Role of EUS in the preoperative staging of pancreatic cancer: a large single-center experience

BACKGROUND

Current methods for staging pancreatic cancer can be inaccurate, invasive, and expensive. Endoscopic ultrasound (EUS) is reported to be highly accurate for local staging of gastrointestinal tumors including pancreatic cancer. The aim of this study was to assess the utility of EUS and CT for staging pancreatic cancer by comparing staging accuracies in surgical patients and evaluating the potential impact of EUS staging and training.

METHODS

This was a preoperative comparison of the diagnostic operating characteristics of these procedures in a referral-based academic medical center. Data were collected on 151 consecutive patients referred with confirmed pancreatic cancer between April 1990 and November 1996. All patients had preoperative CT and EUS performed for staging. In patients undergoing surgery, the surgical staging and/or findings were used to confirm EUS and CT staging.

RESULTS

Eighty-one (60%) of 151 patients underwent surgery and made up the study subset. In these 81 patients, surgical exploration provided a final T staging in 93% (75 of 81), N staging in 88% (71 of 81) and data on vascular invasion in 93% (75 of 81). In the surgical patient group, with surgical correlation, EUS accuracy for T staging was as follows: T1 92%, T2 85%, T3 93%, and for N staging was: N0 72%, and N1 72%. CT accuracy for T staging was as follows: T1 65%, T2 67%, T3 38%, and for N staging was as follows: N0 52% and N1 100%. CT failed to detect a mass in 26% of patients with a confirmed tumor at surgery. Overall accuracy for T and N staging was 85% and 72% for EUS and 30% and 55% for CT, respectively. The ability to accurately predict vascular invasion was 93% for EUS and 62% for CT (p < 0.001). EUS was 93% accurate for predicting local resectability versus 60% for CT (p < 0.001). Last, the data were divided into two groups for the senior endosonographer's experience: procedures performed between 1990 and 1992 (98 cases) and 1993 and 1994 (53 cases). This analysis revealed that 7 of 9 instances of mis-staging (78%) occurred in the earlier group, during the learning phase for EUS.

CONCLUSIONS

EUS is more accurate than CT for staging pancreatic malignancies, including predicting vascular invasion and local resectability. EUS staging was significantly better than CT for T1, T2, and T3 tumors. EUS staging accuracy improved after 100 cases, thus suggesting a correlation between the accuracy of EUS staging and the number of procedures performed.

Endoscopic ultrasound-guided fine-needle aspiration biopsy using linear array and radial scanning endosonography

BACKGROUND

Endoscopic ultrasound (EUS) accurately stages gastrointestinal malignancies but is less able to differentiate between neoplastic and inflammatory processes. EUS-guided fine-needle aspiration (EUS FNA) has been reported useful for obtaining a diagnosis in suspected gastrointestinal lesions. We report our entire experience with EUS FNA using both radial and linear array endosonography, including our diagnostic accuracy and complication rate.

METHODS

Two hundred eight consecutive patients (119 men, 89 women) referred for EUS evaluation of suspected gastrointestinal or mediastinal masses underwent EUS-guided FNA. We performed EUS FNA using radial scanning or linear array endosonography and a 23 gauge, 4 cm needle or a 22 gauge, 12 cm needle. Data collected included lesion types, number of passes, complications, and diagnostic accuracy.

RESULTS

Two hundred eight lesions were targeted, with a total of 705 FNA passes (mean 3.39 passes/patient). Overall diagnostic accuracy for our study population was 87% with a 89% sensitivity and 100% specificity. The diagnostic accuracy for each subgroup was 95% for mediastinal lymph node, 85% for intra-abdominal lymph node, 85% for pancreatic, 84% for submucosal, and 100% for perirectal masses. EUS FNA provided an adequate specimen in 90% of patients. The FNA results were similar for both types of endosonography. We observed immediate complications in 2% (4 of 208) of patients. All complications occurred with EUS FNA of pancreatic lesions and consisted of bleeding and pancreatitis in 2 patients each. For EUS FNA of pancreatic masses there was a 1.2% (2 of 121) risk of pancreatitis, 1% (1/121) risk of severe bleeding, and risk of death in less than 1%.

CONCLUSIONS

EUS-guided FNA appears to be technically feasible, safe, and accurate for obtaining diagnostic tissue of suspicious gastrointestinal and mediastinal lesions and provides important preoperative information.

5-year incidence of adenomas after negative colonoscopy in asymptomatic average-risk persons [see comment]

BACKGROUND & AIMS

Cost-effectiveness of colorectal cancer screening will be maximized by selecting the widest screening intervals that effectively prevent cancer mortality. However, data on the incidence of neoplasia in persons with no abnormal findings on initial examination are limited. The aim of this study was to describe the incidence of colonic neoplasia 5 years after negative screening colonoscopy in asymptomatic average-risk persons.

METHODS

We previously reported the results of screening colonoscopy in 496 asymptomatic average-risk persons, 368 of whom had no neoplasia identified. Colonoscopy to the cecum was performed in 154 of these persons at a mean of 66 months after the initial negative colonoscopy.

RESULTS

Forty-one (27%) had at least one adenoma, but only 1 person had an adenoma > or = 1 cm and none had cancer, severe dysplasia, or villous or tubulovillous histology. Hyperplastic polyps at the initial examination did not predict incident adenomas. Regular nonsteroidal anti-inflammatory drug use was associated with a decreased rate of incident adenomas.

CONCLUSIONS

In average-risk persons, the interval between screening examinations can be safely expanded beyond 5 years, provided the initial examination is a carefully performed complete colonoscopy that is negative for colonic adenomas or cancer.

Stent-induced pancreatic ductal and parenchymal changes: correlation of endoscopic ultrasound with ERCP

BACKGROUND

Polyethylene pancreatic duct stents induce morphologic changes of the pancreatic duct in the majority of patients. This study was undertaken to determine if parenchymal abnormalities are present in patients undergoing short-term pancreatic duct stenting and to correlate these findings with the pancreatogram obtained at stent removal.

METHODS

Twenty-five patients underwent pancreatic duct stenting and had an endoscopic ultrasound evaluation of the pancreas at stent removal. The pancreatograms were evaluated at stent removal for ductal irregularity, narrowing, and side branch changes. Endoscopic ultrasound was used to assess for differences in the echo characteristics of the pancreatic parenchyma around the stent compared with the rest of the gland.

RESULTS

Of the 16 patients evaluated by ERCP at stent removal, 9 (56%) had 1 or more new ductographic changes. Endoscopic ultrasound identified parenchymal changes in the stented region in 17 of 25 patients (68%). Four patients who had parenchymal changes in the stented region on endoscopic ultrasound at stent removal had a follow-up study at a mean time of 16 months. Two patients had (new) changes suggestive of focal chronic pancreatitis in the stented region.

CONCLUSION

Short-term pancreatic duct stenting induced both ductal and parenchymal changes in more than 50% of patients. Chronic pancreatitis may be a consequence of pancreatic duct stenting.

Alterations in pancreatic ductal morphology following polyethylene pancreatic stent therapy

BACKGROUND

Polyethylene stents placed in the main pancreatic duct induce morphologic alterations that may resemble chronic pancreatitis.

METHODS

We reviewed the sequential pancreatograms of stented patients who had long-term follow-up after stent removal.

RESULTS

Forty patients (66%) had a normal baseline pancreatogram, whereas 21 (34%) showed changes of chronic pancreatitis. In 49 of 61 patients (80.3%), one or more had new morphologic changes immediately after stent withdrawal graded as mild (69%), moderate (29%), or severe (2%). Changes included ductal irregularity (49%), narrowing (35.5%), and side branch change (15.5%). Sixteen of the 21 patients (76.1%) with an abnormal baseline pancreatogram had worsening of the baseline abnormality or additional changes while stented, whereas 33 of 40 (82.5%) with a normal baseline developed new morphologic changes. Correlation of stent-induced changes with stent size, length, patency at removal, and duration of stenting failed to show an association. Twenty-five patients with stent-induced changes had a follow-up pancreatogram at a mean of 192 days (10 to 740) after stent removal. There was complete resolution of the changes in 64%, partial resolution in 32%, and no improvement in 5%.

CONCLUSION

Morphologic changes induced by polyethylene pancreatic duct stents occurred in 80% of patients. More than one third of these changes did not resolve during the follow-up period. Because of concern over stent-induced fibrosis, the use of pancreatic stents should remain largely experimental.

Detection of embryologic ventral pancreatic parenchyma with endoscopic ultrasound

BACKGROUND

The prevalence of detecting the embryologic ventral pancreas (ventral anlage) with endoscopic ultrasound (EUS) is unknown.

PURPOSE

To determine the frequency of, and factors associated with, EUS findings consistent with the ventral anlage.

METHODS

One hundred patients undergoing upper gastrointestinal EUS for any indication were prospectively evaluated for the presence of a focal, hypoechoic area in the pancreatic head using a radial scanning echoendoscope. Multiple clinical and EUS variables were tested against the ability to detect the ventral anlage.

RESULTS

The overall detection rate of the ventral anlage was 59%. The ventral anlage was detected in 75% of patients undergoing EUS for nonpancreatic indications, compared to 40% of patients undergoing EUS to evaluate suspected pancreatic disease (p< 0.001). EUS detected the ventral anlage in 72% of patients with a normal EUS-appearing pancreatic head, compared to 29% of patients who had abnormal pancreatic head parenchyma (mass or chronic pancreatitis) on EUS (p < 0.001). Multivariate analysis revealed the only variable associated with detecting the ventral anlage was abnormal pancreatic head parenchyma on EUS.

CONCLUSION

The ventral anlage is frequently detected during pancreatic EUS, with a significantly lower rate of detection in patients with EUS findings of a pancreatic head mass or diffuse chronic pancreatitis.