Biomedical subjects

Paulo A S Kadri

Publications and source records attributed to Paulo A S Kadri.

5 recordsLinked to original sources

PubMed2005

Surgical clipping of complex basilar apex aneurysms: a strategy for successful outcome using the pretemporal transzygomatic transcavernous approach.

OBJECTIVE: Complex basilar apex aneurysms (large size, wide and complex neck, tortuous parent vessels) continue to pose a challenge in treatment. Endovascular treatment has a high risk of recanalization, and surgical treatment is limited by the space and time necessary to achieve safe clipping. To overcome these obstacles, a modification of previously reported approaches was developed. The pretemporal transzygomatic transcavernous approach and a clipping strategy were used in the treatment of 21 high-complexity basilar apex aneurysms. METHODS: By use of the pretemporal route, the zygomatic notch was widened, the anterior clinoid was removed, the cavernous sinus was partially exposed, and the oculomotor nerve was mobilized. The depth of the field was widened by further cavernous exposure and the removal of the posterior clinoid. Temporary clips were applied to the basilar trunk perforator-free zone to preserve visualization of the aneurysm neck and perforators and to maintain collateral flow to the brainstem. RESULTS: Twenty-one high-complexity basilar apex aneurysms, 11 of which caused subarachnoid hemorrhage, were treated. Twenty (95%) were successfully clipped (Glasgow Outcome Scale scores, 4 or 5 in 90.5% at discharge; Rankin Disability Score, 1 in 90.5% at 1-yr follow-up). Complications were transient oculomotor palsy in all patients, small thalamic infarct in one patient, and cerebrospinal fluid leak in another. There was no surgical mortality. Delayed follow-up angiography in 19 of the 21 patients showed no residual aneurysm. CONCLUSION: We report the largest series of a unique, challenging group of complex basilar apex aneurysms treated with the pretemporal transzygomatic transcavernous approach, which provided improved safety of clipping by 1) increased visualization of the basilar apex and perforator arteries, 2) improved maneuverability of clip application, 3) a safer perforator-free location, and 4) preservation of brainstem collateral flow.

Basilar Artery↗

PubMed2004

Surgical treatment of dumbbell-shaped jugular foramen schwannomas.

OBJECT: Schwannomas of the jugular foramen are rare, comprising between 2 and 4% of intracranial schwannomas. The authors retrospectively analyzed their surgical experience with schwannomas of the lower cranial nerves that presented with intra- and extracranial extensions through an enlarged jugular foramen. The transcondylar suprajugular approach was used without sacrificing the labyrinth or the integrity of the jugular bulb. In this report the clinical and radiological features are discussed and complications are analyzed. METHODS: This retrospective study includes six patients (three women and three men, mean age 31.6 years) with dumbbell-shaped jugular foramen schwannomas that were surgically treated by the senior author during a 5.5-year period. One patient had undergone previous surgery elsewhere. Glossopharyngeal and vagal nerve deficits were the most common signs (appearing in all patients), followed by hypoglossal and accessory nerve deficits (66.6%). Two or more signs or symptoms were present in every patient. Three tumors presented with cystic degeneration. In four patients the jugular bulb was not patent on neuroimaging studies. The suprajugular approach was used in five patients; the origin of the tumor from the 10th cranial nerve could be defined in three of them. All lesions were completely resected. No death or additional postoperative cranial nerve deficits occurred in this series. Aspiration pneumonia developed in one patient. Preoperative deficits of the ninth and 10th cranial nerves improved in one third of the patients and half recovered mobility of the tongue. No recurrence was discovered during the mean follow-up period of 32.8 months. CONCLUSIONS: With careful, extensive preoperative evaluation and appropriate planning of the surgical approach, dumbbell-shaped jugular foramen schwannomas can be radically and safely resected without creating additional neurological deficits. Furthermore, recovery of function in the affected cranial nerves can be expected.

Accessory Nerve Diseases↗

PubMed2004

The anatomical basis for surgical preservation of temporal muscle.

OBJECT: Mobilizing the temporal muscle is a common neurosurgical maneuver. Unfortunately, the cosmetic and functional complications that arise from postoperative muscular atrophy can be severe. Proper function of the muscle depends on proper innervation, vascularization, muscle tension, and the integrity of muscle fibers. In this study the authors describe the anatomy of the temporal muscle and report technical nuances that can be used to prevent its postoperative atrophy. METHODS: This study was designed to determine the susceptibility of the temporal muscle to injury during common surgical dissection. The authors studied the anatomy of the muscle and its vascularization and innervation in seven cadavers. A zygomatic osteotomy was performed followed by downward mobilization of the temporal muscle by using subperiosteal dissection, which preserved the muscle and allowed a study of its arterial and neural components. The temporal muscle is composed of a main portion and three muscle bundles. The muscle is innervated by the deep temporal nerves, which branch from the anterior division of the mandibular nerve. Blood is supplied through a rich anastomotic connection between the deep temporal arteries (anterior and posterior) on the medial side and the middle temporal artery (a branch of the superficial temporal artery [STA]) on the lateral side. CONCLUSIONS: Based on these anatomical findings, the authors recommend the following steps to preserve the temporal muscle: 1) preserve the STA; 2) prevent injury to the facial branches by using subfascial dissection; 3) use a zygomatic osteotomy to avoid compressing the muscle, arteries, and nerves, and for greater exposure when retracting the muscle; 4) dissect the muscle in subperiosteal retrograde fashion to preserve the deep vessels and nerves; 5) deinsert the muscle to the superior temporal line without cutting the fascia; and 6) reattach the muscle directly to the bone.

Atrophy↗

PubMed2004

Malignant progression in meningioma: documentation of a series and analysis of cytogenetic findings.

OBJECT: The malignant progression of benign tumors is well documented in gliomas and other systemic lesions. It is also well known that some meningiomas become progressively aggressive despite their original benign status. The theory of clonal evolution is widely believed to explain malignant progression in meningioma; however, the data used to explain stepwise progression have typically been derived from the cytogenetic analysis of different types of tumors of different grades and in different patients. In this study, the authors examined the data obtained in a group of patients with meningiomas that showed clear histopathological progression toward a higher grade of malignancy and then analyzed the underlying cytogenetic findings. METHODS: Among 175 patients with recurrent meningiomas, 11 tumors showed a histopathological progression toward a higher grade that was associated with an aggressive clinical course. Six tumors progressed to malignancy and five to the atypical category over a period averaging 112 months. Tests for MIB-1 and p53 and cytogenetic studies with the fluorescence in situ hybridization (FISH) method were performed in successive specimens obtained in four patients. The MIB-1 value increased in subsequent samples of tumors. Cytogenetic analysis with FISH showed deletions of 22, 1p, and 14q. In all but one case, these aberrations were also present in the previous specimen despite its lower hispathological grade. CONCLUSIONS: The authors documented the progression of meningiomas from benign to a higher histological grade. These tumors were associated with a complex karyotype that was present ab initio in a histologically lower-grade tumor, contradicting the stepwise clonal evolution model. Although it was limited to the tested probes, the FISH method appears to be more accurate than the standard cytogenetic one in detecting these alterations. Tumors that present with complex genetic alterations, even those with a benign histological grade, are potentially aggressive and require closer follow up.

Adult↗

PubMedDate not supplied

Microsurgery for malignant gliomas.

Reflections directly involving the ongoing, intense research activities in biology, the neurosciences and in neurosurgery are discussed including the evolving diagnostic and treatment modalities of primary and secondary malignant gliomas of the central nervous system. The etiology of this enigmatic disease remains obscure, and a curative therapy is still not available. Nevertheless, as a result of changing paradigms in neuroanatomy, neuropathology, neurophysiology, neuroradiology and in neurosurgery, and taking into account the broader selection of adjuvant therapies available, well circumscribed malignant gliomas, which are in predilected compartments of the brain, can be efficiently resected. Good life quality and a respectable survival time are achieved in the majority of patients.

Brain Neoplasms↗