Iatrogenic Cerebral Amyloid Angiopathy After Cardiac Surgery: Two Case Reports.

Two patients developed probable cerebral amyloid angiopathy following cardiac surgery for transposition of the great vessels involving cadaveric dura mater patches.

• Both patients presented with symptomatic hematomas as the revealing clinical feature.
• Neuroimaging features met criteria for probable CAA according to Boston 2.0 criteria.
• Both cases featured early onset of CAA.
• Neither patient had hereditary causes of CAA identified.

PET amyloid imaging and CSF analysis confirmed diffuse brain amyloidosis in both patients.

• 18F-flutemetamol PET imaging evidenced diffuse brain amyloidosis in both cases.
• CSF analysis showed abnormal Aβ levels in both patients.
• These findings supported a diagnosis of iatrogenic CAA rather than spontaneous or genetic CAA.

The cases demonstrate that Aβ transmission leading to CAA can occur through non-neurosurgical procedures involving CNS-derived cadaveric tissues.

• Both patients underwent cardiovascular surgery, not neurosurgery, removing a previously present confounding factor in prior iatrogenic CAA cases.
• The proposed mechanism of transmission was use of cadaveric dura mater patches during cardiac surgery.
• The authors state these cases 'add to the growing evidence regarding Aβ transmissibility in humans and remove the confounding factor of neurosurgery.'

The authors propose diagnostic criteria for iatrogenic CAA that include exclusion of genetic causes, evidence of CNS Aβ accumulation, early onset, and a suggestive medical history.

• Iatrogenic CAA diagnosis should be considered after exclusion of genetic causes.
• Patients should have early-onset clinical and neuroimaging features of CAA.
• Evidence of Aβ accumulation in the CNS is required.
• A suggestive medical history involving exposure to potentially contaminated CNS-derived tissues is necessary.

The authors conclude that treatments at risk for iatrogenic CAA should not be limited to neurosurgery but should include cardiovascular procedures involving CNS tissues.

• Identified at-risk treatments include cardiovascular procedures using cadaveric dura mater.
• Exposure to cadaveric human growth hormone is also identified as a risk factor.
• The finding broadens the scope of procedures considered capable of transmitting Aβ pathology.