Cerebral Air Embolism after Esophagogastroduodenoscopy: Insight on Pathophysiology, Epidemiology, Prevention and Treatment

Middle cerebral artery hypodense dot sign in iatrogenic air embolism

Air embolism is a rare cause of stroke, usually associated with medical procedures, with gastrointestinal endoscopy rarely implicated. Here, we present a case of a patient who experienced cerebral air embolism post-gastroscopy, presenting with aphasia and right hemiparesis due to left M2 occlusion with spontaneous and complete recovery. CT scan revealed a hypodense defect in the left Sylvian fissure, representing a "hypodense dot sign" suggestive of an air embolism. The hypodense MCA sign, previously described in fat embolism cases, could also indicate air embolism, supporting prompt diagnosis and proper intervention.

Analysis of Tomographic Images of a Catastrophic Gas Embolism during Endoscopic Retrograde Cholangiopancreatography

Endoscopic retrograde cholangiopancreatography (ERCP) is a commonly performed minimally invasive procedure. Air embolism in a patient undergoing ERCP is relatively rare, accounting for approximately 2-3% of procedures performed, and a catastrophic air embolism is even rarer. Symptoms of air embolism can come from the cardiopulmonary and nervous system. It is important to remember this in the differential diagnosis of complications of ERCP, as early detection is crucial. In the case presented here, the diagnostic CT scan performed immediately after the incident brings awareness of how massive an air embolism can be. The CT results showed gas bubbles entering both the superior and inferior vena cava. The presence of air has been captured in the bile ducts, duodenum wall, heart, femoral veins and intracranially. Risk factors for this complication include previous biliary surgeries, the presence of prostheses and stents, cholangitis, liver tumors and anatomical anomalies such as hepatobiliary fistulas, as well as intrahepatic and extrahepatic anatomical leaks. As gas embolism is associated with serious health consequences, knowledge of the problem and adequate preparation may reduce the occurrence of the problem. Attention should be paid to basic and easily obtainable precautions when performing the procedure, such as the patient's hemodynamic status, adequate hydration and positioning during the procedure.

Fatal cerebral air embolism post esophageal endoscopy with dilatation: A case report

This is a case of a patient who underwent an esophageal dilatation for benign esophageal strictures. As a consequence of the procedure, she developed an esophageal rupture and multiple cerebral and cerebellar air emboli resulting in infarction. The patient died after being placed on comfort care measures. The postmortem examination revealed focal breach of the esophageal mucosa but no sites of cardiac or vascular shunting that could account for the transit of air from the esophagus to the central nervous system. The phenomenon of vascular air entry as a consequence of upper gastrointestinal endoscopic intervention is an uncommon but very serious complication of balloon dilatation therapy. Instances of progression to intracranial arterial gas embolism are even less common, but are well described in a small number of case reports. We present a fatal case of central nervous system air embolism post-balloon dilatation therapy with associated antemortem imaging, autopsy, and microscopic images followed by a discussion of potential mechanisms of entry of air into the brain.

Preventing esophageal complications from atrial fibrillation ablation: A review

Atrioesophageal fistula is a life-threatening complication of ablation treatment for atrial fibrillation. Methods to reduce the risk of esophageal injury have evolved over the last decade, and diagnosis of this complication remains difficult and therefore challenging to treat in a timely manner. Delayed diagnosis leads to treatment occurring in the context of a critically ill patient, contributing to the poor prognosis associated with this complication. The associated mortality risk can be as high as 70%. Recent important advances in preventative techniques are explored in this review.

Preventative techniques used in current clinical practice are discussed, which include high-power short-duration ablation, esophageal temperature probe monitoring, cryotherapy and laser balloon technologies, and use of proton pump inhibitors. A lack of randomized clinical evidence for the effectiveness of these practical methods are found. Alternative methods of esophageal protection has emerged in recent years, including mechanical deviation of the esophagus and esophageal temperature control (esophageal cooling). Although these are fairly recent methods, we discuss the available evidence to date. Mechanical deviation of the esophagus is due to undergo its first randomized study. Recent randomized study on esophageal cooling has shown promise of its effectiveness in preventing thermal injuries. Lastly, novel ablation technology that may be the future of esophageal protection, pulsed field ablation, is discussed.

The findings of this review suggest that more robust clinical evidence for esophageal protection methods is warranted to improve the safety of atrial fibrillation ablation.

Suspected cerebrovascular air embolism during endoscopic esophageal varices ligation under sedation with fatal outcome: A case report

BACKGROUND

Air embolism is a very rare, yet serious and potentially fatal complication of digestive endoscopic treatment. Air embolism is the result of air directly entering the arteries or veins. However, to recognize neurological dysfunction under sedation can be difficult. Therefore, it is extremely important to identify high-risk groups and take preventive measures.

CASE SUMMARY

Herein, we report a 74-year-old female patient with esophageal varices who suffered from consciousness disturbance after the third endoscopic ligation of esophageal varices under sedation. Combined with the patient’s imaging examination results and medical history, we highly suspected that the patient had developed paradoxical cerebral air embolism during endoscopic ligation. We learned that the patient died at a later follow-up. In order to be able to identify and prevent the occurrence of air embolism early, we summarize and analyze the risk factors, pathogenesis, clinical manifestations, prevention and treatment options of gastrointestinal endoscopy complicated by cerebral air embolism.

CONCLUSION

Electroencephalographic monitoring helps to recognize the occurrence of air embolism in time and increase the patient's chance of survival.

Paradoxical and Retrograde Air Embolism from Pressurized Peripheral Bolus

Introduction

Cerebral air embolism is a rare, yet serious neurological occurrence with unclear incidence and prevalence. Here, we present a case of fatal cerebral arterial and venous cerebral gas embolism in a patient with infective endocarditis and known large right-to-left shunt and severe tricuspid regurgitation following pressurized fluid bolus administration. Case Presentation. A 32-year-old female was admitted to the medical intensive care unit from a long-term acute care facility with acute on chronic respiratory failure. Her medical history was significant for intravenous heroin and cocaine abuse, methicillin-sensitive Staphylococcus aureus tricuspid valve infective endocarditis on vancomycin, patent foramen ovale, septic pulmonary embolism with cavitation, tracheostomy with chronic ventilator dependence, multifocal cerebral infarction, hepatitis C, nephrolithiasis, anxiety, and depression. After intravenous fluid administration, she became unresponsive with roving gaze, sluggish pupils, and hypotensive requiring vasopressors. CT of the brain showed diffuse arterial and venous cerebral air embolism secondary to accidental air administration from fluid bolus. Magnetic resonance imaging of the brain showed diffuse global anoxic injury and flattening of the globe at the optic nerve insertion. Given poor prognosis, her family chose comfort measures and she died.

Conclusions

Fatal cerebral air embolism can occur through peripheral intravenous routes when the lines are inadequately primed and fluids administered with pressure. Caution must be exercised in patients with right-to-left shunting as air may gain access to systemic circulation.

When in Trouble Think of the Bubble: Paradoxical Cerebral Arterial Gas Embolism after Endoscopic Retrograde Cholangiopancreatography

Air embolism (a result of direct communication with the vasculature and an external pressure gradient from the gastrointestinal or the biliary tract), although rare, is a potentially devastating adverse event seen in endoscopic retrograde cholangiopancreatography (ERCP) procedures. Whether venous, arterial, or paradoxical, the clinical presentation ranges from asymptomatic patients to cardiorespiratory arrest. This is of particular importance because it makes the diagnosis of air embolism even more difficult in an already sedated patient. Since early recognition increases the chances of patients' survival, endoscopists should be highly motivated and trained to recognize this complication as early as possible. With only 60 cases of air embolism reported (and even fewer related to paradoxical air embolism), we aimed to report a case of paradoxical cerebral air embolism in a patient undergoing ERCP due to a common bile duct stricture and to provide a mini-review of this clinical entity that can serve as a bedside quick reference guide for endoscopists worldwide.

Carbon dioxide: the cause of devastating stroke without hemodynamic compromise during laparoscopic nephrectomy with injury of the inferior vena cava: A case report

RATIONALE

Carbon dioxide pneumoperitoneum in laparoscopic surgery can bring about occult perioperative cerebral infarction, advancing our understanding of the causes of severe postoperative delayed recovery.

PATIENT CONCERNS

Here, we report the case of a 35-year-old woman who underwent a right renal tumor resection in our institution, during which a raised pneumoperitoneum pressure (from 15 to 20 mm Hg) was adopted by the surgeon to prevent errhysis and to help stop the bleeding. Despite an accidental minor tearing of the inferior vena cava, vital signs remained stable throughout the procedure, and no obvious abnormality was observed in either end tidal carbon dioxide values or blood gas analysis. However, the patient unexpectedly suffered delayed recovery after the operation, presenting incomplete left hemiplegia and a positive Babinski sign.

DIAGNOSES

Perioperative stroke was diagnosed by anesthesiologists, after excluding the effects of anesthesia. Cerebral hemorrhage was excluded, as no obvious abnormality was found in the density of brain parenchyma in the emergency computed tomography examination, and a digital subtraction angiography showed no abnormal thrombosis. Further magnetic resonance diagnosis led us to consider diffuse gas embolisms to be the cause of this acute stroke; a right echocardiography revealed that a patent foramen ovale (PFO) may account for the global cerebral gas embolisms.

INTERVENTIONS

The patient received neuroprotective drugs (Vinpocetine, Edaravone, and Xingnaojing, which are commonly used as a standard of care in China), antiplatelets and other symptomatic treatments, plus dexamethasone to relieve edema. A contrast-enhanced echocardiography of the right heart was performed, the results of which were consistent with the sonography of a PFO.

OUTCOMES

The patient was hospitalized for 14 days and eventually discharged after recovery. At the latest follow-up in August 2019, the patient recovered without residual neurological sequelae.

LESSONS

Our results emphasize the need for vigilance regarding adverse cardiovascular and neurological events caused by carbon dioxide gas embolisms when encountering the inadvertent situation of vessels rupturing. Timely monitoring of paradoxical gas embolism by transoesophageal echocardiography is necessary and can avert the risk of severe complications. Urgent consideration should be given to stopping pneumoperitoneum and switching to laparotomy for hemostasis so that the patient can obtain the best benefit-risk ratio.