1,721,191 research outputs found
Commentary: Intraoperative positioning nerve injuries
No full textCommentary: Intraoperative positioning nerve injurie
Sellar metastasis from clear cell sarcoma: Description of the first case
No full textMetastases to the sellar region and pituitary gland are rare and usually occur in advanced cancers, commonly breast and lung adenocarcinomas. Metastases from sarcomas to the pituitary gland are extremely rare. Here, we report the case of a 52-year-old man who had undergone surgery and radiotherapy for a clear cell sarcoma (CCS) of the knee at age of 42. The patient underwent resection of 2 distinct metastatic lung nodules 9 years later. During follow-up, he developed a persistent headache and diabetes insipidus. MRI revealed a sellar and suprasellar lesion, which was removed with an endoscopic trans-sphenoidal approach. Histopathology was consistent with CSS metastasis. At 2-year follow-up, there was no evidence of local recurrence in the sella, while a single brain metastasis was documented, together with other deposits in the paravertebral and pelvic muscles. CCS is a rare, aggressive neoplasm usually involving the deep soft tissue of the extremities, including trunk or limb girdles, and extensive surgical removal, along with adjuvant chemo- and radiotherapy, significantly prolongs survival. Nevertheless, prognosis remains poor, mainly due to frequent local recurrences and eventually distant metastases, usually within regional lymph nodes, lung, and bone. To the best of our knowledge, this is the first description of a sellar metastasis from CCS
Hypoglossal-facial anastomosis
No full textThe aim of this paper was to report on further experience with a new technique for reanimation of the facial nerve. This procedure allows a straight end-to-side hypoglossal-facial anastomosis without interruption of the 12th cranial nerve or the need for graft interposition. It is technically demanding and time consuming but offers an effective, reliable, and extraordinarily quick means of reinnervating the facial muscles, including the orbicularis oculi muscle, thus avoiding the need for a gold weight in the eyelid or a fascial sling
Idiopathic spinal cord herniation: diagnostic, surgical and follow up data obtained in five case
No full textIdiopathic spinal cord herniation (ISCH) is a rare, although increasingly recognized, cause of myelopathy. It is the result of an anterior dural defect in the thoracic spine through which the spinal cord herniates. Surgical restoration of the herniated cord to its normal position is usually followed by significant improvement in patients' clinical status. Differing surgical techniques have been used to manage the dural defect. In this report the authors discuss the cases of five patients (four women and one man) with ISCH treated during a 13-year period. Clinical and imaging findings in each patient are reported. Two different surgical techniques were used to treat this condition: dural defect enlargement in two cases and dural patch secured with stitches in three. The intra- and postoperative findings are discussed in relation to the two surgical techniques. Based on the results and complications in these five cases, the authors now believe that ISCH should be treated, when feasible, by using a dural patch to close the dural defect at the site of the herniation
3D printed training model with sensorized arachnoid for endoscopic transsphenoidal surgery: development and initial validation
Full text linkBackground
Endoscopic transsphenoidal surgery is a relatively novel technique with a long learning curve: it is used to resect tumors that grow in the sella, which is located at the center of the skull base, immediately below the optic nerves and brain that are wrapped by the arachnoid, containing the cerebrospinal fluid (CSF). One of the challenging aspects of this surgery is to remove the tumor while not damaging the arachnoid to avoid the potentially life-threatening complication of post-operative CSF leak.
Objective
This work presents the development of a new 3D-printed CT-based training model with a sensorized tank capable of reproducing the descent in the sella of the suprasellar arachnoid pushed by the cerebrospinal fluid (CSF) during removal of a sellar tumor with endoscopic transsphenoidal surgery. The system provides real-time feedback about the force exerted by the operating surgeon through the pressure sensor integrated into the tank.
Development
The model and the tank were fabricated using additive manufacturing technologies and silicone mold casting to reproduce soft tissues like skin and mucosa. The arachnoid membrane and the CSF were mimicked with a polymeric film and distilled water, while the pituitary adenoma was mimicked with boiled egg white.
Validation
The correlation between the pressure of the CSF and the exerted force was investigated in characterization tests. Eleven experienced surgeons were asked to simulate the resection of a pituitary adenoma using the model. At the end of the experience, a survey was conducted amongst surgeons to evaluate the model and its usefulness as a tool for training.
Conclusions
The collected data allowed the definition of the force threshold values for the risk of CSF leak. The maximum force exerted by surgeons is 0.526 N. Surgeons considered the arachnoid well simulated and thought that the model could be a helpful training tool for endoscopic transsphenoidal surgery
A Novel 3D Printed Sensorized Surgical Instrument to Characterize Pituitary Adenoma: Development and Initial Validation
No full textThe pituitary adenoma (PA) is a tumor that grows in the sellar region, near the pituitary gland. PAs are usually removed surgically by expert neurosurgeons and otolaryngologists through the nasal cavities, with the so-called endoscopic transsphenoidal approach. One of the most challenging complications is that the consistency of PAs remains unpredictable until the surgeon approaches it during the surgery, thus meaning that surgeons must choose intraoperatively the most suitable technique to resect PAs. In this work is presented a novel and improved version of the solutions reported in the literature. The instruments consist of a body and a highly deformable tip fabricated through additive manufacturing technologies and a magnetoresistive sensor which measures the variation of the magnetic field when the tip is compressed due to the contact with the adenoma and then this system is capable of discerning soft tissues consistency. Two different tips with four arms were assessed, one with a 0.45 mm thickness and the other with a 0.75 mm thickness to find a trade-off between the stability of the tip and its deformability. Compression tests with samples of different Shore 00 hardness were conducted, to explore how the probe behaves with material with different hardness. Tests were conducted with specimens made of boiled egg white, which according to literature and expert surgeons, its consistency is similar to PAs. A preliminary value of hardness of 16.08 ± 2.02 for 0.45 mm tips and 16.17 ± 4.37 for 0.75 mm tips were measured for the boiled egg white. According to results, the 0.45 mm tips are more suitable for the application of the sensorized probe due to the lower uncertainties. In addition, force data measured during tests with the egg white specimen, are in line with data found in the literature about the force exerted during neurosurgical approaches. These results can be considered a preliminary analysis of how the probe would behave with a real PA
Preliminary Study on a 3D Printed Sensorized Probe to Characterize Pituitary Adenoma Hardness
No full textEndoscopic endonasal transsphenoidal surgery approach, is a new surgical technique used by otolaryngologists and neurosurgeons to resect pituitary adenoma (PA). The most challenging aspect is related to the fact that the strategy of the resection changes according to the hardness of PAs, which is mostly soft, but it can also be harder (fibrous adenoma). This work proposes a first attempt to develop an alternative and innovative sensorized probe capable to discern the different hardness of soft materials. The proposed solution can be implemented in training models in order to give feedback to the users. The probe was developed thanks to additive manufacturing Fused Filament Fabrication (FFF) technology. Inside the probe there is a magneto resistive sensor and a magnet that is glued on the tip in order to measure the variation of the magnetic field linked to the movement of the magnet. After a preliminary electrically characterization of the probe, tests were conducted with three different silicones with slightly different Shore A attested hardness in order to verify if the probe is able to discern the materials. The first results show a high repeatability with a mean variation < 1%. Future work will be conducted with ex-vivo samples of pituitary adenomas in order to characterize their hardness and to classify the different types of PAs with a hardness parameter, and also to find the best material to mimic the consistency for training models
Letter to the Editor Regarding “Top 100 Most Cited Neurosurgical Articles on COVID-19: A Bibliometric Analysis”
No full textBACKGROUND: Distal medium vessel occlusions (DMVOs) are increasingly recognized as a next target for endovascular thrombectomy (EVT). Our objective was to investigate safety and clinical outcomes of EVT for DMVO of the middle cerebral artery (MCA).METHODS: We analyzed data of the Lille Reperfusion Registry from January 2017 to September 2020. Patients with a primary or secondary DMVO of the MCA seen on pretreatment angiogram were included. Only patients with a eTICI score 2b50-2b67 on initial angiogram were considered. Baseline characteristics, angiographic clinical, and safety outcomes were compared between patients treated with EVT or standard medical treatment (no-EVT).RESULTS: Of the 171 patients included, 96 received EVT (46.9% male, 68.7 +/- 15.8 years) and 75 received standard medical treatment (44% male, 73.9 +/- 13.1 years). EVT patients had a better improvement of the NIHSS score at discharge (adjusted mean difference: 3.71; 95% CI: 1.18-6.24). In the distal M2 occlusions subgroup, EVT was significantly associated with a higher rate of early neurologic improvement (adjusted OR: 3.62 95% CI: 1.31-10.03), NIHSS improvement at discharge (adjusted mean difference: 5.23; 95% CI: 2.18-8.29), and improved modified Rankin Scale score at 3 months (adjusted common OR for 1 point improvement: 3.06; 95% CI: 1.30 to 7.23). Symptomatic intracranial hemorrhage occurred in 3.1% in the EVT group and in 9.5% in the no-EVT group.CONCLUSIONS: EVT for DMVO of the MCA appears to be safe and may lead to improved clinical outcomes. This effect was especially pronounced in patients with distal M2 occlusions, warranting randomized trials to validate this result
Preliminary study of a sensorized system for real-time feedback for arachnoid collapse during neurosurgical training
No full textThe transsphenoidal surgery approach is a new minimally invasive procedure used by neurosurgeons to treat pituitary adenomas. One of the most challenging aspects of the surgery is handling the arachnoid membrane when it starts collapsing, as it is a thin and fragile membrane that contains the cerebrospinal fluid (CSF). 3D-printed training models do not provide a system capable of mimicking the arachnoid collapse during surgery. This work reports the results of two tests on a specifically designed system capable of reproducing the arachnoid and the CSF within. The system consists of a jar filled with distilled water and sealed with a food film and a screw cap. In addition, a pressure sensor is inserted into the system to measure the change in pressure generated by an indenter connected to a load cell. The idea is to correlate the indentation force with the pressure variation. Data show a promising result in both tests, with a evident correlation between force and pressure. The first test shows a linear trend, with an R2 = 0.984 for the loading phase and a R2 = 0.999 for the unloading phase. The second test shows a linear trend with R2 = 0.954 from the unloading phase, while as for the loading phase, it has a nonlinear trend for values of applied force less than 1 N, which then tends to a linear trend above this value, with an R2 = 0.996. However, there is a low repeatability when comparing one test with another due to the initial conditions of the food film, residual stresses and deformations once positioned on the top of the jar and closed by the cap, and probable pressure losses in the system
Design and experimental characterization of a small flexible TMR-based indentation probe for soft tissue hardness estimation
No full textThe endoscopic transsphenoidal approach is a surgical method used to remove pituitary adenomas—benign tumors located near the pituitary gland. The success of this procedure depends heavily on assessing the tumor’s consistency, which is currently based on the surgeon’s tactile feedback and experience. This study presents the development of a novel sensor-based probe designed to provide real-time measurements of tissue hardness, supporting more objective surgical decision-making. The probe integrates a tunneling magneto resistance (TMR) sensor with a deformable, 3D-printed tip made of thermoplastic polyurethane. The tip features micro-beams that deform upon contact with tissue; the extent of deformation, measured by the TMR sensor, correlates with tissue stiffness. The flexible structure was fabricated using fused filament fabrication, and the process was characterized to control micro-beam dimensions by adjusting print parameters such as layer height, print speed, and nominal line width. A regression model was developed to predict beam width with high accuracy and repeatability. Eighteen probe designs, combining different beam widths (0.42 mm-0.63 mm) and numbers (3-5), were tested through indentation experiments on samples with Shore 000 hardness ranging from 51 to 83 (ASTM D2240), including a cooked egg white sample as a biological tissue analogue. Results revealed that probes with 4 and 5 beams printed at lower speeds offered superior sensitivity, linearity, and uniformity. In these configurations, the probe was able to estimate the hardness of adenoma-like materials with errors below 2%. These findings validate the proposed system’s potential for clinical use in evaluating soft to moderately firm tumors during surgery
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