A nomogram predicting the relationship between recanalization time and successful endovascular recanalization of non-acute internal carotid artery occlusion in a Chinese population.

Different recanalization times for endovascular interventions may affect the success of non-acute internal carotid artery occlusion procedures. Nomograms can provide personalized and more accurate risk estimates based on predictive values. Therefore, we developed a nomogram to predict the probability of success of endovascular recanalization procedures for non-acute internal carotid artery occlusion. We performed a single-center retrospective analysis of data collected from patients who underwent endovascular treatment for non-acute internal carotid artery occlusion between January 2015 and December 2022. Multifactorial logistic regression analyses were performed to identify independent predictors affecting the success rate of non-acute internal carotid artery occlusion procedures and to create nomograms. The model was differentiated and calibrated using the area under the ROC curve (AUC-ROC) and calibration plots. Internal validation of the model was performed by using resampling (1000 replications). In total, 46 patients were identified and a total of 39 patients met the study criteria. Predictors in the nomogram included vascular occlusion proximal morphology, reversed flow of the ophthalmic artery, and recanalization time. The model showed good resolution with an ROC area of 0.917 (95% CI: 0.814-0.967). The nomogram can be used to personalize, visualize, and accurately predict the surgical success of endovascular treatment of non-acute internal carotid artery occlusion.

Acute Internal Carotid Artery Occlusion Long after Carotid Revascularization by Vein Graft.

We report the case of a 27-year-old woman with acute internal carotid artery occlusion long after carotid artery revascularization by vein graft. She presented with sudden unconsciousness and left hemiparesis. Her right carotid artery was revascularized with an ipsilateral internal jugular vein graft during a carotid body tumor resection 10 years ago. Computed tomography angiography revealed a right internal carotid artery terminus occlusion. Intravenous rt-PA and mechanical thrombectomy were performed, resulting in successful recanalization. Her neurological symptoms gradually recovered. When examining the embolic source, carotid ultrasonography for the vein graft showed intimal thickening, some high-echoic plaques, and lumen dilation, but no thrombus was observed. Color Doppler imaging showed laminar flow at the graft. Angiography after thrombectomy also showed pooling of contrast at the vein graft. We suspected that the blood flow stagnation at the vein graft induced thrombus formation; therefore, anticoagulation therapy was initiated. One year later, she was independent without recurrence of stroke, and anticoagulation therapy was replaced with aspirin because she went abroad. However, a carotid ultrasonography exam the following year revealed a huge thrombus at the graft. Anticoagulation therapy was resumed; subsequently, the thrombus decreased. In conclusion, we could monitor the long-term change in the vein graft by ultrasonography. Moreover, anticoagulation therapy was more effective.

Contrast agent retention sign in angiography predicts acute internal carotid artery embolic occlusion.

BACKGROUND: Identification of acute internal carotid artery embolism (ICAE) and internal carotid artery atherosclerotic stenosis (ICAAS) in acute ischemic stroke patients is important for selection of treatment. The presence of contrast agent retention on pre-procedural angiographic images is more common in patients with ICA occlusion caused by embolism compared to patients with ICA atherosclerotic stenosis. This study aimed to evaluate effectiveness of contrast agent retention sign for predicting ICAE. METHODS: Sixty-five patients with ICA occlusion who underwent emergency endovascular treatment from September 2014 to September 2020 were included in this retrospective analysis. Patients were divided into ICAE (n = 46) and ICAAS (n = 19) groups. Clinical characteristics, imaging data and ICA contrast agent retention signs of patients were collected. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnosis accuracy of contrast agent retention sign were conducted. RESULTS: The positive ICA contrast agent retention sign was significantly more common in patients with ICAE (60.87% vs 0.00%, P < 0.001) than that of patients with ICAAS, but significantly lower in male patients (53.57% vs 81.08%, P = 0.017). There were significantly more patients with positive sign had occlusion in C6 segment (64.29% vs 13.51%, P < 0.001) and no outflow tract (85.71% vs 5.41%, P < 0.001) compared with negative sign group. There were significantly fewer patients with postive sign had occlusion in C1 segment (0.00% vs 40.54%, P < 0.001) compared with negative sign group. The sensitivity, specificity, PPV, NPV and diagnosis accuracy of contrast agent retention sign for predicting ICAE occlusion were 60.87%, 100%, 100%, 51.35% and 72.31%, respectively. CONCLUSION: The ICA contrast agent retention sign has very high specificity and moderate sensitivity for detection of acute ICAE.

Usefulness of contralateral carotid angiography in revascularization therapy of acute internal carotid artery occlusion.

OBJECTIVE The vascular lumen of an acutely occluded internal carotid artery (ICA) generally contains numerous thrombi. Therefore, carotid angiography on the affected side during revascularization therapy of acute ICA occlusion has a potential risk of causing distal embolization. In this study the authors propose the use of contralateral carotid angiography. METHODS Six patients with acute ICA occlusion underwent revascularization therapy using a stent retriever or Penumbra system. Revascularization therapy was performed with placement of a 9-Fr balloon-guiding catheter (BGC) in the affected ICA and a 4-Fr diagnostic catheter in the contralateral ICA. During the procedure, the 9-Fr BGC was kept inflated, and all control angiography was performed from the 4-Fr diagnostic catheter. After thrombectomy, contralateral carotid angiography combined with manual aspiration from the 9-Fr BGC was performed to assess the presence or absence of residual thrombi in the affected ICA. The 9-Fr BGC was deflated only after the complete absence of residual thrombi in the affected ICA was confirmed. RESULTS The time required for introducing the 4-Fr diagnostic catheter into the contralateral ICA was within a few minutes in all patients. Residual thrombi in the affected ICA were found in 3 of 6 patients. The residual thrombi in these 3 patients were completely removed; thus, distal embolization was prevented. CONCLUSIONS Contralateral carotid angiography is useful for avoiding distal embolization during revascularization therapy of acute ICA occlusion. Further studies involving a larger number of patients are warranted to verify the clinical efficacy of this contralateral carotid angiography.