osteogenesis" and "distraction") OR "distraction osteogenesis" 2. "airway" OR "obstruction" OR "airway obstruction" OR "airway resistance" OR "apnea" OR "sleep" OR "sleep apnea" OR "obstructive" OR ("obstructive" AND "sleep" AND "apnea") OR “breathing” OR “breathe” OR “resp” OR “respiration” 3. #1 AND #2 Figure 1
Details of search terms used in the systematic literature review.
screening, 23 met criteria for full article review. The remaining abstracts were rejected mainly because they did not include airway outcomes in their analyses. Full article review yielded 16 studies meeting inclusion criteria.13e26 A flow diagram adopted from Moher et al.29 depicts search, screening and exclusion processes (Figure 2).
Study characteristics Data extraction and analysis were performed as outlined above. All articles reported subjective outcomes, which were mostly based on caregiver observation of snoring and/or apneic episodes. Objective airway outcomes were described as follows: cephalometry in 9 studies,13,14,16,17,19e22,25 polysomnography in 9 studies,13,14,16,19e23,27 quantitative computed tomography in 7 studies,18e21,23,25e27 and decannulation rates in 9 studies.13e16,20,24,26e28 There were 210 patients who underwent midface DO procedures. Subcranial Le Fort III osteotomy with application of external distractor device was the most common procedure, followed by monobloc DO with external device. Subjects ranged in age from 4 months to 23.2 years and all patients had syndromic craniosynostosis with midface retrusion/hypoplasia. All studies encountered were case series. Study characteristics, along with individual study Quality Assessment Scores, are summarized in Table 1.
Polysomnographic outcomes Pre- and post-operative polysomnography was reported in 67 patients, and most demonstrated improvements postmidface DO. However, raw data was not available in most studies (only mean data) and some studies reported patients with no improvements.23 Furthermore, although apnea-hypopnea index (respiratory distress index) was reported in 7 of 9 studies, the exact definition of apnea or hypopnea was not mentioned. Time of follow-up also varied (2 studies) or was not reported. Polysomnographic outcomes are summarized in Table 2.
Cephalometric outcomes Cephalometric outcomes (Table 3) were reported in 135 patients. The images were compared pre- and postoperatively and measured from a number of standard and non-standard reference points. Commonly, Point A measurements (the most posterior point on the maxilla below the level of the anterior nasal spine), which were reported in 5 studies (78 patients), demonstrated a mean increase of 16.49 mm, following midface DO procedures. The upper incisal edge was also a common point of reference and was measured in 4 studies. The mean increase in distance of this measurement was calculated to be 18.47 mm. Finally, the
Please cite this article in press as: Taylor BA, et al., Upper airway outcomes following midface distraction osteogenesis: A systematic review, Journal of Plastic, Reconstructive & Aesthetic Surgery (2014), http://dx.doi.org/10.1016/j.bjps.2014.02.013
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B.A. Taylor et al.
Records identified through database searching (n = 360)
Screening
Identification
4
Additional records identified by hand searching bibliographies (n = 8)
Abstracts screened (n = 368)
Eligibility
Full-text articles assessed for eligibility (n = 23)
Records excluded (n = 345)
Studies excluded, with reasons (n = 7) Non-LeFort III (1) No distraction (1) Combined procedures (3) No outcomes (2)
Included
Studies with airway outcomes (n = 16)
Figure 2
Flow diagram of article selection process.
SNA angle, which describes the angular vector between the sella, nasion, and Point A, was reported in 6 studies totaling 120 patients. The mean increase in the SNA angle was 18 . Volumetric analysis based on cephalometric data was quantitatively reported in 4 studies. Ko et al. reported an increase in mean upper airway volume of 16.64 cm3 (85%),25 and Xu et al. reported an increase of 9.13 mL (64.30%) postoperatively.19 Nout et al. reported an increase in mean upper airway volume by 37.4 20.7%21 and an increase in mean upper airway volume by 29.26%.27
Computed tomography Seven studies used computed tomography (CT) images for post-midface DO analysis.18e21,23,25e27 Three studies used reconstructed sagittal CT images to report standard cephalometric measurements,23,26 while 5 studies used 3dimensional reconstructions and volumetric analysis using computer software programs.19e21,25,27 All studies reported an increase in upper airway volume at the level of the nasopharynx and/or velopharynx.
Decannulation rates and other clinical outcomes Post-operative decannulation rates were included in 9 articles (Table 4). Of the 38 patients who had a tracheostomy, 25 (65.7%) were safely decannulated after undergoing midface DO. All patients remained decannulated at least until the time of study completion. Reported follow-up
times ranged from 6 months to lifetime, however, 2e5 years was the most common time frame. Subjective outcomes, including respiratory distress, nighttime snoring or apneic episodes were mentioned in all studies. Mostly, data was gathered through parent and clinician report of respiratory features observed during the pre- and post-operative period. Positive results were reported in most cases.
Adverse outcomes All articles meeting criteria for the systematic review were screened for adverse outcomes. No significant intraoperative complications were reported. Post-operative complications were divided into severe and non-severe categories. Severe complications included meningitis (2 patients), cerebrospinal fluid leak (13 patients), unplanned tracheostomy (3 patients), and superficial abscesses requiring incision and drainage (3 patients). One death was reported 9 months post-operatively which occurred immediately following a tracheal reconstruction procedure, and was seemingly unrelated to the original craniofacial procedure. Non-severe complications were mostly transient and included local wound/pin-site infections (16 patients), asymmetric/incomplete advancements (10 patients), external frame slip/device dissemblance (7 patients), transient trismus (8 patients), and transient velopharyngeal insufficiency/hypernasality (6 patients). Other rare adverse
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Upper airway outcomes following midface distraction osteogenesis Table 1
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Characteristics of studies included in the systematic review.
Study
Country
Quality score
Study design
N
Patient characteristics
Objective outcomes
Fearon, 200514
United States
5
Case series
41
Cephalometry Polysomnography Decannulation
Cedars, 199913
United States
4
Case series
14
Ettinger, 201123
United States
4
Case series
12
Nelson, 200816
United States
3
Case series
18
Xu, 200919
China
3
Case series
11
Mathijssen, 200615
France
4
Case series
17
Bradley, 200817
United States
4
Case series
13
Ponniah, 200818
United States
4
Case series
10
Flores, 200920
United States
4
Case series
20
Age: mean 8 years, range 3e16 years Sex: unspecified Indications: craniofacial dysostosis with midface retrusion Intervention: subcranial Le Fort III osteotomies, external distractors Age: range 4 years and 1-month-12 years and 8 months Sex: unspecified Indications: craniofacial dysostosis, midfacial cleft Intervention: subcranial Le Fort III osteotomies, internal distractors Age: mean 8.6 years, range 4.6e17.8 years Sex: unspecified Indications: syndromic midface hypoplasia and sleep apnea Intervention: subcranial Le Fort III osteotomies, external distractors Age: mean 10.4 years, range 2.7e17.4 years Sex: 11 males; 7 females Indications: syndromic bilateral coronal synostosis with midface hypoplasia Intervention: subcranial Le Fort III osteotomies, internal and external distractors Age: mean 10.2 years, range 5e16 years Sex: unspecified Indications: syndromic craniosynostosis with midface retrusion Intervention: Le Fort III osteotomies, external distractors (5 had monobloc procedure) Age: mean 6 years, range 4 monthse18 years Sex: unspecified Indications: faciocraniosynostosis and associated midface retrusion Intervention: Le Fort III osteotomies, external distractors Age: mean 8.6 years, range 5e15 years Sex: unspecified Indications: syndromic craniosynostosis Intervention: combined facial bipartition and monobloc distraction Age: mean 9 years, range 4 monthse15 years Sex: unspecified Indications: syndromic craniosynostosis Intervention: 3 monobloc, 7 facial bipartition Age: mean 5.7 years, range 3e12 years Sex: 10 males; 10 females Indications: syndromic craniosynostosis with midface hypoplasia Intervention: subcranial Le Fort III osteotomies; external distractors
Cephalometry Polysomnography Decannulation
Polysomnography Quantitative computed tomography
Decannulation Cephalometry Polysomnography
Polysomnography Quantitative computed tomography (volumetric assessment)
Decannulation
Cephalometry
Quantitative computed tomography
Cephalometry Decannulation Polysomnography Quantitative computed tomography (volumetric analysis) (continued on next page)
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B.A. Taylor et al. Table 1 (continued ) Study
Country
Quality score
Study design
N
Patient characteristics
Objective outcomes
Nout, 201021
United States
4
Case Series
19
Computed tomography Cephalometry Polysomnography
Mitsukawa, 201022
Japan
3
Case series
5
Meling, 200424
Norway
3
Case series
4
Ko, 201225
Taiwan
3
Case series
5
Ahmad, 201226
United Kingdom
4
Case series
12
Nout, 201227
United States
4
Case Series
10
Cohen, 199928
United States
1
Case Series
5
Age: mean 14.6 years Sex: 9 males, 10 females Indications: syndromic craniosynostosis Intervention: LeFort III distraction osteogenesis (18); LeFort II osteotomy (1) Age: mean 18.4 months, range 7 months-2 years Sex: 2 males; 3 females Indications: syndromic craniosynostosis with obstructive respiratory disorders Intervention: Le Fort III osteotomy; transfacial pinning system (3 had frontoorbital distraction simultaneously) Age: range 17 months-15 years Sex: 2 males; 2 females Indications: syndromic craniosynostosis with midface retrusion and severe respiratory obstruction or exophthalmos Intervention: monobloc distraction; internal distractors Age: mean 9.4 years, range 4.8e18.4 years Sex: 3 males; 2 females Indications: syndromic craniosynostosis with midface retrusion Intervention: monobloc distraction; external distractors Age: mean 18 months, range 4e30 months Sex: unspecified Indications: syndromic craniosynostosis with multiple functional problems Intervention: monobloc distraction; external distractors Age: mean 12.9 years, range 1.5e23.2 years Sex: unspecified Indications: syndromic craniosynostosis Intervention: 9 LeFort III osteotomies (5 had Monobloc procedure), 1 LeFort I Age: range 9 months- 5 years Sex: 1 male, 4 females Indications: syndromic craniosynostosis with multiple functional problems Intervention: Monobloc (3), monobloc with facial bipartition (2)
outcomes included scarring, corneal abrasion, poor pain control, hyperacusis, maxillary sinusitis, transient enophthalmos, and temporalis wasting (13 patients).
Discussion Results of midface DO procedures encountered in this review indicate that most patients had subjective improvements in symptoms of respiratory distress, nighttime snoring and apneic episodes. However, most studies relied
Polysomnography Cephalometry
Decannulation
Cephalometry Quantitative computed tomography
Computed tomography Decannulation Polysomnography
Quantitative computed tomography (volumetric analysis) Decannulation Polysomnography Decannulation
on subjective parental reporting of respiratory and sleeprelated symptoms, introducing a significant potential bias. There was no standardized duration of observation, which may affect reported outcomes since relapse has been reported in the past. Polysomnographic results were compared pre- and postoperatively in 9 studies. Overall, improvements or normalization of sleep apnea was reported in most patients. However, the specific timing of post-operative polysomnography was only available in 2 studies, which varied between 6 and 18 months. Therefore, we cannot comment
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Upper airway outcomes following midface distraction osteogenesis Table 2
Polysomnographic outcomes.
Study
N
Polysomnographic outcomes
Fearon14
12
Mean respiratory disturbance index Preoperative: 23.45 Postoperative: 10.99 P Z 0.004 Mean minimum oxygen saturation 80.39% 89.00% P Z 0.006 2 tracheostomy patients had “substantial falls” in their oxygen saturations when capped 3 had initial improvement in their end-tidal CO2 levels; 2 had partial return of OSA on testing at 2.5 years but remained off BiPAP Mean apnea hypopnea index Preoperative: 20.7 (range, 5.7e51.3) Postoperative: 9.5 (range, 2.1e22.7) 8 had improved apnea hypopnea index 4 no improvement or worsened apnea hypopnea index Mean respiratory distress index Preoperative: 33.4 37.57 (range, 1.8e109.2) Postoperative: 12.6 26.32 (range, 0.00e72.0) P < 0.05 Mean apnea hypopnea index Preoperative: 30 and 14.4 Postoperative: 4.4 and 1.1, respectively
Cedars et al.13
Ettinger et al.23
5
12
Nelson et al.16
18
Xu et al.19
2
Improved average and lowest O2 levels Flores et al.20
3
Nout et al.21
4
Mitsukawa et al.22
2
Nout et al.27
10
Preoperative: 3 severe apnea (respiratory distress index>10) Postoperative: 2 moderate apnea (respiratory distress index 5e10) and 1 mild apnea (respiratory distress index 2e5) Post-operative polysomnography showed significant improvement in OSA in 4/4 patients One of which had complete resolution of symptoms while 3 retained mild residual OSA Mean apnea hypopnea index Preoperative: 23.6 and 17.7 Postoperative: 1.7 and 0.8, respectively Mean apnea hypopnea index Preoperative: 38 (range 8e66) Postoperative: 6.42 (range 0.5e26) Oxygen desaturation index Preoperative: 21.91 (range 1.5e56) Postoperative: 5.84 (range 0e8.5) (continued on next page)
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Table 2 (continued ) Study
N
Polysomnographic outcomes Post-operative polysomnography showed improvement of OSA in 6/10 patients Two had complete resolution of symptoms while 4 remained symptomatic to a lesser extent
OSA: obstructive sleep apnea; BiPAP: bi-level positive airway pressure.
on the persistence of these positive results as no long-term data is available. Also, the definition of apnea and hypopnea was not available in most studies. This is especially important to define in pediatric sleep studies, since
Table 3 Study
Cephalometric outcomes. N Cephalometric outcomes (means)
41 SNA angle increased from 70 to 87 Point A advanced 17 mm Upper incisal edge advanced 18 mm 6 Early postoperative (1 week to 4 months) Cedars Point A advanced 14 mm (9e19.5 mm) et al.13 Orbitale advanced 15 mm (12e20.5 mm) Late postoperative (12 to 25 months) Point A advanced 0.5 mm (0e2 mm) Orbitale retruded 1 mm (3.5e0.5 mm) 18 Midface advanced (incisal edge) Nelson 20.5 7.4 mm (range, 10e30 mm) et al.16 13 Midface horizontal advancement Bradley (mean): 14 1 mm et al.17 Maxillary horizontal advancement (mean) 13 1 mm Xu et al.19 11 Midface advanced 20.27 8.04 mm Point A-nasion-point B (ANB) angle increased from 3.47 3.60 to 7.16 3.41 Flores 20 Point A advanced 16.2 mm (range, et al.20 6.2e26.1 mm; SD, 5.64) Velar angle increased from 121 to 148 , P < 0.001 Nasopharyngeal space increased from 3.9 to 13.0 mm, P < 0.001 Velopharyngeal space increased from 2.0 to 5.9 mm, P < 0.01 19 Horizontal advancement (point A) Nout 13.2 4.7 mm et al.21 Vertical advancement (Sella) 6.7 4.6 mm SNA angle 12.4 5.4 Mitsukawa 2 Area of upper face (cm2) et al.22 Patient 1: 15.8 to 24.6 (43% increase) Patient 2: 24.1 to 35.8 (48.5% increase) Ko et al.25 5 Supraorbital region advanced 15.3 mm Orbitale advanced 17.7 mm Anterial nasal spine advanced 22.1 mm Point A advanced 23.1 mm Fearon
14
Abbreviations: SNA, sella-nasion-subspinale; SD, standard deviation.
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B.A. Taylor et al. Table 4
Decannulation rates and other clinical outcomes.
Study
N 14
Fearon Cedars et al.13 Meling et al.24
3 2 4
Nelson et al.16
18
Mathijssen et al.15
17
Flores et al.20
10
Ahmad et al.26 Nout et al.27 Cohen et al.28
9 3 2
Clinical outcomes 2 of 3 decannulated 1 of 2 decannulated 3 of 4 decannulated All 4 had cessation of preoperative respiratory problems and improved sleep quality 5 of 6 decannulated 6 of 9 no longer required continuous or bilevel positive airway pressure 4 of 7 decannulated 1 with mild and 1 with severe respiratory impairments improved postoperatively 1 of 2 decannulated 9 of 10 patients with significant airway compromise improved 6 of 9 decannulated 1 of 3 decannulated 2 of 2 decannulated
controversy still exists regarding what should be considered “normal sleep” in children.30 Finally, there were no studies that assessed daytime features related to OSA. Regarding the actual polysomnography testing, lack of descriptive details was noted in all but 1 study. For instance, there was no mention of who scored the sleep study results (e.g. certified sleep specialist) and whether the tests were conducted in an accredited sleep lab. Future studies of midface DO procedures would benefit from standardization of follow-up times, polysomnography procedures and clearly defined definitions of apnea and hypopnea to permit direct comparisons between studies. Post-operative decannulation was successful in 65.7% of patients who required a tracheostomy. Decision to decannulate was based on post-operative improvements or normalization of polysomnography with a capped tracheostomy in 5 studies. The remaining articles did not describe how the decision to decannulate was made. The most common follow-up time was between 2 and 5 years postoperatively, and no studies described delayed failures requiring repeat tracheostomies. However, it is difficult to comment on the possibility of late post-operative failures, due to limited longitudinal follow-up times in some studies. Imaging analysis typically involved cephalometry, with few studies reporting 3-dimensional volumetric outcomes with CT images. Although similar, each study used a unique method of measurement, preventing direct comparison of the results. Thus, it is difficult to reliably condense the results produced by the various imaging modalities used. Overall, there was an increase in cephalometric and CT volumetric dimensions in all reviewed studies. Yet, the timing of post-operative imaging was not uniform and was
unspecified in some studies. Future studies would benefit from the use of standardized measurements and timing of post-operative imaging.
Conclusion Midface DO is an important tool in the armamentarium of the craniofacial reconstructive surgeon but long-term outcome is lacking regarding the success and complication rates for these procedures. Most studies included in this review reported improved airway and respiratory status in patients post-midface DO, based on polysomnography, cephalometry, decannulation rates, and imaging studies. Yet, majority of the studies were small case series, which inherently lacked statistical validity. Unfortunately, the lack of standardization of protocols, follow-up, and outcome measures makes comparisons between studies impossible. Further, in cases where patients did not improve, details were lacking. A prospective multicenter cohort trial with standardized distraction protocols, clearly defined and consistent outcome measures is required to fully elucidate the long-term outcomes of midface DO. Of particular promise is objective quantitative measure, such as volumetric analysis by 3-dimensional CT. This modality offers precise documentation of airway changes and may be standardized between centres, making it an important emerging tool for midface DO patient follow-up.
Funding None.
Conflicts of interest None.
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