From fixed-pressure paediGAV to programmable proGAV/proSA serial valves for pediatric hydrocephalus within the 1st year of life: a technical single-center analysis

OBJECTIVE

Programmable valves have gained increasing popularity in the complex treatment of pediatric hydrocephalus. Over the last decade, adjustable serial valves have gradually replaced fixed-pressure valves in the authors' department. The present study investigates this development by analyzing shunt- and valve-related outcomes for this vulnerable population.

METHODS

A retrospective analysis of all shunting procedures between January 2009 and January 2021 in children younger than 1 year of age was performed at the authors' single-center institution. Postoperative complications and surgical revisions were set as outcome parameters. Shunt and valve survival rates were evaluated. Statistical analysis compared children who underwent implantation of the Miethke proGAV/proSA programmable serial valves with those who underwent implantation of the fixed-pressure Miethke paediGAV system.

RESULTS

Eighty-five procedures were evaluated. The paediGAV system was implanted in 39 cases and the proGAV/proSA in 46 cases. The mean ± SD follow-up was 247.7 ± 140 weeks. In 2009 and 2010, paediGAV valves were used exclusively, but by 2019, the use of proGAV/proSA had evolved into the first-line therapy. The paediGAV system was significantly more often revised (p < 0.05). The main indication for revision was proximal occlusion, with or without impairment to the valve. The valve and shunt survival rates of proGAV/proSA were significantly prolonged (p < 0.05). The surgery-free valve survival of proGAV/proSA was 90% after 1 year and 63% after 6 years. There were no overdrainage-related revisions of proGAV/proSA valves.

CONCLUSIONS

Favorable shunt and valve survival validates the increasing use of programmable proGAV/proSA serial valves in this delicate population. Potential benefits in postoperative treatment should be addressed in prospective multicenter studies.

Endoscope-assisted resection of brainstem cavernous malformations

Targeted surgical precision and minimally invasive techniques are of utmost importance for resectioning cavernous malformations involving the brainstem region. Minimisation of the surgical corridor is desirable but should not compromise the extent of resection. This study provides detailed information on the role of endoscopy in this challenging surgical task. A retrospective analysis of medical documentation, radiologic studies and detailed intraoperative video documentation was performed for all consecutive patients who underwent surgical resection of brainstem cavernous malformations between 2010 and 2020 at the authors’ institution. A case-based volumetry of the corticotomy was performed and compared to cavernoma dimensions. A total of 20 procedures have been performed in 19 patients. Neuroendoscopy was implemented in all cases. The mean size of the lesion was 5.4 (± 5) mm3. The average size of the brainstem corticotomy was 4.5 × 3.7 (± 1.0 × 1.1) mm, with a median relation to the cavernoma’s dimension of 9.99% (1.2–31.39%). Endoscopic 360° inspection of the resection cavity was feasible in all cases. There were no endoscopy-related complications. Mean follow-up was 27.8 (12–89) months. Gross-total resection was achieved in all but one case (95%). Sixteen procedures (80%) resulted in an improved or stable medical condition. Eleven patients (61.1%) showed further improvement 12 months after the initial surgery. With the experience provided, endoscopic techniques can be safely implemented in surgery for BSCM. A combination of neuroendoscopic visualisation and neuronavigation might enable a targeted size of brainstem corticotomy. Endoscopy can currently be considered a valuable additive tool to facilitate the preparation and resection of BSCM.

Time-Multiplexed Illumination for simultaneous Structural and Functional Voltage Sensitive Dye Recordings with a single Photo Sensor

The in-vivo optical imaging of the cortical surface provides the ability to record different types of biophysiological signals, e.g., structural information, intrinsic signals, like blood oxygenation coupled reflection changes as well as extrinsic properties of voltage sensitive probes, like fluorescent voltage-sensitive dyes. The recorded data sets have very high temporal and spatial resolutions on a meso- to macroscopic scale, which surpass conventional multi-electrode recordings. Both, intrinsic and functional data sets, each provide unique information about temporal and spatial dynamics of cortical functioning, yet have individual drawbacks. To optimize the informational value it would thus be opportune to combine different types of optical imaging in a near simultaneous recording.Due to the low signal-to-noise ratio of voltage-sensitive dyes it is necessary to reduce stray light pollution below the level of the camera's dark noise. It is thus impossible to record full-spectrum optical data sets. We address this problem by a time-multiplexed illumination, bespoke to the utilized voltage sensitive dye, to record an alternating series of intrinsic and extrinsic frames by a high-frequency CMOS sensor. These near simultaneous data series can be used to compare the mutual influence of intrinsic and extrinsic dynamics (with regards to extracorporeal functional imaging) as well as for motion compensation and thus for minimizing frame averaging, which in turn results in increased spatial precision of functional data and in a reduction of necessary experimental data sets (3R principle).

A New Clip Generation for Microsurgical Treatment of Intracranial Aneurysms-The First Case Series

OBJECTIVE

Considerable effort has been made in order to reduce surgical invasiveness while maintaining optimal exploiting of the operative space in aneurysm surgery. One aspect of this evolution is represented by the Lazic (Peter Lazic GmbH, Tuttlingen, Germany) aneurysm clip system. The purpose of this study was to illustrate the new generation clip system in practiced aneurysm surgery.

METHODS

A retrospective analysis of all aneurysm surgeries in our departments between December 2015 and January 2018 using the new D-Clip system was performed. Evaluation included standardized retrospective review of the main surgeon, the nursing staff, as well as an analysis of surgical video documentation by objective reviewers.

RESULTS

Forty-five patients with 50 intracranial aneurysms underwent surgical clipping using the D-Clip system. A total of 64 permanent and 19 temporary D-Clips were applied. Nine clips needed to be replaced. All aneurysms could be occluded totally. Surgeons considered handling and manoeuvrability of clip application as feasible and good in all cases (100%), even under impaired visibility circumstances (14%). Objective video analysis revealed comparable results. Nursing staff scored handling and practicability of D-Clips equivalent to the preceding L-Clip generation. There were no intraoperative complications. Surgery-related postoperative morbidity was 6.7%.

CONCLUSIONS

The new D-Clip system combines an attenuated design for minimally invasive clipping procedures with traditional mechanisms of common clip systems. It therefore appears to be highly versatile in the context of variable different aneurysm morphologies and locations while maintaining high standard surgical safety and efficacy.