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Hyuk Ahn

Publications and source records attributed to Hyuk Ahn.

8 recordsLinked to original sources
PubMed2005

Impact of the maze operation combined with left-sided valve surgery on the change in tricuspid regurgitation over time.

BACKGROUND: Atrial fibrillation (AF) has been reported to be a predisposing factor for the progression of TR in patients with previous mitral or combined mitral/aortic valve surgery. We hypothesized that the maze operation (MAZE) can prevent the progression of tricuspid regurgitation (TR) in these patients. METHODS AND RESULTS: We analyzed 170 patients (age, 45.5+/-10.9 years) who had undergone mitral or combined mitral/aortic valve surgery. On the basis of preoperative rhythm, patients were divided into 3 groups; GrI was composed of 44 patients with sinus rhythm, GrII of 48 who had undergone MAZE, and GrIII of 78 with AF who had not undergone MAZE. Echocardiographic examinations were performed before, immediately after, and 92.2+/-17.2 (range, 50 to 131) months after surgery. Preoperative and immediate postoperative clinical and echocardiographic parameters were similar among the groups. Insignificant TR at the immediate postoperative examination worsened with time in 7.3% of GrI (3 of 41), 12.8% of GrII (6 of 47), and 38.8% of GrIII (26 of 67) patients at the final examination (P=0.63 for GrI versus GrII, P=0.001 for GrI versus GrIII, P=0.005 for GrII versus GrIII). The incidence of significant TR at the final echocardiographic examination was higher in GrIII (39.7%) compared with GrI (9.1%) and GrII (14.6%) (P=0.001 for GrI versus GrIII, P=0.005 for GrII versus GrIII), whereas GrI and GrII did not show any difference (P=0.63). By multivariate analysis, the only factor identified to prevent TR progression was the group factor (GrI and GrII versus GrIII, P=0.002 and P=0.005, respectively). In a subgroup analysis of GrII according to the presence or absence of atrial mechanical activity, the absence of atrial mechanical activity was identified as an independent parameter for the progression of TR (P=0.001). CONCLUSIONS: AF predisposes patients undergoing mitral valve surgery to the progression of TR, which can be prevented by MAZE. This additional benefit of MAZE is largely dependent on the restoration and maintenance of atrial mechanical function.

Adolescent↗
PubMed2005

Long-term result of 1144 CarboMedics mechanical valve implantations.

BACKGROUND: It has been reported that the CarboMedics mechanical valve has acceptable valve-related complication rates. The aim of this study was to evaluate the long-term performance of the CarboMedics valve. METHODS: Between August 1988 and September 1999, we implanted 1144 CarboMedics valves in 850 patients (aortic, 179; mitral, 385; double-valve, 234; tricuspid, 52). Mean patient age was 44.5 +/- 12.5 years. Follow-up was completed in 95.3% and the median follow-up period was 7.9 years (6753 patient-years). Patients were divided into four groups according to implanted valve location and number (aortic, mitral, double, and tricuspid valve groups). RESULTS: The overall hospital mortality rate was 3.4%, and the mortality rates in these groups were 1.7% in the aortic, 2.6% in the mitral, 4.7% in the double, and 9.6% in the tricuspid valve. The tricuspid valve group revealed a significantly higher mortality rate than the aortic and mitral valve groups (p < 0.05). Overall 10-year survival was 87.1% +/- 2.6%, 88.9% +/- 1.7%, 82.4% +/- 2.9%, and 77.5% +/- 7.0% in the aortic, mitral, double, and tricuspid valve groups, respectively. Age and tricuspid valve replacement were identified as significant risk factors of long-term survival by multivariate analysis (p < 0.05), and 99.4% +/- 0.6%, 98.2% +/- 0.8%, 99.2% +/- 0.8%, and 87.6% +/- 0.5% in the aortic, mitral, double, and tricuspid valve groups were free of valve thrombosis at 10 years. The tricuspid valve group demonstrated a significantly higher rate of valve thrombosis (p < 0.05). CONCLUSIONS: This long-term study of patients that received CarboMedics valve implantation demonstrates that the CarboMedics prosthetic valve has an acceptable incidence of valve-related complications. However, it should be noted that tricuspid valve replacement indicated a higher level of overall mortality and valve thrombosis.

Adult↗
PubMed2003

Ascending aorta-abdominal aorta bypass for Takayasu's arteritis.

Three patients with type III Takayasu's arteritis were referred to us because of the upper extremity hypertension and vascular claudication of the lower extremities. They underwent extra-anatomic ascending aorta-abdominal aorta bypass with vascular graft under a median sternotomy and a splitted midline laparotomy incision without cardiopulmonary bypass. The postoperative course was uneventful. Upper extremity hypertension and vascular claudication were completely resolved.

Aorta↗
PubMed2002

Successful treatment in a patient with Takayasu's arteritis and Marfan syndrome.

We report an unusual case of concomitant Takayasu's arteritis and Marfan syndrome manifesting left main coronary ostial obstruction and annuloaortic ectasia. Simultaneous surgical treatment consisting of left coronary ostium endarterectomy, coronary artery bypass grafting, and Bentall operation was performed. This case is unique in that the cardiovascular manifestations of Takayasu's arteritis and Marfan syndrome were both simultaneously presented and surgically treated.

Adult↗
PubMed2002

Midterm result of leaflet extension technique in aortic regurgitation.

OBJECTIVES: Aortic valve leaflet extension using glutaraldehyde-fixed autopericardium in aortic regurgitation (AR) is technically demanding, and it is not a popular procedure among surgeons. This study evaluates the effectiveness and clinical feasibility of the leaflet extension technique as a treatment modality for AR. MATERIALS AND METHODS: From March 1995 to March 2001, 34 consecutive patients underwent the leaflet extension technique. The mean age of the 26 men and eight women was 31.0+/-14.3 years (range 16-68). They were all diagnosed with pure aortic valve regurgitation, and nine (27.3%) had associated mitral valvular heart diseases. Accurate measurement of the leaflet free margins was performed with a pair of compasses before leaflet extension. Glutaraldehyde-fixed autopericardium was designed according to the free margin lengths. Leaflet extension was performed in three aortic leaflets for 29 patients but only one leaflet was extended in the remaining four. The nine patients with associated mitral valvular heart disease also underwent mitral valvuloplasty. Mean cardiopulmonary bypass time and ischemic time in 25 isolated AR group were 128.7+/-26.5min (range 70--180) and 101.5+/-25.5min (range 41-150), respectively. RESULTS: There was no incidence of in-hospital mortality. Immediate postoperative echocardiography revealed grade II AR in one, grade I AR in ten and no AR in the remaining 23 patients. Mean follow-up duration was 49.6+/-18.8 months (range 4.1-77.1). Echocardiographic AR grades during follow-up were grade II in 13, grade I in 11 and no AR in eight. The remaining two patients underwent reoperation, one aortic valve replacement because of subacute bacterial endocarditis that occurred 7 months after leaflet extension, and the other Ross operation because of the dehiscence of the valvuloplasty suture site that developed 4 months later (AR associated with Behcet's disease). There was one case of mortality due to malignant mesothelioma 4 years after aortic valvuloplasty. The cumulative survival rate was 94.1% at 5 years. Freedom from reoperation was 93.8% at 1 year and after. CONCLUSIONS: The leaflet extension technique is an acceptable surgical treatment modality for AR and its clinical results were confirmed in this study to be very good. A careful long-term follow-up study will be necessary to evaluate the long-term durability of the glutaraldehyde-preserved autologous pericardium as a leaflet tissue.

Adult↗
PubMed2002

Factors affecting warfarin therapy following cardiac valve surgery.

OBJECTIVE: To determine the factors that affect the initial response to warfarin therapy in Korean patients after cardiac valve surgery. METHODS: A retrospective analysis of 127 patients who had undergone cardiac valve surgery at Seoul National University Hospital was performed. On the first day, most patients received warfarin 5 mg, while some received an individualized warfarin dose according to their physician's decision. Doses to be given on the following days were determined based on daily international normalized ratio (INR) and the previous doses. To measure warfarin sensitivity, the warfarin dose index (WDI), defined as the INR divided by the mean warfarin dose administered during the preceding 3 days, was introduced. The effects of age, gender, weight, serum albumin concentration, baseline INR, cardiopulmonary bypass time, and concurrent administration of amiodarone were evaluated. RESULTS: The patients' weight, initial serum albumin concentration, and baseline INR value influenced their initial response to warfarin. The initial WDI correlated negatively with the initial serum albumin concentration (p < 0.001) and body weight (p < 0.05) and positively with the baseline INR (p < 0.01). The initial WDI of the patients taking amiodarone was significantly higher (mean +/- SD 0.74 +/- 0.34) than that of patients without amiodarone (0.46 +/- 0.22) (p < 0.001). Maintenance doses correlated negatively with the initial warfarin response (p < 0.001) and positively with body weight (p = 0.053). CONCLUSIONS: The factors associated with an increased initial warfarin response in patients after cardiac valve surgery were high baseline INR, low postoperative serum albumin concentration, and concurrent administration of amiodarone. Thus, patients with any of these factors should receive a smaller initial warfarin dose. Also, to predict the warfarin maintenance dose from the initial response, the effect of transient changes in the sensitivity to warfarin during the initial period should be considered.

Adult↗