Fully endoscopic occipital transtentorial approach for pineal region tumors

The occipital interhemispheric transtentorial approach: historical perspective and evolution over time

PURPOSE

Access to the pineal region has always represented a fascinating challenge to the neurosurgeons. Almost equally thrilling is the historical evolution from the hard beginnings with extremely high mortality rates to the current surgical outcomes, with excellent resection rates without long-term morbidity for most of the patients. The purpose of this paper is to provide an overview of the historical evolution of the occipital interhemispheric transtentorial (OITT) approach and its role in the development of access to the pineal region.

METHODS

Review of the literature highlights the occipital transtentorial approach from the historical context prior its description and the beginning to the current modifications and new recent insights.

RESULTS

The occipital transtentorial approach described initially by Poppen in 1966 has played a key role in the progress and success accessing the pineal area.

CONCLUSION

This historical review aims to highlight the extraordinary effort of those neurosurgeons who guided and led the development of one of the most important approaches to the pineal region.

Microsurgical Management of Pineal Region Tumors

BACKGROUND

Pineal tumors are rare, and the pineal region is a challenging surgical location for neurosurgeons. The present study aimed to investigate the effects of microsurgical management in patients with pineal region tumors and explore probable factors associated with preoperative hydrocephalus, postoperative hydrocephalus remission, and prolonged hospital length of stay (LoS).

METHODS

A retrospective study of patients with pineal region tumors who underwent microsurgical management at the First Affiliated Hospital of Soochow University (Jiangsu, China) between 1 January 2010 and 31 October 2022 was conducted.

RESULTS

Data from 36 patients were included in this study. The top 5 common symptoms included headache (58%), dizziness (44%), double vision (22%), vomiting (19%), and nausea (14%). Patients with a lower Karnofsky Performance Score (KPS), younger age, and larger maximum tumor diameters were more vulnerable to preoperative hydrocephalus. Preoperative hydrocephalus also led to a prolonged postoperative LoS (P = 0.021). Patients with a lower KPS score (P = 0.020) or larger maximum tumor diameters (P = 0.045) were more likely to achieve postoperative remission of hydrocephalus. Most postoperative complications led to increased hospital LoS.

CONCLUSIONS

Microsurgical resection of pineal tumors yielded favorable long-term outcomes. Patients with a lower KPS score, younger age, and larger maximum tumor diameters were more vulnerable to preoperative hydrocephalus and prolonged LoS. Patients with a lower KPS score or larger tumor diameter were likely to achieve significant remission of hydrocephalus after tumor resection.

Optic nerve sheath diameter correlates with both success and failure of hydrocephalus treatment in pediatric patients with pineal region lesions

BACKGROUND

Pineal region lesions in children are heterogenous pathologies often symptomatic due to occlusive hydrocephalus and thus elevated intracranial pressure (ICP). MRI-derived parameters to assess hydrocephalus are the optic nerve sheath diameter (ONSD) as a surrogate for ICP and the frontal occipital horn ratio (FOHR), representing ventricle volume. As elevated ICP may not always be associated with clinical signs, the adjunct of ONSD could help decision making in patients undergoing treatment. The goal of this study is to assess the available magnetic resonance imaging (MRI) of patients with pineal region lesions undergoing surgical treatment with respect to pre- and postoperative ONSD and FOHR as an indicator for hydrocephalus.

METHODS

Retrospective data analysis was performed in all patients operated for pineal region lesions at a tertiary care center between 2010 and 2023. Only patients with pre- and postoperative MRI were selected for inclusion. Clinical data and ONSD at multiple time points, as well as FOHR were analyzed. Imaging parameter changes were correlated with clinical signs of hydrocephalus before and after surgical treatment.

RESULTS

Thirty-three patients with forty operative cases met the inclusion criteria. Age at diagnosis was 10.9 ± 4.6 years (1-17 years). Hydrocephalus was seen in 80% of operative cases preoperatively (n = 32/40). Presence of hydrocephalus was associated with significantly elevated preoperative ONSD (p = 0.006). There was a significant decrease in ONSD immediately (p < 0.001) and at 3 months (p < 0.001) postoperatively. FOHR showed a slightly less pronounced decrease (immediately p = 0.006, 3 months p = 0.003). In patients without hydrocephalus, no significant changes in ONSD were observed (p = 0.369). In 6/6 patients with clinical hydrocephalus treatment failure, ONSD increased, but in 3/6 ONSD was the only discernible MRI change with unchanged FOHR.

CONCLUSIONS

ONSD measurements may have utility in evaluating intracranial hypertension due to hydrocephalus in patients with pineal region tumors. ONSD changes appear to have value in assessing hydrocephalus treatment failure.

Optimal therapeutic strategies for pineal region lesions

Background

The removal of pineal region lesions are challenging, and therapeutic strategies for their removal remain controversial. The current study was conducted to identify the characteristics and the optimal therapeutic strategies for pineal region lesions.

Methods

This retrospective study reviewed the treatments of 101 patients with pineal region lesions, and different characteristics and therapeutic strategies were observed.

Results

There were no statistical differences in the total resection ratio, complications, and prognosis outcomes between the hydrocephalus group and non-hydrocephalus group, except patients in the hydrocephalus group were younger and pediatric patients had an increased level of intracranial infections. Treatments of lesions and hydrocephalus secondary to pineal region lesions were two integral parts to therapeutic strategies. For the management of lesions, germinoma or non-germinoma were diagnosed preoperatively, and resection or diagnostic radiation were chosen to deal with pineal region lesions. Endoscopic-assisted surgery provided a higher total resection rate. For the management of hydrocephalus, endoscopic third ventriculostomy (ETV) had the better therapeutic effect. Additionally, cerebrospinal fluid (CSF) diversion before radiotherapy or resection did not improve prognosis outcome, but it was necessary for patients with severe hydrocephalus. Logistical regression analysis indicated that age, lesion size, reoperation ratio, and intracranial complications were predictors of prognosis outcome.

Conclusion

More attention should be paid to intracranial infections in pediatric patients with hydrocephalus secondary to pineal region lesions, and CSF diversion before radiotherapy or resection did not promote prognosis outcome, but it was necessary for patients with severe hydrocephalus. Age, lesion size, reoperation ratio, and intracranial complications may be the predictors of prognosis outcome. Most importantly, the surgical algorithm for pineal region lesions which was based on preoperatively diagnosis (non-germinoma and germinoma) is useful, especially for developing countries.

Neuroendoscopy: The State of the Art

Over the past century, neuroendoscopy developed into a mainstay of neurosurgical practice, allowing for minimally invasive approaches to the ventricles, skull base, and spine. Its development, however, is far from over. Current challenges are inherent in the very feature that renders neuroendoscopy appealing-the small channels of the modern endoscope allow surgery to be performed with minimal tissue retraction, but they also make hemostasis and resection of large masses difficult. New optics allow for significantly improved image quality; yet open craniotomy often allows for 3-dimensional visualization and bimanual dissection and is part of everyday neurosurgical training. Finally, the utilization of neuroendoscopy remains limited, presenting ongoing challenges for neurosurgical teaching and achievement of technical mastery.