Follow-up imaging to detect recurrence of surgically treated pediatric arteriovenous malformations

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>The true postoperative incidence of arteriovenous malformation (AVM) recurrence in the pediatric population remains largely unreported. Some literature suggests that delayed imaging studies should be obtained at 6 months to 1 year after negative findings on a postoperative angiogram. The aim of this study was to describe the timing of AVM recurrences after resection and the neuroimaging modalities on which the recurrences were detected.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>This study was performed in a retrospective cohort of all pediatric patients treated surgically for AVM resection by a single neurosurgeon between 2005 and 2010. Patients were followed after resection with MR angiography (MRA) or conventional angiography, when possible, at various time points. A visual scale for compactness of the initial AVM nidus was used, and the score was correlated with probability of recurrence after surgery.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>A total of 28 patients (13 female, 15 male) underwent an AVM resection. In 18 patients (64.3%) an intraoperative angiogram was obtained. In 4 cases the intraoperative angiogram revealed residual AVM, and repeat resections were performed immediately. Recurrent AVMs were found in 4 children (14.3%) at 50, 51, 56, and 60 weeks after the initial resection. Recurrence risk was 0.08 per person-year. No patient with normal results on an angiogram obtained at 1 year developed a recurrence on either a 5-year angiogram or one obtained at 18 years of age. All patients with recurrence had a compactness score of 1 (diffuse AVM); a lower compactness score was associated with recurrence (p = 0.0003).</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>All recurrences in this cohort occurred less than 15 months from the initial resection. The authors recommend intraoperative angiography to help ensure complete resection at the time of the surgery. Follow-up vascular imaging is crucial for detecting recurrent AVMs, and conventional angiography is preferred because MRA can miss smaller AVMs. One-year follow-up imaging detected these recurrences, and no one who had negative results on an angiogram obtained at 1 year had a late recurrence. However, not all of the patients have been followed for 5 years or until 18 years of age, so longer follow-up is required for these patients. A lower compactness score predicted recurrent AVM in this cohort.</jats:p></jats:sec>

Postoperative imaging for detection of recurrent arteriovenous malformations in children

“…16 This finding lends support to the concept that delayed postoperative DSA is needed to monitor for recurrent AVM in children. However, it should be noted that long-term follow-up in our series identified 1 patient with a recurrence 6 years after complete resection with a previously negative surveillance DSA at 4 years (Case 3), as illustrated in Fig.…”

“…3,6,24,28 Accumulating evidence has demonstrated that AVMs recur in children. 1,2,14,16 The rate of hemorrhage associated with recurrent AVMs is not well defined, largely due to relatively small numbers of patients available for study. We confirm in our series that recurrences do occur in the pediatric population, and demonstrate that they can present with hemorrhage despite recent negative imaging.…”

“…Some studies recommend imaging 6-12 months after a negative postoperative digital subtraction angiogram to rule out recurrent or residual AVM. 13,16,20,29 With reported cases of recurrence occurring 3 months to 16 years after primary treatment, 1,2,13,16,26,29 a more extended imaging protocol is likely necessary to capture recurrence and prevent associated morbidity. Follow-up imaging, however, carries additional risk, cost, and time.…”

“…1,2,9,10,16,23,29 Although the underlying cause of this apparently different biology is unclear, 26 it is an important factor to consider in the management and postoperative follow-up of pediatric patients with AVMs. In addition to patient age, deep venous drainage and diffuse nidus have been identified as potential risk factors for recurrence.…”

“…In addition to patient age, deep venous drainage and diffuse nidus have been identified as potential risk factors for recurrence. 14,16,18 abbreviations AChA = anterior choroidal artery; AVM = arteriovenous malformation; CTA = CT angiography; DSA = digital subtraction angiography; EVD = external ventricular drain; ICA = internal carotid artery; ICH = intracerebral hemorrhage; MRA = MR angiography; mRS = modified Rankin Scale. obJective The optimal method for detecting recurrent arteriovenous malformations (AVMs) in children is unknown.…”