Contemporary management of Hirschsprung disease in New Zealand.

BACKGROUND: The aim of this study was to report the contemporary management of Hirschsprung disease (HD) in New Zealand. METHODS: We undertook a national multi-centre retrospective review of all newly diagnosed cases of HD during a 16-year period (2000-2015). Demographics, genetic and syndromic associations, family history, radiology and histology results and surgical interventions were analysed. RESULTS: A total of 246 cases (males:females 4:1) were identified, an incidence of 1:3870 live births. Short-segment disease was present in 81.7%, long-segment disease in 8.5%, total colonic aganglionosis in 6.5% and unknown in 3.3%. HD was diagnosed by 4 weeks' corrected gestational age in 67%. Thirty cases (12%) also had Trisomy 21. Fifty-three (21.5%) patients required a repeat rectal biopsy for definitive diagnosis. A contrast enema was performed in 55% and identified the transition zone with 69% accuracy. Primary pull-through surgery was undertaken in 59% (65% of short-segment cases) at a median age of 27 days; others were initially managed by a defunctioning stoma. The commonest definitive procedure was a Soave-Boley endorectal pull-through (79%) (or similar variant). During a median follow-up of 7.4 years, six (2.5%) survivors underwent a redo pull-through, 13 (5.5%) an appendicostomy, 16 (6.8%) a defunctioning stoma and 10 never had a definitive procedure. Total colonic aganglionosis was significantly more likely to be fatal (12.5% versus 0.5%, P < 0.0005) or associated with a permanent end stoma (27.5% versus 4.5%, P < 0.0005). CONCLUSIONS: Most New Zealand born infants with short-segment HD are currently managed by primary pull-through, usually in the first months of life.

Declining incidence of pyloric stenosis in New Zealand.

BACKGROUND: Pyloric stenosis is a relatively common paediatric surgical condition, but a worldwide decline in its incidence has been observed in recent decades. The objective of this study was to identify if the incidence of pyloric stenosis in New Zealand has been declining. METHODS: A retrospective review of the four New Zealand paediatric surgical centres' theatre databases from 2007 to 2017. Demographic data were recorded for all infants who had a pyloromyotomy and annual incidences of pyloric stenosis calculated. RESULTS: A total of 393 infants underwent a pyloromyotomy for pyloric stenosis during the study period. Most infants (81%) were of European ethnicity. There was a significant decline (P = 0.0001) in the national incidence of pyloric stenosis from 0.73/1000 live births (LB) in 2007 to 0.39/1000 LB in 2017. From 2007 to 2017, the incidence of male infants with pyloric stenosis declined from 1.27/1000 LB to 0.62/1000 LB. The current annual incidence of pyloric stenosis in New Zealand is 0.39/1000 LB. CONCLUSIONS: The incidence of pyloric stenosis in New Zealand has significantly declined in the last decade and is currently the lowest reported incidence in the world involving a predominantly European cohort. A decline in male infants developing pyloric stenosis was also observed. Further study is required to investigate causes for this low incidence and declining trend.

Ethnic variations in the childhood prevalence of Hirschsprung disease in New Zealand.

BACKGROUND: Epidemiological studies have suggested that there may be ethnic variations in the prevalence of Hirschsprung disease (HD) but no study has systematically investigated this issue or potential ethnic variations in the extent of aganglionosis in HD. This study aimed to investigate this in a childhood population in New Zealand. METHODS: A multicentre national retrospective review was undertaken of all newly diagnosed cases of HD at each of the four paediatric surgical centres in New Zealand over a 16-year period (January 2000 to December 2015). Original histological, radiological and operative reports were obtained and analysed. Self-identified ethnicity was recorded from admission documents. Birth statistics were obtained from Statistics New Zealand. RESULTS: A total of 246 cases of HD were identified. The prevalence of HD was 1:3790 live births for European, 1:6610 among Maori, 1:1834 among Pacific Peoples, 1:3847 among Asian and 1:5694 among Middle Eastern. The prevalence of HD was statistically significantly greater in Pacific Peoples (P < 0.0005). The proportion of children with long-segment HD was also significantly greater in Pacific and Asian populations than others (P = 0.04). These findings were not due to differences in the proportion of familial cases of HD among the different populations. CONCLUSIONS: The prevalence and phenotype of HD varies significantly between different ethnic groups within New Zealand. This may well be related to variations in the frequencies of HD-associated gene mutations within these populations.

Surgical closure of patent ductus arteriosus in preterm low birth weight infants.

BACKGROUND AND AIM OF THE STUDY: In many preterm low-birth-weight infants, ductus arteriosus fails to close spontaneously. This study evaluates the results of surgical ligation of symptomatic patent ductus arteriosus (PDA) in preterm low birth weight infants. METHODS: We reviewed the medical records of all infants undergoing surgical closure of PDA from January 1987 to December 2005. Demographic data, age and weight at operation, surgical technique to close PDA and outcome were analyzed. RESULTS: One hundred and forty-five infants underwent surgical closure of PDA in which either indomethacin treatment had failed or was contraindicated. The mean gestational age was 25.5 +/- 2.3 (range 24-36 weeks) and the mean birth weight was 837.7 +/- 277.2 g (450-1000 g). The average age and weight at operation were 14.1 (+/-1.8) days and 881.7 g (+/-338.1), respectively. PDA was surgically closed by left thoracotomy using either nonabsorbable suture (73%) or hemoclips (27%). Postoperative complications occurred in 10 patients, which included intraoperative bleeding (6), pneumothorax (1), left vocal cord paralysis (1), lymphatic leak (1), and injury to left phrenic nerve (1). There was no mortality related to surgical closure of PDA. CONCLUSION: We conclude that surgical closure of hemodynamically significant PDA is safe and effective in preterm low birth weight infants when pharmacological treatment is ineffective or contraindicated. The associated morbidity is minimal and no surgery-related mortality was observed.

Comparative study between window and conventional enterostomies in preterm neonates with small bowel perforations.

OBJECTIVES: Small bowel perforations in the neonatal period can be secondary to necrotizing enterocolitis (NEC), ischemic necrosis, or occlusive anomalies of the small bowel; furthermore, they may be of no discernible cause. Depending on the clinical condition of the infant and the extent of the disease, a number of surgical options are available; one of which is exteriorization. To reduce the morbidity of stoma among patients, we adopted a technique called window enterostomy (WEnt). The objectives of this study were to describe the technique and to compare WEnt with conventional enterostomy (CEnt) in preterm infants undergoing surgery for focal NEC or isolated small bowel perforation (ISBP). METHODS: We reviewed all cases of NEC and ISBP between January 1996 and March 2006 from our institution. Patients with focal NEC or ISBP who required a surgical intervention were included and categorized into the WEnt and the CEnt groups. We collected multiple data as study variables: demographics; site of perforation; operative time; need for a second operation; postoperative morbidity; duration of total parenteral nutrition; and postoperative weight gain. RESULTS: Twenty-four neonates met the criteria for study inclusion. Of these, 14 underwent CEnt and 10 underwent WEnt. The median gestational age and birth weight of the neonates were 25.4 weeks (SD = 1.4) and 814.4 g (SD = 195.1), respectively. In comparing the 2 groups, we found statistically significant differences in the operative time for the primary and secondary procedures, duration of total parenteral nutrition, time to full oral feeding, and weekly postoperative weight gain. The rate of postoperative complications was higher among the infants from the CEnt group. CONCLUSION: Our results suggest that WEnt is a quick and workable technique with minimal morbidity for preterm neonates with focal NEC or ISBP.

Is contralateral exploration necessary in preterm infants with unilateral inguinal hernia?

PURPOSE: Contralateral inguinal exploration has been the preferred approach to preterm infants with unilateral inguinal hernia. There is no literature evidence to justify this. The aim of this prospective study is to analyze the incidence and to determine any risk factors for the development of contralateral metachronous hernia (MH) in the preterm when compared with term infants. METHODS: Preterm and term infants with unilateral inguinal hernia younger than 6 months who underwent surgery were included. Those infants who subsequently developed MH were analyzed. RESULTS: Two hundred sixty-six patients met the inclusion criteria. One hundred five were preterm and 161 were term. Ten preterm (10.31%) and 9 term infants (5.92%) presented subsequently with MH (P =.18). All but 1 were male. There was no relation between the side of hernia, presentation with incarceration, age at surgery, sex of the patient, and the development of MH. However, a trend toward a higher incidence of MH in very low birth weight and early gestational age preterms was noted. CONCLUSION: There is no significant difference between the occurrence of MH in preterm when compared with term infants. Routine contralateral exploration in preterm infants with its associated risks is therefore not justified in unilateral hernia.

Comparison of suture ligation and clip application for the treatment of patent ductus arteriosus in preterm neonates.

OBJECTIVE: We reviewed the experience of 2 centers performing surgical ligation of patent ductus arteriosus in preterm neonates to identify whether the choice of surgical technique--suture ligation or clip application--affected outcome. METHODS: Between 2000 and 2005, 67 newborn infants had open surgical closure of patent ductus arteriosus: 33 by suture ligation and 34 by clip application. The groups were similar in age and sex. RESULTS: The average length of the procedure was 55.8 +/- 13.7 minutes for suture ligation and 30.8 +/- 8.7 minutes for clip application (P < .05). Six neonates had intraoperative bleeding in the suture ligation group. Four patients had significant postoperative complications in the suture ligation group, compared with 2 in the clip application group. CONCLUSIONS: This study demonstrates that clip application results in a significant reduction in the operative time and, possibly, in less morbidity.

Long-term dilatation of caustic strictures of the oesophagus.

Caustic strictures of the oesophagus (CSO) in children are managed in different ways. Our study looks into the results of long-term dilatation of such strictures. Of 109 children admitted to our hospital with caustic ingestion, 10 developed strictures. The dilatations were carried out for periods varying from 9 months to 4 years. While 3 patients needed surgical treatment, 7 did not and did well. The oesophageal perforation rate with dilatations was only 0.47% (2 perforations from a total of 424 dilatations). Long-term dilatations are successful in managing a majority of CSO in children and are associated with minimal complications.