Considerations on surgical strategies and associated risk profiles for endoscopic tumor biopsies within the third ventricle and periaqueductal region

INTRODUCTION

Neuroendoscopic techniques have proven to be a successful and minimally-invasive technique for tumor biopsies within the third ventricle in pediatric patients. However, a comprehensive assessment of associated surgical strategies, techniques, and morbidity is essential to optimize patient outcomes.

METHODS

This retrospective study analyzed full endoscopic tumor biopsies in pediatric patients with tumors in the third ventricle and periaqueductal region. Data from 1995 to 2022 were collected from medical records, imaging, and intraoperative video documentation.

RESULTS

In this study, 16 shear endoscopic tumor biopsies were performed using the transventricular transforaminal approach. Tumors were located in the anterior or mid part of the third ventricle (50%) or in the periaqueductal and pineal recess region (50%). Preoperative hydrocephalus was seen in 81.25%. Tumor biopsies were harvested successfully in all cases. Simultaneous ETV was performed in 12 (75%) cases and additional septostomy in 3 (18.75%). Significant intraoperative bleeding occurred in 3 cases (18.75%). All bleeding situations could be successfully managed with continuous irrigation. Histopathology revealed astrocytoma as the predominant diagnosis (75%). No new neurologic deficits were observed, except for one case of transient oculomotor nerve paralysis after ETV. Hydrocephalus persisted in 18.6% of all cases with the need of urgent ventriculoperitoneal shunting in two patients.

CONCLUSION

In conclusion, neuroendoscopy emerges as an effective technique for tumor biopsies within the third ventricle in pediatric patients, offering the added advantage of simultaneous treatment of obstructive hydrocephalus. However, it is essential to acknowledge the specific intra- and postoperative risks associated with various surgical strategies. The safe management and achievement of favorable clinical results demand extensive experience and expertise.

The minimally invasive transventricular endoscopic approach to third ventricular lesions in pediatric patients-all-rounder with limitations?

INTRODUCTION

The surgical management of third ventricular lesions poses unique challenges, requiring careful consideration of various approaches and techniques. This study focuses on the transventricular transforaminal endoscopic approach and aims to provide insights into its indications, limitations, technical nuances, and potential complications in pediatric patients.

METHODS

A retrospective analysis was conducted using data from a 13-year period on pediatric patients who were subjected to transforaminal endoscopic surgery for third ventricular lesions. The study utilized a prospectively maintained internal database, extracting demographic data, preoperative assessment, surgical details, and postoperative follow-up information. The surgical technique is presented in detail, and exemplary case reports highlight relevant surgical considerations.

RESULTS

Out of 578 endoscopic transforaminal procedures, 24 surgeries were performed on pediatric patients with third ventricular lesions. Performed procedures consisted of cyst resection (13 cases), solid tumor resection (4 cases), and tumor biopsies with CSF pathway restoration (7 cases). The mean age at the time of surgery was 7.6 years. Postoperatively, 14 patients showed transient nausea and vomiting (58.3%); 10 patients showed pneumocephalus on postoperative MRI (41.7%). No emergency postoperative re-interventions nor perioperative mortality were observed.

CONCLUSION

The endoscopic transventricular transforaminal approach is a safe approach for lesion resection, CSF pathway restoration, and tumor biopsy in pediatric patients with third ventricle lesions. The author's results support the use of this minimally invasive technique as an alternative to more extensive approaches, particularly to the interforniceal interhemispheric approach. However, surgical success is highly dependent to the individual surgeon's experience and moreover to a suitable indication setting. Careful preoperative planning and knowledge of the approaches' pro and cons is mandatory for successful application of this approach.

Image Quality and Related Outcomes of the ShuntScope-Guided Catheter Implantation in Adult Hydrocephalus: Experience of 63 Procedures

BACKGROUND

 Ventricular catheter (VC) placement in the selected subset of adult hydrocephalus can be highly challenging due to abnormal anatomical configuration or the need for trans-aqueductal stent placement. Transluminal endoscopy with the ShuntScope has been invented to increase the success rate of catheter placement. This study evaluates the image qualities of ShuntScope and related surgical outcomes in adults.

METHODS

 A retrospective analysis of all adult patients undergoing VC placement using the ShuntScope from November 2011 to July 2022 in the authors' department was performed. Demographic, clinical, and radiologic data were evaluated. The visualization quality of the intraoperative endoscopy was stratified into excellent, medium, and poor, and compared to the postoperative catheter tip placement. Follow-up evaluation included the surgical revision rate due to proximal catheter misplacement.

RESULTS

 A total of 63 ShuntScope-assisted surgeries have been performed on 60 adults. The mean age of the patients was 48.43 years. The most common underlying pathology was a tumor- or cyst-related cerebrospinal fluid (CSF) impairment in 38.33%, followed by a pseudotumor cerebri in 21.66%. The achieved image quality was excellent in 39.68%, medium in 47.62%, and poor in 12.7%. Ideal catheter placement was achieved in 79.37%. There were no intraoperative complications associated with the use of the ShuntScope. The revision rate due to suboptimal proximal VC placement was 4.76% during a mean follow-up period of 27.75 months. A statistical correlation between the image quality and accuracy of the catheter position was observed (p < 0.001).

CONCLUSION

 The ShuntScope can be considered an important addition to standard surgical tools in treating a selected subset of adult hydrocephalus. Direct visualization might even help achieve correct placement of the catheter in the cases with blurred vision and limited visual overview.

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.

Image quality and related outcomes of the ShuntScope for catheter implantation in pediatric hydrocephalus-experience of 65 procedures

PURPOSE

Ventricular catheter implantation in pediatric hydrocephalus can become a highly challenging task due to abnormal anatomical configuration or the need for trans-aqueductal stent placement. Transluminal endoscopy with the ShuntScope has been invented to increase the rate of successful catheter placements. This study aims to evaluate ShuntScope's image qualities and related surgical outcomes in the pediatric population.

METHODS

A retrospective analysis of all pediatric patients undergoing ventricular catheter placement using the ShuntScope from 01/2012 to 01/2022 in the author's department was performed. Demographic, clinical, and radiological data were evaluated. The visualization quality of the intraoperative endoscopy was stratified into the categories of excellent, medium, and poor and compared to the postoperative catheter tip placement. Follow-up evaluation included the surgical revision rate due to proximal catheter occlusion.

RESULTS

A total of 65 ShuntScope-assisted surgeries have been performed on 51 children. The mean age was 5.1 years. The most common underlying pathology was a tumor- or cyst-related hydrocephalus in 51%. Achieved image quality was excellent in 41.5%, medium in 43%, and poor in 15.5%. Ideal catheter placement was achieved in 77%. There were no intraoperative complications and no technique-related morbidity associated with the ShuntScope. The revision rate due to proximal occlusion was 4.61% during a mean follow-up period of 39.7 years. No statistical correlation between image grade and accuracy of catheter position was observed (p-value was 0.290).

CONCLUSION

The ShuntScope can be considered a valuable addition to standard surgical tools in treating pediatric hydrocephalus. Even suboptimal visualization contributes to high rates of correct catheter placement and, thereby, to a favorable clinical outcome.

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.

The semisitting position in pediatric neurosurgery: pearls and pitfalls of a 10-year experience

OBJECTIVE

The authors sought to investigate the pearls and pitfalls of using the semisitting position in pediatric neurosurgery, with special focus on related morbidity and surgical practicability.

METHODS

All pediatric cases at a single institution were evaluated retrospectively. Those patients who underwent procedures in the semisitting position between December 2010 and December 2020 were included in the final analysis. Results were compared with all children who underwent surgery in the prone position for posterior fossa lesions within the same time frame.

RESULTS

A total of 42 posterior fossa surgeries were performed in 38 children in the semisitting position between December 2010 and December 2020. The mean patient age at the time of surgery was 8.9 years (range 13 months-18 years). The data of 24 surgeries performed in the prone position in 22 children during the same time frame were analyzed in comparison. Three children (7.9%) were diagnosed with a persistent foramen ovale preoperatively. The surgery was completed in all cases. The incidence of venous air embolism (VAE) was 11.9%. There was no VAE-related hemodynamic instability, infarction, or death. Endoscopic techniques were applied safely in 14 cases (33.3%). Postoperative pneumocephalus occurred significantly more frequently in patients who had undergone procedures in the semisitting position (p < 0.05), but without the need for intervention. During 1 surgery (2.4%), the patient experienced a postoperative skull fracture and epidural bleeding due to the skull clamp application. Clinical status of the patients immediately after surgery was improved or stable in 33 of the 42 surgeries (78.6%) performed in the semisitting position.

CONCLUSIONS

With attentive performance and an experienced surgical team, the semisitting position is a safe option for posterior fossa surgery in the pediatric population. With a comparable complication profile, the semisitting position offers excellent anatomical exposure, which is ideal for the application of endoscopic visualization. Careful skull clamp application and appropriate monitoring are highly recommended.

P06.05 The Sitting Position in the Very Young Pediatric Population: Pearls and Pitfalls of a 10-Years’ Experience

BACKGROUND

To investigate pearls and pitfalls of the sitting positioning in the pediatric population with special focus on related morbidity and surgical practicability.

MATERIAL AND METHODS

A retrospective analysis of a prospectively maintained internal database was performed. All pediatric patients younger than 18 years at date of surgery, who underwent procedures in sitting position between 01/2010 and 10/2020 were included into this analysis.

RESULTS

A total of 42 of posterior fossa surgeries were performed in 38 children between 01/2010 and 10/2020. Mean age at surgery was 8.9 years (13 months - 18 years). Mean height and weight were 134.4 (± 30.2) cm and 36.6 (± 21.7) kg respectively. Three children (7.9%) were diagnosed with persistent foramen ovale. Electrophysiologic monitoring was unremarkable during positioning in all cases. Mean time needed for anesthesiologic preparation and positioning was 84.5 (± 20.6) minutes. Perioperative blood transfusion was needed in 5 cases (11.9%). Incidence of VAE was 11.9%. There was no VAE related severe complication. One child (2.4%) showed postoperative skull fracture and epidural bleeding due to skull clamp application. Clinical status immediately after surgery was favorable or stable in 33 of the cases (78.6%).

CONCLUSION

Attentive performance and an experienced surgical team provided; the sitting position remains a safe variant for posterior fossa surgery in the pediatric population. Precautious skull clamp application and appropriate monitoring is highly recommended. Considering eloquent aspects, the sitting position offers excellent anatomical exposure and is ideal for combination with endoscopic techniques.

miRNA-26a expression influences the therapy response to carmustine wafer implantation in patients with glioblastoma multiforme

BACKGROUND

Glioblastoma multiforme is the most frequent malignant brain tumor in adults being marked with a very poor prognosis. Therapy concept implies concomitant radio-chemotherapy and facultative implantation of carmustine-eluted wafer. Current literature suggests microRNA 26a expression in glioblastoma to interact with alkylating chemotherapy. Subsequently, the aim of this study was to investigate the correlation of miRNA-26a expression and carmustine wafer implantation and its potential usefulness as a predictive marker for therapy response.

METHODS

In total, 229 patients with glioblastoma multiforme were included into the final analysis. Of them, 80 cases were recruited from the Saarland University Medical Center for a retrospective matched-pair analysis stratified after therapy regime: One group (carmustine wafer group; n=40) received concomitant radio-chemotherapy with carmustine wafer implantation. The other group (control group; n=40) only received concomitant radio-chemotherapy. The results were confirmed by comparing them with an independent dataset of 149 patients from the TCGA database. All tumor specimens were evaluated for miRNA-26a expression, MGMT promoter methylation, and IDH1 R132H mutation status, and the results were correlated with the clinical data.

RESULTS

Twenty-three patients in the carmustine wafer group showed low expression of miRNA-26a, while 17 patients showed a high expression. In the control group, 28 patients showed low expression, while 12 patients showed a high expression. The patients with high miRNA-26a expression in the carmustine wafer group were characterized by a significantly longer overall (hazard ratio [HR] 2.750 [95% CI 1.352-5.593]; p=0.004) and progression-free survival (HR 3.091 [95% CI 1.436-6.657]; p=0.003) than patients with low miRNA-26a expression. The 17 patients in the carmustine wafer group with high miRNA-26a expression showed a significantly longer progression-free survival (p=0.013) and overall survival (p=0.007) compared with the control group. There were no such correlations identified within the control group. TCGA datasets supported these findings.

CONCLUSIONS

MiRNA-26a expression turned out to be a promising predictor of therapy response and clinical outcome in glioblastoma patients treated with carmustine wafer implantation. For evaluation of the role of miRNA-26a in a combined therapy setting, further studies are needed in order to translate general findings to the patient's individual situation.

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.

Spontaneous Elevation of Blood Pressure After SAH: An Epiphenomenon of Disease Severity and Demand, But Not a Surrogate for Outcome?

BACKGROUND

Spontaneous blood pressure increase is frequently observed after aneurysmal subarachnoid hemorrhage (aSAH). These episodes of spontaneous blood pressure alterations are usually tolerated under the assumption of an endogenous response to maintain cerebral perfusion. The relevance of blood pressure variability and its relationship to disease severity and outcome, however, remain obscure.

METHODS

A total of 115 consecutive patients with aSAH were included for this retrospective analysis of a continuously collected data pool. Demographics, initial clinical severity of aSAH (HH°, mFS), treatment modality, clinical course, and outcome (development of DCI, cerebral infarction, and GOS after 3 months) were recorded. Hemodynamic information-recorded automatically with a frequency of 1/15 min-was analyzed for spontaneous blood pressure increase (SBI) and endogenous persistent hypertension (EPH) after exclusion of iatrogenic factors and relevant co-medication. Subgroup analysis included stratification for day 0-3, 4-14, and 14-21.

RESULTS

SBI and EPH incidence varied from 17 to 84% depending on detection threshold (15-35 mmHg) and time period under scrutiny. Incidence of blood pressure increase correlated with disease severity upon admission (p < 0.05), but the anticipated association with outcome was not observed. SBI and EPH were more likely to occur between day 4 and 14 (p < 0.001), but only early occurrence (day 0-3) was associated with higher incidence of DCI (p < 0.05). Persistent blood pressure elevation between day 4 and 21 was associated with fewer DCI. However, no influence of spontaneous upregulation on clinical outcome after three months was observed.

CONCLUSIONS

Spontaneous hemodynamic upregulation is a frequent phenomenon after aSAH. Our data support the hypothesis that spontaneous blood pressure alterations reflect an endogenous, demand-driven response correlating with disease severity. Early alterations may indicate an aggravated clinical course, while later upregulation in particular-if permitted-does not translate into a higher risk of unfavorable outcome.