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Biomedical subjects

L F Williams

Publications and source records attributed to L F Williams.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1988

Is total pelvic exenteration reasonable primary treatment for rectal carcinoma?

Total pelvic exeneration (TPE) is reasonable primary surgical therapy in select patients with large bulky locally invasive rectal cancers that can be removed en bloc. Many do not have either nodal or distant metastasis. Furthermore, TPE can be curative and often is palliative for similar lesions that are recurrent or nonresponsive to radiation therapy. Operative mortality rates should be under 10% and can be under 5% for primary cases. Although improvement in preoperative management and operative technique, especially with urinary conduits and postoperative care is clear, both early and late complications are significant. Unfortunately, preoperative identification of those patients requiring TPE rather than abdominoperineal or low anterior resection remains poor. Furthermore, recent improvements in techniques for pelvic slings to prevent small bowel entrapment and protection from irradiation or myocutaneous flaps to obliterate the massive dead space are not yet clearly established as preventors of either early or later complications.

Carcinoma↗
PubMed1988

Efficacy of computerized tomography in the preoperative staging of pancreatic carcinoma.

The increasing use of nonoperative methods for the diagnosis and palliative treatment of pancreatic cancer has placed greater emphasis on computerized tomography (CT) in staging of this malignancy. The present study was done to review our experience with CT in staging pancreatic cancer, specifically its efficacy in predicting lesions amenable to curative versus noncurative surgical treatment. Sixty six consecutive patients with pancreatic cancer who were considered potential candidates for surgical resection and who had preoperative CT scans over the 4-year period from 1982 through 1986 were studied. Preoperative CT scans were reviewed by a radiologist without knowledge of patients' surgical management. CT criteria for unresectable disease include hepatic and distant metastasis as well as evidence of locally advanced disease, including peripancreatic fascial extension, extension of tumor to locally contiguous structures, vascular encasement/invasion, and local lymphadenopathy. CT predicted resectability with a sensitivity of 75 per cent and a positive predictive value of 38 per cent. Unresectability was predicted with a sensitivity of 72 per cent and positive predictive value of 93 per cent. CT incorrectly predicted unresectable disease in three patients who had a curative resection. CT was most reliable when it predicted unresectability due to the presence of hepatic and/or distant metastasis. CT predicted unresectability with least sensitivity using criteria for locally advanced disease. Therapeutic decisions for nonoperative management of patients with pancreatic cancer based upon CT predictions of unresectable disease, especially predictions of unresectability solely on the basis of locally advanced disease, can not be recommended at this time.

Adenocarcinoma↗
PubMed1988

Hemorrhage from a Dieulafoy type ulcer of the colon: a new cause of lower gastrointestinal bleeding.

Massive bleeding from a submucosal artery and small mucosal erosion has been termed Dieulafoy's ulcer or Exulceratio Simplex. The condition was originally described in the stomach but there have been reports of three similar lesions found in the colon. A patient with massive bleeding from a submucosal artery in the ascending colon with complete angiographic and histologic examination is the fourth case reported in the literature. This lesion is identical to previous clinical and pathological descriptions of Dieulafoy's ulcers presenting in the stomach. This pathologic entity may exist in the colon and can cause massive bleeding. Diagnosis is by angiography and by pathologic confirmation of the lesion. Treatment is primarily surgical resection because the massive bleeding precludes colonoscopic control of bleeding. The differential diagnosis of massive colonic hemorrhage should include this lesion.

Arteries↗
PubMed1986

Efficacy of polyglycolic acid mesh sling in keeping the small bowel in the upper abdomen after abdominal surgery: a 12-month study in baboons.

The purpose of this study was to determine if a "sling" made of polyglycolic acid (PGA) would be a reliable method of preventing small bowel descent into the pelvis following abdominal surgery. Baboons were used, as they respond to infection and ambulate similarly to humans. Animals had the small bowel mobilized to the upper abdomen and had the PGA "sling" sewn into place. Documentation of small bowel position was evaluated by upper gastrointestinal series over the 12-month study. Small bowel descent into the pelvis was prevented by utilization of the PGA "sling." Animals were sacrificed and autopsied, and sections of small bowel were taken. There was no evidence of mesh, obstruction, sepsis, fistulae, or herniation in animals at autopsy. Small bowel sections were considered normal histologically. Utilization of PGA sling appears to be a safe and reliable method of preventing small bowel descent into the pelvis after abdominal surgery.

Abdomen↗
PubMed1986

Residents' experience in the surgery of trauma.

Performance of surgery for trauma is an important part of residency training, yet what constitutes an adequate exposure to trauma surgery is ill defined. A retrospective review of records at a metropolitan receiving hospital was carried out for the academic year 1981-1982. Of the 50,902 patients treated in the Emergency Room more than one third were seen by a surgical resident. During this period 1,651 patients were admitted to General Surgery with traumatic injuries; 193 (12%) required intensive care. Two hundred twenty-seven major operations were performed by the General Surgical Service. For each patient operated on, 56 were seen in the Emergency Room and six required admission for nonoperative care of their injuries. Furthermore, less than 50% of patients admitted to the I.C.U. required surgery. An adequate education in trauma must be based on a large experience in the nonoperative resuscitation, diagnosis, and treatment of trauma victims. Nevertheless, the number of cases performed as operating surgeon provides a useful means of evaluation experience in trauma. Thirty cases are suggested as an appropriate level of exposure to the surgery of trauma, yet only one third of applicants to the American Board of Surgery attained this level.

Boston↗
PubMed1985

Increases in gallbladder prostaglandin synthesis before the formation of cholesterol gallstones.

Increased synthesis of prostaglandins in the wall of the gallbladder may play a role in the pathogenesis of cholesterol gallstones by mediating mucus hypersecretion and thereby accelerating nucleation and the precipitation of cholesterol-supersaturated bile. We induced gallstones in prairie dogs and guinea pigs by feeding a cholesterol-supplemented diet for periods as long as 6 weeks. Gallbladder prostaglandin synthesis was quantitated by specific radioimmunoassays that measured the amount of various prostanoids released from the gallbladder during in vitro incubation. The gallbladders of cholesterol-fed prairie dogs showed increased synthesis of prostaglandin E2, prostaglandin F2a, and thromboxane and increased concentrations of glycoprotein in gallbladder bile. These changes were evident as early as 2 weeks after institution of the cholesterol diet, although cholesterol gallstones did not form until 4 or more weeks. In contrast, cholesterol feeding of the guinea pig did not induce cholesterol supersaturation. In this species pigment gallstones formed, probably as a result of a cholesterol-induced hemolytic anemia, and gallbladder mucus hypersecretion did not occur. Pigment gallstone formation in the guinea pig was associated with an increase in prostacyclin synthesis, but the synthesis of prostaglandin F2a and thromboxane was decreased. Increased prostaglandin synthesis may contribute to the formation of cholesterol gallstones but does not appear to participate in pigment gallstone formation.

Animals↗
PubMed1984

Signet ring carcinoma of the pancreas, a rare variant with very high CEA values. Immunohistologic comparison with adenocarcinoma.

Signet ring carcinoma of the pancreas is rare. We report a case which was remarkable for (1) diffuse, infiltrating growth which suggested chronic pancreatitis at laparotomy, and (2) an associated very high circulating carcinoembryonic antigen (CEA) level of 6400 ng/ml. The case report and autopsy are presented. Twelve other cases of pancreatic adenocarcinoma (non-signet ring) are compared with the signet ring carcinoma with respect to CEA staining and circulating levels. We conclude immunocytochemical staining of biopsy tissue for CEA is a useful adjunct in the interpretation of circulating CEA levels in pancreatic carcinoma.

Adenocarcinoma↗
PubMed1984

Effect of dietary cholesterol and indomethacin on cholelithiasis and gallbladder motility in guinea pig.

This study examines the effects of dietary cholesterol and subcutaneous indomethacin on gallstone formation, gallbladder motility, and bile composition in guinea pigs. Guinea pigs on cholesterol diets developed gallstones which were not primarily composed of cholesterol and were not prevented by indomethacin. Animals receiving cholesterol diets showed significant gallbladder enlargement which was inhibited by indomethacin. Cholesterol did not alter gallbladder pressure-volume relationships or the response to CCK, while indomethacin diminished gallbladder tone. Although cholesterol feeding did not appear to alter smooth muscle contractility in the guinea pig gallbladder, it caused significant gallbladder enlargement by a mechanism which may be dependent on prostaglandins.

Animals↗
PubMed1984

Amino acid clearance and prognosis in surgical patients with cirrhosis.

To measure the effects of cirrhosis on amino acid (AA) flux and to assess the value of the central plasma clearance rate of amino acids (CPCR-AA) as a hepatocyte function test, 35 patients with cirrhosis were studied before and after operation. Fourteen of these patients died after the operation. CPCR-AA measures the number of milliliters of plasma cleared of AA per minute by the liver and other visceral tissues. It is the ratio of AA entry rate into plasma (from peripheral tissues plus infusion) to the arterial AA plasma concentration. Preoperative CPCR-AA measurements in 21 fasted patients with cirrhosis who were not infected revealed a pattern of AA plasma concentration and exchange similar to that previously observed in patients with sepsis with normal liver function. Whereas the concentration of AA in both groups was slightly lower than normal, the CPCR-AA of each was more than four times that of normal postabsorptive people (p less than 0.01). However, preoperative values of CPCR-AA in patients with cirrhosis who survived was 220 +/- 26 ml/M2/min while that in those who died was 97 +/- 16 ml/M2/min (p less than 0.001). Postoperative measurements remained relatively unchanged: survivors 212 +/- 24 ml/M2/min and those who died 89 ml/M2/min (p less than 0.0005). Measurements in vitro of the hepatic protein synthetic rate in liver biopsy specimens taken at operation correlated well with CPCR-AA values obtained immediately before operation in 10 patients (r = 0.73; p less than 0.01). Thus in patients with cirrhosis visceral amino acid uptake and hepatic protein synthesis are maximally stimulated. Nevertheless, if the preoperative CPCR-AA does not approach the value of 284 +/- 76 ml/M2/min previously observed in patients with sepsis who recover, the patient with cirrhosis is prone postoperatively to die of overwhelming infection and multisystem failure.

Amino Acids↗