✓ The fiberoptic endoscope has never gained popularity among neurosurgeons although it is ideally suited for navigating within the cerebral ventricles. Recent advances in optics and miniaturization make the application of endoscopy in neurosurgery more practical. The authors report eight children who underwent ventriculoscopic fenestration of symptomatic loculated cerebrospinal fluid (CSF) collections. These CSF collections were either isolated ventricular cysts or trapped lateral ventricles secondary to obstruction at the foramen of Monro. Cyst wall dissection was carried out with a “saline torch” dissector which was introduced through a working channel in the ventriculoscope. The torch was used to coagulate vessels and to sculpt large windows in cyst walls or in the septum pellucidum. Ventriculoscope-guided cyst fenestration can be performed safely and easily under direct vision. The technique may permit simplification of shunt systems in some patients and elimination of shunts in others.
Carl B. Heilman and Alan R. Cohen
Carl B. Heilman, Eddie S. K. Kwan and Julian K. Wu
✓ Endovascular balloon occlusion is an alternative treatment for surgically unclippable cerebral aneurysms. The results of aneurysm occlusion with either a silicone or a latex balloon in a common carotid artery bifurcation aneurysm model are compared to determine which type of balloon was least likely to result in aneurysm recurrence. Five rabbits each underwent endovascular balloon occlusion with either a silicone or a latex balloon, with seven rabbits serving as controls. At 3 months postocclusion, nine of the 10 balloon-treated aneurysms had recurred. The recurrent aneurysm tended to be larger in animals treated with silicone than with latex balloons. A dense fibrotic response was present around the collar of the latex balloons, but no significant fibrotic response was found in the silicone balloon group. This study suggests that with currently available balloons, the initial complete angiographic obliteration of an aneurysm following balloon occlusion should not be interpreted as a cure and that periodic follow-up angiography should be performed.
Clemens M. Schirmer and Carl B. Heilman
Intracranial hemangiopericytomas are frequently located along the dural sinuses along the skull base and represent rare, aggressive CNS neoplasms that are difficult to distinguish from meningiomas based on both imaging and gross characteristics. The authors of this study describe 3 patients with these lesions and review the pertinent literature.
Two men and 1 woman, whose median age at the time of the initial presentation was 37 years (range 20–53 years), constitute this series. They underwent multimodal treatment consisting of resection, embolization, radiation therapy, and in 1 case chemotherapy.
Two of the 3 patients treated were alive after a mean follow-up of 93 months (range 4–217 months). One patient died 217 months after the initial diagnosis. The longest tumor progression–free interval after the initial or secondary resection was 43 months (range 4–84 months).
Hemangiopericytomas have been reclassified as mesenchymal nonmeningothelial tumors. They have an inevitable tendency to recur locally and metastasize distally. The mainstay of therapy remains an aggressive attempt to achieve gross-total resection at the initial surgery. Postoperative adjuvant radiotherapy should be offered to all patients, regardless of the degree of resection achieved. Diligent long-term follow-up is paramount as local recurrences and distal metastases can develop sometimes years after the initial treatment.
Report of 5 cases
Sameer H. Halani, Mina G. Safain and Carl B. Heilman
Arachnoid cysts are common, accounting for approximately 1% of intracranial mass lesions. Most are congenital, clinically silent, and remain static in size. Occasionally, they increase in size and produce symptoms due to mass effect or obstruction. The mechanism of enlargement of arachnoid cysts is controversial. One-way slit valves are often hypothesized as the mechanism for enlargement. The authors present 4 cases of suprasellar prepontine arachnoid cysts in which a slit valve was identified. The patients presented with hydrocephalus due to enlargement of the cyst. The valve was located in the arachnoid wall of the cyst directly over the basilar artery. The authors believe this slit valve was responsible for the net influx of CSF into the cyst and for its enlargement. They also present 1 case of an arachnoid cyst in the middle cranial fossa that had a small circular opening but lacked a slit valve. This cyst did not enlarge but surgery was required because of rupture and the development of a subdural hygroma. One-way slit valves exist and are a possible mechanism of enlargement of suprasellar prepontine arachnoid cysts. The valve was located directly over the basilar artery in each of these cases. Caudad-to-cephalad CSF flow during the cardiac cycle increased the opening of the valve, whereas cephalad-to-caudad CSF flow during the remainder of the cardiac cycle pushed the slit opening against the basilar artery and decreased the size of the opening. Arachnoid cysts that communicate CSF via circular, nonslit valves are probably more likely to remain stable.
Mina G. Safain, Walter C. Dent and Carl B. Heilman
Epidermoid cysts are rare lesions accounting for 1% of intracranial tumors with approximately 50% located within the cerebello-pontine angle (CPA). Resection is complicated by their close anatomical relation to critical neurovascular structures and their tendency to be densely adherent making complete removal a significant neurosurgical challenge. We present a 35-year-old woman with left sided tongue numbness and lower lip paresthesias with a CPA epidermoid. An endoscopic assisted retrosigmoid approach was utilized for resection. A 30-degree endoscope was used to assist in removal of unseen tumor in Meckel's cave, medial to the lower cranial nerves, and along the ventral pons.
The video can be found here: http://youtu.be/bv0lMPbX7BY.
Clemens M. Schirmer and Carl B. Heilman
Neuroendoscopic treatment of colloid cysts is limited by the reach and flexibility of the instruments that can be passed through the working channels of the rigid neuroendoscope. The authors describe a case of a third ventricular colloid cyst where a large solid colloid fragment was recovered using a nitinol stone retrieval basket as a flexible wall-guided atraumatic salvage instrument. A flexible nitinol stone retrieval basket was successfully used through an endoscopic working channel to retrieve a large portion of the colloid cyst from the occipital horn of the lateral ventricle in a 70-year-old man who presented with progressive memory loss, urinary incontinence, and slowness of gait. A flexible nitinol stone retrieval basket can be safely and effectively maneuvered in the ventricular system, using the ventricular wall for deflection, and can be used to retrieve colloid cyst fragments as a salvage technique. Remaining free-floating large colloid cyst fragments in the ventricular system do not necessarily require a second craniotomy or bur hole for access but may be retrieved using a nitinol stone retrieval basket.
Emily Anderson, Robert S. Heller, Ronald M. Lechan and Carl B. Heilman
A 71-year-old female patient was referred in 2013 for evaluation of an asymptomatic nonsecreting pituitary adenoma. The adenoma, measuring 13 mm in height by 10 mm in width, was discovered incidentally on imaging in 2012. Biochemical testing demonstrated a nonfunctioning adenoma. Given the relatively small lesion size and the lack of symptoms, observation was preferred over surgical intervention. The patient was monitored with routine MRI, which until 2016 demonstrated minimal growth. In early 2016, the patient developed recurrence of metastatic breast cancer and was treated with palbociclib, a cyclin-dependent kinase (CDK) 4/6 inhibitor. This inhibitor acts on a pathway believed to be involved in pituitary adenoma tumorigenesis. One year after starting palbociclib, routine imaging demonstrated significant regression of her pituitary adenoma. The authors hypothesize that inhibition of the CDK4/6 pathway by palbociclib contributed to adenoma regression in this patient, and that palbociclib may represent a possible adjuvant therapy for the treatment of nonfunctioning pituitary adenomas.
Carl B. Heilman, Eddie S. Kwan, Richard P. Klucznik and Alan R. Cohen
✓ Cirsoid aneurysms of the scalp are notoriously difficult lesions to manage. The authors report a patient in whom a large traumatic cirsoid aneurysm of the scalp was eliminated using a combined neurosurgical and interventional neuroradiological approach. Transarterial embolization was utilized to reduce arterial blood supply to the fistula. Thrombogenic Gianturco spring coils were then introduced via direct percutaneous puncture of the aneurysm. The aneurysm thrombosed and the multiple tortuous scalp vessels disappeared. One month after embolization, a small area of skin necrosis over the aneurysm necessitated surgical excision of the lesion. The thrombosed aneurysm was easily resected with minimal blood loss. Percutaneous embolization with thrombogenic coils in this case was a safe and effective ablative technique.
Robert S. Heller, Carlos A. David and Carl B. Heilman
Surgical resection of sphenoid wing tumors and intraorbital pathology carries the dual goal of appropriately treating the target pathology as well as correcting proptosis. Residual proptosis following surgery can lead to cosmetic and functional disability. The authors sought to quantitatively assess the effect of orbital volume before and after reconstruction to determine the optimal strategy to achieve proptosis correction.
All surgeries involving orbital wall reconstruction for orbital or intracranial pathology that preoperatively resulted in proptosis between 2007 and 2017 were reviewed. Proptosis was measured by the exophthalmos index (EI): the ratio of the distance of the anterior limit of each globe to a line drawn between the anterior limit of the frontal processes of the zygomas, comparing the pathological eye to the normal eye. Postoperative radiographic measurements were taken at least 60 days after surgery to allow surgical swelling to abate. The orbit contralateral to the pathology was used as an internal control for normal anatomical orbital volume. Cases with preoperative EI < 1.10, orbital exenteration, or enucleation were excluded.
Twenty-three patients (16 females and 7 males, with a mean age of 43.6 ± 22.8 years) were treated surgically for tumor-associated proptosis. Nineteen patients harbored meningiomas (11 en-plaque; 8 sphenoid wing), and one patient each harbored an orbital schwannoma, glomangioma, arteriovenous malformation, or cavernous hemangioma. Preoperative EI averaged 1.28 ± 0.10 (range 1.12–1.53). Median time to postoperative imaging was 19 months. Postoperatively, the EI decreased to a mean of 1.07 ± 0.09. Greater increases in size of the reconstructed orbit were positively correlated with greater quantitative reductions in proptosis (p < 0.01). Larger volume of soft tissue pathology was also associated with achieving greater proptosis correction (p < 0.01). Residual exophthalmos (defined as EI > 1.10) was present in 8 patients, while reconstruction in 2 patients resulted in clinically asymptomatic enophthalmos (defined as EI < 0.95). Tumor invasion into the superior orbital fissure sinus was associated with residual proptosis (p = 0.04).
Proptosis associated with intracranial and orbital pathology represents a surgical challenge. The EI is a reliable and quantitative assessment of proptosis. For orbital reconstruction in cases of superior orbital fissure involvement, surgeons should consider rebuilding the orbit at slightly larger than anatomical volume.