The investigators are testing the ability of vacuum dressings to improve wound healing for patients having large hernias surgically repaired who are at risk of having wound complications. The trial will randomly be giving some patients having this surgery the vacuum dressing and some a standard dressing and observing how their wounds heal in hospital and at follow-up appointments.

This study is a multicentre, clinical randomized controlled trial comparing the use of incisional negative pressure wound therapy versus standard sterile dressings in high-risk ventral hernia repairs. The trial will be enrolling patients undergoing elective or emergent ventral hernia repair who have risk factors for surgical wound complications and randomizing them to either receive a PREVENA incisional negative pressure wound therapy system dressing for 7 days post-operatively or a standard sterile dressing.for 2 days post-operatively. The primary outcome will be a composite of a variety of surgical site complications including wound infection, dehiscence, seroma / hematoma formation, non-healing wound, early hernia recurrence, and fistula formation. These will be evaluated by unblinded clinical judgement of treating physicians, and blinded assessment with ultrasonography. Secondary outcomes will include perceived difference in Quality of Life and cost-effectiveness of the intervention.

Inclusion Criteria:

1. patients undergoing surgical repair of ventral or incisional hernias greater than 3 cm in largest diameter

2. have one or more of the following risk factors for post-operative surgical site complications:

   1. Body Mass Index (BMI) greater than or equal to 30
   2. diagnosis of diabetes mellitus (either type I or II)
   3. previous history of hernia recurrence
   4. active smoker
   5. presence of colostomy or ileostomy
   6. age greater than 64
   7. chronic obstructive pulmonary disease
   8. chronic kidney disease
   9. clinically immunocompromised.

Exclusion Criteria:

1. the abdomen is left open post-operatively, or
2. if the patient has a sensitivity to silver.

Given the physical differences in the negative pressure wound therapy systems compared to standard sterile dressings, patient participants and care providers will not be able to be blinded. Ultrasound evaluators and statisticians, however, will be.