Brainstem Cavernous Malformations Management: Microsurgery vs. Radiosurgery, a Meta-Analysis

Identification of predictive factors for better outcomes in LINAC-based radiation treatment for cerebral cavernous malformation

The effectiveness of radiation therapy in the treatment of cerebral cavernous malformations (CCM) remains debatable. However, numerous studies have shown a reduction in hemorrhage risk following radiotherapy for CCM. Therefore, herein, we share our experiences utilizing linear accelerator (LINAC)-based radiation for treating CCMs, with the aim of identifying the key factors influencing the therapeutic outcomes. We conducted a retrospective review of all patients with non-brainstem CCMs who underwent radiation treatment, as recorded in the NOVALIS registry at our institution. T2-weighted MR images were used for volumetric assessments using the iPlan radiotherapy planning software. To determine the independent predictors of nidus volume reduction and perilesional brain edema (PBE), we performed multivariate Cox regression analysis to calculate hazard ratios. Twenty patients with 31 non-brainstem CCMs were enrolled in this study. Analysis revealed age as an independent predictive factor for both nidus volume reduction and PBE after radiation treatment for CCM. Furthermore, a single fraction dose of 17 Gy or more was identified as an independent predictor of nidus volume decrease, while a single fraction dose of 18 Gy or more was found to be an independent risk factor for PBE in patients with CCM following LINAC-based radiation therapy. LINAC-based radiation therapy for non-brainstem CCMs with a single fraction radiation dose between 16.5 and 17.5 Gy, or a biologically equivalent dose of approximately 120 Gy, may be the most effective at reducing nidus volume and limiting side effects, particularly in patients under the age of 55 years. We further observed that the risk of PBE increased as the maximum radiation dose delivered to a 1 cc volume of the surrounding normal brain exceeded approximately 17.3 Gy. Therefore, we believe that calculating the D1cc of the normal brain may help to predict the occurrence of PBE when radiotherapy is administered to non-brainstem CCMs.

Management of intracranial cavernous malformations using conservative vs. surgical and/or radiosurgical treatment: A systematic review and meta‑analysis

Intracranial cavernous malformations (CMs) are vascular lesions with a high bleeding rate. At present, the debate regarding their treatment is still ongoing. The present systematic review and meta-analysis aimed to evaluate the safety of surgery or radiosurgery (SRS) for the management of CMs and to determine their potential outcomes compared with conservative treatment. The present systematic review and meta-analysis investigated the relative articles involving the management of intracranial CMs, namely their natural history (conservative treatment) vs. surgical/SRS treatment through electronic databases until June, 2023. The collected variables included the first author's name, the study period covered, the year of publication, the total number of patients examined and their age, and the number of males. In total, six articles met the eligibility criteria. The total number of patients was 399 (157 in the surgery/SRS group and 242 in the conservative treatment group). The results revealed that surgical or SRS management is a safe procedure for CMs compared with conservative treatment. Notably, the use of hemosiderin in the pre-MRI, the free of seizures parameter and the neurological deficit parameters were associated with improved outcomes in the surgical or SRS group of patients.

A rare case of rebleeding brainstem cavernoma in a 5-month-old-girl

Background

Brainstem cavernomas (BSCs) are relatively rare intracranial vascular lesions that, if left untreated, can be devastating to the patient. The lesions are associated with a myriad of symptoms, depending on their size and location. However, medullary lesions present acutely with cardiorespiratory dysfunction. We present the case of a 5-month-old child with a BSC.

Case Description

A 5-month-old child presented for the 2^nd time with sudden respiratory distress and excessive salivation. On the first presentation, brain magnetic resonance imaging (MRI) showed a 13 × 12 × 14 mm cavernoma at the pontomedullary junction. She was managed conservatively but presented 3 months later with tetraparesis, bulbar palsy, and severe respiratory distress. A repeat MRI showed enlargement of the cavernoma to 27 × 28 × 26 mm with hemorrhage in different stages. After hemodynamic stabilization, complete cavernoma resection was performed through the telovelar approach with neuromonitoring. Postoperatively, the child recovered motor function, but the bulbar syndrome persisted with hypersalivation. She was discharged on day 55 with a tracheostomy.

Conclusion

BSCs are rare lesions that are associated with severe neurological deficits due to the compactness of important cranial nerve nuclei and other tracts in the brainstem. Early surgical excision and hematoma evacuation for superficially presenting lesions can be lifesaving. However, the risk of postoperative neurological deficits is still a major concern in these patients.

Case report: Delayed outflow obstruction of a DVA: A rare complication of brainstem cavernoma surgery

Introduction

Developmental venous anomalies (DVAs) are considered variants of normal transmedullary veins. Their association with cavernous malformations is reported to increase the risk of hemorrhage. Expert consensus recommends meticulous planning with MR imaging, use of anatomical “safe zones”, intraoperative monitoring of long tracts and cranial nerve nuclei, and preservation of the DVA as key to avoiding complications in brainstem cavernoma microsurgery. Symptomatic outflow restriction of DVA is rare, with the few reported cases in the literature restricted to DVAs in the supratentorial compartment.

Case

We present a case report of the resection of a pontine cavernoma complicated by delayed outflow obstruction of the associated DVA. A female patient in her 20's presented with progressive left-sided hemisensory disturbance and mild hemiparesis. MRI revealed two pontine cavernomas associated with interconnected DVA and hematoma. The symptomatic cavernoma was resected via the infrafacial corridor. Despite the preservation of the DVA, the patient developed delayed deterioration secondary to venous hemorrhagic infarction. We discuss the imaging and surgical anatomy pertinent to brainstem cavernoma surgery, as well as the literature exploring the management of symptomatic infratentorial DVA occlusion.

Conclusion

Delayed symptomatic pontine venous congestive edema is extremely rare following cavernoma surgery. DVA outflow restriction from a post-operative cavity, intraoperative manipulation, and intrinsic hypercoagulability from COVID-10 infection are potential pathophysiological factors. Improved knowledge of DVAs, brainstem venous anatomy, and “safe entry zones” will further elucidate the etiology of and the efficacious treatment for this complication.