Mucin-hypersecreting intraductal neoplasms of the pancreas: a precursor to cystic pancreatic malignancies

BACKGROUND

Muncin-hypersecreting intraductal pancreatic neoplasms were first described in 1982 and have been observed in increasing numbers since. They are observed primarily by endoscopic retrograde cholangiopancreatography (ERCP) and are characterized by an intraductal papillary neoplasm that secretes thick mucin, causing pancreatic duct dilatation and obstructive pancreatitis.

METHODS

Twenty patients are presented, 14 male and six female, with an average age of 59 +/- 11 years. All patients presented with abdominal pain, and most had nausea and vomiting, weight loss, and documented pancreatitis. Of the preoperative studies, ERCP was positive in all patients. Computed tomography scan, endoscopic ultrasonogram, and cytologic findings were less sensitive. Tumor markers were only positive in one patient. All 20 patients were treated surgically. Nine underwent Whipple procedure, one patient had a total pancreatectomy, and nine had distal pancreatic resections. The first patient in the series did not have a pancreatic resection, and his disease evolved into a lethal cystadenocarcinoma causing his death 99 months later.

RESULTS

Histopathologic findings were interpreted as borderline malignant in 17 of the 20 patients, and three patients had evidence of invasive adenocarcinoma. Two of these three patients had nodal or distant metastases at the time of diagnosis, and all three died of adenocarcinoma. Seventeen of the patients are alive and well, although two of three with positive pancreatic margins have had recurrent symptoms and have been successfully reresected.

CONCLUSIONS

The mucin-producing intraductal papillary tumor of the pancreas is a newly described variant of pancreatic cancer. It presents with symptoms of pancreatitis and has a progressive but more indolent course than the more lethal invasive ductal cancers. Patients with unexplained pancreatitis should undergo ERCP investigation, and aggressive surgical therapy should be carried out because the prognosis for this lesion, when appropriately treated, is more favorable than the usual pancreatic cancer.

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.

Lansoprazole heals erosive reflux esophagitis resistant to histamine H2-receptor antagonist therapy

PURPOSE

We conducted a randomized, double-blind, multicenter clinical trial to determine whether lansoprazole was superior to continued therapy with histamine H2-receptor antagonist therapy in healing erosive reflux esophagitis.

METHODS

Investigators from nine medical centers enrolled 159 patients with endoscopically documented esophageal erosions and/or ulcers that had failed to heal with 12 or more wk of at least standard dosages of histamine H2-receptor antagonist therapy. Patients received ranitidine 150 mg b.i.d. for 8 wk or lansoprazole 30 mg for 4 wk followed by either lansoprazole 30 mg or lansoprazole 60 mg for another 4 wk of treatment. Patients underwent endoscopy at screening and at weeks 2, 4, and 8.

RESULTS

At 2, 4, and 8 wk of therapy, healing rates were significantly higher in the lansoprazole group compared with the ranitidine group (p < 0.001). By 8 wk, 84% of the lansoprazole group were healed as opposed to only 32% of the ranitidine group. Lansoprazole was superior to ranitidine in providing relief of upper abdominal burning and daytime heartburn (p < 0.001) and reducing the need for antacids (p < 0.001). Lansoprazole patients had less interference with sleep and less day time drowsiness than ranitidine patients (p = 0.05). The percentages of patients with adverse events were similar in both groups. Fasting serum gastrin levels at weeks 4 and 8 were significantly higher in the lansoprazole group compared with the ranitidine group.

CONCLUSION

Eight weeks of lansoprazole therapy is safe, superior to continued ranitidine therapy, and effective in healing more than 80% of patients with erosive reflux esophagitis previously resistant to histamine H2-receptor antagonist therapy.

Colonoscopic miss rates of adenomas determined by back-to-back colonoscopies

BACKGROUND & AIMS

The miss rate of colonoscopy for neoplasms is poorly understood. The aim of this study was to determine the miss rate of colonoscopy by same day back-to-back colonoscopy.

METHODS

Two consecutive same day colonoscopies were performed in 183 patients. The patients were randomized to undergo the second colonoscopy by the same or a different endoscopist and in the same or different position.

RESULTS

The overall miss rate for adenomas was 24%, 27% for adenomas < or = 5 mm, 13% for adenomas 6-9 mm, and 6% for adenomas > or = 1 cm. Patients with two or more adenomas at the first examination were more likely than patients with no or one adenoma detected at the first examination to have one or more adenomas at the second examination (odds ratio, 3.3; 95% confidence interval, 1.69-6.46). Right colon adenomas were missed more often (27%) than left colon adenomas (21%), but the difference was not significant. There was evidence of variation in sensitivity between endoscopists, but significant miss rates for small adenomas were found among essentially all endoscopists.

CONCLUSIONS

Using current colonoscopic technology, there are significant miss rates for adenomas < 1 cm even with meticulous colonoscopy. Miss rates are low for adenomas > or = 1 cm. The results suggest the need for improvements in colonoscopic technology.

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.

Prospective multicenter trial of esophageal Z-stent placement for malignant dysphagia and tracheoesophageal fistula

BACKGROUND

Conventional esophageal prosthesis placement has been associated with a 6% to 8% perforation rate and numerous postplacement complications. Expandable esophageal stents have been developed to preclude the above but there are few studies that have prospectively defined clinical results and subsequent stent-related complications.

METHODS

All patients who underwent esophageal Z-stent placement at nine university or referral hospitals were prospectively assessed. Data collected included patient demographics, acute and subacute placement problems, the ability to occlude airway fistulas, prestent and poststent dysphagia scores, and patient survival.

RESULTS

Fifty-four of 56 patients (96%) with refractory dysphagia or malignant esophagoairway fistulae had 73 Z-stents successfully inserted. Initial distal deployment occurred in 13% of the patients and an additional 17% required balloon dilation to achieve maximal diameter. Acute placement complications occurred in 11% of patients and included severe pain (3), bleeding from necrotic tumor (2), and hiatal hernia intussusception (1). No perforations occurred. Eight of 11 patients (73%) had complete tracheoesophageal fistula occlusion and mean dysphagia score (+/- SD) improved from 2.6 (0.7) to 1.1 (1.2) (p < 0.01). Fifteen stents (27%) had delayed migration at a mean of 1 month and 3 required surgery for retrieval. Three patients had ultimate stent erosion resulting in bleeding in 2 (exsanguination 1) or fistula (treated with a conventional stent).

CONCLUSIONS

The authors conclude that esophageal Z-stents can be placed safely and successfully in the majority of patients. The tendency of distal deployment during placement and subsequent migration problems at a time distant from placement in a patient subset deserve attention and are currently being addressed.

Hemoglobin damages the cultured endothelial cell monolayer from bovine cerebral arteries

We demonstrated that hemoglobin reaches the endothelial layers by an immunoelectron microscopic analysis in a rabbit subarachnoid hemorrhage model. Next, the effects of hemoglobin on cerebral artery endothelial cells were investigated both morphologically and histochemically using a cultured monolayer from a bovine endothelial cell system. The cultured monolayer was incubated with six different concentrations of hemoglobin ranging from 0 to 10(-5) M for 24 hrs on two-chambered glass slides. The denuded area of the glass slide increased dose dependently while the intensity of the actin fiber decreased. Superoxide dismutase did not modify this change. In a preliminary study, the endothelial cell membrane showed a hemoglobin binding molecule (94.5k dalton). This study thus suggests that the effects of hemoglobin on the endothelial monolayer were partly caused by the direct binding of hemoglobin to the membrane.

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.

Radiation exposure to patients and personnel during interventional ERCP at a teaching institution

BACKGROUND

This study was designed to determine the radiation dose to patients and personnel during ERCP procedures.

METHODS

Phantom studies were performed to compare dosimetry for two image capture systems and to determine the effectiveness of shielding in reducing stray radiation. Radiation techniques and dosimetry were recorded in 72 patients undergoing ERCP.

RESULTS

Phantom studies indicated that increasing fluoroscopy voltage from 75 to 96 kV decreased entrance dose by 50%. Image capture by digital radiography decreased radiation exposure by 66%. Shielding decreased stray radiation exposure by 93%. All patients underwent cholangiography (n = 71) and/or pancreatography (n = 53). The mean number of interventional ERCP procedures performed per patient was 1.8 (range, 0 to 6). The mean measured patient entrance dose was 80 mGy (8 R; range, 0.2 to 73 R); however, the calculated mean entrance dose (based on measured intensifying screen doses) may have been as high as 3000 mGy (30 R; range, 0.8 to 300 R). Measured patient exposure increased with fluoroscopy time (r = 0.9) and with the number of interventions performed (r = 0.3). The mean dose to personnel was estimated at 0.04 mR.

CONCLUSIONS

The patient radiation dose depended most on fluoroscopy time. The dose may be lowered by minimizing fluoroscopy time, using higher voltage and lower current for fluoroscopy, and using digital radiography for documentation. Personnel were adequately protected.

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.

Effects of meperidine on the pancreatic and biliary sphincter

BACKGROUND

Opioids are traditionally avoided during sphincter of Oddi manometry because of indirect evidence suggesting that these agents cause sphincter of Oddi spasm. This study was undertaken to determine the direct effects of meperidine on the biliary and pancreatic sphincter.

METHODS

Forty-seven patients were prospectively evaluated by sphincter of Oddi manometry in the conventional retrograde fashion. Manometry was initially performed with intravenous diazepam sedation alone. The manometry was repeated 3 to 5 minutes after meperidine was administered.

RESULTS

The basal sphincter pressure of the biliary sphincter, pancreatic sphincter, and the combined sphincter group were not significantly altered by meperidine. Concordance (normal versus abnormal) between the basal sphincter pressure before and after meperidine was seen in 44 of 47 patients (94%). Meperidine produced a significant increase in the pancreatic, biliary, and combined sphincter phasic frequency and a significant decrease in the phasic duration. The pancreatic and combined sphincter phasic pressures were significantly reduced following meperidine administration. Seventeen manometry tracings (36%) were believed to be qualitatively better after meperidine, while only four (8.5%; p < .001) were qualitatively better with diazepam alone.

CONCLUSION

Meperidine can be used for additional analgesia during sphincter of Oddi manometry if the basal sphincter pressure is the parameter used to determine therapy.

Early recognition of post-ERCP pancreatitis by clinical assessment and serum pancreatic enzymes

BACKGROUND

This study evaluates the relative value of clinical assessment and serum pancreatic enzymes in the discharge management of outpatients undergoing ERCP.

METHODS

Two hundred thirty-one patients who underwent ERCP had a detailed clinical assessment performed 2 h after the procedure and blood drawn for amylase and lipase.

RESULTS

One-third of the patients who later developed pancreatitis had no pain 2 h after the end of the procedure, whereas an equal number who had no pancreatitis did complain of pain. Values below 276 U/L for amylase and 1000 U/L for lipase were useful in ruling out pancreatitis with negative predictive values of 0.97 and 0.98, respectively. Based on the data of this study a discharge algorithm for outpatients undergoing ERCP is proposed.

CONCLUSIONS

In contrast to clinical assessment, which is unreliable, it is possible to stratify patients according to their risk of developing pancreatitis according to their 2-h serum amylase and lipase values. This helps to rationalize the discharge management of outpatients undergoing ERCP at a time when careful utilization of resources, especially the avoidance of unnecessary hospital admissions, becomes increasingly more important.

Sphincter of Oddi dysfunction

Evidence continues to accumulate indicating that sphincter of Oddi dysfunction may give rise to cholestasis, pancreatitis, or upper abdominal pain syndromes. Diagnosis of such dysfunction may be inferred from noninvasive tests or more precisely defined by manometric studies. Both the biliary and pancreatic sphincters are commonly involved. If medical therapy is ineffective, sphincter ablation via endoscopy or laparotomy should be considered for highly symptomatic patients. Complication rates of invasive techniques remain relatively high and risk:benefit ratio should be carefully considered. Future research as to etiology, more defined pathophysiology, more accurate noninvasive evaluation, and optimal therapies are awaited.

Sphincter of Oddi dysfunction

Evidence continues to accumulate indicating that sphincter of Oddi dysfunction may give rise to cholestasis, pancreatitis, or upper abdominal pain syndromes. Diagnosis of such dysfunction may be inferred from noninvasive tests or more precisely defined by manometric studies. Both the biliary and pancreatic sphincters are commonly involved. If medical therapy is ineffective, sphincter ablation via endoscopy or laparotomy should be considered for highly symptomatic patients. Complication rates of invasive techniques remain relatively high and risk:benefit ratio should be carefully considered. Future research as to etiology, more defined pathophysiology, more accurate noninvasive evaluation, and optimal therapies are awaited.

Complex biliary stones: treatment with a small choledochoscope and laser lithotripsy

PURPOSE

To evaluate the use of a small choledochoscope and laser lithotripsy in the treatment of complex biliary stone disease.

MATERIALS AND METHODS

Twenty-five consecutive patients with complex biliary stone disease not amenable to surgical therapy, peroral endoscopic removal, or simple percutaneous retrieval techniques underwent 35 stone-removal procedures. A 3.4-mm endoscope and a pulsed dye coumarin green laser were used to pulverize and remove stones through preexisting, mature transhepatic biliary drain tracts (n = 18), t-tube tracts (n = 3), cholecystostomy tube tracts (n = 3), and a hepaticocutaneous enterostomy (n = 1). Procedures in 14 of the 25 patients (56%) were performed on an outpatient basis.

RESULTS

Twenty-four of the 25 patients (96%) were cleared of their stone burden and underwent subsequent catheter therapy of strictures or abscesses as necessary. Complications of the stone removal included fever and chills in six patients (24%) and mild bleeding from a bile duct wall during removal of an adherent stone in one patient.

CONCLUSION

Use of a small choledochoscope and a coumarin green pulsed dye laser is safe and effective in the management of complex biliary stone disease.

Colonoscopy evaluations: justification by cost?

The type of colonic imaging (radiological vs colonoscopic) for evaluating symptomatic patients without evidence of bleeding in both an efficacious and cost-conserving manner has become a very debated issue. In a randomized, controlled clinical trial, the authors hoped to examine the prevalence of neoplasm and the effectiveness and cost-effectiveness of initial diagnostic strategies of colonoscopy versus flexible sigmoidoscopy and air contrast barium enema in patients without evidence of intestinal bleeding. One hundred forty-nine patients over the age of 40 with symptoms suggestive a colonic disease without evidence of bleeding (no hematechezia, negative test for fecal occult blood, and normal serum hemoglobin) were randomized to undergo either initial colonoscopy or flexible sigmoidoscopy plus barium enema. Patients with incomplete lower GI tests were referred for the corresponding alternative imaging modality. Cost analyses using sensitivity analysis were performed. Baseline information with respect to age, race, sex, inpatient status, reason for referral, mean weight loss, hemoglobin, blood urea nitrogen, and albumin were similar in both groups. Eighteen patients (24%) who initially received air contrast barium enema and flexible sigmoidoscopy then required colonoscopy, whereas only five patients (6%) who initially underwent colonoscopy first required air contrast barium enema plus flexible sigmoidoscopy. The study found that: a) The prevalence of cancer in the study was low (one of 149 patients); b) initial colonoscopy detected more persons with adenomas than that of air contrast barium enema plus flexible sigmoidoscopy (23 of 75 patients vs 13 of 74 patients, odds radio, 2.07, CI,0.90-4.92; this approached significance); and c) air contrast barium enema plus flexible sigmoidoscopy detected more diverticulosis (46 of 74 patients vs 31 of 75 patients, odds ratio, 0.41, 95% CI, 0.21-0.87). The significant conclusions were that patients undergoing flexible sigmoidoscopy plus air contrast barium enema were more likely to undergo alternative procedures and that sensitivity analysis suggested that, for most areas in the United States, initial colonoscopy would be more cost-effective for the outcome of detection of adenomas (1).

Surgical treatment of obstructive pancreatitis

BACKGROUND

Unlike chronic calcific pancreatitis, obstructive pancreatitis occurs as a consequence of an obstruction or stricture in the main pancreatic duct. The purpose of this paper is to identify the best method of surgical treatment for patients with obstructive pancreatitis.

METHODS

Retrospective analysis of 224 patients surgically treated for chronic pancreatitis during a 7-year period (1988 through 1994) identified 23 patients with obstructive pancreatitis. Patients were classified by surgical treatment into pancreaticoduodenectomy (five patients), side-to-side pancreaticojejunostomy (nine patients), or distal pancreatectomy (nine patients) groups and analyzed.

RESULTS

Despite similar demographics, patients treated with distal pancreatectomy had significantly better outcomes (seven of nine) than those treated with either pancreaticoduodenectomy (zero of four) or side-to-side pancreaticojejunostomy (two of eight) at a mean follow-up of 26 months (chi-squared, p = 0.009). Multivariate analysis revealed stricture location, cause of pancreatitis, maximal duct dilatation, exocrine insufficiency, or continued alcohol intake had no influence on surgical outcome in this series (p = 0.698, logistic regression analysis).

CONCLUSIONS

At 2 years of follow-up, distal pancreatectomy provided superior relief from pain and recurrent pancreatitis compared with pancreaticoduodenectomy or side-to-side pancreaticojejunostomy. Obstructive pancreatitis is best treated by distal rather than proximal pancreatic resection or drainage.

Does routine intravenous glucagon administration facilitate colonoscopy? A randomized trial

BACKGROUND

Previous studies on the routine use of glucagon in colonoscopy have produced conflicting results.

METHODS

Two separate studies were performed. In one study (Study 1), 80 consecutive patients were randomized after cecal intubation to receive 1 mg glucagon (n = 41) or placebo (n = 39), intravenously, in double-blind fashion. In a second study (Study 2) 90 sedated patients undergoing colonoscopy were randomized to receive 1 mg glucagon (n = 46) or placebo (n = 44), intravenously, just before colonoscope insertion. In each study, colonoscope insertion and withdrawal time, therapeutic intervention time, the presence and severity of colonic spasm, colonoscopy yield, and side effects were recorded.

RESULTS

Mean withdrawal time in Study 1 was similar in those receiving glucagon (6.85 min) and in those receiving placebo (6.92 min). Mean insertion time in Study 2 (5.07 min) was identical between groups. Spasm scores and colonoscopy yield did not differ between glucagon and placebo in either study. There was a trend toward more side effects (nausea and vomiting) with glucagon in Study 1. Glucagon did not facilitate insertion or withdrawal in the subset of patients with diverticulosis.

CONCLUSIONS

Routine use of intravenous glucagon in a dosage of 1 mg does not facilitate colonoscopy by experienced examiners.