2024 FSA Podium and Poster Abstracts
P062: PREVENTION OF VASCULAR AIR EMBOLISM IN A PATIENT WITH PERSISTENT LEFT SUPERIOR VENA CAVA (PLSVC) UNDERGOING NEUROSURGERY IN SITTING POSITION
Hala Baaj1; Gabriel Garcia, MD2; Gerald Rosen, MD3; 1Florida International University, Herbert Wertheim College of Medicine; 2Cleveland Clinic Florida; 3Mount Sinai Medical Center
Incidence of embolism in patients undergoing sitting position craniotomy and posterior fossa surgery is high, > 25% [1]. Standard preventive measures include adequate patient positioning, hydration, clinical inspection, hemodynamic monitoring and monitoring of oxygen saturation and end-tidal nitrogen and end-tidal carbon dioxide. A 65-year-old female patient with metastatic breast cancer to the brain was found to have a PLSVC upon placement of a central venous catheter for prophylactic treatment of vascular air embolism.
Introduction: During any operative situation when the patient’s head is positioned 10 cm above the mid-thorax (> 20 degrees elevation), a potential negative pressure exists between the venous sinuses of the head and the central venous system. Air entrainment into the central venous system may collect in the right side of the heart and obstruct pulmonary flow. Thus, detection of air embolism is crucial, either via the most sensitive method of the TEE followed by precordial Doppler and PA catheter or the less sensitive Transcranial Doppler, end-tidal nitrogen and end-tidal carbon dioxide.
Case Report: Patient is a 65-year-old female with metastatic breast cancer to the brain, hypertension, and a BMI of 27.3. Her head CT showed right posterior fossa with significant surrounding vasogenic edema, favoring the presence of an intra-axial mass. Patient was scheduled to have right posterior fossa craniectomy/craniotomy for biopsy and excision of right posterior fossa lesion. Given the high risk of venous air embolism during a sitting position craniotomy, the anesthesiology team placed a central venous catheter for air embolism prophylactic treatment. The patient was positioned head down until the catheter was inserted and catheter’s hub occluded. A single portable supine AP view of the chest showed central venous catheter traversing a duplicated LSVC with its tip terminating over the expected region of the coronary sinus. CVP line was removed due to abnormal anatomy (duplicated LSVC) and femoral line placed for vasopressors as needed.
Discussion: PLSVC is a common congenital malformation of thoracic venous return usually found incidentally via imaging or placement of central venous lines. The majority of LSVC cases drain into the right atrium via a coronary sinus and are asymptomatic without significant adverse long term outcomes. However, a minority can drain into the left atrium, directly or indirectly via an unroofed coronary sinus. To confirm correct central venous catheter placement, a portable supine AP view chest X-ray was performed on patient. It showed central venous catheter traversing a duplicated LSVC with its tip terminating over the coronary sinus.
Conclusion: This case highlights the importance of suspecting LSVC when a dilated coronary sinus is identified during TEE imaging. In the four-chamber view, LSVC can be recognized as a large circular structure alongside the lateral annulus of the mitral valve. It can also be identified as a posterior vessel entering the right atrium [2]. In mid-esophageal views, PLSVC may be seen close to the left atrial appendage and left upper pulmonary vein [3]. Confirmatory imaging of PLSVC includes TTE, TEE, venous angiography, CT or MRI.
1)PMID: 17197859
2)PMID: 35734721
3)PMID: 20532458