• Journal of Chest Surgery
• /
• v.49 no.4
• /
• pp.264-272
• /
• 2016

Background: We analyzed the long-term results of ascending aortic replacement and arch aortic replacement in acute DeBakey type I aortic dissections to measure the differences in the distal aortic changes with extension of the aortic replacement. Methods: We reviewed 142 cases of acute DeBakey type I aortic dissections (1996-2015). Seventy percent of the cases were ascending aortic replacements, and 3 0% of the cases underwent total arch aortic replacement, which includes the aorta from the root to the beginning of the descending aorta with the 3 arch branches. Fourteen percent (20 cases) resulted in surgical mortality and 86% of cases that survived had a mean follow-up period of $6.6{\pm}4.6years$. Among these cases, 64% of the patients were followed up with computed tomography (CT) angiograms with the duration of the final CT check period of $4.9{\pm}2.9years$. Results: There were 15 cases of reoperation in 13 patients. Of these 15 cases, 13 cases were in the ascending aortic replacement group and 2 cases were in the total arch aortic replacement group. Late mortality occurred in 13 cases; 10 cases were in the ascending aortic replacement group and 3 cases were in the total arch aortic replacement group. Eight patients died of a distal aortic problem in the ascending aortic replacement group, and 1 patient died of distal aortic rupture in the total arch aortic replacement group. The follow-up CT angiogram showed that 69.8% of the ascending aortic replacement group and 35.7% of the total arch aortic replacement group developed distal aortic dilatation (p=0.0022). Conclusion: The total arch aortic replacement procedure developed fewer distal remnant aortic problems from dilatation than the ascending aortic replacement procedure in acute type I aortic dissections.

• Journal of Chest Surgery
• /
• v.23 no.3
• /
• pp.488-500
• /
• 1990

Author compared the effect of surgical methods between 40 patients who received mitral valve replacement with complete excision of the mitral valve[resected group] and 41 patients who received mitral valve replacement with preservation of posterior chorda tendineae and posterior mitral leaflet[preserved group] from 1985. 2. to 1989. 4. at cardiothoracic department of Pusan National University Hospital.v 1. There was no significant difference between the preserved group and resected group in cardiopulmonary bypass time and aortic cross clamping time and NYHA classification. 2. In preserved group of Mitral stenosis and Mitral regurgitation, the left ventricular functions were much improved after mitral valve replacement than resected group, but there was not so difference between the preserved group and reserved group in Mitral steno-regurgitation. 3. There were remarkable decrease in complication rate in preserved group compared to resected group. And also the death rates were remarkably decreased in preserved group which was 4.9% compared to resected group which was 17.5%. As the preservation of the posterior mitral leaflet and chorda tendineae during mitral valve replacement in mitral valve disease showed significantly improved effects in the maintaining of left ventricular function and reducing the postoperative complication, I assume the preservation of posterior mitral leaflet and chordae during mitral valve replacement will bring better result.

• Journal of Chest Surgery
• /
• v.26 no.6
• /
• pp.457-462
• /
• 1993

We retrospectively studied 34 patients who underwent operations of ascending aortic aneurysm and aortic valve replacement from August 1979 to July 1992 at the Yonsei Cardiovascular Center. Eight patients underwent supracoroanry non-composite graft replacement and separate aortic valve replacement[group I]. Twenty six patients underwent valved composite graft replacement with reimplantation of coronary arteries[group II]. Two cases in group II died within 1 month after the operation. Among the 32 survivors 28 patients have been followed up for an average of 59 months ranging from 1 months to 159 months. During the follow up periods, a pseudoaneurysm around the ascending aorta and a newly developed dissecting aneurysm in remaining aorta were noted in group II. There were 6 late deaths: 2 cases in group I and 4 cases in group II. Three cases among the 6 late deaths have stigmata of Marfan`s syndrome[1 cases in group I and 2 case in group II]. There was no statistically significant difference in actuarial survival rates between group I and group II[p > 0.05]. This study suggests that non-composite supracoronary graft interposition with separate aortic valve replacement is a safe surgical technique in patients who have normal aortic annulus and normal position of coronary ostia. However in degenerative disease such as cystic medial necrosis, composite graft replacement is recommended because this procedure eliminates entire abnormal tissue.But it seems to be important that the suture technique and strict follow-up in patients with diseased aortic wall.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.9 no.2
• /
• pp.81-86
• /
• 2014

In this paper, a jointly optimal group replacement and spare provisioning policy is presented. Most maintenance policies assume that the spare inventory is always available, but in practice the maintenance schedule is affected by the availability of spare inventory. We present a maintenance-inventory model which jointly optimizes the group replacement interval and spare ordering quantity. Group replacement policy is used when a group of units are put in operation simultaneously. The operating fleet is replaced altogether at a predetermined number of units are failed. A sufficient level of spare inventory is carried to perform a number of group replacement. A cost rate expression which considers the group maintenance cost and inventory holding cost is derived and a heuristic method for searching the optimum value of decision variables is suggested. Numerical examples demonstrate the analytical results and the performance of the presented model.

• Korean Journal of Adult Nursing
• /
• v.18 no.2
• /
• pp.183-193
• /
• 2006

Purpose: The purpose of the study was to test the effects of music therapy on postoperative pain in patients with total hip replacement. Method: The research design was a nonequivalent control group pretest-posttest design. The subjects were composed of thirty patients with total hip replacement. Fifteen of them were assigned to the experimental group and fifteen to the control group. Fifteen minutes tailored music therapy was given to the experimental group during five consecutive days. The instruments used for this study were pain NRS(numerical rating scale). The data were analyzed using percent, mean, standard deviation, ${\chi}^2-test$ and repeated measure ANOVA using SPSS WIN 11.0. Results: Hypothesis 1 "The score of pain NRS of experimental group will be lower than those of control group" was accepted(F=15.945, p<.001). Hypothesis 2 "The frequency of PCA analgesics of experimental group will be fewer than those of control group" was accepted (t=-2.312, p=.028). Hypothesis 3 "The vital signs(pulse, systolic BP and diastolic BP) of experimental group will be different from those of control group" was rejected. Conclusion: This music therapy can be recommended as an efficient nursing intervention to reduce postoperative pain in patients with total hip replacement.

• The Journal of Korean Physical Therapy
• /
• v.25 no.6
• /
• pp.417-421
• /
• 2013

Purpose: This study was to identify the effect of cervical stabilization exercise on pain and structure in patients with cervical artificial disc replacement. Methods: Forty-four individuals with cervical artificial disc replacement volunteered to participate from FEB 2012 to MAR 2013 in this study. They were allocated to either Experimental Group (EG) or Control Group (CG), with 22 subjects in each group. Subjects from the EG performed cervical stabilization exercise program and subjects from the CG performed isometric exercise program. Assessment tools were made with the Visual Analogue Scale (VAS), Neck Disability Index (NDI), and Cervical Lordosis Angle (CLA). Results: In this study, in within-group and between-group comparison, the EG and CG showed significant differences in all parameters(p<0.05). But EG showed more improvement than CG at all parameters. Conclusion: These findings suggest that cervical stabilization exercise may be favorably used to improve VAS, NDI and CLA in patients with cervical artificial disc replacement. Further studies with larger sample and long-term follow-up period need to generalize the results of this study.

• Journal of Chest Surgery
• /
• v.18 no.3
• /
• pp.446-455
• /
• 1985

A total and consecutive 156 patients have undergone cardiac valve surgery including 13 closed mitral commissurotomy, 13 open mitral commissurotomy, one mitral annuloplasty, 75 mitral valve replacement, one aortic annuloplasty, 24 aortic valve replacement, 3 tricuspid valve replacement, 25 double valve replacement and one triple valve replacement. 155 prosthetic valves were replaced in a period between September 1976 and August 1985. There were 68 males and 88 females with age range from 8 to 69 yrs [mean 36.5 yr]. Out of replaced valves, 61 was tissue valve including 54 Carpentier-Edwards, and 4 was mechanical valves including 74 St. Jude Medical, and the position replaced was 101 valves for mitral, 46 for aortic and 8 for tricuspid. Single valve replacement in 102 cases, double valve replacement in 25 cases [17 for AVR+MVR, and 8 for MVR+TVR], and only one case was noted in the triple valve replacement. Early mortality within 30 days after operation was noted in 11 cases [7%]; 7 after MVR, 2 after DVR, and each one after open mitral commissurotomy and mitral annuloplasty. Cause of death was valve thrombus, cerebral air embolism, low output syndrome, uncontrollable arrhythmia, parapneumonic sepsis, acute cardiac tamponade and left atrial rupture. 7 late deaths were noted during the follow-up period from 1 to 104 months [average 48 month]; three due to valve and left atrial thrombus formation, two due to CVA from overdose of warfarin, and each one due to congestive heart failure and chronic constrictive pericarditis, Anticoagulants after prosthetic valve replacement were maintained with warfarin, dipyridamole and aspirin to the level of around 50% of normal prothrombin time in 79 cases, and Ticlopidine with aspirin in 47 cases to compare the result of each group. There were 11 major thromboembolic episodes including 3 deaths in the warfarin group. Two cases of CVA due to overdose of warfarin was noted in the warfarin group. In the ticlopidine group, there was only one left atrial thrombus confirmed at the time of autopsy. Among the survived 138 cases, nearly all cases[136 cases] were included in NYHA functional class I and II during the follow-up period. In conclusion, surgical treatment of the cardiac valve disease in 156 clinical cases revealed excellent result with acceptable operative risk and late mortality. Prevention of thrombus formation with anti-platelet aggregator Ticlopidine has better result than warfarin group presently with no specific side effect such as bleeding or gastrointestinal trouble.

• Journal of Chest Surgery
• /
• v.40 no.12
• /
• pp.817-824
• /
• 2007

Background: There are two choices for heart valve replacement-the use of a tissue valve and the use of a mechanical valve. Using a tissue valve, additional surgery will be problematic due to valve degeneration. If the risk of additional surgery could be reduced, the tissue valve could be more widely used. Therefore, we analyzed the risk factors and mortality of patients undergoing repeated heart valve replacement and primary replacement. Material and Method: We analyzed 25 consecutive patients who underwent repeated heart valve replacement and 158 patients who underwent primary heart valve replacement among 239 patients that underwent heart vale replacement in out hospital from January 1995 to December 2004. Result: There were no differences in age, sex, and preoperative ejection fraction between the repeated valve replacement group of patients and the primary valve replacement group of patients. In the repeated valve replacement group, the previously used artificial valves were 3 mechanical valves and 23 tissue valves. One of these cases had simultaneous replacement of the tricuspid and aortic valve with tissue valves. The mean duration after a previous operation was 92 months for the use of a mechanical valve and 160 months for the use of a tissue valve. The mean cardiopulmonary bypass time and aortic cross clamp time were 152 minutes and 108 minutes, respectively, for the repeated valve replacement group of patients and 130 minutes and 89 minutes, respectively, for the primary valve replacement group of patients. These results were statistically significant. The use of an intra aortic balloon pump (IABP) was required for 2 cases (8%) in the repeated valve replacement group of patients and 6 cases (3.8%) in the primary valve replacement group of patients. An operative death occurred in one case (4%) in the repeated valve replacement group of patients and occurred in nine cases (5.1%) in the primary valve replacement group of patients. Among postoperative complications, the need for mechanical ventilation over 48 hours was different between the two groups. The mean follow up period after surgery was $6.5{\pm}3.2$ years. The 5-year survival of patients in the repeated valve replacement group was 74% and the 5-year survival of patients in the primary valve replacement group was 95%. Conclusion: The risk was slightly increased, but there was little difference in mortality between the repeated and primary heart valve replacement group of patients. Therefore, it is necessary to reconsider the issue of avoiding the use of a tissue valve due to the risk of additional surgery, and it is encouraged to use the tissue valve selectively, which has several advantages over the use of a mechanical valve. In the case of a repeated replacement, however, the mortality rate was high for a patient whose preoperative status was not poor. A proper as sessment of cardiac function and patient status is required after the primary valve replacement. Subsequently, a secondary replacement could then be considered.

• Journal of Chest Surgery
• /
• v.20 no.1
• /
• pp.13-21
• /
• 1987

To clarify the difference between the outcome of warfarin anticoagulation and the antiplatelet [Aspirin, Dipyridamole] therapy after bioprosthetic heart valve replacement, we compared the following two groups. Group I [Warfarin group] consisted of 557 patients undergone lonescu - Shiley valve replacement between January, 1979 and December, 1985, and treated with scheduled warfarin therapy at Seoul National University Hospital. Group II [Antiplatelet group] consisted of 128 patients undergone lonescu - Shiley, Carpentier - Edwards or Wessex bioprosthetic valve replacement between March, 1983 and December, 1986, and treated primarily with antiplatelet therapy [Aspirin plus Dipyridamole] at SeJong General Hospital. The two groups were similar with respect to age, number of valves utilized per patient, type of operation and risk factors of thromboembolism. In group I, 522 patients excluding 35 hospital death [hospital mortality 6.3%], and in group II, 119 survivors excluding 9 hospital death [hospital mortality 7.0%] were followed. In group I, there were 13 fatal complications, of which seven were thromboembolic [0.6% / pt-yr] and six hemorrhagic [0.5%/pt-yr] during the period of four years. In group II, there were 3 fatal thromboembolic complications [2.3%/pt-yr] during the period of four years. This showed no statistically significant difference. Apart from fatal complications, there were lots of warfarin related minor complications in group I comparing with those of group II. The actuarial probability of the freedom from thromboembolism and of the freedom from fatal complications were very similar at each corresponding years postoperatively. As a result, warfarin anticoagulation in patients with bioprosthetic valve replacement did not reveal any significant advantages over antiplatelet therapy.

• Journal of the Korea Safety Management & Science
• /
• v.6 no.1
• /
• pp.61-70
• /
• 2004

In this paper, a group replacement policy based on a failure count is analysed. For a group of identical repairable units, a maintenance policy is performed with two phase considerations: a repair interval phase and a waiting interval phase. Each unit undergoes minimal repair at failure during the repair interval. Beyond the interval, no repair is made until a number of failures. The expected cost rate expressions under the policy is derived. A method to obtain the optimal values of decision variables are explored. Numerical examples are given to demonstrate the results.