Short-term risk prediction after major lower limb amputation: PERCEIVE study

BACKGROUND

The accuracy with which healthcare professionals (HCPs) and risk prediction tools predict outcomes after major lower limb amputation (MLLA) is uncertain. The aim of this study was to evaluate the accuracy of predicting short-term (30 days after MLLA) mortality, morbidity, and revisional surgery.

METHODS

The PERCEIVE (PrEdiction of Risk and Communication of outcomE following major lower limb amputation: a collaboratIVE) study was launched on 1 October 2020. It was an international multicentre study, including adults undergoing MLLA for complications of peripheral arterial disease and/or diabetes. Preoperative predictions of 30-day mortality, morbidity, and MLLA revision by surgeons and anaesthetists were recorded. Probabilities from relevant risk prediction tools were calculated. Evaluation of accuracy included measures of discrimination, calibration, and overall performance.

RESULTS

Some 537 patients were included. HCPs had acceptable discrimination in predicting mortality (931 predictions; C-statistic 0.758) and MLLA revision (565 predictions; C-statistic 0.756), but were poor at predicting morbidity (980 predictions; C-statistic 0.616). They overpredicted the risk of all outcomes. All except three risk prediction tools had worse discrimination than HCPs for predicting mortality (C-statistics 0.789, 0.774, and 0.773); two of these significantly overestimated the risk compared with HCPs. SORT version 2 (the only tool incorporating HCP predictions) demonstrated better calibration and overall performance (Brier score 0.082) than HCPs. Tools predicting morbidity and MLLA revision had poor discrimination (C-statistics 0.520 and 0.679).

CONCLUSION

Clinicians predicted mortality and MLLA revision well, but predicted morbidity poorly. They overestimated the risk of mortality, morbidity, and MLLA revision. Most short-term risk prediction tools had poorer discrimination or calibration than HCPs. The best method of predicting mortality was a statistical tool that incorporated HCP estimation.

O075 Antithrombotic therapy for aortic and peripheral artery aneurysms: a systematic review and meta-analysis

Introduction

The role of antithrombotic agents in aneurysm progression and outcomes following surgical or endovascular intervention is unclear.

Methods

A systematic review and meta-analysis was performed. Medline, Embase, and CENTRAL databases were searched. Randomised-controlled trials and observational studies investigating the effect of antithrombotic therapy on clinical outcomes for patients with aortic or extracranial peripheral arterial aneurysms were included. Aneurysm growth rate, major adverse cardiovascular or limb events, mortality, endoleaks, re-intervention rates, and other outcomes were captured.

Results

Fifty-seven studies involving 121,451 patients were included (26 antiplatelets, 12 anticoagulants, 16 any antithrombotic agent(s), 2 intra-operative heparin). Aspirin reduced growth rates of aortic aneurysms under surveillance (mean difference -0.9mm/y, 95%CI -1.74 to -0.07, p=0.03; GRADE certainty: moderate). For aortic aneurysms undergoing intervention, anti-thrombotics increased 30-day mortality (odds ratio [OR] 2.30, 95%CI 1.51 to 3.51, p<0.001; GRADE certainty: moderate). Antiplatelets reduced long-term all-cause mortality (hazard ratio [HR] 0.84, 95%CI 0.76 to 0.92, p<0.001; GRADE certainty: moderate), whilst anticoagulants increased this risk (HR 1.64, 95%CI 1.14 to 2.37, p=0.008; GRADE certainty: very low). Anticoagulants increased incidence of endoleaks under 3 years, and re-intervention rates (p<0.05 for all). Antithrombotic agents did not significantly affect rupture rates in aortic aneurysms. Meta-analysis was not possible for ruptured aneurysms and popliteal aneurysms.

Conclusion

There is moderate quality evidence that aspirin reduces aneurysm growth rates. Antiplatelet agents reduced all-cause mortality in aneurysms after intervention; whilst anticoagulants increased this risk, along with endoleaks and re-interventions. Well-designed trials are required to determine therapeutic benefits of antithrombotic agents for patients with aneurysms.

Take-home message

Antiplatelets may have a role in reducing aneurysm growth rates and all-cause mortality; whilst anticoagulants are associated with increased mortality, endoleaks, and re-interventions. Well-designed trials are required to determine therapeutic benefits of antithrombotic agents for patients with aneurysms.

The Significance of Inflow Artery and Tourniquet Derived Cephalic Vein Diameters on Predicting Successful Use and Patency of Arteriovenous Fistulas for Haemodialysis

OBJECTIVE

To investigate the significance of inflow artery and cephalic vein diameters on predicting patency of radiocephalic and brachiocephalic arteriovenous fistulas (AVFs).

DESIGN

Single centre study with retrospective analysis of prospectively collected data between November 2010 and July 2015.

METHODS

A detailed history and physical examination was undertaken, including age, gender, history and duration of haemodialysis, cause of chronic kidney disease, and the presence of comorbidities/risk factors. Pre-operative arterial and venous upper extremity mapping was performed and inner vessel diameter was recorded, using a tourniquet for the veins. Outcome measures included AVF use (functionality), primary, primary assisted, secondary, and functional secondary patency.

RESULTS

One hundred and thirty five AVFs (57 and 78 radiocephalic and brachiocephalic AVFs, respectively) were constructed and followed up for 5 years. A cephalic vein diameter <4.3 mm (lower three quartiles) was the single independent predictor of inferior secondary and also functional secondary patency of radiocephalic AVFs (p = .02, HR 11.2, 95% CI 1.44-90.9). A brachial artery diameter ≤4.1 mm (lowest quartile) was an independent predictor of AVF functionality (57% vs. 83% for larger arteries, p = .017), and inferior primary, primary assisted, secondary, and functional secondary patency of brachiocephalic AVFs (primary assisted patency 21.9% vs. 55.9% at 3 years, p = .001/log-rank test, HR 3.1, p = .002/Cox regression). The presence of lower extremity PAD or use of dual antithrombotics was also independently associated with an inferior secondary patency. The number of risk factors (brachial artery diameter ≤4.1 mm, PAD, and use of dual antithrombotics) demonstrated risk stratification capabilities for functional secondary patency.

CONCLUSIONS

Among patients undergoing radiocephalic AVFs, a tourniquet derived cephalic vein diameter <4.3 mm was the single independent predictor of inferior secondary and functional secondary patency. Among patients undergoing brachiocephalic AVFs, all patency rates were inferior in the presence of a brachial artery diameter ≤4.1 mm and secondary patency was inferior in the presence of multiple risk factors.

Combined modalities in the prevention of venous thromboembolism: A review of the literature

Objective

Despite recent advances in the field of venous thromboembolism (VTE) prophylaxis and adherence to guideline recommendations, VTE remains a serious problem, especially in high-risk groups. The aim of the present review was to summarize the evidence supporting the use of combined modalities, both physical and pharmacological, in VTE prevention.

Methods

Using Medline, original studies on the value of combined modalities in VTE prevention were identified. Keywords used for physical methods included elastic stockings and intermittent pneumatic compression, and for pharmacological methods included unfractionated and low molecular weight heparin. Relevant articles from their bibliography were also retrieved.

Results

Combined pharmacological and physical modalities were more effective than each modality alone in a variety of specialties, including orthopaedic, general and cardiac surgery, as shown by 14 of the 18 randomized or case-control studies retrieved. Mean reduction in VTE incidence was 69% (range 16–100%).

Conclusion

Combined modalities are more effective than single modalities in VTE prophylaxis. These results endorse their use, especially in high-risk patients, and support this otherwise typical recommendation of the consensus documents on VTE prophylaxis.

Editor's Choice - Management of Secondary Aorto-enteric and Other Abdominal Arterio-enteric Fistulas: A Review and Pooled Data Analysis

OBJECTIVES

To compare management strategies for secondary abdominal arterio-enteric fistulas (AEFs).

METHODS

This study is a review and pooled data analysis. Medline and Scopus databases were searched for studies published between 1999 and 2015. Particular emphasis was given to short- and long-term outcomes in relation to AEF repair type.

RESULTS

Two hundred and sixteen publications were retrieved, reporting on 823 patients. In-hospital mortality was 30.7%. Open surgery had higher in-hospital mortality (246/725, 33.9%), than endovascular methods (7/98, 7.1%, p < .001, OR 6.7, 95% CI 3-14.7, including staged endovascular to open surgery, 0/13, 0%). In-hospital mortality after graft removal/extra-anatomical bypass grafting was 31.2% (66/226), graft removal/in situ repair 34% (137/403), primary closure of the arterial defect 62.5% (10/16), and for miscellaneous open procedures 41.3% (33/80), p = .019. Among the subgroups of in situ repair, homografts were associated with a higher mortality than impregnated prosthetic grafts (p = .047). There was no difference in recurrent AEF-free rates between open and endovascular procedures. Extra-anatomical bypass/graft removal and in situ repair had a lower AEF recurrence rate than primary closure and homografts. Late sepsis occurred more often after endovascular surgery (2-year rates 42% vs. 19% for open, p = .001). The early survival benefit of endovascular surgery was blunted during follow-up, although it remained significant (p < .001). Within the in situ repair group, impregnated prosthetic grafts were associated with the worst overall and AEF related mortality free rates and vein grafts with the best. No recurrence, sepsis, or mortality was reported following staged endograft placement to open repair after a mean follow-up of 16.8 months (p = .18, p = .22, and p = .006, respectively, compared with patients in other groups).

CONCLUSIONS

Endovascular surgery, where appropriate, is associated with better early survival than open surgery for secondary AEFs. Most of this benefit is lost during long-term follow-up, implying that a staged approach with early conversion to in situ vein grafting may achieve the best results in selected patients.

Aorto-iliac aneurysm infected by Brucella: distinctive presentation patterns of a rare entity

There is currently a lack of information on presentation patterns and the appropriate investigation and treatment of aortic brucellosis. Herein a case affecting the iliac component of an aorto-iliac aneurysm, managed successfully with in situ graft repair, is reported. A review of the literature identified 25 cases, with the infrarenal abdominal aorta (65%) followed by the ascending thoracic aorta (23%) being mostly affected; only our case involved the iliacs. Aortic brucellosis affected mostly older men, caused pain more often than fever (in 73% and 57%, respectively), and involved frequently the spine or the aortic valve (n = 14, 56%). Preoperative diagnosis was made more often in the presence of fever (67% versus 18% in afebrile patients, P = 0.021). In situ aneurysm repair in the form of open (54%) or endovascular (8%) grafting was mostly performed. Mortality was 12% and graft infection was 13% at two years. In conclusion, aortic brucellosis has unique presentation patterns, usually affecting an abnormal or aneurysmal aorta and/or due to a contiguous spinal or aortic valve infection. Acute symptomatology with pain and/or fever occurs very often and should raise suspicion for aortic infection. Despite the seriousness of aortic involvement, mortality and reinfection rates are within acceptable levels.

Prevention and treatment of venous thromboembolism--International Consensus Statement

The aim of this document is to provide a clear and concise account of the evidence regarding efficacy or harm for various methods available to prevent and manage venous thromboembolism (VTE).

Endovascular management of aortoenteric fistulas with aortic cuff extenders: report of two cases

Despite immediate open surgery, aortoenteric fistula (AEF) remains a highly lethal condition. Endovascular management is widely employed, although there is no agreement on its role as a definite treatment or, because of a high incidence of recurrent bleeding and sepsis, as a bridge to open repair. Two cases of secondary AEFs after distant elective abdominal aortic aneurysm repair are presented. The first patient was a 76-year-old man and the second one a 70-year-old man. Both patients presented with hematemesis, had no signs of sepsis and were successfully managed with endovascular surgery, using aortic cuff extenders. Postoperative course was uneventful for both patients who were discharged on long-term antibiotics. However, during follow-up the first patient was readmitted four times; twice due to infection (at 2 and 6 months, respectively) and twice due to recurrent bleeding (at 5 and 9 months, respectively). The last episode of bleeding was managed with axillobifemoral bypass grafting, removal of the prostheses and closure of the aortic stump and the duodenal defect, but the patient died on the 5th postoperative day from multiple organ failure. The second patient remained asymptomatic until the 16th postoperative month when he developed lumbar spine osteomyelitis as a direct extension of graft infection and was deemed inoperable due to multiple comorbidities. Endovascular management of AEF can achieve satisfactory short-term results. Due to the high rate of recurrent bleeding and sepsis it should be used as a temporary measure and a bridge to open repair, whenever this is feasible.

Can combined (mechanical and pharmacological) modalities prevent fatal VTE?

AIM

The aim of this paper was to perform a systemic review and meta-analysis of the efficacy of combined modalities (intermittent pneumatic leg compression and pharmacological prophylaxis, treatment group) against single modalities alone (control group) in preventing pulmonary embolism (PE), including fatal PE and deep-vein thrombosis (DVT) in high-risk patients.

METHODS

Databases searched included the Cochrane Central Register of Controlled Trials, the Specialized Register of the Peripheral Vascular Diseases Group, MEDLINE and EMBASE.

RESULTS

Seventeen studies, six of them randomized controlled trials (RCTs), which enrolled a total of 9998 patients in a variety of specialties were identified. Sixteen of the included studies evaluated the role of combined modalities on the incidence of symptomatic PE. These showed a reduction in symptomatic PE from 2.83% (122/4313) in the control group to 0.86% (33/3838) in the treatment group. Odds ratio was 0.34, 95% Confidence interval (CI) 0.23 to 0.50. Fatal PE was reduced from 0.56% (11/1972) in the control group to 0.07% (1/1377) in the treatment group (results were available in 10 studies). Odds ratio was 0.37 (95% CI; 0.09 to 1.48). Fourteen studies investigated the role of combined modalities on the incidence of DVT. These showed a reduction in DVT from 6.18% (200/3238) in the control group to 2.05% (63/3074) in the treatment group. Odds ratio was 0.31, 95% CI 0.23 to 0.43.

CONCLUSION

Combined prophylactic modalities decrease significantly the incidence of PE and DVT, compared to single modalities, but the reduction seen in fatal PE did not reach statistical significance. Further research on the role of combined modalities in reducing DVT and PE is necessary.

Long-term complication and patency rates of Vectra and IMPRA Carboflo Vascular Access Grafts with aggressive monitoring, surveillance and endovascular management

The purpose of this study is to compare infection, pseudoaneurysm formation and patency rates during long-term follow-up of polyurethane and polytetrafluoroethylene (PTFE) vascular access grafts maintained with contemporary endovascular methods. During a 34-month period, 239 polyurethane and 125 carbon-impregnated PTFE vascular access grafts were placed in 324 consecutive patients. Thirty-six patients (9.9%) developed a pseudoaneurysm (anastomotic, n = 6 or at the needle-stick site, n = 30). An additional 19 patients (5.2%) required graft excision for infection. Three-year graft infection and pseudoaneurysm formation (at needle-stick site) rates were similar in polyurethane and PTFE grafts (11% versus 8%, P = 0.61, and 17% versus 23%, P = 0.72, respectively). Three-year secondary patency was better in polyurethane than PTFE grafts (69% versus 57%, respectively, P = 0.012). Straight upper arm polyurethane grafts had the best secondary patency ( P = 0.001). Contemporary long-term secondary patency of vascular access grafts is satisfactory. Further follow-up is necessary to compare late infection and pseudoaneurysm formation rates.

Basilic vein transposition: what is the optimal technique?

OBJECTIVES

To compare the outcome of the one-stage basilic vein transposition (BVT) fistula with a modified, two-stage technique.

DESIGN

Retrospective case-controlled study, performed in an academic centre.

MATERIAL

A total of 173 candidates for BVT fistula (87 males, mean age 61 years).

METHODS

In one-stage BVT, the basilic vein is mobilised through a single incision, placed inside an anterolateral arm tunnel and anastomosed with the brachial artery. In two-stage procedures, the fistula-arterial anastomosis is created first, followed by the second stage, after fistula maturation several weeks later, when the basilic vein is mobilised through two skip incisions, transected near the anastomosis, placed inside an anterolateral arm tunnel and reanastomosed. Morbidity and fistula maturation rate were the main outcome measures.

RESULTS

In one-stage BVT (n=76), the incidence of venous hypertension, wound haematomas and all complications (17%, 13% and 43%, respectively) was significantly higher than in two-stage procedures (n=98) (4%, p=0.004, 3%, p=0.012 and 11%, p<0.001, respectively). Time (68 days) to fistula use was significantly decreased in one-stage BVT than in two-stage procedures (132 days, p<0.001) but failure to mature rate was equivalent (15% vs. 18%, p=0.49).

CONCLUSIONS

Our results indicate that the two-stage BVT fistula through two skip-arm incisions is superior to the established one-stage procedure in terms of less morbidity but at the cost of a second operation and longer time to access use. Further research comparing these two techniques is necessary. Until this issue is resolved, an individualised approach is suggested.

Combined intermittent pneumatic leg compression and pharmacological prophylaxis for prevention of venous thrombo-embolism in high-risk patients

BACKGROUND

It has been suggested that combined modalities (methods of treatment) are more effective than single modalities in preventing venous thrombo-embolism (defined as deep vein thrombosis and pulmonary embolism, or both) in high-risk patients.

OBJECTIVES

To assess the efficacy of intermittent pneumatic leg compression combined with pharmacological prophylaxis versus single modalities in preventing venous thrombo-embolism in high-risk patients.

SEARCH STRATEGY

The Cochrane Peripheral Vascular Diseases (PVD) Group searched the reference lists of their Specialised Register (last searched 17 July 2007) and the Cochrane Central Register of Controlled Trials (CENTRAL) (last searched The Cochrane Library 2008, issue 3) for relevant articles to identify additional trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or controlled clinical trials (CCTs) of combined intermittent pneumatic leg compression and pharmacological interventions used to prevent venous thrombo-embolism in high-risk patients.

DATA COLLECTION AND ANALYSIS

Data extraction was undertaken independently by two review authors using data extraction sheets.