Microsurgical repair by autografting in traumatic injuries of peripheral nerves.

BACKGROUND: Peripheral nerve injuries (PNI) with traumatic origin in upper and lower extremities are pathologies with an important quality-of-life considerations. For neurosurgeons, it is mandatory to understand their physiopathological mechanism and a proper treatment. The authors describe a series of 50 patients with traumatic PNI who underwent microsurgical reconstruction by autologous graft between 1993 and 2014. METHODS: Patients aged less than 65, who had neurological deficit in a range 3-12 months and severe and persistent nerve injury at electrophysiological examination were included in the study. After grafting, the overall functional recovery of the neurological deficit, the main prognostic factors (age, injured nerve, damage mechanism, gap length and surgical timing) and the postoperative functional outcome were analyzed. Neurological and electrophysiological follow-up was at 6-/12-/24-/48 months after surgery. RESULTS: The results showed that the best neurological recovery can be found in young patients with cut injuries of the upper limbs and that the outcome mainly depends on involved nerve, lesion type and minimum gap length. Moreover, follow-up for these pathologies should last till 48 months. CONCLUSIONS: In the future, these results could be further improved by the rising new techniques of nerve repair and the advances in neurobiology.

Fluorescein-assisted stereotactic needle biopsy of brain tumors: a single-center experience and systematic review.

Over the last years, fluorescence-based technology has begun an emergent intraoperative method for diagnostic confirmation of brain tumor tissue in stereotactic needle biopsy. However, the actual level of evidence is quite low, especially about fluorescein sodium (FL) application. This method needs to be further validated and better analyzed about its impact in clinical practice. Retrospective analysis of 11 cases with contrast-enhancing brain tumors, underwent awake stereotactic needle biopsy with intraoperative FL assistance (group 1), was verified under the operative microscope filter. This group was matched with a control group of 18 patients (group 2). In addition, a systematic literature review was performed in PubMed/Medline database according to PRISMA statement. All studies concerning FL or 5-ALA application in stereotactic biopsy as intraoperative confirmation of brain tumor tissue were included. The primary endpoint was the evaluation of diagnostic accuracy. In group 1, all fluorescent specimens were diagnostic. The number of samplings was the useful minimum and non-use of intraoperative neuropathological examination allowed to significantly reduce procedure time (42.09 vs 69.72 min of group 2). No complications occurred, and the average hospitalization time after procedure was 1.09 days (vs 2.33 of group 2). Literature analysis supports the usefulness of photodiagnosis and its high diagnostic yield especially at the core of high-grade/contrast-enhancing tumors. FL assistance during stereotactic biopsy of contrast-enhancing brain tumors may give a real-time confirmation of tumor tissue, maximizing the diagnostic yield, and reducing time of procedure, morbidity, and hospitalization.

Palatal Position of Patient Tracker for Magnetic Neuronavigation System: Technical Note.

OBJECTIVE: Recently, the neuronavigation system (NS) has become an essential intraoperative tool for many neurosurgical procedures, allowing for precise lesion localization. It is particularly important to avoid errors during the navigation process. Here we report a novel technique using palatal positioning of the patient tracker to ensure optimal accuracy during magnetic navigation in various neurosurgical procedures. METHODS: This retrospective study included a total of 34 patients treated in our institution between June 2017 and January 2018. The patients were split into 2 groups who underwent surgery under general anesthesia: a microscopic transcranial group and an endoscopic endonasal group. Preoperative and postoperative navigation accuracy was assessed by 2 neurosurgeons. RESULTS: After our surgical planning navigation protocol was applied, both transcranial and endonasal procedures were successfully performed under navigation guidance in all but 1 patient. There were no intraoperative or postoperative complications related to the tracker mounted under the hard palate. In 33 cases a maximal tracking view and optimal navigation accuracy was achieved, for a success rate of 97%. CONCLUSIONS: The positioning of the patient tracker under the hard palate proved safe, accurate, and feasible in 97% of our patients. In our case series, it met the main goal of avoiding device displacement without a sense of invasiveness and postoperative patient discomfort.

Cerebrovascular disorders and Fahr's disease: Report of two cases and literature review.

Fahr's disease is a rare idiopathic nosological entity, characterized by calcification of the basal ganglia and dentate nuclei of the cerebellum. Sometimes it may be associated to other diseases like cerebrovascular disorders. However, this link remains unclear and it needs to be further validated. We report two cases of patients with cerebrovascular disorders and Fahr's disease. In the first case, a 69-years-old woman with right internal capsule-basal ganglia haemorrhage. In the second case, a 72-years-old woman with ischemic stroke and pericallosal artery aneurysm. The physiopathology is discussed and concerning literature is reviewed.

Multimodal use of indocyanine green endoscopy in neurosurgery: a single-center experience and review of the literature.

During the last 10 years, microscope-integrated indocyanine green fluorescence (m-ICG) has been widely used for assessing real-time blood flow during aneurysm surgery. More recently, an endoscope-integrated indocyanine green fluorescence (e-ICG) has been adopted as a versatile tool during different endoscopic neurosurgical procedures. The purpose of the present report is to evaluate multimodal applications of e-ICG during different endonasal, intraventricular, aneurysm and brain tumor surgeries and provide technical nuances. In addition, we reviewed the literature and identified and compare several overlapping case series of patients treated via an endoscopic integrated indocyanine green fluorescence technique. A total of 40 patients were retrospectively evaluated. Patients were divided into four main groups: (1) endoscopic endonasal approaches (n = 14); (2) ventricular endoscopic approach including patients undergoing third ventriculostomy (n = 8) and tumor biopsy (n = 1); (3) aneurysms surgery (n = 9); and (4) brain parenchymal tumors (n = 8). All patients were successfully treated using the e-ICG dynamic endoscopic visualization, and there were no perioperative complications. Such unique features open up a promising field of applications beyond the use of m-ICG in different surgical field due to the longer duration of e-ICG fluorescence up to 35 ± 7 min. E-ICG represents a new and effective technique for longer real-time visualization of vascular structures preserving normal tissues and functions during different transcranial and endonasal approaches. As the technology and e-ICG resolution improves, the technique has the potential to become a critical tool for different applications in neurosurgery.

Septic complication following porous hydroxyapatite cranioplasty: prosthesis retention management.

After failing of autologous cranioplasty or when the bone flap is unavailable, the alloplastic (heterologous) materials are the choice for cranial reconstruction. No agreement has been reported about the material with a significant lower risk of septic complications. This is due to extremely heterogeneous prognostic factors related not only to the material used but also to the surgical procedures and/or to the timing of the procedure. More attention should be focused on the material whose characteristic could enable a delay in bacterial colonization, where an antibiotic therapy could be effective, without need of prosthesis removal. Four cases of severe septic complication following cranioplasty with porous hydroxyapatite (HA) prosthesis are presented. Patients were conservatively treated, without heterologous bone flap removal. All of our patients presented reasons for delaying HA cranioplasty removal: patients #1, 3, and 4 had an associated shunted hydrocephalus and the need for not removing the prosthesis was related to the predictable recurrence of overshunting and/or sinking skin flap syndrome. In patient #4, the revision surgery would have also damaged the microvascular flap with latissimus dorsi muscle used by plastic surgeon for skin reconstruction. In patient #2, the patient refused revision surgery. In all cases, systemic and/or radiological signs of infection were observed. In patient #2 the infective process surrounded completely the HA prosthesis, while it was located in the epidural region in patients #1 and 4. In patient #3, a surgical curettage of the infected wound was performed over the HA prosthesis. Following prosthesis retention management with antibiotic therapy, all patients revealed systemic and/or radiological signs of sepsis resolution at follow-up. The possibility to avoid a prosthesis removal with effective antibiotic treatment is mainly due to the combination of three factors: targeted antibiotic therapy, good anatomical area revascularization (resulting of an "in situ" intake of antibiotics), and the biomimetism of HA prosthesis. Further investigations in a larger number of cases need to confirm these observations.

Fluorescein-Guided Surgery for High-Grade Glioma Resection: An Intraoperative "Contrast-Enhancer".

BACKGROUND: Fluorescein sodium salt is widely used in medicine as fluorescein isothiocyanate and commonly named fluorescein (FL). This fluorophore has been used as a fluorescent tracer for many applications, especially in ophthalmic surgery. It was initially used in neuro-oncology in 1948 to control tumor resection margins. After a transient disuse, it has recently had a second spring with the development of dedicated filters for operating microscopes, although it is still under evaluation in clinical use. The aim of this study is to contribute to the investigation according to which FL-guided surgery for high-grade glioma (HGG) is related to better rates of gross total resection (GTR) and so to a better outcome. METHODS: We retrospectively analyzed 23 cases of patients with new diagnosis of HGG, operated on in our unit by intraoperative FL use with a filter system directly integrated into an operative microscope (group 1). Fluorescence was compared with histology by biopsies carried out both in the fluorescent areas and in the periphery of fluorescent areas. Group 1 was matched with a control group of 25 patients with HGG operated on in our unit during the last 2 years without FL guidance (group 2). RESULTS: No side effects occurred related to FL. Histology and intraoperative neuronavigation showed strong correspondence with fluorescent and nonfluorescent areas. GTR rate was significantly higher in group 1 (82.6%) than in group 2 (52%). CONCLUSIONS: Intraoperative fluorescein-guided surgery showed safety and feasibility. Our and other studies suggest an improvement of GTR rate in HGG than nonuse.

Evaluation of matrix metalloproteinase type IV-collagenases in serum of patients with tumors of the central nervous system.

The basement membrane collagen IV-degrading matrix metalloproteinases -2 and -9 (MMPs) are most often linked to the malignant phenotype of tumor cells by playing a critical role in invasion, metastasis, angiogenesis, and vasculogenesis. We verified the activity of these two MMPs in the sera of patients affected by brain tumors (20 gliomas, 28 meningiomas and 20 metastasis) by zymography. The sera of 25 healthy volunteers with no concomitant illnesses were used for controls. Zymography showed four dominant gelatinolytic bands of 240, 130, 92 (MMP-9) and 72 (MMP-2) kDa. No statistically significant variations of MMP-2 proteolytic activity between patients and healthy individuals were observed. On the contrary, MMP-9 (both monomeric and multimeric forms) lytic activities were significantly higher in tumors specimens compared to healthy controls (p < 0.001). Moreover, MMP-9 immunohistochemistry revealed: (1) a strong reactivity in neoplastic vessels of high-grade gliomas showing an inverse correlation with serum multimeric gelatinolytic activity; (2) a cytoplasmatic reactivity in meningiomas with a significantly increase in atypical meningioma compared with low-grade ones (p = 0.036); (3) a positive correlation between MMP-9 and Ki-67 (Sperman Rho coefficient r = 0.418 and p = 0.034). Our results suggest that serum and tissue MMP-9 might provide clinicians additional objective information in intracranial neoplasms. Finally, it should be possible to use MMP-9 as a target for new forms of therapy. Nevertheless, due to the small number of patients included in the study, the conclusion may not be transferable to the general population and therefore further evaluations are needed.

Contemporary occurrence of hydrocephalus and Chiari I malformation in sagittal craniosynostosis. Case report and review of the literature.

Chiari malformation type I (CM-I) and hydrocephalus are often associated with complex craniosynostosis. On the contrary, their simultaneous occurrence in monosutural synostosis is extremely rare. The pathophysiological hypothesis is that they may alter posterior fossa growth and lead to cerebellar tonsil herniation also without skull base primary involvement. Hydrocephalus is multifactorial and may be secondary to fourth ventricle outlet obstruction. The management of these cases is quite complex and not well defined. Cranial vault remodeling should be the only treatment when CM-I is asymptomatic and not related to syringomyelia. Suboccipital decompression should be reserved only in complicated CM-I, usually as a second surgical step following the correction of the supratentorial deformity. In our opinion, the associated hydrocephalus should be treated first in order to normalize intracranial hypertension before opening the cranial sutures. We report the case of a 26-month-old child that presented with sagittal craniosynostosis, hydrocephalus, and CM-I. He was managed by performing endoscopic third ventriculostomy (ETV) first and cranial vault remodeling thereafter. Clinico-radiological outcome was very satisfying. Concerning literature is reviewed; physiopathology and surgical management are discussed.

Vascularized nerve grafts: an experimental study.

OBJECTIVE: The aim of this study is to define an experimental model in order to promote the functional recovery of the nerves using grafts with vascular support (Vascular Nerve Grafts - VNG). The aim of this study is to define, on an experimental model in normal recipient bed, whether the functional recovery with VNG is superior to that obtained non-vascularized graft (NNG). METHODS: Twenty male rabbits, which underwent dissection of sciatic nerve, were later treated by reinnervation through an autograft. In 10 animals the reconstruction of sciatic nerve was realized with VNG; in 10 control animals the reconstruction of sciatic nerve was realized with NNG. RESULTS: The VNG group showed a better axonal organization and a significantly higher number of regenerated axons in the early phases (after 30 days) than the NNG group, whereas the difference in the axonal number at day 90 was less significant; besides, the axon diameter and the myelin thickness were not significantly improved by VNG group. DISCUSSION: Our data suggests that the use of VNG leads to a faster regeneration process and a better functional recovery, although the final results are comparable to those of the NNG. VNG improve the quality of the axonal regeneration (axonal diameter and Schwann cells), although the increase in the axonal number is not significant and does not improve the long-term functional outcome.