Identification of venous variants in the pineal region with three-dimensional preoperative magnetic resonance imaging navigation in patients harbouring tumors in this area: significance for surgical approach to the lesion

Pineal Apoplexy: Highlighting the Causes, Treatment, and Outcome

BACKGROUND

 Pineal apoplexy, alternatively referred to as pineal hemorrhage or pineal gland hemorrhagic stroke, is an infrequent pathologic condition characterized by bleeding within the pineal gland. In this review, we encompass the primary factors contributing to this uncommon ailment.

METHODS

 The retrieval of pertinent research, including patients with pineal apoplexy, was conducted through PubMed, Google Scholar, and Scopus databases. This study exclusively incorporated comprehensive articles written in the English language. The search encompassed the MeSH terms "pineal apoplexy" and "pineal hemorrhage."

RESULTS

 A total of 41 articles were identified, encompassing a collective sample size of 57 patients. The median age of the patients in the study was 30 years, with a range spanning from 1 to 73 years. There were 27 males, representing 47.4% of the participants. The study identified the most often reported symptoms as headache (49; 86%), nausea/vomiting (19; 33.3%), and Parinaud's syndrome (16; 28.1%). The treatment options encompass several approaches, including open resection, shunting, ventriculostomy, endoscopic aspiration, and conservative care. In the conducted study, a notable number of patients, amounting to 45 cases (78.9%), indicated an amelioration of their symptoms upon their discharge.

CONCLUSION

 Data from a cohort of 57 cases provide insights into symptoms, lesions, treatments, and outcomes. Management approaches range from conservative measures to surgical interventions, with prognosis hinged on timely intervention. This investigation serves as a valuable resource for clinicians and researchers, underscoring the need for early diagnosis before permanent neurologic dysfunction happens and tailored treatments for optimal outcomes in pineal apoplexy cases.

The TIGR triangle of the pineal region: a virtual reality anatomic study

BACKGROUND

In this morphometric study, we describe the anatomy of the TIGR triangle, which is bordered by the tentorial surface of the cerebellum, the internal cerebral vein and vein of Galen complex, and the vein of Rosenthal. These structures define the window, or deep keyhole, to access the pineal region in non-midline supracerebellar infratentorial approaches.

METHODS

The posterior fossa anatomy of 16 patients was studied in virtual reality (VR), and the TIGR triangles were defined and measured with special attention on its angular orientation in the posterior fossa. The angular expanse of the posterior fossa was measured and recorded as the transverse-sigmoid junction (TSJ) angle. Because a perpendicular corridor through an anatomic aperture provides the best exposure, we studied the starting point along the TSJ angle that offers the best exposure of TIGR.

RESULTS

In the 31 posterior fossa sides included in the study, the perpendicular trajectory through the TIGR triangle was on average 27.13° CI 95% (range: 5.97°-48.53°) from the midline. When comparing the SCIT variants, both the paramedian and lateral approaches provided near-perpendicular trajectory through the TIGR triangle in a majority of specimens. However, the modified paramedian approach, with starting point defined as TSJ angle/3, provided the most perpendicular path through the TIGR triangle.

CONCLUSION

We studied the size, spatial orientation, and morphology of the TIGR triangle. Our data indicated that the best exposure of TIGR is through a modified paramedian SCIT approach, in which the starting point one third of the way from midline to the TSJ.

The Anatomy of the Convergence of Major Deep Cerebral Veins in the Pineal Region: A Computed Tomography Angiography Study

BACKGROUND

The anatomy of the veins in the pineal region is one of the most complex areas in the brain because all major deep cerebral veins converge there: the internal cerebral veins (ICVs), the great cerebral vein of Galen (GV), the basal veins (BVs), and the internal occipital veins (IOVs). The aim of this study was to comprehensively describe the anatomy of the veins in the pineal region using computed tomography angiography.

METHODS

Head computed tomography angiography scans of 250 adult Polish patients were evaluated. We assessed the location of the junction of 2 ICVs and the presence of a narrowing of the GV and arachnoid granulation at the GV-straight sinus junction. We evaluated the presence, appearance, and termination of the BV, and the presence and termination of the IOV.

RESULTS

The study showed that 2 ICVs usually converged posterior to the splenium of the corpus callosum (62.4%). Narrowing of the BV was observed in 51.2% of patients, and the arachnoid granulation was found in 25.2%. The 3 segments of the BV were well visualized in 66% of the studied hemispheres. The BV flowed into the GV in 34.8% of the hemispheres. The IOV was present in 90.2% of the hemispheres and terminated medially in 84.5%.

CONCLUSIONS

Because an injury to major deep cerebral veins may result in severe postoperative neurologic deficits, it is essential for neurosurgeons to be familiar with both normal and variant patterns of veins in the pineal region.

Safe handling of veins in the pineal region-a mixed method study

Surgical experience in pineal surgery is largely confined to a few experienced surgeons and may be lost when they stop their practice. The objective of this study is to systematically preserve and analyze valuable practical knowledge of pineal region surgical venous anatomy. A survey was constructed to obtain experienced surgeons' perception of estimated risks and individual experience following occlusion of veins during pineal surgery. Data were qualitative and analyzed with a mixed methods approach. Of the 126 invited neurosurgeons, 40 submitted completed questionnaires. General agreement existed of which veins were associated with high and low risks following occlusion. The risk of death was estimated to be high with sacrifice of the vein of Galen (83%), both internal cerebral veins (69%) and the basal veins (58%). The risk of death was estimated to be lower with the sacrifice of both superior vermian veins (13%) and one internal occipital vein (10%). Importantly, a sub-group of experienced surgeons reported substantial risk of death and consequences with the sacrifice of cerebellar bridging veins (8-13%). Our findings provide a coherent picture of surgical risk with venous sacrifice, which can inform the surgical community of systematically gathered views from aggregated surgeries of a very large cohort of patients. Extensive presurgical radiological workup and anatomical studies seemed to correlate more cautious risk estimations. Our findings increase available knowledge of risks of venous complications.

Neurosurgical Virtual Reality Simulation for Brain Tumor Using High-definition Computer Graphics: A Review of the Literature

Simulation and planning of surgery using a virtual reality model is becoming common with advances in computer technology. In this study, we conducted a literature search to find trends in virtual simulation of surgery for brain tumors. A MEDLINE search for “neurosurgery AND (simulation OR virtual reality)” retrieved a total of 1,298 articles published in the past 10 years. After eliminating studies designed solely for education and training purposes, 28 articles about the clinical application remained. The finding that the vast majority of the articles were about education and training rather than clinical applications suggests that several issues need be addressed for clinical application of surgical simulation. In addition, 10 of the 28 articles were from Japanese groups. In general, the 28 articles demonstrated clinical benefits of virtual surgical simulation. Simulation was particularly useful in better understanding complicated spatial relations of anatomical landmarks and in examining surgical approaches. In some studies, Virtual reality models were used on either surgical navigation system or augmented reality technology, which projects virtual reality images onto the operating field. Reported problems were difficulties in standardized, objective evaluation of surgical simulation systems; inability to respond to tissue deformation caused by surgical maneuvers; absence of the system functionality to reflect features of tissue (e.g., hardness and adhesion); and many problems with image processing. The amount of description about image processing tended to be insufficient, indicating that the level of evidence, risk of bias, precision, and reproducibility need to be addressed for further advances and ultimately for full clinical application.

Radical resection of nongerminomatous pineal region tumors via the occipital transtentorial approach based on arachnoidal consideration: experience on a series of 143 patients

BACKGROUND

The role of radical resection for nongerminomatous pineal region tumors is still controversial. The purpose of this study was to present the surgical results in a large series and evaluate the feasibility of radical surgical strategy.

METHODS

We retrospectively reviewed the records of 143 patients with nongerminomatous pineal region tumors surgically treated via an occipital transtentorial approach between 2000 and 2011. The tumor was small (<2 cm) in 14.7 % of patients, medium (2-4 cm) in 52.4 %, and large (>4 cm) in 32.9 %.

RESULTS

Gross total tumor removal was achieved in 91.6 % of patients, subtotal in 7.0 %, and partial in 1.4 %. Histological diagnosis was nongerminomatous germ cell tumor in 41.3 %, pineal parenchymal tumor in 14.7 %, glial tumors in 28.7 %, and miscellaneous in 15.4 %. The overall complication and mortality rate was 18.2 % and 0.7 %, respectively. Permanent morbidity occurred in 5.6 % of patients, including hemianopsia in 3.5 % and Parinaud syndrome in 2.1 %. Hydrocephalus was resolved in 82.1 % without surgery for the CSF diversion. Sixty-eight patients with malignant tumors underwent radiotherapy; 35 also received adjuvant chemotherapy. One hundred thirty patients were successfully followed up with a mean duration of 43 months. Finally, 86.9 % of the patients achieved a favorable functional outcome (mRS ≤ 2), 3.1 % had an mRS score of 3, 1.5 % had an mRS score of 4, and 8.5 % had died (mRS = 6).

CONCLUSIONS

Radical surgery was recommended as the optimal treatment for nongerminomatous pineal region tumors. Favorable results could be achieved by experienced neurosurgeons. Hydrocephalus could be cured by radical tumor removal in the majority of cases. The occipital transtentorial approach was indicated for most pineal region tumors, but surgeon's preference and experience should also be considered. New understanding of the arachnoid membranes of this region may be helpful for tumor resection.

Pineal region masses--imaging findings and surgical approaches

The anatomy of the pineal region is complex. Despite advances in surgical techniques since the first reported successful pineal region surgery in the early 20th century, pineal region surgery remains challenging owing to the proximity of deep cerebral veins and dorsal midbrain structures critical for vision. In this article, we review the relevant surgical anatomy of the pineal region and discuss historically important and current surgical approaches. We describe specific imaging features of pineal region masses that may affect surgical planning and review neoplastic and nonneoplastic masses that occur in the pineal region.