Botox injection into the lower esophageal sphincter induces hiatal paralysis and gastroesophageal reflux

Background: Endoscopic intrasphincteric injection of Botox (ISIB) is used routinely for the treatment of achalasia esophagus and other spastic motor disorders. Studies show that the ISIB reduces the smooth muscle lower esophageal sphincter (LES) pressure. The esophageal hiatus, formed by the right crus of diaphragm, surrounds the cranial half of the LES and works like an external LES. We studied the effects of ISIB on the LES and hiatal contraction and gastroesophageal reflux (GER). Fourteen patients treated with ISIB were studied. Esophageal manometry-impedance recordings were performed before and after the ISIB. Hiatal contraction was assessed during tidal inspiration, forced inspiration, Müller’s maneuver, and straight leg raise. In 6 subjects, the manometry were repeated 6–12 mo after the ISIB. The esophagogastric junction (EGJ) pressure was measured at end expiration (LES pressure) and at the peak of maneuvers (hiatal contraction). Transdiaphragmatic pressure (pdi; force of diaphragmatic contraction) was measured at the peak of forced inspiration. GER was measured from the impedance recordings. The EGJ pressure at end expiration (LES pressure) decreased significantly after the Botox injection. The peak EGJ pressure at tidal inspiration, forced inspiration, Müller’s maneuver, and straight leg raise was also dramatically reduced by the ISIB. There was no effect of Botox on the pdi during forced inspiration. Seven of 10 subjects demonstrated GER during maneuvers following the ISIB. Six to 12 mo after ISIB, the LES and hiatal contraction pressure returned to the pre-ISIB levels. ISIB, in addition to decreasing LES pressure, paralyzes the esophageal hiatus (crural diaphragm) and induces GER. NEW & NOTEWORTHY The sphincter mechanism at the lower end of the esophagus comprises smooth muscle lower esophageal sphincter (LES) and skeletal muscle crural diaphragm (hiatus). Current thinking is that the endoscopic intrasphincteric injection of Botox (ISIB), used routinely for the treatment of achalasia esophagus, reduces LES pressure. Our study shows that ISIB, even though injected into the LES, diffuses into the hiatus and causes its paralysis. These findings emphasize the importance of esophageal hiatus as an important component of the antireflux barrier and that the ISIB is refluxogenic.

Impact of upper airway configuration assessed by CT on CPAP titration in OSA patients during Müller's maneuver

Objectives Continuous positive airway pressure (CPAP) is the current gold-standard treatment for moderate to severe obstructive sleep apnea (OSA), and upper airway anatomy plays an increasingly important role in evaluating the efficacy of CPAP therapy. The aim of this observational study was to investigate the influence of upper airway anatomy on CPAP titration in OSA patients assessed by computed tomography (CT) during Müller's maneuver. Methods Consecutive patients under investigation for OSA by undergoing polysomnography and CT scan of the upper airway while awake were enrolled. Successful full-night manual titration was performed to determine the optimal CPAP pressure level for OSA patients in supine position using a nasal mask. Results A total of 157 subjects (134 males and 23 females) were included. Both apnea–hypopnea index (AHI) and LaSO2 significantly correlated with CPAP titration level, upper airway length (UAL), distance from mandibular plane to hyoid bone (MPH), and neck circumference (all p<0.05). There were significant positive correlations between CPAP titration level and UAL (r=0.348, p=0.000) and MPH (r=0.313, p=0.002). Stepwise multiple linear regression analyses were performed to evaluate the independent predictors of AHI, LaSO2, and CPAP titration level. CPAP titration level was identified as an independent explanatory variable for AHI and LaSO2 after adjustment for confounders. Multiple linear regression analyses also indicated that body mass index (BMI) and UAL were independently associated with CPAP titration level (all p<0.05). Conclusions Upper airway abnormalities combined with anthropometric parameters play important roles in CPAP titration for OSA patients, providing additional insight into the factors influencing OSA treatment strategies. UAL and BMI should be taken into consideration when choosing CPAP titration level to improve CPAP compliance.

The Relationship Between Modified Mallampati Score, Müller’s Maneuver and Drug-Induced Sleep Endoscopy Regarding Retrolingual Obstruction

Objectives: This study explored the correlation between clinical explorations, including modified Mallampati score and Müller’s maneuver, with drug-induced sleep endoscopy (DISE) findings regarding retrolingual obstruction. Methods: One hundred forty-two obstructive sleep apnea patients were enrolled in this prospective study. All of the patients received clinical explorations including modified Mallampati scoring and Müller’s maneuver in the clinic. Drug-induced sleep endoscopy was further evaluated in the operating room. Results: A significant relationship was noted between modified Mallampati score and retrolingual obstruction during DISE. In contrast, no significant relationship was noted between Müller’s maneuver and DISE findings regarding retrolingual obstruction. Conclusions: A significant discrepancy existed between retrolingual airway collapse evaluated by modified Mallampati score and Müller’s maneuver. Modified Mallampati score is more correlated with DISE regarding retrolingual obstruction compared to Müller’s maneuver. It should therefore be used as an initial evaluation of retrolingual obstruction when DISE is unavailable.

Patogenesis dan diagnosis gangguan napas saat tidur dengan Drug Induce Sleep Endoscopy (DISE)

Latar belakang: Obstructive sleep apnea (OSA) ialah penyakit kronis yang terjadi akibat episode intermiten sumbatan jalan napas komplit atau sebagian saat tidur. OSA dapat menimbulkan komplikasi seperti hipertensi, diabetes melitus, stroke dan excessive daytime sleepiness yang dapat berakibat fatal. OSA merupakan bagian dari gangguan napas saat tidur. Tujuan: Mengindentifikasi letak atau level dan konfigurasi sumbatan pada saat tidur. Tinjauan pustaka: Cara untuk mendiagnosis OSA adalah nasofaringolaringoskopi dengan Muller`s maneuver, pemeriksaan polisomnography (PSG), dan drug induce sleep endoscopy (DISE). Pemeriksaan PSG merupakan standar baku emas untuk mendapakan nilai apnea-hipopnea index (AHI) yang menentukan derajat OSA. Pemeriksaan untuk mengidentifikasi lokasi sumbatan jalan napas yang menyebabkan peningkatan resistensi aliran udara adalah Muller`s maneuver dan DISE. Pada pemeriksaan DISE, digunakan propofol atau midazolam secara intravena untuk menstimulasi keadaan sumbatan pada saat tidur, dilanjutkan dengan pemeriksaan nasofaringolaringoskopi. Kesimpulan: Pemeriksaan ini merupakan cara yang sangat terpercaya untuk menentukan level sumbatan pada keadaan tidur, sehingga jenis tindakan operasi yang dilakukan menjadi lebih tepat. Kata kunci: Drug induced sleep endoscopy, midazolam, propofol, manuver Muller’s, obstructive sleep apnea, polisomnografi ABSTRACT Background: Obstructive sleep apnea (OSA) is a common chronic disorder caused by intermittent episodes of complete or partial upper airway obstruction during sleep. It may lead to complications such as hypertension, diabetes mellitus, stroke, as well as excessive daytime sleepiness which can be fatal. OSA is a part of sleep disorder breathing. Purpose: To identify the sites or the levels of obstruction and its configuration. Literature review: Muller’s maneuver upon nasopharyngoscopy, polysomnography (PSG), and drug-induced sleep endoscopy (DISE) are the modalities for diagnosing OSA. Polysomnography is the gold standard examination for OSA, one of the variables; the apnea-hipopnea index (AHI) is used to determine the presence and severity of OSA. Muller’s maneuver and DISE are the examination to identify the sites responsible for increase in airflow resistance. DISE technique uses intravena injection of propofol or midazolam to produce obstruction in a “natural sleep” condition followed by nasopharyngolaryngoscopy examination. Conclusion: DISE is considered as a very reliable means to define the level of obstruction during sleeping, thus could help to determine appropriate surgery. Keywords: Drug induced sleep endoscopy, midazolam, propofol, Muller’s maneuver, obstructive sleep apnea, polisomnography