Endoscopic Assisted Supraorbital Keyhole Approach or Endoscopic Endonasal Approach in Cases of Tuberculum Sellae Meningioma: Which Surgical Route Should Be Favored?

OBJECTIVE

Keyhole approaches are under investigation for skull base tumor surgery. They are expected to have a low complication rate with the same successful resection rate compared with endoscopic endonasal procedures. In this study, we compare our current series of tuberculum sellae meningiomas resected via an endoscopic endonasal or microsurgical supraorbital keyhole approach.

METHODS

Between 2011 and 2016, 16 patients were treated using the supraorbital keyhole procedure and 6 patients received an endoscopic endonasal procedure. Both surgical techniques were analyzed and compared concerning complications, surgical radicality, endocrinologic, and ophthalmologic outcome and recurrences in patients' follow-up.

RESULTS

The 2 different approaches yielded similar rates of gross total resection (endonasal 83% [5 of 6] vs. supraorbital 87% [14 of 16]), near total resection (17% [1 of 6] vs. 13% [2 of 16]), and visual recovery (endonasal 66% [2 of 3] vs. supraorbital 60% [3 of 5]). An extension lateral to the internal carotid artery was noted in 81% (13 of 16) of the supraorbital cases and in none of the endonasal cases. Tumor volume was 14.9 cm³ (±8.2 cm³) for supraorbital tumors versus 2.1 cm³ (±0.8 cm³) for the endonasal approach.

CONCLUSIONS

Both approaches provide minimally invasive surgical routes accessing meningiomas of the sellar region. The ideal approach should be tailored to the individual patient considering the tumor anatomy, lateral extension, and the experience of the surgeon with both surgical approaches. We suggest using the supraorbital approach for larger meningiomas of sellar region with far lateral extension or broad vascular encasement.

The endoscopic endonasal transsphenoidal approach to sellar lesions allows a high radicality: The benefit of angled optics

OBJECTIVE

The endonasal endoscopic approach is currently under investigation for perisellar tumour surgery. A higher resection rate is to be expected, and nasal complications should be minimized. Here, the authors report their technique of transnasal endoscopic neurosurgery with a special reference to the impact of the use of angled optics.

MATERIAL AND METHODS

Two-hundred-and-seventy-one endoscopic endonasal transsphenoidal procedures were performed for sellar lesions between January 2000 and August 2013. One-hundred-and-twenty-nine patients out of them could be used for analysing the use of angled endoscopes including completed follow up, MR imaging as resection control and documentation of the intraoperative use and benefit of angled optics. Exclusion criteria were: planned incomplete resection or incomplete data set. The surgical technique was carefully analysed; and these cases were followed prospectively.

RESULTS

Standard technique was a mononostril approach with 0° endoscopes. Angled endoscopes were used for assessment of radicality during the tumour resection and at the end of the procedure. In 95 cases (72%), an angled endoscope was used. Remnant tumour was visualized with angled optics in 27 of the 95 cases (28%). In all these cases, remnant tumour tissue was subsequently further removed. Complete resection was seen on MRI FU in 91 of 95 cases (96%) in this subgroup. In the cases without application of angled optics, there was already a sufficient sight via the 0° endoscope (14/34; 42%), or a significant bleeding from the cavernous sinus made the application of an angled endoscope impossible (19/34; 55%). On follow up, MRI revealed radical tumour resection in 93% (120/129). In the subgroup without angled optics use, radicality reached 88% (30/34) in contrast to 96% in the angled optics subgroup. Recurrent tumour growth was observed in four patients (3%).

CONCLUSIONS

The endscopic technique has been shown to be safe and successful with a high radicality and only minor complications. The application of various angled endoscopes allows a look "around the corner" resulting in a potentially higher radicality of tumour resection in endonasal transsphenoidal surgery.

Mononostril endoscopic transsphenoidal approach to sellar and peri-sellar lesions: Personal experience and literature review

OBJECTIVE

The endonasal endoscopic approach to skull base is still under investigation. The main goal is the minimal invasive approach to pathologies with a better rate of resection without retraction of the brain tissue. Here, the authors report their technique of transnasal endoscopic neurosurgery using a mononostril approach and its development.

METHODS

The supplementary video demonstrates the different steps of the mononostril approach and resection of a pituitary adenoma. All video-recorded procedures that were carried out between 2000 and 2013 using this technique were analysed. The patients were followed prospectively.

RESULTS

Visualization and handling were good in 246/251 (98%). In three cases, we had to switch to microscopy because of severe bleeding of the cavernous sinus. On follow-up, magnetic resonance imaging revealed radical tumour resection in 92% of all cases when intended. There was no mortality, and the low complication rate was remarkable.

CONCLUSION

Our mononostril approach of transnasal transsphenoidal surgery shows better results compared with previously published reports in regards to radicality, low cerebrospinal fluid leaks and morbidity. The very low rate of nasal complains is particularly remarkable.

Endoscopic endonasal transsphenoidal approach to sellar lesions: a detailed account of our mononostril technique

Objective The endonasal endoscopic approach is currently under investigation for perisellar tumor surgery. A higher resection rate is to be expected and nasal complications should be minimized. Here, the authors report their technique of transnasal endoscopic neurosurgery after 218 procedures. Methods Between October 2000 and September 2011, 210 patients received 218 endoscopic endonasal transsphenoidal procedures for perisellar lesions. Procedures were video recorded. The surgical technique was carefully analyzed. These cases were prospectively followed. Results Standard technique was mononostril approach with 0-degree optics. 30-degree and-after availability-45-degree optics were used for assessment of radicality. On follow-up, magnetic resonance imaging revealed radical tumor resection in 94 out of 104 cases (90.3%). Recurrent tumor growth was observed in five younger patients (2.2%). There was no mortality and a low complication rate. Three patients (1.4%) complained postoperatively of nasal congestion or reduced nasal air flow; however, no complaints were considered to be severe. Conclusion In comparison with other literature reports, the results are comparable or even better with respect to surgical radicality. The very low rate of nasal complaints is particularly remarkable. The technique has been shown to be safe and successful with a high radicality and only minor complications.

Preservation of hormonal function by identifying pituitary gland at endoscopic surgery

OBJECTIVE

The endonasal endoscopic approach has been established for perisellar tumor surgery with a higher resection rate and reduced complications. We analyzed the potential to identify the pituitary gland under endoscopic view, at surgery and see its relation to postoperative hormonal insufficiency in endonasal endoscopic procedures.

METHODS

Between January 2011 and January 2014, 70 cases of pituitary adenomas with preoperative intact pituitary function underwent endoscopic endonasal transsphenoidal procedures for intrasellar pathologies. Endocrinologists and neurosurgeons followed these patients prospectively. Special attention was paid to intraoperative identification of gland tissue, surgical complications, degree of resection and postoperative hormonal insufficiency.

RESULTS

The pituitary gland was identified in 57 out of 70 procedures (81.4%). Eleven percent (8 of 70 patients) had persistent pituitary insufficiency. Two of these 8 patients belonged to the group with pituitary gland identification (2 out of 57); thus, when the pituitary gland was identified during the procedure postoperative hormonal insufficiency was seen in 3.5% of cases. Failure of pituitary gland identification presented with hormonal insufficiency of 46.2%. In analysis with Fisher's exact test, there was a high significant correlation between the identification of the pituitary gland intraoperatively and normal pituitary function postoperatively (p<0.005). On follow up radical tumor resection was seen in 88% (62 of 70 patients).

CONCLUSIONS

This study indicates that identification and preservation of pituitary gland tissue and function is possible in endoscopic transsphenoidal surgery. This preservation of gland tissue is a positive predictor of postoperative normal pituitary function.

The use of intraoperative computed tomography navigation in pituitary surgery promises a better intraoperative orientation in special cases

OBJECTIVE

The safety of endoscopic skull base surgery can be enhanced by accurate navigation in preoperative computed tomography (CT) and magnetic resonance imaging (MRI). Here, we report our initial experience of real-time intraoperative CT-guided navigation surgery for pituitary tumors in childhood.

MATERIALS AND METHODS

We report the case of a 15-year-old girl with a huge growth hormone-secreting pituitary adenoma with supra- and perisellar extension. Furthermore, the skull base was infiltrated. In this case, we performed an endonasal transsphenoidal approach for debulking the adenoma and for chiasma decompression. We used an MRI neuronavigation (Medtronic Stealth Air System) which was registered via intraoperative CT scan (Siemens CT Somatom). Preexisting MRI studies (navigation protocol) were fused with the intraoperative CT scans to enable three-dimensional navigation based on MR and CT imaging data. Intraoperatively, we did a further CT scan for resection control.

RESULTS

The intraoperative accuracy of the neuronavigation was excellent. There was an adjustment of <1 mm. The navigation was very helpful for orientation on the destroyed skull base in the sphenoid sinus. After opening the sellar region and tumor debulking, we did a CT scan for resection control because the extent of resection was not credible evaluable in this huge infiltrating adenoma. Thereby, we were able to demonstrate a sufficient decompression of the chiasma and complete resection of the medial part of the adenoma in the intraoperative CT images.

CONCLUSIONS

The use of intraoperative CT/MRI-guided neuronavigation for transsphenoidal surgery is a time-effective, safe, and technically beneficial technique for special cases.

Aqueductal stenting with an intra-catheter endoscope--a technical note

INTRODUCTION

Aqueductoplasty as well as aqueductal stenting is an accepted therapy option in short-segment aqueductal stenosis and isolated fourth ventricle. Over the years, different techniques with only slight modifications by using a conventional neuroendoscope with a working sheath to introduce different instruments have been presented. In summary, the use of Fogarty balloon catheters or flexible endoscopes to pass the narrowed aqueduct is recommended.

METHODS

This technical report describes a substantially new technique for this purpose. Six patients underwent aqueductal stenting with a new intracatheter endoscope.

RESULTS

Aqueductal stenting was possible in 4 out of 6 cases. No complications occurred. Handling of this new technique was good and easy without a prolonged learning curve. All four stents did work appropriately, and the procedure was considered to be successful. Of the two failures, the technique was abandoned and endoscopic third ventriculostomy (ETV) was performed in one. In the other case, suboccipital shunting was done.

CONCLUSION

This technical report describes a substantially new technique for aqueductal stenting. The combination of an intracatheter miniature endoscope and a prepared ventricular catheter enables careful and elegant aqueductal stenting. Large or flexible endoscopes, balloons, or special instruments to place a stent have become completely obsolete in selected cases.

Automated intracranial pressure-controlled cerebrospinal fluid external drainage with LiquoGuard

INTRODUCTION

LiquoGuard is a new device for intracranial pressure (ICP)-controlled drainage of cerebrospinal fluid (CSF). This present study evaluates the accuracy of ICP measurement via the LiquoGuard device in comparison with Spiegelberg. Thus, we compared data ascertained from simultaneous measurement of ICP using tip-transducer and tip-sensor devices.

MATERIAL AND METHODS

A total of 1,764 monitoring hours in 15 patients (range, 52-219 h) were analysed. All patients received an intraventricular Spiegelberg III probe with the drainage catheter connected to the LiquoGuard system. ICP reading of both devices was performed on an hourly basis. Statistical analysis was done by applying Pearson correlation and Wilcoxon-matched pair test (p < 0.05).

RESULTS

Mean ICP values were 11 ± 5 mmHg (Spiegelberg) and 10 ± 7 mmHg (LiquoGuard); the values measured with both devices correlated well (p = 0.001; Pearson correlation =0.349; n = 1,764). In two of the 15 patients with slit ventricles, episodes of significant differences in measured values could be observed. Both patients suffering from slit ventricles failed to produce reliable measurement with the external transducer of the LiquoGuard.

CONCLUSIONS

LiquoGuard is a valuable new device for ICP-controlled CSF drainage. However, LiquoGuard tends to provide misleading results in slit ventricles. Thus, before these drawbacks are further analysed, the authors recommend additional ICP measurement with internal tip-sensor devices to avoid dangerous erroneous interpretation of ICP data.

Red blood cell transfusion in neurosurgery

BACKGROUND

The necessity of red blood cell (RBC) transfusions in neurosurgical procedures is under debate. Although detailed recommendations exist for many other surgical disciplines, there are very limited data on the probability of transfusions during neurosurgical procedures.

METHODS

Three-thousand and twenty-six consecutive adult patients undergoing neurosurgical procedures at Saarland University Hospital from December 2006 to June 2008 were retrospectively analyzed for administration of RBCs. The patients were grouped into 11 main diagnostic categories for analysis. The transfusion probability and cross-match to transfusion ratio (C/T ratio) were calculated.

RESULTS

Overall, the transfusion probability for neurosurgical procedures was 1.7 % (52/3,026). The probability was 6.5 % for acute subdural hematoma (7/108), 6.2 % for spinal tumors (5/80), 4.6 % for intracerebral hemorrhage (ICH, 4/98), 2.8 % for abscess (3/108), 2.4 % for traumatic brain injury (4/162), 2.3 % for cerebral ischemia (1/44), 1.9 % for subarachnoid hemorrhage (SAH) /aneurysms (4/206), 1.4 % for brain tumors (10/718), 0.8 % for hydrocephalus (2/196), 0.4 % for degenerative diseases of the spine (5/1290), including 3.6 % (3/82) for posterior lumbar interbody fusion (PLIF) and 0 % for epidural hematoma (0/15). The transfusion probabilities for clipping and coiling of SAH were 2.9 % (2/68) and 1.7 % (2/120) respectively.

CONCLUSIONS

The probability of blood transfusion during neurosurgical procedures is well below the 10 % level which is generally defined as the limit for preoperative appropriation of RBCs. Patients with spinal tumors, acute subdural hematomas or ICH, i.e., patients undergoing large decompressive procedures of bone or soft tissue, had a higher probability of transfusion.

Clonal cytogenetic progression within intratumorally heterogeneous meningiomas predicts tumor recurrence

Meningiomas arise from the coverings of the brain or the spinal cord. They are mostly benign and can be surgically cured. However, in approximately 5% of the cases, they turn into malignant forms with aggressive clinical behavior and increased risk of tumor recurrence. Cytogenetically meningiomas are well characterized, with normal karyotype or monosomy of chromosome 22 in most tumors and clinically relevant secondary losses of other autosomes and sex chromosomes in a subset of anaplastic tumors. Statistical analyses were performed for 1064 karyotypes derived from 661 meningiomas with respect to progression, and recurrence of the tumor. The order of accumulating genetic aberrations has previously been biostatistically estimated with oncogenetic tree models, and a genetic progression score derived from these models was shown to be predictive for tumor recurrence. Although more homogeneous than other cancer types, meningiomas show considerable intratumoral cytogenetic heterogeneity, particularly in their anaplastic form. We observed different cytogenetic patterns in tumor cells of 224 out of 661 (33.4%) meningiomas. The present study demonstrates that it is not sufficient to consider only the most frequent cytogenetic pattern observed in a sufficient set of cells derived from the same tumor. Even a single cell with more advanced genetic progression may start a clone and indicates also clinical progression. Cox regression analysis reveals that the clone with most advanced progression is a leading marker for recurrence in meningiomas. The aim of this study was the analysis of genetic heterogeneity on single cell basis. Further we investigated if there is a substantial correlation between the intratumoral heterogeneity of a given meningioma and its recurrence risk. We were able to show that the selection of single genetically advanced cells improves the prediction of clinical meningioma progression in a more precise manner.

Sinonasal outcome after endoscopic mononostril transsphenoidal surgery: A single center cohort study

OBJECTIVE

The endoscopic endonasal approach has been well established for skull base surgery. However, there are only few studies pointing out nasal complaints after surgery. In this study, the authors evaluated postoperative nasal complaints and complications after mononostril endoscopic procedures.

METHODS

All patients operated on parasellar and sellar pathologies at our department via an endoscopic mononostril transnasal transsphenoidal approach from January 2011 to May 2015 were analyzed. To assess specific postoperative nasal pathological conditions and complaints, a questionnaire was established. Applicable data of 79 patients with additional ENT follow-up could be included. Endpoints were the quantitative evaluation of complications and correlation of these data.

RESULTS

There was no vascular injury or worsening of visual function. Two patients had persisting CSF fistula and one of them meningitis. There was a significant decrease of nasal complaints during follow up after 2 years (p < 0.001). Further surgical treatment by ENT physician was necessary in 11.4%. Resurgery significantly increased the risk of postsurgical complaints (p < 0.005). The use of a tamponade significantly reduced the risk of postsurgical reduced nasal airflow (p = 0.026) and sinusitis (p = 0.002).

CONCLUSIONS

Endoscopic endonasal procedures to skull base lesions achieve high radicality with low complication rates. However, they induce temporary and permanent nasal complaints and complications. Thereby, resurgeries increase the risk of nasal complaints and the use of nasal tamponades might increase the sinonasal outcome. Further prospective studies are necessary to objectify the evaluation of postsurgical nasal complications.

Management of severe intraoperative hemorrhage during intraventricular neuroendoscopic procedures: the dry field technique

OBJECTIVE

The unexpected intraoperative intraventricular hemorrhage is a rare but feared and life-threatening complication in neuroendoscopic procedures because of loss of endoscopic vision. The authors present their experience with the so-called "dry field technique" (DFT) for the management of intraventricular hemorrhages during purely endoscopic procedures. This technique requires the aspiration of the entire intraventricular CSF to achieve clear visualization of the bleeding source.

METHODS

More than 500 neuroendoscopic intraventricular procedures were retrospectively analyzed over the last 24 years for documented severe hemorrhages, which were treated by the application of the DFT.

RESULTS

The technique was required in 6 cases, including tumor resection/biopsy, cyst resection, and intraventricular lavage. Additionally, the technique was applied as part of the planned strategy in 3 cases of endoscopic tumor removal. The hemorrhage was stopped in all cases and no associated postoperative deficits occurred.

CONCLUSIONS

Although severe hemorrhages are rare, the neurosurgeon needs to be aware of them and has to establish strategies for their management. Most hemorrhages can be stopped by constant irrigation and coagulation. In the other rare cases, the DFT is a safe, reliable technique and can be easily incorporated into endoscopic surgery.

Perioperative olfactory dysfunction in patients with meningiomas of the anteromedial skull base

Olfactory dysfunction represents a main symptom in olfactory groove meningiomas (OGM). Besides this, olfactory function has been sparsely investigated in patients suffering from supratentorial meningiomas. Here, the authors explore pre- and postoperative variables associated with olfactory dysfunction in supratentorial meningioma patients. This is a retrospective study on supratentorial meningioma patients who underwent meningioma resection between January 2015 and January 2016. Preoperative and postoperative olfactory performance was quantified using a lateralized sniffin' stick odor identification test. Meningiomas affecting the olfactory system (n = 23) were compared to meningiomas in other locations among the control group (n = 40). Meningiomas that affected the olfactory system had odds of 3.6 and 3.7 in being associated with ipsilateral (lesional) and bilateral anosmia, respectively. Subgroup analysis revealed that meningiomas causing a midline shift across the frontal base and older age represented risk factors for preoperative anosmia. The odds of experiencing acquired postoperative ipsilateral anosmia were significantly increased in olfactory system affecting meningiomas (OR 11.1). Subgroup analysis highlighted OGMs to represent the predominant location associated with deterioration. General surgical complications predisposed patients to loss of contralateral (OR 12.3) and bilateral olfactory function (OR 27.8). Older age and meningiomas causing a midline shift across the frontal base predispose patients to preoperative olfactory dysfunction. Resection of OGMs and surgical complications are risk factors for postoperative olfactory deterioration to anosmia. Likely, olfactory dysfunction is underrecognized even in OGMs. In OGM surgery, however, preoperative lateralized testing might be critical to selecting an appropriate surgical route to preserve olfactory function. Clin. Anat. 32:524-533, 2019. © 2019 Wiley Periodicals, Inc.

Prognosis of pituitary adenomas in the early 1970s and today-Is there a benefit of modern surgical techniques and treatment modalities?

OBJECTIVE

Neurosurgical techniques for the treatment of sellar pathologies have been evolving continuously over the last decades. Additionally to the innovation of approaches and surgical techniques, this progress yielded to the application of modern intraoperative surgical tools as well as peri- and intraoperative imaging. Until now, no long-term analysis of the impact of new therapy concepts on the patient's outcome exists. Aim of this study was to analyse the impact of new operative approaches on perioperative mortality and morbidity as well as the long-term outcome after pituitary surgery.

PATIENTS AND METHODS

Three groups of patients were compared in this retrospective analysis of surgically treated pituitary adenomas between the years of 1963 and 2014. Group A contains 93 patients, treated between 1963-1980 with a mean follow-up of 12.1 years (±14.3years), group B comprises 89 patients treated between 1990 and 2000 with a mean follow-up of 10.1 years (±8.1years) and group C consists of 95 patients treated between 2011-2014 with a mean follow-up of 3.4 years (±1.9years).

RESULTS

The surgical treatment was performed significantly earlier today on smaller tumors with less preoperative complaints (p<0.01). Panhypopituitarism was detected only in 9.5% of the cases in group C compared to 50.8% in group A (p<0.01). Also, the incidence of revision surgery (5.6 vs. 2% vs 0%), postoperative hemorrhage (10.8% vs. 3.4% vs. 1%) and diabetes insipidus (34.4% vs. 11.2% vs. 5.2%) was decreased (p<0.01). Moreover, a significant postoperative improvement of ophthalmological complaints was detected (p<0.001). The long-term follow-up showed 40% of the entire recurrence rate occurring after the ninth postoperative year. The progression-free survival time increased significantly from group A to group B (p<0.05).

CONCLUSIONS

The results demonstrate a benefit of the recent developments of pituitary surgery in the short-term results as well as in the long-term outcome. The prognosis of pituitary adenoma patients could be improved by the introduction of new surgical approaches and techniques in the last decades. Also the perioperative morbidity and mortality rate has been reduced clearly since the 1970s. Furthermore our results emphasise the necessity of lifelong follow-up of all patients with successfully treated pituitary adenomas.

Establishment of a molecular cytogenetic analysis for native tumor tissue of meningiomas-suitable for clinical application

Background

Meningiomas are mostly benign tumors which arise from the meninges. They are among the cytogenetically best-studied solid tumors, mostly displaying a normal karyotype or, as a typical primary aberration, monosomy of chromosome 22. Further secondary chromosomal aberrations, especially the deletion of chromosome 1p, are correlated with increasing biological aggressiveness up to malignancy. These data are derived from the cytogenetical characterization of 661 meningiomas, from which the genetic progression score (GPS) has been developed. Due to the high expenditure of time and the expert knowledge for the cytogenetical characterization, the aim of this work was to establish an equally reliable yet more rapid clinical diagnosis based on fluorescence in situ hybridization (FISH) on meningiomas. Thus a comparison between the native tumor tissue and the primary culture of the same tumor was done in order to determine the most efficient method for a molecular cytogenetic characterization. The diagnostic procedure has to deliver fast and robust results, since they must enable the attending physician to plan the appropriate follow-up regimens for the patients. All in all, preparations of native tumor tissue as well as preparations of cell culture of 22 meningiomas were tested with FISH for aberrations concerning the prognostically relevant chromosome regions 1p and 9p, and the chromosomes 10, 14, 18 and 22 in comparison with the particular karyotypes revealed by conventional karyotyping using G-banding.

Results

The FISH examinations between native and cultured cells showed an accordance of 93.4%. The comparison of FISH data and karyotyping presented accordance to the greatest possible extent concerning the chromosomes 14, 18 and 22, but to detect the progression associated losses of 1p and 9p FISH is the most sensitive method.

Conclusions

The raised data reveal that both methods can be used for a significant analysis of chromosome aberrations on meningiomas. As a result of that the complex primary culture could also be avoided. Therefore a clinical diagnosis based on FISH on meningiomas is at hand for the assignment of patients to a suitable follow-up regimen.

The extended endoscopic approach to perisellar and skull base lesions: is one nostril enough?

The extended endonasal endoscopic approach to the skull base is still under investigation. The main advantage of using this technique is to approach lesions in a minimally invasive manner resulting without brain retraction. Here, the authors present the results of extended endonasal endoscopic surgery via one nostril. All skull base procedures performed via an endonasal approach at the author's Department between January 2011 and May 2017 were analysed prospectively. Special attention was paid to complications, radicality, advantages and disadvantages of the endoscopic technique. Additionally, the application of various telescopes and the technique of dural closure were analysed. Sixty-two patients were operated on various pathologies of the skull base via an extended endonasal approach. Seven pathologies were resected via binostril technique. All other pathologies could be exposed by the mononostril technique. In 2 of 62 cases, the authors had to switch to binostril technique. MRI revealed radical gross total resection in 93% of all cases when intended. Overall complication rate was 16% (9/55) in the mononostril and 57% (4/7) in the binostril cohort. Seven patients in the mononostril cohort (13%) versus three patients in the binostril cohort (43%) complained of postoperative nasal congestion. This clinical report shows that many extended skull base lesions can be treated by a mononostril endonasal approach. In selected cases, this technique might represent an alternative to the binostril approach. Nevertheless, the binostril technique offers a better range of manipulation and exposure and should be preferred in difficult and very extended cases.

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.

Endoscopic Treatment of Intracranial Arachnoid Cysts: A Retrospective Analysis of a 25-Year Experience

BACKGROUND

Since the development of neuroendoscopy, pure endoscopic fenestration for intracranial arachnoid cysts (ACs) became more and more popular and is actually preferred by many neurosurgeons.

OBJECTIVE

To explore their techniques and experiences with endoscopic treatment of intracranial ACs over a 25-yr period.

METHODS

A total of 95 endoscopic procedures in 87 patients with 88 intracranial ACs performed at the authors’ departments between February 1993 and October 2018 were retrospectively analyzed. Particular respect was given to surgical technique, complications, patients’ outcome, and radiological benefit in relation to cyst location.

RESULTS

Patients’ ages ranged from 23 d to 81 yr (mean: 29.9 yr). Cysts were located temporobasal (n = 31; 35.2%), paraxial supratentorial (n = 14; 15.9%), suprasellar/prepontine (n = 14; 15.9%), quadrigeminal (n = 12; 13.6%), infratentorial (n = 11; 12.5%), and supratentorial intraventricular (n = 6; 6.8%). Four different endoscopic techniques were applied: cystocisternostomies (n = 48; 50.5%), ventriculocystostomies (n = 23; 24.2%), cystoventriculostomies (n = 14; 14.7%), and ventriculocystocisternostomies (n = 10; 10.5%). Pure endoscopic technique was feasible in 89 of the 95 surgeries (93.7%). Clinical improvement was documented after 82 surgeries (86.3%) and radiological benefit after 62 surgeries (65.3%). Recurrences developed in 8 cases (8.4%). Overall complication rate was 21.1% (n = 20), postoperative new shunt dependency was observed in 4.2% of the cases (n = 4).

CONCLUSION

Pure endoscopic AC fenestration is a safe, effective, and less invasive technique providing high success and low permanent complication rates. The most frequent temporobasal cysts are the most difficult to treat endoscopically. A long-term follow-up is recommended because recurrences may occur many years after first treatment.

The endoscopic surgical resection of intrasellar lesions conserves the hormonal function: a negative correlation to the microsurgical technique

BACKGROUND

The endonasal endoscopic approach is still currently under investigation for sellar tumor surgery: a higher resection rate is to be expected and complications should be minimized. The authors report their surgical results of endonasal endoscopic neurosurgery with special focus on postoperative hypopituitarism in comparison to microsurgical procedures.

METHODS

Sixty patients received endoscopic endonasal transsphenoidal procedures for sellar pathologies. All patients were followed up prospectively. A second group of 60 patients received microsurgical transsphenoidal procedures for sellar pathologies in our neurosurgical department before and were prospectively followed until now. Special attention was paid to hormonal insufficiency and medical substitution.

RESULTS

Sixty-eight percent (41 of 60) of the patients who underwent microsurgical procedures showed a new persisting pituitary insufficiency postoperatively. Twenty-three patients (55.5%) were substituted with thyroxine, hydrocortisone and sexual hormones and one patient (2.5%) also with ADH cause of global pituitary insufficiency. In 19 cases without any hormonal insufficiency after microsurgical procedures nine patients (47%) showed remnant tumor in follow-up MRI. The patients who underwent endoscopic procedures for pituitary adenomas revealed significant (P<0.01) less new persistent hormonal insufficiency with 13% of all cases (8/60). Five patients (62.5%) were substituted with thyroxine and hydrocortisone, two patients (25%) substituted with thyroxine, hydrocortisone and sexual hormones and one patient also with ADH because of global pituitary insufficiency. Thereby, in follow-up MRI and hormonal testing, radical tumor resection was detected in 92% in the endoscopic group.

CONCLUSIONS

This study seems to indicate that a better intraoperative identification and preservation of pituitary gland is possible in endoscopic transsphenoidal surgery with consecutive lower postoperative hypopituitarism rate.

Fluorescence imaging of meningioma cells with somatostatin receptor ligands: an in vitro study

BACKGROUND

The use of five-aminolevulinic acid (5-ALA) in the staining of malignant glioma cells has significantly improved intraoperative radicality in the resection of gliomas in the last decade. Currently, there is no comparable selective fluorescent substance available for meningiomas. There is however a demand for intraoperative fluorescent identification of, e.g., invasive skull base meningiomas to help improve safe radical resection. Meningiomas show high expression of the somatostatin receptor type 2, offering the possibility of receptor-targeted imaging. The authors used a somatostatin receptor-labeled fluorescence dye in the identification of meningiomas in vitro. The aim of this study was to evaluate the possibility of selective identification of meningioma cells with fluorescent techniques.

METHODS

Twenty-four primary human meningioma cell cultures were analyzed. The tumor cells were incubated with FAM-TOC (5,6-Carboxyfluoresceine-Tyr3-Octreotide). As a negative control, four human dura tissues were cultured as well as a mixed cell culture in vitro and incubated with the same somatostatin receptor-labeled fluorescence substance. After incubation, fluorescence signal and intensity in all cell cultures were analyzed at three different time points using a fluorescence microscope with 488 nm epi-illumination.

RESULTS

Sixteen WHO I, six WHO II, two WHO III meningioma primary cell cultures, and four dura cell cultures were analyzed. Fluorescence was detected in all meningioma cell cultures (22 cell culture stained strongly, 2 cell cultures moderately) directly after incubation up until 4 h later. There were no differences in the quality and quantity of fluorescence signal between the various meningioma grades. The fluorescence signal persisted unchanged during the analyzed period. In the negative control, dura cell cultures remained unstained.

CONCLUSIONS

This study demonstrates the use of FAM-TOC in the selective fluorescent identification of meningioma cells in vitro. Further evaluation of the chemical kinetics of the applied somatostatin receptor ligand and fluorescence dye is warranted. As a next step, an experimental animal model is needed to evaluate these promising results in vivo.