Sacral Nerve Innervation of the Human Bladder

Abstract

T HE LARGE number of patients with paraplegia resulting from World War I I has created new interest in the neurogenic bladder, and consequently in bladder innervation. Advances in the control of urinary tract infections and in rehabilitative procedures have been extensive, giving patients with spinal cord injuries life expectancies of many years, instead of the average of 18 months after World War I. I t has been possible for many patients with a paraplegia to return to useful community life. Many have not been able to attain this goal because of their inability to exercise control over urination. The problem of adequate control of urination becomes more difficult in neurogenic bladders treated for months or years with indwelling catheters. A thickened and chronically infected bladder wall with marked hypertonicity and very limited capacity is the almost inevitable result of such treatment. The bladder becomes useless as a reservoir for urine. A large number of patients with bladders in this condition were available for study, and the present investigation of the nerve supply to the bladder was carried out in an effort to throw some light on possible therapy. The investigation was limited to the sacral nerves for the following reasons: (1) There is little evidence that the hypogastric nerves, the other source of bladder innervation, have any great effect on bladder function. 2'~'4' 7,12,14,15, 16,17 (~) The lmnbar sympathetic nerves have been removed in many patients without apparent deleterious effects on bladder function. (3) Bladder automaticity usually appears after spinal cord injury before any evidence of reflex sympathetic activity is seen. (4) The sacral nerves are readily accessible as they emerge from their corresponding sacral foramina. (5) During the operation of anterior rhizotomy for disabling spasticity, s the question arose as to which sacral nerves must be spared to maintain automatic bladder function. Knowledge of human bladder innervation has been taken largely from comparison with experimental animals 20,~1 and from anatomical dissections. Latariet and BonneO 3 found from their dissections that the 3rd sacral nerve ($3) and the 4th sacral nerve ($4) contribute fibers to the bladder. Cordie#