Gamma Knife surgery for intracranial arteriovenous malformations in children: a retrospective study in 103 patients

Radiosurgery With Prior Embolization Versus Radiosurgery Alone for Intracranial Arteriovenous Malformations: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

The addition of adjuvant embolization to radiosurgery has been proposed as a means of improving treatment outcomes of intracranial arteriovenous malformations (AVMs). However, the relative efficacy and safety of radiosurgery with adjuvant embolization vs radiosurgery alone remain uncertain. Moreover, previous systematic reviews and meta-analyses have included a limited number of studies and did not consider the effects of baseline characteristics, including AVM volume, on the outcomes. This systematic review aimed to evaluate the efficacy of preradiosurgery embolization for intracranial AVMs with consideration to matching status between participants in each treatment group.

METHODS

A systematic review and meta-analysis were conducted by searching electronic databases, including PubMed, Scopus, and Cochrane Library, up to January 2023. All studies evaluating the utilization of preradiosurgery embolization were included.

RESULTS

A total of 70 studies (9 matched and 71 unmatched) with a total of 12 088 patients were included. The mean age of the included patients was 32.41 years, and 48.91% of the patients were female. Preradiosurgery embolization was used for larger AVMs and patients with previous hemorrhage ( P < .01, P = .02, respectively). The obliteration rate for preradiosurgery embolization (49.44%) was lower compared with radiosurgery alone (61.42%, odds ratio = 0.56, P < .01), regardless of the matching status of the analyzed studies. Although prior embolization was associated higher rate of cyst formation ( P = .04), it lowered the odds of radiation-induced changes ( P = .04). The risks of minor and major neurological deficits, postradiosurgery hemorrhage, and mortality were comparable between groups.

CONCLUSION

This study provides evidence that although preradiosurgery embolization is a suitable option to reduce the AVM size for future radiosurgical interventions, it may not be useful for same-sized AVMs eligible for radiosurgery. Utilization of preradiosurgery embolization in suitable lesions for radiosurgery may result in the added cost and burden of an endovascular procedure.

The impact of embolization on radiosurgery obliteration rates for brain arteriovenous malformations: a systematic review and meta-analysis

There exists no consensus in the literature regarding the impact of pre-stereotactic radiosurgery (SRS) embolization on obliteration rates and clinical outcome after radiosurgery treatment of intracranial arteriovenous malformations (AVM). We performed a systematic review of four databases and included studies with at least 10 patients evaluating obliteration rates of intracranial AVMs treated with SRS alone (SRS cohort) and combined pre-SRS embolization followed by SRS (E + SRS cohort). Meta-analytic results were pooled together via random-effects models. A total of 43 studies, with 7103 patients, were included in our analysis. Among our included patients, complete obliteration was achieved in 51.5% (964/1871) of patients in the E + SRS cohort as compared to 61.5% (3217/5231) of patients in the SRS cohort. Meta-analysis of the pooled data revealed that obliteration was significantly lower in the E + SRS cohort (pooled OR = 0.64, 95% CI = 0.54-0.75, p < 0.0001). The use of pre-SRS embolization was significantly associated with lower AVM obliteration rates when compared to treatment with SRS alone. Our analysis seeks to provide a macroscopic insight into the complex interaction between pre-SRS embolization and brain AVM obliteration rates and prognosis. Pre-SRS embolization may still be beneficial in select patients, and further studies are needed to identify patients who benefit from neoadjuvant AVM embolization.

Chinese Cerebrovascular Neurosurgery Society and Chinese Interventional & Hybrid Operation Society, of Chinese Stroke Association Clinical Practice Guidelines for Management of Brain Arteriovenous Malformations in Eloquent Areas

Aim: The aim of this guideline is to present current and comprehensive recommendations for the management of brain arteriovenous malformations (bAVMs) located in eloquent areas. Methods: An extended literature search on MEDLINE was performed between Jan 1970 and May 2020. Eloquence-related literature was further screened and interpreted in different subcategories of this guideline. The writing group discussed narrative text and recommendations through group meetings and online video conferences. Recommendations followed the Applying Classification of Recommendations and Level of Evidence proposed by the American Heart Association/American Stroke Association. Prerelease review of the draft guideline was performed by four expert peer reviewers and by the members of Chinese Stroke Association. Results: In total, 809 out of 2,493 publications were identified to be related to eloquent structure or neurological functions of bAVMs. Three-hundred and forty-one publications were comprehensively interpreted and cited by this guideline. Evidence-based guidelines were presented for the clinical evaluation and treatment of bAVMs with eloquence involved. Topics focused on neuroanatomy of activated eloquent structure, functional neuroimaging, neurological assessment, indication, and recommendations of different therapeutic managements. Fifty-nine recommendations were summarized, including 20 in Class I, 30 in Class IIa, 9 in Class IIb, and 2 in Class III. Conclusions: The management of eloquent bAVMs remains challenging. With the evolutionary understanding of eloquent areas, the guideline highlights the assessment of eloquent bAVMs, and a strategy for decision-making in the management of eloquent bAVMs.

Microsurgery for Spetzler-Martin Grade I-III Arteriovenous Malformations: Analysis of Surgical Results and Correlation of Lawton-Young Supplementary Grade and Supplemented Spetzler-Martin Score with Functional Outcome

OBJECTIVE

To analyze the results of microsurgery for Spetzler-Martin (SM) grade I-III AVMs and evaluate the correlation of the Lawton-Young (LY) supplementary grade, supplemented Spetzler-Martin (SM-Supp/combined) score with the functional outcome.

METHODS

A total of 42 patients with SM grade I-III AVMs who had undergone surgery at our institute during a 3-year period (June 2013 to May 2016) were included in the present study.

RESULTS

All 42 patients had undergone primary surgery without previous embolization. Three patients (7.1%) had died due to surgical site hematoma in the postoperative period. One patient was lost to follow-up. The mean follow-up period for the remaining patients was 27 ± 14 months (range, 12-62 months). At the final follow-up examination of ≥12 months (FFU), 92.7% of the patients had a good outcome (modified Rankin scale [mRS] score ≤1), with an improved or unchanged mRS score in 87.8%. An AVM size >3 cm, diffuse AVM, SM grade III, and SM-Supp score >5 were associated with worsened mRS score at discharge and FFU. Higher LY grade (IV and V), eloquent AVM location, deep venous drainage, age >40 years, and unruptured presentation were not associated with worsened mRS score at both discharge and FFU. Of the 20 ARUBA-eligible patients, 19 (95%) had good outcomes. Postoperative angiograms for 39 patients revealed complete excision of the AVM in 37 (94.9%) and a residual AVM in 2 (5.1%).

CONCLUSIONS

High cure rates and excellent clinical outcomes can be expected with microsurgery for most patients with SM grade I-III AVMs. An AVM size >3 cm, diffuse AVM nidus, SM grade III, and SM-Supp score >5 are associated with postoperative worsening of functional scores in patients with SM grade I-III AVMs.

Linear Accelerator Stereotactic Radiosurgery of Central Nervous System Arteriovenous Malformations: A 15-Year Analysis of Outcome-Related Factors in a Single Tertiary Center

BACKGROUND

Linear accelerator stereotactic radiosurgery is one of the modalities available for the treatment of central nervous system arteriovenous malformations (AVMs). The aim of this study was to describe our 15-year experience with this technique in a single tertiary center and the analysis of outcome-related factors.

METHODS

From 1998 to 2013, 195 patients were treated with linear accelerator-based radiosurgery; we conducted a retrospective study collecting patient- and AVM-related variables. Treatment outcomes were obliteration, posttreatment hemorrhage, symptomatic radiation-induced changes, and 3-year neurologic status. We also analyzed prognostic factors of each outcome and predictability analysis of 5 scales: Spetzler-Martin grade, Lawton-Young supplementary and Lawton combined scores, radiosurgery-based AVM score, Virginia Radiosurgery AVM Scale, and Heidelberg score.

RESULTS

Overall obliteration rate was 81%. Nidus diameter and venous drainage were predictive of obliteration (P < 0.05), ruptured status and previous embolization were not related to rate of obliteration, and low-grade AVMs had higher obliteration rates. Posttreatment hemorrhage incidence was 8.72%; nidus diameter was the only predictor (P = 0.05). Symptomatic radiation-induced changes occurred in 11.79% of patients and were significantly associated with unruptured status (P < 0.05). Treatment success as a composite measure was obtained in 70.77% of patients. Receiver operating characteristic curves were presented for each scoring system and outcome measure; best area under the curve was 0.687 for Lawton combined score in the obliteration outcome.

CONCLUSIONS

In the long-term, linear accelerator-based radiosurgery is a useful, valid, effective, and safe modality for treatment of brain AVMs.

Stereotactic radiosurgery of intracranial arteriovenous malformations

Stereotactic radiosurgery for intracranial arteriovenous malformations (AVMs) has been performed since the 1970s. When an AVM is treated with radiosurgery, radiation injury to the vascular endothelium induces the proliferation of smooth muscle cells and the elaboration of extracellular collagen, which leads to progressive stenosis and obliteration of the AVM nidus. Obliteration after AVM radiosurgery ranges from 60% to 80%, and relates to the size of the AVM and the prescribed radiation dose. The major drawback of radiosurgical AVM treatment is the risk of bleeding during the latent period (typically 2 years) between treatment and AVM thrombosis.

Analysis of changing paradigms of management in 179 patients with spinal tuberculosis over a 12-year period and proposal of a new management algorithm

OBJECTIVE

To describe management and outcome in a large cohort of patients with spinal tuberculosis (TB).

METHODS

Of 212 patients with spinal TB treated between January 1999 and June 2011, 179 patients were included in the study (≥6 months follow-up; mean age, 34.8 years; age range, 10-75 years). The cohort was divided into two groups (n = 89 and n = 90); group I was treated from 1999-2003, and group II was treated from 2004-2011.

RESULTS

The study cohort comprised 93 male patients. Mean age was 34.8 years ± 7.2 (range, 10-75 years). Mean duration of symptoms was 2.4 months. Sensorimotor deficits were present in 167 patients (93.5%; 74 patients were paraplegic), pain was present in 156 patients (87%), bladder involvement was present in 127 patients (71.7%), and extraspinal TB was present in 36 patients (22.3%). Of patients, 92% were receiving prior chemotherapy; one fifth of these patients were on second-line chemotherapy. Thoracic spine involvement was most common (n = 86; 57%), followed by cervical spine (n = 50; 29%), craniovertebral junction (n = 22; 15%), and lumbosacral spine (n = 20; 10.5%). Surgery was performed in 146 patients (68% instrumented fusions and 16% circumferential fusions). Mean follow-up was 20.2 months (range, 6-60 months). Sensorimotor deficits improved in 89% of patients, pain improved in 71%, bladder symptoms improved in 88%, and paraplegia improved in 77%. Patients in group II had a higher incidence of cord compression (P < 0.01), severe vertebral body collapse (P < 0.001), and paraplegia (P < 0.001). Group II patients underwent more instrumented surgeries (P < 0.01), especially circumferential fusions (P < 0.001). The improvement in paraplegia was better after 2004 (group II). Bladder symptoms correlated with the timing of surgery (P < 0.1).

CONCLUSIONS

Medical treatment of spinal TB is the mainstay; however, radical, instrumented surgeries should be offered when indicated. The presence of paraplegia should not preclude surgery. A practical management paradigm is also suggested.

Clinico-radiological outcomes following gamma knife radiosurgery for pediatric arteriovenous malformations

PURPOSE

The aim of this study was to evaluate clinico-radiological outcomes following gamma knife radiosurgery (GKS) for pediatric arteriovenous malformations (AVMs).

METHODS

The present series included 39 children (3-17 years of age) who underwent GKS for cerebral AVMs between January 2002 and February 2008. Twenty-five patients presented with hemorrhages. The median AVM volume was 1.5 cm³, and the median marginal dose was 20 Gy. All patients continued to have follow-up for more than 24 months with serial magnetic resonance images (MRIs)/angiograms. Current school performance has been evaluated using a telephone survey answered by the patients' parents.

RESULTS

Follow-up angiograms, available in 34 patients, confirmed complete obliteration in 16 patients. Serial MRIs indicated obliteration of the nidus in one of five patients without angiography. The diffuse nidus structure and low marginal dose were significantly associated with incomplete obliteration. Twelve patients underwent a second GKS, and subsequent angiographies, available in six patients, demonstrated complete obliteration in two of them. Complications included new-onset seizures (n = 1), apraxia (n = 1), and temporal horn entrapment requiring a shunt operation (n = 1). School performance declined in 14 out of 32 patients. Both the AVM volume and modified AVM score were found to be reliable predictors of school performance.

CONCLUSIONS

The results of the present study substantiate the diffuse and other atypical features of pediatric AVMs as major determinants of treatment failure following GKS. Considering the apparent declination of school performance, future prospective studies would be required to investigate the possible late-effects of GKS on neuropsychological function.

Diagnosis and management of arteriovenous malformations in children

Arteriovenous malformation (AVM) is the most common cause of spontaneous intraparenchymal hemorrhage in children, excluding hemorrhages of prematurity and early infancy. Because most children diagnosed with an AVM undergo initial treatment emergently, the natural history of AVMs in the pediatric population is not well understood. Most pediatric AVMs do not come to clinical attention unless they hemorrhage. Therefore, their optimal management remains controversial. Children with intracranial AVMs represent a special challenge in that they harbor unacceptable lifelong risks of hemorrhage and potential neurologic deficits. Patients should be evaluated on a case-by-case basis to determine the best multidisciplinary treatment regimen that can be used to preserve neurologic function and eradicate the AVM with the lowest risk of mortality. Successful treatment depends on the location and size of the AVM, its hemodynamic properties, the clinical condition of the patient, and the treatment modality selected. The armamentarium for AVM management has grown with technological advances and now includes microsurgical resection, endovascular embolization, radiosurgery, or any combination of these modalities. Microsurgical resection remains the gold standard for treatment of accessible pediatric AVMs, especially in cases that present with intracranial hemorrhage. Newer modalities, such as embolization and radiosurgery, have provided additional tools to help children with large or deep-seated lesions that would be deemed unresectable with microsurgical techniques alone. Long-term follow-up with repeated diagnostic imaging is important despite complete obliteration of the lesion to rule out the small possibility of AVM recurrence.