REVIEW Outcomes of dura-splitting technique compared to conventional duraplasty technique in the treatment of adult Chiari I malformation: a systematic review and meta-analysis Amin Tavallaii 1 & Ehsan Keykhosravi 1 & Hamid Rezaee 2 & Mohammad Ali Abouei Mehrizi 2 & Ahmad Ghorbanpour 2 & Ali Shahriari 3 Received: 18 March 2020 /Revised: 14 May 2020 /Accepted: 8 June 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Chiari malformation type I is a developmental abnormality with an array of surgical techniques introduced for the management of it. The most common technique is foramen magnum decompression with duraplasty. Dura-splitting technique as one of the non- dura-opening techniques is a less known procedure that spares the internal layer of the dura and can theoretically result in fewer complications compared to duraplasty. So, we performed a review of literature and meta-analysis on different clinical and radiological aspects of this technique and compared its outcomes to duraplasty. MOOSE guidelines were followed. A systematic search of three databases based on predefined search strategy and inclusion/exclusion criteria was performed. After quality assessment and data extraction by two authors, summarized data were presented in form of tables, and meta-analysis results were illustrated in forest plots. A review of 10 included studies consisting of 370 patients revealed significantly shorter operation duration and less intraoperative blood loss in the dura-splitting technique compared to duraplasty. Interestingly, there was no significant difference between these two techniques in terms of clinical and radiological outcomes. Overall complication rate and incidence of CSF-related complications or infections were significantly in favor of the dura-splitting technique. Dura-splitting technique can be considered as a safe and effective surgical procedure for Chiari I malformation with comparable outcomes and fewer complications compared to duraplasty, although this interpretation is derived from retrospective observational studies and lack of a prospective clinical trial is evident. Keywords Chiari malformation type I . Dura splitting . Duraplasty . Outcome Introduction Chiari malformation-I (CM-I) is herniation of cerebellar ton- sils, 5 mm, or greater, below the foramen magnum with asso- ciated developmental abnormalities of posterior fossa [1]. This condition may result in syringomyelia due to an obstruc- tion of the flow of cerebrospinal fluid (CSF) at the craniocervical junction [2]. Clinical findings usually appear in the third and fourth decades of life. Magnetic resonance imaging (MRI) is the gold standard test for diagnosing CM- I. There is an array of surgical techniques as treatment of this malformation. Traditionally, the most known technique is suboccipital craniectomy and duraplasty, but recently, differ- ent studies reported good outcomes and low complication rates using techniques without duraplasty such as craniectomy alone or craniectomy and dura splitting. In craniectomy with duraplasty technique, after completion of suboccipital craniectomy, dura will be opened and expanded with Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10143-020-01334-y) contains supplementary material, which is available to authorized users. * Amin Tavallaii tavallaeia@mums.ac.ir 1 Akbar Children Hospital, Neurosurgery Department, Mashhad University of Medical Sciences, Neurosurgery department office, 1st floor, Ghaem hospital, Ahmadabad Blvd., P.O. Box: 9176699199, Mashhad, Iran 2 Neurosurgery Department, Mashhad University of Medical Sciences, Mashhad, Iran 3 Faculty of Medicine, Islamic Azad University of Mashhad, Mashhad, Iran Neurosurgical Review https://doi.org/10.1007/s10143-020-01334-y