Microsurgery for Spetzler- Martin Grade I-III AVMs: Analysis of surgical results and correlation of Lawton-Young supplementary grade, supplemented Spetzler- Martin score with functional outcome

Abstract Objective To analyze the results of microsurgery for Spetzler- Martin(SM) Grade I-III AVMs and evaluate correlation of Lawton-Young (LY) supplementary grade, supplemented Spetzler- Martin (SM-Supp/combined)score with functional outcome. Methods and Results All 42 patients with SM grade I-III AVMs operated at our Institute during 3 years(June 2013 to May 2016) period were included in this study. All these patients underwent primary surgery without prior embolization. Three patients(7.1%) died in the postoperative period due to surgical site hemorrhage. One patient was lost to follow-up. Mean follow-up in remaining patients was 27 + 14 months (Range: 12-62). At a final follow-up of 12 months or more (FFU), good outcome [Modified Rankin scale(mRS) 1] was noted in 92.7% of the patients and improved or unchanged mRS scores were noted in 87.8% of the patients. AVM size> 3cms, diffuse AVM, SM grade III,SM-Supp score>5 were found to be associated with worsening of mRS scores at the time of discharge and FFU. Higher LY grade(IV/V), eloquent location of AVM, deep venous drainage, age>40yrs, unruptured presentation were not associated with worsening of mRS scores both at discharge and FFU. Good outcome was noted in 19( 95%) of the 20 ARUBA eligible patients. Postoperative angiogram performed in 39 patients revealed complete excision of AVM in 37(94.9%) and residual AVM in 2(5.1%) patients. Conclusions High cure rates and excellent clinical outcomes can be expected with microsurgery in majority of patients with Spetzler-Martin grades I-III AVMs. AVM size> 3cms, diffuse AVM, SM grade III,SM-Supp score>5 are associated with postoperative neurological worsening.