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Biomedical subjects

R H Hawes

Publications and source records attributed to R H Hawes.

At least 127 records · Page 7Linked to original sources
PubMed1995

The problem fellow.

Problems encountered in training GI fellows range from illnesses that affect patient care (impaired physician) to problems in the timely acquisition of the technical, cognitive, and personal skills required to perform endoscopy competently and independently. The key for fellowship programs in addressing potential problems is to develop a system that monitors fellows and provides regular feedback along with early intervention. The existence of such a program will benefit the program, the fellows, and the public.

Clinical Competence↗
PubMed1995

Endoscopic retrograde cholangiopancreatography in pregnancy.

BACKGROUND: Pancreaticobiliary disease in pregnancy is relatively uncommon. The frequency of choledocholithiasis in pregnancy requiring intervention has been reported to be as low as one in 1200 deliveries. Traditionally, intervention in these patients has been surgical. Although surgery has an overall low morbidity and mortality for the expectant mother, it carries with it a 4- to 6-wk recovery period and a possibly increased risk of fetal wastage. Published information regarding the role and safety of ERCP in pregnancy is limited. This series of 23 pregnant patients undergoing ERCP was collected from six different medical centers. METHODS: Twenty-three pregnant patients with symptomatic pancreaticobiliary disease underwent a total of 29 ERCPs (three patients had diagnostic ERCP, and 20 had therapeutic ERCP). Fifteen, eight, and six procedures were performed in the first, second, and third trimesters, respectively. The only ERCP complication was pancreatitis in one patient. There was one spontaneous abortion (3 months after ERCP) and one neonatal death; however, casual relationship to ERCP was not apparent. CONCLUSION: Diagnostic and therapeutic ERCP appears reasonably safe and effective in pregnancy. Cautious and selective use of this procedure offers a viable alternative to surgery or observation in patients with emergent pancreaticobiliary problems.

Adult↗
PubMed1995

Endoscopic ultrasonography of the pancreas.

The pancreas is the most technically demanding area to image with EUS. This technique, however, has found a clinical niche in evaluating patients with pancreatic cancer to determine resectability and likely will play a prominent role in the future in diagnosis through ultrasonographically directed FNA. Its role in localization of neuroendocrine tumors is established as long as preoperative localization is important in management. It is unlikely that a competing technology will develop in the near future with resolution the same or better than EUS. The role of EUS in the evaluation of early chronic pancreatitis is still under investigation, but it is likely that it can play a role adjunctive to ERCP. If FNA can be demonstrated to be safe and the interpretation of the cytology is accurate, then EUS could play an important role in this area. In the future, EUS may be used to acutely aspirate pancreatic pseudocysts and potentially could be useful in differentiating pseudocysts amenable to endoscopic drainage versus those that would be managed best by percutaneous or surgical drainage. With some design modifications, it may be feasible in the future to use ultrasonographic guidance to puncture pseudocysts and then place nasocystic drains or internal stents. These areas will need further investigation and further technological development.

Biopsy, Needle↗
PubMed1995

Endoscopic ultrasound and clinical competence.

The last few years have seen substantial growth in technology, research, and performance of endoscopic ultrasound. Unfortunately, opportunities for training in EUS have not kept pace with this growth. To improve the breadth and quality of training in EUS, resources will need to be channeled in two directions. One is the development of endoscopic ultrasound training programs in academic centers. These would provide the expertise and the number of patients necessary to train selected GI fellows in EUS. The second direction is toward development of systems for retraining of physicians already in practice. We believe that this would require the development of EUS simulation systems combined with a short, intense, hands-on training in centers of excellence. How fast these training systems will develop is dependent upon market forces. If the information provided by EUS can be proven to reduce costs and if the results improved patient's quality of life, the development of training programs for EUS would accelerate markedly.

Clinical Competence↗
PubMed1994

Gallbladder ejection fraction and its relationship to sphincter of Oddi dysfunction.

Theoretically, relative distal common bile duct obstruction due to sphincter of Oddi dysfunction may be a cause of poor gallbladder evacuation observed on quantitative cholescintigraphy. In this study, the relationship of sphincter of Oddi dysfunction to the gallbladder ejection fraction by quantitative cholescintigraphy was explored. Eighty-one patients with biliary-type pain and otherwise normal evaluations underwent quantitative cholescintigraphy, sphincter of Oddi manometry, and ERCP. Abnormalities of stimulated quantitative cholescintigraphy and/or sphincter of Oddi manometry were present in 70% of this study group. Manometric evidence of sphincter dysfunction was present in patients with similar frequency irrespective of the degree of gallbladder evacuation. In conclusion, abnormalities of quantitative cholescintigraphy and sphincter manometry appear to be independent factors, although frequent findings in this patient population.

Adolescent↗
PubMed1994

The yield of a second screening flexible sigmoidoscopy in average-risk persons after one negative examination.

BACKGROUND/AIMS: The American Cancer Society recommends that asymptomatic persons aged > or = 50 years undergo sigmoidoscopy every 3-5 years. However, the yield of a second examination 3 years later in persons who are initially negative is unknown. The aim of this study was to determine the yield of a second flexible sigmoidoscopy in average-risk persons aged > or = 50 years after an initial negative examination. METHODS: Two hundred fifty-nine asymptomatic, average-risk persons who had undergone a negative screening flexible sigmoidoscopy examination at age > or = 50 years underwent a second examination at least 2 years later (mean, 3.4 years). RESULTS: The second examination found adenomas in 15 (6%) screenees, but no cancers or large (> 1 cm) or severely dysplastic adenomas were detected. Persons aged > or = 60 years at the time of the second examination were more likely (10%) to have adenomas than those < 60 years (3%) (odds ratio, 3.76; 95% confidence interval, 1.17-12.2), but no advanced lesions were found in persons aged > or = 60 years. CONCLUSIONS: These data suggest that the American Cancer Society should consider changing its recommendation for screening flexible sigmoidoscopy in asymptomatic, average-risk persons to 5-year intervals after a negative examination.

Adenoma↗
PubMed1994

High-intensity focused ultrasound.

High-intensity focused ultrasound (HIFU) is a technology that permits the use of ultrasound waves used for imaging and then focuses them as one would use a magnifying glass to focus sunlight. The ultrasound energy is absorbed by tissue and converted to heat and can be used to ablate tissue. This article summarizes the technology, mechanism of action, technique, and early clinical results of HIFU, then concludes with some potential future applications of this technology.

Humans↗
PubMed1993

New staging techniques. Endoscopic ultrasound.

Rectal ultrasonography allows detailed images of rectal tumors and provides the most accurate method of staging rectal cancer. Ultrasound assessment of the extent of tumor invasion and lymph node involvement is superior to computed tomography (CT) scan, though CT is still the best method to assess liver involvement. Ultrasound assessment of cancers above the peritoneal reflection is less useful clinically because it currently does not alter management. Outcome studies have not been reported using ultrasound to stage rectal cancer but should be forthcoming. Inflammation present at the leading edge of the tumor is the greatest cause for overstaging, and difficulty in determining tumor involvement into, but not through, the muscularis propria is another important cause of inaccurate staging. Lymph node assessment can be problematic, but future developments in ultrasound-guided fine-needle aspiration cytology holds promise for more accurate assessment of lymph node status. Surgery will remain the standard method to treat rectal cancer, but new methods, such as high-intensity focused ultrasound, may provide new ways to treat some patients.

Colonic Neoplasms↗
PubMed1993

Endoscopic retrograde cholangiography and laparoscopic cholecystectomy: stones, stents and sphincterotomy.

Endoscopic retrograde cholangiopancreatography (ERCP) is clearly a useful adjunct in the management of patients undergoing laparoscopic cholecystectomy who have common bile duct stones. Whether endoscopic sphincterotomy plus laparoscopic cholecystectomy is superior to traditional open cholecystectomy and bile duct exploration is a question which remains to be answered by prospective, randomized trials. The immense popularity of laparoscopic cholecystectomy may prohibit such a study in the USA. In expert hands, endoscopic stone extraction is usually successful, so ERCP can be deferred until after cholecystectomy unless there is serious suspicion of a duct stone preoperatively. Actual clinical practice will depend, however, on the skill of the surgeon, the skill of the endoscopist, and the commitment to removing the gallbladder laparoscopically. It would seem prudent for surgeons to continue to direct their energy toward conquering the common bile duct via the laparoscope, and leave ERCP and stone extraction in the realm of the endoscopist who has been extensively trained in this difficult technique. Proficiency at ERCP, sphincterotomy and stone extraction requires considerable training, and the procedure should not be attempted by individuals who have performed fewer than 100 ERCPs and 25 individually supervised sphincterotomies, according to the ASGE Standards of Training, 1992. As experience with video endoscopic surgery increases and technology improves, it will become possible to remove most duct stones at the time of cholecystectomy, thus obviating the need for endoscopic sphincterotomy. In addition, ERCP should be regarded as the treatment of choice for postoperative cystic duct stump leaks. Studies have shown that any type of biliary decompression, i.e. sphincterotomy, stents or nasobiliary catheters, will be successful. The authors recommend that, in the absence of duct stones, stenting or nasobiliary catheters be used as they are less invasive. Bile duct leaks may also be managed endoscopically, but success depends on the individual characteristics of the duct injury. The decision to manage late onset strictures endoscopically should be individualized, and consideration of local endoscopic expertise, operative risk, interval between surgery and stricture, and the patient's wishes should be made.

Bile Ducts↗
PubMed1993

Prospective evaluation of endoscopic ultrasonography and endoscopic retrograde cholangiopancreatography in patients with chronic abdominal pain of suspected pancreatic origin.

Twenty asymptomatic paid volunteers (13 females, 7 males, mean age 34 years, range 21-52 years), underwent endoscopic ultrasonography (EUS) to assess variation in the appearance of ductular and parenchymal features of the pancreas. Following this investigation, 69 patients with chronic abdominal pain of suspected pancreaticobiliary origin were evaluated with EUS followed by endoscopic retrograde cholangiopancreatography (ERCP) and in 16 patients secretin stimulated intraductal pure pancreatic juice (PPJ) collection. Thirty patients were found to have chronic pancreatitis based on clinical, ERCP and/or PPJ data, and EUS was abnormal in 24 of these individuals. All of the 19 patients with abnormal pancreatograms also had an abnormal EUS. Twenty-two of the 30 patients with chronic pancreatitis had early disease (no or minimal changes on ERCP). In this subgroup of patients, the sensitivity of EUS was 86% versus 50% for ERCP (p = 0.01). For all patients, the sensitivity, specificity and accuracy of EUS in diagnosing chronic pancreatitis was 80%, 86% and 84% respectively. Using logistic regression analysis eight EUS features were found to be indicative of chronic pancreatitis including echogenic foci within the gland, focal regions of reduced echogenicity within the gland, increased thickness/echogenicity of the main pancreatic duct (MPD) wall, accentuation of the gland's lobular pattern, cysts, an irregular contour or dilation of the MPD and side branch dilation (p < or = 0.05). Generation of a receiver operating characteristic curve to assess the sensitivity and specificity of EUS in diagnosing chronic pancreatitis based on the number of abnormal findings demonstrated that sensitivity and specificity were optimal when three or more abnormal parenchymal and/or ductular features were found. These results suggest that EUS can play an adjunctive role to ERCP and PPJ in the diagnosis of early chronic pancreatitis.

Abdominal Pain↗
PubMed1993

Colonic adenomas in asymptomatic women with a history of breast cancer.

One hundred ninety-three asymptomatic women with a personal history of breast cancer underwent screening colonoscopy. One hundred sixty-eight women had breast cancer as their only potential risk factor for colonic neoplasia, and 25 had a family history of colorectal neoplasia in addition to their personal history of breast cancer. Among women with breast cancer, increasing age and body weight were each predictive of an increasing prevalence of colonic adenomas. The prevalence of colonic adenomas in women aged 50-75 yr whose only potential risk factor was breast cancer was 18%, and was identical to the prevalence of colonic adenomas in 186 asymptomatic average-risk control women aged 50-75 yr (odds ratio 1.0, 95% CI 0.54-1.87). We conclude that a personal history of breast cancer does not predict a higher prevalence of colonic adenomas.

Adenoma↗
PubMed1993

Colonic neoplasia in asymptomatic persons with negative fecal occult blood tests: influence of age, gender, and family history.

Six hundred twenty-one asymptomatic persons with negative fecal occult blood tests (ages 50-75 yr), including 496 with no known risk factors for colorectal cancer and 125 with a single first-degree relative with a history of colonic neoplasia developed after age 40, underwent screening colonoscopy. Three Dukes A cancers were detected in average-risk persons. The overall prevalence of adenomatous polyps was 27%. Multiple logistic regression analysis revealed that increasing age and male gender were both strong predictors of colonic neoplasia (p < 0.001). A positive family history of a single first-degree relative with colorectal cancer was not associated with an increased prevalence of colonic neoplasia (p = 0.29), although an effect may be present if the relative was < 60 yr at diagnosis. Overall 16% of males and 7% of women > or = 60 yr had at least one adenoma that was large (> or = 1 cm in size), villous or tubulovillous, or had grade 3 dysplasia. We conclude that the prevalence of colonic neoplasia in asymptomatic persons with negative fecal occult blood tests is substantial, particularly in elderly males. A family history of a single first-degree relative diagnosed at age > or = 60 yr with colorectal cancer is not associated with an increased prevalence of colonic adenomas.

Adenoma↗
PubMed1992

Comparison of intraoperative and endoscopic manometry of the sphincter of Oddi.

Despite the potential utility of intraoperative manometry of the sphincter of Oddi, limited data are available validating its use. The current study was undertaken to validate the method of intraoperative sphincter of Oddi manometry by comparing the pressure tracings obtained at operation (transduodenal sphincteroplasty and transampullary septoplasty) and endoscopy (preoperative) in the same group of patients. Seventy-four patients with idiopathic pancreatitis or unexplained disabling pancreaticobiliary pain had sphincter of Oddi manometry performed endoscopically and intraoperatively within six weeks of each other. Thirty-five patients had manometric evaluation of the bile duct segment of the sphincter of Oddi. The mean basal sphincter pressure determined endoscopically and intraoperatively was 41.1 +/- 6.4 millimeters of mercury (mean plus or minus standard error of the mean) and 42.0 +/- 6.8 millimeters of mercury (not significantly different, p > 0.05), respectively. There was no significant difference between the biliary sphincter phasic pressure, phasic frequency and phasic duration, as recorded by the two techniques. Fifty-five patients had manometric evaluation of the pancreatic duct sphincter. The mean basal sphincter pressure determined endoscopically and intraoperatively (after biliary sphincteroplasty) was 111.9 +/- 9.9 millimeters of mercury and 102.7 +/- 8.7 millimeters of mercury, respectively (not significantly different, p > 0.05). There was no significant difference in the pancreatic sphincter phasic duration and phasic frequency determined by the two techniques. However, the pancreatic sphincter phasic pressure was significantly higher when measured endoscopically (p < 0.001). Overall, 70 percent of patients benefited from surgical sphincter ablation therapy. Patients with an elevated basal sphincter pressure determined intraoperatively were more likely to improve than those with a normal basal sphincter pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Laparoscopic cholecystectomy and ERCP with sphincterotomy in an elderly patient with situs inversus.

Situs inversus viscerum (transposition of the viscera) is a rare condition with a genetic predisposition that is autosomal recessive. We present a patient with situs inversus, cholelithiasis, and choledocholithiasis who was successfully treated via laparoscopic cholecystectomy and endoscopic retrograde cholangiopancreatography with sphincterotomy. This paper further expands the application of these techniques and shows that they can be safely and effectively applied in the setting of situs inversus, although attention must be paid to the details of left-right reversal.

Aged↗
PubMed1991

Screening colonoscopy in asymptomatic average-risk persons with negative fecal occult blood tests.

Colonoscopy was performed on 210 asymptomatic average-risk persons, aged 50-75 years, who had negative fecal occult blood test results. Colonoscopy was complete to the cecum in 209 subjects. Fifty-three subjects (25%) had adenomas and two had cancer. All of the adenomas greater than or equal to 1 cm in size and both cancers occurred in subjects aged greater than or equal to 60 years. Fifty-one percent of subjects with adenomas and one with cancer had no neoplasms distal to the sigmoid-descending colon junction. One subject had a major postpolypectomy hemorrhage that stopped spontaneously. Screening colonoscopy, therefore, has a high yield for detection of neoplasms in asymptomatic average-risk persons aged greater than or equal to 60 years with negative fecal occult blood test results. The yield is low in persons aged 50-54 years and intermediate in persons aged 55-59 years.

Adenoma↗