This clinical study is performed in several German, Dutch and Belgian hospitals to evaluate the efficacy of Vacuum Assisted Closure® (V.A.C.®) for the treatment of postsurgical abdominal wound healing impairments after surgery. Therefore the underlying layer of fibrous tissue that permeates the internal organs must be intact.

Main outcome measure is the time until complete wound closure that sustained for a minimum of 14 days. Furthermore the therapy options will be examined regarding several other clinical, safety, patient reported and economic parameters.

Patients will be assigned equally and by chance to both treatment groups. Study participants as well as the attending doctors and nurses will be informed about the assignment to the respective treatment arm.

The primary outcome measure and some of the secondary parameters like reappearance of the wound and the development of the wound size over time, examined within an active study treatment time of 42 days, will be photographed and analysed under the use of a central computer system. The central analysing personal will not be informed about patient details or therapy allocation.

Patients with at first closed belly wounds with wound healing disorder in the postoperative course after surgery without an opening of the underlying layer of fibrous tissue are eligible to be included in the trial if the diagnosis of a wound healing impairment in the postoperative course is manifested as a wound with spontaneous dehiscence, a wound that requires an active reopening of the suture by the treating physician or a wound that cannot be closed by primary intention and requires further treatment to achieve permanent closure.

Study participants will be selected and enrolled within clinical surgical departments which provide the respective personal, structural and scientific background for the conduction of the trial project.

Trial therapy will be started in-hospital and may be continued in ambulatory care. It is very important to examine the therapy options also in the ambulant care setting thus study participants with good health who are able to continue the specific wound treatment in ambulant should be transferred to the ambulant service as soon as possible.

The Institute for Research in Operative Medicine as part of the Private University of Witten /Herdecke is planning and performing a clinical trial project to evaluate the efficacy of Vacuum Assisted Closure® (V.A.C.®) Therapy for the treatment of postsurgical abdominal wound healing impairments after surgery without fascial dehiscence. The clinical trial project is fully financed by Kinetic Concepts Incorporated (KCI). The V.A.C.® Therapy devices that will be used in this study include the ActiV.A.C.® Therapy System, InfoV.A.C.® Therapy System, and V.A.C. Freedom® Therapy System. All V.A.C.® Therapy devices to be utilized in this study bear the CE mark and will be operated within normal conditions of use and according to manufacturer's specifications.

Background of the clinical trial project is the decision of the Joint Federal Committee of Germany (Gemeinsamer Bundesausschusses (G-BA)) that Vacuum assisted closure therapy is inadmissible to be a standard benefit of health insurance companies in Germany.

This decision is based on systematic review & meta-analysis of existing trials performed by Institute for Quality and Economic Efficiency in the Healthcare System (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen (IQWiG)) which showed an insufficient state of evidence regarding the efficacy of negative pressure wound therapy for the treatment of acute and chronic wounds.

This study project compares Vacuum Assisted Closure® and standard conventional wound therapy in the treatment of acute abdominal wounds after surgery without fascial dehiscence and will be conducted in abdominal surgical hospital departments with the required structural, manpower, and scientific qualifications. Patients will be stratified according to hospital and wound size. Trial therapy will be started in-hospital and may be continued in ambulatory care.

The study is designed as a multinational, multicentre, prospective randomized controlled, adaptive design, clinical superiority trial, with blinded photographic analysis of the primary endpoint.

The primary objective is to compare the clinical, safety, and economic outcomes of V.A.C.® Therapy and SCWT in postsurgical abdominal wound healing impairments without fascial dehiscence.

The primary outcome to be observed in this study is time to complete abdominal wound closure where closure is observed at or before day 42 and is confirmed to have been sustained for a period of at least 14 consecutive days. This study design also will allow detailed description of specific covariates to determine their effect on response variables (healing).

This study's hypothesis is that the use of the V.A.C.® Therapy System, when compared to SCWT in the management of post-surgical abdominal wound healing impairments with intact fascia, will result in a decrease in the time to achieve complete wound closure with confirmation after subsequent 14 days.

Using V.A.C.® Therapy is an effective and safe treatment option for hospitals as well as for outpatient care for treatment of subcutaneous abdominal wounds with wound healing impairment in the postoperative course.

Randomisation to treatment arms will be performed at a 1:1 ratio. Randomisation will be performed via a centralized system with an Internet-based tool. To address issues of blinding, wound photo documentation will be obtained during the trial and confirmation of wound closure will be assessed via blinded photographic analysis, which will serve as the method of primary endpoint analysis.

Primary closed abdominal wounds with wound healing disorder in the postoperative course after surgical intervention without fascial dehiscence are eligible to be included in the trial if the diagnosis of a wound healing impairment in the postoperative course is manifested as a wound with spontaneous dehiscence, a wound that requires an active reopening of the suture by the treating physician or a wound that cannot be closed by primary intention and requires further treatment to achieve permanent closure.

During active recruitment phase, the pre-trial estimates indicate approximately 600 patients will be required to yield the target of 552 evaluable participants. Using an adaptive design study sample-size calculations will be re-estimated upon planed interim analysis of study data of 250 patients. Patients will be enrolled from approximately 25 centres in Germany, the United Kingdom, Belgium and the Netherlands.

The evaluation of the primary Endpoint defined as time (number of days) to achieve complete wound closure verified by photo documentation and blinded, computer-based wound quality assessment as well as wound closure confirmation after 14 consecutive days and secondary endpoints including clinical endpoints like recurrences, safety endpoints, patient reported outcome parameters and economic-based outcome measures will provide data regarding efficacy and efficiency of NPWT therapy for the treatment of acute post-surgical abdominal wound healing impairment in hospital as well as in the ambulant setting.

The results of the study will be provided to make a contribution to the final decision of the Joint Federal Committee about NPWT to be a standard benefit of health insurance companies in Germany for inpatient and / or outpatient care.

Inclusion Criteria:

• Written informed consent
• Post-surgical subcutaneous abdominal wound healing impairment
• Minimum wound size eligible for the application of the randomized treatment- Inclusion, randomization, adequate wound pre-treatment (Debridement) and start of therapy within 48 hours after reopening of the wound, diagnosis for nonclosable wound or in case of spontaneous wound dehiscence

Exclusion Criteria:

• Age < 18
• Noncompliance with study procedures, visit schedule and follow up
• Pregnancy
• Present or nonclosable defect of the abdominal fascia
• Any pre-existing or ongoing organ system failure, that cannot be stabilized or solved by appropriate medical treatment
• Necrotic tissue with eschar present
• Non-enteric and unexplored fistulas
• Malignancy of the wound
• Use of any other device based on the principle of negative pressure wound therapy on the study wound within ≤ 8 days prior to screening
• Competing therapies or procedures
• Simultaneous participation in other clinical trials