Biomedical subjects

Axel Perneczky

Publications and source records attributed to Axel Perneczky.

10 recordsLinked to original sources

PubMed2007

White matter fiber tracking computation based on diffusion tensor imaging for clinical applications.

Fiber tracking allows the in vivo reconstruction of human brain white matter fiber trajectories based on magnetic resonance diffusion tensor imaging (MR-DTI), but its application in the clinical routine is still in its infancy. In this study, we present a new software for fiber tracking, developed on top of a general-purpose DICOM (digital imaging and communications in medicine) framework, which can be easily integrated into existing picture archiving and communication system (PACS) of radiological institutions. Images combining anatomical information and the localization of different fiber tract trajectories can be encoded and exported in DICOM and Analyze formats, which are valuable resources in the clinical applications of this method. Fiber tracking was implemented based on existing line propagation algorithms, but it includes a heuristic for fiber crossings in the case of disk-shaped diffusion tensors. We successfully performed fiber tracking on MR-DTI data sets from 26 patients with different types of brain lesions affecting the corticospinal tracts. In all cases, the trajectories of the central spinal tract (pyramidal tract) were reconstructed and could be applied at the planning phase of the surgery as well as in intraoperative neuronavigation.

Adolescent↗

PubMed2005

Tumors of the lateral and third ventricle: removal under endoscope-assisted keyhole conditions.

OBJECTIVE: Intraventricular tumors usually are managed by approaches and microsurgical techniques that need retraction and dissection of important brain structures. Minimally invasive endoscopic procedures achieve a remarkable alternative to conventional microneurosurgical techniques. Endoscope-assisted microneurosurgery may be a minimally invasive technique with maximally effective treatment. Using the keyhole concept for planning the surgical strategy, the reduction of the brain retraction is achieved, which is one of the main benefits of this technique. METHODS: We treated 35 patients (16 female patients and 19 male patients) with tumors in the lateral (n = 8) and the third (n = 27) ventricle. Patient age at the date of surgery ranged from 5 to 73 years. The follow-up period ranged from 6 to 83 months. The tumors were operated on using transcortical, transcallosal, or suboccipital transtentorial or infratentorial supracerebellar approaches after precise planning of the skin incision, the trephination, and the trajectory to the center of the tumor, performed earlier with a magnetic resonance imaging scan. RESULTS: Total removal of the tumor was achieved in 28 patients (78.5%). In 2 patients (6.5%), recurrent tumor occurred. In 5 patients (15%), parts of the tumors remained because of infiltration of eloquent areas. Overall clinical improvement was achieved in 31 patients (87%). Three patients (10%) were unchanged and 1 patient (3%) deteriorated. CONCLUSION: Endoscope-assisted keyhole neurosurgery seems to be a safe method of removing tumors in all regions inside the ventricular system with a low risk of permanent neurological deficits. The exact surgical corridor planning on the basis of the keyhole strategy offers less traumatic exposure of even deep-seated endoventricular tumors.

Adolescent↗

PubMed2005

Ten-year experience with the supraorbital subfrontal approach through an eyebrow skin incision.

OBJECTIVE: More than ever before, the priority in contemporary neurosurgery is to achieve the greatest therapeutic effect while causing the least iatrogenic injury. The evolution of microsurgical techniques with refined instrumentation and illumination and the enormous development of preoperative and intraoperative diagnostic tools enable neurosurgeons to treat different lesions through limited and specific keyhole approaches. METHODS: Based on our surgical experience, the technique of supraorbital subfrontal craniotomy is described in detail in this article. After an eyebrow skin incision is made, a limited supraorbital craniotomy is performed with a width of 15 to 25 mm and a height of 10 to 15 mm. RESULTS: We have been using the supraorbital keyhole craniotomy since 1985 and have approached a variety of lesions within the anterior, middle, and posterior cranial fossae. During a 10-year period between July 1994 and June 2004, the lesions treated via the supraorbital approach in our department comprised 1125 intracranial tumors or cystic lesions, cerebral aneurysms, and other miscellaneous diseases, performed by 23 different surgeons and residents. Of these 1125 patients, we operated on 471 of them, and information obtained from 450 contributed to the follow-up data. Three months after surgery, the Glasgow Outcome Scale scores for this very heterogeneous group of patients were as follows: 5 in 387 patients (86.0%), 4 in 29 patients (6.4%), 3 in 16 patients (3.5%), 2 in 10 patients (2.2%), and 1 in 8 patients (1.8%). Of the 450 patients, 229 were treated for intracranial aneurysms, 93 for cranial base meningiomas, 39 for craniopharyngiomas, 23 for pituitary adenomas, 18 for deep-seated brainstem tumors, and 48 for other miscellaneous frontotemporal or suprasellar lesions. CONCLUSION: In our experience, the supraorbital craniotomy allows a wide, intracranial exposure for extended, bilaterally situated, or even deep-seated intracranial areas, according to the strategy of keyhole craniotomies. The supraorbital craniotomy offers equal surgical possibilities with less approach-related morbidity owing to limited exposure of the cerebral surface and minimal brain retraction. In addition, the short skin incision within the eyebrow and careful soft tissue dissection result in a pleasing cosmetic outcome.

Craniopharyngioma↗

PubMed2005

Endoscopic aqueductoplasty through a tailored craniocervical approach.

OBJECT: Neuroendoscopy has an essential role in the management of occlusive hydrocephalus due to a membranous obstruction of the sylvian aqueduct. Well-known endoscopic methods include endoscopic third ventriculostomy (ETV) and endoscopic aqueductoplasty through a frontal burr hole. Building on their experience in the endoscopic management of hydrocephalus, the authors realized that not all of their patients with aqueductal obstruction were eligible for the aforementioned lines of treatment. Certain anatomical situations made it impossible to perform ETV or endoscopic aqueductoplasty through a frontal burr hole. Long-term complications of the shunt system led the authors to seek an alternative form of treatment for these patients. In this study, they present a new endoscopic approach to performing aqueductoplasty through the fourth ventricle. METHODS: Endoscopic aqueductoplasty was performed in five patients by using a tailored craniocervical approach. In all patients a caudally located membranous obstruction of the sylvian aqueduct was present, and the authors were able to relieve the membranous obstruction in all patients without complications. All patients experienced improvement, which was demonstrated clinically and on imaging studies. CONCLUSIONS: Caudal endoscopic aqueductoplasty is a safe and effective method of treatment in the management of a caudally located membranous obstruction of the sylvian aqueduct. This should be considered as an alternative endoscopic method when other endoscopic solutions are not suitable.

Adolescent↗

PubMed2003

[Biportal neuroendoscopy of the prepontine cisterns].

INTRODUCTION: While bi- or multiportal approaches have been adopted in different fields of surgery including abdominal and spine surgery, the uniportal access into the skull is a traditional principle in neurosurgery. In this preclinical cadaver study the authors developed combinations of biportal endoneurosurgical dissections in the prepontine subarachnoid space to test the safety of this technique. METHODS: In 34 fresh post-mortem adult human cadavers and 14 formaldehyde-fixed adult human head specimen a total of 48 biportal endoscopical dissections were carried out. 0 degree, 30 degrees, and 70 degrees lens scopes with a diameter of 1.7 and 4.2 mm and trochars with a diameter of 5.0 to 6.5 mm were used. RESULTS: Six different endoscopic routes to the prepontine region and a total of 10 different combinations of this approaches could be described. Useful and safe biportal combinations were: 1. supraorbital on both sides, 2. supraorbital combined with ipsilateral anterior subtemporal, 3. supraorbital combined with contralateral anterior subtemporal, 4. supraorbital combined with ipsilateral posterior subtemporal, 5. supraorbital combined with ipsilateral frontal interhemispheric, 6. supraorbital combined with contralateral frontal interhemispheric, 7. anterior subtemporal combined with ipsilateral frontal interhemispheric, 8. anterior subtemporal combined with contralateral frontal interhemispheric. CONCLUSION: The biportal endomicrosurgical strategy offered effective and safe dissections within the prepontine subarachnoid space.

Adult↗

PubMed2003

Surgical technique of the supraorbital key-hole craniotomy.

BACKGROUND: The enormous development of microsurgical techniques and instrumentation together with preoperative planning using the excellent preoperative diagnostic facilities available, enables neurosurgeons to treat more complicated diseases through smaller and more specific approaches. METHODS: The technical details of the supraorbital key-hole craniotomy are described in this article as it has been evolving in our experience for more than 10 years. After an eyebrow skin incision with careful soft tissue dissection and single frontobasal burr-hole trephination, a supraorbital craniotomy is carried out with a diameter of about 1.5 x 2.5 cm. As a real frontolateral approach, the supraorbital craniotomy avoids removal of the orbital rim, the lesser sphenoid wing or the zygomatic arch. RESULTS AND CONCLUSIONS: The supraorbital craniotomy allows wide intracranial exposure of the deep-seated supra- and parasellar region, according to the concept of key-hole approaches. The limited craniotomy requires minimal brain retraction thus significantly decreasing approach-related morbidity. In addition, the short skin incision within the eyebrow, the careful soft tissue dissection, and the single burr hole trephination result in a pleasing cosmetic outcome.

Brain Diseases↗

PubMed2002

[Endosonographic anatomy of the ventricular system].

A preclinical cadaver study was performed to test a transendoscopic sonographic probe for neurosurgery. In 25 fresh post-mortem adult human cadaver with a total of 39 endo-sonographic dissections in the ventricular system were carried out. A sonograph with an outer diameter of 6 F was used and radial sonograms were made by a real-time image technique. First results showed precise imaging, comparable to a CT in a neighbouring area of 3 cm. In this publication, the authors describe the endo-neurosonographic anatomy of the ventricular system. The sonographic probe was advanced through the working canal of a ventriculoscope, then the endoscopic and sonographic imaging were compared. Results were documented by parallel sonographic and endoscopic photo and video recordings. Based on the authors experience, it is revealed that the additional sonographic view could also be used as a navigation tool.

Adult↗

PubMed2002

Topographic microsurgical anatomy of the paraclinoid carotid artery.

In this publication, the authors describe the microanatomic topography of the entire paraclinoid area with respect to the paraclinoid segment of the internal carotid artery and its surrounding anatomical structures. Special attention was given to the borders of the paraclinoid area, cavernous sinus, arterial vessels, and cranial nerves passing through the region. The paraclinoid region was defined as a pyramid-formed space formed by the dural covering of the anterior clinoid process. The superior border is formed by the continuity of the anterior petroclinoid fold, anteriorly on the superior surface of the anterior clinoid process and medially in the direction of the diaphragma sellae. This dural sheet encircles the internal carotid artery and forms the so-called distal dural ring of the internal carotid artery. The medial border of the paraclinoid region is formed by the body of the sphenoid bone and the adjacent periosteal sheet. The inferior border is formed by a fibrous plate between the middle and anterior clinoid processes. This so-called proximal dural ring separates the venous compartments of the cavernous area from the paraclinoid area. The lateral border is formed by the lateral surface of the anterior clinoid process with its dural covering. The arterial supply of this region is provided by branches of the intracavernous carotid segment and the ophthalmic artery. The important nerves in close vicinity to the paraclinoidal area are the optic and the oculomotor nerves. Understanding and knowledge of the topographic anatomy of the paraclinoid area is essential for microsurgical exposure of this region.

Adult↗

PubMed2002

Histological findings in coil-packed experimental aneurysms 3 months after embolization.

OBJECTIVE: Knowledge regarding tissue reactions within coil-packed aneurysms is poor. The purpose of this study was to analyze histological changes in a chronic experimental bifurcation aneurysm model that might explain the protective effect of Guglielmi detachable coils. METHODS: The aneurysms were produced by means of a venous graft pouch at a surgically created bifurcation of the carotid artery in the neck of rabbits. After 3 weeks, embolization with Guglielmi detachable coils was performed in the treatment group but not in the control group (seven rabbits each). At the time of embolization, six of seven treated aneurysms were completely occluded according to radiological criteria. Twelve weeks later, all aneurysms were explanted after final angiography. Histological examinations were performed with coils in situ. RESULTS: Six of seven embolized aneurysms demonstrated complete occlusion in final angiography. But gross pathology revealed that all specimens had differently sized open cavities between the coils. In only two cases, these spaces were very small and the aneurysmal sacs were filled with coils and tissue by more than 90%. Light microscopy demonstrated intraluminal granulation tissue and strong chronic inflammatory wall thickening with numerous foreign body cells at the interface between coils and tissue. Coils were partially incorporated into the aneurysmal wall, sometimes close to the surface and occasionally even outside the wall within the surrounding tissue. CONCLUSION: The protective effect of Guglielmi detachable coil treatment in our chronic experimental bifurcation aneurysms results from formation of intraluminal granulation tissue and wall thickening attributable to chronic inflammation.

Animals↗

PubMed2002

Primary myelomeningocele closure and consequences.

PURPOSE OF REVIEW: Myelomeningocele, the most frequently occurring open neural tube defect, requires lifelong care of the patient by medical professionals and by relatives. A basic understanding of the neurosurgical measures that have to be taken in the newborn, the infant, the child and the adult is important also for physicians of other disciplines involved in the treatment of patients with myelomeningocele. RECENT FINDINGS: The most recent topic broadly discussed in this context is the role of foetal neurosurgery for closure of the neural tube defect. There is ongoing debate as to whether the beneficial postnatal effects of a prenatal operation in the unborn foetus outweighs the possible complications for the mother as well as the child. SUMMARY: As some of the problems associated with myelomeningocele occur only later in life, it will still take many years until the beneficial, as well as the adverse, effects of prenatal neurosurgical procedures can be evaluated.

Arachnoid Cysts↗