• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.513-519
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• 2021

Metallic suture anchors are very useful and common fixation devices that are inserted into the target bone to sustain the tendon of a patient with musculus supraspinatus tendon ruptures. On the other hand, the presence of a metallic material prosthesis, such as a metal suture anchor, causes severe MR imaging artifacts, including field distortion, signal loss, and failure of fat suppression. The difference in magnetic susceptibility between metal and other organic materials causes magnetic field distortion surrounding the prosthesis. The resulting magnetic field inhomogeneity makes the images with a lower signal-to-noise ratio and distortion. For a patient with a suture anchor implanted, MR imaging is the golden standard for determining the postoperative prognosis, and a fat-saturation sequence is one of the imaging methods most affected by metal-induced artifacts. In this study, three fat-saturation sequences were compared. Artifact quantification and contrast comparison between the supraspinatus tendon and the surrounding muscle were presented. The images obtained using the STIR pulse sequence showed fewer susceptibility artifacts and better visibility in the supraspinatus tendon and the tissue area. Therefore, the STIR sequence is the most appropriate fat-saturation imaging method for patients with a metallic prosthesis.

• The Journal of the Korean bone and joint tumor society
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• v.14 no.2
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• pp.140-145
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• 2008

After limb salvage operation becomes popular, reconstruction method of epi-metaphyseal osteosarcoma is relatively standardized though it may be operator's matter of preference. Most limb salvage techniques presently used are prosthesis reconstruction and osteoarticular allograft. In the case of prosthesis, it is very stable and shows good postoperative functional score, however, finally, it has a weak point of requirement for removal procedure due to failure. In the long run, allograft reconstruction has a good merit. But, it has a weak point of difficulties in securing the demanded size and shape. Allograft reconstruction should be performed only in the case of safe margin and established indication. In limb salvage operation, intercalary reconstruction is useful method in diaphyseal osteosarcoma, however, in metaphyseal osteosarcoma, the indication is not confirmed. We treated 17 year old osteosarcoma patient with localized in the tibial medial condyle with proximal medial condylectomy and pasteurized bone reconstruction in the conviction of safe surgical margin. We report this case because we guess if this procedure may be applied to premature patients, despite failure hemiarthroplasty can be tried successfully.

• Journal of Chest Surgery
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• v.31 no.3
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• pp.242-246
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• 1998

From January 1988 to December 1995, 27 patients, 11 men and 16 women, underwent surgical intervention at our institution for prosthetic valve dysfunctions. The mean age was 43.5$\pm$12.2 years. Seventeen(63.0%) patients had the mitral valve replacement, 8(29.6%) the aortic valve, 1(3.7%) the aortic composite graft, and 1(3.7%) the tricuspid valve. Mean follow-up period was 49.5$\pm$30.9 months. In 12 bioprostheses, mean interval between the previous valve replacement and the reoperation was 104.9$\pm$34.9 months. The causes of redo surgery were structural deterioration of the prosthetic valve (12/12, 100%), paravalvular leak (2/12, 16.7%), and prosthetic valve endocarditis(1/12, 8.3%). In 15 mechanical prostheses, the mean interval was 55.2$\pm$43.7 months. The causes of redo surgery were pannus formation (8/15, 53.3%), paravalvular leak(4/15, 26.7%), and valve thrombosis(3/15, 20.0%). Posto- perative complications occurred in 7 patients (25.9%). There was no intraoperative death. But one patient, who received mechanical aortic valve replacement died on the 3rd postoperative day due to low cardiac output and multiorgan failure.

• Journal of Chest Surgery
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• v.29 no.10
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• pp.1111-1117
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• 1996

Structural deterioration of the bioprosthetic xenograft valves due to primary tissue failure occurs in two modes: from fatigue lesions with tear and wear with or without calcification and from calcification with obstruction. Two groups of consecutive 56 patients with the Hancock porcine ortic valve(HM) and of 1 13 patients with the standard-profile onescu-Shiley bovine pericardial valve(ISM) explanted from mitral position at the time of re-replacement surgery for primary tissue failure at Seoul national University Hospital until 1994, were studied for clinical and pathological features. Their ages at primary implant were 31.9 $\pm$9.2 years In HM and 30.4$\pm$ 12.5 years in ISM. Hemodrnamic dysfunction of the failed mitral bloprostheses were predominantly insufficiency in HM(64.3%) and stenosis in ISM(51.3%)(p<0.001). Pathologic findings of the explanted mitral valves reflected these hemodynamic changes, revealing failure more often from tissue damage(tears and wears) in HM and more often from calcification in ISM(p< 0.001). Explant period(from primary implant to explant) was relatively short in ISM(8.7$\pm$2.6years), compared with the one in HM(10.4 $\pm$2.6 years)(p<0.001). In conclusion, both the Hancock and the lonescu-shiley valves would fail from calcification as well as issue damage. However, while the Hancock porcine valves in mitral position failed more frequently from tissue failure and insufficiency, the standard-profile lonescu-Shiley pericardial valves did from calcification and stenosis, especially in young pAtients . Although the possibility of less occurrence of valve failure from mechanical reasons may be expected with newer generation bloprostheses, it does not seem to Improve durability significantly unless further refinement in antimineralization is achieved. Therefore, clinical use of the glutaraldehyde-treated bioprosthetic valves is, at present, limited to the patients of advanced age groups.

• Journal of Chest Surgery
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• v.28 no.9
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• pp.822-828
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• 1995

This paper reports 15 native valve endocarditis cases had surgical operation in the past 10 years at the department of Cardiovascular and Thoracic Surgery, Chonbuk National University Hospital. In this study, 10 cases out of 15 were in class I or II by the New York Heart Association functional classification. None of the cases had a history of taking addictive drugs. Five cases were congenital heart disease, three cases were rheumatic heart disease and two cases were degenerative heart disease. Thus 10 cases had the underlying disease. All cases had antibiotics treatment for 3 to 6 weeks before operation. In the culture test, only four cases were positive in the blood culture and one case was positive in the excised valve culture. Organisms on blood and valve culture were Streptococcus epidermis, Streptococcus viridans, Staphylococcus aureus and Staphylococcus epidermidis. In the 10 cases without ventricular septal defect, the aortic valve was involved in four, mitral in four, both in two and involved valves in the 5 cases with ventricular septal defect were tricuspid in three, pulmonic in two. Eight cases had operation because they showed moderate congestive heart failure due to valvular insufficiency and vegetation with or without embolism. Seven cases had operation because they showed persistent or progressive congestive heart failure and/or uncontrolled infection. Five cases with ventricular septal defect underwent the closure of ventricular septal defect, vegetectomy and leaflet excision of the affected valves without valve replacement. In the cases without ventricular septal defect, the affected valves were replaced with St. Jude mechanical prosthesis. Postoperative complications were recurrent endocarditis in two, embolism in one, allergic vasculitis in two, spleen rupture in one and postpericardiotomy syndrome in one. At the first postoperative day, one case died of cerebral embolism. At the 11th postoperative month, one case died of recurrent endocarditis and paravalvular leakage in spite of a couple of aortic valve replacement. In the survived cases[13 cases in this study , all cases but one became class I or II by the New York Heart Association functional classification.

• Journal of Chest Surgery
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• v.28 no.1
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• pp.23-30
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• 1995

From January 1985 to December 1992, of 1257 patients who underwent a heart valve replacement 210 [16.8% underwent reoperation on prosthetic heart valves, and 6 of them had a second valve reoperation. The indications for reoperation were structural deterioration [176 cases, 81.5% , prosthetic valve endocarditis [25 cases, 11.6% , paravalvular leak [12 cases, 5.6% , valve thrombosis [2 cases, 0.9% and ascending aortic aneurysm [1 case, 0.4% . Prosthetic valve failure developed most frequently in mitral position [57.9% and prosthetic valve endocarditis and paravalvular leak developed significantly in the aortic valve [40%, 75% [P<0.02 . Mean intervals between the primary valve operation and reoperation were 105.3$\pm$28.4 months in the case of prosthetic valve failure, 61.5$\pm$38.5 months in prosthetic valve endocarditis, 26.8$\pm$31.2 months in paravalvualr leak, and 25.0$\pm$7.0 months in valve thrombosis. In bioprostheses, the intervals were in 102.0$\pm$23.9 months in the aortic valve, and 103.6$\pm$30.8 months in the mitral valve. The overall hospital mortality rate was 7.9% [17/26 : 15% in aortic valve reoperation [6/40 , 6.5% in reoperation on the mitral prostheses [9/135 and 5.7% in multiple valve replacement [2.35 . Low cardiac output syndrome was the most common cause of death [70.6% . Advanced New York Heart Association class [P=0.00298 , explant period [P=0.0031 , aortic cross-clamp time [P=0.0070 , prosthetic valve endocarditis [P=0.0101 , paravalvularr leak [P=0.0096 , and second reoperation [P=0.00036 were the independent risk factors, but age, sex, valve position and multiple valve replacement did not have any influence on operative mortality. Mean follow up period was 38.6$\pm$24.5 months and total patient follow up period was 633.3 patient year. Actuarial survival at 8 year was 97.3$\pm$3.0% and 5 year event-free survival was 80.0$\pm$13.7%. The surgical risk of reoperation on heart valve prostheses in the advanced NYHA class patients is higher, so reoperation before severe hemodynamic impairment occurs is recommended.

• Journal of Dental Anesthesia and Pain Medicine
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• v.17 no.3
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• pp.205-213
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• 2017

Background: This study retrospectively investigated outcomes following dental implantation in patients with special needs who required general anesthesia to enable treatment. Method: Patients underwent implant treatment under general anesthesia at the Clinic for the Disabled in Seoul National University Dental Hospital between January 2004 and June 2017. The study analyzed medical records and radiographs. Implant survival rates were calculated by applying criteria for success or failure. Results: Of 19 patients in the study, 8 were males and 11 were females, with a mean age of 32.9 years. The patients included 11 with mental retardation, 3 with autism, 2 with cerebral palsy, 2 with schizophrenia, and 1 with a brain disorder; 2 patients also had seizure disorders. All were incapable of oral self-care due to serious cognitive impairment and could not cooperate with normal dental treatment. A total of 27 rounds of general anesthesia and 1 round of intravenous sedation were performed for implant surgery. Implant placement was performed in 3 patients whose prosthesis records could not be found, while 3 other patients had less than 1 year of follow-up after prosthetic treatment. When the criteria for implant success or failure were applied in 13 remaining patients, 3 implant failures occurred in 59 total treatments. The cumulative survival rate of implants over an average of 43.3 months (15-116 months) was 94.9%. Conclusion: For patients with severe cognitive impairment who are incapable of oral self-care, implant treatment under general anesthesia showed a favorable prognosis.

• Journal of Periodontal and Implant Science
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• v.44 no.3
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• pp.102-108
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• 2014

Purpose: Rehabilitation of the incomplete dentition by means of osseointegrated dental implants represents a highly predictable and widespread therapy; however, little is known about potential risk factors that may impair long-term implant success. Methods: From 2004 to 2012, a total of 13,147 implants were placed in 4,316 patients at the Academy for Oral Implantology in Vienna. The survival rates after 8 years of follow-up were computed using the Kaplan-Meier method, and the impact of patient- and implant-related risk factors was assessed. Results: Overall implant survival was 97% and was not associated with implant length (P=0.930), implant diameter (P=0.704), jaw location (P=0.545), implant position (P=0.450), local bone quality (P=0.398), previous bone augmentation surgery (P=0.617), or patient-related factors including osteoporosis (P=0.661), age (P=0.575), or diabetes mellitus (P=0.928). However, smoking increased the risk of implant failure by 3 folds (P<0.001) and a positive history of periodontal disease doubled the failure risk (P=0.001). Conclusions: Summing up the long-term results of well over 10,000 implants at the Academy for Oral Implantology in Vienna it can be concluded that there is only a limited number of patients that do not qualify for implant therapy and may thus not benefit from improved quality of life associated with fixed implant-retained prostheses.

• Journal of Chest Surgery
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• v.19 no.1
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• pp.58-67
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• 1986

Aggressive revascularization of the ischemic lower extremities in atherosclerotic, occlusive diseases or acute embolic arterial occlusion due to cardiac valvular disease by thromboembolectomy or an arterial bypass operation has been advocated by some authors. We have performed 68 first time vascular operations, including thromboembolectomies on RR patients with ischemic lower extremities, within an 11-year-and-6-month period, from January 1974 to June 1984. We have reviewed and analyzed our vascular operative procedures and post operative results. The patients upon whom thromboembolectomies were performed were 42 males and 13 females ranging from 5 to 72 years of age. The major arterial occlusive sites were common iliac artery in 20 cases, femoral artery in 21 cases, popliteal artery in 8 cases, common iliac artery and femoral artery in 4 cases, and femoral artery and popliteal artery in 3 cases. The underlying causes of arterial occlusive disease were atherosclerosis obliterans in 34 cases; Buerger`s disease in 3 cases; emboli due to cardiac valvular disease in 13 cases; and vascular trauma in 4 cases, including cardiac catheterization in I of those cases. Arterial bypass operations with autogenous or artificial vascular prosthesis were done in 31 cases. Amputations were done on 2 patients carrying out any more vascular operative procedures would have been of no benefit to them. Our bypass operations for ischemic lower extremities were classified as follows: those done between the abdominal aorta and the femoral artery in 17 cases, including those done between the aorta and the bifemoral arteries with a Y graft in four of those cases and long ones done from the axillary to the femoral artery in 4 cases. Five patients died in the hospital following vascular surgery for ischemic lower extremities, the causes of death were not directly related to the vascular reconstructive operative procedures. The leading causes of death were respiratory failure due to metastatic lung carcinoma: renal failure due to complications from atherosclerosis obliterans; sepsis from open, contaminated fractures of the tibia and fibula; and myocardial failures due to open heart surgery in one case and reconstructive surgery of the ascending aorta in another.

• The Journal of Advanced Prosthodontics
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• v.15 no.2
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• pp.63-71
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• 2023

PURPOSE. The aim of this study was to assess the effect of hemispherical dimple structures on the retention of cobalt-chromium (Co-Cr) crowns cemented to titanium abutments, with different heights and numbers of dimples on the axial walls. MATERIALS AND METHODS. 3.0-mm and 6.0-mm abutments (N = 180) and Co-Cr crowns were prepared. The experimental groups were divided into two and four dimple groups. The crowns were cemented by TempBond and PANAVIA F 2.0 cements. The retention forces were measured after thermal treatments. A two-way Analysis of Variance (ANOVA) and post-hoc Tukey HSD test were conducted to analyze change in retention forces by use of dimples between groups, as well as t test for the effect of abutment height change (α = .05). RESULTS. Results of the two-way ANOVA showed a statistically significant difference in retention force due to the use of dimples, regardless of the types of cements used (P < .001). A significantly higher mean retention forces were observed in the groups with dimples than in the control group, using the post hoc Tukey HSD test (P < .001). Results of t test displayed a statistically significant increase in the retention force with 6.0-mm abutments compared with 3.0-mm abutments (P < .001). The groups without dimples revealed adhesive failure of cements, while the groups with dimples showed mixed failure of cements. CONCLUSION. Use of hemispherical dimples was effective for increasing retention forces of cemented crowns.