Information for Scientists

Background of this investigator initiated clinical trial is the decision of the Joint Federal Committee of Germany (Gemeinsamer Bundesausschusses (G-BA)) that Vacuum assisted closure therapy (Negative Pressure Wound Therapy [NPWT]) in outpatient care 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.

Study Outline

This study project compares Vacuum Assisted Closure® and standard conventional wound therapy (SCWT) 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.

Primary Objective

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 within a maximum study treatment time of 42 days and 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.
The study aims to show that 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.


Randomization to treatment arms will be performed at a 1:1 ratio. Randomization 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.

Inclusion Criteria

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.

Endpoint Analysis

498 cases fulfilling all inclusion and no exclusion criteria with at least one visit to be documented after randomization are necessary for the final analysis that will be primarily be performed based on the intention to treat population. It is estimated that up to 550 patients will be included in the study. A planned interim analysis has been performed after reaching 250 evaluable patients. A significant superiority or inferiority of one of the therapy arms has not been demonstrated, thus the study will be continued until reaching the a priori planned number of 498 analyzable cases.


The results of the study will be provided in a final report and a publication and may contribute 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.