Tumefactive cyst with a vascular blush as a late complication after combined embolization and stereotactic radiosurgery treatments for a cerebral arteriovenous malformation

Experimental study of the effects of absorbable gelatin sponge and non‑absorbable polyvinyl alcohol particle material used in transcatheter arterial embolization on liver tissues

Hepatic trauma is a leading cause of death in major abdominal trauma, and transcatheter arterial embolization has been widely used to treat it. However, there is limited research on whether absorbable gelatin sponge (AGS) and non-absorbable polyvinyl alcohol particles (PVA) have different effects on liver tissue, making it an important area of exploration. The present study investigated this issue using animal experiments by performing transhepatic arterial embolization with AGS and PVA. The effects on normal liver tissue in rabbits were examined by detecting liver function and inflammatory indexes, conducting histopathological examination, and using western blotting to detect apoptotic proteins. There were significant differences between the AGS and PVA groups after embolization. The AGS group exhibited a trend of improvement at ~1 week after embolization, and all indicators were statistically different until day 21 compared with the PVA group. The AGS group exhibited improved repair of hepatocytes and the biliary system based on H&E staining, while the PVA group exhibited more severe necrosis of the hepatocytes and biliary system around the embolization site. The western blotting results indicated that the Bcl-2/Bax ratio decreased on day 1 and day 3, and then rebounded in the AGS group on days 7 and 21, demonstrating gradual repair of hepatocytes compared with the PVA group.

Severe adverse radiation effects complicating radiosurgical treatment of brain arteriovenous malformations and the potential benefit of early surgical treatment

Treatment of brain arteriovenous malformations (AVM) with stereotactic radiosurgery is rarely complicated by severe adverse radiation effects (ARE). The treatment of these sequelae is varied and often ineffectual. We present three cases of brain AVMs treated with SRS, all complicated by severe AREs. All three cases failed to respond to what is currently considered the standard treatment - corticosteroids - and indeed one patient died as a result of the side effects of their extended use. Two cases were successfully treated with surgical excision of the necrotic lesion resulting in immediate clinical improvement. Having considered the experience described in this paper and reviewed the published literature to date we suggest that surgical treatment of AREs should be considered early in the management of this condition should steroid therapy not result in early improvement.

Angiographic "Blush" After Stereotactic Radiosurgery Ablation of Residual Arteriovenous Malformation in Pediatric Patient: Case Report and Review of Literature

INTRODUCTION

While surgical resection remains a primary treatment for accessible arteriovenous malformations (AVMs), stereotactic radiosurgery (SRS) has become thoroughly integrated into the AVM armamentarium; however, delayed sequelae of this treatment have become evident with increased long-term follow-up. To our knowledge, this is the second case of an aberrant local arterial angiographic blush without early venous drainage or an associated lesion following AVM SRS.

CASE DESCRIPTION

An 8-year-old female presented with a ruptured 4-cm right medial frontal periventricular Spetzler-Martin grade 3 AVM with isolated intraventricular hemorrhage. She underwent subtotal resection followed by SRS. Six years later, diagnostic cerebral angiography demonstrated a prominent arterial-phase filling microvasculature without early venous drainage in the region of the irradiated residual AVM nidus.

CONCLUSION

Although there is a paucity of information on angiographic blush following AVM SRS, consensus in the literature suggests that without early venous drainage, these lesions appear to pose an insignificant threat to the patient. These angiographic findings may be on a spectrum of delayed cerebrovascular radiation changes, and thus indefinite follow-up may be considered, especially in pediatric patients.

Cyst Formation Following Radiosurgery for AVMs: Report of 3 Cases

Background:

Stereotactically-focused radiosurgery (SRS) for the treatment of arteriovenous malformations (AVM) has been in widespread use for over two decades. Over this timeframe the indications for treatment, standardization of radiation dosage, and the results expected from treatment have been elaborated. Less well known are the long-term complications associated with SRS. We report three patients who had SRS for the treatment of AVM who developed a cyst at the site of treatment as a late complication.

Methods:

From 201 patients treated by SRS for an AVM, three developed a cyst at the treatment site. Their clinical presentation, the characteristics of the AVMs and the treatment were reviewed, as well as similar cases gleaned from the literature.

Results:

Three women, aged 28-43 years, had an AVM treated by: craniotomy and clipping of arterial feeders followed by SRS, by craniotomy for resection followed by SRS or by endo vascular embolization and SRS. The patients did well following treatment but two of them developed a symptomatic and the other an asymptomatic cyst at the treatment site 3-19 years later. The symptomatic patients underwent marsupialization of the cyst and the other is under observation.

Conclusion:

Stereotactic radiosurgery is an established and safe treatment for patients with AVMs. Delayed cyst formation can occur many years after treatment and long term follow-up is indicated in patients whose AVM has been treated with SRS.

Operative intervention for delayed symptomatic radionecrotic masses developing following stereotactic radiosurgery for cerebral arteriovenous malformations--case analysis and literature review

CASE REPORT

We report two cases of operative intervention that was beneficial in the treatment of delayed symptomatic radionecrotic masses that had developed following stereotactic radiosurgery (SRS) using the gamma knife (GK) for the treatment of cerebral arteriovenous malformations (AVM).

DISCUSSION

Case 1 involved a small craniotomy for decompression of a large cerebral multiloculated cyst, which had become symptomatic 84 months following gamma knife treatment for a left frontal lobe AVM. Case 2 involved surgical excision of an occipital radionecrotic mass 72 months following GK treatment for an occipital AVM. This patient had suffered from longstanding symptomatic cerebral oedema, which on occasions had become life threatening. Case 2 is also the first report of a radionecrotic mass occurring post-SRS for an AVM, which conversely appeared to demonstrate increased uptake on single photon emission computed tomography (SPECT) scan. The first literature review of such delayed symptomatic radionecrotic lesions is presented. There appears to be a late onset of symptoms (average 55 months, range 12-111 months) associated with such radionecrosis. Drainage of such cysts or excision of the mass lesion appears to be consistently beneficial to the patients and appears to be uncomplicated.

CONCLUSION

We recommend early surgical intervention for such delayed symptomatic radionecrotic masses that do not resolve following non-operative management. We also recommend caution in interpretation of SPECT scan results when attempting to differentiate radionecrosis from neoplasia.