Minimally invasive versus open repair of Bochdalek hernia: a meta-analysis Emily Chan, Carolyn Wayne, Ahmed Nasr ⁎ Children’s Hospital of Eastern Ontario, University of Ottawa, Ottawa, ON, Canada abstract article info Article history: Received 1 February 2014 Accepted 13 February 2014 Key words: Congenital diaphragmatic hernia Minimally invasive surgery Recurrence Outcomes Background: Diaphragmatic hernia can be repaired by open or minimally invasive surgery (MIS), although it is unclear which technique has better outcomes. Our objective was to compare the outcomes of these procedures in a systematic review and meta-analysis. Methods: We sought all publications describing both techniques through MEDLINE, Embase, and CENTRAL. Our primary outcome of interest was recurrence. We conducted statistical analyses using Review Manager 5.2. Results: We did not identify any randomized controlled trials. Our pooled estimate of results from 10 studies showed that total recurrence was higher after MIS (OR: 2.81 [1.73, 4.56], p b 0.001). Subgroup analyses indicated higher recurrence after MIS for patch repairs (OR: 4.29 [2.13, 8.67], p b 0.001), but not for primary repairs. Operative time was longer for MIS (MD: 55.25 [40.21, 70.28], p b 0.001), while postoperative ventilator time and postoperative mortality were higher after open surgery (MD: 1.33 [0.05, 2.62], p = 0.04; OR: 7.54 [3.36, 16.90], p b 0.001, respectively). Conclusions: Recurrence rate is higher after MIS than open repair when a patch is used. Operative time is also longer with MIS. Poorer outcomes after open surgery may be a result of selection bias rather than surgical technique. Surgeons should carefully consider the potential morbidity associated with MIS when deciding on a repair method. © 2014 Elsevier Inc. All rights reserved. Congenital diaphragmatic hernia (CDH) is a condition in which the diaphragm fails to develop properly, resulting in a defect that allows the abdominal contents to herniate into the thoracic cavity. The most common type of CDH is the Bochdalek hernia, which presents as a posterolateral defect and comprises 95% of all CDH cases [1,2]. Surgery for CDH repair can be performed by the traditional open approach (either laparotomy or thoracotomy), or by minimally invasive surgery (MIS), which has become increasingly popular since the late 1990s [3]. MIS procedures may have several benefits, including decreased postoperative pain and improved wound cosm- esis [4]. However, MIS may be risky in neonates, who are vulnerable to hypothermia and acidosis caused by CO 2 insufflation [3]. Controversy exists regarding which operative technique (MIS or open surgery) leads to the best outcomes, particularly with respect to recurrence of the CDH. Existing literature reports conflicting findings, underscoring the lack of consensus in this area. Thus, our objective was to conduct a systematic review and meta-analysis of all published literature comparing surgical repair techniques for CDH. We compared MIS versus open surgery for Bochdalek-type CDH, examining periopera- tive and postoperative outcomes. 1. Methods 1.1. Literature search To identify all studies comparing MIS with open surgery for CDH repair, we conducted an electronic search of MEDLINE (1966 onwards), Embase (1980 onwards), and the Cochrane Central Register of Controlled Trials (CENTRAL). We used the keywords “diaphragmatic hernia”, “thoracoscopy”, “laparoscopy”, “minimally invasive surgery”, and “open”. We excluded any studies that did not pertain to humans and children. We also excluded editorials, case reviews, and any studies that did not compare outcomes of MIS with open surgery for Bochdalek-type hernias. Finally, we hand-searched the reference sections of all relevant articles to identify additional studies. 1.2. Quality assessment 1.2.1. Assessment tool Methodological Index for Non-Randomized Studies (MINORS) [5]: We used this index to assess the quality of nonrandomized studies. The MINORS criteria comprise 12 items; each item is assigned a score from 0–2, for a maximum score of 24 (comparison studies) or 16 (noncomparison studies). Higher scores are indicative of greater methodological quality. Journal of Pediatric Surgery 49 (2014) 694–699 ⁎ Corresponding author at: Pediatric Surgery, Children’s Hospital of Eastern Ontario, University of Ottawa, Ottawa, ON, Canada, K1H 8L6. E-mail address: anasr@cheo.on.ca (A. Nasr). http://dx.doi.org/10.1016/j.jpedsurg.2014.02.049 0022-3468/© 2014 Elsevier Inc. All rights reserved. Contents lists available at ScienceDirect Journal of Pediatric Surgery journal homepage: www.elsevier.com/locate/jpedsurg