Quantitative Characterization of Safe Irrigation for Ventricular Shunt Catheters

Primary Objective: To collect pressure and flow rate measurements during shunt revision
surgeries in human patients.

Pressure recordings of the injected fluid will be obtained using disposable off-the-shelf
sterile pressure transducers (which are typically used for intracranial and arterial
pressures monitoring) readily available in the operating room. First, the surgeon will
attempt to flush the catheter using the Alcyone in-line Flusher device. If this fails, the
surgeon may elect to attempt to flush using a standard syringe attached to the catheter. The
flow rates will be measured by video, recording the syringe during the flushing maneuver, and
then extracting plunger motion information by applying image processing on the acquired
videos. In the event the recording equipment is not available (in that these operations are
usually unscheduled and sometimes urgent), the same irrigation techniques may be used without
the pressure recordings.

Secondary Objective: To analyze the collected data and establish maximal allowable injection
pressure and flow rate. The collected data segments for each patient will be analyzed and
maximal values for pressure and the saline injection rate will be recorded in a spreadsheet.
Inter-patient variation in the results, presumably due to different degrees of occlusion,
will be statistically evaluated. We will also determine if any of the catheters which appear
occluded in the operating room resume flow with the flushing maneuvers.

Inclusion Criteria:

1. Subjects must be 30 days to 35 years of age, of any race or gender.

2. Subjects must be scheduled to undergo a neurosurgical procedure potentially requiring
a revision of neurosurgical catheters.

3. Subjects aged >18 years of age must be willing and able to provide written informed
consent. Parental consent will be required for minors.

Exclusion Criteria:

1. Inability or unwillingness of subject or parent/guardian to give informed
consent/assent.

2. Judgment of the investigator, surgeon, or any member of the care team (including
anesthesiology or operating room nursing staff) that participation in the study will
interfere with, or be detrimental to, administration of optimal healthcare of the
subject.

3. Inability or unwillingness of subject to endure the test or any other condition that
would preclude or bias the results of the study according to the judgment of the
investigator.