{"id":"4d26cee6-8791-43cb-ac7a-26713c5861b5","slug":"retrosigmoid-transhorizontal-fissure-approach-for-the-resection-of-a-pontine-cavernous-malformation-three-dimensional-operative-video","title":"Retrosigmoid transhorizontal fissure approach for the resection of a pontine cavernous malformation: Three-dimensional operative video","authors":["Gerardo Y. Guinto-Nishimura","Rodrigo Uribe-Pacheco","Marcos Vinicius Sangrador-Deitos","Matias Baldoncini","Juan Villalonga","Yael Beristain","Alvaro Campero"],"abstract":"Background: Brainstem cavernous malformations (BSCMs) represent a surgical challenge due to their location deep within critical neural pathways. While histologically benign, BSCMs exhibit an aggressive clinical course, with a higher risk of bleeding and rebleeding than supratentorial cavernomas, often leading to significant neurological deficits. Management options include surveillance, radiosurgery, and microsurgical resection. Surgical treatment is especially complex, as it requires a delicate balance between the expected risk of rebleeding against the potential surgical morbidity. Favorable outcomes have been reported after microsurgical resection in multiple series. A precise understanding of brainstem safe-entry zones is essential to access these lesions and minimize parenchymal transgression. Case Description: We present the case of a young patient with bleeding from a pontine middle peduncular BSCM. Microsurgical resection was performed through a retrosigmoid transhorizontal fissure approach in a semi-sitting position, optimizing working angles while minimizing cerebellar retraction. This approach provides safe access through the middle cerebellar peduncle, allowing a more versatile dissection away from critical neural pathways compared to other safe-entry zones, minimizing brainstem manipulation. Key surgical nuances and relevant considerations in the decision-making process are demonstrated in this three-dimensional operative video. A complete resection was achieved, and the patient remained neurologically intact on long-term follow-up. The patient consented to the procedure and publication of this work. Conclusion: This case illustrates the surgical and anatomical complexity of pontine BSCMs and highlights the importance of tailoring the surgical approach to the lesion´s location, planned pial access, required exposure, dissection trajectory, and surgeon experience. 1) 01:16 - Anatomical description. 2) 03:20 - Patient positioning and incision. 3) 03:57 - Horizontal fissure dissection. 4) 05:15 - Pial incision. 5) 06:40 - Circumferential dissection and resection. Institutional review board approval is not required. The authors certify that they have obtained all appropriate patient consent. There are no conflicts of interest. The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI. https://doi.org/10.25259/SNI_711_2025 The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Journal or its management. The information contained in this article should not be considered to be medical advice; patients should consult their own physicians for advice as to their specific medical needs.","thumbnailUrl":"https://sni-digital-videos.s3.amazonaws.com/placeholders/specialty/skull-base.png","publishDate":"2025-12-19T00:00:00.000Z","doi":"10.25259/SNI_711_2025","categories":["Skull Base","Video Abstract"],"fullTextUrl":"https://surgicalneurologyint.com/api/articles/4d26cee6-8791-43cb-ac7a-26713c5861b5/pdf"}