Transcranial Doppler 24 Hours after Carotid Endarterectomy Accurately Identifies Patients Not at Risk of Cerebral Hyperperfusion Syndrome

Abstract

WHAT THIS PAPER ADDSA validated prediction model for prevention of cerebral hyperperfusion syndrome (CHS) following carotid endarterectomy (CEA) is lacking; however, early recognition of cerebral hyperperfusion (CH) is crucial to prevent this complication. Intra-operative transcranial Doppler (TCD) is the gold standard to predict the risk of CH in CEA patients under general anaesthesia, but this study finds that post-operative TCD 24 h after CEA is more effective at predicting CH and CHS and is excellent at identifying patients NOT at risk of CHS after CEA. This has clinical relevance for cerebral monitoring protocols in centres performing CEA under general anaesthesia.Objectives: Intra-operative transcranial Doppler (TCD) is the gold standard for prediction of cerebral hyperperfusion syndrome (CHS) in patients after carotid endarterectomy (CEA) under general anaesthesia. However, post-operative cerebral perfusion patterns may result in a shift in risk assessment for CHS. This is a study of the predictive value of additional post-operative TCD measurements for prediction of CHS after CEA. Methods: This was a retrospective analysis of prospectively collected data in patients undergoing CEA with available intra-and post-operative TCD measurements between 2011 and 2016. The mean blood flow velocity in the middle cerebral artery (MCAV mean ) was measured pre-operatively, intra-operatively, and postoperatively at two and 24 h. Intra-operative MCAV mean increase was compared with MCAV mean increase two and 24 h post-operatively in relation to CHS. Cerebral hyperperfusion (CH) was defined as MCAV mean increase ! 100%, and CHS as CH with the presence of headache or neurological symptoms. Positive (PPV) and negative predictive values (NPV) of TCD measurements were calculated to predict CHS. Results: Of 257 CEA patients, 25 (9.7%) had CH intra-operatively, 45 (17.5%) 2 h post-operatively, and 34 (13.2%) 24 h post-operatively. Of nine patients (3.5%) who developed CHS, intra-operative CH was diagnosed in two and post-operative CH in eight (after 2 h [n ¼ 5] or after 24 h [n ¼ 6]). This resulted in a PPV of 8%, 11%, and 18%, and a NPV of 97%, 98%, and 99% for intra-operative, 2 h and 24 h post-operative TCD, respectively. Conclusions: TCD measurement of the MCAV mean 24 h after CEA under general anaesthesia is most accurate to identify patients who are not at risk of CHS.

Variation in perioperative cerebral and hemodynamic monitoring during carotid endarterectomy

“…systolic BP ≤140 mmHg). 14,23,24 As a consequence, a standard 160 mmHg maximum BP policy will still allow for severe complications of CHS to occur despite following a BP policy.…”

“…As a consequence, only a small subset of patients requires strict and immediate BP lowering and monitoring on a HCU while the majority of operated patients can safely be discharged for further BP regulation via the nursing ward or via the outpatient clinic. 14,25 This risk based strategy will lead to a decrease in hospital costs and is more patient-friendly than standard extended strict BP monitoring by a radial artery line.…”

“…12,13 Postoperative TCD measurements two hours and 24 hours in addition to intraoperative TCD measurements have been shown to increase the prediction rate for CHS. 12,14 Recent guidelines by the European Society for Vascular Surgery (ESVS) recommend preoperative antihypertensive treatment in patients with hypertension to maintain long-term BP <140/90 mmHg. Furthermore, when preoperative systolic BP exceeds 180 mmHg, it is advised to first treat hypertension before proceeding with CEA.…”

Mechanically Induced Vasospasm‐Evaluation of Spasmolytic Efficacy of 10 Pharmaceutical Agents Using Laser Speckle Contrast Imaging

“…In an actual clinical setting, there is concern about hyperperfusion. For example, post‐carotid endarterectomy prolonging cerebral hyperperfusion could potentially result in adverse events such as headache, edema, and even intracerebral hemorrhage [36]. However, the hyperperfusion after endarterectomy is caused by the structural change of the carotid artery, which is long‐term.…”

Higher serum occludin after successful reperfusion Is associated with early neurological deterioration

“…33 Studies showed that postoperative cerebral blood flow velocity increased by more than 100% compared with that before surgery, suggesting cerebral hyperperfusion syndrome. 34 We can also use postoperative CTP imaging to observe cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) to identify END. 33,35 In short, postoperative serum biomarker (occludin) combined with cranial imaging (CT/CTP/ TCD) could significantly improve the detection rate of END, which will have important guiding value for clinicians.…”