Objectives
This is a protocol for a Cochrane Review (intervention). The objectives are as follows:
To assess the efficacy and safety of plastic stents and metal stents in individuals undergoing endoscopic ultrasound‐guided transmural drainage of pancreatic fluid collections.
Background
Description of the condition
Pancreatitis or inflammation of the pancreas can lead to the development of fluid collections in and around the pancreas. These collections of fluid are known as pancreatic fluid collections (PFCs). On average, 40% to 70% of pancreatitis episodes are complicated by the formation of PFCs (Patra 2014). Both acute pancreatitis and chronic pancreatitis can lead to the development of PFCs (Kim 2012). Younger age, severe pancreatitis, elevated creatinine, raised C‐reactive protein (CRP), and alcohol as an aetiology are known risk factors for the formation of PFCs (Cui 2014). Revised Atlanta classification defines and classifies pancreatic fluid collections into four subtypes: acute peripancreatic fluid collection, acute necrotic collection, pseudocyst, and walled‐off pancreatic necrosis (WOPN) (Banks 2013; Sheu 2012). In individuals with acute interstitial pancreatitis, a leak in the peripheral pancreatic duct causes an acute peripancreatic fluid collection, whilst in necrotising pancreatitis, pancreatic parenchymal necrosis and liquefaction lead to the formation of an acute necrotic collection. The majority of acute peripancreatic fluid collections resolve four weeks into the course of the illness, whilst 10% may develop into a pseudocyst with the formation of a well‐defined wall. In contrast, most acute necrotic collections develop into walled‐off necrosis (Manrai 2018). When PFCs were followed up with radiological imaging, three‐fourths of collections resolved spontaneously within six months. The rest may require drainage if they became symptomatic (Yeo 1990). Treatment of symptomatic PFCs is determined by the maturity of the cyst wall, contents of the cyst, and proximity to the gastrointestinal (GI) lumen. In the first four weeks, PFCs are not drained, as the cyst wall may not have been well formed. Management at this stage is conservative with analgesics, enteral nutrition, and antibiotics (Forsmark 2007). PFCs cause symptoms by virtue of their size, infection, or compression, leading to abdominal pain, sepsis, and feeding intolerances and weight loss, or both. Rarely, they may obstruct the GI tract or fistulise to adjacent abdominal organs or blood vessels. Treatment of a mature and symptomatic PFC is either by percutaneous, surgical, or endoscopic drainage (Baron 2002).
See Appendix 1 for a glossary of terms.
Description of the intervention
The safety and efficacy of endoscopic transmural drainage of PFCs were reported as early as the 1980s (Sahel 1987). Since then, percutaneous and endoscopic drainage has largely replaced surgery as the preferred initial drainage procedure for PFCs (Akshintala 2014). Prior to the advent of endoscopic ultrasound (EUS), endoscopic drainage was done by direct puncture of the submucosal bulge produced by PFC on the gut wall (Hookey 2006). This technique was a relatively blind procedure and had the risk of inadvertent vessel puncture and perforation. A randomised controlled trial comparing EUS‐ and oesophagogastroduodenoscopy (EGD)‐guided drainage of PFCs showed that the technical success of EGD‐guided drainage was only 33% (Varadarajulu 2008). Performing the drainage under EUS guidance has considerably reduced the risks and improved technical success, especially in non‐bulging PFCs. Currently, EUS guided drainage is considered the standard of care for endoscopic transmural drainage of PFCs. The procedure involves visualising the PFC on EUS and creating a fistula tract between the PFC and the gut lumen. The fistula is created using a combination of EUS fine needle aspiration cytology (FNAC) needle, cautery tipped knife (cystotome), and dilating balloons. Following the creation of the fistula, plastic (double pigtail plastic stents or straight stents) or fully covered metal stents are placed across the fistula to allow the drainage of the contents of the PFC into the gut lumen. Lumen apposing metal stents (LAMS) are a new addition to the repertoire for therapeutic endoscopists that were developed in order to reduce the stent migration. Placement of LAMs across the fistula provides secure access to the PFC, allowing for direct visualisation of the cavity and, if required, endoscopic necrosectomy (Itoi 2012; Rinninella 2015; Varadarajulu 2013).
How the intervention might work
In most instances, PFCs resolve spontaneously without any symptoms. Treatment is warranted if the PFC produces symptoms either due to mass effect or secondary infection (Elmunzer 2018). Drainage of the PFC is a quick and effective form of treatment. EUS‐guided drainage is currently considered standard of care for collections close to the gut wall.
Why it is important to do this review
EUS‐guided drainage of PFCs requires the placement of either plastic stents or metal stents across the fistula tract for drainage of the contents of the PFC. Metal stents have a larger diameter, which facilitates better drainage and, if required, easier access of the endoscope into the lumen of PFC for direct necrosectomy. On the other hand, plastic stents are cheaper and can be kept in place for a longer period of time than metal stents, although due to their smaller diameter they have the risk of stent blockage. There are two published meta‐analyses comparing plastic and metal stents for transmural drainage of PFCs, but the results are unclear. We aim to conduct a systematic review using Cochrane methodology to address the benefits and harms of plastic versus metal stents for EUS‐guided drainage of PFC.
Objectives
To assess the efficacy and safety of plastic stents and metal stents in individuals undergoing endoscopic ultrasound‐guided transmural drainage of pancreatic fluid collections.
Methods
Criteria for considering studies for this review
Types of studies
We will include randomised controlled trials (RCTs). We will include studies reported as full text, those published as abstract only, and unpublished data. We will include cluster‐randomised studies and exclude cross‐over studies (see Unit of analysis issues).
Types of participants
We will include individuals undergoing EUS‐guided drainage of pancreatic fluid collection with either plastic stents or metal stents. We will include participants irrespective of their age, sex, or the aetiology of pancreatitis.
Types of interventions
We will include trials comparing plastic stents (of any type or number) with metal stents (of any type or size). We will include the following co‐interventions provided they are not part of the randomised treatment.
Endoscopic retrograde cholangio pancreatography (ERCP) and pancreatic duct stenting
Endoscopic necrosectomy
Percutaneous drainage
Placement of nasocystic drain
Types of outcome measures
Primary outcomes
Clinical success (as defined by primary trials).
All‐cause mortality.
Serious adverse events (e.g. GI bleeding, sepsis, perforation and migration of the stent, and any adverse events leading to prolonged hospital stay).
Secondary outcomes
Technical success: successful deployment of a plastic or metal stent.
Re‐intervention rates: number of additional endoscopic/surgical procedures required.
Recurrence of PFCs during follow up: presence of PFCs at follow‐up.
Search methods for identification of studies
We will design the search strategies with the help of the Cochrane Gut Group Information Specialist before performing literature searches. We will place no restrictions on language of publication when searching the electronic databases or reviewing reference lists of identified studies.
Electronic searches
We will conduct a literature search to identify all published and unpublished RCTs in all languages. We will translate non‐English language papers and fully assess them for potential inclusion in the review as necessary.
We will search the following electronic databases; validated RCT filters will be used in MEDLINE and Embase only:
Cochrane Central Register of Controlled Trials (CENTRAL; via Ovid Evidence‐Based Medicine Reviews Database (EBMR), from inception) (Appendix 2);
MEDLINE (1946 to present; via Ovid) (Appendix 3);
Embase (1974 to present; via Ovid); (Appendix 4); and
LILACS (Latin American and Caribbean Health Science Information Database).
We will also search clinical trial registers/trial result registers:
ClinicalTrials.gov (www.clinicaltrials.gov/);
the World Health Organization International Clinical Trials Registry Platform (www.who.int/trialsearch);
Clinical Trials Registry – India (ctri.nic.in/Clinicaltrials/login.php);
metaRegister of Controlled Trials (isrctn.com/page/mrct).
Searching other resources
We will check the reference lists of all primary studies and review articles for additional references. We will also contact manufacturers and experts in the field to identify additional studies and enquire about ongoing and unpublished studies.
Data collection and analysis
Selection of studies
Two review authors (RS and SC) will independently screen titles and abstracts for potential inclusion in the review. All of the potential studies identified as a result of the search will be coded as either 'retrieve' (eligible, potentially eligible, or unclear) or 'do not retrieve'. We will retrieve the full texts of potentially eligible studies. Two review authors (RS and SC) will independently screen the full texts, identify studies for inclusion, and identify and record reasons for exclusion of the ineligible studies. Any disagreements will be resolved through discussion. We will identify and exclude duplicates and collate multiple reports of the same study so that each study, rather than each report, is the unit of interest in the review. We will record the selection process in sufficient detail to complete a PRISMA flow diagram and a 'Characteristics of excluded studies' table.
Data extraction and management
We will use a standardised data collection form for study characteristics and outcome data that will have been piloted on at least one study included in the review. One review author (RS) will independently extract study characteristics from the included studies. We will extract the following study characteristics.
General information: journal name, year of publication, author's name and address for communication.
Methods: study design, total duration study and run‐in, number of study centres and location, study setting, withdrawals, date of the study.
Participants: number of participants, mean age, gender, comorbidities, aetiology, cyst size, type of PFC (WOPN/pseudocyst), necrotic content within the cyst, location of cyst, duration of symptoms, site of drainage, inclusion criteria, exclusion criteria.
Interventions: number, size, and the type of plastic/metal stents.
Outcomes: primary and secondary outcomes specified and collected, and time points reported.
Notes: funding for trial, notable conflicts of interest of trial authors.
Two review authors (RS and SC) will independently extract outcome data from the included studies. In the 'Characteristics of included studies' table, we will note if the study authors reported outcome data in an unuseable way. Any disagreements will be resolved by consensus. One review author (RS) will copy the data from the data collection form into the Review Manager 5 file (Review Manager 2020). We will double‐check that the data have been entered correctly by comparing the study reports with the data presented in the systematic review. A second review author will spot‐check study characteristics for accuracy against the trial report.
Assessment of risk of bias in included studies
Two review authors (RS and RK) will independently assess the risk of bias for each included study using the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2021). Any disagreement will be resolved by discussion or by involving a third review author (SC). We will assess risk of bias according to the following domains.
Random sequence generation
Allocation concealment
Blinding of participants and personnel
Blinding of outcome assessment
Incomplete outcome data
Selective outcome reporting
Other bias
We will grade each potential source of bias as high, low, or unclear and provide a quote from the study report and rationale for our judgment in the risk of bias table. We will summarise the risk of bias judgements across studies for each of the domains listed. We will consider blinding separately for different key outcomes where necessary. For example, for unblinded outcome assessment, risk of bias for all‐cause mortality may be very different than for a person‐reported pain scale. We will note in the risk of bias table where information on risk of bias relates to unpublished data or correspondence with a study author.
When considering treatment effects, we will take into account the risk of bias for the studies that contribute to that outcome as part of the GRADE methodology.
Assessment of bias in conducting the systematic review
We will conduct the review according to this published protocol and report any deviations from it in the 'Differences between protocol and review' section of the systematic review.
Measures of treatment effect
We will analyse dichotomous data as risk ratios (RRs) and continuous data as mean difference (MD). We will ensure that higher scores for continuous outcomes have the same meaning for a given outcome, explain the direction to the reader, and report where the directions were reversed if this was necessary.
We will undertake meta‐analyses only where this is meaningful, that is if the treatments, participants, and the underlying clinical question are similar enough for pooling to make sense.
A common way that skewed data are indicated in studies is by the reporting of medians and interquartile ranges. Should we encounter this, we will note that the data are skewed and consider the implications of the skewed data. If the data are skewed, we will not perform a meta‐analysis, but will provide a narrative summary instead.
Where multiple trial arms are reported in a single trial, we will include only the relevant arms. If two comparisons (e.g. drug A versus placebo and drug B versus placebo) must be entered into the same meta‐analysis, we will halve the control group to avoid double counting.
Unit of analysis issues
We will consider the individual participant as the unit of analysis. We will exclude cross‐over trials, as this is not an appropriate study design in evaluating the efficacy of stents because once drainage is performed, it will cause permanent modification of the condition (fluid collection). For cluster‐randomised studies, we will consider individual clusters as the unit of analysis. However, we do not expect to find cluster‐randomised studies.
Dealing with missing data
We will record attrition and missing outcome data for each study and contact study authors to request missing outcome data. When study authors do not provide data for missing summary statistics (e.g. standard deviations), we will base our calculations on other reported outcomes, following the methods outlined in Chapter 6 of the Cochrane Handbook (Higgins 2021). When study authors do not provide data for missing specified outcomes, we will analyse the data using intention‐to‐treat analysis.
Assessment of heterogeneity
We will use the Chi2 test to assess the heterogeneity amongst the studies (P < 0.10 indicates significant heterogeneity). We will then report the magnitude of the heterogeneity amongst the trials using the I2 statistic, which will be roughly interpreted as follows:
0% to 40%: might be unimportant;
30% to 60%: may represent moderate heterogeneity;
50% to 90%: may represent substantial heterogeneity;
75% to 100%: considerable heterogeneity.
If we identify substantial heterogeneity as per the Cochrane Handbook (greater than 50%), we will explore it by prespecified subgroup analysis (Higgins 2021).
Assessment of reporting biases
If we are able to pool more than 10 trials, we will create and examine a funnel plot to explore possible publication biases. We will use Egger's test to determine the statistical significance of the reporting bias (Egger 1997). We will consider P < 0.05 to be a statistically significant reporting bias.
Data synthesis
We will perform the meta‐analysis using Review Manager 5 (Review Manager 2020). We will use a random‐effects model by default. To test the robustness of our findings, regardless of which method was chosen, we will conduct sensitivity analyses for primary outcomes using fixed‐effect models. In the case of divergence between the two models, we will present both results; otherwise, we will present only results from the random‐effects model.
Subgroup analysis and investigation of heterogeneity
We plan to carry out the following subgroup analyses.
Participants with walled‐off necrosis versus pseudocysts
Studies at high/unclear risk of bias versus low risk of bias
Metal stents versus single/multiple plastic stents
We will analyse the following outcomes in the subgroup analysis.
Clinical success
Re‐intervention rates
Serious adverse events
Sensitivity analysis
We will perform sensitivity analysis defined a priori to assess the robustness of our conclusions. This will involve:
fixed‐effect versus random effects;
restricting the analysis to trials published as full text and excluding studies only available as abstracts or communication.
Reaching conclusions
We will only base our conclusions on findings from the quantitative or narrative synthesis of studies included in this review. We will avoid making recommendations for practice; our implications for research will give the reader a clear sense of the needed focus of future research and remaining uncertainties in the field.
Summary of findings and assessment of the certainty of the evidence
We will create a summary of findings table with all the primary outcomes defined. We will use the five GRADE considerations (study limitations, consistency of effect, imprecision, indirectness, and publication bias) to assess the certainty of the body of evidence based on the studies that contributed data to the meta‐analyses for each outcome, classifying it as high, moderate, low, or very low. We will use the methods and recommendations described in Section 8.5 and Chapter 12 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2021), employing GRADEpro GDT software(GRADEpro GDT). We will justify all decisions to downgrade or upgrade the certainty of the evidence in the footnotes, and provide comments to aid the reader's understanding of the review where necessary. We will consider whether there is additional outcome information that was not incorporated into the meta‐analyses, note this in the comments, and state if it supports or contradicts the results of the meta‐analyses.
Acknowledgements
We acknowledge the help and support of the Cochrane Gut Group. The authors would also like to thank the following editors and peer referees who provided comments to improve the protocol: Sarah Rhodes (Editor), Emma Neary (Peer Reviewer), Rakesh Kochar (Peer Reviewer), Yuhong (Cathy) Yuan (Information Specialist and Managing Editor), James Scheiman (Contact Editor), Teo Quay (Managing Editor), Frances Tse (Contact Editor), Lisa Winer(Copy Editor) and Grigorios Leontiadis (Sign‐Off Editor).
The Methods section of this protocol is based on a standard template used by the Cochrane Gut Group.
Appendices
Appendix 1. Glossary of terms
Endoscopic ultrasound (EUS): a gastrointestinal endoscopic procedure that uses ultrasound waves to obtain images of the lining and walls of the abdominal organs and chest.
EUS fine needle aspiration cytology (FNAC): a biopsy needle is inserted through the endoscope, and tissue is obtained for histological analyses with the help of EUS.
Endoscopic retrograde cholangio pancreatography (ERCP): an endoscopic procedure wherein a combination of gastrointestinal endoscope and x‐ray is used to diagnose and treat biliary and pancreatic diseases.
Nasocystic drain: a small‐caliber plastic tube that is placed into the pancreatic cystic cavity and routed through the nose and connected to a drain outside to allow continuous drainage of the pancreatic cyst contents.
Appendix 2. CENTRAL search strategy (via Ovid Evidence‐Based Medicine Reviews Database (EBMR)
exp pancreatic juice/
(pancrea* adj5 (juice or fluid* or excret* pseudocyst* or abscess*)).tw,kw.
exp pancreatic pseudocyst/
(Walled off pancreatic necrosis or WOPN).tw,kw.
or/1‐4
exp stents/
(stent or stents or stenting* or stented).tw,kw.
or/6‐7
5 and 8
exp plastics/
exp plasticizers/
plastic*.tw,kw.
exp metals/
metal*.tw,kw.
or/10‐14
9 and 15
Appendix 3. MEDLINE search strategy (via Ovid)
exp pancreatic juice/
(pancrea* adj5 (juice or fluid* or excret* pseudocyst* or abscess*)).tw,kw.
exp pancreatic pseudocyst/
(Walled off pancreatic necrosis or WOPN).tw,kw.
or/1‐4
exp stents/
(stent or stents or stenting* or stented).tw,kw.
or/6‐7
5 and 8
exp plastics/
exp plasticizers/
plastic*.tw,kw.
exp metals/
metal*.tw,kw.
or/10‐14
9 and 15
randomized controlled trial.pt.
controlled clinical trial.pt.
randomized.ab.
placebo.ab.
randomly.ab.
trial.ab.
groups.ab.
or/17‐23
exp animals/ not humans.sh.
24 not 25
16 and 26
Note: Lines 17‐26. Cochrane Highly Sensitive Search Strategy for identifying randomized trials in MEDLINE: sensitivity‐maximizing version (2008 revision); Ovid format.
Appendix 4. Embase search strategy (via Ovid)
exp pancreas juice/
(pancrea* adj5 (juice or fluid* or excret* pseudocyst* or abscess*)).tw,kw.
exp pancreas pseudocyst/
(Walled off pancreatic necrosis or WOPN).tw,kw.
or/1‐4
exp stent/
(stent or stents or stenting* or stented).tw,kw.
or/6‐7
5 and 8
exp plastic/
exp plasticizer/
plastic*.tw,kw.
exp metals/
metal*.tw,kw.
or/10‐14
9 and 15
random:.tw.
placebo:.mp.
double‐blind:.tw.
or/17‐19
exp animal/ not human.sh.
20 not 21
16 and 22
Note: Lines 17‐20 Hedge Best balance of sensitivity and specificity filter for identifying "therapy studies"in Embase. hiru.mcmaster.ca/hiru/HIRU_Hedges_EMBASE_Strategies.aspx
Contributions of authors
Conceiving the protocol: RS
Designing the protocol: RS, SC, RK
Co‐ordinating the protocol: RS, SC, RK
Designing the search strategies: RS, SC
Writing the protocol: RS
Providing general advice on the protocol: SC, RK
Performing previous work that was the foundation of the current study: RS, SC
Sources of support
Internal sources
-
Christian Medical College, Vellore, India
Salaries and infrastructure support for all authors
-
Prof. BV Moses Centre for Advanced Research in Evidence‐Informed Healthcare, India, India
Technical support for protocol development and review completion
External sources
No sources of support provided
Declarations of interest
RS: has declared that they have no conflict of interest. RK: has declared that they have no conflict of interest. SDC: has declared that they have no conflict of interest.
New
References
Additional references
Akshintala 2014
- Akshintala VS, Saxena P, Zaheer A, Rana U, Hutfless SM, Lennon AM, et al. A comparative evaluation of outcomes of endoscopic versus percutaneous drainage for symptomatic pancreatic pseudocysts. Gastrointestinal Endoscopy 2014;79(6):921-8; quiz 983.e2, 983.e5. [DOI] [PubMed] [Google Scholar]
Banks 2013
- Banks PA, Bollen TL, Dervenis C, Gooszen HG, Johnson CD, Sarr MG, et al. Classification of acute pancreatitis - 2012: Revision of the Atlanta classification and definitions by international consensus. Gut 2013;62(1):102-11. [DOI] [PubMed] [Google Scholar]
Baron 2002
- Baron TH, Harewood GC, Morgan DE, Yates MR. Outcome differences after endoscopic drainage of pancreatic necrosis, acute pancreatic pseudocysts, and chronic pancreatic pseudocysts. Gastrointestinal Endoscopy 2002;56(1):7-17. [DOI] [PubMed] [Google Scholar]
Cui 2014
- Cui ML, Kim KH, Kim HG, Han J, Kim H, Cho KB, et al. Incidence, risk factors and clinical course of pancreatic Fluid Collections in acute pancreatitis. Digestive Diseases and Sciences 2014;59(5):1055-62. [DOI] [PubMed] [Google Scholar]
Elmunzer 2018
- Elmunzer BJ. Endoscopic drainage of pancreatic fluid collections. Clinical Gastroenterology and Hepatology 2018;16(12):1851-63.e3. [DOI] [PubMed] [Google Scholar]
Forsmark 2007
- Forsmark CE, Baillie J, AGA Institute Clinical Practice and Economics Committee, AGA Institute Governing Board. AGA Institute technical review on acute pancreatitis. Gastroenterology 2007;132(5):2022-44. [DOI] [PubMed] [Google Scholar]
GRADEpro GDT [Computer program]
- McMaster University (developed by Evidence Prime, Inc.) GRADEpro Guideline Development Tool. McMaster University (developed by Evidence Prime, Inc.), 2020. Available from gradepro.org.
Higgins 2021
- Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA, editor(s). Cochrane handbook for systematic reviews of interventions version 6.2 (updated February 2021). Cochrane, 2021. Available from training.cochrane.org/handbook.
Hookey 2006
- Hookey LC, Debroux S, Delhaye M, Arvanitakis M, Le Moine O, Devière J. Endoscopic drainage of pancreatic-fluid collections in 116 patients: a comparison of etiologies, drainage techniques, and outcomes. Gastrointestinal Endoscopy 2006;63(4):635-43. [DOI] [PubMed] [Google Scholar]
Itoi 2012
- Itoi T, Binmoeller KF, Shah J, Sofuni A, Itokawa F, Kurihara T, et al. Clinical evaluation of a novel lumen-apposing metal stent for endosonography-guided pancreatic pseudocyst and gallbladder drainage (with videos). Gastrointestinal Endoscopy 2012;75(4):870-6. [DOI] [PubMed] [Google Scholar]
Kim 2012
- Kim KO, Kim TN. Acute pancreatic pseudocyst: incidence, risk factors, and clinical outcomes. Pancreas 2012;41(4):577-81. [DOI] [PubMed] [Google Scholar]
Manrai 2018
- Manrai M, Kochhar R, Gupta V, Yadav TD, Dhaka N, Kalra N, et al. Outcome of acute pancreatic and peripancreatic collections occurring in patients with acute pancreatitis. Annals of Surgery 2018;267(2):357-63. [DOI] [PubMed] [Google Scholar]
Patra 2014
- Patra PS, Das K, Bhattacharyya A, Ray S, Hembram J, Sanyal S, et al. Natural resolution or intervention for fluid collections in acute severe pancreatitis. BJS (British Journal of Surgery) 2014;101(13):1721-8. [DOI] [PubMed] [Google Scholar]
Review Manager 2020 [Computer program]
- Nordic Cochrane Centre, The Cochrane Collaboration Review Manager 5 (RevMan 5). Version 5.4. Copenhagen: Nordic Cochrane Centre, The Cochrane Collaboration, 2020.
Rinninella 2015
- Rinninella E, Kunda R, Dollhopf M, Sanchez-Yague A, Will U, Tarantino I, et al. EUS-guided drainage of pancreatic fluid collections using a novel lumen-apposing metal stent on an electrocautery-enhanced delivery system: a large retrospective study (with video). Gastrointestinal Endoscopy 2015;82(6):1039-46. [DOI] [PubMed] [Google Scholar]
Sahel 1987
- Sahel J, Bastid C, Pellat B, Schurgers P, Sarles H. Endoscopic cystoduodenostomy of cysts of chronic calcifying pancreatitis: a report of 20 cases. Pancreas 1987;2(4):447-53. [DOI] [PubMed] [Google Scholar]
Sheu 2012
- Sheu Y, Furlan A, Almusa O, Papachristou G, Bae KT. The revised Atlanta classification for acute pancreatitis: a CT imaging guide for radiologists. Emergency Radiology 2012;19(3):237-43. [DOI] [PubMed] [Google Scholar]
Varadarajulu 2008
- Varadarajulu S, Christein JD, Tamhane A, Drelichman ER, Wilcox CM. Prospective randomized trial comparing EUS and EGD for transmural drainage of pancreatic pseudocysts (with videos). Gastrointestinal Endoscopy 2008;68(6):1102-1111. [DOI] [PubMed] [Google Scholar]
Varadarajulu 2013
- Varadarajulu S, Bang JY, Sutton BS, Trevino JM, Christein JD, Wilcox CM. Equal efficacy of endoscopic and surgical cystogastrostomy for pancreatic pseudocyst drainage in a randomized trial. Gastroenterology 2013;145(3):583-90.e1. [DOI] [PubMed] [Google Scholar]
Yeo 1990
- Yeo CJ, Bastidas JA, Lynch-Nyhan A, Fishman EK, Zinner MJ, Cameron JL. The natural history of pancreatic pseudocysts documented by computed tomography. Surgery, Gynecology & Obstetrics 1990;170(5):411-7. [PubMed] [Google Scholar]