Concentric folds in the bladder: a new sign of chronic outlet obstruction and neurogenic bladder.

The finding of concentric folds in the bladder on excretory urography is a hitherto unreported but reliable sign of chronic urinary retention, usually due to outlet obstruction or neurogenic bladder. In a study of 152 consecutive patients with urinary retention, the presence of typical concentric folds alone was found to be as common and, therefore, as sensitive an indicator as trabeculation. The sign is useful in evaluating the significance of the incompletely emptied bladder on the post-void film, and in detecting unsuspected disease. A false-positive rate of 1.5% was found in a control series of 190 women, and no false-positive findings were seen in 214 men concurrently studied. A hypothesis concerning the mechanism of concentric fold formation is advanced.

Acute traumatic vertebral arteriovenous fistula: balloon occlusion with the use of a contralateral approach.

A traumatic fistula of the left vertebral artery to vertebral and epidural veins with an expanding suboccipital false aneurysm was trapped by endovascular occlusion with detachable balloons. The lesion was not amenable to treatment using the left vertebral artery alone for access. Distal trapping was accomplished by catheterizing the (contralateral) right vertebral artery and placing the balloon retrograde into the distal segment of the left vertebral artery. This maneuver extends the range of vertebral artery lesions for which detachable balloons, either alone or as an adjunct to operation, can be used.

Spontaneous migration of a bullet in the central nervous system.

An example of spontaneous migration of a metallic foreign body within the subarachnoid space is illustrated. An intracranial bullet is shown to move within the cisterns of the posterior fossa and then down the subarachnoid space of the spinal canal. The patient's symptoms correlate well with the movement of the foreign body.