Yunhee Choi

Nomogram Predicting Long-Term Survival After D2 Gastrectomy for Gastric Cancer

PURPOSE The aim of this study was to combine clinicopathologic variables associated with overall survival after gastric resection with D2 lymphadenectomy (D2 gastrectomy) for gastric cancer into a prediction nomogram. PATIENTS AND METHODS We retrospectively analyzed 7,954 patients who underwent D2 gastrectomy for gastric cancer at Seoul National University Hospital (SNUH) in Seoul, Korea. Two thirds of the patients were randomly assigned to the training set (n = 5,300), and one third were assigned to the validation set (n = 2,654). Multivariate analysis by Cox proportional hazards regression was performed using the training set, and the nomogram was constructed. Discrimination and calibration were performed using the SNUH validation set. Additional external validation was performed using the data set (n = 2,500) from Cancer Institute Ariake Hospital (CIAH) in Tokyo, Japan. RESULTS The multivariate Cox model identified age at diagnosis, sex, location, depth of invasion, number of metastatic lymph nodes, and number of examined lymph nodes as covariates associated with survival. In the SNUH validation set, the nomogram exhibited superior discrimination power compared with the seventh American Joint Committee on Cancer TNM classification (Harrells C-index, 0.78 v 0.69, respectively; P < .001). Calibration of the nomogram predicted survival corresponding closely with the actual survival. In the CIAH validation set, discrimination was good (C-index, 0.79), and the predicted survival was within a 10% margin of ideal nomogram. CONCLUSION We developed a nomogram predicting 5- and 10-year overall survival after D2 gastrectomy for gastric cancer. Validation using the SNUH and CIAH data sets revealed good discrimination and calibration, suggesting good clinical utility. The nomogram improved individualized predictions of survival.

Spontaneous Evolution in Bilirubin Levels Predicts Liver-related Mortality in Patients with Alcoholic Hepatitis

The accurate prognostic stratification of alcoholic hepatitis (AH) is essential for individualized therapeutic decisions. The aim of this study was to develop a new prognostic model to predict liver-related mortality in Asian AH patients. We conducted a hospital-based, retrospective cohort study using 308 patients with AH between 1999 and 2011 (a derivation cohort) and 106 patients with AH between 2005 and 2012 (a validation cohort). The Cox proportional hazards model was constructed to select significant predictors of liver-related death from the derivation cohort. A new prognostic model was internally validated using a bootstrap sampling method. The discriminative performance of this new model was compared with those of other prognostic models using a concordance index in the validation cohort. Bilirubin, prothrombin time, creatinine, potassium at admission, and a spontaneous change in bilirubin levels from day 0 to day 7 (SCBL) were incorporated into a model for AH to grade the severity in an Asian patient cohort (MAGIC). For risk stratification, four risk groups were identified with cutoff scores of 29, 37, and 46 based on the different survival probabilities (P<0.001). In addition, MAGIC showed better discriminative performance for liver-related mortality than any other scoring system in the validation cohort. MAGIC can accurately predict liver-related mortality in Asian patients hospitalized for AH. Therefore, SCBL may help us decide whether patients with AH urgently require corticosteroid treatment.

The Selection of Open or Percutaneous Endoscopic Lumbar Discectomy According to an Age Cut-off Point: Nationwide Cohort Study.

Study Design. Retrospective cohort study. Objective. To provide an age cut-off of percutaneous endoscopic lumbar discectomy (PELD) for optimal reoperation rate with nationwide population-based data. Summary of Background Data. Open discectomy is the standard operation for lumbar herniated intervertebral disk disease (HIVD). PELD has shown noninferior outcome to open discectomy and there is increasing interest with regard to PELD. However, PELD may not be a suitable option for all age groups. Methods. We selected 15,817 patients who underwent open discectomy (n = 12,816) or PELD (n = 3001) in 2003 from the Korean Health Insurance Review & Assessment Service (HIRA) database. All patients in the cohort were followed until December 31, 2008, and the minimum follow-up period was 5 years. A time-to-event survival analysis was conducted. The primary endpoint was any type of second lumbar spine surgery during the follow-up period. Minimum P-value approach and a 2-fold cross-validation approach were utilized to determine an age cut-off point. Results. The optimal age cut-off point was determined as 57 years. PELD for older patients (≥57 years) had a higher reoperation risk during the postoperative 3.4 years (hazard ratio [HR] at 1 yr, 1.75; 2 yr, 1.57; and 3 yr, 1.41). However, the reoperation risk was not higher after PELD for patients younger than 57 years, from 1.9 years, than open discectomy (HR at 2 yr, 0.86; 3 yr, 0.78; 4 yr, 0.70; and 5 yr, 0.63). Conclusion. In the present study, we showed that an age cut-off point of PELD for optimal reoperation rate may be 57 years, based on nationwide population-based data. The reoperation rate does not seem to be higher for patients younger than 57 years after PELD than after open discectomy; however, PELD for older patients should be applied after careful consideration. Level of Evidence: 3

Increased Volume of Lumbar Surgeries for Herniated Intervertebral Disc Disease and Cost-effectiveness Analysis: A Nationwide Cohort Study

Study Design. Retrospective cohort study of a nationwide database. Objective. The primary objective was to summarize the use of surgical methods for lumbar herniated intervertebral disc disease (HIVD) at two different time periods under the national health insurance system. The secondary objective was to perform a cost-effectiveness analysis by utilizing incremental cost-effectiveness ratio (ICER). Summary of Background Data. The selection of surgical method for HIVD may or may not be consistent with cost effectiveness under national health insurance system, but this issue has rarely been analyzed. Methods. The data of all patients who underwent surgeries for HIVD in 2003 (n = 17,997) and 2008 (n = 38,264) were retrieved. The surgical methods included open discectomy (OD), fusion surgery, laminectomy, and percutaneous endoscopic lumbar discectomy (PELD). The hospitals were classified as tertiary-referral hospitals (≥300 beds), medium-sized hospitals (30–300 beds), or clinics (<30 beds). ICER showed the difference in the mean total cost per 1% decrease in the reoperation probability among surgical methods. The total cost included the costs of the index surgery and the reoperation. Results. In 2008, the number of surgeries increased by 2.13-fold. The number of hospitals increased by 34.75% (731 in 2003 and 985 in 2008). The proportion of medium-sized hospitals increased from 62.79% to 70.86%, but the proportion of surgeries performed at those hospitals increased from 61.31% to 85.08%. The probability of reoperation was highest after laminectomy (10.77%), followed by OD (10.50%), PELD (9.20%), and fusion surgery (7.56%). The ICERs indicated that PELD was a cost-effective surgical method. The proportion of OD increased from 71.21% to 84.12%, but that of PELD decreased from 16.68% to 4.57%. Conclusion. The choice of surgical method might not always be consistent with cost-effectiveness strategies, and a high proportion of medium-sized hospitals may be responsible for this change. Level of Evidence: 4

Effect of perioperative oral nutritional supplementation in malnourished patients who undergo gastrectomy: A prospective randomized trial

Background: The aim of this study was to examine the effect of a perioperative oral nutritional supplement in malnourished patients who undergo gastrectomy. Methods: Patients who were determined as being moderately or severely malnourished according to a patient‐generated subjective global assessment or who had a body mass index <18.5, were enrolled. The oral nutritional supplement group received 500 mL/d of standard oral nutritional supplement for 2 weeks before gastrectomy and for 4 weeks postoperatively. The primary endpoint was postoperative complications (Clavien‐Dindo classification ≥II). The secondary endpoints included body weight changes, biochemical parameters, and quality of life survey results. Results: A total of 127 patients (65 in the oral nutritional supplement group and 62 in the control group) were enrolled. The complication rates were not significantly different (29.2% versus 37.1%, P = .346). However, the incidences of overall complications, complications persisting until postoperative week 3 or 5, and severe complications (grade ≥IIIa) were significantly lower in the oral nutritional supplement group for patients with patient‐generated subjective global assessment grade C. Total lymphocyte counts were significantly higher in the oral nutritional supplement group at postoperative weeks 3 and 5. For most patients, oral nutritional supplement was well tolerated preoperatively. However, only 26.2% and 50.8% of the patients in the oral nutritional supplement group could consume >250 mL/d of oral nutritional supplement postoperatively during the 2nd and 4th weeks, respectively. Conclusions: The routine application of perioperative oral nutritional supplement is not recommended for malnourished patients receiving gastrectomy. However, perioperative standard oral nutritional supplement administration may reduce the incidence, severity, and duration of complications after gastrectomy in severely malnourished patients (patient‐generated subjective global assessment grade C).

Risk Factors and Prognosis for Acute Progression of Myelopathic Symptoms in Patients Ossification of the Posterior Longitudinal Ligament After Minor Trauma

Study Design. A retrospective cohort study. Objective. The aim of this study was to identify the risk factors for acute progression of myelopathic symptoms (PMS) associated with ossification of the posterior longitudinal ligament (OPLL) after minor trauma and to compare the prognosis between an acute PMS group and a chronic PMS group. Summary of Background Data. Although the prevalence of OPLL among patients with cervical myelopathy is high, few studies have been published regarding the risk factors for acute PMS associated with OPLL after minor trauma. Methods. Patients with OPLL who had histories of minor trauma and had undergone surgery were divided according to clinical course into an acute (within 48 hours, n = 38) and a chronic PMS group (n = 32). The type of trauma and the clinical and radiologic characteristics were compared. The clinical outcomes were also compared at admission and at 1 and 2 years postoperatively. Results. The types of trauma were significantly different between the two groups (P < 0.05). Univariate analysis revealed that older age, a narrower space available for the cord, and a higher rate of stenosis in the spinal canal were associated with acute PMS after minor trauma (P = 0.014, 0.020, and 0.006, respectively). However, the rate of stenosis in the spinal canal was the only risk factor that was identified in a multivariate analysis (P = 0.023; odds ratio, 0.872; 95% confidence interval, 0.774–0.982). The Japanese Orthopedic Association scores at the initial visit and at postoperative years 1 and 2 were significantly lower in the acute PMS group than in the chronic PMS group (P < 0.001, P < 0.001, and P < 0.001, respectively). Conclusion. One risk factor for acute PMS in patients with OPLL after minor trauma is a higher rate of stenosis of the spinal canal. Patients with acute PMS exhibited unfavorable neurologic outcomes. Preventive surgical treatment may be recommended for patients with significant OPLL with mild cervical myelopathy. Level of Evidence: 3