Peroral pancreatoscopy in the diagnosis of mucin-producing tumors of the pancreas

The role of pancreatoscopy in the diagnostic work-up of intraductal papillary mucinous neoplasms: a systematic review and meta-analysis

BACKGROUND

Confirming the diagnosis, invasiveness, and disease extent of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas is challenging. The aim of this study was to summarize the literature on the efficacy and safety of peroral pancreatoscopy (POP) in the diagnosis of IPMN, including the impact of pre- and intraoperative POP on the management of IPMN.

METHODS

The EMBASE, Medline Ovid, Web of Science, Cochrane CENTRAL, and Google Scholar databases were systematically searched for articles. Eligible articles investigated cohorts of patients who underwent POP for (suspected) IPMN.

RESULTS

25 articles were identified and included in this review; with 22 of these reporting on the diagnostic yield of POP in IPMN and 11 reporting on the effect of pre- or intraoperative POP on clinical decision-making. Cannulation and observation rates, and overall diagnostic accuracy were high across all studies. Frequently reported visual characteristics of IPMN were intraductal fish-egg-like lesions, hypervascularity, and granular mucosa. Overall, the adverse event rate was 12 %, primarily consisting of post-endoscopic retrograde cholangiopancreatography pancreatitis, with a pooled rate of 10 %, mostly of mild severity. Regarding the impact of POP on clinical decision-making, POP findings altered the surgical approach in 13 %-62 % of patients.

CONCLUSION

POP is technically successful in the vast majority of patients with (suspected) IPMN, has a consistently high diagnostic accuracy, but an adverse event rate of 12 %. Data on intraoperative pancreatoscopy are scarce, but small studies suggest its use can alter surgical management. Future studies are needed to better define the role of POP in the diagnostic work-up of IPMN.

Peroral Pancreatoscopy with Videoscopy and Narrow-Band Imaging in Intraductal Papillary Mucinous Neoplasms with Dilatation of the Main Pancreatic Duct

Background/Aims

Endoscopic evaluation of intraductal papillary mucinous neoplasms (IPMNs) is useful in determining whether the lesions are benign or malignant. This study aimed to examine the usefulness of peroral pancreatoscopy (POPS) in determining the prognosis of IPMNs.

Methods

POPS with videoscopy was performed using the mother–baby scope technique. After surgery, computed tomography/magnetic resonance cholangiopancreatography or ultrasonography and blood tests were performed every 6 months during the follow-up.

Results

A total of 39 patients with main pancreatic duct (MPD)–type IPMNs underwent POPS using a videoscope, and the protrusions in the MPD were observed in 36 patients. The sensitivity and specificity of cytology/biopsy performed at the time of POPS were 85% and 87.5%, respectively. Of 19 patients who underwent surgery, 18 (95%) patients had negative surgical margins and 1 (5%) patient had a positive margin.

Conclusions

In IPMNs with dilatation of the MPD, POPS is considered effective if the lesions can be directly observed. The diagnosis of benign and malignant lesions is possible depending on the degree of lesion elevation. However, in some cases, slightly elevated lesions may increase in size during the follow-up or multiple lesions may be simultaneously present; therefore, careful follow-up is necessary.

Role of pancreatoscopy in management of pancreatic disease: A systematic review

BACKGROUND

Per-oral pancreatoscopy (POP) plays a role in the diagnosis and therapy of pancreatic diseases. With recent technological advances, there has been renewed interest in this modality.

AIM

To evaluate the efficacy and safety of POP in management of pancreatic stone disease and pancreatic ductal neoplasia.

METHODS

To determine the safety and efficacy of POP in the management of pancreatic diseases, a systematic search was conducted in MEDLINE, EMBASE and Ovid. Articles in languages other than English and case reports were excluded. All published case series were eligible. Data specific to POP were extracted from studies, which combined cholangiopancreatoscopy. Ten studies were included in the analysis of POP therapy for pancreatic stone disease, and 15 case series satisfied the criteria for inclusion for the role of POP in the management of pancreatic ductal neoplasia. The examined data were subcategorized according to adjunctive modalities, such as direct tissue sampling, cytology, the role of intraoperative POP, intraductal ultrasound (IDUS) and POP combined with image-enhancing technology.

RESULTS

The success rate for complete ductal stone clearance ranged from 37.5%-100%. Factors associated with failure included the presence of strictures, multiple stones and the inability to visualize the target area. Although direct visualization can identify malignant and premalignant conditions, there is significant overlap with benign diseases. Visually-directed biopsies provide a high degree of accuracy, and represent a unique approach for tissue acquisition in patients with ductal abnormalities. Addition of pancreatic fluid cytology increases diagnostic yield for indeterminate lesions. Protrusions larger than 3 mm noted on IDUS are significantly more likely to be associated with malignancy. The rate of adverse events associated with POP ranged from 0%-35%.

CONCLUSION

Current evidence supports wider adoption of pancreatoscopy, as it is safe and effective. Improved patient selection and utilization of novel technologies may further enhance its role in managing pancreatic disease.

Current role of endoscopic pancreatoscopy

PURPOSE OF REVIEW

To provide an overview of the field of pancreatoscopy and to summarize the data informing its clinical utility.

RECENT FINDINGS

Regarding the technological advance of pancreatoscopy, recent studies are the first to report the use of digital, single-operator pancreatoscopy (SpyGlass DS; Boston Scientific, Natick, MA). New data on the use of preoperative pancreatoscopy offer promising results for the potential to optimize treatment of intraductal papillary mucinous neoplasms and to differentiate between benign and malignant pancreatic strictures. Finally, there has been accumulating evidence for the use of pancreatoscopy-guided lithotripsy for the management of painful chronic calcific pancreatitis.

SUMMARY

Endoscopic pancreatoscopy offers the advantage of direct visualization of the pancreatic duct, allowing for optimal macroscopic assessment, targeted tissue acquisition and guided therapies such as lithotripsy of pancreatic duct stones. The data informing some aspects remain limited, but the accumulating literature forms our understanding of the current and future role of pancreatoscopy in the management of pancreatic disease.

Endoscopic Management of Pancreatic Cysts

Management of pancreatic cystic lesions relies on patients' clinical presentation, imaging, and endoscopic ultrasound. Current research in basic science, radiology, and endoscopy is evolving and making progress in this condition which is relatively common in the general population. This review focuses on the recent endoscopic ultrasound approaches to the diagnosis of these pancreatic disorders.

Role of per-oral pancreatoscopy in the evaluation of suspected pancreatic duct neoplasia: a 13-year U.S. single-center experience

BACKGROUND AND AIMS

The role of per-oral pancreatoscopy (POP) in the evaluation of occult pancreatic duct (PD) lesions remains limited to case series. The aim of this study was to evaluate the ability of POP to differentiate malignant from benign diseases of the PD.

METHODS

Patients who underwent POP between 2000 and 2013 for the evaluation of indeterminate PD strictures, dilatations, or with suspected or known main duct intraductal papillary mucinous neoplasm were identified. Main outcome measurements were visual impression accuracy, POP tissue sampling, efficacy, and safety of POP.

RESULTS

During the study period, 79 patients who underwent POP for the evaluation of pancreatic stricture or dilatation were identified. Technical success was achieved in 78 (97%). In the PD neoplasia group (n = 33), the final diagnosis was based on index confirmatory POP-guided tissue sampling in 29 (88%). For the detection of PD neoplasia, POP visual impression had a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 87%, 86%, 83%, 91%, and 87%, respectively. When combined with POP-guided tissue sampling, the values were 91%, 95%, 94%, 93%, and 94%, respectively. Of 102 POPs performed, adverse events were noted in 12 (12%) cases.

CONCLUSIONS

This study demonstrates a high technical success rate, visual impression accuracy, and tissue sampling capability of POP. Examinations were performed by endoscopists with expertise in pancreatoscopy interpretation, and the results may not be generalizable.

Single-operator pancreatoscopy is helpful in the evaluation of suspected intraductal papillary mucinous neoplasms (IPMN)

BACKGROUND AND OBJECTIVE

Even when advanced cross-sectional imaging modalities have been employed, endoscopic evaluation of intraductal papillary mucinous neoplasms (IPMN) is often required in order to assess the final character and extent of lesions. The current study addresses the use of SpyGlass single-operator peroral pancreatoscopy in suspected IPMN.

DESIGN

A prospective, non-randomized exploratory cohort study.

SETTING

Single-center.

PATIENTS AND INTERVENTION

A prospective study-cohort of 44 consecutive patients in a single tertiary referral center who underwent ERCP and peroral pancreatoscopy, was prospectively collected between July 2007 and March 2013 because of a radiological signs of IPMN. These IPMN-findings were discovered incidentally in 44% of the cases.

MAIN OUTCOME MEASUREMENTS

Diagnostic accuracy (specificity & sensitivity) and complications.

RESULTS

The targeted region of the pancreatic duct was reached with the SpyGlass system in 41 patients (median age 65 years, 41% female). Three patients were excluded from analysis because of failed deep cannulation of the pancreatic duct. Brush cytology was taken in 88% and direct biopsies in 41%. IPMN with intermediate or high-grade dysplasia was the main final diagnosis (76%) in 22 patients who had surgery. Out of the 17 patients with a final diagnosis of MD-IPMN, 76% were correctly identified by pancreatoscopy. Of the 9 patients with a final diagnosis of BD-IPMN, the pancreatoscopy identified 78% of the cases correctly.The incidence of post-ERCP pancreatitis was 17%. Pancreatoscopy was found to have provided additional diagnostic information in the vast majority of the cases and to affect clinical decision-making in 76%.

LIMITATIONS

Single-center study.

CONCLUSIONS

Single-operator peroral pancreatoscopy contributed to the clinical evaluation of IPMN lesions and influenced decision-making concerning their clinical management. The problem of post-procedural pancreatitis needs further attention.

Italian consensus guidelines for the diagnostic work-up and follow-up of cystic pancreatic neoplasms

This report contains clinically oriented guidelines for the diagnostic work-up and follow-up of cystic pancreatic neoplasms in patients fit for treatment. The statements were elaborated by working groups of experts by searching and analysing the literature, and then underwent a consensus process using a modified Delphi procedure. The statements report recommendations regarding the most appropriate use and timing of various imaging techniques and of endoscopic ultrasound, the role of circulating and intracystic markers and the pathologic evaluation for the diagnosis and follow-up of cystic pancreatic neoplasms.

Peroral pancreatoscopy using the SpyGlass system for the assessment of intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND

Peroral pancreatoscopy (POPS) using a mother-baby endoscope system is often useful for assessment of intraductal papillary mucinous neoplasm (IPMN) of the pancreas with main pancreatic duct (MPD) involvement, but is not widely used for several reasons. The aim of this study was to evaluate the usefulness of the SpyGlass Direct Visualization System for assessment of IPMN.

METHODS

Seventeen patients diagnosed with possible IPMN with MPD dilation underwent peroral pancreatoscopy using the SpyGlass system at our institution. The quality of visualization and the sensitivities of cytological and pathological investigations for diagnosing malignant lesions were evaluated.

RESULTS

Peroral pancreatoscopy was performed using the SpyScope in 12 patients and an endoscopic retrograde cholangiopancreatography (ERCP) catheter in five patients. Sufficient visualization was achieved in 92% of cases using the SpyScope and 40% of cases using the ERCP catheter. Biopsy under direct visualization was successful in seven patients. Biopsy specimens showed adenocarcinoma in one patient, benign neoplastic epithelium in five patients, and regenerative changes in one patient; and had 25% sensitivity and 100% specificity for detecting malignancy. SpyGlass pancreatoscopy with irrigation cytology had 100% sensitivity and 100% specificity for detecting malignancy. SpyGlass pancreatoscopy was useful for determining the operative excision line in three patients. There were no severe procedure-related adverse events.

CONCLUSIONS

Peroral pancreatoscopy using the SpyGlass system seems to be feasible and useful for assessment of IPMN with a dilated MPD.

Potential usefulness of mucin immunohistochemical staining of preoperative pancreatic biopsy or juice cytology specimens in the determination of treatment strategies for intraductal papillary mucinous neoplasm

We classified resected intraductal papillary mucinous neoplasms (IPMNs) into four subtypes (gastric, intestinal, pancreatobiliary and oncocytic) according to their morphological features and mucin expression, determined their clinicopathological characteristics and investigated the possibility of preoperatively diagnosing these subtypes. Sixty resected tumors, 4 preoperative tumor biopsies and 10 preoperative pancreatic juice cytology specimens were analyzed. The gastric and intestinal types accounted for the majority of IPMNs. Non-gastric type IPMNs were of high-grade malignancy. Many of the pancreatobiliary-type IPMNs were in an advanced stage and were associated with a poor prognosis. The results of mucin immunohistochemical staining of preoperative biopsy and surgically resected specimens were in agreement with each other, and in close agreement with those for pancreatic juice cytology specimens obtained from 10 patients during endoscopic retrograde cholangiopancreatography (ERCP). The immunostaining of preoperative biopsy specimens and ERCP-obtained pancreatic juice cytology specimens may be useful in the differential diagnosis of gastric and intestinal types of IPMN. If such techniques enable the preoperative diagnosis of IPMN subtypes, their use in combination with conventional preoperative imaging modalities may lead to surgical treatment best suited for the biological characteristics of the four subtypes.

Endoscopic diagnosis of intraductal papillary-mucinous neoplasm of the pancreas by means of peroral pancreatoscopy using a small-diameter videoscope and narrow-band imaging

BACKGROUND

Intraductal papillary-mucinous neoplasm (IPMN) is an intraductal tumor in which the mucin-producing epithelium shows proliferated papillary and a wide variety of pathological changes ranging from hyperplasia to adenocarcinoma. Therefore, it is important to determine whether an IPMN is benign or malignant. In the present study of patients with IPMN, the protrusion was observed by a peroral pancreatoscopy (PPS) using a small-diameter videoscope and narrow-band imaging (NBI). We carried out the differential diagnosis of benign lesion to malignant lesion.

METHODS

Between April 2003 and May 2009, PPS using a small-diameter videoscope by means of NBI was carried out on 21 hospitalized patients with IPMN (10 cases of adenocarcinoma, 11 cases of adenoma or hyperplasia; 14 males and seven females, with a mean age of 69.4 years).

RESULTS

Fifteen focal lesions of the 16 cases in the head of the pancreas (93.7%) and four focal lesions of the five cases in the pancreatic body (80%) were observable, whereas two lesions (adenocarcinoma in the pancreatic body, and adenoma in the uncus of pancreas) were not observable. Endoscopically, seven cases were classified as villous type and two cases as vegetative type, and nine cases were diagnosed as adenocarcinoma. Ten cases with sessile type or semipedunculated type were diagnosed as adenoma or hyperplasia. Vascular patterns and protrusions were detected more clearly in the NBI images than under white light observation.

CONCLUSIONS

When combined with a videoscope and NBI, pancreatoscopy provided a clear image and was useful for evaluating whether the IPMN was benign or malignant.

Management of pancreaticobiliary disease using a new intra-ductal endoscope: The Texas experience

AIM: To evaluate a new single-operator mini-endoscope, Spyglass^®, for its performance, feasibility and safety in the management of pancreaticobiliary disease.

METHODS: In a multicenter retrospective analysis of patients undergoing intraductal endoscopy, we evaluated 128 patients (71 men, mean age 57.6 years). Indications were therapeutic (TX) in 72 (56%) and diagnostic (DX) in 56 (44%).

RESULTS: Peroral endoscopy was performed in 121 and percutaneous in seven. TX indications included CBD stones in 41, PD stones in six, and biliary strictures in 25. DX indications included abnormal LFT’s in 15, abnormal imaging in 38 and cholangiocarcinoma staging in three. Visualization of the stone(s) was considered good in 31, fair in six, and poor in four. Advancement of the electrohydraulic lithotripsy probe was not possible in three patients and proper targeting of the lesion was partial in four patients. A holmium laser was used successfully in three patients. Ductal clearance was achieved in 37 patients after one procedure and in four patients after two procedures. Diagnosis of biliary strictures was modified in 20/29 and confirmed to be malignant in 10/23. Of the modified patients, no diagnosis was available in 17. Spyglass^® demonstrated malignancy in 8/17 and non-malignancy in nine. Suspected pathology by imaging studies and abnormal LFT’s was modified in 43/63 (66%). Staging of cholangiocarcinoma demonstrated multicentric cholangiocarcinoma in 2/3. There was no morbidity associated with the use of Spyglass^®.

CONCLUSION: Spyglass Spyscope^® is a first generation, single operator miniature endoscope that can evaluate and treat various biliary and pancreatic tract diseases.

Pancreatoscopy: present and future role

Current imaging modalities do not allow for direct access to the pancreatic duct. Because of this limitation, diagnosis and assessment of pancreatic diseases require radiographic imaging and cytologic analysis. Although many of these techniques have excellent specificity for the detection of pancreatic cancer, they offer no therapeutic capabilities and are relatively poor in early detection of cancer and in differentiating chronic pancreatitis from malignancy, particularly when the conditions coexist. Currently available cholangioscopes are too large to access the pancreatic duct without sphincterotomy or balloon dilation, increasing the risk of instrumentation trauma to the pancreas. Novel, dedicated pancreatoscopes have recently been developed and are under investigation in clinical trials. Preliminary evidence suggests that these new technologies allow for direct visualization of the pancreatic ducts, with the potential for forceps biopsy in suspected malignancy and endotherapy for pancreatic calculi. Future and ongoing clinical trials will better define the utility and roles of these new endoscopy tools.

Preclinical characterization of the Spyglass peroral cholangiopancreatoscopy system for direct access, visualization, and biopsy

BACKGROUND

Current cholangioscopes are restricted to 2 deflection angles and require more than 1 operator. The newly developed Spyglass peroral cholangiopancreatoscopy system provides 4-way deflected steering by a single operator.

OBJECTIVE

To evaluate access and biopsy in all simulated biliary-duct quadrants with the Spyglass system, high-level disinfection of the reusable Spyglass optical probe, and feasibility of in vivo biopsy.

DESIGN

Laboratory simulations comparing biliary-duct access and biopsy with the Spyglass versus a conventional system, laboratory determination of high-level disinfection effectiveness, and observational investigation of biopsies in a porcine model.

SETTING

Research laboratories.

MAIN OUTCOME MEASUREMENTS

Rate ratios (RR) and 95% confidence intervals (CI) for successful access to all quadrants and simulated biopsy.

RESULTS

Success rates for access in all quadrants were significantly higher with the Spyglass system than with the control system, both without (RR 1.71, 95% CI 1.39-2.29) and with (RR 2.00, 95% CI 1.56-2.78) biopsy forceps loaded. Higher success rates were also attained by using the Spyglass system to access biopsy targets (RR 2.09, 95% CI 1.60-2.91) and to perform simulated biopsies (RR 2.94, 95% CI 2.05-4.52). Microbial species log reductions of 6.0 to 7.0 were achieved by high-level disinfection of Spyglass optical probes. In 31 in vivo porcine biopsies yielding adequate gross specimens, the quality for histologic examination was excellent to adequate for 90% of specimens.

LIMITATIONS

Study procedures were performed by a single nonblinded operator. All data were collected ex vivo or in animals, and clinical applicability remains to be determined.

CONCLUSIONS

The Spyglass system allows access and biopsy in all quadrants and merits clinical investigation.

What are the useful biological and functional markers of early-stage chronic pancreatitis?

Early-stage chronic pancreatitis may be undetected as a clinical entity. However, it may carry a definite risk for subsequent secondary damage, depending on the etiology of the disease. Therefore, the most important question is whether indeed the patient in question does have early-stage chronic pancreatitis rather than oligosymptomatic advanced-stage chronic pancreatitis. This can be easily determined by appropriate imaging such as abdominal computed tomography. For early changes, endoscopic ultrasound is superior to any other technique. Endosonography may also tell about anatomical obstacles (e.g., papillary stenosis, pancreas divisum) that may be treated to prevent progression of the disease. Treatment options at this stage are endoscopic for the most part. Depending on the etiology and familiar/hereditary background of the given patient, one must look further into molecular markers. Such markers may give an estimate on the progression or dynamics of the disease in the future and include mutations in the cationic (PRSS1) and anionic (PRSS2) trypsinogen genes as well as mutations in the serine protease (SPINK1) or cystic fibrosis (CFTR) genes. Admitted ly, these are not markers of early-stage chronic pancreatitis but must be investigated if and when such pathogenesis is suspected. Further, rare forms of chronic pancreatitis, such as autoimmune pancreatitis, which can be cured by appropriate medical treatment with steroids, must be excluded. Markers for autoimmune pancreatitis are elevated serum IgG, especially IgG4, and autoantibodies to carbonic anhydrase (type II) and lactoferrin. It is noteworthy that these markers, present in almost every Asian patient with autoimmune pancreatitis, are mostly lacking in Caucasian populations of patients with autoimmune pancreatitis.

Pancreatic juice cytology in the diagnosis of intraductal papillary mucinous neoplasm of the pancreas: significance of sampling by peroral pancreatoscopy

BACKGROUND

The examination of pancreatic juice cytology could hypothetically contribute to the establishment of a definite diagnosis of malignant intraductal papillary mucinous neoplasm of the pancreas (IPMN), but to the authors' knowledge, its significance has not been confirmed to date. The current study was conducted to assess the diagnostic value of pancreatic juice cytology in IPMN and to examine the usefulness of peroral pancreatoscopy (POPS) in sampling pancreatic juice.

METHODS

The study subjects were comprised of 103 patients with IPMN who underwent surgical resection of pancreatic tumors (adenoma in 29 patients, borderline in 17 patients, carcinoma in situ in 25 patients, and invasive carcinoma in 32 patients). Pancreatic juice was collected with a catheter in 71 patients and by POPS in 32 patients. Patients with pancreatic carcinoma (n = 81) and chronic pancreatitis (n = 76) also were investigated.

RESULTS

The cytologic diagnosis was found to be of nondiagnostic value in only one patient with an IPMN, whereas it was of no diagnostic value in 14 of the patients with pancreatic carcinoma (17.3%), a difference that was statically significant (P < 0.001). The location of the IPMN (either in the pancreas or the pancreatic ducts) was not found to significantly affect the diagnostic value of the test. The sensitivity for IPMN was 62.2% when pancreatic juice was collected by POPS, and was 38.2% when it was collected using a catheter. In the case of pancreatic carcinoma, the sensitivity of pancreatic juice cytology was found to be 25.4%, which was significantly lower than that for IPMN when the pancreatic juice was collected by POPS (P < 0.001).

CONCLUSIONS

Pancreatic juice cytology was found to have better diagnostic value in the patients with IPMNs compared with those with pancreatic carcinoma. POPS was found to be useful for the collection of pancreatic juice.

Long-term follow-up of intraductal papillary mucinous neoplasm of the pancreas with ultrasonography

BACKGROUND & AIMS

Most intraductal papillary mucinous neoplasms of the pancreas (IPMNs) have a favorable prognosis. This study was undertaken to clarify the clinical course of IPMNs and to set the criteria for surgical treatment on the basis of long-term follow-up by periodic transabdominal ultrasonography (US).

METHODS

Eighty-one patients with IPMN were periodically subjected to US (>3 years); 27 were reviewed retrospectively (12 with benign neoplasms [adenoma, borderline] and 15 with malignant tumors [carcinoma in situ, invasive cancer]) and 54 prospectively. US examination was focused on the main pancreatic duct (MPD) diameter, cyst diameter, and presence or absence and height of the protruding lesion. Differences between the benign and malignant groups were examined to set the criteria for surgical treatment. Follow-up results of prospective patients were investigated.

RESULTS

The increase of the MPD or the cyst diameter was significantly greater in the malignant group (P < .01). Maximum increases of the MPD diameter by 2.2 mm/year, the cyst diameter by 11.3 mm/year, and emergence or increase of the height of the protruding lesion by 3.3 mm/year were predominantly observed in the malignant group (accuracy, 90.9%, 81.3%, and 81.5%, respectively). The majority of the prospective patients showed no significant changes of these parameters; however, 2 patients (3.7%) were operated on, with the post-surgery histopathologic diagnosis of cancer.

CONCLUSIONS

Periodic imaging follow-up is useful to detect a malignant IPMN. Changes in MPD diameter, cyst diameter, and/or size of the protruding lesion are the practical criteria for selecting surgery.

Distinguishing benign from malignant intraductal papillary mucinous tumors of the pancreas by imaging techniques

OBJECTIVES

It is often difficult to differentiate benign from malignant intraductal papillary mucinous tumors (IPMTs). This study aimed to differentiate them using various imaging techniques.

METHODS

Receiver operating characteristic curves were used to establish optimal cutoff values to differentiate benign from malignant tumors in 121 patients with histologically confirmed IPMTs.

RESULTS

For branch duct type, accuracy for malignancy was highest using endoscopic ultrasonography (EUS) to measure the cyst diameter, and accuracy was 68.2% at a cutoff value of 33.9 mm. For main duct type, accuracy was highest, 71.1% at a cutoff value of 8.4 mm for main duct diameter, with magnetic resonance cholangiopancreatography. For all imaging techniques and findings, accuracy was highest using EUS, 76.4% at a cutoff value of 5.4 mm for height of protrusion. Each imaging technique had a positive predictive value of 80% if the cut off value for the height of the protruding lesion was met.

CONCLUSIONS

Malignancy can be strongly suspected when the height of protrusion exceeds the respective cutoff values. EUS was most effective to differentiate benign IPMTs from malignant tumors by assessing the height of protrusion.

Direct cholangioscopy and pancreatoscopy

Direct cholangiopancreatoscopy has played a minor role in the diagnosis and treatment of pancreaticobiliary disorders, initially because of instrument fragility and suboptimal imaging, and later because of improvements in noninvasive and semi-invasive imaging techniques. Digital scopes provide superior images and hold the promise of increased application and improved durability.

Duodenoscope assisted cholangiopancreatoscopy: a review of clinical applications

Duodenoscope assisted cholangiopancreatoscopy allows direct visualization of the pancreatic duct and bile duct. There are several circumstances where direct ductal visualization might be helpful in clarifying a diagnosis or providing targeted treatment. Duodenoscope assisted cholangiopancreatoscopy is currently employed for a variety of indications including: indeterminate ductal strictures and filling defects, marginal chronic pancreatitis, treatment of large intraductal stones, localization of intraductal papillary mucinous tumors, and localization and treatment of hemobilia. There have however been no randomized controlled trials evaluating the diagnostic or therapeutic functions of duodenoscope assisted cholangiopancreatoscopy. This article reviews recent descriptive studies that attempt to clarify the clinical role of this technology.

The role of ultrasound in biliary and pancreatic diseases

The possibilities and the limits of transabdominal ultrasonography (US) in the diagnosis of bilio-pancreatic diseases are reviewed here in the light of the last 10 years' research. US remains the method of choice for the diagnosis of gallstones and is generally accepted as an initial imaging technique in gallstone complications, such as acute cholecystitis. Moreover the method can be useful for the detection of the biliary complications after laparoscopic cholecystectomy and after liver transplantation. US is still considered the first diagnostic procedure when stones are suspected in the common bile duct. The use of color Doppler can provide a differential diagnosis of gallbladder cancer with respect to other benign inflammatory or polypoid lesions. Color Doppler US allows to detect vascular complications of acute pancreatitis such as pseudoaneurysms. US is still considered useful for the initial screening of the pancreatic cancer. However, for staging other imaging techniques must be employed. With US useful informations are obtained in the diagnosis of cystic tumors of the pancreas and of pancreatic metastases. US is generally of little use for the diagnosis of endocrine tumors.

Efficacy of peroral pancreatoscopy in the diagnosis of pancreatic diseases

BACKGROUND

The aim of this study was to evaluate the usefulness of peroral pancreatoscopy in the diagnosis of pancreatic diseases.

METHODS

Both 3.7-mm (thin) and 0.8-mm (ultra-thin) diameter fiberoptic pancreatoscopes were used in 115 cases (pancreatic cancer, 35; benign ductal stenosis, 20; intraductal papillary-mucinous tumor, 60).

RESULTS

Observation rates for pancreatic cancer, benign ductal stenosis, and intraductal papillary-mucinous tumor were, respectively, 63%, 80%, and 95%. Tumor vessels and papillary tumor were observed when pancreatic cancer was smaller than 2 cm but not when the tumor was larger than 2 cm. Stenosis without significant mucosal changes was observed in 62% of cases of benign ductal stenosis. Coarse mucosa and friability were observed more frequently in association with pancreatic cancer than benign ductal stenosis. Granular mucosa or papillary tumor could be observed in 74% of cases of intraductal papillary-mucinous tumor. Papillary tumor was observed with increasing frequency in cases of intraductal papillary-mucinous tumor as the degree of malignancy increased.

CONCLUSIONS

Peroral pancreatoscopy with an ultra-thin fiberscope is useful in the diagnosis of minute pancreatic lesions. Peroral pancreatoscopy with a thin fiberscope can provide a definitive diagnosis of intraductal papillary-mucinous tumor including the degree of malignancy.

Endoscopic ultrasonography and endoscopic retrograde cholangiopancreatography imaging for pancreaticobiliary pathology: the gastroenterologist's perspective

With advances in noninvasive radiologic technology, additional adjunctive techniques are developing, and the roles for ERCP and EUS are continuously changing. In a diagnostic setting, ERCP is currently best reserved for patients with a high likelihood of needing endoscopic therapy, and EUS is especially useful for cases in which other imaging techniques have been inconclusive or are of inferior diagnostic capability. In a therapeutic setting, ERCP and EUS retain important roles in the management of both benign and malignant pancreatic and biliary disease. Certainly, technological advances also directly affect these modalities and expanded applications for ERCP and EUS for the pancreas and biliary tract are anticipated.

The role of ERCP and pancreatoscopy in cystic and intraductal tumors

ERCP and pancreatoscopy may establish a diagnosis of IPMT and differentiate it from a pseudocyst or cystic neoplasm of the pancreas. These techniques may also assess risk of malignancy, extent of disease, allow tissue sampling, and provide therapeutic intervention.

The role of pancreatoscopy in the preoperative evaluation of intraductal papillary mucinous tumor of the pancreas

BACKGROUND

Intraductal papillary mucinous tumor of the pancreas is a rare neoplasm managed by operative resection of the affected segment of the pancreas.

GOALS

To evaluate the role of peroral pancreatoscopy in the diagnosis and preoperative localization of the affected region of the pancreatic duct and to undertake the appropriate operation for each patient.

STUDY

Five patients with suspected intraductal papillary mucinous tumor of the pancreas were studied using endoscopic retrograde cholangiopancreatography, computed tomography of the abdomen, endoscopic ultrasonography, and peroral pancreatoscopy. The findings from these studies were compared, and operative resection was performed in each patient based on pancreatoscopic findings.

RESULTS

Of the five patients with suspected intraductal papillary mucinous tumor, only four had histologically confirmed tumor, and the remaining one patient had a retention cyst of the pancreas. Pancreatoscopy correctly identified all four patients with the tumor while excluding the diagnosis of papillary tumor in one.

CONCLUSION

Peroral pancreatoscopy is valuable in the preoperative evaluation of intraductal papillary mucinous tumor of the pancreas, especially in the localization of such tumor.

Spectrally encoded miniature endoscopy

A method for performing miniature endoscopy with a high number of resolvable points is presented. This approach, spectrally encoded endoscopy (SEE), uses a broad-bandwidth light source and a diffraction grating to simultaneously detected the reflectivity at multiple points along a transverse line within the sample. As opposed to images from miniature optical fiber bundle endoscopes, the number of resolvable points in SEE images is dependent on the spectral width and the groove density of the diffraction grating. We acquired images of a human finger in vivo, using a 550-mu;m -diameter SEE system to demonstrate the feasibility of this technique.