Defining capabilities in deployed UK military prehospital emergency care

The UK military prehospital emergency care (PHEC) operational clinical capability framework must be updated in order that it retains its use as a valid operational planning tool. Specific requirements include accurately defining the PHEC levels and the 'Medical Emergency Response Team' (MERT), while reinforcing PHEC as a specialist area of clinical practice that requires an assured set of competencies at all levels and mandatory clinical currency for vocational providers.A military PHEC review panel was convened by the Defence Consultant Advisor (DCA) for PHEC. Each PHEC level was reviewed and all issues which had, or could have arisen from the existing framework were discussed until agreement between the six members of this panel was established.An updated military PHEC framework has been produced by DCA PHEC, which defines the minimum requirements for each operational PHEC level. These definitions cover all PHEC providers, irrespective of professional background. The mandatory requirement for appropriate clinical exposure for vocational and specialist providers is emphasised. An updated definition of MERT has been agreed.This update provides clarity to the continually evolving domain of UK military PHEC. It sets out the PHEC provider requirements in order to be considered operationally deployable in a PHEC role. There are implications for training, manning and recruitment to meet these requirements, but the processes required to address these are already underway and well described elsewhere.

Building stronger bonds: The impact of family support and communication on suicidal behaviors among Black men who have sex with men

INTRODUCTION

It has been well documented that men who identify with a sexual orientation other than heterosexual are at a greater risk for suicide-related outcomes. What is less known are the protective factors that can reduce such negative outcomes and contribute to their resilience.

METHODS

This study used data collected between December 1, 2021, and January 2022 to understand how family factors contribute to or prevent depression symptoms and suicide outcomes among young Black men who have sex with men (BMSM) ages 18 to 29 (N = 400). A path analysis was conducted to explore the direct and indirect effects of suicide attempts.

RESULTS

Surprisingly, there were nuanced findings that showed having a family member or friend die by suicide was indirectly associated with suicide planning and suicide attempts. It was also unexpectedly noted that there was a positive relationship between higher rates of depressive symptoms and higher levels of support from family members.

CONCLUSIONS

The population focused on in this study is understudied and has unique needs. Identifying familial support may not automatically reduce the thoughts and plans of young BMSM, which is an example of why their intersecting marginalized identities must be considered when conducting further research, creating interventions, and providing therapeutic services.

Sarah Waller's Help-Seeking Model: Understanding African American Women Intimate Partner Violence Survivors' Help-seeking Process

African American women overwhelmingly experience the poorest outcomes resulting from intimate partner violence (IPV) victimization. Despite theoretical advancements, there remain a paucity of theories that explicate this marginalized population's comprehensive help-seeking process that includes the domestic violence service provision system and the Black church. We conducted 30 in-depth, semi-structured interviews with women who self-identified as African American. We utilized sensitizing concepts from the Transtheoretical Model of Change and Intersectionality theories, along with Agency framework and employed constructivist grounded theory methodology. Sarah's Help-Seeking Model emerged from the data and includes nine phases: (1) Awareness, (2) Acknowledgment, (3) Assessment, (4) Enough, (5) Enlist, (6) Escalate, (7) Reject, (8) Resolve, and (9) Restoration. This is the first theory that identifies how this vulnerable and underserved population's mental health and social support-seeking process is partially mediated by mistrust of law enforcement, disappointment in linkage to care and services, fear of death, and willingness to survive.

The Relationship between Religion, Substance Misuse, and Mental Health among Black Youth

Studies suggest that religion is a protective factor for substance misuse and mental health concerns among Black/African American youth despite reported declines in their religious involvement. However, few studies have investigated the associations among religion, substance misuse, and mental health among Black youth. Informed by Critical Race Theory, we evaluated the correlations between gender, depression, substance misuse, and unprotected sex on mental health. Using multiple linear regression, we assessed self-reported measures of drug use and sex, condom use, belief in God, and religiosity on mental health among a sample of Black youth (N = 638) living in a large midwestern city. Results indicated drug use, and sex while on drugs and alcohol, were significant and positively associated with mental health symptoms. Belief in God was negatively associated with having sex while on drugs and alcohol. The study's findings suggest that despite the many structural inequalities that Black youth face, religion continues to be protective for Black youth against a myriad of prevalent problem behaviors.

Measurements on the external load acting on aquatic resistance fins during flexion/extension movements using a robotic joint

Aquatic resistance training has been proven to be beneficial to many people, in particular those struggling with degenerative joint diseases or recovering from other musculoskeletal issues as the reaction forces acting on the joints become lower, but without compromising the cardiovascular and neuromuscular benefit of the movement. Little has been written on the load produced by or measurements of the devices used in aquatic resistance training. Therefore, uncertainties exist regarding details of how much load can be applied onto the foot when performing the movements and how to quantify progression. In this study, an instrumented robotic arm was designed, built, and used to measure the load acting on the three different types of fins during a simulated flexion/extension movement of a knee. The angular velocities of the knee ranged from 25°/s to 150°/s, which represent the physiological range of in vivo movements. The results demonstrated that the load followed a second-order polynomial with the angular velocities. The load is therefore a function of the angular velocity, the surface area of the fins, and the location of the fins away from the joint center rotation. We modeled the progression of speeds at maximal voluntary movements based on previous studies. The maximum loads measured between 11 kg and 13 kg in extension and 6 kg and 9 kg in flexion at 150°/s rotational velocity.

Self-help group experiences among members recovering from substance use disorder in Kuantan, Malaysia

This qualitative study aims to explore the factors that motivate people in recovery from substance use disorder in Kuantan to remain in a self-help group. A total of five recovering self-help group members participated in this study. The findings indicated that people in recovery decided to continue their participation in a self-help group in order to obtain support that helps them sustain their recovery. Furthermore, respondents explained that the self-help group empowers them to give back to society. The respondents in this study also emphasized that the presence of a positive group leader is vital in maintaining their motivation to continue their participation in the self-help group.

Family Matters: The Support of Parents to Change Black Male's Attitudes Towards HIV

This study explored the associations between family (mother and father support), peers, and individual factors (self-efficacy) and how these relationships influence HIV attitudes among African American males 12 to 19 years of age, with an average age of 16 years. For this study, we used restricted data obtained from Wave I of the National Longitudinal Study of Adolescent to Adult Health (ADD Health). Descriptive statistics suggest that most of the sample had negative attitudes towards HIV. Bivariate regression analysis followed by a linear regression analysis was conducted to identify the factors that were associated with HIV attitudes. Major findings from regression analysis indicate that mother support, father support, self-efficacy, and age, predicted HIV attitudes. Mother support positively predicted positive HIV attitudes and surprisingly, father support negatively predicted HIV attitudes. Our findings can be used to better inform HIV prevention and intervention programs to help Black males stay healthy.

Reimaging an AIDS free generation: Examining youth and young adults' personal agency and its association with HIV testing

Exploring youth and young adult's agency may be a way to increase HIV testing and help end the HIV epidemic. We used data from the National Survey of Teens and Young Adults (15-24) on HIV/AIDS (N = 1,437). Data were collected from September 21-October 1, 2012. The sample included 748 girls and 689 boys; and the mean age is 20 years (SD: 3.02). Youth and young adults completed a 40-question survey on attitudes and knowledge about HIV. Using a multivariable logistic regression analysis, study findings suggest that focusing on protective health behaviors like the role youth can play in ending the epidemic and hearing about an AIDS-free generation were both associated with an increase in HIV testing. Our study finds that enhancing the role and influence of personal agency can inform HIV prevention and intervention programs that are specific to youth.

Associations between Parent-Child Communication on Sexual Health and Drug Use and Use of Drugs during Sex among Urban Black Youth

Black youth and their families living in urban settings may experience unique stressors that contribute to underlying issues due to the environmental context. Such factors may exacerbate and promote drug use and engagement in risky sexual behaviors, unknowingly. Little is known about how family factors, peer pressure, condom use, and other related factors are associated with substance use and engaging in sexual behaviors while on drugs among urban African American youth aged 12-22 (N = 638). We used regression models to examine associations between parental bonding, parent-adolescent sexual health communication, condom use, peer pressure on substance use, and having sex while on drugs. Multivariate results indicated that parental bonding was statistically significant and associated with drug use (OR: 1.36, 95%CI: 1.36). Our study highlights that parental bonding plays a critical role in youth using drugs while living in urban environments.

Correlates of depression among Black girls exposed to violence

Depression rates for youth remanded to juvenile detention is double that of the general population and Black girls are especially vulnerable. A dearth of literature analyzes the factors that are correlated with depression among system-involved Black girls, ages 12-17 years old. We utilized personal agency to examine the relationship between risk factors (i.e., abuse history, and fear of condom negotiation) and protective factors (i.e., condom self-efficacy, and perceived social support) that might correlate with depression among Black girls exposed to violence. Findings indicate that fear of condom negotiation, abuse history and low condom self-efficacy are correlated with depressive symptomology while self-esteem and perceived social support are protective factors that may serve as a buffer against girls' feelings of helplessness and hopelessness. The findings of this study suggest several implications for prevention and intervention efforts to reduce the depression-related risks among justice-involved Black females, including strategies that promote healing within their social support networks.

Understanding of personal agency among youth to curtail HIV rates

We aimed to discover which social factors influence protective health behaviors among Black youth. We measured study variables based on data from the National Survey of Teens and Young Adults on HIV/AIDS. Participants include youth aged 15 to 24 who completed a 40-question, web-based survey. The analytical sample of participants (n = 270) only comprised African American youth, mean age 20 years (SD: 0.28). Using multiple regression analysis, study findings suggest that focusing on protective health behaviors, such as personal agency among youth, with variables like personal perception and concern and HIV testing could be one way to reduce their risk of HIV transmission. Enhancing the role and influence of personal agency given their testing behaviors can inform HIV prevention and intervention programs that are specific to Black youth. Our findings identify targets for intervention to enhance personal agency in this population, including enhancing HIV risk prevention.

REBOA at Role 2 Afloat: resuscitative endovascular balloon occlusion of the aorta as a bridge to damage control surgery in the military maritime setting

Role 2 Afloat provides a damage control resuscitation and surgery facility in support of maritime, littoral and aviation operations. Resuscitative endovascular balloon occlusion of the aorta (REBOA) offers a rapid, effective solution to exsanguinating haemorrhage from pelvic and non-compressible torso haemorrhage. It should be considered when the patient presents in a peri-arrest state, if surgery is likely to be delayed, or where the single operating table is occupied by another case. This paper will outline the data in support of endovascular haemorrhage control, describe the technique and explore how REBOA could be delivered using equipment currently available in the Royal Navy Role 2 Afloat equipment module. Also discussed are potential future directions in endovascular resuscitation.

Effects of high intensity resistance aquatic training on body composition and walking speed in women with mild knee osteoarthritis: a 4-month RCT with 12-month follow-up

OBJECTIVE

To investigate the effects of 4-months intensive aquatic resistance training on body composition and walking speed in post-menopausal women with mild knee osteoarthritis (OA), immediately after intervention and after 12-months follow-up. Additionally, influence of leisure time physical activity (LTPA) will be investigated.

DESIGN

This randomised clinical trial assigned eighty-seven volunteer postmenopausal women into two study arms. The intervention group (n = 43) participated in 48 supervised intensive aquatic resistance training sessions over 4-months while the control group (n = 44) maintained normal physical activity. Eighty four participants continued into the 12-months' follow-up period. Body composition was measured with dual-energy X-ray absorptiometry (DXA). Walking speed over 2 km and the knee injury and osteoarthritis outcome score (KOOS) were measured. LTPA was recorded with self-reported diaries.

RESULTS

After the 4-month intervention there was a significant decrease (P = 0.002) in fat mass (mean change: -1.17 kg; 95% CI: -2.00 to -0.43) and increase (P = 0.002) in walking speed (0.052 m/s; 95% CI: 0.018 to 0.086) in favour of the intervention group. Body composition returned to baseline after 12-months. In contrast, increased walking speed was maintained (0.046 m/s; 95% CI 0.006 to 0.086, P = 0.032). No change was seen in lean mass or KOOS. Daily LTPA over the 16-months had a significant effect (P = 0.007) on fat mass loss (f² = 0.05) but no effect on walking speed.

CONCLUSIONS

Our findings show that high intensity aquatic resistance training decreases fat mass and improves walking speed in post-menopausal women with mild knee OA. Only improvements in walking speed were maintained at 12-months follow-up. Higher levels of LTPA were associated with fat mass loss.

TRIAL REGISTRATION NUMBER

ISRCTN65346593.

Efficacy of progressive aquatic resistance training for tibiofemoral cartilage in postmenopausal women with mild knee osteoarthritis: a randomised controlled trial

OBJECTIVE

To study the efficacy of aquatic resistance training on biochemical composition of tibiofemoral cartilage in postmenopausal women with mild knee osteoarthritis (OA).

DESIGN

Eighty seven volunteer postmenopausal women, aged 60-68 years, with mild knee OA (Kellgren-Lawrence grades I/II and knee pain) were recruited and randomly assigned to an intervention (n = 43) and control (n = 44) group. The intervention group participated in 48 supervised aquatic resistance training sessions over 16 weeks while the control group maintained usual level of physical activity. The biochemical composition of the medial and lateral tibiofemoral cartilage was estimated using single-slice transverse relaxation time (T2) mapping and delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC index). Secondary outcomes were cardiorespiratory fitness, isometric knee extension and flexion force and knee injury and OA outcome (KOOS) questionnaire.

RESULTS

After 4-months aquatic training, there was a significant decrease in both T2 -1.2 ms (95% confidence interval (CI): -2.3 to -0.1, P = 0.021) and dGEMRIC index -23 ms (-43 to -3, P = 0.016) in the training group compared to controls in the full thickness posterior region of interest (ROI) of the medial femoral cartilage. Cardiorespiratory fitness significantly improved in the intervention group by 9.8% (P = 0.010).

CONCLUSIONS

Our results suggest that, in postmenopausal women with mild knee OA, the integrity of the collagen-interstitial water environment (T2) of the tibiofemoral cartilage may be responsive to low shear and compressive forces during aquatic resistance training. More research is required to understand the exact nature of acute responses in dGEMRIC index to this type of loading. Further, aquatic resistance training improves cardiorespiratory fitness.

TRIAL REGISTRATION NUMBER

ISRCTN65346593.

Effects of short term water immersion on peripheral reflex excitability in hemiplegic and healthy individuals: A preliminary study

BACKGROUND

Reflex excitability is increased in hemiplegic patients compared to healthy controls. One challenge of stroke rehabilitation is to decrease the effects of hyperreflexia, which may be possible with water immersion. Methods/Aims: The present study examined the effects of acute water immersion on electrically-evoked Hmax:Mmax ratios (a measure of reflex excitability) in 7 hyperreflexive hemiplegic patients and 7 age-matched healthy people. Hmax:Mmax ratios were measured from soleus on dry land (L1), immediately after (W1) and 5 minutes after immersion (W5), and again after five minutes on land (L5).

RESULTS

Water immersion led to an acute increase in Hmax:Mmax ratio in both groups. However, after returning to dry land, there was a non-significant decrease in the Hmax:Mmax ratio of 8% in the hemiplegic group and 10% in healthy controls compared to pre-immersion values.

INTERPRETATION

A short period of water immersion can decrease peripheral reflex excitability after returning to dry land in both healthy controls and post-stroke patients, although longer immersion periods may be required for sustainable effects. Water immersion may offer promise as a low-risk, non-invasive and non-pharmaceutical method of decreasing hyperreflexivity, and could thus support aquatic rehabilitation following stroke.

Relationship between lower limb neuromuscular performance and bone strength in postmenopausal women with mild knee osteoarthritis

OBJECTIVES

To investigate whether neuromuscular performance predicts lower limb bone strength in different lower limb sites in postmenopausal women with mild knee osteoarthritis (OA).

METHODS

Neuromuscular performance of 139 volunteer women aged 50-68 with mild knee OA was measured using maximal counter movement jump test, isometric knee flexion and extension force and figure-of-eight-running test. Femoral neck section modulus (Z, mm(3)) was determined by data obtained from dual-energy X-ray absorptiometry. Data obtained using peripheral quantitative computed tomography was used to asses distal tibia compressive (BSId, g(2)/cm(4)) and tibial mid-shaft bending (SSImax(mid), mm(3)) strength indices.

RESULTS

After adjustment for height, weight and age, counter movement jump peak power production was the strongest independent predictor for Z (β=0.44; p<0.001) and for BSId (β=0.32; p=0.003). This was also true in concentric net impulse for Z (β=0.37; p=0.001) and for BSId (β=0.40; p<0.001). Additionally, knee extension force (β=0.30; p<0.001) and figure-of-eight-running test (β= -0.32; p<0.001) were among strongest independent predictors for BSId after adjustments. For SSImax(mid), concentric net impulse (β=0.33; p=0.002) remained as the strongest independent predictor after adjustments.

CONCLUSIONS

Neuromuscular performance in postmenopausal women with mild knee OA predicted lower limb bone strength in every measured skeletal site.

Training-related risk factors in the etiology of overuse injuries in endurance sports

AIM

The purpose of this study was to clarify training-related risk factors for overuse injuries.

METHODS

This was twelve-month retrospective study which was done by self-reported postal questionnaire. The study group consisted of 446 men and women top-level Finnish athletes representing three different endurance sports (cross-country skiing, swimming, long-distance running) between the ages of 15-35. Self-reported anthropometric and training-related variables (such as starting age of training, years of active training, hours trained yearly, competition hours and weekly resting days) and occurrence of overuse injuries.

RESULTS

Athletes with less than 2 rest days per week during the training season had 5.2-fold risk (95% confidence intervals [CI] 1.89-14.06, P=0.001) for an overuse injury, and athletes who trained more than 700 hours during a year had 2.1-fold risk (95% CI 1.21-3.61, P=0.008) for an overuse injury compared to the others. Athletes who reported a tendon injury were on average two years older than athletes without such an injury (P<0.001).

CONCLUSION

We found that low number of recovery days and a high amount of training are training-related risk factors for overuse injuries in top-level endurance athletes. The higher number of tendon overuse injuries in older than younger athletes may indicate that age-related degeneration plays an important role in the etiology of tendon injuries. These findings should be taken into account when planning exercise programs for endurance athletes.

Type of sport is related to injury profile: a study on cross country skiers, swimmers, long-distance runners and soccer players. A retrospective 12-month study

This 12-month retrospective questionnaire compared the occurrence of sports injuries in 149 cross country skiers, 154 swimmers, 143 long-distance runners and 128 soccer players aged 15-35 years. Soccer had significantly more injuries (5.1 injuries/1000 exposure hour) than other sports (2.1-2.8, P<0.001). More runners than soccer players reported overuse injuries (59% vs 42%, P=0.005), locating typically in the foot in runners, soccer players and skiers. Swimmers reported overuse injuries in the shoulder more commonly than skiers (40% vs 1%, P<0.001), who also intensively load shoulders. Acute injuries in skiers (80%) and in swimmers (58%), and overuse injuries in skiers (61%), occurred during exercise other than own event. In soccer and running the absence time from sport because of injuries was significantly longer than in skiing and swimming. No severe permanent disabilities occurred due to injury but seven women quit sports because of injury. In conclusion, type of loading is strictly associated with the anatomical location of an overuse injury as shown by the difference in shoulder injury incidence between swimmers and cross country skiers. In some sports, a significant proportion of acute injuries occur in other than the main event.

Late coronary artery stenosis regression within the Gianturco-Roubin intracoronary stent

The late angiographic outcome of the Gianturco-Roubin intracoronary stent has not been well defined. To investigate serial changes within the stent, we studied 23 patients (15 men and 8 women, median age 63) who had late angiographic follow-up ( > 1 year) after undergoing Gianturco-Roubin stenting for angioplasty-associated acute or threatened native coronary artery closure. Coronary angiography before and after stenting, at 6-month follow-up, and at late return was analyzed with quantitative coronary angiography. The median time from stent deployment to late angiographic follow-up was 27 months. As expected, stenting significantly increased the median minimal lumen diameter (MLD) acutely from 1.0 to 2.46 mm. Median percent diameter stenosis decreased from 66% to 18%. Although at 6 months there was a significant loss of the acute gain (median MLD decreased from 2.46 to 1.9 mm), with a corresponding increase in percent stenosis from 18% to 31%, late angiography demonstrated lesion regression, median MLD increasing from 1.9 to 2.15 mm (p = 0.004), and percent stenosis decreasing from 31% to 21% (p = 0.0026). No patient had a significant decline in minimal lesion diameter, and 5 patients had a > 50% increase in MLD at late follow-up. Linear regression analysis of 6-month MLD and late lumen gain suggested that lesions with the greatest regression were those with the lowest lumen diameters at 6-month angiography. Late angiographic analysis demonstrated significant lesion regression within the Gianturco-Roubin stent, which was sometimes dramatic. In suggesting that coronary arteriography at 6 months may underestimate the late angiographic benefit of intracoronary stenting, these data have important clinical implications, and imply that patients with a stable clinical course and angiographic stent restenosis may often be followed rather than routinely redilated.

Microwave ablation of canine atrial tachycardia induced by aconitine

We tested the efficacy of microwave-frequency energy for ablating atrial tachycardia in eight open-chest dogs. Five other dogs served as controls. Atrial tachycardia was induced by direct application of aconitine crystals to the epicardial atrial surface or by injection of aconitine solution (0.15 mg/ml) into the right or left atrial myocardium. Atrial tachycardias (n = 15) developed at a cycle length of 253 +/- 64 msec or within 245 +/- 116 sec after topical application or injection of aconitine. Catheter ablation was attempted on 10 atrial tachycardias in 8 experiment dogs by using continuous, unmodulated microwave energy from a 915 MHz frequency signal generator via a 7F helical or whip antenna catheter. Successful ablation was defined as conversion of atrial tachycardia to sinus rhythm during delivery of microwave energy and maintenance of sinus rhythm for > 5 minutes after termination of energy delivery. All 10 atrial tachycardias were successfully ablated by 2.3 +/- 1.6 applications of microwave energy for each atrial tachycardia induced. Forward microwave power level was 50.5 +/- 8.1 W, and the duration of energy application was 25.0 +/- 27.6 seconds. Sinus rhythm resumed 9.5 +/- 9.2 seconds after the onset of microwave energy application. After a mean follow-up of 10.4 minutes, seven atrial tachycardias recurred, most likely the result of diffusion of aconitine beyond the perimeter of rhe ablation lesions. Atrial tachycardia did not recur in 3 of 3 dogs that had larger ablation lesion. Gross examination revealed 10 demarcated round or oval transmural lesions in the right or left atrium, ranging from 12.6 to 105.6 mm2 in area.(ABSTRACT TRUNCATED AT 250 WORDS)

General concepts in the morphologic assessment of operatively excised cardiac valves--Part II

This 2-part article discusses general morphologic assessment of operatively excised cardiac valves and applies these principles to functional classifications. All cardiac valves are categorized into stenotic and purely regurgitant (no element of stenosis) groups based upon structural features: presence or absence of commissural fusion, calcific deposits, and degree and location of fibrosis. Of 2,980 operatively excised cardiac valves reviewed between 1962 and 1992, the most common lesion was aortic stenosis, followed by mitral stenosis and the combination of aortic and mitral stenosis.

Pathology of aortic valve stenosis and pure aortic regurgitation. A clinical morphologic assessment--Part I

This two-part article examines the histologic and morphologic basis for stenotic and purely regurgitant aortic valves. Part I discusses stenotic aortic valves and Part II will discuss causes of purely regurgitant aortic valves. In over 95% of stenotic aortic valves, the etiology is one of three types: congenital (primarily bicuspid), degenerative, or rheumatic. Other rare causes of stenotic aortic valves include active infective endocarditis, homozygous type II hyperlipoproteinemia, and systemic lupus erythematosis. The causes of pure aortic regurgitation are multiple but can be separated into diseases affecting the valve (normal aorta) (infective endocarditis, congenital bicuspid, rheumatic, floppy), diseases affecting the walls of aorta (normal valve) (syphilis, Marfan's, dissection), disease affecting both aorta and valve (abnormal aorta, abnormal valve) (ankylosing spondylitis), and diseases affecting neither aorta nor valve (normal aorta, normal valve) (ventricular septal defect, systemic hypertension). Diseases affecting the aortic valve alone are the most common subgroup of conditions producing pure aortic valve regurgitation.

General concepts in the morphologic assessment of operatively excised cardiac valves--Part I

This two-part article discusses the general morphologic assessment of operatively excised cardiac valves and applies these principles to functional classifications. All cardiac valves are categorized into stenotic and purely regurgitant (no element of stenosis) groups based upon structural features: presence or absence of commissural fusion, calcific deposits, and degree and location of fibrosis. Of 2980 operatively excised cardiac valves reviewed between 1962 and 1992, the most common lesion was aortic stenosis, followed by mitral stenosis and the combination of aortic and mitral stenosis.

Embolus in transit

Since the advent of echocardiography, embolus in transit, historically found during surgical exploration or on postmortem examination, has been found with increasing frequency on antemortem examination. There is an inherent high mortality rate with this condition and awareness of the association between deep venous thrombosis and embolus in transit is paramount. On echocardiography the embolus is typically seen as a pleomorphic mass moving in a tumbling fashion. The most frequent symptoms are dyspnea and near syncopal episodes. The most common signs are diastolic "tumor plop" and a systolic ejection murmur heard on auscultation. Despite the success of some medical interventions, surgery should be strongly considered in patients with embolus in transit.

Histological and angiographic effects of a pulsed holmium:YAG laser in normal and atherosclerotic human coronary arteries and aorta

OBJECTIVE

The aims were (1) To determine the histological and angiographic effects of holmium:YAG laser energy delivered through clinical multifibre laser catheters on fresh cadaveric coronary arteries; and (2) to relate the placement of optical fibres in the catheter to patterns of tissue ablation in cadaveric aorta.

METHODS

Eight fresh cadaveric hearts and segments of aorta were used. Hearts were mounted on a new pressure perfusion device. The laser catheter was delivered over a guidewire in the lumen until it met an area of resistance. The coronary artery lumen was perfused at approximately 100 mm Hg mean pressure. These arterial areas were identified on angiography, marked, and then exposed to laser energy in the range 600-3000 mJ.mm-2. Normal and atherosclerotic areas of fresh cadaveric aortic strips were exposed to increasing laser energies using either constant or increasing fluence. Coronary arteries were pressure perfused with formalin for 18-24 h at 100 mm Hg mean pressure, and aortic strips were immersed in 5% formalin. Light and scanning electron microscopy studies were carried out.

RESULTS

There were no perforations or dissections by angiography in the fresh coronary arteries. One of 15 normal coronary artery segments and 10 of 16 of the pressure perfused, fixed, atherosclerotic coronary artery segments showed thermal changes associated with atherosclerotic plaque ablation. In aortic tissue, thermal effects extended 0 to 0.6 mm lateral to the ablated crater. Acoustic effects were seen only in the aortic strips after ablation at fluences > 1000 mJ.mm-2. The "dead spaces" around the optical fibres in the catheter resulted in significant amounts of coagulated tissue fragments remaining in the crater.

CONCLUSIONS

Holmium:YAG laser energy delivered through multifibre catheters ablated atherosclerotic tissue in coronary arteries with minimal damage to the normal walls. The cadaveric coronary artery perfusion apparatus is useful for assessing catheter delivery and mobility and the effects of laser energy on the coaxially orientated normal and atherosclerotic coronary arterial wall.

The natural history of intimal flaps in a canine model

The natural history of arterial intimal flaps has not been well defined. This study characterizes the natural history of unrepaired intimal flaps. Thirty-nine 1-, 2-, and 3-mm hemispheric, distally based intimal flaps were made in 4- to 5-mm diameter canine femoral and carotid arteries. Twenty arteries had 2- and 3-mm intimal flaps and were monitored for short-term arterial thrombosis and flap extension. Nineteen had 1- and 2-mm intimal flaps and were monitored for thrombosis, long-term development of neointimal hyperplasia, arterial stenosis, and persistence of the flap. While 40% of the arteries with 3-mm intimal flaps developed thrombosis in 3 to 5 days, only 3% of the arteries with 1- or 2-mm intimal flaps developed thrombosis. Most 1- to 2-mm intimal flaps resolved and the subsequent development of neointimal hyperplasia or arterial stenosis was minimal. Arteries with hemodynamically significant stenoses from intimal flaps warrant repair, while arteries with smaller intimal flaps may not require repair.

Pathogenesis of aneurysm formation opposite prosthetic patches used for coarctation repair. An experimental study

Patch graft angioplasty for coarctation repair has been associated with late aneurysm formation opposite the prosthetic patch in some patients. Etiologic possibilities for this aneurysm formation include congenital abnormality of the aortic wall, surgical interruption of the vasa vasorum, intimal disruption because of extensive excision of the coarctation web, and rigidity of the prosthetic patch. To assess the effect of extensive intimal excision on the development of aneurysms, we operated on 12 dogs, performing a left thoracotomy and aortoplasty with Dacron (n = 6) or polytetrafluoroethylene patches (n = 6) and concomitant intimal excision opposite the patch. Ten control dogs underwent angioplasty with Dacron (n = 5) and polytetrafluoroethylene patches (n = 5) without excision of the intima. Serial aortograms of all animals showed aneurysm formation of the aorta opposite the patch in eight of the 12 dogs undergoing intimal excision. In contrast, no aneurysms developed in the control dogs (p less than 0.001). An additional five dogs underwent longitudinal aortotomy, intimal excision, and primary closure. Three dogs in this group demonstrated an aneurysm angiographically (p less than 0.02). Histologic analysis of the aneurysms and the control aortas revealed hyperplastic ingrowth of the intima over the denuded surface in the animals undergoing intimal excision. The elastic fibers in the media were intact and organized except in two aneurysmal specimens. We conclude that extensive resection of the intima with or without patch angioplasty predisposes aneurysm formation opposite the aortotomy and should be avoided during coarctation repair.

Acute congestive heart failure due to the arteritis of rheumatoid arthritis: early diagnosis by endomyocardial biopsy: a case report

A 49-year-old man with rheumatoid arthritis presented with acute congestive heart failure. Acute viral myocarditis was suspected clinically as a Gallium-67 myocardial scan was positive. Percutaneous catheter-directed biopsy of the right ventricular endomyocardium, however, revealed heavy endothelial deposits of IgM in the small blood vessels of the myocardium. Prednisone therapy resulted in normalization of both the myocardial Gallium-67 scan and left ventricular ejection fraction with resolution of the symptoms of congestive heart failure. This is the first report documenting rheumatoid arteritis antemortem by myocardial biopsy.

Externally stented polytetrafluoroethylene valved conduits for right heart reconstruction. An experimental comparison with Dacron valved conduits

Valve-containing conduits have made possible the repair of many congenital anomalies that involve right ventricular-pulmonary arterial discontinuity. The distressing problem of neointimal peel formation with eventual conduit obstruction in patients with Dacron valved conduits has led to the need for premature replacement in many patients. Externally stented polytetrafluorethylene has demonstrated superior patency in the venous system experimentally and clinically and was believed to have potential advantages over Dacron for conduit construction. This study compares the transconduit resistance and the thickness of the neointimal peel in right ventricular-pulmonary arterial conduits constructed of externally stented polytetrafluoroethylene with those of woven Dacron. The 19 mm externally stented polytetrafluoroethylene conduits (Impra, Inc.) containing a Hancock porcine valve (Extracorporeal Inc.) were implanted in six adult mongrel dogs followed by proximal occlusion of the pulmonary artery. In six additional animals, a Dacron valved conduit of similar size and length was inserted. Cardiac output, transconduit gradient, and resistance were measured at operation and at 3 months. All conduits were subsequently explanted, opened longitudinally, and the thickness of the neointimal peel (excluding suture lines) measured. No hemodynamic differences were noted during the 3 month follow-up. However, the thickness of the neointimal peel was fourfold greater in Dacron conduits (609 +/- 144 mu) than in the conduits constructed of externally stented polytetrafluoroethylene (156 +/- 50 mu) (p less than 0.01). The thick peel in Dacron conduits extended into the outflow portion of the porcine valve cusps and prevented their full excision. The neointima in externally stented polytetrafluoroethylene conduits was thin and uniform and did not extend onto the leaflets or limit their mobility. This study demonstrated that the early hemodynamic performance of externally stented polytetrafluoroethylene conduits was comparable to that of Dacron conduits; Dacron conduits were subject to an accelerated rate of peel formation that affected leaflet mobility and may be a factor in early valve degeneration; a thin neointima formed in externally stented polytetrafluoroethylene conduits and valve leaflet motion was preserved. This study showed that externally stented polytetrafluoroethylene conduits offer advantages over Dacron valved conduits and warrant clinical application.

Second malignant neoplasms complicating Hodgkin's disease: the National Cancer Institute experience

The medical records of all patients treated for Hodgkin's disease during the years 1964-1981 were reviewed. Four hundred seventy-three previously untreated patients were analyzed. Thirty-four subsequent second malignant neoplasms were observed in 33 patients among those treated for Hodgkin's disease. Eight cases of acute nonlymphocyctic leukemia, one case of chronic myeloid leukemia, three cases of non-Hodgkin's lymphoma, three cases of sarcoma, and 19 other tumors were identified. The ten-year estimated risk of leukemia by treatment was the following: radiotherapy only (0), chemotherapy only (0.02), initial combined radiotherapy-chemotherapy (0.06), and salvage combined radiotherapy-chemotherapy (0.09). The ten-year estimated risk of solid tumors was 0.07 overall, with all treatment groups associated with similar risks. Unlike some other reports, a greater risk of leukemia in patients who began treatment for Hodgkin's disease at age 40 or older was not found. However, a positive association was noted between increasing risk of solid tumors and increasing patient age.

Intensive combined modality therapy including low-dose TBI in high-risk Ewing's Sarcoma Patients

Twenty-four high-risk Ewing's sarcoma patients were treatedf on an intensive combined modality protocol including low-dose fractionated total body irradiation (TBI) and autologous bone marrow infusion (ABMI). Twenty patients (83%) achieved a complete clinical response to the primary and/or metastatic sites following induction therapy. The median disease-free interval was 18 months, and nine patients remain disease-free with a follow-up of 22 to 72 months. Local failure as a manifestation of initial relapse occurred in only three patients (15%), each having synchronous distant failure. Eight patients failed initially with only distant metastases, usually within 1-2 years following a complete clinical response. Two patients with a single metastasis were again rendered disease-free and remain free from second relapse with 18 and 30 months follow-up. No other relapsed patient was able to be rendered disease-free, and most died of progressive disease within 6 to 12 months of relapse. Two patterns of granulocyte recovery following consolidative therapy (include TBI) and ABMI were recognized. Seventeen patients reached a total granulocyte count of >500 cells/mm3 within 4 weeks of ABMI (early graulocyte recovery), while seven patients required >4 weeks from ABMI (late granulocyte recovery). The time of platelet recovery (>50,000/mm3) was different for the groups with early and late granulocyte recovery (25 days vs. 54 days, p <.001). Six of seven patients with late granulocyte recovery received locl high-dose irratiation to >1/2 pelvis prior to bone marrow storage. Patients with late recovery did not tolerate maintenance chemotherapy. However, there was no difference in disease-free and overall survival, when compaing the groups with early and late granulocyte recovery. We conclude that these high-risk Ewing's sarcoma patients remain a poor-prognosis group in spite of intensive combined modality therapy include low-dose TBI. The control of microscopic systemic disease remains the major challenge to improving the cure rate. A new combined modality protocol with high-dose 'therapeutic' TBI (800 rad/2 fractions) is being used and the protocol design is outlined.