Posterior Fossa ve Pineal Bölge Cerrahisinde Yarı Oturur Pozisyon: Tek Merkezli Deneyim

Yıl 2025, Cilt: 9 Sayı: 2, 285 - 292, 31.08.2025

Serkan Civlan , Nevzat Doğukan Erbek , Berk Burak Berker , Rasim Asar , Emrah Egemen , Turan Evran , Erdal Çoşkun

Öz

Amaç: İntrakraniyal cerrahide yarı oturur pozisyon; beyin omurilik sıvısı ve venöz kanın yerçekimiyle daha iyi drenajı, daha net görüş alanı,
azalmış intrakraniyal basınç ve minimal serebellar retraksiyon gibi önemli cerrahi avantajlar sağlar. Tarihsel olarak venöz hava embolisi gibi
komplikasyonlarla ilişkilendirilmiş olsa da, anestezi yönetimi ve intraoperatif izlemdeki son gelişmeler bu pozisyonun güvenliğini belirgin
şekilde artırmıştır.
Gereç ve Yöntemler: 2019 ile 2024 yılları arasında, deneyimli bir beyin cerrahı tarafından tek bir merkezde yarı oturur pozisyonda
gerçekleştirilen ardışık 17 intrakraniyal cerrahi olgusu retrospektif olarak analiz edildi. Hastaların demografik verileri, lezyon özellikleri, cerrahi
ayrıntılar ve klinik sonuçları incelendi. Preoperatif kardiyak değerlendirme ile belirgin sağdan sola intrakardiyak şant dışlandı. İntraoperatif
olarak venöz hava embolisini saptamak amacıyla sürekli end-tidal CO₂ monitörizasyonu kullanıldı.
Bulgular: Lezyonlar serebellum ve pineal bölgede yer alan çeşitli intrakraniyal patolojileri kapsamaktaydı. On beş olguda (%88) total
rezeksiyon sağlandı. Hiçbir olguda klinik olarak anlamlı venöz hava embolisi ya da diğer intraoperatif komplikasyon gözlenmedi ve hiçbir
hastada postoperatif nörolojik defisit gelişmedi. Bulgularımız, uygun cerrahi teknik ve perioperatif protokollerle uygulandığında yarı oturur
pozisyonun güvenli ve etkili olduğunu gösteren güncel literatürü desteklemektedir. Retrospektif tasarım, küçük örneklem hacmi ve yüksek
duyarlılıklı izlem araçlarının kullanılmamış olması gibi sınırlılıklar bulunsa da, elde edilen veriler ciddi komplikasyon oranlarının düşük
olduğunu bildiren son çalışmalarla uyumludur.
Sonuç: Yarı oturur pozisyon, seçilmiş intrakraniyal cerrahilerde güvenli ve avantajlı bir cerrahi yaklaşım olarak öne çıkmakta; üstün cerrahi
görüş alanı ve düşük komplikasyon oranları ile olumlu klinik sonuçlar sunmaktadır. Bu bulguların güçlendirilmesi için daha büyük hasta
serilerini içeren, karşılaştırmalı ve ileriye dönük çalışmalar önerilmektedir

Anahtar Kelimeler

Yarı oturur pozisyon , Posterior fossa cerrahisi , Kraniotomi , Hava embolisi

Semi-Sitting Position in Posterior Fossa and Pineal Region Surgery: Single-Center Experience

Öz

Aim: The semi-sitting position for intracranial surgery provides substantial surgical advantages, including improved gravitational drainage
of cerebrospinal fluid and venous blood, clearer visualization, reduced intracranial pressure, and minimized cerebellar retraction. Although
historically associated with complications such as venous air embolism, recent advancements in anesthetic management and intraoperative
monitoring have markedly enhanced its safety profile
Material and Methods: We retrospectively analyzed 17 consecutive intracranial surgeries performed in the semi-sitting position at a single
center between 2019 and 2024 by a senior neurosurgeon. Patient demographics, lesion characteristics, surgical details, and outcomes
were reviewed. Preoperative cardiac evaluation excluded patients with significant right-to-left intracardiac shunts. Continuous end-tidal CO₂
monitoring was used intraoperatively to detect venous air embolism.
Results: Pathologies included diverse intracranial lesions in the cerebellum and pineal region. Gross total resection was achieved in 15
cases (88%). No clinically significant VAE or other intraoperative complications were detected, and no postoperative neurological deficits
occurred. Our series supports the growing body of evidence that semi-sitting position is both safe and effective when applied with appropriate
technique and perioperative protocols. Despite limitations related to retrospective design, small sample size, and the absence of highly
sensitive monitoring tools, our findings are consistent with recent literature reporting low rates of serious complications.
Conclusion: The semi-sitting position remains a viable and advantageous surgical approach for selected intracranial procedures, offering
excellent surgical exposure and favorable clinical outcomes with minimal complication rates. Further prospective studies with larger cohorts
and comparative controls are recommended to reinforce these findings.

Anahtar Kelimeler

Semi-sitting position , Posterior fossa surgery , Craniotomy , Air embolism

Etik Beyan

The study was conducted in accordance with the rules of the Declaration of Helsinki and approved by the Ethics Committee of Pamukkale University (09.07.2025/E-60116787-020-719081)

Destekleyen Kurum

-

Teşekkür

-

Kaynakça

• 1. De Martel T. Surgical treatment of cerebral tumors. Technical considerations. Surg Gynecol Obstet. 1931;52:381–385.
• 2. Tufegdzic B, Lamperti M, Siyam A, Roser F. Air-embolism in the semi-sitting position for craniotomy: A narrative review with emphasis on a single centers experience. Clin Neurol Neurosurg. 2021 Oct;209:106904. doi: 10.1016/j.clineuro.2021.106904. Epub 2021 Aug 27. PMID: 34482115.
• 3. Türe H, Harput MV, Bekiroğlu N, Keskin Ö, Köner Ö, Türe U. Effect of the degree of head elevation on the incidence and severity of venous air embolism in cranial neurosurgical procedures with patients in the semisitting position. J Neurosurg. 2018 May;128(5):1560-1569. doi: 10.3171/2017.1.JNS162489. Epub 2017 Jul 14. PMID: 28707996.
• 4. Saladino A, Lamperti M, Mangraviti A, Legnani FG, Prada FU, Casali C, Caputi L, Borrelli P, DiMeco F. The semisitting position: analysis of the risks and surgical outcomes in a contemporary series of 425 adult patients undergoing cranial surgery. J Neurosurg. 2017 Oct;127(4):867-876. doi: 10.3171/2016.8.JNS16719. Epub 2016 Dec 16. PMID: 27982770.
• 5. Feigl GC, Decker K, Wurms M, Krischek B, Ritz R, Unertl K, Tatagiba M. Neurosurgical procedures in the semisitting position: evaluation of the risk of paradoxical venous air embolism in patients with a patent foramen ovale. World Neurosurg. 2014 Jan;81(1):159-64. doi: 10.1016/j.wneu.2013.01.003. Epub 2013 Jan 4. PMID: 23295634.
• 6. Hermann EJ, Hatipoglu Majernik G, Scheinichen D, Al-Afif S, Heissler HE, Palmaers T, Krauss JK. Resection of posterior fossa tumors in the semi-sitting position in children younger than 4 years of age. Childs Nerv Syst. 2023 Jan;39(1):159-167. doi: 10.1007/s00381-022-05725-y. Epub 2022 Nov 9. PMID: 36348035; PMCID: PMC9968679.
• 7. Klein J, Juratli TA, Weise M, Schackert G. A Systematic Review of the Semi-Sitting Position in Neurosurgical Patients with Patent Foramen Ovale: How Frequent Is Paradoxical Embolism? World Neurosurg. 2018 Jul;115:196-200. doi: 10.1016/j. wneu.2018.04.114. Epub 2018 Apr 26. PMID: 29704690.
• 8. Al-Afif S, Lang JM, Abdulbaki A, Palmaers T, Scheinichen D, Abu-Fares O, Hermann EJ, Krauss JK. The safety and utility of the semi-sitting position for clipping of posterior circulation aneurysms. Acta Neurochir (Wien). 2024 Aug 20;166(1):341. doi: 10.1007/s00701-024-06229-1. PMID: 39160268; PMCID: PMC11333526.
• 9. Rabelo N, Silva B, Cunha C, Furtado I, Valli D, Filho L, Marchini L, Pereira VHP, Passos GS, Dias L, Tanaka J, Plastina F, Rabelo N. Semi-sitting position in neurosurgery: a review. Arq Bras Neurocir. 2016;35(2). doi:10.1055/s-0036-1572507.
• 10. Karmakar A, Khan M, Saracoglu A, Ergenc M, Hussein MIH, Orompurath M, Saracoglu K, Gangineni K, Kumar N. Craniotomy in semi-sitting position: a 4-year single institution experience [Preprint]. Res Sq. 2023. doi:10.21203/rs.3.rs-3821842/ v1.
• 11. Türe U, Harput MV, Kaya AH, Baimedi P, Firat Z, Türe H, Bingöl CA. The paramedian supracerebellar-transtentorial approach to the entire length of the mediobasal temporal region: an anatomical and clinical study. Laboratory investigation. J Neurosurg. 2012 Apr;116(4):773-91. doi: 10.3171/2011.12. JNS11791. Epub 2012 Jan 20. PMID: 22264179.
• 12. Wu X, Wang X, Song G, Li M, Hou C, Chen G, Guo H, Xiao X, Tang J, Lin Q, Bao Y, Liang J. The effects of different surgical positions (semi-sitting and lateral position) on the surgical outcomes of large vestibular schwannoma: study protocol for a randomized controlled trial. Trials. 2022 Jun 14;23(1):492. doi: 10.1186/s13063-022-06437-z. PMID: 35701794; PMCID: PMC9194341.
• 13. Ammirati M, Lamki TT, Shaw AB, Forde B, Nakano I, Mani M. A streamlined protocol for the use of the semi-sitting position in neurosurgery: a report on 48 consecutive procedures. J Clin Neurosci. 2013 Jan;20(1):32-4. doi: 10.1016/j. jocn.2012.05.037. Epub 2012 Nov 21. PMID: 23178073; PMCID: PMC3840951.
• 14. Serra C, Akeret K, Staartjes VE, Ramantani G, Grunwald T, Jokeit H, Bauer J, Krayenbühl N. Safety of the paramedian supracerebellar-transtentorial approach for selective amygdalohippocampectomy. Neurosurg Focus. 2020 Apr 1;48(4):E4. doi: 10.3171/2020.1.FOCUS19909. PMID: 32234984.
• 15. Machetanz K, Leuze F, Mounts K, Trakolis L, Gugel I, Grimm F, Tatagiba M, Naros G. Occurrence and management of postoperative pneumocephalus using the semi-sitting position in vestibular schwannoma surgery. Acta Neurochir (Wien). 2020 Nov;162(11):2629-2636. doi: 10.1007/s00701-020-04504-5. Epub 2020 Jul 25. PMID: 32712719; PMCID: PMC7550361.
• 16. Al-Afif S, Elkayekh H, Omer M, Heissler HE, Scheinichen D, Palmaers T, Nakamura M, Hermann EJ, Samii M, Krauss JK. Analysis of risk factors for venous air embolism in the semisitting position and its impact on outcome in a consecutive series of 740 patients. J Neurosurg. 2021 Nov 5;137(1):258-265. doi: 10.3171/2021.7.JNS211107. PMID: 34740183.
• 17. Himes BT, Mallory GW, Abcejo AS, Pasternak J, Atkinson JLD, Meyer FB, Marsh WR, Link MJ, Clarke MJ, Perkins W, Van Gompel JJ. Contemporary analysis of the intraoperative and perioperative complications of neurosurgical procedures performed in the sitting position. J Neurosurg. 2017 Jul;127(1):182-188. doi: 10.3171/2016.5.JNS152328. Epub 2016 Aug 5. PMID: 27494821.
• 18. Hurth H, Ebner FH, Clement E, Naros G, Rosenberger P, Kasper EM, Tatagiba M, Drexler B. The risk of intraoperative venous air embolism from neurosurgical procedures performed in the lounging position: an in-depth analysis of detection, management, and outcomes of 1000 consecutive cases. J Neurosurg. 2024 Sep 20;142(3):797-807. doi: 10.3171/2024.5.JNS232449. PMID: 39303312.
• 19. Fathi AR, Eshtehardi P, Meier B. Patent foramen ovale and neurosurgery in sitting position: a systematic review. Br J Anaesth. 2009 May;102(5):588-96. doi: 10.1093/bja/aep063. Epub 2009 Apr 4. PMID: 19346525.
• 20. Kurihara M, Nishimura S. Estimation of the head elevation angle that causes clinically important venous air embolism in a semi-sitting position for neurosurgery: a retrospective observational study. Fukushima J Med Sci. 2020 Aug 4;66(2):67-72. doi: 10.5387/fms.2019-33. Epub 2020 Jun 5. PMID: 32507799; PMCID: PMC7470760.
• 21. Toung TJ, McPherson RW, Ahn H, Donham RT, Alano J, Long D. Pneumocephalus: effects of patient position on the incidence and location of aerocele after posterior fossa and upper cervical cord surgery. Anesth Analg. 1986 Jan;65(1):65-70. PMID: 3455673.