Ventricular catheter placement is a common neurosurgical procedure often resulting in inaccurate intraventricular positioning. We conducted a comparison of the accuracy of endoscopic and conventional ventricular catheter placement in adults.

A retrospective analysis of data was performed on 37 consecutive patients undergoing ventriculo-peritoneal shunt (VPS) insertion with endoscopy and 40 randomly selected, unmatched patients undergoing VPS insertion without endoscopy, for the treatment of hydrocephalus of varied etiology. A grading system for catheter tip position was developed consisting of five intraventricular zones, V1-V5, and three intraparenchymal zones, A, B, C. Zones V1 for the frontal approaches and V1 or V2 for the occipital approaches were the optimal catheter tip locations. Postoperative scans of each patient were used to grade the accuracy of ventricular catheter placement.

Seventy-six percent of all endoscopic ventricular catheters were in zone V1 and 100% were within zones V1-V3. No endoscopically inserted catheters were observed in zones V4, V5 or intraparenchymally. Thirty-eight percent of the conventionally placed catheters were in zone V1, 53% in zones V1-3 and 15% intraparenchymally. There was a statistically significant difference in the percentage of catheters in optimal location versus in any other location, favoring endoscopic guidance (p<0.001).

We conclude that endoscopic ventricular catheter placement provides improved positioning accuracy than conventional techniques.

Stereotactic insertion of catherters into deep-seated tumors or developmental cysts is easily accomplished, but connecting the catheter to an Ommaya reservoir while maintaining catheter position can be difficult. We describe a technique for easy placement of a catheter-Ommaya reservoir construct with one pass.

Standard stereotactic imaging is performed. The distance from the outer table of the skull to the target point is measured. A catheter-Ommaya reservoir construct is assembled to this length and directed to the target position with a standard Cosman-Robert-Wells (CRW) stereotactic frame.

Use of this technique placed catheters into tumor or developmental cysts accurately and with no surgical complications in 12 patients.

This technique is simple, safe, reliable, and requires no special equipment. It avoids the risk of dislodging the catheter when it is being connected to the Ommaya reservoir, reducing the chances of cyst leakage and collapse.

Hyperostosis of the bone overlying meningiomas has been reported in up to 50% of cases. The skull becomes infiltrated by meningothelial tumor cells, necessitating removal of the hypertrophied bone to achieve a complete tumor resection. Unfortunately, aesthetic reconstruction of large bony defects can pose a significant challenge intra-operatively. Custom cranioplasty implants are very expensive and can only be fabricated after the bony defect exists, requiring a second surgery for implantation. Although numerous composite materials exist to repair the defects at the time of tumor resection, the challenge is to create an implant that fits appropriately without shifting and approximates the natural curvature of the skull. We have developed a technique for an “in situ cranioplasty” using a composite construct with strength in compression and tension.

After the skull is reshaped by shaving down part of the hyperostotic bone, titanium mesh is molded to the surface of the skull and screwed into the surrounding normal bone. The bone flap is then removed by drilling a trough at the outer margin of the tumor-involved skull and removing a ring of normal surrounding bone. The central portion of tumor involved skull is then craniectomized. The mesh can be reapplied and the full thickness of the central bone can be reconstructed with polymethylmethacrylate, yielding a solid construct perfectly matched to the patient's natural head shape.

This novel technique yields a sturdy, aesthetic, and cost-effective result which can be used to address any cranial vault defect at the time of tumor resection.

Larger intracranial tumors require extended operating times and may be associated with increased perioperative complications. There are few reports describing the experience of resecting large meningiomas ≥5cm in a variety of locations. As a group, it remains largely unknown whether these relatively rare lesions are amenable to radical resection, and what factors influence their resectability.

Sixty-seven patients undergoing surgery for a large intracranial meningioma (≥5cm in the longest dimension) between 1998 and 2004 were retrospectively reviewed. The surgeries were performed at a single institution University of California at San Francisco. Predictors of resectability were assessed via multivariate logistical regression analysis.

Thirty-nine (58%) patients underwent gross total resection (GTR) (Simpson grades I/II). There were no cases of perioperative mortality. At last follow-up, symptoms improved in 39 (58%) patients, remained unchanged in 20 (30%), and were aggravated in 8 (12%). In the multivariate model for all large meningiomas, age>45 years [OR(95%CI);0.127 (0.026-0.616),p=0.01] and superior sagittal sinus involvement [OR(95%CI);0.160 (0.026-0.976),p=0.05] were negative predictors of GTR, while preoperative embolization [OR(95%CI);8.087(1.719-38.044),p=0.008] was positively associated with GTR. For only supratentorial meningiomas, superior sagittal sinus involvement [OR (95%CI);0.077 (0.010-0.571),p=0.01] and preoperative embolization [OR(95%CI);10.492(1.961-56.135),p=0.006] were independently associated with GTR.

This study evaluated a subset of large intracranial meningiomas ≥5cm. The results indicate that GTR can be achieved in the majority of cases with limited morbidity and mortality, where symptoms will likely improve and recurrences seldom occur. This study may provide useful insights for patients undergoing surgery for large intracranial meningiomas.

Metastatic renal cell carcinoma to the choroid plexus is a rare condition and can be easily confused with meningioma.

A 61-year-old female presented with progressive neurologic deterioration and MRI findings of obstructive hydrocephalus and a homogeneously contrast enhancing 3 cm oval mass in the trigone of the left lateral ventricle.

Despite radiologic, intraoperative gross features, and frozen pathology all consistent with meningioma, the final pathology revealed metastatic renal cell carcinoma.

Renal cell carcinoma metastatic to the choroid plexus can mimic intraventricular meningioma. We present a review of the literature and comparison of the radiological features of meningiomas and metastatic renal cell carcinoma. We also discuss the use of an under-utilized technique, the contralateral transcallosal approach, in the surgical treatment of this intraventricular lesion.

Increased growth of meningiomas during pregnancy as well as postpartum clinical regression of symptoms have been reported but remain poorly understood. A better understanding of the factors that contribute to these observations, including potential factors associated with pregnancy, could enable design of more effective adjuvant therapies.

We describe the presentation of a meningioma during the immediate postpartum period. Serial imaging demonstrated subsequent rapid decrease in size of the tumour prior to any intervention. The lesion was resected, and the tissue was subjected to immunostaining for gene products associated with pregnancy, including estrogen receptor (ER), progesterone receptor (PR), platelet-derived growth factor receptor B (PDGFRB), fibroblastic growth factor receptor 2 (FGFR-2), epidermal growth factor receptor (EGFR) and human placental lactogen (hPL).

The lesion proved to be an atypical fibroblastic meningioma grade II (WHO). Immunostaining demonstrated significant staining for PR, PDGFRB, and FGFR-2. No specific staining for ER, EGFR, or hPL was identified.

Although clinical regression of meningioma following pregnancy is well-recognized, imaging data are much less abundant. This report provides clear clinical and imaging documentation of a meningioma associated with pregnancy. In addition, the growth factor profile of this tumour suggests the importance of PR, PDGFRB, and FGFR-2 as potential therapeutic targets.