Introduction
Laryngeal cleft (LC), a fissure defect between laryngotrachea and upper esophagus, is a rare congenital anomaly occurring in less than 0.1% of the general population.1-3 LC is important to be early recognized to prevent unnecessary diagnostic work-up, medication and associated morbidities. The main presenting symptoms of stridor, chronic cough and recurrent aspiration are non-specific. Direct visual confirming its presence and identifying type are clinically challenging. Rigid endoscopy (RE) is capably separating and inspecting inter-arytenoids and hypopharyngeal region, therefore, being recommended as confirmatory diagnosis of LC.3-7 However, due to the need for general anesthesia, lack of RE expertise in many centers, the application of RE can be challenging in common practices for diagnosing LC.
Flexible endoscopy (FE) allows direct inspection of the dynamic structures of pharyngolaryngeal space (PLS) and aeroesophageal tracts (AET), therefore is the preferred first-line visual examination.8,9 However, defects in the posterior larynx may not be readily noticeable due to the inherent collapse hypopharynx, which usually displays a normal appearance. Even with apparent symptoms and a high index of suspicion, LC could still be overlooked by experienced operator using traditional FE technique.3,10,11 Trachsel’s group published a report of FE assisted with using continuous positive airway pressure via an endoscopy face mask for the diagnosis of LC.12 We here like to share our experiences by applying a more simple technique of positive airway pressure (PPV) to evaluate LC.
“Pharyngeal oxygen with optional nose-closure and abdomen-compression (PhO2-NC-AC)” is a novel technique of noninvasive ventilation (NIV).13-15 Clinically, it is a safe and convenient method of producing PPV without using any ventilation or airway devices of Ambu-bag, face mask, nasal prong, laryngeal mask airway, endotracheal tube or ventilator. FE with this NIV (FE-NIV) can ensure adequate oxygenation during many interventional procedures of AET in pediatrics, even in severe asphyxiated status.16-18In this NIV, maneuvers of prolonged nose-closure, 1 to 5 second, can create sustained pharyngeal inflation (SPI) with enough, dynamic and controllable PPV to expand the PLS and allows precise FE assessment.19 Over the last two decades, we have routinely using this FE-NIV and SPI (FE-NIV-SPI) technique and have successfully detected many LC lesions at their first FE inspection of larynx.
We like to share our experiences using this novel FE-NIV-SPI technique alone to screen for LC lesions and report characteristics of our patients.