gms | German Medical Science

Objective: The contemporary concept of the so called Chiari malformation (CM) comprises different conditions in respect of the underlying pathology, also classified as CM0, CM1, CM1.5 and CM2. Specific treatment options should be offered according to the individual clinical condition. The presented clinical series reflects the variety of the clinical Chiari spectrum.

Methods: This is a retrospective study of a consecutive single unit (5 surgeons) series of patients who underwent foramen magnum decompression between 2010 and 2019 due to CM. Patients managed conservatively or with shunting procedure alone were excluded. Demographic data, diagnostic findings, relevant comorbidities, surgical treatment and outcome data are presented.

Results: A total of 96 patients have been operated. Mean age was 10 years (range 0.2 – 60 y; 4 < 1 y; 10 > 18 y). 50 patients were male, 46 female. 48(50%) presented with additional syringomyelia at time of surgery, 36 (37.5%) with scoliosis. 11 patients required secondary surgeries (7 own / 4 external). The following CM subtypes have been treated: CM0 (4), CM1 (47), CM1.5 (27) and CM2 (18). Associated syrinx and scoliosis were most often seen in CM2 patients (67%, 83%). All CM0 patients underwent intradural management. In the CM1 group 25 (53%) received bone only decompression (11 [41%] in CM1.5), 23 (49%) intradural inspection and dural augmentation (36 [49%] in CM1.5), 14 (30%) tonsillar shrinking (25 [34%] in CM1.5) and additional instrumentation due to instability in 1 (2%) patient (8 [11%] in CM1.5). In the CM2 group, 6 bone only and 10 intradural procedures with dural augmentation and additional tonsillar shrinking in 2 have been performed. The overall complication rate after complete follow up is 8.3%, leading to secondary surgery in 2 (2.1%) cases (CSF collections). Resolution or improvement of symptoms could be observed in all patients, syringomyelia resolution in 11 out 32 patients (CM2 excluded). There was no statistical difference regarding CM type, treatment and outcome. Bone only decompression provides similar results in CM1, CM1.5 and CM2 compared to intradural procedures, but syrinx resolution takes a longer time.

Conclusion: Different CM subtypes require specific surgical treatment. Bone only decompression seems to have similar good results in respect of resolving symptoms and syringomyelia as well as preventing scoliosis progress compared to intradural techniques. No severe complications occured. Secondary complication surgery became necessary in 2 patients only.