Endovascular treatment of brain arteriovenous malformations: clinical outcomes of patients included in the registry of a pragmatic randomized trial
Authors: Raymond Jean , Gentric Jean-Christophe , Magro Elsa , Nico Lorena , Bacchus Emma , Klink Ruby , Cognard Christophe , Januel Anne-Christine , Sabatier Jean-François , Iancu Daniela , Weill Alain , Roy Daniel , Bojanowski Michel W. , Chaalala Chiraz , Barreau Xavier , Jecko Vincent , Papagiannaki Chrysanthi , Derrey Stéphane , Shotar Eimad , Cornu Philippe , Eker Omer F. , Pelissou-Guyotat Isabelle , Piotin Michel , Aldea Sorin , Beaujeux Rémy , Proust François , Anxionnat René , Costalat Vincent , Corre Marine Le , Gauvrit Jean-Yves , Morandi Xavier , Brunel Hervé , Roche Pierre-Hugues , Graillon Thomas , Chabert Emmanuel , Herbreteau Denis , Desal Hubert , Trystram Denis , Barbier Charlotte , Gaberel Thomas , Nguyen Thanh N. , Viard Geraldine , Gevry Guylaine , Darsaut Tim E. , _ _ , _ _ , Raymond Jean , Roy Daniel , Weill Alain , Iancu Daniela , Bojanowski Michel W. , Chaalala Chiraz , Darsaut Tim E. , O’Kelly Cian J. , Chow Michael M. C. , Findlay J. Max , Rempel Jeremy L. , Fahed Robert , Lesiuk Howard , Drake Brian , dos Santos Marlise , Gentric Jean-Christophe , Nonent Michel , Ognard Julien , El-Aouni Mourad Cheddad , Magro Elsa , Seizeur Romuald , Timsit Serge , Pradier Olivier , Desal Hubert , Boursier Romain , Thillays François , Roualdes Vincent , Piotin Michel , Blanc Raphael , Aldea Sorin , Cognard Christophe , Januel Anne-Christine , Sabatier Jean-François , Calviere Lionel , Gauvrit Jean Yves , Raoult Hélène , Eugene François , Bras Anthony Le , Ferre Jean-Christophe , Paya Christophe , Morandi Xavier , Lecouillard Isabelle , Nouhaud Elodie , Ronziere Thomas , Trystram Denis , Naggara Olivier , Rodriguez-Regent Christine , Kerleroux Basile , Barbier Charlotte , Gaberel Thomas , Emery Evelyne , Touze Emmanuel , Papagiannaki Chrysanthi , Derrey Stéphane , Eker Omer F. , Riva Roberto , Pellisou-Guyotat Isabelle , Guyotat Jacques , Berhouma Monsef , Dumot Chloé , Biondi Alessandra , Thines Laurent , Bougaci Nassim , Charbonnier Guillaume , Bracard Serge , Anxionnat René , Gory Benjamin , Civit Thierry , Bernier-Chastagner Valérie , Barreau Xavier , Marnat Gaultier , Jecko Vincent , Penchet Guillaume , Gimbert Edouard , Huchet Aymeri , Herbreteau Denis , Boulouis Grégoire , Bibi Richard , Ifergan Héloïse , Janot Kévin , Velut Stéphane , Brunel Hervé , Roche Pierre-Hugues , Graillon Thomas , Peyriere Hadrien , Kaya Jean-Marc , Touta Adamou , Troude Lucas , Boissonneau Sébastien , Clarençon Frédéric , Shotar Eimad , Sourour Nader , Lenck Stéphanie , Premat Kévin , Boch Anne-Laure , Cornu Philippe , Nouet Aurélien , Costalat Vincent , Bonafe Alain , Dargazanli Cyril , Gascou Gregory , Lefevre Pierre-Henri , Riquelme Carlos , Corre Marine Le , Beaujeux Rémy , Pop Raoul , Proust François , Cebula Hélène , Ollivier Irène , Spatola Giorgio , Spell Laurent , Chalumeau Vanessa , Gallas Sophie , Ikka Léon , Mihalea Cristian , Ozanne Augustin , Caroff Jildaz , Chabert Emmanuel , Mounayer Charbel , Rouchaud Aymeric , Caire François , Ricolfi Frédéric , Thouant Pierre , Cao Catherine , Mourier Klaus-Luc , Farah Walid , Nguyen Thanh N. , Abdalkader Mohamad , Huynh Thien , Tawk Rabih G. , Carlson Andrew P. , Silva Luciana Alves Oliveira , Froio Nayara de Lima , Silva Gisele Sampaio , Mont’Alverne Francisco J. A. , Martins Jose Luri , Mendes George Nunes , Miranda Rodrigo Rivera 
Published: November 2022

OBJECTIVE
The role of endovascular treatment in the management of patients with brain arteriovenous malformations (AVMs) remains uncertain. AVM embolization can be offered as stand-alone curative therapy or prior to surgery or stereotactic radiosurgery (SRS) (pre-embolization). The Treatment of Brain AVMs Study (TOBAS) is an all-inclusive pragmatic study that comprises two randomized trials and multiple registries.

METHODS
Results from the TOBAS curative and pre-embolization registries are reported. The primary outcome for this report is death or dependency (modified Rankin Scale [mRS] score > 2) at last follow-up. Secondary outcomes include angiographic results, perioperative serious adverse events (SAEs), and permanent treatment-related complications leading to an mRS score > 2.

RESULTS
From June 2014 to May 2021, 1010 patients were recruited in TOBAS. Embolization was chosen as the primary curative treatment for 116 patients and pre-embolization prior to surgery or SRS for 92 patients. Clinical and angiographic outcomes were available in 106 (91%) of 116 and 77 (84%) of 92 patients, respectively. In the curative embolization registry, 70% of AVMs were ruptured, and 62% were low-grade AVMs (Spetzler-Martin grade I or II), while the pre-embolization registry had 70% ruptured AVMs and 58% low-grade AVMs. The primary outcome of death or disability (mRS score > 2) occurred in 15 (14%, 95% CI 8%–22%) of the 106 patients in the curative embolization registry (4 [12%, 95% CI 5%–28%] of 32 unruptured AVMs and 11 [15%, 95% CI 8%–25%] of 74 ruptured AVMs) and 9 (12%, 95% CI 6%–21%) of the 77 patients in the pre-embolization registry (4 [17%, 95% CI 7%–37%] of 23 unruptured AVMs and 5 [9%, 95% CI 4%–20%] of 54 ruptured AVMs) at 2 years. Embolization alone was confirmed to occlude the AVM in 32 (30%, 95% CI 21%–40%) of the 106 curative attempts and in 9 (12%, 95% CI 6%–21%) of 77 patients in the pre-embolization registry. SAEs occurred in 28 of the 106 attempted curative patients (26%, 95% CI 18%–35%, including 21 new symptomatic hemorrhages [20%, 95% CI 13%–29%]). Five of the new hemorrhages were in previously unruptured AVMs (n = 32; 16%, 95% CI 5%–33%). Of the 77 pre-embolization patients, 18 had SAEs (23%, 95% CI 15%–34%), including 12 new symptomatic hemorrhages [16%, 95% CI 9%–26%]). Three of the hemorrhages were in previously unruptured AVMs (3/23; 13%, 95% CI 3%–34%).

CONCLUSIONS
Embolization as a curative treatment for brain AVMs was often incomplete. Hemorrhagic complications were frequent, even when the specified intent was pre-embolization before surgery or SRS. Because the role of endovascular treatment remains uncertain, it should preferably, when possible, be offered in the context of a randomized trial.