Finnish study of intraoperative irrigation versus drain alone after evacuation of chronic subdural haematoma (FINISH) is a prospective, nationwide, randomized, controlled, multicentre trial to assess the role of intraoperative irrigation in the operative treatment of chronic subdural haematomas.

Why is this trial needed?

Surgery for chronic subdural haematomas (CSDHs) is the most common emergency neurosurgical procedure. CSDHs are typically caused by minor head trauma, leading to a haemorrhage in between the dura mater and the arachnoid membrane. For symptomatic CSDHs, the treatment is burr-hole evacuation, followed by intraoperative irrigation and placement of a subdural drainage.

Although irrigation is widely considered an imperative (‘uncontested’) part of the surgical procedure, the true value of irrigation has never been established in a randomized controlled trial setting. In the FINISH trial, we will compare single burr-hole evacuation of CSDH, subsequent intraoperative irrigation and the use of a drain to evacuation of CSDH without irrigation (drain alone).

What is the primary objective of the FINISH trial?

The aim of this trial is to study whether intraoperative irrigation adds any benefit to simple evacuation and subsequent drainage in the treatment of CSDHs. FINISH is a non-inferiority trial. The primary outcome is symptomatic CSDH recurrence requiring reoperation within 6 months. If there is no difference in recurrence rates between intraoperative irrigation and no irrigation, CSDH surgery can be performed faster and more safely by omitting the need to irrigate.

Where are we now?

The trial recruitment was completed in August 2022 and the last follow-up in the February 2023. We intend to publish the main results of the study by the end of 2023/beginning of 2024.

The FINISH trial protocol was published in BMJ Open in 2020.

Principal investigators

Kimmo Lönnrot

MD, PhD, Neurosurgeon, Senior researcher

Rahul Raj

MD, PhD, docent

Project team

Pihla Tommiska, Christoph Schwartz, Riku Kivisaari, Teemu Luostarinen, Jarno Satopää, Jonas Ranstam (trial statistician), Janek Frantzen, Jussi Posti, Teemu Luoto, Ville Leinonen, Sami Tetri, Timo Koivisto, Simo Taimela and Teppo Järvinen


Rahul Raj, Pihla Tommiska, Timo Koivisto, Ville Leinonen, Nils Danner, Jussi P. Posti, Dan Laukka, Teemu Luoto, Minna Rauhala, Sami Tetri, Tommi K. Korhonen, Jarno Satopää, Riku Kivisaari, Teemu Luostarinen, Christopher Schwartz, Thomas Czuba, Simo Taimela, Kimmo Lönnrot, Teppo Järvinen