A Diagnosis of Vitamin D Deficiency Is Associated With Increased Rates of Primary Patellar Instability and Need for Recurrent Surgical Stabilization

BACKGROUND

Vitamin D has been proven experimentally to affect musculoskeletal health. The purpose of this study was to identify the relationship between vitamin D deficiency and patellar instability.

HYPOTHESIS

Vitamin D deficiency is associated with an increased risk of experiencing primary patellar instability and recurrent patellar dislocation after primary surgical stabilization.

STUDY DESIGN

Retrospective comparative study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A 1:1 matched retrospective study of 328,011 patients diagnosed with vitamin D deficiency was performed using the PearlDiver database. Incidence of primary patellar instability was calculated according to sex and age. Rates of primary patellar instability and surgical stabilization for recurrent dislocation were calculated with sex- and age-specific stratifications. Multivariable logistic regression was used to compare the rates of primary injury and recurrent stabilization while controlling for demographics and medical comorbidities.

RESULTS

A total of 656,022 patients were analyzed. The overall 1-year incidence rate of patellar instability in patients with vitamin D deficiency was 82.6 per 100,000 person-years (95% CI, 73.2-92.9), compared with 48.5 (95% CI, 41.4-56.5) in the matched control. Women were significantly more likely to experience primary patellar instability within 1 (adjusted odds ratio [aOR] = 1.45; 95% CI, 1.12-1.88) and 2 years (aOR, 1.31; 95% CI, 1.07-1.59) of hypovitaminosis D diagnosis. Patients aged 10 to 25 years with hypovitaminosis D were at greater risk of requiring recurrent patellar stabilization for both men (aOR, 2.48; 95% CI, 1.06-5.80) and women (aOR, 1.77; 95% CI, 1.04-3.02).

CONCLUSION

Patients diagnosed with vitamin D deficiency experienced higher rates of primary patellar instability and have greater risk of requiring recurrent surgical stabilization for subsequent dislocations.

CLINICAL RELEVANCE

These results suggest that monitoring and proactively treating vitamin D deficiency in the physically active patient may lower the risk of suffering primary patellar instability or recurrence after surgical stabilization.

Statistical Fragility Analysis of Open Reduction Internal Fixation vs Primary Arthrodesis to Treat Lisfranc Injuries: A Systematic Review

BACKGROUND

There is a lack of consensus in the use of open reduction internal fixation (ORIF) vs primary arthrodesis (PA) in the management of Lisfranc injuries. Statistical fragility represents the number of events needed to flip statistical significance and provides context to interpret P values of outcomes from conflicting studies. The current study evaluates the statistical fragility of existing research with an outcome-specific approach to provide statistical clarity to the ORIF vs PA discussion. We hypothesized that statistical fragility analysis would offer clinically relevant insight when interpreting conflicting outcomes regarding ORIF vs PA management of Lisfranc injuries.

METHODS

All comparative studies, RCTs, and case-series investigating ORIF vs PA management of Lisfranc injuries published through October 5, 2023, were identified. Descriptive characteristics, dichotomous outcomes, and continuous outcomes were extracted. Fragility index and continuous fragility index were calculated by the number of event reversals needed to alter significance. Outcomes were categorized by clinical relevance, and median FI and CFI were reported.

RESULTS

A total of 244 studies were screened. Ten studies and 67 outcomes (44 dichotomous, 23 continuous) were included in the fragility analysis. Of the 10 studies, 4 studies claimed PA to correlate with superior outcomes compared to ORIF with regard to functional scores and return to function outcomes. Of these 4 studies, 3 were statistically robust. Six studies claimed PA and ORIF to have no differences in outcomes, in which only 2 studies were statistically robust.

CONCLUSION

The overall research regarding ORIF vs PA is relatively robust compared with other orthopaedic areas of controversy. Although the full statistical context of each article must be considered, studies supporting PA superiority with regard to functional scores and return to function metrics were found to be statistically robust. Outcome-specific analysis revealed moderate fragility in several clinically relevant outcomes such as functional score, return to function, and wound complications.

Peroneus Longus Tendon Autograft May Present a Viable Alternative for Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To examine the available literature to better understand the objective and patient-reported outcomes using peroneus longus tendon (PLT) autograft compared with more commonly used autografts, such as the quadrupled hamstring tendons (HT), in patients undergoing primary for anterior cruciate ligament reconstruction (ACLR).

METHODS

A comprehensive search of published literature in PubMed, Web of Science, Cochrane Library, Ovid, and EMBASE databases was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Inclusion criteria included patients undergoing ACLR with PLT autograft, inclusion of patient-recorded outcome measures, and availability in English language. Publications that included only biomechanical analysis or ACLR with use of allograft or combination grafts were excluded.

RESULTS

A total of 16 studies (Level of Evidence range: I-IV) met inclusion criteria, with follow-up ranging from 3 months to 5 years. In the available case series, patient-reported outcomes ranged from Lysholm = 80.7 to 95.1, International Knee Documentation Committee 78.1 to 95.7. In prospective cohorts and randomized controlled trials, PLT performance was comparable with HT autografts (PLT/HT: Lysholm = 88.3-95.1/86.5-94.9, International Knee Documentation Committee = 78.2-92.5/87.4-93.4). The majority of PLT grafts diameters were equal or greater than HT counterparts with a mean of >8 mm (PLT/HT: 7.0-9.0 mm/7.65-8.5 mm). There was minimal donor-site morbidity associated with PLT harvest.

CONCLUSIONS

Although limitations exist within the available literature, existing evidence suggests that PLT autograft routinely produces adequately sized grafts with comparable early outcomes to HT autograft and low risk of donor-site morbidity. However, the PLT autograft is yet to demonstrate superiority to any of the more-traditional autograft selections.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I-IV studies.

Significant Association between a Diagnosis of Hypovitaminosis D and Rotator Cuff Tear, Independent of Age and Sex: A Retrospective Database Study

PURPOSE

As high rates of vitamin D deficiency have been demonstrated in orthopedic patient cohorts, this study aimed to characterize the association between a diagnosis of hypovitaminosis D and primary rotator cuff tear (RCT), primary rotator cuff repair (RCR), and postoperative complications in different sex and age cohorts.

METHODS

In this retrospective cohort study using PearlDiver, a nationwide administrative claims database, records for all patients aged 30 to 89 yr who received a diagnosis of hypovitaminosis D between January 1, 2011, and October 31, 2018, were queried. Rates of primary RCT, primary RCR, and postoperative complications including subsequent surgery were calculated within sex- and age-specific cohorts and compared with matched control cohorts using multivariable logistic regression.

RESULTS

Among the 336,320 patients included in the hypovitaminosis D cohort, these patients were significantly more likely to experience an RCT (odds ratio (OR), 2.70; 95% confidence interval (CI), 2.55-2.85) as well as a full-thickness RCT (OR, 2.36; 95% CI, 2.17-2.56) specifically within 2 yr of their diagnosis. Women with hypovitaminosis D were more likely to undergo surgery to address their full-thickness tears (OR, 1.37; 95% CI, 1.09-1.74). There was no difference in the rates of revision RCR or irrigation and debridement. However, women with hypovitaminosis D were significantly more likely to undergo manipulation under anesthesia (OR, 1.16; 95% CI, 1.03-1.31).

CONCLUSIONS

Patients diagnosed with hypovitaminosis D were significantly more likely to suffer from a primary RCT and to undergo manipulation under anesthesia within a year of their RCR. Although many risk factors for RCT are unmodifiable, vitamin D deficiency is a readily modifiable risk factor with several treatment regimens demonstrating positive effects on musculoskeletal health.

Arm Health in Elite Collegiate Summer League Baseball Players Assessed by the Kerlan-Jobe Orthopaedic Clinic Score

CONTEXT

Collegiate baseball players with professional aspirations often participate in summer leagues; foremost among them is the Cape Cod Baseball League (CCBL). Injuries acquired during the collegiate baseball season can be carried into the CCBL season and vice versa.

OBJECTIVE

To assess the history of throwing arm injury and current functionality in midseason CCBL players.

DESIGN

Cross-sectional study.

SETTING

Online questionnaire.

PATIENTS OR OTHER PARTICIPANTS

A total of 123 CCBL players participated. Qualifying athletes were ≥18 years old and were rostered CCBL players with remaining collegiate eligibility.

MAIN OUTCOME MEASURE(S)

After collecting background information, we used the Kerlan-Jobe Orthopaedic Clinic (KJOC) Shoulder and Elbow questionnaire to assess the history of throwing arm injury and current functionality. The maximum KJOC score is 100.0; higher scores correspond with greater functionality.

RESULTS

The mean KJOC score was 86.6 ± 14.5 (n = 92); 24.5% (23/94) of players reported a prior diagnosis of throwing arm injury other than a strain or sprain. A total of 49 (49/96, 51.0%) players had undergone rehabilitation for a throwing arm injury, and 7 (7/96, 7.3%) had experienced a medical procedure. Players with no previous treatment (n = 41, mean KJOC score = 88.9 ± 19.0) more frequently demonstrated KJOC scores of ≥90 than players with such treatment (n = 55, 80.9 ± 17.1; P < .001). The 18 players with time-loss arm injury in the last year had lower mean KJOC scores (71.3 ± 20.0) than players with no injury or time loss (90.3 ± 9.8; P < .001). Similarly, players who reported current arm trouble (n = 15) had lower KJOC scores (71.6 ± 17.5) than players with healthy arms (89.5 ± 11.9; P < .001).

CONCLUSIONS

The average KJOC score of the CCBL players was <90, with particularly low scores in athletes with prior arm injury and treatment.

Young Age and Concomitant or Prior Bony Realignment Procedures are Associated with Decreased Risk of Failure of Osteochondral Allograft Transplantation in the Knee: A Nationwide Database Study

OBJECTIVE

Osteochondral allograft (OCA) transplantation is a restorative surgical option for large, full-thickness chondral or osteochondral defects in the knee. Variability in outcomes reporting has led to a broad range of graft survival rates. Using rate of salvage surgery following OCA as a failure metric, the purpose of this study was to analyze the incidence and risk factors for failure in a nationwide cohort.

DESIGN

The M151Ortho PearlDiver database was queried for patients aged 20 to 59 who underwent primary OCA between 2010 and 2020. Patients with prior cartilage procedures or arthroplasty were excluded. Kaplan-Meier survival analysis was performed to characterize cumulative rate of salvage surgery, defined as any patient subsequently undergoing revision OCA, autologous chondrocyte implantation (ACI), osteochondral autograft transfer system (OATS), unicompartmental knee arthroplasty (UKA), or total knee arthroplasty (TKA). Multivariable logistic regression was used to determine the effect of several variables on odds of salvage surgery.

RESULTS

Around 6,391 patients met inclusion criteria. Cumulative 5-year salvage rate was 1.71%, with 68.8% in the first 2 years. Age 20 to 29 and concomitant or prior bony realignment procedures were associated with significantly decreased rate of salvage surgery (age-adjusted odds ratio [aOR] = 0.49, 95% confidence interval [CI], 0.24-0.99, P = 0.046; realignment-aOR = 0.24, 95% CI, 0.04-0.75, P = 0.046).

CONCLUSIONS

In the largest OCA cohort studied to date, less than 2% of patients required salvage surgery. Young age and bony realignment were protective. These findings suggest that OCA in the knee is a durable cartilage-restoration procedure, especially in young patients with corrected alignment.

A Diagnosis of Vitamin D Deficiency Is Associated With Increased Rates of Anterior Cruciate Ligament Tears and Reconstruction Failure

PURPOSE

To characterize the association between a diagnosis of hypovitaminosis D and primary anterior cruciate ligament (ACL) tear, primary anterior cruciate ligament reconstruction (ACLR), and revision ACLR in different sex and age cohorts.

METHODS

In this retrospective cohort study of the PearlDiver claims database, records were queried between January 1, 2011, and October 31, 2018 for all patients aged 10 to 59 years who received a diagnosis of hypovitaminosis D. Rates of primary ACL tears, primary reconstruction, and revision reconstruction were calculated for sex- and age-specific cohorts and compared with a control of patients without a diagnosis of hypovitaminosis D. Incidence rates for primary ACL injuries were calculated, and multivariable logistic regression was used to compare rates of ACL injury, primary reconstruction, and revision reconstruction while controlling for age, sex, Charlson Comorbidity Index, and several other comorbidities.

RESULTS

Among the 328,011 patients (mean age 41.9 ± 12.6 years, 65.8% female) included in both the hypovitaminosis D and control cohorts, the incidence of ACL tears was 115.2 per 100,000 person-years (95% confidence interval [CI] 107.2-123.7) compared with 61.0 (95% CI 55.2-67.2) in the demographic- and comorbidity-matched control cohort. The study cohort was significantly more likely to suffer an ACL tear over a 1- (aOR 1.67, 95% CI 1.41-1.99, P < .001) and 2-year (aOR 1.81, 95% CI 1.59-2.06, P < .001) period. This trend remained for both male patients at the 1- (aOR 1.66, 95% CI 1.29-2.14, P < .001) and 2-year (aOR 1.68, 95% CI 1.37-2.06, P < .001) mark and female patients at the 1- (aOR 1.69, 95% CI 1.33-2.14, P < .001) and 2-year (aOR 1.80, 95% CI 1.51-2.14, P < .001) mark. Finally, patients with vitamin D deficiency had a significantly increased likelihood of undergoing a revision ACLR within 2 years of a primary reconstruction (aOR 1.28, 95% CI 1.05-1.55, P = .012).

CONCLUSIONS

This study reports an association between patients previously diagnosed with hypovitaminosis D and significantly increased rates of both index ACL tears (81% increase within 2 years of diagnosis) and revision ACLR (28% within 2 years). These results identify a population with increased odds of injury and provide valuable knowledge as we expand our understanding of the relationship between vitamin D and musculoskeletal health.

LEVEL OF EVIDENCE

Level III, retrospective database study.

Association of Emergency Department Evaluation With Public Insurance Use and Treatment Delays for ACL Injury

Background

Utilization of an emergency department (ED) visit for anterior cruciate ligament (ACL) injury is associated with high cost and diagnostic unreliability.

Hypothesis

Patients initially evaluated at an ED for an ACL injury would be more likely to be from a lower income quartile, use public insurance, and experience a delay in treatment.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients in the Rhode Island All Payers Claims Database who underwent ACL reconstruction (ACLR) between 2012 and 2021 were identified using the Current Procedure Terminology (CPT) code 29888. Patients were stratified into 2 cohorts based on CPT codes for ED or in-office services within 1 year of ACLR. A chi-square analysis was used to test for differences between cohorts in patient and surgical characteristics. Multivariable linear and logistic regression were used to determine how ED evaluation affected timing and outcome variables.

Results

While adjusting for patient and operative characteristics, patients in the ED cohort were more likely to have Medicaid (29% vs 12.5%; P < .001) and be in the lowest income quartile (44.6% vs 32.1%; P < .001). ED visit and Medicaid status were associated with increased time to (1) diagnostic magnetic resonance imaging, adding 7.97 days on average (95% CI, 4.14-11.79 days; P < .001) and 8.40 days (95% CI, 3.44-13.37 days; P = .001), respectively; and (2) surgery, adding 20.30 days (95% CI, 14.10-26.49 days; P < .001) and 12.88 days (95% CI, 5.15-20.60 days; P = .001), respectively. Patients >40 years who were evaluated in the ED were 2.5 times more likely to require subsequent ACLR (odds ratio, 2.50 [95% CI, 1.01-6.21]; P = .049).

Conclusion

In this study, patients who visited the ED within 1 year before ACLR were more likely to have a lower income, public insurance, increased time to diagnostic imaging, and increased time to surgery, as well as decreased postoperative physical therapy use and increased subsequent ACLR rates in the 40-49 years age-group.

Arthroscopic Simulation in Orthopaedic Surgery Training

Surgical simulation has become a commonly utilized and well-researched training adjunct in nearly all surgical specialties. Balancing high-quality orthopaedic surgical training in the face of work hour restrictions and efficiency pressures has become a challenge to educators and trainees alike. Surgical simulation is an opportunity to enhance such training and potentially permit trainees to be better equipped for the operating room. In orthopaedics, various low-fidelity, high-fidelity, and virtual reality simulation platforms are readily available to almost all trainees and permit simulation of a wide array of arthroscopic surgeries. In this review, we seek to highlight the potential utility of simulation-based training in orthopaedic surgery, the various types of available simulators, and review the evidence for simulator use.

Differences in the Medical Advisability of Online Pitching Recommendations for Youth Softball Players Based on Website Source

Background

Guidelines regarding injury prevention in fast-pitch softball pitchers have yet to be widely adopted, risking the online dissemination of misleading advice.

Purpose/Hypothesis

The purpose of this study was to assess the source and medical advisability of online pitching recommendations for youth softball players and highlight the risk of misinformation. It was hypothesized that many popular websites would contain content discordant with current medical guidelines regarding windmill softball pitching recommendations.

Study Design

Cross-sectional study.

Methods

A Google search using the phrase "youth softball pitching recommendations" was performed. Up to 100 websites were extracted and analyzed for website source type (commercial, medical/educational, or athletic organization) and informational quality (advisable, neutral, or discordant). The latter was determined with respect to the STOP Sports Injuries guidelines for arm injury prevention in youth softball players. Descriptive and inferential statistics were used to assess potential associations between website source type and the informational quality of content therein.

Results

A total of 86 websites were included in the analysis. Website source type was significantly predictive of informational quality (P = .018). Among the 3 source types, medical/educational websites had the highest proportion classified as advisable (12/24 [50.0%]) and the lowest proportion classified as discordant (3/24 [12.5%]). Only 17.6% (6/34) of commercial websites were advisable, and advisable websites as a whole were more likely to be from medical/educational sources than athletic organization (P = .016) or commercial (P = .026) sources. The advisability rate among all websites was 25.6% (22/86). Although there was a significant association between position in the search results (first 10 vs remaining 76) and website source type (P = .006), there was no association between position and informational quality (P = .116). The first 10 websites, which trended toward greater advisability than the remaining 76 websites (P = .060), were more likely than the remaining websites to be medical/educational sources (P = .002).

Conclusion

Website source type was significantly predictive of medical advisability. Medical/educational websites were the most advisable, while commercial and athletic organization websites were especially poor in their advisability. The overall advisability rate was only 25.6%. When making recommendations to patients, sports medicine providers should highlight the prevalence of discordant online softball pitching guidelines and take the opportunity to share medically advisable resources.

Extensor Carpi Ulnaris Instability: A Comprehensive Review of Pathology and Operative Techniques

The extensor carpi ulnaris (ECU) is primarily responsible for extension and ulnar deviation at the wrist. Secondary to repetitive loading of, or acute trauma to the flexed, supinated and ulnarly deviated wrist, the ECU tendon can be a common source of ulnar-sided wrist pain. Common pathology includes ECU tendinopathy, tenosynovitis, tendon instability, and tendon rupture. Extensor carpi ulnaris pathology commonly occurs in athletes and patients with inflammatory arthritis. Given the multitude of available methods to treat ECU tendon pathology, the aim of our study was to outline operative management of ECU tendon pathology, with emphasis on reviewing techniques for addressing ECU instability. We acknowledge a continuing debate between anatomical and nonanatomical techniques for ECU subsheath reconstruction. However, use of a portion of the extensor retinaculum for nonanatomical reconstruction is commonly used and demonstrates successful outcomes. Future comparative studies on ECU fixation are required to increase data on patient outcomes, to further define and standardize these techniques.

Lack of Consensus in Rehabilitation Protocols After Posterior Shoulder Stabilization

Background

Posterior shoulder instability is being identified and treated more frequently by orthopaedic providers. After posterior shoulder stabilization, long-term outcomes in function and mobility are largely dependent on the postoperative rehabilitation period. Thus, it is important to assess the consistency between protocols at different institutions.

Purpose/Hypothesis

The purpose of this study was to investigate the variability among rehabilitation protocols published by academic orthopaedic programs and their affiliates. It was hypothesized that there would be little consistency in the duration of immobilization, timing of functional milestones, and start dates of various exercises.

Study Design

Cross-sectional study.

Methods

Rehabilitation protocols after posterior shoulder stabilization that were published online from Accreditation Council for Graduate Medical Education (ACGME)-accredited orthopaedic surgery programs and their affiliates were evaluated for recommendations on immobilization, exercises, activities, range of motion (ROM), and return-to-sport goals.

Results

Of the 204 ACGME-accredited orthopaedic surgery programs, 22 programs and 17 program affiliates had publicly available rehabilitation protocols that were included for review. There were 37 programs (94.9%) that recommended the use of sling immobilization for a mean of 4.7 ± 1.8 weeks postoperatively. Active ROM of the elbow, wrist, and hand was the most common early ROM exercise to be recommended (36 programs; 92.3%). The goal of 90° passive external rotation demonstrated the widest range of recommended start dates (0-12 weeks postoperatively). Late ROM exercises and start dates varied between protocols, with the largest standard deviation found in achieving full active ROM (13.5 ± 3.6 weeks). Resistance exercises showed a wide range of recommended start dates. Bench presses and push-ups began, on average, at 13.1 ± 3.4 and 15.3 ± 3.2 weeks, respectively. Return to sport was recommended at 21.7 ± 3.6 weeks.

Conclusion

There was a high level of variability in postoperative rehabilitation protocols after posterior shoulder stabilization among orthopaedic programs and their affiliates, suggesting that a standard protocol for rehabilitation has yet to be established.

Prevalence of abnormalities on cardiac MRI in unselected patients after recovery from acute SARS-CoV-2 infection and correlation with markers of immunity and coagulation: the SETANTA study

Background

Previous studies have reported ongoing cardiac inflammation as assessed by cardiac magnetic resonance imaging (CMR) in a significant proportion of patients several months after recovery from SARS-CoV-2 infection, many of whom had no or minimal symptoms at the time of infection.

Purpose

The aim of SETANTA was to investigate the prevalence of cardiac abnormalities by CMR in unselected patients in Ireland after acute SARS-CoV-2 infection and the correlation with immunological response and biomarkers of coagulation.

Methods

This was a prospective, observational, community-based study (clinicaltrials.gov identifier NCT04823182). Consecutive patients recovered from recent SARS-CoV-2 infection at 3 primary care sites were invited to participate. Key inclusion/exclusion criteria and outcomes of interest are shown in Figure 1.

Results

100 participants were enrolled (Feb-Sept 2021) at a median of 188 (IQR, 125, 246) days after positive SARS-CoV-2 swab. At index infection, 18% and 35% reported severe and moderate symptoms, respectively; 14% were hospitalized; 3% were admitted to intensive care for ventilatory support. At enrolment, 83% had ongoing symptoms. 85% had detectable SARS-CoV-2 antigens. CMR and laboratory findings are shown in Figure 1.

Conclusion

Among an unselected cohort of patients recovered from acute SARS-CoV2 infection, we report a low prevalence of cardiac abnormalities by CMR, despite a high prevalence of moderate/severe symptoms at presentation and a high prevalence of persistent symptoms. Correlation with biomarkers of immunity and coagulation will be available at ESC 2022.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): WomenAsOne

Initial experience and validation of a novel tool to assess patient experience in the catheterization laboratory (PATCATH), in patients undergoing coronary angiography or angioplasty

Funding Acknowledgements

Type of funding sources: None.

Background

Patient-reported experience metric (PREM) questionnaires are an important tool for evaluating patient experience.

Purpose

Validated PREM tools may help to identify areas of quality improvement within healthcare.

Methods

A novel tool developed by the Patient Initiative Committee of the European Association of Percutaneous Intervention (EAPCI), in association with the European Society of Cardiology Patient Forum was designed to capture patient experience in the catherization laboratory. The questionnaire is divided into 3 domains assessing experience before, during and after coronary angiography or angioplasty (Figure 1, Panels A-C). Responses were recorded on a scale of strongly agree, agree, disagree, or strongly disagree. Consecutive patients undergoing a coronary angiography or angioplasty received the questionnaire to complete anonymously during recovery following catheterization.

Results

A total of 100 valid responses were received over a four week pilot experience. Most patients had an angiogram procedure (80%). A total of 52% were grouped in the higher age category (≥66 years) (Table 1). Patient response indicated a high level of satisfaction with the experience before the procedure: 98.6% of patients strongly agreed or agreed with statements assessing positive experience reflecting a level of knowledge of why the procedure was recommended and perceived level of support (Figure 1, Panel A). 98.5% strongly agreed or agreed with statements assessing positive experience of comfort, safety, communication and understanding during the procedure (Figure 1, Panel B). A total of 9.6% of patients within the higher age category provided no response regarding their understanding for why a treatment decision was made, whilst all patients in the lower age category responded. After the procedure, 59.3% strongly agreed or agreed with statements assessing positive experience: with lower levels of positive experience for questions related to lifestyle changes (60%), comprehension of a rehabilitation program (46%), medication prescription (58%) and treatment duration (53%) (Figure 1, Panel C). However, 15.2% of questions in this domain had no response, particularly those related to prescribed medication. A lower positive experience was observed between higher versus lower age categories respectively (44.2% & 77.1%) regarding an understanding of necessary lifestyle changes.

Conclusion

The results of our initial experience with a novel PREMs tool highlight high levels of positive experience before and after diagnostic angiography and a lower level of positive experience in the period after the procedure. Completing this tool at a later stage or post-hospital discharge (i.e., following additional education interventions) may help to capture a higher positive response related to after the intervention. To validate these findings, this PREM tool should be evaluated further in additional patient cohorts across multiple sites.

A meta-analysis of randomised controlled trials investigating the impact of colchicine on major adverse cardiovascular events in acute coronary syndrome

Background/Introduction

Colchicine has been shown to reduce inflammation and has a potential to stabilise atherosclerotic plaques. Prior meta-analyses on the topic suggest its role in reducing components of major adverse cardiovascular events (MACE).

Purpose

The aim of the present meta-analysis was to delineate the effect of colchicine on post-PCI (percutaneous intervention) MACE among acute coronary syndrome (ACS) patients.

Methods

We included randomised controlled trials (RCTs) comparing colchicine to placebo in ACS patients undergoing PCI. To identify potentially relevant trials a PUBMED search was undertaken using the MESH terms “colchicine” and “cardiovascular system”. Eligible RCTs published up to November 2020 were included. Our search strategy also included presentations from the proceedings of international meetings. The primary endpoint was MACE. However, definitions of MACE varied between included studies. Study level odds ratios (ORs) and 95% confidence intervals (CI) of MACE were pooled using the Mantel-Haenszel method and random effects model. Forest plots were generated using Review Manager (RevMan) 5.4 software.

Results

Our initial search identified 1,049 articles for potential inclusion. Of them, 4 RCTs were found to be eligible: COPS, COLCHICINE-PCI, COLCOT time-to-Initiation (TTI) 0–3 days and PODCAST-PCI.

A pool of 2,709 patients were randomly allocated to treatment with either colchicine (n=1,367) or placebo (n=1,342). Patients received colchicine either prior to angiography or within 3 days post-procedure. Follow up duration ranged from 30 days to 3 years during which MACE were recorded. Mean age of the whole analysed cohort was 60.3±10.5 years. 73% were male. 51% had history of hypertension, 26% had diabetes mellitus, 38% were current smokers. There were 89 events in the colchicine group as opposed to 133 events in the placebo group. The risk of post-PCI MACE was lower in patients treated with colchicine as compared with placebo (OR 0.63, 95% CI 0.48–0.84, p=0.001) (see figure 1). Heterogeneity was not detectable (I2=0).

Conclusions

Our results indicate lower risk of MACE in patients treated with colchicine. This indicates a potential use of colchicine in patients undergoing PCI in an ACS setting. Further investigations in larger cohorts are warranted to test this effect.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Interleukin 6 –174 G/C polymorphism: its relation to coronary artery disease and circulating IL-6 levels – a systematic review and meta-analysis

Introduction

Circulating IL-6 levels and at least one polymorphic form of IL6 gene (IL6 –174 G/C, rs1800795) have been found to be independently associated with coronary artery disease (CAD). However, the association status of this polymorphism with CAD remains unclear.

Purpose

We conducted a systematic review and updated meta-analysis to comprehensively ascertain the association status of IL6 –174 G/C with CAD and its effect on the levels of circulating IL-6 in humans.

Methods

Comprehensive online search was undertaken to find relevant case-control/cohort studies investigating the association of IL6 –174 G/C with CAD. The association status of –174 G/C with CAD amongst pooled sample as well as separately amongst different ancestral populations was assessed. Association of –174 G/C with circulating IL-6 levels was also assessed amongst pooled sample as well as separately for CAD cases and CAD-free controls. Study-level odds ratios (OR) and 95% confidence intervals (CI) were pooled by Mantel-Haenszel fixed-effects models.

Results

Quantitative synthesis for assessing the role of this polymorphic variant in CAD was performed using 55 separate qualifying studies with a collective sample size of 51,213 (19,160 cases / 32,053 controls). The pooled association of –174 G/C with CAD was found to be statistically significant through dominant (OR= 1.15, 95% CI= 1.05–1.25, p=0.002) as well as allelic genetic model comparisons (OR= 1.13, 95% CI= 1.06–1.21, p=0.0003). Asian and Asian-Indian ancestral subgroups showed significant association with CAD in both genetic model comparisons (OR range= 1.29 to 1.53, p value range ≤0.02). Other ancestral subgroups did not show any meaningful association. Circulating IL-6 levels were found to be significantly higher amongst the “C” allele carriers in the pooled sample (Standard mean difference, SMD= 0.31, 95% CI= 0.01–0.22 pg/ml, p=0.009) as well as the CAD-free control subgroup (SMD= 0.10, 95% CI= 0.02–0.17 pg/ml, p=0.009). CAD case subgroup did not show any significant association (p=0.12).

Conclusions

The present systematic review and meta-analysis confirms an association between IL6 –174 G/C polymorphism residing in the IL6 gene and CAD, especially amongst Asian and Asian-Indian ancestral groups. Upregulation of plasma IL-6 levels in the “C” allele carriers seem to be at least partly responsible for the observed association. Further investigations with large structured case-control studies amongst these ancestral groups are warranted.

Funding Acknowledgement

Type of funding sources: None.

Assessment of stent optimization in clinical practice using optical coherence tomography: a multicentric observational study

Background

Stent under-expansion obtained at the time of percutaneous coronary intervention (PCI) has been shown to be associated with worse outcomes.

Purpose

We sought to define OCT assessed optimal stent expansion index which associates with lower incidence of major adverse cardiac events (MACE) during follow-up in a sample of patients stented at five high volume centers of central Europe.

Methods

We analyzed 370 lesions stented during the period between 2012 and 2018, with their final procedural results imaged using optical coherence tomography (OCT). QIvus Research Edition v3.1 (Medis, Leiden, NL) was used for OCT analysis. The stented segment was split in two equal halves. Stent expansion index (SEI) was calculated for both halves separately by dividing minimum stent area by the mean reference lumen area [(proximal reference area + distal reference area)/2]. Smallest of the two prevailed as the SEI of that case. MACE during post-PCI follow-up was defined as composite of all-cause death, myocardial infarction, stent thrombosis and target lesion revascularization. Data is expressed as mean±SD or median (Interquartile range). Incidence of subsequent MACE is expressed as crude rates (%).

Results

A total of 316 cases (370 lesions), aged 64.6±11.7 years were included for OCT analysis. Of them, 78.8% were males, 22.8% were diabetics, 75.9% were hypertensives while 35.1% had family history of coronary artery disease. 38.0% of the cases had acute coronary syndrome at presentation. 62.4% of treated lesions were complex (Type B2/C). A mean of 1.11±0.34 stents/scaffolds were implanted per treated lesion. Analyzed segment length was 20.4 (15.17, 27.0) mm.

Minimal stent area (MSA) in the overall stented segment was 6.02 mm2 (4.65, 7.93). Median stent expansion index (minimum) was 0.79 (0.71, 0.86). Median follow-up duration was 557 days (326, 1,096). 47 lesions (12.7%) suffered MACE during follow-up. Receiver operating characteristic (ROC) curve analysis using Youden's rule identified 0.84 as SEI cut-off powered to predict post-PCI MACE (AUC= 0.60, sensitivity= 0.85, specificity= 0.34). MACE was observed in 38/249 (15.3%) of lesions with SEI≤0.84 and in 9/121 (7.4%) of lesions with SEI&gt;0.84 (p=0.03). Univariate regression analysis of MACE revealed significant association with SEI≤0.84 (OR=2.2, 95% CI=1.1–4.8, p=0.04) Adaptive Lasso regression identified SEI≤0.84 (OR=4.1, 95% CI=1.3–12.6, p=0.02) and coronary calcification at baseline (OR=2.7, 95% CI=1.1–6.6, p=0.03) as independent predictors of MACE during follow-up. Kaplan-meier curve for MACE free survival with optimal SEI (n=121) and sub-optimal SEI (n=249) subgroups using SEI cut-off of 0.84, however showed modest separation (p=0.11).

Conclusions

The present study identified SEI&gt;0.84 associated with lower incidence of MACE as optimal cut-off in daily practice. Along with SEI of ≤0.84, coronary calcification was also significantly associated with MACE during post PCI follow-up.

Funding Acknowledgement

Type of funding sources: None.

P5630Morphometric and qualitative differences in neointimal tissue six months after implantation of bioresorbable scaffolds versus conventional everolimus eluting stents in ISAR-Absorb MI trial

Background

Bioresorbable scaffolds (BRS) are novel devices designed to overcome the long-term limitations of permanent metallic stent implantation. Optical coherence tomography (OCT) surveillance can provide important insights on the process of vessel wall healing at follow-up.

Purpose

We sought to compare OCT-assessed healing at 6 months after implantation of everolimus-eluting BRS and everolimus-eluting metallic stents (EES) in patients treated for acute myocardial infarction (AMI).

Methods

ISAR-Absorb MI is a multicentre, 2:1 randomized trial comparing outcomes of patients with AMI stented with BRS or conventional EES. Angiographic surveillance was planned for all patients at 6–8 months follow-up. Patients who had OCT surveillance at follow-up were included for the present analysis. Analysis of contiguous OCT cross-sections- 1 mm apart was performed at a centralized core laboratory. Tissue characterisation using a 256-level grey-scale signal intensity (GSI) analysis was also performed for all neointimal regions of interest (ROI) with thickness of 100 to 400 μm. ROI's were classified as mature using a standard cut-off GSI score of 109.7. Generalised linear mixed model (GLMM) was used as appropriate. Statistical analysis was performed using R software. Data is presented as numbers, percentages or median (Interquartile range, IQR).

Results

Median follow-up interval was 216 days. 70 patients in the BRS arm and 33 patients in the EES arm were available for analysis. Stented length was 19.8 mm (13.6, 24.5) and 22.3 mm (16.7, 26.4) in BRS and EES arms respectively (p=0.73). Minimum lumen area [5.13 (3.95, 6.71) vs. 4.83 (3.63, 6.92) mm2] and minimum stent area [5.78 (4.88, 7.34) vs. 6.36 (4.70, 7.45) mm2] were comparable between BRS and EES.

2,262 frames (1,529 in BRS, 733 in EES) with 20,033 struts (12,704 in BRS, 7,329 in EES) were assessed. Overall strut coverage was better with BRS compared to EES (97.5% vs. 91.1% respectively, p<0.001). Malapposed (1.1% vs. 0.5%, p=0.54) and uncovered struts (7.3% vs. 1.3%, p<0.001) were more common with EES. Neointimal coverage was comparable amongst both stent groups [85.5 (61.9, 124.1) vs. 71.5 (33.4, 133.0) μm in BRS and EES groups respectively, p=0.50].

GSI analysis in 95 cases (65 cases, 2,233 ROIs in BRS; 30 cases, 1,210 ROIs in EES) showed that immature ROIs were numerically more common in the EES group as compared to the BRS group (75.4 vs. 57.0% respectively; p=0.35).

Two-year clinical follow-up and analysis of correlation of clinical outcomes with OCT findings will also be available for presentation at ESC Congress 2019.

Conclusions

In selected patients undergoing OCT imaging at 6–8 months after implantation of BRS and conventional EES for AMI, we observed generally favourable healing characteristics with high rates of strut coverage, low rates of strut malapposition and fewer areas of immature neointimal areas with BRS in comparison to EES.

Acknowledgement/Funding

The study was predominantly funded by Deutsches Herzzentrum München and in part by a grant from Abbott Vascular

Is There an Association Between Noncontact Anterior Cruciate Ligament Injuries and Decreased Hip Internal Rotation or Radiographic Femoroacetabular Impingement? A Systematic Review

PURPOSE

To perform a systematic review to determine if there is (1) an association between decreased hip internal rotation and anterior cruciate ligament (ACL) tear rates; (2) an association between radiographic femoroacetabular impingement (FAI) and ACL tear rates; and (3) biomechanical evidence demonstrating increased strain in the ACL of patients with decreased hip internal rotation.

METHODS

A systematic review was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies investigating relationships between hip motion, hip radiographs, and ACL tear were sought. Studies with Levels of evidence I-IV were eligible for inclusion. Study methodology/evidence were evaluated using Methodological Index for Non-Randomized Studies (MINORS), Strengthening the Reporting of Observational Studies in Epidemiology (STROBE), and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria.

RESULTS

Eleven studies were analyzed (2 cadaveric in vitro models, 8 clinical studies measuring hip internal rotation (2 concurrently assessing radiographic FAI), and 1 clinical study assessing radiographic FAI alone). Mean MINORS, STROBE, and GRADE for the studies was 82.4%, 20.9 out of 22, and "low," respectively. A total of 959 subjects (84.8% male; mean age 23.6 ± 3.8 years) were analyzed. Overall, 378 subjects sustained 427 ACL tears (399 primary ACL ruptures, 28 reruptures). Six of 8 clinical studies identified a significant association between limited rotation (internal rotation [IR; loss greater than 10°-20°], external rotation [ER], or combined IR + ER [loss greater than 20°]) and ACL tears. Two studies found an association between ACL ruptures and radiographic cam/pincer impingement. Two cadaveric models found a significant association between ACL strain and limited hip internal rotation.

CONCLUSIONS

This systematic review identified a significant association between ACL tear and both limited hip rotation and radiographic FAI.

LEVEL OF EVIDENCE

Level IV, systematic review of Levels II-IV studies.

Angiographic and clinical outcomes of patients treated with everolimus-eluting bioresorbable stents in routine clinical practice: Results of the ISAR-ABSORB registry

OBJECTIVES

We aimed to analyze angiographic and clinical results of patients undergoing BRS implantation in a real-world setting.

BACKGROUND

Angiographic and clinical outcome data from patients undergoing implantation of drug-eluting bioresorbable stents (BRS) in routine clinical practice is scant.

METHODS

Consecutive patients undergoing implantation of everolimus-eluting BRS at two high-volume centers in Munich, Germany were enrolled. Data were collected prospectively. All patients were scheduled for angiographic surveillance 6-8 months after stent implantation. Quantitative coronary angiographic analysis was performed in a core laboratory. Clinical follow-up was performed to 12 months and events were adjudicated by independent assessors.

RESULTS

A total of 419 patients were studied. Mean age was 66.6 ± 10.9 years, 31.5% had diabetes mellitus, 76.1% had multivessel disease, and 39.0% presented with acute coronary syndrome; 49.0% of lesions were AHA/ACC type B2/C, 13.1% had treatment of bifurcation lesions. Mean reference vessel diameter was 2.89 ± 0.46 mm. At angiographic follow-up in-stent late loss was 0.26 ± 0.51 mm, in-segment diameter stenosis was 27.5 ± 16.1, and binary angiographic restenosis was 7.5%. At 12 months, the rate of death, myocardial infarction, or target lesion revascularization was 13.1%. Definite stent thrombosis occurred in 2.6%.

CONCLUSIONS

The use of everolimus-eluting BRS in routine clinical practice is associated with high antirestenotic efficacy in patients undergoing angiographic surveillance. Overall clinical outcomes at 12 months are satisfactory though stent thrombosis rates are not insignificant. Further study with longer term follow-up and larger numbers of treated patients is required before we can be sure of the role of these devices in clinical practice.

Restenosis in bare metal and drug-eluting stents: distinct mechanistic insights from histopathology and optical intravascular imaging

An increasing body of evidence points to the existence of important differences in the processes of restenosis following drug-eluting stent (DES) as compared to bare metal stent implantation. Preclinical investigation and human autopsy studies have shown that the high efficacy of DES in comparison with bare metal stents in preventing restenosis is achieved at the collateral cost of a delay in healing of the stented arterial segment. Moreover bare metal stent restenosis is typically characterised by a homogeneous tissue rich in smooth muscle cells; whereas DES restenosis is more often hypocellular and proteoglycan-rich. In addition, in-stent neoatherosclerosis appears to have an accelerated course in DES. Angiographic surveillance studies show that while neointimal formation peaks six months after bare metal stenting, neointimal formation after DES therapy is temporally right shifted and remains a dynamic ongoing process (late luminal loss creep) even out to five years. The widespread availability of high resolution optical coherence tomography (OCT) is affording better understanding of the pathophysiology of in-stent restenosis. While bare metal stent restenosis is characterized by predominantly homogenous high-signal tissue echogenicity, layered pattern or heterogeneous tissue composition is more common in DES restenosis. Moreover, preliminary data suggests that tissue attenuation may increase in a time-dependent manner. Nevertheless, the paucity of direct histopathological correlation studies means that the tissue composition of these lesions remains speculative. Data from specifically designed imaging-pathology correlation studies in suitable preclinical models of restenosis and in autopsy specimens is eagerly awaited. Furthermore, although long-term longitudinal clinical follow-up is necessary to define the clinical relevance of optical imaging findings, the nature of restenosis as a disease entity means that its natural history is often altered by a mandate for repeat intervention directly following data acquisition.

From bench to bedside: initial experience with the Primus drug-coated balloon catheter

AIM

Drug-coated balloon (DCB) technology has emerged as a promising therapy particularly in the treatment of coronary in-stent restenosis. Although a variety of devices are available for clinical use, clinical outcomes have been variable and scope for significant improvement exists.

METHODS

In a preclinical study, a total of 10 juvenile healthy farm pigs underwent catheter-based DCB deployment in coronary arteries with angiographic and pathological follow-up at 7 or 28 days. Animals were randomly allocated to the PRIMUS or Dior® DCB (N.=10 per group) and evaluated by histopathology and morphometric analysis. In a first-in-man clinical study a total of 19 consecutive patients presenting with restenosis within drug-eluting stents were treated with the PRIMUS DCB. Clinical follow-up was performed out to 6 months.

RESULTS

Neointimal thickness was similar between the PRIMUS and Dior® DCB groups, while fibrin deposition and inflammation were more sustained in the PRIMUS group at 28 days. In 19 consecutive patients presenting with in-stent restenosis of drug-eluting stents, treatment with the PRIMUS DCB catheter resulted in high procedural efficacy. There were no adverse clinical events observed out to 6 months.

CONCLUSION

The PRIMUS DCB demonstrates high preclinical safety and excellent acute performance and safety. Further studies are needed to delineate the relative merits of this novel DCB compared to other devices.

Traumatic tricuspid regurgitation and right-to-left intra-atrial shunt--an unusual complication of a horse-kick

A 63-year-old male presented with sudden onset chest pain and dyspnoea following a kick to the praecordium while gelding a horse. Transthoracic echocardiography showed evidence of flail tricuspid valve leaflets, severe tricuspid regurgitation and a widely patent foramen ovale with a right-to-left shunt. Due to progressive severe systemic hypoxemia the patient underwent emergent surgical intervention. Operative findings confirmed rupture of the anterior and septal tricuspid valve papillary muscles. Successful papillary muscle reattachment was performed in association with tricuspid annuloplasty and suture closure of his patent foramen ovale. Disruption of the tricuspid valve is well described as consequence of blunt trauma to the chest wall and is often well tolerated, coming to light many years post injury. Valve disruption due to rupture at the papillary muscle level, however, typically results in greater severity of tricuspid regurgitation and the abrupt rise in right intra-atrial pressure may lead to a right-to-left shunt across a patent foramen ovale. Where hemodynamic compromise ensues, prompt surgical intervention is mandated.

Polymer coatings and delayed arterial healing following drug-eluting stent implantation

The antirestenotic efficacy of drug-eluting stent (DES) technology is based on the local delivery and modulated release of cytotoxic drugs targeted at inhibition of neointimal hyperplasia. Control of drug-release kinetics is a critical component of device efficacy. To date this has been most effectively performed by stent coatings comprised of non-erodable (permanent) polymer which facilitate drug loading and delay elution of the active drug. In fact all 4 of the systems currently approved by the Food and Drug Administration (FDA) use a permanent polymer-based drug release system. Balancing the need for lipophilicity (to bind active drug) with hydrophilicity (which offers superior biocompatibility) is a key challenge in polymer technology. Delayed arterial healing (DAH) following DES implantation has been demonstrated in human autopsy studies and animal models and is implicated in late thrombotic occlusion and delayed loss of antirestenotic efficacy. It is characterised by 1) persistent fibrin deposition; 2) delayed endothelialization; 3) chronic inflammation; and 4) persistent platelet activation. Within segment heterogeneity in degree of healing is typical. Inflammatory response to polymer residue plays an important role and may be non-specific (monocyte-macrophage predominant) or hypersensitivity related. Failure of early preclinical models to sufficiently predict DAH in man was an important problem. Second generation DES attempt to address the issue of DAH by using thinner stent struts, lower drug load and more biocompatible polymer. At present the focus of development is towards biodegradable polymer coatings which offer the attractive prospect of controlled drug-release without the potential for late polymer-associated adverse effects. This review highlights the role of polymer coatings in determination of DES efficacy, summarises the preclinical and clinical evidence linking polymer coatings with DAH and evaluates the promise of third generation polymer-free and biodegradable polymer DES.

Multivessel percutaneous coronary intervention: a review of the literature and fallacies in its interpretation

Since its inception in the 1960s, coronary revascularization has established itself as a fundamental therapy for treating the acute and chronic manifestations of atherosclerotic coronary disease. Catheter-based techniques were realized in the late 1970s and have evolved from balloon dilatation of simple, discrete stenoses to complex, multivessel interventions across the spectrum of coronary disease presentations. In retrospect, there were two defining technological developments the introduction of coronary stenting which enabled more stable acute outcomes and the evolution of drug-eluting stents which ameliorated the effect of neointimal hyperplasia the dominant cause of delayed loss of efficacy. The role of catheter-based intervention in multivessel disease is well established in the treatment of ST-elevation myocardial infarction and acute coronary syndromes. On the contrary, in the arena of in stable coronary disease, its utility is keenly debated. The pace of development in cardiovascular pharmacology has rendered early investigation of best treatment strategies largely obsolete, while newer revascularization techniques have successfully extended the remit of catheter-based multivessel intervention strategies to include left main stem disease, bifurcation stenosis and chronic occlusions. Consequently complete revascularization is now available via a percutaneous approach and conventional beliefs relating to choice of revascularization strategy deserve re-assessment. The authors present a contemporary review of the literature and a challenge against fallacies in its interpretation.

Ionic and acid-base consequences of exposure to increased salinity in the zebra mussel, Dreissena polymorpha

Dreissena polymorpha, an invasive freshwater bivalve, displays physiological characteristics that reflect its ancestry in brackish water, yet it has limited ability to withstand modest increases in salinity. We examined changes in hemolymph ion concentrations and acid-base variables in mussels transferred to and incubated in 10% artificial seawater (ASW) for 7 days and then returned to pondwater (PW) for a further 7 days. Hemolymph was sampled (10 animals per sample period) every 4 h for the first 24-h incubation and at 72 h and 168 h for both the transfer to 10% ASW and the transfer back to PW. The initial response to transfer to 10% ASW was a rapid attainment of an apparent isoosmotic steady state, with most hemolymph ion concentrations rising and attaining steady state within 12 h. Hemolymph magnesium rose more slowly, and hemolymph calcium declined despite an increase in its concentration in the bathing medium. Hemolymph pH rose significantly during the first 24 h, from 7.96 to 8.25, as a result of increases in bicarbonate; pH subsequently returned to normal through increases in PCO2. When animals were returned to PW after 7 days' incubation in ASW, the response of the major hemolymph ions was largely the reverse of that effected by the transfer to ASW. Hemolymph pH was not altered significantly until after 72 h in PW, when declines in bicarbonate lowered the pH to 7.73. Strong ion difference (SID) was related significantly to hemolymph pH. Hemolymph calcium and magnesium showed a reciprocal relationship throughout both transfer and incubation. Solubility interactions between sulfate and calcium and magnesium may be important in determining calcium availability in solution. The Na/K ratio in hemolymph was maintained within relatively narrow bounds throughout the procedure and may contribute to the mussels' ability to volume-regulate during an osmotic challenge. Overall, the responses of D. polymorpha to modest changes in salinity were largely the result of passive processes.

Pneumopericardium and pneumothorax contralateral to venous access site after permanent pacemaker implantation

A 77-year-old female underwent implantation of a left-sided dual chamber permanent pacemaker for symptomatic bradycardia with active fixation leads. Eight hours after the procedure, the patient complained of shortness of breath and was found to have a 30% right pneumothorax on chest X-ray. Immediately, a chest tube was inserted, promptly relieving the symptoms. A CT scan of the chest revealed extrusion of the helix of the screw-in atrial lead, through the wall of the right atrial appendage. The helix was abutting a bulla in the right lung, the likely cause for pneumothorax and pneumopericardium. The atrial lead was explanted without incident.

Kidney function and sulfate uptake and loss in the freshwater bivalve Toxolasma texasensis

Toxolasma texasensis acclimated to an artificial pondwater (PW) maintained a concentration of SO4 in the blood of about 1-2 mmol l(-1) . The anion transport inhibitor DIDS (5,5'-diisothiocyanatostilbene 2, 2'-disulfonic acid) reduced the uptake of 35SO4 from the bathing medium by 54%. The clearance of polyethylene glycol (PEG) injected into the blood of T. texasensis ranged between 0.8 and 1.3 ml g(-1) dry tissue h(-1), and provided an estimate of renal filtration in PW-acclimated animals. The clearance of radioactive 35SO4 simultaneously injected into the same animal was about 16% of the PEG clearance, suggesting that sulfate was being reabsorbed by the kidney. Para-aminohippuric acid was cleared about 4.6 times faster than PEG, indicating that this organic acid was subjected to secretion in addition to filtration. When the normal osmotic gradient was abolished by acclimating T. texasensis to 10% seawater (SW), the PEG clearance decreased to 0.17 ml g(-1) dry tissue h(-1). Sulfate clearance in animals acclimated to PW or 10% SW was the same. However, in mussels acclimated to 10% SW, the calculated amount of SO4 reabsorbed was significantly reduced relative to mussels acclimated to PW. T. texasensis conserved SO4 when acclimated to PW, and reduced reabsorption when acclimated to the sulfate-rich 10% SW. When mussels acclimated to 10% SW were returned to PW, there was a transient increase in sulfate clearance during the first 8 h because filtration exceeded reabsorption.

Paracellular solute uptake by the freshwater zebra mussel Dreissena polymorpha

A hyperosmotic solution of mannitol or glucose (100 mM) in pond water caused an increase in paracellular solute movement between the bathing medium and body fluids of Dreissena polymorpha. Small molecules (< 5,000 Da) in the bath entered the mussel, and 80-85% of the sodium and chloride in the blood was lost within 12 h. Blood total solute was elevated within 4 h of exposure to hyperosmotic conditions, but the rise was attributed to the gain of glucose or mannitol from the bath and not to an elevation of ion concentration as a result of the osmotic loss of water. Lanthanum in the bathing solution was able to penetrate the paracellular junctional complex between gill epithelial cells in mussels exposed to hyperosmotic conditions but was rarely observed in pond water-acclimated animals. Colloidal gold (6 nm diam) was unable to penetrate the paracellular space but was accumulated in endocytotic vesicles in many epithelial cells. The "leakiness" of the epithelial tissue may be a critical factor in the low blood solute concentrations in freshwater mussels despite high rates of ion transport in these animals.

Acute myelomonocytic leukemia with abnormal eosinophils presenting as an ovarian mass: a report of two cases and a review of the literature

Acute myelomonocytic leukemia is a neoplastic blood disease that can occur as an extramedullary tumor called a granulocytic sarcoma. Granulocytic sarcoma can be the presenting feature of acute leukemia and can occur as an abdominal or pelvic mass. Two cases of granulocytic sarcomas presenting as ovarian masses in patients with acute myelomonocytic leukemia with a characteristic inversion of chromosome 16 are described and the current literature regarding treatment and prognosis is reviewed.

Acid-Base and Ionic Regulation, During and Following Emersion, in the Freshwater Bivalve, Anodonta grandis simpsoniana (Bivalvia: Unionidae)

Specimens of the boreal clam, Anodonta grandis simpsoniana were emersed at 10{deg}C for 6 days and then reimmersed for 24 h. The clams lost water at a rate of 1.6% total water per day. After 144 h of emersion, water weight had declined by almost 15%, while extracellular fluid (ECF) osmolality had increased 30% to 52 mOsm kg-1. Control levels were reattained after 6 h reimmersion. ECF Po2 declined rapidly in the first 24 h of emersion, but remained near 20 Torr for the full 6-day exposure. After an initial rapid fall, pH declined at a slower rate, reaching 7.494 +/- 0.037 (mean +/- SEM) at 144 h. Pco2 was elevated from 0.6 +/- 0.6 to 12.4 +/- 1.1 Torr after 96 h, but no further increase was noted. ECF [Ca] increased threefold to 13.1 +/- 0.8 mmol l-1, while [HCO3app] rose from 5.4 +/- 0.3 to a maximum of 12.9 +/- 0.8 mmol 1-1 after 144 h. ECF [Na] and [Cl] were not affected by emersion. On reimmersion, recovery was rapid, with pH, Po2 and Pco2 returning to control within 2 h, while [Ca] and [HCO3app] remained elevated until 24 h after reimmersion. A 1:1 stoichiometry between [Ca] and [HCO3app] existed throughout the emersion and reimmersion periods. In the absence of protein buffers, the fall in ECF pH was arrested by the mobilization of calcium carbonate, presumably from the shell. By 96 h emersion Pco2 and Po2 had stabilized, suggesting that diffusion gradients sufficient to allow limited gas exchange had been established.

Behavioral and Metabolic Responses to Emersion and Subsequent Reimmersion in the Freshwater Bivalve, Corbicula fluminea

When exposed to air, the freshwater bivalve, Corbicula fluminea, displayed valve movement behaviors, such as mantle edge exposure, wider gaping "ventilatory" response, and an escape or "burrowing" response. The proportion of the emersion period spent in these behaviors, relative to valve closure, increased with decreasing temperature. Emersion at 35°C inhibited valve movement behaviors, whereas emersion in a nitrogen atmosphere stimulated ventilatory activity. High rates of aerial oxygen uptake (Mo2) were associated with initial valve opening and ventilatory behaviors, and lower Mo2 occurred during bouts of mantle edge exposure. Heart rate was affected by temperature, but not by mantle edge exposure. Heart rate increased during burrowing and ventilatory behaviors suggesting a hydraulic function for hemolymph. Emersed C. fluminea had short bursts of heat production followed by longer periods of lower heat flux when measured by direct calorimetry. The mean heat production rate was 1.11 mW (g dry tissue)-1, significantly higher than the mean value for clams exposed in a nitrogen atmosphere, 0.50 mW (g dry tissue)-1. On reimmersion, C. fluminea showed no significant "oxygen debt" until after three days aerial exposure. The bursts of activity, while emersed, may be the result of periodic renewal of oxygen stores followed by immediate oxygen use.

Diastematomyelia: prenatal ultrasonic appearances

Four cases of in-utero diastematomyelia are presented and the ultrasonic features described. Characteristic findings are localised widening of the posterior ossification centres with a central echogenic focus at the point of widening, visible on coronal scanning, and absence of a posterior defect or soft tissue mass on transverse scanning. The aetiology and management of the condition is discussed. The cases illustrate that widening of the posterior ossification centres can occur in the absence of overt spina bifida and the prenatal detection of diastematomyelia will allow for early postnatal investigation and treatment.