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Kenneth J Chang

Publications and source records attributed to Kenneth J Chang.

13 recordsLinked to original sources
PubMed2026

Endoscopic Ultrasound-Guided Versus Transjugular Portal Pressure Measurements: Systematic Review and Meta-Analysis.

PURPOSE: Published reviews of endoscopic ultrasound-guided portal pressure gradient (EUS-PPG) have emphasized feasibility and safety. We performed a systematic review and meta-analysis specifically to evaluate how closely EUS-based portal pressure measurements track invasive comparator measurements in prospective paired studies and to summarize agreement, technical success, and adverse events. METHODS: We searched major databases through January 2026 for prospective cohorts reporting same-patient EUS-based portal pressure measurement and invasive hemodynamic measurements. Correlations were pooled with random-effects models and analyzed separately for studies comparing EUS-PPG with hepatic venous pressure gradient (HVPG) and studies comparing EUS-based portal measurements with direct portal venous pressure. Agreement and threshold discordance were summarized descriptively. RESULTS: Six prospective cohorts (127 attempted procedures) were included. In studies using HVPG as the comparator, the pooled correlation was 0.82 (95% CI, 0.72-0.89; I2 = 0%). In studies comparing EUS-based portal measurements with direct portal venous pressure, the pooled correlation was 0.86 (95% CI, 0.72-0.93; I2 = 16.9%). Technical success was 95.3%. EUS-PPG-attributed adverse events occurred in 2.4% of procedures, with no procedure-related deaths. Agreement data were limited. Reported limits of agreement were wide (approximately - 6 to + 7 mmHg), and discrepancies of 5 mmHg or greater occurred in 4 of 30 paired measurements. CONCLUSIONS: EUS-based portal pressure measurement is feasible and shows a strong association with invasive hemodynamic comparators, but the evidence base remains small (six cohorts, 127 attempted procedures). Further study will be necessary to establish patient-level agreement, procedural reproducibility, EUS-specific clinically significant portal hypertension thresholds, and whether HVPG-based decision thresholds can be transferred to EUS-derived measurements.

Humans↗
PubMed2005

Risk of pancreatic adenocarcinoma: disparity between African Americans and other race/ethnic groups.

BACKGROUND: African Americans have a higher incidence of pancreatic adenocarcinoma compared with non-Hispanic whites. Whether other clinical differences exist between these two groups is not well known. METHODS: The authors conducted a population-based retrospective analysis of all patients with pancreatic adenocarcinoma in both a regional and a statewide database between 1988 and 1998. Their goal was to evaluate differences in incidence rates, clinical presentation, including age at diagnosis, gender, and tumor characteristics, and treatment among race/ethnic groups. RESULTS: African Americans had a higher age-adjusted incidence rate of pancreatic adenocarcinoma (8.78) compared with non-Hispanic whites (5.89), Hispanics (5.09), Asians (4.75), and all race/ethnicities combined (5.82). African Americans also presented at a later stage of disease and received less surgery than all other race/ethnicities, despite equal availability of medical insurance. The analyses also revealed gender differences. In general, males maintained a higher incidence rate of pancreatic adenocarcinoma than females across all race/ethnicities. In all race/ethnic groups, females were diagnosed at an older age and an earlier stage of disease than males. The proportional hazard mortality ratio for females age < 60 was significantly less than that for males in the same age group (P < 0.02), even after accounting for stage and treatment. CONCLUSIONS: African Americans in California had a higher incidence rate of pancreatic adenocarcinoma, had a slightly higher risk of presenting with advanced-stage disease and with nonresectable tumors (i.e., tumors located in the body or tail of the pancreas), and underwent less surgical treatment than all other race/ethnicities. Younger females in all race/ethnic groups had a survival advantage over males of the same age.

Adenocarcinoma↗
PubMed2005

Endoscopic ultrasound-guided fine-needle injection.

With the development of linear array echoendoscopes and the ability to perform endoscopic ultrasound (EUS)-guided fine-needle aspiration, the delivery of therapeutic agents with fine-needle injection (FNI) emerged. EUS-guided FNI is an attractive delivery system because of its minimal invasiveness and low complication rate. This approach is effective in performing celiac plexus neurolysis for pain relief in patients with pancreatic cancer. The most exciting area of interest involves the delivery of antitumor agents in patients with locally advanced cancer, such as cancer of the pancreas or esophagus. The involvement of EUS-guided FNI in tumor therapy adds a host of potential new applications that continue to swing the pendulum of EUS from a diagnostic to a therapeutic modality.

Antineoplastic Agents↗
PubMed2005

Endoscopic palliation of pancreatic adenocarcinoma.

PURPOSE OF REVIEW: Endoscopic therapies have become an indispensable modality in the treatment and palliation of complications from pancreatic adenocarcinoma. This review focuses on treatment of biliary obstruction, malignant gastric outlet obstruction, and intractable abdominal pain resulting from unresectable pancreatic adenocarcinoma. Novel and emerging endoscopic approaches are also briefly discussed. RECENT FINDINGS: Endoscopic placement of a biliary stent is the modality of choice for palliation of biliary obstruction. Biliary self-expanding metal stents should be placed if expected survival is more than 6 months and plastic stents if expected survival is less than 6 months. For endoscopic palliation of gastric outlet obstruction, enteral self-expanding metal stents should be placed. Biliary self-expanding metal stents should be considered prior to the placement of a duodenal stent. Palliation of intractable abdominal pain can safely be performed with endoscopic ultrasound-guided celiac plexus neurolysis using bupivacaine and absolute alcohol. Exciting novel endoscopic approaches are being evaluated especially in the area of drug-eluted biliary stents, endoscopic creations of enteral anastomoses, and endoscopic ultrasound-guided injection of gene vectors. SUMMARY: The frontier of endoscopic palliative therapies for pancreatic adenocarcinoma is expanding. Clinical trials are needed to evaluate novel endoscopic approaches.

Adenocarcinoma↗
PubMed2005

Negative predictive value of endoscopic ultrasound in a large series of patients with a clinical suspicion of pancreatic cancer.

OBJECTIVES: Endoscopic ultrasound (EUS) has been shown to be very accurate in the diagnosis and staging of pancreatic cancer. The accuracy of EUS in predicting the absence of pancreatic cancer in a large series of patients with a clinical suspicion of pancreatic cancer is not well documented. Our aim was to determine the negative predictive value (NPV) of EUS in patients with a suspicion of pancreatic cancer. METHODS: We retrospectively reviewed, from our EUS database (between January 1999 and March 2003), 693 patients who were suspected of having pancreatic cancer and had EUS examinations. A total of 155 patients were found by EUS to have a completely normal pancreas. Indications for EUS in these patients included: weight loss/abdominal pain; and/or pancreatic enlargement/fullness on computed tomography (CT); and/or bile duct/pancreatic duct narrowing on endoscopic retrograde cholangiopancreatography; and/or an elevated CA 19-9. Follow-up information was obtained in 135/155 (87%) patients from patient phone calls and/or physician visits and/or CT scan. The mean follow-up period was 25 months (range 8-48 months). RESULTS: No patients developed pancreatic cancer during the follow-up period. Following the EUS examination, no work-up was required in 119/135 (88%) of patients. CT scan was performed in 16 patients at 6 months post-procedure, none of which showed a pancreatic mass. The NPV of EUS in excluding pancreatic cancer in those patients with follow-up was 100%. CONCLUSION: EUS is highly specific in the diagnosis of pancreatic cancer with a NPV of 100% and obviates the need for further diagnostic testing. In patients with a clinical suspicion of pancreatic cancer, EUS should be considered as the initial diagnostic modality.

Adult↗
PubMed2004

Reduced expression of epidermal growth factor receptor-related protein in hepatocellular carcinoma: implications for cancer growth.

BACKGROUND/AIMS: The mitogenic signaling pathway of epidermal growth factor receptor (EGFR) is activated in a variety of cancers, including hepatocellular carcinoma (HCC). The recently cloned EGFR-related protein (ERRP) has been proposed to be a negative regulator of EGFR. The expression of ERRP in non-malignant liver cells and in HCC, and its relation to cell proliferation, have not been examined. METHODS: Paraffin sections of formalin-fixed HCC specimens of 51 HCCs and 10 normal liver specimens were immunostained with anti-ERRP and anti-p53 antibodies. To determine the relationship between ERRP expression and cell proliferation, we performed double staining for ERRP and proliferating cell nuclear antigen (PCNA) in the same HCC specimens. RESULTS: In normal liver, ERRP was expressed in 100% of specimens, while in non-malignant liver tissue from HCC, ERRP expression was present in 50% of the specimens (p < 0.001). In contrast, ERRP expression was present only in 14% of the HCC specimens. The expression of ERRP in cancer cells was inversely correlated with proliferative activity and tumor size (p < 0.001, p < 0.05, respectively). No significant correlation was found between p53 expression and the expression of ERRP. CONCLUSIONS: Human HCC, which has been shown to be associated with increased activation of EGFR, exhibits a substantial reduction in ERRP expression. The inverse relationship between ERRP expression, proliferative activity of tumor cells and tumor size suggests that in some HCC, ERRP is a negative regulator of HCC growth.

Carcinoma, Hepatocellular↗
PubMed2004

Acute pancreatitis after EUS-guided FNA of solid pancreatic masses: a pooled analysis from EUS centers in the United States.

BACKGROUND: The aim of this study was to determine the frequency and the severity of pancreatitis after EUS-guided FNA of solid pancreatic masses. A survey of centers that offer training in EUS in the United States was conducted. METHODS: A list of centers in which training in EUS is offered was obtained from the Web site of the American Society for Gastrointestinal Endoscopy. Designated program directors were contacted via e-mail. The information requested included the number of EUS-guided FNA procedures performed for solid pancreatic masses, the number of cases of post-procedure pancreatitis, and the method for tracking complications. For each episode of pancreatitis, technical details were obtained about the procedure, including the location of the mass, the type of fine needle used, the number of needle passes, and the nature of the lesion. RESULTS: Nineteen of the 27 programs contacted returned the questionnaire (70%). In total, 4909 EUS-guided FNAs of solid pancreatic masses were performed in these 19 centers over a mean of 4 years (range 11 months to 9 years). Pancreatitis occurred after 14 (0.29%): 95% CI[0.16, 0.48] procedures. At two centers in which data on complications were prospectively collected, the frequency of acute pancreatitis was 0.64%, suggesting that the frequency of pancreatitis in the retrospective cohort (0.26%) was under-reported (p=0.22). The odds that cases of pancreatitis would be reported were 2.45 greater for the prospective compared with the retrospective cohort (95% CI[0.55, 10.98]). The median duration of hospitalization for treatment of pancreatitis was 3 days (range 1-21 days). The pancreatitis was classified as mild in 10 cases, moderate in 3, and severe in one; one death (proximate cause, pulmonary embolism) occurred after the development of pancreatitis in a patient with multiple comorbid conditions. CONCLUSIONS: EUS-guided FNA of solid pancreatic masses is infrequently associated with acute pancreatitis. The procedure appears to be safe when performed by experienced endosonographers. The frequency of post EUS-guided FNA pancreatitis may be underestimated by retrospective analysis.

Acute Disease↗
PubMed2002

A resource utilization projection study of EUS.

BACKGROUND: EUS has emerged as standard practice with respect to the diagnosis and staging of GI malignancies. Whether currently available resources are sufficient to meet the potential need for EUS is uncertain. This study examines the hypothetical demand for EUS in the United States. METHODS: EUS cases performed at 3 centers with well-established expertise in EUS in 1997 were retrospectively reviewed and trends were extrapolated to national cancer statistics. Indications for EUS fell into 3 categories: (1) diagnosis/staging of esophageal, gastric, pancreatic, or rectal cancers (established indications); (2) suspected GI malignancy (obligate "rule out"); and (3) "other" (emerging indications). Hypothetical total numbers of cases in which EUS could be performed in the United States were calculated taking into consideration the expected number of GI malignancies for which EUS would be appropriate (based on cancer statistics for 2000), the fraction unresectable by CT, the fraction of elderly nonsurgical candidates, proportionate "rule out" cases, as well as "other" emerging indications. RESULTS: The calculated hypothetical number of cases (United States) in which EUS would be indicated is 79,568 per year (10,287 esophagus, 10,666 stomach, 23,069 pancreas, and 35,546 rectal). If "other" indications remained constant at 12%, there would potentially be 89,116 EUS procedures performed per year, with a conservative estimate of 79,572 per year. CONCLUSIONS: This model suggests that currently available EUS resources are not sufficient to meet hypothetical demand. Future considerations include the number of endoscopy units in which EUS is performed, the capacity of individual units, and the implications for training programs in the United States.

Digestive System Neoplasms↗
PubMed2002

Endoscopic ultrasound of the pancreas: tissue acquisition and intervention.

Endoscopic ultrasound is an established modality for staging gastrointestinal and pancreatic malignancies. Since the development of the linear array echoendoscope, the field of interventional endoscopy has continued to evolve as an adjunctive method to standard endosonography. The ability to sample extraluminal lesions or lymph nodes has overcome the initial limitations of endoscopic ultrasound and provided a list of attractive endoscopic ultrasound-guided therapeutic applications.This review focuses on recent advancements in the field of interventional endosonography related to the diagnosis and therapy of pancreatic diseases. In particular, the article reviews the role of endoscopic ultrasound-guided fine-needle aspiration in diagnosing various pancreatic diseases; the role of endoscopic ultrasound-guided fine-needle injection in delivering neurolytic, chemotherapeutic, or biologic agents; and emerging procedures like endoscopic ultrasound-assisted biliary bypass in the setting of malignant biliary obstruction.

Journal Article↗