Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Kenan I. Arnautović is active.

Publication


Featured researches published by Kenan I. Arnautović.


Journal of Neurological Surgery Reports | 2014

Cerebellar Glioblastoma Multiforme Presenting as Hypertensive Cerebellar Hemorrhage: Case Report

Goran Lakičević; Kenan I. Arnautović; Dario Mužević; Thomas Chesney

Background Cerebellar glioblastoma multiforme (GBM) is rare and presents with increased intracranial pressure and cerebellar signs. The recommended treatment is radical resection, if possible, with radiation and chemotherapy. Clinical Presentation A 53-year-old man presented with hypertensive cerebellar bleeding and a 2-day history of severe headaches, nausea, vomiting, gait instability, and elevated blood pressure. Computed tomography (CT) showed a left cerebellar hematoma with no obstruction of cerebrospinal fluid and no hydrocephalus. CT angiography showed no signs of pathologic blood vessels in the posterior cranial fossa. The patient was observed in the hospital and discharged. Subsequent CT showed complete hematoma resorption. Two weeks later, he developed headaches, nausea, and worsening cerebellar symptoms. Magnetic resonance imaging (MRI) showed a 4-cm diameter tumor in the left cerebellar hemisphere where the hemorrhage was located. The tumor was radically resected and diagnosed as GBM. The patient underwent radiation and chemotherapy. At a follow-up of 1.5 years, MRIs showed no tumor recurrence. Conclusion Hypertensive cerebellar hemorrhage may be the first presentation of underlying tumor, specifically GBM. Patients undergoing surgery for cerebellar hemorrhage should have clot specimens sent for histologic examination and have pre- and postcontrast MRIs. Patients not undergoing surgery should have MRIs done after hematoma resolution to rule out underlying tumor.


World Neurosurgery | 2017

First Report of Coexistence of Two Ectopic Pituitary Tumors: Rathke Cleft Cyst and Silent Adrenocorticotropic Hormone Adenoma

Mirza Pojskić; Blazej Zbytek; Neal S. Beckford; Frederick A. Boop; Kenan I. Arnautović

BACKGROUNDnRathke cleft cysts (RCCs) and pituitary adenomas (PAs) are thought to have a common embryonic ancestry; however, PAs with a concomitant RCC inside the sella turcica are rarely observed. Ectopic pituitary tumors are also rare.nnnCASE DESCRIPTIONnWe present the case of a 65-year-old woman with an ectopic RCC in the sphenoid sinus and outside the sella turcica concomitant with an adrenocorticotropic hormone (ACTH)-staining, clinically silent PA. The patient had headache but no endocrine or visual disturbances. Preoperative magnetic resonance imaging revealed infrasellar cystic lesion in the sphenoid sinus with erosion of the clivus and intact sellar floor. The patient underwent gross total microsurgical resection through the transnasal route with an uneventful postoperative course.nnnCONCLUSIONSnTo our knowledge, this is the first reported ectopic RCC located outside the sella turcica with a concomitant ACTH-staining PA. This also appears to be the first ACTH-staining adenoma concomitant with RCC reported in the literature, regardless of location, not presenting with Cushing disease. This case shows that we can now include pituitary adenoma with or without a concomitant RCC in the differential diagnosis of processes in the sphenoid sinus. As both PAs and RCCs are benign sellar lesions, surgical management of a concomitant occurrence of these tumors mainly depends on the size of the lesions and their clinical manifestations. For patients with PA and concomitant RCC, surgical resection should be considered, as there is an approximatrely 20% recurrence rate of the cyst after resection and the possibility of future clival erosion, if left untreated.


Journal of Neurological Surgery Reports | 2015

Diffuse Large B-Cell Lymphoma of the Frontal Sinus Presenting as a Pott Puffy Tumor: Case Report.

Nickalus R. Khan; Goran Lakičević; Thomas R. Callihan; George L. Burruss; Kenan I. Arnautović

Objectiveu2003Sinonasal non-Hodgkin lymphoma (NHL) is a very rare condition. NHL located specifically in the frontal sinus is even rarer with only 14 cases in the literature reported to date. A unique case of diffuse large B-cell lymphoma of the frontal sinus that presented first and was treated as suspected Pott puffy tumor is presented along with a review of the literature. Case Reportu2003A 69-year-old white man with a history of sinusitis and two recent endoscopic sinus surgeries presented with enlargement of his right forehead. Computed tomography and magnetic resonance images revealed a dense opacification of the frontal sinus bilaterally, thickening and enhancement of the dura mater behind the right frontal sinus, and local osteomyelitis-like lytic bone changes. A bifrontal craniotomy was performed. Radical exoneration of the frontal sinus, copious antibiotic-impregnated irrigation after culture swabs, and resection of presumed granulation tissue was performed. Culture swabs remained negative, but histopathology revealed diffuse large B-cell lymphoma. Subsequent chemotherapy was administered. Conclusionu2003Sinonasal NHL is very rare but can occur in the frontal sinus and may present as a suspected Pott puffy tumor. A high clinical suspicion is necessary for early diagnosis and treatment.


Skull Base Surgery | 2018

Microsurgical Decompression of Trigeminal Neuralgia Caused by Simultaneous Double Arterial (SCA and AICA) and Petrosal Vein Complex Compression

Domagoj Gajski; Alicia Dennis; Kenan I. Arnautović

Trigeminal neuralgia is a chronic pain disorder affecting the face. In approximately 80% of cases, it is most commonly caused, when the root entry zone (REZ) of the trigeminal nerve is compressed by the superior cerebellar artery (SCA). The etiology of the remaining 20% of cases is distributed among venous, arteriovenous malformations, posterior fossa tumors, multiple sclerosis plaque compressions, and other pathologies. Combinations of those compressive factors are very rare. 1 2 3 4 Herein, we present a video clip of microvascular decompression (MVD) in a 73-year-old female, who has failed conservative treatment with 6 medications over 10 years. She was affected by a unique triple compression of the right REZ by the SCA, anterior inferior cerebellar artery (AICA), and petrosal vein complex ( Fig. 1A ). Right-sided microsurgical decompression of the REZ of the trigeminal nerve through standard retrosigmoid craniotomy was performed by the senior author (K.I.A.). The SCA and AICA were separated from the nerve using Teflon pledgets. The petrosal vein complex was coagulated and divided, freeing up the right trigeminal nerve ( Fig. 1B ). The patient was discharged home on the third postoperative day with complete resolution of trigeminal neuralgia. The link to the Video can be found at: https://youtu.be/PYVvImGW0yE .


Skull Base Surgery | 2018

Microsurgical Resection of Tuberculum Sellae Meningioma through Left Cranio-orbital Approach

Mirza Pojskić; Kenan I. Arnautović

In this video clip, the authors present the resection of a tuberculum sellae meningioma with compression of the left optic nerve and a chiasm ( Fig. 1 ) through a standard cranial orbital (CO) skull base approach. 1 2 3 The key step in the tumor resection was microsurgical dissection of left and right A1 segments of the anterior cerebral artery and the anterior communicating artery and the separation of the tumor from these vascular structures. This was followed by careful separation of the meningioma from both optic nerves, the chiasm and the pituitary stalk. The final step was coagulation and resection of the tumor origin on the dura of the tuberculum sellae, devascularizing the tumor. Once this was achieved, the tumor was removed. Using this approach, an optimal surgical corridor to the sellar area was provided while minimizing the retraction of frontal and temporal lobes. The link to the video can be found at: https://youtu.be/O59Fj2dNXB0 .


Operative Neurosurgery | 2018

Microsurgical Resection of Medulla Oblongata Hemangioblastoma: 2-Dimensional Operative Video

Mirza Pojskić; Kenan I. Arnautović

Abstract This video demonstrates the microsurgical resection of brainstem hemangioblastoma. The patient is a 32-yr-old woman with Von Hippel Lindau syndrome who presented with quadriparesis and inability to swallow. Magnetic resonance imaging (MRI) of the neuroaxis revealed a brainstem cystic lesion with contrast-enhancing tumor nodule right along the posterior aspect of the lower part of medulla oblongata. The surgery was performed in the prone position with suboccipital craniectomy and partial C1 posterior arch removal. The aim of the surgery was to remove the tumor nodule.1-12 The tumor was separated from the right dorsal nerve roots, and then progressively dissected with coagulation of arterial feeders and draining vein and division of the pia circumferentially. Postoperative MRI revealed complete resection. The patient completely recovered from her quadriparesis and difficulty swallowing.


Operative Neurosurgery | 2018

Microsurgical Resection of Spinal Cord Hemangioblastoma: 2-Dimensional Operative Video

Mirza Pojskić; Kenan I. Arnautović

Abstract This video demonstrates microsurgical resection of spinal cord hemangioblastoma. Hemangioblastomas are rare, benign, highly vascularized tumors classified as grade I according to World Health Organization classification systems. About 3% of all intramedullary tumors are hemangioblastomas.1,2 Spinal cord hemangioblastomas are either sporadic3,4 or manifestations of von Hippel-Lindau (VHL) disease in 20% to 45% of patients.5,6 u2003A 30-year-old male presented with sudden onset urinary incontinence. Magnetic resonance imaging showed contrast enhancing intramedullary tumor with adjacent cyst in T11, and syringomyelia extending to C1. Surgical resection followed rules that apply to resection of arteriovascular malformations: coagulation of arterial feeders precedes the coagulation of the draining vein, which is preserved until the end of surgery.2,4,5,7,8 u2003First, posterior midline myelotomy was performed and the tumor cyst was drained in order to develop a dissection plane. Following this, we continuously separated dorsal nerve roots from the tumor nodule using microsurgical technique. The key step in tumor resection is devascularization of the tumor, achievable in 2 ways.2,7,9-13 The circumferential detachment of the normal pia from the tumor pia is crucial in developing a plane of dissection. The coagulation and division of arterial feeders while preserving the drainage vein further devascularizes the tumor. Once the tumor mural nodule was detached from the spinal cord, the drainage vein was coagulated last and the tumor was removed. The patient fully recovered from his incontinence and was neurologically intact. Screening for VHL disease was negative. u2003Written consent was obtained directly from the patient.


Journal of Neurosurgery | 2018

Retrospective single-surgeon study of 1123 consecutive cases of anterior cervical discectomy and fusion: a comparison of clinical outcome parameters, complication rates, and costs between outpatient and inpatient surgery groups, with a literature review

Jack Mullins; Mirza Pojskić; Frederick A. Boop; Kenan I. Arnautović

OBJECTIVE Outpatient anterior cervical discectomy and fusion (ACDF) is becoming more common and has been reported to offer advantages over inpatient procedures, including reducing nosocomial infections and costs, as well as improving patient satisfaction. The goal of this retrospective study was to evaluate and compare outcome parameters, complication rates, and costs between inpatient and outpatient ACDF cases performed by 1 surgeon at a single institution. METHODS In a retrospective study, the records of all patients who had undergone first-time ACDF performed by a single surgeon in the period from June 1, 2003, to January 31, 2016, were reviewed. Patients were categorized into 2 groups: those who had undergone ACDF as outpatients in a same-day surgical center and those who had undergone surgery in the hospital with a minimum 1-night stay. Outcomes for all patients were evaluated with respect to the following parameters: age, sex, length of stay, preoperative and postoperative pain (self-reported questionnaires), number of levels fused, fusion, and complications, as well as the presence of risk factors, such as an increased body mass index, smoking, and diabetes mellitus. RESULTS In total, 1123 patients were operated on, 485 (43%) men and 638 (57%) women, whose mean age was 50 years. The mean follow-up time was 25 months. Overall, 40.5% underwent 1-level surgery, 34.3% 2-level, 21.9% 3-level, and 3.2% 4-level. Only 5 patients had nonunion of vertebrae; thus, the fusion rate was 99.6%. Complications occurred in 40 patients (3.6%), with 9 having significant complications (0.8%). Five hundred sixty patients (49.9%) had same-day surgery, and 563 patients (50.1%) stayed overnight in the hospital. The inpatients were older, were more commonly male, and had a higher rate of diabetes. Smoking status did not influence the length of stay. Both groups had a statistically significant reduction in pain (expressed as a visual analog scale score) postoperatively with no significant difference between the groups. One- and 2-level surgeries were done significantly more often in the outpatient setting (p < 0.001). The complication rate was 4.1% in the outpatient group and 3.0% in the inpatient group; there was no statistically significant difference between the 2 groups (p = 0.339). Significantly more complications occurred with 3- and 4-level surgeries than with 1- and 2-level procedures (p < 0.001, chi-square test). The overall average inpatient cost for commercial insurance carriers was 26% higher than those for outpatient surgery. CONCLUSIONS Anterior cervical discectomy and fusion is safe for patients undergoing 1- or 2-level surgery, with a very significant rate of pain reduction and fusion and a low complication rate in both clinical settings. Outpatient and inpatient groups undergoing 3- or 4-level surgery had an increased risk of complications (compared with those undergoing 1- or 2-level surgery), with a negligible difference between the 2 groups. This finding suggests that these procedures can also be included as standard outpatient surgery. Comparable outcome parameters and the same complication rates between inpatient and outpatient groups support both operative environments.


Journal of Neurosurgery | 2018

The suboccipital ligament

Kelsey Alabaster; M. Fred Bugg; Bruno Splavski; Frederick A. Boop; Kenan I. Arnautović

OBJECTIVE A fibrous structure located dorsal to the dura at the posterior craniocervical junction stretches horizontally between the bilateral occipital condyles and the upper borders of the C-1 laminae. Partially covered by the occipital bone, this structure is always encountered when the bone is removed from the foramen magnum rim during approaches to the posterior cranial fossa. Although known to surgeons, this structure has not been defined, studied, or named. The most appropriate name for this structure is the suboccipital ligament, and a detailed rationale for this name is provided. METHODS This 3-year-long study included 10 cadaveric specimens and 39 clinical patients: 31 consecutive surgically treated patients with Chiari Type I malformations (CM-I subgroup) and 8 other patients with posterior fossa pathologies (non-CM-I subgroup). The dimensions were defined, the function of this ligament was hypothesized, size and histological composition were compared between patient subgroups, and its origin and relationship to the surrounding structures were analyzed. Possible statistical differences in the parameters between the 2 groups were also evaluated. RESULTS The suboccipital ligament consists of horizontally oriented hyaline fibers and has a median length of 35 mm, height of 10 mm, and thickness of 0.5 mm. These dimensions are not significantly different between the CM-I and non-CM-I patients. The median age of the patients was 43 years, with CM-I patients being significantly younger (median 35 years) than non-CM-I patients (median 57 years). There was no statistically significant difference in weight, height, and body mass index between patient subgroups. There was no significant correlation between the body mass index or height of the patients and the dimensions of the ligament. No statistically significant differences existed between the subgroups in terms of smoking history, alcohol consumption, and the presence of diabetes mellitus, hypertension, hydrocephalus, or headaches. The ligament tissue in the CM-I patients was disorganized with poorly arranged collagen bands and interspersed adipose tissue. These patients also had more hyalinized fibrosis and showed changes in the direction of fibers, with hyaline nodules ranging from 0 to 2+. The result of the histological evaluation of the suboccipital ligament for hyaline nodules, calcification, and ossification was graded as 2+ if present in 3 or more medium-power magnification fields (MPFs); 1+ if present in 1-2 MPFs; and 0, if present in less than 1 MPF. Histological examination of the ligaments showed structural differences between CM-I and non-CM-I patients, most notably the presence of hyaline nodules and an altered fiber orientation in CM-I patients. CONCLUSIONS The suboccipital ligament extends between the occipital condyle and the superior edge of the C-1 lamina, connecting the contralateral sides, and appears to function as a real ligament. It is ventral to the occipital bone, which covers approximately two-thirds of the height of the ligament and is loosely attached to the dura medially and more firmly laterally. Because of its distinctive anatomy, characteristics, and function, the suboccipital ligament deserves its own uniform designation and name.


Journal of Neurological Surgery Reports | 2018

Anterior Clinoid Metastasis Removed Extradurally: First Case Report

Mirza Pojskić; Blazej Zbytek; Kenan I. Arnautović

Background u2003We report a case of isolated metastasis on the anterior clinoid process (ACP) mimicking meningioma. Clinical Presentation u2003A 58-year-old male presented with headaches, right-sided visual disturbances, and blurred and double vision. The cause of double vision was partial weakness of the right III nerve, resulting from compression of the nerve by “hypertrophied” tumor-involved right anterior clinoid. Medical history revealed two primary malignant tumors—male breast cancer and prostate cancer (diagnosed 6 and 18 months prior, respectively). The patient was treated with chemotherapy and showed no signs of active disease, recurrence, or metastasis. Postcontrast head magnetic resonance imaging (MRI) showed extra-axial well-bordered enhancing mass measuring 1.6u2009×u20091.1u2009×u20091u2009×u20091 cm (anteroposterior, transverse, and craniocaudal dimensions) on the ACP, resembling a clinoidal meningioma. Extradural clinoidectomy with tumor resection was performed via right orbitozygomatic pretemporal skull base approach. Visual symptoms improved. Follow-up MRI showed no signs of tumor residual or recurrence. Conclusion u2003This is the first case report of a metastasis of any kind on ACP. Metastasis should be included as a part of the differential diagnosis of lesions of the anterior clinoid. Extradural clinoidectomy is a safe and effective method in the treatment of these tumors.

Collaboration


Dive into the Kenan I. Arnautović's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Frederick A. Boop

University of Tennessee Health Science Center

View shared research outputs
Top Co-Authors

Avatar

Nickalus R. Khan

University of Tennessee Health Science Center

View shared research outputs
Top Co-Authors

Avatar

Marko Kovacevic

Josip Juraj Strossmayer University of Osijek

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Bruno Splavski

Josip Juraj Strossmayer University of Osijek

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

George L. Burruss

University of Tennessee Health Science Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Matthew VanLandingham

University of Tennessee Health Science Center

View shared research outputs
Researchain Logo
Decentralizing Knowledge