Abstract: A method of draining cerebrospinal fluid from a human brain. The method includes providing a drainage catheter having a proximal end and a distal end. The drainage catheter has a plurality of openings formed therein. The plurality of openings includes a first opening, a second opening, and a most proximal opening. The second opening is disposed closer to the distal end than the first opening. A cross-sectional area of the first opening is less than a cross-sectional area of the second opening. The distal end of the drainage catheter is inserted into a human brain. Cerebrospinal fluid is drained from the human brain. The cerebrospinal fluid passes into the drainage catheter through the plurality of openings and out of the drainage catheter through the proximal end. A rate at which the cerebrospinal fluid passes through the drainage catheter is controlled to maintain intracranial pressure within a selected range.

Abstract: A method of draining cerebrospinal fluid from a human brain. The method includes providing a drainage catheter having a proximal end and a distal end. The drainage catheter has a plurality of openings formed therein. The plurality of openings includes a first opening, a second opening, and a most proximal opening. The second opening is disposed closer to the distal end than the first opening. A cross-sectional area of the first opening is less than a cross-sectional area of the second opening. The distal end of the drainage catheter is inserted into a human brain. Cerebrospinal fluid is drained from the human brain. The cerebrospinal fluid passes into the drainage catheter through the plurality of openings and out of the drainage catheter through the proximal end. A rate at which the cerebrospinal fluid passes through the drainage catheter is controlled to maintain intracranial pressure within a selected range.

Abstract: An improved drainage catheter having one or more inlet holes along the length of the catheter is described whereby the cross-sectional areas of the successive inlet holes decreases, the decrease first occurring at the inlet hole immediately following the most proximal inlet hole. This change in cross-sectional area alters the typical inflow of fluid into the catheter such that a disproportionately high volume of fluid no longer enters the most proximal inlet hole. This decrease in inflow at the most proximal inlet hole results in less deposition of debris within the catheter at that position. With less deposition of debris at this location, the likelihood of complete catheter failure is reduced. A preferred embodiment is described wherein the change in cross-sectional area results in approximately uniform inflow into all inlet holes.