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Ali Sajadi and Nicolas de Tribolet

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Nicolas de Tribolet

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Pierre-Yves Dietrich and Nicolas de Tribolet

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Luca Regli, Antoine Uske, and Nicolas de Tribolet

Object. The goal of this study was to delineate the angioanatomical features that determine whether a patient with an unruptured middle cerebral artery (MCA) aneurysm is treated using endovascular coil placement or surgical clipping.

Methods. Thirty consecutive patients harboring 34 unruptured MCA aneurysms were evaluated. Patients with unruptured aneurysms are managed prospectively according to the following protocol: the primary treatment recommendation is endovascular packing with Guglielmi detachable coils (GDCs). Surgical clipping is recommended after failed attempts at coil placement or in the presence of angioanatomical features that contraindicate that type of endovascular therapy.

Of 34 unruptured MCA aneurysms, two (6%) were successfully embolized and 32 (94%) were clipped. Of these 32 surgically treated aneurysms, in 11 (34%) an attempt at GDC embolization had failed, whereas in 21 (66%) primary clipping was performed because of unfavorable angioanatomy. Of the 13 aneurysms treated endovascularly, two (15%) were successfully excluded, whereas GDC treatment failed in 11 (85%). An unfavorable dome/neck ratio (< 2) and an arterial branch originating at the aneurysm base were the reasons for embolization failure.

Conclusions. Careful evaluation of the angioanatomy of unruptured aneurysms allows selection of the most appropriate treatment. However, for unruptured MCA aneurysms, surgical clipping appears to be the most efficient treatment option. Series of unruptured aneurysms are ideal for comparing treatment results.

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Philippe P. Maeder, Reto A. Meuli, and Nicolas de Tribolet

✓ This study was undertaken to evaluate the capacity of three-dimensional (3-D) time-of-flight (TOF) magnetic resonance (MR) angiography with VoxelView (VV) 3-D volume rendering to detect and characterize intracranial aneurysms and to compare this rendering technique with that of maximum intensity projection (MIP).

Forty patients with a total of 53 intracranial aneurysms (10 giant and subgiant, 43 saccular) were consecutively admitted to University Hospital, Lausanne, Switzerland, and investigated with 3-D TOF MR angiography. Source images of the 43 saccular aneurysms were processed with both MIP and VV. The aneurysm detection rate of the two techniques and their ability to characterize features of an aneurysm, such as its neck and its relation to the parent vessel, were compared. Intraarterial digital subtraction angiography was used as the gold standard to which these techniques could be compared and evaluated.

Four aneurysms, less than 3 mm in size, were missed using MIP compared to three missed using VV. The representation of aneurysmal morphology using VV was superior to that found using conventional angiography in nine cases, equal in 16 cases, and inferior in seven cases. The representation of the aneurysm neck using VV was superior to MIP in 21 cases, equal in 17 cases, and inferior in one case; it was superior to that shown using conventional angiography in 10 cases, equal in 18 cases, and inferior in four cases.

Time-of-flight MR angiography in conjunction with both MIP and VV 3-D reconstruction was able to visualize all aneurysms that were larger than 3 mm. Compared to MIP, VV provides a better definition of the aneurysm neck and the morphology of saccular aneurysms, making VV valuable for use in a preoperative diagnostic workup.

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Mitsuhiro Tada, Annie-Claire Diserens, Isabelle Desbaillets, and Nicolas de Tribolet

✓ To elucidate which cytokine receptors may be expressed by human glioblastoma and normal astrocytic cells, the presence of messenger ribonucleic acid (RNA) for a number of cytokine receptors was examined in 16 glioblastoma cell lines and adult and fetal astrocytes. A complementary deoxyribonucleic acid copy of total RNA was synthesized and amplified with specific primers using the polymerase chain reaction method. The receptors studied were interleukin (IL)-1 receptor type I (IL-1RI) and type II (IL-1RII), p75 and p55 tumor necrosis factor (TNF) receptors (p75TNFR and p55TNFR), interferon (IFN)-α/β and -γ receptors (IFN-α/βR and IFN-γR), granulocyte-macrophage (GM) colony-stimulating factors receptor α subunit (GM-CSFR), G-CSF receptor (G-CSFR), M-CSF receptor (c-fms, M-CSFR), stem cell factor receptor (c-kit, SCFR), IL-6 receptor (IL-6R), and IL-8 receptor (IL-8R). Transcripts for IL-1RI, p55TNFR, IFN-α/βR, and IFN-γR were present in all cell lines. The presence of IL-1RII, p75TNFR, GM-CSFR, M-CSFR, SCFR, IL-6R, and IL-8R was identified in 13, eight, seven, eight, 14, three, and one cell lines, respectively. Normal astrocytes were positive for IL-1RI, p75TNFR, p55TNFR, IFN-α/βR, IFN-γR, M-CSFR, and SCFR, showing a similarity to glioblastoma cells. Expression of IL-1RII was observed in adult astrocytes but not in fetal astrocytes. Furthermore, gene expression was assessed in normal brain tissue and 11 glioblastoma tissue specimens. The normal brain tissue expressed IL-lRI, IL-1RII, IFN-α/βR, M-CSFR, and SCFR. Of the 11 glioblastoma tissue specimens, IL-1RI was positive in 11, IL-1RII in 10, p75TNFR in nine, p55TNFR in nine, IFN-α/βR in 10, IFN-γR in 10, GM-CSFR in two, G-CSFR in three, IL-8R in eight, and M-CSFR and SCFR in 11. These expressions were consistent with those in the cell lines, except for IL-8R. It is concluded that glioblastoma cells and normal astrocytes express a similar set of cytokine receptor genes in vitro and in vivo. Possible autocrine loops are suggested for IL-1α/IL-1RI, TNF-α/p55TNFR, IFN-β/IFN-α/βR, M-CSF/M-CSFR, and SCF/SCFR in glioblastomas.

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François Porchet, Anne Chollet-Bornand, and Nicolas de Tribolet

Object. This study was undertaken to evaluate the long-term benefit in 202 patients who were surgically treated via a microsurgical far-lateral approach for foraminal or extraforaminal lumbar disc herniations.

Methods. All patients underwent surgery at the authors' institute since 1987 and represented 6.5% of all lumbar spinal disc surgeries. There were 67 women and 135 men who ranged in age from 19 to 78 years (mean age 58 years). All patients had unilateral leg pain due to lumbar disc herniations into or lateral to the lateral interpedicular compartment. One patient underwent surgery at the L1–2 level, nine at L2–3, 48 at L3–4, 86 at L4–5, and 58 at the L5—S1 level. The mean follow-up period was 50 months (range 12–120 months). Outcome was defined as excellent (no pain), good (some back pain), fair (moderate radiculopathy), and poor (unchanged or worse) based on Macnab classification. Overall, excellent and good results were achieved in 62 (31%) and 85 (42%) patients, respectively, and fair and poor results in 40 (20%) and 15 (7%) patients, respectively. Of 11 recurrent disc herniations, four presented in an extreme-lateral position, five in a paramedian location, and two on the contralateral side. There were three minor complications related to surgery, seven general complications, and no case of spinal instability.

Conclusions. The far-lateral approach is a safe, effective procedure that avoids the risk of secondary spinal instability.

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Nicolas de Tribolet

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Sylvia Miescher, Theresa L. Whiteside, Nicolas de Tribolet, and Vladimir von Fliedner

✓ Mononuclear cells infiltrating human brain tumors were isolated from seven of nine surgical biopsy specimens. These cells were small T11+,T3+ lymphocytes that did not express DR antigens or the receptor for interleukin-2. In addition, large granular lymphocytes were recovered from two of these tumors. The clonogenic potential of tumor-infiltrating lymphocytes (TIL's) was assessed by limiting-dilution analysis (LDA) using a microculture system that permits proliferation of virtually 100% of normal peripheral blood T lymphocytes (PBL-T's).

In comparison to normal and autologous PBL-T's, TIL's had a strikingly reduced proliferative potential revealed by a decrease in the frequency of proliferating T lymphocyte precursors calculated by LDA. On average, only one of every 100 T cells from TIL's was able to proliferate, as compared to one of every two or all of the T cells from the patient's peripheral blood or from normal donors. Furthermore, the TIL populations showed depressed proliferative responses to the lectins phytohemagglutinin and concanavalin A and to the phorbol ester 12-0-tetradecanoyl-phorbol-13-acetate. Clonal analysis performed on the proliferating microcultures from three tumors demonstrated that the majority of these clones possessed cytolytic activity against various tumor cell targets. Among clones tested for cytolytic activities with glioma cells, four lysed cultured autologous tumor cells, and the specific lysis was > 50% in all cases. Numerous clones with natural killer (NK)-like activity were obtained from two TIL preparations, and the frequency of cytolytic T lymphocyte precursors with NK-like activity was determined for one of these preparations and was found to be higher than that in the patient's peripheral blood. Glioma cells grown in culture and then mixed with normal peripheral blood lymphocytes (PBL's) were capable of inhibiting the PBL's response to lectins. This inhibitory property may account in part for the observed poor clonogenicity of TIL's from brain tumors. Nevertheless, nearly all proliferating clones displayed cytotoxicity against either autologous or allogeneic tumor cell targets and may imply selective accumulation of cytolytic effector cells at the tumor site.

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Yutaka Sawamura, Nicolas de Tribolet, Nobuaki Ishii, and Hiroshi Abe

✓ Because intracranial germinomas are readily curable with radiation and chemotherapy or radiation therapy alone, the role of radical surgery has become debatable. This study assesses the optimum degree of surgical resection for intracranial germinomas.

Twenty-nine patients who underwent surgery for germinoma were retrospectively analyzed (male/female ratio 27:2, median age 18 years). Among these 29 patients there were 10 solitary pineal, seven solitary neurohypophyseal/hypothalamic, and 12 multifocal or disseminated tumors. Biopsy samples were obtained in 16 patients (stereotactically in eight, transsphenoidally in four, and via frontotemporal craniotomy in four). Partial resection was attained in five patients (via a frontotemporal approach in three and occipitotranstentorially in two). Gross-total resection was achieved via an occipitotranstentorial route in eight patients with pineal masses. After surgery, 10 patients were treated with radiotherapy alone, and 19 received radiation and chemotherapy; complete remission was achieved in all 29 patients. The overall tumor-free survival rate was 100% at a median follow-up period of 42 months. There was no significant difference in outcome related to the extent of surgical resection. Postoperative neurological improvement was seen in only two patients, whereas transient postoperative complications, mainly upgaze palsy, were observed in six. One patient experienced a slight hemiparesis, bringing the surgical morbidity rate to 3% (one of 29).

It is concluded that radical resection of intracranial germinomas offers no benefit over biopsy. The primary goal of surgery should be to obtain a sufficient volume of tumor tissue for histological examination. If there is strong evidence of germinoma on radiological studies, biopsy samples should be obtained. When a perioperative histological diagnosis of pure germinoma is made during craniotomy, no risk should be taken in continuing the resection.