The Implementation of the Classification of Intraoperative Adverse Events (ClassIntra) for Neurosurgical Procedures

Surgeons strive for the best possible outcome of their surgeries with the greatest possible chance for recovery of the patients. Therefore, monitoring and quality improvement is increasingly important in surgery. As there are well-defined scores and classifications to describe the postoperative course regarding morbidity, mortality and neurological status, no validated classification for intraoperative quality exists by now. However, Dell-Kuster et al. introduced a novel classification for assessing all intraoperative adverse events: ClassIntra. This classification was developed in a Delphi consensus containing international, interdisciplinary, and validated in a multicentre cohort study across all surgical disciplines. The classification defines intraoperative adverse events as any deviation from the ideal intraoperative course occurring between skin incision and skin closure and contains any event related to surgery and anaesthesia. Depending on the kind of adverse event, the ClassIntra score ranges from 0 (no event) to 5 (intraoperative death). A prospective study with a main focus on neurosurgery covering the whole spectrum of elective and emergency procedures is needed. Hereby, the outcome parameters need to be defined specific for neurosurgical procedures including a preoperative and postoperative neurological status.

Primary outcomes

• Complications according to Clavien-Dindo classification [within two weeks after surgery]: Grade 0 to V (0 no complication, V death)
• Comprehensive Complication Index [within two weeks after surgery]: Based on Clavien-Dindo classification with a scale from 0 to 100 (0 no complication, 100 death)
• Neurological status [within two weeks after surgery]: classified to NANO scale, NIHSS, modified Rankin Scale, Glasgow Outcome Scale
• Neurological outcome (NANO scale) [within two weeks after surgery]: according to neurological assessment in neuro-oncology (NANO) with a scale from 0 to 23 (0 no neurological deficit, 23 multiple neurological deficits)
• Neurological outcome (NIHSS) [within two weeks after surgery]: according to National Institutes of Health Stroke Scale (0 no stroke symptoms 1-4 minor stroke 5-15 moderate stroke 16-20 moderate to severe stroke 21-42 severe stroke)
• Neurological outcome (mRS) [within two weeks after surgery]: according to modified Rankin Scale with a scale from 0 to 6 (0 no symptoms, 6 dead)
• In-hospital mortality [within two weeks after surgery]: Death of the patient

Secondary outcomes

• Length of ICU stay [within two weeks after surgery]
• Length of hospital stay [within two weeks after surgery]
• Readmission rate [within 90 days after surgery]: Readmission to hospital after discharge

Sex: All, ages: 18 Years to 100 Years

Inclusion Criteria:

* Patients undergoing surgery at a neurosurgical department

Exclusion Criteria:

* Patients under 18 years

• Dell-Kuster S, Gomes NV, Gawria L, Aghlmandi S, Aduse-Poku M, Bissett I, Blanc C, Brandt C, Ten Broek RB, Bruppacher HR, Clancy C, Delrio P, Espin E, Galanos-Demiris K, Gecim IE, Ghaffari S, Gie O, Goebel B, Hahnloser D, Herbst F, Ioannidis O, Joller S, Kang S, Martin R, Mayr J, Meier S, Murugesan J, Nally D, Ozcelik M, Pace U, Passeri M, Rabanser S, Ranter B, Rega D, Ridgway PF, Rosman C, Schmid R, Schumacher P, Solis-Pena A, Villarino L, Vrochides D, Engel A, O'Grady G, Loveday B, Steiner LA, Van Goor H, Bucher HC, Clavien PA, Kirchhoff P, Rosenthal R. Prospective validation of classification of intraoperative adverse events (ClassIntra): international, multicentre cohort study. BMJ. 2020 Aug 25;370:m2917. doi: 10.1136/bmj.m2917. PMID 32843333
• Results publication: Drexler R, Ricklefs FL, Pantel T, Gottsche J, Nitzschke R, Zollner C, Westphal M, Duhrsen L. Association of the classification of intraoperative adverse events (ClassIntra) with complications and neurological outcome after neurosurgical procedures: a prospective cohort study. Acta Neurochir (Wien). 2023 Aug;165(8):2015-2027. doi: 10.1007/s00701-023-05672-w. Epub 2023 Jul 5. PMID 37407852

• Richard Drexler, MD, Principal investigator, Universitätsklinikum Hamburg-Eppendorf