Microsurgical third ventriculocisternostomy as an alternative to ETV: report of two cases

[Microsurgical ventriculostomy of the third ventricle with access through a burrhole in the treatment of midly located deep-seated brain tumors]

BACKGROUND

Currently, endoscopic third ventriculostomy and simultaneous biopsy of deep midline brain tumors are a generally accepted option in neurooncology. Nevertheless, effectiveness of this surgery and diagnostic accuracy of biopsy are not without drawbacks. An alternative to endoscopic surgery may be simultaneous microsurgical third ventriculostomy and biopsy of deep midline tumors.

OBJECTIVE

To evaluate effectiveness and safety of burr hole microsurgical third ventriculostomy in the treatment of deep midline brain tumors.

MATERIAL AND METHODS

We used transcortical (25 cases) and transcallosal (8 cases) approaches for microsurgical third ventriculostomy.

RESULTS

Initially scheduled biopsy was performed in 19 cases, partial resection in 6 cases, subtotal resection in 4 cases and total resection in 4 cases. All patients underwent microsurgical third ventriculostomy. In 12 cases, stenting of stoma was performed in addition to ventriculostomy. Biopsy was informative in all cases. Postoperative follow-up period ranged from 3 to 44 months (mean 29 months). There was no postoperative hydrocephalus and need for shunting procedure.

CONCLUSION

Burr hole microsurgery may be an alternative to endoscopic surgery for the treatment of pineal, periaqueductal and third ventricular tumors.

Cosmetic Outcomes of Supraorbital Keyhole Craniotomy Via Eyebrow Incision: A Systematic Review and Meta-Analysis

Background  Supraorbital eyebrow craniotomy is a minimally invasive alternative to a frontotemporal craniotomy and is often used for tumor and vascular pathologies. The purpose of this study was to investigate how patient cosmetic outcomes are affected by technique variations of this approach. Methods  PubMed, Embase, and Scopus databases were systematically searched, and results were reported according to PRISMA guidelines. For the meta-analysis portion, the DerSimonian-Laird random effects model was used, and the primary end points were patient satisfaction and percentage of permanent cosmetic complications. Results  A total of 2,629 manuscripts were identified. Of those, 124 studies (8,241 surgical cases) met the inclusion criteria. Overall, 93.04 ± 11.93% of patients reported favorable cosmetic outcome following supraorbital craniotomy, and mean number of cases with permanent cosmetic complications was 6.62 ± 12.53%. We found that vascular cases are associated with more favorable cosmetic outcomes than tumor cases ( p  = 0.0001). Addition of orbital osteotomy or use of a drain is associated with adverse cosmetic outcomes ( p  = 0.001 and p  = 0.0001, respectively). The location of incision, size of craniotomy, utilization of an endoscope, method of cranial reconstruction, skin closure, use of antibiotics, and addition of pressure dressing did not significantly impact cosmetic outcomes ( p  > 0.05 for all). Conclusions  Supraorbital craniotomy is a minimally invasive technique associated with generally high favorable cosmetic outcomes. While certain techniques used in supraorbital keyhole approach do not pose significant cosmetic risks, utilization of an orbital osteotomy and the addition of a drain correlate with unfavorable cosmetic outcomes.

Extra-axial endoscopic third ventriculostomy: preliminary experience with a technique to circumvent conventional endoscopic third ventriculostomy complications

OBJECTIVE

Endoscopic third ventriculostomy (ETV) is mostly safe but may have serious complications. Most of the complications are inherent to the procedure's intra-axial nature. This study aimed to explore an alternative route to overcome inherent issues with conventional ETV. The authors performed supraorbital, subfrontal extra-axial ETV (EAETV) via the lamina terminalis.

METHODS

This prospective study began in October 2021 and included patients with obstructive triventricular hydrocephalus with a Glasgow Coma Scale score of 8 or more and a minimum follow-up of 3 months. Patients with multiloculated hydrocephalus and those younger than 1 year of age were excluded. The preoperative parameters etiology, symptoms, Evans' Index, frontal occipital horn ratio (FOHR), and third ventricle index were recorded. The surgical procedure is described. Postoperative evaluation included clinical (modified Rankin Scale [mRS]) and radiological assessment with CT and cine phase-contrast MRI. Preoperative and postoperative parameters were compared statistically.

RESULTS

Ten patients were included in this study. Six patients had acute hydrocephalus, and 4 had chronic hydrocephalus. After EAETV, all patients showed clinical improvement. An mRS score of 0 or 1 was achieved in 9 patients, but the mRS score remained at 4 in a patient with tectal tuberculoma. There was a significant reduction in Evans' Index, FOHR, and third ventricle index after EAETV (p < 0.05). The mean percent reduction in Evans' Index was 20.80% ± 13.89%, the mean percent reduction in FOHR was 20.79% ± 12.98%, and the mean percent reduction in the third ventricle index was 37.45% ± 14.74%. CSF flow voids were seen in all cases. The results of CSF flow quantification parameters were as follows: mean peak velocity 3.82 ± 0.93 cm/sec, mean average velocity 0.10 ± 0.05 cm/sec, mean average flow rate 46.60 ± 28.58 μL/sec, mean forward volume 39.90 ± 23.29 μL, mean reverse volume 34.10 ± 15.98 μL, mean overall flow amplitude 74.00 ± 27.61 μL, and mean stroke volume 37.00 ± 13.80 μL. One patient developed a minor frontal lobe contusion. The frontal air sinus was breached in 5 patients, but none had CSF rhinorrhea. Transient supraorbital hypesthesia was seen in 3 patients. No patient had electrolyte disturbance or change in thirst or fluid intake habits.

CONCLUSIONS

EAETV is a feasible, safe, and effective surgical alternative to conventional ETV.

Supraorbital Keyhole Craniotomy in Pediatric Neurosurgery: A Systematic Review of Clinical Outcomes and Cosmetic Outcomes

BACKGROUND

Supraorbital keyhole craniotomy is a minimally invasive approach used to access the parasellar region with advantages of decreased cortical exposure, simple closure, and decreased risk of postoperative cerebrospinal fluid leak. The incision of this approach, however, has raised cosmetic concerns, especially for pediatric patients. The aim of this study is to assess postoperative complications and cosmeses of the supraorbital keyhole approach for resection of intracranial lesions in pediatric patients.

METHODS

A literature search of PubMed, Scopus, and Web of Science databases was performed on June 1, 2021, searching for all studies of pediatric patients undergoing supraorbital keyhole craniotomy for surgical resection of lesions in the anterior fossa/sellar region.

RESULTS

Of 729 unique hits, 15 supraorbital keyhole studies reporting on 177 pediatric cases were included in the final review. Quality of all included studies was moderate. Overall, the surgery was well tolerated with a low number of severe adverse events. A wide variety of pathologies were treated with this approach. Complications of surgery included changes in vision, epidural hematoma, subdural hematoma, cerebrospinal fluid leak, and wound infection. At 6 weeks of follow-up, surgical scars in most patients were noted to be minimally detectable. At 3-6 months of follow-up, scars were no longer visible. Cosmetic complications included 5 bone defects, 1 split eyebrow, and 1 case of ptosis.

CONCLUSIONS

This study suggests that supraorbital keyhole craniotomy is a safe and effective approach to access the parasellar region in pediatric patients with excellent cosmetic outcomes reported across multiple institutions.

Supraorbital Keyhole Craniotomy via Eyebrow Incision: A Systematic Review and Meta-Analysis

BACKGROUND

Supraorbital eyebrow keyhole craniotomy is a minimally invasive alternative to a frontotemporal craniotomy and is often used for tumor resection and aneurysm clipping. The purpose of this study is to provide a contemporary review on the outcomes related to this approach and to determine whether they vary with the type of pathology and the addition of an endoscope.

METHODS

PubMed, Embase, and Scopus databases were systematically searched, and results were reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. For the meta-analysis portion, the DerSimonian-Laird random effects model was used.

RESULTS

A total of 2629 manuscripts were identified. of those, 124 studies (8241 surgical cases) met the inclusion criteria. Mean total complication rate was 26.7 ± 25.7% and the mean approach-related mortality rate was 1.3 ± 2.8%. Technical success, defined as gross total tumor resection or complete aneurysm clipping, was achieved in 83.6 ± 21.5% of the cases. Vascular pathologies were associated with greater technical success, lower total complications, and longer length of hospital stay compared with tumor cases (P < 0.05 for all). For vascular cases, addition of the endoscope yielded lower technical success (P = 0.001) and lower complication rate (P = 0.041). The use of the endoscope for tumor pathologies did not affect technical success, complications, mortality, length of hospital stay, operative time, or reoperation rate (P > 0.05).

CONCLUSIONS

The supraorbital craniotomy via an eyebrow incision is a feasible minimally invasive approach with an overall high technical success rate for both vascular and tumor pathologies.

Anatomic study of the lamina terminalis: neurosurgical relevance in approaching lesions within and around the third ventricle

BACKGROUND

The lamina terminalis (LT) represents an important neurosurgical corridor by which to fenestrate the third ventricle into the subarachnoid space or to approach lesions of the third ventricle. However, a comprehensive review of its anatomy and approaches to it for various pathologies is lacking in the literature. We studied the anatomy of the LT in 21 cadavers and described the LT as observed in cadaveric dissections. We also reviewed the literature regarding the detailed anatomy and pathology of the LT. In addition, a case illustration that demonstrates the use of this structure as a corridor to third ventricular tumors is presented. Our aim was to explore the anatomy of the LT through cadaveric dissection, a review of the literature, and a case study.

METHODS

Twenty-one adult cadaver heads underwent microdissection of the LT with a focus on the working distance available to enter the third ventricle and related vascular structures.

RESULTS

Inferior to the anterior communicating artery was the safer region to open due to the lack of perforating arteries. A working distance of approximately 1 cm can be expected through the LT.

CONCLUSIONS

This information may aid neurosurgeons during approaches through and around the LT.

Endoscopic transventricular third ventriculostomy through the lamina terminalis

Object

Endoscopic third ventriculostomy (ETV) has become a well-accepted option for obstructive hydrocephalus. However, standard ventriculostomy at the floor of the third ventricle might not be feasible under certain conditions. Here, the authors report in detail on their initial experience with an alternative option of endoscopic ventriculostomy through the lamina terminalis via a transventricular route.

Methods

Endoscopic third ventriculostomy through the lamina terminalis from a transventricular transforaminal route was evaluated in 4 cadaveric human heads and in 4 clinical cases.

Results

In all 4 human cadavers, an opening of the lamina terminalis via a transventricular approach could be achieved without injury to either the optic chiasm or the anterior cerebral arteries. In the 4 clinical cases, an accurate and reliable ventriculostomy was performed at the lamina terminalis. The bur hole was placed directly at the coronal suture 2 cm lateral from the midline. After identifying the optic chiasm and the anterior cerebral arteries, a blunt perforation was made just anterior to the optic chiasm by using perforation forceps and a balloon catheter. After the opening, the stoma was inspected with a 0° and 30° rod lens endoscope, and its patency as well as the preservation of vessels and optic nerves was checked. No complications occurred, although all patients suffered from a clinically silent fornical contusion at the foramen of Monro.

Conclusions

Endoscopic opening of the lamina terminalis via a transventricular transforaminal route appears to be feasible. No complications were observed. Although no conclusions on the clinical success rate can be drawn, the reliable anatomical opening and known success rate for anterior subfrontal approaches suggest that the technique represents an alternative in a small subgroup of patients in whom a standard ETV cannot be performed.