Victor K. Chen

Endoscopic ultrasound-guided fine needle aspiration biopsy of patients with suspected pancreatic cancer: diagnostic accuracy and acute and 30-day complications.

OBJECTIVES:The aims of this study were to evaluate the diagnostic accuracy of endoscopic ultrasound–guided fine needle aspiration (EUS-FNA) in patients with suspected pancreatic cancer, and to assess immediate, acute, and 30-day complications related to EUS-FNA.METHODS:All patients with suspected pancreatic cancer were prospectively evaluated. A single gastroenterologist performed all EUS-FNAs in the presence of a cytopathologist. Immediate complications were evaluated in all patients. An experienced nurse called patients 24–72 h and 30 days after the procedure. Reference standard for the classification of the final diagnosis included: surgery (n = 48), clinical or imaging follow-up (n = 63), or death from the disease (n = 47).RESULTS:A total of 158 patients (mean age 62.3 yr) underwent EUS-FNA during the study period. The mean tumor size was 32 × 26 mm. The median number of passes was three (range one to 10). Of these patients, 44% had at least one failed attempt at tissue diagnosis before EUS-FNA. The sensitivity, specificity, PPV, NPV, and accuracy of EUS-FNA in solid pancreatic masses were 84.3%, 97%, 99%, 64%, and 84%, respectively. Immediate self-limited complications occurred in 10 of the 158 EUS-FNAs (6.3%). Of 90 patients contacted at 24–72 h, 78 patients (87%) responded. Of the 90 patients, 20 (22%) reported at least one symptom, all of which were minor except in three cases (one self-limited acute pancreatitis and two emergency room visits, one of which led to admission). In all, 83 patients were contacted at 30 days, and 82% responded. No additional or continued complications were reported.CONCLUSIONS:EUS-FNA is highly accurate in identifying patients with suspected pancreatic cancer, especially when other modalities have failed. Major complications after EUS-FNA are rare, and minor complications are similar to those reported for upper endoscopy. It seems that follow-up at 1 wk might capture all of the adverse events related to EUS-FNA.

Endoscopic ultrasound-guided fine needle aspiration biopsy of suspected cholangiocarcinoma

BACKGROUND AND AIMS Despite advances in endoscopic techniques for sampling bile duct strictures, the diagnosis of cholangiocarcinoma remains a challenge. The purpose of this study was to evaluate the yield of EUS-FNA and its impact on patient management for patients with suspected cholangiocarcinoma. METHODS All patients undergoing EUS for the evaluation of suspected malignant biliary strictures were prospectively evaluated over a 23-month period. A single gastroenterologist performed all EUS-FNAs in the presence of a cytopathologist. Reference standard for final diagnosis included surgery, death from disease, and clinical and/or imaging follow-up. RESULTS Twenty-eight patients (mean age 67 years [SD +/- 11], 72% male) were evaluated. Most patients (91%) presented with obstructive jaundice, and all except 1 had nondiagnostic sampling of the biliary lesions either at ERCP (88%), percutaneous transhepatic cholangiogram (n = 2), and/or computed tomography-guided biopsy (n = 1). Sixty-seven percent (14/21) had no definitive mass seen on prior abdominal imaging studies. The mean tumor size by EUS was 19 mm x 16 mm with a median number of passes to diagnosis of 3 (range 1-7). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 86%, 100%, 100%, 57%, and 88%, respectively. EUS-FNA had a positive impact on patient management in 84% of patients: preventing surgery for tissue diagnosis in patients with inoperable disease (n = 10), facilitating surgery in patients with unidentifiable cancer by other modalities (n = 8), and avoiding surgery in benign disease (n = 4). CONCLUSIONS Given the apparent accuracy and safety of EUS with FNA for imaging bile duct mass lesions and for obtaining a tissue diagnosis in patients with suspected cholangiocarcinoma, this technology may represent a new approach to diagnosis especially when other methods fail. The ability to obtain a definite diagnosis has a significant impact on patient management.

A Primer on Natural Orifice Transluminal Endoscopic Surgery: Building a New Paradigm

Access to the abdominal cavity is required for diagnostic and therapeutic endeavors for a variety of medical and surgical diseases. Historically, abdominal access has required a formal laparotomy to provide adequate exposure. Natural orifice transluminal endoscopic surgery (NOTES) is an emerging experimental alternative to conventional surgery that eliminates abdominal incisions and incision-related complications by combining endoscopic and laparoscopic techniques to diagnose and treat abdominal pathology. During NOTES, commercially available flexible video endoscopes are used to create a controlled transvisceral incision via natural orifice access to enter the peritoneal cavity. Common incision-related complications such as wound infections, incisional hernias, postoperative pain, aesthetic disdain, and adhesions could be minimized or eliminated by NOTES. NOTES has evolved from more than 2 centuries of technological innovations and continued growth in the field of surgical endoscopy. Innovative surgical endoscopists have slowly developed means to surpass the constraints of the gastrointestinal lumen by using a flexible endoscope. The future of surgical endoscopy may be the shared entity of NOTES, which further integrates endoscopy, gastroenterology, and minimally invasive and general surgery. Although the promise of NOTES is electrifying to surgeons and endoscopists, several key issues need to be characterized prior to the incorporation of NOTES into routine practice. This article reviews the status, contemporary body of literature, limitations, and potential future implications accompanying the development of NOTES.

Endoscopic ultrasound-guided fine needle aspiration is superior to lymph node echofeatures: a prospective evaluation of mediastinal and peri-intestinal lymphadenopathy.

BACKGROUND AND OBJECTIVE:The additional diagnostic value of endoscopic ultrasound-fine needle aspiration (EUS-FNA) over lymph node (LN) echofeatures alone in evaluating lymphadenopathy is unknown. The objectives of this study are (1) to prospectively evaluate the utility of EUS-FNA in evaluating mediastinal or peri-intestinal lymphadenopathy and to compare its yield to that of echofeatures alone and (2) to determine clinical and endosonographic features predictive of malignant involvement of LNs.METHODS:All consecutive patients who underwent EUS-FNA of a LN over a 22-month period were prospectively evaluated. Reference standard for final diagnosis included: surgery (n = 76), long-term clinical and/or imaging follow-up (n = 74), or death from disease (n = 26).RESULTS:One hundred and eighty-three EUS-FNAs of LNs were performed in 137 patients with no major complications. Locations of the biopsied LNs included 31% subcarinal, 21% celiac, 21% peripancreatic, 13% periesophageal, 4.4% aortopulmonary window, 3.2% perigastric, and 3.3% perirectal. Mean LN size was 20.5 mm (SD ± 11.1) × 13.2 mm (SD ± 7.97). The mean number of EUS-FNA passes was three (range 1–7). The sensitivity, specificity, PPV, and NPV of EUS-FNA of LNs were 98.3%, 100%, 100%, and 98.4%, respectively. EUS-FNA was more accurate compared to LN echofeatures alone (99.4% vs 75.4%, p < 0.001). Mediastinal LNs were 2.77 times less likely to be malignant as compared to other LN locations. In multivariable analysis, the number of LN echofeatures, site of LN, and patients age were associated with malignant involvement (p = 0.001).CONCLUSIONS:EUS-FNA is superior to LN echofeatures in evaluating lymphadenopathy. Endosonographic LN features alone are particularly unreliable in the mediastinum, necessitating tissue confirmation. EUS-FNA can safely, reliably, and accurately sample mediastinal and peri-intestinal LNs obviating the need for more invasive testing or surgical intervention.

Expandable Metal Biliary Stents Before Pancreaticoduodenectomy for Pancreatic Cancer: A Monte-Carlo Decision Analysis

BACKGROUND & AIMS Endoscopic placement of plastic or self-expandable metal biliary stents (SEMS) relieves obstructive jaundice from pancreatic cancer. Short-length, distally placed SEMS do not preclude subsequent pancreaticoduodenectomy. We sought to determine whether SEMS placement in patients whose surgical status is uncertain is cost-effective for management of obstructive jaundice. METHODS A Markov model was constructed to evaluate costs and outcomes associated with endoscopic biliary stenting for obstructive jaundice. Strategies evaluated were: (1) initial plastic stent with plastic stents for subsequent occlusions in nonsurgical candidates after staging (plastic followed-up by [f/u] plastic), (2) initial plastic with subsequent SEMS (plastic f/u metal), (3) initial short-length SEMS with subsequent plastic (metal f/u plastic), and (4) initial short-length SEMS with subsequent expandable metal stent (metal f/u metal). Published stent occlusion rates, ERCP complication rates and outcomes, cholangitis rates and outcomes, pancreatic cancer mortality rates, and Whipple complication rates were used. Costs were based on 2004 Medicare standard allowable charges and were accrued until all patients reached an absorbing health state (death or pancreaticoduodenectomy) or 24 cycles (24 mo) ended. RESULTS Average costs per patient from Monte Carlo simulation were: (1) metal f/u metal,

A Cost-Minimization Analysis of Alternative Strategies in Diagnosing Pancreatic Cancer

19,935; (2) plastic f/u metal, 20,157 dollars; (3) metal f/u plastic, 20,871 dollars; and (4) plastic f/u plastic, 20,878 dollars. For initial plastic stents to be preferred over short-length metal stents, 70% or more of pancreatic cancers would need to be potentially resectable by pancreaticoduodenectomy. CONCLUSIONS In patients undergoing ERCP before definitive cancer staging, short-length SEMS is the preferred initial cost-minimizing strategy.

In vivo characterization of pancreatic and lymph node tissue by using EUS spectrum analysis: a validation study.

BACKGROUND:Several modalities currently exist for tissue confirmation of suspected pancreatic cancer prior to therapy. Since there is a paucity of cost-minimization studies comparing these different biopsy modalities, we analyzed costs and examined effectiveness of four alternative strategies for diagnosing pancreatic cancer.METHODS:A decision analysis model of patients with suspected pancreatic cancer was constructed. We analyzed costs, failure rate, testing characteristics, and complication rates of four commonly employed diagnostic modalities: 1) computerized tomography or ultrasound-guided fine-needle aspiration (CT/US-FNA), 2) endoscopic retrograde cholangiopancreatography with brushings (ERCP-B), 3) Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA), and 4) laparoscopic surgical biopsy. If the first attempt with a particular modality failed, a different modality was employed to identify the most preferable secondary biopsy strategy.RESULTS:This analysis identifies EUS-FNA as the preferred initial modality for the diagnosis of pancreatic cancer. Resultant expected costs and strategies in decreasing optimality include: 1) EUS-FNA (

Endoscopic Doppler Ultrasound Versus Endoscopic Stigmata-Directed Management of Acute Peptic Ulcer Hemorrhage: A Multimodel Cost Analysis

1,405), 2) ERCP-B (

Creation of an effective and reproducible nonsurvival porcine model that simulates actively bleeding peptic ulcers.

1,432), 3) CT/US-FNA (

High Resolution Arma Model Reconstruction for NDE Ultrasonic Imaging

3,682), and 4) surgery (