Free Tissue Transfer in Diabetic Foot Ulcers: A Systematic Review and Meta-Analysis

OBJECTIVE

Free tissue transfer is a powerful reconstructive method for patients with substantial diabetic foot ulcers. This study aimed to perform an updated systematic review and meta-analysis investigating the flap characteristics, concurrent revascularisation rates, complications, and outcomes associated with free tissue transfer in diabetic foot ulcers.

METHODS

Two reviewers performed a systematic review of various databases since their inception, with no language restriction. Only data for free tissue transfer in non-traumatic diabetic foot ulcer patients were extracted from included studies where a heterogeneous population was studied. Outcome data were pooled using random effects meta-analysis for binomial data.

RESULTS

Of 632 studies identified, 67 studies encompassing 1 846 patients and 1 871 free flaps were included. A median of 18 patients [IQR 9, 37] per study, with a median age of 58.5 years [56, 63], were followed up for a median of 15 months [7, 25]. Most studies had serious risk of bias (n = 47 studies, 70%); sixteen (24%) had moderate risk of bias; and four (6%) had low risk of bias. The proportion of patients who underwent revascularisation was 75% (95% CI 60 - 87%; n = 36 studies) with a median time of 8 days between procedures. The pooled complete flap survival, major amputation, and ambulation rates were 88% (85 - 92%, n = 49 studies), 10% (7 - 14%, n = 50 studies), and 87% (80 - 92%, n = 36 studies), respectively. Death at individual study follow up was 6% (3 - 10%, n = 26 studies). The overall certainty of evidence was very low.

CONCLUSION

Free tissue transfer may be a useful treatment modality for recalcitrant diabetic foot ulcers in selected patients. Future studies should investigate long term functional outcomes and aim to develop patient selection algorithms to select the most suitable candidates for this procedure.

Trends in the incidence, surgical management and outcomes of type B aortic dissections in Australia over the last decade

OBJECTIVES

This study aims to investigate the incidence and in-hospital outcomes of surgical repair for type B aortic dissection (TBAD) in Australia.

METHODS

Data were obtained from the Australasian Vascular Audit (AVA) and the Australian Institute of Health and Welfare (AIHW). The former is a total practice audit mandated for all members of the Australian and New Zealand Society for Vascular Surgery (ANZSVS) while the latter is an independent government agency which records all healthcare data in Australia. All cases of TBAD which underwent surgical intervention (endovascular or open repair) between 2010 and 2019 were identified using prospectively recorded data from the AVA (New Zealand data was excluded). The primary outcomes were temporal trends in procedures and hospital mortality; secondary outcomes were complications and risk factors for mortality. All admissions and procedures for, and hospital deaths from, TBAD in Australia were identified in AIHW datasets using the relevant diagnosis and procedure codes, with age-standardized rates calculated for the period 2000-01 to 2018-19.

RESULTS

A total of 567 cases of TBAD underwent vascular surgical intervention (AVA data, Australia). Of these, 96.3% were treated by endovascular repair. There was an increase in the annual procedure number from 45 in 2010 to 88 in 2019. In-hospital mortality was 4.8% for endovascular repair and 19% for open repair (p = 0.021). From 2000-01 to 201819, the age-standardized procedure rates for TBAD (Australia) doubled, the proportion of admitted patients undergoing a procedure rose from 28% to 43%, and in-hospital deaths fell by 25%.

CONCLUSION

There has been an increasing incidence of vascular surgical intervention for TBAD in Australia. The majority of patients received endovascular therapy while the mortality from surgically managed TBAD appears to be falling.

Controlling the controls: what is negative pressure wound therapy compared to in clinical trials?

AIM

Surgical site infections (SSIs) are common following colorectal operations. Clinical trials suggest that closed incision negative pressure wound therapy (ciNPWT) may reduce SSIs compared to a 'standard of care' group. However, wound management in the standard of care group may vary. The aim of this review was to assess the control arms in trials of ciNPWT for potential confounding variables that could influence the rates of SSI and therefore the trial outcomes.

METHODS

A mapping review of the PubMed database was undertaken in the English language for randomized controlled trials that assessed, in closed surgical wounds, the use of ciNPWT compared to standard of care with SSI as an outcome. Data regarding wound care to assess potential confounding factors that may influence SSI rates were compared between the ciNPWT and standard of care groups. Included were the method of wound closure, control dressing type, frequency of dressing changes and postoperative wound care (washing).

RESULTS

Twenty-seven trials were included in the mapping review. There was heterogeneity in ciNPWT duration. There was little control in the comparator standard of care groups with a variety of wound closure techniques and different control dressings used. Overall standard of care dressings were changed more frequently than the ciNPWT dressing and there was no control over wound care or washing. No standard for 'standard of care' was apparent.

CONCLUSION

In randomized trials assessing the intervention of ciNPWT compared to standard of care there was considerable heterogeneity in the comparator groups and no standard of care was apparent. Heterogeneity in dressing protocols for standard of care groups could introduce potential confounders impacting SSI rates. There is a need to standardize care in ciNPWT trials to assess potential meaningful differences in SSI prevention.

Excluder Stent Graft-Related Outcomes in Patients with Aortic Neck Anatomy Outside of Instructions For Use (IFU) within the Global Registry for Endovascular Aortic Treatment (GREAT): Mid-term Follow-Up Results

BACKGROUND

The utilisation rate of endovascular aortic aneurysm repair has increased continuously over the past 2 decades. Endovascular aortic aneurysm repair is still performed frequently in patients with an unfavourable proximal seal zone, despite the associated late complications.

PURPOSE

We aimed to evaluate the mid-term durability of the GORE® EXCLUDER® AAA Endoprosthesis, featuring the C3 delivery system, in patients with a proximal neck anatomy outside the instructions for use (IFU).

METHODS

A retrospective sub-analysis of the Global Registry for Endovascular Aortic Treatment including patients treated for abdominal aortic aneurysms with the GORE EXCLUDER AAA Endoprosthesis (W.L. Gore & Associates, Inc, Flagstaff, Arizona) was performed. A "challenging neck" was defined as those treated outside the IFU with an aortic neck length <15 mm and/or aortic neck angle >60°. Cox proportional analyses were used to test for time-to-event differences between those treated within and outside the IFU while accounting for covariates, specifically proximal neck length and neck angle. The main outcomes assessed were 5-year all-cause mortality, 5-year endoleak development (type I or III), and 5-year device-related reinterventions.

FINDINGS

Of the 3,324 patients included in the analysis, 411 (12.4%) had a challenging neck and 2,913 (87.6%) did not. The patients in the challenging neck group were significantly older (74.9 years vs. 73.2 years, p≤0.0001) and had a significantly larger aortic aneurysm diameter at the time of the intervention than those treated within the IFU (61.2 mm vs. 56.4 mm, P< 0.0001), shorter proximal neck length (18 mm vs. 30 mm, P< 0.0001) and larger infrarenal neck angle (60.8° vs. 25.8°, P< 0.0001). In the multivariate analysis, brachial access site and challenging neck were not independent risk factors; increased age was associated with a shorter time to mortality (hazard ratio 1.051, 95% confidence interval 1.039-1.062, P< 0.0001), as was the use of tobacco (hazard ratio 1.329, 95% confidence interval 1.124-1.571, P= 0.0009). The 5-year all-cause mortality (36.2% vs. 27.5%, P= 0.002) and aorta-related mortality (3.8% vs. 1.1%, P= 0.002) were significantly higher in the challenging neck group. The risk of death within 5 years also increased significantly at 1.1% per millimetre increase in the abdominal aortic aneurysm diameter (P= 0.0005). Furthermore, the rates of type Ia endoleak development (7% vs. 1.2%, P< 0.001) and requirement for reintervention (13.3% vs. 9.7%, P< 0.001) were higher in those treated outside the IFU (challenging neck group).

CONCLUSIONS

Treatment with the Excluder AAA Endograft outside the IFU was associated with higher 5-year mortality values, increased type Ia endoleak development rates, and a greater need for reintervention compared with treatment within the IFU. This reiterates that fenestrated and open treatments should be strongly considered in cases with aortic neck anatomies outside the IFU. Infrarenal endovascular intervention outside the IFU should only be used when there is no alternative, with meticulous procedural planning and intervention to promote satisfactory outcomes.

The Impact of Endograft Selection on Outcomes Following Treatment Outside of Instructions for Use (IFU) in Endovascular Abdominal Aortic Aneurysm Repair (EVAR)

Background Endovascular aneurysm repair (EVAR) has become the treatment modality of choice in patients with abdominal aortic aneurysms. This has resulted in endograft utilization within instructions for use (IFU) and in cases with proximal neck anatomy outside of IFU. Purpose To identify whether graft selection influences outcomes following EVAR outside of IFU. Methodology A retrospective analysis was conducted from previously published data for 636 patients, collated from the Endurant Stent Graft Natural Selection Global Post-Market Registry (ENGAGE) and the Global Registry for Endovascular Aortic Treatment (GREAT). Patients were recruited into the ENGAGE registry between 2009 and 2011 and into the GREAT registry between August 2010 and October 2016. In ENGAGE, they received the Medtronic Endurant stent graft (Medtronic Vascular Inc, Dublin, Ireland) for infrarenal AAA repair while patients analyzed in GREAT received the Gore Excluder stent-graft (W. L. Gore & Associates, Flagstaff, Arizona). Analyses were performed to evaluate all-cause mortality, aneurysm-related mortality, endoleak occurrence, and surgical reintervention rates between the two cohorts. Results Of the 636 patients, 225 were from ENGAGE (mean age 73 years) and 411 were from GREAT (mean age 75 years). 17.8% were treated outside of IFU in the ENGAGE registry, while 12.4% were treated outside IFU in the GREAT cohort. Five-year freedom from all-cause mortality was similar in both cohorts (65.6% vs. 63.8%). The rate of type IA endoleak development was lower in the Excluder cohort, although this may have been impacted by the fact that only endoleaks that underwent reintervention were recorded within GREAT analysis (Endurant 10.6% vs. Excluder 7.0%). The reintervention rate was 16% at five years following the Endurant aortic graft while it was 13.3% at five years with the Excluder. Conclusion Treatment outside of IFU, be it with a suprarenal or an infrarenal fixation device, is associated with worse outcomes. This analysis reinforces the importance of the consideration of either fenestrated or open repair in those aneurysms that fail to satisfy IFU while endovascular repair in such a setting should be reserved as a last resort strategy.

The Impact of Endograft Selection on Mid-Term Outcomes in Female Patients Following Endovascular Aortic Aneurysm Repair (EVAR) for Abdominal Aortic Aneurysm (AAA)

Background Abdominal aortic aneurysms (AAA) are far more common in male than female gender, although they appear to have a more aggressive pathophysiology in females. Given the lower incidence of AAA in females, it has been difficult to assess the impact of graft selection for endovascular aortic aneurysm repair (EVAR) in this cohort. Purpose To identify whether graft selection influences outcomes following AAA endoluminal repair in female patients. Methodology A retrospective analysis of published data for 711 female patients was conducted, collating data from three cohorts - Endurant Stent Graft Natural Selection Global post-market registry (ENGAGE), Global Registry for Endovascular Aortic Treatment (GREAT) and U.S. Zenith multicenter trial in combination with the Zenith female registry. Patients were recruited into the ENGAGE registry between 2009 and 2011, the GREAT registry between August 2010 and October 2016, and into the Zenith registry between 2000 and 2003. Patients from ENGAGE received the Medtronic Endurant stent graft for infrarenal AAA repair, patients analysed in GREAT received the Gore Excluder stent graft and the Zenith group received the Cook Zenith stent graft. Analyses were performed to evaluate all-cause mortality, aorta-related mortality, endoleak occurrence and surgical reintervention rates between the three cohorts. Results Of the 711 females, 133 were from ENGAGE (mean age 76 years), 538 were from GREAT (mean age 75 years) and 40 were from Zenith (mean age 74 years). The rates of co-morbidities between the three groups were broadly similar except for atherosclerotic disease which was more commonly observed in those treated with the GORE Excluder. The rate of endoleaks was lower when the Excluder stent was utilised as compared to the other two stents (Excluder 6.7% vs. Zenith 12.5% vs. Endurant 35.3%) even considering the limited follow-up of the Zenith group to two years as compared to five years for both ENGAGE and GREAT. All-cause mortality was similar in all three groups across the period examined while aorta-related mortality was uncommon. Reintervention rate was 15% at two years following the utilisation of the Zenith aortic graft while the rate of intervention at five years was broadly similar between ENGAGE and GREAT. Conclusion The newer generation, lower profile aortic endografts appear to have provided a safe and successful tool in the management of AAA in female patients, despite more complex aortic anatomy with shorter infrarenal neck length and larger aortic neck angulation.

Mycotic Abdominal Aortic Aneurysm in the Endovascular Era

A mycotic aneurysm is a localised dilatation of an artery due to destruction of the vessel wall by infection. Diagnosis is based on clinical, microbiological, and radiological findings. Typical management includes antibiotic therapy and open surgical debridement with or without revascularisation. This case of mycotic aortic aneurysm highlights the utilisation of endovascular grafts in the treatment of such pathology. This may improve both short and long term morbidity and mortality as compared to open intervention.