Vesico-puborectalis reflex. Description of a new reflex and its clinical significance. Preliminary report

Abstract

This paper reports a new reflex which I call “vesico-puborectalis reflex” and which was studied in 18 healthy volunteers with an average age of 43.2 years. The technique comprised the introduction of a balloon-tipped catheter into the empty urinary bladder. A concentric needle electrode was introduced into the puborectalis muscle. The vesical balloon was inflated with air in increments of 50 ml and the puborectalis myoelectric activity was recorded by a standard EMG apparatus. The vesical balloon was then removed and the puborectalis EMG response to suprapubic vesical compression was recorded while the urinary bladder was empty and while it was filled with saline in increments of 50 ml. Vesical balloon distension evoked puborectalis contraction provided the inflated volume was above 50 ml of air. The duration of puborectalis contraction increased with increased vesical distension. The reflex puborectalis response did not occur when the muscle was anesthetized. The latency of the reflex was calculated. Suprapubic manual compression evoked puborectalis contraction with both a full urinary bladder and sudden compression. The vesico-puborectalis reflex seems to play an important role in urinary continence. The puborectalis contracts reflexly upon increased vesical distension or sudden compression of a full bladder. It thus guards against involuntary leak of urine. Detectable changes in latency, amplitude or duration of the evoked response would indicate a defect in the reflex pathway. The vesico-puborectalis reflex could thus be included as an investigative tool in the study of micturition disorders.