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Biomedical subjects

L F Williams

Publications and source records attributed to L F Williams.

At least 19 recordsLinked to original sources
PubMed1991

Unexpected findings in gastrointestinal tract surgery.

We discussed the proper management of patients with asymptomatic lesions incidentally found during laparotomy for other problems. For common or important lesions, information about the natural history, significance, treatment guidelines, and possible risks or complications related to operations on such incidentalomas were given. Thus, we discussed gallstones, masses of the upper and lower gastrointestinal tract, and masses in solid organs, such as liver, ovaries, and pancreas.

Digestive System Diseases↗
PubMed1991

Variation in the size and number of stone fragments after gallbladder lithotripsy.

Ninety-four gallbladder ultrasound examinations were carried out in 11 patients at intervals for the first 40 days after lithotripsy. No dissolution or other active therapy was carried out during this time. Fragment size and number were measured to determine the postlithotripsy variability. Analysis of variance (ANOVA) showed no significant changes in fragment size or number over time. The changes in fragment size and number compared to the previous measurements were then evaluated. Again, ANOVA showed no significant changes between times. The average change in absolute size was 3.1 +/- 0.6 mm, and the average change in absolute number was 1.4 +/- 0.5. We conclude that fragment size and number as determined by ultrasound do not vary significantly with time during the first 40 days. The absolute size change measured to the nearest millimeter should be at least 4 mm to surpass the 95% confidence interval. Similarly, the absolute change in number should be at least 2 to be regarded as significant.

Analysis of Variance↗
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↗
PubMed1990

Changes in gallbladder volume do not affect cystic duct resistance.

To our knowledge, the relationship between gallbladder volume and cystic duct function has not been studied. We hypothesized that changes in gallbladder volume would influence cystic duct resistance. The effect of gallbladder volume changes on cystic duct resistance to both prograde (emptying) and retrograde (filling) steady-state flow was tested in 12 dogs under basal cholecystokinin-stimulated conditions utilizing a multiport catheter with a highly compliant balloon placed within the gallbladder fundus. Gallbladder volume was regulated by varying balloon volume from empty to just beyond physiologic distention. Cystic duct resistance was not affected by balloon volume under basal or stimulated conditions or by the direction of perfusate flow. This study demonstrated no relationship between gallbladder volume and cystic duct resistance and did not demonstrate a cystic duct sphincter mechanism at physiologic gallbladder volumes.

Animals↗
PubMed1990

Intrinsic nerves affect gallbladder contraction in the guinea pig.

Muscarinic antagonists block gallbladder contraction induced by cholecystokinin in vivo but have little effect on gallbladder muscle strips. This study examined the effect of neural blockade on cholecystokinin-octapeptide-induced contraction of the intact guinea pig gallbladder in vitro using cholecystokinin-octapeptide applied to the gallbladder serosa, the lumen, or both compartments simultaneously. Simultaneous cholecystokinin stimulation of both the lumen and serosa was the most potent stimulus to contraction, and the responses were significantly inhibited by atropine and tetrodotoxin. Cholecystokinin in the gallbladder lumen alone evoked contraction by a dose-dependent mechanism that was entirely blocked by atropine or tetrodotoxin. Serosal application of cholecystokinin was the least potent, resulting in contractile responses and low sensitivity to neural blockers comparable to effects reported in muscle strips. The results suggest that cholecystokinin can cause gallbladder contraction by stimulating muscle receptors, neural receptors, or both, and combined neural and muscular stimulation is the most potent contractile stimulus.

Animals↗
PubMed1990

The usefulness of small-bowel manometry in the diagnosis of gastrointestinal motility disorders.

Motility disorders of the gastrointestinal (GI) tract have traditionally been diagnosed by excluding mechanical small-bowel obstruction. In order to diagnose GI motility disorders in a positive fashion, small-bowel manometry was performed on 15 patients who were referred to the authors with intestinal motility disorders. Intestinal manometry was performed after first positioning a 200-cm multilumen tube into the small intestine. Ports located at 10-cm intervals were perfused with sterile water and connected to pressure transducers to record intraluminal pressures with a multichannel chart recorder. This low compliance water perfusion manometry system allowed examination of both fasting and postprandial motility. Intestinal manometry was able to assist in the diagnosis of two patients that had true mechanical small-bowel obstruction. One patient had a stenosis of the gastrojejunostomy and three patients had a functional gastric outlet obstruction secondary to a motility disorder in the Roux limb. One patient had a functional obstruction from a reversed jejunal loop and eight patients were identified as having intestinal pseudo-obstruction. We found intestinal manometry was a helpful adjunct in the diagnosis of GI motility disorders.

Adult↗
PubMed1989

Effect of low extracellular calcium on gallbladder contraction in vitro.

Increases in intracellular calcium ion mediate smooth muscle contraction, but the requirement for extracellular calcium availability during this process is unclear. We studied the intact guinea pig gallbladder in an organ bath to define the effect of low bath calcium on contractile responses to varying doses of cholecystokinin-octapeptide, histamine, and acetylcholine. The contractile responses to cholecystokinin-octapeptide and acetylcholine were dependent on the presence of calcium in the bath, with a 40-100% reduction in contraction when buffer with no added calcium was used. In contrast, the contractile response to histamine was unchanged when stimulation was carried out in low calcium buffer. The contractions of the guinea pig gallbladder induced by cholecystokinin-octapeptide and acetylcholine, but not histamine, appear to require near-physiologic levels of extracellular calcium.

Acetylcholine↗
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

Gastrointestinal tuberculosis: resurgence of an old pathogen.

Thirteen patients with gastrointestinal tuberculosis (GITB) were treated at our hospitals from 1977-1987. Ten of these patients were seen during the last four years. Three patients required operative intervention for management of complications of their disease. This review discusses the presentation, diagnosis, and operative management of GITB. The authors feel that the increasing prevalence of GITB noted in their institution is primarily the result of the growing prevalence of mycobacterium tuberculosis pneumonia across the nation. With the recent influx of patients from areas of endemic tuberculosis and the increasing number of immunosuppressed patients, a surge in the number of patients presenting with GITB is likely to occur in the United States. Surgeons must be conversant with the diverse clinical features and operative management of this disease.

Cecal Diseases↗
PubMed1989

Pancreatoduodenectomy with pyloric preservation for carcinoma of the pancreas: a cautionary note.

Radical pancreatoduodenectomy for treatment of pancreatic carcinoma has been the surgical standard of care for the past four decades. The recent popularization of pylorus-sparing pancreatoduodenectomy to treat benign pancreatic disease, because of its decreased morbidity and long-term nutritional consequences, has led to the use of this procedure in cases of pancreatic carcinoma. We report recent experience with three patients with pancreatic carcinoma in whom pyloric preservation would have compromised the potential chance for curative resection or compromised palliation because of occult spread of tumor to a region not resected with this new operative approach. Two patients had proximal, microscopic intramural spread of pancreatic adenocarcinoma within the duodenum or antrum--a mode of spread not previously reported with pancreatic carcinoma. Both patients had no other evidence of metastatic involvement, and both would have had positive surgical margins in a pylorus-sparing pancreatoduodenectomy. A third case demonstrates a true submucosal recurrence of pancreatic carcinoma after a pylorus-sparing pancreatoduodenectomy. It is debatable that any case demonstrating intramural spread within the duodenum could be cured with a standard Whipple resection as this may well represent another sign of incurability, like lymphatic or perineural spread, but it is clearly a major potential obstacle to palliation if submucosal recurrences occur as a result of the use of the pylorus-sparing pancreatoduodenectomy in cases of pancreatic cancer. The use of pylorus-sparing pancreatoduodenectomy in resectable pancreatic cancers must be viewed skeptically at this time.

Adenocarcinoma↗
PubMed1989

Pseudo-pseudo-obstruction. A clinically relevant concept.

Four patients with small bowel obstruction were treated nonoperatively after being misdiagnosed as chronic idiopathic intestinal pseudo-obstruction. Three patients with pseudo-pseudo-obstruction developed significant morbidity, and one patient died while being treated medically. Differentiation between pseudo-obstruction and mechanical obstruction can be difficult and may require laparotomy to establish the diagnosis. Intestinal manometry suggested a mechanical cause for obstruction in two patients and should be done in all patients that carry the diagnosis of intestinal pseudo-obstruction. Other clues to the diagnosis of intestinal pseudo-obstruction are discussed. Intestinal pseudo-obstruction is an uncommon disease that should not be a diagnosis of exclusion but should be diagnosed using historical, radiographic, manometric, pathologic, and operative data.

Aged↗
PubMed1988

Intraabdominal sepsis after hepatic trauma.

In a review of 58 patients who survived liver trauma seen at Boston City Hospital, 10 patients had 13 intraabdominal abscesses and 1 died from overwhelming sepsis. Multivariate analysis of risk factors revealed that the number of units of perioperative, postoperative, and total blood transfused were each highly significant (p less than 0.0001). Mode of injury, hepatic resection, gastrointestinal tract perforation, and the number of associated injuries were not significant risk factors when transfusion requirements were accounted for. Fever and leukocytosis were unreliable predictors of abscess formation. The available literature suggests a strong relationship between intraperitoneal bleeding and septic complications.

Abdomen↗
PubMed1988

Mesenteric ischemia.

Mesenteric ischemia secondary to vascular disease remains a significant problem in patients presenting with acute abdominal conditions, especially if they are elderly. Although rare, it is nevertheless an important and perhaps increasing cause of death or significant morbidity. Occasionally, it may be a mode of dying, but more often, it is the reason for death. Individual cases can manifest an almost overwhelming spectrum from chronic to acute, mild to catastrophic, arterial to venous, occlusive to hemodynamic, extensive to limited, or precisely diagnosed to accidentally found. Treatment principles are well defined, but continued refinement of supportive therapies of several types is occurring. In contrast, improved screening tests that can lead to early specific etiologic diagnosis remain at the experimental stage. Thus, good "clinical suspicion" is foremost and essential.

Abdomen, Acute↗
PubMed1988

Obstruction of the large and small intestine.

This article provides an overview of mechanical small and large bowel obstruction with emphasis on newer diagnostic and therapeutic surgical techniques. Small and large intestinal pseudo-obstruction is discussed with reference to its diagnosis and appropriate treatment.

Abdomen, Acute↗