Friday, October 31, 2008
14655

The Effect of Medical Co-Morbidities on Recurrence Using Prosthetic Materials with Component Separation for Complex Ventral Hernia Repair

Mazen S. Harake, MD, Amy Shanks, MS, Melanie G. Urbanchek, PhD, Daniel J. Krochmal, MD, Laura Pressley, BA, William M. Kuzon, Jr, MD, PhD, and Michael G. Franz, MD.

Background: Medical co-morbidities affect complication and recurrence rates after ventral hernia repair. However, the relationship between co-morbid conditions and complication and recurrence rates after repair using the component separation technique with or without prosthetic implants is uncertain.

Purpose: This retrospective study reviewed our series of patients at the University of Michigan, to determine the effect of medical co-morbidities on recurrence comparing complex incisional hernias repaired using the component separation technique (CST) without a prosthesis or CST with the addition of an underlay prosthesis.

Methods: After receiving Institutional Review Board approval, one hundred and forty-four patients were identified that were treated between March 2002 and November 2007. In all patients, the surgical technique involved bilateral musculofascial release of the external oblique muscle lateral to the linea semilunaris line.  In 66 of 144 patients, a single-layer prosthesis (alloplastic or biologic) was implanted beneath the fascial edges of the defect as an “underlay” with moderate tension.  After bilateral midline advancement of musculofascial units, a tension-free midline fascial closure was performed.  Patient demographics, preoperative risk factors, surgical indications, operative technique and details, and postoperative complications including recurrence rates were extracted from the clinical record.  The co-morbidities examined included cardiovascular disease, diabetes, obesity, hypertension, renal dysfunction, cancer, alcohol and substance abuse, and smoking.  Pearson Chi-Square, Fisher’s Exact Test, and Mann Whitney U Test were used for analysis using SPSS v. 15 as appropriate.

Results CST was performed in 78 patients without a prosthesis and in 66 patients using an underlay Prosthesis.  There were no significant differences between the groups in terms of average age (52 versus 57 years), Body Mass Index (33 versus 35 kg/m2), male ratio (50% versus 39%), average number of co-morbidities (1.5 versus 1.4), or history of previous surgeries (72% versus 76%). The average size of hernia defect in each group was not statistically different (318 cm2 versus 353 cm2). Postoperative complications including infection (37% versus 21%) and skin dehiscence (26% versus 9%) were increased in patients repaired using CST without prosthesis compared with CST and prosthesis (p 0.05). In the CST without prosthesis group compared to the CST with prosthesis group, the post-operative recurrence rate was 24% (n=19) versus 11% (n=7) (p = 0.03). Of the risk factors studied, only smoking was determined to be significantly higher in patients in the CST group without prosthesis. For the subset of patients that developed recurrence post-operatively, there was no significant difference between the two groups when comparing risk factors including obesity, elderly age, diabetes, smoking, hypertension, cancer, size of defect, or average number of co-morbidities.

Conclusions: We conclude that co-morbid factors do not predict recurrence when comparing patients undergoing complex ventral hernia repair using component separation technique without prosthesis or component separation with prosthesis. Recurrence rate and postoperative complications decrease with the addition of a prosthetic implant to the component separation technique in incisional hernia repair. For optimal outcomes and decreased recurrence afterventral hernia repair, these data suggest that the use of a prosthetic implant underlay improves patient outcomes.