Vascular access training for REBOA placement: a feasibility study in a live tissue-simulator hybrid porcine model

Background

The use of resuscitative endovascular balloon occlusion of the aorta (REBOA) in patients with severe haemorrhagic shock is increasing. Obtaining vascular access is a necessary prerequisite for REBOA placement in these situations.

Methods

During the EVTM workshop (September 2017, Örebro, Sweden), 21 individuals participated in this study, 16 participants and five instructors. A formalised curriculum was constructed including basic anatomy of the femoral region and basic training in access materials for REBOA placement in zone 1. Key skills: (1) preparation of endovascular toolkit, (2) achieving vascular access in the model and (3) bleeding control with REBOA. Scoring ranged from 0 to 5 for non-anatomical skills. Identification of anatomical structures was either sufficient (score=1) or insufficient (score=0). Five consultants performed a second identical procedure as a post test.

Results

Consultants had significantly better overall technical skills in comparison with residents (p=0.005), while understanding of surgical anatomy showed no difference. Procedure times differed significantly (p<0.01), with residents having a median procedure time of 3 min and 24 s, consultants 2:33 and instructors 1:09.

Conclusion

This comprehensive training model using a live tissue-simulator hybrid porcine model can be used for femoral access and REBOA placement training in medical personnel with different prior training levels. Higher levels of training are associated with faster procedure times. Further research in open and percutaneous access training is necessary to simulate real-life situations. This training method can be used in a multistep training programme, in combination with realistic moulage and perfused cadaver models.

The Dutch Audit of Carotid Interventions: Transparency in Quality of Carotid Endarterectomy in Symptomatic Patients in the Netherlands

BACKGROUND

The Dutch Audit for Carotid Interventions (DACI) registers all patients undergoing interventions for carotid artery stenosis in the Netherlands. This study describes the design of the DACI and results of patients with a symptomatic stenosis undergoing carotid endarterectomy (CEA). It aimed to evaluate variation between hospitals in process of care and (adjusted) outcomes, as well as predictors of major stroke/death after CEA.

METHODS

All patients with a symptomatic stenosis, who underwent CEA and were registered in the DACI between 2014 and 2016 were included in this cohort. Descriptive analyses of patient characteristics, process of care, and outcomes were performed. Casemix adjusted hospital procedural outcomes as (30 day/in hospital) mortality, stroke/death, and major stroke/death, were compared with the national mean. A multivariable logistic regression model (backward elimination at p > 0.10) was used to identify predictors of major stroke/death.

RESULTS

A total of 6459 patients, registered by 52 hospitals, were included. The majority (4,832, 75%) were treated <2 weeks after their first hospital consultation, varying from 40% to 93% between hospitals. Mortality, stroke/death, and major stroke/death were, respectively, 1.1%, 3.6%, and 1.8%. Adjusted major stroke/death rates for hospital comparison varied between 0 and 6.5%. Nine hospitals performed significantly better, none performed significantly worse. Predictors of major stroke/death were sex, age, pulmonary disease, presenting neurological symptoms, and peri-operative shunt.

CONCLUSION

CEA in The Netherlands is associated with an overall low mortality and (major) stroke/death rate. Whereas the indicator time to intervention varied between hospitals, mortality and (major) stroke/death were not significantly distinctive enough to identify worse practices and therefore were unsuitable for hospital comparison in the Dutch setting. Additionally, predictors of major stroke/death at population level could be identified.

Connecting perspectives on quality and safety: patient-level linkage of incident, adverse event and complaint data

Background and objective

Incident, adverse event (AE) and complaint data are typically used separately, but may be related at the patient level with one event triggering a cascade of events, ultimately resulting in a complaint. This study examined relations between incidents, AEs and complaints that co-occurred in admissions.

Methods

Independently and routinely collected incident, AE and complaint data were retrospectively linked for surgical admissions in an academic centre (2008–2014). Two investigators reviewed whether incidents/AEs in admissions were clinically related and in what sequence (incident preceding vs following AE). Likelihood of occurrence of AEs and AE cascades (ie, ≥3 AEs) was studied using logistic regression analyses.

Results

Complaints were filed for 33 (0.1%) of 26 383 admissions. Complaints filed by patients with incidents and/or AEs (n=13) mostly addressed quality/safety problems, whereas other complaints mostly addressed relationship problems. Incidents and AEs co-occurred in 730 (2.8%) admissions, which seemed clinically related in 34% of these cases. Incidents with related AEs preceded as well as followed AEs (56.6%/44.4%). Patients with incidents were at greater risk of AEs than patients without incidents, even for seemingly unrelated AEs (OR 1.4; 95% CI 1.3 to 1.6). Risk of AE cascades was greater when patients with AEs also had incidents, regardless of whether these seemed related (unrelated: OR 2.0; 95% CI 1.6 to 2.5; related: OR 5.7; 95% CI 4.3 to 7.4) or whether incidents preceded or followed AEs in these admissions (53% vs 52%, P>0.05).

Conclusions

Patient-level linkage of incident, AE and complaint data can reveal relations between events that otherwise remain obscured, such as incidents that trigger as well as follow AEs, introducing event cascades, regardless of whether clinical relations seem present.

No Clinical Benefit of Intramuscular Delivery of Bone Marrow-derived Mononuclear Cells in Nonreconstructable Peripheral Arterial Disease: Results of a Phase-III Randomized-controlled Trial

BACKGROUND AND AIMS

Prospects for no-option, end-stage peripheral artery disease (PAD) patients remain poor. Although results from open and semiblinded studies fuel hope for cell-based strategies in no-option patients, so far conclusions from the available placebo-controlled studies are not supportive. With the intention to end the remaining controversy with regard to cell therapy for PAD we conducted a confirmatory, double-blinded randomized placebo-controlled phase 3 trial.

STUDY DESIGN

This randomized controlled trial was registered (NCT00539266). Inclusion criteria included stable or progressive disabling PAD, no imminent need for amputation, absent accepted options for revascularization. Diabetic disease was an exclusion criterion. Bone marrow (500-700 mL) was harvested and bone marrow-derived mononuclear cells were concentrated to 40 mL. Concentrated cells or placebo (diluted blood) were intramuscularly injected at 40 locations of the calf muscle.

RESULTS

Fifty-four patients (mean (sd) age 58.2 (14.2) yrs, 58% males) were randomized. Twenty-eight patients received BM-MNCs, 26 placebo. Baseline criteria were similar in the 2 groups. No significant differences were observed for the primary (number of amputations, (pain free) walking distance) and secondary outcome parameters (ankle brachial index, pain scores, quality of life (SF-36)).

DISCUSSION

This fully blinded replication trial of autologous BM-MNC fails to confirm a benefit for cell therapy in no-option PAD patients, consequently BM-MNC therapy should not be offered as a clinical treatment. Apparent contrasting conclusions from open and controlled studies underscore the importance of a controlled trial design in evaluating cell-based interventions in PAD.

The protective role of Toll-like receptor 3 and type-I interferons in the pathophysiology of vein graft disease

BACKGROUND

Venous grafts are commonly used as conduits to bypass occluded arteries. Unfortunately, patency rates are limited by vein graft disease (VGD). Toll like receptors (TLRs) can be activated in vein grafts by endogenous ligands. This study aims to investigate the role of TLR3 in VGD.

METHODS

Vein graft surgery was performed by donor caval vein interpositioning in the carotid artery of recipient Tlr2^-/-, Tlr3^-/-, Tlr4^-/- and control mice. Vein grafts were harvested 7, 14 and 28d after surgery to perform immunohistochemical analysis. Expression of TLR-responsive genes in vein grafts was analysed using a RT²-profiler PCR Array. mRNA expression of type-I IFN inducible genes was measured with qPCR in bone marrow-derived macrophages (BMM).

RESULTS

TLR2, TLR3 and TLR4 were observed on vein graft endothelial cells, smooth muscle cells and macrophages. Tlr3^-/- vein grafts demonstrated no differences in vessel wall thickening after 7d, but after 14d a 2.0-fold increase (p = 0.02) and 28d a 1.8-fold increase (p = 0.009) compared to control vein grafts was observed, with an increased number of macrophages (p = 0.002) in the vein graft. Vessel wall thickening in Tlr4^-/- decreased 0.6-fold (p = 0.04) and showed no differences in Tlr2^-/- compared to control vein grafts. RT²-profiler array revealed a down-regulation of type-I IFN inducible genes in Tlr3^-/- vein grafts. PolyI:C stimulated BMM of Tlr3^-/- mice showed a reduction of Ifit1 (p = 0.003) and Mx1 (p < 0.0001) mRNA compared to control.

CONCLUSIONS

We here demonstrate that TLR3 can play a protective role in VGD development, possibly regulated via type-I IFNs and a reduced inflammatory response.

Alloimmune Responses of Humanized Mice to Human Pluripotent Stem Cell Therapeutics

There is growing interest in using embryonic stem cell (ESC) and induced pluripotent stem cell (iPSC) derivatives for tissue regeneration. However, an increased understanding of human immune responses to stem cell-derived allografts is necessary for maintaining long-term graft persistence. To model this alloimmunity, humanized mice engrafted with human hematopoietic and immune cells could prove to be useful. In this study, an in-depth analysis of graft-infiltrating human lymphocytes and splenocytes revealed that humanized mice incompletely model human immune responses toward allogeneic stem cells and their derivatives. Furthermore, using an “allogenized” mouse model, we show the feasibility of reconstituting immunodeficient mice with a functional mouse immune system and describe a key role of innate immune cells in the rejection of mouse stem cell allografts.

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Innate immunity is crucial in rejection of minor HA mismatched grafts

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Stem cell alloimmune responses modeled with an “allogenized mouse”

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Humanized mice are unable to fully model immune responses to stem cell allografts

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Splenocytes and graft-infiltrating lymphocytes display an exhausted phenotype

Leukocyte Dynamics during the Evolution of Human Coronary Atherosclerosis: Conclusions from a Sevenfold, Chromogen-Based, Immunohistochemical Evaluation

Atherosclerosis is a complex process with strong inflammatory component. We developed a straightforward sevenfold staining protocol for simultaneous assessment of dominant leukocyte classes, vascularization, and expression of the putative foam cell maker CD36. The method was applied on human coronaries covering the full spectrum of atherosclerotic disease. Results confirm the progressive association of macrophages and T cells with the process and a global presence of mast cells. B cells are exclusively present in adventitial follicles that accompany the process plaque destabilization (thin cap and ruptured lesions) and are otherwise absent. Neutrophils are only present as part of the hemorrhage that accompanies plaque rupture. This study does not classify CD36 as a key factor in foam cell formation. Observed macrophage accumulation in the neointima of stabilized fibrous calcified plaques is consistent with a process of neoatherosclerosis. This study on human coronaries shows a progressive association of macrophage and T-cell abundance with plaque progression. Follicle-like structures are transiently present during the process of plaque destabilization. Plaque healing is accompanied by cessation of the inflammatory response but followed by a new cycle of atherosclerosis.

Autologous iPSC-Based Vaccines Elicit Anti-tumor Responses In Vivo

Cancer cells and embryonic tissues share a number of cellular and molecular properties, suggesting that induced pluripotent stem cells (iPSCs) may be harnessed to elicit anti-tumor responses in cancer vaccines. RNA sequencing revealed that human and murine iPSCs express tumor-associated antigens, and we show here a proof of principle for using irradiated iPSCs in autologous anti-tumor vaccines. In a prophylactic setting, iPSC vaccines prevent tumor growth in syngeneic murine breast cancer, mesothelioma, and melanoma models. As an adjuvant, the iPSC vaccine inhibited melanoma recurrence at the resection site and reduced metastatic tumor load, which was associated with fewer Th17 cells and increased CD11b+GR1hi myeloid cells. Adoptive transfer of T cells isolated from vaccine-treated tumor-bearing mice inhibited tumor growth in unvaccinated recipients, indicating that the iPSC vaccine promotes an antigen-specific anti-tumor T cell response. Our data suggest an easy, generalizable strategy for multiple types of cancer that could prove highly valuable in clinical immunotherapy.

CXCL8 hyper-signaling in the aortic abdominal aneurysm

There are indications for elevated CXCL8 levels in abdominal aortic aneurysm disease (AAA). CXCL8 is concurrently involved in neutrophil-mediated inflammation and angiogenesis, two prominent and distinctive characteristics of AAA. As such we considered an evaluation of a role for CXCL8 in AAA progression relevant. ELISA's, real time PCR and array analysis were used to explore CXCL8 signaling in AAA wall samples. A role for CXCL8 in AAA disease was tested through the oral CXCR1/2 antagonist DF2156A in the elastase model of AAA disease. There is an extreme disparity in aortic wall CXCL8 content between AAA and aortic atherosclerotic disease (median [IQR] aortic wall CXCL8 content: 425 [141-1261] (AAA) vs. 23 [2.8-89] (atherosclerotic aorta) µg/g protein (P < 1 · 10^-14)), and abundant expression of the CXCR1 and 2 receptors in AAA. Array analysis followed by pathway analysis showed that CXCL8 hyper-expression in AAA is followed increased by IL-8 signaling (Z-score for AAA vs. atherosclerotic control: 2.97, p < 0.0001). Interference with CXCL8 signaling through DF2156A fully abrogated AAA formation and prevented matrix degradation in the murine elastase model of AAA disease (p < 0.001). CXCL8-signaling is a prominent and distinctive feature of AAA, interference with the pathway constitutes a promising target for medical stabilization of AAA.

Randomized trial of one-hour sodium bicarbonate vs standard periprocedural saline hydration in chronic kidney disease patients undergoing cardiovascular contrast procedures

Background

Guidelines advise periprocedural saline hydration for prevention of contrast induced-acute kidney injury (CI-AKI). We analysed whether 1-hour sodium bicarbonate hydration administered solely prior to intra-arterial contrast exposure is non-inferior to standard periprocedural saline hydration in chronic kidney disease (CKD) patients undergoing elective cardiovascular diagnostic or interventional contrast procedures.

Methods

We performed an open-label multicentre non-inferiority trial between 2011–2014. Patients were randomized to 1 hour pre-procedure sodium bicarbonate hydration (250 ml 1.4%, N = 168) or 4–12 hours saline hydration (1000 ml 0.9%, N = 165) prior to and following contrast administration (2000 ml of saline total). Primary outcome was the relative serum creatinine increase (%) 48–96 hours post contrast exposure. Secondary outcomes were: incidence of CI-AKI (serum creatinine increase>25% or >44μmol/L), recovery of renal function, the need for dialysis, and hospital costs within two months follow-up.

Results

Mean relative creatinine increase was 3.1% (95%CI 0.9 to 5.2%) in the bicarbonate and 1.1% (95%CI -1.2 to 3.5%) in the saline arm, mean difference 1.9% (95%CI -1.2 to 5.1%, p-non-inferiority <0.001). CI-AKI occurred in 11 (6.7%) patients randomized to sodium bicarbonate and 12 (7.5%) to saline (p = 0.79). Renal function did not fully recover in 40.0% and 44.4% of CI-AKI patients, respectively (p = 0.84). No patient required dialysis. Mean costs for preventive hydration and clinical preparation for the contrast procedure were $1158 for sodium bicarbonate vs. $1561 for saline (p < 0.001).

Conclusion

Short hydration with sodium bicarbonate prior to elective cardiovascular diagnostic or therapeutic contrast procedures is non-inferior to standard periprocedural saline hydration in CKD patients with respect to renal safety and results in considerable healthcare savings.

Trial registration

Netherlands Trial Register (http://www.trialregister.nl/trialreg/index.asp), Nr NTR2699

The problem with using patient complaints for improvement

'The Problem with…' series covers controversial topics related to efforts to improve healthcare quality, including widely recommended, but deceptively difficult strategies for improvement and pervasive problems that seem to resist solution.

Toward Best Practices for Surgical Morbidity and Mortality Conferences: A Mixed Methods Study

OBJECTIVE

To assess formats for surgical morbidity and mortality conferences (M&M) for strengths and challenges.

DESIGN

A mixed methods approach with local observations to assess key domains of M&M practice (i.e., goals, structure, and process/content) and surveys to assess participants' expectations and experiences.

SETTING

Surgical departments of two teaching hospitals (Boston, USA and Leiden, Netherlands).

PARTICIPANTS

Participants of surgical M&M, including attending surgeons, residents, physician assistants, and medical students (total n = 135).

RESULTS

Surgical M&M practices at both hospitals had education as its overarching goal, but varied in structure and process/content. Expectations were similar at both sites with ≥80% of participants (n = 90; 67% response) expecting M&M to be focused on education as well as quality improvement (QI), blame-free, mandatory for both residents and attendings, and to lead to changes in clinical practice. However, compared to expectations, significantly fewer participants at both sites experienced: a QI focus (both p < 0.001); mandatory faculty attendance (p = 0.004; p < 0.001) and changes to practice (both p < 0.001). In comparison, at the site where an active moderator and QI committee are present, respondents seemed more positive about experiencing a QI focus (73% vs 30%) and changes to practice (44% vs 16%).

CONCLUSION

Despite variation in M&M practice, the same (unmet) expectations existed at both hospitals, indicating that certain challenges may be more universal. M&M was reported to be well-focused on education, and certain aspects (e.g., active moderator and QI committee) seemed beneficial, but expectations were not met for the conference's focus and function for QI. Greater exchange of "best practices" for M&M may enhance the conference's value for improving surgical care.

Patients' perceptions of conservative treatment for a small abdominal aortic aneurysm

BACKGROUND

An abdominal aortic aneurysm (AAA) is a progressive, generally symptomless disease that could ultimately result in a fatal rupture. Current guidelines advise conservative follow-up, and preventive surgical repair once the risk of rupture outweighs the cost of repair (55 mm in men). In developed countries, the majority of patients are diagnosed with AAAs less than 55 mm, and so enter a period of conservative surveillance. An important question is how patients perceive and cope with risk of rupture, AAA diagnosis and treatment, and presented AAA information. The goal of this study was to gain insight into patients' perceptions of conservative treatment for a small AAA to increase patient satisfaction.

METHODS

We conducted semistructured in-depth interviews and used questionnaires measuring health-related quality of life (RAND 36-Item Health Survey 1.0), illness-perceptions (Illness Perception Questionnaire - Revised), and anxiety and depression (Hospital Anxiety and Depression Scale). Interviews were audio recorded and transcript contents were analyzed based on grounded theory. Mean scores of the questionnaires were compared to (population) reference groups.

RESULTS

This study included ten male patients under surveillance for a small AAA from two hospitals in the Netherlands. Patients expressed no fear for AAA rupture, and also reported low levels of anxiety and depression in both the interviews and the Hospital Anxiety and Depression Scale. The presence of an AAA did not affect their social life or emotional well-being. The reported poorer physical health on RAND 36-Item Health Survey 1.0 presumably reflected common presence of comorbidities. Participants stated to that they were content with the frequency and setup of AAA surveillance. However, they generally lacked knowledge about AAA disease and/or treatment options.

CONCLUSION

Conservative AAA follow-up ensures patients that the risks of AAA disease are limited. The vascular surgeon is the most important source of AAA information to patients, and patients fully rely on their vascular surgeon to take control in AAA treatment.

Barriers and facilitators to learn and improve through morbidity and mortality conferences: a qualitative study

OBJECTIVES

To explore barriers and facilitators to successful morbidity and mortality conferences (M&M), driving learning and improvement.

DESIGN

This is a qualitative study with semistructured interviews. Inductive, thematic content analysis was used to identify barriers and facilitators, which were structured across a pre-existing framework for change in healthcare.

SETTING

Dutch academic surgical department with a long tradition of M&M.

PARTICIPANTS

An interview sample of surgeons, residents and physician assistants (n=12).

RESULTS

A total of 57 barriers and facilitators to successful M&M, covering 18 themes, varying from 'case type' to 'leadership', were perceived by surgical staff. While some factors related to M&M organisation, others concerned individual or social aspects. Eight factors, of which four were at the social level, had simultaneous positive and negative effects (eg, 'hierarchy' and 'team spirit'). Mediating pathways for M&M success were found to relate to available information, staff motivation and realisation processes.

CONCLUSIONS

This study provides leads for improvement of M&M practice, as well as for further research on key elements of successful M&M. Various factors were perceived to affect M&M success, of which many were individual and social rather than organisational factors, affecting information and realisation processes but also staff motivation. Based on these findings, practical recommendations were formulated to guide efforts towards best practices for M&M.

A registry-based rationale for discrete intervention thresholds for open and endovascular elective abdominal aortic aneurysm repair in female patients

OBJECTIVE

An evidence-based consensus for a female-specific intervention threshold for abdominal aortic aneurysms (AAAs) is missing. This study aims to analyze sex-related differences in the epidemiology of ruptured AAA to establish an intervention threshold for women.

METHODS

The Dutch Surgical Aneurysm Audit (DSAA) is a compulsory, nation-wide registry of AAA repairs in The Netherlands. All patients with emergency or elective AAA repair between January 1, 2013, and December 31, 2015, were included in the analysis. The main outcomes were age, sex, AAA diameter at time of rupture, and 30-day postoperative mortality.

RESULTS

A total of 1561 ruptured AAA repairs (14.7% women) and 7063 cases of elective AAA repair (13.7% women) were included in the analysis. Women had significantly smaller mean ± standard deviation AAA diameter at time of rupture than men; 70.5 ± 14.4 mm and 78.6 ± 17.5 mm, respectively. In male patients, 8% of ruptures occurred at diameters below the 55 mm intervention threshold. The female equivalent of this eighth percentile is 52 mm. Female patients had significantly higher 30-day mortality after emergency repair, namely, 33% for women versus 24.2% for men, but were also significantly older, mean ± standard deviation age 76.7 ± 7.1 years and 73.9 ± 8.3 years for women and men, respectively. Correcting for age reduced the 30-day mortality risk for women after ruptured AAA repair from 1.53 (95% confidence interval, 1.14-2.04) to 1.27 (95% confidence interval, 0.92-1.73). Outcome after open elective repair was significantly worse for women compared with men, with a 30-day mortality of 7.97% 30 for women and 4.27% for men (P < .01).

CONCLUSIONS

The equivalent of the 55-mm intervention threshold for elective endovascular AAA repair in men is 52 mm in women. The almost doubled mortality risk for elective open repair in women implies that the optimal point for open repair is at higher diameters, very possibly at least 55 mm.

Adventitial adipogenic degeneration is an unidentified contributor to aortic wall weakening in the abdominal aortic aneurysm

OBJECTIVE

The processes driving human abdominal aortic aneurysm (AAA) progression are not fully understood. Although antiinflammatory and proteolytic strategies effectively quench aneurysm progression in preclinical models, so far all clinical interventions failed. These observations hint at an incomplete understanding of the processes involved in AAA progression and rupture. Interestingly, strong clinical and molecular associations exist between popliteal artery aneurysms (PAAs) and AAAs; however, PAAs have an extremely low propensity to rupture. We thus reasoned that differences between these aneurysms may provide clues toward (auxiliary) processes involved in AAA-related wall debilitation. A better understanding of the pathophysiologic processes driving AAA growth can contribute to pharmaceutical treatments in the future.

METHODS

Aneurysmal wall samples were collected during open elective and emergency repair. Control perirenal aorta was obtained during kidney transplantation, and reference popliteal tissue obtained from the anatomy department. This study incorporates various techniques including (immuno)histochemistry, Western Blot, quantitative polymerase chain reaction, microarray, and cell culture.

RESULTS

Histologic evaluation of AAAs, PAAs, and control aorta shows extensive medial (PAA) and transmural fibrosis (AAA), and reveals abundant adventitial adipocytes aggregates as an exclusive phenomenon of AAAs (P < .001). Quantitative polymerase chain reaction, immunohistochemistry, Western blotting, and microarray analysis showed enrichment of adipogenic mediators (C/EBP family P = .027; KLF5 P < .000; and peroxisome proliferator activated receptor-γ, P = .032) in AAA tissue. In vitro differentiation tests indicated a sharply increased adipogenic potential of AAA adventitial mesenchymal cells (P < .0001). Observed enrichment of adipocyte-related genes and pathways in ruptured AAA (P < .0003) supports an association between the extent of fatty degeneration and rupture.

CONCLUSIONS

This translational study identifies extensive adventitial fatty degeneration as an ignored and distinctive feature of AAA disease. Enrichment of adipocyte genesis and adipocyte-related genes in ruptured AAA point to an association between the extent of fatty degeneration and rupture. This observation may (partly) explain the failure of medical therapy and could provide a lead for pharmaceutical alleviation of AAA progression.

Systematic review of mortality risk prediction models in the era of endovascular abdominal aortic aneurysm surgery

BACKGROUND

The introduction of endovascular aneurysm repair (EVAR) has reduced perioperative mortality after abdominal aortic aneurysm (AAA) surgery. The objective of this systematic review was to assess existing mortality risk prediction models, and identify which are most useful for patients undergoing AAA repair by either EVAR or open surgical repair.

METHODS

A systematic search of the literature was conducted for perioperative mortality risk prediction models for patients with AAA published since 2006. PRISMA guidelines were used; quality was appraised, and data were extracted and interpreted following the CHARMS guidelines.

RESULTS

Some 3903 studies were identified, of which 27 were selected. A total of 13 risk prediction models have been developed and directly validated. Most models were based on a UK or US population. The best performing models regarding both applicability and discrimination were the perioperative British Aneurysm Repair score (C-statistic 0·83) and the preoperative Vascular Biochemistry and Haematology Outcome Model (C-statistic 0·85), but both lacked substantial external validation.

CONCLUSION

Mortality risk prediction in AAA surgery has been modelled extensively, but many of these models are weak methodologically and have highly variable performance across different populations. New models are unlikely to be helpful; instead case-mix correction should be modelled and adapted to the population of interest using the relevant mortality predictors.

The Consequences of Real Life Practice of Early Abdominal Aortic Aneurysm Repair: A Cost-Benefit Analysis

BACKGROUND

The reported 54 mm median intervention diameter for endovascular aneurysm repair (EVAR) in the Vascular Quality Initiative and European data from the Pharmaceutical Aneurysm Stabilisation Trial (PHAST) implies that in real life the majority of abdominal aortic aneurysm (AAA) repairs occur at diameters smaller than the consensus intervention threshold of 55 mm. This study explores the potential consequences of this practice.

METHODS

The differences between real life AAA repair and consensus based intervention threshold were explored in reported data from vascular quality initiatives and PHAST. The subsequent consequences of advancement of endovascular aneurysm repair (EVAR) were estimated using a multistate model based on life tables for the EVAR Medicare population.

RESULTS

There appears an approximate 5 mm difference in AAA diameter between real life practice and consensus intervention threshold. Assuming a 2.5 mm annual growth rate, this results in an approximately 2 year advancement of AAA repair. According to the model used, early repair reduces overall small aneurysm patient mortality by 2.3%, it results in 21.9% more EVAR procedures, more EVAR related deaths, and 42.3% and 36.8% more open and endovascular re-interventions, respectively. Cost-benefit estimates imply 482 fewer AAA related deaths, but 140 extra EVAR related deaths for a population of more than 30,000 AAA patients, and a 300 million USD increase in health costs for the 8 year observation period in the Medicare population.

CONCLUSIONS

In the real life situation a large proportion of EVAR procedures appear to occur before reaching the consensus threshold. Although this reduces mortality, it comes at a cost of approximately 1 million USD per prevented rupture related death.

The Effects of Spacing, Naps, and Fatigue on the Acquisition and Retention of Laparoscopic Skills

BACKGROUND

Earlier research has shown that laparoscopic skills are trained more efficiently on a spaced schedule compared to a massed schedule. The aim of the study was to estimate to what extent the spacing interval, naps, and fatigue influenced the effectiveness of spacing laparoscopy training.

METHODS

Overall 4 groups of trainees (aged 17-41y; 72% female; N_massed = 40; N_break = 35; N_break-nap = 37; N_spaced = 37) without prior experience were trained in 3 laparoscopic tasks using a physical box trainer with different scheduling interventions. The first (massed) group received three 100-minute training sessions consecutively on a single day. The second (break) group received the sessions interrupted with two 45-minute breaks. The third (break-nap) group had the same schedule as the second group, but had two 35-minute powernap intervals during the breaks. The fourth (spaced) group had the 3 sessions on 3 consecutive days. A retention session was organized approximately 3 months after training.

RESULTS

The results showed an overall pattern of superior performance at the end of training and at retention for the spaced group, followed by the break-nap, break, and massed group, respectively. The spaced and break-nap group significantly outperformed the break and massed group, with effect sizes ranging from 0.20 to 0.37.

CONCLUSIONS

Spacing laparoscopic training over 3 consecutive days or weeks is superior to massed training, even if the massed training contains breaks. Breaks with sleep opportunity (i.e., lying, inactive, and muted sensory input) enhance performance over training with regular breaks and traditional massed training.

Adjusted Hospital Outcomes of Abdominal Aortic Aneurysm Surgery Reported in the Dutch Surgical Aneurysm Audit

OBJECTIVE/BACKGROUND

The Dutch Surgical Aneurysm Audit (DSAA) is mandatory for all patients with primary abdominal aortic aneurysms (AAAs) in the Netherlands. The aims are to present the observed outcomes of AAA surgery against the predicted outcomes by means of V-POSSUM (Vascular-Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity). Adjusted mortality was calculated by the original and re-estimated V(physiology)-POSSUM for hospital comparisons.

METHODS

All patients operated on from January 2013 to December 2014 were included for analysis. Calibration and discrimination of V-POSSUM and V(p)-POSSUM was analysed. Mortality was benchmarked by means of the original V(p)-POSSUM formula and risk-adjusted by the re-estimated V(p)-POSSUM on the DSAA.

RESULTS

In total, 5898 patients were included for analysis: 4579 with elective AAA (EAAA) and 1319 with acute abdominal aortic aneurysm (AAAA), acute symptomatic (SAAA; n = 371) or ruptured (RAAA; n = 948). The percentage of endovascular aneurysm repair (EVAR) varied between hospitals but showed no relation to hospital volume (EAAA: p = .12; AAAA: p = .07). EAAA, SAAA, and RAAA mortality was, respectively, 1.9%, 7.5%, and 28.7%. Elective mortality was 0.9% after EVAR and 5.0% after open surgical repair versus 15.6% and 27.4%, respectively, after AAAA. V-POSSUM overestimated mortality in most EAAA risk groups (p < .01). The discriminative ability of V-POSSUM in EAAA was moderate (C-statistic: .719) and poor for V(p)-POSSUM (C-statistic: .665). V-POSSUM in AAAA repair overestimated in high risk groups, and underestimated in low risk groups (p < .01). The discriminative ability in AAAA of V-POSSUM was moderate (.713) and of V(p)-POSSUM poor (.688). Risk adjustment by the re-estimated V(p)-POSSUM did not have any effect on hospital variation in EAAA but did in AAAA.

CONCLUSION

Mortality in the DSAA was in line with the literature but is not discriminative for hospital comparisons in EAAA. Adjusting for V(p)-POSSUM, revealed no association between hospital volume and treatment or outcome. Risk adjustment for case mix by V(p)-POSSUM in patients with AAAA has been shown to be important.

[Assessments during Medical Specialists Training: quantity or quality?]

Structured assessments form a mandatory part of Dutch Medical Specialist Training, but create administrative workload for both the staff and supervisors. One could argue that the quality of the narrative feedback is more important than the extensive reporting in learning portfolios, and that the focus should be on continuous on-the-job coaching.

[How we can learn better and more safely from serious incidents; translation of 'Just Culture' and 'Safety-II' into clinical practice]

After a serious incident, all involved expect it will provide an opportunity to learn and that improvements will follow. However, 'safe' learning is often threatened due to a primary focus on accountability. Focus should, instead, be on the needs of both patients and care providers, with the goal of repairing damage and restoring trust in the wider sense - a culture of justice ('Just Culture'). Common daily practice is a more realistic focus for further investigation, with active involvement of healthcare professionals ('Safety-II'). This means that an event is no longer reduced to 'human failure' but that complex work processes and interdependencies are thoroughly investigated, as to understand how things mostly go well but sometimes also go wrong. Deeper insight into the context of a serious incident and its relation to daily practice could ensure that plans for improvement are more closely aligned with this daily practice. Primary focus on the needs of those involved, and appreciation of the complex context, can allow for a safe and realistic approach to learning from undesirable events, such as serious incidents.

[How does a surgeon decide that surgery is the best option?Assessing whether or not to operate]

All abdominal surgical procedures have a certain risk/benefit ratio. Recently, the way surgeons come to a decision whether to operate, or not, was discussed in the Annals of Surgery. First, the assessment of the decision for an operative versus a non-operative strategy was addressed on the basis of clinical vignettes. The perceptions concerning risk/benefit balance varied considerably between surgeons and these perceptions predicted the decision to operate. In a second paper, surgeons were randomized to either an arm in which they were exposed to a risk calculator or to a control arm. The decisions of the risk-calculator arm were less varied, but did not alter the likelihood of recommending an operation. Perhaps surgeons decide to operate or not rather intuitively, based on clinical and laboratory information. Alternatively, they may consider the statistically significant difference in risk/benefit to be less relevant. A better insight into surgeons' decision making and the way in which they weigh benefits against risks is very useful, but it is proving to be a considerable research challenge.