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Publication Open Access A novel and simple machine learning algorithm for preoperative diagnosis of acute appendicitis in children(Springer, 2020) Türkmen, İnan Utku; Namlı, Gözde; Özturk, Çiğdem; Esen, Ayşe B.; Eray, Y. Nur; Akova, Fatih; Aydın, Emrah; Eroğlu, Egemen; Faculty Member; faculty Member; School of Medicine; 32059; N/AIntroduction: there is a tendency toward nonoperative management of appendicitis resulting in an increasing need for preoperative diagnosis and classification. For medical purposes, simple conceptual decision-making models that can learn are widely used. Decision trees are reliable and effective techniques which provide high classification accuracy. We tested if we could detect appendicitis and differentiate uncomplicated from complicated cases using machine learning algorithms. Materials and methods: we analyzed all cases admitted between 2010 and 2016 that fell into the following categories: healthy controls (Group 1); sham controls (Group 2); sham disease (Group 3), and acute abdomen (Group 4). The latter group was further divided into four groups: false laparotomy; uncomplicated appendicitis; complicated appendicitis without abscess, and complicated appendicitis with abscess. Patients with comorbidities and whose complete blood count and/or pathology results were lacking were excluded. Data were collected for demographics, preoperative blood analysis, and postoperative diagnosis. Various machine learning algorithms were applied to detect appendicitis patients. Results: there were 7244 patients with a mean age of 6.84 +/- 5.31 years, of whom 82.3% (5960/7244) were male. Most algorithms tested, especially linear methods, provided similar performance measures. We preferred the decision tree model due to its easier interpretability. With this algorithm, we detected appendicitis patients with 93.97% area under the curve (AUC), 94.69% accuracy, 93.55% sensitivity, and 96.55% specificity, and uncomplicated appendicitis with 79.47% AUC, 70.83% accuracy, 66.81% sensitivity, and 81.88% specificity. Conclusions: machine learning is a novel approach to prevent unnecessary operations and decrease the burden of appendicitis both for patients and health systems.
Publication Metadata only Anastomoses of the vestibular, cochlear, and facial nerves(Lippincott Williams and Wilkins (LWW), 2012) Unel, Sacide; Yilmaz, Mehmet; Albayram, Sait; Isik, Zehra; Ceyhan, Elvan; Isildak, Huseyin; Teixido, Michael; Savas, Yildiray; Kiris, Adem; Department of Mathematics; Ceyhan, Elvan; Faculty Member; Department of Mathematics; College of Sciences; N/AThe internal auditory canal (IAC) is 10 to 17 mm in length, and the facial nerve and vestibulocochlear nerve, which consist of the cochlear nerve, the superior vestibular nerve, and the inferior vestibular nerve, run together in the IAC packaged in dura mater. Oort first described the vestibulocochlear anastomoses in 1918, which is important for the understanding of the pathogenesis and pathophysiology of otologic disorders. The current study documents the existence of vestibulofacial and vestibulocochlear neural connections and topographical relationship of the nerves as part of a radiologic evaluation of 73 human temporal bones from brainstem to the lateral portion of IAC.Publication Metadata only Anatomic variations of the human falx cerebelli and its association with occipital venous sinuses(Taylor & Francis, 2021) Solmaz, Bilgehan; Dalçık, Hakkı; Aydoğmuş, Evren; Kara, Erdoğan; Aslıyüksek, Hızır; N/A; Çavdar, Safiye; Tanış, Özgül; Güler, Orhan Ulaş; Altunkaya, Leyla; Faculty Member; Undergraduate Student; Undergraduate Student; Undergraduate Student; School of Medicine; School of Medicine; School of Medicine; School of Medicine; 1995; N/A; N/A; N/APurpose Human falx cerebelli is an important anatomical structure in regard to its relations with venous structures during infratentorial approach to reach cerebellar tumors, vascular malformations, traumatic hemorrhage and Chiari malformations. The present study aim to describe the different types of variations of the falx cerebelli, its morphological features and its association with occipital venous sinuses. Method In this study 49 dura mater was obtained from the Institution of Forensic Medicine. The length, width and the depth of the falx cerebelli were measured using a digital compass. The data obtained were statistically analyzed in relation to age and gender. The relations of the falx cerebelli with the occipital sinus was documented. Histological sections from the falx cerebelli were stained with Hematoxylin Eosin to evaluate the fine structure. Results Among the 49 falx cerebelli examined 36 (73.5%) were classified as normal. The average length, width and depth of the normal falx cerebelli was 3.7, 1.0 and 0.4 cm respectively. of the 49 falx cerebelli in 1 (2%) case it was absent, in 5 cases (10.2%) duplicate, in 5 cases (10.2%) triplicate, in 1 (2%) case quadruplets and in 1 case (2%) it was five-folded. The proximal and the distal attachments of the falx cerebelli showed 3 types of variations; both attachments triangular, the proximal attachments triangular and the distal ramified and distal attachments triangular and the proximal attachments ramified. The drainage of the occipital sinus of falx cerebelli with variations were evaluated. The increased number of falx cerebelli highly corresponded with the increased number of occipital sinus. Conclusions The dural-venous variation in the posterior cranial fossa can be problematic in various diagnostic and operative procedures of this region. Neurosurgeons should be aware of such variations, as these could be potential sources of haemorrhage during the midline suboccipital and infratentorial approaches.Publication Metadata only Before and after what has changed in the attitude of Turkish society regarding face transplantations?(Lippincott Williams & Wilkins, 2019) Findikcioglu, Kemal; Sibar, Serhat; Otgoz, Duygu; N/A; Özmen, Selahattin; Faculty Member; School of Medicine; Koç University Hospital; 125951Face transplantation is one of the most popular and controversial subjects of plastic surgery today. Although there are various surveys on the subject, there is no study comparing the past and the present social viewpoint and behavioral preferences for face transplantations across the world. In this study, we aimed to investigate the changes in the views of the Turkish society with respect to face transplantation from past to present. For this purpose, 1000 volunteer participants were questioned in terms of demographics and their perspective and preferences on organ and face transplantation. The results of the study were compared with the past data, and based on the results, the level of consciousness and awareness of the Turkish society about the subject has increased; the rate risk taking for immunosuppression has decreased, and instead, the rate of having an undecided stance has increased, and this attitude continues even if the risk is resolved. With these results, we can conclude that the greatest handicap for face transplantation in the Turkish society today is immunosuppression and the associated risks. We believe that new drug protocols and monitoring of patient outcomes for longer periods as well as more extensive clinical applications may be beneficial in addressing this issue.Publication Metadata only Can TRIF/TICAM-1 dependent pathway be target pathway in lumbar intervertebral disc degeneration?(Turkish Neurosurgical Society, 2023) ALIZADA, Orkhan; AKYOL, Sibel; OZLEN, Fatma; CETINTAS, Semih Can; TURK, Okan; HANCI, Murat; N/A; Akgün, Mehmet Yiğit; N/A; Koç University HospitalAIM: To elucidate the role of the TIR-domain-containing adaptor-inducing interferon-β (TRIF) dependent pathway in intervertebral disc degeneration (IVD). MATERIAL and METHODS: A total of adult male patients with low back pain (LBP) (+/- radicular pain) were further evaluated by magnetic resonance imaging (MRI) with surgical indication for microscopic lumbar disc herniation (LDH). Preoperatively, patients were classified according to Modic Changes (MC), nonsteroidal anti-inflammatory drugs (NSAIDs) use, and the presence of radicular pain in addition to the LBP. RESULTS: The age of the 88 patients ranged from 19 to 75 years (mean: 47.3 ± 19.6 years). Twenty eight of the patients were evaluated as MC I (31.8%), 40 as MC II (45.4%), and 20 as MC III (22.7%). The majority of patients (81.8%) had radicular LBP, while 16 patients (18.1%) had only LBP. Predominantly, 55.6% of all patients were taking NSAIDs. Levels of all adaptor molecules were highest in the MC I group and lowest in the MC III group. The levels of IRF3, TICAM1, TICAM2, NF-kB p65, TRAF6, and TLR4 were significantly increased in the MC I group compared to the MC II and MC III groups. The variations of the individual adaptor molecules showed no statistically significant difference in the use of NSAIDs and radicular LBP. CONCLUSION: As a result of the impact assessment, the current study clearly demonstrated for the first time that the TRIF-dependent signalling pathway plays a crucial role in the degeneration process in human lumbar intervertebral disc specimens. © 2023. All Right Reserved.Publication Metadata only Can weight of the resected stomach predict weight loss results after laparoscopic sleeve gastrectomy?(Lippincott Williams and Wilkins, 2024) Sobutay, Erman; Bilgic, Cagri; Kabaoglu, Burcak; N/A; Yavuz, Yunus; School of MedicineBackground: Laparoscopic sleeve gastrectomy (LSG) is the most commonly performed bariatric procedure worldwide. Many factors have been investigated in the literature to predict weight loss outcomes after LSG. However, insufficient data regarding the resected stomach weight (RGW) exists. This retrospective study aimed to investigate the association between RGW and weight loss outcomes 1 year after LSG. Materials and Methods: Fifty-four patients who underwent LSG in a tertiary care center were evaluated retrospectively. The statistical analyses were performed to investigate the correlation between preoperative demographics, RGW, and the excess weight loss percentage (%EWL) and percent total weight loss (%TWL). Results: The mean RGW was 169.7 +/- 40.1, ranging from 101 to 295 grams. The RGW was significantly correlated with preoperative weight (r=0.486; P<0.001), body mass index (r=0.420; P=0.002), and age (r=0.327; P=0.01). However, RGW did not predict postoperative weight loss, as measured by percent total weight loss (%TWL) and percent excess weight loss (%EWL), respectively (r=0.044; P=0.75 and r=-0.216; P=0.11). Multiple linear regression analysis identified age as a negative predictor for both %TWL (beta=-0.351, P=0.005) and %EWL (beta=-0.265, P=0.03), while preoperative body mass index was a negative predictor for %EWL (beta=-0.469, P<0.001). Conclusion: The RGW, although correlated with patient characteristics, does not serve as a reliable predictor of postoperative weight loss in the first year after LSG. Further research is needed to improve predictive models and patient care in bariatric surgery.Publication Metadata only Case series and descriptive cohort studies in neurosurgery: the confusion and solution(Springer, 2014) Esene, Ignatius N.; Ngu, Julius; El Zoghby, Mohamed; Sikod, Anna M.; Kotb, Ali; Dechambenoit, Gilbert; El Husseiny, Hossam; N/A; Solaroğlu, İhsan; Faculty Member; School of Medicine; 102059Case series (CS) are well-known designs in contemporary use in neurosurgery but are sometimes used in contexts that are incompatible with their true meaning as defined by epidemiologists. This inconsistent, inappropriate and incorrect use, and mislabeling impairs the appropriate indexing and sorting of evidence. Using PubMed, we systematically identified published articles that had "case series" in the "title" in 15 top-ranked neurosurgical journals from January 2008 to December 2012. The abstracts and/or full articles were scanned to identify those with descriptions of the principal method as being "case series" and then classified as "true case series" or "non-case series" by two independent investigators with 100 % inter-rater agreement. Sixty-four articles had the label "case series" in their "titles." Based on the definition of "case series" and our appraisal of the articles using Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines, 18 articles (28.13 %) were true case series, while 46 (71.87 %) were mislabeled. Thirty-five articles (54.69 %) mistook retrospective (descriptive) cohorts for CS. CS are descriptive with an outcome-based sampling, while "descriptive cohorts" have an exposure-based sampling of patients, followed over time to assess outcome(s). A comparison group is not a defining feature of a cohort study and distinguishes descriptive from analytic cohorts. A distinction between a case report, case series, and descriptive cohorts is absolutely necessary to enable the appropriate indexing, sorting, and application of evidence. Researchers need better training in methods and terminology, and editors and reviewers should scrutinize more carefully manuscripts claiming to be "case series" studies.Publication Metadata only Challenges in using the posterior inferior cerebellar artery for revascularization of the anterior inferior cerebellar artery: a microsurgical anatomic study(Elsevier, 2021) Keser, Nese; Elshamy, Walid; Chen, Xinpu; Velioglu, Murat; Is, Merih; Xu, Yinfu; Eroksuz, Melih; Ermutlu, Ilcim; Huryol, Cagin; Jian, Ruan; N/A; Ateş, Özkan; Faculty Member; School of Medicine; 118533Background: A bypass is usually required to prevent ischemia during the treatment of anterior inferior cerebellar artery (AICA) aneurysms. The intracranial (IC)-to-IC bypass provides several advantages over the extracranial-to-IC bypass in the posterior fossa. However, there are only 2 case reports about AICA revascularization with the posterior inferior cerebellar artery (PICA). We aimed to investigate the microsurgical anatomical challenges for PICA to AICA anastomosis. Methods: Ten cadaveric heads injected with colored silicone were inspected on both sides using a lateral transcondylar approach. After the donor and recipient arteries were examined from the posterior side, neurovascular contents of the posterior fossa were excised and the origin, course, and variations of both arteries were investigated from the anterior view. The diameters of the AICA and PICA segments and the intersegment distance were measured. Results: PICA variations and posteromedial origins from the vertebral artery were identified in 8 of the 20 right and 6 of the 20 left sides, and the first segment of the PICA was not present in 7 sides. Furthermore, in 18 sides, the PICA was trapped between the lower cranial nerves and dentate ligaments. Therefore the donor artery could not be brought closer than 1 cm to the recipient artery in 19 sides. Moreover, AICA variations were identified in 6 sides, and in 12 sides, the diameter of the recipient artery was <1 mm. Conclusions: The mostly PICA-related issues made PICA-to-AICA anastomosis unfeasible in all cadaveric heads included in the study.Publication Metadata only Clinical and genetic spectrum from a prototype of ciliopathy: Joubert syndrome(Elsevier B.V., 2023) Aksu Uzunhan, Tuğçe; Ertürk, Biray; Aydın, Kürşad; Ayaz, Akif; Yarar, Murat Hakkı; Gezdirici, Alper; İçağasıoğlu, Dilara Füsun; Gökpınar İli, Ezgi; Uyanık, Bülent; Eser, Metin; Kutbay, Yaşar Bekir; Topçu, Yasemin; Kılıç, Betül; Bektaş, Gonca; Ekici, Barış; Chousein, Amet; Yüksel, Atıl; Altunoğlu, Umut; Akçay, Ayfer Arduç; Avcı, Şahin; Kayserili, Hülya; Faculty Member; Faculty Member; Faculty Member; Faculty Member; School of Medicine; School of Medicine; School of Medicine; School of Medicine; 126174; 162811; N/A; 7945Objective: Joubert syndrome is a neurodevelopmental disorder with a distinctive hindbrain malformation called molar tooth sign, causing motor and cognitive impairments. More than 40 genes have been associated with Joubert syndrome. We aim to describe a group of Joubert syndrome patients clinically and genetically emphasizing organ involvement. Methods: We retrospectively collected clinical information and molecular diagnosis data of 22 patients with Joubert syndrome from multiple facilities. Clinical exome or whole-exome sequencing were performed to identify causal variations in genes. Results: The most common variants were in the CPLANE1, CEP290, and TMEM67 genes, and other causative genes were AHI1, ARMC9, CEP41, CSPP1, HYLS1, KATNIP, KIAA0586, KIF7, RPGRIP1L, including some previously unreported variants in these genes. Multi-systemic organ involvement was observed in nine (40%) patients, with the eye being the most common, including Leber's congenital amaurosis, ptosis, and optic nerve coloboma. Portal hypertension and esophageal varices as liver and polycystic kidney disease and nephronophthisis as kidney involvement was encountered in our patients. The HYLS1 gene, which commonly causes hydrolethalus syndrome 1, was also associated with Joubert syndrome in one of our patients. A mild phenotype with hypophyseal hormone deficiencies without the classical molar tooth sign was observed with compound heterozygous and likely pathogenic variants not reported before in the KATNIP gene. Conclusion: Some rare variants that display prominent genetic heterogeneity with variable severity are first reported in our patients. In our study of 22 Joubert syndrome patients, CPLANE1 is the most affected gene, and Joubert syndrome as a ciliopathy is possible without a classical molar tooth sign, like in the KATNIP gene-affected patients. © 2022 Elsevier B.V.Publication Metadata only Clinical and molecular study of ELMO-2-related massive intraosseous vascular malformations lessons learned from 25 years of follow-up(2019) Vargel, İbrahim; Çalış, Mert; Canter, Halil İbrahim; N/A; Çil, Barbaros Erhan; Faculty Member; School of Medicine; Koç University Hospital; 169993Massive intraosseous vascular malformations, a relatively rare entity in the vascular malformation spectrum, deserves attention as involving the membranous bones of the craniofacial skeleton and may lead to severe life-threatening hemorrhages and even death. The main aim of this study was to summarize the 25 years of clinical experience with these vascular malformation osseous patients, focus on the molecular and genetic aspect of the clinical entity, and to emphasize the certain challenging conditions in the treatment of these patients. All the patients appeared to be unaffected at birth, whereas initial symptoms occasionally began with painless swelling in the mandible in early childhood. The disease was progressive in behavior especially in the pubertal ages and was specifically involving the maxilla and mandible of the craniofacial skeleton in all the patients. Calvarium and cranial base were the second most common involved regions among these patients (62.5%). Clavicular (50%), costal (25%), and vertebral (25%) involvements were also a significant manifestation of the disease. Tissue samples obtained from the affected individuals and the blood samples from their families were matched, revealing a loss of function mutation in the ELMO-2 gene of chromosome 20 leading to developmental abnormality of the vascular structures via RAC1 signaling and leading to abnormally enlarged vessels in the intraosseus portion of the membranous bone. Immunohistochemical staining revealed positive CD31 and smooth muscle actin staining but negative proliferation and maturity markers such as Ki-67, desmin, h-caldesmon, and myofibroblast-like desmin. The follow-up of 3 of 5 patients ended up with mortality (60%). vascular malformation osseous is intraosseous vascular malformation with aggressive biological behavior associated with ELMO-2 gene mutation. Further studies for obtaining prenatal diagnosis and achievement of gene therapy should take place. As the disease rapidly progresses as the affected individual grows, surgical interventions should be taken into consideration before the initiation of complications.