Rekonstruktive Chirurgie zur Behandlung von Druckgeschwüren (Dekubitus)
Abstract
Background
The management of pressure ulcers involves several interventions ranging from pressure‐relieving measures such as repositioning, to treatments that can include reconstructive surgery. Such surgery may be considered for recalcitrant wounds when full thickness skin loss arises and deeper structures such as muscle fascia and even bone are exposed. The surgery commonly involves wound debridement followed by the addition of new tissue into the wound. Whilst reconstructive surgery is an accepted means of ulcer management, the benefits and harms of surgery compared with non‐surgical treatments, or alternative surgical approaches are not clear.
Objectives
To assess the effects of reconstructive surgery for healing pressure ulcers (stage II or above), comparing surgery with no surgery or comparing alternative forms of surgery in any care setting.
Search methods
We searched the following electronic databases to identify reports of relevant randomised clinical trials (searched 26 September 2016): the Cochrane Wounds Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL. We also searched three clinical trials registers and reference lists of relevant systematic reviews, meta‐analyses and health technology assessment reports.
Selection criteria
Published or unpublished randomised controlled trials that assessed reconstructive surgery in the treatment of pressure ulcers.
Data collection and analysis
Two review authors independently performed study selection. We planned that two review authors would also assess the risk of bias and extract study data.
Main results
We did not identify any studies that met the review eligibility criteria nor any registered studies investigating the role of reconstructive surgery in the management of pressure ulcers.
Authors' conclusions
Currently there is no randomised evidence that supports or refutes the role of reconstructive surgery in pressure ulcer management. This is a priority area and there is a need to explore this intervention with more rigorous and robust research.
PICO
Laienverständliche Zusammenfassung
Rekonstruktive Chirurgie zur Behandlung von Druckgeschwüren (Dekubitus)
Fragestellung
Unser Ziel war es, die Evidenz bezüglich der Frage, ob rekonstruktive Chirurgie eine wirksame Behandlung für die Heilung von Druckgeschwüren ist, zusammenzufassen. Wir konnten keine randomisierten kontrollierten Studien zu dieser Frage finden.
Hintergrund
Druckgeschwüre sind Haut‐ und Gewebeschäden, die weitgehend Personen betreffen, die über eine lange Zeit in der gleichen Position verbleiben. Wenn Körperteile, besonders jene, die wenig Fett haben, wie die untere Lendenwirbelsäule (Rücken) und die Ferse, einem konstanten äußeren Druck ausgesetzt sind (z.B. sitzen auf dem gleichen Körperbereich ohne Veränderung der Position), wird der Blutfluss zur Haut und das darunterliegende Gewebe beschränkt, was zu einem Gewebezerfall führen kann. Zu den Menschen mit Risiko Druckgeschwüre zu entwickeln, gehören ältere Personen und solche mit Mobilitätsproblemen wie Rollstuhlfahrer und Langzeitkrankenhauspatienten. Druckgeschwüre können anhand eines Klassifikationsystems unterteilt werden. Beim Stadium I‐Geschwür besteht noch intakte Haut, beim Stadium II‐Geschwür gibt es einen Teilverlust der Haut und Gewebeverlust und umfasst oft flache Wunden. Stadium III‐ und IV‐Geschwüre sind offene Wunden mit tiefem Gewebeschaden. Druckgeschwüre sind schwerwiegende Wunden, deren Behandlung teuer ist. Deswegen konzentriert sich die Pflege auf ihre Prävention. Wenn Geschwüre auftreten, gehören zu den Behandlungsmöglichkeiten Wundverbände, Antibiotika und Antiseptika. Rekonstruktive Chirurgie ist oft für tiefe oder schwer zu heilende Druckgeschwüre, oder beides, vorbehalten. Es gibt verschiedene Arten von Operationen, die durchgeführt werden können. Die meisten beinhalten die Entfernung von totem Gewebe aus der Wunde. Danach wird unter Verwendung von Fett, Muskel und/oder Haut aus anderen Teilen des Körpers des Patienten, der durch die Wunde entstandene Hohlraum gefüllt.
Studienmerkmale
Wir suchten im September 2016 nach randomisierten, kontrollierten Studien, die den Einsatz von Operationen zur Behandlung von Druckgeschwüren untersuchten. Obwohl rekonstruktive Chirurgie für Druckgeschwüre weit verbreitet ist, fanden wir keine randomisierten, kontrollierten Studien, die die potenziellen Nutzen und Schäden im Zusammenhang mit der Operation oder die optimale Wahl der chirurgischen Technik untersuchten. Viele Studien, die von diesem Review ausgeschlossen wurden, berichteten Daten von Personengruppen, die sich einer rekonstruktiven Chirurgie unterzogen, ohne jedoch die Ergebnisse für ähnliche Gruppen, die keine Operation oder unterschiedliche Operationen hatten, zu vergleichen. Dies bedeutet, dass es nicht möglich ist, die Nutzen und Risiken einer Operation oder verschiedener chirurgischer Techniken abzuwägen.
Hauptergebnisse
Wir fanden keine randomisierten kontrollierten Studien zur rekonstruktiven Chirurgie bei Druckgeschwüren.
Qualität der Evidenz
Die Nutzen und Schäden der rekonstruktiven Chirurgie für die Behandlung von Druckgeschwüren sind ungewiss. Dies macht gründlichere Forschung in diesem Bereich erforderlich, insbesondere, weil diese Frage von Patienten, Pflegepersonal und Gesundheitsexperten priorisiert wurde.
Diese laienverständliche Zusammenfassung ist auf dem Stand von September 2016.
Authors' conclusions
Background
Description of the condition
Pressure ulcers, also known as bedsores, decubitus ulcers and pressure injuries, are localised areas of ischaemic injury to the skin and underlying tissue. They are caused by prolonged external mechanical forces such as pressure or shear beyond the normal physiological constraints (EPUAP‐NPUAP‐PPPIA 2014). These forces are higher in the presence of an underlying bony prominence such as the sacrum, ischium, trochanter and heel (Vanderwee 2007), which is where pressure sores tend to occur.
Populations at greatest risk include those with spinal cord injuries (Gefen 2014), and non‐ambulatory individuals. People with prolonged impaired consciousness can be affected, like those having long surgery (Chen 2012; Primiano 2011) people in intensive care (Ranzani 2016) and people found incapacitated through intoxication (Yanagawa 2011). Furthermore, acute and chronic comorbidities that limit mobility or tactile sensation increase risk, with the elderly population most vulnerable (Allman 1997; Bergstrom 1998; Berlowitz 1990; Berlowitz 1997; Brandeis 1994). It is not uncommon for these pressure ulcers to occur with systemic disease such as diabetes (Brem 2003). Incontinence can increase the risk of ulceration by producing a moist, contaminated environment for the skin injury (Brandeis 1994). Poor nutritional status also impairs the ability of some individuals to heal these complex wounds (Allman 1997; Donini 2005). However, there is currently limited evidence for the effectiveness of nutritional intake interventions for preventing or treating pressure ulcers (Langer 2014; Smith 2013).
Pressure ulcers vary in severity. One of the most widely recognised systems for categorising pressure ulcers is that of the National Pressure Ulcer Advisory Panel, which is summarised below (NPUAP 2016).
Category/Stage I ‐ non‐blanchable erythema: "Intact skin with non‐blanchable redness of a localised area usually over a bony prominence. Darkly pigmented skin may not have visible blanching; its colour may differ from the surrounding area. The area may be painful, firm, soft, warmer or cooler as compared to adjacent tissue. Category I may be difficult to detect in individuals with dark skin tones. May indicate "at risk" persons."
Category/Stage II ‐ partial thickness: "Partial thickness loss of dermis presenting as a shallow open ulcer with a red pink wound bed, without slough. May also present as an intact or open/ruptured serum‐filled or sero‐sanguinous filled blister. Presents as a shiny or dry shallow ulcer without slough or bruising (bruising indicates deep tissue injury). This category should not be used to describe skin tears, tape burns, incontinence associated dermatitis, maceration or excoriation."
Category/Stage III ‐ full thickness skin loss: "Full thickness tissue loss. Subcutaneous fat may be visible but bone, tendon or muscle are not exposed. Slough may be present but does not obscure the depth of tissue loss. May include undermining and tunnelling. The depth of a Category/Stage III pressure ulcer varies by anatomical location. The bridge of the nose, ear, occiput and malleolus where there is little subcutaneous tissue (adipose) can form Category/Stage III ulcers that are shallow. In contrast, areas of significant adiposity can develop extremely deep Category/Stage III pressure ulcers. Bone/tendon is not visible or directly palpable."
Category/Stage IV ‐ full thickness tissue loss: "Full thickness tissue loss with exposed bone, tendon or muscle. Slough or eschar may be present. Often includes undermining and tunnelling. The depth of a Category/Stage IV pressure ulcer varies by anatomical location. The bridge of the nose, ear, occiput and malleolus which have little subcutaneous tissue (adipose), can form ulcers that are shallow. Category/Stage IV ulcers can extend into muscle and/or supporting structures (e.g. fascia, tendon or joint capsule) making osteomyelitis or osteitis likely to occur. Exposed bone/muscle is visible or directly palpable."
Prevalence estimates vary according to the population being assessed, the data collection methods used and decisions about whether or not stage I pressure ulcers should be included (since there is no active wound at this stage, but patients are 'at risk'). A large survey of hospital patients undertaken in several European countries returned a pressure ulcer prevalence (stage II and above) of 10.5% (Vanderwee 2007). In 2009, a US estimate for pressure ulcer prevalence (stage II and above) across acute care, long‐term care and rehabilitation settings was 9% with prevalence highest in long‐term acute care settings (26%) (VanGilder 2009). In the UK, national pressure ulcer data are collected across community and acute settings ‐ although data collection is not yet universal ‐ as part of the National Health Service (NHS) Safety Thermometer initiative (Power 2012). Five per cent of patients across these settings were estimated to have a pressure ulcer in January 2014 (National Safety Thermometer 2014).
We note that all the prevalence figures quoted above are for populations currently receiving medical care. The point prevalence of pressure ulceration in the total adult population was recently estimated using a cross‐sectional survey undertaken in Leeds, UK. Of the total adult population of 751,485, the point prevalence of pressure ulceration per 1000 was 0.31 (Hall 2014). UK pressure ulcer prevalence estimates specifically for community settings have reported rates of 0.77 per 1000 adults in a UK urban area (Stevenson 2013).
Pressure ulcers have a large impact on those affected and can be painful, and become infected or malodorous. After adjustment for age, sex and co‐morbidities, people with pressure ulcers have a lower health‐related quality of life than those without pressure ulcers (Essex 2009). The financial cost of treating ulcers in the UK was recently estimated as being between GBP 1214 for a stage I ulcer, to GBP 14,108 for a stage IV ulcer (Dealey 2012). In 2004, the total annual cost of treating pressure ulcers in the UK was estimated as being GBP 1.4 to 2.1 billion, which was equivalent to 4% of the total NHS expenditure (Bennett 2004). Pressure ulcers have been shown to increase length of hospital stay, readmission and mortality rates (Lyder 2012), and add considerably to the cost of an episode of hospital care (Chan 2013). Figures from the USA suggest that half a million hospital stays in 2006 had the diagnosis of 'pressure ulcer'; for adults, the total hospital costs of these stays was USD 11 billion (Russo 2008). Costs to the Australian healthcare system for treating pressure ulceration have been estimated at AUD 285 million per annum (Graves 2005).
Traditional approaches to managing pressure ulcers have been to utilise conservative measures such as dressings that are often associated with a protracted investment of resources. Surgical intervention for pressure ulcers is reserved for the most recalcitrant of pressure sores. In theory, if the aetiology of pressure sores is removed and nutrition optimised (Bergstrom 1996; Bergstrom 1992), the majority should heal. Surgery is usually indicated after failure of conservative measures and usually reserved for stage III and IV ulcers (Margara 2003). Debridement of unhealthy and necrotic tissue, underlying bursae (fibrotic capsule) and bone if necessary remains the cornerstone of surgical management, with or without immediate soft tissue cover (Conway 1956). Other than the choice of surgical reconstruction, quality of local tissues, aetiological factors, patient co‐morbidities, education status and motivation contribute significantly to successful outcomes (Kruger 2013).
Description of the intervention
This review focuses on the evidence for the surgical reconstruction of pressure ulcers, where surgical reconstruction is defined as any surgical procedure that leads to primary epithelial closure of the wound. A diverse spectrum of surgical procedures can be performed to help heal pressure ulcers, however selection must be based on a number of participant and wound level factors. Many surgical procedures start with thorough debridement, involving excision of the fibrotic capsule or bursa that forms around the chronic wound, to healthy bleeding tissue. If the residual tissue is badly scarred, skin is subject to further breakdown. If there is underlying dead or infected tissue or heterotrophic ossification (formation of ectopic bone) this should be debrided.
Once surgical debridement has been performed, reconstructive surgical methods conducted include the following (Maslauskas 2009):
Primary wound closure: involves direct advancement of the wound edges either directly or in layers to close the wound (Simman 2009).
Skin grafts: involve harvesting a thin piece of skin that is surgically removed from a donor area to replace skin in the defect or denuded area. Skin grafts are occasionally used to treat pressure ulceration when all precipitating factors for pressure sore formation have been removed. They are used to facilitate quick wound cover and subsequently to accelerate wound healing (Srivastava 2009).
Local random pattern flaps: this reconstructive method involves surgically moving the local tissues around the wound, based on a random pattern of blood supply, into the wound defect (Nesbit 2015).
Regional flaps including:
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muscle or musculocutaneous flaps; this surgical approach involves moving whole or part of a named muscle based on a defined blood supply with or without a skin island to provide cover to the wound (Liu 2013);
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fascial or fasciocutaneous flaps; this surgical approach involves moving a surgically defined fascial based island of tissue with its intact blood supply with or without skin to cover the wound (Robertson 2015);
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perforator flaps; this is a refinement of the previous musculocutaneous or fasciocutaneous flaps approach whereby the specific perforating blood vessels are identified in the flap and dissected to allow either greater movement or less muscle sacrifice as well as separation of components to each flap (Koshima 1993).
Free flaps: this surgical approach involves raising a defined island of tissue with an artery and vein that is surgically detached and moved to the site of the wound where other local arteries or veins of similar size are identified and then the vessels are surgically anastomosed to re‐establish blood flow to the island of tissue (Lemaire 2008).
Tissue expansion: this surgical approach involves a gradual increment and recruitment of tissue surrounding a pressure ulcer. It is performed by expanding the skin with a tissue expander, which is inserted into a subcutaneous pocket near the ulcer and slowly expanded at a defined rate with saline. Once the skin and soft tissues are expanded to a volume capable of covering the pressure ulcer, the expander is removed and the tissues are inset to cover the wound. Another method is to apply slow skin traction over the wound with an incremental traction dressing, which works on the same principle of gradual mechanical traction on skin, promoting tissue creep (Johnson 1993). Eventually the extra skin recruited can be used to close the wound (Wagh 2013).
All of the above approaches can be performed as a one‐stage procedure, or part of a multistage procedure to increase the likelihood of the tissue surviving manipulation, reduce the overall surgical impact on the patient and ensure that all infected or aggravating factors are minimised. This is particularly important as the skin quality around pressure ulcers is usually sub‐optimal (Maslauskas 2009).
How the intervention might work
Surgery is indicated when conservative measures have failed to accelerate the healing process in pressure ulceration, but only when all other parameters are optimised. Thus, surgical closure is often reserved for more complex pressure ulcers (most often stage III or IV but occasionally stage II), with strong consideration of the probability of ulcer recurrence in each individual. The underpinning rationale for reconstructive surgery is that following the removal of devitalised tissue, the wound defect is filled with vascularised healthy tissue with adequate skin cover, which then forms a healed wound.
Why it is important to do this review
In general, much of the current literature around the treatment of pressure ulcers focuses on their non‐surgical management. It is also important to assess current evidence regarding the clinical effectiveness of surgery to assess its potential for use in suitable patient populations. Surgical options have increased with the advent of more novel approaches such as perforator flaps and free tissue transfer, although it is difficult to find any figures regarding the number of people with pressure ulcers treated using reconstructive surgery in any country. The published UK National Institute for Health and Clinical Excellence (NICE) guidelines on the prevention and management of pressure ulcers (NICE 2014), does not make any specific recommendations or suggestions regarding reconstructive surgery for people with these wounds. A recent review of the evidence for all treatments for pressure ulcers included four studies investigating the role of reconstructive surgery, but it did not identify randomised controlled trials, and as a result, could only draw very limited conclusions (Smith 2013). The role of surgery in closing pressure ulcers was prioritised highly by patients, carers and health professionals in a James Lind Alliance priority setting partnership (Cullum 2016).
The production of a current and robust Cochrane systematic review is required to present an overview of the current evidence base to help inform decision‐making in the treatment of pressure ulcers as well as to guide possible future research.
Objectives
To assess the effects of reconstructive surgery for healing pressure ulcers (category/stage II or above), comparing surgery with no surgery or comparing alternative forms of reconstructive surgery in any care setting.
Methods
Criteria for considering studies for this review
Types of studies
We planned to include published and unpublished randomised controlled trials (RCTs), including cluster‐RCTs, irrespective of language of report. We intended to exclude cross‐over trials and exclude studies using quasi‐randomisation.
Types of participants
We planned to include studies that recruited adults with a diagnosis of a pressure ulcer (category/stage II or above) managed in any care setting. We excluded studies involving participants with category/stage I ulcers. We accepted study authors' definitions of stage II or above, unless it was clear that they included wounds with unbroken skin. We planned to exclude studies with mixed wound populations; that is studies that did not restrict inclusion to pressure ulcers only and which may have included participants with other types of wounds such as venous leg or diabetic foot ulcers, although we did not find any such studies.
Types of interventions
The primary intervention was reconstructive surgery for pressure ulceration (where reconstructive surgery is defined as any surgical procedure that leads to epithelial closure of the wound). We planned to include any RCT in which the use of a specific surgical closure technique was the only systematic difference between treatment groups and anticipated that likely comparisons would include surgery compared with no surgery and different types of surgery compared with each other. We anticipated that reconstructive surgery would often include a stage of surgical wound debridement. We would have included this as a co‐intervention, extracted data and discussed it in the presentation of results. We did not plan to treat surgical debridement alone as a type of reconstructive surgery. Other co‐intervention details would have included postoperative protocols. Where there was evidence of a difference in use of co‐interventions between groups, we would not have considered the type of reconstructive surgery to be the only systematic difference between groups and we would have excluded these studies.
Types of outcome measures
We listed primary and secondary outcomes below. If a study was otherwise eligible (i.e. correct study design, population and intervention/comparator) but did not report a listed outcome then we planned to contact the study authors where possible to establish whether an outcome of interest here was measured but not reported, however this was not required in this review.
We planned to report outcome measures at the latest time point available for a study (assumed to be length of follow‐up if not specified) and the time point specified in the methods as being of primary interest (if this was different from latest time point available). For all outcomes we planned to class outcome measures from:
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less than one week to eight weeks as short‐term;
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from eight weeks to 16 weeks as medium‐term; and
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more than 16 weeks as long‐term.
Primary outcomes
The primary outcomes for this review were complete wound healing and wound breakdown.
Complete wound healing
We accepted study authors' definitions of wound healing. We planned to record whether healing was defined immediately following surgery or whether healing was not confirmed until some defined period following surgery when the surgery was deemed to be successful.
For this review we regarded the following as providing the most relevant and rigorous measures of outcome;
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Time to complete wound healing. We planned to record whether this had been correctly analysed using techniques that account for data censoring and with adjustment for prognostic covariates such as baseline size;
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The proportion of ulcers healed (frequency of complete healing).
Where both the outcomes above were reported we planned to present the data in a summary outcome table for reference and report time to healing.
Wound breakdown
We planned to present data on wound breakdown using the following two outcomes that would be presented separately:
Wound dehiscence
We planned to assess this as the proportion of wounds that dehisce along the wound edges that have been apposed and held together with sutures, staples, etc. in the reconstructive surgery. We intended to record study authors' definitions of wound dehiscence.
Wound recurrence
This was defined as occurrence of a new pressure ulcer on the same site as a previous ulcer.
Secondary outcomes
Secondary outcomes were as follows:
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Resource use: resource use (including measurements of resource use such as number of dressing changes, nurse visits, length of hospital stay, re‐admission and re‐operation/intervention);
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Health‐related quality of life: we planned to include quality of life where it was reported using a validated scale such as the SF‐36 or EQ‐5D or a validated disease‐specific questionnaire such as the Cardiff Wound Impact Schedule. We did not plan to include ad hoc measures of quality of life that were unvalidated or were not common to multiple trials;
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Wound infection: we planned to accept study authors' definitions of wound infection;
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Costs: any costs applied to resource use;
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Incidence of secondary ulceration: this would have applied to a second pressure ulcer that formed in a different area during the follow‐up period.
Search methods for identification of studies
Electronic searches
We searched the following electronic databases:
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the Cochrane Wounds Specialised Register (searched 26 September 2016);
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the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library, 2016, Issue 2);
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Ovid MEDLINE (1946 to 26 September 2016);
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Ovid MEDLINE (In‐Process & Other Non‐Indexed Citations) (searched 26 September 2016);
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Ovid Embase (1974 to 26 September 2016);
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EBSCO CINAHL Plus (1937 to 26 September 2016).
The search strategies used for CENTRAL, Ovid MEDLINE, Ovid Embase and EBSCO CINAHL can be found in Appendix 1. We combined the Ovid MEDLINE search with the Cochrane Highly Sensitive Search Strategy for identifying randomised trials in MEDLINE: sensitivity‐ and precision‐maximising version (2008 revision) (Lefebvre 2011). We combined the Embase search with the Ovid Embase filter developed by the UK Cochrane Centre (Lefebvre 2011). We combined the CINAHL searches with the trial filters developed by the Scottish Intercollegiate Guidelines Network (SIGN 2015). There were no restrictions with respect to language, date of publication or study setting. Citations were de‐duplicated as part of the search process so identical records included more than once would be removed prior to screening. We also searched the following registers:
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WHO International Clinical Trials Registry Platform (ICTRP) apps.who.int/trialsearch/Default.aspx
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ClinicalTrials.gov www.clinicaltrials.gov/
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EU Clinical Trials Register www.clinicaltrialsregister.eu/ctr‐search/search.
Searching other resources
We aimed to identify other potentially eligible trials or ancillary publications by searching the reference lists of retrieved included trials as well as relevant systematic reviews, meta‐analyses and health technology assessment reports.
Data collection and analysis
Selection of studies
Two review authors independently assessed the titles and abstracts of the citations retrieved by the searches for relevance. After the initial assessment, we obtained full‐text copies of all studies considered to be potentially relevant. Two review authors independently checked the full papers for eligibility. We resolved disagreements by discussion and, where required, we sourced the input of a third review author. We did not need to contact study authors to query any study details with regard to eligibility. We recorded all reasons for exclusion of studies for which we had obtained full copies. We completed a PRISMA flowchart to summarise this process (Liberati 2009).
Where studies had been reported in multiple publications/reports we obtained all the available publications. Whilst a study would only be included once in the review, we planned to extract data from all reports to ensure maximal relevant data were obtained.
Data extraction and management
We planned to extract and summarise details of the eligible studies using a data extraction sheet. Two review authors would have extracted data independently and resolved disagreements by discussion, drawing on a third review author where required. Where data was missing from reports, we planned to contact the study authors to obtain this information. Where a study with more than two intervention arms was included, we anticipated only extracting data from intervention and control groups that met the eligibility criteria.
We planned to extract the following data where possible by treatment group for the pre‐specified interventions and outcomes in this review. We planned to collect outcome data for relevant time points as described in Types of outcome measures:
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Country of origin
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Type of wound and surgery
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Unit of randomisation (per participant) ‐ single wound or multiple wounds on the same participant
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Unit of analysis
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Trial design (e.g. parallel, cluster)
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Care setting
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Number of participants randomised to each trial arm
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Eligibility criteria and key baseline participant data
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Details of treatment regimen received by each group
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Duration of treatment
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Details of any co‐interventions
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Primary and secondary outcome(s) (with definitions)
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Outcome data for primary and secondary outcomes (by group)
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Duration of follow‐up
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Number of withdrawals (by group)
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Publication status of study
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Source of funding for trial.
Assessment of risk of bias in included studies
We planned that two review authors would independently assess included studies using the Cochrane approach for assessing risk of bias as detailed in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011a). This tool addresses six specific domains: sequence generation, allocation concealment, blinding, incomplete data, selective outcome reporting and other issues. In this review we planned to record issues with unit of analysis, for example where a cluster trial had been undertaken but analysed at the individual level in the study report (Appendix 2). We planned to assess blinding and completeness of outcome data for each of the review outcomes separately. If comparisons had been included we anticipated that blinding of participants and personnel would not have been possible. For this reason, the assessment of the risk of detection bias would have focused on whether blinded outcome assessment was reported (because assessment of wound outcomes such as breakdown and healing can be subjective and at high risk of detection bias when outcome assessment is not blinded). We planned to present our assessment of risk of bias using two 'Risk of bias' summary figures; one that is a summary of bias for each item across all studies, and a second that shows a cross‐tabulation of each trial by all of the risk of bias items.
For trials using cluster randomisation, we also planned to consider the risk of bias considering: recruitment bias, baseline imbalance, loss of clusters, incorrect analysis and comparability with individually randomised trials (Higgins 2011b) (Appendix 3).
Measures of treatment effect
For dichotomous outcomes we planned to calculate the risk ratio (RR) with 95% confidence intervals (CI). For continuously distributed outcome data we planned to use the mean difference (MD) with 95% CIs, where trials used the same or a similar assessment scale. If trials used different assessment scales, we planned to use the standardised mean difference (SMD) with 95% CIs. We planned to only consider mean or median time to healing without survival analysis as a valid outcome if reports specified that all wounds had healed (i.e. if the trial authors regarded time to healing as a continuous measure as there was no censoring). We planned to report time‐to‐event data (e.g. time to complete wound healing) as hazard ratios (HR) where possible in accordance with the methods described in the Cochrane Handbook for Systematic Reviews of Interventions (Deeks 2011). If studies reporting time‐to‐event data (e.g. time to healing) did not report a hazard ratio, then, where feasible, we planned to estimate this using other reported outcomes, such as the numbers of events, through the application of available statistical methods (Parmar 1998), however this was not required.
Unit of analysis issues
Where studies randomised at the participant level and measured outcomes at the wound level, (e.g. wound healing), we planned to treat the participant as the unit of analysis when the number of wounds assessed appeared equal to the number of participants (e.g. one wound per person).
Particular unit of analysis issues in wound care trials can occur when (1) studies randomise at the participant level, use the allocated treatment on multiple wounds per participant, and then analyse outcomes per wound, or (2) studies undertake multiple assessments of an outcome over time per participant. These approaches would have been treated as cluster trials, alongside more standard cluster designs – such as delivery of interventions at an organisational level.
Where a cluster trial had been conducted and correctly analysed, effect estimates and their standard errors would have been meta‐analysed using the generic inverse‐variance method in RevMan.
We planned to record where a cluster‐randomised trial had been conducted but incorrectly analysed. This would have been recorded as part of the 'Risk of bias' assessment. If possible we planned to approximate the correct analyses based on Cochrane Handbook for Systematic Reviews of Interventions guidance (Higgins 2011c). We would have used information on:
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the number of clusters (or groups) randomised to each intervention group; or the average (mean) size of each cluster;
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the outcome data ignoring the cluster design for the total number of individuals (for example, number or proportion of individuals with events, or means and standard deviations); and
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an estimate of the intracluster (or intraclass) correlation coefficient (ICC).
If the study data could not be analysed correctly, we planned to extract and present outcome data but not analyse the data further.
Dealing with missing data
It is common to have data missing from trial reports. Excluding participants post‐randomisation from the analysis, or ignoring those participants who were lost to follow‐up, compromises the randomisation and potentially introduces bias into the trial. Where there was missing data we planned to contact the relevant study authors to ask whether these data were available.
Where data remained missing for a proportion of the wounds healed, we planned to assume that if randomised participants were not included in the results section of the paper, their wound did not heal (i.e. in the analysis, missing participants would be considered in the denominator but not the numerator).
For continuous variables (e.g. length of hospital stay and for all secondary outcomes) we would have presented available data from the study reports/study authors and we did not plan to impute missing data. Where measures of variance were missing we planned to calculate these wherever possible. If calculation was not possible we planned to contact study authors. Where these measures of variation were not available we planned to exclude the study from any relevant meta‐analyses that we conducted.
Assessment of heterogeneity
Assessment of heterogeneity is a complex, multi‐faceted process. We planned to consider clinical and methodological heterogeneity: that is the degree to which the included studies varied in terms of participants, interventions, outcomes and characteristics such as length of follow‐up. We planned to supplement this assessment of clinical and methodological heterogeneity with information regarding statistical heterogeneity, assessed using the Chi² test (we would have considered a significance level of P < 0.10 to indicate statistically significant heterogeneity) in conjunction with the I² statistic (Higgins 2003). The I² statistic examines the percentage of total variation across RCTs that is due to heterogeneity rather than chance (Higgins 2003). In general I² values of 25%, or less, may mean a low level of heterogeneity (Higgins 2003), and values of 75%, or more, indicate very high heterogeneity (Deeks 2011). However, these figures are only a guide and it is recognised that statistical tests and metrics may miss important heterogeneity ‐ thus whilst we planned to assess these, the overall assessment of heterogeneity would have looked at these measures in combination with the methodological and clinical assessment of heterogeneity. See Data synthesis for further information about how potential heterogeneity would have been handled in the data analyses.
Assessment of reporting biases
Reporting biases arise when the dissemination of research findings is influenced by the nature and direction of results. Publication bias is one of a number of possible causes of 'small study effects', that is, a tendency for estimates of the intervention effect to be more beneficial in smaller RCTs. Funnel plots allow a visual assessment of whether small study effects may be present in a meta‐analysis. A funnel plot is a simple scatter plot of the intervention effect estimates from individual RCTs against some measure of each trial's size or precision (Sterne 2011). We planned to present funnel plots for meta‐analyses comprising 10 RCTs or more using Review Manager 5.3 (RevMan) (RevMan 2014).
Data synthesis
We planned to combine details of included studies in a narrative review according to type of comparator, possibly by location of/type of wound and then by outcomes by time period. We planned to consider clinical and methodological heterogeneity and undertake pooling when studies appeared appropriately similar in terms of wound type, intervention type, duration of follow‐up and outcome type.
In terms of meta‐analysis, our default approach would have been to use the random‐effects model. We planned to only use a fixed‐effect approach when we considered clinical heterogeneity to be minimal and estimated statistical heterogeneity as non‐statistically significant for the Chi² value and 0% for the I² assessment (Kontopantelis 2012a). We planned to adopt this approach as it is recognised that statistical assessments can miss potentially important between‐study heterogeneity in small samples hence the preference for the more conservative random‐effects model (Kontopantelis 2012b). Where clinical heterogeneity was thought to be acceptable or of interest we planned to consider meta‐analysis even when statistical heterogeneity was high but we would have attempted to interpret the causes behind this heterogeneity, possibly using meta‐regression for this purpose (Thompson 1999). However we did not undertake this in this review.
We planned to present data using forest plots where possible. For dichotomous outcomes we planned to present the summary estimate as a risk ratio (RR) with 95% CI. Where continuous outcomes were measured in the same way across studies, we planned to present a pooled mean difference (MD) with 95% CI. We planned to pool standardised mean difference (SMD) estimates where studies measured the same outcome using different methods. For time‐to‐event data, we planned to plot (and, if appropriate, pool) estimates of hazard ratios and 95% CIs as presented in the study reports using the generic inverse variance method in RevMan 5 (RevMan 2014).
We planned to obtain pooled estimates of treatment effect using Cochrane RevMan software (version 5) (RevMan 2014).
'Summary of findings' tables
We planned to present the main results of the review in 'Summary of findings' tables. These tables present key information concerning the quality of the evidence, the magnitude of the effects of the interventions examined and the sum of the available data for the main outcomes (Schünemann 2011a). The 'Summary of findings' tables also include an overall grading of the evidence related to each of the main outcomes using the GRADE approach, which defines the certainty of a body of evidence as the extent to which one can be confident that an estimate of effect or association is close to the true quantity of specific interest. The certainty of a body of evidence involves consideration of within‐trial risk of bias (methodological quality), directness of evidence, heterogeneity, precision of effect estimates and risk of publication bias (Schünemann 2011b). We plan to present the following outcomes in the 'Summary of findings' tables.
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Complete wound healing
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Wound dehiscence
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Wound recurrence
Subgroup analysis and investigation of heterogeneity
Where feasible we planned to explore the findings based on the following groups (not undertaken):
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Ulcer stage
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Type of surgery.
Sensitivity analysis
Where possible we planned to perform sensitivity analyses to explore the effect of the following criterion on any pooled analysis (not undertaken):
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Removal of studies at high risk of bias for any domain.
Elements of this methods section are based on the standard Cochrane Wounds protocol template.
Results
Description of studies
Results of the search
The search retrieved 597 unique records. We obtained 33 full texts as potentially relevant to this review. We took a comprehensive approach to checking other reviews and guidelines in the field of reconstructive surgery as well as trials registers and did not identify any additional records. No studies met the inclusion criteria for this review (Figure 1).
Study flow diagram
Included studies
We did not include any studies for analysis in this review and there were no pending studies awaiting assessment.
No relevant ongoing studies were located.
Excluded studies
We excluded 33 studies (Characteristics of excluded studies). Of these 19 were excluded because they did not assess reconstructive surgery as an intervention. A further seven were excluded because they were not randomised controlled trials. Five were excluded because they were neither accessing reconstructive surgery nor randomised controlled trials and two were excluded as they were systematic reviews.
Risk of bias in included studies
It was not possible to undertake a risk of bias assessment because no studies met the inclusion criteria.
Effects of interventions
Meta‐analysis or a narrative synthesis was not possible in this study as no studies met the inclusion criteria.
Discussion
Summary of main results
Despite an extensive search of numerous electronic databases, reviews, guidelines and clinical trials registers we did not identify any studies that met the inclusion criteria for this review. We excluded studies because they were not RCTs or because they did not evaluate reconstructive surgery for the management of pressure ulcers. We did not identify any relevant randomised controlled trials as being in progress.
Overall completeness and applicability of evidence
There is no randomised, controlled trial evidence regarding the effects of reconstructive surgical techniques on the management of pressure ulcers, thus this area is lacking a robust evidence base.
Potential biases in the review process
This review employed a robust search strategy to locate as much relevant evidence as possible relevant to the objectives of this review. We located all potentially relevant papers and translated them where required. There were no restrictions on the language of studies assessed. We also searched trials registers and did not find any relevant on‐going or previously conduct but unpublished studies. It is possible, however, that there may be additional unpublished data that we have not been able to access.
We did consider the use of a broader inclusion criteria in order to avoid an "empty" review (Yaffe 2012). However broadening the eligibility criteria to include quasi‐randomised or controlled clinical studies would have yielded no further studies. The studies we did identify were largely retrospective cohort studies or case series.
Agreements and disagreements with other studies or reviews
There is a lack of rigorous evidence regarding the benefits and harms of reconstructive surgery for people with pressure ulcers (Levine 2013). Some systematic reviews have regarded surgical reconstruction for pressure ulcers favourably but these have included non‐randomised case series and/or retrospective studies, hence their usefulness in decision making is limited. NICE guidelines on the prevention and management of pressure ulcer (NICE 2014) do not refer to reconstructive surgery in their recommendations, also reflecting the lack of robust evidence in this area.
Study flow diagram
