• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.176-183
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• 2020

A ship has three types of diving systems (Diver Stage Diving, Wet Bell Diving and Scuba Diving) to carry out a search-and-rescue operation. To reduce the possibility of decompression sickness, any diving systems shall comply with the decompression procedure according to the decompression table corresponding to the diving depth and diving time. The decompression procedure is largely divided into two methods: underwater decompression and underwater-onboard decompression. In particular, the surface interval shall not exceed 5 minutes, which is the phase from underwater decompression to underwater-onboard decompression, in accordance with the U.S Navy Diving Manual. However, the surface interval is greater than 5 minutes as a result of using Wet Bell Diving. This paper describes the result of cause analysis and measurement with improved Wet Bell Diving. Using improved Wet Bell Diving reduced the surface interval to less than 5 minutes. The result of the research can be used for operation and improving the performance of diving systems.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.88-96
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• 2021

When oil tankers, large passenger ships and cargo ships sink under the sea owing to various maritime accidents, the residual cargo oil or fuel oil in the such vessels could pose direct risk to factor for the marine environment and it require safe and rapid removal. Although domestic and foreign salvage companies are adopting various recovery methods and technologies with customizations according to each site during recovery operations studies on reasonable assessment modules for the operation process are relatively insufficient. In this study, the data from trapped-oil recovery operations performed at different site conditions were collected and analyzed in order to designed an operation assessment module, define the operational process steps in terms of preparation, implementation and completion, and derive key factors for each detailed process. Subsequently, the module was designed in such a way as to construct performance indicators to assess these key factors. In order to exclude subjective opinions from the assessment as much as possible, the assessment each item was constructed with indicators based on data that could be evaluated quantitatively and its usefulness was verified by applying the module to the trapped-oil recovery operation cases. We expect this the method and the technology assessment module for the trapped-oil recovery operation on sunken vessels will help to verify the adequacy of the trapped-oil recovery such operation before or after. Furthermore, it is expected that the continuous accumulation of assessment data and feedback from past or future operation cases will contribute toward enhancing the overall safety, efficiency and field applicability of trapped-oil recovery operation.

• Korean Journal of Bronchoesophagology
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• v.6 no.2
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• pp.147-151
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• 2000

Background and Objectives： Metastasis to the submental and submandibular lymph nodes rarely occurs in squamous cell carcinoma of the larynx and hypopharynx. The aim of this study is to evaluate the effectiveness of level I neck dissection in squamous cell carcinoma of larynx and hypopharynx. Materials and Methods : Forty-three patients with pathologically positive cervical nodal involvement in squamous cell carcinoma of larynx and hypopharynx treated between 1989 to 1998 were reviewed. Fifteen patients were treated with neck dissection including level 1,28 patients were treated with neck dissection excluding the level 1. Results : The regional recurrence at the level I in patients treated with neck dissection excluding the level I, was shown in only one case (recurrence rate 3.6%), but this patient was efficiently managed with salvage operation and adjuvant radiotherapy. No recurrence was shown in patients treated with neck dissection including the level I. So, total recurrence rate at the level I was 2.3%. Conclusion : This study suggests that dissection of the level I is not justified in squamous cell carcinoma of larynx and hypopharynx even if metastasis to cervical lymph node was confirmed preoperatively (cN+).

• The Journal of the Korean bone and joint tumor society
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• v.3 no.1
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• pp.1-8
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• 1997

Osteosarcoma is the most common primary bony malignancy and its survivorship has been progressed markedly through refined chemotherapy and surgery. But still there are many non-responders and analysis of prognostic factors may be helpful for them. Two hundred and sixty-six patients were enlisted between Mar, 1985 and Sep. 1994. Among them our inclusion criteria were: 1)primary, nonmetastatic classical osteosarcoma 2)extremity in location 3)no prior treatment at other institute and completed neoadjuvant chemotherapy and surgery according to our protocol. One hundred and eleven cases were eligible. Analyzed factors were:age, sex, location, tumor size, and pathologic response. Statistical methods were log-rank test for univariate and Cox's test for multivariate analysis. Male to female ratio was 69:42 with an average age of 17.2 years. Locations of tumor were distal femur 59, proximal tibia 29, and proximal humerus 8. Tumor size were measured by its maximal diameter and 48 cases were above 10cm and 47 cases were below 10cm. For pathologic response, 57 cases showed more than 90% and 54 cases were less than that. Limb salvage procedure was 101 cases and amputation was 10 cases and their local recurrence rate were 3.6%. Average follow-up period was 24(9-78.2) months and their final status was CDF 86, AWD 8, NED 5, and DOD 12 cases. In univariate study: type of operation(p=0.005), tumor size(p=0.005), and pathologic response(p=0.02) were significant variables. Pathologic response(p=0.03) and type of operation(p=0.01) were meaningful prognostic factors on multivariate analysis. But the latter result was interpreted as a bias, so pathologic response remained as a sole meaningful prognostic factor. More aggressive chemotherapy will be needed to improve the survival.

• Journal of Chest Surgery
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• v.5 no.1
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• pp.19-24
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• 1972

The recent development of cardiovascular surgery as well as aortoarteriogaphy has been established excellent operative result with great aid of limb-salvage. However, less consideration or less experience still exists on the regard of vascular accident and vascular disease, as well as vascular surgery in Korea. During the last 13 years, we experienced only two cases of aorto-iliac occlusion,acute and chronic, regardless of having had more than 300 cases of mitral valvotomy and gradual increasing tendency of arteriosclerosis and hypertension in Korea. Therefore it is noteworthy to report the cases in order to promote the consideration for vascular surgery. Case 1; 52 year old female who had 20 years history of mitral stenosis with uricular fibrillation and received medical treatment for recent 1 year in the medical department. 10 days before admission, acute saddle emboli developed and 15 days after the onset, embolectomy through both common femoral arteries on the groin and abdominal approach was made. The progression of emboll to the right popliteal bifurcation was found by arteriography on operating table and retrograde flushing with heparin solution by the polyethylene catheter inserted through posterior tibial artery. The operation was successful, but 9 hours after operation sudden death occurred. Considering this case, first, mitral valvotomy already before might prevent peripheral embolizatlon, secondarily, the more early detection and surgery might also prevent the progression of emboli. Thirdly, although preoperative or postoperatlve heparinization is controversial for mitraI stenosis, heparinization might prevent additional emboli to vital organs in this case Cases 2; 66 year old female who had 4 years history of left hip and calf intermittent claudication and has had rest pain, inability to walk and ischemic necrosis on the the left leg since last 3 months prior to admission to the orthopedic department under the suspicion of herniated disc. Absence of pulsation on the groin and aortography evidenced aortoillac occlusion predominantly on the left side. Thromboendarterectomy was made and the operative result was successful with absence of claudication, healing of ulcer and aortographic patency of occlusive site. This chronic occlusion is considered to result from arteriosclerosis in origin with the evidence of moderate hypertension, x-ray evidence of calcified plaque on the aortic knob and operative finding of palpable plaques.

• Journal of Chest Surgery
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• v.44 no.1
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• pp.51-57
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• 2011

Background: Up to now, lobectomy, bilobectomy and pneumonectomy combined with extensive lymph node dissection have been regarded as the standard procedures for non-small cell lung cancer (NSCLC). In high-risk patients, however, limited resection (LR) has been attempted as a salvage procedure, and, recently, indication for LR has been extended to selected cases with early-stage NSCLC. Material and Methods: Among the 773 patients who underwent surgical procedures for NSCLC in Seoul National University Bundang Hospital from May 2003 to December 2008, 43 patients received LR. Medical records of these patients were retrospectively reviewed. Results: Mean age at operation was $66.0{\pm}12.4$ years, and there were 30 males. Twenty-five patients underwent conservative limited resection (CLR) and 18 underwent intentional limited resection (ILR). Indications for CLR were multiple primary lung cancer in 9 (9/25, 36%) and severe concomitant diseases in 5 (5/25, 20%). Of these, 6 patients underwent segmentectomy and 19 received wedge resection. During the follow-up period of $28.0{\pm}17.8$ months, 15 patient developed recurrent lung cancer. ILR was selectively performed in lesions almost purely composed of ground glass opacity (${\geq}$95%), or in small solid lesions (${\leq}$2 cm). Of these, 11 patients underwent segmentectomy and 7 underwent wedge resection. During the follow-up period of $31.7{\pm}11.6$ months, no patient developed recurrence. Conclusion: Intermediate-term outcome of LR for early-stage lung cancer is comparable to that of standard operation. For the delineation of the indications and appropriate surgical techniques for LR, prospective randomized multi-institutional study may be expedient.

• Journal of Chest Surgery
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• v.38 no.2 s.247
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• pp.152-156
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• 2005

Background: Occlusive complications after arterial revascularization are difficult to treat and have high recurrence rate. This study was performed to establish an effective treatment modality and to evaluate the factors affecting the occlusive complications by analysis of clinical data. Material and Method: During the period of 5 years. 33 patients (55 reoperations) were studied at the Department of Thoracic and Cardiovascular Surgery, Pusan National University Hospital following 173 arterial revascularization surgeries. The clinical characteristics, operating methods, the time intervals of reoperation, used graft, and the results of treatment were evaluated retrospectively. Result: All the patients were men except one and the mean age was 63.5 years old. The mean time internal from first operation to reoperation was 11.9 months. The cause of arterial occlusive diseases were 28 atherosclerosis and 5 Burger's diseases, Associated diseases were Hypertension $(57.6\%)$, Diabetes mellitus $(33.3\%)$, heart failure $(18.2\%)$, and so on. The mean rate of reoperation was 1.67 times and the most common type of first operation was femoro-popliteal bypass grafting $(57.6\%)$. The graft that used revascularization surgery were 25 cases of PTFE and 6 case were Dacron. There was no statistical difference between two groups. The kinds of reoperations were thrombectomy in 20 cases, angioplasty 18 cases, re-bypass surgery in 13 cases, and lumbar sympathectomy in 4 cases. The results of reoperation were 15 cases of functional recovery, 7 cases of limb salvage, 5 cases of above-knee amputation. 3 cases of below-knee amputation and 3 deaths. Conclusion: The main cause of occlusive complications are occlusion of inflow or outflow artery. Treatments were different according to the first operation methods and graft used. The most frequent time of reoperation was within one year after the first operation. We believe that graft surveillance especially during the first year is very important factor in observing the patient. We can look forward to improving limb salvage rate to perform additional treatment such as radiological interventions and lumbar sympathectomy.

• The Journal of the Korean bone and joint tumor society
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• v.17 no.1
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• pp.36-43
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• 2011

Purpose: This study was designed to verify intermediate-term functional and radiological results of limb salvage operation using endoprosthetic replacement system ($MUTARS^{(R)}$) used in patients with a malignant bone tumor. Materials and Methods: Thirty one cases which used $MUTARS^{(R)}$ tumor prosthesis were reviewed. The mean age of the patients was 49.2 years and the mean follow up was 39.8 months. We retrospectively reviewed complications, and evaluated functionally and radiologically by Enneking functional score, ISOLS radiological implants evaluation system at last follow-up. Results: 3 patients had died of disease, distant metastasis was seen in 4 patients and local recurrence was seen in 1 patients. Complications were developed in 12 patients. (infection 6, leg length discrepancy 2, aseptic loosening 2, periprosthetic femoral fracture 1, screw loosening 1) Mean value of total functional scores were 81.2% in proximal femur, 77.4% in distal femur, 78.1% in proximal tibia, and 80.2% in proximal humerus. The overall radiological result was relatively satisfactory. Conclusion: Our results suggest limb salvage with the $MUTARS^{(R)}$ endoprosthesis is successful with good functional and radiological results. But we should be careful with complications such as infection.

• Radiation Oncology Journal
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• v.14 no.3
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• pp.221-228
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• 1996

Purpose : We tried to evaluate the clinical characteristics, the treatment methods, the results of treatments, and the Patterns of failure in ovarian dysgerminoma retrospectively According to the results we would like to suggest the proper management guideline of stage la ovarian dysgerminoma patients who want to maintain fertility. Materials and Methods : Between 1975 and 1990, 34 patients with ovarian dysgerminoma were treated at the Yonsei University Hospital. The case records of these patients have been reviewed for presenting symptoms, treatment methods, local control and survival following treatment. Excluded from analysis were five patients with mixed ovarian germ cell tumors and gonadoblastomas (46,XY) Treatment results of the twenty nine patients were analysed by each treatment modality. Twenty one patients were treated with surgery and postoperative adjuvant radiotherapy (group 2). The other eight patients were treated with operation alone (group 2). The median age of twenty-nine patients was 23 years with a range of 8 to 39 years. Presenting symptoms were abdominal mass (20) pelvic discomfort or pain (5) et al. Radiotherapy was performed by 10MV LINAC or Co-60 teletherapy unit. The total radiation dose of the whole abdomen was 20-25 Gy/3weeks, 1-1.5 Gy/fraction with a boost to the whole pelvis 10-15 Gy/l-2weeks 1.8-2.0 Gy/fraction. Advanced stage disease (stage II or stage III) patients received prophylactic mediastinal and supraclavicular irradiation to a dose of 16-26 Gy. Median duration of follow-up of living patients was 80 months (range 13-201 months). Results : All of the twenty one patients of group 1 were alive without disease ($100\%$). Among the eight patients who were not treated with radiotherapy (group 2), six patients developed local recurrence. Four Patients referred with recurrent disease were treated with salvage radiotherapy. Three of four patients were salvaged and one Patient who had recurrent intra-abdominal disease died of progressed carcinomatosis at 11 months after salvage radiotherapy. The other two patients with recurrence were salvaged with chemotherapy (1 patient) or re-operation (1 Patient). Twenty eight patients remained alive without disease at last follow up, so the 5 year local control rate and 5 year overall survival rate for all groups were $96.6\%$ (28/29), respectively. Among thirteen patients with stage la unilateral tumors seven patients were treated with postoperative radiotherapy and the other six patients were treated with unilateral salpingo-oophorectomy alone. Five patients who did not received radiotherapy developed local failure but all of the recurrent ovarian dysgerminomas were salvaged with radiotherapy, chemotherapy or re-operation. So all the 13 patients with stage la ovarian dysgerminoma were free of disease from 20-201 months (median 80 months). Conclusion : The authors consider external irradiation to be an effective treatment as a complement to surgery in ovarian dysgerminoma. For those patients with disease presenting in stage la tumors who wish to maintain fertility, unilateral salpingo-oophorectomy alone may be curative and spare ovarian function considering excellent salvage rate of recurrent ovarian dysgerminoma in present study.

• The Journal of the Korean bone and joint tumor society
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• v.14 no.2
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• pp.157-162
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• 2008

Nowadays, most of the malignant bone tumor patient underwent limb salvage operation, however, reconstructive options for skeletally immature group are still controversial. There are three necessary conditions of most ideal reconstructive method in treating the skeletally immature children. As the epiphyseal plate sacrification is usually inevitable in malignant bone tumor around knee joint, ideal reconstructive technique would be as follows; 1)minimal or no damage to theadjacent epiphyseal plate, 2) maintaining mobile joint, 3) index procedure does not disturb subsequent operation such as lengthening. Segmental resection and reconstruction using autogenous pasteurized graft was done for 4 years old meta-diaphyseal osteosarcoma of femur. At 6 months from index operation, plain radiograph showed pasteurized bone resorption and loosening of fixation devise. To overcome the complication, we used allograft reconstruction by impacting the proximal host bone to the fluted portion of allobone. Three months later, proximal bone union was observed and patient showed good functional outcome.