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Clarençon, Frédéric

0000-0002-6442-8239

Mayo Clinic

Department of Neuroradiology, Pitié-Salpêtrière Hospital, Paris, France.

Citations 5

Factors associated with early neurological deterioration in minor distal medium vessel acute ischemic stroke: A multinational multicenter study
Lakhani, Dhairya A. , Salim, Hamza , Yedavalli, Vivek , Milhem, Fathi , Adeeb, Nimer , Faizy, Tobias D. , Naamani, Kareem El, Henninger, Nils , Sundararajan, Sri Hari , Khalife, Jane, Ghozy, Sherief, Tan, Benjamin Yong‐Qiang , Regenhardt, Robert W. , Heit, Jeremy J. , Rouchaud, Aymeric, Fiehler, Jens, Puri, Ajit S., Dyzmann, Christian , Colasurdo, Marco, Filipe, João Pedro , Abdalkader, Mohamad , Marrota, Thomas, Spears, Julian , Biswas, Arundhati , Clarençon, Frédéric , Varela, Ricardo , Baker, Amanda , Altschul, David , Gonzalez, Nestor R. , Möhlenbruch, Markus , Costalat, Vincent, Gory, Benjamin, Stracke, Christian Paul , Hecker, Constantin, Shaikh, Hamza , Griessenaur, Christoph, Liebeskind, David S. , Alexandre, Andrea , Tancredi, Illario, Kalsoum, Erwah , Lubicz, Boris , Patel, Aman B. , Guenego, Adrien , Investigators, for the MAD MT, Salim, Hamza , Faizy, Tobias D , Henninger, Nils , Tan, Benjamin Yq , Cancelliere, Nicole M , Alexandru Radu, Răzvan , Ota, Takahiro , Jabbour, Pascal , Clarençon, Frédéric , Siegler, James E , Nguyen, Thanh N , Essibayi, Muhammed Amir , Gonzalez, Nestor R , Marnat, Gaultier , Pedicelli, Alessandro , Alexandre, Andrea M , Guenego, Adrien , Dmytriw, Adam A , Liebeskind, David S. , Heit, Jeremy J , Altschul, David J , Regenhardt, Robert W , Lakhani, Dhairya , Yedavalli, Vivek S , Varela, Ricardo , Musmar, Basel , Daraghma, Motaz , Naamani, Kareem El , Kühn, Anna Luisa , Khalife, Jane , Ghozy, Sherief , Scarcia, Luca , Yeo, Leonard Ll , Cancelliere, Nicole M , Rouchaud, Aymeric , Sheth, Sunil A , Puri, Ajit S , Colasurdo, Marco , Renieri, Leonardo , Harker, Pablo , Radu, Răzvan Alexandru , Klein, Piers , Marotta, Thomas R. , Mowla, Ashkan , Jabbour, Pascal , Siegler, James E. , Nguyen, Thanh N. , Essibayi, Muhammed Amir , Costalat, Vincent , Gory, Benjamin , Hecker, Constantin , Griessenauer, Christoph J. , Tancredi, Illario , Mendes Pereira, Vitor , Wintermark, Max , Dmytriw, Adam A. , Investigators, for the MAD MT

International Journal of Stroke | September 16, 2025 | Volume: 21 | Issue: 3 | Pages: 343-352

10.1177/17474930251381946 Get It

Background: Patients with acute ischemic stroke secondary to distal and medium vessel occlusion (AIS-DMVO) and minor strokes present a challenge in determining the most appropriate emergent treatment. Factors leading to early neurological deterioration (END) in this patient population are understudied, but END is known to result in poor functional outcomes. Therefore, we aimed to investigate the factors contributing to END in minor AIS-DMVO cases. Methods: We included patients with AIS-DMVO and minor strokes from 37 sites across North America, Asia, and Europe. Minor stroke was defined as a baseline National Institutes of Health Stroke Scale (NIHSS) score of ⩽5. The primary outcome measure, END, was defined as a shift of ⩾4 points in the NIHSS score at day one after treatment compared to baseline. Univariable and multivariable logistic regression analyses were performed to identify factors associated with END. Results: Among 559 consecutive patients with DMVO and minor strokes, END was reported in 68 patients. In multivariable analysis, mechanical thrombectomy (MT) was independently associated with higher odds of END (adjusted odds ratio [aOR] 2.37, 95% CI 1.12–5.02, p = 0.02), while intravenous thrombolysis (IVT) was associated with lower odds of END (aOR 0.46, 95% CI 0.26–0.81, p = 0.008). However, the association between MT and END was no longer statistically significant in the IPTW-adjusted analysis (OR 1.65, 95% CI 0.69–3.98, p = 0.26). Hypertension and antiplatelet use at baseline were also independently associated with END. Among MT-treated patients, successful and excellent recanalization and first-pass effect were protective against END. Conclusion: MT was associated with END in patients with minor AIS-DMVO, although this association was not significant after IPTW adjustment. IVT was independently associated with reduced risk of END. These findings support careful patient selection and further study in randomized trials.
Baseline predictors of poor clinical outcome despite recanalization of distal middle cerebral artery occlusions
Chafai, Imene , Salim, Hamza , Musmar, Basel , Adeeb, Nimer , Yedavalli, Vivek , Tjoumakaris, Stavropoula , Henninger, Nils , Nedelcu, Simona , Sundararajan, Sri Hari , Kühn, Anna Luisa , Khalife, Jane , Tan, Benjamin Yong‐Qiang , Heit, Jeremy J. , Regenhardt, Robert W. , Puri, Ajit S , Dyzmann, Christian , Filipe, João Pedro , Marotta, Thomas R. , Spears, Julian , Biswas, Arundhati , Clarençon, Frédéric , Varela, Ricardo , Baker, Amanda , Altschul, David , Gonzalez, Nestor R. , Möhlenbruch, Markus , Costalat, Vincent , Stracke, Christian Paul , Shaikh, Hamza , Liebeskind, David S. , Alexandre, Andrea , Tancredi, Illario , Faizy, Tobias D. , Kalsoum, Erwah , Patel, Aman B. , Wang, Maud , Lubicz, Boris , Guenego, Adrien , ##, On behalf of the MAD MT Investigators, Tjoumakaris, Stavropoula , Ghozy, Sherief , Scarcia, Luca , Tan, Benjamin Yq , Heit, Jeremy J , Regenhardt, Robert W , Cancelliere, Nicole M , Bernstock, Joshua D , Rouchaud, Aymeric , Fiehler, Jens , Sheth, Sunil A , Essibayi, Muhammed Amir , Colasurdo, Marco , Marnat, Gaultier , Renieri, Leonardo , Filipe, João Pedro , Harker, Pablo , Alexandru Radu, Răzvan , Marotta, Thomas R , Spears, Julian , Ota, Takahiro , Mowla, Ashkan , Jabbour, Pascal , Clarençon, Frédéric , Nguyen, Thanh N , Varela, Ricardo , Altschul, David J , Gonzalez, Nestor R , Möhlenbruch, Markus A , Gory, Benjamin , Stracke, Paul , Hecker, Constantin , Shaikh, Hamza A , Liebeskind, David S. , Pedicelli, Alessandro , Alexandre, Andrea M , Tancredi, Illario , Faizy, Tobias D , Kalsoum, Erwah , Fahed, Robert , Wang, Maud , Mendes Pereira, Vitor , Lubicz, Boris , Dmytriw, Adam A , Guenego, Adrien , Kühn, Anna Luisa , Musmar, Basel , Salim, Hamza , Yedavalli, Vivek S , Henninger, Nils , Nedelcu, Simona , Ghozy, Sherief , Cancelliere, Nicole M , Bernstock, Joshua D. , Rouchaud, Aymeric , Fiehler, Jens , Essibayi, Muhammed Amir , Colasurdo, Marco , Renieri, Leonardo , Harker, Pablo , Radu, Răzvan Alexandru , Mowla, Ashkan , Jabbour, Pascal , Nguyen, Thanh N. , Baker, Amanda, Aziz‐Sultan, Mohammad Ali , Hecker, Constantin , Fahed, Robert , Dmytriw, Adam A. , ##, On behalf of the MAD MT Investigators

Interventional Neuroradiology | July 16, 2025 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.1177/15910199251342841 Get It

Objective Mechanical thrombectomy (MT) is well-established for the treatment of acute ischemic stroke (AIS) from large vessel occlusion (LVO), with growing data supporting the expansion to distal and medium vessel occlusions (DMVO). Despite successful recanalization in DMVO, certain patients still experience poor long-term clinical outcomes, prompting our study to comprehensively explore pre-MT factors influencing outcome despite excellent recanalization (final modified Thrombolysis in Cerebral Infarction [mTICI] score ≥2c). Methods We retrospectively examined data from patients who consecutively underwent MT for a primary middle cerebral artery (MCA) DMVO across 37 centers in North America, Asia, and Europe. We identified baseline clinical and imaging factors associated with poor clinical outcome (defined as a modified Rankin Scale [mRS] score of 3–6) at 3 months, despite excellent recanalization using a multivariable model. Results Between September 2017 and July 2021, 623 patients achieved mTICI > 2b and they were included in our study. Among them, 198 (32%) experienced a poor clinical outcome (mRS 3–6). Predictors of poor clinical outcome included higher age (OR 1.05 [1.03–1.07], p < 0.001), higher NIHSS at admission (OR 1.12 [1.08–1.15], p < 0.001), higher baseline mRS (OR 1.77 [0.96–3.26], p = 0.067), and diabetes (OR 1.59 [1.01–2.48], p = 0.044). Higher ASPECTS was associated with a decreased risk of poor clinical outcome (OR 0.82 [0.71–0.94], p = 0.006). Conclusion Older age, diabetes, higher baseline mRS, and NIHSS were associated with poor clinical outcome in MCA DMVO despite excellent recanalization. Conversely, a higher ASPECTS decreased the probability of such an outcome.
Efficacy and safety of mechanical thrombectomy in distal medium middle cerebral artery occlusion ischemic stroke patients on low-dose aspirin
Salim, Hamza , Yedavalli, Vivek , Milhem, Fathi , Adeeb, Nimer , Naamani, Kareem El, Henninger, Nils , Sundararajan, Sri Hari , Khalife, Jane, Ghozy, Sherief, Tan, Benjamin Yong‐Qiang , Regenhardt, Robert W. , Heit, Jeremy J. , Rouchaud, Aymeric, Puri, Ajit S., Dyzmann, Christian , Colasurdo, Marco, Filipe, João Pedro , Harker, Pablo, Abdalkader, Mohamad , Marrota, Thomas, Spears, Julian , Biswas, Arundhati , Clarençon, Frédéric , Varela, Ricardo , Baker, Amanda , Altschul, David , Gonzalez, Nestor R. , Möhlenbruch, Markus , Costalat, Vincent, Gory, Benjamin, Stracke, Christian Paul , Hecker, Constantin, Shaikh, Hamza, Griessenaur, Christoph, Liebeskind, David S. , Alexandre, Andrea , Tancredi, Illario, Faizy, Tobias D. , Kalsoum, Erwah , Lubicz, Boris , Patel, Aman B. , Guenego, Adrien , Salim, Hamza , Henninger, Nils , Tan, Benjamin Yq , Cancelliere, Nicole M , Alexandru Radu, Răzvan , Ota, Takahiro , Jabbour, Pascal , Clarençon, Frédéric , Siegler, James E , Nguyen, Thanh N , Essibayi, Muhammed Amir , Gonzalez, Nestor R , Pedicelli, Alessandro , Alexandre, Andrea M , Faizy, Tobias D , Guenego, Adrien , Dmytriw, Adam A , Liebeskind, David S. , Heit, Jeremy J , Altschul, David J , Regenhardt, Robert W , Yedavalli, Vivek S , Varela, Ricardo , Musmar, Basel , Daraghma, Motaz , Naamani, Kareem El , Kühn, Anna Luisa , Khalife, Jane , Ghozy, Sherief , Scarcia, Luca , Cancelliere, Nicole M , Bernstock, Joshua D. , Rouchaud, Aymeric , Fiehler, Jens , Sheth, Sunil A , Puri, Ajit S , Colasurdo, Marco , Renieri, Leonardo , Harker, Pablo , Radu, Răzvan Alexandru , Klein, Piers , Marotta, Thomas R. , Mowla, Ashkan , Jabbour, Pascal , Siegler, James E. , Nguyen, Thanh N. , Essibayi, Muhammed Amir , Costalat, Vincent , Gory, Benjamin , Hecker, Constantin , Griessenauer, Christoph J. , Tancredi, Illario , Wintermark, Max , Mendes Pereira, Vitor , Dmytriw, Adam A.

International Journal of Stroke | January 29, 2025 | Volume: 20 | Issue: 6 | Pages: 669-678

10.1177/17474930251317883 Get It

Background: Acute ischemic stroke (AIS) from distal medium vessel occlusion (DMVO) presents unique treatment challenges. Mechanical thrombectomy (MT) is emerging as a viable option for these patients, yet the role of pre-stroke aspirin treatment is unclear. This study evaluates the impact of pre-stroke low-dose aspirin on outcomes in DMVO patients undergoing MT. Methods: We conducted a multinational, multicenter, propensity score-weighted analysis within the Multicenter Analysis of primary Distal medium vessel occlusions: effect of Mechanical Thrombectomy (MAD-MT) registry. Patients with AIS due to DMVO, treated with MT, were included. We compared outcomes between patients on pre-stroke low-dose aspirin (75–100 mg) and those not on antiplatelet therapy. The primary outcome was functional independence at 90 days (modified Rankin Scale (mRS), 0–2). Secondary outcomes included excellent functional outcome at 90 days (mRS, 0–1), mortality, and day 1 post-MT National Institutes of Health Stroke Scale (NIHSS) score. Safety outcomes focused on hemorrhagic complications, including symptomatic intracerebral hemorrhage (sICH). Results: Among 1354 patients, 150 were on pre-stroke low-dose aspirin. After applying inverse probability of treatment weighting (IPTW), aspirin use was associated with significantly better functional outcomes (mRS, 0–2: odds ratio (OR) = 1.89, 95% confidence interval (CI) = 1.14 to 3.12) and lower 90-day mortality (OR = 0.56, 95% CI = 0.32 to 1.00). The aspirin group had lower NIHSS scores on day 1 (β = −1.5, 95% CI = −2.8 to −0.27). The sICH rate was not significantly different between the groups (OR = 0.92, 95% CI = 0.60 to 1.43). Conclusions: Pre-stroke low-dose aspirin was associated with improved functional outcomes and reduced mortality in patients with DMVO undergoing MT, without a significant increase in sICH. These findings suggest that low-dose aspirin may be safe and associated with more frequent excellent outcomes for this patient population. Further prospective studies are needed to validate these results and assess long-term outcomes.
Pretreatment predictors of very poor clinical outcomes in medium vessel occlusion stroke patients treated with mechanical thrombectomy
Yedavalli, Vivek , Salim, Hamza , Adeeb, Nimer , Naamani, Kareem El, Henninger, Nils , Sundararajan, Sri Hari , Kühn, Anna Luisa, Khalife, Jane, Ghozy, Sherief, Tan, Benjamin Yong‐Qiang , Heit, Jeremy J. , Regenhardt, Robert W. , Cancelliere, Nicole M , Rouchaud, Aymeric , Sheth, Sunil, Essibayi, Muhammed Amir , Puri, Ajit S , Dyzmann, Christian , Colasurdo, Marco , Barreau, Xavier , Filipe, João Pedro , Marotta, Thomas R. , Spears, Julian , Biswas, Arundhati , Clarençon, Frédéric , Varela, Ricardo , Baker, Amanda , Altschul, David , Gonzalez, Nestor R. , Möhlenbruch, Markus , Costalat, Vincent , Stracke, Christian Paul , Shaikh, Hamza , Liebeskind, David S., Alexandre, Andrea , Tancredi, Illario , Faizy, Tobias D. , Kalsoum, Erwah , Lubicz, Boris , Patel, Aman B. , Guenego, Adrien , Liebeskind, David S. , Henninger, Nils , Tan, Benjamin Yq , Cancelliere, Nicole M , Alexandru Radu, Răzvan , Ota, Takahiro , Jabbour, Pascal , Clarençon, Frédéric , Siegler, James E , Nguyen, Thanh N , Gonzalez, Nestor R , Pedicelli, Alessandro , Alexandre, Andrea M , Guenego, Adrien , Dmytriw, Adam A , Liebeskind, David S. , Heit, Jeremy J , Altschul, David J , Salim, Hamza , Regenhardt, Robert W , Essibayi, Muhammed Amir , Yedavalli, Vivek S , Rouchaud, Aymeric , Colasurdo, Marco , Varela, Ricardo , Musmar, Basel , Naamani, Kareem El , Kühn, Anna Luisa , Khalife, Jane , Ghozy, Sherief , Scarcia, Luca , Bernstock, Joshua D. , Fiehler, Jens , Sheth, Sunil A , Renieri, Leonardo , Harker, Pablo , Radu, Răzvan Alexandru , Mowla, Ashkan , Jabbour, Pascal , Siegler, James E. , Nguyen, Thanh N. , Gory, Benjamin , Aziz‐Sultan, Mohammad Ali , Hecker, Constantin , Mendes Pereira, Vitor , Dmytriw, Adam A.

International Journal of Stroke | July 30, 2024 | Volume: 19 | Issue: 10 | Pages: 1123-1133

10.1177/17474930241270524 Get It

Background: Acute ischemic stroke (AIS) from primary medium vessel occlusions (MeVO) is a prevalent condition associated with substantial morbidity and mortality. Despite the common use of mechanical thrombectomy (MT) in AIS, predictors of poor outcomes in MeVO remain poorly characterized. Methods: In this prospectively collected, retrospectively reviewed, multicenter, multinational study, data from the MAD-MT (Multicenter Analysis of primary Distal medium vessel occlusions: effect of Mechanical Thrombectomy) registry were analyzed. The study included 1568 patients from 37 academic centers across North America, Asia, and Europe, treated with MT, with or without intravenous tissue plasminogen activator (IVtPA), between September 2017 and July 2021. Results: Among the 1568 patients, 347 (22.2%) experienced very poor outcomes (modified Rankin score (mRS), 5–6). Key predictors of poor outcomes were advanced age (odds ratio (OR): 1.03; 95% confidence interval (CI): 1.02 to 1.04; p < 0.001), higher baseline National Institutes of Health Stroke Scale (NIHSS) scores (OR: 1.07; 95% CI: 1.05 to 1.10; p < 0.001), pre-operative glucose levels (OR: 1.01; 95% CI: 1.00 to 1.02; p < 0.001), and a baseline mRS of 4 (OR: 2.69; 95% CI: 1.25 to 5.82; p = 0.011). The multivariable model demonstrated good predictive accuracy with an area under the receiver-operating characteristic (ROC) curve of 0.76. Conclusions: This study demonstrates that advanced age, higher NIHSS scores, elevated pre-stroke mRS, and pre-operative glucose levels significantly predict very poor outcomes in AIS-MeVO patients who received MT. These findings highlight the importance of a comprehensive risk assessment in primary MeVO patients for personalized treatment strategies. However, they also suggest a need for cautious patient selection for endovascular thrombectomy. Further prospective studies are needed to confirm these findings and explore targeted therapeutic interventions.
Intrasaccular flow disruption for ruptured aneurysms: an international multicenter study
Diestro, Jose Danilo Bengzon , Dibas, Mahmoud , Adeeb, Nimer , Regenhardt, Robert W. , Vranic, Justin E. , Guenego, Adrien , Lay, Sovann V. , Balushi, Ali Al , Shotar, Eimad , Premat, Kévin , Möhlenbruch, Markus , Foreman, Paul M. , Vachhani, Jay A. , Župančić, Vedran , Hafeez, Muhammad Ubaid , Rai, Hamid, Tutino, Vincent M. , Mirshani, Shervin, Ghozy, Sherief , Alotaibi, Naif M. , Rabinov, James D. , Ren, Yifan , Goren, Oded , Piano, Mariangela , Michelozzi, Caterina , Elens, Stéphanie , Starke, Robert M. , Nguyên, Anh , Jones, Jesse , Psychogios, Marios, Spears, Julian , Bullrich, María Bres , Mayich, Michael , Salem, Mohamed M. , Burkhardt, Jan‐Karl , Jankowitz, Brian T. , Ulfert, Christian , Lubicz, Boris , Puri, Ajit S , Pero, Guglielmo , Asadi, Hamed , Siddiqui, Adnan H. , Ducruet, Andrew F. , Albuquerque, Felipe C , Kan, Peter , Kalousek, Vladimir , Lylyk, Pedro , Boddu, Srikanth , Stapleton, Christopher J. , Knopman, Jared , Jabbour, Pascal , Tjoumakaris, Stavropoula , Clarençon, Frédéric , Aziz‐Sultan, Mohammad Ali , Patel, Aman B. , Dmytriw, Adam A. , Shotar, Eimad , Saliou, Guillaume , Lylyk, Ivan , Vachhani, Jay A , Rai, Hamid , Tutino, Vincent M , Harker, Pablo , Ren, Yifan , Schirmer, Clemens M , Michelozzi, Caterina , Elens, Stephanie , Hassan, Ameer E , Nguyen, Anh , Jones, Jesse , Parra-Fariñas, Carmen , Salem, Mohamed M , Domingo, Ricardo A , Tawk, Rabih, Pero, Guglielmo , Albuquerque, Felipe C , Kan, Peter , Kalousek, Vladimir , Jabbour, Pascal , Tjoumakaris, Stavropoula , Clarençon, Frédéric , Cuellar-Saenz, Hugo H , Dmytriw, Adam A , Siddiqui, Adnan H , Dibas, Mahmoud , Ghozy, Sherief , Diestro, Jose Danilo B , Regenhardt, Robert W , Hafeez, Muhammad U , Ulfert, Christian , Lay, Sovann V , Burkhardt, Jan‐Karl , Renieri, Leonardo , Naamani, Kareem El , Saliou, Guillaume , Lylyk, Iván , Rutledge, Caleb , Harker, Pablo , Schirmer, Clemens M. , Kühn, Anna Luisa , Hassan, Ameer E , Salehani, Arsalaan , Psychogios, Marios‐Nikos , Domingo, Ricardo A. , Huynh, Thien , Tawk, Rabih G. , Panni, Pietro , Griessenauer, Christoph J. , Du, Rose , Jabbour, Pascal , Limbucci, Nicola , Cuellar, Hugo , Cognard, Christophe

Journal of NeuroInterventional Surgery | July 22, 2022 | Volume: 15 | Issue: 9 | Pages: 844-850

10.1136/jnis-2022-019153 Get It

Background The Woven EndoBridge (WEB) device is a novel intrasaccular flow disruptor tailored for bifurcation aneurysms. We aim to describe the degree of aneurysm occlusion at the latest follow-up, and the rate of complications of aneurysms treated with the WEB device stratified according to rupture status. Methods Our data were taken from the WorldWideWeb Consortium, an international multicenter cohort including patients treated with the WEB device. Aneurysms were classified into two groups: ruptured and unruptured. We compared clinical and radiologic outcomes of both groups. Propensity score matching (PSM) was done to match according to age, gender, bifurcation, location, prior treatment, neck, height, dome width, daughter sac, incorporated branch, pretreatment antiplatelets, and last imaging follow-up. Results The study included 676 patients with 691 intracranial aneurysms (529 unruptured and 162 ruptured) treated with the WEB device. The PSM analysis had 55 pairs. In both the unmatched (85.8% vs 84.3%, p=0.692) and matched (94.4% vs 83.3%, p=0.066) cohorts there was no significant difference in the adequate occlusion rate at the last follow-up. Likewise, there were no significant differences in both ischemic and hemorrhagic complications between the two groups. There was no documented aneurysm rebleeding after WEB device implantation. Conclusion There was no significant difference in both the radiologic outcomes and complications between unruptured and ruptured aneurysms. Our findings support the feasibility of treatment of ruptured aneurysms with the WEB device.