Cardiovascular Surgical Procedures

Cerebral perfusion monitoring, via an 8 channel EEG covering both cerebral hemispheres enables  side to side comparison. A pre- incision and post- incision baseline EEG is acquired, which provide  comparable basis to any changes that might occur, during the entirety of the procedure especially  during certain critical times such as: 

Clamp placement: At this point any decrease in EEG frequency represents cerebral ischemia to the  affected hemisphere. Changes occur within the first two minutes of clamp placement. 

Shunt placement can as an unintended consequence cause thrombosis leading to stroke. Utilizing EEG  we can detect any stroke activity as it occurs. Removal of shunt and clamp can also have similar  results. 

Additionally, bilateral Somatosensory monitoring (SSEP) from the upper limbs is also monitored. This  serves as a secondary safety measure. It corroborates EEG findings by providing proof or lack of proof  of an active primary sensory cortex on each hemisphere. 

The monitoring approach varies slightly for these depending on the location of the aneurysm on the  aorta. However as a general rule Somatosensory Evoked Potentials, Transcranial Motor Evoked  Potentials (TcMEPs) and EEG's to monitor for proper perfusion is utilized. 

During Thoracic and ThoracoAbdominal aortic repairs, risk of neurological complications increase  after 30 minutes of spinal cord ischemia. SSEP and TcMEP can quickly detect loss of perfusion to the  spinal cord. Loss of wave forms typically occurs within 2 minutes of cross clamping. 

The same method can be utilized to ensure proper cerebrospinal fluid (CSF) flow in cases where CSF drainage is employed. 

For infrarenal and femoral artery clamping, the lower extremities is targeted, for peripheral perfusion  utilizing lower limb SSEPs and TcMEPs. Loss of waveforms happen almost instantly when perfusion  stops. 



The strategic use of hypothermic circulatory arrest for cerebral protection during aortic arch surgery  can be critical to patient safety. Utilizing EEG can pinpoint the exact moment cerebral hypothermia  occurs by monitoring cerebral activity via EEG Waves, which will slow down at about 28 degrees  Celsius and continue to slow with lowering temperatures until complete loss or flattening of waveforms  occurs at hypothermic temperatures which is typically between 19-22 degrees.

The integrity of the recurrent laryngeal nerve is monitored, Utilizing a 4 channel recording  electrode on the endotracheal tube . These electrodes can guard against possible pressure or damage to  the nerves caused by retraction or by any mechanical/surgical manipulation. Additionally a flush tipped  90mm direct nerve stimulation probe is provided . These have proven to be an invaluable tool for nerve  preservation during excision of mass and can be useful in pre/post excision signal acquisition, to  document the integrity of the nerve.

Neuromonitoring for Cardiovascular Procedures

Carotid Endarterectomy:

Aortic Aneurysm Repairs/Dissections:

Thyroidectomy: