45 research outputs found
Intra-operative MRI facilitates tumour resection during trans-sphenoidal surgery for pituitary adenomas
Background During trans-sphenoidal microsurgical resection of pituitary adenomas, the extent of resection may be difficult to assess, especially when extensive suprasellar and parasellar growth has occurred. In this prospective study, we investigated whether intra-operative magnetic resonance imaging (iMRI) can facilitate tumour resection.
Methods Twenty patients with macroadenomas, (16 non-functioning, three growth-hormone secreting and one pharmaco-resistant prolactinoma) were selected for surgery in the iMRI. The mean tumour diameter was 27 mm (range 11–41). The mean parasellar grade, according to the Knosp classification, was 2.3. Pre-operative coronal and sagittal T1-weighted and T2-weighted images were obtained. The trans-sphenoidal tumour resection was performed at the edge of the tunnel of a Signa SP 0.5-Tesla MRI. The surgeon aimed at a radical tumour resection that was followed by a peri-operative MRI scan. When a residual tumour was visualised and deemed resectable, an extended resection was performed, followed by another MRI scan. This procedure was repeated until the imaging results were satisfactory. In all patients, we were able to obtain images to assess the extent of resection and to classify the resection as either total or subtotal.
Results After primary resection, eight out of 20 cases were classified as total resections. A second resection was performed in 11 of 12 cases classified as subtotal resections, and in four of these, total resection was achieved. A third resection was performed in three of the remaining seven cases with subtotal resections, but we did not achieve total resection in any of these cases. Therefore, the use of iMRI increased the number of patients with total resection from 8/20 (40%) to 12/20 (60%). The only observed complication was a transient spinal fluid leakage.
Conclusion Intra-operative MRI during trans-sphenoidal microsurgery is useful in selected patients for a safe and more complete resection.
This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited
Insulin Production and Signaling in Renal Tubules of Drosophila Is under Control of Tachykinin-Related Peptide and Regulates Stress Resistance
The insulin-signaling pathway is evolutionarily conserved in animals and regulates growth, reproduction, metabolic homeostasis, stress resistance and life span. In Drosophila seven insulin-like peptides (DILP1-7) are known, some of which are produced in the brain, others in fat body or intestine. Here we show that DILP5 is expressed in principal cells of the renal tubules of Drosophila and affects survival at stress. Renal (Malpighian) tubules regulate water and ion homeostasis, but also play roles in immune responses and oxidative stress. We investigated the control of DILP5 signaling in the renal tubules by Drosophila tachykinin peptide (DTK) and its receptor DTKR during desiccative, nutritional and oxidative stress. The DILP5 levels in principal cells of the tubules are affected by stress and manipulations of DTKR expression in the same cells. Targeted knockdown of DTKR, DILP5 and the insulin receptor dInR in principal cells or mutation of Dilp5 resulted in increased survival at either stress, whereas over-expression of these components produced the opposite phenotype. Thus, stress seems to induce hormonal release of DTK that acts on the renal tubules to regulate DILP5 signaling. Manipulations of S6 kinase and superoxide dismutase (SOD2) in principal cells also affect survival at stress, suggesting that DILP5 acts locally on tubules, possibly in oxidative stress regulation. Our findings are the first to demonstrate DILP signaling originating in the renal tubules and that this signaling is under control of stress-induced release of peptide hormone
Endoscopic versus microscopic transsphenoidal surgery in the treatment of pituitary tumors: systematic review and meta-analysis of randomized and non-randomized controlled trials
ABSTRACT We conducted a systematic review and meta-analysis of randomized and non-randomized controlled trials that compared pure endoscopic with microscopic transsphenoidal surgery (TSS) in the resection of pituitary tumors. Embase, PubMed, Lilacs, and Central Cochrane were used as our data sources. The outcomes were total tumor resection, achievement of biochemical control of functioning adenomas, hospital stay and surgery complications. The randomized trials were analyzed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Two randomized and three prospective controlled non-randomized studies were included. Two studies, including 68 patients, evaluated total tumor resection and the meta-analysis did not show differences between the groups [RR: 1.45 (95% CI: 0.87, 2.44)]. Three studies involving 65 patients analyzed the achievement of biochemical control and no statistical difference was found [RR: 0.94 (95% CI: 0.7, 1.26)]. All five studies compared the frequency of postoperative complications between intervention and control group and meta-analysis favored for a low rate of postoperative complications in the endoscopic TSS group [(RR: 0.37 (95% CI: 0.16, 0.83)]. Due to the low evidence level and low number of observations, the results of our meta-analysis should not be viewed as a final proof of inferiority or superiority of one approach in relation to the other. More data including higher numbers of observations are needed
Tuberculum sellae meningiomas: surgical considerations
We report our experience on the treatment of tuberculum sellae meningiomas (TSMs) regarding the involvement of the optic canal and clinical outcomes. We reviewed 23 patients who were operated on between January 1997 and December 2008. The surgical approach was unilateral subfrontal supraorbital osteotomy in one piece. Attempts were made to improve visual function via extra/intradural unroofing of the optic canal, which released the optic nerve. Visual symptoms were present preoperatively in 21 patients, and two patients were asymptomatic. Visual acuity remained intact in 6 patients, improved in 10, was unchanged in 5 patients, and worsened in 2 patients. The postoperative visual field was normal or improved in 17 patients, unchanged in four patients, and worsened in two patients. The optic canal and clinoid were drilled extradurally in eight patients and intradurally in nine patients. Total resection of TSMs was achieved in 19 patients. Incomplete resection occurred in two patients. Decompression of the optic canal seemed to increase the visual outcome.Apresentamos nossa experiência em 23 pacientes operados com meningiomas do tubérculo da sela, com enfoque na descompressão do nervo óptico e nos sintomas visuais do pós-operatório. Vinte e três pacientes com meningiomas do tubérculo da sela foram operados entre janeiro de 1997 e dezembro de 2008, através do acesso subfrontal via ostetomia supraorbital. Remoção do teto do canal óptico por via extra ou intradural foi realizada em 17 pacientes. Sintomas visuais no pré-operatório ocorreram em 21 pacientes, 2 eram assintomáticos. Melhora visual ocorreu em 10, permaneceu inalterada em 5 e piorou em 2 pacientes. No pós-operatório o campo visual normalizou-se em 17 pacientes, permaneceu inalterado em 4 e diminuiu em 2. Descompressão dos nervos ópticos foi realizada em 17 pacientes. Ressecção total dos meningiomas do tubérculo da sela foi possível em 19 pacientes. Abertura do canal óptico permitiu a manipulação do nervo óptico sem novos déficites
Endocrinologic, neurologic, and visual morbidity after treatment for craniopharyngioma
Craniopharyngiomas are locally aggressive tumors which typically are focused in the sellar and suprasellar region near a number of critical neural and vascular structures mediating endocrinologic, behavioral, and visual functions. The present study aims to summarize and compare the published literature regarding morbidity resulting from treatment of craniopharyngioma. We performed a comprehensive search of the published English language literature to identify studies publishing outcome data of patients undergoing surgery for craniopharyngioma. Comparisons of the rates of endocrine, vascular, neurological, and visual complications were performed using Pearson’s chi-squared test, and covariates of interest were fitted into a multivariate logistic regression model. In our data set, 540 patients underwent surgical resection of their tumor. 138 patients received biopsy alone followed by some form of radiotherapy. Mean overall follow-up for all patients in these studies was 54 ± 1.8 months. The overall rate of new endocrinopathy for all patients undergoing surgical resection of their mass was 37% (95% CI = 33–41). Patients receiving GTR had over 2.5 times the rate of developing at least one endocrinopathy compared to patients receiving STR alone or STR + XRT (52 vs. 19 vs. 20%, χ2P < 0.00001). On multivariate analysis, GTR conferred a significant increase in the risk of endocrinopathy compared to STR + XRT (OR = 3.45, 95% CI = 2.05–5.81, P < 0.00001), after controlling for study size and the presence of significant hypothalamic involvement. There was a statistical trend towards worse visual outcomes in patients receiving XRT after STR compared to GTR or STR alone (GTR = 3.5% vs. STR 2.1% vs. STR + XRT 6.4%, P = 0.11). Given the difficulty in obtaining class 1 data regarding the treatment of this tumor, this study can serve as an estimate of expected outcomes for these patients, and guide decision making until these data are available
