“Modified Double Protection Closed Compartment” Aspiration Technique for Free Floating Thrombus in Tandem Occlusion

A 63-year-old lady, diagnosed case of rheumatic heart disease with severe mitral valve stenosis, was admitted in the cardiothoracic surgery department for mitral valve replacement surgery. Anticoagulants were stopped before planned surgery. During hospital stay and presurgical workup, she had in-hospital stroke with complains of sudden-onset left-sided numbness and heaviness. After few minutes, she developed left-sided upper and lower limb weakness, and slurring of speech with some altered mentation. Examination revealed Glasgow Coma Scale of 14/15 with power of grade 0/5 in the left side and calculated National Institute of Health Stroke Scale (NIHSS) score of 14. Being in-hospital stroke, the stroke team was alerted immediately and she was advised magnetic resonance imaging of the brain, which showed patchy areas of restricted diffusion in the right internal carotid artery (ICA) (middle cerebral artery [MCA] and anterior cerebral artery [ACA]) territory ([ Fig. 1A ]). There was a significant clinical-radiological mismatch. We suspected a large vessel occlusion in view of high NIHSS score. Thrombolytic therapy was deferred in this case, as the patient had been on anticoagulant medication until 24 hours prior to the onset of stroke symptoms. Patient was immediately taken for digital subtraction angiography within 45 minutes of onset of stroke symptoms, which showed occlusion of the right distal common carotid artery (CCA) ([ Fig. 1B ]). Fig. 1 ( A ) Magnetic resonance (MR) brain showed focal areas of bright signal/restriction suggestive of acute ischemic changes seen in the right middle cerebral artery (MCA) territory. ( B ) Digital subtraction angiography showing hypodensity suggestive of occlusion (green arrow) of right distal common carotid artery (CCA). ( C , D ) Digital subtraction angiography with intracranial angiogram showing occlusion (blue and red arrow, circle) of the right middle cerebral artery (MCA-M2). With the patient under monitored anesthesia care, using retrograde approach, over Terumo 035 guidewire, Neuron Max (Penumbra) was navigated up to the distal cervical ICA with aspiration maintained. Controlled angiogram showed occlusion of the right MCA M2 segment ([ Fig. 1C ] and [ D ]). Thereafter, using Solumbra technique with Solitaire 4 × 40 mm (Medtronic) and 4MAX (Penumbra) aspiration catheter, MCA clot was removed with single pass. Final control angiogram of the right ICA showed mTICI3 recanalization of the right MCA territory. Finally, Neuron Max (Penumbra) was pulled and brought proximal in the right CCA with continuous aspiration on, to look for the residual clots/stenosis. CCA run showed near-complete occlusion of the right distal CCA with evidence of large residual free-floating thrombus extending from the distal CCA to the proximal ICA ([ Fig. 2A ]). Fig. 2 After retrograde approach and mechanical thrombectomy (MT) for middle cerebral artery (MCA) M2 clot—( A ) Left internal carotid artery (ICA) floating thrombus (marked as red circle). ( B ) Right vertebral artery (VA) angiogram—lateral view, showing dominant posterior communicating (PCom) (marked as red arrow) and reformation of the right terminal ICA. ( C ) With balloon guide catheter (BGC) inflated and contralateral puncture—5F Envoy was also placed in the distal common carotid artery (CCA). ( D ) “Modified Double Protection Closed Compartment” technique. ( E ) Clot captured. ( F , G ) Complete recanalization of the right ICA. Contralateral femoral approach was used to demonstrate the anterior communicating (ACom) and posterior communicating (PCom) collaterals. Left vertebral artery injection showed right terminal ICA, MCA, and ACA branches perfusing via dominant PCom. Right ACA territory is also perfused via ACom collaterals ([ Fig. 2B ]). In view of floating clot with anterograde flow in the ICA, we anticipated further distal embolization. Further treatment decision was also governed by multiple factors such as relatively midage and high clot burden. We decided to use a Walrus (Acandis) balloon guide catheter (BGC) for proximal control and exchanged the NeuronMax 088 (Penumbra), to prevent the risk of clot migration during aspiration. Through contralateral femoral approach, we navigated the 5 × 20 mm Viatrac (Abbott) balloon in distal cervical ICA beyond the clot via Envoy 5F (Codman – Johnson & Johnson™), for distal control. This created a closed compartment, for the purpose of minimizing distal clot migration during aspiration ([ Fig. 2C ] and [ D ]). We used a Inspira 072 (Infinity Neuro) aspiration catheter to reduce the clot burden, keeping the double protection. Eventually, we tried aspiration with Walrus (Acandis) BGC with distal balloon protection in situ and were able to retrieve partial clots. Walrus (Acandis) BGC was wedging to the anterior wall. So, to remove the residual clots and overcome the angulation of the artery, we shifted to NeuronMax 088 (Penumbra) to engage and aspirate the residual clot, with the continuous inflation of the distal balloon, for the distal protection. The subsequent angiographic run demonstrated complete opacification of the right ICA up to the inflated balloon with no evidence of residual intraluminal thrombus. Distal balloon deflation and withdrawal were performed while maintaining inflation and aspiration of the BGC. Final control angiography revealed mTICI3 recanalization of the right ICA territory without new perfusion deficits in the MCA compared to the baseline angiographic run ([ Fig. 2F ] and [ G ]). The patient showed no signs of neurological decline following the procedure. A repeat computed tomography brain scan performed the next day, also revealed no new or worsening brain infarcts. The patient underwent a comprehensive evaluation to determine the etiology of the stroke. Echocardiogram showed mitral valve severe stenosis with enlarged left atrium and raised pulmonary artery pressure; however, no thrombus/clot was observed. Long-term Holter monitoring did not detect any clinically significant arrhythmias, and the tracings were normal. Additional laboratory studies, including hypercoagulability profile—homocysteine, protein C and S, antithrombin III, and anticardiolipin antibody levels, were unremarkable. The patient demonstrated significant clinical improvement during hospitalization, with left-sided motor strength increasing to 4 +/5 and improved speech with on-discharge modified Rankin Scale score of 1. This case highlights the critical importance of aggressive intervention in instances where clinical decision-making may significantly influence patient outcomes. This is a modified version of the “Double Protection Closed Compartment” approach described earlier in literature by Ojha et al.[ 1 ] [ 2 ] [ 3 ] A potential limitation of our technique is the risk of distal clot migration during balloon advancement for distal protection. To mitigate this, proximal BGC inflation with aspiration was maintained to induce flow arrest/reversal, thereby reducing the likelihood of clot embolization. The technique we used in this case, “Modified Double Protection Closed Compartment” and also its minute detailing, may offer a valuable approach for managing high-risk cases of this nature ([ Fig. 3A ] and [ B ]). Fig. 3 ( A ) “Modified Double Protection Closed Compartment” technique for right internal carotid artery (ICA)—floating thrombus.( B ) Pictorial representation of “Modified Double Protection Closed Compartment” aspiration technique. Publication History Article published online: 14 July 2026 © 2026. The Author(s). 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