Reliability of bedside tests for diagnosing peripheral arterial disease in patients prone to medial arterial calcification: A systematic review

BACKGROUND

Medial arterial calcification (MAC), frequently associated with diabetes mellitus (DM) and chronic kidney disease (CKD), is a systemic vascular disorder leading to stiffness and incompressible arteries. These changes impede the accuracy of bedside tests to diagnose peripheral arterial disease (PAD). This review aimed to evaluate the reliability of bedside tests for the detection of PAD in patients prone to MAC.

METHODS

A systematic search (Pubmed, Embase, Web of Science, Cochrane, and Emcare) was performed according to the PRISMA guidelines to identify relevant studies providing data on the performance of bedside tests for the detection of PAD in patients prone to MAC. Studies were included when bedside test were compared to a reference standard. Primary endpoints were the positive and negative likelihood ratios (PLR, NLR). Methodological quality and risk of bias were evaluated using the QUADAS-2 tool.

FINDINGS

In total, 23 studies were included in this review. The most commonly evaluated test was the ankle-brachial index (ABI), followed by toe-brachial index (TBI), toe pressure (TP) measurements, and continuous wave Doppler (CWD). The majority of patients were older, male, and had DM. We found that ABI <0·9 was helpful to diagnose PAD, but failed to rule out PAD (NLR >0·2). The same applied for TP (NLR >0·3) and TBI (5 out of 6 studies revealed an NLR >0·2). CWD (loss of triphasic pattern) is reliable to exclude PAD (NLR 0-0·09), but was only validated in two studies. Overall, methodological quality was poor which led to risk of bias in 20 studies.

INTERPRETATION

The diagnosis of PAD in patients prone to MAC remains challenging. The ABI performed reasonably in the diagnosis of PAD, while the CWD (loss of triphasic signal) can be used to rule out PAD. This systematic review showed that test performances were generally poor with serious concerns in methodological quality of the included studies. We therefore counsel against the use of a single bedside test.

FUNDING

None to declare.

Computed tomography follow-up after elective proximal aortic surgery: Less is more?

STUDY OBJECTIVE

The added value of computed tomography (CT) follow-up after elective proximal aortic surgery is unclear. We evaluated the benefit of CT follow-up by assessing the incidence of aorta-related complications and reinterventions detected during routine CT follow-up.

METHODS

Data on 314 patients undergoing first time elective proximal aortic surgery between 2000 and 2015 were collected. The primary study end points were aorta-related complications and reinterventions, detected during routine CT follow-up. Secondary study endpoints included all aorta-related complications and reinterventions, irrespective of the mode of detection and survival.

RESULTS

Median CT follow-up time was 6.8 (IQR 4.1-9.8) years, during which a total of 1303 routine follow-up CT-scans (median 4, IQR 3-5) were performed. During CT follow-up, aorta-related complications were detected in 18 (5.7%) patients, of which 6 (1.6%) underwent reintervention. In total, 28 aorta-related complications were observed in 23 (7.3%) patients, of which 9 led to reintervention. In order to detect 1 aorta-related complication leading to reintervention, 218 routine follow-up CT-scans were required. The unadjusted and EuroSCORE II adjusted hazard ratios of not undergoing CT follow-up on mortality were 1.260 (95% CI 0.705-2.251) and 0.830 (95% CI 0.430-1.605), respectively.

CONCLUSIONS

Following first time elective proximal aortic surgery, aorta-related complications are uncommon, are not always detected during CT follow-up and, if detected, often do not result in reintervention. Therefore, a more conservative CT follow-up protocol could be considered in selected patients to reduce lifetime radiation burden and health care costs.

Measuring What Matters at Morbidity and Mortality Conferences: A Scoping Review of Effectiveness Measures

OBJECTIVE

Efforts to study morbidity and mortality conferences (M&MC) are hampered by the lack of rigorous instruments to assess the effectiveness of the conferences for the purpose of quality improvement and medical education. This might limit further advancement of the practice. The aim of this scoping review was to determine commonly used effectiveness measures of M&MC in the literature.

METHOD

A scoping review was performed of quantitative, qualitative, and mixed methods studies of M&MC, using databases from PubMed, Emcare, Embase, Web of Science, and the Cochrane library. Studies were included if an outcome was described after a general evaluation or an intervention to M&MC. Study quality was assessed with the Quality Assessment Tool for Studies with Diverse Designs.

RESULTS

A total of 43 articles were included in the review. The majority used a quantitative (n = 23) or mixed (n = 17) design, with surveys as the most frequent method used for data collection (n = 29). The overall Quality Assessment Tool for Studies with Diverse Designs scores were modest (64%). Outcome measures used to evaluate the effectiveness of M&MC were clustered in the following categories: "participant experiences," "characteristics of the meeting," "medical knowledge," "actions for improvement," and "clinical outcomes."

CONCLUSIONS

This review found a wide variety of effectiveness measures for M&MC. Rather than using isolated measures, approaches that combine multiple effectiveness measures could offer a more comprehensive assessment of M&MC. Although there was a preference for quantitative metrics, this fails to seize the opportunity of qualitative methods to yield insights into sociological purposes of M&MC, such as building professional identities and safety culture.

Doppler Ultrasonography Derived Maximal Systolic Acceleration: Value Determination With Artificially Induced Stenosis

In diagnosing peripheral arterial disease (PAD), medial arterial calcification (MAC) hampers arterial compression and could lead to unreliable ankle brachial index (ABI), toe brachial index (TBI) and toe pressure (TP). Doppler ultrasonography (DUS) derived maximal systolic acceleration (ACCmax) might be more accurate to diagnose PAD. In an in vitro study, a strong correlation between ACCmax and the severity of stenotic disease was determined. The aim of this study was to investigate the ACCmax in correlation with conventional non-invasive diagnostics in an in vivo setting. Methods: In twelve healthy individuals, an arterial stenosis was mimicked by compression on the common femoral artery by an ultrasounds probe, creating a local stenosis of 50%, 70% and 90%. The ABI, TBI, TP and several DUS parameters (including ACCmax) were assessed at the ankle during these different degrees of stenosis. All DUS parameters were measured separately by two observers to determine the interobserver variability. Results: Overall the ABI, TBI, TP, ACCmax, ACCsys and PSV decreased significantly when the degree of stenosis increased. The ACCmax showed the highest correlation with the degree of stenosis (r −.884), compared to ABI (r −.726), TBI (r −.716) and TP (r −.758). Furthermore, the interobserver variability of ACCmax was excellent, with an intraclass correlation coefficient (ICC) of .97. Conclusion: ACCmax is an accurate non-invasive DUS parameter to diagnose and assess the severity of a mimicked arterial stenosis in healthy individuals. Further prospective assessment of the clinical value of ACCmax and its potential benefits in patients with PAD is needed.

Treatment Outcome Trends for Non-Ruptured Abdominal Aortic Aneurysms: A Nationwide Prospective Cohort Study

OBJECTIVE

The Dutch Surgical Aneurysm Audit (DSAA) initiative was established in 2013 to monitor and improve nationwide outcomes of aortic aneurysm surgery. The objective of this study was to examine whether outcomes of surgery for intact abdominal aortic aneurysms (iAAA) have improved over time.

METHODS

Patients who underwent primary repair of an iAAA by standard endovascular (EVAR) or open surgical repair (OSR) between 2014 and 2019 were selected from the DSAA for inclusion. The primary outcome was peri-operative mortality trend per year, stratified by OSR and EVAR. Secondary outcomes were trends per year in major complications, textbook outcome (TbO), and characteristics of treated patients. The trends per year were evaluated and reported in odds ratios per year.

RESULTS

In this study, 11 624 patients (74.8%) underwent EVAR and 3 908 patients (25.2%) underwent OSR. For EVAR, after adjustment for confounding factors, there was no improvement in peri-operative mortality (aOR [adjusted odds ratio] 1.06, 95% CI 0.94 - 1.20), while major complications decreased (2014: 10.1%, 2019: 7.0%; aOR 0.91, 95% CI 0.88 - 0.95) and the TbO rate increased (2014: 68.1%, 2019: 80.9%; aOR 1.13, 95% CI 1.10 - 1.16). For OSR, the peri-operative mortality decreased (2014: 6.1%, 2019: 4.6%; aOR 0.89, 95% CI 0.82 - 0.98), as well as major complications (2014: 28.6%, 2019: 23.3%; aOR 0.95, 95% CI 0.91 - 0.99). Furthermore, the proportion of TbO increased (2014: 49.1%, 2019: 58.3%; aOR 1.05, 95% CI 1.01 - 1.10). In both the EVAR and OSR group, the proportion of patients with cardiac comorbidity increased.

CONCLUSION

Since the establishment of this nationwide quality improvement initiative (DSAA), all outcomes of iAAA repair following EVAR and OSR have improved, except for peri-operative mortality following EVAR which remained unchanged.

[Appreciative calamity investigation]

Calamity investigations often lead to recommendations that are difficult to implement and that are of little relevance, because the analysis is carried out according to a cause and effect system. The complexity of care provision requires a different method that respects the complexity of day-to-day care and is able to assess it correctly. Research according to the Safety-II philosophy clearly shows the variable interactions and dependencies present in daily work. These investigations require more effort and time, but lead to better recommendations, better recognition among professionals and an appreciative way of interviewing. This is to the satisfaction of calamity investigators, involved professionals and patients and family. This method of investigation requires an investment in time and people of the healthcare institution.

Association of Hospital Volume with Perioperative Mortality of Endovascular Repair of Complex Aortic Aneurysms: A Nationwide Cohort Study

OBJECTIVE

We evaluate nationwide perioperative outcomes of complex EVAR and assess the volume-outcome association of complex EVAR.

SUMMARY OF BACKGROUND DATA

Endovascular treatment with fenestrated (FEVAR) or branched (BEVAR) endografts is progressively used for excluding complex aortic aneurysms (complex AAs). It is unclear if a volume-outcome association exists in endovascular treatment of complex AAs (complex EVAR).

METHODS

All patients prospectively registered in the Dutch Surgical Aneurysm Audit who underwent complex EVAR (FEVAR or BEVAR) between January 2016 and January 2020 were included. The effect of annual hospital volume on perioperative mortality was examined using multivariable logistic regression analyses. Patients were stratified into quartiles based on annual hospital volume to determine hospital volume categories.

RESULTS

We included 694 patients (539 FEVAR patients, 155 BEVAR patients). Perioperative mortality following FEVAR was 4.5% and 5.2% following BEVAR. Postoperative complication rates were 30.1% and 48.7%, respectively. The first quartile hospitals performed <9 procedures/yr; second, third, and fourth quartile hospitals performed 9-12, 13-22, and ≥23 procedures/yr. The highest volume hospitals treated the significantly more complex patients. Perioperative mortality of complex EVAR was 9.1% in hospitals with a volume of < 9, and 2.5% in hospitals with a volume of ≥13 (P = 0.008). After adjustment for confounders, an annual volume of ≥13 was associated with less perioperative mortality compared to hospitals with a volume of < 9.

CONCLUSIONS

Data from this nationwide mandatory quality registry shows a significant effect of hospital volume on perioperative mortality following complex EVAR, with high volume complex EVAR centers demonstrating lower mortality rates.

Inaccurate Risk Assessment by the ACS NSQIP Risk Calculator in Aortic Surgery

OBJECTIVES

The aim of this retrospective study was to assess the predictive performance of the American College of Surgeons (ACS) risk calculator for aortic aneurysm repair for the patient population of a Dutch tertiary referral hospital.

METHODS

This retrospective study included all patients who underwent elective endovascular or open aortic aneurysm repair at our institution between the years 2013 and 2019. Preoperative patient demographics and postoperative complication data were collected, and individual risk assessments were generated using five different current procedural terminology (CPT) codes. Receiver operating characteristic (ROC) curves, calibration plots, Brier scores, and Index of Prediction Accuracy (IPA) values were generated to evaluate the predictive performance of the ACS risk calculator in terms of discrimination and calibration.

RESULTS

Two hundred thirty-four patients who underwent elective endovascular or open aortic aneurysm repair were identified. Only five out of thirteen risk predictions were found to be sufficiently discriminative. Furthermore, the ACS risk calculator showed a structurally insufficient calibration. Most Brier scores were close to 0; however, comparison to a null model though IPA-scores showed the predictions generated by the ACS risk calculator to be inaccurate. Overall, the ACS risk calculator showed a consistent underestimation of the risk of complications.

CONCLUSIONS

The ACS risk calculator proved to be inaccurate within the framework of endovascular and open aortic aneurysm repair in our medical center. To minimize the effects of patient selection and cultural differences, multicenter collaboration is necessary to assess the performance of the ACS risk calculator in aortic surgery.

A New Doppler-Derived Parameter to Quantify Internal Carotid Artery Stenosis: Maximal Systolic Acceleration

OBJECTIVE

Doppler ultrasonography (DUS) is used as initial measurement to diagnose and classify carotid artery stenosis. Local distorting factors such as vascular calcification can influence the ability to obtain DUS measurements. The DUS derived maximal systolic acceleration (ACCmax) provides a different way to determine the degree of stenosis. While conventional DUS parameters are measured at the stenosis itself, ACCmax is measured distal to the internal carotid artery (ICA) stenosis. The value of ACCmax in ICA stenosis was investigated in this study.

MATERIAL AND METHODS

All carotid artery DUS studies of a tertiary academic center were reviewed from October 2007 until December 2017. Every ICA was included once. The ACCmax was compared to conventional DUS parameters: ICA peak systolic velocity (PSV), and PSV ratio (ICA PSV/ CCA PSV). ROC-curve analysis was used to evaluate accuracy of ACCmax, ICA PSV and PSV ratio as compared to CT-angiography (CTA) derived stenosis measurement as reference test.

RESULTS

The study population consisted of 947 carotid arteries and was divided into 3 groups: <50% (710/947), 50-69% (109/947), and ≥70% (128/947). Between these groups ACCmax was significantly different. Strong correlations between ACCmax and ICA PSV (R² 0.88) and PSV ratio (R² 0.87) were found. In ROC subanalysis, the ACCmax had a sensitivity of 90% and a specificity of 89% to diagnose a ≥70% ICA stenosis, and a sensitivity of 82% and a specificity of 88% to diagnose a ≥50% ICA stenosis. For diagnosing a ≥50% ICA stenosis the area under the curve (AUC) of ACCmax (0.88) was significantly lower than the AUC of PSV ratio (0.94) and ICA PSV (0.94). To diagnose a ≥70% ICA stenosis there were no significant differences in AUC between ACCmax (0.89), PSV ratio (0.93) and ICA PSV (0.94).

CONCLUSIONS

ACCmax is an interesting additional DUS measurement in determining the degree of ICA stenosis. ACCmax is measured distal to the stenosis and is not hampered by local distorting factors at the site of the stenosis. ACCmax can accurately diagnose an ICA stenosis, but was somewhat inferior compared to ICA PSV and PSV ratio to diagnose a ≥50% ICA stenosis.

Perfusion Patterns in Patients with Chronic Limb-Threatening Ischemia versus Control Patients Using Near-Infrared Fluorescence Imaging with Indocyanine Green

In assessing the severity of lower extremity arterial disease (LEAD), physicians rely on clinical judgements supported by conventional measurements of macrovascular blood flow. However, current diagnostic techniques provide no information about regional tissue perfusion and are of limited value in patients with chronic limb-threatening ischemia (CLTI). Near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) has been used extensively in perfusion studies and is a possible modality for tissue perfusion measurement in patients with CLTI. In this prospective cohort study, ICG NIR fluorescence imaging was performed in patients with CLTI and control patients using the Quest Spectrum Platform^® (Middenmeer, The Netherlands). The time–intensity curves were analyzed using the Quest Research Framework. Fourteen parameters were extracted. Successful ICG NIR fluorescence imaging was performed in 19 patients with CLTI and in 16 control patients. The time to maximum intensity (seconds) was lower for CLTI patients (90.5 vs. 143.3, p = 0.002). For the inflow parameters, the maximum slope, the normalized maximum slope and the ingress rate were all significantly higher in the CLTI group. The inflow parameters observed in patients with CLTI were superior to the control group. Possible explanations for the increased inflow include damage to the regulatory mechanisms of the microcirculation, arterial stiffness, and transcapillary leakage.

A histopathological classification scheme for abdominal aortic aneurysm disease

OBJECTIVE

Two consensus histopathological classifications for thoracic aortic aneurysms (TAAs) and inflammatory aortic diseases have been issued to facilitate clinical decision-making and inter-study comparison. However, these consensus classifications do not specifically encompass abdominal aortic aneurysms (AAAs). Given its high prevalence and the existing profound pathophysiologic knowledge gaps, extension of the consensus classification scheme to AAAs would be highly instrumental. The aim of this study was to test the applicability of, and if necessary to adapt, the issued consensus classification schemes for AAAs.

METHODS

Seventy-two AAA anterolateral wall samples were collected during elective and emergency open aneurysm repair performed between 2002 and 2013. Histologic analysis (hematoxylin and eosin and Movat Pentachrome) and (semi-quantitative and qualitative) grading were performed in order to map the histological aspects of AAA. Immunohistochemistry was performed for visualization of aspects of the adaptive and innate immune system, and for a more detailed analysis of atherosclerotic lesions in AAA.

RESULTS

Because the existing consensus classification schemes do not adequately capture the aspects of AAA disease, an AAA-specific 11-point histopathological consensus classification was devised. Systematic application of this classification indicated several universal features for AAA (eg, [almost] complete elastolysis), but considerable variation for other aspects (eg, inflammation and atherosclerotic lesions).

CONCLUSIONS

This first multiparameter histopathological AAA consensus classification illustrates the sharp histological contrasts between thoracic and abdominal aneurysms. The value of the proposed scoring system for AAA disease is illustrated by its discriminatory capacity to identify samples from patients with a nonclassical (genetic) variant of AAA disease.

Towards Patient Centred Outcomes for Elective Abdominal Aortic Aneurysm Repair: A Scoping Review of Quality of Life Scales

OBJECTIVE

In order to better incorporate the patient's perspective in medical decision making, core outcome sets (COS) are being defined. In the field of abdominal aortic aneurysm (AAA), efforts to capture the patient's perspective focus on generic quantitative quality of life (QoL) scales. The question arises whether these quantitative scales adequately reflect the patient's perspective on QoL, and whether they can be included in the QoL aspect of COS. A scoping review of QoL assessment in the context of elective AAA repair was undertaken.

DATA SOURCES

PubMed, Embase, Web of Science, and the Cochrane Library.

REVIEW METHODS

A scoping review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines. Articles reporting QoL assessment in the context of elective AAA repair were identified. Quantitative studies (i.e., traditional QoL scales) were aligned (triangulation approach) with qualitative studies (i.e., patient perspective) to identify parallels and discrepancies. Mean Short Form 36 item survey (SF-36) scores were pooled using a random effects model to evaluate sensitivity to change.

RESULTS

Thirty-three studies were identified, of which 29 (88%) were quantitative and four (12%) qualitative. The 33 studies reported a total of 54 quantitative QoL scales; the most frequently used were the generic SF-36 (16 studies) and five dimension EuroQol (EQ-5D; eight studies). Aneurysm specific scales were reported by one study. The generic quantitative scales showed poor alignment with the patient's perspective. The aneurysm specific scales better aligned but missed "concerns regarding symptoms" and "the impact of possible outcomes/complications". "Self control and decision making", which was brought forward by patients in qualitative studies, was not captured in any of the current scales.

CONCLUSION

There is no established tool that fully captures all aspects of the patient's perspective appropriate for a COS for elective AAA repair. In order to fulfil the need for a COS for the management of^, AAA disease, a more comprehensive overview of the patient's perspective is required.

Near-infrared fluorescence imaging with indocyanine green for quantification of changes in tissue perfusion following revascularization

OBJECTIVES

Current diagnostic modalities for patients with peripheral artery disease (PAD) mainly focus on the macrovascular level. For assessment of tissue perfusion, near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) seems promising. In this prospective cohort study, ICG NIR fluorescence imaging was performed pre- and post-revascularization to assess changes in foot perfusion.

METHODS

ICG NIR fluorescence imaging was performed in 36 patients with PAD pre- and post-intervention. After intravenous bolus injection of 0.1 mg/kg ICG, the camera registered the NIR fluorescence intensity over time on the dorsum of the feet for 15 min using the Quest Spectrum Platform®. Time-intensity curves were plotted for three regions of interest (ROI): (1) the dorsum of the foot, (2) the forefoot, and (3) the hallux. Time-intensity curves were normalized for maximum fluorescence intensity. Extracted parameters were the maximum slope, area under the curve (AUC) for the ingress, and the AUC for the egress. The non-treated contralateral leg was used as a control group.

RESULTS

Successful revascularization was performed in 32 patients. There was a significant increase for the maximum slope and AUC egress in all three ROIs. The most significant difference was seen for the maximum slope in ROI 3 (3.7%/s to 6.6%/s, p < 0.001). In the control group, no significant differences were seen for the maximum slope and AUC egress in all ROIs.

CONCLUSIONS

This study shows the potential of ICG NIR fluorescence imaging in assessing the effect of revascularization procedures on foot perfusion. Future studies should focus on the use of this technique in predicting favorable outcome of revascularization procedures.

Functional Performance After Complex Endovascular Aortic Repair: A Single-Center Retrospective Cohort Study

Purpose

Complex endovascular aortic repair (EVAR) procedures provide a treatment option for patients with aortic aneurysms involving visceral branches. Good technical results and short-term outcomes have been reported. Whether complex EVAR provides acceptable functional outcomes is not clear. The current study aims to describe postoperative functional outcomes in complex EVAR patients—an older and relatively frail patient group.

Materials and Methods

A single-center retrospective cohort study was performed, using data from a computerized database of consecutive patients who underwent complex EVAR in the Leiden University Medical Center (LUMC, The Netherlands) between July 2013 and September 2020. As of May 2017, patients scheduled for complex EVAR were referred to a geriatric care pathway to determine (Instrumental) Activities of Daily Living ((I)ADL) scores at baseline and, if informed consent was given, after 12 months. For the total patient group, adverse functional performance outcomes were: discharge to a nursing home and 12-month mortality. For the patients included in geriatric follow-up, the additional outcome was the incidence of functional decline (defined by a ≥2 point increase in (I)ADL-score) at 12-month follow-up

Results

Eighty-two patients underwent complex EVAR, of which 68 (82.9%) were male. Mean age was 73.3 years (SD=6.3). Within 30 days postsurgery, 6 patients (7.3%) died. Mortality within 12 months for the total patient group was 14.6% (n=12). After surgery, no patients had to be discharged to a nursing home. Fifteen patients (18.3%) were discharged to a rehabilitation center. Twenty-three patients gave informed consent and were included in geriatric follow-up. Five patients (21.7%) presented functional decline 12 months postsurgery and 4 patients had died (17.4%) by that time. This means that 39.1% of the patients in the care pathway suffered an adverse outcome.

Conclusion

To our knowledge, this is the only study that examined functional performance after complex EVAR, using a prospectively maintained database. No patients were newly discharged to a nursing home and functional performance results at 12 months are promising. Future multidisciplinary research should focus on determining which patients are most prone to deterioration of function, so that efforts can be directed toward preventing postoperative functional decline.

Assessment of Tissue Viability Following Amputation Surgery Using Near-Infrared Fluorescence Imaging With Indocyanine Green

BACKGROUND

Patients with chronic limb threatening ischemia have a risk of undergoing a major amputation within 1 year of nearly 30% with a substantial risk of re-amputation since wound healing is often impaired. Quantitative assessment of regional tissue viability following amputation surgery can identify patients at risk for impaired wound healing. In quantification of regional tissue perfusion, near-infrared (NIR) fluorescence imaging using Indocyanine Green (ICG) seems promising.

METHODS

This pilot study included adult patients undergoing lower extremity amputation surgery due to peripheral artery disease or diabetes mellitus. ICG NIR fluorescence imaging was performed within 5 days following amputation surgery using the Quest Spectrum Platform^Ⓡ. Following intravenous administration of ICG, the NIR fluorescence intensity of the amputation wound was recorded for 10 minutes. The NIR fluorescence intensity videos were analyzed and if a fluorescence deficit was observed, this region was marked as "low fluorescence." All other regions were marked as "normal fluorescence."

RESULTS

Successful ICG NIR fluorescence imaging was performed in 10 patients undergoing a total of 15 amputations. No "low fluorescence" regions were observed in 11 out of 15 amputation wounds. In 10 out of these 11 amputations, no wound healing problems occurred during follow-up. Regions with "low fluorescence" were observed in 4 amputation wounds. Impaired wound healing corresponding to these regions was observed in all wounds and a re-amputation was necessary in 3 out of 4. When observing time-related parameters, regions with low fluorescence had a significantly longer time to maximum intensity (113 seconds vs. 32 seconds, P = 0.003) and a significantly lesser decline in outflow after five minutes (80.3% vs. 57.0%, P = 0.003).

CONCLUSIONS

ICG NIR fluorescence imaging was able to predict postoperative skin necrosis in all four cases. Quantitative assessment of regional perfusion remains challenging due toinfluencing factors on the NIR fluorescence intensity signal, including camera angle, camera distance and ICG dosage. This was also observed in this study, contributing to a large variety in fluorescence intensity parameters among patients. To provide surgeons with reliable NIR fluorescence cut-off values for prediction of wound healing, prospective studies on the intra-operative use of this technique are required. The potential prediction of wound healing using ICG NIR fluorescence imaging will have a huge impact on patient mortality, morbidity as well as the burden of amputation surgery on health care.

Effects of hospital preference for endovascular repair on postoperative mortality after elective abdominal aortic aneurysm repair: analysis of the Dutch Surgical Aneurysm Audit

BACKGROUND

Increased use of endovascular aneurysm repair (EVAR) and reduced open surgical repair (OSR), has decreased postoperative mortality after elective repair of abdominal aortic aneurysms (AAAs). The choice between EVAR or OSR depends on aneurysm anatomy, and the experience and preference of the vascular surgeon, and therefore differs between hospitals. The aim of this study was to investigate the current mortality risk difference (RD) between EVAR and OSR, and the effect of hospital preference for EVAR on overall mortality.

METHODS

Primary elective infrarenal or juxtarenal aneurysm repairs registered in the Dutch Surgical Aneurysm Audit (2013-2017) were analysed. First, mortality in hospitals with a higher preference for EVAR (high-EVAR group) was compared with that in hospitals with a lower EVAR preference (low-EVAR group), divided by the median percentage of EVAR. Second, the mortality RD between EVAR and OSR was determined by unadjusted and adjusted linear regression and propensity-score (PS) analysis and then by instrumental-variable (IV) analysis, adjusting for unobserved confounders; percentage EVAR by hospital was used as the IV.

RESULTS

A total of 11 997 patients were included. The median hospital rate of EVAR was 76.6 per cent. The overall mortality RD between high- and low-EVAR hospitals was 0.1 (95 per cent -0.5 to 0.4) per cent. The OSR mortality rate was significantly higher among high-EVAR hospitals than low-EVAR hospitals: 7.3 versus 4.0 per cent (RD 3.3 (1.4 to 5.3) per cent). The EVAR mortality rate was also higher in high-EVAR hospitals: 0.9 versus 0.7 per cent (RD 0.2 (-0.0 to 0.6) per cent). The RD following unadjusted, adjusted, and PS analysis was 4.2 (3.7 to 4.8), 4.4 (3.8 to 5.0), and 4.7 (4.1 to 5.3) per cent in favour of EVAR over OSR. However, the RD after IV analysis was not significant: 1.3 (-0.9 to 3.6) per cent.

CONCLUSION

Even though EVAR has a lower mortality rate than OSR, the overall effect is offset by the high mortality rate after OSR in hospitals with a strong focus on EVAR.

Perfusion Parameters in Near-Infrared Fluorescence Imaging with Indocyanine Green: A Systematic Review of the Literature

(1) Background: Near-infrared fluorescence imaging is a technique capable of assessing tissue perfusion and has been adopted in various fields including plastic surgery, vascular surgery, coronary arterial disease, and gastrointestinal surgery. While the usefulness of this technique has been broadly explored, there is a large variety in the calculation of perfusion parameters. In this systematic review, we aim to provide a detailed overview of current perfusion parameters, and determine the perfusion parameters with the most potential for application in near-infrared fluorescence imaging. (2) Methods: A comprehensive search of the literature was performed in Pubmed, Embase, Medline, and Cochrane Review. We included all clinical studies referencing near-infrared perfusion parameters. (3) Results: A total of 1511 articles were found, of which, 113 were suitable for review, with a final selection of 59 articles. Near-infrared fluorescence imaging parameters are heterogeneous in their correlation to perfusion. Time-related parameters appear superior to absolute intensity parameters in a clinical setting. (4) Conclusions: This literature review demonstrates the variety of parameters selected for the quantification of perfusion in near-infrared fluorescence imaging.

Preoperative Anticoagulation Management in Everyday Clinical Practice: An International Comparative Analysis of Work-as-Done Using the Functional Resonance Analysis Method

OBJECTIVES

Preoperative anticoagulation management (PAM) is a complex, multidisciplinary process important to patient safety. The Functional Resonance Analysis Method (FRAM) is a novel method to study how complex processes usually go right at the frontline (labeled Safety-II) and how this relates to predefined procedures. This study aimed to assess PAM in everyday practice and explore the usability and utility of FRAM.

METHODS

The study was conducted at an Australian and European Cardiothoracic Surgery Department. A FRAM model of work-as-imagined was developed using (inter)national guidelines. Semistructured interviews with 18 involved professionals were used to develop models reflecting work-as-done at both sites, which were presented to staff for validation. Workload in hours was estimated per process step.

RESULTS

In both centers, work-as-done differed from work-as-imagined, such as in the division of tasks among disciplines (e.g., nurses/registrars rather than medical specialists), but control mechanisms had been developed locally to ensure safe care (e.g., crosschecking with other clinicians). Centers had organized the process differently, revealing opportunities for improvement regarding patient information and clustering of clinic visits. Presenting FRAM models to staff initiated discussion on improvement of functions in the model that are vital for success. Overall workload was estimated at 47 hours per site.

CONCLUSIONS

This FRAM analysis provided insight into PAM from the perspective of frontline clinicians, revealing essential functions, interdependencies and variability, and the relation with guidelines. Future studies are warranted to study the potential of FRAM, such as for guiding improvements in complex systems.

Learning From Morbidity and Mortality Conferences: Focus and Sustainability of Lessons for Patient Care

OBJECTIVE

It remains unclear to what extent the morbidity and mortality conference (M&M) meets the objective of improving quality and safety of patient care. It has been suggested that M&M may be too focused on individual performance, hampering system-level improvement. The aim of this study was to assess focus and sustainability of lessons for patient care that were derived from M&M.

METHODS

This is an observational study of routinely collected data on evaluated complications and identified lessons at surgical M&M for 8 years, assessing type and recurrence of lessons and cases from which these were drawn. Semistructured interviews with clinicians were qualitatively analyzed to explore factors contributing to lesson focus and recurrence.

RESULTS

Three hundred eighteen lessons were drawn from 10,883 evaluated complications, primarily for those that were more severe, related to surgical or other treatment, and occurring in nonemergent, lower risk cases (all P < 0.001). Most lessons targeted intraoperative (43%) rather than preoperative or postoperative care as well as specifically technical (87%) and individual-level issues (74%). There were 43 recurring lessons (14%), mostly about postoperative care (47%) and medication management (50%). Interviewed clinicians attributed the intraoperative, technical focus primarily to greater appeal and control but identified an array of factors contributing to lesson recurrence, such as typical staff turnover in teaching hospitals.

CONCLUSIONS

This study provided empirical evidence that learning at M&M has a tendency to focus on intraoperative, technical performance, with challenges to sustain lessons for more system-level issues. Morbidity and mortality conference formats need to anticipate these tendencies to ensure a wide focus for learning with lasting and wide impact.

The Association Between Complications, Incidents, and Patient Experience: Retrospective Linkage of Routine Patient Experience Surveys and Safety Data

OBJECTIVES

Linkage of safety data to patient experience data may provide information to improve surgical care. This retrospective observational study aimed to assess associations between complications, incidents, patient-reported problems, and overall patient experience.

METHODS

Routinely collected data from safety reporting on complications and incidents, as well as patient-reported problems and experience on the Picker Patient Experience Questionnaire 15, covering seven experience dimensions, were linked for 4236 surgical inpatients from an academic center (April 2014-December 2015, 41% response). Associations between complication and/or incident occurrence and patient-reported problems, regarding risk of nonpositive experience (i.e., grade of 1-5 of 10), were studied using multivariable logistic regression.

RESULTS

Patient-reported problems were associated with occurrence of complications/incidents among patients with nonpositive experiences (odds ratio [OR] = 2.8, 95% confidence interval [CI] = 1.6-4.9), but not among patients with positive experiences (OR = 1.0, 95% CI = 0.6-1.5). For each experience dimension, presence of patient-reported problems increased risk of nonpositive experience (OR range = 2.7-4.4). Patients with complications or incidents without patient-reported problems were at lower risk of a nonpositive experience than patients with neither complications/incidents nor reported problems (OR = 0.5; 95% CI = 0.3-0.9). Occurrence of complications/incidents only increased risk of nonpositive experience when patients also had problems on "continuity and transition" or "respect for patient preferences" dimensions.

CONCLUSIONS

Linking safety data to patient experience data can reveal ways to optimize care. Staff seem able to ensure positive patient experiences despite complications or incidents. Increased attention should be paid to respecting patient preferences, continuity, and transition, particularly when complications or incidents occur.

Systematic approach towards reliable estimation of abdominal aortic aneurysm size by ultrasound imaging and CT

Background

The management of abdominal aortic aneurysm (AAA) is fully dictated by AAA size, but there are no uniform measurement guidelines, and systematic differences exist between ultrasound- and CT-based size estimation. The aim of this study was to devise a uniform ultrasound acquisition and measurement protocol, and to test whether harmonization of ultrasound and CT readings is feasible.

Methods

A literature review was undertaken to evaluate evidence for ultrasound-based measurement of AAA. A protocol for measuring AAA was then developed, and intraobserver and interobserver reproducibility was tested. Finally, agreement between ultrasound readings and CT-based AAA diameters was evaluated. This was an observational study of patients with a small AAA who participated in two pharmaceutical intervention trials.

Results

Based on a literature review, an ultrasound acquisition and reading protocol was devised. Evaluation of the protocol showed an intraobserver repeatability of 1.6 mm (2s.d.) and an interobserver intraclass correlation coefficient (ICC) of 0.97. Comparison of protocolled ultrasound readings and local CT readings indicated a good correlation (r = 0.81), but a systematic +4.1-mm difference for CT. Harmonized size readings for ultrasound imaging and CT increased the correlation (r = 0.91) and reduced the systematic difference to +1.8 mm by CT. Interobserver reproducibility of protocolized CT measurements showed an ICC of 0.94 for the inner-to-inner method and 0.96 for the outer-to-outer method.

Conclusion

The absence of harmonized size acquisition and reading guidelines results in overtreatment and undertreatment of patients with AAA. This can be avoided by the implementation of standardized ultrasound acquisition and a harmonized reading protocol for ultrasound- and CT-based readings.

Stakeholder Values and Preferences in Lower Limb Amputation for No-Option Chronic Limb Threatening Ischemia

PURPOSE

This study focusses on identifying values and preferences of patients, caregivers and healthcare professionals who have dealt with lower limb amputation for no-option chronic limb threatening ischemia. No-option chronic limb threatening ischemia is defined as limb ischemia for which no treatment options exist and where lower limb amputation is necessary in the short term. The values and preferences identified in this study can help improve decision-making processes.

PATIENTS AND METHODS

This was a qualitative study, using semi-structured interviews to gather data from patients, caregivers and healthcare professionals. Participants were selected from the patient and employee population of an academic medical center in The Netherlands. Nine patients and seven caregivers who dealt with lower limb amputation for no-option chronic limb threatening ischemia six to twelve months prior to the interview and were not cognitively impaired were selected. Nine healthcare professionals dealing with patients with no-option chronic limb threatening ischemia and lower limb amputation were selected.

RESULTS

Lower limb amputation was explicitly discussed late in the disease process, sometimes during an emergency setting. Patients stated goals were never discussed, healthcare professionals stated they were. The most important goal for patients was to live independently after lower limb amputation. Patients and caregivers feel healthcare professionals should be upfront about the possible necessity of lower limb amputation. Reasons to undergo lower limb amputation were absence of treatment options, pain and wanting to enjoy life again. Participants indicated accelerating lower limb amputation was not a viable option.

CONCLUSION

All stakeholders reported overlapping values and preferences regarding main reasons for lower limb amputation, the primary goals after lower limb amputation, and the absence of a desire to accelerate lower limb amputation. The main difference in values and preferences is the preferred timing of discussing lower limb amputation.