Gerlinde Dahmen

Anterior chamber angle measurement with optical coherence tomography: Intraobserver and interobserver variability

PURPOSE: To assess intraobserver and interobserver variability of anterior segment optical coherence tomography (AS‐OCT) as an objective diagnostic tool to quantify the anterior chamber angle and opening width. SETTING: University Eye Clinic, Lübeck, Germany. METHODS: The anterior chamber angle and opening width were assessed in 18 eyes of 9 healthy volunteers by 2 observers. Intraobserver reproducibility was evaluated by calculating an intraclass correlation coefficient (ICC) in a mixed model. Each observer had a separate model using information from 5 scans. Interobserver variability was determined by Bland‐Altman analysis. The ICC was calculated in a mixed model using a residual maximum likelihood method. The results of 3 and 5 repeated scans were evaluated to indicate the change to 1 measurement application. RESULTS: The mean anterior chamber angle measurement was 35.9 degrees ± 5.7 (SD) for observer A and 36.2 ± 5.7 degrees for observer B. The ICC was 0.94 and 0.91, respectively. The mean opening width was 315 ± 62 μm for observer A and 317 ± 60 μm for observer B. The ICC was 0.97 and 0.93, respectively. Interobserver comparisons showed a mean difference between anterior chamber angle measurements of −0.27 ± 1.6 degrees, a limit of agreement (LOA) interval from −3.52 to 2.98 degrees, and an ICC estimate of 0.96. The mean difference in opening width measurements was 2.40 ± 12.40 μm, the LOA from −27.20 to 22.40 μm, and the estimated ICC 0.96. Using 1 instead of the mean of 5 measurements, the LOA range increased by 3.46 degrees for the anterior chamber angle and 30.0 μm for the opening width. CONCLUSION: Anterior chamber angle and opening width measurements by OCT showed low intraobserver and interobserver variability, indicating OCT is a valuable technique for quantitative assessment that provides reproducible measurements and objective documentation by different examiners.

Midterm Results of the Ross Procedure Preserving the Patient’s Aortic Root

Background—Since the early 1990s, the pulmonary autograft is predominantly implanted as a freestanding root for less aortic valve regurgitation is reported. However, there is a certain risk of dilatation of the root over time potentially impairing valve function. We favor since 8 years the original subcoronary or inclusion technique to preserve the root of the patient as a restrain to dilatation. Methods and Results—Between June 1994 and May 2002 the subcoronary (n=228) and inclusion technique (n=17) were performed in 245 patients (191 male, 54 female), mean age 45.7±13.4 (15–70) years. The underlying aortic valve disease was an aortic insufficiency in n=83, stenosis in n=48, a combined aortic valve disease in n=111 and an acute endocarditis in n=19 patients. Previous aortic valve surgery was performed in n=23. Last follow-up investigations (within last year) including echocardiography was performed at a mean follow-up of 29.4±24.7 months (553.7 patient years). Hospital mortality was n=2, late mortality n=4 (all noncardiac). Two patients were lost to follow-up (99% complete clinical follow-up). Reoperations were necessary in n=7 valves (autograft: endocarditis n=1, malpositioning n=1, leaflet prolapse n=1; homograft: stenosis n=2, insufficiency n=2). Autograft insufficiency (AI) was AI 0 in n=154, AI I n=66, AI II n=8. The maximum/mean pressure gradient across the autograft was 6.6±3.4 (2.1 to 25.9)/3.6±1.8 (1.2 to 13.2) mm Hg, respectively. Homograft insufficiency was 0 in n=167, I in n=54, II in n=9, and III in n=1. Maximum and mean transhomograft pressure gradients were 11.7±6.8 (2.2 to 42.6)/6.2±3.8 (1.2 to 24.5) mm Hg. Most patients were NYHA class I (n=214), class II (n=19), class III (n=2). Significant aortic root dilatation was not observed. Conclusions—Aortic valve replacement with a pulmonary autograft in the subcoronary or inclusion technique provides excellent hemodynamics with no root dilatation at least in a mid term postoperative period. Transhomograft pressure gradients are slightly increased. Longer term results with special emphasis on the pulmonary homograft are necessary.

Echocardiographic and hemodynamic characteristics of reconstructed bicuspid aortic valves at rest and exercise

Die operative Korrektur erkrankter bikuspider Aortenklappen als Alternative zum herkömmlichen Aortenklappenersatz gewinnt zunehmendes Interesse. Ziel der vorliegenden Studie ist die Untersuchung der Klinik und Hämodynamik von Patienten nach Rekonstruktion ihrer erkrankten bikuspiden Aortenklappe in Ruhe und insbesondere unter—bislang nicht beschriebenen—Belastungsbedingungen. Zwischen März 1994 und September 2002 wurde eine Rekonstruktion insuffizienter bikuspider Aortenklappen bei 25 Patienten durchgeführt (mittleres Alter 35±12,1 Jahre, Gruppe A, präoperativer mittlerer Insuffizienzgrad 2,8). Die Patienten wurden klinisch und echokardiographisch nach 2,1±2,4 (0,1–8,9) Jahren in Ruhe und unter Belastung untersucht und mit 20 gesunden altersentsprechenden Probanden verglichen (Gruppe B). Es traten keine Todesfälle, Nachoperationen, thromboembolische oder Blutungskomplikationen auf. Zum Zeitpunkt der Nachuntersuchung waren 21 Patienten in der NYHA-Klasse I, 4 Patienten in der NYHA-Klasse II; der mittlere Grad der Aortenklappeninsuffizienz betrug 1,0, wobei ein Patient eine Insuffizienz >II° hatte. Der maximale und mittlere Druckgradient (dPmax/mean) über die Aortenklappe betrug 14±5,5/ 7±2,6 mmHg (Gruppe A) gegenüber 7±2,5/3,6±1,1 mmHg (Gruppe B). Die Aortenklappenöffnungsfläche lag im Mittel bei 2,6±0,8 (Gruppe A) und 2,9±0,6 cm2 (Gruppe B, p=0,025), der Aortenklappenwiderstand bei 13,4±4,8 (Gruppe A) vs. 13,6±2,9 dyn• s • cm–5 (Gruppe B, p>0,05). Alle Personen wurden ergometrisch bis 100 W belastet (dPmax/mean 21±6,8/11±3,6, Gruppe A vs. 11±2,9/6±1,3 mmHg (Gruppe B, p<0,01). 56% der Patienten der Gruppe A und 85% der Individuen der Gruppe B konnten bis 175 W belastet werden (dPmax/mean 24,5±8,3/12±4,2 bzw. 16±3,6/8±1,4 mmHg, p<0,01). Herzfrequenz- und Blutdruckverhalten waren vergleichbar zwischen den Gruppen. In der Gruppe A war die linksventrikuläre Massenregression postoperativ (369,3±76,4 g) im Vergleich zu präoperativ (277,3±80,7 g) signifikant (p<0,01), erreichte jedoch keine Normalwerte (Gruppe B: 227,8±71,1 g; p<0,01). Die Rekonstruktion der bikuspiden Aortenklappe reduziert die linksventrikuläre Volumenbelastung signifikant. Trotz einer rückständigen geringen subklinischen Obstruktion und Regurgitation nach Rekonstruktion ist das hämodynamische Verhalten der bikuspiden Aortenklappe unter Belastungsbedingen mit der nativen Aortenklappe vergleichbar. Die klinische Relevanz dieser Untersuchungsergebnisse muss in Langzeitstudien weiter evaluiert werden. Repair of diseased bicuspid aortic valves has gained increasing interest as an alternative to conventional valve replacement. Hemodynamic data at exercise have not been reported before. The aim of this study was to investigate the clinical and echocardiographic status of patients after bicuspid aortic valve repair at rest and exercise. Between 03/94 and 09/02 a reconstruction of an incompetent bicuspid aortic valve was performed in 25 patients (mean age 35±12.1 years, group A, mean insufficiency 2.8 preoperatively). Patients were investigated clinically and echocardiographically after 2.1±2.4 (0.1–8.9) years at rest and exercise and compared to 20 controls (group B). Clinical followup was complete. There were no deaths, reoperations, thromboembolic or bleeding complications. At last examination 21 patients were in NYHA class I, n=4 in NYHA class II and mean aortic valve insufficiency (AI) was 1.0 with one patient having an AI>II°. Maximum and mean pressure gradient (dPmax/mean) across the aortic valve at rest were 14±5.5/7±2.6 mmHg for patients of group A and 7±2.5/3.6±1.1 mmHg in group B. Mean AVA at rest was 2.6±0.8 (group A) vs 2.9±0.6 cm2 (group B, p=0.025), valvular resistance 13.4±4.8 (group A) vs 13.6±2.9 dyn• s •cm–5 (group B, p>0.05). All individuals were stressed up to 100 W (dPmax/mean 21±6.8/11±3.6, group A vs 11±2.9/6±1.3 mmHg, group B). 56% of group A and 85% of group B could be stressed up to 175 W with dPmax/mean 24.5±8.3/12±4.2 and 16±3.6/8±1.4 mmHg, respectively (p<0. 01). Heart rate and blood pressure behavior were comparable. Left ventricular mass regression (preoperatively 369.3±76.4 vs 277.3±80.7 g at last examination, p<0.01) was significant in group A but did not reach normal values (group B, 227.8±71.1; p<0.01). Bicuspid aortic valve reconstruction reduces left ventricular volume load significantly. Although residual mild subclinical obstruction and incompetence were observed, the behavior of hemodynamics at exercise was comparable to controls. The clinical relevance of these findings in long term follow-up has to be evaluated.