Keywords
obstructive sleep apnea syndrome - soft palate - obstructive sleep apnea hypopnea
syndrome - sleep-disordered breathing - nasopharyngeal diseases - sleep apnea syndromes
Introduction
Obstructive sleep apnea syndrome (OSAS) is a sleep disorder caused by an excessive
narrowing of the pharyngeal airway that collapses during inspiration, resulting in
increased negative intrathoracic pressure, which in turn exacerbates the condition.[1] The consequence of the collapse of the upper airway is the reduction of blood oxygenation;
for this reason, OSAS is considered a systemic disease, and over the last decades,
attention to persistent snoring, particularly when associated with apnea syndrome,
has hugely increased.[2] These obstructive respiratory events are typically associated with cortical arousals
and microdesaturation, which entail a fragmentation of sleep and an increase in the
activity of the sympathetic nervous system.[3] The prevalence of the disease is settled at ∼ 3–7%, and there are many factors that
makes people predisposed to develop this disorder, such as age, male gender, obesity,[4] family history, menopausal and craniofacial abnormalities, and habits such as smoking
cigarettes and abusing alcohol.[5] It can be considered a multisystem disease because poor oxygenation of the body
at night determines important repercussions on the whole organism. This disease also
affects children, and in most of cases it is related to adenotonsillar hypertrophy.[6] Several surgical techniques have been developed in recent years, including anterior
palatoplasty,[2] lateral pharyngoplasty,[7] and expansion sphincter pharyngoplasty.[8]
The purpose of the present study is to describe our surgical experience on modified
expansion sphincter pharyngoplasty (MESP) in upper airway multilevel surgery.
Material and Methods
A total of 20 patients with moderate to severe OSAS were recruited in our Ear Nose
and Throat (ENT) Department between September 2012 and February 2015. The sample consisted
of 19 men and 1 woman, with an average age of 50 years (mean: 25 ± 8 years). The selected
patients had an mean apnea-hypopnea index (AHI) of 40.9 ± 22.7. All of the enrolled
patients refused the ventilatory therapy with continuous positive airway pressure
(CPAP). We excluded patients with macroglossia, craniofacial abnormalities, and body
mass index (BMI) higher than 35.
All of the patients underwent an anamnestic data collection, with a subjective assessment
of the daytime sleepiness with the Epworth Sleepiness Scale (ESS), and a snoring assessment
with a 0–10 visual analogue scale (VAS; snoring: 0 = no snoring; 10 = maximum loudness
of snoring) administered to their bed partners.
The patients underwent a clinical evaluation, which included the collection of anthropometric
data (neck circumference, BMI), an ENT examination with rhinofibroscopy of the upper
airway to grade the obstruction with Müller maneuver, using the grading proposed by
Vicini.[9] This grading consists of the evaluation of the collapse at the nasal level (N),
the oropharyngeal level (O), and the hypopharyngeal level (H). It is a quantitative
evaluation of the collapse, in which 1 corresponds to lower than 25% of collapse;
2, from 25 to 50%; 3, from 50 to 75%; and 4, more than 75% of collapse. And we also
evaluated the dynamic pattern of the circular (c), transverse (t) and antero-posterior
(a-p) collapses.
From this evaluation we selected for MESP the patients with an oropharyngeal transverse
pattern of collapse.
These patients were subjected to an upper airway multilevel surgery. In our practice,
this consists of nasal, oropharyngeal and hyoid suspension surgeries.
In our surgical practice, in patients with nasal diseases such as significant deviation
of the nasal septum or polyposis, we preferred to anticipate the nasal surgery, followed
by the oropharyngeal and hypopharyngeal surgeries two or three months later. In patients
with relevant nasal obstruction we performed a multilevel surgery associating the
nasal surgery, just in case of turbinate hypertrophy, with submucosal radiofrequency
surgery without nasal packing, to prevent possible respiratory complications upon
awakening, or immediate post-operative complications.
The oropharyngeal surgery consists of a tonsillectomy if the patients have not already
been operated. The palatal surgery consists of an anterior palatoplasty[2] and MESP. The latter, unlike the original surgical intervention described by Pang,[8] does not enable the incision through the whole thickness of the palate, where a
pocket is created, in which a portion of the palatopharyngeus muscle, which is not
completely dissected, is fixed to the pterygoid hamulus. The hypopharyngeal surgery
consists of a hyoid bone suspension.[10]
The follow-up was performed three months after the multilevel surgery.
For the descriptive statistics, the results were expressed as absolute and relative
frequencies for the categorical variables, or as the mean ± standard deviation (SD)
for the continuous variables. A comparison of the quantitative variables between pre
and postoperative was performed using the Student t-test. All tests were two-sided, and values of p < 0.05 were considered statistically significant. The statistical analyses were performed
using the Microsoft Excel 2003 (Microsoft Corporation, Redmond, WA, US) software and
imported into the R-project (R Foundation for Statistical Computing, Vienna, Austria)
software, version 2.15.2.
Results
All of the patients had a history of snoring associated with apnea, and, in most of
cases, also with frequent arousal and sudden awakening. A total of 7 patients were
undergoing pharmacological treatment for hypertension, 2 patients had major vessel
atherosclerosis, and 2 other patients had a history of mild depressive anxiety disorder.
In total, 3 patients were smokers, 3 were former smokers, and none normally drank
alcohol. Respiratory allergies were reported by three patients.
Daytime sleepiness was evaluated with the ESS, and a pathologic score was achieved
by 11 patients, with an average value of 10.4.
After surgery ([Table 1]), the postoperative assessment revealed in all patients a reduction in daytime sleepiness,
with the persistence of a pathological score in three patients. The postoperative
ESS mean score results were of 6.5 (p < 0,05).
Table 1
Surgical procedures: modified expansion sphincter pharyngoplasty, tonsillectomy, turbinate
surgery, anterior pharyngoplasty, hyoid suspension
|
Patient
|
Surgical procedure
|
Preop AHI
|
Postop AHI
|
Reduction (%)
|
Success of Sher criteria
|
|
I
|
MESP-T
|
37.9
|
19.3
|
49.1
|
YES
|
|
II
|
MESP-TONS-T
|
79
|
20
|
74.7
|
YES
|
|
III
|
MESP-TONS-T
|
18
|
9
|
50
|
YES
|
|
IV
|
MESP-TONS
|
17
|
8.5
|
50
|
YES
|
|
V
|
MESP-T
|
31.7
|
29.6
|
6.6
|
NO
|
|
VI
|
MESP-TONS-T
|
19.7
|
7.6
|
61.6
|
YES
|
|
VII
|
MESP-TONS-T
|
55.8
|
26
|
53.4
|
NO
|
|
VIII
|
MESP-TONS-T
|
27
|
13
|
51.8
|
NO
|
|
IX
|
MESP-TONS
|
30.8
|
15
|
51.3
|
YES
|
|
X
|
MESP-TONS-T
|
70
|
25
|
64.3
|
NO
|
|
XI
|
MESP-TONS
|
16
|
5
|
68.7
|
YES
|
|
XII
|
MESP-TONS-T-H
|
73
|
30
|
58.9
|
NO
|
|
XIII
|
MESP-TONS
|
33
|
3.5
|
89.4
|
YES
|
|
XIV
|
MESP-TONS-T-H
|
58
|
19
|
67.2
|
YES
|
|
XV
|
MESP-T-H
|
30
|
13
|
56.6
|
YES
|
|
XVI
|
MESP-ANT- TONS-T-H
|
28.4
|
10
|
64.8
|
YES
|
|
XVII
|
MESP-TONS-T- H
|
64
|
30
|
53.1
|
NO
|
|
XVIII
|
MESP-TONS-H
|
30
|
12
|
60
|
YES
|
|
XIX
|
MESP-ANT-TONS-T-H
|
38
|
16
|
57.9
|
YES
|
|
XX
|
MESP-ANT-TONS-T-H
|
78
|
30
|
61.5
|
YES
|
|
TOTAL
|
41.7 (±21.5)
|
17.4 (±8.9)
|
57.5%
|
65%
|
Abbreviations: AHI, apnea-hypopnea index; ANT, anterior pharyngoplasty; MESP, modified
expansion sphincter pharyngoplasty; H, hyoid suspension; postop, postoperative; preop,
preoperative; T, turbinate surgery; TONS, tonsillectomy.
The preoperative snoring score evaluated by a 10-point VAS was in average 9.2; postoperatively,
the average of this score was reduced to 4.5 (p < 0.05).
From the collection of the anthropometric data, the mean BMI of the sample was of
28.6 kg/m2 (mean: ± 3.06); in 5 patients, it was between 30 kg/m2 and 35 kg/m2. In the postoperative evaluation, three months after the surgery, the BMI remained
unchanged in all patients. The mean preoperative neck circumference was 41 cm, and
it remained unchanged in the postoperative evaluation.
Upon the oropharyngeal examination, 1 patient had been previously tonsillectomized,
having, for that reason, tonsillar grade 0; 11 patients had grade I; 6 had grade II;
and 2 had grade III. No patient had tonsillar grade IV. All of the patients had prolapse
of the soft palate, with hypertrophy of the uvula and posterior palatine pillars.
A total of 13 patients had hypertrophy of the lower turbinates, 8 patients had non-stenosing
nasal septum deviation, and 3 patients had been previously subjected to septal defect
correction surgery. Three patients had nasopharyngeal hypertrophic lymphoid tissue.
Upon dynamic endoscopy with Müller maneuver in the pre- and postoperative evaluations,
we observed ([Table 2]) a reduction in nasal obstruction, decreasing from a mean value of 2.2 to a mean
value of 1.85 (p < 0.05). Oropharyngeal obstruction was predominantly transverse in all patients according
to the selection criteria, and it decreased postoperatively from a mean value of 3.15
to 1.2 (p < 0.05). Regarding the hypopharyngeal obstruction, we observed a preoperative reduction
from a mean value of 1.7 to 1 (p < 0.05) ([Fig. 1]). From the pre- and postoperative polysomnographic evaluations, we obtained the
results described in [Table 1] by evaluating the success rates according to Scher criteria (AHI reduction > 50%
and < 20%).[11] We highlighted a reduction in the mean AHI of 57.5%, which decreased postoperatively
from a mean value of 41.7 (±21.5) to 17.4 (±8.9; p < 0.05), with a success rate according to the Sher criteria of 65%.
Fig. 1 Mean value of the collapse during Müller maneuver in the pre- and postoperative assessments.
N: nose; O: oropharynx; H: hypopharynx; postop, postoperatively; preop, preoperatively.
Table 2
Müller maneuver in the pre- and postoperative assessments
|
Patient
|
Preop Müller
|
Postop Müller
|
|
I
|
N2 O3T H2T
|
N2 O1T H1T
|
|
II
|
N3 O4T H2T
|
N3 O1T H1T
|
|
III
|
N2 O4T H3T
|
N2 O2T H2T
|
|
IV
|
N3 O3T H1T
|
N3 O1T H1T
|
|
V
|
N1 O3T H2T
|
N1 O2T H1T
|
|
VI
|
N3 O3T H1AP
|
N3 O1T H1T
|
|
VII
|
N2 O3T H1T
|
N2 O1T H1T
|
|
VIII
|
N3 O3T H0
|
N3 O1T H0
|
|
IX
|
N3 O3T H2T
|
N3 O1T H2T
|
|
X
|
N3 O3T H2T
|
N3 O1T H1T
|
|
XI
|
N3 O3T H1T
|
N3 O1T H1T
|
|
XII
|
N1 O3T H1T
|
N1 O1T H1T
|
|
XIII
|
N3 O4T H3T
|
N1 O1T H1T
|
|
XIV
|
N1 O4T H0
|
N0 O1T H0
|
|
XV
|
N3 O4T H1T
|
N1 O2T H1T
|
|
XVI
|
N2 O4T H3T
|
N1 O1T H1T
|
|
XVII
|
N3 O4T H3T
|
N1 O1T H1T
|
|
XVII
|
N3 O4T H3T
|
N1 O1T H1T
|
|
XIX
|
N2 O4T H2T
|
N1 O1T H1T
|
|
XX
|
N3 O4T H2T
|
N2 O1T H1T
|
Abbreviations: AP, antero-posterior collapse; H, hypopharynx; N, nose; O, oropharyx;
T, transverse collapse.
With this multilevel approach, we found an acceptable postoperative pain treated with
paracetamol 1 g every 8 hours for the first 3 postoperative days, and then administered
on request the following days. After the fifth postoperative day, none of the patients
reported any need for analgesic therapy. We reported few postoperative complications:
in two cases, an early hemorrhage occurred in the first postoperative day, and no
case of fluid reflux from the nose was reported. In two cases, the patients presented
a feeling of a persistent foreign body in the pharynx for a few months after the intervention;
however, this was spontaneously resolved. In eight patients without a significant
AHI reduction, we proposed an orthodontic treatment with a mandibular advancing device
(MAD), obtaining further improvement in the OSAS.
Discussion
A multilevel procedure for the surgical therapy of OSAS was presented for the first
time in 1989 by Waite and colleagues.[12] Fujita[13] was the first who discriminated between retropalatal and retrolingual obstructions,
and, based on his insights, Riley et al[14] developed the concept of multilevel surgery.
In 2003, Cahali[7] was the first to focus the attention on the lateral pharyngeal wall in the development
of OSAS. The author proposed the lateral pharyngoplasty, which has as its main purpose
the stiffening and enlargement of the lateral walls, unlike the uvulopalatopharyngoplasty,
in which the surgical goal is purely acaric of the soft palate, which is shortened
and stiffened, and the only intervention on the sidewall is related to the tonsillectomy.[1] Cahali has shown that the obstruction linked to the sidewalls of the pharynx is
the only risk factor, in addition to the BMI and neck circumference, which act independently
in the determinism of OSAS.[15] Even the expansion sphincter pharyngoplasty (ESP), which was developed by Pang and
Woodson in 2007,[8] is based on the assumption that the pharyngeal obstruction is mainly related to
the collapse of the lateral wall. This technique is much more conservative and respectful
of palatal anatomy than the previous approaches. Based on the site and pattern of
obstruction, we selected the patients with oropharyngeal transverse collapse to treat
with MESP, which is even more respectful of the anatomical structures than the original
technique proposed by Pang.
Such a technique has proven to be effective if used in selected patients; it is quite
safe, and the postoperative pain felt by the patients is comparable to the pain felt
after a tonsillectomy. We did not find any significant complications, either short-
or long-term, with the exception of two cases of postoperative bleeding, which is
a frequent complication of tonsillectomy in adult patients. None of the patients presented
postoperative reflux of fluids through the nose. This technique has also achieved
excellent compliance in terms of postoperative functional recovery; the oral feeds
resumed on the first postoperative day, with a liquid and semiliquid diet without
postoperative dysphagia. In the postoperative endoscopic controls, following Müller
Maneuver, we found a significant improvement in the transverse oropharyngeal collapse
pattern. The mean AHI of all patients decreased by half compared with what is was
preoperatively.
Overall, the quality of the sleep of the patients improved, despite the fact that
there was no substantial change in polysomnographic parameters in one patient. Waking
state and patient concentration skills were overall improved, as evidenced by the
average postoperative ESS. Patient number V did not achieve a significant improvement
in the AHI probably because of its poor selection because he/she exhibited important
retrognathia and a depressive syndrome in pharmacological treatment. In patients numbers
VII, X, XII, XVII and XX, the OSAS was extremely severe, but they were not compliant
with the nasal continuous positive airway pressure (NCPAP) therapy; in these cases
there was a reduction of > 50% in the AHI, but it did not reach a value below 20%,
probably due to the high starting values.
Conclusion
Modified expansion sphincter pharyngoplasty in multilevel surgical therapy preceded
by careful selection of patients has proven to be effective in treating patients with
moderate to severe syndromes. Such results are even more encouraging if we refer in
particular to the constant sensitive reduction in daytime sleepiness and the relatively
low incidence of postoperative complications. However, the non-indifferent percentage
of only partial improvements obtained in terms of postoperative AHI should not be
neglected. Therefore, this therapy in our opinion cannot yet be considered completely
reliable in every single case. It is, therefore, in our view, to be proposed, in cases
of moderate to severe syndromes, in patients who are not compliant with the CPAP,
or in patients with significant anatomical conformation that would presuppose a good
surgical success according to the Friedman classification,[16] in particular with hypertrophy of the palatine tonsils.
Lastly, the possibility in the case of partial surgical success to implement the treatment
with mandibular advancement devices should be considered.[17]
Remembering postoperative CPAP, however, usually at lower pressures than before surgery,
is still possible in failures, considering the substantial preservation of functional
anatomy of the upper airway after the surgery we performed.
