The usefulness of indocyanine green during surgery for hypervascular posterior fossa tumors

Surgical Outcome of Large Solid Posterior Fossa Hemangioblastoma without Preoperative Embolization

BACKGROUND

 Large solid hemangioblastoma in the posterior fossa has an abundant blood supply as an arteriovenous malformation. The presence of adjacent vital neurovascular structures makes them vulnerable and difficult to operate. Complete surgical resection is always a challenge to the neurosurgeon.

MATERIAL AND METHOD

 We share the surgical difficulties and outcome in this case series of large solid hemangioblastomas without preoperative embolization as an adjunct. This study included five patients (three men and two women, with a mean age of 42.2 years). Preoperative embolization was attempted in one patient but was unsuccessful. All the patients have headache (100%) and ataxia (100%) as an initial symptom. A ventriculoperitoneal shunt was inserted in one case before definite surgery due to obstructive hydrocephalus. The surgical outcome was measured using the Karnofsky Performance Status (KPS) score.

RESULT

 The tumor was excised completely in all the cases. No intra- and postoperative morbidity occurred in four patients; one patient developed transient lower cranial nerve palsy. Mean blood loss was 235 mL, and no intraoperative blood transfusion was needed in any case. The mean follow-up period was 14.2 months. The mean KPS score at last follow-up was 80.One patient had a KPS score of 60.

CONCLUSION

 Our treatment strategy is of circumferential dissection followed by en bloc excision, which is the optimal treatment of large solid hemangioblastoma. The use of adjuncts as color duplex sonography and indocyanine green video angiography may help complete tumor excision with a lesser risk of complication. Preoperative embolization may not be needed to resect large solid posterior fossa hemangioblastoma, including those at the cerebellopontine angle location.

Second-Window Indocyanine Green for Visualization of Hemangioblastoma: A Case Report With Two-Dimensional Operative Video

BACKGROUND AND IMPORTANCE

The proper differentiation of neoplastic tissue from adjacent brain parenchyma can pose a great challenge, especially in eloquent areas of the brain. With the novel technique, "Second-Window Indocyanine Green," injection of a near-infrared fluorophore (ICG) allows for intraoperative visualization of tumors by taking advantage of the compromised vasculature surrounding the tumor. Thus, such a technique may demonstrate utility for hemangioblastomas, which are hypervascular tumors of the central nervous system.

CLINICAL PRESENTATION

Here we present the case of a 39-yr-old male with a demonstrated cystic mass in the left cerebellum, with additional edema spreading towards the vermis. A total of 5 mg/kg of ICG was delivered intravenously 24 h prior to the operation. The tumor was approached via the infratentorial suboccipital approach. We observed strong near-infrared fluorescence through the intact dura, consistent with the tumor location. Surgical pathology confirmed a final diagnosis of cerebellar hemangioblastoma. There was complete resection of the tumor, with the patient discharged uneventfully.

CONCLUSION

We report the first successful case of fluorescence-guided surgery of a cerebellar hemangioblastoma using near-infrared fluorescence imaging with the Second-Window ICG technique. This joins a growing series of publications that demonstrate the efficacy of a novel application of ICG, a near-infrared fluorophore, in accurate intraoperative visualization of neoplastic tissue. While the use of a dedicated near-infrared platform (ie, the VisionSense Iridium [Visionsense, Philadelphia, Pennsylvania]) yields a higher signal-to-background ratio, a neurosurgical microscope (ie, the Leica OH6 [Leica Microsystems, Wetzlar, Germany]) may also provide a suitable option in cases where fluorescence is very strong.

Utility of indocyanine green in the detection of radiologically silent hemangioblastomas: case report

Hemangioblastomas (HBs) are rare, benign, hypervascularized tumors. Fluorescent imaging with indocyanine green (ICG) can visualize tumor angioarchitecture. The authors report a case of multiple HBs involving two radiologically silent lesions only detected intraoperatively by ICG fluorescence. A 26-year-old woman presented with a cystic cerebellar mass on the tentorial surface of the left cerebellar hemisphere on MRI. A left paramedian suboccipital approach was performed to remove the mural nodule with the aid of ICG injection. The first injection, applied just prior to removing the nodule, highlighted the tumor and vessels. After resection, two new lesions, invisible on the preoperative MRI, surprisingly enhanced on fluorescent imaging 35 minutes after the ICG bolus. Both silent lesions were removed. Histological analysis of all three lesions revealed they were positive for HB. The main goal of this report is to hypothesize possible explanations about the mechanism that led to the behavior of the two silent lesions. Intraoperative ICG videoangiography was useful to understand the 3D angioarchitecture and HB flow patterns to perform a safe and complete resection in this case. Understanding the HB ultrastructure and pathophysiological mechanisms, in conjunction with the properties of ICG, may expand potential applications for their diagnosis and future treatments.

Efficacy of Intra-arterial Indocyanine Green Videoangiography in Hemangioblastoma Surgery: A Case Report

Intravenous indocyanine green (ICG) videoangiography is reportedly useful for vascular neurosurgery, and for treating hemangioblastoma due to its high vascularity. Videoangiography obtained after intra-arterial ICG injection has emerged as a more useful option than that after intravenous injection. This report offers the first description of a case of hemangioblastoma successfully treated using intra-arterial ICG videoangiography, and describes the efficacy of this technique. A 20-year-old man presented with progressive cerebellar ataxia and dysphagia. Magnetic resonance imaging (MRI) revealed an enhanced solid tumor in the medulla oblongata. Digital subtraction angiography (DSA) showed a highly vascularized tumor. Surgery was performed to remove the tumor in a hybrid operating room. A catheter was introduced into the vertebral artery (VA) for intra-arterial ICG videoangiography. Superficial feeders and drainers were identified and flow dynamic changes in the tumor were assessed by intra-arterial ICG videoangiography. The tumor was removed after confirming lack of flow in the drainer. Intra-arterial ICG videoangiography was more useful than intravenous ICG videoangiography in hemangioblastoma surgery for identifying feeders and drainers and assessing flow dynamics in the tumor. Use of Flow 800 made these findings simpler and easier to evaluate.