Karl Kwok

Prediction of malignancy in cystic neoplasms of the pancreas: A population-based cohort study

OBJECTIVES:Pancreatic cystic neoplasms (PCNs) are being detected with increased frequency. The aims of this study were to determine the incidence of malignancy and develop an imaging-based system for prediction of malignancy in PCN.METHODS:We conducted a retrospective cohort study of patients ≥18 years of age with confirmed PCN from January 2005 to December 2010 in a community-based integrated care setting in Southern California. Patients with history of acute or chronic pancreatitis were excluded. Malignancy diagnosed within 3 months of cyst diagnosis was considered as pre-existing. Subsequent incidence of malignancy during surveillance was calculated based on person-time at risk. Age- and gender-adjusted standardized incidence ratio (SIR) was calculated with the non-cyst reference population. Recursive partitioning was used to develop a risk prediction model based on cyst imaging features.RESULTS:We identified 1,815 patients with confirmed PCN. A total of 53 (2.9%) of patients were diagnosed with cyst-related malignancy during the study period. The surveillance cohort consisted of 1,735 patients with median follow-up of 23.4 months. Incidence of malignancy was 0.4% per year during surveillance. The overall age- and gender-adjusted SIR for pancreatic malignancy was 35.0 (95% confidence level 26.6, 46.0). Using recursive partitioning, we stratified patients into low (<1%), intermediate (1–5%), and high (9–14%) risk of harboring malignant PCN based on four cross-sectional imaging features: size, pancreatic duct dilatation, septations with calcification as well as growth. Area under the receiver operator characteristic curve for the prediction model was 0.822 (training) and 0.808 (testing).CONCLUSIONS:Risk of pancreatic malignancy was lower than previous reports from surgical series but was still significantly higher than the reference population. A risk stratification system based on established imaging criteria may help guide future management decisions for patients with PCN.

Patient Preferences for Management of Cystic Neoplasms of the Pancreas: A Cross-Sectional Survey Study.

Objective The aim of this study was to determine how patient anxiety, knowledge, and cancer worry influence preferences for management of pancreatic cysts. Methods We performed a prospective, cross-sectional study using a disease-specific survey instrument. We included patients older than 18 years who were diagnosed with a pancreatic cyst. A telephone survey instrument was developed to assess baseline anxiety using the Hospital Anxiety and Depression Scale (HADS), knowledge regarding pancreatic cysts, cancer worry, and patient preferences using a standard gamble. Results Of the 100 studied participants (median age, 65 years; 72% women), median Hospital Anxiety and Depression Scale score was 4 (normal range). In terms of knowledge, 96% of the patients were not aware of their specific cyst type, and 58% were unaware of the possibility of any cyst-related malignancy. Overall, 8% of respondents had some degree of cancer worry. Respondents were more willing to undergo magnetic resonance imaging surveillance compared with endoscopic ultrasound or surgery. Knowledge of cyst type was a significant predictor of willingness to undergo invasive testing. Conclusions There is a significant gap in patient knowledge with respect to pancreatic cysts. Greater emphasis on patient education can help patients make informed decisions regarding cyst management.

Competing Risks for Mortality in Patients With Asymptomatic Pancreatic Cystic Neoplasms: Implications for Clinical Management

Objectives:Pancreatic cystic neoplasms (PCNs) are being detected with increased frequency. Current clinical practice guidelines emphasize management based on cyst-related features. We aimed to evaluate the impact of comorbidity on mortality in PCN patients via competing risk analysis.Methods:We analyzed a retrospective cohort of patients diagnosed between 2005–2010, with follow-up through 2015, for overall and cause-specific mortality. Comorbidities were classified by the Charlson comorbidity index. We used Cox proportional hazards regression to evaluate the independent effect of cyst features, age, gender, and comorbidities on cause-specific mortality. Subgroup analysis was performed to determine the cause-specific mortality based on four a priori clinical profiles—healthy patients with low- or high-risk cysts, and high-comorbidity patients with low- or high-risk cysts.Results:A total of 1,800 patients with PCNs comprised the study cohort (median follow-up 5.7 years). A total of 402 deaths (22.3%) occurred during the study period: 43 pancreatic cancer and 359 non-pancreatic cancer deaths. Compared to healthy patients without any high-risk cyst features (reference group), patients with high comorbidity as well as high-risk cyst features had an increased risk of overall mortality (Cox hazard ratio 6.30, 95% confidence interval (CI) 4.71, 8.42, P<0.01), pancreatic cancer mortality (subdistribution hazard ratio (SHR) 51.13, 95% CI 6.35, 411.29, P<0.01), as well as non-pancreatic cancer mortality (SHR 5.24, 95% CI 3.85, 7.12, P<0.01). Meanwhile, low-risk patients with a high-risk cyst were more likely to experience pancreatic cancer mortality (SHR 68.14, 95% CI 9.27, 501.01, P<0.01) rather than non-pancreatic cancer mortality (SHR 1.22, 95% CI 0.88, 1.71, P=0.23), compared to the reference group. Similarly, compared to the reference group, high-risk patients with a low-risk cyst were more likely to experience non-pancreatic cancer mortality (SHR 3.96, 95% CI 2.98, 5.26, P<0.01) rather than pancreatic cancer mortality (SHR 2.35, 95% CI 0.14, 38.82, P=0.55).Conclusions:Most of the deaths in the study were unrelated to pancreatic cancer. This has implications for clinical management. By applying patient-related factors in conjunction with cyst features, we defined commonly encountered patient profiles to help guide PCN clinical management.

EUS-FNA of a Compressive Left Ventricular Intrapericardial Mass

During workup of new lower-extremity edema, a 47-year-old woman with rheumatoid arthritis who had previously been receiving immunosuppressive therapy was found to have a pericardial mass with effusion on transthoracic echocardiogram (TTE). Computed tomography (CT) of the thorax revealed a 3.9 × 7.0 × 8.3 cm mass in the pericardial space abutting the lateral left ventricle, extending to the pulmonary artery and left atrial appendage, and causing a mass effect (a). Given the location, endoscopic ultrasound–guided fine-needle aspiration (EUS-FNA) was favored over CT-guided or surgical approaches. The patient underwent EUS under standard monitored anesthesia care and received a single dose of periprocedure antibiotics (ciprofloxacin and metronidazole). The accessory channel of the echoendoscope (Olympus UCP-140) was flushed with povidone–iodine. Pericardial FNA was performed using a standard technique without incident (b). Postprocedure TTE revealed no hemodynamic changes. Cytology was bland with predominantly amorphous debris. After multidisciplinary consultation, the patient underwent thoracoscopic surgery, in which dense adhesions with necrotic “cheesy” material were observed in the pericardial spaces. Surgical pathology similarly revealed dense collagenized fibrosis in pericardial tissue and acellular debris. No infectious or infiltrative processes were identified. Over the year following diagnosis, the patient developed worsening right heart pressure, severe anasarca, and hypotension, and she subsequently expired. (Informed consent was obtained from the patient’s next of kin to publish these images.)

A novel adjunctive cleansing method to reduce colony-forming units on duodenoscopes.

Background and study aims: Endoscopic retrograde cholangiopancreatography-related infections are of increasing global concern due to the emergence of multidrug-resistant bacteria such as carbapenem-resistant enterobacteriaceae (CRE), with bacterial biofilm production postulated as one cause of persistent infection from such virulent organisms. Because N-acetylcysteine (NAC) has been shown to possess antibacterial and biofilm-disruption properties, we aimed to evaluate if NAC would demonstrate clinical utility in reducing the colony forming units (CFU) at the elevator end of a duodenoscope, one of the hardest areas to clean. Patients and methods: This was a pilot study of 16 procedures involving the use of a duodenoscope. After use, the elevator tip of a duodenoscope was cultured and submerged for 30 minutes, either in 20 % NAC (200 mg/mL, intervention) or in sterile water (control). After 30 minutes, the elevator tip was re-cultured. Results: Submersion of the distal end of a duodenoscope in 20 % NAC (200 mg/mL) for 30 minutes resulted in a statistically significant reduction in bacterial colony forming units compared to control (average reduction 41.6 % vs 8.8 %, P = 0.001). There was no visible damage and no optical distortion to the duodenoscope after submersion in NAC. Conclusions: In summary, NAC may be a safe, simple, and useful adjunct to currently available methods of duodenoscope reprocessing. Further research may better define NAC’s role in duodenoscope reprocessing, either broadly or specifically after procedures suspected to produce a high risk of bacterial contamination (e. g. choledocholithiasis).