Incidence of and Causes for Ventriculoperitoneal Shunt Failure in Children Younger Than 2 Years: A Systematic Review.

OBJECTIVES: Ventriculoperitoneal (VP) shunting is commonly used to treat pediatric hydrocephalus, but failure rates are high. VP shunt failure in children is mostly caused by infection and/or proximal/distal shunt obstruction. However, to our knowledge, no previous reviews have discussed this topic using only clinical studies when age-related data could be obtained. This systematic review aimed at reevaluating what is already known as the most common causes of shunt failure and to determine the incidence and causes of VP shunt failure during the first 2 years of life as a step to establish solid evidence-based guidelines to avoid VP shunt failure in infants. METHODS: We performed a search using the search terms "Cerebrospinal Fluid Shunts" (Medical Subject Headings [MeSH]) AND failure [All Fields] AND ("humans" [MeSH] AND English [lang] AND "infant" [MeSH]). Only articles that specifically discussed VP shunt complications in children < 2 years were included. RESULTS: We found that the most common causes of VP shunt failure in children < 2 years were shunt obstruction and infection, both observed in a range. CONCLUSION: VP shunt failure is very common in infants, mostly resulting from obstruction and infection. Future studies should focus on methods designed to avoid these complications or on alternative treatments for hydrocephalus.

Neuronavigation and 3D fluoroscopy-guided lag screw reduction and osteosynthesis for traumatic spondylolistheses of the axis: a path worth exploring?

OBJECTIVE In traumatic spondylolistheses of the axis, there is a marked heterogeneity of the observed injury patterns, with a wide range of the severity-from stable fractures, which can be treated conservatively with very good success, to highly unstable fractures, which should be treated surgically. A number of classification systems have been devised to assess the instability of the injuries and to derive a corresponding therapy recommendation. In particular, the results and recommendations regarding medium-severity cases are still inconclusive. Minimally invasive percutaneous procedures performed using modern techniques such as 3D fluoroscopy and neuronavigation have the potential for improvements in the therapeutic outcome and procedural morbidity against open surgical procedures and conservative therapy. METHODS A minimally invasive method using 3D fluoroscopy and neuronavigation for percutaneous lag screw osteosynthesis of the pars interarticularis was performed in 12 patients with a Levine-Edwards Type II fracture. Ten patients had an isolated hangman's fracture and 2 patients had an additional odontoid fracture of the axis (Type II according to the Anderson and D'Alonzo classification system). Complications, operating parameters, screw positions, and bony fusion were evaluated for the description and evaluation of the technique. RESULTS In 6 men and 6 women, percutaneous lag screw osteosynthesis was performed successfully. Correct placement could be verified postoperatively for all inserted screws. In the case series, nonunion was not observed. In all patients with a complete follow-up, a bony fusion, an intact vertebral alignment, and no deformity could be detected on CT scans obtained after 3 months. CONCLUSIONS The percutaneous pars interarticularis lag screw osteosynthesis is a minimally invasive and mobility-preserving surgical technique. Its advantages over alternative methods are its minimal invasiveness, a shortened treatment time, and high fusion rates. The benefits are offset by the risk of injury to the vertebral arteries. The lag screw osteosynthesis is only possible with Levine-Edwards Type II fractures, because the intervertebral joints to C-3 are functionally preserved. A further development and evaluation of the operative technique as well as comparison with conservative and alternative surgical treatment options are deemed necessary.

Is it safe to sacrifice the superior hypophyseal artery in aneurysm clipping? A report of two cases.

Clipping of paraclinoid internal carotid artery aneurysms related to the superior hypophyseal artery (SHA) carries risk of occlusion of this artery when originating distal to the neck of the aneurysm. Sometimes it is inevitable to sacrifice the artery to achieve total aneurysm occlusion. Otherwise a residual aneurysm would remain, which may lead to aneurysm regrowth and subsequent rupture. However, consequences of SHA sacrifice are rarely reported in the literature. In the two presented cases, the SHA was found originating distal to the neck and within the wall of the aneurysm, making the optimal clipping of the aneurysm at the neck unfeasible without trapping of the SHA. Intraoperative indocyanine green (ICG) angiography revealed a retrograde blood flow in the SHA distal to the clip in both patients, indicating some collateral circulation. No endocrinologic deficits were encountered after surgery. The vision was not affected in one patient. In the other patient, bilateral visual field defects occurred, which improved partially in the follow-up 2 months after surgery. The consequences of SHA occlusion are difficult to predict. A large variety of anatomical variations of the vascular anatomy exists. Intraoperative ICG angiography may help to estimate collateral blood flow but is not able to predict visual decline. Although final conclusions cannot be drawn from two patients, it seems that in case of multiplicity of superior hypophyseal complex, sacrifice of one even larger branch is safe. However, visual sequelae have to be taken into consideration when a single SHA has to be sacrificed for total aneurysm clipping.