Biomedical subjects

H Bertalanffy

Publications and source records attributed to H Bertalanffy.

At least 19 recordsLinked to original sources

PubMed2003

The Doppler-guided transfalcine venous approach in selected cases of vein of Galen malformations.

OBJECTIVE: This investigation was performed to evaluate the specific procedural issues and indications of a surgically assisted Doppler-guided endovascular transfalcine venous approach for the treatment of vein of Galen aneurysmal malformations (VGAM) in critically ill neonates. PATIENTS AND METHODS: Two neonates out of a clinical series of 15 children (8 males and 7 females) with vein of Galen malformations were treated by our neurovascular team, using a combined surgically assisted endovascular transfalcine approach. In the biplanar angiography room a radiographically guided craniotomy (1.5 cm) was placed over the cranial projection of the falciforme sinus. After craniotomy the orthograd flow of the falciforme sinus was identified by Doppler ultrasonography. The sinus was punctured by an i. v. cannula with injection port and was sutured to the skin. A microcatheter was maneuvered over a guide into the malformation under fluoroscopic control. For embolization Guglielmi electrolytically detachable platinum coils were placed into the malformation as an embolic agent. Neurological examination records, available MR images, computed tomographic scans, pre- and postembolization angiograms and follow-up data were analyzed. RESULTS: In both individuals the malformation was classified as VGAM. The follow-up was 6 and 7 months, respectively. No technique associated morbidity or mortality occurred in the present series. At discharge both selected neonates were in stable condition and the flow in the VGAMs could be significantly reduced by a combination of approaches including the venous transfalcine approach. Meanwhile, 6 months after birth one neonate died due to a deterioration of the pulmonary hypertension. CONCLUSIONS: Endovascular treatment is presently the most efficient strategy to allow neonates and infants survive the early manifestation of vein of Galen malformations and probably render a normal neurological development. Consequently, a combination of approaches in selected cases including the Doppler guided venous transfalcine route should be regarded as a preferential treatment modality, especially in patients with arterial vasospasms and venous stenosis.

Cerebral Angiography↗

PubMed2003

[Aneurysmal subarachnoid hemorrhage: role of computerized tomography for correct prediction of the ruptured aneurysm site].

OBJECTIVE: To investigate if the intracisternal distribution of subarachnoid hemorrhage (SAH) following aneurysm rupture allows the correct prediction of the symptomatic aneurysm site. [nl] METHODS: Ninety-nine consecutive patients with acute SAH and angiographically proven aneurysm were included into the study. The parent vessel of the diagnosed aneurysms were the anterior communicating artery (ACoA) in 38 patients, the middle cerebral artery (MCA) in 26 patients, the internal carotid artery (ICA) in 25 patients, the pericallosal artery (A2) in 5 patients, the basilar artery (BA) in 4 patients and the vertebral artery (VA) in 1 patient. In 21 patients, an additional asymptomatic aneurysm was diagnosed. The initial computerized tomography (CT) scans of the 99 patients were given to 2 experienced vascular neurosurgeons, who were blinded for the angiography findings. The 2 investigators had to predict the site of the ruptured aneurysm. [nl] RESULTS: Investigator 1 correctly predicted the aneurysm site in 56 (57 %), investigator 2 in 59 of the 99 patients (60 %). Investigator 1 correctly identified 81 % of the MCA aneurysms, and investigator 2 74 % of the ACoA aneurysms. However, in only 46 of the 99 patients (47 %), the aneurysm site was correctly predicted by both investigators together. [nl] CONCLUSION: The results indicate, that the distribution of the subarachnoid blood as shown on the first CT scan after aneurysm rupture barely allows to predict the symptomatic aneurysm site. Thus, neurosurgical decision making (identification of the ruptured aneurysm in patients with multiple aneurysms; surgical exploration in patients with non-perimesencephal SAH, but negative angiography) should not rely on the first CT scan after SAH.

Adult↗

PubMed2002

Combined intrathecal baclofen and morphine infusion for the treatment of spasticity related pain and central deafferentiation pain.

OBJECTIVES: Complex pain syndromes due to spasticity and central deafferentation often fail to respond to medical therapy and create challenging problems in the pain management. So far, only spasticity associated musculosceletal pain has been reported to respond to intrathecal baclofen application [1, 2]. METHODS: We report the treatment of severe neuropathic pain in a patient with ED and the combined intrathecal application of baclofen and morphine in 5 patients with severe spasticity related pain. RESULTS: Continuous intrathecal baclofen infusion resulted in a pain free period of 20 months in the patient with ED. Patients with spasticity treated with intrathecal application of baclofen and morphine were pain free for a mean period of 2 years. CONCLUSION: Intrathecal baclofen and morphine application proved to be effective in spasticity related and central deafferentation pain and should therefore be considered in the management of these patients.

Afferent Pathways↗

PubMed2002

The punctate midline myelotomy concept for visceral cancer pain control--case report and review of the literature.

INTRODUCTION: Nauta et al. first reported on a successful punctate midline myelotomy (PMM) at the spinal cord Th 10 level for the treatment of intractable pelvic cancer pain. CASE STUDY: The authors published another case history of a patient with multiple anaplastic carcinomas of the small intestine, peritoneal carcinosis and retroperitoneal lymphomas, suffering from severe visceral pain in the hypo-, meso-, and epigastrium. Nauta's PMM was successfully performed at the level Th 4. Narcotic medication was tapered from 30 mg i.v. morphine per hour preoperatively to 5 mg per hour within 5 days postoperatively. Pain intensity decreased from 10 to 2-3 on the visual analog scale. Only minor transient side effects appeared postoperatively. Pain reduction remained until the patient died from the extended disease five weeks later. DISCUSSION: Meanwhile Nauta et al. reported on 5 additional patients, in whom PMM led to a sufficient pain reduction. Another paper reported on sufficient control of visceral pain due to advanced stomach cancer after a modified Th 1-2 PMM. CONCLUSION: PMM sufficiently controls not only pelvic visceral pain, but also visceral pain generated in the meso- and epigastrium. The findings support the concept of a midline dorsal column visceral pain pathway.

Abdominal Neoplasms↗

PubMed2002

[Analysis of factors affecting the prognosis of vertebral metastases].

The goal of this study was to evaluate factors for the prognosis of patients with metastatic spinal tumors. 139 patients with vertebral metastases were studied. The modified Tokuhashi Score (a preoperative score composed of six parameters) and single factors were analysed with statistical methods. The modified Tokuhashi Score showed a significant correlation (p = 0,0019) with survival time of patients. Additionally, only the Karnofsky Index as single parameter showed statistically significant correlation(p = 0.0016). Regarding the logistic regression, primary tumor, age, sex and Karnofsky Index were identified as prognostic factors for survival time. This trial could demonstrate that the Tokuhashi Score is a successful predicting tool for the assessment of prognosis of patients with vertebral metastases.

Adult↗

PubMed2002

[Recommendations for the management of unruptured intracranial aneurysms].

Optimal management of patients with unruptured intracranial aneurysms (UIAs) remains controversial. Recent studies have found conflicting data regarding the natural history and the treatment outcome of UIAs. Based on the recommendations published by the American Heart Association, the Section of Vascular Neurosurgery of the German Society of Neurosurgery has formed a task force to summarize the available data and to develop a practical framework for the management of UIAs. For UIAs, only evidence from nonrandomized historical cohort comparisons and case series without control subjects are available, supporting only grade C recommendations (options), but no standards (grade A) and no guidelines (grade B). The present recommendations have been developed as a neurosurgical, neuroradiological and neurological consensus. They are based on the existing data of both treatment risks and the risks of the natural history of UIAs.

Autoradiography↗

PubMed2002

Helium (argon) plasma coagulation in neurosurgery. morphology of tissue damage and reparation.

Plasma coagulation, used in some neurosurgical operative settings, is currently under experimental investigation for the precise assessment of the kind and extent of tissue damage. We established a standardised trial to investigate the effects of helium (argon) plasma coagulation - H(A)PC - on rat brain tissue. The tissue reactions were observed with common methods of morphology including immunohistology and electron microscopy. A time dependent profile of the tissue reactions was performed from day 1 after operation up to 6 weeks. The tissue reaction consisted of clearly demarcated concentric zones. The depth of the lesion was about 1 mm maximally, at the beginning. Reparative forces acted at variance both in the different layers and at the edges versus the center of the damage. A manifold but reproducible picture emerges in the various compartments allowing the study of different aspects of organisation and/or elimination of tissue components. This study has demonstrated that a defined circumscribed and reproducible small lesion can be performed with H(A)PC. As in other areas of surgery, this technique has proven to be minimally traumatic. Clinical application of this technique in neurosurgery is therefore promising. In addition, H(A)PC lesions are obviously best suited for morphological studies of early and late reparative reactions in cells and tissues.

Animals↗

PubMed2002

Phase I clinical trial on adjuvant active immunotherapy of human gliomas with GD2-conjugate.

The objective of this study was to determine the feasibility, toxicity, and potential therapeutic benefits of an adjuvant active immunotherapy using a tumour specific ganglioside (GD2) conjugate for the adjuvant treatment of recurrent or progressive gliomas. Seven patients with proven GD2 expression in surgical specimens underwent a vaccination course with GD2-KLH/MPL-A conjugate. The follow-up was performed according to WHO guidelines regarding common toxicity criteria. Antibody titres against the ganglioside and the adjuvants were analysed. All patients developed a local type 4 reaction. Anti-GD2-antibody titres could not be detected, despite high titres against the immunoadjuvants. No tumour regression was observed. The disease remained stable for a median of 21.5 weeks (6-34 weeks). The median survival time after the first immunization was 47 weeks. The medial total survival time was 76 weeks. Adverse effects have not been observed. Active GD2-KLH/MPL-A immunization was technically feasible, but did not elicit anti-GD2 antibody generation.

Adjuvants, Immunologic↗

PubMed2001

Treatment-induced neoangiogenesis in cerebral arteriovenous malformations.

We investigated the angiogenetic and proliferative activity of the endothelium of 30 consecutive surgical cases of AVM treated at our institution by immunohistochemical detection of the PCNA, MIB-1, Flk-1 and VEGF antibodies. Endothelial positive immunostaining was observed in 87% of the cases for PCNA, in 20% for MIB-1, and in 80% for Flk-1. Of 22 individuals treated with incomplete embolization prior to surgery, 17 showed an expression of VEGF (77%), but only two of the eight patients (25%) who were treated without prior embolization exhibited such an immunoreaction (P=0.0086). The proliferation and growth of cerebral AVMs is documented by endothelial expression of PCNA and MIB-1. The statistically significantly higher expression of VEGF in partially obliterated (embolized) AVMs is most likely caused by transient regional hypoxia within the AVM nidus that mediates neoangiogensis. It points out the clinical relevance of a complete occlusion in order to avoid neovascularization associated with subsequent morbidity and mortality.

Antigens, Nuclear↗

PubMed2001

Operative management of third ventriculostomy in cases of thickened, non-translucent third ventricular floor: technical note.

Today, endoscopic third ventriculostomy is an established operative modality in occlusive hydrocephalus. The elemental step in third ventriculostomy is the perforation of the floor of the third ventricle. Especially with a thickened third ventricular floor, anatomical orientation can be disturbed and perforation of third ventricular floor technically difficult. The combination of a neuronavigation system with an endoscope provides interactive image-guided neuroendoscopy. Exact planning of the approach is thus possible and the ideal trajectory to the target area can be determined. We have combined interactive neuronavigation and intraoperative fluoroscopy for incorporating real-time feedback to optimize endoscopy in patients with a thickened third ventricular floor selected for third ventriculostomy.

Endoscopy↗

PubMed2001

Incorrect vector after calibration of surgical instruments for image guidance. The problem and the solution: technical note.

Recently, the use of intra-operative image guidance has gained an increasing role in neurosurgery for both spinal and cerebral interventions. Some modern neuronavigation systems are able to register any surgical instrument and create a virtual pointer. A virtual elongation of the digitized instrument is frequently used for neuroendoscopic procedures and spinal instrumentation. The instrument is equipped with a universal instrument adapter clamp and digitized by touching the tip of the instrument into a calibration cone. An algorithm calculates the vector of the instrument using two points: the tip of the instrument, and the geometrical center of the instrument adapter geometry. If a virtual elongation of the calibrated instrument is performed, the neuronavigation software may calculate an incorrect virtual target point. We developed an instrument calibration matrix (ICM) that automatically calibrates the correct vector, tip, and diameter of the instrument used for image-guided surgery. The ICM is easy to handle and does not cause a time delay during surgery. Virtual elongation of the surgical instruments shows correct anatomic data, which are fundamental for planning ventricular tapping and spinal screw placement in particular. The instrument calibration matrix is essential if surgical instruments are digitized and used for neuronavigation. It helps to avoid mis-planning of surgical vectors and mis-placement of the used instruments.

Calibration↗

PubMed2001

Silent period in the mentalis muscle induced by facial nerve and cutaneous stimulation.

The aim of this study was to demonstrate that silent periods of the mentalis muscle are induced after facial nerve stimulation and cutaneous stimulation in normal subjects. When the marginal mandibular branch of the facial nerve and the cutaneous nerve in areas adjacent to the lower lip were stimulated during slight voluntary contraction of the mentalis muscle, silent periods were elicited with surface electrodes on the mentalis muscle. The early phase and the late phase of the silent period were elicited by marginal mandibular branch stimulation. The early phase of the silent period was recognized following the F waves and it disappeared at 36.3 msec. The average duration of the late phase of the silent period was 59.2 msec, with an average latency of 62.5 msec. Only the late phase of the silent period after cutaneous stimulation could be elicited, with a duration and latency of 55.9 msec and 54.0 msec respectively. The authors conclude that the silent period is able to be elicited in the mentalis muscle by peripheral nerve stimulation, and is one of the late responses in facial muscles.

Adult↗

PubMed2001

Image-guided placement of eye muscle electrodes for intraoperative cranial nerve monitoring.

OBJECTIVE: Monitoring of the oculomotor system during cranial base or brainstem surgery requires extraocular intraorbital insertion of electromyography electrodes. We investigated the use of image-guidance technology for anatomically correct intraorbital electrode placement. METHODS: For neuronavigation, an optical tracking system was used in a standard fashion. Needle electrodes were inserted percutaneously into the lateral rectus, inferior rectus, and superior oblique muscle along the axis of a hand-held pointer or by means of an electrode applicator to allow direct tracking with the navigation system. Electromyographic monitoring was performed by multichannel recordings of free running or evoked activity from the selected muscles. RESULTS: We have used this method in 10 patients; 5 had cranial base tumors and 5 underwent operations for brainstem lesions. No additional instruments or resources were required compared with the routine setup, and no intraorbital structures were injured. Successful monitoring of oculomotor, trochlear, or abducent nerve function was possible in each case. CONCLUSION: This method may have the potential to increase the safety and success rate of intraoperative electro-ophthalmography during microsurgery focused on preservation of neurological function.

Abducens Nerve↗

PubMed2001

Endothelial proliferation, neoangiogenesis, and potential de novo generation of cerebrovascular malformations.

OBJECT: To date, both arteriovenous malformations (AVMs) and cavernomas have been considered to be congenital malformations. A recent survey of the literature has shown the potential for de novo generation of both familial and sporadic cavernomas as well as AVMs. Therefore, it was of interest to determine the biological behavior of these lesions in detail. METHODS: The proliferative and angiogenic capacities of the endothelium of 13 cavernomas and 25 AVMs obtained in patients recently treated (1997-1998) at one institution were studied. Immunohistochemical staining for proliferating cell nuclear antigen (PCNA), MIB-1, and vascular endothelial growth factor (VEGF) and its receptor Flk-1 was performed using standard staining procedures. Positive immunostaining of the nuclei of endothelial cells was observed in specimens of both AVMs and cavernomas for PCNA (80% of AVMs and 85% of cavernomas), and Flk-1 (80% of AVMs and 31% of cavernomas). Endothelial expression of VEGF in the 18 incompletely embolized AVMs was found in 72% of cases but only in 28% of the seven cases in which patients did not undergo endovascular treatment: it was found in 38% of cavernomas. Endothelial expression of MIB-1 was found in 12% of AVMs but in no cavernomas. CONCLUSIONS: These results indicate that there is endothelial proliferation as well as neoangiogenesis in cerebral cavernomas and AVMs. The increased level of angiogenesis in only partially obliterated AVMs underscores the need for radical and complete occlusion of cerebral AVMs to avoid recurrences and further risks of morbidity.

Adult↗

PubMed2001

Frameless navigation and endoscopy.

OBJECT: Frameless computerized neuronavigation has been increasingly used in intracranial endoscopic neurosurgery. However, clear indications for the application of neuronavigation in neuroendoscopy have not yet been defined. The purpose of this study was to determine in which intracranial neuroendoscopic procedures frameless neuronavigation is necessary and really beneficial compared with a free-hand endoscopic approach. METHODS: A frameless infrared-based computerized neuronavi- gation system was used in 44 patients who underwent intracranial endoscopic procedures, including 13 third ventriculostomies, nine aqueductoplasties. eight intraventricular tumor biopsy procedures or resections, six cystocisternostomies in arachnoid cysts, five colloid cyst removals, four septostomies in multiloculated hydrocephalus, four cystoventriculostomies in intraparenchymal cysts, two aqueductal stent placements, and fenestration of one pineal cyst and one cavum veli interpositi. All interventions were successfully accomplished. In all procedures, the navigational system guided the surgeons precisely to the target. Navigational tracking was helpful in entering small ventricles, in approaching the posterior third ventricle when the foramen of Monro was narrow, and in selecting the best approach to colloid cysts. Neuronavigation was essential in some cystic lesions lacking clear landmarks, such as intraparenchymal cysts or multiloculated hydrocephalus. Neuronavigation was not necessary in standard third ventriculostomies, tumor biopsy procedures, and large sylvian arachnoid cysts, or for approaching the posterior third ventricle when the foramen of Monro was enlarged. CONCLUSIONS: Frameless neuronavigation has proven to be accurate, reliable, and extremely useful in selected intracranial neuroendoscopic procedures. Image-guided neuroendoscopy improved the accuracy of the endoscopic approach and minimized brain trauma.

Biopsy↗

PubMed2000

Spinal type IV arteriovenous malformations (perimedullary fistulas) in children.

OBJECTS: Intradural perimedullary spinal arteriovenous fistula (AVF) is a synonym for type IV spinal arteriovenous malformation (AVM). It is an important clinical differential diagnosis in all patients with slowly progressive or acute spinal symptoms. Perimedullary AVFs are rare in the paediatric age group. We report the treatment regimen and the clinico-radiological findings for these malformations at our institution. METHODS: Of four paediatric patients, three individuals with persistent fistulas after endovascular treatment were operated on. The malformations were obliterated completely in all patients without any morbidity. In three patients previously documented neurological symptoms resolved during follow-up. CONCLUSIONS: If slowly progressive or acute radicular or medullary symptoms arise in children, a spinal arteriovenous malformation should be ruled out by MRI. A combined endovascular and surgical treatment of paediatric spinal AVM type IV (perimedullary AVFs) carries a low risk of morbidity and is reasonably effective.

Adolescent↗

PubMed2000

Early experiences of haemostasis on brain tumour surgery with Argon Plasma Coagulation (APC).

OBJECTIVE: We first applied a novel haemostatic strategy involving Argon Plasma Coagulation (APC), an innovative no-touch electrocoagulation technique in which a high-frequency alternating current is delivered to the tissue through ionized argon gas, to brain tumour surgery, and report its usefulness and limitations. METHODS: The APC system we used comprised an APC 300 developed by ERBE Elektromedizin GmbH, Germany. We applied APC to 13 brain tumours in 12 patients (5 meningiomas, 4 sarcomas, 2 glioblastomas, and 2 pituitary adenomas). To avoid unnecessary thermal injury to the tissue as much as possible, power/gas flow settings of 20 and 40 W were used. The impact time was varied individually but was around several seconds per one impact. The argon jet (1.5-4.5 L/min) clears a field of pooled blood and evenly conducts electrical energy to the target tissue. A thin and flexible probe particularly increased the usefulness of APC for haemostasis on deep-seated skull base tumour operations under a microscope. CONCLUSION: All patients were successfully treated and satisfied with the surgical results without any complications due to APC. APC appears to be an excellent alternative strategy for achieving haemostasis on vascular-rich brain tumour surgery, and may be valuable for the management of patients with coagulation defects.

Adenoma↗

PubMed2000

Advanced image-guided skull base surgery.

BACKGROUND: Tumors of the skull base frequently encase or extend into normal neural and vascular structures. Preoperative planning and intraoperative identification of anatomic landmarks is especially important in complex tumors since it helps avoid or minimize surgical morbidity. METHODS: By creating a surgical plan the image guidance software offers help in the establishment of a surgical approach. During surgery, the neuronavigation system displays the location of anatomic landmarks of the skull base regardless of any erosion or displacement. RESULTS: A series of 10 patients with complex tumors in various skull base locations is reported. Osseous structures are easily identified using the CT-based image guidance since these landmarks do not shift due to CSF loss. Image fusion of CT and MRI data gives additional information on the displacement of soft tissue structures. Image fusion in a substraction mode is helpful when a tumor has invaded bony structures or when the encasement of major vessels has to be visualized. CONCLUSION: The preoperative data preparation (planning of the approach, image fusion) plays a vital role in modern neuronavigation and contributes useful information during surgery for complex skull base tumors. Such advanced neuronavigation increases the efficacy and safety of intraoperative maneuvers. Eroded and distorted anatomic landmarks are not subject to a significant amount of intraoperative shift throughout the surgical procedure.

Adult↗