Hisayoshi Kawahara

Esophageal body and lower esophageal sphincter function in healthy premature infants

BACKGROUND & AIMS Gastroesophageal reflux is a common problem in premature infants. The aim of this study was to use a novel manometric technique to measure esophageal body and lower esophageal sphincter pressures in premature infants. METHODS Micromanometric feeding assemblies (OD, < or = 2 mm) incorporating 4-9 manometric channels were used in 49 studies of 27 premature neonates. Esophageal body motility was recorded at three sites for 20 minutes after feeding. Twenty attempts (one per minute) were made to stimulate swallowing via facial stimulation (Santmyer reflex). In 32 studies lower esophageal sphincter pressures were recorded (sleeve) for 15 minutes before and after feeding. RESULTS Peristaltic motor patterns were less common than non-peristaltic motor patterns (26.6% vs. 73.4%; P < 0.0001) that comprised 31.1% synchronous, 34.6% incomplete, and 6.3% retrograde pressure waves. Reflex swallowing was elicited more frequently in neonates older than 34 weeks postconceptional age than in younger infants (33.4% vs. 20.4%; P < 0.05). Mean lower esophageal sphincter pressure was 20.5 +/- 1.7 mm Hg before and 13.7 +/- 1.3 mm Hg after feeding (P < 0.0005). CONCLUSIONS Premature infants show nonperistaltic esophageal motility that may contribute to poor clearance of refluxed material. In contrast, the lower esophageal sphincter mechanisms seem well developed.

Esophageal atresia in Osaka: A review of 39 years' experience☆

BACKGROUND One hundred fifty-nine patients who had esophageal atresia with or without tracheoesophageal fistula have been treated at Osaka University Medical School and its affiliated hospitals since the initial (Japanese) experience of Dr T. Ueda in 1957. METHODS These cases were divided chronologically into three groups. With earlier recognition of surgical neonates and the development of perinatal care, the long-term survival of these patients has steadily improved over 39 years from 28% in the first period (1957 to 1967) to 80% in the third period (1980 to 1995). Of 141 patients treated in the second and third periods (1968 to 1995), 92 (65.2%) had associated anomalies. Cardiovascular and gastrointestinal malformations were the most frequently seen major anomalies. VATER or VACTER association was seen in 12.8% (18 of 141) of these patients. Survival of these cases according to Waterston risk factors was 100% for group A, 100% for group B, and 50% for group C, whereas the new classification proposed by Spitz showed survival of 92% for group 1, 50% for group 2, and 0% for group 3, showing better differentiation among the three groups. RESULTS There was a long gap between the proximal and distal esophageal ends in seven patients (type A), in all of whom primary anastomosis was possible after 28 to 128 days of elongation by bouginage. Although the survival of esophageal atresia patients dramatically improved in recent years, there is still a high incidence of early and long-term postoperative complications, ie, anastomotic leakage (26.5%), recurrent fistula (7.2%), anastomotic stricture (49.1%), postoperative pneumonia or atelectasis (57.0%), tracheomalacia (25.8%), and gastroesophageal reflux (52.0%). CONCLUSIONS Recently, there have been changing patterns in the occurrence of complications, which are mainly attributed to technical improvement, better perinatal care and early recognition of pathophysiologic conditions such as tracheomalacia and gastroesophageal reflux.

Effect of baclofen on emesis and 24-hour esophageal pH in neurologically impaired children with gastroesophageal reflux disease.

Objectives Gastroesophageal reflux disease (GERD) is difficult to control with medical therapy in neurologically impaired children. The gamma-aminobutyric acid type B receptor agonist baclofen was recently reported to reduce reflux in adult patients with GERD by reducing the incidence of transient lower esophageal sphincter relaxations. The current study was undertaken to investigate the effects of baclofen on GERD in neurologically impaired children. Methods Eight neurologically impaired children with GERD between 2 months and 16 years were studied. Baclofen (0.7 mg/kg/day) was administered orally or via nasogastric tube in three divided doses 30 minutes before meals for 7 days. The frequency of emesis on and off baclofen were recorded as a measure of clinical impact. Twenty-four–hour esophageal pH monitoring was conducted before and on the seventh day of the administration of baclofen. Results The frequency of emesis was significantly decreased (P = 0.03). The total number of acid refluxes was significantly decreased both during the entire 24-hour period (P = 0.01) and during the postprandial period (P = 0.049). The number of acid refluxes longer than 5 minutes was significantly decreased during the 24-hour period (P = 0.02). The percentage total time of esophageal pH <4.0 and esophageal acid clearance time were not significantly different during the 24-hour period or during the postprandial period. No adverse effects were observed, except for a slight reduction in muscle tone in one subject. Conclusions In this 1-week trial, repetitive administration of baclofen reduced the frequency of emesis and the total number of acid refluxes in neurologically impaired children with GERD.

Biliary Atresia Associated With Congenital Structural Anomalies

BACKGROUND/PURPOSE Although biliary atresia (BA) is rarely associated with other congenital anomalies, the presence of a distinct subgroup of patients with accompanying structural anomalies such as situs inversus, polysplenia, or portal vein anomalies has been postulated. The authors present 7 patients with this association. METHODS Of 87 patients with BA treated in the past 19 years, 7 (8.0%) have had multiple congenital structural anomalies. RESULTS These anomalies included situs inversus in 4, polysplenia in 5, preduodenal portal vein in 5, absent portal vein in 1, absent inferior vena cava in 2, malrotation of the intestine in 5, and congenital heart disease in 3 patients. In these 7 patients, hepatic portoenterostomy (HPE) was performed at the age from 63 to 158 days with an average of 92 days. The porta hepatis was abnormal in position in 1 patient. The connective tissue at the porta hepatis was diminished in 6 patients. Histologically, liver fibrosis was mild in 2 and moderate in 5 patients. Bile excretion was good initially in all patients but gradually diminished in 5 patients. Five patients had multiple episodes of cholangitis, followed by sepsis, liver failure, or cardiac failure and subsequently died at the age from 2 months to 6 years. Of the other 2 patients who underwent HPE recently, 1 is doing well and the other has had one episode of cholangitis. CONCLUSIONS BA in association with other congenital structural anomalies may have a poor prognosis. These patients have poor bile secretion after HPE mainly because of delayed operation.

The effect of metronidazole on TPN-associated liver dysfunction in neonates

The effect of metronidazole (MNZ) on hepatic dysfunction associated with total parenteral nutrition (TPN) in neonates was investigated. Neonates receiving TPN for more than 2 weeks were divided into three groups. In group 1, TPN was given alone, in group 2, 25 mg/kg/d of MNZ was administered intravenously for the first 2 weeks of TPN, and in group 3, 50 mg/kg/d of MNZ was given for the first 3 weeks of TPN. Several parameters of liver function tests (LFTs) during the first 4 weeks of TPN were compared among these three groups. There was no significant difference of these parameters between group 1 and group 2. Although there was no significant difference of alkaline phosphatase, gamma-glutamyl transpeptidase, direct bilirubin, and total bile acid between groups 1 and 3, transaminase (glutamic oxaloacetic, glutamic pyruvic) of group 3 remained significantly lower than those of group 1. In conclusion, the administration of MNZ 50 mg/kg/d for 3 weeks, at least, prevented the elevation of transaminase during TPN in neonates, suggesting the possible involvement of intestinal anaerobic flora in the pathogenesis of TPN-associated liver dysfunction.

Mechanisms underlying the antireflux effect of Nissen fundoplication in children

BACKGROUND/PURPOSE It is reported that the main mechanism responsible for gastroesophageal reflux (GER) is transient lower esophageal sphincter (LES) relaxation in children. However, the effect of Nissen fundoplication on transient LES relaxation has not been investigated in children. This study examined the effect of Nissen fundoplication on motor patterns of the LES in children with pathological GER. METHODS Esophageal manometry and pH were recorded concurrently for 2 hours after administration of apple juice (10 mL/kg). In seven children documented to have pathological GER by prolonged esophageal pH monitoring (%time pH less than 4.0>5.0), studies were performed preoperatively and 1 to 3 months after surgery. RESULTS Nissen fundoplication virtually eliminated reflux in all patients. Percentage of time pH was less than 4.0 reduced from 15+/-9 to 0+/-0. Basal LES pressure did not change significantly (pre, 21+/-10 mm Hg v post, 27+/-9 mm Hg). The number of transient LES relaxation reduced significantly from 13+/-4 to 7+/-7, and the mean nadir LES pressures during swallow-induced LES relaxation and transient LES relaxation increased significantly from 1+/-1 mm Hg to 13+/-5 mm Hg and from 0+/-0 mm Hg to 11+/-7 mm Hg, respectively. CONCLUSIONS Our findings suggest the antireflux effects of Nissen fundoplication may be based on changes of LES motor patterns that result in incomplete LES relaxation and reduction of the number of transient LES relaxation.

Prenatal diagnosis of congenital diaphragmatic hernia and perinatal care: assessment of lung hypoplasia

To assess the severity of lung hypoplasia, we have attempted to measure the lung thorax transverse area ratio (L/T) by using ultrasonic echography and to select immediate surgery after delivery by caesarean section. The evaluation of L/T for an index of lung hypoplasia was made by arterial blood gas data and clinical courses. Of 14 fetuses diagnosed, 13 had left sided CDH and one right sided case, from 11 to 38 weeks of pregnancy, 10 cases survived. The L/T in 14 fetuses with CDH was from 0.08 to 0.36 (mean 0.2 +/- 0.073) and was significantly lower than that of the controls. L/T was correlated best with data of arterial pH, PCO2, preductal A-aDO2 before operation and the duration of mechanical ventilation in survivors. Although L/T was also significantly low in the cases with severe grade, diaphragmatic patch closure and ECMO therapy, no significant differences were noted in L/T between survivors and non-survivors. These results indicated that L/T may predict the severity of lung hypoplasia in CDH and that the combination of perinatal management bases on prenatal diagnosis of CDH and ECMO support may improve the outcome of fatal CDH with severe lung hypoplasia.

Mechanisms responsible for recurrent gastroesophageal reflux in neurologically impaired children who underwent laparoscopic Nissen fundoplication

BackgroundIn this study, we attempted to define the lower esophageal sphincter (LES) motor events associated with the occurrence of gastroesophageal reflux (GER) in neurologically impaired children in whom of GER disease recurred after laparoscopic Nissen fundoplication (LNF).MethodsOf 45 neurologically impaired children who had previously undergone LNF, six children in whom recurrence of GER disease was documented by 24-h esophageal pH monitoring were studied. Concurrent esophageal manometry and pH monitoring were conducted for 1 h both before and after the administration of apple juice (10 ml/kg).ResultsA total of 89 reflux episodes were recorded in the course of the study. Of these, 51 episodes (57%) were associated with transient LES relaxation. In the remainder, reflux occurred across a contracted LES in 21 episodes (24%) and during absent basal LES tone in 15 episodes (17%). In four of six patients, transient LES relaxation was responsible for more than half of the reflux episodes.ConclusionTransient LES relaxation is the predominant mechanism of reflux in neurologically impaired children with recurrent GER after LNF.

Impact of esophageal bile exposure on the genesis of reflux esophagitis in the absence of gastric acid after total gastrectomy

OBJECTIVE:The role of duodenal contents refluxing into the esophagus in producing reflux esophagitis (RE) remains unclear. We aimed to assess the impact of esophageal bile exposure on the genesis of RE in reference to esophageal pH changes in the absence of gastric acid after total gastrectomy.METHODS:Thirty patients having undergone total gastrectomy were studied with concurrent 24-h esophageal pH and bilimetric monitoring, and were divided into two groups based on endoscopic esophageal mucosal findings: without RE, group 1 (n = 24) and with RE, group 2 (n = 6). Esophageal bile exposure was defined as bilirubin absorbance >0.14 detected in the esophagus.RESULTS:1) The percentage total time of esophageal bilirubin absorbance >0.14 was not correlated with that of esophageal pH >7.0, >7.4, and >8.0. 2) All parameters for esophageal bilirubin absorbance >0.14 in group 2 were significantly higher than those in group 1, whereas none of the parameters for esophageal pH >7.0, >7.4, and >8.0 showed a significant difference between the two groups. 3) The percentage total time of esophageal bilirubin absorbance >0.14 was over 50% in all subjects with RE, and six of seven subjects with that over 50% had RE.CONCLUSIONS:Esophageal bile exposure plays an important role in the genesis of RE in the absence of gastric acid, which is assessed better with the measurement of esophageal bilirubin absorbance than that of esophageal pH.

Meconium-related ileus in extremely low-birthweight neonates: etiological considerations from histology and radiology.

Background:  A nationwide survey on neonatal surgery conducted by the Japanese Society of Pediatric Surgeons has demonstrated that the mortality of neonatal intestinal perforation has risen over the past 15 years. The incidence of intestinal perforation in extremely low‐birthweight (ELBW) neonates has been increasing as more ELBW neonates survive and as the live‐birth rate of ELBW has increased. In contrast to necrotizing enterocolitis (NEC) and focal intestinal perforation (FIP), the pathogenesis of meconium‐related ileus, defined as functional bowel obstruction characterized by delayed meconium excretion and microcolon, remains unclarified.