title: Is pooled data analysis of ventral and incisional hernia repair acceptable?
abstract: OBJECTIVE
  In meta-analyses and systematic reviews comparing laparoscopic with open repair of ventral hernias, data on umbilical, epigastric, and incisional hernias are pooled. Based on data from the Herniamed Hernia Registry, we aimed to investigate whether the differences in the therapy and treatment results justified such an approach.
  
  
  METHODS
  Between 1st September 2009 and 31st August 2013, 31,664 patients with a ventral hernia were enrolled in the Herniamed Hernia Registry. The implicated hernias included 16,206 umbilical hernias, 3,757 epigastric hernias, and 11,701 incisional hernias. Data on the surgical techniques, postoperative complication rates, and 1-year follow-up results were subjected to statistical analysis to identify any significant differences between the various hernia types.
  
  
  RESULTS
  The laparoscopic IPOM technique was used significantly more often for incisional hernia than for epigastric hernia, 31.3 vs. 24.0%, respectively, and was used for 12.9% of umbilical hernias (p < 0.0001). Likewise, the open technique with suturing of defect was used significantly more often for umbilical hernia than for epigastric hernia, 56.1 vs. 35.4%, respectively, and was used for 12.5% of incisional hernias (p < 0.0001). The postoperative complication rates of 3.2% for umbilical hernia and 3.5% for epigastric hernia were significantly lower than for incisional hernia, at 9.2% (p < 0.0001). That was also true for the reoperation rates due to postoperative complications, of 1.0 vs. 1.2 vs. 4.2% (p < 0.0001). The 1-year follow-up revealed significantly higher recurrence rates as well as rates of chronic pain needing treatment of 6.3 and 7.9%, respectively, for incisional hernia, compared with 4.1 and 4.3%, respectively, for epigastric hernia, and 2 and 1.9%, respectively, for umbilical hernia (p < 0.0001).
  
  
  CONCLUSIONS
  Since significant differences were identified in the therapy and treatment results between umbilical hernia, epigastric hernia, and incisional hernia, scientific studies should be conducted comparing the various surgical techniques only for a single hernia type.
authors.affiliation: Department of Surgery, Centre for Minimally Invasive Surgery, Vivantes Hospital Berlin, Academic Teaching Hospital of Charité Medical School , Berlin , Germany.
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Köckerling
authors.affiliation: Department of Surgery, Centre for Minimally Invasive Surgery, Vivantes Hospital Berlin, Academic Teaching Hospital of Charité Medical School , Berlin , Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Schug-Paß
authors.affiliation: StatConsult GmbH , Magdeburg , Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Adolf
authors.affiliation: Department of Surgery, Wilhelmsburger Hospital Groß-Sand, Academic Teaching Hospital of University Hamburg , Hamburg , Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Reinpold
authors.affiliation: Hernia Center Cologne , Cologne , Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Stechemesser
keywords: complications; epigastric hernia; incisional hernia; primary ventral hernia; recurrence; umbilical hernia; ventral hernia