Changes in Saphenous Vein Stump and Low Incidence of Endovenous Heat-Induced Thrombosis After Radiofrequency Ablation of Great Saphenous Vein Incompetence.

BACKGROUND: Relationship between the distance of the catheter tip from the saphenous femoral junction and the length of residual stump after radiofrequency ablation (RFA) has not been sufficiently examined. OBJECTIVE: The purpose of this study was to investigate the change of great saphenous vein (GSV) stump with clinical outcomes after RFA. MATERIAL AND METHODS: From January 2014 to September 2014, 67 patients (91 limbs) underwent GSV RFA and the collected data were analyzed prospectively. Change of GSV stump length and clinical symptoms was evaluated at 1-, 3-, and 6-month intervals. Ablations were performed between 2 to 2.5 cm distal to the saphenofemoral junction. RESULTS: The residual GSV stump decreased in length to 1.465 ± 0.504 cm at the first month follow-up. This length persisted throughout the 1-, 3-, and 6-month follow-ups. There were no statistically significant differences during the follow-up period. Both the Venous Clinical Severity Score and the Aberdeen Varicose Vein Symptom Severity Score was significantly improved at 1 month and improved even further at 3 months. One patient (1.1%) developed endovenous heat-induced thrombosis (EHIT) Class 3 at 1-month follow-up and was treated with anticoagulation. CONCLUSION: This study has shown that the adequate positioning of RFA catheter tip (2.0-2.5 cm) is recommended to decrease the incidence of EHIT.

Outcome of ClosureFAST radiofrequency ablation for large-diameter incompetent great saphenous vein.

PURPOSE: There is limited data on the outcomes of radiofrequency ablation (RFA) for large diameter saphenous veins. This study aimed to determine whether the large-diameter great saphenous vein (GSV) affected closure rate, complications, and clinical and quality of life (QoL) improvement. METHODS: From January 2012 to September 2016, a total of 722 limbs were treated with ClosureFAST RFA in a single center. Patients were divided into 2 groups according to the vein diameter measured 3 cm below the saphenofemoral junction (group A ≤ 12 mm, group B > 12 mm). Vein closure was evaluated with duplex scan at 3-5 days, 1, 3, 6, and 12 months postoperatively. The incidence of complications, improvements in symptoms (measured by the Venous Clinical Severity Score [VCSS]) and QoL (measured by the Aberdeen Varicose Vein Symptom Severity Score [AVSS]) were evaluated. RESULTS: Groups consisted of 663 GSVs in group A (mean diameter, 6.00 ± 1.74 mm) and 59 in group B (mean diameter, 13.17 ± 1.28 mm). Vein closure rates at 12 months were 98.9% in group A and 100% in group B (P = 0.428). There was no significant difference in the incidence of complications. Both groups showed marked improvements in the VCSS and the AVSS with no significant differences. CONCLUSION: For large-diameter veins, RFA showed comparable outcomes in terms of closure rate, complications, clinical and QoL improvements.

Thrombosed native hemodialysis fistulas: Technical and clinical outcomes of endovascular recanalization and factors influencing patency.

PURPOSE: To evaluate the technical and clinical results of endovascular recanalization of thrombosed native hemodialysis fistula and the factors influencing patency. METHODS: A retrospective study was conducted with 73 patients who had thrombosed arteriovenous fistulas and were treated with endovascular methods. Patient characteristics, arteriovenous fistula-related characteristics, and endovascular procedures were analyzed. Technical and clinical results and patency rates were evaluated. The factors influencing patency were analyzed using a univariate and multivariate Cox proportional hazards model. RESULTS: Technical and clinical success rates were 93% (68/73) and 85% (62/73), respectively. At 3, 6, and 12 months, the primary patency rates were 87.9%, 73.3%, and 64.8%; assisted primary patency rates were 89.2%, 78.6%, and 70.7%; and secondary patency rates were 90.8%, 87.2%, and 83.1%, respectively. Previous intervention and cephalic arch stenosis were risk factors for lower primary and assisted primary patency (p < 0.05 for all). Cephalic arch stenosis was the only risk factor for lower secondary patency (p < 0.05). No major complications associated with the procedures were noticed. CONCLUSION: Endovascular treatment was effective for the immediate recanalization of thrombosed arteriovenous fistula. In addition, previous intervention and cephalic arch stenosis were significantly related to lower arteriovenous fistula patency.

Effect of nicotine on human umbilical vein endothelial cells (HUVECs) migration and angiogenesis.

The effects of nicotine on vascular endothelial cells have not been completely elucidated. We performed this study to assess the changes in cellular behaviors of human umbilical vein endothelial cells (HUVECs) treated with nicotine. We examined changes in cell count and morphology and assayed cellular migration with Boyden chamber and microcapillary tube formation in a Matrigel matrix following treatment with various concentrations of nicotine. Compared to the control, nicotine stimulated cell proliferation, migration, and tube formation at concentrations similar to those found in smokers. Although there were no specific morphological changes in HUVECs treated with nicotine at the concentration similar to that in smokers, at high concentration (10(-4) M), morphological changes such as cytoplasmic vacuolization and irregular cell shape were observed, which were assumed to be the result of direct cytotoxicity of nicotine. In HUVECs, nicotine enhanced cellular proliferation, migration and angiogenesis in vitro, and thus caused a functional change, not a morphological change at a concentration similar to that in habitual smokers.

A nontraumatic, noniatrogenic pseudoaneurysm of the cephalic vein presenting as an upper arm mass.

We report a case of pseudoaneurysm of the cephalic vein which was diagnosed in a 13-year-old boy who presented with a superficial mass in the right upper arm. The patient had no history of trauma, venipuncture, or intravenous drug addiction. Ultrasonic examination revealed a defect in the anterior wall of the cephalic vein and a surrounding vascular pool which included the inner thrombus. The mass was easily peeled off and completely excised after ligation of the afferent and efferent cephalic vein. Pathologic examination revealed it to be a pseudoaneurysm of the cephalic vein. This may represent the first case of venous pseudoaneurysm in the English-language medical literature without causative preceding events. Clinical features, including etiology, diagnosis, treatment, and complications, of this extremely rare lesion are also discussed.

Use of Self-Assembling Peptides to Enhance Stem Cell Function for Therapeutic Angiogenesis.

The use of nanomaterials for biomedical applications has become a promising field in regenerative medicine. Self-assembling peptides (SAPs) have been proposed as a good candidate because they are able to self-assemble into stable hydrogels and interact with cells or molecules when combined together. This in turn can lead to the improved survival or action of cells or molecules to obtain the desired effects. In this study, we investigated whether the combination of mesenchymal stem cells (MSCs) with SAPs could improve angiogenesis in ischemic hindlimbs of rats compared to MSC or SAP treatment alone. The combination of MSCs and SAPs showed an overall higher expression of angiogenesis markers on fluorescent immunohistochemical analysis and a lower degree of fibrosis and cell apoptosis, which in turn led to an overall tendency for improved perfusion of the ischemic hindlimbs. Finally, SAPs also showed the ability to recruit endogenous host MSCs into the site of action, especially when modified to incorporate substance P as a functional motif, which when injected with exogenous MSCs, allowed for the dual presence of MSCs at the site of action. Overall, these results suggest that SAPs can be applied with stem cells to potentiate angiogenesis, with potential therapeutic application in vascular diseases.

How to treat arteriovenous graft infection: total versus partial graft excision.

INTRODUCTION: Arteriovenous graft (AVG) infection can result in life-threatening sepsis and loss of vascular access. A retrospective study was performed to establish an appropriate treatment strategy for AVG infection. METHODS: A total of 50 cases of AVG infection were treated between January 2005 and June 2016. The surgical methods used were total graft excision (TGE) (n = 34), or partial graft excision (PGE) with interposition graft (n = 16). RESULTS: Infection was noted at a puncture site (n = 22), a prior incision for surgery or endovascular therapy (n = 20), and abandoned (currently unused) grafts (n = 5). Infection occurred within 1 month after AVG creation (n = 1), or any intervention (n = 14), and more than 1 month after creation or intervention (n = 35). Simultaneous remote infection was identified in 7 patients, 2 of whom underwent an operation for infective endocarditis and spondylitis. After PGE, 5 patients (5/16, 31.2%) having recurrent infection were treated with further graft excision; however, no patient showed life-threatening complications. After TGE, a central venous catheter (CVC) was inserted and used for a median period of 90 days. Among 34 patients who underwent TGE, new vascular access was created in 18 patients at a median period of 2 months later, and 12 patients continued to use a CVC until last follow-up or death. CONCLUSIONS: PGE could be a treatment option for AVG infection to achieve both infection eradication and vascular access preservation in selected patients. Because of a higher risk of recurrent infection, sufficient surgical removal and careful postoperative management are warranted.

The prevalence of primary hyperparathyroidism in Korea: a population-based analysis from patient medical records.

PURPOSE: Because primary hyperparathyroidism (PHPT) is difficult to recognize, it has a high likelihood of being underdiagnosed. In this study, we estimated the incidence of PHPT and evaluated PHPT diagnosis in Korea. METHODS: To calculate the prevalence of PHPT, we examined the medical records of patients that were hospitalized for urolithiasis between 2013 and 2016 at a single institute, and then identified those who were diagnosed with PHPT from the same group. A Korea-wide insurance claim database was used to ascertain the number of urolithiasis patients and the number of parathyroidectomies performed in Korea. The incidence of PHPT in the Korean population was estimated using the ratio of patients who presented with urolithiasis as the initial symptom of PHPT. RESULTS: During the 4-year study period, 4 patients from the 925 urolithiasis patients enrolled in this study (0.4%) were diagnosed with PHPT. During this same period, there were 85,267 patients with urolithiasis in Korea, and the estimated number of PHPT patients was 341, which was 0.4% of 85,267. Considering that 12% to 23% of patients with PHPT are initially diagnosed with urolithiasis, the total number of PHPT patients was estimated to range from 1,483 to 2,842. The number of patients who underwent parathyroidectomy due to PHPT was 1,935 during the study period. CONCLUSION: The number of patients we estimated to have PHPT corresponded closely with the number of patients undergoing parathyroidectomy during the study period. Considering the number of nonsymptomatic PHPT patients, PHPT may be properly diagnosed in Korea.

Improvements of deep vein reflux following radiofrequency ablation for saphenous vein incompetence.

Objectives The aim of this study was to describe the changes of deep vein reflux after radiofrequency ablation for great saphenous vein incompetence. Method The data on 139 limbs which were treated with radiofrequency ablation for great saphenous vein incompetence were prospectively collected and reviewed. Results Deep vein reflux was present in 43 of 139 limbs (30.9%). There were no significant differences in the rate of successful closure, the incidence of procedure-related complications, and the improvements of symptoms and quality of life between the limbs with or without deep vein reflux. With a mean follow-up of 5.9 months, the peak reflux velocity and duration of reflux were improved in all limbs with deep vein reflux and it was completely corrected in 13 limbs (30.2%) after radiofrequency ablation. Conclusions The presence of deep vein reflux does not affect the treatment outcomes of radiofrequency ablation for great saphenous vein incompetence and is improved in all patients. Deep vein reflux is not a barrier to performing radiofrequency ablation.

Early Experiences of Sandwich Technique to Preserve Pelvic Circulation during Endovascular Aneurysm Repair.

PURPOSE: To report experiences of the sandwich technique (ST) for preservation of pelvic flow during endovascular repair of complex aortic or aortoiliac aneurysms. MATERIALS AND METHODS: Eight patients underwent elective endovascular aneurysm repair (EVAR) using the ST between March 2013 and February 2017. The anatomic indications for the ST were complex aortoiliac aneurysms (5 cases), abdominal aortic aneurysms (AAA) with non-diseased short common iliac arteries (2 cases) and AAA with unilateral occluded iliac artery (1 case). The ST was performed through both femoral and brachial approach. Patient clinical and radiologic data were collected and analyzed. RESULTS: Eight patients (7 male; mean age, 73.4 years) were followed over a mean period of 277 days (range, 9-1,106 days). The technical success rate was 100%. The primary patency rate of the iliac stent-grafts was 88% (14/16 cases). One internal iliac and 1 external iliac stent-graft occlusion was observed during the early postoperative period. There was 1 gutter endoleak which disappeared spontaneously within 4 days, and there were 2 type II endoleaks: one treated by coil embolization after 13 months, and the other observed without treatment. There were no cases of sac growth or aneurysm-related deaths, and no cases of buttock claudication or impotence. CONCLUSION: The ST is a safe and feasible technique to preserve pelvic circulation during endovascular treatment of complex aortoiliac aneurysms. The need to expand the indications for complex EVARs with adjunctive procedures, such as the ST is highlighted in situations where branched/fenestrated device availability is limited.

The 13-year experience of performing pancreaticoduodenectomy in a mid-volume municipal hospital.

PURPOSE: Pancreaticoduodenectomy (PD) is a complex surgery associated with high morbidity, mortality, and cost. Municipal hospitals have their important role in the public health and welfare system. The purpose of this study was to identify the feasibility as well as the cost-effectiveness of performing PD in a mid-volume municipal hospital based on 13 years of experience with PD. METHODS: From March 2003 to November 2015, 183 patients underwent PD at Seoul Metropolitan Government - Seoul National University Boramae Medical Center.. Retrospectively collected data were analyzed, with a particular focus on complications. Hospital costs were analyzed and compared with a national database, with patients divided into 2 groups on the basis of medical insurance status. RESULTS: The percentage of medical aid was significantly higher than the average in Korean hospitals. (19.1% vs. 5.8%, P = 0.002). Complications occurred in 88 patients (44.3%). Postoperative pancreatic fistula (POPF) occurred in 113 cases (61.7%), but the clinically relevant POPF was 24.6% (grade B: 23.5% and grade C: 1.1%). The median hospital stay after surgery was 20 days (range, 6-137 days). In-hospital mortality was 3.8% (n = 7), with pulmonary complications being the leading cause. During the study period, improvements were observed in POPF rate, operation time, and hospital stay. The mean total hospital cost was 13,819 United States dollar (USD) per patient, and the mean reimbursement from the National Health Insurance Service (NHIS) to health care providers was 10,341 USD (74.8%). The patient copayment portion of the NHIS payment was 5%. CONCLUSION: Performing PD in a mid-volume municipal hospital is feasible, with comparable results and cost-effectiveness.

Transoral endoscopic thyroidectomy for papillary thyroid microcarcinoma: initial experience of a single surgeon.

PURPOSE: Recently, transoral endoscopic thyroidectomy (TOET) is receiving attention because it is regarded as a true minimally invasive surgery in that it does not leave scars on any part of the body and the area of flap dissection is similar to that of open surgery. In this study, we present the surgical procedures and initial outcomes of TOET in the treatment of papillary thyroid microcarcinoma (PTMC) patients. METHODS: The medical records of patients who underwent TOET for PTMC between July 2016 and February 2017 were retrospectively reviewed. Indication of TOET was PTMC without capsular invasion or lymph node metastasis on preoperative imaging studies. RESULTS: Ten female patients were enrolled. Seven patients underwent thyroid lobectomy and three patients underwent isthmusectomy. The mean age and tumor size was 43.3 ± 11.5 years and 0.6 ± 0.2 cm, respectively. Operation time for lobectomy and isthmusectomy was 121.1 ± 30.7 (range, 65-148) and 90.0 ± 9.2 minutes (range, 82-100 minutes), respectively. The mean number of retrieved lymph nodes was 2.7 ± 1.7. Two patients had transient vocal cord palsy, which recovered in three months. There was no case with subcutaneous emphysema, surgical site infection, postoperative bleeding, or mental nerve injury. CONCLUSION: TOET was feasible and could be performed safely for PTMC. TOET might become a new treatment option for the patients who do not want to leave visible scars on the body.

Prognostic Influence of Preoperative Fibrinogen to Albumin Ratio for Breast Cancer.

PURPOSE: Elevated serum concentration of fibrinogen and decreased serum concentration of albumin have been reported to be markers of elevated systemic inflammation. We attempted to investigate the prognostic influence of preoperative fibrinogen to albumin ratio (FAR) for breast cancer. METHODS: Data from 793 consecutive primary breast cancer patients were retrospectively analyzed. Serum levels of fibrinogen and albumin were tested before curative surgery. Subjects were grouped into two groups according to the cutoff value determined by performing the receiver operating characteristic curve analysis: the high FAR group (FAR>7.1) and the low FAR group (FAR≤7.1). Overall survival was assessed using the Kaplan-Meier estimator. Independent prognostic significance was analyzed using the Cox proportional hazards model. RESULTS: The high FAR group had a worse prognosis compared to the low FAR group (log-rank test, p<0.001). The prognostic effect of FAR was more significant than that of single markers such as fibrinogen (log-rank test, p=0.001) or albumin (log-rank test, p=0.001). The prognostic effect of FAR was prominent in the stage II/III subgroup (log-rank test, p<0.001) and luminal A-like subtype (log-rank test, p<0.001). FAR was identified as a significant independent factor on both univariate (hazard ratio [HR], 2.722; 95% confidence interval [CI], 1.659-4.468; p<0.001) and multivariate analysis (HR, 2.622; 95% CI, 1.455-4.724; p=0.001). CONCLUSION: Preoperative FAR was a strong independent prognostic factor in breast cancer. Its prognostic effect was more prominent in the stage II/III subgroup and in the luminal A-like subtype. Therefore, preoperative FAR can be utilized as a useful prognosticator for breast cancer patients. Further studies are needed to validate its applications in clinical settings.

Unexpected Appendiceal Pathologies and Their Changes With the Expanding Use of Preoperative Imaging Studies.

PURPOSE: The preoperative diagnosis of acute appendicitis is often challenging. Sometimes, pathologic results of the appendix embarrass or confuse surgeons. Therefore, more and more imaging studies are being performed to increase the accuracy of appendicitis diagnoses preoperatively. However, data on the effect of this increase in preoperative imaging studies on diagnostic accuracy are limited. We performed this study to explore unexpected appendiceal pathologies and to delineate the role of preoperative imaging studies in the diagnosis of acute appendicitis. METHODS: The medical records of 4,673 patients who underwent an appendectomy for assumed appendicitis between 1997 and 2012 were reviewed retrospectively. Pathological results and preoperative imaging studies were surveyed, and the frequencies of pathological results and preoperative imaging studies were investigated. RESULTS: The overall rate of pathology compatible with acute appendicitis was 84.4%. Unexpected pathological findings, such as normal histology, specific inflammations other than acute appendicitis, neoplastic lesions, and other pathologies, comprised 9.6%, 3.3%, 1.2%, and 1.5%, respectively. The rate of unexpected pathological results was significantly reduced because of the increase in preoperative imaging studies. The decrease in normal appendices contributed the most to the reduction while other unexpected pathologies did not change significantly despite the increased use of imaging studies. This decrease in normal appendices was significant in both male and female patients under the age of 60 years, but the differences in females were more prominent. CONCLUSION: Unexpected appendiceal pathologies comprised 15.6% of the cases. Preoperative imaging studies reduced them by decreasing the negative appendectomy rate of patients with normal appendices.

Prevalence and characteristics of clinically significant retained common bile duct stones after laparoscopic cholecystectomy for symptomatic cholelithiasis.

PURPOSE: To investigate the prevalence and clinical features of retained symptomatic common bile duct (CBD) stone detected after laparoscopic cholecystectomy (LC) in patients without preoperative evidence of CBD or intrahepatic duct stones. METHODS: Of 2,111 patients who underwent cholecystectomy between September 2007 and December 2014 at Seoul Metropolitan Government-Seoul National University Boramae Medical Center, 1,467 underwent laparoscopic cholecystectomy for symptomatic gallbladder stones and their medical records were analyzed. We reviewed the clinical data of patients who underwent postoperative endoscopic retrograde cholangiopancreatography (ERCP) for clinically significant CBD stones (i.e., symptomatic stones requiring therapeutic intervention). RESULTS: Overall, 27 of 1,467 patients (1.84%) underwent postoperative ERCP after LC because of clinical evidence of retained CBD stones. The median time from LC to ERCP was 152 days (range, 60-1,015 days). Nine patients had ERCP-related complications. The median hospital stay for ERCP was 6 days. CONCLUSION: The prevalence of clinically significant retained CBD stone after LC for symptomatic cholelithiasis was 1.84% and the time from LC to clinical presentation ranged from 2 months to 2 years 9 months. Therefore, biliary surgeons should inform patients that retained CBD stone may be detected several years after LC for simple gallbladder stones.

Predictors of Morbidity and Mortality After Surgery for Intestinal Perforation.

PURPOSE: An intestinal perforation is a rare condition, but has a high mortality rate, even after immediate surgical intervention. The clinical predictors of postoperative morbidity and mortality are still not well established, so this study attempted to identify risk factors for postoperative morbidity and mortality after surgery for an intestinal perforation. METHODS: We retrospectively analyzed the cases of 117 patients who underwent surgery for an intestinal perforation at a single institution in Korea from November 2008 to June 2014. Factors related with postoperative mortality at 1 month and other postoperative complications were investigated. RESULTS: The mean age of enrolled patients was 66.0 ± 15.8 years and 66% of the patients were male. Fifteen patients (13%) died within 1 month after surgical treatment. Univariate analysis indicated that patient-related factors associated with mortality were low systolic and diastolic blood pressure, low serum albumin, low serum protein, low total cholesterol, and high blood urea nitrogen; the surgery-related factor associated with mortality was feculent ascites. Multivariate analysis using a logistic regression indicated that low systolic blood pressure and feculent ascites independently increased the risk for mortality; postoperative complications were more likely in both females and those with low estimated glomerular filtration rates and elevated serum C-reactive protein levels. CONCLUSION: Various factors were associated with postoperative clinical outcomes of patients with an intestinal perforation. Morbidity and mortality following an intestinal perforation were greater in patients with unstable initial vital signs, poor nutritional status, and feculent ascites.

Endovascular recanalization of a thrombosed native arteriovenous fistula complicated with an aneurysm: technical aspects and outcomes.

OBJECTIVE: To evaluate the technical aspects and outcomes of endovascular recanalization of a thrombosed native arteriovenous fistula (AVF) complicated with an aneurysm. MATERIALS AND METHODS: Sixteen patients who had a thrombosed AVF complicated with an aneurysm (two radiocephalic and 14 brachiocephalic) were included in this study. Recanalization procedures were performed by mechanical thrombectomy using the Arrow-Trerotola percutaneous thrombectomy device and adjunctive treatments. We evaluated dose of thrombolytic agent, underlying stenosis, procedure time, technical and clinical success, and complications. The primary and secondary patency rates were calculated using the Kaplan-Meier analysis. RESULTS: The thrombolytic agents used were 100000 U urokinase mixed with 500 IU heparin (n = 10) or a double dose of the mixture (n = 6). The thrombi in aneurysms were removed in all but two patients with non-flow limiting residual thrombi. One recanalization failure occurred due to a device failure. Aspiration thrombectomy was performed in 87.5% of cases (n = 14). Underlying stenoses were found in the outflow draining vein (n = 16), arteriovenous anastomosis or juxtaanastomosis area (n = 5), and the central vein (n = 3). Balloon angioplasty was performed for all stenoses in 15 patients. Two patients with a symptomatic central vein stenosis underwent insertion of a stent after balloon angioplasty. Mean procedure time was 116.3 minutes. Minor extravasation (n = 1) was resolved by manual compression. Both technical and clinical success rates were 93.8% (n = 15). The primary patency rates at 3, 6, and 12 months were 70.5%, 54.8%, and 31.3%, respectively. The secondary patency rates at 3, 6, and 12 months were 70.5%, 70.5%, and 47.0%, respectively. CONCLUSION: Thrombosed AVF complicated with an aneurysm can be successfully recanalized, and secondary patency can be prolonged with endovascular treatment.

Early outcome of the Korean Diagnosis-Related Groups payment system for appendectomy.

PURPOSE: The implementation of the Korean diagnosis-related groups (DRG) payment system has been recently introduced in selected several diseases including appendectomy in Korea. Here, we report the early outcomes with regard to clinical aspects and medical costs of the Korean DRG system for appendectomies in Seoul Metropolitan Government - Seoul National University Boramae Medical Center throughout comparing before and after introduction of DRG system. METHODS: The DRG system was applied since January 2013 at our institute. After the DRG system, we strategically designed and applied our algorithm for the treatment of probable appendicitis. We reviewed the patients who were treated with a procedure of appendectomy for probable appendicitis between July 2012 and June 2013, divided two groups based on before and after the application of DRG system, and compared clinical outcomes and medical costs. RESULTS: Total 416 patients were included (204 patients vs. 212 patients in the group before vs. after DRG). Shorter hospital stays (2.98 ± 1.77 days vs. 3.82 ± 1.84 days, P < 0.001) were found in the group after DRG. Otherwise, there were no significant differences in the perioperative outcomes and medical costs including costs for first hospitalization and operation, costs for follow-up after discharge, frequency of visits of out-patient's clinic or Emergency Department or rehospitalization. CONCLUSION: In the Korean DRG system for appendectomy, there were no significant differences in perioperative outcomes and medical costs, except shorter hospital stay. Further studies should be continued to evaluate the current Korean DRG system for appendectomy and further modifications and supplementations are needed in the future.

Different Responses of Neointimal Cells to Imatinib Mesylate and Rapamycin Compared with Normal Vascular Smooth Muscle Cells.

PURPOSE: This study was designed to investigate whether vascular smooth muscle cells (VSMC) from the neointima showed any different response to anti-proliferative agents, such as rapamycin or imatinib mesylate, compared to VSMCs from normal artery. MATERIALS AND METHODS: Intimal hyperplasia was made by carotid balloon in jury in male rats. Neointimal cells at 4 weeks after injury and normal VSMCs were extracted by enzymatic isolation method and cultured. Cell viability and proliferation were tested in VSMCs from injured left carotid artery and uninjured right carotid artery. Tests were repeated with rapamycin, imatinib mesylate or both in various concentrations. RESULTS: Rapamycin decreased cell viability only at a high concentration of 10(-5) M in uninjured VSMCs. Combined drugs decreased cell viability at a lower concentration of 10(-7) M in uninjured VSMCs, and at a higher concentration of 10(-5) M in neointimal cells. Overall, rapamycin showed cytocidal effects at a high concentration of 10(-5) M, whereas imatinib did not. Cell proliferation of neointima was significantly decreased along with the drug concentration. Cell proliferation of uninjured VSMCs was significantly decreased at higher drug concentrations. Combined drug therapy showed synergistic effects. Overall, neointimal cells are more susceptible to the antiproliferative effects of the drugs. CONCLUSION: Neointimal cells from the injured carotid artery are more susceptible to the antiproliferative effect of imatinib and rapamycin. Both drugs can be a used for the prevention of intimal hyperplasia, which could be investigated through further in vivo studies.

Individualized Cutoff Value of the Preoperative Carcinoembryonic Antigen Level is Necessary for Optimal Use as a Prognostic Marker.

PURPOSE: Carcinoembryonic antigen (CEA) is an important prognostic marker in colorectal cancer (CRC). However, in some stages, it does not work. We performed this study to find a way in which preoperative CEA could be used as a constant prognostic marker in harmony with the TNM staging system. METHODS: Preoperative CEA levels and recurrences in CRC were surveyed. The distribution of CEA levels and the recurrences in each TNM stage of CRC were analyzed. An optimal cutoff value for each TNM stage was calculated and tested for validity as a prognostic marker within the TNM staging system. RESULTS: The conventional cutoff value of CEA (5 ng/mL) was an independent prognostic factor on the whole. However, when evaluated in subgroups, it was not a prognostic factor in stage I or stage III of N2. A subgroup analysis according to TNM stage revealed different CEA distributions and recurrence rates corresponding to different CEA ranges. The mean CEA levels were higher in advanced stages. In addition, the recurrence rates of corresponding CEA ranges were higher in advanced stages. Optimal cutoff values from the receiver operating characteristic curves were 7.4, 5.5, and 4.5 ng/mL for TNM stage I, II, and III, respectively. Those for N0, N1, and N2 stages were 5.5, 4.8, and 3.5 ng/mL, respectively. The 5-year disease-free survivals were significantly different according to these cutoff values for each TNM and N stage. The multivariate analysis confirmed the new cutoff values to be more efficient in discriminating the prognosis in the subgroups of the TNM stages. CONCLUSION: Individualized cutoff values of the preoperative CEA level are a more practical prognostic marker following and in harmony with the TNM staging system.