Endovascular Parent Vessel Occlusion Versus Flow Diversion in the Treatment of Large and Giant Aneurysms: A Randomized Comparison

OBJECTIVE

Parent vessel occlusion (PVO) is a time-honored treatment for unclippable or uncoilable intracranial aneurysms. Flow diversion (FD) is a recent endovascular alternative that can occlude the aneurysm and spare the parent blood vessel. Our aim was to compare outcomes of FD with endovascular PVO.

METHODS

This is a prespecified treatment subgroup analysis of the Flow diversion in Intracranial Aneurysms trial (FIAT). FIAT was an investigator-led parallel-group all-inclusive pragmatic randomized trial. For each patient, clinicians had to prespecify an alternative management option to FD before stratified randomization. We report all patients for whom PVO was selected as the best alternative treatment to FD. The primary outcome was a composite of core-lab determined angiographic occlusion or near-occlusion at 3-12 months combined with an independent clinical outcome (mRS<3). Primary analyses were intent-to-treat. There was no blinding.

RESULTS

There were 45 patients (16.2% of the 278 FIAT patients randomized between 2011 and 2020 in 3 centers): 22 were randomly allocated to FD and 23 to PVO. Aneurysms were mainly large or giant (mean 22 mm) anterior circulation (mainly carotid) aneurysms. A poor primary outcome was reached in 11/22 FD (50.0%) compared to 9/23 PVO patients (39.1%) (RR: 1.28, 95% CI [0.66-2.47]; P = 0.466). Morbidity (mRS >2) at 1 year occurred in 4/22 FD and 6/23 PVO patients. Angiographic results and serious adverse events were similar.

CONCLUSIONS

The comparison between PVO and FD was inconclusive. More randomized trials are needed to better determine the role of FD in large aneurysms eligible for PVO.

A Pragmatic Randomized Trial Comparing Surgical Clipping and Endovascular Treatment of Unruptured Intracranial Aneurysms

BACKGROUND AND PURPOSE

Surgical clipping and endovascular treatment are commonly used in patients with unruptured intracranial aneurysms. We compared the safety and efficacy of the 2 treatments in a randomized trial.

MATERIALS AND METHODS

Clipping or endovascular treatments were randomly allocated to patients with one or more 3- to 25-mm unruptured intracranial aneurysms judged treatable both ways by participating physicians. The study hypothesized that clipping would decrease the incidence of treatment failure from 13% to 4%, a composite primary outcome defined as failure of aneurysm occlusion, intracranial hemorrhage during follow-up, or residual aneurysms at 1 year, as adjudicated by a core lab. Safety outcomes included new neurologic deficits following treatment, hospitalization of >5 days, and overall morbidity and mortality (mRS > 2) at 1 year. There was no blinding.

RESULTS

Two hundred ninety-one patients were enrolled from 2010 to 2020 in 7 centers. The 1-year primary outcome, ascertainable in 290/291 (99%) patients, was reached in 13/142 (9%; 95% CI, 5%-15%) patients allocated to surgery and in 28/148 (19%; 95% CI, 13%-26%) patients allocated to endovascular treatments (relative risk: 2.07; 95% CI, 1.12-3.83; P = .021). Morbidity and mortality (mRS >2) at 1 year occurred in 3/143 and 3/148 (2%; 95% CI, 1%-6%) patients allocated to surgery and endovascular treatments, respectively. Neurologic deficits (32/143, 22%; 95% CI, 16%-30% versus 19/148, 12%; 95% CI, 8%-19%; relative risk: 1.74; 95% CI, 1.04-2.92; P = .04) and hospitalizations beyond 5 days (69/143, 48%; 95% CI, 40%-56% versus 12/148, 8%; 95% CI, 5%-14%; relative risk: 0.18; 95% CI, 0.11-0.31; P < .001) were more frequent after surgery.

CONCLUSIONS

Surgical clipping is more effective than endovascular treatment of unruptured intracranial aneurysms in terms of the frequency of the primary outcome of treatment failure. Results were mainly driven by angiographic results at 1 year.

Endovascular treatment of brain arteriovenous malformations: clinical outcomes of patients included in the registry of a pragmatic randomized trial

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.

Clinical Uncertainty and Equipoise in the Management of Recurrent Glioblastoma

BACKGROUND

A significant proportion of glioblastoma (GBM) patients are considered for repeat resection, but evidence regarding best management remains elusive. Our aim was to measure the degree of clinical uncertainty regarding reoperation for patients with recurrent GBM.

METHODS

We first performed a systematic review of agreement studies examining the question of repeat resection for recurrent GBM. An electronic portfolio of 37 pathologically confirmed recurrent GBM patients including pertinent magnetic resonance images and clinical information was assembled. To measure clinical uncertainty, 26 neurosurgeons from various countries, training backgrounds, and years' experience were asked to select best management (repeat surgery, other nonsurgical management, or conservative), confidence in recommended management, and whether they would include the patient in a randomized trial comparing surgery with nonsurgical options. Agreement was evaluated using κ statistics.

RESULTS

The literature review did not reveal previous agreement studies examining the question. In our study, agreement regarding best management of recurrent GBM was slight, even when management options were dichotomized (repeat surgery vs. other options; κ=0.198 [95% confidence interval: 0.133-0.276]). Country of practice, years' experience, and training background did not change results. Disagreement and clinical uncertainty were more pronounced within clinicians with (κ=0.167 [0.055-0.314]) than clinicians without neuro-oncology fellowship training (κ=0.601 [0.556-0.646]). A majority (51%) of responders were willing to include the patient in a randomized trial comparing repeat surgery with nonsurgical alternatives in 26/37 (69%) of cases.

CONCLUSION

There is sufficient uncertainty and equipoise regarding the question of reoperation for patients with recurrent glioblastoma to support the need for a randomized controlled trial.