Post Operative Wound Complications in Patients With BMI ≥35kg/m2 After Posterior Lumbar Spine Surgery: a Randomized Clinical Trial of Closed-Incision Negative-Pressure Therapy

Methods:

Study Design: Prospective open-label randomized clinical trial of CINPT in obese patients. Subjects will be randomized in a 1:1 to Standard of Care (SOC) and CINPT.

Study Arms: (1) Standard of Care (2) CINPT Sample Size: Based on 30% incidence of wound complications in obese patients undergoing lumbar spine surgery, a sample size of 124 (62 in each cohort) will be needed to detect a decreased incidence of 10% with an α of 0.05 and β of 0.2.

Randomization: Randomization will be done with varying blocks of 4, 6 and 8 using opaque sealed envelopes.

Procedures: All patients will receive standard pre operative prophylactic antibiotics with 2g - 3g Cefazolin or 1g Clindamycin (if patient has known penicillin allergy) based on weight 60 min before incision is made. They will be clipped if needed before being prepped. Each patient will be prepped with alcohol and then either duraprep, chloraprep, or betadine. After the procedure is complete, a subfascial and subcutaneous closed suction drain will be placed in the wound prior to closure. 1 to 3 gram of Vancomycin powder will be placed in the wound. The wound is closed with #1vicryl for the fascial layer followed by 2-0 Vicryl for the subcutaneous layer followed by 3-0 or 4-0 monocryl. In the SOC group, skin glue, Steri-strips, sterile gauze and Tegaderm will be applied to the wound. In the CINPT group, a CINPT dressing will be placed and attached to a compact portable negative pressure unit to deliver 125mmHg continuous pressure for 5 to 7 days. All patients will receive standard wound care instructions before hospital discharge. Patients will return to the clinic in 6±1 days for a wound check and removal of the CINPT.