Effect of Protein Concentration on the Flow of Cerebrospinal Fluid Through Shunt Tubing.

Background: Protein levels in cerebrospinal fluid (CSF) are commonly thought to be related to sterile shunt malfunction.

Objective: To investigate the relationship between protein concentration and flow through CSF shunt tubing and a shunt valve.

Methods: New and explanted shunt catheters were tested with and without a shunt valve attached at various protein concentrations.

Analysis of adjacent segment degeneration with laminectomy above a fused lumbar segment.

Although recent data suggests that lumbar fusion with decompression contributes to some marginal acceleration of adjacent segment degeneration (ASD), few studies have evaluated whether it is safe to perform a laminectomy above a fused segment. This study investigates the hypothesis that laminectomy above a fused lumbar segment does not increase the incidence of ASD, and assesses the benefits and risks of performing a laminectomy above a lumbar fusion. A retrospective review of 171 patients who underwent decompression and instrumented fusion of the lumbar spine was performed to analyze the association between ASD and laminectomy above the fused lumbar segment.

Flow characteristics of cerebrospinal fluid shunt tubing.

Object: Cerebrospinal fluid shunt systems malfunction for a multitude of reasons, including malpostitioning, obstruction of the ventricular or distal catheter, obstruction of the shunt valve, and catheter disruptions or disconnections. The goal of this study was to examine the hydrodynamic resistance and flow in new and explanted catheters and also in catheters with 1 or 2 straight connectors.

Methods: Explanted catheters of multiple lengths, 2-piece catheters, 3-piece catheters, and new catheters were attached to a proximal and distal manometer.

Radiographic PEEK double-lucency finding after anterior cervical discectomy and fusion with local autograft and PEEK spacer: a preliminary study.

Anterior cervical discectomy and fusion (ACDF) is considered a standard neurosurgical treatment for cervical degenerative disc disease, but the methods for determining fusion after ACDF that involves the use of a polyetheretherketone (PEEK) cage are not well defined. The authors examine an image finding called "PEEK double lucency" that may be useful in identifying fusion. This finding was studied to determine if it would be helpful in identifying fusion on radiographs obtained in 148 patients who underwent an ACDF in which a PEEK cage was filled with local autograft bone (bone spurs in the present cases).

Benign extracerebral fluid collections in infancy: clinical presentation and long-term follow-up.

Object: Benign extracerebral fluid collections are common in infants, but there are unanswered questions regarding presentation and long-term outcome. This study was undertaken to establish head size at birth, head size at presentation, head growth over time, history of presentation, indications for surgery, and long-term results.

Methods: Cases of benign extracerebral fluid collections in infancy were retrospectively reviewed.

Single-dose vs multiple-dose antibiotic prophylaxis in instrumented lumbar fusion--a prospective study.

Background: This prospective investigation was designed to determine if the postoperative infection rate in instrumented lumbar spinal fusion is affected by postoperative antibiotic use.

Methods: Two hundred sixty-nine patients were randomized into either a preoperative only protocol or preoperative with an extended postoperative antibiotic protocol. The preoperative only protocol received a single dose of cefazolin IV.

Abdominal pseudocyst: predisposing factors and treatment algorithm.

Abdominal pseudocyst (APC) is an uncommon complication of ventriculoperitoneal shunts. Various predisposing factors have been attributed to it, including the presence of infection and multiple shunt revisions. We reviewed the records of shunt revisions performed over a 20-year period.

Stretching and breaking characteristics of cerebrospinal fluid shunt tubing.

Object: Cerebrospinal fluid (CSF) shunt system malfunction due to silastic tubing fracture necessitates revision surgery in shunt-dependent individuals. The goal of this study was to examine the mechanical stretching and breaking characteristics of new and used CSF shunt tubing catheters to determine if any inherent physical properties predispose the tubing to fracture.

Methods: Fifty-millimeter segments of new and retrieved (used) CSF shunt tubing were stretched to 120 mm in a hydraulic press to determine modulus values (modulus = stress/strain) and to measure permanent tubing deformation imparted by the applied stress and strain.