IRRAflow System Confirmed to More Effectively Remove Collected Blood and Reduce Catheter Infection Rates than Passive Drainage in Head-to-Head Analysis

Stockholm, February 13, 2023 – IRRAS, a commercial-stage medical technology company with a comprehensive portfolio of innovative products for neurocritical care, today announced that the publication of the first comparative study detailing the use of the company’s novel IRRAflow system.  This study, which was conducted under the guidance of Dr. Adnan Siddiqui and the team from the Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, one of the world’s leading centers for neurosurgical innovation, was published in the peer-reviewed Operative Neurosurgery medical journal.  The manuscript concludes that IRRAS’ IRRAflow system when used for the treatment of chronic subdural hematomas (cSDH) results in favorable clinical outcomes, low complication and revision rates, faster clearance of collected blood, and reduced rates of catheter infections compared to passive drainage using an external ventricular drain (EVD).

The manuscript, titled “Use of Novel Automated Active Irrigation With Drainage Versus Passive Drainage Alone for Chronic Subdural Hematoma—A Propensity Score-Matched Comparative Study With Volumetric Analysis,” retrospectively analyzed the treatment of 55 patients, 21 treated with IRRAflow and 34 treated with passive drainage, that underwent propensity score matching to ensure appropriate similarities in patient demographics, baseline comorbidities, and hematoma volume.

After the completion of the analysis, the surgeons found that the use of IRRAflow resulted in a statistically significant higher rate of hematoma clearance (0.5 ± 0.4 mL/day with IRRAflow vs. 0.4 ± 0.5 mL/day with passive drainage) and a statistically significant reduction in catheter-related infections.  Additionally, in the subgroup analysis that looked procedures that were performed using a burrhole alone, treatment with IRRAflow also resulted in significantly lower hematoma expansion at discharge and significantly improved brain expansion.

Furthermore, the data from this clinical study showed that the use of IRRAflow resulted in a nonsignificant reduction in duration of catheter placement (3.7 ± 2.2 with IRRAflow vs. 4.4 ± 4.1 with passive drainage), total hospital length of stay (6.8 ± 3.0 with IRRAflow vs. 10.6 ± 16.2  with passive drainage), and rate of seizure activity (0 patients with IRRAflow vs. 3 patients with passive drainage), each suggesting a trend that may have shown significance with a larger sample size.

A chronic subdural hematoma is a collection of blood and blood breakdown products between the surface of the brain and its outer layer that generally occurs after head trauma in an older patient.  As the world’s population progressively ages, the increasing incidence of cSDH will be a burden to patients and a future challenge for neurosurgical clinics.[1] The incidence of chronic subdural hematomas (CSDH) ranges from 1.72 to 20.6 per 100,000 persons per year and is projected to become the most common cranial neurosurgical condition among adults by the year 2030.[2],[3]

"This recently published clinical data confirms the positive impact that IRRAflow can have on the lives of patients suffering from intracranial bleeding," said Will Martin, President and Chief Executive Officer of IRRAS. "This study is a critical next step in the growing pool of clinical evidence that demonstrates the impact of IRRAflow by providing head-to-head data that confirms that IRRAflow's combination of irrigation and drainage results in both more effective blood removal and safer clinical outcomes than traditional treatment methods."


IRRAS is a global medical care company focused on delivering innovative medical solutions to improve the lives of critically ill patients. IRRAS designs, develops, and commercializes neurocritical care products that transform patient outcomes and decrease the overall cost of care by addressing complications associated with current treatment methodologies. IRRAS markets and sells its comprehensive, innovative IRRAflow and Hummingbird ICP Monitoring product lines to hospitals worldwide through its direct sales organization in the United States and select European countries as well as an international network of distribution partners.

IRRAS maintains its headquarters in Stockholm, Sweden, with corporate offices in Munich, Germany, and San Diego, California, USA. For more information, please visit

IRRAS is listed on Nasdaq Stockholm (ticker: IRRAS).

For more information, please contact:

Sten Gustafsson
Director, Investor Relations
+46 102 11 5172

The information was released for public disclosure, through the agency of the contact person above, on February 13, 2023, at 8:30 (CET).

[1] Rauhala M, Luoto TM, Huhtala H, Iverson GL, Niskakangas T, Öhman J, Helén P. The incidence of chronic subdural hematomas from 1990 to 2015 in a defined Finnish population. J Neurosurg. 2019 Mar 22:1-11. doi: 10.3171/2018.12.JNS183035. [Epub ahead of print] PubMed PMID: 30901751.

[2] Yang W, Huang J. Chronic Subdural Hematoma: Epidemiology and Natural History. Neurosurg Clin N Am. 2017 Apr;28(2):205-210. doi: 10.1016/ Epub 2017 Feb 1. Review. PubMed PMID: 28325454

[3] Balser D, Farooq S, Mehmood T, Reyes M, Samadani U. Actual and projected incidence rates for chronic subdural hematomas in United States Veterans Administration and civilian populations. J Neurosurg. 2015 Mar 20:1-7. [Epub ahead of print] PubMed PMID: 25794342; PubMed Central PMCID: PMC4575892.

Irras Radio Irras Academy

At IRRAS, your privacy and the protection of your personal data are important to us. To ensure GDPR compliance, this website does not store or track any personal information, including Google Analytics or form submission data.
By using the website, you acknowledge and accept our policy.