Cardiorenal Syndrome in Right Heart Failure Due to Pulmonary Arterial Hypertension-The Right Ventricle as a Therapeutic Target to Improve Renal Function.

Cardiorenal syndrome (CRS) due to right ventricular (RV) failure is a disease entity emerging as a key indicator of morbidity and mortality. The multifactorial aspects of CRS and the left-right ventricular interdependence complicate the link between RV failure and renal function. RV failure has a direct pathophysiological link to renal dysfunction by leading to systemic venous congestion in certain circumstances and low cardiac output in other situations, both leading to impaired renal perfusion. Indeed, renal dysfunction is known to be an independent predictor of mortality in patients with pulmonary arterial hypertension (PAH) and RV failure. Thus, it is important to further understand the interaction between the RV and renal function. RV adaptation is critical to long-term survival in patients with PAH. The RV is also known for its remarkable capacity to recover once the aggravating factor is addressed or mitigated. However, less is known about the renal potential for recovery following the resolution of chronic RV failure. In this review, we provide an overview of the intricate relationship between RV dysfunction and the subsequent development of CRS, with a particular emphasis on PAH. Additionally, we summarize potential RV-targeted therapies and their potential beneficial impact on renal function.

The efficacy of aspirin versus low-molecular-weight heparin for venous thromboembolism prophylaxis after knee and hip arthroplasty: A systematic review and meta-analysis of randomized controlled trials.

PURPOSE: The purpose of this study was to assess the efficacy of aspirin versus low-molecular-weight heparin (LMWH) in preventing venous thromboembolism (VTE) following hip and knee arthroplasty. METHODS: PubMed/Medline, Embase, Cochrane Library and Google Scholar databases were searched from inception till June 2024 for original trials investigating the outcomes of aspirin versus LMWH in hip and knee arthroplasty. The primary outcome was VTE. Secondary outcomes included minor and major bleeding events, and postoperative mortality within 90 days. This review was conducted per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS: A total of 7 randomized controlled trials with 12,134 participants were included. The mean ages for the aspirin and LMWH cohorts were 66.6 (57.6-69.0) years and 66.8 (57.9-68.9) years, respectively. There was no statistically significant difference in the overall risk of VTE between the aspirin and the LMWH cohorts (odds ratio [OR]: 0.95; 95% confidence interval [CI]: 0.48-1.89; p: 0.877). A subanalysis based on the specific VTE entity (pulmonary embolism [PE] or deep venous thrombosis) showed a significantly higher PE risk for patients receiving aspirin than the LMWH cohort (OR: 1.79; 95% CI: 1.11-2.89; p: 0.017). There was no difference in minor (OR: 0.64; 95% CI: 0.40-1.04; p: 0.072) and major bleeding (OR: 0.77; 95% CI: 0.40-1.47; p: 0.424) episodes across both groups. Furthermore, subanalysis among the total knee arthroplasty group showed that the aspirin cohort was significantly more likely to suffer VTEs than their LMWH counterparts (OR: 1.55; 95% CI: 1.21-1.98; p < 0.001). CONCLUSION: This study demonstrated a significantly higher risk of PE among patients receiving aspirin compared to LMWH following hip or knee arthroplasty for osteoarthritis. Aspirin was associated with a significantly higher overall VTE risk among patients undergoing knee arthroplasty, in particular. This might suggest the inferiority of aspirin compared to LMWH in preventing VTE following such procedures. LEVEL OF EVIDENCE: Level I.

The epidemiology of pelvic ring fractures in Qatar.

PURPOSE: This study aimed to determine the incidence of pelvic ring fractures and their associated epidemiological profile in Qatar. METHODS: A retrospective cross-sectional study was performed at the only level I trauma centre in Qatar for patients diagnosed with pelvic ring fractures between January 2016 and December 2018. Age, sex, mechanism of injury, fracture classification and associated characteristics, mode of treatment, associated nerve injuries, and other complications were analyzed. RESULTS: A total of 327 consecutive patients were included, with an average age of 32.6 years. Most of the included patients were males, 85% (279), with a male: female ratio of 6:1. The incidence of pelvic fractures was 3.887/100,000 across the three years. High-speed motor vehicle collisions (MVC) were the most common mechanism of injury (108, 33%), followed by falling from height (105, 32%). Young-Burgess lateral compression (LC) fracture type was the most frequent (224, 68.5%) and was associated with 25% of the entire mortalities. Nine (2.8%) cases were open fractures, and 12% (39) were deemed unstable. Around 29% of cases had associated injuries, with an overall mortality rate of 4.9% (16) observed. Most fractures were treated nonoperatively(n = 283,86.5%). CONCLUSION: This study demonstrated the epidemiology of pelvic fractures in Qatar. MVC and work-related injuries were predominant in a younger cohort compared to the literature. Also, the mortality rate was lower than those reported in the literature. Therefore, well-trained surgeons and specialized trauma centres for treating these injuries are recommended.

High mortality rate and restricted mobility in above knee amputation following periprosthetic joint infection after total knee arthroplasty: A systematic review.

PURPOSE: To systematically review the literature on the outcomes of above knee amputation as a salvage procedure after periprosthetic joint infection in total knee arthroplasty. METHODS: This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Medline, Scopus, Web of Science, and Embase electronic databases were utilized to identify all studies evaluating clinical outcomes of patients with above knee amputation following PJI from inception to June 24, 2023. Studies were excluded for failure to report functional outcomes specifically related to AKA in PJI following TKA, utilizing surgical interventions other than amputation, AKA indicated for other reasons than PJI, technical studies, conference abstracts, case reports and non-English language. The quality of studies was assessed with the Methodological Index for Non-Randomized Studies (MINORS) criteria. RESULTS: Seven retrospective studies, categorized as Therapeutic Level III evidence, were analyzed, involving a total of 188 patients who underwent AKA following PJI after TKA. The findings consistently indicate that post-AKA, patients experienced a notable decline in their level of independence and reported worsening ambulatory status. Infection and wound complications were common post-AKA, leading to revision surgeries, while the mortality rate ranged from 9 to 50% in the included studies. Polymicrobial organisms were frequently found in pre-AKA PJI, with MRSA being a common causative organism. CONCLUSIONS: AKA due to PJI following TKA is associated with restricted mobility and high mortality rate. Polymicrobial infections and MRSA were identified as common infecting organisms, emphasizing the complexities and challenges associated with managing these infections. The reported functional outcomes, ambulatory status, complications, reoperations, and mortality rates highlight the importance of providing comprehensive, individualized care to these patients.

Success rate of single versus multiple debridement, antibiotics, and implant retention (DAIR) in hip and knee periprosthetic joint infection: a systematic review and meta-analysis.

PURPOSE: This systematic review aimed to compare outcomes between multiple and single debridement, antibiotics, and implant retention (DAIR) procedures for early periprosthetic joint infection (PJI) in hip and knee arthroplasty. METHODS: Four databases were searched from inception till January 2024 for original studies investigating the outcomes of multiple DAIR in hip and knee PJI. The primary outcome was the success rate in eradicating joint infection. This review was conducted per PRISMA guidelines. RESULTS: A total of 9 observational studies with 1104 participants were included, with a mean age and BMI of 58.37 years (95%CI: 25.77-90.98) and 31.43 kg/m2 (95%CI: 28.89-34.98), respectively. The mean follow-up period was 58.37 months (95%CI: 25.77-90.98), and the average MINORS score assigned to the review was 17.6 ± 3.46, indicating a low overall risk of bias. An equivalent success rate between single and double DAIR was observed, at 67% (95%CI: 64-71%) and 70% (95%CI: 48-86%), respectively, with no statistically significant difference between the two treatment modalities (p = 0.740). Additionally, the success rate for triple DAIR ranged from 50 to 60%. CONCLUSION: This study suggests that double DAIR is a valid treatment option for acute PJI after TKA and THA, with a success rate comparable to single DAIR (70% vs. 67%, p = 0.740). Triple DAIR achieved success rates ranging from 50 to 60%. However, caution is warranted when interpreting these results due to heterogeneity in host comorbidity factors, DAIR protocols, and antibiotic regimens. LEVEL OF EVIDENCE: Therapeutic, Level III.

The outcomes of total hip arthroplasty in developmental dysplasia of hip versus osteoarthritis: a systematic review and meta-analysis.

PURPOSE: This systematic review and meta-analysis aimed to compare the outcomes of total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH) and those with osteoarthritis (OA). METHODS: Four databases were searched from inception till February 2023 for original studies that compared the outcomes of THA in DDH and OA. The primary outcome was the revision rate; the secondary outcomes were dislocation and failure modes (i.e. aseptic loosening, PJI, instability, and periprosthetic fractures), hospital stay and costs. This review was conducted as per PRISMA guidelines, and the risk of bias was assessed using the Newcastle-Ottawa scale. RESULTS: A total of 9 observational studies with 575,255 THA (469,224 hips) were included, with a mean age of 50.6 years and 62.1 years for DDH and OA groups, respectively. There was a statistically significant difference in revision rate between DDH and OA patients in favour of OA (OR, 1.66; 95% CI 1.11-2.48; p-value, 0.0251). However, dislocation rate (OR, 1.78, 95% CI 0.58-5.51; p-value, 0.200), aseptic loosening (OR, 1.69; 95% CI 0.26-10.84; p-value, 0.346) and PJI (OR, 0.76; 95% CI 0.56-1.03; p-value, 0.063) were comparable across both groups. CONCLUSION: A higher revision rate following total hip arthroplasty was associated with DDH compared with osteoarthritis. However, both groups had similar dislocation rates, aseptic loosening and PJI. Consideration of confounding factors, such as patient age and activity level, is crucial when interpreting these findings. LEVEL OF EVIDENCE : III. TRIAL REGISTRATION: PROSPERO registration: CRD42023396192.

Correlation between anthropometric measurements and graft size in anterior cruciate ligament reconstruction: a systematic review and meta-analysis.

PURPOSE: This systematic review and meta-analysis aimed to investigate the correlation between anthropometric measurements and graft size in anterior cruciate ligament (ACL) reconstruction. METHODS: A systematic search of Ovid MEDLINE, Embase, and Cochrane Library databases was conducted for observational studies published until March 2023 that reported the relationship between anthropometric data [height, weight, body mass index (BMI), age, gender, thigh length, and circumference] and ACL graft size. Correlation coefficients (COR) and their associated 95% confidence intervals were used as the primary effect size. This review was conducted in line with PRISMA guidelines. RESULTS: A total of 42 observational studies involving 7110 patients were included, with a mean age of 29.8 years. Statistically significant, moderately positive correlations were found between graft size and height (COR: 0.49; 95% CI: 0.41-0.57; p-value: < 0.001), weight (COR: 0.38; 95% CI: 0.31-0.44; p-value: < 0.001), thigh circumference (COR: 0.40; 95% CI: 0.19-0.58; p-value: < 0.001), and thigh length (COR: 0.35; 95% CI: 0.18-0.50; p-value: < 0.001). However, age and gender were insignificantly correlated with graft size (p-value: NS). A subanalysis based on graft type showed a significant positive correlation between height and graft diameter, which was more significant in the peroneus tendon than in hamstring grafts (COR: 0.76 vs. 0.45; p-value: 0.020). CONCLUSION: This study demonstrated a moderate positive correlation between anthropometric measurements (height, weight, thigh circumference, and length) and ACL graft size, along with a weak positive correlation with BMI. Age and gender showed no significant correlation. These findings support the predictability and selection of ACL graft size based on pre-operative patient anthropometric data. LEVEL OF EVIDENCE: Level of Evidence: IV. PROSPERO registration number: CRD42023416044.

Reliability of artificial intelligence in predicting total knee arthroplasty component sizes: a systematic review.

PURPOSE: This systematic review aimed to investigate the reliability of AI predictive models of intraoperative implant sizing in total knee arthroplasty (TKA). METHODS: Four databases were searched from inception till July 2023 for original studies that studied the reliability of AI prediction in TKA. The primary outcome was the accuracy ± 1 size. This review was conducted per PRISMA guidelines, and the risk of bias was assessed using the MINORS criteria. RESULTS: A total of four observational studies comprised of at least 34,547 patients were included in this review. A mean MINORS score of 11 out of 16 was assigned to the review. All included studies were published between 2021 and 2022, with a total of nine different AI algorithms reported. Among these AI models, the accuracy of TKA femoral component sizing prediction ranged from 88.3 to 99.7% within a deviation of one size, while tibial component sizing exhibited an accuracy ranging from 90 to 99.9% ± 1 size. CONCLUSION: This study demonstrated the potential of AI as a valuable complement for planning TKA, exhibiting a satisfactory level of reliability in predicting TKA implant sizes. This predictive accuracy is comparable to that of the manual and digital templating techniques currently documented in the literature. However, future research is imperative to assess the impact of AI on patient care and cost-effectiveness. LEVEL OF EVIDENCE III: PROSPERO registration number: CRD42023446868.

Impact of age on unicompartmental knee arthroplasty outcomes: a systematic review and meta-analysis.

PURPOSE: Unicompartmental knee arthroplasty (UKA) is an effective treatment for late knee osteoarthritis (OA). Young age (< 60 years) has been associated with worse outcomes. The goal of this systematic review and meta-analysis is to study the effect of age on UKA outcomes. METHODS: The primary objective was to compare the UKA revision rate in young patients with that of old patients, using the age thresholds of 60 and 55 years. Secondary objectives were patient-reported outcome measures (PROMs) and implant design. Five databases were searched in December 2021 for original comparative studies with a minimum of 1-year follow-up. No restrictions were placed on the type of UKA prosthesis. RESULTS: A total of 11 observational studies with 6130 knees were included. A mean MINORS score of 19 was assigned to the review. The mean age of patients was 64 years, with average follow-up of 7.5 ± 2.98 years. There was no significant difference in revision rate, incident or PROMs between young and old patients in the analysis for each age threshold. Further sub-analysis adjusting for implant type in mobile- and fixed-bearing prostheses also showed similar results between those above and under 60 and 55 years. CONCLUSION: Young age was not associated with a higher revision rate or lower functional scores. Thus, this review provides evidence that age alone is not a contraindication to UKA, but the surgical choice must be based on several elements, and this finding should be applied in context, given the binary division and heterogeneity of patients. LEVEL OF EVIDENCE: III.

Outcomes of drain versus no drain in total knee arthroplasty: a retrospective cohort study.

PURPOSE: The use of suction drains in total knee arthroplasty (TKA) remains controversial. The aim of this study is to compare the outcomes of patients who received suction drains versus those who did not, focusing on blood loss, blood transfusion need, and length of hospital stay. METHODS: A retrospective observational cohort study was conducted at a tertiary hospital between January 1, 2015, and December 30, 2019, and included 262 patients who underwent unilateral non-traumatic primary TKA and were over 18 years old. The Institutional Review Board (IRB) approved the study (MRC-02-20-278). RESULTS: A total of 262 patients were included, with an age range of 47 to 91 years. Most of the included patients were females, 74.4% (195). Hypertension was the most frequent risk factor, 67.6%, followed by diabetes. Of 262 patients, 156 (59.5%) received a drain. The drain group had significantly longer hospital stay, 30% longer tourniquet time, greater haemoglobin and haematocrit drops, higher count of transfused packed RBC units, and lower use of anticoagulants. Moreover, tranexamic acid (TXA) use (n = 106) in surgery reduced hospital stays, tourniquet time, drain output, and increased pre- and postoperative haemoglobin and hematocrit levels compared to no TXA group (n = 156) (p < 0.05, z-score reported). CONCLUSIONS: This study found that patients who received a drain had longer hospital stays and greater blood loss and transfusion rates compared to those who did not. The use of TXA in surgery was associated with improved outcomes and reduced overall complications.

The outcomes of total hip replacement in osteonecrosis versus osteoarthritis: a systematic review and meta-analysis.

PURPOSE: This systematic review and meta-analysis aimed to compare the outcomes of THA in patients with osteonecrosis (ON) and those with osteoarthritis (OA). METHODS: Four databases were searched from inception till December 2022 for original studies that compared the outcomes of THA in ON and OA. The primary outcome was the revision rate; the secondary outcomes were dislocation and Harris hip score. This review was conducted in line with PRISMA guidelines, and the risk of bias was assessed using the Newcastle-Ottawa scale. RESULTS: A total of 14 observational studies with 2,111,102 hips were included, with a mean age of 50.83 ± 9.32 and 55.51 ± 8.95 for ON and OA groups, respectively. The average follow-up was 7.25 ± 4.6 years. There was a statistically significant difference in revision rate between ON and OA patients in favour of OA (OR: 1.576; 95%CI: 1.24-2.00; p-value: 0.0015). However, dislocation rate (OR: 1.5004; 95%CI: 0.92-2.43; p-value: 0.0916) and Haris hip score (HHS) (SMD: - 0.0486; 95%CI: - 0.35-0.25; p-value: 0.6987) were comparable across both groups. Further sub-analysis adjusting for registry data also showed similar results between both groups. CONCLUSION: A higher revision rate, periprosthetic fracture and periprosthetic joint infection following total hip arthroplasty were associated with osteonecrosis of the femoral head compared with osteoarthritis. However, both groups had similar dislocation rates and functional outcome measures. This finding should be applied in context due to potential confounding factors, including patient's age and activity level.

Open versus closed intramedullary nailing of femur shaft fractures in adults: a systematic review and meta-analysis.

PURPOSE: This systematic review and meta-analysis aimed to compare the outcomes of open- versus closed-reduction and intramedullary nailing (IMN) of adult femur shaft fractures. METHODS: Four databases were searched from inception until July 2022 for original studies that compared the outcomes of IMN following open-reduction versus closed-reduction technique. The primary outcome was the union rate; the secondary outcomes were time to union, nonunion, malalignment, revision, and infection. This review was conducted in line with PRISMA guidelines. RESULTS: A total of 12 studies with 1299 (1346 IMN cases) patients were included, with a mean age of 32.3 ± 3.25. The average follow-up was 2.3 ± 1.45 years. There was a statistically significant difference in union rate (OR, 0.66; 95% CI, 0.45-0.97; p-value, 0.0352), nonunion (OR, 2.06; 95% CI, 1.23-3.44; p-value, 0.0056), and infection rate (OR, 1.94; 95% CI, 1.16-3.25; p-value, 0.0114) between the open-reduction and closed-reduction groups in favour of the latter. However, malalignment was significantly higher in the closed-reduction group (OR, 0.32; 95% CI, 0.16-0.64; p-value, 0.0012), whereas time to union and revision rates were similar (p = NS). CONCLUSION: This study showed that closed-reduction and IMN had more favourable union rate, nonunion, and infection rates than the open-reduction group, yet malalignment was significantly less in the open-reduction group. Moreover, time to union and revision rates were comparable. However, these results must be interpreted in context due to confounding effects and the lack of high-quality studies.

Trauma and orthopaedic surgery response at the world's largest sporting event: an analysis of the FIFA World Cup Qatar 2022.

PURPOSE: The purpose of this study is to analyse the impact of the FIFA World Cup Qatar 2022 on the Orthopaedic Surgery department at Hamad Medical Corporation and its response to the challenges posed by the world's largest sporting event. METHODS: A retrospective analysis was conducted on the epidemiology, crisis management plan, and training program adaptations at the Orthopaedic Surgery department during the World Cup. Descriptive analysis of the number and types of surgeries performed, patient demographics, and the disaster preparedness plan were performed. RESULTS: During the tournament period (November-December 2022), 706 patients (4.22% football fans) were operated on, with an average age of 44 ± 17 years. Most patients were males, 67%. Of the 706 patients, 60.33% were emergency cases, 38.24% were elective, 1.27% were limb-saving, and one life-saving procedure was performed, comparable to pre-tournament numbers. The patients were of 77 different nationalities, reflecting the diverse background of Qatar's population and the international fanbase of the tournament. CONCLUSIONS: This analysis provides valuable insights for future mega sporting events and highlights the importance of crisis management and training program adaptation for optimal patient care and resident training advancement. The findings demonstrate the crucial role of the Orthopaedic Surgery Department in responding to the challenges posed by large-scale events.

Epidemiology of proximal humerus fractures in Qatar.

OBJECTIVE: This study aimed to investigate the epidemiological characteristics and treatment options of proximal humerus fractures at a level one trauma center and to compare our data with the current literature. METHODS: A retrospective review was conducted on all patients diagnosed and treated for proximal humerus fractures at Hamad General Hospital, a level one trauma center, between January 2018 and December 2019. Age, gender, mechanism of injury, fracture classification, mode of treatment, implant type, length of hospital stay, associated injuries and complications were analyzed. RESULTS: A total of 190 patients with a mean age of 52.4 years were included; 56.8% were males. The incidence of proximal humerus fracture was 4.1/100,000 per year. Falling from a standing height was the most common cause of injury (50.5%). Additionally, Neer's two-part fracture was found to be the most common type (n = 132, 69%). Forty-one patients (21.3%) had other associated injuries. Most fractures were treated nonoperatively with an arm sling (n = 138, 72.6%). CONCLUSION: In summary, the incidence of proximal humerus fractures during the two-year study period was found to be 4.1 per 100,000 persons per year. Our results showed a lower incidence of proximal humerus fractures with a predominance of males and younger patients in Qatar's population compared to females and older patients in the developed countries. Our results may contribute to the development of effective strategies for preventing and treating proximal humerus fractures, and can provide important data for further high-level clinical research. LEVEL OF EVIDENCE: IV.

The role of cerclage wiring in the management of subtrochanteric and reverse oblique intertrochanteric fractures: a meta-analysis of comparative studies.

PURPOSE: Subtrochanteric and reverse oblique intertrochanteric fractures are challenging and often difficult to reduce. While intramedullary nailing (IMN) is considered the standard treatment, achieving anatomic reduction prior to fixation is essential. This study aimed to assess the impact of cerclage wiring with IMN on the outcomes and complication rate in treating subtrochanteric and reverse oblique intertrochanteric fractures. METHODS: This meta-analysis was conducted in line with PRISMA guidelines. The primary outcome was the time to union. The secondary outcomes were operative time, blood loss, quality of reduction, reduction alignment (if in varus), complications and reoperations. PubMed, Cochrane, Web of Science and Google Scholar were searched till July 2021. Articles that compared intramedullary nailing (IMN) versus intramedullary nailing and cerclage wiring (IMN-C) in the treatment of subtrochanteric and reverse oblique intertrochanteric fractures were included. The risk of bias was assessed using the Newcastle-Ottawa scale. RESULTS: This meta-analysis included 415 patients with subtrochanteric and reverse oblique intertrochanteric fracture from six comparative studies. Our findings showed that IMN-C was significantly associated with higher mean duration of surgery and blood loss. However, IMN-C had significantly lower mean time to union compared to IMN alone. In addition, IMN-C had lower pooled prevalence of varus reduction and overall complications. CONCLUSION: This study showed that the use of cerclage wiring is associated with lower time to union, lower prevalence of varus reduction and overall complications. Therefore, cerclage wiring augmentation is a safe technique with low complication rate and may be advised whenever open reduction is needed in the management of subtrochanteric and reverse oblique intertrochanteric fractures.

Immunogenicity of SARS-CoV-2 Vaccine in Dialysis.

BACKGROUND: Patients receiving maintenance dialysis represent a high-risk, immune-compromised population with 15%-25% COVID-19 mortality rate who were unrepresented in clinical trials of mRNA vaccines. METHODS: All patients receiving maintenance dialysis who received two doses of SARS-CoV-2 mRNA vaccines with antibody test results drawn ≥14 days after the second dose, as documented in the electronic health record through March 18, 2021, were included. Response was on the basis of levels of Ig-G against the receptor binding domain of the S1 subunit of SARS-CoV-2 spike-antigen (seropositive ≥2 U/L) using an FDA-approved semiquantitative chemiluminescent assay (ADVIA Centaur XP/XPT COV2G). RESULTS: Among 186 patients on dialysis from 30 clinics in eight states tested 23±8 days after receiving two vaccine doses, there were 165 (88.7%) responders with 70% at maximum titer. There was no significant difference between BNT162b2/Pfizer (148 out of 168, 88.1%) and mRNA-1273/Moderna (17 out of 18, 94.4%), P=0.42. All 38 patients with COVID-19 history were responders, with 97% at maximum titer. Among patients without COVID-19, 127 out of 148 (85.8%) were responders, comparable between BNT162b2/Pfizer (113 out of 133) and mRNA-1273/Moderna (14 out of 15) vaccines (85.0% versus 93.3%, P=0.38). CONCLUSIONS: Most patients receiving maintenance dialysis responded after two doses of BNT162b2/Pfizer or mRNA-1273/Moderna vaccine, suggesting the short-term development of antispike antibody is good, giving hope that most of these patients who are vulnerable, once immunized, will be protected from COVID-19. Longer-term evaluation is needed to determine antibody titer durability and if booster dose(s) are warranted. Further research to evaluate the approach to patients without a serologic response is needed, including benefits of additional dose(s) or administration of alternate options.

Synovial fluid calprotectin in diagnosing periprosthetic joint infection: A meta-analysis.

PURPOSE: Periprosthetic joint infection (PJI) is one of the most debilitating complications following joint replacement surgery. Synovial biomarkers, such as Calprotectin, have become valuable in the diagnosis of PJI. This meta-analysis aimed to investigate the role of synovial Calprotectin as a diagnostic test in PJI. METHODS: This meta-analysis was conducted with adherence to PRISMA guidelines. PubMed, Cochrane, Web of Science, and Google Scholar were searched until February 2022. Inclusion criteria were as follows: all studies in which the patients with joint replacements were evaluated for PJI; synovial Calprotectin was the biomarker of choice to diagnose PJI; standardized guidelines were used as the gold standard for the diagnosis; and a comparison between the guidelines and Calprotectin results was made. Diagnostic parameters such as sensitivity, specificity, diagnostic odds ratio (DOR), positive predictive value, negative predictive value, and area under the curve (AUC) were calculated for the included studies to evaluate synovial Calprotectin for PJI diagnosis. RESULTS: The total number of the included patients was 618 from eight studies. The pooled sensitivity, specificity, and diagnostic odds ratio of Calprotectin test were 92% (95%CI: 84%-98%), 93% (95%CI: 84%-99%), and 187.61 (95%CI: 20.21-1741.18), respectively. The results showed that the negative and positive likelihood ratios of the Calprotectin test were 0.07 (95%CI: 0.02-0.22) and 9.91 (95%CI: 4.11-23.93), respectively. The SROC showed that the area under the curve for Calprotectin test was 0.935. CONCLUSION: Synovial Calprotectin is a valuable biomarker as it provides a reliable and rapid diagnosis of PJI. It has the potential to be used in clinical practice due to its high sensitivity and specificity that are comparable to the other utilized biomarkers. Another advantage is its low cost relative to other biomarkers.

Transcriptomics of Human Arteriovenous Fistula Failure: Genes Associated With Nonmaturation.

RATIONALE & OBJECTIVE: Improving arteriovenous fistula (AVF) outcomes requires better understanding of the biology underlying maturation or failure. Our current knowledge of maturation relies on extrapolation from other vascular pathologies, which does not incorporate unique aspects of AVF remodeling. This study compares the RNA expression of pre-access (native) veins and AVFs with distinct maturation outcomes. STUDY DESIGN: Case-control study. SETTING & PARTICIPANTS: 64 patients undergoing 2-stage AVF surgeries at a single center. 19 native veins and 19 AVF samples were analyzed using RNA sequencing (RNA-seq). 58 native veins were studied using real-time polymerase chain reaction; 45, using immunohistochemistry; and 19, using Western blot analysis. PREDICTOR: RNA expression in native veins and AVFs. OUTCOME: Anatomic nonmaturation, defined as an AVF that never achieved an internal diameter ≥ 6mm. ANALYTICAL APPROACH: Pre-access native veins and AVF samples were obtained from patients undergoing 2-stage AVF creation. Veins that subsequently matured or failed after access creation were analyzed using RNA-seq to search for genes associated with maturation failure. Genes associated with nonmaturation were confirmed using real-time polymerase chain reaction, immunohistochemistry, and Western blot analysis. In addition, the association between pre-access gene expression and postoperative morphology was evaluated. RNA-seq was also performed on AVFs to search for transcriptional differences between AVFs that matured and those that failed at the time of transposition. RESULTS: Pro-inflammatory genes (CSF3R, FPR1, S100A8, S100A9, and VNN2) were upregulated in pre-access veins that failed (false discovery rate < 0.05), and their expression colocalized to smooth muscle cells. Expression of S100A8 and S100A9 correlated with postoperative intimal hyperplasia and the product of medial fibrosis and intimal hyperplasia (r=0.32-0.38; P < 0.05). AVFs that matured or failed were transcriptionally similar at the time of transposition. LIMITATIONS: Small sample size, analysis of only upper-arm veins and transposed fistulas. CONCLUSIONS: Increased expression of proinflammatory genes in pre-access veins appears to be associated with greater risk for AVF nonmaturation.

Fibrotic Venous Remodeling and Nonmaturation of Arteriovenous Fistulas.

The frequency of primary failure in arteriovenous fistulas (AVFs) remains unacceptably high. This lack of improvement is due in part to a poor understanding of the pathobiology underlying AVF nonmaturation. This observational study quantified the progression of three vascular features, medial fibrosis, intimal hyperplasia (IH), and collagen fiber organization, during early AVF remodeling and evaluated the associations thereof with AVF nonmaturation. We obtained venous samples from patients undergoing two-stage upper-arm AVF surgeries at a single center, including intraoperative veins at the first-stage access creation surgery and AVFs at the second-stage transposition procedure. Paired venous samples from both stages were used to evaluate change in these vascular features after anastomosis. Anatomic nonmaturation (AVF diameter never ≥6 mm) occurred in 39 of 161 (24%) patients. Neither preexisting fibrosis nor IH predicted AVF outcomes. Postoperative medial fibrosis associated with nonmaturation (odds ratio [OR], 1.55; 95% confidence interval [95% CI], 1.05 to 2.30; P=0.03, per 10% absolute increase in fibrosis), whereas postoperative IH only associated with failure in those individuals with medial fibrosis over the population's median value (OR, 2.63; 95% CI, 1.07 to 6.46; P=0.04, per increase of 1 in the intima/media ratio). Analysis of postoperative medial collagen organization revealed that circumferential alignment of fibers around the lumen associated with AVF nonmaturation (OR, 1.38; 95% CI, 1.03 to 1.84; P=0.03, per 10° increase in angle). This study demonstrates that excessive fibrotic remodeling of the vein after AVF creation is an important risk factor for nonmaturation and that high medial fibrosis determines the stenotic potential of IH.

Dialysis Arteriovenous Fistula Failure and Angioplasty: Intimal Hyperplasia and Other Causes of Access Failure.

The arteriovenous fistula (AVF) is the preferred hemodialysis access type because it has better patency rates and fewer complications than other access types. However, primary failure remains a common problem impeding AVF maturation and adding to patients' morbidity and mortality. Juxta-anastomotic (or inflow) stenosis is the most common reason leading to primary failure, and percutaneous transluminal angioplasty continues to be the gold-standard treatment with excellent success rates. Intimal hyperplasia (IH) has been traditionally blamed as the main pathophysiologic culprit, but new evidence raises doubts regarding the contribution of IH alone to primary failure. We report a 64-year-old man with a 2-stage brachiobasilic AVF that was complicated by failure 4 months after creation. An angiogram showed multiple juxta-anastomotic and midfistula stenotic lesions. Percutaneous transluminal angioplasty was successful in assisting maturation and subsequently cannulating the AVF for hemodialysis treatment. We failed to identify the underlying cause of stenosis because biopsy specimens from fistula tissue obtained at the time of transposition revealed no occlusive IH. This case emphasizes the need for additional research on factors contributing to AVF failure besides IH and highlights the need for more therapeutic options to reduce AVF failure rate.