Systemic Air Embolism With Hepatic Portal Venous Gas (HPVG) Following Endoscopic Balloon Dilatation of Esophageal Stricture

Abstract

Introduction: Systemic air embolism is a rare complication of endoscopy and balloon dilatation, though ERCP related air embolism has been seen. HPVG has been seen with ulcerative colitis, diverticulitis, suppurative cholangitis and ERCP. Arterial cerebral air embolism requires an intracardiac shunt though arterio-venous fistulas in the lung and thebesian vein transgression is possible. Symptomatology commonly includes cardiopulmonary collapse, while fatalities from cerebral embolism have also been seen. Supportive measures play an important role in management, while hyperbaric oxygen therapy remains first line therapy. Depressed level of consciousness, poor hemodynamics and sometimes bleeding should raise suspicion of the complication. Case: 25-yearold HIV positive male was transferred to our medical ICU from an outside facility for hyperbaric therapy, for suspected systemic air embolism in the form of hepatic portal venous gas and visualization of air in the cerebral cortical veins. Patient was found to be unresponsive following his fourth balloon dilatation of esophageal strictures followed by some improvement in mental status but right sided hemiparesis and confusion. Hemodynamics declined requiring dopamine infusion for bradycardia and hypotension. Emergent CT scans showed above mentioned findings along with air in the esophageal mucosal wall. Patient was treated with 2.4 atmosphere pressure for 90 mins with improvement in hemodynamics and gradual improvement of condition with no residual deficits. Esophageal perforation was later ruled out using swallow studies. Discussion: Mechanisms suggested for air embolism mainly include mucosal irritation and disruption, mucosal edema, blind loop formation and infection followed by transgression of air into the venous system. Insufflation of air into the gastrointestinal tract for interventional procedures may facilitate this movement of air even though it is kept at low pressures. HPVG deserves to be its own entity with wide causality. Oft en seen as centrifugal branching lucency from portahepatis towards the capsule, it can be diff erentiated from pneumobilia which is centripetal owing to bile flow towards the hilum. Slower rate of air migration may be tolerated better as the body is able to absorb it, while cardiovascular collapse and death may be seen with sudden, large air emboli, especially if air is shunted across a patent foramen ovale to the arterial side in which case fatal cerebral embolism may be seen. Though rare, it should always be considered in case of peri or post-procedural hemodynamic compromise or alteration of mental status including loss of consciousness.