Curative Resection of T1a Inlet Patch Adenocarcinoma With Traction-Assisted Endoscopic Submucosal Dissection.

Esophageal inlet patch (EIP) adenocarcinoma is extremely rare. We present a case of a 58-year-old man who underwent a diagnostic esophagogastroduodenoscopy for dysphagia and found to have a 2 cm polypoid mass arising from an EIP. Biopsies and staging were consistent with T1aN0M0 EIP adenocarcinoma. While surgical resection was the main method of treatment of these lesions, very few case reports have shown that endoscopic resection can successfully remove these lesions. After multidisciplinary discussion, the patient underwent curative traction-assisted endoscopic submucosal dissection-which is the first known case report to highlight the success of this technique.

Endoscopic Management of Esophageal Cancer.

Advances in technology and improved understanding of the pathobiology of esophageal cancer have allowed endoscopy to serve a growing role in the management of this disease. Precursor lesions can be detected using enhanced diagnostic modalities and eradicated with ablation therapy. Furthermore, evolution in endoscopic resection has provided larger specimens for improved diagnostic accuracy and offer potential for cure of early esophageal cancer. In patients with advanced esophageal cancer, endoluminal therapy can improve symptom burden and provide therapeutic options for complications such as leaks, perforations, and fistulas. The purpose of this review article is to highlight the role of endoscopy in the diagnosis, treatment, and palliation of esophageal cancer.

Zenker's peroral endoscopic myotomy, or flexible or rigid septotomy for Zenker's diverticulum: a multicenter retrospective comparison.

BACKGROUND: Treatment of Zenker's diverticulum has evolved from open surgery to endoscopic techniques, including flexible and rigid endoscopic septotomy, and more recently, peroral endoscopic myotomy (Z-POEM). This study compared the effectiveness of flexible and rigid endoscopic septotomy with that of Z-POEM. METHODS: Consecutive patients who underwent endoscopic septotomy (flexible/rigid) or Z-POEM for Zenker's diverticulum between 1/2016 and 9/2019 were included. Primary outcomes were clinical success (decrease in Dakkak and Bennett dysphagia score to ≤ 1), clinical failure, and clinical recurrence. Secondary outcomes included technical success and rate/severity of adverse events. RESULTS: 245 patients (110 females, mean age 72.63 years, standard deviation [SD] 12.37 years) from 12 centers were included. Z-POEM was the most common management modality (n = 119), followed by flexible (n = 86) and rigid (n = 40) endoscopic septotomy. Clinical success was 92.7 % for Z-POEM, 89.2 % for rigid septotomy, and 86.7 % for flexible septotomy (P = 0.26). Symptoms recurred in 24 patients (15 Z-POEM during a mean follow-up of 282.04 [SD 300.48] days, 6 flexible, 3 rigid [P = 0.47]). Adverse events occurred in 30.0 % rigid septotomy patients, 16.8 % Z-POEM patients, and 2.3 % flexible septotomy patients (P < 0.05). CONCLUSIONS: There was no difference in outcomes between the three treatment approaches for symptomatic Zenker's diverticulum. Rigid endoscopic septotomy was associated with the highest rate of complications, while flexible endoscopic septotomy appeared to be the safest. Recurrence following Z-POEM was similar to flexible and rigid endoscopic septotomy. Prospective studies with long-term follow-up are required.

Is transoral incisionless fundoplication (TIF) an answer to post-peroral endoscopic myotomy gastroesophageal reflux? A multicenter retrospective study.

BACKGROUND: The use of peroral endoscopic myotomy (POEM) for achalasia has a high incidence of post-procedural gastroesophageal reflux (GER). Transoral incisionless fundoplication (TIF) may be an ideal endoscopic treatment. We report our experience with the use of post-POEM TIF. METHODS: In this multicenter retrospective study, post-POEM patients with GER who underwent TIF were included. The study end points were: (i) technical success; (ii) safety; (iii) effectiveness (changes in symptoms, scores, proton pump inhibitor [PPI] use, pH studies). RESULTS: 12 patients underwent TIF after POEM, nine of whom had daily symptoms, with 91.7% requiring twice daily (BID) PPIs. Technical success was achieved in all patients. Two adverse events occurred. There were significant decreases in the percentage of patients on BID PPIs (P = 0.03), frequency of daily symptoms (P = 0.03), Reflux Severity Index questionnaire, and GERD Health-related Quality of Life scores (P = 0.03 and P = 0.003; n = 6). pH studies performed in seven of the patients showed a significant reduction in the mean DeMeester score (P = 0.05) and mean percentage acid exposure time (P = 0.04). CONCLUSION: Our experience suggests that TIF may be effective and safe in treating GER after POEM. Larger prospective trials are needed.

A Puzzling Case of Pouch Pathology.

A 36-year-old man with familial adenomatous polyposis secondary to an adenomatous polyposis coli mutation status post proctocolectomy with ileal pouch-anal anastomosis presented with hematochezia. Pouchoscopy revealed a 4-cm indurated mass in the distal ileal pouch just 17 months after a normal pouchoscopy. Histopathology was diagnostic for Burkitt lymphoma, and the patient achieved complete remission with subsequent chemotherapy. Although there are reports of Burkitt lymphoma in patients with ileal pouch-anal anastomosis, to date, this is the first report in a patient with familial adenomatous polyposis. This case highlights the presentation of a rapidly enlarging tumor not commonly seen in the adult gastroenterology population.

The role of endoscopic ultrasound in evaluating patients with bile duct dilation of unclear etiology.

OBJECTIVE: Bile duct dilation (BDD) of unclear etiology is a common indication for further imaging via endoscopic ultrasound (EUS). We aimed to assess the yield of EUS in determining BDD etiology in patients with prior non-diagnostic imaging studies. METHODS: A retrospective chart review was performed at a single, tertiary-care university hospital for patients referred for EUS for BDD with or without pancreatic duct dilation (PDD). EUS-guided fine needle aspiration (FNA) was performed if a focal lesion was identified. Cases with an etiology of BDD diagnosed or strongly suggested by prior imaging were excluded. EUS findings believed to represent a structural cause for BDD included a wide range of pancreaticobiliary and luminal pathology as well as patients' clinical factors. RESULTS: In total, 307 patients were identified. Findings to explain BDD were found by EUS in 213 patients for a diagnostic yield of 69.4%. Patients with jaundice were significantly more likely to receive a diagnosis by EUS than those without (78.8% vs 55.3%, P < 0.01). Notably, 8.1% of patients with normal liver function test (LFT) had a EUS-diagnosed malignancy. Patients' age, narcotic use, concurrent PDD and prior cholecystectomy did not appear to influence the EUS yield. CONCLUSIONS: EUS continues to play a substantial role in evaluating BDD of unclear etiology, most notably in patients with jaundice. In addition, given that 8.1% of asymptomatic patients without jaundice or abnormal LFT had malignancy diagnosed on EUS, the use of EUS for BDD of unclear etiology remains warranted.

Practice patterns, techniques, and outcomes of flexible endoscopic myotomy for Zenker's diverticulum: a retrospective multicenter study.

BACKGROUND: Flexible endoscopic myotomy has been increasingly performed for Zenker's diverticulum using various endoscopic techniques and devices. The main aims of this study were to assess practice patterns and compare outcomes of endoscopic myotomy for Zenker's diverticulum. METHODS: Procedures performed at 12 tertiary endoscopy centers from 1/2012 to 12/2018 were reviewed. Patients (≥ 18 years) with Zenker's diverticulum who had dysphagia and/or regurgitation and underwent endoscopic myotomy were included. Outcomes assessed included technical success, clinical success, and adverse events. RESULTS: 161 patients were included. Traditional endoscopic septotomy was performed most frequently (137/161, 85.1 %) followed by submucosal dissection of the septum and myotomy (24/161, 14.9 %). The hook knife (43/161, 26.7 %) and needle-knife (33/161, 20.5 %) were used most frequently. Overall, technical and clinical success rates were 98.1 % (158/161) and 78.1 % (96/123), respectively. Adverse events were noted in 13 patients (8.1 %). There was no significant difference in technical and clinical success between traditional septotomy and submucosal dissection groups (97.1 % vs. 95.8 %, P = 0.56 and 75.2 % vs. 90.9 %, P  = 0.16, respectively). Clinical success was higher with the hook knife (96.7 %) compared with the needle-knife (76.6 %) and insulated tip knife (47.1 %). Outcomes were similar between centers performing > 20, 11 - 20, and ≤ 10 procedures. CONCLUSIONS: Flexible endoscopic myotomy is an effective therapy for Zenker's diverticulum, with a low rate of adverse events. There was no significant difference in outcomes between traditional septotomy and a submucosal dissection approach, or with centers with higher volume, though clinical success was higher with the hook knife.

Management of patients after failed peroral endoscopic myotomy: a multicenter study.

BACKGROUND: Although peroral endoscopic myotomy (POEM) is highly effective for the management of achalasia, clinical failures may occur. The optimal management of patients who fail POEM is not well known. This study aimed to compare the outcomes of different management strategies in patients who had failed POEM. METHODS: This was an international multicenter retrospective study at 16 tertiary centers between January 2012 and November 2019. All patients who underwent POEM and experienced persistent or recurrent symptoms (Eckardt score > 3) were included. The primary outcome was to compare the rates of clinical success (Eckardt score ≤ 3) between different management strategies. RESULTS : 99 patients (50 men [50.5 %]; mean age 51.4 [standard deviation (SD) 16.2]) experienced clinical failure during the study period, with a mean (SD) Eckardt score of 5.4 (0.3). A total of 29 patients (32.2 %) were managed conservatively and 70 (71 %) underwent retreatment (repeat POEM 33 [33 %], pneumatic dilation 30 [30 %], and laparoscopic Heller myotomy (LHM) 7 [7.1 %]). During a median follow-up of 10 (interquartile range 3 - 20) months, clinical success was highest in patients who underwent repeat POEM (25 /33 [76 %]; mean [SD] Eckardt score 2.1 [2.1]), followed by pneumatic dilation (18/30 [60 %]; Eckardt score 2.8 [2.3]), and LHM (2/7 [29 %]; Eckardt score 4 [1.8]; P = 0.12). A total of 11 patients in the conservative group (37.9 %; mean Eckardt score 4 [1.8]) achieved clinical success. CONCLUSION : This study comprehensively assessed an international cohort of patients who underwent management of failed POEM. Repeat POEM and pneumatic dilation achieved acceptable clinical success, with excellent safety profiles.

Reviews on Current Liquid Biopsy for Detection and Management of Pancreatic Cancers.

Pancreatic cancer is the fourth leading cause of cancer death in the United States. Pancreatic cancer presents dismal clinical outcomes in patients, and the incidence of pancreatic cancer has continuously increased to likely become the second most common cause of cancer-related deaths by as early as 2030. One of main reasons for the high mortality rate of pancreatic cancer is the lack of tools for early-stage detection. Current practice in detecting and monitoring therapeutic response in pancreatic cancer relies on imaging analysis and invasive endoscopic examination. Liquid biopsy-based analysis of genetic alterations in biofluids has become a fundamental component in the diagnosis and management of cancers. There is an urgent need for scientific and technological advancement to detect pancreatic cancer early and to develop effective therapies. The development of a highly sensitive and specific liquid biopsy tool will require extensive understanding on the characteristics of circulating tumor DNA in biofluids. Here, we have reviewed the current status of liquid biopsy in detecting and monitoring pancreatic cancers and our understanding of circulating tumor DNA that should be considered for the development of a liquid biopsy tool, which will greatly aid in the diagnosis and healthcare of people at risk.

The Utility of EUS-FNA to Determine Surgical Candidacy in Patients with Pancreatic Cancer after Neoadjuvant Therapy.

BACKGROUND: In patients with borderline resectable pancreatic cancer (BRPC) or locally advanced pancreatic cancer (LAPC) who undergo neoadjuvant therapy, CT imaging is the standard of care for restaging. However, differentiating residual tumor from post-treatment inflammation with CT is unreliable. The diagnosis of periarterial soft tissue cuffing (PSTC) near major vessels is key to guiding resectability. The goal of this study was to assess the utility of EUS-FNA in determining the etiology of PSTC in BRPC or LAPC after neoadjuvant treatment. METHODS: We performed a retrospective analysis of patients referred for EUS-FNA of PSTC following downstaging therapy for LAPC or BRPC at our tertiary medical center. Negative EUS-FNA cytology results were compared with surgical pathology after resection. Patients with positive EUS-FNA cytology results were either followed clinically or results were compared to surgical pathology if surgery was attempted despite the positive cytology. RESULTS: Fourteen patients were included in the study of whom four had positive cytology. Two of these patients had progression of disease, and two had attempted resection with positive surgical pathology (100% true positives). All ten patients with negative cytology underwent attempted surgical resection. Nine patients (90%) achieved negative margins, and one patient (10%) had a positive surgical margin. The sensitivity, specificity, and accuracy of EUS-FNA for determining resectability were 80%, 100%, and 92.9%, respectively. CONCLUSIONS: In this series of patients with BRPC or LAPC and persistent PSTC after downstaging neoadjuvant treatment, EUS-FNA accurately determined surgical resectability and should be considered as part of the evaluation of such patients.

Endoscopic Therapies for Gastroparesis.

PURPOSE OF REVIEW: Gastroparesis remains a difficult-to-treat disease with limited therapeutic options. Though patients often have a common syndrome of stereotypic symptoms, the underlying pathophysiology is heterogeneous, often leading to variable treatment responses. Due to limitations in medical and surgical therapies, endoscopic options have been increasingly explored. These options can be broadly categorized into pyloric-directed therapy, non-pyloric-directed therapy, and nutritional support. In this review, we will highlight current and emerging endoscopic options, such as gastric per-oral endoscopic myotomy (G-POEM). RECENT FINDINGS: Early retrospective studies on G-POEM offer encouraging results up to one year out, with an acceptable safety profile. Other pyloric-directed therapies, such as pyloric dilation and stenting, have also been explored. While emerging endoscopic therapeutic options are encouraging, efficacy will likely depend on a better characterization of underlying pathophysiology and improved patient selection. Future prospective, controlled studies are needed.

Per-Pass Performance Characteristics of Endoscopic Ultrasound-Guided Fine-Needle Aspiration of Malignant Solid Pancreatic Masses in a Large Multicenter Cohort.

OBJECTIVES: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is widely performed for the evaluation of pancreatic masses. We evaluated the performance characteristics of EUS-FNA in obtaining a diagnosis of pancreatic malignancy. METHODS: We performed a multicenter study of patients who underwent EUS-FNA for a solid pancreatic mass. Endoscopic ultrasound-guided FNA was standardized using a 25-gauge needle, slow-pull stylet technique for specimen acquisition, and on-site cytopathology. For the primary analysis, only malignant cytology was regarded as positive. A secondary analysis was performed in which malignant and/or suspicious cytology was regarded as positive. RESULTS: A total of 138 patients underwent EUS-FNA. In the primary analysis, the sensitivity of EUS-FNA for malignancy was 56.7% on first pass, 73.3% on second pass, 83.3% on third pass, 89.2% on fourth pass, and 90.8% on fifth pass, with no increase beyond the fifth pass. In the secondary analysis, the sensitivity was 75.0% on first pass, 89.2% on second pass, 93.3% on third pass, and 95.8% on fourth pass, with no increase beyond the fourth pass. No significant relationship was seen between lesion size and diagnostic yield. CONCLUSIONS: Using a 25-gauge needle, the maximal diagnostic yield of EUS-FNA for a solid pancreatic mass is reached after 4 needle passes.

A Comprehensive Assessment of Accurate Lymph Node Staging and Preoperative Detection in Resected Pancreatic Cancer.

BACKGROUND: The current (seventh edition) American Joint Commission on Cancer (AJCC) Staging System for pancreatic ductal adenocarcinoma (PDAC) dichotomizes pathologic lymph node (LN) involvement into absence (pN0) or presence (pN1) of disease. The recently announced eighth edition also includes stratification on the number of positive nodes. Furthermore, LNs detected on preoperative imaging (CT, MRI, or endoscopic ultrasound-EUS) are considered to be pathologically involved in other gastrointestinal cancers. However, this is less well defined for PDAC. Therefore, the three aims of this study were to determine (1) whether the new AJCC staging system led to more accurate staging, (2) the number of nodes needed to be examined to detect pathologic involvement, and (3) if pN disease could be reliably detected on preoperative imaging in PDAC. METHODS: A retrospective review of all patients undergoing pancreatectomy at a single US academic center from January 1990 to September 2015. Pathology reports of resected specimens were reviewed to determine the total number of LNs examined and those positive for metastasis. CT, MRI, and/or EUS reports were used to determine the presence or absence of preoperatively detectable LN enlargement. RESULTS: Of the 490 surgical resections for PDAC, pN1 disease was detected in 59.4% (n = 291) and was positively correlated with the number of LNs pathologically examined (P < 0.001). Patients with pN1 disease had a shorter overall survival (OS) than those without nodal involvement (25.1 vs. 44.0 months; P < 0.001); however, OS was not different when stratifying by the number of nodes as on the eighth AJCC system. Pathologic examination of > 20 LNs in treatment naïve patients was optimal to detect pN1 disease and predict longer OS for those without nodal involvement (median survival > 41.1 months, P = 0.03 when compared to < 15 or 15-19 LNs examined). LNs were detected by CT, MRI, or EUS in 30.7% (103/335) of patients. The positive predictive value (PPV) of preoperative LN detection for pathologic involvement was 77.3% for treatment naïve patients and 84.2% for those without biliary obstruction. CONCLUSIONS: Although the LN scoring in the seventh PDAC AJCC Staging System was sufficient to predict OS of our patients, more LNs than previously considered (20 vs. 15) were optimal to detect pathologic involvement. Preoperative LN detection was an accurate predictor of pN1 disease for treatment naïve patients without biliary obstruction.

Endoscopic ultrasound with or without fine-needle aspiration has a meaningful impact on clinical care in the pediatric population.

BACKGROUND AND OBJECTIVES: The safety and utility of endoscopic ultrasound (EUS) for the evaluation and management of gastrointestinal (GI) tract disorders among adults has been established. The literature on safety and efficacy in a pediatric referral population (under 21 years of age) is limited. We hypothesized that EUS is safe and useful in the pediatric population. We reviewed the pediatric EUS experience at a single tertiary-care system. We describe the indications, findings, safety, technical success rate, and impact on clinical outcomes. PATIENTS AND METHODS: All patients 21 years of age or younger referred for EUS between 5, 2007 and 11, 2012 were identified from our electronic medical record databases. Retrospective chart review was then conducted to document demographics, procedure indications, procedure type (diagnostic or therapeutic), type of anesthesia used, EUS findings, and the clinical impact of EUS on the subsequent management of the patients. RESULTS: Seventy EUS procedures were attempted in 58 patients during the study. Of these, two EUS procedures were aborted due to inadequate moderate sedation and 68 were successfully completed. The median age at initial endoscopy was 18 years (range 6-21 years), 50% were male and 65% were Caucasian. Four patients underwent EUS-guided pseudocyst drainage. Among the remaining 54 patients, the indications for EUS were the evaluation of GI mucosal/submucosal lesions (n = 14), acute or recurrent pancreatitis (n = 10), localization of suspected insulinoma (n = 8), evaluation of pancreatic abnormalities seen on prior imaging (n = 6), surveillance of tumors or evaluation of luminal lesions in hereditary syndromes (n = 6), abdominal pain of suspected pancreatobiliary origin (n = 5), and other rare indications (n = 5). Fine-needle aspiration was performed in 13 (9 diagnostic, 4 therapeutic) and trans-gastric fine-needle contrast injection of the pancreatic duct was performed in one patient without any complications. Sedation (data available for 66 procedures) included general endotracheal anesthesia in 38 (57%), monitored anesthesia care (MAC) in 19 (29%), and moderate sedation in 9 (14%). There were 4 minor intra-procedural anesthesia-related complications (laryngospasm in 2 and hypoxemia from airway obstruction and secretions in 2) in MAC and general endotracheal anesthesia (GA) cases, and 1 postprocedural complication (fever after pseudocyst drainage). EUS can achieve the diagnostic or therapeutic goal and ruled out suspected pathology in 88% of cases precluding need for additional testing. CONCLUSIONS: (1) EUS in the pediatric population is technically successful and efficacious. (2) Therapeutic and diagnostic EUS impacted clinical care decisions. (3) There is a low risk of immediate significant complications. (4) The overall efficacy and safety support the performance of EUS in a pediatric population by experienced endoscopists.

Evaluation of the 2015 AGA guidelines on pancreatic cystic neoplasms in a large surgically confirmed multicenter cohort.

Background and study aims The American Gastroenterological Association (AGA) recently published guidelines for the management of asymptomatic pancreatic cystic neoplasms (PCNs). We aimed to evaluate the diagnostic characteristics of the AGA guidelines in appropriately recommending surgery for malignant PCNs. Patients and methods A retrospective multicenter study was performed of patients who underwent endoscopic ultrasound (EUS) for evaluation of PCNs who ultimately underwent surgical resection from 2004 - 2014. Demographics, EUS characteristics, fine-needle aspiration (FNA) results, type of resection, and final pathologic diagnosis were recorded. Patients were categorized into 2 groups (surgery or surveillance) based on what the AGA guidelines would have recommended. Performance characteristics for the diagnosis of cancer or high-grade dysplasia (HGD) on surgical pathology were calculated. Results Three hundred patients underwent surgical resection for PCNs, of whom the AGA guidelines would have recommended surgery in 121 (40.3 %) and surveillance in 179 (59.7 %) patients. Among patients recommended for surgery, 45 (37.2 %) had cancer, whereas 76 (62.8 %) had no cancer/HGD. Among patients recommended for surveillance, 170 (95.0 %) had no cancer/HGD; however, 9 (5.0 %) patients had cancer that would have been missed. For the finding of cancer/HGD on surgical pathology, the AGA guidelines had 83.3 % sensitivity (95 % CI 70.7 - 92.1), 69.1 % specificity (95 % CI 62.9 - 74.8), 37.2 % positive predictive value (95 % CI 28.6 - 46.4), 95.0 % negative predictive value (95 % CI 90.7 - 97.7), and 71.7 % accuracy (95 % CI 67.4 - 74.6). Conclusions The 2015 AGA guidelines would have resulted in 60 % fewer patients being referred for surgical resection, and accurately recommended surveillance in 95 % of patients with asymptomatic PCNs. Future prospective studies are required to validate these guidelines. Meeting presentations: Presented in part at Digestive Diseases Week 2016.

Doppler Endoscopic Probe Monitoring of Blood Flow Improves Risk Stratification and Outcomes of Patients With Severe Nonvariceal Upper Gastrointestinal Hemorrhage.

BACKGROUND & AIMS: For 4 decades, stigmata of recent hemorrhage in patients with nonvariceal lesions have been used for risk stratification and endoscopic hemostasis. The arterial blood flow that underlies the stigmata rarely is monitored, but can be used to determine risk for rebleeding. We performed a randomized controlled trial to determine whether Doppler endoscopic probe monitoring of blood flow improves risk stratification and outcomes in patients with severe nonvariceal upper gastrointestinal hemorrhage. METHODS: In a single-blind study performed at 2 referral centers we assigned 148 patients with severe nonvariceal upper gastrointestinal bleeding (125 with ulcers, 19 with Dieulafoy's lesions, and 4 with Mallory Weiss tears) to groups that underwent standard, visually guided endoscopic hemostasis (control, n = 76), or endoscopic hemostasis assisted by Doppler monitoring of blood flow under the stigmata (n = 72). The primary outcome was the rate of rebleeding after 30 days; secondary outcomes were complications, death, and need for transfusions, surgery, or angiography. RESULTS: There was a significant difference in the rates of lesion rebleeding within 30 days of endoscopic hemostasis in the control group (26.3%) vs the Doppler group (11.1%) (P = .0214). The odds ratio for rebleeding with Doppler monitoring was 0.35 (95% confidence interval, 0.143-0.8565) and the number needed to treat was 7. CONCLUSIONS: In a randomized controlled trial of patients with severe upper gastrointestinal hemorrhage from ulcers or other lesions, Doppler probe guided endoscopic hemostasis significantly reduced 30-day rates of rebleeding compared with standard, visually guided hemostasis. Guidelines for nonvariceal gastrointestinal bleeding should incorporate these results. ClinicalTrials.gov no: NCT00732212 (CLIN-013-07F).

Digital PCR Improves Mutation Analysis in Pancreas Fine Needle Aspiration Biopsy Specimens.

Applications of precision oncology strategies rely on accurate tumor genotyping from clinically available specimens. Fine needle aspirations (FNA) are frequently obtained in cancer management and often represent the only source of tumor tissues for patients with metastatic or locally advanced diseases. However, FNAs obtained from pancreas ductal adenocarcinoma (PDAC) are often limited in cellularity and/or tumor cell purity, precluding accurate tumor genotyping in many cases. Digital PCR (dPCR) is a technology with exceptional sensitivity and low DNA template requirement, characteristics that are necessary for analyzing PDAC FNA samples. In the current study, we sought to evaluate dPCR as a mutation analysis tool for pancreas FNA specimens. To this end, we analyzed alterations in the KRAS gene in pancreas FNAs using dPCR. The sensitivity of dPCR mutation analysis was first determined using serial dilution cell spiking studies. Single-cell laser-microdissection (LMD) was then utilized to identify the minimal number of tumor cells needed for mutation detection. Lastly, dPCR mutation analysis was performed on 44 pancreas FNAs (34 formalin-fixed paraffin-embedded (FFPE) and 10 fresh (non-fixed)), including samples highly limited in cellularity (100 cells) and tumor cell purity (1%). We found dPCR to detect mutations with allele frequencies as low as 0.17%. Additionally, a single tumor cell could be detected within an abundance of normal cells. Using clinical FNA samples, dPCR mutation analysis was successful in all preoperative FNA biopsies tested, and its accuracy was confirmed via comparison with resected tumor specimens. Moreover, dPCR revealed additional KRAS mutations representing minor subclones within a tumor that were not detected by the current clinical gold standard method of Sanger sequencing. In conclusion, dPCR performs sensitive and accurate mutation analysis in pancreas FNAs, detecting not only the dominant mutation subtype, but also the additional rare mutation subtypes representing tumor heterogeneity.

Endoscopic Ultrasound-Guided Fine Needle Aspiration Accurately Diagnoses Smaller Pancreatic Neuroendocrine Tumors Compared To Computer Tomography-Guided Fine Needle Aspiration.

INTRODUCTION: The role of EUS-guided FNA as a highly sensitive modality in the diagnosis of pancreatic adenocarcinoma is well documented. However, there is little published data on the role of EUS-FNA in diagnosing pancreatic neuroendocrine tumors (NETs). OBJECTIVE: The aim of this study is to compare the sensitivity of EUS-FNA to that of CT-FNA for diagnosing pancreatic NETs. METHODS: This is a single institution retrospective analysis of the operating characteristics of EUS-FNA and CT-FNA in detecting pancreatic NETs. Only patients with a final diagnosis of pancreatic NET were selected for this study. Procedure related data, including tumor size and location, and presence of a cytotechnologist were recorded. The results of each FNA were compared to the final clinico-pathological diagnosis to calculate sensitivity. RESULTS: Twenty-eight patients undergoing FNA (19 by EUS, 9 by CT) were analyzed. NETs diagnosed by EUS-FNA were smaller compared with CT-FNA (2.7 ± 0.9cm vs. 6.5 ± 2.1cm, p = 0.009) and were more often found in the pancreatic head (47.4% vs. 11.1%, p = 0.035). There were no significant differences in sensitivity between EUS-FNA and CT-FNA specimens (73.7% vs. 88.9%, p = 0.33). CONCLUSION: EUS-guided FNA is as sensitive as CT-guided FNA in diagnosing pancreatic NETs, but its main advantage is in the diagnosis of smaller pancreatic NETs in the head of the pancreas. It may also be the preferred approach in the diagnosis of multifocal pancreatic NETs in the setting of MEN I Syndrome.

Laparoscopic-Assisted Percutaneous Endoscopic Gastrostomy.

There are a variety of techniques for gastrostomy tube placement. Endoscopic and radiologic approaches have almost entirely superseded surgical placement. However, an aging population and significant advancements in modern healthcare have resulted in patients with increasingly complex medical issues or postsurgical anatomy. The rising prevalence of obesity has also created technical challenges for proceduralists of many specialties. When patients with these comorbidities develop the need for long-term enteral nutrition and feeding tube placement, standard approaches such as percutaneous endoscopic gastrostomy (PEG) by endoscopists and percutaneous image-guided gastrostomy (PIG) by interventional radiologists may be technically difficult or impossible. For these challenging situations, laparoscopic-assisted PEG (LAPEG) is an alternative option. LAPEG combines the advantages of PEG with direct intraperitoneal visualization, helping ensure a safe tube placement tract free of intervening organs or structures. In this review, we highlight some of the important factors of first-line gastrostomy techniques, with an emphasis on the utility and procedural technique of LAPEG when they are not feasible.