Multimodal Use of Contact Endoscopy in Neurosurgery: Case Series with Technical Note and Literature Review.

BACKGROUND: Originally adopted for the cytological screening of cervical and uterine cancer, contact endoscopy (CE) is now widely used in several fields of oncological surgery. The CE method, with magnification power up to 150x, was designed to enhance visualization and identify microscopic changes indicative of precancerous and cancerous lesions at early stages. In this pilot study, we evaluated the multimodal applications of CE during different endoscopic intracranial neurosurgical procedures. METHODS: Twenty patients with skull base lesions underwent surgery using different minimally invasive endoscopic approaches (endonasal, transorbital, and supraorbital). CE was used to distinguish the pathology from the surrounding healthy tissue by positioning the endoscope either in proximity or directly onto the target tissue. Special attention was given to the visualization of the margins of the lesion to differentiate compression/displacement from infiltration of the normal surrounding tissue. RESULTS: With its unprecedented range of magnification, CE could clearly identify the microvascular pattern and cytological architecture of a tissue not detectable by simple white light endoscopy, with no reported damage due to heat transmission or iatrogenic injuries. All the lesions diagnosed as "presumed neoplastic tissue" by CE were confirmed by histopathology. The most promising results were observed in surgeries for meningioma and pituitary adenoma, as these lesions exhibit distinctive microvascular networks. CONCLUSIONS: CE represents a new and effective technique for the in vivo identification of pathological microvascular and tissue features, allowing preservation of normal tissue during different endoscopic approaches. The use of CE could improve diagnostic accuracy and assist in intraoperative decision-making, becoming a key tool in various applications in neurosurgical field.

Primary Anaplastic-Lymphoma-Kinase-Positive Large-Cell Lymphoma of the Central Nervous System: Comprehensive Review of the Literature.

BACKGROUND: Primary anaplastic-lymphoma-kinase (ALK)-positive large-cell lymphoma of the central nervous system (PCNS ALK-positive ALCL) is a rare entity, with a limited consensus reached regarding its management. While this pathology often presents as solitary lesions, the occurrence of multiple tumors within the brain is not uncommon. The lack of distinctive radiological features poses a diagnostic challenge, leading to delays in initiating targeted therapy. METHODS: We conducted a comprehensive literature search, identifying seventeen publications for qualitative analysis. RESULTS: The management options and reported patient outcomes in the literature varied significantly, emphasizing the need for a patient-specific approach. The emergence of ALK-specific inhibitors represents a new frontier in this field, demonstrating promising results. CONCLUSION: PCNS ALK-positive ALCL necessitates a comprehensive understanding and optimized management strategies. A tailored therapeutic approach, integrating surgical intervention with radiotherapy and chemotherapy, appears pivotal in addressing this pathology. The implementation of a therapeutic protocol is anticipated for further advancement in this field.

Enhance Safety in Aneurysm Surgery: Strategies for Prevention of Intraoperative Vascular Complications.

Complications during surgery for intracranial aneurysms can be devastating. Notorious pitfalls include premature rupture, parent vessel occlusion, local cerebral injury and brain contusion, and incomplete neck obliteration. These unfavorable intraoperative events can result in major neurological deficits with permanent morbidity and even mortality. Herein, the author highlights the relevant surgical strategies used in his daily practice of aneurysm surgery (e.g., aneurysm clipping with adenosine-induced temporary cardiac arrest), application of which may help prevent vascular complications and enhance surgical safety through reduction of the associated risks, thus allowing improvement of postoperative outcomes. Overall, all described methods and techniques should be considered as small pieces in the complex puzzle of prevention of vascular complications during aneurysm surgery.

Concomitant, Single Burr Hole Endoscopic Third Ventriculostomy and Tumor Biopsy for Pineal Lesions: Feasibility, Safety, and Benefits.

Obtaining a prompt diagnosis, avoiding indwelling ventriculoperitoneal shunt, and enhancing the predictive value of pathologic examinations are only some of the advantages conferred by a simultaneous third ventriculostomy and tumor biopsy in patients with pineal region tumors. The objective of this study was to retrospectively search the literature on concomitant, single burr hole endoscopic third ventriculostomy (ETV) and tumor biopsy (TB) for pineal region tumors and to analyze the feasibility, surgical safety, and benefits of these 2 combined procedures. Consequently, a comprehensive, systematic literature search was performed in compliance with the updated PRISMA 2020 guidelines within electronic databases MEDLINE/PubMed, EMBASE, PLOS, and Cochrane Library. Statistical analysis was performed with IBM SPSS 28.0.1.1(14), using Kendall's and Spearman's tests, with a P < 0.05 considered significant. A total of 25 studies were selected and included in this review, for a total of 368 patients (mean age 20.6 years; range 1-86 years; SD 17.5). More than two-thirds of the procedures were operated with a rigid endoscope and 27.6% were performed with either a flexible endoscope, a combination of the 2, or not otherwise specified. Germinoma represented the most frequent diagnosis (20.1%) followed by astrocytoma (12.9%) and pineocytoma (9.9%). The single-entry approach allowed a correct histologic diagnosis in 88.7% of the examined cases. Summing up, concomitant ETV and TB represent a valuable option for the management of non-communicating hydrocephalus and the initial assessment of pineal region tumors. The histologic confirmation rate was 88.7% in the examined cohort, with only 10% of the biopsies yielding inconclusive results.

Surgical planning, manufacturing and implantation of an individualized cervical fusion titanium cage using patient-specific data.

BACKGROUND: Most cervical fusion cages imperfectly mimic the anatomy of the intervertebral disc space. The production of individualized cages might be the next step to further improve spinal implants due to their enhanced load-bearing surface. OBJECTIVE: To evaluate the planning, manufacturing, and implantation of an individualized cervical cage in co-operation with EIT and 3D Systems. METHODS: A digital 3D model of the patient's cervical spine was rendered from the patients CT data. It was then possible to correct degenerative deformities by digitally repositioning the vertebrae and virtually resecting the osteophytes. The implantation of the cage can be simulated to check the accuracy of the fit. The cage is made of trabecular titanium and manufactured by Direct Metal Printing. RESULTS: The pilot project for the implantation of the first individualized cervical cage ever, resulted in a highly accurate fit. During surgery, the cage self-located into the correct position after suspending distraction due to the implants unique end plate design. Furthermore, it was impossible to move the cage in any direction with the inserting instrument after suspending distraction for the same reason. Thus, it can be assumed that an individualized cervical implant provides excellent primary stability. CONCLUSION: Preconditions for the manufacturing of individualized cervical fusion cages using specific patient data are given. The implantation is uncomplicated. The improved load-bearing surface will lower the rate of implant dislocation and subsidence. The production of individualized cages at a reasonable price has to be evaluated by spine surgeons and the industry.

How Relevant Is Occlusion of Associated Developmental Venous Anomaly in Cerebral Cavernoma Surgery? A Clinical and Radiographic Comparison Study.

BACKGROUND: A developmental venous anomaly (DVA) associated with cerebral cavernous malformation (CCM) is the most common combined vascular malformation. Microsurgical resection of the CCM and avoidance of damage to the adjacent DVA is an overall accepted treatment regimen. Several publications have demonstrated serious consequences that possibly occur after damage of the associated DVA. Conversely, some authors have reported cases of injured DVAs without any relevant postoperative complications. This study compared the clinical and radiologic outcome in patients with and without occlusion of an associated DVA, following microsurgical removal of intracerebral cavernomas. METHODS: In this single-center evaluation, all consecutive CCM surgical patients from January 1, 2006, to December 31, 2011, were reviewed in a retrospective cohort study. Follow-up was from 12 months to 7 years. The patients were divided into three groups: group I, CCM without associated DVA; group II, damage and occlusion of the associated DVA during CCM removal; and group III, preservation of the associated DVA following CCM removal. Preservation and damage, respectively, of the DVA were defined by evaluation of the corresponding pre- and postoperative magnetic resonance (MR) image sequences. The clinical and radiographic findings in all three groups were evaluated and compared. RESULTS: A total of 38 patients underwent microsurgical resection of a CCM. Overall, 24 patients (63%) had no associated DVA (group I), in 10 patients (26%) the associated DVA was impaired and occluded (group II), and in 4 patients (11%) the associated DVA was surgically not impaired and confirmed as preserved (group III). The rate of postoperative neurologic deficits was 37.5% in group I, 10% in group II, and 75% in group III (p = 0.05). Subgroup analysis in patients with preserved DVA (group III) showed a higher incidence of new postoperative neurologic deficits than in patients with impaired DVA (group II) (p = 0.041). However, no significant difference was seen in patients with no associated DVA (group I) and patients with impaired DVA (group II) (p =0.215). The average postoperative Karnofsky score was 88.33 ± 9.17 in group I, 92.0 ± 6.32 in group II,; and 90.0 ± 8.16 in group III (p =0.51). The peri-resectional edema volume in group I was 8.90 ± 9.75 cm(3); in group II, 8.16 ± 3.78 cm(3); and in group III, 2.48 ± 1.48 cm(3) (p = 0.35). The location (eloquent or noneloquent region) of the CCM and the DVA, respectively, was the only significant factor for any additional neurologic deficit (p = 0.001). CONCLUSION: Our results demonstrated similar postoperative clinical outcomes and radiographic findings between patients with impaired and unimpaired DVA after resection of CCMs. Postoperative MR images showed less peri-resectional edema in patients with preserved and unimpaired DVA. However, these results will not convert the paradigm in cavernoma surgery to preserve the associated DVA. The overall goal is still preservation of unimpaired venous drainage, but our results show that the occlusion of a DVA adjacent to a CCM can be tolerated because of a low risk of complications.

Surgical Treatment of Inadvertent Internal Carotid Artery Lesion by Extraintracranial High-flow Bypass. A Case Report and Review of the Literature.

Internal carotid artery (ICA) injury following transsphenoidal surgery is a rare but potentially fatal complication. Usually, endovascular occlusion of the ICA or stent graft placement is the treatment of these vascular complications described in literature. We present a case of ICA perforation during transsphenoidal surgery in a patient with limited collateral cerebral blood flow and with ectasia of the ICA that rule out an endovascular treatment. We report the surgical revascularization via high-flow extra-intracranial radial artery bypass and consicutive artery ligation.

Clipping of a partially thrombosed giant VA aneurysm.

Microsurgical aspects of clipping of a giant partially thrombosed VA aneurysm in a 57-year-old female are presented and explained in the form of a short video. The presentation includes preparation of the VA, PICA and perforating arteries, the clipping of the aneurysm itself as well as the reduction of the aneurysm mass using ultrasonic tissue ablation. In addition pre- and post-operative imaging and superimposed text is used to illustrate the presented anatomy. The video can be found here: http://youtu.be/7so8qPMQ1Jk .

Reconstruction of the anterior skull base after major trauma or extensive tumour resection.

BACKGROUND: The authors describe their experience with the reconstruction of complex anterior skull base defects after trauma or tumour resection using a "sandwich" technique with pericranial flap, titanium mesh and TachoSil. METHODS: Description of surgical anatomy, surgical technique, indications, limitations, complications, specific perioperative considerations and specific information to give to the patient about surgery and potential risks. A summary of ten key points is given. CONCLUSIONS: After a bifrontal craniotomy and a subfrontal approach, it is possible to achieve a reliable reconstruction of the anterior skull base in a watertight manner by fixing a pericranial flap or a fascia lata graft to the orbital roofs and planum sphenoidale with an individually tailored titanium mesh and closing the frontobasal dura leasion with TachoSil.

Experience with a modular PEEK system for cervical vertebral body replacement.

STUDY DESIGN: A retrospective case series. SUMMARY OF BACKGROUND DATA: The authors present their experience with the ATHLET vertebral body replacement (VBR) system in combination with the TOSCA plating system for the treatment of cervical spondylotic myelopathy. METHODS: Data obtained from 20 cases were reviewed. Corpectomy and VBR with the ATHLET system was performed in all cases. Patients underwent preoperative and postoperative assessment involving the Japanese Orthopedic Association score, Odom criteria, and radiographic studies to determine the position of the implant as well as cervical lordosis. The mean follow-up period was 20 months (16-28 mo). RESULTS: Implantation of the ATHLET VBR itself was uncomplicated in all cases. The adjustment of the implants' height could be done in 2 mm steps. With increasing height of the implant, the angle of lordosis increases comparable with physiological conditions. The authors performed 13 one-level and 7 two-level corpectomies; from the latter group there were 2 revision cases (10%) with implant dislocation. Four cases (20%) of secondary subsidence of the implant were observed radiographs 12 months postoperatively; in all cases treatment remained conservative. Ten patients (50%) had excellent, 4 (30%) good, 2 (10%) satisfactory, and 2 (10%) poor outcome according to Odom criteria. The average improvement of the Japanese Orthopedic Association score was 1.6. All cases achieved osseous fusion without complications, 55% of them had an improvement, and 15% of them had no change of the sagittal contour. CONCLUSIONS: The ATHLET VBR is easy to implant and avoids bone graft site morbidity. Due to a relatively high rate of secondary subsidence of the implant (20%) and secondary dislocation (10%) in combination to a poor to satisfactory outcome according to Odom criteria in 20%, the authors do not recommend the use of this PEEK implant for cervical VBR.

Management of complex cervical instability.

PURPOSE: Illustrative cases are presented to demonstrate the surgical management of complex instability of the cervical spine. METHODS: Six patients with different underlying pathologies are presented along with their clinical and radiologic findings, surgical procedures, complications, and outcomes. RESULTS: Five patients underwent anteroposterior (AP) decompression and stabilization, of which two required secondary posterior stabilization because of dislocation or subsidence of the anterior osteosynthesis. In another case, a patient with a two-level corpectomy, a stable situation was achieved with an anterior approach only. The outcomes, measured according to Odom's criteria, were excellent in one patient, good in three patients, and fair in two patients. CONCLUSIONS: In cases of complex cervical instability, combined AP decompression and stabilization minimizes the risk of anterior plate failure or dislocation of the vertebral body prosthesis. However, there may be increased risk of adjacent-level degeneration. Therefore, a combined procedure should be considered in selected patients. Not all patients with cervical instability require circumferential surgery. In two-level corpectomy cases, the decision between the less invasive anterior-only approach and the more stable combined approach can be difficult. However, in patients with proof of poor bone quality or with metabolic disorders, a more stable combined approach should be considered.

Hybrid Solutions for the Surgical Treatment of Multilevel Degenerative Cervical Disk Disease.

Background In different stages of cervical degenerative disk disease, the combination of dynamic and nondynamic implants may be considered. The aim of this study was to investigate the applicability of criteria to assist decision making in these cases. Methods Thirty patients with spondylotic cervical radiculopathy and a coincidence of soft disk and hard disk herniation were surgically treated with a hybrid solution (combination of total disk replacement and cage fusion). The control group included 32 patients who underwent two-level cage fusion. Pre- and postoperative Japanese Orthopaedic Association (JOA) scores and range of motion (ROM) were compared. Results Twenty-three patients underwent two-level hybrid solution and 7 underwent three-level treatment. The most frequent solution (n = 13) was a combination of a dynamic implant at C5-C6 and a nondynamic implant at C6-C7. The mean JOA score improved from 13.9 to 15.6 points after surgery (mean deviation [MD] 1.6, 95% confidence interval [CI] 2.1 to 1.2, p < 0.001). ROM showed a slight trend to increase (MD 0.8, 95% CI -0.9 to 2.6, p = 0.193). In the control group, the mean JOA score improved from 13.3 to 15.1 points after surgery (MD 1.4, 95% CI 2.1 to 1.2, p < 0.001). The comparison of the postoperative JOA scores and recovery rates between the hybrid treatment group and the control group did not show significant differences. Conclusions In cases of coincident soft and hard degenerative cervical disk disease at adjacent levels, the combination of a disk prosthesis and a nondynamic implant is a safe and effective treatment option and an alternative to multilevel fusion.

Modified open-door laminoplasty for the surgical treatment of cervical spondylotic myelopathy in elderly patients.

BACKGROUND: The authors describe their experience with a modified version of the standard technique of open-door laminoplasty for the surgical treatment of spondylotic myelopathy in elderly patients with temporary removal of the laminae, extensive decompression, and pre-plating of the laminae beyond the surgical field. METHODS: Description of surgical anatomy, surgical technique, indications, limitations, complications, and specific perioperative considerations, as well as specific information to give to the patient about surgery and potential risks. A summary of ten key points is given. CONCLUSIONS: Transection of the laminae on both sides (temporary laminectomy) and pre-plating of the laminae outside of the surgical field has several advantages: better decompression of the spinal canal and the neuroforamina on both sides, easier undercutting of adjacent vertebral arches for cranio-caudal decompression, and no risk of spinal cord injury by the screwdriver when attaching plates to the laminae.

Distractable titanium cages versus PEEK cages versus iliac crest bone grafts for the replacement of cervical vertebrae.

OBJECTIVE: To analyse the advantages and disadvantages of distractable titanium cages, polyether-etherketone cages, and iliac crest bone graft for the replacement of cervical vertebral bodies (VBR). METHODS: The clinical and radiological results of 32 patients who underwent cervical corpectomy for the decompression of the spinal canal were retrospectively analysed and discussed. RESULTS: For the vertebral body replacement the authors used distractable titanium cages (n = 6), PEEK cages (n = 19), and iliac crest bone graft (n = 7). The neurological outcomes according to postoperative JOA scores did not show significant differences between the three groups. PEEK cages showed a high rate of secondary subsidence (32%). DISCUSSION: Despite the risk of donor site morbidity the authors recommend iliac crest bone graft as primary choice for VBR because of its excellent fusion rate and its cost effectiveness. For revision cases we recommend titanium cages.

Surgical management of cervical spondylotic myelopathy - indications for anterior, posterior or combined procedures for decompression and stabilisation.

BACKGROUND: The authors describe their experience with the choice of anterior, posterior and combined approaches for the surgical treatment of spondylotic myelopathy. METHODS: Description of surgical anatomy, surgical technique, indications, limitations, complications, specific perioperative considerations and specific information to give to the patient about surgery and potential risks and a summary of 10 key points is given. CONCLUSIONS: If the disease extends behind the posterior vertebral body and if reestablishing spinal sagittal and coronal balance is an aim, then the anterior approach is the best choice. In cases of predominant posterior spinal cord compression and lordotic configuration the posterior approach should be preferred. Decompression of three or more levels, especially in combination with poor bone quality, requires a combined approach.

The past, present and future of minimally invasive spine surgery: a review and speculative outlook.

In the last 25 years of spinal surgery, tremendous improvements have been made. The development of smart technologies with the overall aim of reducing surgical trauma has resulted in the concept of minimally invasive surgical techniques. Enhancements in microsurgery, endoscopy and various percutaneous techniques, as well as improvement of implant materials, have proven to be milestones. The advancement of training of spine surgeons and the integration of image guidance with precise intraoperative imaging, computer- and robot-assisted treatment modalities constitute the era of reducing treatment morbidity in spinal surgery. This progress has led to the present era of preserving spinal function. The promise of the continuing evolution of spinal surgery, the era of restoring spinal function, already appears on the horizon. The current state of minimally invasive spine surgery is the result of a long-lasting and consecutive development of smart technologies, along with stringent surgical training practices and the improvement of instruments and techniques. However, much effort in research and development is still mandatory to establish, maintain and evolve minimally invasive spine surgery. The education and training of the next generation of highly specialized spine surgeons is another key point. This paper will give an overview of surgical techniques and methods of the past 25 years, examine what is in place today, and suggest a projection for spine surgery in the coming 25 years by drawing a connection from the past to the future.

Training models for vascular microneurosurgery.

INTRODUCTION: The number of microsurgical clippings of cerebral aneurysms is continuously decreasing. This will lead to fewer possibilities for practical training in aneurysm surgery, especially for the younger generation. Accordingly, realistic models for microsurgical training are mandatory. METHODS: We present a microsurgical setup for training on a PVC rat and on a lifelike vascular training model with specific plastic vessels (PVA), and an anatomical head as well as an experimental animal model (rabbit carotid artery bifurcation model). End-to-end and end-to-side anastomoses were performed with three different levels of difficulty and three different levels of expertise on the PVC rat model. The results of the animal bifurcation aneurysm model are also described. RESULTS: With increasing surgical complexity, the duration of surgery and rate of incorrect sutures of the vessel wall rise significantly. The overall patency rate of anastomosis is clearly reduced in the setup with increasing complexity grades. CONCLUSION: The PVC rat model as well as the PVA vascular kit with realistic skull and craniotomy sites is a perfect tool for advanced microvascular anastomosis training. The experimental animal model represents a higher level of vascular surgery expertise and additionally is a perfect model for practicing appropriate clip application and clip occlusion of aneurysms.

Materials and techniques for osseous skull reconstruction.

This review paper gives an overview and summarizes the different methods of cranioplasty for reconstruction of the bony skull. There are various origins of cranial defects including trauma, tumours, congenital deformities or postoperative defects due to the surgical procedure itself. The overall goal of skull reconstruction is, on the one hand, appropriate closure, and on the other hand, the perfect cosmetic result. The cranioplasty should be safe, fast and easy to handle. Cost-effectiveness of the procedure represents a further important point. To solve these complex and multimodal problems, different techniques and also various materials for the reconstruction are available. This report details the usual procedures for skull reconstruction, as well as the advantages and limitations of the different materials and operative strategies.