Interventional procedure consultation document

Negative pressure wound therapy for the open abdomen

Negative pressure (vacuum) therapy for abdomens left open after trauma or surgery to help healing

Trauma or surgery to the abdomen can result in a wound that cannot be closed by traditional techniques. Such wounds can take many months to heal. In negative pressure (vacuum) wound therapy, a foam dressing with a drainage tube is put into the wound. The tube is attached to a small vacuum unit that applies suction to the wound, removing excess blood and fluid. This may allow the wound to heal faster. Negative pressure wound therapy can be used for periods of a few days to a few weeks.

 

The National Institute for Health and Care Excellence (NICE) is examining negative pressure wound therapy for the open abdomen and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. NICE’s Interventional Procedures Advisory Committee has considered the available evidence and the views of specialist advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about negative pressure wound therapy for the open abdomen.

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

• comments on the provisional recommendations
• the identification of factual inaccuracies
• additional relevant evidence, with bibliographic references where possible.

Note that this document is not NICE’s formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that NICE will follow after the consultation period ends is as follows.

• The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
• The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

For further details, see the Interventional Procedures Programme manual, which is available from the NICE website (www.nice.org.uk/ipprogrammemanual).

Through its guidance NICE is committed to promoting race and disability equality, equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our interventional procedures guidance. In particular, we aim to encourage people and organisations from groups who might not normally comment on our guidance to do so.

In order to help us promote equality through our guidance, we should be grateful if you would consider the following question:

Are there any issues that require special attention in light of NICE’s duties to have due regard to the need to eliminate unlawful discrimination, advance equality of opportunity, and foster good relations between people with a characteristic protected by the equalities legislation and others?

Please note that NICE reserves the right to summarise and edit comments received during consultations or not to publish them at all where in the reasonable opinion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate.

Closing date for comments: 21 June 2013

Target date for publication of guidance: 25 September 2013

 

 

1                      Provisional recommendations

1.1                  Current evidence on the safety and efficacy of negative pressure wound therapy (NPWT) for the open abdomen is adequate to support the use of this procedure provided that normal arrangements are in place for consent, audit and clinical governance.

1.2                  NPWT for the open abdomen should only be carried out by healthcare professionals with specific training in the procedure and in accordance with manufacturer’s instructions when commercial products are used.

1.3                  NICE encourages further research into the role of NPWT for the open abdomen. Patient selection should be documented and research should report on efficacy outcomes such as impact on wound care and healing rates, and duration of hospital stay.

 

 

 

2                      Indications and current treatments

2.1                  NPWT for the open abdomen may be used to manage open abdominal wounds (laparostomy) in which the gut and other intraperitoneal organs are exposed. These patients can be divided into 3 groups:

(a) patients who have had surgery that did not involve the gastrointestinal tract, and in whom delayed primary closure is planned within about 1 week (for example, after ‘damage-control’ surgery for trauma or repair of a ruptured abdominal aneurysm)

(b) patients who have had gastrointestinal tract surgery for the management of abdominal sepsis associated with severe gastrointestinal disease (including anastomotic dehiscence, visceral perforation or inflammatory bowel disease) or severe pancreatitis

(c) patients who have had abdominal wound dehiscence.

Internal fistulae may occur in any of these groups, either before or after use of NPWT is considered.

2.2                  Open abdomens may be managed in a number of different ways, including application of a ‘Bogota bag’, systems with a ‘zipper’ allowing lavage, or various types of dressings. NPWT is an alternative to these methods. All of these techniques may be used as a prelude to delayed primary closure of the abdomen (especially in group (a) above). Alternatively, split-thickness skin grafts, mesh repair, muscle flaps or a combination of these may be used to close the abdomen (referred to in some of the published evidence as fascial closure).

 

 

 

3                      The procedure

3.1                  The aims of NPWT for the open abdomen include removing infected material and helping nursing care by reducing escape of fluid; its use may also influence the possibility of delayed primary closure.

3.2                  NPWT uses a sealed suction system to remove exudate and infected material from the abdominal cavity. The systems and techniques used vary widely, but the underlying principle is that the abdominal contents are covered with a foam sponge or other porous dressing (for example, gauze), with a membrane between the sponge/dressing and the abdominal contents. The entire wound and surrounding skin are covered with an adhesive transparent membrane, which is perforated by a drainage tube attached to the suction system. This applies negative pressure and removes fluid, at the same time preventing escape of fluid, because the membrane adheres to the skin all the way around the wound. A sensing device (a pad placed on top of the foam dressing) may be used to ensure that the prescribed amount of negative pressure is being applied to the wound.

3.3                  Several different commercial systems are available for negative pressure wound therapy, each of which requires specific training for safe and effective use. A number of non-commercial systems have also been described.

 

 

 

 

4                      Efficacy

This section describes efficacy outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview.

4.1                  A meta-analysis of 4303 patients reported delayed primary fascial closure rates of 58% (95% confidence interval [CI] 51 to 65) for NPWT, 78% (95% CI 56 to 94) for Wittmann patch, 44% (95% CI 27 to 61) for zipper, 36% (95% CI 26 to 46) for mesh, 28% (95% CI 8 to 55) for Bogota bag and 13% (95% CI 3 to 28) for packing. A non-randomised comparative study of 578 patients treated by NPWT or other temporary abdominal closure techniques reported delayed primary fascial closure rates of 45% (84/187) and 61% (114/187) respectively (p=0.002, matched pair analysis).

4.2                  The non-randomised comparative study of 578 patients treated by NPWT or other temporary abdominal closure techniques reported that 14% (27/187) and 11% (20/187) of patients respectively needed prosthetic replacement of the abdominal wall (p=0.28, matched pair analysis). A case series of 111 patients reported that 7% (8/111) of patients needed abdominal wall reconstruction with a polypropylene mesh.

4.3                  The Specialist Advisers listed key efficacy outcomes as reduction of exudate from the open abdomen, early fascial closure, shorter length of hospital stay, lower mortality, lower rate of secondary procedures to reconstruct the abdominal wall and improvement in patients’ quality of life.

 

 

 

5                      Safety

This section describes safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview.

5.1                  Mortality of 22% (95% CI 18 to 28) for NPWT, 33% (95% CI 25 to 42) for packing 30% (95% CI 24 to 37) for mesh, 30% (95% CI 23 to 36) for zipper, 28% (95% CI 20 to 37) for Bogota bag and 16% (95% CI 5 to 30) for Wittmann patch were reported in the meta-analysis of 4303 patients. Mortality rates of 26% (48/187) for patients treated by NPWT and 29% (55/187) for patients treated by other temporary abdominal closure techniques (p=0.40, matched pair analysis) were reported in the non-randomised comparative study of 578 patients. Mortality of 30% (33/111) was reported in the case series of 111 patients.

5.2                  Fistulae were reported in 7% (95% CI 5 to 9) of patients treated by NPWT compared with 13% (95% CI 5 to 23) treated by zipper, 11% (95% CI 6 to 16) treated by packing, 8% (95% CI 5 to 10) treated by mesh, 8% (95% CI 2 to 16) treated by Bogota bag and 3% (95% CI 1 to 5) treated by Wittmann patch in the meta-analysis of 4303 patients. Intestinal fistulae were reported in 8% (15/187) of patients treated by NPWT and in 10% (18/187) of patients treated by other techniques (p=0.58, matched pair analysis) in the non-randomised comparative study of 578 patients. Intestinal fistulae that were considered possibly to be related to NPWT were reported in 7% (8/111) of patients in the case series of 111 patients (7 occurred during treatment and 1 after treatment).

5.3                  Intestinal failure (defined as the need for parenteral nutrition for more than 28 days) was reported in 15% (28/187) of patients treated by NPWT and in 15% (28/187) of patients treated by other techniques (p=1.00, matched pair analysis) in the non-randomised comparative study of 578 patients.

5.4                  Abscess was reported in 4% (95% CI 2 to 7) of patients treated by NPWT compared with 16% (95% CI 4 to 19) treated by zipper, 12% (95% CI 1 to 31) treated by Bogota bag, 9% (95% CI 5 to 13) treated by mesh, 7% (95% CI 2 to 16) treated by packing and 2% (95% CI 0.1 to 8) treated by Wittmann patch, in the meta-analysis of 4303 patients. Abdominal abscess was reported in 5% (5/111) of patients in the case series of 111 patients (1 occurred during treatment and 4 after treatment).

5.5                  Intervention to control bleeding was reported in 12% (23/187) of patients treated by NPWT and in 17% (31/187) of patients treated by other techniques (p=0.25, matched pair analysis) in the non-randomised comparative study of 578 patients.

5.6                  The Specialist Advisers stated that it could sometimes be difficult to remove the foam component of NPWT because of granulation tissue which had anchored it to the wound. In addition to the adverse events described above, the Specialist Advisers drew attention to pain as an adverse event reported in the literature. They listed theoretical adverse events as bowel perforation, and in the longer term an increased risk of cancerous cell regeneration.

 

 

 

6                      Committee comments

6.1                  The Committee noted variations in outcome (specifically delayed closure) which seemed to be related to the type of abdominal pathology (sepsis or trauma) for which the abdomen had been left open. In addition, the Committee noted that there was a lack of evidence about efficacy outcomes of NWPT, such as impact on wound care, healing rates, and duration of hospital stay. These considerations underpinned the recommendations in section 1.3.

 

 

 

7                      Further information

7.1                  This guidance is a review of ‘Negative pressure wound therapy for the open abdomen’ NICE interventional procedure guidance 322 (2009).

7.2                  For related NICE guidance see the NICE website.

Bruce Campbell
Chairman, Interventional Procedures Advisory Committee
May 2013