Outcomes of fenestrated and branched endovascular aneurysm repair with an inverted contralateral limb.

OBJECTIVE: To report technical success and evaluate clinical outcomes of fenestrated and branched endovascular aortic repair (F/B-EVAR) incorporating a contralateral inverted limb. METHODS: Patients who underwent F/B-EVAR with a custom-made bifurcated device containing an inverted limb between January 2010 and September 2023 were retrospectively analyzed. Time-to-event data were analyzed using the Kaplan-Meier method. RESULTS: A total of 32 patients (26 men; mean age 77±6.2 years) were included in the analysis. Technical success was achieved in 28 patients (87.5%). Two technical failures resulted from misplaced contralateral limbs in patients with previous endovascular aortic repair (EVAR), necessitating one open conversion due to a type 3b endoleak, and one femoro-femoral crossover bypass after occlusion of a misplaced contralateral limb. Additionally, two technical failures were attributed to a type 3c endoleak and a type 1c endoleak, originating from a fenestrated device at the level of the left and right renal artery, respectively. One patient (3.1%) died <30 days post-operatively due to a subdural hemorrhage. Estimated patient survival after 1 and 2 years was 92.7%±5.1%, and 74.3%±10.1%, respectively. No aneurysm-related deaths were observed. During the median follow-up of 13 months, one (3.1%) inverted limb occluded, in addition to the occlusion resulting from a misplaced contralateral limb, and was treated with a femoro-femoral crossover bypass. One target vessel (right renal artery) occluded (0.9%), resulting in a permanent, significantly reduced renal function. Freedom from overall reintervention after 1 and 2 years was 73.5%±8.0% and 68.3%±9.0%, respectively. An additional four patients (12.5%) presented with a type 3c endoleak during follow-up scans, three of which originated from fenestrations at the level of the renal stents. There were no junctional problems between the inverted limb device and the main endograft, and no significant correlation was found between the one-sealing-stent inverted limb device design and the onset of type 3 endoleak (log-rank p=.064). CONCLUSION: F/B-EVAR incorporating an inverted limb can be a viable endovascular option to manage complex aneurysms with a short renal artery to bifurcation distance. However, using the inverted limb presents a notable technical challenge and could be associated with a higher need for reintervention. Carefully confirming correct cannulation of the inverted limb is warranted.

Is patient-reported outcome after treatment of unstable pelvic ring injuries related to pelvic symmetry? A prospective study.

PURPOSE: To determine the relation between pelvic symmetry, as measured by the cross-measurement technique, and patient-reported outcome measures (PROMs) in terms of functional status and health-related quality of life. METHODS: In this prospective cohort study, X and Y measurements were taken according to the cross-measurement technique on AP radiographs of patients who were treated for an unstable pelvic ring injury in a level-1 trauma center. Patients completed PROMs at the time of admission (recalled pre-injury score) and one year following their injury, reporting their functional status with the Short Musculoskeletal Function Assessment (SMFA-NL), specifically the lower extremity dysfunction (LED), problems with daily activities (PDA) and mental and emotional problems (MEP) subscales, and quality of life with EuroQol-5D (EQ-5D). Subgroup analyses were also performed. PROMs were used to analyze the relation between pelvic symmetry and patient-reported outcome, using Spearman's Rank correlation coefficients. RESULTS: A total of 130 patients (mean age 58 (SD18) years) with an unstable pelvic ring injury were included, of which 95 (73%) sustained type-B injuries and 35 (27%) type-C injuries. Sixty-three (49%) patients were treated operatively. The median pelvic symmetry ratio was 1.01 (IQR: 0.05). Weak or no correlations were found between the pelvic symmetry scores and the outcome measurements (Spearman's correlation coefficients: LED r = 0.09; PDA r = 0.11; MEP r=-0.02; and EQ-5D r=-0.08). Subgroup analyses revealed no correlations. CONCLUSIONS: No significant relation was found between pelvic symmetry, measured radiologically, and functional status and health-related quality of life, one year following an unstable pelvic ring injury.

Machine Learning Based Prediction of Post-operative Infrarenal Endograft Apposition for Abdominal Aortic Aneurysms.

OBJECTIVE: Challenging infrarenal aortic neck characteristics have been associated with an increased risk of type Ia endoleak after endovascular aneurysm repair (EVAR). Short apposition (< 10 mm circumferential shortest apposition length [SAL]) on the first post-operative computed tomography angiography (CTA) has been associated with type Ia endoleak. Therefore, this study aimed to develop a model to predict post-operative SAL in patients with an abdominal aortic aneurysm based on the pre-operative shape. METHODS: A statistical shape model was developed to obtain principal component scores. The dataset comprised patients treated by standard EVAR without complications (n = 93) enriched with patients with a late type Ia endoleak (n = 54). The infrarenal SAL was obtained from the first post-operative CTA and subsequently binarised (< 10 mm and ≥ 10 mm). The principal component scores that were statistically different between the SAL groups were used as input for five classification models, and evaluated by means of leave one out cross validation. Area under the receiver operating characteristic curves (AUC), accuracy, sensitivity, and specificity were determined for each classification model. RESULTS: Of the 147 patients, 24 patients had an infrarenal SAL < 10 mm and 123 patients had a SAL ≥ 10 mm. The gradient boosting model resulted in the highest AUC of 0.77. Using this model, 114 patients (77.6%) were correctly classified; sensitivity (< 10 mm apposition was correctly predicted) and specificity (≥ 10 mm apposition was correctly predicted) were 0.70 and 0.79 based on a threshold of 0.21, respectively. CONCLUSION: A model was developed to predict which patients undergoing EVAR will achieve sufficient graft apposition (≥ 10 mm) in the infrarenal aortic neck based on a statistical shape model of pre-operative CTA data. This model can help vascular specialists during the planning phase to accurately identify patients who are unlikely to achieve sufficient apposition after standard EVAR.

Geometric Analysis of the Gore Excluder Conformable Endoprosthesis in the Infrarenal Aortic Neck: One Year Results of the EXCeL Registry.

OBJECTIVE: The Gore Excluder Conformable Endoprosthesis (CEXC) is designed to treat challenging infrarenal anatomy because of its active angulation control, repositionability, and enhanced conformability. This study evaluated 30 day and one year position and apposition of the CEXC in the infrarenal neck. METHODS: Patients treated with the CEXC between 2018 and 2022 with an available 30 day computed tomography angiogram (CTA) were selected from four hospitals in a prospective registry. Endograft apposition (shortest apposition length [SAL]) and position (shortest fabric distance [SFD]) were assessed on the 30 day and one year CTAs. Maximum infrarenal aortic curvature was compared between the pre- and post-operative CTAs to evaluate conformability of the CEXC. RESULTS: There were 87 patients with a 30 day CTA, and for 56 of these patients the one year CTA was available. Median (interquartile range [IQR]) pre-operative neck length was 22 mm (IQR 15, 32) and infrarenal angulation was 52° (IQR 31, 72). Median SAL was 21.2 mm (IQR 14.0, 29.3) at 30 days for all included patients. The SAL in 13 patients (15%) was < 10 mm at 30 days, and one patient had a SAL of 0 mm and a type Ia endoleak. There was no significant difference in SAL between patients within and outside instructions for use. The SAL significantly increased by 1.1 mm (IQR -2.3, 4.7; p = .042) at one year. The SAL decreased in seven patients (13%), increased in 13 patients (23%), and remained stable in 36 patients (64%). Median SFD was 2.0 mm (IQR 0.5, 3.6) at 30 days, which slightly increased by 0.3 mm (IQR -0.5, 1.8; p = .019) at one year. One patient showed migration (SFD increase ≥ 5 mm). Median endograft tilt was 15.8° (IQR 9.7, 21.4). Pre-operative maximum infrarenal curvature was 36 m-1 (IQR 26, 56) and did not significantly change thereafter. CONCLUSION: In most patients, the CEXC was implanted close to the renal arteries, and sufficient (≥ 10 mm) post-operative apposition was achieved at 30 days, which slightly increased at one year. Post-operative endograft tilt was relatively low, and aortic geometry remained unchanged after implantation of the CEXC, probably due to its high conformability.

Endosutured Aneurysm Repair of Abdominal Aortic Aneurysms with Short Necks Achieves Acceptable Midterm Outcomes-Results from the Peru Registry.

BACKGROUND: The study aims to describe midterm outcomes following treatment of infrarenal abdominal aortic aneurysms (AAAs) with short necks by endosutured aneurysm repair using the Heli-FX EndoAnchor system. METHODS: This is a retrospective study of prospectively collected data from 9 vascular surgery departments between June 2010 and December 2019, including treated AAAs with neck lengths ≤10 mm. The decision for the use of EndoAnchors was made by the treating surgeon or multidisciplinary aortic committee according to each center's practice. There were 2 Groups further assessed according to neck length, A (≥4 and <7 mm) and B (≥7 and ≤10 mm). The main outcomes analyzed were technical success, freedom from type Ia endoleaks (TIaELs), sac size increase, all-cause and aneurysm-related mortality. RESULTS: Seventy-six patients were included in the study, 17 fell into Group A and 59 into Group B. Median follow-up for the cohort was 40.5 (interquartile range 12-61) months. A median of 6 (interquartile range 3) EndoAnchors were deployed in each subject. Technical success was 86.8% for the total group, 82.4% and 88.1% (P = 0.534) for Groups A and B respectively. Six out of 10 (60%) of TIaELs at the completion angiographies showed spontaneous resolution. Cumulative freedom from TIaEL at 3 and 5 years for the total group was 89% and 84% respectively; this was 93% and 74% for Group A and 88% at both intervals in Group B (P = 0.545). In total, there were 7 (9.2%) patients presenting with TIaELs over the entire study period. Two (11.8%) in Group A and 5 (8.5%) in Group B (P = 0.679). There were more patients with sac regression in Group B (Group A = 6-35.3% vs. Group B = 34-57.6%, P = 0.230) with no statistical significance. All-cause mortality was 19 (25%) patients, with no difference (4-23.5% vs. 15-25.4%, P = 0.874) between groups; whereas aneurysm-related mortality occurred in 1 patient from Group A and 3 from Group B. CONCLUSIONS: This study demonstrates reasonable outcomes for patients with short-necked AAAs treated by endosutured aneurysm repair in terms of TIaELs up to 5-year follow-up. EndoAnchor use should be judiciously evaluated in short necks and may be a reasonable option when anatomical constraints are encountered, mainly for those with 7-10 mm neck lengths. Shorter neck length aspects, as indicated by the results from Group A, may be an alternative when no other options are available or feasible.

Importance of sac regression after EVAR and the role of EndoAnchors.

The initial success and widespread adoption of endovascular aneurysm repair (EVAR) for the treatment of abdominal aortic aneurysms have been tempered by numerous reports of secondary interventions and increased long-term mortality compared with open repair. Over the past decade, several studies on postoperative sac dynamics after EVAR have suggested that the presence of sac regression is a benign feature with a favorable prognosis. Conversely, increasing sacs and even stable sacs can be indicators of more unstable sac behavior with worse outcomes in the long-term. Endoleaks were initially perceived as the main drivers of sac behavior. However, the observation that sac regression can occur in the presence of endoleaks, and vice versa - increasing sacs without evidence of endoleak - on imaging studies, suggests the involvement of other contributing factors. These factors can be divided into anatomical factors, patient characteristics, sac thrombus composition, and device-related factors. The shift of interest away from especially type 2 endoleaks is further supported by promising results with the use of EndoAnchors regarding postoperative sac behavior. This review provides an overview of the existing literature on the implications and known risk factors of post-EVAR sac behavior, describes the accurate measurement of sac behavior, and discusses the use of EndoAnchors to promote sac regression.

Health Literacy and Disease Knowledge of Patients With Peripheral Arterial Disease or Abdominal Aortic Aneurysm: A Scoping Review.

OBJECTIVE: This scoping review summarises health literacy and disease knowledge in patients with abdominal aortic aneurysm (AAA) or peripheral arterial disease (PAD) and the influencing factors. DATA SOURCES: A systematic search was conducted in PubMed, Embase, PsychINFO, and CINAHL covering the period January 2012 to October 2022. REVIEW METHODS: This scoping review was undertaken in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Inclusion criteria encompassed studies addressing health literacy, knowledge, perception, or awareness in patients with AAA or PAD. Two authors independently reviewed abstracts and full texts, resolving any discrepancies through discussion or by consulting a third author for consensus. All article types were included except letters, editorials, study protocols, reviews, and guidelines. No language restrictions were applied. Primary outcomes were health literacy and disease knowledge. Secondary outcomes were factors that could influence this. Quality assessment was done using the Mixed Methods Appraisal Tool (MMAT). RESULTS: The review included 32 articles involving a total of 5 268 patients. Four articles reported health literacy and the rest disease knowledge. Ten studies (31%) met all quality criteria. Twenty studies were quantitative, eight were qualitative, and four were mixed methods studies. The review revealed inadequate health literacy in the majority of patients, and disease knowledge was relatively low among patients with AAA and PAD, with disparities in measures and assessment tools across studies. Factors influencing health literacy and disease knowledge included socioeconomic status, education, income, and employment. CONCLUSION: This scoping review revealed low health literacy and low disease knowledge in patients with AAA and PAD. Standardised health literacy assessment may contribute to improve communication strategies and decision aids to enhance patients' understanding and engagement in healthcare decisions, however further research is needed to prove its merits.

Safety and Feasibility of the BYCROSS® Atherectomy Device for the Treatment of Femoropopliteal Arterial Obstructions: Single-Center Short-Term Outcomes.

Background: Endovascular techniques have gained preference over peripheral arterial bypass surgery due to their minimally invasive nature; however, endovascular treatments often show limited efficacy in arterial segments with a high atherosclerotic load. The use of atherectomy devices enables the removal of calcified plaque material and may promote arterial wall remodeling. This study assessed the technical success, safety, and feasibility of the BYCROSS® atherectomy device in femoropopliteal lesions. Methods: This single-center, retrospective cohort study analyzed elective patients undergoing BYCROSS® atherectomy for chronic peripheral arterial disease from March 2022 to May 2023. Patient data, procedural details, and outcomes were retrospectively collected from electronic patient records. The primary performance endpoints of this study were technical success, complications, and patency rates. Primary safety endpoints included 30-day and short-term major adverse limb events (MALEs), major adverse cardiovascular events (MACEs), and mortality rate. Results: The study included 19 patients (median age, 71 years; 63% male) with Fontaine class IIb (26%), III (21%), or IV (53%). The BYCROSS® atherectomy device was used to treat 22 limbs in the femoropopliteal tract, of which 11 lesions (50%) were occlusions and 11 were stenoses, with a median length of 24 cm (interquartile range: 17-38). Technical success was achieved in all cases: 4.5% required atherectomy only, 50% required additional balloon angioplasties, 41% required balloon angioplasties and stenting, and 4.5% required segments only stenting. Additional treatment of below-the-knee arteries was performed in 12 patients. Procedurally related complications (not limited to the use of the BYCROSS® device) occurred in 23% of limbs, including distal embolization and laceration. At 30 days, mortality was 5%, the MACE rate was 11%, and the MALE rate was 0%. The observed mortality rate was not directly related to the procedure. Patency (<50% restenosis at duplex ultrasound) was 83% at 30 days. Conclusions: The use of the BYCROSS® atherectomy device for the treatment of femoropopliteal lesions appears to be safe and feasible, with high technical success and low MALE and MACE rates in a challenging population with long-segment femoropopliteal lesions. Long-term follow-up in larger patient series is needed to confirm these findings and to determine the durability of this technique.

3D-assisted corrective osteotomies of the distal radius: a comparison of pre-contoured conventional implants versus patient-specific implants.

PURPOSE: There is a debate whether corrective osteotomies of the distal radius should be performed using a 3D work-up with pre-contoured conventional implants (i.e., of-the-shelf) or patient-specific implants (i.e., custom-made). This study aims to assess the postoperative accuracy of 3D-assisted correction osteotomy of the distal radius using either implant. METHODS: Twenty corrective osteotomies of the distal radius were planned using 3D technologies and performed on Thiel embalmed human cadavers. Our workflow consisted of virtual surgical planning and 3D printed guides for osteotomy and repositioning. Subsequently, left radii were fixated with patient-specific implants, and right radii were fixated with pre-contoured conventional implants. The accuracy of the corrections was assessed through measurement of rotation, dorsal and radial angulation and translations with postoperative CT scans in comparison to their preoperative virtual plan. RESULTS: Twenty corrective osteotomies were executed according to their plan. The median differences between the preoperative plan and postoperative results were 2.6° (IQR: 1.6-3.9°) for rotation, 1.4° (IQR: 0.6-2.9°) for dorsal angulation, 4.7° (IQR: 2.9-5.7°) for radial angulation, and 2.4 mm (IQR: 1.3-2.9 mm) for translation of the distal radius, thus sufficient for application in clinical practice. There was no significant difference in accuracy of correction when comparing pre-contoured conventional implants with patient-specific implants. CONCLUSION: 3D-assisted corrective osteotomy of the distal radius with either pre-contoured conventional implants or patient-specific implants results in accurate corrections. The choice of implant type should not solely depend on accuracy of the correction, but also be based on other considerations like the availability of resources and the preoperative assessment of implant fitting.

3D surgical planning including patient-specific drilling guides for tibial plateau fractures.

Aims: Proper preoperative planning benefits fracture reduction, fixation, and stability in tibial plateau fracture surgery. We developed and clinically implemented a novel workflow for 3D surgical planning including patient-specific drilling guides in tibial plateau fracture surgery. Methods: A prospective feasibility study was performed in which consecutive tibial plateau fracture patients were treated with 3D surgical planning, including patient-specific drilling guides applied to standard off-the-shelf plates. A postoperative CT scan was obtained to assess whether the screw directions, screw lengths, and plate position were performed according the preoperative planning. Quality of the fracture reduction was assessed by measuring residual intra-articular incongruence (maximum gap and step-off) and compared to a historical matched control group. Results: A total of 15 patients were treated with 3D surgical planning in which 83 screws were placed by using drilling guides. The median deviation of the achieved screw trajectory from the planned trajectory was 3.4° (interquartile range (IQR) 2.5 to 5.4) and the difference in entry points (i.e. plate position) was 3.0 mm (IQR 2.0 to 5.5) compared to the 3D preoperative planning. The length of 72 screws (86.7%) were according to the planning. Compared to the historical cohort, 3D-guided surgery showed an improved surgical reduction in terms of median gap (3.1 vs 4.7 mm; p = 0.126) and step-off (2.9 vs 4.0 mm; p = 0.026). Conclusion: The use of 3D surgical planning including drilling guides was feasible, and facilitated accurate screw directions, screw lengths, and plate positioning. Moreover, the personalized approach improved fracture reduction as compared to a historical cohort.

Perceptions, Experiences, Barriers and Facilitators Regarding Nutritional Intake of Patients with Chronic Limb Threatening Ischemia: A Qualitative Study.

BACKGROUND: Patients with chronic limb threatening ischemia (CLTI) are at high risk for amputation and other cardiovascular adverse events. Nutrition-related symptoms and malnutrition are common in the CLTI population, and lead to worse clinical outcomes. Understanding of the factors influencing nutritional intake is required to determine whether optimization of nutritional intake in this population requires interventions. Therefore, this study aimed to describe perceptions and experiences on nutrition of patients with CLTI, and to identify perceived barriers and facilitators influencing their nutritional intake. METHODS: In this phenomenological qualitative study, individual semi-structured, face-to-face interviews were conducted with patients with CLTI who lived independently. Interviews were transcribed verbatim, and reflexive thematic analysis was performed. RESULTS: Twelve participants were interviewed. Five themes were generated: (1) lack of nutritional risk perception, (2) role of nutrition for health, functioning, and surviving, (3) multiple factors influencing nutritional intake, (4) limited nutritional advice, and (5) no intention to change current nutritional intake. CONCLUSIONS: Patients with CLTI perceive nutritional intake as a necessity to survive and function. Patients express limited risk perception regarding adequate nutritional intake and undernutrition. Nutritional intake is mainly based on non-health-related factors, as habits and taste, and multiple barriers hinder nutritional intake. Patients received no or only limited nutritional advice. Together this leads to an expressed lack of intention to change nutritional intake. Findings of this study stress the urgency for patient-centered nutritional support, to increase nutrition-related knowledge and motivation, to prevent or treat undernutrition, and may improve clinical outcomes in patients with CLTI.

Development of patient-specific osteosynthesis including 3D-printed drilling guides for medial tibial plateau fracture surgery.

PURPOSE: A substantial proportion of conventional tibial plateau plates have a poor fit, which may result in suboptimal fracture reduction due to applied -uncontrolled- compression on the bone. This study aimed to assess whether patient-specific osteosyntheses could facilitate proper fracture reduction in medial tibial plateau fractures. METHODS: In three Thiel embalmed human cadavers, a total of six tibial plateau fractures (three Schatzker 4, and three Schatzker 6) were created and CT scans were made. A 3D surgical plan was created and a patient-specific implant was designed and fabricated for each fracture. Drilling guides that fitted on top of the customized plates were designed and 3D printed in order to assist the surgeon in positioning the plate and steering the screws in the preplanned direction. After surgery, a postoperative CT scan was obtained and outcome was compared with the preoperative planning in terms of articular reduction, plate positioning, and screw direction. RESULTS: A total of six patient-specific implants including 41 screws were used to operate six tibial plateau fractures. Three fractures were treated with single plating, and three fractures with dual plating. The median intra-articular gap was reduced from 6.0 (IQR 4.5-9.5) to 0.9 mm (IQR 0.2-1.4), whereas the median step-off was reduced from 4.8 (IQR 4.1-5.3) to 1.3 mm (IQR 0.9-1.5). The median Euclidean distance between the centre of gravity of the planned and actual implant was 3.0 mm (IQR: 2.8-3.7). The lengths of the screws were according to the predetermined plan. None of the screws led to screw penetration. The median difference between the planned and actual screw direction was 3.3° (IQR: 2.5-5.1). CONCLUSION: This feasibility study described the development and implementation of a patient-specific workflow for medial tibial plateau fracture surgery that facilitates proper fracture reduction, tibial alignment and accurately placed screws by using custom-made osteosynthesis plates with drilling guides.

Initial and Residual 3D Fracture Displacement Is Predictive for Patient-Reported Functional Outcome at Mid-Term Follow-Up in Surgically Treated Tibial Plateau Fractures.

BACKGROUND: Conventional measures of fracture displacement have low interobserver reliability. This study introduced a novel 3D method to measure tibial plateau fracture displacement and its impact on functional outcome. METHODS: A multicentre study was conducted on patients who had tibial plateau fracture surgery between 2003 and 2018. Eligible patients had a preoperative CT scan (slice thickness ≤ 1 mm) and received a Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire. A total of 362 patients responded (57%), and assessment of initial and residual fracture displacement was performed via measurement using the 3D gap area (mm2). Patients were divided into four groups based on the 3D gap area size. Differences in functional outcome between these groups were assessed using analysis of variance (ANOVA). Multiple linear regression was used to determine the association between fracture displacement and patient-reported outcome. RESULTS: Functional outcome appeared significantly worse when initial or residual fracture displacement increased. Multivariate linear regression showed that initial 3D gap area (per 100 mm2) was significantly negatively associated with all KOOS subscales: symptoms (-0.9, p < 0.001), pain (-0.0, p < 0.001), ADL (-0.8, p = 0.002), sport (-1.4, p < 0.001), and QoL (-1.1, p < 0.001). In addition, residual gap area was significantly negatively associated with the subscales symptoms (-2.2, p = 0.011), ADL (-2.2, p = 0.014), sport (-2.6, p = 0.033), and QoL (-2.4, p = 0.023). CONCLUSION: A novel 3D measurement method was applied to quantify initial and residual displacement. This is the first study which can reliably classify the degree of displacement and indicates that increasing displacement results in poorer patient-reported functional outcomes.

Diagnostic potential of plasma biomarkers and exhaled volatile organic compounds in predicting the different stages of acute mesenteric ischaemia: protocol for a multicentre prospective observational study (TACTIC study).

INTRODUCTION: Acute mesenteric ischaemia (AMI) is a life-threatening condition with short-term mortality of up to 80%. The diagnosis of AMI has remained troublesome due to the non-specific clinical presentation, symptoms and laboratory findings. Early unambiguous diagnosis of AMI is critical to prevent progression from reversible to irreversible transmural intestinal damage, thereby decreasing morbidity and improving survival. The present study aims to validate a panel of plasma biomarkers and investigate volatile organic compound (VOC) profiles in exhaled air as a tool to timely and accurately diagnose AMI. METHODS AND ANALYSIS: In this international multicentre prospective observational study, 120 patients (>18 years of age) will be recruited with clinical suspicion of AMI. Clinical suspicion is based on: (1) clinical manifestation, (2) physical examination, (3) laboratory measurements and (4) the physician's consideration to perform a CT scan. The patient's characteristics, repetitive blood samples and exhaled air will be prospectively collected. Plasma levels of mucosal damage markers intestinal fatty acid-binding protein and villin-1, as well as transmural damage marker smooth muscle protein 22-alpha, will be assessed by ELISA. Analysis of VOCs in exhaled air will be performed by gas chromatography time-of-flight mass spectrometry. Diagnosis of AMI will be based on CT, endovascular and surgical reports, clinical findings, and (if applicable) verified by histopathological examination. ETHICS AND DISSEMINATION: The study protocol was approved by the Medical Research Ethics Committee (METC) of Maastricht University Medical Centre+ and Maastricht University (METC azM/UM), the Netherlands (METC19-010) and the Ethics Committee Research UZ/KU Leuven, Belgium (S63500). Executive boards and local METCs of other Dutch participating centres Gelre Ziekenhuizen (Apeldoorn), Medisch Spectrum Twente (Enschede), and University Medical Centre Groningen have granted permission to carry out this study. Study results will be disseminated via open-access peer-reviewed scientific journals and national/international conferences. TRIAL REGISTRATION NUMBER: NCT05194527.

Development of a Statistical Shape Model and Assessment of Anatomical Shape Variations in the Hemipelvis.

Knowledge about anatomical shape variations in the pelvis is mandatory for selection, fitting, positioning, and fixation in pelvic surgery. The current knowledge on pelvic shape variation mostly relies on point-to-point measurements on 2D X-ray images and computed tomography (CT) slices. Three-dimensional region-specific assessments of pelvic morphology are scarce. Our aim was to develop a statistical shape model of the hemipelvis to assess anatomical shape variations in the hemipelvis. CT scans of 200 patients (100 male and 100 female) were used to obtain segmentations. An iterative closest point algorithm was performed to register these 3D segmentations, so a principal component analysis (PCA) could be performed, and a statistical shape model (SSM) of the hemipelvis was developed. The first 15 principal components (PCs) described 90% of the total shape variation, and the reconstruction ability of this SSM resulted in a root mean square error of 1.58 (95% CI: 1.53-1.63) mm. In summary, an SSM of the hemipelvis was developed, which describes the shape variations in a Caucasian population and is able to reconstruct an aberrant hemipelvis. Principal component analyses demonstrated that, in a general population, anatomical shape variations were mostly related to differences in the size of the pelvis (e.g., PC1 describes 68% of the total shape variation, which is attributed to size). Differences between the male and female pelvis were most pronounced in the iliac wing and pubic rami regions. These regions are often subject to injuries. Future clinical applications of our newly developed SSM may be relevant for SSM-based semi-automatic virtual reconstruction of a fractured hemipelvis as part of preoperative planning. Lastly, for companies, using our SSM might be interesting in order to assess which sizes of pelvic implants should be produced to provide proper-fitting implants for most of the population.

Radiographic Predictors of Conversion to Total Knee Arthroplasty After Tibial Plateau Fracture Surgery: Results in a Large Multicenter Cohort.

BACKGROUND: Radiographic measurements of initial displacement of tibial plateau fractures and of postoperative reduction are used to determine treatment strategy and prognosis. We assessed the association between radiographic measurements and the risk of conversion to total knee arthroplasty (TKA) at the time of follow-up. METHODS: A total of 862 patients surgically treated for tibial plateau fractures between 2003 and 2018 were eligible for this multicenter cross-sectional study. Patients were approached for follow-up, and 477 (55%) responded. The initial gap and step-off were measured on the preoperative computed tomography (CT) scans of the responders. Condylar widening, residual incongruity, and coronal and sagittal alignment were measured on postoperative radiographs. Critical cutoff values for gap and step-off were determined using receiver operating characteristic curves. Postoperative reduction measurements were categorized as adequate or inadequate on the basis of cutoff values in international guidelines. Multivariable analysis was performed to assess the association between each radiographic measurement and conversion to TKA. RESULTS: Sixty-seven (14%) of the patients had conversion to TKA after a mean follow-up of 6.5 ± 4.1 years. Assessment of the preoperative CT scans revealed that a gap of >8.5 mm (hazard ratio [HR] = 2.6, p < 0.001) and step-off of >6.0 mm (HR = 3.0, p < 0.001) were independently associated with conversion to TKA. Assessment of the postoperative radiographs demonstrated that residual incongruity of 2 to 4 mm was not associated with increased risk of TKA compared with adequate fracture reduction of <2 mm (HR = 0.6, p = 0.176). Articular incongruity of >4 mm resulted in increased risk of TKA. Coronal (HR = 1.6, p = 0.05) and sagittal malalignment (HR = 3.7 p < 0.001) of the tibia were strongly associated with conversion to TKA. CONCLUSIONS: Substantial preoperative fracture displacement was a strong predictor of conversion to TKA. Postoperative gaps or step-offs of >4 mm as well as inadequate alignment of the tibia were strongly associated with an increased risk of TKA. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Carotid calcium burden derived from computed tomography angiography as a predictor of all-cause mortality after carotid endarterectomy.

OBJECTIVE: Carotid endarterectomy (CEA) aims to reduce the risk of stroke in patients with atherosclerotic carotid disease. Preoperative risk assessments that predict complications are needed to optimize the care in this patient group. The current approach, namely relying solely on symptomatology and degree of stenosis, is outdated and calls for innovation. The Agatston calcium score was applied in several vascular specialties to assess cardiovascular risk profile but has been little studied in carotid surgery. It is hypothesized that a higher calcium burden at initial presentation equates to a worse prognosis attributable to an increased cerebrovascular and cardiovascular risk profile. The aim was to investigate the association between preoperative ipsilateral calcium score and postoperative all-cause mortality in patients undergoing CEA. METHODS: This single-center retrospective cohort study included 89 patients who underwent CEA at a tertiary referral center between 2010 and 2018. Preoperative calcium scores were measured on contrast-enhanced computed tomography images with patient-specific Hounsfield thresholds at the level of the carotid bifurcation. The association between these calcium scores and all-cause mortality was analyzed using multivariable adjusted Cox proportional hazard analysis. RESULTS: Cox proportional hazard analysis demonstrated a significant association between preoperative ipsilateral carotid calcium score and all-cause mortality (hazard ratio, 1.10; 95% confidence interval, 1.03-1.16; P = .003). After adjusting for age, preoperative estimated glomerular filtration rate, and diabetes mellitus, a significant association remained (hazard ratio, 1.07; 95% confidence interval, 1.00-1.15; P = .05). CONCLUSIONS: A higher calcium burden was predictive of worse outcome, which might be explained by an overall poorer health status. These results highlight the potential of calcium measurements in combination with other traditional risk factors, for preoperative risk assessment and thus for improved patient education and care.

The Influence of Extracerebral Tissue on Continuous Wave Near-Infrared Spectroscopy in Adults: A Systematic Review of In Vivo Studies.

Near-infrared spectroscopy (NIRS) is a non-invasive technique for measuring regional tissue haemoglobin (Hb) concentrations and oxygen saturation (rSO2). It may be used to monitor cerebral perfusion and oxygenation in patients at risk of cerebral ischemia or hypoxia, for example, during cardiothoracic or carotid surgery. However, extracerebral tissue (mainly scalp and skull tissue) influences NIRS measurements, and the extent of this influence is not clear. Thus, before more widespread use of NIRS as an intraoperative monitoring modality is warranted, this issue needs to be better understood. We therefore conducted a systematic review of published in vivo studies of the influence of extracerebral tissue on NIRS measurements in the adult population. Studies that used reference techniques for the perfusion of the intra- and extracerebral tissues or that selectively altered the intra- or extracerebral perfusion were included. Thirty-four articles met the inclusion criteria and were of sufficient quality. In 14 articles, Hb concentrations were compared directly with measurements from reference techniques, using correlation coefficients. When the intracerebral perfusion was altered, the correlations between Hb concentrations and intracerebral reference technique measurements ranged between |r| = 0.45-0.88. When the extracerebral perfusion was altered, correlations between Hb concentrations and extracerebral reference technique measurements ranged between |r| = 0.22-0.93. In studies without selective perfusion modification, correlations of Hb with intra- and extracerebral reference technique measurements were generally lower (|r| < 0.52). Five articles studied rSO2. There were varying correlations of rSO2 with both intra- and extracerebral reference technique measurements (intracerebral: |r| = 0.18-0.77, extracerebral: |r| = 0.13-0.81). Regarding study quality, details on the domains, participant selection and flow and timing were often unclear. We conclude that extracerebral tissue indeed influences NIRS measurements, although the evidence (i.e., correlation) for this influence varies considerably across the assessed studies. These results are strongly affected by the study protocols and analysis techniques used. Studies employing multiple protocols and reference techniques for both intra- and extracerebral tissues are therefore needed. To quantitatively compare NIRS with intra- and extracerebral reference techniques, we recommend applying a complete regression analysis. The current uncertainty regarding the influence of extracerebral tissue remains a hurdle in the clinical implementation of NIRS for intraoperative monitoring. The protocol was pre-registered in PROSPERO (CRD42020199053).

Determination of the gained proximal sealing zone length after debranching of the left subclavian artery in thoracic endovascular aortic repair.

BACKGROUND: For descending thoracic aortic aneurysms (TAA) in proximity of the aortic arch, debranching of the left subclavian artery (LSA) may be necessary to extend proximal sealing in zone 2. The aim of this study was to determine the added proximal apposition length gained from LSA debranching during thoracic endovascular aortic repair (TEVAR). METHODS: This multicenter retrospective study (2010-2020) included patients who underwent elective TEVAR in zone 2 for a degenerative TAA where the LSA was surgically debranched. The endograft position on the first postoperative computed tomography angiography (CTA) scan was assessed using post-processing software. The analysis included the shortest apposition length (SAL), the tilt of the proximal edge of the endograft, and the distance between the endograft and the left common carotid artery. Clinical endpoints (neurological complications and endoleaks) at 30 days were also reported. RESULTS: Twenty-two patients were included. The median interval between TEVAR and the first postoperative CTA was 3 days (2-10 days). Median SAL was 9.2 mm (1.3-26.4 mm), of which 8.6 mm (1.3-16.2 mm) was gained proximal of the LSA, including the LSA orifice. In 12 patients (55.5%) the SAL was <10 mm. The median tilt was 18.3° (13.9°-22.2°). Seven endoleaks were reported on the first CTA: 1 type Ia, 2 type Ib, 3 type II, and 1 type III. CONCLUSIONS: Debranching the LSA adds valuable sealing length in zone 2, but the SAL was still relatively short in many patients, putting these patients at risk for a future type Ia endoleak. Accurate assessment of the circumferential apposition on postoperative CTA follow-up in these high-risk patients with short, complex landing zones seems mandatory. Evaluation of apposition in a larger population with longer follow-up is advised.