Atlantoaxial Stabilization Using C1 Lateral Mass and C2 Pedicle/Translaminar Screw Fixation by Intraoperative C1- and C2-Direct-Captured Navigation with Preoperative Computed Tomography Images.

In C1-C2 posterior fixation, the C1 lateral mass and C2 pedicle/translaminar screw insertion under spine navigation have been used frequently. To avoid the risk of neurovascular damage in atlantoaxial stabilization, we assessed the safety and effectiveness of a preoperative computed tomography (CT) image-based navigation system with intraoperative independent C1 and C2 vertebral registration. It is ideal when a reference frame can be linked directly to the C1 posterior arch for C1-direct-captured navigation, but there is a mechanical challenge. A new spine clamp-tracker system was implemented recently, which allows reliable C1- and C2- direct-captured navigation in nine patients with traumatic C2 fractures. In this way, there was no misalignment of C1-C2 screws. C1 lateral mass screws were used except for one case, and translaminar screws were primarily used as an anchor for C2. The C1 lateral mass screw locations, which are 19 mm laterally from the C1 posterior arch's center, are taken to be constant. However, there is one unusual circumstance in which using a C1 laminar hook instead of a C1 lateral mass screw appears to be a beneficial substitute. The increase of surgical accuracy for posterior C1-C2 screw fixation without cost constraints is significantly facilitated by intraoperative C1- and C2-direct-captured navigation with preoperative computed CT images.

A Case of Undiagnosed Sleep Disorder with Hearing Difficulty and Dizziness.

INTRODUCTION: The aim of this case report was to investigate the relationship between sleep disorders and audio vestibular symptoms. CASE REPORT: A case of undiagnosed sleep disorder, presenting as a temporary auditory processing difficulty, is presented. The disorder was initially treated as sudden deafness with dizziness. A 23-year-old male patient complained of acute hearing disturbance despite normal results on pure tone audiometry. The patient was initially administered a steroid injection in the hospital. After treatment, his hearing symptoms improved only slightly and he reported balance difficulty with rightward spontaneous nystagmus. Vestibular rehabilitation was performed. We also suspected that his hearing symptom was due to an auditory processing difficulty. Despite steroid treatment and vestibular rehabilitation, neither of his symptoms improved. We subsequently identified the presence of insomnia. He was prescribed zolpidem 5 mg, which slightly improved his symptoms, and referred to a sleep specialist for further examination. Polysomnography was performed, which identified restless leg syndrome and sleep disturbance with delayed sleep phase syndrome. After pharmacological treatment, his sleep disturbance, hearing difficulty, and balance disorder completely resolved. CONCLUSION: Sleep disorders may provoke reversible auditory processing difficulties. We should carefully evaluate patients for a potentially undiagnosed sleep disorder, even in patients chiefly complaining of intractable sensory dysfunction such as hearing or balance disturbance.

Anesthetic management of bidirectional cavopulmonary shunt in a patient with pulmonary atresia with intact ventricular septum associated with sinusoidal communications.

Pulmonary atresia with intact ventricular septum (PAIVS) is sometimes associated with coronary artery anomalies, including right ventricle (RV)-to-coronary artery fistulas (sinusoidal communications), coronary artery stenoses, and coronary artery occlusions. In some cases, the coronary circulation depends entirely or partly on the desaturated systemic venous blood supply from the RV. Under these circumstances, decompression of the RV can result in fatal myocardial ischemia. A 6-month-old boy, diagnosed with PAIVS associated with sinusoidal communications, underwent a bidirectional cavopulmonary shunt procedure under venoarterial cardiopulmonary bypass (CPB). During CPB, to prevent RV decompression, we maintained right atrial pressure above 5 mmHg and used a pump perfusion rate of 30%-40% of the calculated value based on body surface area. Although electrocardiography showed slight ST depression and bradycardia, myocardial contractility after weaning from CPB was adequate to maintain the circulation with the administration of dobutamine and atrial pacing. In patients with PAIVS and RV-dependent coronary circulation, it is important to maintain coronary artery perfusion throughout the period of anesthesia.