Cranial decompression and expansion surgery for the treatment of refractory idiopathic intracranial hypertension: case report and systematic review

Objective: The purpose of this study is to systematically review the literature on the clinical outcomes following different surgical techniques in patients with refractory idiopathic intracranial hypertension (IIH). Background: IIH is a condition characterised by increased cranial pressure (ICP) in the absence of an intracranial lesion that does not adequately respond to different medical and surgical therapies. Cranial decompression or expansion surgeries are a last resort therapy for patients with refractory IIH. Methods: A systematic literature search of the databases of PubMed, Embase and Medline from inception to 2019 was performed. Searches were limited to the English language and to clinical studies. Studies were included if clinical outcomes following different cranial decompression or expansion techniques were reported. We also add one case of our own experience with performing a bilateral frontoparietal expansion craniotomy and subtemporal craniectomy. Results: Five manuscripts, describing 38 procedures, met the inclusion criteria. Thirty-one patients were female (82%). The mean age was 26.2 years. The techniques studied included subtemporal craniectomy (27/38, 71%), internal cranial expansion (10/38, 26%), and cranial morcellation decompression (1/38, 3%). Thirty-five patients presented with headaches of which 17 noted postoperative improvement or resolution (49%). Visual deficits were documented in 30 patients and 25 reported postoperative improvement (83%). Papilledema disappeared in 23 of 32 patients with this sign at presentation (72%). In our patient, symptoms completely resolved postoperatively and a 6% increase in intracranial volume was measured. Conclusions: Cranial vault decompression or expansion surgeries may be an effective last resort therapy for patients with refractory IIH. These surgeries expand the intracranial volume, and thus may normalise ICP, leading to clinical improvement.