gms | German Medical Science

Objective: Chronic subdural hematomas (cSDH) are a frequent disease especially in elderly patients and often require surgical treatment. While different approaches exist, a common and widely used technique to evacuate the hematoma is the drilling of burrholes and placement of subdural drains. This study aims to analyze whether the location of burrhole placement plays a role in the rate of revision surgery in these patients.

Methods: A single center retrospective analysis of cSDH-patients treated with hematoma drainage by burrhole craniotomy trephanation between 2007-2014 was performed. At first, exact location of the burrholes (frontal vs. parietal) as well as surgical complications were assessed. For further analysis, only patients with revision surgery were selected. Demographic as well as imaging and clinical data were collected from these patients’ hospital records. The modified Rankin scale (mRS) was documented at admission and discharge. Statistical analysis for possible correlations of the burrhole placement with the patients’ clinical parameters was performed.

Results: Screening of 844 patients revealed frontal burrhole placement in 611 (72%) and parietal placement in 233 (28%) cases, respectively. Revision surgery was performed in 71 patients (8%). In this subgroup (16 female / 55 male; age 77±22 years), burrhole placement was more frequent in the frontal than in the parietal region (76% vs. 23%). Further analysis of the patients with revision surgery revealed ataxia as the most common symptom (22%) and a mean mRS on admission of 3.7±0.8. Furthermore, 56% of these patients were on anticoagulant therapy. Hematomas were predominantly located on the left side (35%) with a mean diameter of 1.83±0.75 cm. Duration of surgery was 37±17 min and a single subdural drain was placed in 56% of cases. The reason for revision surgery was recurrent hematoma or secondary bleeding in most of these cases (79%), with a median time to surgery of 5 days (IQR 2-11). During revision surgery, a craniotomy was performed in 55% of cases. After a mean hospital stay of 9±6 days, patients were mostly discharged to another hospital or rehab facility (70%) with a mean mRS of 3.4±1.1 and improvement of symptoms in 81% of cases. Statistical analysis revealed no significant impact of frontal vs. parietal burrhole placement on the various clinical parameters.

Conclusion: Placement of burrholes in the frontal region compared to the parietal region shows a trend towards a higher rate of revision surgery without reaching statistical significance. Furthermore, patients with frontal burrholes required multiple revision surgeries more frequently (40% vs. 20%) whereas patients with parietal burrholes could be discharged home more often (42% vs. 25%) and had better improvement of symptoms (86% vs. 79%).