Magnetic resonance-guided laser interstitial thermal therapy for posterior fossa neoplasms.

PURPOSE: Magnetic resonance-guided laser interstitial thermal therapy (LITT) has been increasingly used to treat a number of intracranial pathologies, though its use in the posterior fossa has been limited to a few small series. We performed a multi-institutional review of targets in the posterior fossa, reporting the efficacy and safety profile associated with laser ablation in this region of the brain. METHODS: A retrospective review of patients undergoing LITT in the posterior fossa was performed from August 2010 to March 2020. Patient demographic information was collected alongside the operative parameters and patient outcomes. Reported outcomes included local control of the lesion, postoperative complications, hospital length of stay, and steroid requirements. RESULTS: 58 patients across four institutions underwent LITT in the posterior fossa for 60 tumors. The median pre-ablation tumor volume was 2.24 cm3. 48 patients (50 tumors) were available for follow-up. An 84% (42/50) overall local control rate was achieved at 9.5 months median follow up. There were two procedural complications, including insertional hemorrhage and laser misplacement and 12/58 (21%) patients developed new neurological deficits. There was one procedure related death. The median length of hospital stay was 1 day, with 20.7% of patients requiring discharge to a rehabilitation facility. CONCLUSIONS: LITT is an effective approach for treating pathology in the posterior fossa. The average target size is smaller than what has been reported in the supratentorial space. Care must be taken to prevent injury to surrounding structures given the close proximity of critical structures in this region.

Widening the Operative Corridor-Evaluating the Transcortical Approach to Giant Falcine Meningiomas.

BACKGROUND: Giant falcine meningiomas are surgically complex as they are deep in location, concealed by normal brain parenchyma, in close proximity to various neurovascular structures, and frequently involve the falx bilaterally. Although classically accessed using a bifrontal craniotomy and interhemispheric approach, little data exist on alternative operative corridors for these challenging tumors. We evaluated perioperative and long-term outcomes in patients undergoing transcortical resection of giant bilateral falcine meningiomas. METHODS: From 2013 to 2022, fourteen patients with giant bilateral falcine meningiomas treated via a transcortical approach at our institution were identified. Perioperative and long-term outcomes were evaluated to determine predictors of adverse events. Corticectomy depth was also analyzed to determine if it correlated with increased postoperative seizure rates. RESULTS: 57.1% of cases were WHO grade 2 meningiomas. Average tumor volume was 77.8 ± 46.5 cm3 and near/gross total resection was achieved in 78.6% of patients. No patient developed a venous infarct or had seizures in the 6 months after surgery. Average corticectomy depth was 0.83 ± 0.71 cm and increasing corticectomy depth did not correlate with higher risk of postoperative seizures (P = 0.44). Increasing extent of tumor resection correlated with lower tumor grade (P = 0.011) and only 1 patient required repeat resection during a median follow-period of 24.9 months. CONCLUSIONS: The transcortical approach is a safe alternative corridor for accessing giant, falcine meningiomas, and postoperative seizures were not found to correlate with increasing corticectomy depth. Further prospective studies are necessary to determine the best approach to these surgically complex lesions.

An Update on Tissue Contraction in Immediate Breast Reconstruction Using an Adjustable Implant Partially Filled With Air.

Background With the use of nipple-sparing mastectomy (NSM) and skin-sparing mastectomy (SSM) techniques, utilizing a prepectoral underfilled adjustable saline implant allows for tissue contraction and thickening of the flap. This procedure allows for immediate reconstruction using an adjustable implant as a spacer with less risk of skin flap compromise and improves cosmetic outcomes. Methods A retrospective chart review of patients presenting to a single surgeon from September 2013 to September 2021 for breast reconstruction utilizing an underfilled prepectoral adjustable implant following SSM or NSM was performed. Baseline patient demographics, clinical information, postoperative complications, conversion to silicone implant, and contraction distance were recorded and analyzed. Results Fifty-four patients underwent prepectoral breast reconstruction using a Spectrum™ adjustable implant following an NSM or SSM. Tissue contraction and skin flap elevation were observed in all patients. The amount of tissue contraction averaged 4.4 cm (mean). Seven patients (12.96%) developed seromas. Four patients (7.41%) developed hematomas in the early postoperative period. Two patients (3.67%) developed capsular contracture. Two patients (3.67%) had a displaced port. After converting the air to saline, 25 patients (46.29%) opted for a secondary reconstructive procedure to exchange the saline implants for silicone gel implants. Conclusion Tissue contraction reduces the need for skin excision in ptotic breasts undergoing reconstruction procedures following NSM or SSM. The partially filled implant initially functions as a spacer to prevent flap adherence to the pectoral muscle and minimizes tension on the flap to promote flap thickening, elevation around the underfilled implant, and maximizes breast projection and overall aesthetic outcome.

Supralesional Ablation Volumes Are Feasible in the Posterior Fossa and May Provide Enhanced Symptomatic Relief.

BACKGROUND: Laser interstitial thermal therapy (LITT) for posterior fossa lesions remains rare as the small size of the infratentorial compartment, proximity to the brainstem, and thickness/angulation of the occipital bone creates barriers to procedural success. Furthermore, evaluation of the effect of ablation volume on outcomes is limited. OBJECTIVE: To analyze our institutional experience with LITT in the posterior fossa stratifying perioperative and long-term outcomes by ablation volumes. METHODS: Seventeen patients with posterior fossa lesions treated with LITT from 2013 to 2020 were identified. Local progression-free survival (PFS), overall survival, steroid dependence, and edema reduction were evaluated with Kaplan-Meier analysis grouped by ablation volume. Preoperative, postoperative, and last known Karnofsky Performance Status (KPS) were compared using a matched paired t test. RESULTS: No differences in pathology, preoperative KPS, or preoperative lesion volume were found between patients with total (100%-200% increase in pre-LITT lesion volume) versus radical (>200% increase in pre-LITT lesion volume) ablations. Patients who underwent radical ablation had a higher postoperative KPS (93 vs 82, P = .02) and higher KPS (94 vs 87, P = .04) and greater reduction in perilesional edema at last follow-up (P = .01). Median follow-up was 80.8 wk. CONCLUSION: Despite obvious anatomical challenges, our results demonstrate that radical ablations are both feasible and safe in the posterior fossa. Furthermore, radical ablations may lead to greater decreases in perilesional edema and improved functional status both immediately after surgery and at last follow-up. Thus, LITT should be considered for patients with otherwise unresectable or radioresistant posterior fossa lesions.

The Use of BrainPath Tubular Retractors in the Management of Deep Brain Lesions: A Review of Current Studies.

BACKGROUND: Traditional retraction to access deep intraparenchymal brain lesions results in vascular disruption. Tubular retractors such as the BrainPath tubular retractor system were developed to reduce retractor-related force injuries via radial dispersion of force. Our study seeks to assess the indications, benefits, and complications associated with BrainPath retractors. METHODS: A literature search of PubMed MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Cochrane Database of Systematic Reviews was performed. The search terminology used was "BrainPath OR Brain-Path." The BrainPath Web site was also examined. Postoperative morbidity and mortality were analyzed to estimate complications linked to using the retractor. RESULTS: Twenty-nine articles (n = 289 patients) met the inclusion criteria. BrainPath was used primarily for tumor resections and hematoma evacuations. These cases were subdivided into groups based on lesion location, size, and resection volume for further analysis. Gross total resection was achieved in 79% of tumor excisions and subtotal resection in 21%. Hematoma evacuation >90% of original hematoma volume was achieved in 65.1% of cases, 75%-90% of original volume in 21.7%, and <75% in the remaining 13.2%. The complication rate attributed to retractor use was 8.3%. CONCLUSIONS: This report is the first formal assessment of the BrainPath tubular retraction system, highlighting technical considerations of the retractor from the surgeon's perspective, patient outcomes, and complications. The retractor is a safe, efficacious system that can be used for tumor resection or biopsy and hematoma evacuation. However, further randomized controlled trials are indicated to accurately assess complication rates and outcomes.

Treatment of Bilateral Giant Fusiform Petrocavernous Aneurysms.

Aneurysms of the petrous segment of the internal carotid artery (ICA) are exceedingly rare. They are thought to arise from traumatic, mycotic, or congenital etiologies. We present a case of bilateral giant fusiform aneurysms of the petrocavernous ICA treated with bilateral flow-diverting stent placement. An 18-year-old male presented to our institution with headaches, nausea, vomiting and blurry vision that had been present since the day prior. Visual exam revealed decreased visual acuity bilaterally and a temporal field cut superiorly and inferiorly of the left eye. CT and MR imaging revealed bilateral lesions of the petrous segment of the ICA bilaterally. Catheter angiography demonstrated bilateral giant fusiform aneurysm of the petrocavernous ICA. The patient was treated with aspirin 325 mg and clopidogrel 75 mg orally daily for one week prior to the exam. VerifyNow (Accriva; San Diego, CA) confirmed adequate platelet inhibition. The right ICA was treated first, with a multiple flow-diverting stent construct. No complications were noted and the patient was discharged to home two days later. He was brought back three weeks later, and the left ICA was treated with a multiple flow-diverting stent construct. Again, no complications were noted and the patient was discharged uneventfully. The patient returned for his six-month follow-up angiogram with improvement of his visual acuity and resolution of headaches. However, the patient had ceased taking both anti-platelet medications six weeks prior. Angiography revealed no filling of the aneurysm in the right ICA, however, the left ICA was occluded at the origin. The patient was resumed on daily aspirin 325 mg orally and will have follow-up catheter angiography at 12 months. Petrous segment ICA aneurysms are rare. Most are thought to arise from trauma, infection, or congenital etiologies. These aneurysms are typically fusiform in nature, and can extend into the cavernous segment of the ICA. The natural history of these aneurysms is not well understood given their rarity. Current literature advocates for asymptomatic patients to be treated conservatively given that the natural history is not well known. Treatment is recommended in symptomatic patients, who may present with symptoms of local mass effect or ischemic stroke due to emboli. Endovascular options include flow diverting stent or covered stent placement, coil embolization with or without stent-assistance, or ICA occlusion. Open surgical options include trapping and high-flow bypass. When bilateral lesions are present, the management algorithm must be amended. We elected to treat the asymptomatic side first (right ICA), due to the presence of a significant kink within the aneurysm on the left. Once the right side was treated successfully, the symptomatic side was treated with a multiple stent construct. The patient's six-month angiogram demonstrated occlusion of the left ICA, likely due to non-compliance with antiplatelet medications. This further reiterates the need for dual-antiplatelet therapy and patient education and compliance with flow diverting stents. We report a rare case of bilateral giant fusiform petrocavernous aneurysms treated with bilateral Pipeline embolization devices in multiple device construct, demonstrating the feasibility and safety of this treatment option for this pathology.

Intracranial Tubular Retractor Systems: A Comparison and Review of the Literature of the BrainPath, Vycor, and METRx Tubular Retractors in the Management of Deep Brain Lesions.

In neurosurgery, parenchymal injury resulting from focal exertion of pressure on retracted tissue is a common complication associated with the use of plate and self-sustaining retractors to access deep intraparenchymal lesions. Tubular retractors, including Vycor, BrainPath, and METRx, were developed to reduce retraction injuries via radial dispersion of force. Our study seeks to compare these retraction systems and assess their respective indications, benefits, and associated complications. A systematic review of PubMed MEDLINE, Cochrane Central Register of Controlled Trials, Web of Science, and Cochrane Database of Systematic Reviews was performed. Twenty-nine articles (n = 289 patients) for BrainPath, 12 articles (n = 106 patients) for Vycor, and 3 articles for METRx (n = 31 patients) met the inclusion criteria. This report is the first formal comparison of the BrainPath, Vycor, and METRx tubular retraction systems. We found that all 3 retractors were effective in accessing intraparenchymal lesions. Although we found that the retractor systems were used more commonly in different locations and for different diseases, there was no significant difference in complications or mortality among the 3 retractors.

Use of Vycor Tubular Retractors in the Management of Deep Brain Lesions: A Review of Current Studies.

BACKGROUND: Traditional manual retraction to access deep-seated brain lesions has been associated with complications related to vascular compromise of cerebral tissue. Various techniques have been developed over time to minimize injury, such as self-sustaining retractors, neuronavigation, and endoscopic approaches. Recently, tubular retractors, such as the ViewSite Brain Access System (VBAS), have been developed to reduce mechanical damage from retraction by dispersing the force of the retractor radially over the parenchyma. Therefore, we sought to review the current literature to accurately assess the indications, benefits, and complications associated with use of VBAS retractors. METHODS: A literature search for English articles published between 2005 and 2019 was performed using the MEDLINE database archive with the search terminology "Vycor OR ViewSite OR Brain-Access-System NOT glass." The VBAS website was also examined. Only articles detailing neurosurgical procedures using the VBAS tubular retractor system alone, or in combination with other retractors, were included. Postoperative morbidity and mortality were analyzed to estimate complications linked to using the retractor. RESULTS: Twelve publications (106 patients) met the inclusion criteria. The VBAS retractor was used for tumor resections, hematoma evacuations, cyst removal, foreign body extractions, and lesion resection in toxoplasmosis and multiple sclerosis. These cases were subdivided into groups based on lesion location, size, and resection volume for further analysis. Gross total resection was achieved in 63% of tumor excisions, and subtotal resection was achieved in 37%. Hematoma evacuation was successful in all cases. There were 3 short-term postoperative complications linked to the retractor, with an overall complication rate of 2.8%. CONCLUSIONS: This report is the first formal assessment of the VBAS, highlighting technical considerations of the retractor from the surgeon's perspective, patient outcomes, and complications. The retractor is a safe and efficacious tubular retraction system that can be used for tumor biopsy and resection, colloid cyst removal, hematoma evacuation, and removal of foreign bodies. However, further randomized controlled trials are indicated to accurately assess complication rates and outcomes.

Multifocal Intracranial Ganglioglioma in a Sexagenarian: Case Report and Review of the Current Literature.

BACKGROUND: Gangliogliomas are rare, well-differentiated, low-grade neoplasms that most often occur unifocally in children and most commonly affect the temporal lobe. Gangliogliomas that occur in patients age >40 years tend to have worse prognoses. These tumors generally stain positively for neural and glial cell markers, as well as CD34. Here we report an unprecedented case of multifocal intracranial ganglioglioma in an adult age >40 who had a favorable course, and review the current literature on multifocal intracranial gangliogliomas. CASE DESCRIPTION: A 60-year-old female presented to her ophthalmologist with blurry vision in the right eye and an unremarkable neurologic exam. She was referred for brain imaging, which showed multiple lesions in both cerebral hemispheres. Biopsy of the right occipital lesion was elected, as it enhanced the most on magnetic resonance imaging. CONCLUSIONS: Multifocal intracranial gangliogliomas are exceedingly rare tumors, especially in adults. These tumors present unique management barriers because as they are multifocal at the time of diagnosis, making resection more technically challenging. In our review, the average age at diagnosis was 19.2 years, and 80% of the cases had at least 1 lesion in the temporal lobe. Two studies opted for resection of intracranial tumors, whereas the remaining studies performed biopsy with conservative management and serial imaging. Biopsy was performed in all cases. We present the first case of an intracranial multifocal ganglioglioma in a patient age >40 years with lesions in the occipital lobe, corpus callosum, and frontal lobe at presentation.

Laser Ablation for Cerebral Metastases.

Laser interstitial thermal therapy is a minimally invasive surgical alternative to craniotomy that uses laser light through a fiber optic probe placed within a target lesion to create thermal tissue damage, resulting in cellular death. It is used in neuro-oncology to treat inaccessible lesions and obviate morbidity in high-risk patients. Overall complication rates and outcome measures are comparable with those seen in radiation and/or craniotomy. Laser interstitial thermal therapy can be an effective option for recurrent brain metastases. Prospective, randomized trials must be performed to evaluate the efficacy of laser interstitial thermal therapy as a primary treatment for brain metastases.

Rare Tumor-to-Tumor Metastases Involving Lung Adenocarcinoma to Petroclival Meningiomas.

BACKGROUND: Lung carcinoma metastasizing to a skull base meningioma remains an extremely rare phenomenon, with only 3 studies reported. Furthermore, no documented cases have been reported in the petroclival region. Thus, we have presented the first 2 cases of tumor-to-tumor metastasis (TTM) in which a petroclival lesion, initially thought to be purely meningioma, was also found to contain metastatic lung adenocarcinoma. CASE DESCRIPTION: We present the cases of 2 patients with a known history of lung adenocarcinoma and stable petroclival meningioma who had presented with new-onset neurologic deficits. Repeat imaging studies for both patients found an increased lesion size and peritumoral enhancement; thus, both patients underwent emergent craniotomy for complete lesion resection. Intraoperatively, both lesions had zones of markedly different tumoral texture. On histologic analysis, both lesions showed metastatic lung adenocarcinoma contained within the primary petroclival meningioma. CONCLUSION: Skull base TTM is a rare entity for which no specific management guidelines have been created. Therefore, even if the imaging characteristics suggest a more benign process, skull base TTM should remain high on the differential diagnosis for patients with a known primary cancer and new-onset, rapidly progressive, neurologic deficits. Close clinical follow-up with short-interval repeat imaging in this subset of patients might prevent misdiagnosis and facilitate prompt treatment.