A case of right middle cerebral artery 'tendonectomy' following mitral valve replacement surgery

Case of postoperative mitral and tricuspid valve repair with large vessel occlusion ischaemic stroke: successfully treated with mechanical thrombectomy extracting subocclusive thrombus containing foreign material

A woman in her 60s with a history of prior ischaemic stroke developed acute onset slurring of speech, left-sided facial droop and left-sided weakness and was found on CT angiography to have a subocclusive thrombus multiple days after undergoing mitral and tricuspid valve repair surgery. A stent retriever and aspiration catheter were used to successfully remove the subocclusive material which was identified as 'foreign material' on histology. Ultimately, the patient demonstrated clinical improvement.Foreign material embolism is a rare but serious complication that can occur during or after mitral and tricuspid valve repair surgery. It can cause ischaemic stroke and prompt recognition and immediate intervention are necessary to prevent serious complications.The case report highlights the successful use of stent retriever-mediated suction thrombectomy to remove a foreign material embolism in a patient. It emphasises the importance of timely intervention to prevent serious complications and shows the potential benefits of this technique.

Mechanical thrombectomy in ischemic stroke after cardiovascular procedures: a propensity-matched cohort analysis

BACKGROUND

Stroke after a cardiovascular procedure (CVP) is a devastating complication adversely affecting outcome. Mechanical thrombectomy (MT) has not been investigated systematically in this population.

OBJECTIVE

To carry out a retrospective study in patients undergoing MT for early stroke after CVP, aiming to further characterize this cohort of patients, and to evaluate the efficacy, safety, procedural characteristics, and outcome of MT.

METHODS

A single-center stroke registry of patients who received MT was analyzed. Baseline and procedural parameters, mortality, functional outcome, recanalization rates, and complications were evaluated. Propensity score matching was carried out, identifying a control cohort with non-periprocedural large vessel occlusion (LVO).

RESULTS

Overall 913 patients were included (mean age 73.0 (±13.0) years, 52.5% female, median National Institutes of Health Stroke Scale score 15 (10-19)). Eleven patients with a LVO after a recent (<30 days postoperatively) CVP were identified (n=3 transcatheter aortic valve and n=1 surgical aortic valve replacements (SAVR), n=3 coronary bypass grafting (CABG) surgeries, n=2 SAVR+CABG, and n=2 aortic surgeries). After matching, 8 patients in the CVP group were compared with 16 patients in the matched cohort. Comparable rates of reperfusion were achieved. Time from symptom onset to groin puncture (171.5 min (136.3, 178.3) vs 284.0 min (215.0, 490.5); p=0.039), as well as recanalization (195.0 min (146.0, 201.0) vs 419.0 min (274.0, 613.0); p=0.028) was faster in the CVP group. However, this was not reflected by an improved outcome (modified Rankin Scale score after 90 days: 5.5 (3.3, 6.0) vs 5.0 (4.0, 6.0), mortality after 90 days 50.0% vs 37.5%). Complications did not differ between the groups.

CONCLUSIONS

Use of MT for LVO stroke in patients after a recent CVP is a safe and efficient treatment in comparison with patients with a non-periprocedural LVO undergoing MT.

Symptomatic Intracranial Artery Stenosis Due to an Unknown Embolus Following Cardiac Surgery: A Case Report

Intracranial artery occlusion due to a foreign body is a complication associated with cardiac surgery that is treated by various techniques. However, little is known about appropriate strategies for symptomatic intracranial artery stenosis due to an unknown embolic source. We reported a case of middle cerebral artery (MCA) stenosis after mitral valve repair (MVR) for infective endocarditis (IE). An 80-year-old man presented with right hemiplegia. MR angiography findings were normal, and diffusion-weighted imaging revealed subtle ischemic change in the left MCA territory. The patient was diagnosed with cardioembolic stroke owing to IE and performed MVR. Four days later, he suddenly presented with consciousness disorder and left hemiplegia. Computed tomography (CT) confirmed a very low-density area within the right MCA. MR angiography revealed right MCA stenosis, which corresponded to the low-density area on CT images. Diffusion-weighted imaging revealed new ischemic change in the right MCA territory. Angiography confirmed an irregular stenosis at the right M2 with antegrade blood flow, and the hemiplegia resolved during angiography. Conservative therapy was performed; however, the resting 123 I-IMP-single photon emission CT revealed moderate perfusion defect in the right MCA territory, and transient left hemiplegia appeared every few days. Therefore, 19 days after the initial transient ischemic attack, the patient was performed superficial temporal artery–MCA anastomosis, and the patient responded with a good clinical course without recurrence of the ischemic symptoms. This strategy may be a safe and effective treatment for symptomatic intracranial artery stenosis due to an unknown embolic source.

Clot Composition Analysis as a Diagnostic Tool to Gain Insight into Ischemic Stroke Etiology: A Systematic Review

Mechanical thrombectomy renders the occluding clot available for analysis. Insights into thrombus composition could help establish the stroke cause. We aimed to investigate the value of clot composition analysis as a complementary diagnostic tool in determining the etiology of large vessel occlusion (LVO) ischemic strokes (International Prospective Register of Systematic Reviews [PROSPERO] registration # CRD42020199436). Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we ran searches on Medline (using the PubMed interface) and Web of Science for studies reporting analyses of thrombi retrieved from LVO stroke patients subjected to mechanical thrombectomy (January 1, 2006 to September 21, 2020). The PubMed search was updated weekly up to February 22, 2021. Reference lists of included studies and relevant reviews were hand-searched. From 1,714 identified studies, 134 eligible studies (97 cohort studies, 31 case reports, and six case series) were included in the qualitative synthesis. Physical, histopathological, biological, and microbiological analyses provided information about the gross appearance, mechanical properties, structure, and composition of the thrombi. There were non-unanimous associations of thrombus size, structure, and composition (mainly proportions of fibrin and blood formed elements) with the Trial of Org 10172 in Acute Stroke Treatment (TOAST) etiology and underlying pathologies, and similarities between cryptogenic thrombi and those of known TOAST etiology. Individual thrombus analysis contributed to the diagnosis, mainly in atypical cases. Although cohort studies report an abundance of quantitative rates of main thrombus components, a definite clot signature for accurate diagnosis of stroke etiology is still lacking. Nevertheless, the qualitative examination of the embolus remains an invaluable tool for diagnosing individual cases, particularly regarding atypical stroke causes.

Acute ischemic stroke secondary to cardiac embolus of a 'foreign body' material after a redo sternotomy for mitral valve replacement: A case report

Cardiac surgery has been shown to be associated with increased risk of acute ischemic stroke. This report presents a case of a successful mechanical embolectomy procedure to treat a patient for an acute ischemic stroke, which was caused by the cardiac embolization of a 'foreign body' containing debris following a redo sternotomy procedure for mitral valve replacement and tricuspid valve annuloplasty.

Histology of Thrombectomy Specimen Reveals Cardiac Tumor Embolus in Cryptogenic Young Stroke

A 25-year-old woman presented with acute onset of right hemiplegia and global aphasia with National Institutes of Health Stroke Scale score of 19. Computed tomography angiography demonstrated occlusion of the left proximal middle cerebral artery. She was thrombolysed with intravenous recombinant tissue plasminogen activator (0.6 mg/kg) within 3 hours of onset of symptoms and was taken up for mechanical thrombectomy. The retrieved specimen appeared pale white and soft; histopathologic examination revealed a papillary neoplasm composed of papillae with hyalinized cores lined by endothelium, consistent with papillary fibroelastoma of cardiac origin. Transesophageal echocardiography showed no abnormalities, which can be explained by complete embolization of the mass into the cerebral circulation. On follow-up after 5 months, the patient recovered with only minimal aphasia and no cardiac symptoms. Our experience with this case highlights the importance of histopathologic examination of the mechanical thrombectomy specimen, as it provided the only clue to the etiology of stroke.