Apical Approach Research Articles

Nerve-sparing radical retropubic prostatectomy: techniques and clinical considerations

There are essentially two ways to accomplish nerve preservation during radical retropubic prostatectomy: the 'apical approach' described by Walsh and the so-called 'lateral approach', a simplified method where the dissection is initially conducted on the portion of the bundles that courses posterolateral to the prostate. Do the different techniques differ in the ability to preserve potency and in the positive surgical margins rate? No previous study has addressed this question. Above all, the preoperative and intraoperative indications to spare or not the nerves remain a matter of debate. The present review is an attempt to elucidate these questions in light of the current literature.

Gas‐phase interaction between DNA and RNA bases and copper (II) ion: A density functional study

AbstractThis investigation, performed at Becke's three‐parameter functional with Perdew–Wang correlational functional/6‐311+G(2df,2p) level, can provide information about the geometry of all possible adducts originating from the interaction of Cu2+ cation with the most stable tautomers of DNA and RNA free bases. Several attachment sites for both purine and pyrimidine bases have been taken into account. Monocoordination or bicoordination has been observed in all the obtained complexes. The copper ion (II) has the major affinity for the most stable tautomer of guanine base. We have observed that an interesting behavior occurs when the copper ion interacts with the bases in an apical approach. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004

6 VENTRICULAR INTER‐ AND LEFT VENTRICULAR INTRA VENTRICULAR SYSTOLIC ASYNCHRONY IN PATIENTS WITH DILATED CARDIOMYOPATHY AND THE EFFECT OF CARDIAC RESYNCHRONIZATION THERAPY

Aim: Data dealing with the effect of cardiac resynchronization therapy (CRT) on myocardial or interventricular systolic asynchrony derived by pulsed Doppler tissue imaging (PDTI) and pulsed flow Doppler imaging are scare. The purpose of this study was to evaluate ventricular inter‐ and left ventricular intraventricular systolic asynchrony and to describe the effects of CRT on Doppler imaging in patients with dilated cardiomyopathy (DCM) and reduced left ventricular ejection fraction (LVEF). Methods: 217 consecutive patients (96 patients with left bundle branch bloc[LBBB]) with DCM underwent a standard and PDTI echocardiography examination. We measured the interval between Q wave in the electrocardiogram and the beginning of the systolic velocity profile (Q ‐ Sb) recorded from the right and left ventricular outflow tract by pulsed Doppler imaging (PWD) and from 5 basal segments (right ventricle, septal‐, lateral‐, anterior‐, inferior left ventricle) by PDTI from an apical approach. In 18 patients a biventricular pacing system was implanted and the effect of the cardiac resynchronization therapy was evaluated 1 month after implantation by echo examination. Results: A high‐grade interventricular systolic asynchrony (> 60 ms) was measured in 3 patients (2.5%) without LBBB versus 33 patients (16%) with LBBB. A severe left ventricular intraventricular systolic asynchrony (> 60 ms) was documented in 33 patients (27%) without LBBB versus 27 patients (28%) with LBBB. CRT in 18 patients reduced the interventricular systolic asynchrony from 52 ± 29 (20–116) ms to 14 ± 10 (0–32) ms (p < 0.01). Left ventricular intraventricular systolic asynchrony was reduced from 87 ± 35 (42–168) ms to 29 ± 14 (4–52) ms (p < 0.001). All patients with CRT showed an improvement in NYHA functional status. Conclusions: Patients with LBBB and DCM showed a significant intense degree of interventricular systolic asynchrony compared with patients without LBBB. The incidence of high‐grade left ventricular intraventricular systolic asynchrony was not influenced by LBBB. CRT is able to reduce inter‐ and left ventricular intraventricular systolic asynchrony. We recommend the use of PWD and PDTI in all patients with DCM as an additional important selection criteria for CRT.

383 The impact of cholesterol on coronary flow reserve in hypertensive patients without evidence of coronary heart disease

Background: It has been demonstrated that the maximal oxygen uptake (VO2max) is strictly related to functional status (NYHA Class) in patients with idiopathic dilative cardiomyopathy (IDC) and therefore represents an important clinical predictor. The VO2max is the physiological trigger to increase the coronary flow reserve (CFR). At present it is possible noninvasively evaluate the CFR by transthoracic echocardiography on left anterior descending (LAD) coronary artery. Methods: We have consecutively enrolled 26 patients (pts), 16 Male mean age 64±b12 years, all affected with IDC confirmed by normal coronary artery with angiography. Each of them underwent TTE, evaluating the standard parameters such as LVEDV, LVESV (ml), EF (%) and Stress-Echo with Dipirydamole (0,84 mg/Kg over 6 m’) evaluating the LV contractility (WMSI) and simultaneously the CFR on LAD, calculated as the maximum peak-rest diastolic flow velocity (LADDFVDp-r) ratio, using a high frequency probe in 2ˆ harmonic (7 MHz). We utilized an off axis apical approach under the guide of color-Doppler and when necessary we injected a contrast agent (Sonovue 2ml in bolus) to improve the signal-noise coronary flow ratio. All pts underwent within 24 hour the effort test (treadmill) with gas analysis evaluating particularly the VO2max (ml/kg/m’) and anaerobic threshold. We considered as clinical parameter the NYHA Class. Results: We found the following mean values: EDV = 226 ± 63ml, ESV = 144 ± 52ml, EF = 36 ± 6%, WMSIb = 1,8 ± 0,3, LADDFVr 31 ± 4cm/s, LADDFVp = 59 ± O8cm/s, CFR = 1,9 ± 0,2, VO2max = 19 ± O6, NYHA Class = 2,3 ± 0,8 The parameters that demonstrated a significance linear statistical relationship were: NYHA Class vs MVO2: r = 0,70 p = 0.002 NYHA Class vs RC: r = 0.92 p = 0.001 VO2max vs CFR: r = 0.60 p = 0.016 VO2max vs LADDFVDr: r = 0.60 p = 0.020 The feasibility of CFR study in pts affected with IDC was excellent: 27/27 pts (100%) Conclusion: The excellent relationship between the NYHA Class and VO2max and between CFR and VO2max suggest us to consider the CFR of LAD in daily practice as an important functional predictor: this, in the next future could have a relevant therapeutic and prognostic impact in pts with IDC.

Evaluation of mitral valve prolapse using newly developed real-time three-dimensional echocardiographic system with real-time volume rendering.

The development of a real-time three-dimensional (RT3D) image acquisition system and direct digital links between ultrasound equipment and the data processing computer facilitate improved 3D image reconstruction. However, at present time, it is hard to promptly display 3D images and is also ineffective for a practical use. The objective of this study was to assess the feasibility of a new transthoracic RT3D echocardiographic system for evaluation of mitral valve prolapse. Eighteen patients with mitral valve prolapse diagnosed by transthoracic two-dimensional (2D) echocardiography and M-mode were examined through this technique (11 male, mean age 42 +/- 17 years). Since visualization of mitral valve from apical four-chamber view was better than that of the parasternal approach, only apical approach was used for mitral valve evaluation. This system is capable of acquiring volumetric data from mechanical scanning of the phased-array transducer (3.5 MHz) as well as displaying the volume rendered images of the structure without storing the image data and reconstruction of the object. The prolapse of leaflet could be seen in 14/ 18 (77%) of patients with mitral valve prolapse based on conventional echocardiography. The newly developed transthoracic RT 3D ultrasound system without a reconstruction process seemed to be a useful noninvasive tool for diagnosis of mitral valve prolapse and detection of prolapsed leaflet or scallop, which is very important for deciding on a reliable surgical technique.

Apical transthoracic Doppler echocardiography can be useful for analysis of postoperative early function of the left internal thoracic artery

J Thorac Cardiovasc Surg D. Croce and Brian F. Buxton Mitsumasa Hata, Jai S. Raman, Motomi Shiono, Nanao Negishi, Yukiyasu Sezai, Elizabeth postoperative early function of the left internal thoracic artery Apical transthoracic Doppler echocardiography can be useful for analysis of http://jtcs.ctsnetjournals.org/cgi/content/full/123/2/385 the World Wide Web at: The online version of this article, along with updated information and services, is located on

Alveolar bone resorption following coronal versus apical approach in a mucoperiosteal flap surgery procedure in the rat mandible.

In several publications, we have reported that a distinct resorptive phase of alveolar bone developed during 3 weeks following elevation of a mucoperiosteal flap in rats by a coronal surgical approach. In the present study, we compared the alveolar bone loss after mucoperiosteal flap surgery by a coronal approach (COR) to a surgical approach incising the mucosa close to the tooth apices and separating the mucoperiosteum toward the tooth crown (apical approach, AP). Eighteen Wistar rats were divided into 2 experimental groups; each group consisted of 9 rats. In the first group, COR was performed on both buccal and lingual aspects on the right side of the rat mandible, while the left side served as a sham-operated control. In the second experimental group, AP was performed. In the AP group, the outer aspect (buccal or lingual) of the alveolar bone was slightly resorbed usually at the level where the mucosa was incised. In many sections, extensive modeling of new trabecular bone was seen, coronal to the surgical incision. On the contrary, the coronal surgical approach revealed an extensive resorptive phase, mainly of the periodontal aspect of the alveolar bone. The results of this study show that periodontal surgery by a coronal surgical approach stimulates a burst of remodeling of the alveolar bone in a very specific pattern.

Quantitative analysis of hibernating myocardium by dobutamine tissue Doppler echocardiography

Dobutamine stress echocardiography is a useful modality to detect hibernating myocardium in patients with chronic coronary artery disease.1,2 A quantitative assessment of myocardial wall velocities can be obtained by tissue Doppler echocardiography (TDE) analysis,3–5 a method that can quantify regional myocardial velocities objectively and detect subtle alteration of contractility during stress echo.6–8 In patients with coronary artery disease, TDE has been applied to the study of old or recent infarctions apparently related to a 1-vessel stenosis in patients free from left ventricular dysfunction.5,9 A decrease in myocardial velocity gradients has also been reported during dobutamine challenge on 1-vessel coronary lesions without myocardial infarction.6 Our study addresses a population of patients presenting with left ventricular dysfunction with ejection fraction <50% related to chronic and severe 3-vessel disease. To image more segments in these patients with multivessel disease, we used an apical TDE approach at rest and under dobutamine. The study was designed to test if the obtained quantitative information could enable detection of viable or nonviable segments in this specific population.

Contrast medium echocardiography-assisted pericardial drainage

The most effective treatment for pericardial effusion and cardiac tamponade is removal of the pericardial fluid. Surgical pericardiotomy is associated with high mortality and morbidity. Similarly, subcostal percutaneous blind pericardiocentesis was reported to have unacceptably high mortality and complication rates. Major complications associated with blind needle punctures are right heart penetration, hemopericardium, puncture of the coronary arteries, liver and lung bleeding. Even under fluoroscopic guidance and electrocardiographic needle monitoring high complication rates persist. Pericardial drainage has been often inadequate, with frequent recurrences of significant pericardial effusions. Two-dimensional echocardiographically guided pericardiocentesis is reported to improve efficacy and safety of percutaneous puncture. Moreover, it allows immediate verification of the procedural success. We evaluated the efficacy and safety of an echocardiographically guided contrast agent controlled pericardiocentesis. This is a retrospective, descriptive study on 126 consecutive patients who underwent percutaneous pericardiocentesis at the University Hospital Essen, Germany, from 1995 to June 2000. There were 51 women (41%) and 75 men (55%) with a mean age of 52 +/- 14 years. Standard techniques for quantification of pericardial effusion were used. Depending on the localization of the pericardial effusion an apical or subxiphoidal approach was chosen. The puncture was performed under echocardiographic guidance and the position of the needle was controlled by injection of contrast agent. Over a long guidewire a pigtail catheter was inserted through a sheath for further drainage of pericardial fluid. The catheter was removed after a maximum of 48 hours to avoid infection of the pericardial cavity. An apical approach was chosen in 98 patients (78%), a subcostal in 28 patients (22%). The procedure was successful in 99% of the attempts. No death or clinical complication occurred. The maximal pericardial diameter measured by two-dimensional echocardiography was 32 +/- 16 mm before and 5.3 +/- 2 mm after drainage. The calculated pericardial effusion was 657 +/- 342 ml. A fluid volume of 605 +/- 342 ml could be drained. In all patients a pericardial catheter was placed for 1.4 +/- 0.8 days. Recurrence of pericardial effusion occurred in 18 patients (14%). Of these, 15 patients underwent repeated successful pericardiocentesis (2.5 +/- 0.8), and 3 patients were referred to surgical pericardiotomy. Pericardiocentesis under echocardiographic contrast agent guidance is a safe, successful and cost effective procedure for diagnostic and therapeutic drainage of pericardial effusion. Two-dimensional echocardiography allows localization of the optimal puncture site as well as the quantification of the effusion depth. The injection of contrast agents into the pericardial cavity improves the safety and accuracy of the procedure. Even recurrent pericardial effusions can be treated successfully.

Improved assessment of mitral valve stenosis by volumetric real-time three-dimensional echocardiography

OBJECTIVESThis study was performed to determine the feasibility, accuracy and reproducibility of real-time volumetric three-dimensional echocardiography (3-D echo) for the estimation of mitral valve area in patients with mitral valve stenosis.BACKGROUNDPlanimetry of the mitral valve area (MVA) by two-dimensional echocardiography (2-D echo) requires a favorable parasternal acoustic window and depends on operator skill. Transthoracic volumetric 3-D echo allows reconstruction of multiple 2-D planes in any desired orientation and is not limited to parasternal acquisition, and could thus enhance the accuracy and feasibility of calculating MVA.METHODSIn 48 patients with mitral stenosis (40 women; mean age 61 ± 13 years) MVA was determined by planimetry using volumetric 3-D echo and compared with measurements obtained by 2-D echo and Doppler pressure half-time (PHT). All measurements were performed by two independent observers. Volumetric data were acquired from an apical view.RESULTSAlthough 2-D echo allowed planimetry of the mitral valve in 43 of 48 patients (89%), calculation of the MVA was possible in all patients when 3-D echo was used. Mitral valve area by 3-D echo correlated well with MVA by 2-D echo (r = 0.93, mean difference, 0.09 ± 0.14 cm2) and by PHT (r = 0.87, mean difference, 0.16 ± 0.19 cm2). Interobserver variability was significantly less for 3-D echo than for 2-D echo (SD 0.08cm2 versus SD 0.23cm2, p < 0.001). Furthermore, it was much easier and faster to define the image plane with the smallest orifice area when 3-D echo was used.CONCLUSIONSTransthoracic real-time volumetric 3-D echo provides accurate and highly reproducible measurements of mitral valve area and can easily be performed from an apical approach.

Validation of the ejection fraction-velocity ratio: a new simplified “function-corrected” index for assessing aortic stenosis severity

A new echocardiographic method for the evaluation of aortic stenosis (AS) severity has recently been introduced: the fractional shortening-velocity ratio (FSVR = fractional shortening/4 Vmax2). An important advantage of the method is the possibility of avoiding the difficulties related to the measurement of left ventricular outflow tract in calcific AS for assessing the continuity equation. FSVR, however, also shows some significant limitations especially in patients with regional wall motion abnormalities and conduction defects. To overcome this problem, we developed a new index: the ejection fraction-velocity ratio (EFVR = ejection fraction/4 Vmax2), where percent ejection fraction and Vmax have been obtained with an apical echocardiographic approach. In 343 consecutive patients with AS, aortic valve area was measured by cardiac catheterization (Gorlin), whereas FSVR and EFVR were calculated by echo-Doppler examination performed within 24 hours. Mean valve area was 0.70 ± 0.30 cm2, mean EFVR was 0.78 ± 0.41, and mean FSVR was 0.45 ± 0.26. The linear correlation area-EFVR was highly significant (r = 0.88). Correlation valve area-FSVR was also significant (r = 0.82). EFVR allowed identification of patients with severe AS (area ≤0.8 cm2) with good sensitivity (88%) and specificity (85%), whereas FSVR demonstrated sensitivity of 88% and specificity of 73%. Thus, the EFVR, a very simple and not time-consuming index, is strongly related to aortic valve area in patients with AS. It allows identification of patients with severe AS with good sensitivity and specificity (better than FSVR). The EFVR, taking into consideration both ejection fraction and transvalvular pressure gradient, may be very useful in the evaluation of patients with AS and left ventricular dysfunction.

Aortic regurgitant flow by color Doppler measurement of the local velocity 7 mm above the leak orifice--Part 1: in vitro measurements.

The flow convergence method enables the determination of flow across restrictive orifices. It was validated for planar orifice plates and atrioventricular valves. However, its quantitative application to aortic regurgitation is complicated due to the complex valve anatomy which distorts the converging flow field. An open angle formed by the leaflets causes relatively lower velocities in the region near the orifice, resulting in underestimation of flow. Confinement of the flow convergence region by the ascending aorta relatively increases the velocities at greater distance to the orifice and can cause overestimation of flow. We hypothesized that there is a region at intermediate distance to the orifice, where both these effects on the flow field are minimal, so that the local velocity there is only a function of flow. In a flow model, aortic regurgitation was simulated. The flow convergence was imaged by color Doppler. Different scanning directions were used (analogue to apical and parasternal approach). Velocity profiles across the flow convergence were read along the line from the scanhead to the orifice. At a distance of 7 mm to the orifice, a uniform value was found for the ratio of local velocity v(7 mm)/flow (=0.28 cm(-2)). Variations in size (3.5 to 7 mm), site (central versus lateral) and leaflet angle (planar versus inverted funnel) of the orifice and in the scanning approach had only a minimal effect on this value. The aortic regurgitant flow convergence is characterized by a relatively uniform V (7 mm)/Q. Independent of variations in the anatomy and the scanning approach, this value directly reflects flow.

Application of pulsed-Doppler tissue imaging in patients with dual chamber pacing: the importance of conduction time and AV delay on regional left ventricular wall dynamics.

Pulsed-Doppler tissue imaging (pDTI) is able to measure myocardial wall velocities (systolic: S; early diastolic: E; late diastolic: A) and their timings. Relationships have been demonstrated between the pre-ejection period and indexes of left ventricular systolic function. This study was designed to examine with pDTI the effects of variations in atrioventricular delay (AVD) (100 ms, 150 ms, 200 ms) on myocardial dynamics and on their timings at the basal interventricular septum (IVS) from an apical approach and at the posterior wall (PW) from the parasternal view. These data were compared with stroke volume measurements recorded from the left ventricular outflow tract. Seventeen patients with dual chamber pacemakers (7 because of complete heart block, 10 with sick sinus syndrome and first-degree AV block) were studied; full atrial and ventricular capture was present at any AVD. These data were also compared with those obtained in 10 age-matched healthy volunteers with comparable heart rates. Optimal atrial contribution to left ventricular filling and, consequently, best systolic performance were achieved when AVD was programmed such that a mean interval of 77 ms was allowed between the end of the A wave and the beginning of the S wave, similar to what was measured in the healthy control group by pDTI. The noninvasive measurement of timings of the cardiac cycle by pDTI is helpful to determine the optimal AVD in individual patients.

Automated Assessment of Mitral Regurgitant Volume and Regurgitant Fraction by a Newly Developed Digital Color Doppler Velocity Profile Integration Method

Recent development of the automated cardiac flow measurement (ACFM) method has provided automated measurement of stroke volume and cardiac output by spatial and temporal integration of digital Doppler velocity profile data. The purpose of this study was to evaluate the clinical usefulness of the ACFM method using digital color Doppler velocity profile integration in the assessment of mitral regurgitant volume and regurgitant fraction from measurements of both aortic outflow and mitral inflow volumes. We calculated both aortic outflow and mitral inflow volumes from the apical approach with the ACFM and pulsed Doppler (PD) methods in 20 patients with isolated mitral regurgitation. Mitral regurgitant volume and regurgitant fraction were calculated by the following equation: mitral regurgitant volume = (mitral inflow volume) − (aortic outflow volume), % regurgitant fraction = (mitral regurgitant volume)/(mitral inflow volume) × 100. Mitral regurgitant volume and regurgitant fraction were compared with that determined by the PD method. Mitral regurgitant volume measurement by the ACFM method showed a good correlation with that measured by the PD method (r = 0.90, y = 0.77x + 11.6, SEE = 9.0 ml); the mean differences between PD and ACFM measurements was −1.7 ± 12.5 ml. Regurgitant fraction estimated by the ACFM method correlated well with that of the PD method (r = 0.92, y = 0.98x + 2.1, SEE = 8.8%). The mean difference for the measurement of regurgitant fraction between the PD and ACFM methods was 0.8 ± 6.6%. Total time required for mitral regurgitant volume calculation in 1 cardiac cycle by the ACFM method was significantly shorter than that of the PD method (126 ± 15 seconds vs 228 ± 36 seconds, p <0.01). In conclusion, the newly developed ACFM method is simple, quick, and accurate in the automated assessment of mitral regurgitant volume and regurgitant fraction.

Echocardiographic Assessment of Regional and Global Left Ventricular Function Wall-Motion Scoring in Parasternal and Apical Views Versus Apical Views Alone.

The aim of the study was to examine the value of echocardiographic wall-motion scoring in apical views as compared to a conventional combination of apical and parasternal views. In 50 consecutive patients referred to coronary arteriography for potential revascularization, echocardiographic digital image loops of the left ventricle (LV) were recorded in parasternal long- and short-axis views and in apical long-axis, two-, and four-chamber views. Eight of 16 standardized LV segments appear both in the apical and in the parasternal views (group 1 segments). The remaining eight segments are visualized in the apical views only (group 2). Using a cross-over design, two cardiologists independently performed regional wall-motion scoring based on apical views, respectively, based on the combination of parasternal and apical views. Using the conventional approach (parasternal and apical views) 98% of the total 800 segments were scored as compared to 95% when using the mere apical approach (P < 0.05); 94% of the 800 segments were scored from both approaches. The regional wall-motion score was identical in 76% of group 1 segments and in 77% of group 2 segments. It diverged, at most, one score in 94% of group 1 segments and in 91% of group 2 segments (P > 0.05). LV ejection fraction (EF) calculated on the basis of average wall-motion score exclusively assessed from the apex differed little from angiographic EF (mean difference 2.0%, 95% confidence limits +/- 6.6%). Intraobserver variability of wall-motion scores (n = 25 patients) was small and almost identical for the two cardiologists. Similarly, interobserver variability was small and identical for apical views and conventional views. We conclude that there is no substantial loss of information when echocardiographic evaluation of regional and global left ventricular function is performed solely from the apical approach.

Echocardiographic Detection of Left Ventricular Asynergy by Apical Rotational Transducer Approach in Ischemic Heart Disease

Echocardiographic Detection of Left Ventricular Asynergy by Apical Rotational Transducer Approach in Ischemic Heart Disease

Pericardiocentesis and drainage by a silicon rubber line without echocardiographic guidance. Experience in 55 consecutive patients.

Pericardiocentesis and drainage with a silicon rubber line were performed safely in 55 patients via the subxiphoid (80 times) or apical (1 time) approach at the bedside without echocardiographic guidance. The subxiphoid approach, which is close to the posterior of the sternum or the costal cartilage with a small acute-angle (15-30 degrees) to the parietal pericardium in front of the right ventricle, can avoid injuring the heart, liver and lungs. A line with sideholes near the distal end, which provides convenient drainage and has better histocompatibility, can be kept in place for a long period of time (1-82 days). It was also convenient to inject air, drugs or fluid through the line. There were no procedure-related serious complications or deaths. Emergency drainage with the Seldinger technique, especially for small to moderate effusions, is safe and simple.

Left ventricular apical approach for the surgical treatment of congenital mitral stenosis

From June 1987 to October 1991, 12 patients with congenital mitral valve stenosis underwent surgical correction. Their ages ranged from 2 to 74 months. Nine patients were less than 22 months of age. Five patients were in New York Heart Association functional class IV, and seven patients were in class III. In nine, parachute-type mitral stenosis was clearly definite. In three, a complex congenital valvular and subvalvular stenosis was found. Associated anomalies were present in every patient; five had undergone previous operations. Correction of the mitral stenosis was done through an apical left ventriculotomy. The removal of the mitral obstruction starts from below; the papillary muscle was split and the chordae were divided or fenestrated. The commissurotomies were performed from the ventricular aspect of the mitral valve. Associated anomalies were corrected simultaneously. The operative mortality rate was zero. There was one late death, which was unrelated to cardiovascular status. The echocardiographic serial postoperative studies (up to 52 months) showed no significant residual mitral stenosis and normal global and regional function of the left ventricle in all but one patient.

Dual wavelength spectrophotometry as a diagnostic test of the pulp chamber contents

The purpose of this in vitro study was to determine the feasibility of using dual wavelength spectrophotometry to identify teeth with pulp chambers that are either empty, filled with fixed pulp tissue, or filled with oxygenated blood. In phase I of the experiment, a human third molar was prepared so that its pulp space could be filled with oxygenated blood and later emptied. In phase II, the lower jaw of a beagle dog was removed and placed in formalin, thereby fixing the pulps of the teeth. The pulp of the right canine was removed via an apical approach, and attachments were placed in a similar position to those on the human tooth, to allow filling and emptying of the pulp space. Cavit was placed over the exposed fixed pulp in the left canine. Ten readings, which were separated by light source and detector removal and replacement, were taken of the right canine pulp space when it was empty or filled with oxygenated blood, or the left canine pulp space when it was filled with fixed tissue. Distinct and reproducible changes were measured for pulp spaces filled with air, tissue, or oxygenated blood. In phase III, simulated pulp testing on a dog tooth model was performed. Blood was introduced into the root canal space, the chamber was rinsed with water and replaced with air, according to a predetermined code. Spectrophotometer readings were recorded. The identification of pulpal contents was correctly determined in all 20 of the predetermined conditions. The findings indicate that continuous wave spectrophotometry may become a useful pulp testing method.

A new angled transducer for intraoperative epicardial echocardiography.

We tested a new angled transducer developed for intraoperative epicardial echocardiography in 42 patients. This small transducer, 70 x 20 x 15 mm in size, demonstrated superior operability and provided adequate two- or four-chamber imaging from the apical approach, which may lead to high-quality assessment with two-dimensional Doppler flow imaging.