Triple-tissue sampling at ERCP in malignant biliary obstruction

Prospective, blinded assessment of factors influencing the accuracy of biliary cytology interpretation

OBJECTIVES

There is little published data assessing factors that influence the accuracy of biliary cytology. The aim of this study was to (a) prospectively compare interobserver variability among two blinded pathologists interpreting biliary cytology specimens, (b) to describe the predictors of interpathologist agreement, and (c) to characterize the predictors of accurate cytology interpretation.

METHODS

In total, 113 consecutive patients undergoing endoscopic retrograde cholangiopancreatography with brushing of suspicious biliary tract strictures were prospectively enrolled to assess routine cytology (RC) accuracy. The initial RC interpretation was performed by the pathologist on duty with the benefit of the patient's clinical information. Subsequent interpretation was performed by two independent pathologists blinded to the patients' clinical details.

RESULTS

Of the 113 patients, 67 had malignant strictures and 46 had benign strictures. The sensitivity of RC varied from 9% to 24% (p= 0.02), while the specificity varied from 61% to 100% (p < 0.001). Accuracy varied from 43% to 51% (p= n.s.). The rate of equivocal readings was lowest for the initial interpretation (1.7%), p < 0.0001 versus pathologist 1, p= 0.002 versus pathologist 2. Overall correlation of the blinded pathologists' interpretations was moderate, k= 0.66. Neither cytology accuracy nor interpathologist agreement improved with increasing specimen cellularity.

CONCLUSIONS

There is a high rate of interpathologist variation for the biliary cytology interpretation. The knowledge of the patient's clinical information appears to clarify cytology interpretation resulting in fewer equivocal results. We did not detect any reliable predictors of cytology accuracy.

Optimal number of EUS-guided fine needle passes needed to obtain a correct diagnosis

BACKGROUND

The immediate assistance of a cytologist during EUS-guided FNA is not universal. The optimal number of fine needle passes during EUS-guided FNA has not been determined in a prospective study. The aim of this study was to determine the optimal number of passes required to obtain a correct diagnosis.

METHODS

Seven or more passes were made with a fine needle into a variety of lesions during EUS-guided FNA. Adequacy of the aspirate, diagnosis, and a "certainty score" were recorded after each pass and interpreted sequentially by a cytopathologist. Surgical histopathology and 1-year clinical follow-up were used as reference standards. The percentage of correctly diagnosed cases was calculated and stratified according to organ, disease group, and EUS characteristics of the lesion.

RESULTS

Lesions from 95 patients were categorized into the following locations: pancreas, lymph node, and miscellaneous. The sensitivity and specificity for 7 passes from the pancreas and miscellaneous lesion groups were, respectively, 83% and 100%. The sensitivity and specificity for 5 passes from the lymph node group were, respectively, 77% and 100%.

CONCLUSIONS

During EUS-guided FNA, at least 7 passes with a fine needle into pancreatic and miscellaneous lesions, and 5 passes into lymph nodes are needed to ensure a high degree of certainty for making a correct diagnosis.

ERCP-directed brush cytology prepared by the ThinprepR method: test performance and morphology of 149 cases

Conventionally prepared endobiliary brushings are moderately (42%) sensitive and highly (98%) specific in detecting malignancy. The performance and morphological features of brushings prepared by Thinprep, a liquid-based method are mostly unknown. All brushings were retrieved from the laboratory files. Disease was classified as benign or malignant by linkage with the provincial cancer registry and sensitivity, specificity, positive (PPV) and negative predictive values (NPV) calculated. True positives and negatives were reviewed and predictive morphological features analysed by regression tree analysis. Out of 149 brushings, 55 (37%) were positive and 94 (63%) negative. Malignancy was identified in 86 (58%) and benign disease in 63 (42%) of the cases. The sensitivity was 51%, specificity 83%, PPV 80% and NPV 55%. Absolute discriminants of positive and negative brushings were not found, but nuclear cytoplasmic ratio was a useful feature. The performance of Thinprep-prepared brushings from this anatomical site was comparable with conventional preparations.

A prospective comparison of digital image analysis and routine cytology for the identification of malignancy in biliary tract strictures

BACKGROUND & AIMS

Digital image analysis (DIA) allows quantification of nuclear DNA content and may help distinguish benign and malignant strictures of the biliary tract.

METHODS

One hundred ten consecutive patients undergoing endoscopic retrograde cholangiography for suspicious biliary tract strictures were enrolled in a prospective study comparing the accuracy of DIA and routine cytology (RC). Standard brush cytology sampling was performed twice by using 2 cytology brushes per patient. Both brushes were fixed in a single-specimen vial. Each specimen was formed into 1 pellet, and the sample was equally divided for evaluation by DIA and RC. DNA histograms were generated for ploidy analysis. The DIA criterion for malignancy was demonstration of aneuploidy.

RESULTS

Two patients had inadequate samples obtained for DIA analysis, 7 benign patients were excluded because of inadequate follow-up of less than 75 days, and 1 patient was lost to follow-up to clarify malignant versus benign disease. Of the remaining 100 patients, 56 strictures were malignant and 44 were benign. The sensitivities of DIA and RC were 39.3% and 17.9%, respectively (P = 0.014). The specificities of DIA and RC were 77.3% and 97.7%, respectively (P = 0.003). The accuracy of DIA (56.0%) was equivalent to RC (53.0%).

CONCLUSIONS

DIA is a valuable adjunct to RC for detecting malignant strictures of the biliary tract.

Endoscopic ultrasound-guided fine needle aspiration biopsy of suspected cholangiocarcinoma

BACKGROUND AND AIMS

Despite advances in endoscopic techniques for sampling bile duct strictures, the diagnosis of cholangiocarcinoma remains a challenge. The purpose of this study was to evaluate the yield of EUS-FNA and its impact on patient management for patients with suspected cholangiocarcinoma.

METHODS

All patients undergoing EUS for the evaluation of suspected malignant biliary strictures were prospectively evaluated over a 23-month period. A single gastroenterologist performed all EUS-FNAs in the presence of a cytopathologist. Reference standard for final diagnosis included surgery, death from disease, and clinical and/or imaging follow-up.

RESULTS

Twenty-eight patients (mean age 67 years [SD +/- 11], 72% male) were evaluated. Most patients (91%) presented with obstructive jaundice, and all except 1 had nondiagnostic sampling of the biliary lesions either at ERCP (88%), percutaneous transhepatic cholangiogram (n = 2), and/or computed tomography-guided biopsy (n = 1). Sixty-seven percent (14/21) had no definitive mass seen on prior abdominal imaging studies. The mean tumor size by EUS was 19 mm x 16 mm with a median number of passes to diagnosis of 3 (range 1-7). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 86%, 100%, 100%, 57%, and 88%, respectively. EUS-FNA had a positive impact on patient management in 84% of patients: preventing surgery for tissue diagnosis in patients with inoperable disease (n = 10), facilitating surgery in patients with unidentifiable cancer by other modalities (n = 8), and avoiding surgery in benign disease (n = 4).

CONCLUSIONS

Given the apparent accuracy and safety of EUS with FNA for imaging bile duct mass lesions and for obtaining a tissue diagnosis in patients with suspected cholangiocarcinoma, this technology may represent a new approach to diagnosis especially when other methods fail. The ability to obtain a definite diagnosis has a significant impact on patient management.

EUS-guided fine-needle aspiration of suspected hilar cholangiocarcinoma in potentially operable patients with negative brush cytology

BACKGROUND

Despite improvements of diagnostic modalities differentiation between benign and malignant hilar strictures remains a challenge. Hilar neoplasia requires preoperative tissue diagnosis to avoid risk of inappropriate extensive surgery. This is commonly attempted using various techniques at ERCP, which have variable sensitivity and accuracy. We used endosonography-guided fine-needle aspiration (EUS-FNA) for the preoperative diagnosis of hilar cholangiocarcinoma (HC).

METHODS

Prospective evaluation of 44 patients (31 male, mean age: 59 yr) with strictures at the liver hilum were diagnosed by CT and/or ERCP. All were suspicious of HC but had inconclusive tissue diagnosis. They underwent EUS-FNA with linear echo endoscope and 22 gauge needles.

RESULTS

Adequate material was obtained in 43 of 44 patients. Cytology revealed HC in 26 and other malignancies in 5 patients; 12 had benign results: sclerosing cholangitis (n = 4), primary sclerosing cholangitis (n = 4), inflammation (n = 3), sarcoid-like lesion (n = 1). There were no significant differences in age, lesion size, or echo features among patients with adenocarcinomas, other malignancies, or benign lesions. Thirty-two patients underwent surgery, 2 had autopsy, 10 were followed up clinically. Four of the benign results were false negatives. No complications occurred. Accuracy, sensitivity, and specificity were 91%, 89%, and 100%, respectively. EUS and EUS-FNA changed preplanned surgical approach in 27 of 44 patients.

CONCLUSION

These results suggest that EUS-FNA is of value as a new, less-invasive approach for tissue diagnosis of hilar strictures of unknown cause. It was technically feasible without significant risks, when other diagnostic tests were inconclusive and was able to change preplanned management in about half of the patients.

Influence of stricture dilation and repeat brushing on the cancer detection rate of brush cytology in the evaluation of malignant biliary obstruction

BACKGROUND

The sensitivity for cancer detection of brush cytology at ERCP is relatively low. Manipulation of the stricture and repeated tissue sampling may increase the yield. This study compared the cancer detection rate of brush cytology before and after biliary stricture dilation.

METHODS

In patients with a biliary stricture at ERCP of suspected malignant origin, the stricture was sampled with a cytology brush and then dilated with either a graduated dilating catheter or a dilating balloon (4-8 mm). Brushing was then repeated in all patients. Specimens were interpreted as normal, atypical (benign), highly atypical (suspicious for cancer), and malignant. Final diagnoses were based on cytology plus surgery, EUS, percutaneous biopsy, autopsy, or clinical follow-up.

RESULTS

A total of 139 patients with suspected malignant obstructive jaundice underwent 143 ERCPs (116 ultimately found to have malignant obstruction, and 27 benign disease). Dilation was performed with a catheter in 68 cases, balloon in 73, and both in 2. Brush cytology had a sensitivity of 34.5% (40/116) before dilation and 31% (36/116) after dilation (p = NS). However, sensitivity with predilation and postdilation brushing specimens combined was 44% (51/116), which was higher than that for either the predilation or postdilation brush cytology (p = 0.001). Cancer detection rates were 34.7% (17/49) after dilation with the catheter and 27.7% (18/65) after balloon dilation (p = NS).

CONCLUSIONS

Stricture dilation does not improve the sensitivity of brush cytology for the detection of cancer, which remains relatively low. However, repeat brushing increases the diagnostic yield and should be performed when sampling biliary strictures with a cytology brush at ERCP.

Bile duct brushings in a pig model: examination of intraobserver variability and variability in specimen quality obtained in sequential animals and between two different brushes

PURPOSE

In patients with bile duct malignancy, bile duct brushing is plagued by a low yield diagnosing underlying malignancy. There are few data explaining why this is so. This porcine model was designed to examine three variables: 1) examination of inter-observer variability, 2) variability in specimen quality obtained in sequential animals, and 3) variability between two different brushes (one designed for colon with large bristles, one for duodenum with short bristles).

METHODS

En bloc resection of liver, bile ducts, duodenum, and pancreas was performed on three 6-mo-old crossbred pigs at the time of commercial slaughter. In each pig, one common hepatic duct and one common bile duct brushing, all performed by the same investigator, were done. Ten identical vigorous passes were done with each brush (long bristle or short bristle) on virgin epithelium. Specimens were graded for cellularity by three cytopathologists who were blinded to the site or brush size. Interobserver variability as well as variability among sequential animals and between the two different brushes was compared.

RESULTS

Interobserver variability among the three cytologists was almost nil. Cellularity obtained using the short brush alone varied from unsatisfactory to high. Cellularity obtained using the long brush alone varied from unsatisfactory to moderate. Variability of cells obtained from one pig to the next ranged from unsatisfactory to high.

CONCLUSIONS

1) While interobserver variability was very low, variability in cellularity obtained from one pig to the next, and from one brush to the next, was very high. This sampling variability may partially explain the low yield in malignant cells in human malignant biliary brushing. Multiple brushings in one patient may alleviate part of this problem. 2) There was no advantage to either brush type (large bristle or small bristle).

Clinical utility of stent cytology for the diagnosis of pancreaticobiliary neoplasms

OBJECTIVE

ERCP is frequently the technique of choice for the diagnosis and palliative treatment of pancreaticobiliary neoplasms. The sensitivity of tissue sampling techniques has been disappointing. Two small series have reported a high diagnostic yield from cytological examination of cellular debris from removed biliary stents. The aim of this study was to determine the clinical utility of stent cytology for the diagnosis of biliary and pancreatic neoplasia.

METHODS

Patients who had biliary or pancreatic stents removed at ERCP and evaluated cytologically were the subjects of this study. Stents were scraped and washed, and the cellular debris was examined cytologically and recorded as positive, atypical, or negative. Patient demographics, ductal stricture, and stent characteristics were recorded.

RESULTS

Between January, 1994 and January, 2001 a total of 126 biliary stents from 101 patients (61 male, 40 female, mean age 62 yr) and 29 pancreatic stents from 19 patients (seven male, 12 female, mean age 58 yr) were examined. The sensitivity, specificity, positive predictive value, and negative predictive value of biliary and pancreatic stents for the diagnosis of neoplasia were: 11%, 100%, 100%, 53%, and 25%, 100%, 100%, 77.8%, respectively. The sensitivity improved slightly if all degrees of atypia were considered positive for neoplasia. The mean duration of stent placement was 93.6 days for biliary stents and 43.5 days for pancreatic stents.

CONCLUSIONS

Biliary and pancreatic stent cytology has limited clinical utility in the diagnosis of pancreaticobiliary neoplasia, owing to poor sensitivity. In addition, the time lag between stent placement and removal for cytologic examination further limits its contribution to patient management.

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.

Biliary guidewire facilitates bile duct biopsy and endoscopic drainage

BACKGROUND

The introduction of a guidewire through bile duct strictures may facilitate transpapillary bile duct biopsy and subsequent biliary drainage.

METHODS

Endoscopic bile duct biopsy was attempted in 61 patients with bile duct strictures. After the introduction of a guidewire into the bile duct, biopsy forceps were inserted via the papilla. Both devices were inserted through the working channel (3.2 mm in diameter) of a conventional duodenoscope. After the procedure, an endoscopic naso-biliary drainage catheter was advanced along the guidewire. The success rate of inserting the biopsy forceps, the sensitivity of the biopsy, and the success rate of endoscopic biliary drainage after the biopsy were analyzed prospectively.

RESULTS

The final diagnosis was malignant strictures in 50 patients and benign strictures in 11. The success rate of inserting biopsy forceps without performing endoscopic papillary balloon dilation was 85%. The sensitivity of the biopsy for primary bile duct cancer (83%) was significantly higher (P < 0.05) than that of pancreatic cancer (47%). All patients had successful endoscopic biliary drainage after the procedure.

CONCLUSION

A previously placed guidewire facilitates insertion of biopsy forceps and endoscopic biliary drainage. The histological diagnosis of cancer is more likely with bile duct cancer than with pancreatic cancer.

The combination of stricture dilation, endoscopic needle aspiration, and biliary brushings significantly improves diagnostic yield from malignant bile duct strictures

BACKGROUND

Brush cytology, routinely performed at ERCP to assess malignant-appearing biliary strictures, is limited by relatively low sensitivity and negative predictive value. This study assessed whether the combination of stricture dilation, endoscopic needle aspiration, and biliary brushing improves diagnostic yield.

METHODS

In a prospective nonrandomized study, 46 consecutive patients were evaluated with malignant-appearing biliary strictures at ERCP. Twenty-four patients (Group A) underwent standard brush cytology alone and 22 patients (Group B) underwent stricture dilatation to 10F, endoscopic needle aspiration, and subsequent biliary brushing by using the Howell biliary system. The diagnostic yields for both techniques were compared.

RESULTS

Of the 46 patients, 34 had proven malignant strictures (14 Group A, 20 Group B). Compared with brushing alone, the combination of stricture dilatation, endoscopic needle aspiration, and subsequent biliary brushing significantly increased both the sensitivity (57% vs. 85%, p < 0.02) and specificity (80% vs. 100%, p < 0.02) of cytology with positive brushings in all patients with pancreatic or gallbladder carcinoma.

CONCLUSIONS

The combination of stricture dilation, endoscopic needle aspiration, and biliary brushing significantly improves diagnostic yield for malignant bile duct strictures and may particularly be of benefit for extrinsic strictures caused by pancreatic or gallbladder carcinoma.

Pancreatic intraductal sampling during ERCP in patients with chronic pancreatitis and pancreatic cancer: cytologic studies and k-ras-2 codon 12 molecular analysis in 47 cases

BACKGROUND

A preoperative tissue diagnosis of pancreatic cancer is desirable but difficult to obtain.

METHODS

Pancreatic brush cytology, salvage cytology, and collection of pancreatic juice were attempted prospectively during ERCP in 34 patients with pancreatic cancer and 11 with chronic pancreatitis. K-ras-2 codon 12 was analyzed for presence and type of point mutations.

RESULTS

Brush cytology coupled with salvage cytology had a sensitivity of 74%. The addition of cytologic analysis of pancreatic juice did not substantially improve sensitivity (76%). K-ras-2 was mutated in both cancer (87%) and pancreatitis (40%). The specificity for cytology was 100% and for K-ras-2 mutations 60%. Combining cytology with mutation analysis increased sensitivity to 93% but reduced the positive predictive value. The negative predictive value never exceeded 75%. None of the patients with chronic pancreatitis had cancer develop (median follow-up 60 months).

CONCLUSIONS

Pancreatic ductal brushing with salvage cytology is useful in the diagnosis of cancer, whereas cytologic analysis of pancreatic juice can be abandoned. At present, K-ras-2 mutation is not useful for differentiating pancreatic cancer from chronic pancreatitis or the identification of patients with chronic pancreatitis at risk for malignant transformation.

EUS with EUS-guided fine-needle aspiration as the first endoscopic test for the evaluation of obstructive jaundice

BACKGROUND

This study assesses the cost savings associated with using endoscopic ultrasound (EUS) before endoscopic retrograde cholangiopancreatography (ERCP) for evaluating patients with suspected obstructive jaundice.

METHODS

One hundred forty-seven patients with obstructive jaundice of unknown or possibly neoplastic origin had EUS as their first endoscopic procedure. With knowledge of the final diagnosis and actual management for each patient, their probable evaluation and outcomes and their additional costs were reassessed assuming that ERCP would have been performed as the first endoscopic procedure. Also calculated were the additional costs incurred if EUS were unavailable for use after ERCP and had to be replaced by computed tomography or other procedures.

RESULTS

The final diagnoses in these patients included malignancies (65%), choledocholithiasis or cholecystitis (18%), "medical jaundice" (11%), and miscellaneous benign conditions (6%). Fifty-four percent had EUS-guided fine-needle aspiration but only 53% required ERCP after EUS. An EUS-first approach saved an estimated $1007 to $1313/patient, but the cost was $2200 more if EUS was unavailable for use after ERCP. Significant savings persisted through sensitivity analysis.

CONCLUSIONS

Performing EUS with EUS-guided fine-needle aspiration as the first endoscopic procedure in patients suspected to have obstructive jaundice can obviate the need for about 50% of ERCPs, helps direct subsequent therapeutic ERCP, and can substantially reduce costs in these patients.

Multiple bile duct biopsies using a sheath with a side port: usefulness of intraductal sonography

OBJECTIVE

We clarified the number of biopsies required to determine malignancy of the biliary tract on the basis of the type of bile duct tumor.

SUBJECTS AND METHODS

Patients with a biliary tract malignancy (n = 33) and a benign biliary stenosis (n = 3) underwent biopsy via the percutaneous transhepatic route. We performed intraductal sonography using a 20-MHz probe with a 2.0-mm diameter. The sonographic findings were prospectively classified as polypoid, circular, or semicircular. The tip of a long 9-French sheath with a side port was wedged into the stenosis, and six specimens were obtained with a 1.8-mm-diameter forceps with serrated cups.

RESULTS

When cholangiography or intraductal sonography showed a polypoid lesion, the sensitivity of two biopsies was 100% (6/6). When cholangiography showed a stenotic lesion, the sensitivity of nine biopsies (96%, 26/27) was superior to that of two biopsies (74%, 20/27; p < 0.05). When intraductal sonography showed a circular lesion, the sensitivity of three biopsies (100%, 14/14) was superior to that of a single biopsy (64%, 9/14; p < 0.05). When it showed a semicircular lesion, the sensitivity of nine biopsies (92%, 12/13) was superior to that of two biopsies (54%, 7/13; p < 0.05).

CONCLUSION

Bile duct biopsy using a sheath with a side port has a high sensitivity. However, the number of biopsies required depends on the cholangioscopic and intraductal sonographic appearance of the tumor.

Ropeway-type bile duct biopsy forceps with a side slit for a guidewire

BACKGROUND

Transpapillary procurement of bile duct biopsy specimens is an effective diagnostic technique in cases of biliary structure. The utility of new ropeway-type bile duct biopsy forceps with a side slit for a guidewire was investigated in this study.

METHODS

The 12 patients in this study had bile duct cancer (n = 3), cancer of the head of the pancreas (n = 4), gallbladder cancer (n = 1), and benign bile duct stenosis (n = 4). After endoscopic retrograde cholangiography, a guidewire was placed in the bile duct across the stenosis. The new forceps (1.8-mm diameter clamshell-type biopsy forceps without needle) was then introduced through the intact papilla along the guidewire.

RESULTS

In all patients, sufficient tissue for histopathologic evaluation was obtained without complication. In one patient, biopsy specimens were selectively obtained of the left hepatic duct, which was impossible with conventional forceps. In another patient, histologic examination of specimens obtained by using this new forceps showed adenocarcinoma, whereas specimens obtained with a conventional forceps did not contain adenocarcinoma. However, in another patient, biopsy specimens obtained with a conventional forceps contained adenocarcinoma that was not evident in specimens obtained with the new forceps. Dislodgement of the guidewire during procurement of biopsy specimens occurred in 1 patient. In the other 11 patients, an endoscopic biliary drain was inserted over the guidewire.

CONCLUSION

The new ropeway-type biopsy forceps is useful for selectively obtaining biopsy specimens of the bile duct. With this system, access for subsequent endoscopic biliary drainage is maintained.