Climbing the ladder from novice to expert plastic surgeon.

This article reviews the nature of novice and expert thinking and shows how pattern recognition is a key distinction between the two. The article also discusses the ladder that learners climb as they move from medical student to senior staff surgeon and suggests ways of viewing surgical trainees as they progress through the process so that learning activities can be adopted that best fit them.

Some thoughts about creating healthcare professionals that match what societies need.

Healthcare is becoming increasingly complex across the globe; technology, delivery models, economic requirements, demographics and the epidemiology of disease are changing at a rapid pace. Despite the multiple efforts in defining common competencies and standards that all healthcare professionals should meet, it has become clear that educational and training programs have to adjust to the needs of societies they serve, and that the institutions that design and deliver those programs need to be accountable to society for the products they produce. Academic institutions that educate healthcare professionals will have to interact differently with the many stakeholders needed to create effective and efficient, and culturally appropriate healthcare systems. Present day medical education has its roots in the European university which traditionally valued academic freedom, autonomy and independent research over serving society and the job market; future efforts will require a fundamental shift in the outlook and measures of success for academic institutions. The recent outcomes and competency movement is a first step in that direction but more will need to be done. Rather than being one participant, possibly a reluctant one, academia should become the catalyst for change, the hub for stakeholder interactions, and the breeding ground for the new healthcare workforce.

Reform of a traditional clinical curriculum in Japan: experiences at Tokyo Medical and Dental University.

BACKGROUND: Until recently, Japanese legislative guidelines dictated that undergraduate clinical training consisted of students' observations of clinicians' work. In 2006, Tokyo Medical and Dental University initiated a reform of their traditional undergraduate clinical curriculum. The reform integrated students into patient care teams, and included the implementation of a clinical faculty 'tutor'. AIMS: This short communication describes a formative assessment of the reform work. METHOD: In 2007, students, residents, and tutors were surveyed to determine their perceptions of students' integration into clinical activities, and patients' acceptance of students in their medical care. An external consultant observed students' patient care activities, and assessed the methods of and perceived barriers to clinical teaching. RESULTS: Surveys indicated that students were most engaged in history-taking, procedures, and case presentations. Observations revealed students' activities and teaching to be focused on students' case presentations. Perceived barriers to teaching included insufficient time and personnel. Respondents felt that patients were accepting students in their clinical care. CONCLUSIONS: This clinical reform effort includes an increase in students' interactions with patients through history-taking, and teaching through case presentations.

In vivo characterization of coronary atherosclerotic plaque by use of optical coherence tomography.

BACKGROUND: The current understanding of the pathophysiology of coronary artery disease is based largely on postmortem studies. Optical coherence tomography (OCT) is a high-resolution ( approximately 10 microm), catheter-based imaging modality capable of investigating detailed coronary plaque morphology in vivo. METHODS AND RESULTS: Patients undergoing cardiac catheterization were enrolled and categorized according to their clinical presentation: recent acute myocardial infarction (AMI), acute coronary syndromes (ACS) constituting non-ST-segment elevation AMI and unstable angina, or stable angina pectoris (SAP). OCT imaging was performed with a 3.2F catheter. Two observers independently analyzed the images using the previously validated criteria for plaque characterization. Of 69 patients enrolled, 57 patients (20 with AMI, 20 with ACS, and 17 with SAP) had analyzable images. In the AMI, ACS, and SAP groups, lipid-rich plaque (defined by lipid occupying > or =2 quadrants of the cross-sectional area) was observed in 90%, 75%, and 59%, respectively (P=0.09). The median value of the minimum thickness of the fibrous cap was 47.0, 53.8, and 102.6 microm, respectively (P=0.034). The frequency of thin-cap fibroatheroma (defined by lipid-rich plaque with cap thickness < or =65 microm) was 72% in the AMI group, 50% in the ACS group, and 20% in the SAP group (P=0.012). No procedure-related complications occurred. CONCLUSIONS: OCT is a safe and effective modality for characterizing coronary atherosclerotic plaques in vivo. Thin-cap fibroatheroma was more frequently observed in patients with AMI or ACS than SAP. This is the first study to compare detailed in vivo plaque morphology in patients with different clinical presentations.

Focal and multi-focal plaque macrophage distributions in patients with acute and stable presentations of coronary artery disease.

OBJECTIVES: This study was designed to utilize optical coherence tomography (OCT) images of coronary atherosclerotic plaque macrophages to investigate the relationship between macrophage distributions and clinical syndrome. BACKGROUND: The relative significance of focal macrophage infiltration and generalized coronary inflammation for predicting acute coronary events is a currently a source of considerable controversy in cardiology. Lack of a high-resolution cross-sectional imaging modality has limited macrophage evaluation in vivo. METHODS: Intracoronary OCT imaging was performed at culprit and non-culprit plaques in patients presenting with stable angina pectoris, unstable angina pectoris,and ST-segment elevation myocardial infarction. Macrophage densities were quantified from these images and analyzed with respect to the clinical presentations of the patients under investigation. RESULTS: A significantly greater macrophage density was found in unstable patients, both for fibrous and lipid-rich plaques (p = 0.025 and p = 0.002, respectively). Within each patient, the macrophage densities at culprit and non-culprit lesions correlated significantly (r = 0.66, y = 0.88x + 0.43, p = 0.01). Sites of plaque rupture demonstrated a greater macrophage density than non-ruptured sites (6.95 +/- 1.60%, 5.29 +/- 1.17%; p = 0.002). Surface macrophage infiltration was a stronger predictor of unstable clinical presentation than subsurface infiltration for culprit lesions (p = 0.035) but not for remote lesions (p = 0.80). CONCLUSIONS: Our results demonstrate that increases in both multi-focal and focal macrophage densities are highly correlated with symptom severity. By providing a means of detecting increases in plaque macrophage content before an acute event, this technique may aid in determining prognosis and guiding preventive therapy.

Short-term intravenous eptifibatide infusion combined with reduced dose recombinant tissue plasminogen activator inhibits platelet recruitment at sites of coronary artery injury.

OBJECTIVES: This study was designed to determine in a dog model of coronary thrombosis whether short-term eptifibatide (Ep) combined with low-dose plasminogen activator (rt-PA) inhibits platelet recruitment at sites of endothelial damage after normalization of platelet function. BACKGROUND: Ep plus reduced-dose rt-PA has not previously been shown to render a recanalized coronary artery resistant to platelet recruitment after normalization of platelet function. METHOD: Inhibition of platelet recruitment was studied by scanning electron microscopy (SEM) in a canine model of left anterior descending (LAD) thrombosis. In phase I treatment groups were: 1) Ep (n = 6); 2) Ep + rt-PA (n = 6); 3) rt-PA (n = 6); and 4) placebo (n = 4). Coronary blood flow was monitored and LAD segments excised for SEM after 90-min infusion of study drug. In phase II, dogs were randomized to Ep alone (n = 5) or to Ep + rt-PA (n = 5). Coronary blood flow was monitored during and 120 min after cessation of drug when platelet function had returned to normal and LAD segments were excised. RESULTS: All animals except placebo showed reflow. In phase I, SEM showed an absence of platelet aggregates with Ep alone and with Ep + rt-PA, but not with rt-PA alone. In phase II, SEM showed an intimal surface devoid of mural thrombus and platelet aggregates only in Ep + rt-PA treated arteries. Ep-alone treated arteries showed new platelet aggregates at sites of residual mural thrombus. CONCLUSIONS: Short-term infusion Ep plus low-dose rt-PA acutely neutralizes the ability of damaged endothelial surfaces to recruit new platelets by inhibiting platelet aggregation and eliminating residual mural thrombus.

Pressure overload-induced LV hypertrophy and dysfunction in mice are exacerbated by congenital NOS3 deficiency.

To investigate the role of endothelial nitric oxide synthase (NOS3) in left ventricular (LV) remodeling induced by chronic pressure overload, the impact of transverse aortic constriction (TAC) on LV structure and function was compared in wild-type (WT) and NOS3-deficient (NOS3(-/-)) mice. Before TAC, LV wall thickness, mass, and fractional shortening were similar in the two mouse strains. Twenty-eight days after TAC, both WT and NOS3(-/-) mice had increased LV wall thickness and mass as well as decreased fractional shortening. Although the pressure gradient across the TAC was similar in both strains of mice 28 days after TAC, LV mass and posterior wall thickness were greater in NOS3(-/-) than in WT mice, whereas fractional shortening and the maximum rate of developed LV pressure were less. Diastolic function, as measured by the time constant of isovolumic relaxation and the maximum rate of LV pressure decay, was impaired to a greater extent in NOS3(-/-) than in WT mice. The degree of myocyte hypertrophy and LV fibrosis was greater in NOS3(-/-) than in WT mice at 28 days after TAC. Mortality was greater in NOS3(-/-) than in WT mice 28 days after TAC. Long-term administration of hydralazine normalized the blood pressure and prevented the LV dilation in NOS3(-/-) mice but did not prevent the LV hypertrophy, dysfunction, and fibrosis associated with NOS3 deficiency after TAC. These results suggest that the absence of NOS3 augments LV dysfunction and remodeling in a murine model of chronic pressure overload.

Morphology of atrial myocardium in human pulmonary veins: a postmortem analysis in patients with and without atrial fibrillation.

OBJECTIVES: We report an in-depth postmortem morphologic analysis of atrial myocardium in human pulmonary veins (PVs) from patients with and without atrial fibrillation (AF). BACKGROUND: Electrophysiologic studies established the critical role of PVs in the initiation of AF. To date, a paucity of data exists about PV morphology as an arrhythmogenic substrate. METHODS: Longitudinal tissue-strips of PVs were excised and histologically analyzed from the distal part to just beyond the atriovenous junction in the left atrium from 20 patients, obtained at autopsy. Anatomical measurements, including diameters, lengths, and wall-thicknesses of PVs, obtained at autopsy, were made. RESULTS: Histological analysis revealed extension of atrial myocardium into 89% of all PVs. Prevalence of myocardial extension was significantly higher in veins of 6 patients with compared with 14 patients without AF. Other significant differences in the histology of PVs between the two groups were a higher frequency of discontinuity and hypertrophy and a higher degree of fibrosis of the atrial myocardium in the PVs of patients with AF. A marked variation existed in anatomical dimensions of PVs, although no differences were observed between patients with or without AF. CONCLUSIONS: Atrial myocardium was more often present in the PVs of patients with compared with patients without AF. In the first group, the atrial myocardium in the PVs was characterized by more severe discontinuity, hypertrophy, and fibrosis. A marked variation in anatomical dimensions of the PVs existed.

Quantification of macrophage content in atherosclerotic plaques by optical coherence tomography.

BACKGROUND: Macrophage degradation of fibrous cap matrix is an important contributor to atherosclerotic plaque instability. An imaging technology capable of identifying macrophages in patients could provide valuable information for assessing plaque vulnerability. Optical coherence tomography (OCT) is a new intravascular imaging modality that allows cross-sectional imaging of tissue with a resolution of approximately 10 micro m. The aim of this study was to investigate the use of OCT for identifying macrophages in fibrous caps. METHODS AND RESULTS: OCT images of 26 lipid-rich atherosclerotic arterial segments obtained at autopsy were correlated with histology. Cap macrophage density was quantified morphometrically by immunoperoxidase staining with CD68 and smooth muscle actin and compared with the standard deviation of the OCT signal intensity at corresponding locations. There was a high degree of positive correlation between OCT and histological measurements of fibrous cap macrophage density (r=0.84, P<0.0001) and a negative correlation between OCT and histological measurements of smooth muscle actin density (r=-0.56, P<0.005). A range of OCT signal standard deviation thresholds (6.15% to 6.35%) yielded 100% sensitivity and specificity for identifying caps containing >10% CD68 staining. CONCLUSIONS: The high contrast and resolution of OCT enables the quantification of macrophages within fibrous caps. The unique capabilities of OCT for fibrous cap characterization suggest that this technology may be well suited for identifying vulnerable plaques in patients.

Characterization of human atherosclerosis by optical coherence tomography.

BACKGROUND: High-resolution visualization of atherosclerotic plaque morphology may be essential for identifying coronary plaques that cause acute coronary events. Optical coherence tomography (OCT) is an intravascular imaging modality capable of providing cross-sectional images of tissue with a resolution of 10 micro m. To date, OCT imaging has not been investigated in sufficient detail to assess its accuracy for characterizing atherosclerotic plaques. The aim of this study was to establish objective OCT image criteria for atherosclerotic plaque characterization in vitro. METHODS AND RESULTS: OCT images of 357 (diseased) atherosclerotic arterial segments obtained at autopsy were correlated with histology. OCT image criteria for 3 types of plaque were formulated by analysis of a subset (n=50) of arterial segments. OCT images of fibrous plaques were characterized by homogeneous, signal-rich regions; fibrocalcific plaques by well-delineated, signal-poor regions with sharp borders; and lipid-rich plaques by signal-poor regions with diffuse borders. Independent validation of these criteria by 2 OCT readers for the remaining segments (n=307) demonstrated a sensitivity and specificity ranging from 71% to 79% and 97% to 98% for fibrous plaques, 95% to 96% and 97% for fibrocalcific plaques, and 90% to 94% and 90% to 92% for lipid-rich plaques, respectively (overall agreement, kappa=0.83 to 0.84). The interobserver and intraobserver reliabilities of OCT assessment were high (kappa values of 0.88 and 0.91, respectively). CONCLUSIONS: Objective OCT criteria are highly sensitive and specific for characterizing different types of atherosclerotic plaques. These results represent an important step in validating this new intravascular imaging modality and will provide a basis for the interpretation of intracoronary OCT images obtained from patients.

Transmyocardial coil implants: a novel approach to transmyocardial revascularization.

BACKGROUND: Transmyocardial laser revascularization (TMLR) has potential benefit for patients with end-stage coronary artery disease and intractable angina not amenable to conventional revascularization techniques. Neovascularization has been proposed to occur around the laser channels. Our aim was to determine the feasibility of a novel nonlaser myocardial revascularization technique and its effect on angiogenesis in a nonischemic porcine model. METHODS: In the first phase, six transmyocardial stainless steel coil implants (TMI) were deployed to the lateral wall of the left ventricle in each of 6 pigs. The animals were sacrificed at 8 and 12 weeks, with a single animal dying prematurely at 4 weeks, and the myocardium was assessed for new vessel growth. In the second phase, 8 implants were deployed in each of 12 pigs with regular fluoroscopic follow-up until sacrifice at 2 weeks to assess implant stability. RESULTS: The deployment procedure was safe and feasible with no complications evident. A significant increase in new vessels at implant sites with 5.43 +/- 3.67, 4.97 +/- 2.44, and 3.57 +/- 2.29 seen per high power field at 12, 8, and 4 weeks, respectively, compared to 1.00 +/- 1.06 (p < 0.0001) in control myocardium. There was no evidence of implant migration in Phase 2. CONCLUSIONS: TMIs can feasibly be deployed in the nonischemic pig model with a high success rate. The presence of angiogenesis at the implant site and the maintenance of this reaction for 3 months implies that TMI may offer an alternative to TMLR while providing a platform for delivery of angiogenic factors.

Visualization of coronary atherosclerotic plaques in patients using optical coherence tomography: comparison with intravascular ultrasound.

OBJECTIVES: The aim of this study was to evaluate the feasibility and the ability of intravascular optical coherence tomography (OCT) to visualize the components of coronary plaques in living patients. BACKGROUND: Disruption of a vulnerable coronary plaque with subsequent thrombosis is currently recognized as the primary mechanism for acute myocardial infarction. Although such plaques are considered to have a thin fibrous cap overlying a lipid pool, imaging modalities in current clinical practice do not have sufficient resolution to identify thin (< 65 microm) fibrous caps. Optical coherence tomography is a new imaging modality capable of obtaining cross-sectional images of coronary vessels at a resolution of approximately 10 microm. METHODS: The OCT images and corresponding histology of 42 coronary plaques were compared to establish OCT criteria for different types of plaques. Atherosclerotic lesions with mild to moderate stenosis were identified on angiograms in 10 patients undergoing cardiac catheterization. Optical coherence tomography and intravascular ultrasound (IVUS) images of these sites were obtained in all patients without complication. RESULTS: Comparison between OCT and histology demonstrated that lipid-rich plaques and fibrous plaques have distinct OCT characteristics. A total of 17 IVUS and OCT image pairs obtained from patients were compared. Axial resolution measured 13 +/- 3 microm with OCT and 98 +/- 19 microm with IVUS. All fibrous plaques, macrocalcifications and echolucent regions identified by IVUS were visualized in corresponding OCT images. Intimal hyperplasia and echolucent regions, which may correspond to lipid pools, were identified more frequently by OCT than by IVUS. CONCLUSIONS: Intracoronary OCT appears to be feasible and safe. Optical coherence tomography identified most architectural features detected by IVUS and may provide additional detailed structural information.