Digital subtraction angiographic characteristics of progression of moyamoya disease 6 months prior to surgical revascularisation

BackgroundEvidence on the natural angiographic course of moyamoya disease (MMD) is lacking. It takes about 6 months for waiting for revascularisation surgery. The issue of when to perform subtraction angiography (DSA) for follow-up remains unclear. We investigated the natural course of MMD by DSA and attempted to determine the best interval to perform the follow-up DSA.MethodsThis is a single-centre cohort study of Chinese MMD inpatients treated from 1 January 2015 to 31 August 2019. Their angiographic findings were evaluated on Suzuki stage and collateral circulation between two follow-ups of the same hemisphere.ResultsA total of 110 patients who met the criteria were enrolled in this study. After a median 6 months follow-up, five patients (4.5%) had progression, four females and one male. Time interval of progression ranged from 4 to 137 months with a mean of 61.4 months. Of five patients with progression, four had unilateral lesion (two ipsilateral and two contralateral) and one had bilateral lesions. Collateral circulation was changed in three of five patients.ConclusionsThe angiographic evidence of progression in MMD was rare in the short-term follow-up, and most patients with progression had initial unilateral involvement. DSA re-examination may be not needed in patients with bilateral MMD, but needed in unilateral MMD.

Cervical ICA pseudo-occlusion on single phase CTA in patients with acute terminal ICA occlusion: what is the mechanism and can delayed CTA aid diagnosis?

BackgroundSingle-phase CT angiography (CTA) forms the basis of hyperacute stroke imaging but many patients with terminal internal carotid artery (ICA) occlusion exhibit a pseudo-occlusion of the cervical ICA whereby a column of unopacified blood mimics a tandem cervical ICA lesion. We aimed to investigate the utility of a delayed phase acquisition to aid identification of a pseudo-occlusion and investigated the mechanism for this imaging artefact.MethodsThirteen patients with a pseudo-occlusion were compared with 13 patients without. CT, CTA, and digital subtraction angiographic images were reviewed by two interventional neuroradiologists for extension of thrombus into the ophthalmic segment, filling of the posterior communicating artery and ophthalmic artery, and for extension of contrast beyond the cervical segment and outline of the proximal clot surface by contrast on delayed imaging performed at 40 or 80 s.ResultsThose with a pseudo-occlusion demonstrated more frequent thrombus extension into the ophthalmic segment (100% vs 23%, P=0.0001), less frequent filling of the posterior communicating artery (15% vs 85%, P=0.0012), and less frequent filling of the ophthalmic artery (15% vs 92%, P=0.0002) compared with those without a pseudo-occlusion. Delayed CTA imaging showed contrast beyond the cervical segment and meeting the proximal clot face in 2/11 patients. Each of these two patients showed patency of the posterior communicating artery origin.ConclusionThrombus extension into the ophthalmic segment and patency of the posterior communicating artery and ophthalmic artery seem to govern whether a patient with a terminal ICA occlusion exhibits a pseudo-occlusion. Delayed imaging was of limited value in identification of a pseudo-occlusion.

Endovascular treatment of previously clipped aneurysms: continued evolution of hybrid neurosurgery

Background/objectiveThe optimal management of residual or recurrent clipped aneurysms is infrequently addressed in the literature.MethodsWe reviewed our endovascular database from January 1998 to May 2016 to identify patients with clipped aneurysms undergoing subsequent endovascular treatment, evaluating treatment approach, and clinical and angiographic outcomes.Results60 patients underwent endovascular treatment of residual/recurrent clipped aneurysms; 7 rebled prior to endovascular therapy. Treatment was via coiling alone (n=25, 42%), stent assisted coiling (n=15, 25%), balloon assisted coiling (n=8, 13%), flow diversion (n=8, 13%), stenting alone (n=3, 5%), or flow diversion with coiling (n=1, 2%). The procedural permanent neurological morbidity and mortality rates were 3% and 2%, respectively. Over a clinical follow-up of 253.4 patient years (median 3.9 years), there was one rebleed in a patient who had declined further treatment. For 43 patients with at least 1 month of digital subtraction angiographic follow-up (median 3.4 years), complete aneurysm occlusion was seen in 79% of cases. Neck remnants were observed in 14%, and stable small dome remnants were observed in 7% of cases. In a subgroup of 18 patients with ‘clip induced’ narrow neck aneurysms, all domes were initially coil occluded (Raymond 1 or 2); there was no permanent procedural morbidity and no aneurysms required retreatment or recanalized over a median follow-up of 3.9 years.ConclusionsEndovascular treatment of residual or recurrent clipped aneurysms is an excellent treatment approach in well selected patients; ‘clip induced’ narrow neck aneurysms fare particularly well after treatment both angiographically and clinically.

Intra-arterial application of nimodipine in reversible cerebral vasoconstriction syndrome: A diagnostic tool in select cases?

Introduction: Differential diagnoses of the reversible cerebral vasoconstriction syndrome (RCVS) include all forms of intracranial stenotic disease, such as primary or secondary vasculitis of the central nervous system. Here, we tested the hypothesis that angiographic response to intra-arterial nimodipine application may be helpful in differentiating between RCVS and other entities. Methods: A digital subtraction angiographic (DSA) series of nine consecutive patients with suspected RCVS that were treated by intra-arterial nimodipine due to clinical worsening were retrospectively analyzed. Pre- and post-therapeutic DSA findings of patients with later-confirmed RCVS were compared to those in which another diagnosis was finally made. Results: Intra-arterial nimodipine resulted in a normalization of both the diameter of the main trunks of the cerebral vessels and the caliber of the peripheral vessels in all RCVS patients. This was not the case in the non-RCVS patients, in whom only a slight general vasodilatation was observed. Discussion: Our preliminary results indicate that angiographic response to intra-arterial application might be a helpful differential diagnostic tool in select patients with suspected RCVS.

Improved Image Interpretation With Combined Superselective and Standard Angiography (Double Injection Technique) During Embolization of Arteriovenous Malformations

Objective: Interpretation of angioarchitecture during embolization of intracranial arteriovenous malformations (AVMs) is critical to optimizing results. We describe an adjunctive technique to aid in the interpretation of AVM embolization and improve safety. Methods: In the past 100 consecutive patients who underwent AVM embolization by a single surgeon (RAM), each AVM nidus was selectively catheterized and microangiography was performed. After the microcatheter contrast exited the AVM, guiding catheter angiography was performed during the same digital run. The microangiogram was digitally superimposed on the guiding catheter angiogram to delineate important landmarks such as the nidus perimeter, draining veins, and microcatheter tip, which were then drawn on the digital subtraction angiographic monitor with a marking pen in two orthogonal views. Results: Important landmarks were continually visualized during the embolization procedure despite subtracted fluoroscopy (“blank” roadmap). These techniques qualitatively helped to: 1) appreciate the overall size and morphology of the nidus, 2) clearly visualize the safe limits of the embolic injection within the nidus perimeter, 3) clearly visualize draining patterns to help avoid premature venous embolization, 4) decipher small draining veins from arteries, 5) continuously monitor the location and status of the microcatheter tip, and 6) increase the confidence of the surgeon during prolonged embolic injections. Conclusion: The double injection technique, with marking pen demarcation of the nidus perimeter, venous drainage, and microcatheter tip position, was qualitatively useful in every case.