UltraPulse--simulating a human arterial pulse with focussed airborne ultrasound

Medical simulators provide a risk-free environment for trainee doctors to practice and improve their skills. UltraPulse is a new tactile system designed to utilise focussed airborne ultrasound to mimic a pulsation effect such as that of a human arterial pulse. In this paper, we focus on the construction of the haptics component, which can later be integrated into a variety of medical procedure training simulators.

A stable and real-time nonlinear elastic approach to simulating guidewire and catheter insertions based on Cosserat rod

Interventional Radiology procedures (e.g., angioplasty, embolization, stent graft placement) provide minimally invasive therapy to treat a wide range of conditions. These procedures involve the use of flexible tipped guidewires to advance diagnostic or therapeutic catheters into a patient's vascular or visceral anatomy. This paper presents a real-time physically based hybrid modeling approach to simulating guidewire insertions. The long, slender body of the guidewire shaft is simulated using nonlinear elastic Cosserat rods, and the shorter flexible tip composed of a straight, curved, or angled design is modeled using a more efficient generalized bending model. Therefore, the proposed approach efficiently computes intrinsic dynamic behaviors of guidewire interactions within vascular structures. The efficacy of the proposed method is demonstrated using detailed numerical simulations inside 3-D blood vessel structures derived from preprocedural volumetric data. A validation study compares positions of four physical guidewires deployed within a vascular phantom, with the co-ordinates of the corresponding simulated guidewires within a virtual model of the phantom. An optimization algorithm is also implemented to further improve the accuracy of the simulation. The presented simulation model is suitable for interactive virtual reality-based training and for treatment planning.

Off label use of devices and drugs in interventional radiology

AIM

To establish how often off-label device and drug use occurs in interventional radiology (IR) in a UK tertiary referral hospital and consider the wider implications for the interventional radiologist.

MATERIALS AND METHODS

Prospective data were collected during interventional procedures for 1 working week in a university hospital. Out-of-hours procedures and procedures outside the department were excluded. Operators were asked to record the drugs and devices used, the indication, and method of use. The instructions for use/summary of product characteristics were then studied for each device/drug used to assess if the use was on or off-label.

RESULTS

During the study period 52 cases were performed and data were available on 26 cases (50%). In 22 of the 26 cases (84%) there was evidence of off-label use of devices or drugs. Off-label use of drugs included treatment of venous malformations with Fibrovein(©) (sodium tetradecyl sulphate), which is licensed for the treatment of varicose veins in the leg, and intra-arterial injection of heparin, which is licensed for intravenous and subcutaneous use. Off-label device use included placing vascular sheaths in the urinary tract, using angiographic catheters to guide wires in the urinary tract, using sheaths for thrombosuction, reshaping of the tip of most guidewires, and using angioplasty balloons to dislodge the arterial plug at fistula thrombectomy.

CONCLUSION

Off-label device and drugs use is common in a UK tertiary hospital IR department and literature suggests this is common in the wider IR community. There are important clinical and legal implications for off-label use for patients and physicians.

Virtual reality, ultrasound-guided liver biopsy simulator: development and performance discrimination

OBJECTIVES

The aim of this article was to identify and prospectively investigate simulated ultrasound-guided targeted liver biopsy performance metrics as differentiators between levels of expertise in interventional radiology.

METHODS

Task analysis produced detailed procedural step documentation allowing identification of critical procedure steps and performance metrics for use in a virtual reality ultrasound-guided targeted liver biopsy procedure. Consultant (n=14; male=11, female=3) and trainee (n=26; male=19, female=7) scores on the performance metrics were compared. Ethical approval was granted by the Liverpool Research Ethics Committee (UK). Independent t-tests and analysis of variance (ANOVA) investigated differences between groups.

RESULTS

Independent t-tests revealed significant differences between trainees and consultants on three performance metrics: targeting, p=0.018, t=-2.487 (-2.040 to -0.207); probe usage time, p = 0.040, t=2.132 (11.064 to 427.983); mean needle length in beam, p=0.029, t=-2.272 (-0.028 to -0.002). ANOVA reported significant differences across years of experience (0-1, 1-2, 3+ years) on seven performance metrics: no-go area touched, p=0.012; targeting, p=0.025; length of session, p=0.024; probe usage time, p=0.025; total needle distance moved, p=0.038; number of skin contacts, p<0.001; total time in no-go area, p=0.008. More experienced participants consistently received better performance scores on all 19 performance metrics.

CONCLUSION

It is possible to measure and monitor performance using simulation, with performance metrics providing feedback on skill level and differentiating levels of expertise. However, a transfer of training study is required.

Emergency obstetric hysterectomy—an increasing incidence

Ten women underwent obstetric hysterectomy at St George's Hospital, London between 1992 and 1998, with an apparent seven-fold increase in incidence in recent years. All hysterectomies were performed as emergency procedures, with massive postpartum haemorrhage being the major indication for operation in nine cases. Abnormal placentation was the single commonest cause, seven cases being associated with previous caesarean section. There were no maternal or fetal mortalities, but major surgical complications, including urinary tract and vascular injury occurred in one case. In view of the increasing risk of obstetric hysterectomy following previous caesarean section, high risk cases associated with abnormal placentation may be identified using ultrasound, allowing appropriate pre-operative counselling regarding the risk of peripartum hysterectomy.

Physics-based virtual environment for training core skills in vascular interventional radiological procedures

Recent years have seen a significant increase in the use of Interventional Radiology (IR) as an alternative to open surgery. A large number of IR procedures commences with needle puncture of a vessel to insert guidewires and catheters: these clinical skills are acquired by all radiologists during training on patients, associated with some discomfort and occasionally, complications. While some visual skills can be acquired using models such as the ones used in surgery, these have limitations for IR which relies heavily on a sense of touch. Both patients and trainees would benefit from a virtual environment (VE) conveying touch sensation to realistically mimic procedures. The authors are developing a high fidelity VE providing a validated alternative to the traditional apprenticeship model used for teaching the core skills. The current version of the CRaIVE simulator combines home made software, haptic devices and commercial equipments.

Simulators in catheter-based interventional radiology: training or computer games?

Training in interventional radiology (IR) relies on a traditional apprenticeship; to protect patients, expert supervision is mandatory until knowledge, attitudes and practical skills have been certified as satisfactory. However, the current quality of IR training is threatened by reduced time for trainees to learn, as well as a loss of basic diagnostic, training cases to non-invasive imaging. At the same time, IR techniques are becoming a focus of interest to a range of other clinical specialities. To address this training shortfall there is a need to develop novel training alternatives such as simulator models. Few simulator models in any medical field have been successfully validated to show improved clinical skills in treating patients. To date no endovascular simulator has met this standard. A good simulator must be based around key performance measures (metrics) derived from careful analysis of the procedure to be replicated. Metrics can be determined by trained psychologists from a direct analysis of the content of the job or task to be tested. The identification of these critical measures of performance is a complex process which must be tailored to a training curriculum to be effective. Simulators based on flawed metrics will invariably lead to unsatisfactory assessment. It follows that simulator development must involve the statutory licensing authorities. Equally it is essential that we do not assume that training on a particular simulator will correlate with the ability to perform the task in the real world. This "transfer of training" must be rigorously proven by validation studies.

Aortic side branch perfusion alone does not account for high intra-sac pressure after endovascular repair (EVAR) in the absence of graft-related endoleak

OBJECTIVE

to examine the effect of stent-graft deployment on pressure within an aneurysm sac and to investigate the potential sources of intra-sac pressure.

MATERIAL AND METHODS

intra-sac pressure was monitored during and immediately after endovascular repair via an indwelling catheter. Intra-sac pressure was also monitored during conventional open repair and was compared with the pressure measured within patent lumbar and inferior mesenteric side-branches, both before and after restoration of iliac arterial blood flow. Intra-sac and side-branch pressures were recorded and expressed as ratios of simultaneously measured radial artery pressure.

RESULTS

in the absence of a graft-related endoleak (23/25 patients), endovascular repair resulted in a significant reduction in intra-sac pulse pressure (median ratio 0.31 IQR 0.10-0.46). There was no corresponding reduction in mean intra-sac pressure (median ratio 0.91; IQR 0.83-1.00). Application of clamps at conventional open repair resulted in a fall in both intra-sac pressure (median ratio 0.39, IQR 0.32-0.64) and pressure within side-branches (median ratio 0.45, IQR 0.33-0.64). Restoration of iliac blood flow resulted in a modest recovery of the side-branch pressure (median ratio 0.63, IQR 0.57-0.81), which nonetheless remained significantly less than the intra-sac pressure recorded after EVAR (p=0.01).

CONCLUSION

reperfusion of the aneurysm sac through patent side-branches seems insufficient to account for persistent pressurisation of the aneurysm after endovascular repair. This finding supports the hypothesis that pressure may be transmitted directly through stent-graft fabric.

The experiences and challenges of informal caregivers: common themes and differences among whites, blacks, and hispanics

PURPOSE

This study examined commonalities and differences in the experiences and challenges of White, Black, and Hispanic informal caregivers in New York, NY.

DESIGN AND METHODS

A randomly selected representative cross-section of 2,241 households was contacted through telephone interviews. Complete data were available for 380 eligible participants, who were classified as White (n = 164), Black (n = 129) and Hispanic (n = 87). Descriptive, bivariate, and multivariate analyses were conducted to examine differences in caregiving intensity, reported difficulty with providing care, and having unmet needs with care provision.

RESULTS

Over 70% of caregivers had no help from formal caregivers, even though over 80% had been providing care for at least 1 year, and 40% had been providing this care for 20 or more hr per week. Compared with White caregivers, Black caregivers were more likely to provide higher intensity care, to report having unmet needs with care provision, and to experience increased religiosity since becoming caregivers, but were less likely to report difficulty with providing care. Hispanic caregivers were more likely than White caregivers to have help from formal caregivers and to experience increased religiosity since becoming caregivers.

IMPLICATIONS

Although many similarities exist in the experiences and challenges of informal caregivers, gaining insight from different populations of family caregivers would help program planners, policy makers, and formal caregivers to develop and implement culturally sensitive programs and policies that are supportive of the needs of these caregivers in their ever-expanding roles. Future efforts also should focus on exploring the potentially significant role that community resources, in particular, religious institutions, could play in providing outreach and support to racial/ethnic minority caregivers.

Perianeurysmal fibrosis: a relative contra-indication to endovascular repair

OBJECTIVE

Perianeurysmal fibrosis (PAF) with involvement of neighbouring viscera can render open repair of inflammatory aneurysms technically difficult and therefore hazardous. For this reason, endovascular repair (EVAR) has been advocated as the preferred approach for this condition. EVAR is known to induce a systemic inflammatory response in patients but the nature of the local response remains unknown. If significant, such a response could exacerbate rather than ameliorate PAF. The aim of the study was to examine the incidence, course and consequences of perianeurysmal fibrosis detected by computerised tomography (CT) before and after EVAR.

MATERIAL AND METHODS

The clinical records of patients treated by EVAR and followed for at least 6 months were reviewed. Pre and post-operative CT images were independently graded for PAF by three radiologists according to a standard protocol.

RESULTS

PAF was documented preoperatively in six out of a total of 61 patients. In two of these PAF worsened after EVAR resulting in ureteric obstruction and hydronephrosis requiring ureteric stents. In the remaining 4 patients PAF did not reduce postoperatively. PAF of low grade developed postoperatively in 10 out of 55 patients (18%) in whom there was no evidence of PAF on preoperative imaging. Median follow-up was 18 months (range 6-36 months). The development of periaortic fibrosis de novopostoperatively was statistically significant (McNemar's test p=0.002).

CONCLUSION

EVAR does not seem to reverse PAF if this is present preoperatively and it induces this condition in approximately one sixth of patients without evidence of preoperative PAF. The potential for this adverse inflammatory local response should be taken into account when considering EVAR for treatment of aneurysms with perianeurysmal fibrosis and must be weighed against the perceived benefits of this approach.

Decision analysis for small, asymptomatic intracranial arteriovenous malformations

Object

Asymptomatic intracranial arteriovenous malformations (AVMs) represent a clinically challenging problem because of the complex decision making that must be undertaken prior to beginning any type of treatment. In addition, the relative infrequency of these lesions means that there is relatively little experience reported in the literature. The authors use a decision-analysis technique to model the considerations that go into determining the treatment of these lesions in an effort to quantify the various risks and overall benefits conferred by the following three treatment strategies: observation/natural history, microsurgery, and stereotactic radiosurgery.

Methods

The authors conducted a thorough literature search to elucidate the risks and outcomes associated with each treatment option. These values were used to build and run a comprehensive Markov model to determine a base-case analysis. All of the input variables were also subjected to sensitivity analysis to identify the most influential input variables and the crossover points in which favored strategies changed.

The base-case analysis suggested that microsurgery was the favored treatment option because this hypothetical cohort accumulated 21.53 quality-adjusted life years (QALYs) over the course of the model compared with the 16.97 QALYs and 16.40 QALYs for stereotctic radiosurgery and observation, respectively. Sensitivity analysis demonstrated that overall major neurological morbidity and mortality were the most influential input variables both perioperatively and during the radiosurgical “latent” period (that is, up to 2 years posttreatment). The maximum acceptable perioperative combined major neurological morbidity and mortality rate was 6.8%. The latent period combined major neurological morbidity and mortality would need to be 0.7% to make radiosurgery favorable in this analysis.

Conclusions

Results of this decision analysis model suggest that microsurgery in the hands of experienced cerebrovascular surgeons, who can expect a less than 6.8% combined rate of major neurological morbidity and mortality, offers patients a greater overall quality of life over time.

Aortic side branch embolization before endovascular aneurysm repair: incidence of type II endoleak

PURPOSE

To assess the feasibility of embolization of aortic side branches and its impact on the incidence of type II endoleak after endovascular aneurysm repair.

MATERIALS AND METHODS

Endovascular aneurysm repair was performed in 74 patients. Aortic side branch vessels were evaluated on the preoperative angiogram and computed tomography (CT) and, where embolization of lumbar and inferior mesenteric vessels was considered technically possible, this was attempted prior to endovascular repair. Follow-up CT was used to assess the presence of type II endoleak.

RESULTS

Seventy-two patients were followed up for longer than 1 month. Embolization was attempted in 25 cases, successfully in 10, with partial success in 11, and failure in four. Twenty patients with successful or partly successful preoperative embolization were discharged and followed-up. Four (20%) had demonstrable type II endoleak during follow-up, with two of these persisting at latest follow-up. Of 43 patients without previous embolization, there were 10 (23.3%) type II endoleaks during the follow-up period, four of these persisting. In cases with type II endoleak, mean sac diameter change was -0.5 mm in the cases with previous embolization and +3.1 mm without. The mean period to onset of type II endoleak was 6.9 months without, and 15.3 months with, previous embolization.

CONCLUSION

Although the cohort size is below a level that would confer significance, the trend of these findings is such as to suggest a lack of influence of aortic side branch embolization on the incidence of type II endoleak during the follow-up period.

Graft distortion after endovascular repair of abdominal aortic aneurysm: association with sac morphology and mid-term complications

PURPOSE

To investigate the incidence, significance, and mechanism of stent-graft distortion after endovascular repair (EVR) of abdominal aortic aneurysm.

METHODS

EVR of abdominal aortic aneurysm was performed in 51 cases (49 modular, bifurcated; 2 tube). Thirty-two patients were followed for 6 or more months and had equivalent baseline and follow-up images which could be used to determine changes in graft configuration. Sac dimensions were measured using computed tomographic (CT) images and graft-related complications were recorded.

RESULTS

Amongst 32 patients evaluated on follow-up, there was graft distortion in 24. Distorted grafts were significantly (p = 0.002) associated with sac diameter reduction (mean 5 mm) and sac length reduction (mean 8.1 mm). All graft-related complications occurred in the limbs of eight distorted grafts, with a mean reduction of sac length in this group of 7.8 mm on reformatted CT images.

CONCLUSION

There was a highly significant association between graft distortion and limb complications, and reduced sac dimensions.

Freedom from endoleak after endovascular aneurysm repair does not equal treatment success

OBJECTIVE

To determine whether freedom from endoleak after endovascular repair of abdominal aortic aneurysm (EVAR) is a reliable guide to freedom from persistent or recurrent pressurisation of the aneurysm sac (endotension) and therefore freedom from risk of rupture.

PATIENTS AND METHODS

The records of 55 patients followed for more than 3 months after EVAR were reviewed to correlate the presence or absence of endoleak on contrast-enhanced CT and/or angiography with changes in maximum aneurysm diameter (DMAX).

RESULTS

in 22 (40%) patients there was no significant change in DMAX during follow-up. In 21 of these no endoleak was observed on CT or angiography. One patient developed a secondary side-branch endoleak which remains under observation. In 18 (33%) patients, DMAX decreased during follow-up. Thirteen of these remained free of endoleak. Four patients developed secondary endoleaks which were treated by secondary intervention. One patient with persistent primary endoleak suffered fatal aneurysm rupture three days before planned intervention. DMAX increased in 15 (27%) patients. In only five of these could an endoleak be identified on CT and/or angiography. One primary side-branch endoleak persists following failed embolisation. Four secondary endoleaks have been corrected by secondary intervention. Four of the remaining 10 patients died suddenly from unknown cause. All had DMAX greater than 65 mm at last follow-up. One patient underwent late conversion, which suggested continued pressurisation through thrombus at the site of a "sealed" primary proximal endoleak. Two patients are scheduled to undergo embolisation of patent side-branches revealed only by Levovist enhanced Duplex scanning and three patients remain under observation.

CONCLUSION

Freedom from endoleak on conventional imaging incorrectly suggested freedom from endotension in 10 (18%) of our patients. Follow-up after endovascular repair must include regular measurement of DMAX and/or aneurysm sac volume to identify those patients who remain at risk of rupture.

Human first trimester fetal ovaries express oncofetal antigens and steroid receptors

OBJECTIVE

To document the expression of oncofetal antigens and steroid receptors in first trimester human fetal ovaries and to determine the effect of advancing gestation on expression patterns.

METHODS

Fetal gonads were collected from surgical terminations of pregnancy, and fetal sex was determined by fluorescence in situ hybridization. Immunocytochemical analysis was performed on paraffin sections of microdissected fetal ovaries using antibodies to carcinoembryonic antigen (CEA), placental alkaline phosphatase (PLAP), hCG, alpha fetoprotein (AFP), CA 125, estrogen receptor (ER) and progesterone receptor (PR) in 12 first trimester human fetal ovaries. Expression was quantified objectively by measuring percentage area of immunoreactivity (PAI) on whole sections of the ovary using an interactive image analysis system. Two pathologists, blinded to the antibodies used, independently viewed and scored all sections.

RESULTS

PLAP, PR, ER and CEA were expressed in all 12 ovaries (31%, 28%, 21%, and 16% mean PAI, respectively). A diffuse staining pattern was observed at 8 weeks' gestation, which was more focal and confined to the cortical regions of the gonad by 12 weeks' gestation. Putative primordial germ cells were positive for PLAP, PR and ER but rarely for CEA. The expression (PAI) of PLAP and PR was unchanged during the first trimester, whereas that of ER decreased from 28% to 12%. The expression of CEA and hCG decreased from 8 to 11 weeks and then increased markedly by 13 weeks. AFP had a medullary distribution and was expressed in nine of 12 ovaries (mean PAI 18%). CA 125 expression was minimal or undetected.

CONCLUSION

PLAP, ER and PR were the most extensively expressed protein antigens, particularly in fetal ovarian cortex. These variable patterns of expression suggest levels of differentiation in the immature first trimester human fetal ovary.

Cost-effectiveness of surgery for small abdominal aortic aneurysms on the basis of data from the United Kingdom small aneurysm trial

PURPOSE

Although the United Kingdom small aneurysm trial reported no survival benefit for early operation in patients with small (4. 0-5.5 cm) abdominal aortic aneurysms (AAAs), the trial lacked statistical power to detect small but potentially meaningful gains in life expectancy, particularly for specific subgroups. We used decision analysis to better characterize the potential benefits and cost-effectiveness of early surgery.

METHODS

We used a Markov model to assess the marginal cost-effectiveness (incremental cost per quality-adjusted life year [QALY] saved) of early surgery relative to surveillance for small AAAs, using data from the UK Trial. Subgroup analyses were performed by patient age and AAA diameter. Sensitivity analysis was used to evaluate the effect of elective operative mortality on cost-effectiveness.

RESULTS

In our baseline analysis, early operations provided a small survival advantage (0.14 QALYs) at a small incremental cost of $1510. Thus, despite a small survival benefit, early surgery appeared cost-effective ($10, 800/QALY). The small cost differential resulted from the large proportion of patients who underwent surveillance, who eventually underwent AAA repair, and therefore incurred the cost of the surgical procedures. The survival advantage and cost-effectiveness of early operation increased with lower operative mortality, younger age, and larger AAA diameter.

CONCLUSION

Despite the negative conclusions of the UK trial, early surgery may be cost-effective for patients with small AAAs, particularly younger patients (<72 years of age) with larger AAAs (> or = 4.5 cm). Because the gains in life expectancy are relatively small, however, clinical decision making should be strongly guided by patient preferences.

The role of the pulmonary afferent receptors in producing hemodynamic changes during hyperinflation and endotracheal suctioning in an oleic acid-injured animal model of acute respiratory failure

The purpose of this study was to examine the role of the pulmonary afferent receptors in producing hemodynamic changes during hyperinflation and endotracheal suctioning (ETS) in an oleic acid-injured animal model of acute respiratory failure. Previous investigations of hyperinflation as a method to prevent hypoxia-induced sequelae of ETS have demonstrated unrecognized hemodynamic consequences. In this within-subject, repeated-measures study, instrumented, oleic acid-injured dogs had continuous measurements of heart rate (HR), mean aortic blood pressure (MAP), left ventricular pressure (Plv), pulmonary artery pressure (Ppa), right ventricular afterload (Ppa(tm)), right atrial pressure (Pra), and right ventricular filling pressure (Pra(tm)) during hyperinflation and ETS when the vagi were intact and after the pulmonary branches of the vagus nerves had been severed. After severing the vagi, MAP and Plv were decreased and HR and Ppa were increased. With the vagi severed, there was less variation in MAP and Ppa but increased variation in HR. These findings suggest that vagally mediated reflexes from the lungs produce some, but not all, of the hemodynamic effects associated with hyperinflation and ETS. Continued research is necessary to discover a method of hyperoxygenation and suctioning that does not produce potentially harmful hemodynamic effects.

Use of contrast-enhanced ultrasound in follow-up after endovascular aortic aneurysm repair

PURPOSE

To investigate the use of contrast-enhanced ultrasound in the detection of endoleak after endovascular repair of abdominal aortic aneurysm.

MATERIALS AND METHODS

Eighteen patients underwent follow-up on 20 occasions after endovascular aortic aneurysm repair by arterial-phase contrast-enhanced spiral computed tomography (CT). All patients had unenhanced color Doppler ultrasound and Levovist-enhanced ultrasound on the same day. The ultrasound examinations were reported in a manner that was blind to the CT results. CT was regarded as the gold standard for the purposes of the study.

RESULTS

There were three endoleaks shown by CT. Unenhanced ultrasound detected only one endoleak (sensitivity, 33%). Levovist-enhanced ultrasound detected all three endoleaks (sensitivity, 100%). Levovist-enhanced ultrasound indicated an additional six endoleaks that were not confirmed by CT (specificity, 67%; positive predictive value, 33%). In one of these six cases, the aneurysm increased in size, which indicates a likelihood of endoleak. Two of the remaining false-positive results occurred in patients known to have a distal implantation leak at completion angiography.

CONCLUSION

In this small group of patients, contrast-enhanced ultrasound appears to be a reliable screening test for endoleak. The false-positive results with enhanced ultrasound may be due to the failure of CT to detect slow flow collateral pathways. Although the number of patients in this study is small, enhanced ultrasound may be more reliable than CT in detecting endoleak.

Efficacy versus effectiveness of carotid endarterectomy

CONTEXT

Several well-known clinical trials have demonstrated that the value of carotid endarterectomy depends on preoperative symptoms and the degree of carotid artery stenosis. The benefit of surgery also depends on how the results of these clinical trials (defining the efficacy of carotid endarterectomy) are applied to actual clinical practice (the effectiveness of the procedure), where surgical risks are greater.

COUNT

The number of carotid endarterectomies needed to prevent one major stroke or death--that is, the number needed to treat (NNT).

CALCULATION

Reciprocal of the difference between the 5-year cumulative incidence of major stroke or death with medical therapy and the 5-year cumulative incidence of major stroke or death with carotid endarterectomy.

DATA SOURCES

Efficacy was calculated with data from the North American Symptomatic Carotid Endarterectomy Trials and the Asymptomatic Carotid Atherosclerosis Study. In calculating effectiveness, we accounted for increased surgical mortality rates reported in population-based studies.

RESULTS

For symptomatic patients, the NNT predicted by the effectiveness model differed little from that estimated by the efficacy model (10 versus 9 for severe carotid stenosis and 29 versus 23 for moderate carotid stenosis). However, the NNT predicted by the effectiveness model was substantially higher than that predicted by the efficacy model for patients with asymptomatic severe stenosis (63 versus 38).

CONCLUSIONS

In symptomatic patients, carotid endarterectomy is both efficacious and effective for severe and (to a lesser extent) moderate carotid stenosis. However, in asymptomatic patients, the benefits observed in published trials may overestimate those likely to be achieved in clinical practice.

Psammoma bodies on routine cervical smear

Images

Developing patient and family education programs for a transplant center

Patient and family education is an important component of the organ transplant programs at the University of Nebraska Medical Center. The Medical Center is in the process of planning a new transplant center which will employ the family-centered, educationally-intensive cooperative care concept. This approach was chosen as the model for the delivery of care at the Lied Transplant Center because it emphasizes efficient, effective clinical care by requiring active participation by the family or essential other, thereby better preparing both the patient and the family for the transition to home and to the community. This article presents the evolution of patient education in our transplant programs, discusses the educational needs of transplant patients across the continuum of care, provides insight into the process of planning educational programs for the new center and provides a sample module for teaching which is based on the Cooperative Care concept.

Embolization in the palliation of complications of inoperable primary pancreatic neoplasms

Primary pancreatic neoplasm typically presents at an advanced stage where surgical management may not be feasible. These patients are often symptomatic due to biliary obstruction but problems may also include gastrointestinal bleeding and endocrinological complications. We describe two cases illustrating the use of palliative embolization in the control of biochemical and haemorrhagic complications of primary pancreatic neoplasm. In one case, massive gastrointestinal bleeding from an inoperable primary pancreatic carcinoma was controlled by two embolization procedures to produce devascularization of the primary lesion. In a second case, life-threatening hypercalcaemia was thought to be due to secretion of a parathormone-like material from an inoperable islet cell tumour. There was no evidence of liver metastases and the pancreatic mass was embolized, following which serum calcium was reduced to near normal levels with considerable clinical improvement. We conclude that there is a role for embolization of inoperable primary pancreatic neoplasm in the palliation of biochemical or haemorrhagic complications of these tumours.

Self-reported childhood abuse in an adult population in a primary care setting. Prevalence, correlates, and associated suicide attempts

OBJECTIVE

To describe the prevalence of childhood physical, sexual, and emotional abuse and suicide attempts in a sample of adult patients from a primary care setting and to examine the relationship between suicide attempts and a self-reported history of childhood abuse.

DESIGN

Cross-sectional sampling via a self-administered survey that included an abuse questionnaire, the Inventory to Diagnose Depression, and questions regarding suicide.

SETTING

University medical center family medicine practice.

PATIENTS

A convenience sample of patients aged 18 years and older presenting for care. Of the 778 patients approached, 448 patients (58%) consented and returned their surveys. We report only on the 292 surveys (38%) returned with complete information. Subjects were predominantly middle class and white, with a mean age of 37 years.

MEASUREMENT AND MAIN RESULTS

Forty-four percent of the patients reported experience of childhood abuse, and 22% reported multiple forms of abuse. Eighteen percent of abused vs 3% of nonabused patients (P = .00001) reported a history of suicide attempts. Being female, younger, and less educated were associated with any abuse. Females reported more sexual abuse; less educated patients, more physical abuse; and younger patients, more physical and sexual abuse and suicide attempts. Odds ratios for suicide attempts, when adjusted by abuse status, were 6.4 for any abuse (95% confidence intervals [CI], 2.4 to 17.6), 4.1 for sexual abuse (95% CI, 1.7 to 9.9), 3.7 for emotional abuse (95% CI, 1.4 to 10.0), and 1.2 for physical abuse (95% CI, 0.5 to 3.1).

CONCLUSION

A history of childhood abuse was a common experience in this sample. Patients with a history of abuse, particularly sexual and emotional abuse, are at increased risk of suicidal behavior. To facilitate more appropriate care and treatment, primary care practitioners should question patients regarding a history of abuse.

Allogeneic bone marrow transplantation

From highly investigational to standardized therapy, allogeneic BMT has established its role in the treatment of selected diseases. Continued refinements in bone marrow transplantation will increase the number of potential candidates, reduce associated risks, and improve disease-free survival rates. With further exploration into its efficacy, allogeneic BMT will bring new challenges and opportunities for patients, families, and health care providers.

Case report: percutaneous transluminal angioplasty of the inferior mesenteric artery in the treatment of chronic mesenteric ischaemia

Percutaneous transluminal angioplasty (PTA) of the superior mesenteric artery (SMA) and coeliac axis (CA) is a well recognized form of treatment for patients with chronic intestinal ischaemia and carries a low morbidity and mortality. We report a case where PTA of the inferior mesenteric artery in the presence of occluded SMA and CA proved both feasible and highly effective in abolishing the patient's symptoms.

Vein graft surveillance improves patency in femoro-popliteal bypass

Sixty-three patients undergoing femoro-popliteal bypass using autologous vein were prospectively screened for the development of graft related strictures by clinical assessment, intravenous digital subtraction angiography (IVDSA) and Duplex scanning. Eighteen strictures were identified in 14 grafts. Clinical examination detected only 11% of lesions, IVDSA detected 83% of lesions and Duplex scanning detected all 18 lesions. Seventeen lesions had occurred by 6 months from the time of operation which suggests that screening should begin early. Treatment by percutaneous transluminal angioplasty (PTA) was offered for eight strictures and dilatation was complete in all cases. No stricture recurred in the follow-up period. Cumulative patency in this series of screened and selectively treated vein grafts was compared with a previous series of 216 femoro-popliteal vein grafts and an improvement in 1 year potency of 15% was achieved (log rank test, chi 2 = 5.12, P = 0.02).

Intramural pseudodiverticulosis--an unusual cause of benign oesophageal stricture

Three cases of intramural pseudodiverticulosis of the oesophagus are described together with a review of the relevant literature. This unusual condition, diagnosed by characteristic features on the barium swallow, is associated with a high incidence of benign oesophageal stricture which responds readily to endoscopic dilatation.

The primary role of ultrasound in evaluating right-sided diaphragmatic humps and juxtadiaphragmatic masses: a review of 22 cases

Twenty-two successive patients presenting with localised humps on the right hemidiaphragm or juxtadiaphragmatic masses, as revealed on standard chest radiographs, were submitted for ultrasound examination. These were carried out irrespective of the patient's symptoms. Ultrasonography provided a useful adjunct to conventional chest radiography and accurately defined the extent of diaphragmatic humps and the contents of diaphragmatic herniations and juxtadiaphragmatic masses, clearly defining their relationship to the adjacent organs. In most cases further radiological investigations were unnecessary.