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Featured researches published by Ioannis Siasios.


Neurology Research International | 2013

Cerebral Vasospasm Pharmacological Treatment: An Update

Ioannis Siasios; Eftychia Z. Kapsalaki; Kostas N. Fountas

Aneurysmal subarachnoid hemorrhage- (aSAH-) associated vasospasm constitutes a clinicopathological entity, in which reversible vasculopathy, impaired autoregulatory function, and hypovolemia take place, and lead to the reduction of cerebral perfusion and finally ischemia. Cerebral vasospasm begins most often on the third day after the ictal event and reaches the maximum on the 5th–7th postictal days. Several therapeutic modalities have been employed for preventing or reversing cerebral vasospasm. Triple “H” therapy, balloon and chemical angioplasty with superselective intra-arterial injection of vasodilators, administration of substances like magnesium sulfate, statins, fasudil hydrochloride, erythropoietin, endothelin-1 antagonists, nitric oxide progenitors, and sildenafil, are some of the therapeutic protocols, which are currently employed for managing patients with aSAH. Intense pathophysiological mechanism research has led to the identification of various mediators of cerebral vasospasm, such as endothelium-derived, vascular smooth muscle-derived, proinflammatory mediators, cytokines and adhesion molecules, stress-induced gene activation, and platelet-derived growth factors. Oral, intravenous, or intra-arterial administration of antagonists of these mediators has been suggested for treating patients suffering a-SAH vasospam. In our current study, we attempt to summate all the available pharmacological treatment modalities for managing vasospasm.


Journal of Clinical Medicine Research | 2015

Primary Diffuse Large B-Cell Lymphoma of Central Nervous System: Is Still Surgery an Unorthodox Treatment?

Ioannis Siasios; Aggeliki Fotiadou; George Fotakopoulos; Maria Ioannou; Vassilios Anagnostopoulos; Konstantinos Fountas

Primary central nervous system lymphoma (PCNSL) is characterized as an extra-nodal non-Hodgkin lymphoma which develops from the neuraxis. The purpose was to report a case of a patient with a supra-tentorial tumor who underwent subtotal resection of his tumor as his biopsy was not indicative of a PCNSL tumor and had uneventful recovery until his last follow-up. A 42-year-old man was admitted to our department for generalized epileptic seizures. CT and MRI examinations revealed a tumor in his right parietal-occipital lobe that was surrounded by edema and was enhancing after gadolinium administration. The patient underwent a navigation-assisted parieto-occipital craniotomy and posterior parietal transcortical approach for tumor biopsy which was not indicative of PCNSL tumor. The surgical team decided to remove the tumor on site. Histological analysis of the resected specimen showed primary diffuse large B-cell lymphoma. Combined chemotherapy and radiation therapy was applied to the patient, and at his last follow-up (16 months), he is tumor free. In our case as in several other studies during the last decade, the outcome after the surgical resection of a PCNSL tumor in combination to radiation and chemotherapy was unexpectedly good. The role of surgery probably should be reconsidered for single lesion PCNSL tumors.


Neurosurgical Review | 2018

The role of steroid administration in the management of dysphagia in anterior cervical procedures

Ioannis Siasios; Kostas N. Fountas; Dimopoulos; John Pollina

Dysphagia is a common postoperative symptom for patients undergoing anterior cervical spine procedures. The purpose of this study is to present the current literature regarding the effect of steroid administration in dysphagia after anterior cervical spine procedures. We performed a literature search in the PubMed database, using the following terms: “dysphagia,” “ACDF,” “cervical,” “surgery,” “anterior,” “spine,” “steroids,” “treatment,” and “complications.” We included in our review any study correlating postoperative dysphagia and steroid administration in anterior cervical spine surgery. Studies, which did not evaluate, pre- and postoperatively, dysphagia with a specific clinical or laboratory methodology were excluded from our literature review. Five studies were included in our results. All were randomized, prospective studies, with one being double blinded. Steroid administration protocol was different in every study. In two studies, dexamethasone was used. Methylprednisolone was administrated in three studies. In four studies, steroids were applied intravenously, while in one study, locally in the retropharyngeal space. Short-term dysphagia and prevertebral soft tissue edema were diminished by steroid administration, according to the results of two studies. In one study, prevertebral soft tissue edema was not affected by the steroid usage. Furthermore, short-term osseous fusion rate was impaired by the steroid administration, according to the findings of one study. The usage of steroids in patients undergoing anterior cervical spine procedures remains controversial. Multicenter, large-scale, randomized, prospective studies applying the same protocol of steroid administration and universal outcome criteria should be performed for extracting statistically powerful and clinically meaningful results.


Journal of Clinical Medicine Research | 2016

Posterior Reversible Encephalopathy Syndrome Resolving Within 48 Hours in a Normotensive Patient Who Underwent Thoracic Spine Surgery

Kunal Vakharia; Ioannis Siasios; Vassilios G. Dimopoulos; John Pollina

Posterior reversible encephalopathy syndrome (PRES) usually manifests with severe headaches, seizures, and visual disturbances due to uncontrollable hypertension. A patient (age in the early 60s) with a history of renal cell cancer presented with lower-extremity weakness and paresthesias. Magnetic resonance imaging (MRI) of the thoracic spine revealed a T8 vertebral body metastatic lesion with cord compression at that level. The patient underwent preoperative embolization of the tumor followed by posterior resection and placement of percutaneous pedicle screws and rods. Postoperatively, the patient experienced decreased visual acuity bilaterally. Abnormal MRI findings consisted of T2 hyperintense lesions and fluid-attenuated inversion recovery changes in both occipital lobes, consistent with the unique brain imaging pattern associated with PRES. The patient’s blood pressure was normal and stable from the first day of hospitalization. The patient was kept on high-dose steroid therapy, which was started intraoperatively, and improved within 48 hours after symptom onset.


Journal of Clinical Medicine Research | 2016

Anterior Cervical Discectomy and Fusion: Practice Patterns Among Greek Spinal Surgeons

Savvas L. Spanos; Ioannis Siasios; Vassilios G. Dimopoulos; Kostas N. Fountas

Background A web-based survey was conducted among Greek spinal surgeons to outline the current practice trends in regard to the surgical management of patients undergoing anterior cervical discectomy and fusion (ACDF) for degenerative cervical spine pathology. Various practice patterns exist in the surgical management of patients undergoing anterior cervical discectomy for degenerative pathology. No consensus exists regarding the type of the employed graft, the necessity of implanting a plate, the prescription of an external orthotic device, and the length of the leave of absence in these patients. Methods A specially designed questionnaire was used for evaluating the criteria for surgical intervention, the frequency of fusion employment, the type of the graft, the frequency of plate implantation, the employment of an external spinal orthosis (ESO), the length of the leave of absence, and the prescription of postoperative physical therapy. Physicians’ demographic factors were assessed including residency and spinal fellowship training, as well as type and length in practice. Results Eighty responses were received. Neurosurgeons represented 70%, and orthopedic surgeons represented 30%. The majority of the participants (91.3%) considered fusion necessary. Allograft was the preferred type of graft. Neurosurgeons used a plate in 42.9% of cases, whereas orthopedic surgeons in 100%. An ESO was recommended for 87.5% of patients without plates, and in 83.3% of patients with plates. The average duration of ESO usage was 4 weeks. Physical therapy was routinely prescribed postoperatively by 75% of the neurosurgeons, and by 83.3% of the orthopedic surgeons. The majority of the participants recommended 4 weeks leave of absence. Conclusions The vast majority of participants considered ACDF a better treatment option than an ACD, and preferred an allograft. The majority of them employed a plate, prescribed an ESO postoperatively, and recommended physical therapy to their patients.


The Journal of Spine Surgery | 2018

Bowel injury in lumbar spine surgery: a review of the literature

Ioannis Siasios; Kunal Vakharia; Asham Khan; Joshua E. Meyers; Samantha Yavorek; John Pollina; Vassilios G. Dimopoulos

Although rarely documented in the medical literature, bowel perforation injury can be a severe complication of spine surgery. Our goal was to review current literature regarding this complication and study possible methods of avoidance. We conducted a literature search in the PubMed database between January 1960 and March 2016 using the terms abrasion, bowels, bowel, complication, injury, intestine, intra-abdominal sepsis/shock, perforation, lumbar, spine, surgery, visceral. Diagnostic criteria, outcomes, risk factors, surgical approach, and treatment strategy were the parameters extracted from the search results and used for review. Thirty-one patients with bowel injury were recognized in the literature. Bowel injury was more frequent in patients who underwent lumbar discectomy and microdiscectomy (18 of 31 patients, 58.1%). Minimally invasive surgery and lateral techniques involving fusions accounted for 10 of the reported cases (32.3%). Finally, 2 cases (6.5%) were reported in conjunction with sacrectomies and 1 case (3.2%) with posterior fusion plus anterior longitudinal ligament (ALL) release. Diagnosis was made mostly by clinical signs/symptoms of acute abdominal pain, post-surgical wound infection, and abscess or enterocutaneous fistulas. Significant risk factors for postoperative bowel injury were complex surgical anatomy, medical history of previous abdominal surgeries or infections, irradiation before surgery, errors related to surgical technique, lack of surgical experience, and instrumentation failure. The overall mortality rate from bowel injury was 12.9% (4 of 31 patients). The overall morbidity rate was 87.1% (27 of 31 patients). According to our review of the literature, bowel injury is linked to significant morbidity and mortality. It can be prevented with meticulous pre-surgical planning. When it occurs, timely treatment reduces the risks of morbidity and mortality.


Operative Neurosurgery | 2018

Next-Generation Robotic Spine Surgery: First Report on Feasibility, Safety, and Learning Curve

Asham Khan; Joshua E Meyers; Ioannis Siasios; John Pollina

BACKGROUND Pedicle screw placement is a commonly performed procedure. Robot-guided screw placement is a recent technological advance that has shown accuracy and reliability with first-generation platforms. OBJECTIVE To report our initial experience with the safety, feasibility, and learning curve associated with pedicle screw placement utilizing next-generation robotic guidance. METHODS A retrospective chart review was conducted to obtain data for 20 patients who underwent lumbar pedicle screw placement under robotic guidance after undergoing interbody fusion for lumbar spinal stabilization for degenerative disc disease with or without spondylolisthesis. The newest generation Mazor X (Mazor Robotics Ltd, Caesarea, Israel) was used. Accuracy of screw placement was determined to be grade I to IV. Grade I was in the pedicle (no breach/deviation), grade II was breach < 2 mm, grade III was breach 2 to 4 mm, and grade IV was breach >4 mm; breach direction (superior, lateral, inferior, or medial) was also recorded. RESULTS Twenty patients underwent robotically assisted pedicle screw placement of 75 screws at 24 levels. Seventy-four screw placements (98.7%) were grade I; 1 (1.3%) was grade II (medial). No complications occurred. Mean time for screw insertion was 3.6 min. Mean fluoroscopy time was 13.1 s and mean radiation dose was 29.9 mGy. CONCLUSION We found that next-generation robotic spine surgery was safe and feasible with reliable and precise accuracy and a minimal learning curve. As this technology improves, further novel applications are expected to develop. Further research is needed to determine long-term efficacy.


Journal of Craniovertebral Junction and Spine | 2018

Cervical sagittal balance parameters after single-level anterior cervical discectomy and fusion: Correlations with clinical and functional outcomes

Ioannis Siasios; Evan Winograd; Asham Khan; Kunal Vakharia; Vassilios G. Dimopoulos; John Pollina

Background: Normal sagittal cervical alignment has been associated with improved outcome after anterior cervical discectomy and fusion (ACDF). Objective: The aim of this study is to identify alterations of cervical sagittal balance parameters after single-level ACDF and assess correlations with postoperative functionality. Methods: A retrospective chart review was performed between January 2010 and January 2014 to identify adult patients with no previous cervical spine surgery who underwent ACDF at any one level between C2 and C7 for the single-level degenerative disease. Tumor, infection, and trauma cases were excluded from the study. For the included cases, the following data were recorded preoperatively and 6 months–1 year after surgery: sagittal balance-marker measurements of the C1–C2 angle, C2–C7 angle, C7 slope, segmental angle at the operated level, and sagittal vertical axis (SVA) distance between C2 and C7, as well as the neck disability index and visual analog scale of pain. Results: The present study included 47 patients (average age: 51.2 years; range: 28–86 years). A moderate negative correlation between a smaller C2–C7 angle and the presence of right arm pain before treatment was found (P = 0.0281). Postoperatively, functionality scores significantly improved in all patients. C1–C2 angle increased with statistical significance (P = 0.0255). C2–C7 angle, segmental angle, C7 slope, and SVA C2–C7 distance did not change with statistical significance after surgery. C7 slope significantly correlated with overall cervical sagittal balance (P < 0.05). Conclusions: Single-level ACDF significantly increases upper cervical lordosis (C1–C2) without significantly changing lower cervical lordosis (C2–C7). The C7 slope is a significant marker of overall cervical sagittal alignment (P < 0.05).


The Journal of Spine Surgery | 2017

Percutaneous screw placement in the lumbar spine with a modified guidance technique based on 3D CT navigation system

Ioannis Siasios; John Pollina; Asham Khan; Vassilios G. Dimopoulos

Several guidance techniques have been employed to increase accuracy and reduce surgical time during percutaneous placement of pedicle screws (PS). The purpose of our study was to present a modified technique for percutaneous placement of lumbar PS that reduces surgical time. We reviewed 23 cases of percutaneous PS placement using our technique for minimally invasive lumbar surgeries and 24 control cases where lumbar PS placement was done via common technique using Jamshidi needles (Becton, Dickinson and Company, Franklin Lakes, NJ, USA). An integrated computer-guided navigation system was used in all cases. In the technique modification, a handheld drill with a navigated guide was used to create the path for inserting guidewires through the pedicles and into the vertebral bodies. After drill removal, placement of the guidewires through the pedicles took place. The PS were implanted over the guidewires, through the pedicles and into the vertebral bodies. Intraoperative computed tomography was performed after screw placement to ensure optimal positioning in all cases. There were no intraoperative complications with either technique. PS placement was correct in all cases. The average time for each PS placement was 6.9 minutes for the modified technique and 9.2 minutes for the common technique. There was no significant difference in blood loss. In conclusion, this modified technique is efficient and contributes to reduced operative time.


Journal of Clinical Medicine Research | 2017

Magnetic Resonance Spectroscopy and Single-Photon Emission Computed Tomography in the Evaluation of Cerebral Tumors: A Case Report

Ioannis Siasios; Varvara Valotassiou; Eftychia Z. Kapsalaki; Ioannis Tsougos; Panagiotis Georgoulias; Aggeliki Fotiadou; Maria Ioannou; Georgios Koukoulis; Vassilios G. Dimopoulos; Kostas N. Fountas

In their daily clinical practice, physicians have to confront diagnostic dilemmas which cannot be resolved by the application of only one imaging technique. In this case report, we present a 66-year-old woman who was admitted to our institution for the surgical resection of a recently diagnosed brain tumor. The patient had a history of epileptic seizures and was hospitalized in the past for anti-phospholipid syndrome related to a non-Hodgkin lymphoma in remission. Magnetic resonance imaging (MRI) examination revealed an enhancing right parasagittal lesion with significant edema suggestive of a high grade glioma. Advanced MRI techniques including proton magnetic resonance spectroscopy (1H-MRS) showed findings compatible of glioma. An additional examination was performed as part of a protocol that we are routinely performing in our institution for all brain tumors including not only the gold standard advanced MRI techniques but also single-photon emission computed tomography (SPECT) with technetium-99m (Tc99m). Brain SPECT indicated the presence of a meningioma which was verified by the histopathology of the resected specimen. In conclusion, a multimodality approach for the pre-surgical assessment of brain tumors has significant advantages not only for the diagnosis but also for the evaluation of intracranial tumors histology.

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Vassilios G. Dimopoulos

State University of New York System

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John Pollina

State University of New York System

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Kunal Vakharia

State University of New York System

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