Venelin Gerganov

Venelin Gerganov
International Neuroscience Institute Hannover | INI Hannover · Department of Neurosurgery

Professor MD PhD MHM

About

147
Publications
16,907
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2,233
Citations
Introduction
Frontolateral approach to lesions of the anterior fossa, supra-and parasellar area
Additional affiliations
January 2006 - present
International Neuroscience Institute
International Neuroscience Institute
January 2003 - present
Medical University of Sofia
January 2001 - December 2005
Alexandrovska University Hospital

Publications

Publications (147)
Article
Full-text available
Object: An extensive craniopharyngioma is a tumor that extends into multiple compartments (subarachnoid spaces) and attains a size larger than 4 cm. A wide spectrum of approaches and strategies has been used for resection of such craniopharyngiomas. In this report the authors focused on the feasibility and efficacy of microsurgical resection of ex...
Article
Full-text available
Background: Surgery of lesions of the petrous apex involving the inframeatal/infralabyrinthine area is challenging and related to a high risk of complications. Various extensive skull-base approaches have been used. Objective: To present and evaluate our experience with a new hearing-preserving extension of the retrosigmoid approach to the infra...
Article
Full-text available
An increasing number of patients with vestibular schwannomas (VSs) are being treated with radiosurgery. Treatment failure or secondary regrowth after radiosurgery, however, has been observed in 2%-9% of patients. In large tumors that compress the brainstem and in patients who experience rapid neurological deterioration, surgical removal is the only...
Article
Full-text available
The aim of this study was to evaluate and present the results of current surgical treatment of vestibular schwannomas (VSs) and to report the refinements in the operative technique. The authors performed a retrospective study of 200 consecutive patients who had undergone VS surgery over a 3-year period. Patient records, operative reports, follow-up...
Preprint
Olfactory neuroblastoma /ON/, a.k.a. esthesioneuroblastoma is a rare tumor arising from the olfactory epithelium in the upper nasal cavity. Olfactory neuroblastomas are 2-6% of all intranasal tumors with a frequency of 0.4 per 1 million people. The most common symptoms are unilateral nasal obstruction (70%) and epistaxis (50%). Radical surgical res...
Article
Full-text available
Dermal sinus tract /DST/ is a rare congenital disease, characterized by the presence of a pathological fistulous tract, lined by epithelial cells. This tract begins from the surface of the skin and reaches to a various depth in the subcutaneous tissues, sometimes it even reaches the spinal canal. The incidence is 1 case per 2500 live births. Less t...
Article
Background Peritumoral edema (PTE) is rarely present in patients with vestibular schwannomas (VS). We studied the correlation between radiological tumor characteristics and the presence of edema, describe its magnetic resonance imaging features and classify the different edema patterns. Methods We analysed 605 consecutive patients treated for VS a...
Article
Background: Many neurosurgeons prefer conservative treatments in the elderly due to higher rates of mortality and morbidity after surgery. We aim to evaluate safety and efficacy of surgery in elderly patients with frontobasal and suprasellar meningiomas with a simple operative procedure, the frontolateral approach(FLA). Methods: Retrospective an...
Poster
Full-text available
Увод: Дермалният синус е рядко вродено заболяване, което се характеризира с патологичен фистулен ход, покрит от епителни клетки, започващ от повърхността на тялото и достигащ на различна дълбочина в подкожните тъкани до спиналния канал. Честотата на вроден дермален синус е 1 на 2500 живородени деца, по-малко от 1% са локализирани в шиен отдел. Само...
Chapter
Both craniopharyngiomas and Rathke’s cysts are rare pituitary lesions of dysembryogenic origin. Their radiological differentiation may be sometimes difficult due to their occasionally similar imaging characteristics. The surgical management of these lesions, especially of craniopharyngiomas, may be very challenging. Gross total removal of a craniop...
Article
Background: Skull base chordoma can be a challenging surgical entity because of its invasive nature. Objective: In this study, the role of intraoperative magnetic resonance imaging (iMRI) to optimize the resection of skull base chordomas is evaluated. Methods: We performed a retrospective analysis of operated patients with skull base chordomas...
Article
OBJECTIVE The purpose of this prospective study was to evaluate the dysfunction of the nervus intermedius (NI) after vestibular schwannoma (VS) surgery. The authors present a clinically feasible method for this purpose. METHODS In this prospective study, the authors included 30 patients who underwent surgery at the International Neuroscience Insti...
Article
Objective: We present the findings of our prospective study assessing olfactory function outcome in patients undergoing a frontolateral approach for the resection of suprasellar lesions. Methods: Eighteen consecutive patients (7 females, 11 males) surgically treated at our institute for suprasellar tumors were included in this prospective study....
Article
Introduction: reconstruction of skull base after resection of skull base meningioma is of paramount importance. We are presenting a safe and effective method of skull base reconstruction METHODS: a retrospective analysis of patients operated for skull base meningioma from 2007 to 2014. We analyzed the surgical technique, efficiency and safety as w...
Article
Objective: The authors report their experience with 53 cases of surgically treated recurrent VS. Outcome of these tumors was compared with that of primarily operated on VS. Special attention was given to the facial nerve functional outcome. Methods: A retrospective analysis was performed of the patients who underwent surgery for recurrent VS at one...
Article
OBJECTIVE The aim of this study was to analyze the efficacy and risks of microsurgery via the hearing-preserving retrosigmoid approach in patients with intracanalicular vestibular schwannoma (VS) suffering from disabling vestibular symptoms, with special attention to vertigo. METHODS This is a retrospective analysis of 19 patients with intracanali...
Article
Full-text available
OBJECTIVE Microsurgical treatment of recurrent vestibular schwannoma (VS) is difficult and poses specific challenges. The authors report their experience with 53 cases of surgically treated recurrent VS. Outcome of these tumors was compared to that of primarily operated on VS. Special attention was given to the facial nerve functional outcome. MET...
Article
OBJECT Preservation of the pituitary stalk and its vasculature is a key step in good postoperative endocrinological outcome in patients with craniopharyngiomas. In this article, the authors describe the surgical technique of medial optic nerve mobilization for better inspection and preservation of the pituitary stalk. METHODS This operative techni...
Article
OBJECT Removal of jugular foramen (JF) tumors usually requires extensive skull base approaches and is frequently associated with postoperative morbidities such as lower cranial nerve injury. The endoscope-assisted retrosigmoid infralabyrinthine approach is a relatively new approach to tumors extending into the bony canal of the JF. The authors pres...
Article
The aim of this study is to analyze the quantitative DTI parameters of the CST in patients suffering from subcortical gliomas affecting the CST using generally available navigation software. A retrospective study was conducted on 22 subjects with diagnosis of primary cerebral glioma and preoperative motor deficits. Exclusion criteria were: involvem...
Article
Full-text available
Introduction: Lesions of the petrous apex involving the inframeatal/infralabyrinthine region are challenging for surgical removal and have a high risk of approach related complications. Traditionally, various extensive skull-base approaches have been used for these lesions. The aim of this study was to present and evaluate our initial experience wi...
Article
Surgery plays a crucial role in the management of jugular foramen schwannomas (JFSs). Still, it remains challenging, particularly in cases of tumor growth inside the bony canal of the jugular foramen (JF). To present our recent experience with surgical treatment of JFSs, with particular focus on the efficacy and safety of the endoscope-assisted ret...
Article
The pterygopalatine fossa (PPF) and inferomedial orbital apex are difficult regions for open neurosurgical access. The traditional extensive anterior approach (transfacial or transmandibular) and lateral/posterolateral (transcranial) approach were used to access the PPF. The combined endonasal and sublabial transmaxillary approach is a less invasiv...
Article
Peritumoral edema (PTE) in skull base meningiomas correlates to the absence of an arachnoid plane and difference in outcome. In vestibular schwannomas (VS), PTE and its significance for microsurgery and outcome have never been systematically evaluated. To evaluate whether PTE correlates with tumor characteristics, the presence of an arachnoid plane...
Article
The hypoglossal facial anastomosis (HFA) is the gold standard for facial reanimation in patients with severe facial nerve palsy. The major drawbacks of the classic HFA technique are lingual morbidities due to hypoglossal nerve transection . The side-to-end HFA is a modification of the classic technique with less tongue-related morbidities. In this...
Article
Background: Trigeminal schwannomas are the most common intracranial nonvestibular schwannomas, and the dumbbell-shaped subtype is the most challenging. Objective: To evaluate the efficiency and safety of the endoscope-assisted retrosigmoid intradural suprameatal approach (EA-RISA) for dumbbell trigeminal schwannomas and to compare EA-RISA with c...
Article
Object: Trigeminal neuralgia (TGN) occurring after radiosurgical treatment of cerebellopontine or petroclival tumors may be very difficult to control. Our aim was to determine the efficacy of neurosurgical treatment in regards to pain control and to evaluate the procedure-related complication and morbidity rates. Methods: Retrospective study of...
Article
Objective The operative management of cystic vestibular schwannoma is more challenging. In the study we focus on the peculiarity of cystic vestibular schwannoma in terms of management and outcome. We evaluated a homogenous series of consecutive patients with cystic vestibular schwannomas, operated with similar technique and via the same surgical ap...
Article
Introduction: Intraoperative imaging allows for an objective estimation of the extent of tumor removal and the changing relation between tumor rest and surrounding normal structures. The value of intraoperative MRI (iop MRI) for achieving a more radical tumor removal, while decreasing the associated neurological morbidity, has been repeatedly prove...
Chapter
Surgery of vestibular schwannoma has improved in the last decades with progressive increasing rate of complete resection and preservation of facial nerve. The position of the nerve itself and its relation with tumour surface is usually identified intraoperatively and cannot be predicted with traditional magnetic resonance imaging technique in patie...
Chapter
Epidermoid cysts or cholesteatomas have been described fi rst by the French pathologist Cruveilhier in 1829. They are nonneoplastic congenital tumors that arise from ectodermal cells, misplaced during an aberrant closure of the neural tube [ 18, 22 ]. Epidermoids constitute 0.3- 1.8 % of all primary intracranial tumor and are most frequently locate...
Article
Intraoperative magnetic resonance imaging (iopMRI) actually has an important role in the surgery of brain tumors, especially gliomas and pituitary adenomas. The aim of our work was to describe the advantages and drawbacks of this tool for the surgical treatment of cervical intramedullary gliomas. We describe two explicative cases including the setu...
Article
Cranial cavernous malformations (CCMs) constitute a heterogeneous group of lesions that tend to change dynamically over time with related periods of repeated exacerbation and alternating periods of remission. The decision on their management is based on estimating the inherent risk of further morbidity and the risk/benefit related to the particular...
Chapter
The management of jugular foramen (JF) tumors remains a challenge despite the considerable progress over the last decades. Their location deep in a confined space of the skull base and the close proximity or even involvement of vital neural structures and/or major vessels complicates surgical removal. Jugular foramen tumors arise either primary wit...
Chapter
Epidermoids or epidermoid cysts are congenital lesions that arise from ectodermal cells, misplaced during an aberrant closure of the neural tube. They cause gradual displacement of neighboring neural structures and encase cranial nerves and vessels. Over the time, dense adhesions to cranial nerves or to brain stem may develop. Extension into the Me...
Chapter
Meningiomas are the second most frequent tumor of the CP angle after VSs. They comprise 6–15 % of all CP angle tumors and 40–42 % of all posterior cranial fossa meningiomas. Meningiomas, arising from the dura of the posterior surface of the pyramid lateral to the trigeminal nerve, are defined as “CP angle meningiomas” and those arising medial to th...
Chapter
In this chapter, the three main operative approaches to the internal auditory canal and cerebellopontine angle—the retrosigmoid, the translabyrinthine, and the middle fossa approach—are discussed. The middle fossa approach is utilized usually in case of small tumors, in which there is an opportunity to preserve hearing, especially in those located...
Chapter
Schwannomas originate most frequently from the sensory cranial nerves. In the absence of neurofibromatosis, the motor nerves are involved extremely rare. Nonvestibular schwannomas constitute 2–3 % of all CP angle tumors and 8–10 % of all intracranial schwannomas. The most frequent nonvestibular schwannomas are those originating from the trigeminal...
Chapter
Optimizing operative approaches to the cerebellopontine angle requires an understanding of the relationships of the cerebellar arteries, cranial nerves, brain stem, cerebellar peduncles, fissures between the cerebellum and brain stem, and the cerebellar surfaces. In this chapter, the microsurgical anatomy of the cerebellopontine angle by the retros...
Chapter
In this chapter, we review the history of cerebellopontine angle surgery since the initial description of the tumors in the area and the initial attempts at surgical removal. The history of CP angle tumors’ surgery is divided in several periods: initial description of CP angle tumors and first attempts at surgery; period of improvement of the surgi...
Chapter
Neurofibromatosis type 2 is a dominantly inherited tumor predisposition syndrome characterized by a tendency for developing bilateral VSs and other CNS tumors (meningiomas, ependymomas, astrocytomas, or other schwannomas). Typically the syndrome manifests itself during young adulthood—in the second or third decade of life. The severity of the disea...
Chapter
In this chapter, the properties of the most typical and relevant tumors and other pathologies of the cerebellopontine angle and its surroundings are dealt with from a neuropathological point of view in order to present a quick orientation for clinicians interested in macroscopic and microscopic pathomorphology. It is a main intention to provide a b...
Chapter
Despite the major advancement in CP angle surgery, in certain cases, it is impossible to preserve normal facial nerve function. Even if the nerve is preserved anatomically, complete and lasting paralysis may ensue. Comprehensive management of patients with facial nerve paralysis aims at restoration of function and appearance, as well as prevention...
Chapter
This book covers the entire spectrum of cerebellopontine angle lesions, from the most common to the rarest. All aspects are considered, including biological and radiological characteristics, neurological presentation, diagnosis, treatment options and follow-up care. The main focus, however, is on surgical management, which is presented in detail wi...
Article
Ganglion cysts (ganglia) are benign lesions of the soft tissue arising in the periarticular space. We present a 54-year-old woman with a 5-month history of headache and weakness of the tongue with deviation to the left side who had a rare extraneural intradural bilobate ganglion cyst of the atlanto-occipital joint compressing the hypoglossal nerve....
Article
Background The establishment of neuroendoscopy has been one of the major achievements in neurosurgery in the last 2 decades. The use of the endoscope increases efficacy and safety in each procedure. Methods The integration of endoscopy with other operating techniques or imaging technologies enhances the safety and reliability of the technique. Re...
Chapter
Postoperative Cerebrospinal fluid (CSF) fistulas are one of the most important complications in the early period after vestibular schwannoma surgery. The aim of this study was to identify patients likely to develop CSF leaks using a retrospective analysis. Between January 2001 and December 2006, 420 patients underwent retrosigmoidal microsurgical t...
Article
Full-text available
Vestibular schwannomas (VS) are the most common tumors of the cerebellopontine angle (CPA). Their surgical management has reached high standards in the last decade. Treatment options for VS are microsurgical removal or Radiosurgery. The following three basic operative approaches are currently utilized: Retrosigmoid approach (RSA), translabyrinthine...
Article
Full-text available
Different pathologies such as tumors or focal dysplasias can be removed from eloquent areas without subsequent functional deficits. What has not yet been established is the removal of structural abnormalities in sensorimotor area associated with substantial neurological deficits performed in order to accomplish functional improvement. Neurosurgical...
Article
Full-text available
The reliable preoperative visualization of facial nerve location in relation to vestibular schwannoma (VS) would allow surgeons to plan tumor removal accordingly and may increase the safety of surgery. In this prospective study, the authors attempted to validate the reliability of facial nerve diffusion tensor (DT) imaging-based fiber tracking in a...
Article
For postoperative CSF-fistula prevention a better understanding of its origins and risk factors is necessary. To identify the role of the tumor growth for the risk to develop CSF-fistula we performed a retrospective analysis. 519 patients between the years 2000 and 2007 had a retrosigmoidal surgical removal of vestibular schwannoma in a standardize...
Chapter
Intraoperative imaging is one of the major advancement in brain tumor surgery in the last years. The golden standard is intraoperative high-field magnetic resonance imaging. Different types of intraoperative scanner are currently utilized. A schematic classification can be based on the strength of the magnetic field: low field and high field scanne...
Article
The aim of this study was to objectively assess the patients' acceptance for awake craniotomy in a group of neurosurgical patients, who underwent this procedure for removal of lesions in or close to eloquent brain areas. Patients acceptance for awake craniotomy under local anesthesia and conscious sedation was assessed by a formal questionnaire (PP...
Article
Full-text available
Complete resection of grade II gliomas might prolong survival but is not always possible. The goal of the study was to evaluate the location of unexpected grade II gliomas remnants after assumed complete removal with intraoperative (iop) MRI and to assess the reason for their non-detection. Intraoperative MR images of 35 patients with hemispheric g...
Article
Transsphenoidal pituitary adenoma surgery is related to a low morbidity rate. The complications that can occur are classified as intra- and extracranial. The aim of the study is to discuss one group of these complications involving the sphenoid sinus: mucocele and its possible transformation into pyocele. We evaluate clinical presentation, manageme...
Article
The purpose of this study was to identify the anatomy of pineal region venous complex using neuronavigation software when distorted by the presence of a space-occupying lesion and to describe the anatomical relationship between lesion and veins. Moreover we discuss its influence on the choice of the surgical strategy. Of the 33 patients treated at...
Article
Full-text available
Ultrasound (US) is being used increasingly in intraoperative imaging. Its reliability in identifying low-grade gliomas (LGG), however, has not been shown definitively. We compared the quality and reliability of high-end two-dimensional (2D) ultrasound (US) and 1.5 Tesla intraoperative MRI (iopMRI) images in 11 patients with LGG. The parameters eval...