The Use of Acellular Tissue Matrices in Gender-Affirming Surgery: Review of the Literature and Institutional Experience

Wound healing complications are not uncommon after genital gender-affirming surgery and can pose significant challenges for the reconstructive surgeon. Acellular tissue matrices are products that contain extracellular matrix compounds without living cells and are used to expedite and improve wound healing. Some of these products have been described for a variety of different indications in gender-affirming surgery.  In this paper, the authors present a review of the current literature on the use of acellular tissue matrices in gender-affirming surgery as well as the authors' institutional experience in using these products.

Automated devices for identifying peripheral arterial disease in people with leg ulceration: an evidence synthesis and cost-effectiveness analysis

Background

Peripheral artery disease is a common condition caused by narrowing/blockage of the arteries, resulting in reduced blood supply. Peripheral artery disease is associated with an increased risk of vascular complications, but early treatment reduces mortality and morbidity. Leg ulcers are long-lasting wounds, usually treated by compression therapy. Compression therapy is not suitable for people with peripheral artery disease, as it can affect the arterial blood supply. In clinical practice, people with peripheral artery disease are identified by measurement of the ankle-brachial pressure index using a sphygmomanometer and manual Doppler device. However, this method can be uncomfortable for people with leg ulcers and automated devices have been proposed as a more acceptable alternative. The objective of this appraisal was to summarise the clinical and cost-effectiveness evidence on the use of automated devices to detect peripheral artery disease in people with leg ulcers.

Methods

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Clinical effectiveness

To identify reports of relevant studies, we searched major electronic databases and scrutinised the information supplied by the manufacturers of the automated devices under investigation. Due to the lack of evidence on people with leg ulcers, we considered evidence from studies of any design assessing automated devices versus an acceptable reference device in any population receiving ankle-brachial pressure index assessment. We summarised information on diagnostic accuracy of the automated devices and level of agreement with the reference device. For each device, when data permit, we pooled data across studies by conducting random-effects meta-analyses using a Hierarchical Summary Receiving Operating Characteristics model.

Cost-effectiveness

An economic model comprising a decision tree (24 weeks) and Markov models to capture lifetime costs and quality-adjusted life-years associated with venous, arterial and mixed aetiology disease in leg ulcer patients. Analyses were conducted from a United Kingdom National Health Service and Personal Social Services perspective. Costs and quality-adjusted life-years were discounted at 3.5% per year. Deterministic and several probabilistic analyses were used to capture uncertainty surrounding a range of optimistic and pessimistic assumptions about the impact of automated tests on health outcomes (ulcer healing and requirement for invasive management of arterial disease).

Results

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Clinical effectiveness

From the 116 records retrieved by the electronic searches, we included 24 studies evaluating five devices (BlueDop Vascular Expert, BOSO ABI-System 100, Dopplex Ability, MESI ankle-brachial pressure index MD and WatchBP Office ABI). Two studies assessing people with leg ulcers found that automated devices often gave higher ankle-brachial pressure index readings than manual Doppler (underestimation of arterial disease). In the 22 studies involving people without leg ulcers, automated devices generally demonstrated good specificity and moderate specificity. Meta-analysis of 12 studies showed a pooled sensitivity of 64% (95% confidence interval 57% to 71%) and a pooled specificity of 96% (95% confidence interval 92% to 98%) for detection of peripheral artery disease.

Cost-effectiveness

Automated devices cost less than manual Doppler to deliver. However, increased risks of invasive treatment requirements for inappropriately compressed arterial/mixed ulcers due to false-negative results, and increased healing times due to delayed compression of false-positive test results mean that in most scenarios manual Doppler was less costly and had slightly higher quality-adjusted life-years than automated devices. Results are highly uncertain, dependent on many assumptions and should be interpreted cautiously.

Limitations and conclusions

The limited evidence identified for each automated device, especially in people with leg ulcers, and its clinical heterogeneity precludes any firm conclusions on the diagnostic performance and cost-effectiveness of these devices in clinical practice.

Study registration

This study is registered as PROSPERO CRD42022327588.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Evidence Synthesis programme (NIHR award ref: NIHR135478) and is published in full in Health Technology Assessment; Vol. 28, No. 37. See the NIHR Funding and Awards website for further award information.

The clinical efficacy of collagen dressing on chronic wounds: A meta-analysis of 11 randomized controlled trials

Objective

This study aims to evaluate the clinical efficacy of collagen dressing for patients with chronic wounds.

Materials and methods

Relevant randomized controlled trials were searched from the databases such as PubMed, EMBASE, and the Cochrane library as of January 2022. For dichotomous outcomes and continuous outcomes, risk ratio and mean difference were calculated, respectively. Subgroup analysis was performed according to the type of chronic ulcer and follow-up. In addition, trial sequential analysis (TSA) was performed to further verify the results. Jadad score was used to assess the quality of trials. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was utilized to assess the level of evidence for outcomes.

Results

In 11 studies, a total of 961 patients of whom 485 were in the collagen group. Compared with standard of care (SOC) alone, the group that added an extra collagen dressing achieved a higher wound healing rate (Risk Ratio = 1.53; 95% CI, 1.33–1.77). The collagen group also showed a higher healing velocity than the SOC group (Mean Difference, 2.69; 95% CI, 0.87–4.51). In addition, the adverse events related to dressing between the two groups were similar (Risk Ratio = 0.67; 95% CI, 0.44–1.01).

Conclusion

Collagen dressing increases the wound healing rate and may be an effective and safe treatment for chronic wound management. However, more extensive research shall be conducted to substantiate these results.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=245728, identifier: CRD42021245728.

Healing Process, Pain, and Health-Related Quality of Life in Patients with Venous Leg Ulcers Treated with Fish Collagen Gel: A 12-Week Randomized Single-Center Study

The aim of the study was to assess the effectiveness of fish skin collagen and its impact on healing, pain intensity, and quality of life in patients with venous leg ulcers (VLUs). This study included 100 adults with VLUs. Eligible patients were randomized to either tropocollagen gel treatment (group A, n = 47) or placebo alone (group B, n = 45). We applied the gel to the periwound skin for 12 weeks. All groups received standard wound care, including class 2 compression therapy and wound hygiene procedures. We assessed the healing rate (cm2/week) and quality of life (QoL) using the Skindex-29 and CIVIQ scales. In group A, more ulcers healed, and the healing rate was faster. In both study groups, patients showed a significant improvement in quality of life after the intervention, but there was a greater improvement in the tropocollagen group. In group A, the greatest improvement was related to physical symptoms and the pain dimension. This study showed that the application of fish collagen gel to the periwound skin improves the healing process and QoL in patients with VLUs. The 12-week treatment with collagen reduced the severity of physical complaints, pain, and local skin symptoms, which determined the quality of life in patients with VLUs to the greatest extent.

Cost-effectiveness of superabsorbent wound dressing versus standard of care in patients with moderate-to-highly exuding leg ulcers

OBJECTIVE

To determine the cost-effectiveness/utility of a superabsorbent wound dressing (Zetuvit Plus Silicone) versus the current standard of care (SoC) dressings, from the NHS perspective in England, in patients with moderate-to-high exudating leg ulcers.

METHOD

A model-based economic evaluation was conducted to analyse the cost-effectiveness/utility of a new intervention. We used a microsimulation state-transition model with a time horizon of six months and a cycle length of one week. The model uses a combination of incidence base and risk prediction approach to inform transition probabilities. All clinical efficiency, health-related quality of life (HRQoL), cost and resource use inputs were informed by conducting a systematic review of UK specific literature.

RESULTS

Treatment with the superabsorbent dressing leads to a total expected cost per patient for a six month period of £2887, associated with 15.933 expected quality adjusted life weeks and 10.9% healing rate. When treated with SoC, the total expected cost per patient for a six month period is £3109, 15.852 expected quality adjusted life weeks and 8% healing rate. Therefore, the superabsorbent dressing leads to an increase in quality-adjusted life weeks, an increase in healing rate by 2.9% and a cost-saving of £222 per single average patient over six months. Results of several scenario analyses, one-way deterministic sensitivity analysis, and probabilistic sensitivity analysis confirmed the robustness of base-case results. The probabilistic analysis confirmed that, in any combination of variable values, the superabsorbent dressing leads to cost saving results.

CONCLUSION

According to the model prediction, the superabsorbent dressing leads to an increase in health benefits and a decrease in associated costs of treatment.

A Systematic Review of Model-Based Economic Evaluations of Treatments for Venous Leg Ulcers

OBJECTIVE

The aim of this review was to identify, and assess the quality of, published model-based economic evaluations relating to treatments for patients with venous leg ulcers to help inform future decision-analytic models in this clinical area.

METHODS

A systematic literature search was performed on six electronic databases, from database inception until 21 May 2018. Search results were screened against predefined criteria by two independent reviewers. Data was then extracted from the included studies using a standardised form, whilst the decision-analytic model-specific Philips Checklist was used to assess quality and to inform model critique.

RESULTS

A total of 23 models were identified, 12 studies used a Markov modelling approach, five used decision trees and six studies did not detail the model type. Studies were predominantly from the National Health Service (NHS)/payer perspective, with only two taking a societal perspective. Interventions were wide ranging, but dressing technologies (11/23) were most common. The intervention studied was found to be dominant in 22/23 studies. The reporting quality of papers was mostly low, with evidence behind model structures, time horizons and data selection consistently underreported across the included papers.

CONCLUSIONS

This review has identified a sizeable literature of model-based economic evaluations, evaluating treatments for venous leg ulcers. However, the methods used to conduct such studies were generally poorly reported. In particular, the reporting of evidence surrounding the model structure, justification of the time horizon used and the rationale for selecting data inputs should be focused on in any future models developed.