Seong Yeop Ryu

Chemical composition of post-harvest biomass burning aerosols in Gwangju, Korea

Abstract The main objective of this study was to investigate the chemical characteristics of post-harvest biomass burning aerosols from field burning of barley straw in late spring and rice straw in late fall in rural areas of Korea. A 12-hr integrated intensive sampling of particulate matter (PM) with an aerodynamic diameter less than or equal to 10 μm (PM10) and PM with an aerodynamic diameter less than or equal to 2.5 μm (PM25) biomass burning aerosols had been conducted continuously in Gwangju, Korea, during two biomass burning periods: June 4–15, 2001, and October 8–November 14, 2002. The fine and coarse particles of biomass burning aerosols were analyzed for mass and ionic, elemental, and carbonaceous species. The average fine and coarse mass concentrations of biomass burning aerosols were, respectively, 129.6 and 24.2 μg/m3 in June 2001 and 47.1 and 33.2 μg/m3 in October–November 2002. An exceptionally high PM2.5 concentration of 157.8 μg/m3 was observed during biomass burning events under stagnant atmospheric conditions. In the fine mode, chlorine and potassium were unusually rich because of the high content of semi-arid vegetation. Both organic carbon (OC) and elemental carbon increased during the bio-mass burning periods, with the former exhibiting a higher abundance. PM from the open field burning of agricultural waste has an adverse impact on local air quality and regional climate.

Comparison of short-term surgical outcomes between laparoscopic and open total gastrectomy for gastric carcinoma: case-control study using propensity score matching method.

BACKGROUND To evaluate the technical feasibility and safety of laparoscopic total gastrectomy (LTG) for gastric carcinoma, this study compared short-term surgical outcomes between LTG and open total gastrectomy (OTG) using the propensity score matching method. STUDY DESIGN After generating propensity scores given the covariates of age, sex, body mass index, comorbidity, American Society of Anesthesiologists (ASA) score, operators, and tumor stage, 122 patients with LTG were matched to 122 OTG patients using the nearest available score matching. Operative outcomes and hospital courses were compared in the matched groups and in the subgroups by the extent of lymph node dissection (LND). RESULTS The 2 study groups were well balanced with respect to the baseline characteristics of the propensity score derivation model. In the analysis of overall patients, the LTG group showed significantly longer operating time (289 vs 203 min, p < 0.001), but postoperative outcomes, including hospital stay, morbidity, and mortality, were similar in the 2 groups. In the subgroup with D1 + ß LND (perigastric nodes + Nos. 7, 8a, 9, 11p), the LTG group showed no significant differences in hospital stay, morbidity, and mortality from the OTG group. However, in the subgroup with D2 LND (perigastric nodes + Nos. 7, 8a, 9, 10, 11p, 11d, 12a), the LTG group showed significantly increased morbidity (52.6% vs 21.0%, p = 0.007) and tendency toward increased length of hospital stay and mortality as compared with the OTG group. CONCLUSIONS Laparoscopic total gastrectomy is a safe and feasible technique for treatment of upper gastric carcinoma. However, LTG with D2 LND for upper gastric cancer may increase the operative risk and requires considerable experience in laparoscopic surgery.

T4 gastric carcinoma : The benefit of non-curative resection

Background:  The prognosis of patients with gastric carcinoma with invasion of the adjacent organs (T4 gastric carcinoma) is very poor. We evaluated the survival benefit of resection in this group of patients.

Feasibility Study of Early Oral Intake after Gastrectomy for Gastric Carcinoma

Purpose Despite the compelling scientific and clinical data supporting the use of early oral nutrition after major gastrointestinal surgery, traditional bowel rest and intravenous nutrition for several postoperative days is still being used widely after gastric cancer surgery. Materials and Methods A phase II study was carried out to evaluate the feasibility and safety of postoperative early oral intake (water intake on postoperative days (POD) 1-2, and soft diet on POD 3) after a gastrectomy. The primary outcome was morbidity within 30 postoperative days, which was targeted at <25% based on pilot study data. Results The study subjects were 90 males and 42 females with a mean age 61.5 years. One hundred and four (79%) and 28 (21%) patients underwent a distal and total gastrectomy, respectively. The postoperative morbidity rate was within the targeted range (15.2%, 95% CI, 10.0~22.3%), and there was no hospital mortality. Of the 132 patients, 117 (89%) successfully completed a postoperative early oral intake regimen without deviation; deviation in 10 (8%) due to gastrointestinal symptoms and in five (4%) due to the management of postoperative complications. The mean times to water intake and a soft diet were 1.0±0.2 and 3.2±0.7 days, respectively, and the mean hospital stay was 10.0±6.1 days. Conclusions Postoperative early oral intake after a gastrectomy is feasible and safe, and can be adopted as a standard perioperative care after a gastrectomy. Nevertheless, further clinical trials will be needed to evaluate the benefits of early oral nutrition after upper gastrointestinal surgery.

The value of preoperative lung spirometry test for predicting the operative risk in patients undergoing gastric cancer surgery

Purpose We evaluated the predictive value of preoperative lung spirometry test for postoperative morbidity and the nature of complications related to an abnormal pulmonary function after gastric cancer surgery. Methods Between February 2009 and March 2010, 538 gastric cancer patients who underwent laparoscopic (n = 247) and open gastrectomy (n = 291) were divided into the normal (forced expiratory volume in 1 second [FEV1]/forced vital capacity [FVC] ≥ 0.7, n = 441) and abnormal pulmonary function group (FEV1/FVC < 0.7, n = 97), according to the preoperative lung spirometry test. The predictive value of lung spirometry for postoperative morbidity was evaluated using the univariate and multivariate analysis. Results After surgery, the abnormal pulmonary function group showed a significantly increased incidence of local (29.9% vs. 18.1%, P = 0.009) and systemic complications (8.2% vs. 2.0%, P = 0.005) than the normal group. Of local complications, anastomosis leakage and wound complication were found to be more common in the abnormal pulmonary function group. In the univariate and multivariate analysis, an abnormal pulmonary function was an independent predictor for postoperative local complication (odds ratio, 1.75; 95% confidence interval, 1.03 to 2.97) after adjusted by old age, total gastrectomy, open surgery, and tumor-node-metastasis stage. Meanwhile, an old age and a history of pulmonary disease were independent predictors for systemic complication. Conclusion Preoperative lung spirometry is a simple and useful means to predict postoperative morbidity after gastric cancer surgery. In view of its simplicity and low cost, we recommend adding preoperative lung spirometry test to assess the operative risk and aid in proper perioperative treatment planning.

Laparoscopic Distal Gastrectomy for Gastric Cancer in Morbidly Obese Patients in South Korea

Purpose Laparoscopic gastrectomy in obese patients has been investigated in several studies, but its feasibility has rarely been examined in morbidly obese patients, such as in those with a body mass index (BMI) of ≥30 kg/m2. The present study aimed to evaluate the technical feasibility and safety of laparoscopic gastrectomy in morbidly obese patients with gastric cancer. Materials and Methods A total of 1,512 gastric cancer patients who underwent laparoscopic distal gastrectomy (LDG) were divided into three groups: normal (BMI<25 kg/m2, n=996), obese (BMI 25~30 kg/m2, n=471), and morbidly obese (BMI≥30 kg/m2, n=45). Short-term surgical outcomes, including the course of hospitalization and postoperative complications, were compared between the three groups. Results The morbidly obese group had a significantly longer operating time (240 minutes vs. 204 minutes, P=0.010) than the normal group, but no significant differences were found between the groups with respect to intraoperative blood loss or other complications. In the morbidly obese group, the postoperative morbidity and mortality rates were 13.3% and 0%, respectively, and the mean length of hospital stay was 8.2 days, which were not significantly different from those in the normal group. Subgroup analysis showed that postoperative complication rates were not high in morbidly obese patients, independent of the type of anastomosis technique used and level of lymph node dissection. Conclusions LDG is technically feasible and safe in morbidly obese patients with a BMI of ≥30 kg/m2 and early gastric carcinoma. Except for a longer operating time, LDG might represent a reasonable treatment option in these patients.

Analysis of 30-day postdischarge morbidity and readmission after radical gastrectomy for gastric carcinoma: a single-center study of 2107 patients with prospective data.

AbstractPD morbidity and readmission pose a substantial clinical and economic burden to the healthcare system. Comprehensive PD complications and readmission data are essential for developing initiatives to improve patient care. No previous studies have extensively investigated PD complications after gastric cancer surgery.We investigated the incidence, types, treatment, and risk factors of 30-day postdischarge (PD) complications after gastric cancer surgery.Between 2010 and 2013, data concerning complications and readmission within 30 days of hospital discharge were prospectively collected in 2107 patients undergoing gastric cancer surgery.In total, 1642 patients (77.9%) underwent distal gastrectomy, 418 (19.8%) total gastrectomy, and 47 (2.3%) other procedures. Postoperative morbidity and mortality were 17.4% and 0.6%, respectively, with a mean 8.8-day hospital stay. Sixty-one patients (2.9%) developed 30-day PD morbidity (58 local and 3 systemic complications), accounting for 16.6% of overall morbidity; 47 (2.2%) were readmitted; and 7 (0.3%) underwent a reoperation. The mean time to PD complications was 9.5 days after index hospital discharge. The most common complication was intra-abdominal abscess (n = 14), followed by wound, ascites, and anastomosis leakage. No mortality occurred resulting from PD complications. In the univariate and multivariate analyses, underlying comorbidity (hypertension and liver cirrhosis) and obesity were independent risk factors for developing PD complications.The early PD period is a vulnerable time for surgical patients with substantial risk of complication and readmission. Tailored discharge plans along with appropriate PD patient support are essential for improving the quality of patient care.

Outcomes of Abdominal Total Gastrectomy for Type II and III Gastroesophageal Junction Tumors: Single Center's Experience in Korea.

Purpose The aim of this study was to evaluate the surgical outcomes of abdominal total gastrectomy, without mediastinal lymph node dissection for type II and III gastroesophageal junction (GEJ) cancers. Materials and Methods We retrospectively reviewed surgical outcomes in 67 consecutive patients with type II and III GEJ cancers that were treated by the surgical resection between 2004 and 2008. Results Thirty (45%) patients had type II and 37 (55%) had type III tumor. Among the 65 (97%) patients with curative surgery, 21 (31%) patients underwent the extended total gastrectomy with trans-hiatal distal esophageal resection, and in 44 (66%) patients, abdominal total gastrectomy alone was done. Palliative gastrectomy was performed in two patients due to the accompanying peritoneal metastasis. The postoperative morbidity and mortality rates were 21.4% and 1.5%, respectively. After a median follow up of 36 months, the overall 3-years was 68%, without any differences between the Siewert types or the operative approaches (transhiatal approach vs. abdominal approach alone). On the univariate analysis, the T stage, N stage and R0 resection were found to be associated with the survival, and multivariate analysis revealed that the N stage was a poor independent prognostic factor for survival. Conclusions Type II and III GEJ cancers may successfully be treated with the abdominal total gastrectomy, without mediastinal lymph node dissection in the Korean population.

Accuracy of Surgical Diagnosis in Detecting Early Gastric Cancer and Lymph Node Metastasis and Its Role in Determining Limited Surgery

BACKGROUND The aim of this study was to evaluate the accuracy of surgical diagnosis of early gastric cancer (EGC) and lymph node metastasis, and elucidate its role in determining limited surgery for EGC. STUDY DESIGN We reviewed 369 patients undergoing gastrectomy for primary gastric carcinoma. Surgical diagnosis was evaluated by determining its sensitivity, specificity, and accuracy, and was compared with preoperative examinations. RESULTS Sensitivity, specificity, and accuracy of intraoperative diagnosis for EGC were 74.5%, 95.7%, and 83.7%, respectively. The predictive value for EGC by intraoperative diagnosis was 95.7%. Surgical diagnosis of EGC showed higher specificity and predictive value than preoperative examinations did, which significantly reduced the risk of underestimating advanced gastric cancer (AGC) to EGC. The sensitivity, specificity, and accuracy for lymph node metastasis by surgical diagnosis were 73.2%, 78.1%, and 76.4%, respectively. In 70 patients with a discrepancy in the diagnosis of EGC between pre- and intraoperative diagnoses, surgical diagnosis was correct in 63 (90%) patients, but preoperative examination was correct in only 7 (10%) patients. CONCLUSIONS Surgical diagnosis shows better accuracy than preoperative examinations do in detecting EGC and lymph node metastasis. Our results suggest that the decision to perform limited surgery based on surgical diagnosis might reduce the risk of undertreatment of AGC to EGC better than preoperative examinations.

Modified radical lymphadenectomy without splenectomy in patients with proximal gastric cancer: Comparison with standard D2 lymphadenectomy for distal gastric cancer

We assessed the optimal extent of lymph node dissection and the effect of splenectomy in patients with proximal gastric cancer.