Quantification of interstitial cells of Cajal and fibrosis during gastric per-oral endoscopic myotomy and its association with clinical outcomes

Background and study aims Alterations to interstitial cells of Cajal (ICC) and collagen fibrosis have been implicated in the pathogenesis of gastroparesis. We aimed to evaluate the feasibility and safety of pyloric muscle sampling during gastric peroral endoscopic myotomy (G-POEM) and the association between pyloric ICC density and degree of fibrosis with clinical outcomes. Patients and methods This was a single-center prospective study of gastroparetic patients who underwent G-POEM and intraprocedural pyloric muscle biopsies between January 2022 and April 2023. ICC count was estimated using CD117 stain and trichome for collagen fibrosis. Clinical response to G-POEM was defined as an improvement of ≥ 1 point on the Gastroparesis Cardinal Symptom Index. Results Fifty-six patients (median age 60 years, 71.4% women) underwent G-POEM (100% technical success; 71.4% clinical response). ICC depletion (< 10/high-power field) and fibrosis were encountered in 70.4% and 75% of the cases, respectively. There was no difference in mean ICC count between G-POEM responders vs. non-responders (7±3.6 vs. 7.7±3.3; P = 0.9). There was no association between ICC density or degree of fibrosis with the etiology of gastroparesis, duration of symptoms, gastric emptying rate, or pyloric impedance planimetry. Patients who did not respond to G-POEM had a significantly higher degree of moderate/severe fibrosis when compared with those who responded (81.3% vs. 25%; P = 0.0002). Conclusions Pyloric muscle biopsies during G-POEM was feasible and safe. ICC depletion and pyloric muscle fibrosis are common in gastroparetic patients. The degree of fibrosis may be related to pyloric dysfunction and clinical response to G-POEM. Additional studies are needed to confirm these results.

Double-balloon enteroscopy with EUS-guided rendezvous for failed cannulation in patients with history of Roux-en-Y gastric bypass

Video 1Double-balloon enteroscopy with EUS-guided rendezvous for biliary access in patients with a history of Roux-n-Y gastric bypass.

Ultrasound Assisted Endoscopic Gastric Bypass (USA-EGB): a potential endoscopic alternative to surgical bypass, a pre-clinical proof of concept study

Background and study aims Endoscopic weight loss procedures have gained traction as minimally invasive options for the primary treatment of obesity. Thus far, we have developed endoscopic procedures that reliably address gastric restriction but result in significantly less weight loss than surgical gastrointestinal bypass. The goal of this nonsurvival study was to assess the technical feasibility of an endoscopic procedure, that incorporates both gastric restriction and potentially reversible gastrointestinal bypass. Methods Ultrasound-assisted endoscopic gastric bypass (USA-EGB) was performed in three consecutive live swine, followed by euthanasia and necropsy. Procedure steps were: 1) balloon-assisted enteroscopy that determines the length of the bypassed limb; 2) endoscopic ultrasound-guided gastroenterostomy that creates a gastrointestinal anastomosis using a lumen apposing metal stent; 3) endoscopic pyloric exclusion that disrupts transpyloric continuity resulting in complete gastrointestinal bypass; and 4) gastric restriction that reduces gastric volume. Results Complete gastrointestinal bypass and gastric restriction was achieved in all three swine. The mean total procedure time was 131 minutes (range 113-143), mean length of the bypassed limb was 92.5 cm and 180 cm, using short and long overtubes, respectively. There were no significant complications. Conclusions We successfully described USA-EGB in three consecutive live swine. Further studies are needed to access the procedures safety, efficacy, and clinical use.

Radiologic Predictors of Increased Number of Necrosectomies During Endoscopic Management of Walled-off Pancreatic Necrosis

GOALS

No established methods exist to predict who will require a higher number of endoscopic necrosectomy sessions for walled-off necrosis (WON). We aim to identify radiologic predictors for requiring a greater number of necrosectomy sessions. This may help to identify patients who benefit from aggressive endoscopic management.

MATERIALS AND METHODS

This is a multicenter retrospective study of patients with WON at 3 tertiary care centers. WON characteristics on preintervention computed tomography imaging were evaluated to determine if they were predictive of requiring more endoscopic necrosectomy.

RESULTS

A total of 104 patients were included. Seventy patients (67.3%) underwent endoscopic necrosectomy, with median of 2 necrosectomies. WON largest transverse diameters (P=0.02), largest coronal diameters (P=0.01), necrosis pattern [likelihood ratio (LR)=17.85, P<0.001], spread (LR=11.02, P=0.01), hemorrhage (LR=8.64, P=0.003), and presence of disconnected pancreatic duct (LR=6.80, P=0.01) were associated with undergoing ≥2 necrosectomies. Patients with septations/loculations were significantly less likely to undergo ≥2 necrosectomies (LR=4.86, P=0.03).

CONCLUSIONS

Several computed tomography radiologic features were significantly associated with undergoing ≥2 necrosectomies. These could help identify patients who will undergo a higher number of endoscopic necrosectomy sessions.

O26: SIGMA RECEPTORS IN BREAST CANCER – EXAMINING THEIR LIGAND MEDIATED MECHANISMS OF CANCER CELL DEATH AND POTENTIAL FOR CLINICAL DIAGNOSTICS

Introduction

Sigma receptors (SRs) are regularly overexpressed in cancer however their functions remain unknown. Certain Sigma1-receptor (Sig1R) ligands trigger death in breast cancer (BCa) cells but not in non-cancerous breast cells (NCB). In stressed cells, Sig1R is vital to the pro-survival unfolded protein response (UPR). Cancer cells depend on UPR signalling for survival, investigating Sig1R mediated mechanisms in BCa vs. NCB might uncover novel and targetable weaknesses in cancer.

Method

UPR activation by Sig1R antagonist IPAG was examined in BCa cells by Western blotting. Sig1R and UPR marker localizations were examined by immunofluorescence. SR gene expression between 141 matched breast tumour tissue and tumour adjacent normal samples was compared using RNAseq data from The Cancer Genome Atlas (TCGA). Merged microarray datasets were used to compare SR expression in 399 primary breast tumours with relapse (BCaR) vs. 352 without relapse (BCaNR).

Result

Relative to non-cancerous human mammary epithelial cells, Sig1R expression was lowest in MCF7s and highest in MDA-MB-468s. IPAG induced differential temporal activation of all three branches of the UPR in MCF7 and tamoxifen-resistant, low Sig1R expressing cell line LY2. TCGA RNAseq data highlighted SR overexpression in BCa particularly in the basal subtype. Microarray data showed both oestrogen receptor (ER)+ and ER- BCaR primaries had elevated SIGMAR1 compared to BCaNR primaries of the same respective ER status.

Conclusion

BCa cells are dependent on Sig1R mediated signalling. Sig1R expression might indicate the propensity of breast tumours to relapse. Thus, Sig1R represents a potential target in BCa, particularly for aggressive subtypes.

Take-home message

The Sigma-1 receptor (Sig1R) has a vital but unknown pro-survival function in cancer; Sig1R ligands cause death in cancer cells while sparing non-cancerous ones. Characterizing Sig1R mediated signalling may reveal novel, selective therapeutic targets in cancer.

O12: IHC ANALYSIS OF RESIDUAL DISEASE POST NEOADJUVANT TRASTUZUMAB FOR EARLY STAGE BREAST CANCER REVEALS ER/HER2 CROSSTALK THROUGH INCREASED ER SIGNALLING

Introduction

Therapeutic pressure functionally affects oncogenes and related signalling pathways through dynamic alterations in transcriptional and epigenetic alterations. Altered receptor status occurs throughout tumour progression and may be influenced by adjuvant and neoadjuvant therapies. Recurrent transcriptional remodelling events have been described in the progression of primary breast cancer to metastasis, including increased tyrosine kinase signalling, specifically Her2, and loss of ESR1 gene expression. We hypothesise that in the setting of tyrosine kinase inhibition, an increase in estrogen receptor (ER) signalling is observed.

Method

A database of patients recruited to ICORG trial 07/09 was queried to identify patients with histologically confirmed, Her2-overexpressing or Her2 amplified, nonmetastatic, invasive breast cancer who received neoadjuvant trastuzumab, alone or in combination with neoadjuvant systemic chemotherapy. Clinicopathological characteristics recorded include age at diagnosis, clinical stage, receptor status and percentage positivity, and pathological complete response.

Result

A total of 55 patients identified on ICORG trial 09/07 received neoadjuvant trastuzumab. Of these, 27 achieved a complete pathological response (49%; n=27/55). In those with residual disease, a gain in mean ER staining percentage positivity was observed in the residual disease compared to diagnostic biopsy staining (59.22 vs 45.11; p=0.03). A corresponding loss in Her2 percentage staining positivity was also observed (p=0.006).

Conclusion

An inverse correlation was observed between loss of Her2 positivity and percentage gain in ER staining in patients with residual disease following treatment with neoadjuvant trastuzumab. Further study is needed to elucidate the regulatory mechanism of ER/Her2 crosstalk, which may be epigenetically regulated through DNA methylation.

Take-home message

ER/Her2 crosstalk can be demonstrated clinically in IHC analysis of patients with residual disease post neoadjuvant trastuzumab. Tyrosine kinase inhibition in the form of neoadjuvant trastuzumab results in loss of Her2 signalling and corresponding gain in ER signalling.

O43: CLINICAL IMPACT OF GENE FUSIONS IN BREAST CANCER BRAIN METASTASES

Introduction

The incidence of brain metastases is increasing despite longer survival rates for patients with advanced breast cancer. The identification of novel therapeutic targets for these patients is an urgent unmet clinical need. Sequencing of metastatic tumours have largely focused on mutations however gene fusions have an important, yet underappreciated role in tumorigenesis and disease progression. In this study, we investigate the role of gene fusions in brain metastatic disease and their impact on altered therapeutic responses.

Method

RNA sequencing was performed on the largest reported cohort of patient matched primary and resected brain metastatic tumours (45 patients n=90 samples). Expressed gene fusions were detected computationally using STAR-Fusion and Arriba.

Result

We identified differential gene fusion burden in brain metastatic tumours (medium of 58) vs. primary breast tumours (medium of 38) (p &lt; 0.05). Enrichment for fusions in pathways associated with tumour cell plasticity and proliferation with recurrent fusions in known cancer driver genes related to MAPK, HER signaling identified. Of note, a fusion in CDK12 is of clinical importance. Increased genomic alterations and over expression of CDK12 is associated with brain metastases free survival in an independent cohort of primary breast tumours with a recorded history of brain metastases. It has been proposed that inhibition of CDK12 may induce BRCAness in tumours making them sensitive to PARP inhibition.

Conclusion

These results highlight the significant role of gene fusions in breast cancer brain metastases.

Abbreviations

MAPK Mitogen Activated Protein Kinase, HER Human Epidermal Receptor, CDK12 Cyclin Dependent Kinase 12

Take-home message

We highlight the significant role of gene fusions in breast cancer brain metastases and offer specific actionable genomic alterations to be exploited.

Endoscopic ultrasound-guided biliary drainage in benign biliary pathology with normal foregut anatomy: a multicenter study

BACKGROUND AND AIMS

Biliary drainage using endoscopic ultrasound (EUS-BD) has been developed as a novel technique to obtain biliary access and drainage when ERCP fails. Numerous studies have demonstrated its safety and efficacy specifically pertaining to those with malignant distal biliary obstruction or altered foregut anatomy. The aim of this study is to evaluate the safety and efficacy of EUS-BD in benign indications in patients with normal foregut anatomy.

METHODS

We performed a retrospective comparative study from 5 academic medical centers (2008-2018) involving patients with benign biliary obstruction and native foregut anatomy who had an initial failed ERCP with subsequent attempt at biliary decompression via EUS-BD or by repeating ERCP.

RESULTS

36 patients (mean age 61.6 ± 2.2, 38.9% female) who underwent attempted EUS-BD following initial failed ERCP were compared to 50 patients (mean age 62.7 ± 2.3, 73.5% female) who underwent repeat ERCP following an initial failed cannulation. EUS-BD was technically successful in 28 (77.8%) patients with rendezvous being the most common approach (86.1%). A higher level of pre-procedural bilirubin was found to be associated with technical success of EUS-BD (3.65 ± 0.63 versus 1.1 ± 0.4, p value 0.04). Success of repeat ERCP following failed cannulation was 86%. Adverse events were significantly more frequent in the EUS-BD cohort when compared to the repeat ERCP (10 (27.8%) versus 4 (8.0%), p = 0.02, OR 4.32.

CONCLUSIONS

EUS-BD remains a viable therapeutic option in the setting of benign biliary disease, with success rates of 77.8%. Adverse events were significantly more common with EUS-BD vs. repeat ERCP, emphasizing the need to perform in expert centers with appropriate multidisciplinary support and to strongly consider the urgency of biliary decompression before considering same session EUS-BD after failed initial biliary access.

Abstract 4750: Time-of-diagnosis prognostication of pancreatic ductal adenocarcinoma based on single cell RNA-seq and digital cytometry

Introduction: Recent work has described tumor heterogeneity in pancreatic ductal adenocarcinoma (PDAC). Here we use scRNA-seq followed by CIBERSORTx and CytoTRACE to profile specific cell states within PDAC tumors at time-of-diagnosis, and correlate these states with clinical outcomes.

Methods: We performed diagnostic endoscopic ultrasound (EUS) guided core needle biopsies in ten patients with locally advanced/resectable PDAC, from which we generated scRNA-seq data to identify unique cell types and states. To validate the prognostic utility of these signatures, we utilized CIBERSORTx to deconvolve bulk RNA-seq data from two external datasets - 1) 170 cases from The Cancer Genome Atlas (TCGA) and 2) 51 cases from Kirby et al (Mol Oncol 2016). We also used CytoTRACE to predict tumor cell differentiation status from the scRNA-seq data.

Results: From ~9,800 total cells in our single cell cohort, we identified 16 cell types and 25 cell states. Bulk RNA-seq deconvolution was performed using the expression profiles from these 25 cell states. Two groups of malignant ductal cells were found to negatively influence patient survival (p of .008 and .041), and a group CD14+ monocytes and CD4+ T cells were found to positively influence patient survival (p of .011 and .012). We performed further analysis on the two malignant ductal cell populations, which displayed gene expression profiles similar to PDAC subtypes (squamous-like and progenitor) previously described by RNA-seq gene set enrichment analysis (Bailey et al; Moffitt et al). On CytoTRACE analysis of our scRNA-seq data, the squamous-like tumor cell population remained distinct from the larger progenitor population, and was predicted to be significantly more differentiated. We stratified TCGA and Kirby samples based upon cell fraction of this squamous-like population. A Kaplan-Meier estimate was used to quantify survival over time of the two groups (&gt;7% squamous-like vs. &lt;7% squamous-like). The &gt;7% group displayed a marked decrease in survival - log-rank p-values of .025 (TCGA) and .00002 (Kirby). When filtering for only TCGA samples that went on to receive chemotherapy this trend remained highly significant (p of .022), with 46% of the &gt;7% group vs. 82% of the &gt;7% group surviving beyond one year.

Conclusion: scRNA-seq from EUS core biopsies identified distinct prognostic tumor cell state fractions that were corroborated by pre-treatment bulk RNA-seq through deconvolution. These novel investigational and digital cytometric approaches not only confirmed prior tumor subtypes and their prognoses, but also enabled the quantification of their fractions for additional prognostic value. Patients with certain cell state fraction profiles may benefit from combinatorial therapeutic interventions, especially in the context of clinical trials.

Citation Format: Erik Storrs, Abul Usmani, Bradley Krasnick, Chris Wetzel, Thomas Hollander, Prathamesh Chati, Faridi Qaium, Hephzibah Anthony, Ian Sloan, Natalie Cosgrove, Gabriel Lang, Vladimir Kushnir, Daniel Mullady, Dayna Early, William Hawkins, Koushik Das, Ryan Fields, Aadel Chaudhuri. Time-of-diagnosis prognostication of pancreatic ductal adenocarcinoma based on single cell RNA-seq and digital cytometry [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4750.

Safety and efficacy of the use of lumen-apposing metal stents in the management of postoperative fluid collections: a large, international, multicenter study

BACKGROUND

Multiple studies have examined the use of lumen-apposing metal stents (LAMSs) for the drainage of peripancreatic fluid collections. Data on the use of LAMSs for postoperative fluid collections (POFCs) are scarce. POFCs may lead to severe complications without appropriate treatment. We aimed to study the outcomes (technical success, clinical success, rate/severity of adverse events, length of stay, recurrence) of the use of LAMSs for the drainage of POFCs.

METHODS

This international, multicenter, retrospective study involved 19 centers between January 2012 and October 2017. The primary outcome was clinical success. Secondary outcomes included technical success and rate/severity of adverse events using the ASGE lexicon.

RESULTS

A total of 62 patients were included during the study period. The most common etiology of the POFCs was distal pancreatectomy (46.8 %). The mean (standard deviation) diameter was 84.5 mm (30.7 mm). The most common indication for drainage was infection (48.4 %) and transgastric drainage was the most common approach (82.3 %). Technical success was achieved in 60/62 patients (96.8 %) and clinical success in 57/62 patients (91.9 %) during a median (interquartile range) follow-up of 231 days (90 - 300 days). Percutaneous drainage was needed in 8.1 % of patients. Adverse events occurred intraoperatively in 1/62 patients (1.6 %) and postoperatively in 7/62 (11.3 %). There was no procedure-related mortality.

CONCLUSION

This is the largest study on the use of LAMSs for POFCs. It suggests good clinical efficacy and safety of this approach. The use of LAMSs in the management of POFCs is a feasible alternative to percutaneous and surgical drainage.

Safety and efficacy of digital single-operator pancreatoscopy for obstructing pancreatic ductal stones

Background and study aims The role of the digital single-operator pancreatoscopy (D-SOP) with electrohydraulic (EHL) or laser lithotripsy (LL) in treating pancreatic ductal stones is unclear. We investigated the safety and efficacy of D-SOP with EHL or LL in patients with obstructing pancreatic duct stones.

Patients and methods Retrospective analysis of 109 patients who underwent D-SOP for pancreatic stones at 17 tertiary centers in the United States and Europe from February 2015 to September 2017. Logistic regression was performed to identify factors associated with the need for more than one D-SOP with EHL/LL.

Results Most patients were males (70.6 %),mean age 54.7 years. Fifty-nine (54.1 %) underwent EHL and 50 (45.9 %) underwent LL. Mean procedure time was longer in the EHL group (74.4 min vs 53.8 min; P < 0.001). Ducts were completely cleared (technical success) in 89.9 % of patients (94.1 % in EHL vs 100 % in LL; P = 0.243), achieved in a single session in 73.5 % of patients (77.1 % by EHL and 70 % by LL; P= 0.5).D-SOP failed in 11 patients (10.1 %); 6 patients were treated with extracorporeal shockwave lithotripsy (ESWL), 1 with surgery,1 with combined treatment (ESWL + D-SOP EHL) and 3 with other. Fourteen adverse events occurred in 11 patients (10.1 %). Patients with more than three ductal stones were more likely to have technical failure compared to those with less than three stones (17 % vs. 4.8 %; P = 0.04). Having more than three stones was independently associated with the need for more than one D-SOC EHL/LL session (OR 2.94, 95 % CI 1.13 – 7.65).

Conclusion D-SOP with EHL or LL is effective and safe in patients with pancreatic ductal stones.

Discontinuation of proton pump inhibitor use reduces the number of endoscopic procedures required for resolution of walled-off pancreatic necrosis

Background and Objectives

Endoscopic drainage/debridement of symptomatic walled off necrosis (WON) using lumen-apposing metal stents (LAMS) is both safe and effective. While endoscopic management of WON is the standard approach to treatment, the ideal concomitant medical therapy remains unclear. The purpose of this study was to further elucidate the effect of proton pump inhibitor (PPIs) therapy on the technical and clinical success of endoscopic treatment of WON.

Methods

Two hundred and seventy-two patients in 8 centers with WON managed by endoscopic drainage using LAMS were evaluated. Patients were followed for at least 6 months following treatment. The patients were divided into two groups: Those that used PPIs continuously during the therapy and those not on PPIs continuously during the interval of therapy. Outcomes included but were not limited to technical success, clinical success, number of procedures performed, and adverse events.

Results

From 2013 to 2016, 272 patients underwent WON drainage with successful transmural LAMS placement. The two groups were split evenly into PPI users and non-PPI users, and matched in regards to demographics, etiology of pancreatitis, WON size, and location. There was no difference in the technical success between the two groups (100% vs. 98.8%, P = 1), or in clinical success rates (78.7% vs. 77.9%). There was a significant difference in the required number of direct endoscopic necrosectomies to achieve clinical success in the PPI vs. non-PPI group (3.2 vs. 4.6 respectively, P < 0.01). There were significantly more cases of stent occlusion in the non-PPI group vs. PPI group (9.5% vs. 20.1% P = 0.012), but all other documented adverse events were not significantly different.

Conclusion

Discontinuing PPIs during endoscopic drainage and necrosectomy of symptomatic WON appears to reduce the number of endoscopic procedures required to achieve resolution. Continuous PPI results in higher rates of early stent occlusion.

Comparison of FNA and fine-needle biopsy for EUS-guided sampling of suspected GI stromal tumors

BACKGROUND AND AIMS

Subepithelial lesions are found in about 1% of all EGD procedures, and GI stromal tumors are a type of subepithelial lesion commonly encountered. Although the majority of subepithelial lesions are benign, GI stromal tumors have malignant potential, making a definitive diagnosis important. Currently, the criterion standard for the diagnosis of GI stromal tumors is EUS-directed FNA (EUS-FNA). The definitive diagnosis of GI stromal tumors relies on immunohistochemical staining, which depends on enough tissue being submitted to the pathologist. Achieving adequate tissue acquisition from suspected GI stromal tumors by EUS-FNA remains a limitation. Advancements in needle design, however, have improved tissue acquisition and therefore may improve the definitive diagnosis of GI stromal tumors by EUS-FNA. The goal of this study is to compare a fine-needle biopsy (FNB) needle (SharkCore, Medtronics) with FNA needles in definitively diagnosing suspected GI stromal tumors.

METHODS

This is a retrospective, single-center study of consecutive patients with suspected GI stromal tumors by EUS characterization who underwent EUS-FNA or EUS-FNB.

RESULTS

A total of 106 patients (53 men, mean [± standard deviation {SD}] age 62.19 ± 16.33 years) were included in the study undergoing EUS-FNA or EUS-FNB of suspected GI stromal tumors. The needle size that was used most often was 22 gauge in both groups. The average size of the lesions was 27.68 ± 15.70 mm; 71.7% of lesions were located in stomach, 19.8% in the esophagus, 5.7% in the duodenum, and 2.8% in the rectosigmoid colon. Ninety-one patients underwent EUS-FNA and 15 patients underwent EUS-FNB. Adequate tissue was procured, allowing immunohistochemical staining in 59 (64.8%) patients in the FNA group and 15 (100%) patients in the FNB group; P = .006. A diagnosis was reached by immunohistochemical staining in 48 (52.7%) patients in the FNA group and 13 (86.7%) patients in the FNB group; P = .01. Tissue was insufficient to make a cytologic diagnosis in 22 (24.2%) patients in the FNA group compared with none in the FNB group; P = .03. Adequate tissue was procured on the first pass of the FNB needle in the majority of patients (83.3%), whereas only 23.5% of patients had adequate tissue on the first pass by the FNA needle, with a median of 3 passes; P = .00. Tissue was insufficient to perform immunohistochemical staining, and thus a diagnosis could not be confirmed before surgery in 8 of the 34 surgical patients in the FNA group. Ten of 15 patients in the EUS-FNB group underwent surgery, all of whom were correctly diagnosed by FNB. There were no reported immediate adverse events or technical difficulties in either group.

CONCLUSIONS

EUS-FNB by using a SharkCore needle for suspected GI stromal tumors is technically similar and equally safe as FNA, with better tissue acquisition, which was achieved with fewer needle passes and an improved diagnostic yield by immunohistochemical staining.

Long-term outcomes of palliative colonic stenting versus emergency surgery for acute proximal malignant colonic obstruction: a multicenter trial

Background and study aims Long-term data are limited regarding clinical outcomes of self-expanding metal stents as an alternative for surgery in the treatment of acute proximal MBO. The aim of this study was to compare the long-term outcomes of stenting to surgery for palliation in patients with incurable obstructive CRC for lesions proximal to the splenic flexure. Patients and methods Retrospective multicenter cohort study of obstructing proximal CRC patients with who underwent insertion of a SEMS (n = 69) or surgery (n = 36) from 1999 to 2014. The primary endpoint was relief of obstruction. Secondary endpoints included technical success, duration of hospital stay, early and late adverse events (AEs) and survival. Results Technical success was achieved in 62/69 (89.8 %) patients in the SEMS group and in 36 /36 (100 %) patients who underwent surgery (P = 0.09). In the SEMS group, 10 patients underwent stenting as a bridge to surgery and 59 underwent stent placement for palliation. Clinical relief was achieved in 78 % of patients with stenting and in 100 % of patients who underwent surgery (P < 0.001). Patients with SEMS had significantly less acute AEs compared to the surgery group (7.2 % vs. 30.5 %, P = 0.003). Hospital mortality for the SEMS group was 0 % compared to 5.6 % in the surgery group (P = 0.11). Patients in the SEMS group had a significantly shorter median hospital stay (4 days) as compared to the surgery group (8 days) (P < 0.01). Maintenance of decompression without the recurrence of bowel obstruction until death or last follow-up was lower in the SEMS group (73.9 %) than the surgery group (97.3 %; P = 0.003). SEMS placement was associated with higher long-term complication rates compared to surgery (21 % and 11 % P = 0.27). Late SEMS AEs included occlusion (10 %), migration (5 %), and colonic ulcer (6 %). At 120 weeks, survival in the SEMS group was 5.6 % vs. 0 % in the surgery group (P = 0.8). Conclusions Technical and clinical success associated with proximal colonic obstruction are higher with surgery when compared to SEMS, but surgery is associated with longer hospital stays and more early AEs. SEMS should be considered the initial mode of therapy in patients with acute proximal MBO and surgery should be reserved for SEMS failure, as surgery involves a high morbidity and mortality.

A large multicenter study of recurrence after surgical resection of branch-duct intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND

Surgery for pancreatic branch-duct intraductal papillary mucinous neoplasm (BD-IPMN) is indicated for therapy of symptomatic patients and to prevent development of invasive cancer. There is currently no consensus on management of BD-IPMN patients after surgical resection. The aim of this retrospective multicenter study was to determine the recurrence and long-term survival after surgical resection of BD-IPMN and to determine the predictive factors of recurrence.

METHODS

All patients who underwent surgery for BD-IPMN from 2005 to 2011 at 2 centers were identified. The diagnosis of BD-IPMN was based upon imaging and endosonographic analysis, and was confirmed by pathological analysis. The lesions were classified into 4 categories according to the WHO classification. Data on cyst characteristics, operative procedure, recurrence, and follow-up were evaluated. Recurrence was defined as the presence of BD-IPMN or mass in the remnant pancreas after surgery as seen on follow-up imaging. Recurrence suspected on imaging was confirmed via histological analysis when possible.

RESULTS

A number of 271 patients (67% female; mean age 63.4 yrs) with BD-IPMN underwent surgical resection. The mean size of the cyst was 24.2mm (range, 12-80). There were 34 (12.5%) patients with an associated mass. 82 (30.3%) patients had worrisome features in the cyst on pre-operative EUS, included mural nodules (N.=25), solid component (N.=27), debris (N.=25), and a dilated major pancreatic duct (N.=5). 144(53%) patients had a pancreaticoduodenectomy for head lesions, 125 (46%) had distal pancreatectomy for tail/body lesions, and 1 (1%) underwent a total pancreatectomy. Histology showed 86% with noninvasive IPMN (adenoma 31%, moderate dysplasia 24%, severe dysplasia or carcinoma in situ 31%) and 14% with invasive IPMN. The mean patient follow-up was 28 months (range, 10-180 months). Recurrence in the remnant pancreas occurred in 34 (12.5%) patients. Of the patients with recurrence, 3/34 had invasive carcinoma and 31/34 had noninvasive cystic lesions; all patients with invasive carcinoma recurrence were those with a previous invasive IPMN. On MVA, risk factors for cyst recurrence were severe dysplasia/intraductal carcinoma in situ and invasive IPMN even after adjusting for elevated CEA (>193 ng/mL), type of surgery, and cyst size (OR 2.8, 95% CI=1.1-7.3; P=0.028). 3 patients who had invasive IPMN and 1 who had severe dysplasia patient with recurrence died, all because of recurrent cancer, with the mean time from recurrence to death being 36 months.

CONCLUSIONS

The risk of BD-IPMN recurrence after resection depends upon the histological type, with the highest-risk groups being those with severe dysplasia/intraductal carcinoma in situ and invasive IPMN. Even after negative resection margins, the pancreatic remnant still harbors a risk of recurrence which requires long-term surveillance.

From Visual Exploration to Storytelling and Back Again

The primary goal of visual data exploration tools is to enable the discovery of new insights. To justify and reproduce insights, the discovery process needs to be documented and communicated. A common approach to documenting and presenting findings is to capture visualizations as images or videos. Images, however, are insufficient for telling the story of a visual discovery, as they lack full provenance information and context. Videos are difficult to produce and edit, particularly due to the non-linear nature of the exploratory process. Most importantly, however, neither approach provides the opportunity to return to any point in the exploration in order to review the state of the visualization in detail or to conduct additional analyses. In this paper we present CLUE (Capture, Label, Understand, Explain), a model that tightly integrates data exploration and presentation of discoveries. Based on provenance data captured during the exploration process, users can extract key steps, add annotations, and author "Vistories", visual stories based on the history of the exploration. These Vistories can be shared for others to view, but also to retrace and extend the original analysis. We discuss how the CLUE approach can be integrated into visualization tools and provide a prototype implementation. Finally, we demonstrate the general applicability of the model in two usage scenarios: a Gapminder-inspired visualization to explore public health data and an example from molecular biology that illustrates how Vistories could be used in scientific journals. (see Figure 1 for visual abstract).

Endoscopic mucosal resection of large non-ampullary duodenal polyps: technical aspects and long-term therapeutic outcomes

BACKGROUND

Our aim was to evaluate the efficacy, safety and long term outcomes of endoscopic mucosal resection (EMR) of large non-ampullary duodenal polyps.

METHODS

A retrospective review of patients undergoing EMR of non-ampullary duodenal polyps ≥ 10 mm in size was performed. EMR was performed using standard snare polypectomy using pure coagulation current. Patient demographics, polyp site and histopathology, resection technique, use of adjunctive argon plasma coagulation (APC) ablation, adverse events, and residual/recurrent neoplasia at follow-up were evaluated.

RESULTS

59 duodenal lesions were removed by EMR (mean age 62 years, 55.9% men). 17 (28.8%) polyps were located in the bulb, 31 (50.8%) in the 2nd portion and 12 (20.3%) in the 3rd part of the duodenum. The mean size of lesions resected was. Submucosal saline injection followed by hot snare polypectomy was performed for 29 (49%) endoscopies. Adjunctive ablation of focal residual neoplastic tissue with APC was applied in 18 cases (30.5%). Complete endoscopic eradication during a single session was performed successfully in 46 (79%) patients. En-bloc resection was performed in 40 polyps (67%) and piecemeal resection in 19 (32.2%). Procedure complications were acute bleeding (N.=11) and 1 microperforation that was managed with clip closure and antibiotics. The mean follow-up time was 37 months (range 22-53). The overall endoscopic cure rate was 93%. On follow-up surveillance, residual adenoma was identified in 13 (22%) patients; these were all eradicated endoscopically.

CONCLUSIONS

EMR for large non-ampullary duodenal adenomas is a safe and effective technique to achieve complete eradication.

A Rare Case of Acinar Cell Cystadenoma in a 14-Year-Old Adolescent: A Case Report

Background: Acinar cell cystadenoma is a rare pancreatic cyst that has been described in several case reports. This lesion may be incidental or asymptomatic, occurs predominately in females, and has a mean age of onset in the fourth decade.

Case Presentation: A previously healthy 14-year-old male presented with abdominal pain. He was found to have a pancreatic cystic lesion on ultrasound and cross-sectional imaging. His diagnosis remained uncertain despite additional analysis, including endoscopic ultrasound with fine-needle aspiration. The patient underwent successful laparoscopic excision for definitive diagnosis and management with an unremarkable postoperative course. He was diagnosed with a multilocular acinar cell cystadenoma.

Conclusion: Acinar cell cystadenoma is a rare pancreatic cyst whose true malignant potential is unknown. Although there are no formal recommendations for post-operative monitoring and the true risk of recurrence is unknown, we recommended every other year magnetic resonance imaging/magnetic resonance cholangiopancreatography for postresection surveillance for this patient due to the theoretical risk of recurrence with malignant transformation.

Endoscopic ultrasound-fine needle injection for oncological therapy

The minimal invasiveness and precision of endoscopic ultrasound (EUS) has lead to both its widespread use as a diagnostic and staging modality for gastrointestinal and pancreaticobiliary malignancies, and to its expanding role as a therapeutic modality. EUS-guided celiac plexus neurolysis is now a well-accepted modality for palliation of pain in patients with pancreatic cancer. EUS-guided ablation, brachytherapy, fiducial marker placement, and antitumor agent injection have been described as methods of performing minimally invasive oncological therapy. EUS-fine needle injection may be performed as adjunctive, alternative, or palliative treatment. This review summarizes the studies to date that have described these methods. A literature search using the PubMed/MEDLINE databases was performed. While most published studies to date are limited with disappointing outcomes, the concept of a role of EUS in oncological therapy seems promising.

Mass mailing and staff experience in a total recruitment program for a clinical trial: the SHEP experience. Systolic Hypertension in the Elderly Program. Cooperative Research Group

The Systolic Hypertension in the Elderly Program (SHEP) staff contacted 447,921 screenees, of whom 11,919 (2.7%) were originally eligible and 4,736 (1.1%) maintained eligibility and were randomized. The total number of participants enrolled at the 16 clinical centers ranged from 133 to 559. The low yield of screenees to randomizations resulted from the study design, not from low levels of agreement to participate, and required the employment of a variety of recruitment strategies in a prudent overall plan. SHEP was one of the first clinical trials to use mass mailing as a primary strategy of recruitment. The study used mailing lists from seven generic sources. More than 3.4 million letters of invitation were mailed; they yielded an overall response rate of 4.3%. Motor vehicle and voter registration lists provided the greatest numbers of names. Mailings to members of health maintenance organizations (HMOs) and registrants of the Health Care Finance Administration (HCFA) provided the greatest response rates. Considerable variability in response rates existed among clinical centers using generically similar mailing lists. Generally, the number of hours spent on recruitment showed a positive, but not statistically significant, association with randomization yields. The recruitment yield was statistically significantly higher in clinics with experienced recruitment coordinators than in clinics with inexperienced ones (p = 0.0008). From these findings we conclude that mass mailing is an important strategy in an overall recruitment program, that the involvement of experienced recruitment staff is important, and that although the total time spent by staff on recruitment may also improve results, it matters less than the staff's level of recruiting experience.

Recruitment in the Trial of Nonpharmacologic Intervention in the Elderly (TONE)

OBJECTIVE

To compare the effectiveness of different approaches to participant enrollment in a behavior modification trial.

DESIGN

Concurrent, prospective evaluation performed in context of recruitment for a randomized, controlled trial.

SETTING

Four study centers located in Baltimore, Maryland, Memphis, Tennessee New Brunswick, New Jersey, and Winston-Salem, North Carolina.

PARTICIPANTS

Men and women aged 60 to 80 years who were being treated with a prescription medication for control of hypertension.

MAIN OUTCOME MEASURES

Visit counts and percent yields were assessed at each stage of the screening and randomization process. Logistic regression was used to contrast the randomization yields for different recruitment strategies and to explore the impact of sociodemographic characteristics and geographic location on recruitment yields.

RESULTS

The overall randomization yields from a prescreen contact and a first screening visit to enrollment in the trial were 11% and 31%, respectively. Randomization yields varied significantly by participant age, education, and marital status.

CONCLUSIONS

Our results demonstrate the feasibility of recruitment for trials of nonpharmacologic interventions in older people and suggest that mass mailing and mass media advertising campaigns provide an effective means of enrolling in such studies participants with a broad range of personal characteristics.

Differential exercise effects of captopril and nadolol in patients with essential hypertension

In a crossover study, 12 patients with mild to moderate hypertension were given placebo, captopril (12.5 to 50 mg three times a day), and nadolol (20 to 160 mg once a day) to control the resting diastolic blood pressure to a nearly identical degree (p less than 0.0001) (106.1 +/- 4 placebo, 89.6 +/- 8 captopril, 89.8 +/- 7 nadolol). Both drugs lowered (p less than 0.0004) systolic and diastolic blood pressure at rest and during exercise. However, systolic blood pressure lowering during exercise was more pronounced (p less than 0.05) with nadolol than with captopril (difference of 6 mmHg, 16 mmHg, and 21 mmHg at 5.0, 7.0, and 9.0 metabolic equivalents (METS) respectively). Heart rate was lower (p less than 0.05) at rest and during exercise with nadolol as compared with placebo and with captopril. These data imply different mechanisms of action of the two drugs at rest and during exercise and may help in selection of drug therapy in special patient subsets.

Cibenzoline for treatment of ventricular arrhythmias: a double-blind placebo-controlled study

Cibenzoline, a new class I antiarrhythmic drug, was administered to 24 patients with frequent (greater than 30/h) premature ventricular complexes. Three patients discontinued the medication because of epigastric distress before repeat ambulatory electrocardiography. Of the remaining 21 patients, 13 responded to 130 mg twice daily by more than 75% suppression of premature ventricular complex frequency and 6 additional patients responded to 160 mg twice daily during an open-label titration phase. Events of ventricular tachycardia (greater than or equal to 3 beats) were totally suppressed in 9 of 10 patients and markedly diminished in the 1 remaining patient. During a double-blind placebo-controlled crossover phase in 16 patients (21 patients minus 2 nonresponders and 3 who developed side effects), cibenzoline suppressed the number of premature ventricular complexes per 24 hours (4,075 +/- 868 to 1,758 +/- 1,089, p = 0.02), the number of events of ventricular tachycardia (31 +/- 30 to 2 +/- 0, p = 0.01) and the number of premature ventricular complex pairs (61 +/- 28 to 25 +/- 21, p = 0.01). Cibenzoline plasma concentration was 59 to 421 ng/ml in responders and higher (387, 758 and 852 ng/ml, respectively) in the three subjects with side effects (right bundle branch block in one, hypotension in one, gastrointestinal upset and central nervous system complaints in one). Cibenzoline plasma concentration correlated with PR interval (r = 0.55, p = 0.0106) and corrected QT interval (r = 0.58, p = 0.0054). Further clinical investigation of this new antiarrhythmic agent is needed.

Aortic valve replacement in patients with aortic stenosis. Effect on cardiac arrhythmias

Twenty-four hour ambulatory electrocardiography was performed on 28 patients with aortic stenosis without significant coronary artery disease or aortic regurgitation. Compared to a control group of subjects with normal hearts proven by noninvasive and invasive testing, patients with aortic stenosis had higher (p = 0.0001) frequency of premature ventricular contractions (PVC) (3144 +/- 1425 versus 17 +/- 46) per 24 hours and higher (p = 0.001) prevalence of PVC presence (27 of 28 patients versus 39 of 101 normal), and complexity (19 of 28 patients versus 4 of 101 normal). Weak correlations of complexity with left ventricular end-diastolic pressure (r = 0.30) and ejection fraction (r = -0.25) were noted. No correlation of ventricular ectopic activity with peak systolic gradient, aortic valve area, or peak left ventricular systolic pressure was noted. Repeat 24-hour ambulatory electrocardiography performed on 13 patients three months after successful aortic valve replacement did not show significant effect of aortic valve replacement on PVC frequency or complexity.

The effect of age, blood pressure and gender on the incidence of premature ventricular contractions

In order to study the effect of age, blood pressure and gender on premature ventricular contractions (PVCs), 24-hour ambulatory electrocardiography was performed on 338 apparently normal subjects (Group I; 209 men, 129 women, age 17 to 69, mean 48.5 +/- 11.7) and on 100 subjects with normal hearts proven by extensive invasive and noninvasive testing (Group II; 51 men, 49 women, age 16 to 68, mean 48.8 +/- 10.2). Apparently normal subjects (Group I) had a higher prevalence of PVCs (61.8% vs. 39.0%, p less than 0.001) and of complexity (16.3% vs. 4.0%, p less than 0.003) than subjects with normal hearts (Group II). The distribution of subjects according to PVC frequency was bimodal in Group I and unimodal in Group II. PVC prevalence increased with age in both the apparently normal group (p less than 0.001), and in the group with normal hearts (p less than 0.025). On the contrary, apparently normal (Group I) men had almost twice the PVC prevalence (74.6% vs. 41.1%, p less than 0.001) and complexity (20.1% vs. 10.1%, p less than 0.25) than apparently normal women, while gender had no effect on PVC prevalence in subjects with normal hearts (Group II). Systolic blood pressure was also associated with PVC prevalence (p less than 0.001) and complexity (p less than 0.02) in apparently normal subjects (Group I) but not in subjects with normal hearts (Group II). These data indicate: that apparently normal subjects have higher prevalence of PVCs and of PVC complexity than subjects with normal hearts, probably because of undetected cardiac disease; that the increase in PVC prevalence with age is not necessarily due to cardiac disease; and that PVC complexity in apparently normal subjects should raise the suspicion of cardiac disease especially in men, in subjects with hypertension and in the older age group.

The effect of age on heart rate in subjects free of heart disease. Studies by ambulatory electrocardiography and maximal exercise stress test

To delineate the effects of true aging, undetected heart disease and deconditioning on heart rate, we performed 24-hour ambulatory electrocardiography and maximal exercise stress test on 101 subjects with normal hearts. The maximal heart rate recorded was 180 beats/min; the minimum was 35 beats/min. A distinct diurnal pattern was observed. With increasing age, a decrease of the maximal heart rate achieved during exercise stress test (r = 0.27, p = 0.05) or spontaneously recorded during the day (r = 0.41, p = 0.0005) or night (r = 0.24, p = 0.03) was observed. The resting and average heart rates were not affected by age. Older subjects had lower exercise tolerance (r = 0.41, p = 0.0001). Low exercise tolerance was associated with higher increments of heart rate for submaximal exercise levels (r = 0.0001) and lower maximal heart rates (r = 0.43, p - 0.008). These changes of heart rate with age are not due to undetected cardiac disease, because the subjects included in the study were meticulously screened by noninvasive and invasive means.