Revalidation of inferior petrosal sinus sampling: the latest results from a single-center experience.

Cushing's disease (CD), which manifests as excess cortisol secretion, is caused by adrenocorticotrophic hormone (ACTH)-secreting pituitary adenomas. Such adenomas are occasionally difficult to identify on magnetic resonance imaging (MRI), and thorough endocrinological examination may be required to detect them. Inferior petrosal sinus (IPS) sampling (IPSS) has been the gold standard test for distinguishing CD from ectopic ACTH syndrome (EAS). However, IPSS is an invasive procedure, and proper catheterization is occasionally challenging due to anatomical variations. Thus, there have been ongoing debates regarding the necessity of this procedure. Here, we present our recent IPSS data derived from the analysis of 65 patients who were referred to us for possible CD between April 2018 and December 2020 after undergoing meticulous endocrinological testing. Even with detailed MRI, no obvious lesions were identified in 19 patients. IPSS performed on these 19 individuals identified an IPS-to-peripheral ACTH gradient in 15 of them. The four patients who lacked this gradient were subjected to a classical algorithm using concurrently measured prolactin levels, the results of which were consistent with their ultimately confirmed diagnoses: two true-positive and two true-negative diagnoses. These findings support the validity of the algorithm and demonstrate that the prolactin-adjusted IPS-to-peripheral ACTH ratio can improve the differentiation between CD and EAS. We had no false-negative results, but three patients were false-positive. Consequently, those three patients in which no apparent tumor was clarified during surgery could not have any endocrinological improvement postoperatively.

Treatment of an anterior cerebral artery pseudoaneurysm secondary to a transsphenoidal surgery using stent-assisted coiling.

BACKGROUND: Injury of the internal carotid artery (ICA) during transsphenoidal surgery (TSS) is a rare but critical complication. There are several reports on endovascular treatment of ICA injury during TSS. With the recent flourishing of extended TSS, injuries to the distal arteries such as the anterior cerebral artery (ACA) are more likely to occur. CASE DESCRIPTION: In the present case, we report a pseudoaneurysm of the right ACA due to injury during extended TSS for aggressive prolactinoma. Due to the absence of collateral vessels, the pseudoaneurysm had to be obliterated while preserving the parent artery. Hence, we decided to treat the pseudoaneurysm using stent-assisted coiling (SAC). The pseudoaneurysm was completely obliterated and he was discharged without any complications. CONCLUSION: To the best of our knowledge, this is the first case in which an ACA pseudoaneurysm caused by injury during the TSS was treated with SAC and the parent artery was preserved.

Hemostasis through Extended Transsphenoidal Route for Subarachnoid Hemorrhage after Conventional Transsphenoidal Surgery for a Pituitary Adenoma.

This report describes a 49-year-old male patient who presented with a pituitary adenoma extending to the suprasellar region. Subarachnoid hemorrhage (SAH) occurred after conventional transnasal transsphenoidal surgery for a non-functioning pituitary adenoma despite no suprasellar arachnoid membrane breakdown. Through extended transsphenoidal route, the suprasellar hematoma was removed and bleeding from a small vessel thought to be the branch of left superior hypophyseal artery was successfully controlled. Indeed, several case reports regarding this rare complication have been published, but the mechanism of SAH has never been identified and the prognosis was poor in most cases. This report illustrates the origin and mechanism of the bleeding clearly using the intraoperative video. This case suggests that immediate therapeutic intervention is necessary and extended transnasal transsphenoidal repeat surgery is useful for an appropriate hemostasis and removal of hematoma located in the suprasellar region.

Very Low Rate of New Brain Lesions After Vulnerable Carotid Artery Stenting Cases Using Only FilterWire EZ as Distal Embolic Protection.

BACKGROUND: Although carotid artery stenting (CAS) has been widely acknowledged as an effective alternative option for patients at high risk of carotid endarterectomy, embolic stroke is a major complication of CAS. Several reports have emphasized that distal protection filter alone is associated with a high risk of embolic complications of CAS with vulnerable plaque. Thus, relatively complicated protection systems have recently been recommended to prevent distal embolic complications. However, those protection systems require many steps, which, themselves, can also cause complications. The FilterWire EZ embolic protection device (EPD) for use in CAS was approved for national health insurance coverage in Japan in 2010. Since then, we have been using it as an EPD in all CAS procedures, even those with vulnerable plaque. METHODS: The medical records of 80 patients who had undergone CAS from February 2014 to September 2019 at Moriyama Memorial Hospital were retrospectively reviewed. Emergent cases with distal mechanical thrombectomy were not included. We enrolled patients whose target lesion was vulnerable as evaluated by magnetic resonance imaging and who had undergone diffusion-weighted imaging studies the next day. RESULTS: Of the 80 patients, 60 had met the inclusion criteria. No symptomatic embolic complications developed, and only 5 patients (8.3%) had shown new lesions on diffusion-weighted imaging after CAS. The rate of new lesions after CAS with vulnerable plaque was much lower than that in previous studies. We meticulously analyzed the data to determine the predictive factors. CONCLUSION: The FilterWire EZ as an EPD for CAS is quite safe, even for vulnerable carotid stenosis.

A Resuscitation Option for Upper Airway Occlusion Based on Bolus Transtracheal Lung Inflation.

BACKGROUND: Acute laryngospasm sufficient to cause obstructive apnea is a medical emergency that can be difficult to manage within the very short time available for establishing an airway. We have presented substantial evidence that laryngospasm-based obstructive apnea is the cause of sudden death in epilepsy, and airway management is particularly challenging during seizure activity. OBJECTIVE: We sought to determine if the transtracheal delivery of a bolus of oxygen or room air below the level of an obstruction to inflate the lungs could be an effective method to prolong the time available for responders seeking to establish a stable airway, and, if so, what could be learned about optimization of delivery parameters from a rat model. METHODS: Rats were fitted with a t-shaped tracheal tube for controlling access to air and for measuring airway pressures. After respiratory arrest from simulated laryngospasm, bolus transtracheal lung inflation with a volume of gas equivalent to half the vital capacity was delivered to the closed respiratory system as the only resuscitation step. RESULTS: Bolus lung inflation was sufficient for resuscitation, improving cardiac function and re-establishing adequate oxygen status to support life. Inflation steps could be repeated and survival times were approximately 3 times that of non-inflated lungs. CONCLUSION: The properties and consequences of bolus lung inflation are described as a foundation for procedures or devices that can be useful in cases of severe laryngospasm and other cases of upper airway obstruction. LEVEL OF EVIDENCE: 3.

Obstructive apnea due to laryngospasm links ictal to postictal events in SUDEP cases and offers practical biomarkers for review of past cases and prevention of new ones.

Seizure spread into autonomic and respiratory brainstem regions is thought to play an important role in sudden unexpected death in epilepsy (SUDEP). As the clinical dataset of cases of definite SUDEP available for study grows, evidence points to a sequence of events that includes postictal apnea, bradycardia, and asystole as critical events that can lead to death. One possible link between the precipitating seizure and the critical postictal sequence is seizure-driven laryngospasm sufficient to completely obstruct the airway for an extended period, but ictal laryngospasm is difficult to fully assess. Herein, we demonstrate in a rat model how the electrical artifacts of attempts to inspire during airway obstruction and features of the cardiac rhythm establish this link between ictal and postictal activity and can be used as practical biomarkers of obstructive apnea due to laryngospasm or other causes of airway obstruction.

Vagal control of cardiac electrical activity and wall motion during ventricular fibrillation in large animals.

Vagal inputs control pacemaking and conduction systems in the heart. Anatomical evidence suggests a direct ventricular action, but functional evidence that separates direct and indirect (via the conduction system) vagal actions is less well established. We studied vagus nerve stimulation (VNS) during sinus rhythm and ventricular fibrillation (VF) in pigs and sheep to determine: 1) the range of unilateral and bilateral actions (inotropic and chronotropic) and 2) whether VNS alters left ventricular motion and/or electrical activity during VF, a model of abnormal electrical conduction of the left ventricle that excludes sinus and atrioventricular nodal function. Adult pigs (N=8) and sheep (N=10) were anesthetized with urethane and mechanically ventilated. VNS was performed in animals at 1, 2, 5, 10, 20, 50, and 100Hz for 20s. VF was induced with direct current to the ventricles or occlusion of the left anterior descending coronary artery. In 4 pigs and 3 sheep, left ventricular wall motion was assessed from endocardial excursion in epicardial echocardiography. In sheep and pigs, the best frequency among those tested for VNS during sinus rhythm to produce sustained electrical and mechanical ventricular standstill was 50Hz for unilateral or bilateral stimulation. When applied during VF, bilateral VNS increased the variability of the dominant VF frequency, indicating a direct impact on the excitability of ventricular myocytes, and decreased endocardial excursion by more than 50% during VF. We conclude that the vagus nerve directly modulates left ventricular function independently from its effects on the conduction system.

Quantitative video laryngoscopy to monitor recovery from recurrent laryngeal nerve injury in the rat.

Recovery from unilateral vocal-fold paralysis is lengthy, unpredictable, and often incomplete, highlighting the need for better treatments of the injured recurrent laryngeal nerve. To be able to monitor recovery of vocal-fold motion in studies with rats, we developed a procedure for quantitative video laryngoscopy. An asymmetry index was defined as a continuous and robust measure of unequal vocal-fold motion and calculated from spectral-density plots of vocal-fold displacements. In a cohort of 8 animals, unilateral vocal-fold paralysis was observed within seconds after clamping of the right recurrent laryngeal nerve and was accompanied by a markedly negative asymmetry index. Over the next month, the asymmetry index gradually returned to zero, concomitant with a visible recovery of vocal-fold motion. Our results suggest that quantitative video laryngoscopy is a sensitive and discriminating method for monitoring recovery from recurrent laryngeal nerve injury and set the stage for testing novel surgical and pharmacological treatments of unilateral vocal-fold paralysis.