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Biomedical subjects

R H Hawes

Publications and source records attributed to R H Hawes.

At least 73 records · Page 4Linked to original sources
PubMed1998

Pancreatic stenting prevents pancreatitis after biliary sphincterotomy in patients with sphincter of Oddi dysfunction.

BACKGROUND & AIMS: Patients with sphincter of Oddi dysfunction are at high risk of developing pancreatitis after endoscopic biliary sphincterotomy. Impaired pancreatic drainage caused by pancreatic sphincter hypertension is the likely explanation for this increased risk. A prospective, randomized controlled trial was conducted to determine if ductal drainage with pancreatic stenting protects against pancreatitis after biliary sphincterotomy in patients with pancreatic sphincter hypertension. METHODS: Eligible patients with pancreatic sphincter hypertension were randomized to groups with pancreatic duct stents (n = 41) or no stents (n = 39) after biliary sphincterotomy. The primary measured outcome was pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP). RESULTS: Pancreatic stenting significantly decreased the risk of pancreatitis from 26% to 7% (10 of 39 in the no stent group and 3 of 41 in the stent group; P = 0.03). Only 1 patient in the stent group developed pancreatitis after sphincterotomy, and 2 others developed pancreatitis at the time of stent extraction. Patients in the no stent group were 10 times more likely to develop pancreatitis immediately after sphincterotomy than those in the stent group (relative risk, 10.5; 95% confidence interval, 1.4-78.3). CONCLUSIONS: Pancreatic duct stenting protects significantly against post-ERCP pancreatitis in patients with pancreatic sphincter hypertension undergoing biliary sphincterotomy. Stenting of the pancreatic duct should be strongly considered after biliary sphincterotomy for sphincter of Oddi dysfunction; pancreatic sphincter of Oddi manometry identifies which high-risk patients may benefit from pancreatic stenting.

Adult↗
PubMed1998

Clinical implications of endoluminal ultrasonography using through-the-scope catheter probes.

BACKGROUND: Ultrasound catheter probe-assisted endosonography is a relatively new technique. The aim of this prospective multicenter study was to determine its potential clinical impact by assessing changes in diagnostic and therapeutic management affected by catheter probes compared with ultrasound endoscopes. METHODS: Endosonographers at three centers selected theoretic diagnostic and therapeutic plans that would be followed if neither catheter probes nor ultrasound endoscopes were available. Patients with suitable lesions underwent endosonography with catheter probes followed by an ultrasound endoscope. Diagnostic and therapeutic plans were noted after each examination. RESULTS: Sixty-six patients, of whom 15 had a stenotic esophageal cancer, 39 had a mucosal or submucosal lesion, and 12 had a stricture of the pancreaticobiliary system or the gastrointestinal tract, were enrolled. If neither form of endosonography were available, invasive or surgical diagnostic procedures would have been performed on 23 (35%) patients and surgical therapy would have been planned in 31 (47%) patients. Catheter probe-assisted ultrasonography and endoscopic ultrasonography led to a less invasive diagnostic plan in 11 (16%) and 12 (18%) patients and a less invasive therapeutic plan in 10 (15%) and 14 (21%) patients, respectively (p > 0.1 for differences). CONCLUSIONS: Catheter probe-assisted endosonography has a modest effect on diagnostic and therapeutic management, comparable with endoscopic ultrasonography in the same patients. The vast majority of effected changes are toward less invasive management.

Digestive System Neoplasms↗
PubMed1998

Prospective assessment of the ability of endoscopic ultrasound to diagnose, exclude, or establish the severity of chronic pancreatitis found by endoscopic retrograde cholangiopancreatography.

BACKGROUND: Our aim was to verify endoscopic ultrasound (EUS) accuracy to diagnose, rule out, and establish the severity of chronic pancreatitis found by endoscopic retrograde cholangiopancreatography (ERCP). METHODS: Patients undergoing ERCP for unexplained abdominal pain and/or suspected chronic pancreatitis underwent EUS. EUS was performed by experienced operators who were aware of the history but blinded to ERCP results. Chronic pancreatitis was defined using the Cambridge classification: 0 to 1 = "normal," 2 to 4 = "all chronic pancreatitis," 3 to 4 = "moderate to severe chronic pancreatitis." The number of EUS criteria required to obtain sensitivity, specificity, positive and negative predictive values > or = 85% was determined. EUS criteria for chronic pancreatitis are hyperechoic foci, hyperechoic strands, lobularity, hyperechoic duct, irregular duct, visible side-branches, ductal dilation, calcification, and cysts. RESULTS: One hundred twenty-six patients underwent EUS and ERCP. EUS was highly sensitive and specific (> 85%) depending on the number of criteria present. Chronic pancreatitis is likely (PPV > 85%) when more than two criteria (for "all chronic pancreatitis") and more than six criteria (for "moderate to severe chronic pancreatitis") are present. "Moderate to severe chronic pancreatitis" is unlikely (NPV > 85%) when fewer than three criteria are present. Independent predictors of chronic pancreatitis were "calcification" (p = 0.000001), history of alcohol abuse (p = 0.002), and the total number of EUS criteria (p = 0.008). CONCLUSIONS: EUS can accurately diagnose, rule out, and establish the severity of chronic pancreatitis found by ERCP.

Adult↗
PubMed1998

Local staging of anal and distal colorectal tumors with the magnetic resonance endoscope.

BACKGROUND: We prospectively assessed the feasibility and accuracy of endoscopic magnetic resonance (EMR) scanning in the local staging of anal and colorectal cancer as compared to endosonography. METHODS: Fifteen patients with biopsy-proven anal (n = 2), rectal (n = 11), and distal colonic (n = 2) cancer underwent endosonography followed by EMR imaging. Scans were acquired using the magnetic resonance receiver coil incorporated into the tip of the non-ferromagnetic endoscope. Blinded to endosonography results, two radiologists interpreted the EMR images using the TNM system. Staging results were compared to endosonography in all patients and to histopathology in the 13 colorectal cases. RESULTS: EMR imaging, well tolerated in all patients, correlated with endosonography in 10 of 15 and 12 of 15 cases for T- and N-staging, respectively. In the 13 colorectal patients with available histopathology, accuracy of EMR and of endosonography in T-staging was 77% and 85%, respectively; N-staging accuracy was 62% for both. CONCLUSIONS: For anal and distal colorectal neoplasms, EMR imaging is feasible and provides local staging comparable to endosonography.

Adenocarcinoma↗
PubMed1998

A swine model for teaching endoscopic ultrasound (EUS) imaging and intervention under EUS guidance.

BACKGROUND AND STUDY AIMS: Endoscopic ultrasonography (EUS) has evolved into a clinically useful imaging modality. Widespread application of EUS has been hampered by the long learning curve and the paucity of training programs. We report here our efforts to develop an animal model for teaching endoscopic ultrasound. MATERIALS AND METHODS: The protocol for performing endoscopic ultrasound in live pigs included general anesthesia, endotracheal intubation, and mechanical ventilatory support. An echo-endoscope was then inserted into the pig gastrointestinal tract, and attempts were made to obtain ultrasound images that were comparable to human endoscopic ultrasound images. Intervention under EUS guidance was then attempted in the swine. RESULTS: It was possible to image the esophageal and gastric wall, pancreas, aorta, celiac artery, superior mesenteric artery, liver, and portal vein. The images obtained were analogous to human endoscopic ultrasound images. EUS-guided interventional techniques were also carried out, including EUS-guided fine-needle aspiration and celiac plexus neurolysis. CONCLUSIONS: A swine model appears to be useful for hands-on teaching in endoscopic ultrasound imaging and intervention under endoscopic ultrasound guidance.

Animals↗
PubMed1998

Local staging of esophageal cancer using endoscopic magnetic resonance imaging: prospective comparison with endoscopic ultrasound.

BACKGROUND AND STUDY AIMS: The magnetic resonance endoscope consists of a non-ferrous endoscope with a radiofrequency receiver coil incorporated into its tip. The aim of this study was to assess the accuracy of endoscopic magnetic resonance imaging for the local staging of esophageal cancer. PATIENTS AND METHODS: Prospectively, 15 patients with biopsy-proven cancer of the esophagus (n = 9) or gastroesophageal junction (n = 6) underwent endosonography followed by imaging by the magnetic resonance endoscope. The results of endoscopic magnetic resonance imaging were assessed blindly, then compared with those of endosonography, which served as the gold standard. RESULTS: Endoscopic magnetic resonance imaging of transmural tumor invasion agreed with ultrasonography in 11/15 cases and of nodal state in 12/15 cases. Endoscopic magnetic resonance images were inadequate in four cases as a result of motion artifacts. CONCLUSIONS: Endoscopic magnetic resonance imaging of esophageal cancer diagnoses local staging that is comparable to endosonography. In future, the combination of endoscopic and conventional magnetic resonance scanning may provide comprehensive staging of esophageal cancer.

Adenocarcinoma↗
PubMed1998

Indications for EUS-directed FNA.

EUS/FNA is an extremely precise method for sampling lesions surrounding the gastrointestinal tract. As experience widens, so do the indications for its use. However, as endoscopists explore ways to use this technique to improve patient care, a basic premise should be kept in mind: the information obtained should have the potential to affect patient management. There will undoubtedly be refinements in the application of EUS/FNA, but the future looks very promising indeed.

Biopsy, Needle↗
PubMed1998

Endoscopic sphincterotomy for stones by experts is safe, even in younger patients with normal ducts.

OBJECTIVE: To provide current information on the risks of endoscopic sphincterotomy for stone. SUMMARY BACKGROUND DATA: In recent years (since the popularity of laparoscopic cholecystectomy), endoscopic sphincterotomy has been used increasingly for the management of bile duct stones in relatively young and healthy patients. The validity of this trend has been questioned using data on short-term complications derived from earlier decades that involved more elderly and high-risk patients. METHODS: Seven academic centers collected data prospectively using a common database. Complications within 30 days of the procedures were documented by standard criteria. RESULTS: Of 1921 patients, 112 (5.8%) developed complications; two thirds of these events were graded as mild (<3 days in hospital). There was no evidence of increased risk in younger patients or in those with smaller bile ducts. There was only one severe complication and there were no fatalities in 238 patients age <60, with bile duct diameters of <9 mm. CONCLUSION: Sphincterotomy for stones can be performed very safely by experienced endoscopists.

Age Factors↗
PubMed1998

Endoscopic diagnosis and therapy of unexplained (idiopathic) acute pancreatitis.

A significant minority of patients with acute pancreatitis show no obvious cause for the attack during a routine evaluation. There is no consensus regarding the appropriate diagnostic and therapeutic approach in this setting. This article reviews the available data, outlines directions for further investigation, and provides recommendations for management of patients who have recovered from a prior episode of unexplained acute pancreatitis.

Acute Disease↗
PubMed1998

Outcome after laparoscopic cholecystectomy for chronic acalculous cholecystitis.

Patients with typical symptoms of biliary tract disease but no gallstones on ultrasonography may benefit from cholecystectomy for presumed chronic acalculous cholecystitis. We retrospectively analyzed the outcome of 50 patients with a preoperative diagnosis of chronic acalculous cholecystitis based upon history (chronic or recurrent, postprandial right upper quadrant abdominal pain), the absence of acid-peptic disease, and normal biliary sonography treated with laparoscopic cholecystectomy (LC) and transcholecystic cholangiography from 1991 to 1996. All patients had preoperative cholecystokinin-stimulated hepatobiliary scintigraphy (CCK-HBS). There were 42 women and 8 men with a mean age of 43 years. CCK-HBS was abnormal in 45 patients (< or = 35 per cent gallbladder ejection fraction or nonfilling of the gallbladder). There was no postoperative mortality and one morbidity (urinary retention). All patients had microscopic evidence of chronic cholecystitis. At mean follow-up of 30 months, (range, 7-62 months) 39 patients (78%) were free of abdominal pain. Thirty-five of 45 patients with abnormal CCK-HBS were pain free (positive predictive value, 0.78). Four of five patients with normal CCK-HBS were pain free (negative predictive value, 0.20). The positive and negative likelihood ratios for CCK-HBS were 0.99 and 1.13, respectively, confirming that this test was not useful for predicting benefit from LC. Seven patients with persistent right upper quadrant pain had abnormal postoperative sphincter of Oddi manometry; they improved after endoscopic sphincterotomy. Patients with symptoms typical of biliary colic with normal gallbladder sonography and absence of acid-peptic disease benefit from LC in the majority of cases. Those who remain symptomatic after LC may benefit from endoscopic retrograde cholangiopancreatography with sphincter of Oddi manometry and endoscopic sphincterotomy when manometry is abnormal.

Adult↗
PubMed1997

[Initial experiences with magnetic resonance endoscopy].

BACKGROUND: In contrast to endorectal surface coils used to assess pelvic tumors, the magnetic resonance endoscope (MR) has all the features of a standard endoscope. In ex-vivo imaging of the porcine gastrointestinal tract, endoscopic MR demonstrates distinct histological layers of the gastrointestinal wall. The aim of this study was to assess the feasibility and the accuracy of endoscopic MR in local staging of patients with esophageal and rectal cancer. METHODS: From April to August 1996, 12 patients (5 female and 7 male, mean age 63 [range 44-84] years) with histologically proven esophageal (n = 6) and rectal (n = 6) cancer prospectively underwent endoscopic ultrasound (EUS) followed by endoscopic MR. The two radiologists reviewing the endoscopic MR images were blinded to the EUS results. Assessment of T and N stages was compared to EUS and histology. RESULTS: Endoscopic MR was well tolerated in all patients and there were no complications. Image quality was sufficient in 75%. Endoscopic MR T-staging correlated with EUS and histology in 7/12 and 5/7 patients respectively. Discordance was due to overstaging by endoscopic MR. N-staging correlated with EUS and histology in 10/12 and 6/8 cases respectively. Non-correlation was due to a number of false negative results at endoscopic MR. CONCLUSION: These early results demonstrate endoscopic MR to be feasible and to produce comparable local staging to EUS in patients with esophageal and rectal cancer. The ultimate goal will be to combine endoscopic MR with body coil MR imaging (for the assessment of distant metastases) in order to provide "one-step staging" for the entire evaluation of gastrointestinal tumors.

Adult↗
PubMed1997

Magnetic resonance cholangiopancreatography: a novel approach to the evaluation of suspected pancreaticobiliary neoplasms.

BACKGROUND: Magnetic resonance cholangiopancreatography (MRCP) is a new noninvasive diagnostic method for pancreaticobiliary (PB) imaging without endoscopy, sedation, or iodinated contrast. The purpose of this study was to evaluate the ability of MRCP to depict pancreatic and biliary ductal anatomy compared to that of endoscopic retrograde cholangiopancreatography (ERCP) and to evaluate the ability of MRCP to accurately diagnose PB neoplasms. METHODS: Twenty patients had MRCP, and 17 also had ERCP. All studies were read prospectively by experienced reviewers blinded to other imaging data. Pathologic diagnosis was made in all patients. RESULTS: Bile duct dilatation seen by ERCP in 14 of 17 patients was correctly identified by MRCP in all 14 patients, and normal ducts were correctly identified by MRCP in the other 3 patients. The pancreatic duct was visible on MRCP in the pancreatic head in 17 of 20 patients, the body in 17 of 20 patients, and the tail in 15 of 20 patients. At ERCP, pancreatic duct dilatation was present in 11 cases and was identified by MRCP in 10 of them. Eighteen of 20 patients had malignant PB neoplasms. MRCP indicated PB neoplasm in 19 patients. Seventeen of these 19 patients had histologically confirmed malignant neoplasms pathologically, whereas 2 had benign pathology (both chronic pancreatitis). Among the 17 patients who also had ERCP, MRCP and ERCP correctly agreed on a final diagnosis of malignant neoplasm in 14 cases. In the three cases in which MRCP and ERCP disagreed on a final diagnosis, MRCP was correct in one and incorrect in two. CONCLUSIONS: MRCP can accurately and noninvasively delineate PB ductal anatomy and diagnose PB neoplasms comparably to ERCP. MRCP is an interesting new noninvasive method for evaluating patients with suspected PB neoplasms.

Bile Ducts↗