Single-Surgeon in Vivo Experience with the Zeiss QEVO Microinspection Tool: An Analysis of Its Use for Extending the Reach of Operative Visualization

The operating microscope is a foundational tool in modern neurosurgery. Operating microscopes serve increasingly as the lynchpin for highly sophisticated visualization platforms incorporating many complementary technologies. The Zeiss QEVO microinspection tool is a 45-degree viewing endoscopic instrument integrated into the Zeiss KINEVO 900 operating microscope (Carl Zeiss AG, Oberkochen, Germany). The QEVO tool enables surgeons to "look around the corners" of the surgical field to optimize visualization within tight operative corridors. In this article, we document our experience using the QEVO microinspection tool in a series of complex cranial neurosurgery procedures. This report focuses on the handling, visualization, and overall utility of the QEVO tool for achieving optimal visualization in deep cranial corridors.

Surgical Rescue Technique for Incomplete Burr Hole Using a Small Bone Piece and the Craniotome

BACKGROUND

Incomplete penetration of a burr hole sometimes occurs when performing a craniotomy in elderly patients due to osteoporosis. Completion of the burr hole takes more time and may sometimes cause tearing of the dura mater. We have introduced a small bone piece method that can easily and reliably recover an incomplete burr hole safely.

METHODS

1) Cut out a small bone piece of the outer table of about 5-mm size using a rongeur. 2) Place the small bone piece in the center of the incomplete burr hole. 3) Push on the small bone piece with a craniotome after unlocking the safety stop mechanism. 4) Restart and complete the burr hole with the craniotome.

RESULTS

We succeeded in 10 of 11 incomplete burr holes. One case that failed had osteoporosis. There were no complications.

CONCLUSIONS

Application of the unlocked craniotome on the small bone piece can easily complete the burr hole. Less bone deficit is caused compared with making a new burr hole. In addition, time is saved without changing the attachment, and the burr hole is completed safely. This small bone piece method is effective to recover an incomplete burr hole.

The Aalborg Bolt-Connected Drain (ABCD) study: a prospective comparison of tunnelled and bolt-connected external ventricular drains

BACKGROUND

Acutely increased intracranial pressure (ICP) is frequently managed by external ventricular drainage (EVD). This procedure is life-saving but marred by a high incidence of complications. It has recently been indicated that bolt-connected external ventricular drainage (BC-EVD) compared to the standard technique of tunnelled EVD (T-EVD) may result in less complications.

AIM

To prospectively sample and compare two cohorts by consecutive allocation to either BC-EVD or T-EVD from the introduction of the BC-EVD technique in our department and 12 months onward.

METHODS

Patients undergoing ventriculostomy between the 1st of March 2017 and the 28th of February 2018 were considered for inclusion. The neurosurgeon on-call sovereignly set the indication and decided on EVD type (BC-EVD or T-EVD), consequently resulting in two cohorts as 3/7 senior neurosurgeons on call were open to the use of BC-EVD, while 4/7 were reluctant to use this technique. Data was continuously collected using patient records, including results of cerebrospinal fluid (CSF) culturing and available CT/MRI-scans. Recorded complications included CSF leakage, accidental discontinuation, placement-related intracranial haemorrhage, malfunction, migration, infection and revision.

RESULTS

Forty-nine EVDs (32 T-EVDs/17 BC-EVDs) were included; 19/32 (59.4%) T-EVDs and 3/17 (17.6%) BC-EVDs were found to have complications (p = 0.007). The relative risk of complications when using T-EVD was 3.4 times that of BC-EVD.

CONCLUSION

Ventriculostomy by BC-EVD compared to T-EVD reduces incidence and risk of complications and should be the first choice in EVD placement. That said, T-EVD has a role in paediatric patients and for intraoperatively and occipitally placed EVDs.

Fewer complications with bolt-connected than tunneled external ventricular drainage

BACKGROUND

Ventriculostomy/external ventricular drain (EVD) is a common neurosurgical procedure. Various techniques are used to fixate the drain and the objective of this study was, in a retrospective setting, to compare the incidence of complications when using bolt-connected EVD (BC-EVD) versus tunneled EVD (T-EVD).

METHODS

All patients subjected to an EVD performed through a new burr hole from 2009 through 2010 at two Depts. of Neurosurgery in Denmark (Odense and Aarhus) were retrospectively identified. Patient files were evaluated for EVD fixation technique (tunneled or bolt-connected EVD) and complications including unintended removal, catheter obstruction, infection, CSF leakage, and mechanical problems.

RESULTS

A total of 271 patients with 272 separate EVDs met the inclusion criteria. There was a statistically higher rate of complications leading to reinsertion in the tunneled EVD group (40 %), compared to the bolt-connected EVD group (6.5 %). There was no significant difference in infection rates.

CONCLUSIONS

Tunneled EVD has a relatively high frequency of complications leading to reinsertion. The use of Bolt-connected EVD technique can lower this frequency significantly. The number needed to treat is three for preventing a complication requiring reinsertion. Infection rates are low for both types of ventriculostomies. Accordingly, we recommend use of Bolt-connected EVDs in neurosurgical practice.