Endoscopic Eyebrow Approach for Aneurysms.

INTRODUCTION: Considerable effort has been made to reduce surgical invasiveness, since Axel Perneczky introduced the supraorbital eyebrow approach as a core part of his keyhole concept in neurosurgery. But a limited approach does not facilitate an already serious and demanding task as aneurysm surgery. In this regard, the enhancement of the visual field before, during, and after microsurgical aneurysm occlusion is a safe and effective method to increase the quality of treatment. Indications/Contraindications: Based on the individual anatomical findings, the supraorbital keyhole approach provides access to most aneurysms of the anterior circulation. The approach is not recommended in large complex aneurysms, giant aneurysms, BA aneurysms located beneath the dorsum sellae, as well as cases of severe subarachnoid hemorrhage (SAH) and expected brain edema. COMPLICATIONS: Experience with endoscopic procedures in aneurysm surgery is limited to several clinical retrospective articles, and no major complications in conjunction with the endoscope were observed. Outcome and Prognosis: The supraorbital eyebrow approach has a low rate of complications and provides highly favorable cosmetic results. Endoscopic inspection prior to clipping might reduce overexposure and mobilization of the aneurysm. It was found that the rate of intraoperative rupture was decreased. The endoscopic post-clipping control helped significantly to reduce aneurysm remnants and unattended parent, branch, or perforator occlusion. CONCLUSION: The supraorbital eyebrow approach is a safe, effective and elegant approach in the treatment of most aneurysms of the anterior circulation. The additional enhancement of the visual field provided by the endoscope before, during, and after microsurgical aneurysm clipping might decrease the rate of intraoperative aneurysm ruptures and unexpected findings concerning aneurysm remnant occlusion and compromise of involved parent, branching, and perforating vessels.

Endonasal endoscopic or endoscopic-assisted transcranial surgery of Rathke's cleft cysts: does the approach and surgical technique influence the radicality and recurrence rate?

OBJECTIVE: Resections of symptomatic Rathke's cleft cysts (RCCs) are mainly performed via an endonasal transsphenoidal approach. However, there is a lack of equivalent data in current literature concerning transcranial keyhole approach in the treatment of RCCs. In order to find general recommendations for the surgical treatment of RCCs also with regard to recurrence, the object of this study is the analysis and comparison of both techniques. METHODS: Twenty-nine patients having been surgically treated between January 2004 and August 2019 were retrospectively analysed. The transsphenoidal approach was chosen in 16 cases and the transcranial keyhole approach in 13 cases. Both surgical techniques were analyzed and compared concerning preoperative symptoms and cyst characteristics, complications, surgical radicality, endocrinological and ophthalmological outcome and recurrences in patients´ follow up. RESULTS: The postoperative outcome of both techniques was identic and showed highly satisfying success rates with 92% for neurological deficits, 82% for endocrinological dysfunctions and 86% for visual deficits. In contrast, momentous postoperative complications were significantly more likely after transsphenoidal operations. After a mean follow-up time of 5.7 years, the recurrence rates of both cohorts were the same with 0% each. CONCLUSIONS: Regarding its equal outcome with its lower complication rate, the authors suggest using the supraorbital keyhole approach for RCCs whose anatomical configuration allow both techniques. Yet, the decision should always consider the surgeon's personal experience and other individual patient characteristics. Further studies with higher numbers of cases and longer follow-up periods are necessary to analyse the effect of the selected approach on recurrence.

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.

COVID-19: a catalyst for the digitization of surgical teaching at a German University Hospital.

BACKGROUND: The summer semester 2020, had to be restructured due to the SARS-CoV-2 pandemic and the associated contact restrictions. Here, for the first time, the established lectures in lecture halls and small group seminars could not be conducted in presence as usual. A possible tool for the implementation of medical teaching, offers the use of eLearning, online webinars and learning platforms. At present it is unclear how the SARS-CoV-2 pandemic will affect surgical teaching, how digitization will be accepted by students, and how virtual teaching can be expanded in the future. METHODS: The teaching, which was previously delivered purely through face-to-face lectures, was completely converted to digital media. For this purpose, all lectures were recorded and were available to students on demand. The seminars were held as a twice a week occurring online webinar. The block internship was also conducted as a daily online webinar and concluded with an online exam at the end. At the end of the semester, a survey of the students was carried out, which was answered by n = 192 students with an anonymized questionnaire. The questionnaire inquires about the previous and current experience with eLearning, as well as the possibility of a further development towards a purely digital university. RESULTS: There were n = 192 students in the study population. For 88%, the conversion of classes to web-based lectures represented their first eLearning experience. For 77% of all students, the digitization of teaching led to a change in the way they prepare for class. 73% of the participating students are of the opinion that eLearning lectures should continue to be offered. 54% of the students felt that eLearning lectures made more sense than face-to-face lectures. A purely virtual university could be imagined by 41% of the students. CONCLUSION: The conversion of teaching represented the first contact with eLearning for most students. Overall, the eLearning offering was experienced as positive. Due to the new teaching structure, the way of learning had already changed during the semester. Based on the new eLearning content, the already existing formats can be further expanded in the future. Nevertheless, it turned out that the practical-surgical contents and skills cannot be adequately represented by purely online offers; for this, the development of hybrid practice-oriented teaching concepts is necessary.

Olfactory dysfunction in patients undergoing supraorbital keyhole craniotomy for clipping of unruptured aneurysms.

Olfactory performance has rarely been assessed in the perioperative phase of elective aneurysm surgery. Here, we assessed the risk for olfactory deterioration following surgical treatment of unruptured cerebral aneurysm via the supraorbital keyhole craniotomy. A retrospective review of patients with electively treated cerebral aneurysms who underwent perioperative assessment of olfactory function using a sniffin' sticks odor identification test between January 2015 and January 2016 was performed. A subgroup of patients without history of subarachnoid hemorrhage, without prior aneurysm treatment, and confirmed olfactory function underwent supraorbital keyhole craniotomy for aneurysm clipping. Microscopic and endoscopic videos were reviewed for this subgroup. Sixty-four patients who underwent elective aneurysm treatment either via surgical clipping or endovascular aneurysm obliteration were identified. Prior to treatment, 4/64 (6.3%) demonstrated bilateral anosmia. Collectively, 14 patients (21.9%) met subgroup criteria of supraorbital keyhole craniotomy for aneurysm clipping. Here, olfactory performance significantly decreased postoperatively on the side of craniotomy (ipsilateral, P = 0.007), whereas contralateral and bilateral olfactory function remained unaltered (P = 0.301 and P = 0.582, respectively). Consequently, 4/14 patients (28.6%) demonstrated ipsilateral anosmia 3 months after surgery. One patient (1/14, 7.1%) also experienced contralateral anosmia resulting in bilateral anosmia. Intraoperative visualization of the olfactory tract and surgical maneuvers do not facilitate prediction of olfactory outcome. The supraorbital keyhole craniotomy harbors a specific risk for unilateral olfactory deterioration. Lack of perioperative olfactory assessment likely results in underestimation of the risk for olfactory decline. Despite uneventful surgery, prediction of postoperative olfactory function and dysfunction remain challenging. Clin. Anat. 33:316-323, 2020. © 2019 Wiley Periodicals, Inc.

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.

Endoscopic-Assisted Microsurgical Meningioma Resection in the Skull Base via Minicraniotomy: Is There a Difference in Radicality and Outcome between Anterior Skull Base and Posterior Fossa?

Background: Keyhole-based approaches are being explored for skull base tumor surgery; aiming for reduced complications while maintaining resection success rates. This study evaluates skull base meningiomas resected using an endoscopic-assisted microsurgical keyhole approach, comparing outcomes with standard procedures. Methods: Between 2013 and 2019; 71 out of 89 patients were treated using an endoscopic-assisted microsurgical procedure. A total of 42 meningiomas were localized at the anterior skull base and 29 in the posterior fossa. The surgical techniques and use of an endoscope were analyzed and compared in terms of complications, surgical radicality, outcome, and recurrences in the patients' follow-up. Results: The two different cohorts yielded similar rates of GTR (anterior skull base: 80% versus posterior fossa: 82%). The complication rate was 31% for the posterior fossa and 16% for the anterior skull base. An endoscope was used in 79% of all cases. Tumor remnants were detected by means of endoscopic visualization in 58.6% of posterior fossa and 33% of anterior skull base meningiomas. The statistical analysis revealed significantly higher benefits from endoscope use in the posterior fossa cohort (p < 0.05). Conclusions: The results revealed that endoscopy was beneficial in both locations. The identification of remnant tumor tissue and the benefit of endoscopy were clearly higher in the posterior fossa. Endoscopic assistance is a very helpful tool for increasing radicality, providing a better anatomical overview during surgery, and better identifying remnant tumor tissue in skull base meningioma surgery.

Single-step resection and reconstruction of orbito-fronto-temporal pathologies using a PMMA CAD-implant.

BACKGROUND: Resection of bone infiltrating meningiomas of the sphenoid plane and the orbital walls is a highly challenging neurosurgical procedure. In this study, the authors present 11 cases of fronto-orbital and sphenoid wing meningioma which were subjected to tumor resection and cranioplasty using a pre-designed CAD PMMA-implant in one single staged procedure. METHODS: Eleven cases were prospectively analyzed from January 2011 to December 2018. In all cases preoperative CT scans were performed and evaluated, in order to produce a customized PMMA-implant, fitting the osseous defect left after surgical resection of the predefined tumorous mass. Surgery was performed with standard techniques with the addition of availability of preplanned neuronavigational data as well as a matching template of the implant for intraoperative use. After tumor resection, cranioplasty followed using the predesigned PMMA implant. RESULTS: Gross total resection was achieved in 82% (9 of 11 cases). Mean time of surgery for the combined procedure resulted in 223min±99min, with a mean blood loss of 427±192cc. Mean hospital stay for the combined procedure resulted in 11.5±3 days. In 18% of the cases (2/11), patients suffered from late onset infection of the implant and needed a surgical removal. CONCLUSIONS: The presented data show that gross total resection and subsequent single staged bone reconstruction in osseous sphenoid wing and orbital rim meningiomas can be achieved using predesigned PMMA CAD implants with preplanned tumor resection borders with neuronavigational guidance.

Development and Evaluation of an MRI Artifact-Free Aneurysm Clip.

BACKGROUND AND OBJECTIVES: The digital subtraction angiography is still the gold standard in the follow-up after aneurysm surgery, although it remains a repeating invasive technique with accumulating X-ray exposure. An alternative magnetic resonance angiography has the disadvantage of metal-related artifacts. A metal-free aneurysm clip could overcome this problem. Recent advances in manufacturing technologies of fiber-reinforced plastics might allow developing a prototype of a metal-free clip. METHODS: The prototype was formed out of carbon fiber-reinforced polyetheretherketone (CF-PEEK) in accordance with the standard clip design. In vivo and in vitro studies were performed to analyze the central nervous system biocompatibility. The prototype was tested in a phantom in a 3 T MRI scanner and microtomography scanner. For in vivo assessment, the left renal artery of rats was either ligated with a suture, clipped with a regular titanium clip or with the CF-PEEK prototype clip. The animals underwent standard MRI sequences and magnetic resonance angiography and assessment by a blinded neuroradiologist. RESULTS: Phantom studies showed no signs of artifacts. The prototype showed a reliable clamping and reopening after clip application, although the clamping force was reduced. In vivo studies showed a successful occlusion of the renal artery in all cases in the magnetic resonance angiography. Clip artifacts were statistically significant reduced in the prototype group (P < .01). CF-PEEK showed no signs of impaired biocompatibility compared with the titanium samples in vitro and in vivo. CONCLUSION: Former attempts of metal-free aneurysm clips did not meet the criteria of the standard clip design. In this study, the practicability of this new CF-PEEK artifact-free aneurysm clip has been proven. The further fabrication developments should overcome the problem of a reduced clamping force in the future. After clinical approval, it will improve the magnetic resonance image quality and might help to reduce the amount of digital subtraction angiography in the follow-up.

Near-infrared indocyanine green videoangiography versus microvascular Doppler sonography in aneurysm surgery.

INTRODUCTION: The quality of surgical treatment of intracranial aneurysms is determined by complete aneurysm occlusion and restoration of flow in the parent, branching and perforating vessels. In postoperative digital subtraction angiography (DSA), unexpected aneurysm residuals and vessel occlusions are frequently detected. Here, the value of two nearly noninvasive and cost-effective techniques for intraoperative flow evaluation (near-infrared indocyanine green video angiography (ICG-VA) and microvascular Doppler sonography (mDs)) is investigated in a prospective study. PATIENTS AND METHODS: Over a period of 10 months, the authors surgically clipped 50 aneurysms under intraoperative pre- and post-clipping evaluation of flow in the parent, branching and perforating vessels and the aneurysm sack by the two techniques. Intraoperative applicability of each technique was compared to each other and to postoperative digital subtraction angiography as standard evaluation technique. RESULTS: Forty-five aneurysms were totally occluded without vessel compromise (90%). Intraoperatively, ICG-VA was considered useful in 43 cases (86%) and mDs in 44 cases (88%), respectively. Both techniques could compensate each other's weak points to a certain degree; but two branch occlusions (4%) and three neck remnants (6%) were revealed by postoperative DSA. CONCLUSION: Both techniques have specific drawbacks that could be compensated by each other, to a certain extent. Intraoperatively, ICG-VA and mDs should not be considered competitive, but complementary. This study implicates that the combination of both applications on a routine basis assures the quality of aneurysm surgery by nearly noninvasive and cost-effective techniques. However, DSA remains the gold standard for evaluation of aneurysm occlusion.

Novel Software-Derived Workflow in Extracranial-Intracranial Bypass Surgery Validated by Transdural Indocyanine Green Videoangiography.

BACKGROUND: The introduction of image-guided methods to bypass surgery has resulted in optimized preoperative identification of the recipients and excellent patency rates. However, the recently presented methods have also been resource-consuming. In the present study, we have reported a cost-efficient planning workflow for extracranial-intracranial (EC-IC) revascularization combined with transdural indocyanine green videoangiography (tICG-VA). METHODS: We performed a retrospective review at a single tertiary referral center from 2011 to 2018. A novel software-derived workflow was applied for 25 of 92 bypass procedures during the study period. The precision and accuracy were assessed using tICG-VA identification of the cortical recipients and a comparison of the virtual and actual data. The data from a control group of 25 traditionally planned procedures were also matched. RESULTS: The intraoperative transfer time of the calculated coordinates averaged 0.8 minute (range, 0.4-1.9 minutes). The definitive recipients matched the targeted branches in 80%, and a neighboring branch was used in 16%. Our workflow led to a significant craniotomy size reduction in the study group compared with that in the control group (P = 0.005). tICG-VA was successfully applied in 19 cases. An average of 2 potential recipient arteries were identified transdurally, resulting in tailored durotomy and 3 craniotomy adjustments. Follow-up patency results were available for 49 bypass surgeries, comprising 54 grafts. The overall patency rate was 91% at a median follow-up period of 26 months. No significant difference was found in the patency rate between the study and control groups (P = 0.317). CONCLUSIONS: Our clinical results have validated the presented planning and surgical workflow and support the routine implementation of tICG-VA for recipient identification before durotomy.

Minimally invasive superficial temporal artery to middle cerebral artery bypass through a minicraniotomy: benefit of three-dimensional virtual reality planning using magnetic resonance angiography.

OBJECT: The aim of the authors in this study was to introduce a minimally invasive superficial temporal artery to middle cerebral artery (STA-MCA) bypass surgery by the preselection of appropriate donor and recipient branches in a 3D virtual reality setting based on 3-T MR angiography data. METHODS: An STA-MCA anastomosis was performed in each of 5 patients. Before surgery, 3-T MR imaging was performed with 3D magnetization-prepared rapid acquisition gradient echo sequences, and a high-resolution CT 3D dataset was obtained. Image fusion and the construction of a 3D virtual reality model of each patient were completed. RESULTS: In the 3D virtual reality setting, the skin surface, skull surface, and extra- and intracranial arteries as well as the cortical brain surface could be displayed in detail. The surgical approach was successfully visualized in virtual reality. The anatomical relationship of structures of interest could be evaluated based on different values of translucency in all cases. The closest point of the appropriate donor branch of the STA and the most suitable recipient M(3) or M(4) segment could be calculated with high accuracy preoperatively and determined as the center point of the following minicraniotomy. Localization of the craniotomy and the skin incision on top of the STA branch was calculated with the system, and these data were transferred onto the patient's skin before surgery. In all cases the preselected arteries could be found intraoperatively in exact agreement with the preoperative planning data. Successful extracranial-intracranial bypass surgery was achieved without stereotactic neuronavigation via a preselected minimally invasive approach in all cases. Subsequent enlargement of the craniotomy was not necessary. Perioperative complications were not observed. All bypasses remained patent on follow-up. CONCLUSIONS: With the application of a 3D virtual reality planning system, the extent of skin incision and tissue trauma as well as the size of the bone flap was minimal. The closest point of the appropriate donor branch of the STA and the most suitable recipient M(3) or M(4) segment could be preoperatively determined with high accuracy so that the STA-MCA bypass could be safely and effectively performed through an optimally located minicraniotomy with a mean diameter of 22 mm without the need for stereotactic guidance.

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.

Endoscope- versus microscope-integrated near-infrared indocyanine green videoangiography in aneurysm surgery.

OBJECTIVE: The quality of surgical treatment of intracranial aneurysms is determined by complete aneurysm occlusion while preserving blood flow in the parent, branching, and perforating arteries. For a few years, there has been a nearly noninvasive and cost-effective technique for intraoperative flow evaluation: microscope-integrated indocyanine green videoangiography (mICG-VA). This method allows for real-time information about blood flow in the aneurysm and the involved vessels, but its limitations are seen in the evaluation of structures located in the depth of the surgical field, especially through small craniotomies. To compensate for these drawbacks, an endoscope-integrated ICG-VA (eICG-VA) was developed. The objective of the present study was to assess the use of eICG-VA in comparison with mICG-VA for intraoperative blood flow evaluation. METHODS: In the period between January 2011 and January 2015, 216 patients with a total of 248 intracranial saccular aneurysms were surgically treated in the Department of Neurosurgery of Saarland University Medical Center in Homburg/Saar, Germany. During 95 surgeries in 88 patients with a total of 108 aneurysms, intraoperative evaluation was performed with both eICG-VA and mICG-VA. After clipping, evaluation of complete aneurysm occlusion and flow in the parent, branching, and perforating arteries was performed using both methods. Intraoperative applicability of each technique was compared with the other and with postoperative digital subtraction angiography as a standard evaluation technique. RESULTS: Evaluation of completeness of aneurysm occlusion and of flow in the parent, branching, and perforating arteries was more successful with eICG-VA than with mICG-VA, especially for aneurysm neck assessment (88.9% vs 69.4%). For 63.9% of the aneurysms (n = 69), both methods were equivalent, but in 30.6% of the cases (n = 33), the eICG-VA provided better results for evaluating the post-clipping situation. In 4.6% of these aneurysms (n = 5), the information given by the additional endoscope considerably changed the surgical procedure. Thus, one residual aneurysm (0.9%), two neck remnants (1.9%), and two branch occlusions (1.9%) could be prevented. Nevertheless, two incomplete aneurysm occlusions (1.9%) and six neck remnants (5.6%) were revealed by postoperative digital subtraction angiography. CONCLUSIONS: Endoscope-integrated ICG-VA seems to be an improvement that might increase the quality of aneurysm surgery by providing additional information. It offers higher illumination, magnification, and an extended viewing angle. Its main advantage is its ability to assess deep-seated aneurysms, especially through small craniotomies, but further studies are required.

Impact of large volume paracentesis on respiratory parameters including transpulmonary pressure and on transpulmonary thermodilution derived hemodynamics: A prospective study.

INTRODUCTION: Appropriate mechanical ventilation and prevention of alveolar collaps is mainly dependent on transpulmonary pressure TPP. TPP is assessed by measurement of esophageal pressure EP, largely influenced by pleural and intraabdominal pressure IAP. Consecutively, TPP-guided ventilation might be particularly useful in patients with high IAP. This study investigates the impact of large volume paracentesis LVP on TPP, EP, IAP as well as on hemodynamic and respiratory function in patients with liver cirrhosis and tense ascites. MATERIAL AND METHODS: We analysed 23 LVP-procedures in 11 cirrhotic patients ventilated with the AVEA Viasys respirator (CareFusion, USA) which is capable to measure EP via an esophageal tube. RESULTS: LVP of a mean volume of 4826±1276 mL of ascites resulted in marked increases in inspiratory (17.9±8.9 vs. 5.4±13.3 cmH2O; p<0.001) as well as expiratory TPP (-3.0±4.7 vs. -15.9±10.9 cmH2O; p<0.001; primary endpoint). In parallel, the inspiratory (2.4±8.7 vs. 14.1±14.5 cmH2O; p<0.001) and expiratory EP (12.4±6.0 vs. 24.9±11.3 cmH2O; p<0.001) significantly decreased. The effects were most pronounced for the release of the first 500 mL of ascites. LVP evoked substantial decreases in IAP and central venous pressure CVP. By contrast, mean arterial pressure, cardiac index, global end-diastolic volume index, extravascular lung water index and systemic vascular resistance index did not change. Among the respiratory parameters we observed an increase in paO2/FiO2 (247.7±60.9 vs. 208.3±46.8 mmHg; p<0.001) and a decrease in Oxygenation Index OI (4.8±2.0 vs. 5.8±3.1 cmH2O/mmHg; p = 0.002). Tidal volume (510±100 vs. 452±113 mL; p = 0.008) and dynamic respiratory system compliance Cdyn (46.8±15.9 vs. 35.1±14.6 mL/cmH20; p<0.001) increased, whereas paCO2 (47.3±10.7 vs. 51.2±12.3mmHg; p = 0.046) and the respiratory rate decreased (17.1±7.3 vs. 19.6±7.8 min-1; p = 0.010). CONCLUSIONS: In mechanically ventilated patients with decompensated cirrhosis, intraabdominal hypertension resulted in a substantially decreased TPP despite PEEP-setting according to the ARDSNet. In these patients LVP markedly increased TPP and improved respiratory function in parallel with a decline of EP. Furthermore, LVP induced a decrease in IAP and CVP, while other hemodynamic parameters did not change.

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.

Superficial Temporal Artery to Middle Cerebral Artery Bypass via a Minimized Approach: Operative Nuances and Problem-Solving Aspects.

BACKGROUND: The minimized approach for superficial temporal to middle cerebral artery (STA-MCA) bypass surgery is frequently associated with unfamiliar situations and technical problems. OBJECTIVE: Description of operative nuances and evaluation of problem-solving aspects to facilitate potential limitations related with a limited exposure approach. METHODS: In patients who underwent STA-MCA bypass surgery between February 2012 and August 2014, a preoperative high-resolution computed tomography-angiography 3-dimensional dataset was obtained to select the optimal vessels for anastomosis. Intraoperative exposure was assessed under standard neuronavigation. Anastomoses were performed with specific instruments developed by the authors. Intraoperative video documentation and follow-up records were analyzed retrospectively. RESULTS: Seventeen STA-MCA minimally invasive bypass procedures were performed on 12 patients. In all cases, the procedure could be performed through planned craniotomy (mean diameter 2.5 cm). All cases of the procedures dealt with the limitation of surgical field during bypass surgery. The described applications facilitated microsurgical handling in the environment of a limited exposure in all procedures. Follow-up showed all bypasses remained open. CONCLUSIONS: The surgical applications, operative techniques, problem-solving aspects, and development of new instruments are described. Potentially, these suggestions may enhance the surgical confidence and convenience to perform STA-MCA bypass surgery with a minimized approach.

The antileukoprotease secretory leukocyte protease inhibitor (SLPI) and its role in the prevention of HPV-infections in head and neck squamous cell carcinoma.

Recently, we demonstrated a significant inverse correlation between HPV-infection and SLPI-expression suggesting that SLPI protects against HPV-infection of HNSCC. Here we analyzed in a single lab setting 307 formalin-fixed paraffin-embedded HNSCC cases (tonsillar n = 135; non-tonsillar: n = 172) from eight health care centers. Samples were analyzed for SLPI gene- and protein-expression. Annexin A2, its heterotetramer A2t, putatively facilitating HPV- and SLPI-cell entry, was measured to study the correlation between SLPI and annexin A2. Data were correlated with tobacco consumption and HPV-status. Overall, HPV-DNA prevalence was 23.5% (72/307); attributed to: 43.7% (59/135) tonsillar and 7.6% (13/172) non-tonsillar cases. Smoking resulted in 6.44-fold increased and HPV-infection in 3.46-fold decreased SLPI-gene expression in all HNSCC with similar significant results obtained in tonsillar and non-tonsillar SCC separately. Correlating annexin A2- and SLPI-gene expression showed a significant surplus of annexin A2 in HPV-positive tumors (4.21× more annexin A2) and 6.72× more annexin A2 than SLPI in nonsmokers in all HNSCCs and similar significant results for both tumor entities separately. The surplus of annexin A2 in non-smokers and HPV-positive patients supports our hypothesis that decreased SLPI levels facilitate HPV-infection i.e., increased SLPI-expression may protect against HPV-infection of tonsillar and non-tonsillar SCC.

The supraorbital endoscopic approach for aneurysms.

OBJECTIVE: To review our surgical experience in minimally invasive transcranial endoscope-assisted microsurgical treatment of intracranial aneurysms, using the supraorbital keyhole craniotomy. METHODS: The supraorbital keyhole approach was performed through an eyebrow skin incision in 793 cases for treatment of 989 intracranial aneurysms. Of patients, 474 were operated on after subarachnoid hemorrhage, and 319 were operated on under elective conditions. After lateral frontobasal burr hole trephination, a limited subfrontal craniotomy was created. To achieve adequate intraoperative exposure through the limited approach, endoscopes were used routinely. Surgical outcome was assessed using the modified Rankin scale. RESULTS: The transcranial endoscope-assisted microneurosurgery technique was used routinely via a supraorbital approach. In 152 operations (19.1%), the endoscope provided important visual information in the vicinity of the aneurysm, revealing subsequent clip repositioning. The results of incidental aneurysms were excellent with a modified Rankin scale score ≤2 in 96.52%. The overall outcome of ruptured aneurysms was good with a modified Rankin scale score ≤2 in 72.2% of patients. There were no approach-related intraoperative or postoperative complications. CONCLUSIONS: The minimally invasive supraorbital keyhole approach allowed safe surgical treatment of intracranial aneurysms, including after subarachnoid hemorrhage. The markedly improved endoscopic visualization increased the assessment of clip placement with ideal control of surrounding vessels including perforators for identification of incorrect clip position.

Brainstem raphe alterations depicted by transcranial sonography do not result in serotonergic functional impairment.

In transcranial sonography (TCS), hypoechogenic signal of mesencephalic raphe structures has been described as a frequent finding in unipolar depression. It remains unclear if raphe hypoechogenicity represents a correlate for an altered serotonergic system. The loudness dependence of auditory evoked potentials (LDAEP) has been proposed as an indirect indicator of central serotonergic activity. Aim of this study was to evaluate TCS and LDAEP as independent variables of the human cerebral serotonergic system. Sonographic and electrophysiological investigations as well as psychometric assessment were performed blindly in 44 healthy subjects (28.7 ± 7.0 years; 24 females). Hypoechogenic raphe was detected in 6 subjects (13.6%). Three probands (6.8%) exhibit hyperechogenicity of Substantia nigra. LDAEP values ranged between -2.80 and 8.40 mVeff/10dB (2.31 ± 2.44). No correlations between LDAEP and sonographic findings were found. There were no significant correlations with the psychometric assessments. At least in healthy subjects, our findings do not support the hypothesis that abnormal structural finding of hypoechogenic BR in TCS is accompanied by a functional impairment of serotonergic system as assessed by LDAEP. Further multimodal studies on patients with depressive disorders are needed to elucidate the impact of the hypoechogenic raphe signal in the pathophysiology of depression.