Long-term follow-up of two randomized trials comparing laparoscopic Nissen 360° with anterior 90° partial fundoplication.

BACKGROUND: The side-effects of Nissen fundoplication have led to modifications, including partial fundoplications such as an anterior 90° wrap. Five-year follow-up of two randomized trials suggested fewer side-effects following anterior 90° partial fundoplication, but better reflux control after Nissen fundoplication. However, longer-term outcomes have not been reported. This study combined data from previous trials to determine 10-year outcomes. METHODS: From 1999 to 2003, 191 patients were enrolled in two randomized trials comparing anterior 90° partial versus Nissen fundoplication. Trial protocols were similar, and data were combined to determine long-term clinical outcomes. Patients completed annual questionnaires assessing dysphagia, heartburn, medications, satisfaction and other symptoms. Visual analogue scales (0-10), a composite dysphagia score (0-45) and yes/no responses were used. RESULTS: Of the 191 patients, 152 (79·6 per cent) were available for 10-year follow-up. After anterior 90° fundoplication, patients reported less dysphagia to solids (score 2·03 versus 3·18 for the Nissen procedure; P = 0·037). Heartburn scores were lower after Nissen fundoplication (1·90 versus 2·83 for anterior 90° fundoplication; P = 0·035) and fewer patients required proton pump inhibitors (PPIs) (22 versus 39 per cent respectively; P = 0·035). Satisfaction scores were similar for both anterior 90° and Nissen groups (7·45 versus 7·36 respectively; P = 0·566), and the majority considered their original decision for surgery to be correct (86 versus 84 per cent; P = 0·818). CONCLUSION: After 10 years, both procedures achieved similar success as measured by global satisfaction measures. Patients who had a Nissen fundoplication reported more dysphagia, whereas more heartburn and PPI consumption were reported after anterior 90° fundoplication. Registration numbers: ACTRN12607000298415 and ACTRN12607000304437 (http://www.anzctr.org.au/).

ANTECEDENTES: Para evitar los efectos secundarios de la fundoplicatura de Nissen se han propuesto modificaciones técnicas, incluyendo las fundoplicaturas parciales como la plicatura anterior de 90°. El seguimiento a 5 años de dos ensayos aleatorizados sugiere menos efectos secundarios tras la fundoplicatura anterior de 90°, pero mejor control del reflujo con la fundoplicatura de Nissen. Sin embargo, no se han descrito los resultados a largo plazo. Este estudio combinó datos de dos ensayos previos para determinar los resultados a 10 años. MÉTODOS: Entre 1999 y 2003, se reclutaron 191 pacientes en dos ensayos aleatorizados que comparaban la fundoplicatura parcial anterior 90° versus fundoplicatura de Nissen. Los protocolos de ambos ensayos fueron similares, y los datos se combinaron para determinar los resultados clínicos a largo plazo. Los pacientes completaron cuestionarios anuales que evaluaban disfagia, pirosis, medicaciones, satisfacción y otros síntomas. Se utilizaron escalas analógicas visuales (0-10), una variable compuesta para la puntuación de disfagia (0-45) y respuestas sí/no. RESULTADOS: De los 191 pacientes, 152 (79,6%) pudieron seguirse a los 10 años. Tras la fundoplicatura anterior de 90°, los pacientes refirieron menos disfagia a sólidos (2,03 versus 3,18, P = 0,037). Las puntuaciones de pirosis fueron inferiores tras fundoplicatura de Nissen (2,83 versus 1,90, P = 0,035) y menos pacientes tomaban inhibidores de la bomba de protones (proton pump inhibitors, PPIs; 22% versus 39%, P = 0,035). Las puntuaciones de satisfacción fueron similares para ambos grupos de fundoplicatura anterior 90° y Nissen (7,45 versus 7,36, P = 0,566), y la mayoría consideró su decisión original para la cirugía como correcta (86,1% versus. 83,8%, P = 0,818). Las tasas de reoperación fueron similares (10,0% versus 8,8%). CONCLUSIÓN: Después de 10 años, ambos procedimientos lograron un éxito similar medido con medidas de satisfacción global. Los pacientes con fundoplicatura de Nissen referían más disfagia mientras que los pacientes con fundoplicatura anterior 900 describieron más pirosis y consumo de PPIs.

Completion of hand-written surgical consent forms is frequently suboptimal and could be improved by using electronically generated, procedure-specific forms.

INTRODUCTION: Completion of hand-written consent forms for surgical procedures may suffer from missing or inaccurate information, poor legibility and high variability. We audited the completion of hand-written consent forms and trialled a web-based application to generate modifiable, procedure-specific consent forms. METHODS: The investigation comprised two phases at separate UK hospitals. In phase one, the completion of individual responses in hand-written consent forms for a variety of procedures were prospectively audited. Responses were categorised into three domains (patient details, procedure details and patient sign-off) that were considered "failed" if a contained element was not correct and legible. Phase two was confined to a breast surgical unit where hand-written consent forms were assessed as for phase one and interrogated for missing complications by two independent experts. An electronic consent platform was introduced and electronically-produced consent forms assessed. RESULTS: In phase one, 99 hand-written consent forms were assessed and the domain failure rates were: patient details 10%; procedure details 30%; and patient sign-off 27%. Laparoscopic cholecystectomy was the most common procedure (7/99) but there was significant variability in the documentation of complications: 12 in total, a median of 6 and a range of 2-9. In phase two, 44% (27/61) of hand-written forms were missing essential complications. There were no domain failures amongst 29 electronically-produced consent forms and no variability in the documentation of potential complications. CONCLUSION: Completion of hand-written consent forms suffers from wide variation and is frequently suboptimal. Electronically-produced, procedure-specific consent forms can improve the quality and consistency of consent documentation.

One Step Nucleic Acid Amplification (OSNA) positive micrometastases and additional histopathological NSLN metastases: Results from a single institution over 53 months.

INTRODUCTION: The role of sentinel lymph node micrometastases on histopathological analysis is controversial in axillary staging and management in clinically node negative breast cancer. Long-term studies addressing the clinical relevance of occult breast cancer in sentinel lymph nodes based on molecular analysis are lacking. One Step Nucleic Acid Amplification (OSNA), a highly sensitive assay of cytokeratin 19 mRNA, is used intra-operatively for the detection of lymph node macro- and micrometastases in breast cancer. AIM: The aim of this study is to review the rate of micrometastases and further histopathological NSLN metastases, in our unit following the introduction of OSNA in Guildford. METHODS: Data was collected prospectively from the period of introduction 01/12/2008 to 31/05/2013. All patients eligible for sentinel lymph node biopsy were offered OSNA and operations were performed by the consultant breast surgeons. Presence or absence of micro-metastases depends on the agreed cut-off point on the amplification curve. On detection of micrometastases (+) and positive but inhibited (i+) metastases, a level 1 axillary clearance (ANC) was performed and for a macrometastasis (++), a level 3 ANC was carried out. RESULTS: 66% of the patients had negative SLN (n = 672) and 34% (n = 336) had positive sentinel lymph nodes who had further axillary surgery. Of these, 45% (n = 152/336) had macrometastases, 40% (n = 136/336) had micrometastases and 15% (48/336) had positive but inhibited results. There was no difference in the patient demographics and tumour characteristics in the various positive SLN groups. In patients with micrometastases, 15% (20/136) had further positive NLSNs and a further 6% (8/136) had >4 overall positive nodes (SLN + NSLN) thus requiring adjuvant supraclavicular/chest wall radiotherapy (p < 0.05). 25% of node positive patients had further NLSN metastases (85/336) and in these patients, the ratio of positive SLN/harvested SLN (+SLN/SLN) is constant at 1:1. This shows the likelihood of further positive NSLNs if all the harvested lymph nodes are positive. This linear trend is present in both micro-and macrometastases, thus correlating with the size and number of NSLN metastases. CONCLUSION: Our study reflects the tumour burden of NSLNs based on the molecular analysis of the SLN. OSNA has the potential to accurately identify axillary micrometastases. Micro-metastases are important as some of the patients with micrometastases had overall four positive nodes [SLN + NSLN] (criteria for radiotherapy in the absence of other adverse clinicopathological features). Also, our study highlights certain factors that predict the NSLN metastases, pending validation by further prospective long-term data. This will allow accurate calculation of the axillary tumour burden, particularly in patients with micro-metastases.

Search for Nucleon and Dinucleon Decays with an Invisible Particle and a Charged Lepton in the Final State at the Super-Kamiokande Experiment.

Search results for nucleon decays p→e^{+}X, p→µ^{+}X, n→νγ (where X is an invisible, massless particle) as well as dinucleon decays np→e^{+}ν, np→µ^{+}ν, and np→τ^{+}ν in the Super-Kamiokande experiment are presented. Using single-ring data from an exposure of 273.4 kton·yr, a search for these decays yields a result consistent with no signal. Accordingly, lower limits on the partial lifetimes of τ_{p→e^{+}X}>7.9×10^{32} yr, τ_{p→µ^{+}X}>4.1×10^{32} yr, τ_{n→νγ}>5.5×10^{32} yr, τ_{np→e^{+}ν}>2.6×10^{32} yr, τ_{np→µ^{+}ν}>2.2×10^{32} yr, and τ_{np→τ^{+}ν}>2.9×10^{31} yr at a 90% confidence level are obtained. Some of these searches are novel.

Search for neutrinos from annihilation of captured low-mass dark matter particles in the sun by super-kamiokande.

Super-Kamiokande (SK) can search for weakly interacting massive particles (WIMPs) by detecting neutrinos produced from WIMP annihilations occurring inside the Sun. In this analysis, we include neutrino events with interaction vertices in the detector in addition to upward-going muons produced in the surrounding rock. Compared to the previous result, which used the upward-going muons only, the signal acceptances for light (few-GeV/c^{2}-200-GeV/c^{2}) WIMPs are significantly increased. We fit 3903 days of SK data to search for the contribution of neutrinos from WIMP annihilation in the Sun. We found no significant excess over expected atmospheric-neutrino background and the result is interpreted in terms of upper limits on WIMP-nucleon elastic scattering cross sections under different assumptions about the annihilation channel. We set the current best limits on the spin-dependent WIMP-proton cross section for WIMP masses below 200 GeV/c^{2} (at 10 GeV/c^{2}, 1.49×10^{-39} cm^{2} for χχ→bb[over ¯] and 1.31×10^{-40} cm^{2} for χχ→τ^{+}τ^{-} annihilation channels), also ruling out some fraction of WIMP candidates with spin-independent coupling in the few-GeV/c^{2} mass range.

Pre-therapy mRNA expression of TNF is associated with regimen-related gastrointestinal toxicity in patients with esophageal cancer: a pilot study.

PURPOSE: Esophageal cancer has a high mortality rate, and its multimodality treatment is often associated with significant rates of severe toxicity. Effort is needed to uncover ways to maximize effectiveness of therapy through identification of predictive markers of response and toxicity. As such, the aim of this study was to identify genes predictive of chemoradiotherapy-induced gastrointestinal toxicity using an immune pathway-targeted approach. METHODS: Adults with esophageal cancer treated with chemotherapy consisting of 5-fluorouracil and cisplatin and 45-50 Gy radiation were recruited to the study. Pre-therapy-collected whole blood was analyzed for relative expression of immune genes using real-time polymerase chain reaction (RT-PCR). Gene expression was compared between patients who experienced severe regimen-related gastrointestinal toxicity vs. those experiencing mild to moderate toxicity. RESULTS: Blood from 31 patients were analyzed by RT-PCR. Out of 84 immune genes investigated, TNF was significantly elevated (2.05-fold, p = 0.025) in the toxic group (n = 12) compared to the non-toxic group (n = 19). Nausea and vomiting was the most commonly documented severe toxicity. No associations between toxicity and response, age, sex, histology, or treatment were evident. CONCLUSIONS: This study supports evidence of TNF as a predictive biomarker in regimen-related gastrointestinal toxicity. Confirming these findings in a larger cohort is warranted.

Search for trilepton nucleon decay via p→e+νν and p→µ+νν in the Super-Kamiokande experiment.

The trilepton nucleon decay modes p→e+νν and p→µ+νν violate |Δ(B-L)| by two units. Using data from a 273.4 kt yr exposure of Super-Kamiokande a search for these decays yields a fit consistent with no signal. Accordingly, lower limits on the partial lifetimes of τp→e+νν>1.7×10(32) years and τp→µ+νν>2.2×10(32) years at a 90% confidence level are obtained. These limits can constrain Grand Unified Theories which allow for such processes.

First indication of terrestrial matter effects on solar neutrino oscillation.

We report an indication that the elastic scattering rate of solar B8 neutrinos with electrons in the Super-Kamiokande detector is larger when the neutrinos pass through Earth during nighttime. We determine the day-night asymmetry, defined as the difference of the average day rate and average night rate divided by the average of those two rates, to be [-3.2 ± 1.1(stat) ± 0.5(syst)]%, which deviates from zero by 2.7 σ. Since the elastic scattering process is mostly sensitive to electron-flavored solar neutrinos, a nonzero day-night asymmetry implies that the flavor oscillations of solar neutrinos are affected by the presence of matter within the neutrinos' flight path. Super-Kamiokande's day-night asymmetry is consistent with neutrino oscillations for 4 × 10(-5) eV(2) ≤ Δm 2(21) ≤ 7 × 10(-5) eV(2) and large mixing values of θ12, at the 68% C.L.

Impact of participation in randomized trials on outcome following surgery for gastro-oesophageal reflux.

BACKGROUND: Patients may be unwilling to participate in clinical trials if they perceive risks. Outcomes were evaluated following surgery for gastro-oesophageal reflux in patients recruited to randomized trials compared with patients not in trials. METHODS: This study compared outcomes of patients who had surgery for reflux within or outside randomized trials between 1994 and 2009. The choice of procedure outside each trial was according to surgeon or patient preference. Clinical outcomes were determined 1 and 5 years after surgery using a standardized questionnaire, with analogue scales to assess heartburn, dysphagia and overall satisfaction. Subgroup analysis was undertaken for those aged less than 75 years undergoing laparoscopic Nissen fundoplication. RESULTS: Some 417 patients entered six randomized trials evaluating surgery for reflux and 981 underwent surgery outside the trials. The trial group contained a higher proportion of men and younger patients, and patients in trials were more likely to have undergone Nissen fundoplication. At 1 year, patients in the trials had slightly lower heartburn scores and less abdominal bloating, but otherwise similar outcomes to those not in the trials. At 5 years there were no differences, except for a slightly higher dysphagia score for liquids in the trial group. For the subgroup analysis, demographic data were similar for both groups. There were no differences at 1 year, but at 5 years patients enrolled in the trials had higher scores for dysphagia for liquids and heartburn. All of the statistically significant differences were thought unlikely to be clinically relevant. CONCLUSION: Participation in a randomized trial assessing surgery for reflux did not influence outcomes.

Twenty years of experience with laparoscopic antireflux surgery.

BACKGROUND: There are few reports of large patient cohorts with long-term follow-up after laparoscopic antireflux surgery. This study was undertaken to evaluate changes in surgical practice and outcomes for laparoscopic antireflux surgery over a 20-year period. METHODS: A standardized questionnaire, prospectively applied annually, was used to determine outcome for all patients undergoing laparoscopic fundoplication in two centres since commencing this procedure in 1991. Visual analogue scales ranging from 0 to 10 were used to assess symptoms of heartburn, dysphagia and satisfaction with overall outcome. Data were analysed to determine outcome across 20 years. RESULTS: From 1991 to 2010, 2261 consecutive patients underwent laparoscopic fundoplication at the authors' institutions. Follow-up ranged from 1 to 19 (mean 7.6) years. Conversion to open surgery occurred in 73 operations (3.2 per cent). Revisional surgery was performed in 216 patients (9.6 per cent), within 12 months of the original operation in 116. There was a shift from Nissen to partial fundoplication across 20 years, and a recent decline in operations for reflux, offset by an increase in surgery for large hiatus hernia. Dysphagia and satisfaction scores were stable, and heartburn scores rose slightly across 15 years of follow-up. Heartburn scores were slightly higher and reoperation for reflux was more common after anterior partial fundoplication (P = 0.005), whereas dysphagia scores were lower and reoperation for dysphagia was less common (P < 0.001). At 10 years, satisfaction with outcome was similar for all fundoplication types. CONCLUSION: Laparoscopic Nissen and partial fundoplications proved to be durable and achieved good long-term outcomes. At earlier follow-up, dysphagia was less common but reflux more common after anterior partial fundoplication, although differences had largely disappeared by 10 years.

Litigation in breast surgery: unique insights from the English National Health Service experience.

BACKGROUND: The increase in medical negligence claims against the National Health Service (NHS) over the past decade has had a detrimental impact on limited financial and human resources that could otherwise be available for direct clinical care. The aim of this study was to review litigation claims in breast surgery as part of the national Getting It Right First Time quality improvement initiative, with the aim of identifying opportunities to improve clinical practice and patient safety. METHODS: All general and plastic surgical claims notified to NHS Resolution between April 2012 and April 2018 were reviewed. Claims related specifically to breast surgery were retrieved manually, and case summaries were analysed independently by two breast surgeons. RESULTS: From 6915 claims, 449 relating to breast surgery were identified and reviewed. The mean(s.d.) claimant age was 46(13) years. The median number of claims over the 6-year period per NHS trust was 2 (range 0-22). The most frequent causes of litigation were dissatisfaction with cosmetic outcome (121 claims, 26.9 per cent) and patient-reported delays in diagnosis (121, 26.9 per cent). A large proportion of claims related to breast implant surgery (78, 17.4 per cent), and issues regarding consent/communication were common (69, 15.4 per cent). The estimated annual cost of breast surgery litigation claims ranged from £5.57 to £9.59 million (€6.35-11.02 million). CONCLUSION: Patient-reported delays in diagnosis and dissatisfaction with cosmetic outcome are the most common causes of litigation related to breast surgery. These key themes should be the focus for workforce learning, with the aim of improving patient care and experience.

Prognosis of synchronous bilateral breast cancer.

BACKGROUND: The prognosis of patients with synchronous bilateral breast cancer (SBBC) is usually based on the tumour with the worst pathological features. There is little evidence in the literature for this assumption, potentially impairing reasoned decisions on optimal adjuvant therapy. METHODS: This was a case-control study in which 68 women with SBBC were matched with 128 women with unilateral breast cancer. Both the GuysRisk prognostic model and the Nottingham Prognostic Index were used to determine the bilateral tumour with the poorer prognosis. Controls were matched for age, menopausal status, date of diagnosis, histological type and grade, and oestrogen receptor and axillary node status. RESULTS: Both prognostic models indicated the same side tumour with the worst prognosis. Kaplan-Meier survival curves for both disease-free and overall survival showed no significant difference in outcome between the two groups. CONCLUSION: Prognosis was determined by the tumour with the worst prognosis, with no additional worsening of outcome incurred from the second tumour.

A comparative analysis of British and American Society of Echocardiography recommendations for the assessment of left ventricular diastolic function.

At present there are two recognised guidelines for the echocardiographic assessment of left ventricular diastolic function provided by the British Society of Echocardiography and American Society of Echocardiography/European Association of Cardiovascular Imaging. However, no direct comparison of these guidelines has been performed to establish whether they provide similar diastolic grading. One hundred and eighty-nine consecutive patients in sinus rhythm who underwent transthoracic echocardiography for a primary indication of either heart failure assessment or assessment of left ventricular systolic function were extracted from our database (McKesson Cardiology). Left ventricular diastolic function assessment was performed using both guidelines and the results were compared. Chi-square, Kappa score and one-way ANOVA were used to evaluate the data at a level of P < 0.05. The most frequent outcome was unclassifiable diastolic function with significantly more patients being labelled unclassified with the British compared to American guidelines (47.4 vs 20.5%, P < 0.0001). Having excluded all unclassifiable patients, a significant difference still existed between the two guidelines with a higher proportion of grade one outcomes awarded by the ASE/EACVI guidelines. When grading subcategories were individually compared, there was significantly more grade one diastolic gradings awarded by American compared to the British guidelines (40.7 vs 20.1%, P < 0.0001). In 47% of patients it was not possible to grade diastolic function using the British guidelines, compared to 21% using the American guidelines. For those patients where grading was possible, there was a significant difference in patients classified with normal and grade one diastolic function when using British and American guidelines.

Validation of a digital color Doppler flow measurement method for pulmonary regurgitant volumes and regurgitant fractions in an in vitro model and in a chronic animal model of postoperative repaired tetralogy of Fallot.

OBJECTIVES: The purpose of this study was to validate a digital color Doppler (DCD) automated cardiac flow measurement method for quantifying pulmonary regurgitation (PR) in an in vitro and a chronic animal model of the right ventricular outflow tract of postoperative tetralogy of Fallot (TOF). BACKGROUND: There has been no reliable ultrasound method that can accurately quantitate PR. METHODS: We developed an in vitro model of mild pulmonary stenosis and wide-open PR that mimics the patterns of flow seen in patients with postoperative TOF. Thirteen different forward and regurgitant stroke volumes (RSVs) across the noncircular shaped cross-sectional outflow tract flow area were estimated using the DCD method in two orthogonal planes. In six sheep with surgically created PR, 24 different hemodynamic states with PR strictly quantified by electromagnetic probes were also studied. RESULTS: The RSVs and regurgitant fractions (RFs) obtained by the DCD method using average values from two orthogonal planes correlated well with reference values (RSV: r = 0.99, mean difference = 0.02 +/- 0.39 ml/beat for in vitro model; r = 0.97, mean differences = 1.79 +/- 1.84 ml/beat for animal model, RF: r = 0.98, mean difference = -1.10 +/- 4.34% for in vitro model; r = 0.94, mean difference = 2.73 +/- 6.75% for animal model). However, the DCD method using a single plane had limited accuracy for estimating pulmonary RFs and RSVs. CONCLUSIONS: The DCD method using average values from two orthogonal planes provides accurate estimation of RSVs and RFs and should have clinical importance for serially quantifying PR in patients with postoperative TOF.

Three-dimensional echocardiographic reconstruction of mitral valve color Doppler flow events.

In vitro studies have suggested superior accuracy of 3-dimensional echocardiography over conventional methods for the characterization and quantitation of color Doppler flow events. Little in vivo work has been reported in this area; this study demonstrates the feasibility of 3-dimensional reconstruction of mitral valve flow events in an unselected group of adult patients and discusses optimal instrument settings for the acquisition of 3-dimensional datasets.

Misuse of metered-dose inhalers in hospitalized patients.

Metered-dose inhalers (MDIs) have been associated with a high rate of misuse. Medical personnel also have a poor understanding of MDI technique. Hospitalized patients had their MDI technique observed before and after a series of inservices were provided to hospital personnel on correct MDI use. The rate of misuse did not change with 55 of 72 (76 percent) patients making errors in the first group before, and 45 of 55 (82 percent) patients making errors in the second group after staff education (p = 0.46). The average number of errors per patient was 2.39 in group 1 and 2.45 in group 2 (p = 0.93). Alternatives to deal with this high rate of MDI misuse are discussed.

Acute respiratory compromise resulting from tracheal mucous impaction secondary to a transtracheal oxygen catheter.

Transtracheal oxygen catheters are being increasingly used because of savings in oxygen usage and patient preference. The complications of the catheter are believed to be minor and easily managed. Inspissated mucous collections that form at the tip of the SCOOP 1 (Transtracheal Systems, Denver, Colorado) catheter have been reported but are usually easily expectorated by the patient. This report describes a patient who had development of acute respiratory compromise from crusted mucoid impaction of the trachea secondary to transtracheal catheter use. General anesthesia and rigid bronchoscopy were required for removal of the obstructing impaction. Unexplained worsening of respiratory symptoms in patients with transtracheal oxygen catheters should be addressed by prompt stripping of the catheter.

Comparison of ventricular volume and mass measurements from B- and C-scan images with the use of real-time 3-dimensional echocardiography: studies in an in vitro model.

BACKGROUND: Real-time 3-dimensional (3D) echocardiography avoids geometric assumptions in volume analysis and permits immediate visualization in any plane without the need for cardiac or respiratory gating or computation time. This study compared the accuracy of volume and mass assessments between standard long-axis (B-scan) and short-axis (C-scan) views in a simplified but quantifiable left ventricular phantom. METHODS AND RESULTS: The model comprised an inner balloon within an outer balloon separated by ultrasonographic gel. First, to mimic different chamber volumes, 12 volumes (40 to 180 mL) of water within the inner balloon were scanned with a real-time 3D system. Second, 10 volumes (80 to 170 mL) of gel were inserted between the balloons to mimic varying cardiac mass, and the gel volume space (mass) was calculated by subtracting the inner from the outer balloon volume. "Chamber" and "mass" measurements for both B and C scans correlated closely with the actual values (r = 0.99). However, chamber volumes from C scans were consistently less than B-scan values (mean difference from reference for C scans: -5.2 +/- 1.2 mL, P <.0001; for the 2 orthogonal B scans: 0.03 +/- 1.4 mL and -0.9 +/- 1.5 mL, respectively, P = NS). Similarly, for gel volume measurements, B-scan results were closer to actual mass volumes (mean difference 0. 3 +/- 2.5 and 1.7 +/- 2.9 mL) than those of C scans, which tended to underestimate (-4.5 +/- 2.5 mL, P <.0001). CONCLUSION: Our study suggests that real-time 3D echocardiography should provide an accurate means of determining chamber volumes and cardiac mass. However, measurements performed from B-scan views may be closer to the actual values than those from C-scan views, presumably since they are less highly influenced by distortions related to lateral resolution.

Acoustically stimulated transient power scattering explains enhanced detection of the very low velocities in myocardial capillaries by power Doppler imaging: an in vitro study.

BACKGROUND: Although enhanced detection of myocardial perfusion signals by power Doppler imaging during contrast echocardiography has been noted, flow velocities in the coronary microvasculature should generally be below the threshold for Doppler motion detection. It has been suggested that in this situation nonlinear scattering related to acoustically stimulated microsphere oscillation or destruction may be responsible for the detected Doppler shift. METHODS AND RESULTS: This study examined the behavior of MRX 115 (ImaRx Pharmaceuticals) microbubbles during harmonic and nonharmonic power Doppler imaging at varying power outputs (mechanical indexes 0. 3, 0.5, 0.7, and 0.9) in a perfusion tube model under zero-flow conditions. Boluses of MRX 115 0.5-mL suspension were introduced into the model, and flow was halted during each imaging period. Once power Doppler imaging was implemented, a signal was detected as unique sparkling color pixels corresponding to individual bubble destruction events, even in the absence of contrast movement. This phenomenon continued until all contrast bubbles disappeared from the region subjected to power Doppler imaging, usually within 35 to 40 seconds. Off-line videointensity measurements showed that initial power Doppler signal intensity and maximum signal decay rates increased parallel to increasing power output and were substantially greater for nonharmonic than for harmonic imaging modes. CONCLUSION: This relationship between signal intensity and decay rate and acoustic power output suggests that transient scattering related to bubble destruction is responsible for generation of the power Doppler signal in the absence of flow. This would explain the enhanced detection of the very low velocity flows in the myocardial capillaries by power Doppler contrast imaging.

Dobutamine stress echocardiography: improved endocardial border definition and wall motion analysis with tissue harmonic imaging.

BACKGROUND: We performed a study to determine whether tissue harmonic imaging (THI) facilitates wall motion analysis at rest and whether these benefits extend through the stages of a dobutamine stress echocardiography (DSE) study. We also assessed the impact of THI on the feasibility of DSE in technically difficult patients. Finally we tested the hypothesis that THI by improving endocardial border definition (EBD) could enhance the interobserver agreement between trainees and experienced operators for interpreting DSE studies. METHODS: Twenty unselected patients underwent DSE by standard protocol. Parasternal and apical views were obtained with the use of fundamental mode (FND) and THI at baseline, low dose, and peak stress. Segmental EBD was characterized as 1 to 4 (1 = excellent) and segmental wall motion was characterized as 1 to 4/x (1 = normal, x = unable to interpret) by a consensus of 2 experienced observers. A trainee in stress echocardiography independently scored all segments, and these results were compared with the consensus of the experienced readers. RESULTS: EBD improved with THI in 26 +/- 6.7 of 48 segments per patient (54%, 95% confidence interval [CI] 0.40 to 0.68) and deteriorated with THI in only 2 +/- 2.7 (4%, 95% CI 0 to 0.09). Of the total of 48 segments per patient, a mean of 10 +/- 5.7 (21%, 95% CI 0.10 to 0.31) were of inadequate quality to be interpreted for wall motion on FND, and this changed to 4 +/- 3.4 (6%, 95% CI 0.06 to 0.12) on THI (P <.001). EBD improved in a similar degree in all DSE stages 53%, 54%, and 53% for rest, low dose, and peak stress, respectively. Six of the 20 study patients were deemed unsuitable for DSE on FND, and all were changed to suitable subjects on THI. Of the 205 segments deemed unsuitable for interpretation on FND, 140 (68%) were of the anterior and lateral walls of the LV. Improvement with THI was also more prominent on these walls. The mean coefficient of agreement (kappa) for wall motion analysis was 0.82 +/- 0.14 on FND and improved to 0. 92 +/- 0.09 on THI (P <.001). CONCLUSIONS: THI dramatically improves EBD and the ability to confidently score segmental wall motion. Interobserver agreement is also significantly enhanced. These benefits extend to the peak stage of a DSE study. Routine use of THI may enhance the diagnostic accuracy of DSE and extend its application to technically difficult patients previously deemed unsuitable.