Clinical Effects of Tourniquet Use for Nontraumatic Major Lower Limb Amputation: A Two-Center Retrospective Cohort Study.

BACKGROUND: To investigate the effect of tourniquet use on outcomes after major lower limb amputation (MLLA) due to peripheral arterial disease or complications from diabetes mellitus. METHODS: In this 2-center retrospective observational study, vascular patients who underwent MLLA between January 1, 2016 and December 31, 2020 at 2 UK hospitals were identified using operating theater databases. Hospital databases were used to access medical records, operation notes, and laboratory reports. The use of a tourniquet in each MLLA was noted. The primary outcome was postoperative hemoglobin (Hb) drop (g/L). Secondary outcomes were units of allogeneic blood transfused perioperatively, 90-day revision rates, 90-day wound breakdown rates, surgical site infection (SSI) rates (at 30 days), and 90-day mortality. A follow-up index (a measure of follow-up completeness) was calculated for all 30-day and 90-day outcomes. RESULTS: Four hundred seventy two patients underwent MLLA, of which 124 had a tourniquet applied. The median postoperative Hb drop was significantly lower in the tourniquet group compared to the nontourniquet group (13 [interquartile range 5-22] g/L vs. 20 [interquartile range 11-28] g/L; P ≤ 0.001). Thirty three point one percent (41) of tourniquet patients received a blood transfusion perioperatively, compared to 35.6% (124) of nontourniquet patients (P = 0.82). Sixteen percent (76) of patients required surgical revision within 90 days, with no significant difference between the tourniquet and nontourniquet group (20.2% tourniquet vs. 14.7% no tourniquet; P = 0.15). SSI rates (12.0% tourniquet vs. 10.6% no tourniquet, P = 0.66) and 90-day mortality (6.5% tourniquet vs. 10.1% no tourniquet; P = 0.23) were similar. Multivariable regression demonstrated that tourniquet use was independently associated with a reduced hemoglobin drop (ß = -4.671, 95% confidence interval -7.51 to -1.83, P ≤ 0.001) but was not associated with wound breakdown, revision surgery, or SSI. Hypertension, SSI, and below-knee amputation using the skew flap technique were all significant predictors of revision surgery. All follow-up indices were ≥ 0.97. CONCLUSIONS: Tourniquet use in MLLA was associated with a significantly lower fall in postoperative Hb without evidence of harm in terms of SSI, wound breakdown/revision rates, or mortality.

Systematic review and narrative synthesis of surveillance practices after endovascular intervention for lower limb peripheral arterial disease.

OBJECTIVE: The optimal timing and modality of surveillance after endovascular intervention for peripheral arterial disease is controversial, and no randomized trial to assess the value of peripheral endovascular intervention has ever been performed. The aim of this systematic review was to examine the practice of surveillance after peripheral endovascular intervention in randomized trials. METHODS: We used the Medline, Embase, Cochrane Library, and WHO trial registry databases in this systematic review of the literature to capture surveillance strategies used in randomized trials comparing endovascular interventions. Surveillance protocols were assessed for completeness, modalities used, duration, and intensity. RESULTS: Ninety-six different surveillance protocols were reported in 103 trials comparing endovascular interventions. Protocol specification was incomplete in 32% of trials. The majority of trials used multiple surveillance modalities (mean of 3.46 modalities), most commonly clinical examination (96%), ankle-brachial index (80%), duplex ultrasound examination (75%), and digital subtraction angiography (51%). Trials involving infrapopliteal lesions used more angiographic surveillance than trials with femoropopliteal lesions (P = .006). The median number of surveillance visits in the first 12 months after intervention was three and the mean surveillance duration was 21 months. Trials treating infrapopliteal vessels had a higher surveillance intensity compared with those treating femoropopliteal lesions in the first 12 months after endovascular intervention (mean 5 vs 3 surveillance visits; P = .017). Trials with drug-eluting devices had longer surveillance duration compared with those without (mean 26 vs 19 months; P = .020). CONCLUSIONS: There is a high level of variation in the modality, duration, and intensity of surveillance protocols used in randomized trials comparing different types of peripheral endovascular arterial intervention. Further research is required to determine the value and impact of postprocedural surveillance on patient outcomes.

Editor's Choice - Systematic Review and Narrative Synthesis of Randomised Controlled Trials Supporting Implantable Devices for Vascular and Endovascular Procedures.

OBJECTIVE: To identify implantable devices currently used for vascular and endovascular procedures, to ascertain how many have randomised controlled trial (RCT) evidence available, and to assess the quality of that evidence. DATA SOURCES: MEDLINE, Embase, DARE, PROSPERO, clinical trial registries, and Cochrane databases. REVIEW METHODS: A list of current devices used in both vascular and endovascular procedures was generated by searching conference proceedings, manufacturer catalogues, and websites. MEDLINE, Embase, DARE, PROSPERO, clinical trial registries, and Cochrane databases were searched from inception up to June 2020. The primary outcome was the availability of RCTs to support the use of a vascular implantable device. RCTs were then quality assessed using the Cochrane risk of bias tool. RESULTS: A total of 116 current vascular implantable devices were identified. The systematic literature review identified 165 RCTs. Eighty-three of the RCTs (50.3%) applied to 33 of the 116 (28.4%) current implantable devices. When grouped by device type, eight of the 13 types (62%) had at least one RCT performed. There was a high risk of bias across the majority of the RCTs, with only nine (5.4%) deemed to be at low risk of bias. Only 22 (13.3%) RCTs had a clear safety outcome. CONCLUSION: Sixty-two per cent of implantable device types for use in vascular and endovascular interventions had at least one RCT available to show equivalence to previous devices or safety. RCTs were generally of low quality and are decreasing in frequency with time. With medical implantable device failure being increasingly recognised as causing significant harm to patients worldwide, there is a clear need for a more robust implantable device regulation and approval systems.

The PReliMinAry (Pain Relief in Major Amputation) Survey.

OBJECTIVES: Major Lower Limb Amputation (MLLA) is associated with significant peri- and post-operative pain and has been identified as a research priority by patient and healthcare groups. The PReliMinAry survey was designed to evaluate existing MLLA analgesia strategies; identifying areas of equipoise and informing future research. METHODS: A targeted multi-national, multi-disciplinary survey was conducted via SurveyMonkey® (October 5, 2020-November 3, 2020) and advertised via social media and society email lists. The 10-questions explored 'pain-team' services, pre-operative neuroleptic medication, pre-incision peripheral nerve blocks and catheters, surgically placed nerve catheters, post-operative adjunctive regimens, future research engagement and equipoise. RESULTS: Seventy-six responses were received from 60 hospitals worldwide. Twelve hospitals(20%) had a dedicated MLLA pain team, 7(12%) had none. Most pain teams (n = 52; 87%) assessed pain with a 0-10 numerical rating scale. Over half of respondents "never" preloaded patients with oral neuroleptic agents(n= 42/76; 55%). Forty-seven hospitals(78%) utilized patient controlled opioid analgesia. Most hospitals are able to provide pre-incision loco-regional peripheral nerve blocks, nerve catheters and surgical nerve catheters (95%, 77%, and 90% respectively), but use was variable. Ultrasound(US) guided peripheral nerve catheters were "infrequently" or "never" used in 57% of hospitals, whilst 23% "infrequently" or "never" utilize surgically placed nerve catheters. CONCLUSIONS: The survey revealed a preference towards 'single-shot' nerve blocks and surgical catheters. A difference between the use of US guided nerve catheters and those surgically placed likely reflects the difference of literature evaluating these techniques. Most respondents felt there was equipoise surrounding future trials evaluating nerve blocks/catheters, but less so for surgical catheters.

A systematic review of outcome reporting for interventions to treat people with diabetic foot ulceration.

BACKGROUND: Diabetic foot ulceration (DFU) is a challenging clinical problem that affects up to a quarter of patients with diabetes in their lifetime. An agreed set of outcomes for assessing treatments or interventions for DFU has not previously been considered. The aim of this study was to identify outcomes that are reported in clinical studies assessing a treatment or intervention for DFU, to inform the development of a core outcome set (COS). METHODS: Systematic literature searches were performed between January 2016 and March 2019. The search strategy was pre-registered with PROSPERO (CRD42019128250). Two authors independently screened abstracts for full text review. Outcomes were extracted from selected papers verbatim and categorized into domains according to established taxonomy. Consistency of outcome reporting was assessed. Overlapping outcomes were merged independently to condense the extracted list of outcomes for use in forthcoming consensus processes. RESULTS: Of 4645 abstracts identified, 114 studies met the inclusion criteria. There were 69 randomized studies, 40 prospective studies and 5 protocols. Some 948 outcomes were extracted verbatim. Outcome reporting was consistent for 474 (53%) outcomes. De-duplication left 714 unique verbatim outcomes across 33 domains. Merging of overlapping unique verbatim outcomes established 95 merged outcomes. CONCLUSION: This study describes contemporary outcomes reported in studies assessing interventions for DFU. Outcome reporting is considered to be poor as it was consistent in just over half of outcomes extracted. Merging of outcomes has identified 95 outcomes that can be taken forward in the development of a COS.

Groin Wound Infection after Vascular Exposure (GIVE) Risk Prediction Models: Development, Internal Validation, and Comparison with Existing Risk Prediction Models Identified in a Systematic Literature Review.

OBJECTIVE: This study aimed to develop and internally validate risk prediction models for predicting groin wound surgical site infections (SSIs) following arterial intervention and to evaluate the utility of existing risk prediction models for this outcome. METHODS: Data from the Groin wound Infection after Vascular Exposure (GIVE) multicentre cohort study were used. The GIVE study prospectively enrolled 1 039 consecutive patients undergoing an arterial procedure through 1 339 groin incisions. An overall SSI rate of 8.6% per groin incision, and a deep/organ space SSI rate of 3.8%, were reported. Eight independent predictors of all SSIs, and four independent predictors of deep/organ space SSIs were included in the development and internal validation of two risk prediction models. A systematic search of the literature was conducted to identify relevant risk prediction models for their evaluation. RESULTS: The "GIVE SSI risk prediction model" ("GIVE SSI model") and the "GIVE deep/organ space SSI risk prediction model" ("deep SSI model") had adequate discrimination (C statistic 0.735 and 0.720, respectively). Three other groin incision SSI risk prediction models were identified; both GIVE risk prediction models significantly outperformed these other risk models in this cohort (C statistic 0.618 - 0.629; p < .050 for inferior discrimination in all cases). CONCLUSION: Two models were created and internally validated that performed acceptably in predicting "all" and "deep" groin SSIs, outperforming current existing risk prediction models in this cohort. Future studies should aim to externally validate the GIVE models.

Systematic Review and Meta-Analysis of the Effect of Perineural Catheters in Major Lower Limb Amputations.

OBJECTIVE: Controlling pain after major lower limb amputation (MLLA) is of critical importance to patients and clinicians. The aim of this systematic review and meta-analysis was to assess the effect of perineural catheters (PNCs) on post-operative pain, post-operative morphine requirement, in-hospital mortality, long term phantom limb pain, and chronic stump pain. METHODS: A systematic review using PubMed, EMBASE via OVID and the Cochrane library from database inception (1946) to 20 October 2020 was performed according to PRISMA guidelines. Studies involving patients undergoing MLLA which reported on post-operative morphine requirement, pain scores, in-hospital mortality, phantom limb pain (PLP), and chronic stump pain were included. Studies comparing PNC use with epidural or wound site local anaesthetic infusions were excluded. Outcome data were extracted from individual studies and meta-analysis was performed using a random effects (Mantel-Haenszel) model for dichotomous data using an odds ratio (OR) summary statistic with 95% confidence intervals (CI), and with an inverse variance random effects model for continuous data using a standardised mean difference (SMD) summary statistic with 95% CIs. Sensitivity analyses were performed for post-operative pain scores and post-operative morphine requirement. Study quality was assessed using the Downs and Black score, and outcomes were assessed using the GRADE tool. RESULTS: Ten studies reporting on 731 patients were included, with 350 patients receiving a PNC and 381 receiving standard care. PNC use is associated with a reduction in post-operative pain (SMD -0.30, 95% CI -0.58 - -0.01, p = .040, I2 = 54%, GRADE quality of evidence: low) and post-operative morphine requirements (SMD -0.63, 95% CI -1.03 - -0.23, p = .002, I2 = 75%, GRADE quality of evidence: moderate), although the effect of PNC on reduced post-operative morphine requirements is lost on sensitivity analysis of randomised trials only (p = .40). No demonstrable effect was found on in-hospital mortality, PLP, or chronic stump pain (GRADE quality of evidence: low). CONCLUSION: PNC use in amputees is associated with a significant reduction in post-operative pain scores and post-operative morphine requirements, although this latter finding is lost on sensitivity analysis of randomised trials only.

Patient Reported Outcome Measures for Major Lower Limb Amputation Caused by Peripheral Artery Disease or Diabetes: A Systematic Review.

OBJECTIVE: Most major lower limb amputations are related to peripheral artery disease (PAD) or diabetes. Just 40% of patients who undergo major lower limb amputation will use a prosthesis yet measures of surgical success commonly focus on prosthesis use. Patient reported outcome measures (PROMs) are valuable to comprehensively evaluate health related quality of life (HRQL) after surgery. This systematic review aimed to identify and describe PROMs available to assess HRQL in patients after amputation for PAD or diabetes. METHODS: A search was conducted based on the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) for systematic reviews of PROMs. Ovid MEDLINE, Ovid EMBASE, PsycINFO, CINAHL, and Cochrane CENTRAL were also searched from inception until August 2019. Included were articles describing the development, measurement properties, or evaluation of HRQL via a PROM in adult patients after amputation for PAD or diabetes. Studies of amputation exclusively for trauma or malignancy were excluded. Data were collected on study characteristics, PROM characteristics (generic/disease specific), and properties of amputation specific PROMs. RESULTS: Of 3 317 abstracts screened, 111 full text articles were assessed for eligibility and 64 included. Fifty-six studies evaluated HRQL, with 23 (46%) of these using an amputation specific PROM to do so. Eleven different amputation specific PROMs were identified, 10 (91%) of which were developed only for prosthesis users. One measure was suitable for use in all patients after amputation. This "Amputee single item mobility measure" includes a single item evaluating mobility. Nine studies reported some psychometric testing of an amputation specific PROM. CONCLUSION: A well tested, multidimensional PROM applicable to wheelchair and prosthetic users after amputation is lacking and urgently needed for studies in this field. Future work to develop an appropriate measure is required.

Editor's Choice - Systematic Review and Meta-Analysis of Wound Adjuncts for the Prevention of Groin Wound Surgical Site Infection in Arterial Surgery.

OBJECTIVE: Groin incision surgical site infections (SSIs) following arterial surgery are common and are a source of considerable morbidity. This review evaluates interventions and adjuncts delivered immediately before, during, or after skin closure, to prevent SSIs in patients undergoing arterial interventions involving a groin incision. DATA SOURCES: MEDLINE, EMBASE, and CENTRAL databases were searched. REVIEW METHODS: This review was undertaken according to established international reporting guidelines and was registered prospectively with the International prospective register of systematic reviews (CRD42020185170). The MEDLINE, EMBASE, and CENTRAL databases were searched using pre-defined search terms without date restriction. Randomised controlled trials (RCTs) and observational studies recruiting patients with non-infected groin incisions for arterial exposure were included; SSI rates and other outcomes were captured. Interventions reported in two or more studies were subjected to meta-analysis. RESULTS: The search identified 1 532 articles. Seventeen RCTs and seven observational studies, reporting on 3 747 patients undergoing 4 130 groin incisions were included. A total of seven interventions and nine outcomes were reported upon. Prophylactic closed incision negative pressure wound therapy (ciNPWT) reduced groin SSIs compared with standard dressings (odds ratio [OR] 0.34, 95% CI 0.23 - 0.51; p < .001, GRADE strength of evidence: moderate). Local antibiotics did not reduce groin SSIs (OR 0.60 95% CI 0.30 - 1.21 p = .15, GRADE strength: low). Subcuticular sutures (vs. transdermal sutures or clips) reduced groin SSI rates (OR 0.33, 95% CI 0.17 - 0.65, p = .001, GRADE strength: low). Wound drains, platelet rich plasma, fibrin glue, and silver alginate dressings did not show any significant effect on SSI rates. CONCLUSION: There is evidence that ciNPWT and subcuticular sutures reduce groin SSI in patients undergoing arterial vascular interventions involving a groin incision. Local antibiotics did not reduce groin wound SSI, although the strength of this evidence is lower. No other interventions demonstrated a significant effect.

Prognostic Risk Modelling for Patients Undergoing Major Lower Limb Amputation: An Analysis of the UK National Vascular Registry.

OBJECTIVE: Major lower limb amputation is the highest risk lower limb procedure in vascular surgery. Despite this, few high quality studies have examined factors contributing to mortality. The aim was to identify independent risk factors for peri-operative morbidity and mortality and develop reliable models for estimating risk. METHODS: All patients undergoing lower limb amputation above the ankle entered into the UK National Vascular Registry (January 2014-December 2016) were included. Missing data were handled using multiple imputation. Models were developed to evaluate independent risk factors for mortality (the primary outcome) and morbidity using logistic regression, minimising the Bayesian information criterion to balance complexity and model fit. Ethical approval for the study was granted (Wales REC 3 ref:16/WA/0353). RESULTS: All 9549 above ankle joint amputations in the registry were included. Overall, 865 patients (9.1%) died before leaving hospital. Independent factors associated with mortality were emergency admission, bilateral operation, age, American Society of Anesthesiologists' grade, abnormal electrocardiogram, and increased white cell count or creatinine (p < .01 for all). Independent factors reducing mortality were transtibial operation, increased albumin or patient weight, and previous ipsilateral revascularisation procedures (p < .01 for all). A risk model incorporating these factors had good discrimination (C-statistic 0.79, 95% confidence interval 0.77-0.80) and excellent calibration. Morbidity rates were high, with 6.6%, 9.7%, and 4.3% of patients suffering cardiac, respiratory, and renal complications, respectively. The risk model was also predictive of morbidity outcomes (C-statistics 0.74, 0.69, and 0.74, respectively). CONCLUSION: Morbidity and mortality after lower limb amputation are high in the UK. Some potentially modifiable factors for quality improvement initiatives have been identified and accurate predictive models that could assist patient counselling and decision making have been developed.

The Effect of Frailty on Long Term Outcomes in Vascular Surgical Patients.

OBJECTIVE: Frailty is a multidimensional vulnerability due to age associated decline. The impact of frailty on long term outcomes was assessed in a cohort of vascular surgical patients. METHODS: Patients aged over 65 years with a length of stay greater than two days admitted to a tertiary vascular unit over a single calendar year were included. Demographics, mode of admission, and diagnosis were recorded alongside a variety of frailty specific characteristics. Using the previously developed Addenbrookes Vascular Frailty Score (AVFS - 6 point score: anaemia on admission, lack of independent mobility, polypharmacy, Waterlow score > 13, depression, and emergency admission) the effect of frailty on five year mortality and re-admission rates was assessed using multivariable regression techniques. The AVFS was further refined to assess longer term outcomes. RESULTS: In total, 410 patients (median age 77 years) were included and followed up until death or five years from the index admission. One hundred and thirty-four were treated for aortic aneurysm, 75 and 96 for acute and chronic limb ischaemia respectively, 52 for carotid disease, and 53 for other pathologies. The in hospital mortality rate was 3.6%. The one, three, and five year survival rates were 83%, 70% and 59%; and the one, three, and five year re-admission free survival rates were 47%, 29%, and 22% respectively. Independent predictors of five year mortality were age, lack of independent mobility, high Charlson score, polypharmacy, evidence of malnutrition, and emergency admission (p < .010 for all). Patients with AVFS 0 or 1 had restricted mean survival times which were one year longer than those with AVFS 2 or 3 (p < .001), who in turn had restricted mean survival times over one year longer than those with AVFS of 4 or more (p < .001). CONCLUSION: Frailty factors are strong predictors of long term outcomes in vascular surgery. Further prospective studies are warranted to investigate its utility in clinical decision making.

Development of Core Outcome Sets for People Undergoing Major Lower Limb Amputation for Complications of Peripheral Vascular Disease.

OBJECTIVE: Every year, thousands of patients with peripheral vascular disease undergo major lower limb amputation. Despite this, evidence for optimal management is weak. Core outcome sets capture consensus on the most important outcomes for a patient group to improve the consistency and quality of research. The aim was to define short and medium term core outcome sets for studies involving patients undergoing major lower limb amputation. METHODS: A systematic review of the literature and focus groups involving patients, carers, and healthcare professionals were used to derive a list of potential outcomes. Findings informed a three round online Delphi consensus process, where outcomes were rated for both short and medium term studies. The results of the Delphi process were discussed at a face to face consensus meeting, and recommendations were made for each core outcome set. RESULTS: A systematic review revealed 45 themes to carry forward to the consensus survey. These were supplemented by a further five from focus groups. The consensus survey received responses from 123 participants in round one, and 91 individuals completed all three rounds. In the final round, nine outcomes were rated as "core" for short term studies and a further nine for medium term studies. Wound infection and healing were rated as "core" for both short and medium term studies. Outcomes related to mortality, quality of life, communication, and additional healthcare needs were also rated as "core" for short term studies. In medium term studies, outcomes related to quality of life, mobility, and social integration/independence were rated as "core". The face to face stakeholder meeting ratified inclusion of all outcomes from the Delphi and suggested that deterioration of the other leg and psychological morbidity should also be reported for both short and medium term studies. CONCLUSION: Consensus was established on 11 core outcomes for short and medium term studies. It is recommended that all future studies involving patients undergoing major lower limb amputation should report these outcomes.

Antiplatelet and Anticoagulant Use in Randomised Trials of Patients Undergoing Endovascular Intervention for Peripheral Arterial Disease: Systematic Review and Narrative Synthesis.

OBJECTIVE: Randomised trials of new devices for peripheral arterial endovascular intervention are published regularly. The evidence for which antiplatelet and/or anticoagulant (antithrombotic) therapy to use after an intervention is lacking. The aim of this systematic review was to examine the antithrombotic regimens in randomised trials for peripheral arterial endovascular intervention to understand choices made and trends with time or type of device. METHODS: Data sources were the Medline, Embase, and Cochrane Library databases. Randomised trials including participants with peripheral arterial disease undergoing any endovascular arterial intervention were included. Trial methods were assessed to determine whether an antithrombotic protocol had been specified, its completeness, and the agent(s) prescribed. Antithrombotic therapy protocols were classed as peri-procedural (preceding and during intervention), immediate post-procedural (up to 30 days following intervention), and maintenance post-procedural (therapy continuing beyond 30 days). RESULTS: Ninety-four trials were included in narrative synthesis. Study quality was low. None of the trials justified their antithrombotic therapy protocol. Only 29% of trials had complete peri-procedural antithrombotic protocols, and 34% had complete post-procedural protocols. In total, 64 different peri-procedural protocols, and 51 separate post-procedural protocols were specified. Antiplatelet monotherapy and unfractionated heparin were the most common regimen choices in the peri-procedural setting, and dual antiplatelet therapy (55%) was most commonly utilised post procedure. Over time there has been an increasing tendency to use dual therapy (p < .001). This corresponds with the introduction of newer technologies and trials focussed on below knee intervention. CONCLUSION: Randomised trials comparing different types of peripheral endovascular arterial intervention have a high level of heterogeneity in their antithrombotic regimens. Antiplatelet therapy needs to be standardised in trials comparing endovascular technologies to reduce potential confounding. To do this, an independent randomised trial specifically examining antiplatelet therapy following peripheral arterial endovascular intervention is needed.

Atherectomy for peripheral arterial disease.

BACKGROUND: Symptomatic peripheral arterial disease (PAD) has several treatment options, including angioplasty, stenting, exercise therapy, and bypass surgery. Atherectomy is an alternative procedure, in which atheroma is cut or ground away within the artery. This is the first update of a Cochrane Review published in 2014. OBJECTIVES: To evaluate the effectiveness of atherectomy for peripheral arterial disease compared to other established treatments. SEARCH METHODS: The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Allied and Complementary Medicine (AMED) databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 12 August 2019. SELECTION CRITERIA: We included all randomised controlled trials that compared atherectomy with other established treatments. All participants had symptomatic PAD with either claudication or critical limb ischaemia and evidence of lower limb arterial disease. DATA COLLECTION AND ANALYSIS: Two review authors screened studies for inclusion, extracted data, assessed risk of bias and used GRADE criteria to assess the certainty of the evidence. We resolved any disagreements through discussion. Outcomes of interest were: primary patency (at six and 12 months), all-cause mortality, fatal and non-fatal cardiovascular events, initial technical failure rates, target vessel revascularisation rates (TVR; at six and 12 months); and complications. MAIN RESULTS: We included seven studies, with a total of 527 participants and 581 treated lesions. We found two comparisons: atherectomy versus balloon angioplasty (BA) and atherectomy versus BA with primary stenting. No studies compared atherectomy with bypass surgery. Overall, the evidence from this review was of very low certainty, due to a high risk of bias, imprecision and inconsistency. Six studies (372 participants, 427 treated lesions) compared atherectomy versus BA. We found no clear difference between atherectomy and BA for the primary outcomes: six-month primary patency rates (risk ratio (RR) 1.06, 95% confidence interval (CI) 0.94 to 1.20; 3 studies, 186 participants; very low-certainty evidence); 12-month primary patency rates (RR 1.20, 95% CI 0.78 to 1.84; 2 studies, 149 participants; very low-certainty evidence) or mortality rates (RR 0.50, 95% CI 0.10 to 2.66, 3 studies, 210 participants, very low-certainty evidence). One study reported cardiac failure and acute coronary syndrome as causes of death at 24 months but it was unclear which arm the participants belonged to, and one study reported no cardiovascular events. There was no clear difference when examining: initial technical failure rates (RR 0.48, 95% CI 0.22 to 1.08; 6 studies, 425 treated vessels; very low-certainty evidence), six-month TVR (RR 0.51, 95% CI 0.06 to 4.42; 2 studies, 136 treated vessels; very low-certainty evidence) or 12-month TVR (RR 0.59, 95% CI 0.25 to 1.42; 3 studies, 176 treated vessels; very low-certainty evidence). All six studies reported complication rates (RR 0.69, 95% CI 0.28 to 1.68; 6 studies, 387 participants; very low-certainty evidence) and embolisation events (RR 2.51, 95% CI 0.64 to 9.80; 6 studies, 387 participants; very low-certainty evidence). Atherectomy may be less likely to cause dissection (RR 0.28, 95% CI 0.14 to 0.54; 4 studies, 290 participants; very low-certainty evidence) and may be associated with a reduction in bailout stenting (RR 0.26, 95% CI 0.09 to 0.74; 4 studies, 315 treated vessels; very low-certainty evidence). Four studies reported amputation rates, with only one amputation event recorded in a BA participant. We used subgroup analysis to compare the effect of plain balloons/stents and drug-eluting balloons/stents, but did not detect any differences between the subgroups. One study (155 participants, 155 treated lesions) compared atherectomy versus BA and primary stenting, so comparison was extremely limited and subject to imprecision. This study did not report primary patency. The study reported one death (RR 0.38, 95% CI 0.04 to 3.23; 155 participants; very low-certainty evidence) and three complication events (RR 7.04, 95% CI 0.80 to 62.23; 155 participants; very low-certainty evidence) in a very small data set, making conclusions unreliable. We found no clear difference between the treatment arms in cardiovascular events (RR 0.38, 95% CI 0.04 to 3.23; 155 participants; very low-certainty evidence). This study found no initial technical failure events, and TVR rates at six and 24 months showed little difference between treatment arms (RR 2.27, 95% CI 0.95 to 5.46; 155 participants; very low-certainty evidence and RR 2.05, 95% CI 0.96 to 4.37; 155 participants; very low-certainty evidence, respectively). AUTHORS' CONCLUSIONS: This review update shows that the evidence is very uncertain about the effect of atherectomy on patency, mortality and cardiovascular event rates compared to plain balloon angioplasty, with or without stenting. We detected no clear differences in initial technical failure rates or TVR, but there may be reduced dissection and bailout stenting after atherectomy although this is uncertain. Included studies were small, heterogenous and at high risk of bias. Larger studies powered to detect clinically meaningful, patient-centred outcomes are required.

The Safety of Device Registries for Endovascular Abdominal Aortic Aneurysm Repair: Systematic Review and Meta-regression.

OBJECTIVES: New and re-designed stent grafts for endovascular aortic aneurysm repair (EVAR) are released regularly. Manufacturers use data from registries to assess stent graft performance, but little is known about the ability of such registries to detect rates of clinically relevant complications. The aim of this paper was to perform a systematic review and meta-analysis to determine pooled failure rates for EVAR stent grafts, to define an acceptable non-inferiority limit for these devices, and then to calculate the number of patients needed for a new device to achieve non-inferiority against published devices. DATA SOURCES AND REVIEW METHODS: MEDLINE and EMBASE were searched for studies reporting outcomes of specific EVAR grafts being used for intact infrarenal abdominal aortic aneurysms, from inception to November 2016. Meta-regression was performed to pool data and calculate the patient numbers needed to detect non-inferiority of a future graft performance. An expert consensus was performed to define adequate standards for device safety. RESULTS: One hundred and forty-seven moderate quality papers involving 27,058 patients were included. Multiple outcomes were pooled. Of these, the estimated rate (±standard error) of overall endoleak (excluding Type II) at 2 years was 5.7 ± 0.6%. The pooled re-intervention rate was 11.1 ± 0.7% at 2 years. There were differences in pooled endoleak rates between different stent graft types. Expert consensus defined non-inferiority as better performance than the worst performing 25% of stent grafts. The most popular outcome in the expert consensus was cumulative endoleak rate (excluding Type II). The number of patients who would need to be enrolled in a registry to demonstrate non-inferiority at this level was 525. Only two of 147 included studies achieved this. The second most popular choice in the expert consensus was re-intervention rate; 492 patients are required to demonstrate this. CONCLUSIONS: Five hundred and twenty-five patients need to be entered into a registry to demonstrate non-inferiority to previous stent grafts. Almost all previous publications have captured lower patient numbers. With performance varying between devices, and new devices being introduced regularly, there is an urgent need to capture higher quality long-term data on EVAR stent grafts.

Elective Repair of Abdominal Aortic Aneurysm and the Risk of Colonic Ischaemia: Systematic Review and Meta-Analysis.

INTRODUCTION: Colon ischaemia (CI) is a significant complication of open (OR) and endovascular (EVAR) repair of abdominal aortic aneurysm (AAA). With a rapid increase in EVAR uptake, contemporary data demonstrating the differing rates and outcomes of CI between EVAR and OR, particularly in the elective setting, are lacking. The aim was to characterise the risk and consequences of CI in elective AAA repair comparing EVAR with OR. METHODS: A systematic review and meta-analysis of the literature was performed using the Cochrane collaboration protocol and reported according to the PRISMA guidelines. PubMed, MedLine, and EMBASE were searched for studies reporting CI rates after elective AAA repair. Ruptured AAAs were excluded from analysis. RESULTS: Thirteen studies reporting specific outcomes of CI after elective AAA repair, containing 162,750 evaluable patients (78,151 EVAR and 84,599 OR) were included. All studies found a higher risk of CI with OR than with EVAR. Three studies performed confounder adjustment with CI rates of 0.5-1% versus 2.1-3.6% (EVAR vs. OR) and combined odds ratio of 2.7 (2.0-3.5) for the development of CI with OR versus EVAR. The majority of cases of CI occurred within 30 days and were associated with variable mortality (0-73%) and re-intervention rates (27-54%). GRADE assessment of evidence strength was very low for all outcomes. There was a high degree of heterogeneity between studies both methodologically and in terms of CI rates, re-intervention, mortality, and time to development of CI. CONCLUSIONS: EVAR is associated with a reduced incidence of CI compared with OR.

Graft type for femoro-popliteal bypass surgery.

BACKGROUND: Femoro-popliteal bypass is implemented to save limbs that might otherwise require amputation, in patients with ischaemic rest pain or tissue loss; and to improve walking distance in patients with severe life-limiting claudication. Contemporary practice involves grafts using autologous vein, polytetrafluoroethylene (PTFE) or Dacron as a bypass conduit. This is the second update of a Cochrane review first published in 1999 and last updated in 2010. OBJECTIVES: To assess the effects of bypass graft type in the treatment of stenosis or occlusion of the femoro-popliteal arterial segment, for above- and below-knee femoro-popliteal bypass grafts. SEARCH METHODS: For this update, the Cochrane Vascular Information Specialist searched the Vascular Specialised Register (13 March 2017) and CENTRAL (2017, Issue 2). Trial registries were also searched. SELECTION CRITERIA: We included randomised trials comparing at least two different types of femoro-popliteal grafts for arterial reconstruction in patients with femoro-popliteal ischaemia. Randomised controlled trials comparing bypass grafting to angioplasty or to other interventions were not included. DATA COLLECTION AND ANALYSIS: Both review authors (GKA and CPT) independently screened studies, extracted data, assessed trials for risk of bias and graded the quality of the evidence using GRADE criteria. MAIN RESULTS: We included nineteen randomised controlled trials, with a total of 3123 patients (2547 above-knee, 576 below-knee bypass surgery). In total, nine graft types were compared (autologous vein, polytetrafluoroethylene (PTFE) with and without vein cuff, human umbilical vein (HUV), polyurethane (PUR), Dacron and heparin bonded Dacron (HBD); FUSION BIOLINE and Dacron with external support). Studies differed in which graft types they compared and follow-up ranged from six months to 10 years.Above-knee bypassFor above-knee bypass, there was moderate-quality evidence that autologous vein grafts improve primary patency compared to prosthetic grafts by 60 months (Peto odds ratio (OR) 0.47, 95% confidence interval (CI) 0.28 to 0.80; 3 studies, 269 limbs; P = 0.005). We found low-quality evidence to suggest that this benefit translated to improved secondary patency by 60 months (Peto OR 0.41, 95% CI 0.22 to 0.74; 2 studies, 176 limbs; P = 0.003).We found no clear difference between Dacron and PTFE graft types for primary patency by 60 months (Peto OR 1.67, 95% CI 0.96 to 2.90; 2 studies, 247 limbs; low-quality evidence). We found low-quality evidence that Dacron grafts improved secondary patency over PTFE by 24 months (Peto OR 1.54, 95% CI 1.04 to 2.28; 2 studies, 528 limbs; P = 0.03), an effect which continued to 60 months in the single trial reporting this timepoint (Peto OR 2.43, 95% CI 1.31 to 4.53; 167 limbs; P = 0.005).Externally supported prosthetic grafts had inferior primary patency at 24 months when compared to unsupported prosthetic grafts (Peto OR 2.08, 95% CI 1.29 to 3.35; 2 studies, 270 limbs; P = 0.003). Secondary patency was similarly affected in the single trial reporting this outcome (Peto OR 2.25, 95% CI 1.24 to 4.07; 236 limbs; P = 0.008). No data were available for 60 months follow-up.HUV showed benefits in primary patency over PTFE at 24 months (Peto OR 4.80, 95% CI 1.76 to 13.06; 82 limbs; P = 0.002). This benefit was still seen at 60 months (Peto OR 3.75, 95% CI 1.46 to 9.62; 69 limbs; P = 0.006), but this was only compared in one trial. Results were similar for secondary patency at 24 months (Peto OR 4.01, 95% CI 1.44 to 11.17; 93 limbs) and at 60 months (Peto OR 3.87, 95% CI 1.65 to 9.05; 93 limbs).We found HBD to be superior to PTFE for primary patency at 60 months for above-knee bypass, but these results were based on a single trial (Peto OR 0.38, 95% CI 0.20 to 0.72; 146 limbs; very low-quality evidence). There was no difference in primary patency between HBD and HUV for above-knee bypass in the one small study which reported this outcome.We found only one small trial studying PUR and it showed very poor primary and secondary patency rates which were inferior to Dacron at all time points.Below-knee bypassFor bypass below the knee, we found no graft type to be superior to any other in terms of primary patency, though one trial showed improved secondary patency of HUV over PTFE at all time points to 24 months (Peto OR 3.40, 95% CI 1.45 to 7.97; 88 limbs; P = 0.005).One study compared PTFE alone to PTFE with vein cuff; very low-quality evidence indicates no effect to either primary or secondary patency at 24 months (Peto OR 1.08, 95% CI 0.58 to 2.01; 182 limbs; 2 studies; P = 0.80 and Peto OR 1.22, 95% CI 0.67 to 2.23; 181 limbs; 2 studies; P = 0.51 respectively)Limited data were available for limb survival, and those studies reporting on this outcome showed no clear difference between graft types for this outcome. Antiplatelet and anticoagulant protocols varied extensively between trials, and in some cases within trials.The overall quality of the evidence ranged from very low to moderate. Issues which affected the quality of the evidence included differences in the design of the trials, and differences in the types of grafts they compared. These differences meant we were often only able to combine and analyse small numbers of participants and this resulted in uncertainty over the true effects of the graft type used. AUTHORS' CONCLUSIONS: There was moderate-quality evidence of improved long-term (60 months) primary patency for autologous vein grafts when compared to prosthetic materials for above-knee bypasses. In the long term (two to five years) there was low-quality evidence that Dacron confers a small secondary patency benefit over PTFE for above-knee bypass. Only very low-quality data exist on below-knee bypasses, so we are uncertain which graft type is best. Further randomised data are needed to ascertain whether this information translates into an improvement in limb survival.

Morphometric Assessment as a Predictor of Outcome in Older Vascular Surgery Patients.

BACKGROUND: Frailty is a recognized predictor of poor outcome in patients undergoing surgical intervention. Frailty is intricately linked with body morphology, which can be evaluated using morphometric assessment via computerized tomographic (CT) imaging. We aimed to assess the predictive power of such objective assessments in a broad cohort of vascular surgical patients. METHODS: A consecutive series of patients aged over 65 years admitted to a vascular unit, who had undergone CT imaging of the abdomen, were analyzed. Demographic and patient-specific data were collated alongside admission relevant information. Outcomes included mortality, length of stay, health care-related costs, and discharge destination. Images were analyzed for 4 morphometric measurements: (1) psoas muscle area, (2) mean psoas density, (3) subcutaneous fat depth, and (4) intra-abdominal fat depth, all taken at the level of the fourth lumbar vertebra. RESULTS: Two hundred and ten patients were initially analyzed. Forty-four patients had significant retroperitoneal and abdominal abnormalities that limited appropriate CT analysis. Decreased subcutaneous fat depth was significantly associated with mortality, readmission within 12 months, and increased cost of health care (P < 0.01, adjusted for confounders). Psoas muscle area was significantly associated with readmission-free survival. CONCLUSIONS: Morphometric analysis predicts poorer outcome in a broad cohort of vascular surgery patients. Such assessment is likely to enhance patient counseling regarding individual risk as well as enhancing the ability to undertake risk-modified surgical audit.