Tonsillectomy and Expansion Sphincter Pharyngoplasty Operations
Condition: Obstructive Sleep Apnea; Osa Syndrome
MeSH terms: Apnea; Sleep Apnea Syndromes; Sleep Apnea, Obstructive
Study type: Interventional

Summary: 
      Background: To compare the efficacy of tonsillectomy and expansion sphincter pharyngoplasty
      (ESP) in the surgical treatment of obstructive sleep apnea (OSA).

      Methods: Patients with Friedman grade III-IV tonsil hypertrophy and OSA diagnosed with
      polysomnography were separated into two groups according to the surgery performed, as the
      classic tonsillectomy group (Group 1) and the ESP group (Group 2). The primary endpoint of
      the study was to determine the Apnea-Hypopnea Index (AHI) value. The preoperative and
      postoperative AHI scores and the decreases in these scores were noted. The change in AHI was
      calculated as a percentage (preoperative AHI - postoperative AHI/ preoperative AHI x 100) and
      the two groups were compared. An AHI value of <10 events/hour was accepted as cure.
    

Detailed description: 
      Obstructive sleep apnea (OSA) is a frequently seen sleep disorder characterised by the
      stopping or decrease of air flow, which occurs with the collapse of the upper airway during
      sleep. The upper airway can be described as an empty tube and if the air passing through this
      tube decreases or stops, an increase in negative pressure occurs, especially in the soft
      palate and lateral pharyngeal wall, causing pharyngeal collapse The increase in airway
      resistance because of both the upper airway collapse and increase in negative pressure can be
      a reason for loud snoring and apnea, and if not treated can also cause systemic
      complications. Upper airway obstruction formed in OSA can be due to structural anatomic
      factors or to abnormal upper airway motor tonus. The obstruction in the upper airway can
      occur in a single or several anatomic regions such as the soft palate, uvula, palatine
      tonsils, or tongue root. Treatment modalities include lifestyle changes, continuous positive
      airway pressure (CPAP), surgery, and intra-oral devices. The main aim of all treatments is to
      expand the upper airway and attempt to reduce airway collapse. In the surgical treatment
      applied for this purpose, it is aimed to remove pharyngeal tissue that narrows the upper
      airway, increase the stability of the pharyngeal air column, and expand the pharyngeal lumen.

      The lateral pharyngeal wall has a complex structure including several pharyngeal muscles such
      as the palatopharyngeus, superior pharyngeal constrictor, and palatoglossus, and lymphoid
      tissue, and the palatine tonsils. In a previous study, the clinical importance was stated of
      lateral pharyngeal wall collapse in the pathogenesis of OSA. It was suggested in that study
      that the lateral pharyngeal wall could collapse more easily especially in patients with
      severe OSA compared to those without or with mild OSA, and because of this collapse, the
      narrowed lateral pharyngeal wall could be an independent risk factor affecting OSA. The
      palatine tonsils, especially those of Friedman grade III-IV dimensions, which occupy a large
      space in the lateral pharyngeal wall, seem to be a factor causing collapse. In OSA patients
      with grade III-IV tonsil hypertrophy, classic tonsillectomy is recommended as first-line
      treatment and is still the gold standard surgical method. However, sometimes tonsillectomy
      remains insufficient in the treatment of OSA. Therefore, to be able to prevent lateral
      pharyngeal wall collapse and increase stability, surgical techniques have been investigated,
      and lateral pharyngoplasty, relocation pharyngoplasty, and most recently, expansion sphincter
      pharyngoplasty (ESP) have been defined. A previous study has reported that ESP is a suitable
      surgical procedure for patients with moderate or severe OSA who have severe palatal
      circumferential narrowing and greater lateral pharyngeal wall thickness. A meta-analysis that
      included 5 studies also emphasized that ESP was an effective surgical treatment for OSA
      patients. However, to the best of our knowledge, there is no study in the literature that has
      shown whether or not this surgical technique is superior to classical tonsillectomy. The need
      for this method, which is more major surgery than classic tonsillectomy, is not clear.
      Therefore, the aim of this study was to investigate and compare the surgical success of
      classic tonsillectomy and ESP in OSA surgery performed on a patient series in our hospital.

      The study was conducted in the Ear, Nose, and Throat (ENT) Clinic of a city hospital. A full
      ENT examination was made of patients with suspected OSA who presented with complaints of loud
      snoring, witnessed apnea, and daytime sleepiness. Then preoperative polysomnography (PSG) was
      performed on the patients with Friedman grade III-IV tonsil hypertrophy. The study included
      patients aged >18 years with an Apnea-Hypopnea Index (AHI) value of ≥10. Patients were
      excluded from the study if they had not undergone preoperative or postoperative PSG, if they
      had a craniofacial anomaly such as evident retrognathia, any severe cardiac, respiratory, or
      neurological disease, or were determined with an evident obstruction at the tongue base level
      in the endoscopic examination.

      The patients who underwent surgery for a diagnosis of OSA were separated into two groups as
      the classic tonsillectomy (Group 1) and ESP (Group 2) groups. All the operations were
      performed by two surgeons experienced in this subject (MM-AI). The patients were hospitalised
      for at least 2 days postoperatively, with hydration and pain relief provided.

      The primary endpoint of the study was defined as the AHI score. The patients were separated
      into 3 subgroups according to the severity of OSA determined in the PSG recording: mild (AHI
      ≥ 10 and <15 events/hr), moderate (AHI ≥15 and <30 events/hr), and severe (AHI ≥ 30
      events/hr). The preoperative and postoperative AHI scores and the decreases in these scores
      were noted. The change in AHI was calculated as a percentage (preoperative AHI -
      postoperative AHI/ preoperative AHI x 100) and the two groups were compared. An AHI value of
      <10 events/hr was accepted as cure. Success was considered as postoperative AHI <20 events/hr
      or a 50% reduction in the preoperative AHI.

      The daytime sleepiness status of the patients was evaluated using the Epworth Sleepiness
      Scale (ESS). A record was made for each patient of body mass index (BMI), smoking status and
      alcohol consumption, and history of comorbidities. At postoperative 6 months, PSG was
      repeated, the ESS was applied, and BMI was recorded.

      All the operations were performed under general anaesthesia. Tonsillectomy was performed with
      cold dissection including the whole tonsil and capsule, and bleeding was controlled with
      bipolar cauterisation. In the ESP technique, following bilateral tonsillectomy with cold
      dissection and bleeding control with bipolar cauterisation, a uvulopalatal (UP) flap
      procedure was performed. The soft palate over the uvula was marked with a pen, and the uvular
      mucosa was removed with sharp dissection, while protecting the muscle. The tip of the uvula
      was turned towards the soft palate and the long uvular tip was excised. Following the UP flap
      procedure, the palatopharyngeus muscle was identified and the upper half was cut
      horizontally. By opening tunnels to the anterior plica mucosa, the upper half of the
      dissected palatopharyngeus muscle was placed in these tunnels, and was sutured to the
      pterygomandibular raphe with vicryl 2-0 sutures. The mucosal cuts were closed with vicryl 3-0
      sutures. All the patients were discharged on postoperative day 2. Follow-up examinations were
      made at the end of postoperative 1 week, 1, 3, and 6 months. The Clavien-Dindo system was
      used to evaluate complications.

      Statistical Analysis Data analysis was performed using SPSS for Windows, version 26 software
      (SPSS Inc., Chicago, IL, USA). Continuous variables were reported as median (minimum-maximum)
      values, and categorical variables as number (n) and percentage (%). Nominal variables were
      assessed using the Pearson's Chi-square or Fisher's exact test. For parameters that did not
      show normal distribution, the Mann-Whitney U test was applied in comparisons. The Wilcoxon
      signed-rank test was used to compare pre- and post-surgery AHI scores. A value of p< 0.05 was
      considered statistically significant.
    

Intervention name(s): Tonsillectomy; Expansion sphincter pharyngoplasty
Intervention type(s): Procedure; Procedure
Intervention description(s): Tonsillectomy was performed with cold dissection including the whole tonsil and capsule, and bleeding was controlled with bipolar cauterisation.; In the ESP technique, following bilateral tonsillectomy with cold dissection and bleeding control with bipolar cauterisation, a uvulopalatal (UP) flap procedure was performed. The soft palate over the uvula was marked with a pen, and the uvular mucosa was removed with sharp dissection, while protecting the muscle. The tip of the uvula was turned towards the soft palate and the long uvular tip was excised. Following the UP flap procedure, the palatopharyngeus muscle was identified and the upper half was cut horizontally. By opening tunnels to the anterior plica mucosa, the upper half of the dissected palatopharyngeus muscle was placed in these tunnels, and was sutured to the pterygomandibular raphe with vicryl 2-0 sutures. The mucosal cuts were closed with vicryl 3-0 sutures.
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Apnea-Hypopnea Index; Expansion sphincter pharyngoplasty; Obstructive sleep apnea; Tonsillectomy; Upper airway surgery