title: Mesh shift following laparoscopic ventral hernia repair.
abstract: BACKGROUND
  Traditionally, laparoscopic ventral hernia repair (LVHR) is performed by placing the trocars on one side of the abdomen. Tacking the mesh on the operative side can be challenging. We hypothesized that mesh shift may occur as a result of this approach. We define mesh shift as any mesh off-center, where the center is the hernia defect. Our objectives were to evaluate whether mesh shift occurs after LVHR, and to develop a grading system to describe this phenomenon.
  
  
  METHODS
  We conducted a retrospective review of patients who underwent LVHR from 2000 to 2010. We examined patient demographics, comorbidities, radiographic data, surgical data, and outcomes. Using analysis of variance, we analyzed continuous data; we used Chi squared to analyze categorical data. Of the 201 patients, we reviewed 78 postoperative computed tomography (CT) scans. Two surgeons measured mesh overlap of the fascia bilaterally at the level of the hernia defect. We compared a ratio of the two sides of overlap (least overlap/greatest overlap) and classified patients into four grades: grade I, no mesh shift (ratio of 0.5-1.00); grade II, mild mesh shift (ratio of 0.20-0.49); grade III, moderate mesh shift (>0-0.19); and grade IV, major mesh shift with recurrence (<0). Any recurrence was classified as a grade IV shift.
  
  
  RESULTS
  A total of 48% of patients had mesh shift (grade II = 23%; grade III = 10%; and grade IV = 17%). In 92% of the patients with mesh shift, the mesh migrated away from the port placement site, resulting in decreased mesh/fascial overlap. Patients in the four groups had similar demographics, comorbid conditions, hernia characteristics, operative technique, and outcomes (excluding recurrences, which were all grade IV by definition). Whereas differences in time to follow-up CT scan in the different grades were not statistically significant, there was a trend toward increasing shift with time (mean: grade I, 20 mo; grade II, 38 mo; grade III, 50 mo; and grade IV, 26 mo; P = 0.07). A total of 26 patients (33%) had multiple postoperative CT scans. With time, it appears that mesh tended to shift with time (grade I, 68%-46%; grade II, 12%-19%; grade III, 12%-8%, and grade 4, 8%-23%).
  
  
  CONCLUSIONS
  Mesh can shift from the ideal central placement after LVHR. Mesh tends to shift away from the operative side and recurrences tend to occur on the operative side. Mesh shift may be a precursor to hernia recurrence. Recurrence may be a two-step process, beginning first with intra-operative mesh shift followed by additional factors (such mesh contraction) that may accentuate the shift and lead to recurrence. Potential solutions include increasing mesh overlap (≥ 6 cm), performing transcutaneous closure of central defect, securing trans-fascial sutures before tacking, placing operative side tacks first, and consider placing contralateral ports to secure the mesh.
authors.affiliation: Department of Surgery, Michael E. DeBakey VAMC, Baylor College of Medicine, Houston, Texas 77006, USA. ml3@bcm.edu
authors.forename: Mike K
authors.initials: MK
authors.lastname: Liang
authors.forename: Marissa L
authors.initials: ML
authors.lastname: Clapp
authors.forename: Andrea
authors.initials: A
authors.lastname: Garcia
authors.forename: Anuradha
authors.initials: A
authors.lastname: Subramanian
authors.forename: Samir S
authors.initials: SS
authors.lastname: Awad
mesh_terms: D059685:Herniorrhaphy / Q000009:adverse effects*; D006801:Humans; D010535:Laparoscopy / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D013526:Surgical Mesh / Q000009:adverse effects*