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Biomedical subjects

W C Chapman

Publications and source records attributed to W C Chapman.

67 records · Page 4Linked to original sources
PubMed1993

Comparison of laparoscopic cholecystectomy with open cholecystectomy in a single center.

In this retrospective study, we compared the results of 1,283 open cholecystectomies (OCs) performed at our medical center during the pre-laparoscopic era with 1,107 laparoscopic cholecystectomies (LCs) performed from 1990 to 1992. There was no difference in the percentage of cases of acute and chronic cholecystitis in each time period (16.8% in each), nor were there differences in the patient characteristics for each group. The percentage of patients undergoing intraoperative cholangiography was similar for patients with chronic cholecystitis for each period, although the incidence of abnormal cholangiograms was lower in the laparoscopic era (5.8% versus 15.2%, p < 0.001). There was one bile duct injury in the OC group and three in the LC group (although one of these occurred after conversion ot an open procedure), but this difference was not statistically significant. However, there was a higher mortality rate in the patients with acute cholecystitis treated with OC (2.3% versus 0%, p = 0.03) and an increase in the overall complications in the patients with chronic cholecystitis in the OC group (7.5% versus 3.1%, p < 0.001) compared with the LC group. The increase in overall complications appeared to be primarily related to the increased rate of wound-related complications (3.6% versus 0%, p < 0.001) in the patients with chronic cholecystitis in the OC group. LC appears to be a safe procedure with a low incidence of complications including bile duct injury when performed by adequately trained surgeons.

Acute Disease↗
PubMed1993

Dysphagia lusoria: aberrant right subclavian artery with a Kommerell's diverticulum.

A retroesophageal right subclavian artery, the most common congenital aortic arch abnormality, is an unusual cause of dysphagia in adults. The embryologic abnormality of the aortic arch is involution of the fourth vascular arch, along with the right dorsal aorta, leaving the seventh intersegmental artery attached to the descending aorta. This persistent intersegmental artery assumes a retroesophageal position as it proceeds out of the thorax into the arm. Since compression of the esophagus by this right subclavian artery may produce dysphagia, the term "dysphagia lusoria" ("dysphagia by freak of nature"), has been used to describe the symptom complex. The presence of an aneurysm of the artery or Kommerell's diverticulum at its aortic origin is more likely to produce symptoms from esophageal compression. This case presents a middle aged adult with an associated Kommerell's diverticulum and dysphagia. Surgical correction was used to relieve his symptoms and to correct the diverticulum of the proximal right subclavian artery. The embryologic changes that occur are discussed in detail.

Aorta, Thoracic↗
PubMed1991

Pathophysiologic effects of biliary shockwave lithotripsy in a canine model.

At least 10 extracorporeal shockwave lithotripters are under investigation in the United States for treatment of biliary stone disease. Few reports, however, have documented the potential side effects of this new treatment method. In this study, we performed a series of acute and chronic studies in dogs exposed to varying numbers of shockwaves directed at the gallbladder wall via a transthoracic or transabdominal targeting approach. When shockwaves were directed transthoracically, pulmonary hemorrhagic contusions were found which were sometimes large in size. When a transabdominal approach was used, however, only focal areas of hemorrhage were found in the gallbladder wall and adjacent liver with no alterations in postlithotripsy pancreatic or liver enzymes, and normal cholecystokinin-octapeptide stimulated oral cholecystograms were obtained 6 days after treatment. Biliary shockwaves appear to cause few side effects under normal conditions but should be used with caution in patients with potential bleeding disorders. Until further studies are performed, lung tissue should be avoided in the shockwave beam path during treatment.

Abdomen↗
PubMed1991

Are new treatment methods of gallbladder stones the death-knell for gallstone surgery?

Recent advances in elective treatments for gallbladder (GB) gallstones (GS) provide so many options that we may be entering a new therapeutic era. Many of the 20 million Americans with GS are asymptomatic and do not need any treatment unless they are diabetic or cirrhotic, have a porcelain gallbladder, or can have an incidental cholecystectomy while undergoing an elective abdominal operation for other reasons. Therapy is required for significantly symptomatic gallstones and for complications of GS. With the development of so many options for nonoperative treatments, some predicted these would eclipse surgical cholecystectomy as the gold standards. However, such therapies are palliative and leave a "guilty" gallbladder in situ in the presence of lithogenic bile, circumstances inviting the recurrence of GS. The few selected patients for whom a general anesthetic represents an inordinate risk should be considered for biliary lithotripsy or percutaneous cholecystolithotomy, both of which can be done without anesthesia. When anesthesia does not present a risk, laparoscopic cholecystectomy, which incurs minimal disruption of a patient's normal function, has returned cholecystectomy to its position as the therapeutic gold standard for cholelithiasis. Complicated biliary anatomy or disease may dictate the need for traditional open cholecystectomy. However, most patients and referring physicians are demanding laparoscopic cholecystectomy even as this technique is evolving. Its risk for common bile duct injury is uncertain.

Bile Acids and Salts↗
PubMed1991

Ischemic colitis. An ever-changing spectrum?

Ischemic colitis, or more properly colonic ischemia, became a clear clinical entity in the past 25 years. Yet, early diagnosis of this disease with its various presentations remains a difficult task. A 10-year review at our hospital identified 38 patients with colonic ischemia for comparison with the authors' previous experience and with data from the literature. Several important factors emerge: (1) Twice as many cases occurred after operations (34% in this series vs. 16% in the past), probably because fewer and fewer spontaneous cases were hospitalized. (2) Sixteen patients required operative intervention for colonic ischemia with a mortality of 62 per cent, while those treated nonoperatively had a mortality of 14 per cent. Seven of eight postoperative patients who required a second operative procedure for their colonic ischemia died. A high clinical suspicion is necessary in the postoperative patient, as colonic ischemia appears to be more severe among these patients. Moreover, the high incidence of associated cardiovascular disease indicates that early diagnosis, as well as monitoring of the "at-risk" patient, is needed for improvement in survival to occur. New monitoring methods, such as tonometry, may help accomplish this goal.

Adult↗
PubMed1989

Alterations in biliary motility correlate with increased gallbladder prostaglandin synthesis in early cholelithiasis in prairie dog.

Abnormal biliary motility has been observed in humans with gallstones and in animal models; however, the mechanism by which these abnormalities occur remains unknown. In this study we investigated the relationship between cholesterol gallstone formation, changes in biliary motility, and rates of gallbladder prostaglandin synthesis in prairie dogs receiving a 0.34% cholesterol diet for two, four, or six weeks. Gallstones did not occur until four weeks, when the incidence was 14%; after six weeks the incidence was 64%. Gallbladder emptying increased slightly at two weeks before becoming significantly decreased at four and six weeks. In contrast, there was a near linear increase in basal cystic duct resistance which began by two weeks of cholesterol feeding, although sphincter of Oddi resistances remained normal throughout the period of study. The synthesis of prostaglandins E and F2 alpha by the gallbladder was also increased beginning at two weeks and rose to a plateau at four and six weeks. In view of the potent effects of prostaglandins on biliary smooth muscle, these findings suggest that prostaglandins may mediate early changes in gallbladder and cystic duct motility which ultimately result in impaired gallbladder emptying.

Animals↗
PubMed1989

Principles of biliary extracorporeal lithotripsy. Technical considerations and clinical implications.

After recent reports of the successful use of extracorporeal shock-wave lithotripsy for the treatment of gallstone disease, at least 10 different manufacturers have developed lithotripsy systems and initiated clinical trials in the United States. The three major types of lithotripters, classified by the method used to generate shock waves, are the spark-gap, piezoelectric, and electromagnetic systems. Although each type of system generates shock waves by different methods, all currently available systems appear to be able to fragment gallstones. However, there does not appear to be any system that has demonstrated clear clinical superiority in terms of either efficacy or safety. Additional information, both clinical and experimental, is needed before it can be determined if the type of shock-wave generator has a significant effect on outcome. Clearly more than the physical principles of shock-wave lithotripters must be evaluated.

Equipment Design↗
PubMed1989

Tumor seeding from percutaneous biliary catheters.

Percutaneous transhepatic biliary decompression has been used since 1973 as a preoperative surgical adjunct in patients with obstructive jaundice. Tumor seeding along the catheter tract is an unusual complication but it occurred recently in one of our patients who had preoperative biliary drainage for four days. Four months after his pancreaticoduodenectomy, a 2-cm nodule developed at the catheter exit site. This nodule was a metastatic focus of adenocarcinoma similar to his pancreatic tumor. He died 1 month later and at autopsy was found to have numerous metastases along the catheter tract. A review of the world literature found 17 other patients with this complication. Thirteen of the 18 total patients had catheters placed for palliation, while 5 patients underwent preoperative drainage before definitive procedures, and 4 of these patients had undergone "curative" resections. Nine of the 18 patients had biliary obstruction from cholangiocarcinoma, while seven patients had primary pancreatic carcinoma. Positioning of the catheter tip above the obstructing tumor and maintaining the catheter for only a short duration before operation (mean 8 days for resected patients, range 2 to 16 days) did not protect against catheter-related tumor seeding. Patients with suspected malignant obstruction of the biliary tract who may have resectable tumors should not undergo routine preoperative biliary decompression. If, on exploration, the tumor is found to be unresectable, then a palliative bypass may be performed.

Adenocarcinoma↗