Prevention of Seroma Formation and Wound Complications Using NPWT Devices

In collaboration with the Yale Bariatric Surgery Program and General Surgery Department, patients will be identified as 18-years-of-age or older seeking body-contouring procedures (including panniculectomy and abdominoplasty) following massive weight loss or those patients in need of complex abdominal wall reconstruction (i.e. ventral hernia repair) and breast reconstruction necessitating the use of acellular dermal matrix. For the timeframe outlined in this protocol, the Section of Plastic Surgery at Yale performs surgeries in excess of the required numbers needed for this study, ensuring timely completion.

Exclusion criteria will include the FDA-identified contraindications to use of continuous negative pressure suction devices, as follows:

• presence of necrotic tissue
• untreated osteomyelitis
• malignancy (except terminal patients for quality of life issues)
• untreated malnutrition
• use on exposed arteries, veins, or organs
• use on non-enteric and unexplored fistulas Special precaution will be taken when using the NPWT device in patients on anticoagulants, exhibiting otherwise difficult hemostasis, or non-adherent patients.

Following a detailed explanation of the study design as well as the associated risks and benefits that may be incurred by each potential test group, patients who agree to participate in the study (via informed consent) will be categorized by characteristics including past medical history, past surgical history, social history, pre- and post-bariatric surgery total weight loss and BMI and will be randomized into either the control (standard closed suction drains) or experimental (continuous negative pressure via NPWT device) arm of each group, depending on the procedure to be performed, as follows:

1. 30 total patients undergoing panniculectomy alone following massive weight loss
2. 30 total patients undergoing formal abdominoplasty (including undermining of skin flaps, rectus fascia plication and liposuction) following massive weight loss
3. 30 total non-massive weight loss patients undergoing formal lipo-abdominoplasty
4. 30 total patients undergoing ventral hernia repair using acellular dermal matrix
5. 30 total patients undergoing bilateral breast reconstruction using acellular dermal matrix with 30 breasts randomized to conventional closed suction (one breast left vs right) and 30 breasts randomized to continuous negative pressure devices (=60 breasts total)

The control subject arm of each procedure group will be outfitted with 2 standard closed suction Jackson-Pratt (JP) drains for a period of 4 weeks (unless otherwise specified by the principle investigator at the point of follow-up), both as an inpatient and at home. The experimental subject arm of each procedure group will be outfitted with 2 non-compressible Blake drains attached to continuous suction via NPWT device for a period of 4 weeks (unless otherwise specified by the principle investigator at the point of follow-up), both as an inpatient and at home.

In the breast reconstruction group there will be an internal control via the 30 breasts drained conventionally in the same patient.

To achieve better control of variables, the total length of the incision and area of skin- undermining along the midline will also be measured and documented in the massive weight loss patient group to:

1. exactly distinguish the formal abdominoplasty from the panniculectomy patients and
2. evaluate to what extent skin-undermining is a contributing factor to seroma-formation compared to the patients' intrinsic factors.

All patients from group 1 will be wearing compression girdles starting post-operative day #1; patients from groups 2 and 3 will start wearing the compression girdles post-operative day #7 (to minimize the risk of central skin flap necrosis); and patients in group 4 will start wearing a regular abdominal binder on post-operative day #1.

The amount of tumescent solution as well as the amount of lipo-aspirate will be recorded in each patient in groups 2 \& 3.

The following chart will be provided for follow-up lab studies and clinic visits:

Wound-Healing Research Study Schedule and Logistics

Post-Op Follow-up Activities *Duration Week 1 Formal Outpatient Clinic Visit 30 minutes Follow-Up Blood Labs #1 15 minutes Quality of Life Survey #1 30 minutes

Week 2 Formal Outpatient Clinic Visit 30 minutes Follow-up Blood Labs #2 15 minutes Ultrasound Examination #1 15-30 minutes

Week 3 Ultrasound Examination #2 15-30 minutes (No formal clinic visit)

Week 4 Formal Outpatient Clinic Visit 30 minutes Quality of Life Survey #4 30 minutes

Week 8 Formal Outpatient Clinic Visit 30 minutes

*All visit duration times are approximate.

Per routine post-operative protocols, patients will be seen in clinic at week 1, 2, 4, and 8, and as needed clinically. Ultrasounds will be performed for research purposes only at the 2nd and 4th week visits, and diagnostically in the event that complications arise at any other point during the post-operative period. QALY surveys will be performed at the 1st and 4th week post-operative clinic visits.

Together with standard pre-operative blood work, (i.e., complete blood count (CBC), basic electrolyte panel, International Normalized Ratio (INR)/prothrombin time test (PT)/partial thromboplastin test (PTT)), we will also obtain albumin, pre-albumin and total protein levels in each patient on post operative days (PODs) #7 and #14.

Outcomes will be measured as follows:

• Total amount of fluid drainage comparing the two systems at 1, 2, 4, and 8 weeks (as long as drains remain in place)
• Analysis of complication rates including the incidence of infection requiring antibiotics, wound dehiscence, and the need for seroma drainage and/or surgical revision.
• Quantification of seroma formation by ultrasound examination of 5 regions of the abdominal wall: epigastrium (EPI), umbilical (UMB), hypogastrium (HYPO), right iliac fossa (RIF) and left iliac fossa (LIF)], at two postoperative periods: (P1), between postoperative days #11 and #14, and (P2), between postoperative days #18 and #21 as described by DiMartino et al [20], as well as ultrasound of the superior, medial, lateral and inferior portions of the reconstructed breasts.

Subjects included in the control (standard closed suction drains) and experimental arms (NPWT device) of each procedure group will not experience risks to subject privacy, discomforts, or inconveniences associated with participating in this research project that they would not otherwise experience with the use of standard closed suction drains currently being used for post-operative wound care. These standard risks, discomforts, and inconveniences include the potential for bleeding from drain site, infection at drain site, requirement of changing collection vessel when full, and pain. The post-operative ultrasound evaluation is also non-invasive. It is an evaluation which is often performed on patients in the post-operative period to assess for subcutaneous fluid collections.

The cost-effectiveness of each approach to post-surgical drain placement and design will be assessed via tracking patient health care costs associated with the specific surgical procedure performed, the costs associated with immediate post-surgical care, and any follow-up care incurred during the prolonged post-operative period as designated in the study design. The relevant costs will be compared between the control and experimental groups of each arm of the study and the cost-effectiveness ratio will be calculated using an objective, validated quality of life assessment.

Quality of life will be assessed via an incremental cost-effectiveness ratio, namely the repeatedly validated quality adjusted life year (QALY) metric achieved through patient surveys/interviews. The dynamic health assessment survey (DYNHA SF-36) will be used to evaluate patient health outcomes.

The DYNHA SF-36 Health Survey is a computerized adaptive testing (CAT) version of the industry standard, fixed-length Short Form Health Survey (SF-36) that has been translated and made available for use in many country and language-based cohorts [21]. The SF-36 focuses on assessing functional health and well-being, measuring eight health domains, including physical functioning, bodily pain, the ability to engage in work and leisure activities, psychological distress, vitality, and emotional health in order to accurately evaluate an individual's physical and mental status throughout the recovery period. The advantages of a dynamic health assessment include brevity without sacrificing accuracy, a focus on parameters affected by chronic health conditions, reliable outcomes for monitoring individuals, lower data collection costs, and real-time results with built-in interpretation and scoring.

Regarding the breast reconstruction group, we do not feel that by employing two different techniques (i.e. continuous vs intermittent/ bulb suction) in the same patient this would lead to a psychological burden for the patient. We expect that the main outcome difference in this group will be regarding the ease and comfort with the continuous suction device over the standard bulb suction. While the patients will likely prefer one over the other device, this should not have tremendous impact on their recovery in general or in how they cope with their disease.