Early Post-operative CT-Angiography Imaging After EC-IC Bypass Surgery in Moyamoya Patients

Helene Hurth; Till-Karsten Hauser; Patrick Haas; Sophie Wang; Annerose Mengel; Marcos Tatagiba; Ulrike Ernemann; Nadia Khan; Constantin Roder

doi:10.3389/fneur.2021.655943

Early Post-operative CT-Angiography Imaging After EC-IC Bypass Surgery in Moyamoya Patients

Front Neurol. 2021 Mar 25:12:655943. doi: 10.3389/fneur.2021.655943. eCollection 2021.

Authors

Helene Hurth^{1

2}, Till-Karsten Hauser³, Patrick Haas^{1

2}, Sophie Wang^{1

2}, Annerose Mengel^{4

5}, Marcos Tatagiba^{1

2

5}, Ulrike Ernemann^{3

5}, Nadia Khan^{1

2

6}, Constantin Roder^{1

2

5}

Affiliations

¹ Department of Neurosurgery, University Hospital Tuebingen, Tuebingen, Germany.
² Center for Moyamoya and Cerebral Revascularization, University Hospital Tuebingen, Tuebingen, Germany.
³ Department of Diagnostic and Interventional Neuroradiology, University Hospital Tuebingen, Tuebingen, Germany.
⁴ Department of Vascular Neurology, University Hospital Tuebingen, Tuebingen, Germany.
⁵ Center for Neurovascular Diseases ZNET, University Hospital Tuebingen, Tuebingen, Germany.
⁶ Moyamoya Center, University Children's Hospital Zurich, Zurich, Switzerland.

Abstract

Objective: To evaluate the clinical value of early post-operative computed tomographic angiography (CTA) after direct extracranial-intracranial (EC-IC) bypass surgery in moyamoya patients. Methods: A retrospective analysis of all adult moyamoya patients treated at our center from 2013 to 2019 with a direct EC-IC bypass was performed. Early post-operative CTA (within 24 h after surgery) was compared with conventional digital subtraction angiography (DSA) 6-12 months after surgery. If available, magnetic resonance time-of-flight angiography (MR-TOF) was evaluated 3 months and 6-12 months post-operatively as well. Imaging results were analyzed and compared with CTA, MR-TOF and DSA, whereat DSA was used as the final and definite modality to decide on bypass patency. Results: A total of 103 direct EC-IC bypasses in 63 moyamoya patients were analyzed. All inclusion criteria were met in 32 patients (53 direct bypasses). In 84.9% the bypass appeared definitively, in 5.7% uncertainly and in 9.4% not patent according to early post-operative CTA. MR-TOF suggested definitive bypass patency in 86.8% 3 months after surgery and in 93.5% 6-12 months after surgery. DSA 6-12 months post-operatively showed a patency in 98.1% of all bypasses. The positive predictive value (to correctly detect an occluded bypass) on post-operative CTA was 12.5%, the negative predictive value (to correctly detect a patent bypass) was 100% with a sensitivity of 100% and a specificity of 86.5%. Conclusion: Early post-operative CTA has a high predictive value to confirm the patency of a bypass. On the other hand, a high false positive rate of (according to CTA) occluded bypasses after direct EC-IC bypass surgery can be seen. This must be considered critically when initiating possible therapeutic measures.

Keywords: CTA; EC-IC bypass; MR-ToF; computed tomographic angiography; magnetic resonance time-of-flight angiography; moyamoya; neurosurgery; revascularization.