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Biomedical subjects

Andrei Koerbel

Publications and source records attributed to Andrei Koerbel.

At least 19 recordsLinked to original sources
PubMed2006

The impact of petrosal vein preservation on postoperative auditory function in surgery of petrous apex meningiomas.

OBJECTIVE: The importance of preserving the superior petrosal vein has received increasing attention in the surgical treatment of pathologies involving the petrous apex. Recent reports have associated postoperative auditory nerve dysfunction with petrosal vein sacrifice. However, there is no systematic clinical study available thus far focusing on the postoperative auditory function after petrosal vein obliteration. METHODS: In 55 patients with meningiomas involving the petrous apex, pre- and intraoperative findings including petrosal vein sectioning were analyzed retrospectively concerning their impact on postoperative auditory function. RESULTS: The petrosal vein was preserved in 26 (47%) cases. In 27 (49%) cases, this vein was not preserved. Hearing loss occurred in 11% of all cases. In the preserved-vein group, postoperative hearing loss occurred in 3 of 26 (11%) cases and in the sacrificed-vein group in 3 of 27 (11%) cases. CONCLUSION: Sacrifice of the petrosal vein during surgery of petrous apex meningiomas seems not to have an impact on postoperative auditory function.

Adult↗
PubMed2006

The impact of hypotension due to the trigeminocardiac reflex on auditory function in vestibular schwannoma surgery.

OBJECT: Surgical manipulation of the fifth cranial nerve during its intra- or extracranial course may lead to bradycardia or even asystole as well as arterial hypotension, a phenomenon described as the trigeminocardiac reflex (TCR). The authors studied the impact of this reflex on postoperative auditory function in patients undergoing vestibular schwannoma (VS) surgery. METHODS: One hundred patients scheduled for VS surgery were studied prospectively for parameters influencing the postoperative auditory function. The evaluation included sex, age, pre- and postoperative auditory function, preoperative mean arterial blood pressure, preoperative medical diseases or medication (for example, antiarrhythmia drugs), tumor size and localization, and the intraoperative occurrence of the TCR. The TCR, which occurred in 11% of the patients, influenced the postoperative hearing function in the patients with Hannover Class T3 and T4 VSs. With an overall hearing preservation of 47%, 11.1% of the patients in the TCR group and 51.4% of those in the non-TCR group experienced preserved hearing function postoperatively. In cases involving larger tumors (Hannover Class T3 and T4), an intraoperative TCR was associated with a significantly worse postoperative hearing function during VS surgery (p = 0.005). CONCLUSIONS: The hypotension following TCR is a negative prognostic factor for hearing preservation in patients undergoing VS surgery. Patients' knowledge of this can be increased pre- and postoperatively. Further study of this phenomenon will advance the understanding of the underlying mechanisms and may help to improve hearing preservation by controlling the occurrence of the TCR.

Adolescent↗
PubMed2005

Differentiating imaging findings in primary and secondary tumors of the jugular foramen.

The preoperative diagnosis of a jugular foramen tumor may be challenging, since a large variety of unusual lesions may be located in this region. These tumors may be classified as primary lesions (which are located in the jugular foramen or extend from the jugular foramen into the surrounding structures) and as secondary lesions (that extend from the surrounding structures into the jugular foramen). Primary tumors include glomus jugulare tumors, schwannomas, meningiomas and peripheral primitive neuroectodermal tumors, while secondary tumors comprise chordomas, chondrosarcomas, chondroblastomas, giant-cell tumors, cholesterol granulomas, giant cholesterol cyst, endolymphatic sac tumors, reactive myofibroblastic tumors, temporal bone carcinomas and metastases. Accurate preoperative radiological suspicion is of great value for preoperative patient counseling and has a direct impact on the surgical planning in these cases. The present study describes and discusses the main differentiating imaging features of lesions involving the jugular foramen, whose accurate preoperative radiological evaluation is essential for proper surgical planning.

Brain Neoplasms↗
PubMed2005

Ventral extradural spinal meningeal cyst causing cord compression: neurosurgical treatment.

Spinal extradural meningeal cysts are typically formed by a thin fibrotic membranous capsule, macroscopically similar that of an arachnoid membrane, filled by cerebro spinal fluid and related to a nerve root or to the posterior midline. Ventral location is extremely rare and when it occurs they usually cause spinal cord herniation through the ventral dural gap. A 61 year-old man who began with a two years long history of insidious tetraparesis, spasticity and hyperreflexia in lower extremities, and flaccid atrophy of upper limbs, without sensory manifestations, is presented. Investigation through magnetic resonance imaging demonstrated an extensive spinal ventral extradural cystic collection from C6 to T11. The lesion was approached through a laminectomy and a cyst-peritoneal shunt was introduced. The cyst reduced in size significantly and the patient is asymptomatic over a 48 months follow-up. This is the first reported case of a spontaneous ventral extradural spinal meningeal cyst causing cord compression. Cyst-peritoneal shunt was effective in the treatment of the case and it should be considered in cases in which complete resection of the cyst is made more difficult or risky by the need of more aggressive surgical maneuvers.

Arachnoid Cysts↗
PubMed2005

Raeder's syndrome after embolization of a giant intracavernous carotid artery aneurysm: pathophysiological considerations.

We present the case of a 47 years old woman submitted to an endovascular trapping of a left cavernous internal carotid artery aneurysm, in which the distal balloon was inflated, as usually done, within the cavernous segment of the internal carotid artery, different from the proximal one which was inflated inside the carotid canal due to technical problems. Consequently, a clinical picture of Raeder's paratrigeminal neuralgia took place. This is the first case report in the literature with theses characteristics. A review of the anatomic pathways and further considerations about the possible pathophysiological mechanisms involved are presented.

Balloon Occlusion↗
PubMed2005

Evolution of vestibular schwannoma surgery: the long journey to current success.

The extraordinary improvement of patient outcome after surgical treatment for vestibular schwannomas is relatively recent and has occurred mainly over the last 30 years. The introduction of microsurgical techniques has resulted in increasing degrees of precise anatomical and functional preservation of the facial and cochlear nerves. An expanded microsurgical technique accompanied by continuous electrophysiological monitoring has resulted in marked changes in the primary goals for this surgery. Whereas in the past the primary goal of vestibular schwannoma management was to preserve the patient's life, the objective in vestibular schwannoma treatment today is to preserve neurological function. Long-term follow-up examinations show negligible recurrence rates, indicating that the aim of preservation of nerve function does not limit the completeness of tumor removal with modern neurosurgical techniques. Despite these advances in preserving the anatomical integrity of, for example, the cochlear nerve, losses of function and even deafness may occur postoperatively in some cases. Current biological and technical research in experimental and clinical settings addresses these problems. In this article, the authors report in detail the developments achieved in vestibular schwannoma surgery and the great clinicians to whom these results can be credited.

Deafness↗
PubMed2005

Peroneal nerve compression resulting from fibular head osteophyte-like lesions.

BACKGROUND: The anatomical relationship of the fibular head with the fibular nerve is a critical point in regard to injuries of peripheral nerves in the lower extremities. In this location, the peroneal nerve may be injured due to several mechanisms, and osteophyte-like lesions can be considered as a differential diagnosis. METHODS: The suitable literature concerning this association is reviewed and a case is presented. A 15-year-old adolescent boy presented with right peroneal nerve palsy on admission. The radiological examinations (computed tomography and magnetic resonance imaging) demonstrated an osteophytic lesion in the head of the right fibula. The patient underwent surgical decompression of the nerve and resection of the lesion. Postoperatively, there was a complete recovery of the deficits. CONCLUSIONS: The association of osteophyte-like bone changes and peroneal nerve palsy is rare. The differential diagnoses of these lesions include cartilaginous exostoses and osteochondromas, which may be related to hereditary multiple exostoses syndrome. The timing of the treatment plays an important role in the neurological recovery.

Adolescent↗
PubMed2005

Epidermoid cysts of the cavernous sinus.

BACKGROUND: Epidermoid cysts involving the cavernous sinus are rare lesions. They can be divided into 3 different categories: extracavernous, interdural, and true intracavernous. METHODS: This classification of cavernous epidermoid cysts is correlated with the extent of tumor resection and the clinical outcome in reported cases here and elsewhere. RESULTS: Patients with cysts invading or compressing the cavernous sinus present with an excellent functional recovery after surgery independent of the extent of tumor resection. In cases of interdural cysts, there is often an adherence of the tumor capsule to the third and fourth cranial nerves. Therefore, in this group, subtotal resection is a safe strategy to prevent surgical morbidity. However, this policy may lead to a higher incidence of tumor recurrence in these cases. In true intracavernous lesions, a higher rate of total removal is possible despite the increased occurrence of internal carotid artery encasement and cranial nerve displacement. CONCLUSION: Postoperative outcome with preservation of neural and vascular structures in cavernous epidermoid cysts is more likely related to surgical strategy than to tumor localization. Independent of the different tumor origins in these cases, a subtotal resection is usually sufficient to achieve postoperative improvement of the symptoms without additional morbidity.

Adult↗
PubMed2005

Primary intrasellar schwannoma: clinical, aetiopathological and surgical considerations.

Schwannomas originating within the sella turcica are extremely rare. We describe the clinical, radiological and intraoperative findings of a patient with an intrasellar and suprasellar schwannoma. Gross total tumour removal was performed by a trans-sphenoidal approach. Perivascular or ectopic Schwann cells, lateral nerve plexus within the cavernous sinus, as well as Schwann cells from small nerve twigs of the dura are some of the current histopathological hypotheses for the origin of these lesions.

Aged↗
PubMed2005

Peduncular hallucinosis: insights from a neurosurgical point of view.

OBJECTIVE: Peduncular hallucinosis is a rare phenomenon characterized by visual hallucinosis and agitation. It appears mainly in vascular lesions affecting the brainstem, and some recent reports describe the preoperative and postoperative appearance of peduncular hallucinosis in patients affected through tumor compression at the brainstem. METHODS: Detailing the neurosurgical experiences with this syndrome, we review the available literature and provide pathoneurobiological insights to give the neurosurgeon an overall view of this phenomenon. RESULTS: Peduncular hallucinosis resolves spontaneously, and supportive medications might be helpful. Sacrifice of brainstem draining veins during surgery might contribute to the symptoms. CONCLUSION: The cranial base neurosurgeon should be aware not only of the phenomenon but the surgical influence in provoking it.

Brain Neoplasms↗
PubMed2005

Hemodynamic evaluation during balloon test occlusion of the sigmoid sinus: clinical and technical considerations.

Test occlusion of a patent dural sinus requires careful hemodynamic evaluation. We performed balloon test occlusion of the sigmoid sinus in a patient with an advanced-stage temporal bone malignancy that affected the dominant sigmoid sinus. Before and during the test occlusion, intrasinus pressure was monitored upstream from the balloon via the inner lumen of a double-lumen angioplasty balloon microcatheter. On the basis of the hemodynamic findings, permanent balloon occlusion was carried out without complications.

Aged↗
PubMed2004

Management of primary spinal chondrosarcoma: report of two cases causing cord compression.

Chondrosarcomas are malignant tumors that rarely grow inside the spinal canal. Prognosis depends on histological features, patient's age and surgical margins free from tumor. Response to radio and chemotherapy is poor. Ideal treatment consists of total "en-block" resection, not always achievable due to limitation of location, compromise of stability and risk of inducing neurological deficits. Two cases of spinal chondrosarcoma causing cord compression are reported, located in the cervical and thoracic spine. Microsurgical technique consisted of initial debulking followed by removal of margins until limits free from tumor were obtained. Total resection was accomplished and neurological function improved in both cases. Follow-up has been seven and one year respectively, with no evidence of recurrence and preserved neurological functions. Association between chondrosarcoma and estrogen-dependent tumor has been confirmed in this report. Although "en-block" resection of a chondrosarcoma should be tried whenever possible, tumor fragmentation should be considered in difficult cases, as in the present report, in which a long period free from recurrence with good quality of life can be obtained.

Adult↗
PubMed2003

[Prognostic factors in the treatment of the intradural extramedullary tumors: a study of 44 cases].

Between 1993 and 1999, 44 patients submitted to resection of an expansible intradural extramedullary lesion who filled protocol requirements of appropriate follow up were studied. Patients were constituted by 43.2% female and 56.8% male. The mean age was 32.9 years old. Lesion most common location was at the thoracic spine, with 45.5% of the cases, followed by the lumbar level with 18.2%. Tumor extension varied from 1 to 7 vertebral segments, with an average of 2.5 levels. Schwannoma, with 65,9% of the cases, was the most frequent lesion, followed by meningioma with 20.5%. There were 2 cases of neurofibroma and 1 case of paraganglioma, neuroenteric cyst, metastasis and malignant schwannoma. The evolution was of improvement in 56.8%, stability in 31.8% and of worsening in 11.4%. There was no mortality related to the surgical procedure. All cases of worsening had total resection and they had lesions located in the thoracic segment. Total resection is the ideal modality of surgical treatment. However, at the thoracic level, where the peculiarities of spine irrigation prevail, surgical morbidade may be higher (p=0.014).

Adolescent↗
PubMed2003

Posterior fossa gangliocytoma with facial nerve invasion: case report.

A 5 year-old boy with a cerebellar gangliocytoma with a peripheral right facial paresis and ataxia is presented. His MRI showed a heterogenous, diffuse lesion, isointense on T1 and hyperintense on T2-weigthed sequences, involving the right cerebellar hemisphere with direct extension into the right facial nerve. The present case is the first description of a gangliocytoma with direct facial nerve invasion, as demonstrated for the facial nerve paresis and supported by MRI and surgical inspection.

Ataxia↗
PubMed2003

[Magnetic resonance imaging of the intraventricular cavernomas: diagnostic aspects].

Cavernomas are vascular malformations that typically affect the white matter of cerebral hemispheres and brain stem. They are angiographically occult lesions that depend on magnetic resonance imaging (MRI) for their diagnosis, presenting a hypointense perilesional ring caused by hemossiderin deposition as seen in T2 sequences. The ventricular location is rare, and image features may differ. We present two cases with diagnosis made only by histopathologic examination, due to a lack of classic image findings. Cavernous hemangiomas must be included in the differential diagnosis of intraventricular tumors, and total surgical resection is the treatment of choice. Perilesional ring as demonstrated by MRI, must not be expected when dealing with such lesions.

Adolescent↗