Anorectal Manometry in Normal Neonates

ABSTRACT

Anal pressure profiles and resting pressures were evaluated in 46 normal neonates, 28 boys and 18 girls, in order to estimate the normal values of anal canal pressure status. All of them had meconium passed within 24 hours after birth and had more than 2.4kg of birth weight. Age at evaluation of manometry was less than 6 days old. There were no differences between boys and girls in birth weight, birth height, gestational age, birth age, and Apgar score (p<0.05). As results of 46 manometric evaluation, We had the anal sphincter length 18.6+/-3.9mm, the high pressure zone (HPZ), 9.2+/-3.6mm, the vector volume, 2027.2+/-2440.7mmHg2cm, the maximum pressure, 42.3+/- 17.4mmHg, and the position of the maximum pressure, 6.0+/-2.4mm. Among them, only HPZ of boys was longer than girls (p=0.005). In squeezing state, HPZ and the position of maximun pressure were not changed from resting state and boys had greater values in HPZ, vector volume, and maximum pressure than girls. As the birth weight increased, the anal sphincter length (p=0.001) and the HPZ increased (p=0.047). The resting pressures of anal canal were evaluated in three portions; upper portion, 12.8+/-8.6 mmHg, middle portion, 20.3+/-10.8 mmHg, and lower portion, 26.1+/-12.9 mmHg. We have the normal values of anal pressure status in normal neonate and We hope that the results would be useful to evaluate, diagnose and treat the pathologic, preoperative, and postoperative condition of anal canal in neonates.