Open Retroperitoneal Repair for Complex Abdominal Aortic Aneurysms.

BACKGROUND: Open surgical repair (OSR) of complex abdominal aortic aneurysms (CAAAs) can be challenging. We frequently utilize the retroperitoneal (RP) approach for such cases. We audited our outcomes with the aim of establishing the utility and safety of this approach. METHODS: Retrospective analysis was performed of all patients undergoing OSR of an unruptured CAAA via a RP approach in our center over a 7-year period. Data on repairs via a transperitoneal (TP) approach were collected to provide context. Demographic, operative, radiological, and biochemical data were collected. The primary outcome measure was 30-day/inpatient mortality. Secondary outcomes included the need for reoperation, incidence of postoperative chest infection, acute kidney injury (AKI) and length of stay (LOS). All patients received aortic clamping above at least one main renal artery. RESULTS: One hundred and three patients underwent OSR of an unruptured CAAA; 55 via a RP approach, 48 TP. The RP group demonstrated a more advanced pattern of disease with a larger median maximum diameter (65 vs. 61 mm, p= 0.013) and a more proximal extent. Consequently, the rate of supravisceral clamping was higher in RP repair (66 vs. 15%, p < 0.001). Despite this there were no differences in the observed early mortality (9.1 vs. 10%, NS); incidence of reoperation (10.9 vs. 12.5%, NS), chest infection (32.7 vs. 25%, NS), and AKI (52.7 vs. 45.8%, NS); or median LOS (10 vs. 12 days, NS) following RP and TP repair. CONCLUSION: OSR of CAAAs carries significant 30-day mortality. In patients unsuitable for fenestrated endovascular aortic repair or those desiring a durable long-term solution, OSR can be performed through the RP or TP approach. This study has demonstrated that in our unit RP repair facilitates treatment of more advanced AAA utilizing complex proximal clamp zones with similar perioperative morbidity and mortality compared with TP cases utilizing more distal clamping.

Characterising the incidence and mode of visceral stent failure after fenestrated endovascular aneurysm repair (FEVAR).

BACKGROUND: In FEVAR, visceral stents provide continuity and maintain perfusion between the main body of the stent and the respective visceral artery. The aim of this study was to characterise the incidence and mode of visceral stent failure (type Ic endoleak, type IIIa endoleak, stenosis/kink, fracture, crush and occlusion) after FEVAR in a large cohort of patients at a high-volume centre. METHODS: A retrospective review of visceral stents placed during FEVAR over 15 years (February 2003-December 2018) was performed. Kaplan-Meier analyses of freedom from visceral stent-related complications were performed. The outcomes between graft configurations of varying complexity were compared, as were the outcomes of different stent types and different visceral vessels. RESULTS: Visceral stent complications occurred in 47/236 patients (19.9%) and 54/653 stents (8.3%). Median follow up was 3.7 years (IQR 1.7-5.3 years). There was no difference in visceral stent complication rate between renal, SMA and coeliac arteries. Visceral stent complications were more frequent in more complex grafts compared to less complex grafts. Visceral stent complications were more frequent in uncovered stents compared to covered stents. Visceral stent-related endoleaks (type Ic and type IIIa) occurred exclusively around renal artery stents. The most common modes of failure with SMA stents were kinking and fracture, whereas with coeliac artery stents it was external crush. CONCLUSION: Visceral stent complications after FEVAR are common and merit continued and close long-term surveillance. The mode of visceral stent failure varies across the vessels in which the stents are located.

Bypass surgery for chronic lower limb ischaemia.

BACKGROUND: Bypass surgery is one of the mainstay treatments for patients with critical lower limb ischaemia (CLI). This is the second update of the review first published in 2000. OBJECTIVES: To assess the effects of bypass surgery in patients with chronic lower limb ischaemia. SEARCH METHODS: For this update, the Cochrane Vascular Group searched its trials register (last searched October 2016) and the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library (last searched Issue 9, 2016). SELECTION CRITERIA: We selected randomised controlled trials of bypass surgery versus control or any other treatment. The primary outcome parameters were defined as early postoperative non-thrombotic complications, procedural mortality, clinical improvement, amputation, primary patency, and mortality within follow-up. DATA COLLECTION AND ANALYSIS: For the update, two review authors extracted data and assessed trial quality. We analysed data using odds ratio (OR) and 95% confidence intervals (CIs). We applied fixed-effect or random-effects models. MAIN RESULTS: We selected 11 trials reporting a total of 1486 participants. Six trials compared bypass surgery with percutaneous transluminal angioplasty (PTA), and one each with remote endarterectomy, thromboendarterectomy, thrombolysis, exercise, and spinal cord stimulation. The quality of the evidence for the most important outcomes of bypass surgery versus PTA was high except for clinical improvement and primary patency. We judged the quality of evidence for clinical improvement to be low, due to heterogeneity between the studies and the fact that this was a subjective outcome assessment and, therefore, at risk of detection bias. We judged the quality of evidence for primary patency to be moderate due heterogeneity between the studies. For the remaining comparisons, the evidence was limited. For several outcomes, the CIs were wide.Comparing bypass surgery with PTA revealed a possible increase in early postinterventional non-thrombotic complications (OR 1.29, 95% CI 0.96 to 1.73; six studies; 1015 participants) with bypass surgery, but bypass surgery was associated with higher technical success rates (OR 2.26, 95% CI 1.49 to 3.44; five studies; 913 participants). Analyses by different clinical severity of disease (intermittent claudication (IC) or CLI) revealed that peri-interventional complications occurred more frequently in participants with CLI undergoing bypass surgery than PTA (OR 1.57, 95% CI 1.09 to 2.24). No differences in periprocedural mortality were identified (OR 1.67, 95% CI 0.66 to 4.19; five studies; 913 participants). The primary patency rate at one year was higher after bypass surgery than after PTA (OR 1.94, 95% CI 1.20 to 3.14; four studies; 300 participants), but this difference was not shown at four years (OR 1.15, 95% CI 0.74 to 1.78; two studies; 363 participants). No differences in clinical improvement (OR 0.65, 95% CI 0.03 to 14.52; two studies; 154 participants), amputation rates (OR 1.24, 95% CI 0.82 to 1.87; five studies; 752 participants), reintervention rates (OR 0.76, 95% CI 0.42 to 1.37; three studies; 256 participants), or mortality within the follow-up period (OR 0.94, 95% CI 0.71 to 1.25; five studies; 961 participants) between surgical and endovascular treatment were identified. No differences in subjective outcome parameters, indicated by quality of life and physical and psychosocial well-being, were reported. The hospital stay for the index procedure was reported to be longer in participants undergoing bypass surgery than in those treated with PTA.In the single study (116 participants) comparing bypass surgery with remote endarterectomy of the superficial femoral artery, the frequency of early postinterventional non-thrombotic complications was similar in the treatment groups (OR 1.11, 95% CI 0.53 to 2.34). No mortality within 30 days of the index treatment or during stay in hospital in either group was recorded. No differences were identified in patency (OR 1.66, 95% CI 0.79 to 3.46), amputation (OR 1.70, 95% CI 0.27 to 10.58), and mortality rates within the follow-up period (OR 1.66, 95% CI 0.61 to 4.48). Information regarding clinical improvement was unavailable.No differences in major complications (OR 0.66, 95% CI 0.34 to 1.31) or mortality (OR 2.09, 95% CI 0.67 to 6.44) within 30 days of treatment between surgery and thrombolysis (one study, 237 participants) for chronic lower limb ischaemia were identified. The amputation rate was lower after bypass surgery (OR 0.10, 95% CI 0.01 to 0.80). No differences in late mortality were found (OR 1.56, 95% CI 0.71 to 3.44). No data regarding patency rates and clinical improvement were reported.Technical success resulting in blood flow restoration was higher after bypass surgery than thromboendarterectomy for aorto-iliac occlusive disease (one study, 43 participants) (OR 0.01, 95% CI 0 to 0.17). The periprocedural mortality (OR 0.33, 95% CI 0.01 to 8.65), follow-up mortality (OR 3.29, 95% CI 0.13 to 85.44), and amputation rates (OR 0.47, 95% CI 0.08 to 2.91) did not differ between treatments. Clinical improvement and patency rates were not reported.Comparing surgery and exercise (one study, 75 participants) did not identify differences in early postinterventional complications (OR 7.45, 95% CI 0.40 to 137.76) and mortality (OR 1.55, 95% CI 0.06 to 39.31). The remaining primary outcomes were not reported. There was no difference in maximal walking time between exercise and surgery (1.66 min, 95% CI -1.23 to 4.55).Regarding comparisons of bypass surgery with spinal cord stimulation for CLI, there was no difference in amputation rates after 12 months of follow-up (OR 4.00, 95% CI 0.25 to 63.95; one study, 12 participants). The remaining primary outcome parameters were not reported. AUTHORS' CONCLUSIONS: There is limited high quality evidence for the effectiveness of bypass surgery compared with other treatments; no studies compared bypass to optimal medical treatment. Our analysis has shown that PTA is associated with decreased peri-interventional complications in participants treated for CLI and shorter hospital stay compared with bypass surgery. Surgical treatment seems to confer improved patency rates up to one year. Endovascular treatment may be advisable in patients with significant comorbidity, rendering them high risk surgical candidates. No solid conclusions can be drawn regarding comparisons of bypass surgery with other treatments because of the paucity of available evidence. Further large trials evaluating the impact of anatomical location and extent of disease and clinical severity are required.

Endovascular Repair of Type IIIb Endoleak With the Amplatzer Septal Occluder.

PURPOSE: To report the successful treatment of a type IIIb endoleak with an Amplatzer Septal Occluder. CASE REPORT: A 76-year-old man was found to have a type IIIb endoleak in the proximal body component of a fenestrated graft at 4-year surveillance imaging; the leak was associated with rapid aneurysm growth. The anatomy of the graft and position of the fabric defect precluded treatment by relining with a secondary endograft. The defect was demonstrated with catheter angiography, sized with an angioplasty balloon, and repaired using an Amplatzer Septal Occluder. Follow-up imaging at 6 months showed no endoleak and marked reduction in the aneurysm size. CONCLUSION: The Amplatzer Septal Occluder may be considered as an option for managing type IIIb endoleaks.

Causes of successful medico-legal claims following amputation.

INTRODUCTION: The causes of successful medico-legal claims following amputation were reviewed. METHODS: A retrospective analysis of claims handled by the National Health Service Litigation Authority, from 2005 to August 2010, was performed. Under the Freedom of Information Act, the National Health Service Litigation Authority provided limited details on closed claims, settled with damages, following a search of their database with the term "amputation." No demographic data were provided. RESULTS: During this period, 174 claims were settled by the National Health Service Litigation Authority, who paid out more than £36.3 million. The causes of the claims were the need for a lower limb amputation due to a delay in the diagnosis and or treatment of arterial ischaemia (56), an iatrogenic injury (15), the development of preventable pressure sores (15), the delay and or failure to diagnose a limb malignancy (6) and the delay in the management of an infected pseudo-aneurysm (1). Complications following orthopaedic surgery resulted in 25 successful claims as did the delayed diagnosis or mismanagement of 10 lower limb fractures. Additional claims followed the amputation of the wrong toe (1), a retained foreign body (2), an unnecessary amputation (4), inadequate consent (4), failure to provide thrombo-prophylaxis following amputation resulting in death (2) and a diathermy burn injury during an amputation (1). Delay in the diagnosis of and/or failure to manage an injury or infection resulted in 21 upper limb amputations. There was insufficient information provided in the remaining 11 claims to determine how the claim related to an amputation procedure. The largest single payout for damages (£1.9 million) resulted from the failure to diagnose and treat a femoral artery injury following a road traffic accident leading to an eventual below knee amputation. CONCLUSION: Delays in the diagnosis and or treatment of arterial ischaemia were the commonest reasons for a settled claim. Lessons can be learnt from potentially preventable cases that can be incorporated in medical education and training programs with the aim of reducing both amputation rates and litigation costs.

Carotid artery stenting: relationship between experience and complication rate.

To investigate the evidence for the relationship between volume and outcome for carotid artery stenting. We performed a systematic review of the literature to examine the influence of experience and/or volume on outcome for carotid artery stenting. The primary search strategy was to identify studies presenting year-on-year data. The Pubmed, Embase, Medline and the Cochrane Collaboration databases were searched. Studies with over 100 interventions were included. The main outcome measure compared across studies was all stroke/death. Where possible, comparable data were pooled and analysed using meta-regression techniques. It was not possible to perform a standard systematic review and meta-analysis because of the lack of data from randomised studies. When redundant studies were excluded, four sizeable case series and one registry met the inclusion criteria. When the case series results were pooled, the χ²-test for trend demonstrated a significant reduction in the combined stroke and death rate over time. Meta-regression analysis of case series data allowed the setting of thresholds for 'acceptable' stroke/death rates. Where year-on-year data are available, published stroke and death rates for carotid artery stenting show improvements over time. While advances in technology and pharmacology may in part be responsible, temporal improvement in outcomes demonstrated in both early and contemporary time-frames together with the consistency of the results suggests the presence of a learning curve. In active carotid artery stenting units, it may take almost 2-years before the stroke/death rates fall below an arbitrary 5% threshold.

Platelet function following acute cerebral ischemia.

BACKGROUND: Studies have previously identified increased levels of platelet activation following acute ischemic stroke. In order to evaluate new antiplatelet agents and their combinations, there is a need for accurate measures of platelet activation. METHODS: Blood was taken from 17 patients within 24 hours of an acute ischemic stroke, and then at 3, 7, 14 and 42 days. For comparison, a group of 18 stable arteriopaths had identical tests performed. Platelet aggregation was measured using a free platelet counting technique, and platelet surface P-selectin and monocyte platelet aggregates (MPAs) were measured using flow cytometry. Soluble P-selectin and D-dimers were measured by an enzyme linked immune assay. RESULTS: The initial level of MPAs was significantly raised in the stroke patients compared with the stable patients (p = 0.04, 14.2% vs. 9.3%); however, this difference was not significantly higher than later study points (14.2%, 10.1%, 9.3%, 11.9%, 11.3%; days 1, 3, 7, 14 and 42 respectively. Day 1 vs. day 7 p = 0.07 ANOVA). No changes in P-selectin or platelet aggregation were identified. D-dimer levels were significantly higher on day 7 than day 42 (p < 0.01), and fibrinogen levels were elevated on both days 3 and 14 compared with day 42. Fibrinogen levels were not elevated compared with stable patients. CONCLUSIONS: MPA levels are elevated following an acute ischemic stroke compared to stable patients, but no significant change was seen with other platelet markers. This study suggests MPAs are a more sensitive marker of platelet activation than either P-selectin or aggregation.

Soluble but not platelet P-selectin correlates with spontaneous platelet aggregation: a pilot study.

BACKGROUND: P-selectin (PS) is a marker of platelet activation measured on the platelet surface as platelet PS (pPS) or in serum as soluble PS (sPS). Controversy remains over the exact relationship between sPS, pPS, and other markers such as spontaneous platelet aggregation (SPA). OBJECTIVE: To investigate correlations between pPS, sPS, and SPA in patients with peripheral arterial disease. METHODS: SPA, pPS, and sPS levels were measured in venous blood sampled from patients following intermittent claudication (n = 18) or an acute stroke (n = 18). RESULTS: SPA and sPS correlated significantly in the claudicants (Pearson correlation coefficient, r = 0.661; P = .0020) and stroke patients (r = 0.514; P = .020). No significant correlation was identified between pPS and SPA, or sPS and pPS. CONCLUSIONS: The 2 methods of assessing PS are not comparable. Although pPS is accepted as a platelet activation marker, sPS may be a better indicator of aggregation represented by SPA.

Oral antiplatelet agents and bleeding risk in relation to major cardiovascular surgery.

INTRODUCTION: Patients requiring major cardiovascular surgery are likely to be prescribed antiplatelet agents either alone or in combination. By virtue of antiplatelet agent effect, they can potentially increase bleeding complications, especially if used in combination. This article aims to review the evidence and make appropriate recommendations regarding these agents. ASPIRIN: 16 papers are reviewed which concern surgery whilst taking aspirin. The bulk of the evidence is from the coronary bypass setting. CLOPIDOGREL: 14 papers are reviewed which concern surgery whilst taking clopidogrel. DIPYRIDAMOLE: 2 papers are reviewed concerning dipyridamole. CILOSTAZOL: No trials are available concerning surgery and cilostazol. Several relevant publications are reviewed. CONCLUSION: It is the recommendation of the authors that aspirin should usually be continued perioperatively, whilst clopidogrel should be stopped for seven days prior to surgery if at all possible.

Combination antiplatelet therapy in patients with peripheral vascular bypass grafts.

Peripheral bypass graft occlusion occurs in approximately 25% of cases in the 5 years following surgery; hence, therapies directed at reducing the tendency toward thrombotic occlusion are of clinical importance. This trial was conducted to determine if the addition of clopidogrel to aspirin enhances antiplatelet therapy in patients with infrainguinal bypass grafts. A randomized placebo-controlled study was performed on 20 patients over 3 months following infrainguinal bypass surgery. In addition to their regular aspirin therapy, patients were randomized to receive either clopidogrel (group 1) or placebo (group 2) for 1 week. Platelet activation was measured ex vivo by platelet aggregometry and flow cytometry. In group 1, there was a significant reduction in spontaneous (SP), adenosine diphosphate (ADP), and arachidonic acid (AA)-induced platelet aggregation compared with group 2; SP -17% (CI -33, -0.2 p = 0.048), ADP -39%, (CI -56, -22 p = 0.001), AA -21% (CI -39, -4 p = 0.023). Flow cytometry demonstrated a significant reduction in ADP-induced platelet P-selectin expression and GPIIb/IIIa activation following treatment with clopidogrel but not with placebo. This study demonstrated that the addition of clopidogrel to aspirin reduces platelet activation measured by platelet aggregation and flow cytometry, supporting a long-term trial with clinical endpoints.

Current practice in the use of antiplatelet agents in the peri-operative period by UK vascular surgeons.

BACKGROUND: There currently appears to be no firm consensus with regards to the use of antiplatelet agents during the peri-operative period in vascular surgical practice. METHODS: A nine-part questionnaire relating to peri-operative antiplatelet use was sent to 137 ordinary members of the Vascular Surgical Society of Great Britain and Ireland (VSS-GBI). RESULTS: Of the 137 questionnaires sent, 90 were returned (66%). For patients undergoing infra-inguinal bypass, carotid endarterectomy and varicose vein surgery, over 90% of vascular surgeons continue antiplatelet agents peri-operatively; however, in the case of aortic aneurysm repair, this figure is lower (77%). Three of the respondents stated that they would stop clopidogrel, but not aspirin, prior to surgery because of concerns over increased operative bleeding. In patients starting routine heparin prophylaxis against thrombosis, most surgeons opted to continue antiplatelet therapy (82%), although in patients requiring therapeutic heparin treatment, opinions were almost equally split. Most vascular surgeons (93%) would to start an alternative antiplatelet agent if a patient was intolerant of aspirin for gastrointestinal reasons. CONCLUSIONS: Although the benefits of antiplatelet drugs in the long-term reduction of vascular events is established, evidence supporting their use in the peri-operative period is scarce. The general consensus of opinion from this survey suggests that most vascular surgeons do not stop antiplatelet drugs pre-operatively.

Problem-based learning for surgical trainees.

Problem-based learning (PBL) represents an educational technique that many medical schools have adopted for their undergraduate curricula. This article discusses the application of PBL for surgical trainees.