• Title/Summary/Keyword: margin loss function

Search Result 17, Processing Time 0.027 seconds

A 20-year experience of immediate mandibular reconstruction using free fibula osteocutaneous flaps following ameloblastoma resection: Radical resection, outcomes, and recurrence

  • Chai, Koh Siang;Omar, Farah Hany;Saad, Arman Zaharil Mat;Sulaiman, Wan Azman Wan;Halim, Ahmad Sukari
    • Archives of Plastic Surgery
    • /
    • v.46 no.5
    • /
    • pp.426-432
    • /
    • 2019
  • Background The mandible is an important structure that is located in the lower third of the face. Large mandibular defects after tumor resection cause loss of its function. This study assessed the outcomes and tumor recurrence after immediate mandibular reconstruction using a free fibula osteocutaneous flap following radical resection of ameloblastoma. Methods This is a retrospective non-randomized study of outcomes and tumor recurrence of all patients diagnosed with mandibular ameloblastoma from August 1997 until August 2017 (20 years) requiring free fibula osteocutaneous flap reconstruction at a single institution. The patients were identified through an electronic operative database; subsequently, their medical records and photo documentation were retrieved. Results Twenty-seven patients were included in this study. Eighteen patients were male, while nine were female. The majority of the patients (48.1%) were in their third decade of life when they were diagnosed with ameloblastoma. All of them underwent radical resection of the tumor with a surgical margin of 2 cm (hemimandibulectomy in cases with a large tumor) and immediate mandibular reconstruction with a free fibula osteocutaneous flap. Two patients required revision of a vascular anastomosis due to venous thrombosis postoperatively, while one patient developed a flap recipient site infection. The flap success rate was 100%. There was no tumor recurrence during a mean follow-up period of 5.6 years. Conclusions Mandibular ameloblastoma should be treated with segmental mandibulectomy (with a surgical margin of 2 cm) to reduce the risk of recurrence. Subsequent mandibular and adjacent soft tissue defects should be reconstructed immediately with a free fibula osteocutaneous flap.

Comparative study of off-clamp, laparoscopic partial nephrectomy (OCLPN) and conventional hilar control, laparoscopic partial nephrectomy (HCLPN) for renal tumors: One-year follow-up results of renal function change

  • Kang, Su Hwan;Rhew, Hyun Yul;Kim, Taek Sang
    • Kosin Medical Journal
    • /
    • v.33 no.2
    • /
    • pp.191-199
    • /
    • 2018
  • Objectives: We designed the study to compare the oncologic and renal function outcomes of off-clamp, laparoscopic partial nephrectomy (OCLPN) and conventional laparoscopic partial nephrectomy (HCLPN) for renal tumors. Methods: Between March 2008 and July 2015, 114 patients who underwent laparoscopic partial nephrectomy (LPN) of a renal neoplasm were studied. We performed LPN without hilar clamp on 40 patients (OCLPN, Group 1), and conventional LPN with hilar control and renorrhaphy on another 40 patients (HCLPN, Group 2). We retrospectively reviewed the medical records of each patient's age, sex, R.E.N.A.L. nephrometry score (RNS), operation time, complications, hospitalization period, tumor size, positive resection margin, histologic classification of tumor, pathologic stage, Fuhrman grade, estimated blood loss (EBL), warm ischemic time (WIT), and estimated glomerular filtration rate (eGFR) before and one year after surgery. Results: There were no significant differences in age, sex, preoperative eGFR, EBL, surgical (anesthesia) time, and tumor size between the two groups. The mean eGFR was not significantly different between the OCLPN and HCLPN groups 1 month (95 and $86.2mL/min/1.73m^2$, respectively; P = 0.106), 6 months (92.9 and $83.6mL/min/1.73m^2$, respectively; P = 0.151) and 12 months (93.8 and $84.7mL/min/1.73m^2$, respectively; P = 0.077) postoperatively. The change in eGFR after one year was 3.9% in the OCLPN group and -7.9% in the HCLPN group. Conclusions: OCLPN was superior to HCLPN in preserving renal function one year after surgery, and there was no statistically significant difference in tumor treatment results.

THE EFFECTS OF ATELO-COLLAGEN SPONGE INSERTION ON THE PERIODONTAL HEALING OF SECOND MOLARS AFTER IMPACTED MANDIBULAR THIRD MOLAR EXTRACTION (매복 하악 제3대구치 발치와에 Atelo-collagen Sponge 삽입이 제2대구치 예후에 미치는 영향)

  • Nam, Jin-Woo;Kim, Kyung-Wook
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.35 no.2
    • /
    • pp.112-119
    • /
    • 2009
  • Extracellular matrix(ECM) is known to function as a reservoir of endogenous growth factors, can be an effective delivery system of growth factor that easily lost bioactivity in solution. Fibrillar collagens like type I collagen, are the major constituent of the ECM and structural protein of bone. Also, it can be a scaffold for osteoblast migration. The purpose of this study was to compare the effects of absorbable Atelo-collagen Sponge($Teruplug^{(R)}$) insertion in tooth extraction sites on periodontal healing of the mandibular second molar after the extraction of the impacted third molar. The study population comprised 31 cases who had been scheduled for surgical removal of impacted mandibular third molars. All patients were in good general health and were not using any medication that would influence wound healing after surgery. In 15 cases control group, none was inserted into the tooth extraction site. In 16 cases experimental groups, $Teruplug^{(R)}$ was inserted into the tooth extraction site. We evaluated tooth mobility, pocket depth, gingival margin level preoperatively and 1 week, 2 weeks, 4 weeks, and 3 months postoperatively. The change was compared with two groups using Mann-Whitney test. The results were as follows. 1. There was no significant change of tooth mobility on both groups. 2. There was tendency of decreasing of previous pocket depth causing tooth extraction on both groups. 3. On gingival margin level, there was various change according to initial swelling and loss of attachment on both groups. 4. There was tendency of decreasing of gingival margin level on both groups because of removal of inflammation and decreasing of previous pocket depth. 5. There was large change of pocket depth on buccal middle, distal, lingual distal area because of tooth extraction and bone reduction. Compared with the control group and experimental group, we observed significant difference during some periods. The results of this study suggest that absorbable atelo-collagen sponge($Teruplug^{(R)}$) is relatively favorable bone void filler with prevention of tissue collapse, food packing and enhance periodontal healing.

Passive UHF RFID Propagation Characteristics and Reconsideration of Link budget on Practical Communication Area (수동형 UHF RFID 인터페이스에 대한 Link budget의 재해석 및 전파 환경 요소 분석)

  • Jung, Jin-Woo;Park, Kyoung-Tae;Roh, Hyoung-Hwan;Park, Jun-Seok;Kim, Hyeong-Seok
    • 한국정보통신설비학회:학술대회논문집
    • /
    • 2008.08a
    • /
    • pp.469-472
    • /
    • 2008
  • In this paper, we discuss the recent trends on the passive UHF RFID tag chip design techniques and several important system parameters. We also summarize link budget studies on both conventional and modem UHF RFID communications. The paper highlights the reverse link limited case, which has known to be the minor concern if reader continuous wave (CW) can reach the tag in sufficient level. This makes sense when the tag sensitivity is rather high (over 10-12${\mu}W$); however, since the tag chip fabrication technologies have been developed by time, the tag chip threshold levels are now less-dominant in determining link margin. If the tag limitation can be alleviated, the forward link limited case can be resolved; thus, we rather focus on the path-loss problem. Since the path-losses are still exist in both forward and reverse links, and it can be doubled while CW travels the reader-tag-reader path because forward link and reverse link are on the same distance. Consider if reader receiver sensitivity is very high in the worst case. In this case, weaken tag response (i.e., backscatters) cannot reach the level that reader receiver can process tag data; bit-error rate can be higher. Overall, backscatter levels should be high enough so that reader receiver can correctly function. After discussing link budget, we carried out practical measurements on fading effects between two circularly polarized UHF RFID antennas in a small scale area.

  • PDF

Criticality Uncertainty Analysis of Spent Fuel Transport Cask applying Burnup Credit (연소도이득효과(BUC) 적용 사용후핵연료 운반용기의 임계 불확실도 평가)

  • Lee, Gang-Ug;Park, Jea-Ho;Kim, Do-Hyung;Kim, Tae-Man;Yoon, Jeong-Hyun
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.9 no.3
    • /
    • pp.191-198
    • /
    • 2011
  • In general, conventional criticality analyses for spent fuel transport/dry storage systems have been performed based on assumption of fresh fuel concerning the potential uncertainties from number density calculation of Transuranic and Fission Products in spent fuel. However, because of economic loss due to the excessive criticality margin, recently the design of transport/dry storage systems with Burnup Credit(BUC) application has been actively developed. The uncertainties in criticality analyses on transport/storage systems with BUC technique show strong dependance upon initial enrichment and burnup rate, whereas those in the conventional criticality evaluation based on fresh fuel assumption do not show such a dependance. In this study, regulatory-required uncertainties of the criticality analyses for BK 26 Cask, which is conceptually designed spent fuel transport cask with BUC corresponding to the limiting circumstances on nuclear power plants in Korea, are evaluated as a function of initial enrichment and burnup rate. Results of this study will be used as basic data for spent fuel loading curve of BK 26 Cask.

Parenchymal-sparing anatomical hepatectomy based on portal ramification of the right anterior section: A prospective multicenter experience with short-term outcomes

  • Truong Giang Nguyen;Thanh Khiem Nguyen;Ham Hoi Nguyen;Hong Son Trinh;Tuan Hiep Luong;Minh Trong Nguyen;Van Duy Le;Hai Dang Do;Kieu Hung Nguyen;Van Minh Do;Quang Huy Tran;Cuong Thinh Nguyen
    • Annals of Hepato-Biliary-Pancreatic Surgery
    • /
    • v.28 no.1
    • /
    • pp.25-33
    • /
    • 2024
  • Backgrounds/Aims: Parenchymal-sparing anatomical hepatectomy (Ps-AH) based on portal ramification of the right anterior section (RAS) is a new technique to avoid unnecessarily transecting too much liver parenchyma, especially in cases of major anatomical hepatectomy. Methods: We prospectively assessed 26 patients with primary hepatic malignancies having undergone major Ps-AH based on portal ramification of the RAS from August 2018 to August 2022 (48 months). The perioperative indications, clinical data, intra-operative index, pathological postoperative specimens, postoperative complications, and follow-up results were retrospectively evaluated. Results: Among the 26 patients analyzed, there was just one case that had intrahepatic cholangiocarcinoma The preoperative level of α-Fetoprotein was 25.2 ng/mL. All cases (100%) had Child-Pugh A liver function preoperatively. The ventral/dorsal RAS was preserved in 19 and 7 patients, respectively. The mean surgical margin was 6.2 mm. The mean surgical time was 228.5 minutes, while the mean blood loss was 255 mL. In pathology, 5 cases (19.2%) had microvascular invasion, and in the group of HCC patients, 92% of all cases had moderate or poor tumor differentiation. Six cases (23.1%) of postoperative complications were graded over III according to the Clavien-Dindo system, including in three patients resistant ascites or intra-abdominal abscess that required intervention. Conclusions: Parenchymal-sparing anatomical hepatectomy based on portal ramification of the RAS to achieve R0-resection was safe and effective, with favorable short-term outcomes. This technique can be used widely in clinical practice.

The Early Experience with a Laparoscopy-assisted Pylorus-preserving Gastrectomy: A Comparison with a Laparoscopy-assisted Distal Gastrectomy with Billroth-I Reconstruction (복강경 보조 유문부보존 위절제술의 초기 경험: 복강경 보조 원위부 위절제술 후 Billroth-I 재건술과의 비교)

  • Park, Jong-Ik;Jin, Sung-Ho;Bang, Ho-Yoon;Chae, Gi-Bong;Paik, Nam-Sun;Moon, Nan-Mo;Lee, Jong-Inn
    • Journal of Gastric Cancer
    • /
    • v.8 no.1
    • /
    • pp.20-26
    • /
    • 2008
  • Purpose: Pylorus-preserving gastrectomy (PPG), which retains pyloric ring and gastric function, has been accepted as a function-preserving procedure for early gastric cancer for the prevention of postgastrectomy syndrome. This study was compared laparoscopy-assisted pylorus-preerving gastrectomy (LAPPG) with laparoscopy-assisted distal gastrectomy with Billroth-I reconstruction (LADGB I). Materials and Methods: Between November 2006 and September 2007, 39 patients with early gastric cancer underwent laparoscopy-assisted gastrectomy in the Department of Surgery at Korea Cancer Center Hospital. 9 of these patients underwent LAPPG and 18 underwent LADGBI. When LAPPG was underwent, we preserved the pyloric branch, hepatic branch, and celiac branch of the vagus nerve, the infrapyloric artery, and the right gastric artery and performed D1+$\beta$ lymphadenectomy to the exclusion of suprapyloric lymph node dissection. The distal stomach was resected while retaining a $2.5{\sim}3.0\;cm$ pyloric cuff and maintaining a $3.0{\sim}4.0\;cm$ distal margin for the resection. Results: The mean age for patients who underwent LAPPG and LADGBI were $59.9{\pm}9.4$ year-old and $64.1{\pm}10.0$ year-old, respectively. The sex ratio was 1.3 : 1.0 (male 5, female 4) in the LAPPG group and 2.6 : 1.0 (male 13, female 5) in the LADGBI group. Mean total number of dissected lymph nodes ($28.3{\pm}11.9$ versus $28.1{\pm}8.9$), operation time ($269.0{\pm}34.4$ versus $236.3{\pm}39.6$ minutes), estimated blood loss ($191.1{\pm}85.7$ versus $218.3{\pm}150.6\;ml$), time to first flatus ($3.6{\pm}0.9$ versus $3.5{\pm}0.8$ days), time to start of diet ($5.1{\pm}0.9$ versus $5.1{\pm}1.7$ days), and postoperative hospital stay ($10.1{\pm}4.0$ versus $9.2{\pm}3.0$ days) were not found significant differences (P>0.05). The postoperative complications were 1 patient with gastric stasis and 1 patient with wound seroma in LAPPG group and 1 patient with left lateral segment infarct of liver in the LADGB I group. Conclusion: Patients treated by LAPPG showed a comparable quality of surgical operation compared with those treated by LADGBI. LAPPG has an important role in the surgical management of early gastric cancer in terms of quality of postoperative life. Randomized controlled studies should be undertaken to analyze the optimal survival and long-term outcomes of this operative procedure.

  • PDF