Recovery after open versus laparoscopic pyloromyotomy for pyloric stenosis: a double-blind multicentre randomised controlled trial

The current state of evidence-based pediatric surgery

BACKGROUND

The efficiency of medical care in the United States has become intensely scrutinized with expectations from patients, families, payors, lawmakers, and, currently, the President. The most effective vehicle to bring more efficient care is the employment of evidence-based medicine whenever possible. Evidence-based medicine is dependent on best evidence, and best evidence is generated from prospective trials. To evaluate current state of evidence based practice in pediatric surgery we reviewed the literature for trials conducted in our field the past 10 years.

METHODS

All randomized controlled trials from January 1999 through December 2009 published in the English literature were identified through a literature search using PubMed (www.pubmed.com). We included only those in pediatric general surgery excluding transplant, oncology, and the other nongeneral subspecialties.

RESULTS

The search criteria produced 56 manuscripts, of which 51 described appropriate randomization techniques. A definitive trial design with a sample size calculation was utilized in only 19 studies (34%). A statistically significant difference between treatment arms was identified in 29 of the 56 (52%) trials. There were 26 different journals of publication, with the Journal of Pediatric Surgery being most common (20) followed by Pediatric Surgery International (7). The combined total publications from January 1999 through December 2009 for the 26 journals these randomized trials represent 0.04% of all publications. Appendicitis was the most common condition that was studied (n = 10) followed by pyloric stenosis (n = 4). Trials originated in 19 different countries led by the United States (28%), United Kingdom (14%), and Turkey (12%). There was a generally progressive increase in published trials from 1999 to 2009, however, the percentage of prospective articles published in pediatric surgery was similar to a previous review published in 1999.

CONCLUSIONS

The current state of evidence-based surgery in pediatric surgery has remained stable in the first decade of the 21st century. Randomized controlled trials represent less than 0.05% of all publications involving pediatric surgery. Some of the hurdles to evidence based surgery are identified and reviewed.

Air insufflation of the stomach following laparoscopic pyloromyotomy may not detect perforation

Air insufflation of the stomach during laparoscopic pyloromyotomy does not reliably rule-out perforation.

Background:

Undetected perforation during laparoscopic pyloromyotomy can be fatal. Detecting a perforation at the time of laparoscopic pyloromyotomy is difficult. The purpose of this study was to determine whether air insufflation of the stomach reliably detects perforation during laparoscopic pyloromyotomy.

Case Reports:

Between 2007 and 2008, 71 patients underwent laparoscopic pyloromyotomy and 2 patients (3.3%) had perforation. Insufflating the stomach with air did not demonstrate the perforation in either case. Both perforations were detected by careful inspection of the myotomy; a small amount of mucus was seen at the perforation site. Both patients underwent open suture repair with an omental patch and had unremarkable postoperative courses.

Conclusions:

Air insufflation of the stomach during laparoscopic pyloromyotomy does not reliably rule out perforation. As with all procedures with potential complications, a high index of suspicion and careful inspection of the entire myotomy may help detect perforation.

Lack of association between nNOS -84G>A polymorphism and risk of infantile hypertrophic pyloric stenosis in a Chinese population

BACKGROUND

Infantile hypertrophic pyloric stenosis (IHPS) is one of the most common gastrointestinal obstructions in the infancy requiring surgery. Reduced expression of neuronal nitric oxide synthase (nNOS), which plays an important role in the regulation of the human pyloric muscle, is thought to underlie IHPS. The role of nNOS in IHPS has been supported by the genetic association of a functional regulatory nNOS polymorphism (-84G>A) with IHPS in whites. We reasoned that the corroboration of this association in a population of different ethnic origin would prompt follow-up studies and further investigation of the IHPS pathology at molecular level. Thus, we attempted to reproduce the original findings in a Chinese population of comparable size in what would be the first genetic study on IHPS conducted in Chinese.

METHODS

nNOS -84G>A genotypes were analyzed in 56 patients and 86 controls by polymerase chain reaction and DNA sequencing. Logistic regression was used to compute odds ratios.

RESULTS

Our study could not corroborate the association previously reported. Although the frequency of the IHPS-associated allele (-84A) in controls (0.205) was similar to that reported for white controls, there was a dramatic difference in -84A frequencies between white and Chinese patients (0.198). Similarly, there was no difference in the nNOS -84G>A genotype distribution between patients and controls, even when the GA and AA genotypes were combined to compare GG genotype (odds ratio, 1.01; 95% confidence interval, 0.47-2.19).

CONCLUSIONS

Failure to replicate the initial finding does not detract from its validity, because genetic effects may differ across populations. Differences across populations in linkage disequilibrium and/or allele frequencies may contribute to this lack of replication. The role nNOS in IHPS awaits further investigation.

Thoracoscopic repair of congenital diaphragmatic hernia: intraoperative ventilation and recurrence

INTRODUCTION

Thoracoscopic repair of congenital diaphragmatic hernia (CDH) has been described, but its efficacy and safety have not been validated. The aim was to compare our experience of thoracoscopy with laparotomy repair.

METHODS

After ethics approval, we reviewed the notes of neonates with CDH operated in our institution between 2003 and 2008. Two historical groups were compared: infants who underwent laparotomy (2003-2008) or thoracoscopy (2007-2008). Data were compared by t test or Mann-Whitney tests.

RESULTS

Thirty-five children had open repair of CDH, and 13 had thoracoscopic repair. Groups were homogeneous for age and weight. Five (38%) neonates who had thoracoscopy were converted to open for surgical difficulties (n = 4) and O(2) desaturation (n = 1). Patch repair was used in 12 (34%) open and 6 (46%) thoracoscopic repairs. End-tidal CO(2) was significantly elevated during thoracoscopy, but this was not reflected in arterial CO(2) or pH. There were 3 (8%) recurrences after open repair and 2 (25%) after thoracoscopy (P = .19).

CONCLUSION

Thoracoscopic repair of CDH is feasible. Arterial blood gases should be closely monitored. Despite higher EtCO(2), conversion to open was mainly because of difficult repair. A randomized trial is necessary to assess the effect of thoracoscopy on ventilation and recurrences.

The evidence base for neonatal surgery

The practise of evidence based medicine means integrating the clinical expertise with the best available external clinical evidence from systematic research. There is a lack of supporting scientific evidence from rigorous trials in neonatal surgery. The indications for surgery and the type of operation performed in neonates are rarely supported by randomised controlled trials. As a consequence, the majority of the operations performed in neonates are supported by retrospective studies and surgeon preference. This review article is focussed on operations in neonates which are performed by general paediatric surgeons. Only a few randomised controlled trials have been performed in neonatal diseases such as congenital diaphragmatic hernia, necrotizing enterocolitis, pyloric stenosis and inguinal hernia. All of these trials have been based on collaboration between paediatric surgical units highlighting the importance of creating a network of centres that will promote multicentre prospective studies.

Laparoscopic vs open pyloromyotomy: a systematic review and meta-analysis

PURPOSE

The aim of the study was to determine whether laparoscopic pyloromyotomy (LP) or open pyloromyotomy (OP) is the most effective intervention in infants with hypertrophic pyloric stenosis.

METHODS

A systematic review of the published literature was undertaken in February 2009. Prospective studies comparing LP and OP were selected. Age, weight, complications, duration of operation, time to full feedings, postoperative vomiting, and postoperative length of stay (LOS) data were extracted.

RESULTS

Six prospective studies (5 level I, 1 level II) with 625 (303 LP, 322 OP) participants met selection criteria. Combined estimates indicated that LP had a lower total complication rate (odds ratio [OR], 0.58 [0.35, 0.97]; P = .04), mostly due to a lower wound complication rate (OR, 0.42 for LP [0.20, 0.91]; P = .03). Patients who underwent LP also had shorter time to full feedings (mean difference [MD], -11.52 hours [-12.77, -10.27]; P < .00001) and shorter postoperative LOS (MD, -5.71 hours [-8.90, -2.52]; P = .0005). No statistically significant differences were noted in the rates of mucosal perforation, wound infection, postoperative emesis, or operating time. Incomplete pyloromyotomy occurred in 6 patients who underwent LP (OR, 7.74 [0.94, 63.38]; P = .06).

CONCLUSIONS

This meta-analysis favors the laparoscopic approach with significantly reduced rate of total complications, which is mostly due to a lower wound complication rate.