title: Do drainage liquid characteristics serve as predictors for seroma formation after incisional hernia repair?
abstract: BACKGROUND
  Though the occurrence of postoperative seroma after incisional hernia repair using mesh reinforcement is very common, little is known about the genesis of seroma formation. The aim of this study was to determine the characteristics of drainage liquid as a potential predictor for the development of seroma after incisional hernia mesh repair. Furthermore, the characteristics of drainage liquid were compared to the characteristics of seroma liquid.
  
  
  METHODS
  The incidence of postoperative seroma associated with pH value, concentration of lactate, total protein, albumin, propeptide-III-procollagen (P-III-P), hyaluronan, fibronectin and IL-1 receptor antagonist (IL-1-RA) in the drainage liquid were prospectively determined in 38 patients who underwent incisional hernia repair by lightweight polypropylene-polyglactin composite mesh (Vypro-II). The findings were compared to the seroma liquid characteristics of those patients who developed a seroma formation.
  
  
  RESULTS
  In 11 patients (29%), seroma formation was present after removal of the drainage. We observed significantly elevated mean drainage volume (148 +/- 64 ml vs. 93 +/- 71 ml; P = 0.014) and significantly reduced pH value (7.26 +/- 0.12 vs. 7.41 +/- 0.23; P = 0.016) and IL-1-RA (100 +/- 71 U/ml vs. 145 +/- 108 U/ml; P = 0.016) in the drainage liquid of patients with seroma formation in comparison to patients without seroma formation. In addition, we found significantly altered concentration of lactate (9.8 +/- 2.0 mmol/l vs. 5.5 +/- 1.4 mmol/l; P < 0.001), P-III-P (24 +/- 13 U/ml vs. 89 +/- 79 U/ml; P = 0.045) and fibronectin (0.10 +/- 0.03 g/l vs. 0.24 +/- 0.13 g/l; P = 0.005) in the drainage liquid in comparison to seroma liquid.
  
  
  CONCLUSIONS
  The pH value of wound solution proves to be a reliable predictor for the subsequent presence of seroma formation. Furthermore, our findings implicate that seroma formation cannot be seen as persistent drainage liquid.
authors.affiliation: Department of Surgery, RWTH Aachen University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany. cklink@ukaachen.de
authors.forename: C D
authors.initials: CD
authors.lastname: Klink
authors.forename: M
authors.initials: M
authors.lastname: Binnebösel
authors.forename: A H
authors.initials: AH
authors.lastname: Lucas
authors.forename: A
authors.initials: A
authors.lastname: Schachtrupp
authors.forename: U
authors.initials: U
authors.lastname: Klinge
authors.forename: V
authors.initials: V
authors.lastname: Schumpelick
authors.forename: K
authors.initials: K
authors.lastname: Junge
mesh_terms: D004322:Drainage / Q000379:methods*; D005122:Exudates and Transudates / Q000737:chemistry*; D005260:Female; D006555:Hernia, Ventral / Q000601:surgery*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D011098:Polyglactin 910; D011126:Polypropylenes; D011183:Postoperative Complications / Q000628:therapy*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D049291:Seroma / Q000628:therapy*; D018709:Statistics, Nonparametric; D013526:Surgical Mesh
chemical_list: D011126:Polypropylenes; C510058:VyproII; D011098:Polyglactin 910