SURGERY VS EMBOLISATION VS RADIOSURGERY IN CEREBRAL AV MALFORMATIONS

Dr. Manoranjitha Kumari MChDr. Manas PanigrahiKrishna Institute of Medical sciencesHyderabadTelangana, India

AVMs

4% crude annual rupture rate

1% per year for those discovered unruptured

bleeding often mainly confined to the brain arteriovenous malformation itself or originating from the venous side of the malformation

Approaches to eradicate a brain arteriovenous malformation, bled or not, include various treatment techniques (neurosurgery, endovascular embolisation, and stereotactic radiotherapy)

The complexity of the cerebrovacular anatomy of AVMs makes their treatment a challenge with significant inherent risks

The question revolves around “ treat or not to treat”

Should we intervene to change the natural course of the disease

Incidence of haemorrhage

Commonest clinical presentation is haemorrhage with reported frequencies ranging from 30-80%

NOMASS study-first ever AVM hge icidence of 0.55 per 100 000 person years

Hofmeister et al( Stroke 2000)- incidence of Haemorrhage -53% (669/1289 patients)

Natural history of AVMs

Ondra et al 1990reported on prospectively followed 160 untreated ,symptomatic AVMs patients(10-70yrs age) over 27 years , most of the patient presented with haemorrhageduring follow up, 40% (60 patients) suffered atleast one or more haemorrhagethe calculated risk of yearly haemorrhage was 4.

Natural history...

Since there are no reliable data regarding the natural history of AVMs and presumably ruptured brain AVMs have a higher hemorrhagic risk (4.5%–34%) than previously unruptured ones (0.9%–8%),interventional treatment of ruptured brain AVMs is advisable

Ogilvy CS, Stieg PE, Awad I, Brown RD, Jr, Kondziolka D, Rosenwasser R, et al. AHA Scientific Statement: Recommendations for the management of intracranial arteriovenous malformations: A statement for healthcare professionals from a special writing group of the Stroke Council, American Stroke Association. Stroke. 2001;32:1458–71. [PubMed: 11387517]

Stapf C, Mast H, Sciacca RR, Choi JH, Khaw AV, Connolly ES, et al. Predictors of hemorrhage in patients with untreated brainarteriovenous malformation. Neurology. 2006;66:1350–5. [PubMed: 16682666]

Predictors of haemorrhage

Associated arteriovenous fistulas and prenidal, intranidal, or flowrelated aneurysms

as well as small AVM size feeding artery pressures lesions located in a periventricular or intraventricular

locations, presence of deep venous drainage, intranidal or multiple aneurysms, arterial supply via

perforators, vertebrobasilar supply, and basal ganglia location

Overall, deepseated lesions have demonstrated to have an early clinical onset, higher bleeding rates, and increased morbidity and mortality (50%) rather than superficial lesions.

Surg Neurol Int. 2012; 3(Suppl 2): S90–S104.Published online 2012 Apr 26. doi: 10.4103/21527806.95420PMCID: PMC3400489Embolization and radiosurgery for arteriovenous malformations

Haemorrhage related mortality

Fults and kelly et al (Neurosurgery 1984)

61% had hge 1st hge- 13.6% mortality 2nd hge-20% mortality 3rd hge-25% mortality

Hence ruptured AVMs needs treatment...as the mortality rate increases after second and third haemorrhages

Unruptured aneurysm....

ARUBA trial says...116 pt underwent intervention- 33% had

events107 pt underwent medical rx- 10% had

events....hence medical management is superior than intervention.....

Drawbacks of ARUBA trial

Imbalance in randomization of subtypes of AVMs based on SM grade

Patients were followed up only for 33 months.. This is too short period to say about the natural course of the disease

Lack of a standard plan for therapy

Interventions in ARUBA

neurosurgery alone (n=5) embolisation alone (n=30) radiotherapy alone (n=31) embo+MS (n=12) Embo+SRS (n=15)

Selection bias in the treatment modality

Treatment algorhythm

Symptomatic AVMs

Ruptured

MS Embolisation SRS

Unruptured

Medical MS Embolisation SRS

Surgery

high cure rate low complication rate immediacybecome the first-line therapy for

many AVMs

99-100% resection is possible in low grade AVMs

Micro surgery

Cure rates for low grade AVMs are high 99-100%

Morbidity and mortality -high in higher grade AVMs(Zhao et al 2010)

Heros et al(1990)

158 surgical patients 3.8 year follow up Evidences in favor of surgery:1. The risk of hemorrhage following complete

AVM resection is close to non existent(III/B)2. There is a potential for gradual

improvement from post operative deficits(III/B)

3. Surgical resection has an overall positive outcome on seizure control(III/B)

Outcome predictors

SM grade AVM associated with aneurysms which

poses haemorrhagic risk

Haemorrhagic presentation will have deficit at the time of presentation, non haemorrhagic patient will not have at the time but after surgery which will improve over a period of time

Potts MB1 et al 2015

To clarify safety, efficacy, and outcomes associated with AVM resection in the aftermath of A Randomized Trial of Unruptured Brain AVMs (ARUBA), Potts MB1 et al 2015 reviewed their experience with low-grade AVMs-the most favorable AVMs for surgery and the ones most likely to have been selected for treatment outside of ARUBA's randomization process.

J Neurosurg. 2015 Apr;122(4):912-20. doi: 10.3171/2014.12.JNS14938. Epub 2015 Feb 6.Current surgical results with low-grade brain arteriovenous malformations.Potts MB1, Lau D, Abla AA, Kim H, Young WL, Lawton MT; UCSF Brain AVM Study Project.N 232HGE 52%SM1 33%SM2 67%Pre op embo 43%Post op angio obliteration 94%Outcome Good functional outcome mRS

0-1Unrup-91%Rup65%Relative outcomeUnrup-98%Rup-96%

No deaths in unruptured group

And concluded that...

Surgery should be regarded as the "gold standard" therapy for the majority of low-grade AVMs, utilizing conservative embolization as a preoperative adjunct.

High surgical cure rates and excellent functional outcomes in patients with both ruptured and unruptured AVMs support a dominant surgical posture for low-grade AVMS, with radiosurgery reserved for risky AVMs in deep, inaccessible, and highly eloquent locations.

Despite the technological advances in endovascular and radiosurgical therapy, surgery still offers the best cure rate, lowest risk profile, and greatest protection against hemorrhage for low-grade AVMs.

ARUBA results are influenced by a low randomization rate, bias toward nonsurgical therapies, a shortage of surgical expertise, a lower rate of complete AVM obliteration, a higher rate of delayed hemorrhage, and short study duration.

Another randomized trial is needed to reestablish the role of surgery in unruptured AVM management.

Seizure control

Acta Neurochir (Wien). 2012 Jun;154(6):1003-10. doi: 10.1007/s00701-012-1339-8. Epub 2012 Apr 11.Cerebral arteriovenous malformations and seizures: differential impact on the time to seizure-free state according to the treatment modalities.Hyun SJ1, Kong DS, Lee JI, Kim JS, Hong SC. CONCLUSIONS:A multidisciplinary team approach for cerebral

AVMs achieved satisfactory seizure control results.

Microsurgery led to the highest percentage of seizure-free outcomes and had the lowest annual bleeding rate, whereas radiosurgery had a higher bleeding rate.

Median time to seizure-free status in surgically treated patients was shorter than in patients who underwent radiosurgical or endovascular treatment

J Neurointerv Surg. 2014 Nov;6(9):684-90. doi: 10.1136/neurintsurg-2013-010945. Epub 2013 Dec 6.Seizure control for intracranial arteriovenous malformations is directly related to treatment modality: a meta-analysis.Baranoski JF1, Grant RA1, Hirsch LJ1, Visintainer P2, Gerrard JL1, Günel M1, Matou CC1, Spencer DD1, Bulsara KR1. 24 studies 1157 patients MS 78.3% (95% CI 70.1% to 85.8%); SRS 62.8% (95% CI 55.0% to 70.0%); EVE 49.3% (95% CI 32.1% to 66.6%). This is the first meta-analysis designed to study

relative rates of seizure outcomes following the currently utilized AVM treatment modalities. In general, MS results in the highest proportion of seizure control. However, if SRS results in successful obliteration of the AVM, then this modality is the most effective in achieving seizure control.

SRS results of major series ...

Obliteration rate-100 % for AVMs <1, 50%-85% for > 1,Complications 7.4%-26%Re haemorrhage 5-16%

Obliteration rates for SRS

Obliteration rates 54-85%

Embolistation stand alone rx

MS vs Embolisation vs Radiosurgery

MS EMBOLISATION

SRS

Effect of treatment

Immediate Delayed , takes 2 years Having the risk of bleeding during the latency period

Obliteration rates

99-100% 5.9%-84.6% 44-93%

Retreatment rates

Recanalisation rates –14-18%

Disadvantage Deeper lesions AVM having more than 4 feeders

AVM with aneurysms and fistulasRadiation side effects

Stats

Case 1

23 year girlInteractable seizuresSM2

Post op transient parietal hand, sensory seizures with parietal psychosis which improved in 3 months

Seizure free for 1 year

Case 228 female perpartum Ruptured avm , SM2

Conclusion

Since partial obliteration of an AVM does not protect against the risk of hemorrhage from the residual nidus and the bleeding rate remains as much the same to the natural history of the disease, a multidisciplinary neurovascular team must develop an individualized and realistic therapeutic strategy, if feasible, to achieve the definitive eradication of a given AVM with a reasonable risk/benefit ratio.