Comparative Analysis on Surgical Operability and Degree of Exposure of Microsurgical Approaches to Intraforaminal Lumbar Disk Herniations.

BACKGROUND: Intraforaminal lumbar disk herniations (IFDHs) represent a heterogeneous and relatively uncommon disease; their treatment is technically demanding due to the anatomical relationships with nerve roots and vertebral joints. Over time, several approaches have been developed without reaching a consensus about the best treatment strategy. MATERIALS AND METHODS: Authors comparatively analyze surgical operability and exposure in terms of quantitative variables between the different microsurgical approaches to IFDHs, defining the impact of each approach on surgical maneuverability and exposure on specific targets.A comparative microanatomical laboratory investigation was conducted. The operability score (OS) was applied for quantitative analysis of surgical operability. RESULTS: Transarticular and combined translaminar-trans-pars-interarticularis approaches result in providing the best surgical exposure and maneuverability on all targets with surgical controls on both nerve roots, at the expense of a higher risk of iatrogenic instability. Trans-pars-interarticularis approach reaches comparable levels of operability, even limited to the pure foraminal area (lateral compartment); similar findings were recorded for partial facetectomy on the medial compartment. The contralateral interlaminar approach provides good visualization of the foramen without consensual favorable maneuverability, which should be considered the main drawback. CONCLUSIONS: Approach selection has to consider disease location, the possible migration of disk fragments, the degree of nerve root involvement, and risk of iatrogenic instability. According to the findings, authors propose an operative algorithm to tailor the surgical strategy, based both on the precise definition of anatomic boundaries of exposure of each approach and on surgical maneuverability on specific targets.

Posttraumatic extraskeletal chondroma of the posterior neck: A systematic literature review on a rare finding and report of a case.

Extraskeletal chondromas (EC) are uncommon, benign cartilaginous tumours. Most common locations are upper and lower extremities. Location in the neck is extremely rare and reported only within the anterior compartment. Data are limited to just four case reports in the paediatric population. The first case of EC in neck's posterior compartment is described herein. EC present peculiar features on imaging. Aetiology is unclear; however, trauma has been suggested as possible causative mechanism. Treatment of choice is surgical excision; recurrence is not uncommon, but additional removal seems to be resolutive. All cases in literature were asymptomatic, except for one presenting respiratory stridor. The present patient suffered from neck functional limitation and upper limb hypoesthesia. Symptoms improved after surgery in both cases. Imaging follow-up at 6 months in the present case showed no sign of recurrence. ECs are rare, benign lesions. However, they may be preoperatively misinterpreted as more malignant counterparts (both radiologically or histologically), so accurate diagnostic work-up and planning of the surgical procedure are essential.

Anterior selective scalenectomy for periforaminal exposure in the ventral supraclavicular approach.

Aims and Objectives: Route of choice to access cervical paravertebral lesions with foraminal involvement is the anterolateral corridor with its variants. Main limitation of these techniques is represented by the limited surgical access to periforaminal area due to the bulk generated by the anterior scalene muscle (ASM). Over the years, alternative techniques for ASM surgical management have been developed, which are still today a matter of debate. Most popular include ASM scalene complete section (SCS) and ASM medial detachment (SMD). Authors describe an innovative, minimally invasive muscle section technique, the anterior selective scalenectomy (ASS), which reduces the risk of iatrogenic morbidity and optimizes exposure of periforaminal area in anterolateral cervical routes. Materials and Methods: A laboratory investigation was conducted. Technique was applied in a surgical setting, and an illustrative case was reported. Results: ASS is a quick and easy technique to perform. It allows optimization of surgical visibility and control on the periforaminal area in the cervical anterolateral corridor. It respects muscle anatomy and vascularization, favoring functional recovery and management of peri-operative pain; it reduces the risk of morbidity on phrenic nerve and pleura. Considering the minimally invasive nature of the technique, it allows for a slightly more limited exposure compared to traditional techniques while ensuring optimal surgical maneuverability on the target area. Conclusions: ASS represents an effective and safe alternative to traditional ASM section techniques for the exposure of periforaminal area in anterolateral cervical routes. It is indicated in case of lesions with paravertebral development and minimal intraforaminal component in the C3-C6 segment.

The carotid sheath route: An option to approach retrocarotid prespinal tumors with paravertebral extension.

Background: The elective route to approach paravertebral lesions growing into the anterolateral lodge of the neck is widely recognized as the prespinal route with its two major variants. Recently, attention has been focused on the possibility of opening the inter-carotid-jugular window in case of reparative surgery for traumatic brachial plexus injury. Aims: For the first time, the authors validate the clinical application of the carotid sheath route in the surgical treatment of paravertebral lesions expanding into the anterolateral lodge of the neck. Methods: A microanatomic study was conducted to collect anthropometric measurements. The technique was illustrated in a clinical setting. Results: The opening of the inter-carotid-jugular surgical window allows additional access to the prevertebral and periforaminal space. It optimizes the operability on the prevertebral compartment, compared to the retro-sternocleidomastoid (SCM) approach, and on the periforaminal compartment, compared to the standard pre-SCM approach. The surgical control of the vertebral artery is comparable to that obtained with the retro-SCM approach, while the control of the esophagotracheal complex and the retroesophageal space is comparable to the pre-SCM approach. The risk profile on the inferior thyroid vessels, recurrent nerve, and sympathetic chain is superimposable to the pre-SCM approach. Conclusions: The carotid sheath route is a safe and effective option to approach prespinal lesions with retrocarotid monolateral paravertebral extension.

Efficacy of radiotherapy and stereotactic radiosurgery as adjuvant or salvage treatment in atypical and anaplastic (WHO grade II and III) meningiomas: a systematic review and meta-analysis.

The role of radiotherapy (RT) and stereotactic radiosurgery (SRS) as adjuvant or salvage treatment in high-grade meningiomas (HGM) is still debated. Despite advances in modern neuro-oncology, HGM (WHO grade II and III) remains refractory to multimodal therapies. Published reports present aggregated data and are extremely varied in population size, exclusion criteria, selection bias, and inclusion of mixed histologic grades, making it extremely difficult to draw conclusions when taken individually. This current work aims to gather the existing evidence on RT and SRS as adjuvants following surgery or salvage treatment at recurrence after multimodality therapy failure and to conduct a systematic comparison between these two modalities. An extensive systematic literature review and meta-analysis were performed. A total of 42 papers were eligible for final analysis (RT n = 27; SRS n = 15) after searching MEDLINE via PubMed, Web-of-science, Cochrane Wiley, and Embase databases. Adjuvant regimens were addressed in 37 papers (RT n = 26; SRS n = 11); salvage regimens were described in 5 articles (RT n = 1; SRS n = 4). The primary outcomes of the study were the overall recurrence rate and mortality. Other actuarial rates (local and distant control, OS, PFS, and complications) were retrieved and analyzed as secondary outcomes. A total of 2853 patients harboring 3077 HGM were included. The majority were grade II (87%) with a mean pre-radiation volume of 8.7 cc. Adjuvant regimen: 2742 patients (76.4% RT; 23.6% SRS) with an overall grade II/III rate of 6.6/1. Lesions treated adjSRS were more frequently grade III (17 vs 12%, p < 0.001), and received subtotal resection (57 vs 27%, p = 0.001) compared to the RT cohort. AdjSRS cohort had a significantly shorter mean follow-up than adjRT (36.7 vs 50.3 months, p = 0.01). The overall recurrence rate was 38% in adjRT vs 25% in adjSRS (p = 0.01), while mortality did not differ between the groups (20% vs 23%, respectively; p = 0.80). The median time to recurrence was 1.5 times longer in the RT group (p = 0.30). Five-year local control was 55% in adjRT and 26% in adjSRS (p = 0.01), while 5-year OS was 73% and 78% (p = 0.62), and 5-year PFS was 62% and 40% in adjRT and adjSRS (p = 0.008). No difference in the incidence of complications (24% vs 14%, p = 0.53). Salvage regimen: 110 patients (37.3% RT; 62.7% SRS) with a grade II/III rate of 8.6/1. The recurrence rate was 46% in salRT vs 24% in salSRS (p = 0.39), time to recurrence was 1.8 times longer in the salRT group (35 vs 18.5 months, p = 0.74). Mortality was slightly yet not significantly higher in salRT (34% vs 12%, p = 0.54). Data on local and distant control were only available for salSRS. The 5-year OS was 49% and 83% (p = 0.90), and the 5-year PFS was 39% and 50% in salRT and salSRS (p = 0.66), respectively. High-grade meningiomas (WHO grade II and III) receiving adjuvant RT showed a higher overall recurrence rate than meningiomas receiving adjuvant SRS. The adjRT cohort, however, achieved higher 5-year LC and PFS rates, thus suggesting a potentially longer time to recurrence compared to adjSRS patients, who, meanwhile, experienced a significantly shorter follow-up. This result must also consider the higher number of grade III lesions and the smaller extent of resection achieved in the adjSRS group. Overall mortality did not differ between the two groups. No differences in outcome measures were observed in salvage regimens.

Substantially elevated serum glutamate and CSF GOT-1 levels associated with cerebral ischemia and poor neurological outcomes in subarachnoid hemorrhage patients.

Brain injury and cerebral vasospasm during the 14 days after the subarachnoid hemorrhage (SAH) are considered the leading causes of poor outcomes. The primary injury induces a cascade of events, including increased intracranial pressure, cerebral vasospasm and ischemia, glutamate excitotoxicity, and neuronal cell death. The objective of this study was to monitor the time course of glutamate, and associated enzymes, such as glutamate-oxaloacetate transaminase (GOT1), glutamate-pyruvate transaminase (GPT) in cerebrospinal fluid (CSF) and serum, shortly after SAH, and to assess their prognostic value. A total of 74 participants participated in this study: 45 participants with SAH and 29 controls. Serum and CSF were sampled up to 14 days after SAH. SAH participants' clinical and neurological status were assessed at hospitalization, at discharge from the hospital, and 3 months after SAH. Furthermore, a logistic regression analysis was carried out to evaluate the ability of GOT1 and glutamate levels to predict neurological outcomes. Our results demonstrated consistently elevated serum and CSF glutamate levels after SAH. Furthermore, serum glutamate level was significantly higher in patients with cerebral ischemia and poor neurological outcome. CSF GOT1 was significantly higher in patients with uncontrolled intracranial hypertension and cerebral ischemia post-SAH, and independently predicted poor neurological outcomes.

History of Evolution of Posterolateral Approaches to the Thoracic Spine: From Cure of Pott's Disease to Epidural Tumor Resection.

Since the end of the nineteenth century, the wide dissemination of Pott's disease has ignited debates about which should be the ideal route to perform ventrolateral decompression of the dorsal spine in case of paraplegia due to spinal cord compression in tuberculosis spondylitis. It was immediately clear that the optimal approach should be the one minimizing the surgical manipulation on both neural and extraneural structures while optimizing the exposure and surgical maneuverability on the target area. The first attempt was reported by Victor Auguste Menard in 1894, who described, for the first time, a completely different route from traditional laminectomy, called costotransversectomy. The technique was conceived to drain tubercular paravertebral abscesses causing paraplegia without manipulating the spinal cord. Over the following decades, many other routes have been described all over the world, thus demonstrating the wide interest on the topic. Surgical development has been marked by the new technical achievements and by instrumental/technological advancements, until the advent of portal surgery and endoscopy-assisted techniques. In this article, the authors retraced the milestones of this history up to the present days, through a systematic review on the topic.

Temporal Flaps in Head and Neck Reconstructive Surgery: A Systematic Review of Surgical Techniques.

The temporal region is a great source of vascularized flap, providing extremely variable and versatile options for reconstruction in head and neck surgery. Its popularity has led to the conception of a large variety of different flaps, in terms of contents and design. Temporal flaps are highly pliable and flexible, providing adequate bulk to obliterate dead spaces and improving engraftment, thus facilitating wound healing. The need to access different anatomical compartments, often far from the original flap anatomical site, has led surgeons to develop techniques to enlarge pedicles and bulk, by reverting and splitting flaps' contents, as well as through partial mandibular and zygomatic resection. To further increase versatility, a multilayered combination of different regional tissues and muscle segmentation techniques has been described. Historically, each flap has had its own proponents and opponents, but a pointy review systematizing techniques and comparatively analyzing different flaps was still missing in the literature. The field of use of some flaps has been progressively limited by the increasing relevance of free tissue transfers, which nowadays may provide success rates up to 95% with a constrained morbidity, thus offering an effective alternative, when available. Given the wide range of reconstructive strategies based on temporal flaps, there is still a great debate on nomenclature and surgical techniques. The present study systematizes the topic, classifying regional flaps according to contents and indications. Harvesting techniques are described stepwise and schematically illustrated, thus offering an indispensable tool to the armamentarium of reconstructive surgeons.

Gamma Knife radiosurgery as primary treatment of low-grade brainstem gliomas: A systematic review and metanalysis of current evidence and predictive factors.

The current standard of care for surgically inaccessible low-grade brainstem gliomas (BS-LLGs) is external-beam radiotherapy (RT). Developments toward more innovative conformal techniques have focused on decreasing morbidity, by limiting radiation to surrounding tissues. Among these Gamma Knife radiosurgery (SRS-GK) has recently gained an increasingly important role in the treatment of these tumors. Although SRS-GK has not yet been compared with conventional RT in patients harboring focal BS-LGGs, clinical practice has been deeply influenced by trials performed on other tumors. This is the first meta-analysis on the topic, systematically reviewing the most relevant available evidence, comparing RT and SRS-GK as primary treatments of BS-LGGs, focusing on survival, clinical outcome, oncological control, and complications. Predictive factors have been systematically evaluated and analyzed according to statistical significance and clinical relevance.

Role of stereotactic radiosurgery for the treatment of brain metastasis in the era of immunotherapy: A systematic review on current evidences and predicting factors.

Stereotactic radiosurgery (SRS) in combination with immunotherapy (IT) is increasingly used in the setting of melanoma and non-small cell lung cancer (NSCLC) brain metastases (BM). The synergistic properties of this treatment combination are still not deeply understood. IT-SRS appropriate combination has been envisioned as a strategic point in patients' management. Authors performed a systematic review on current evidences up to December 2020. The impact of SRS-IT and different IT schedules on survival, local/distant intracranial control and toxicity, as well as predictive factors for relevant oncological and radiological outcomes has been analyzed. Authors retrieved 23 pertinent studies. Combining SRS with IT resulted in a significant improvement in OS and lesion response with no increase in radionecrosis, hemorrhage or other complications. The present review suggests that combining IT to SRS is safe and effective in providing a significant improvement in relevant clinical and radiological outcomes in melanoma and NSCLC BMs patients.

Impact of C-shaped skin incision on surgical operability in the retrosigmoid approach: when a good start is half of the job.

BACKGROUND: The retrosigmoid approach (RSA) is one of the routes of choice to approach tumors and vascular lesions of the cerebellopontine angle. Among different types of skin incisions and soft tissue dissection techniques, the most widely used variants comprise the straight/lazy S-shaped and the C-shaped incisions. Several reports discuss advantages in terms of functional and clinical outcomes of the C-shaped incision, but scientific considerations about the critical impact of this kind of incision on surgical operability are still extremely limited. OBJECT: Authors comparatively analyze the advantage provided by C-shaped incision in RSA in terms of anatomic exposure and surgical operability, compared with straight/lazy S-shaped one. METHODS: A comparative microanatomical laboratory investigation was conducted. The operability score (OS) was applied for quantitative analysis of surgical operability. RESULTS: C-shaped incision, providing a significant reduction of the overall working distance (-13%) together with an overall increase of the maneuverability area (+ 204.9%), did improve the conizing effect on the surgical corridor. It optimized overall maneuverability of surgical instruments, in terms of angle of attack (+ 27.7%), as well as maneuverability arc (+ 122%), on the entire surgical field. C-shaped incision ensured good operability on all surgical targets (OS ranging from 2 to 3), most significantly improving surgical maneuverability at the porus trigeminus and internal acoustic meatus. CONCLUSION: C-shaped incision in the RSA significantly improves anatomic exposure and surgical operability as compared with straight/lazy S-shaped incision.

Combined, Rib-Sparing, Bilateral Approach to the Ventral Mid and Low Thoracic Spine: Study on Comparative Anatomy and Surgical Feasibility.

BACKGROUND: Pathologies of the ventral thoracic spine represent a challenge, igniting arguments about which should be the ideal surgical approach to access this area. Anterior transthoracic thoracotomy and a number of posterolateral routes have been developed. Among the latter, costotransversectomy has demonstrated to provide good ventral exposure with a lower, but not negligible, morbidity. The optimal approach should be the one minimizing surgical morbidity on both neural and extraneural structures while optimizing exposure. METHODS: The authors described the combined, rib-sparing, bilateral approach (CRBA) to the ventral mid/low-thoracic spine. The technique combines a transfacet pedicle partially sparing approach on one side and a transpedicular with transverse process resection on the contralateral one. A laboratory investigation was conducted. The technique was applied in a surgical setting, and a case was reported. RESULTS: CRBA is rib-sparing, completely extracavitary, and does not require pleural exposure and paraspinal muscle splitting, thus minimizing potential morbidity. The combination of 2 corridors ensures the greatest exposure compared with standard posterolateral approaches. The only blind corner is limited to a small area just in front of the dural sac. A bimanual approach optimizes control during surgical manipulation, even if the area of maneuverability and cross-section areas of surgical corridors are slightly limited compared to traditional costotransversectomy due to the minimally invasive nature of the procedure. CONCLUSIONS: CRBA represents a safe and effective option to access the ventral mid/low thoracic spine. It provides great exposure and bimanual manipulation of the surgical target, minimizes potential morbidity, and avoids entrance into the thoracic cavity and paraspinal muscle splitting.

Combined Technique of Temporal Muscle Augmentation for Muscle Reconstruction in Case of Small to Medium Anatomic Defects.

Inadequate temporal muscle (TM) reconstruction after surgery may hesitate in potentially severe functional and aesthetic sequelae, making it of paramount importance to carefully consider TM reconstruction even in case of small deformities.The authors describe the combined temporal muscle augmentation technique (CTMA), an innovative technique for TM augmentation for muscle reconstruction in case of small to medium substance loss.A cadaver study was conducted as preclinical validation of the technique for the assessment of CTMA coverage capability. CTMA consists in a combination of 2 techniques for muscle surface coverage (MSC) increase: the radial (RA) and the longitudinal augmentation (LA), which enables to harvest a radial (RF) and a longitudinal flap (LF), respectively.Each flap derives from a different muscle-bundle, spearing TM segmentation and functional performance, and are supplied by a specific neuro-vascular peduncle, which makes flaps functionally independent.A surgical case is reported to demonstrate the feasibility of the technique.Combined temporal muscle augmentation technique provides an overall coverage surface of 6.5 ± 0.6 cm, which corresponds to a gap distance of 2.5 ± 0.2 cm, with RF providing a statistically significant larger surface of coverage compared to LF (×2.1; P = 0.0001).Combined temporal muscle augmentation technique is easy and fast to perform displaying a good reconstructive capability with complete preservation of temporal muscle anatomic compartmentalization and segmental vasculature. It might be considered as a safe and effective alternative in the reconstruction of small-to medium TM defects.

The optimal numerosity of the referral population of pituitary tumors centers of excellence (PTCOE): A surgical perspective.

Surgical experience is of paramount importance to reach therapeutic success and minimize operative complications. In the field of pituitary surgery, this led to the concept of Pituitary Center of Excellence (PTCOE) defined as a center where an interdisciplinary team works in collaboration and where surgeons can be trained appropriately to reach and keep excellence in daily practice. To review the literature to define the optimal referral population size to establish a PTCOE to optimize both training and specific field research. A review of the literature was performed about epidemiology. The time needed to observe 200 cases of PAs in a single PTCOE and to reach the minimal surgical experience threshold (MSET) was calculated for different referral population groups. The time needed to reach MSET decreased as population size increased. We defined a population as the optimal one to be served by a single PTCOE with a single dedicated neurosurgeon. PTCOEs should be established after an analysis of the referral population, number of cases suitable for surgical treatment and number of dedicated neurosurgeons.