Associations of collagen type I α2 polymorphisms with the presence of intracranial aneurysms in patients from Germany.

OBJECTIVE: Subarachnoid hemorrhage from ruptured intracranial aneurysms is associated with a severe prognosis. Preventive treatment of unruptured intracranial aneurysms is possible and recommended. However, the identification of risk patients by genetic analyses is not possible because of lack of candidate genes. Collagen type I α2 (COL1A2) has been associated with the presence of aneurysms in patients from Japan, China, and Korea. In this study, we investigate whether COL1A2 is a possible aneurysm candidate gene in the German population. METHODS: Patients admitted with intracranial aneurysms to our department and collaborating departments were enrolled. Three single-nucleotide polymorphisms (SNPs) of the COL1A2 gene, namely rs42524 in exon 28, rs1800238 in exon 32, and rs2621215 in intron 46 were investigated using restriction enzymes and sequencing. HapMap data were used for comparison of allelic frequencies with the normal population by χ2 test to identify significant associations between genotypes and the presence of aneurysms. RESULTS: Two hundred sixty-nine patients were enrolled into the study. There was a significant correlation with the presence of aneurysms for the GC allele of the SNP rs42524 in exon 28 (P = .02). The other polymorphisms did not show significant correlations. CONCLUSIONS: The COL1A2 gene is associated with intracranial aneurysms in a subset of the German population. However, it is not responsible for the majority of aneurysms, and further candidate genes need to be identified to develop sensitive genetic screening for patients at risk.

Clinical acceptance and accuracy assessment of spinal implants guided with SpineAssist surgical robot: retrospective study.

STUDY DESIGN: Retrospective, multicenter study of robotically-guided spinal implant insertions. Clinical acceptance of the implants was assessed by intraoperative radiograph, and when available, postoperative computed tomography (CT) scans were used to determine placement accuracy. OBJECTIVE: To verify the clinical acceptance and accuracy of robotically-guided spinal implants and compare to those of unguided free-hand procedures. SUMMARY OF BACKGROUND DATA: SpineAssist surgical robot has been used to guide implants and guide-wires to predefined locations in the spine. SpineAssist which, to the best of the authors' knowledge, is currently the sole robot providing surgical assistance in positioning tools in the spine, guided over 840 cases in 14 hospitals, between June 2005 and June 2009. METHODS: Clinical acceptance of 3271 pedicle screws and guide-wires inserted in 635 reported cases was assessed by intraoperative fluoroscopy, where placement accuracy of 646 pedicle screws inserted in 139 patients was measured using postoperative CT scans. RESULTS: Screw placements were found to be clinically acceptable in 98% of the cases when intraoperatively assessed by fluoroscopic images. Measurements derived from postoperative CT scans demonstrated that 98.3% of the screws fell within the safe zone, where 89.3% were completely within the pedicle and 9% breached the pedicle by up to 2 mm. The remaining 1.4% of the screws breached between 2 and 4 mm, while only 2 screws (0.3%) deviated by more than 4 mm from the pedicle wall. Neurologic deficits were observed in 4 cases yet, following revisions, no permanent nerve damage was encountered, in contrast to the 0.6% to 5% of neurologic damage reported in the literature. CONCLUSION: SpineAssist offers enhanced performance in spinal surgery when compared to free-hand surgeries, by increasing placement accuracy and reducing neurologic risks. In addition, 49% of the cases reported herein used a percutaneous approach, highlighting the contribution of SpineAssist in procedures without anatomic landmarks.