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Biomedical subjects

K Huibregtse

Publications and source records attributed to K Huibregtse.

At least 109 records · Page 6Linked to original sources
PubMed1990

Clogging of biliary endoprostheses: a new perspective.

Endoscopic palliation with biliary endoprostheses is now an established treatment for benign and malignant strictures of the biliary tree. These endoprostheses, however, tend to clog with time. We investigated this problem by undertaking in vitro studies on stents of different designs made of different polymer materials. The stent that performed best was then tested in an in vivo trial. There was a direct relation in vitro between the frictional coefficient of a polymer and the amount of encrusted material. Catheters perfused in bacterially contaminated bile, irrespective of material and design, accrued significantly more sludge than catheters perfused with sterilised bile. The presence of side holes significantly increased the amount of sludge in the stents, but eliminated any differences between the various materials. We therefore investigated the effect of omitting side holes in a clinical trial which consisted of two groups of 20 patients each. The group treated with conventional stents accrued significantly more sludge in the stents than the group treated with experimental stents without side holes (p less than 0.05). The absence of side holes did not cause incomplete drainage or increase morbidity. Side holes are detrimental to stent patency, which is adversely affected by other factors including bacteria and proteins.

Aged↗
PubMed1989

The mucosa of the gastric remnant harboring malignancy. Histologic findings in the biopsy specimens of 504 asymptomatic patients 15 to 46 years after partial gastrectomy with emphasis on nonmalignant lesions.

Endoscopic bioptic screening of 504 asymptomatic postgastrectomy patients, 15 to 46 years after initial surgery, revealed ten gastric stump cancers of which six turned out to be early cancers; three of the early carcinomas were found during follow-up after prior severe dysplasia. At first endoscopy mild dysplasia was found in 58, moderate dysplasia in 11, and severe dysplasia in none of the patients. Follow-up biopsies in 177 patients showed mild dysplasia in 30, moderate dysplasia in six, and severe dysplasia in six patients. Regression of severe dysplasia was not observed. Both progression and regression of mild and moderate dysplasia occurred. At the first endoscopy the frequency of atrophy, intestinal metaplasia, cystic dilatation of glands, and foveolar hyperplasia in the stomal biopsy specimens was 45%, 35%, 54%, and 47%, respectively; during follow-up, 47%, 48%, 56%, and 56% respectively. These four lesions were significantly more frequent in the biopsy specimens of patients with gastric carcinoma or dysplasia than in the other patients and they were present in the environment of the tumor in all the surgical specimens of the six early cancers detected by the screening. Preoperatively a combination of these four lesions could be demonstrated in only those early gastric cancer patients, in whom more than eight stomal biopsy specimens were taken. Of 34 patients with severe atrophy in three or more stomal biopsy specimens taken at the same time, two manifested early stump cancer during follow-up. Severe dysplasia is a marker of malignancy and demands close follow-up; the value of mild and moderate dysplasia is less clear. The combination of atrophy, especially severe atrophy, intestinal metaplasia, cystic dilatation, and foveolar hyperplasia in the biopsy specimens of a single patient may also point to increased cancer risk. It is advisable to obtain multiple biopsy specimens of the anastomosis, also because early gastric cancer may occur without a suspect macroscopic appearance.

Adolescent↗
PubMed1989

Endoscopic placement of expandable metal stents for biliary strictures--a preliminary report on experience with 33 patients.

The main problem with palliative treatment of extrahepatic cholestasis with an endoscopic biliary endoprosthesis is clogging. One of the factors thought to be of importance is the diameter of the stent. In order to avoid being limited by the size of the instrumentation channel of the endoscope, expandable stents have been developed. In this article we report on our preliminary clinical experience with an endoscopically placed expandable metal stent ("Wallstent") in 33 patients with extrahepatic bile duct stenoses. When fully expanded, the stent has a diameter of 30 F and a length of 6.7 cm. It was possible to successfully place a stent in every patient. Clinical improvement was achieved in all patients except one. Two patients underwent elective surgery, while one died of renal failure. Another died of septic shock after 5 weeks, but no autopsy was performed. In conclusion, our initial experience with this stent shows that at least in the short term biliary drainage was excellent, with no complications of pancreatitis or hemorrhage. Longer follow-up than our 4 weeks is necessary to establish the position of this stent in comparison with the conventional endoprosthesis in the management of obstructive jaundice.

Aged↗
PubMed1989

Early gastric stump cancer: macroscopic and microscopic appearance.

Six cases of early gastric stump cancer are presented. The clinical data and macroscopic and microscopic features are described in detail. All the early cancers were located near the gastro-enterostoma. All the carcinomas were of the intestinal type in accordance with Lauren's criteria, and of type II in accordance with the classification of the Japanese Gastroenterological Society. Two carcinomas were multicentric. No metastases were found. In 4 patients no suspicious lesion was found at the site of the carcinoma, stressing the importance of routine multiple biopsies even when no abnormalities are present. In 4 patients, severe dysplasia was found simultaneously with or prior to the carcinoma in one of the stomal biopsies, stressing the significance of severe dysplasia as a morphological marker for cancer. In addition, dysplastic changes were found surrounding the carcinoma in all the surgical specimens. All the patients are well and alive at least 4 years after resection of the carcinoma. All the carcinomas were found more than 20 years after the initial gastric operation. Early detection of gastric stump cancer is readily possible. Early gastric stump carcinoma has a good prognosis. Surveillance of gastric stump cancer can be intensified by identification of postgastrectomy patients with dysplastic mucosal alterations. Severe dysplasia in particular is a dependable marker for cancer.

Adenocarcinoma↗
PubMed1989

Resectional surgical procedures for carcinoma of the head of the pancreas.

Of a total series of 103 patients with preoperatively diagnosed carcinoma of the head of the pancreas (including ampullary carcinoma, carcinoma of the distal part of the common bile duct and pancreatic duct and acinar cell carcinoma), 78 underwent pancreatic resection. The remaining 25 had palliative surgical treatment, either a gastric or biliary bypass, and are not included in the present study. Three of the 78 patients who underwent pancreatic resection died, and ten patients required early reoperation. Predictive criteria could be formulated for the prognosis and outcome of the patients with carcinoma of the head of the pancreas. The most reliable index for survival time of the patients proved to be the radicality of the resection, which was directly related to the differentiation of the primary tumor. Forty-three of 48 patients who underwent radical resection are alive, with a survival time ranging from three to 49 months. Eleven of 23 patients who underwent palliative resection are alive, with a survival time ranging from two to 29 months. Of 44 patients with well or moderately differentiated adenocarcinoma who underwent radical resection, 38 are alive, with a survival time ranging from six to 41 months (mean of 29 months).

Adenocarcinoma↗
PubMed1988

Carcinoma of the ampulla of Vater: the endoscopic approach.

Carcinoma of the ampulla of Vater is a rare tumor. Early and accurate diagnosis of carcinoma of the ampulla of Vater will lead to early treatment and subsequent better prognosis. Endoscopy and endoscopic retrograde cholangiopancreaticography (ERCP) has been shown to be one of the best diagnostic modalities. Furthermore an endoscopic biliary drainage procedure can be performed immediately following the diagnostic procedure. The tumors may be seen as large, fleshy, friable exophytic growths, as ulcerated tumors into the duodenal wall or as a mass behind the orifice of the papilla, covered with normal duodenal mucosa. Forceps biopsies do not always suffice to show malignancy. Large snare biopsies often are necessary. Occasionally the final diagnosis of malignancy can only be made by examination of the surgical resection specimen. Tumors arising inside the ampulla form a bulge, covered by normal duodenal mucosa. An impacted stone may mimic this picture. Endoscopic papillotomy is then mandatory to make the final diagnosis. Histologic examination of forceps biopsies reveals malignancy in only 60% of cases. When snare biopsy is used, the diagnostic yield increases to 83%. The optimal treatment of carcinomas of the ampulla of Vater is surgical resection. Preoperative biliary drainage should theoretically be of benefit to the patient. The results of preoperative percutaneous drainage studies are, however, conflicting. Carcinoma of the ampulla of Vater is not resectable in 25-50% of the patients because of metastatic disease, deep extension of the tumor or general contraindications for major surgery. Endoscopic papillotomy or stent placement as a definitive treatment modality should be reserved for poor surgical candidates and for those patients with limited life expectancy due to metastatic disease.

Ampulla of Vater↗
PubMed1988

Mortality caused by stomach cancer after remote partial gastrectomy for benign conditions: 40 years of follow up of an Amsterdam cohort of 2633 postgastrectomy patients.

Mortality caused by stomach cancer was analysed in a cohort of 2633 postgastrectomy patients who underwent surgery for benign conditions in the academic medical centre of the University of Amsterdam between 1931-1960. In comparison with mortality from gastric cancer in the general Dutch population, the observed versus expected ratio in the postgastrectomy group was significantly increased among women, after a postoperative latency of more than 15 years (O/E: 4.77; p = 0.011) and among men after a postoperative latency of more than 25 years (O/E: 3.13; p = 0.005). The analysis confirms that the discrepancies in risk appraisal which seem to exist between reports published in Europe and the USA may be explained by the differences in length of follow up in these studies.

Adult↗
PubMed1988

Surgical approaches for unresectable primary carcinoma of the hepatic hilus.

Thirteen patients with proximal malignant obstruction of the biliary tract secondary to primary cholangiocarcinoma are presented. Seven of these patients had bilateral involvement of the major vessels of the porta hepatis, and 12 had bilateral involvement of the main hepatic ducts up to the level of segmental bifurcation. Resection of the tumor was carried out in all of the patients. Extensive resection of the liver with resection of the regional vascular structures was done in six. Another six underwent resection of the liver without resection of the regional vascular structures. The remaining patient underwent resection of the tumor and of the regional revascular structures alone. Vascular resection included resection and reconstruction of both the portal vein and hepatic artery in four patients or only of the portal vein in three. Biliary drainage was carried out by intrahepatic cholangiojejunostomies between segmental hepatic ducts and a Roux-en-Y loop. Two patients died and ten are alive. The quality of postoperative life is satisfactory and the patients are free of sequelae and symptoms secondary to operation or disease. This approach is recommended for the management of a number of patients with bilateral vascular or biliary involvement secondary to primary cholangiocarcinoma of the porta hepatis. For those patients, this approach offers a promising alternative.

Adenoma, Bile Duct↗
PubMed1987

Carcinoma of the ampulla of Vater. The role of endoscopic drainage.

Endoscopically placed biliary endoprostheses were used to treat obstructive jaundice in 71 patients with ampullary carcinoma. Successful placement of an endoprosthesis was achieved in 68 patients (95.8%). Bilirubin declined in 67 patients (98.5%). There was no procedure-related mortality. Twenty-two patients (31%) received further surgical therapy, and 47 received an endoprosthesis as their only therapeutic intervention. In the latter group, bilirubin normalized in 44 of 46 patients surviving longer than 30 days (95.7%). Mean survival was 466 days (median 410, range 23-1515), which compares favorably with surgical palliation. Complications mainly involved clogging of the endoprosthesis, which was easily treated endoscopically and, more significantly, duodenal stenoses secondary to continued tumor growth in almost 25% of the patients. Although endoscopic drainage is a safe and effective method of relieving biliary obstruction in patients with ampullary carcinoma, we feel it should be reserved for poor surgical candidates and for those patients with a limited life expectancy due to metastatic disease.

Adenocarcinoma↗
PubMed1987

Endoscopic palliation of jaundice in gallbladder cancer.

Endoscopically placed biliary endoprostheses were used to treat obstructive jaundice in 64 patients with advanced or recurrent gallbladder carcinoma. Successful placement of an endoprosthesis was achieved in 55 patients (86%). Bilirubin declined in 52 of 55 cases (94.5%) and normalized in 37 of 44 patients (84%) who survived more than 30 days. Procedure-related mortality was 3.1%. The thirty-day mortality of 14.5% was better, and the mean overall survival of 161 days was comparable to published surgical results. Due to the lower cost, improved patient tolerance, and reasonable survival, we consider endoscopic drainage to be the procedure of choice in patients with obstructive jaundice secondary to recurrent and unresectable gallbladder cancer.

Aged↗
PubMed1987

Characterization of the content of occluded biliary endoprostheses.

In an attempt to establish why biliary endoprostheses clog we analysed the contents of 21 occluded endoprostheses. The major components of the endoprosthesis sludge were protein (25%) and an insoluble residue (20%) which consisted mainly of plant fibers. Compared with bile the material was also rich in unconjugated bilirubin, while the major components of bile--bile acids and lecithin--accounted for only 15%. Although the sludge often contained some cholesterol crystals, no cholesterol gallstones or pigment or mixed stones were found. The material contained bacteria, but not in abundance. Scanning electron microscopy of the walls of clogged endoprostheses revealed adherence of amorphous material, probably protein. SDS-polyacrylamide gel electrophoresis of the protein fraction of the material from different endoprostheses showed a characteristic pattern. The material always contained two major bands of approximately 16 and 13 kDalton, which were not observed in corresponding bile samples. The 16 and 13 kDalton proteins bound most avidly to the endoprosthesis wall. We postulate that the initial phase in the clogging process is adsorption of proteins, after which other materials such as bacteria, fibers from food and unconjugated bilirubin bind to the wall of the endoprosthesis.

Bile Acids and Salts↗
PubMed1987

Different response to preliminary biliary drainage in proximal versus distal malignant biliary obstruction.

This study assessed prospectively the results of endoscopic biliary drainage preoperatively in 40 patients with extrahepatic malignant biliary obstruction. The patients were divided into two groups depending upon the location of the obstruction. Those in group 1, n = 20, were patients with proximal malignant obstruction and those in group 2, n = 20, had distal malignant biliary obstruction. Preliminary endoscopic biliary drainage succeeded in lowering the biliary pressure and the incidence of bacteremia in patients in group 2. In contrast, for those in group 1, it failed to reduce the intrabiliary pressure and, thus, in the presence of bile infection led to an increased incidence of bacteremia. From the results of the present study, preliminary endoscopic biliary drainage is recommended for patients with distal malignant biliary obstruction. For those with proximal malignant biliary obstruction, surgical drainage appears to be the method of choice.

Adolescent↗
PubMed1986

Upper intestinal and biliary tract endoprosthesis.

The endoscopic insertion of an endoprosthesis is now a standard procedure in the ultimate palliation of malignant obstructing upper gastrointestinal and biliary malignancy. The commercially available prostheses and introducing devices are adequate for the majority of upper intestinal cancers. For some stricturing lesions, especially when associated with fistula formation, individual adaptation of a tygon prosthesis with extra widening rings is often necessary. Nd: Yag laser vaporisation of mainly exophytic cancerous tissue is mainly indicated for those circumstances which are less amenable to prosthesis insertion such as total luminal obstruction, noncircumferential tumorous involvement, polypoid cancers, excessively necrotic and chronically bleeding tumors, lesions extending within 2 cm of the upper esophageal sphincter, markedly angulated cancers of the cardia with almost horizontal tube positioning and cancerous overgrowth occluding the funnel opening. Overall successful insertion occurs in over 90% of patients. Main complications are perforation 5-8% and early or late dislocation. The procedure related mortality fluctuates around 2 to 4%. Overall results with laser application are roughly comparable. The dysphagia free intervall after laser is only around 6 weeks for the majority of the patients. Transpapillary insertion of a straight Amsterdam-type prosthesis rapidly became a standard procedure for palliation of malignant jaundice. For many patients with pancreatic cancer this endoscopic approach competes favorably with corresponding surgical palliative alternatives. Disappearance of jaundice is to be expected in the vast majority of the patients. The only major unsolved problem remains late clogging with biliary sludge which necessitates insertion of new prostheses. Most problematic to breach are bifurcation tumors. Cholangitis is a major complication if one does not succeed at the first attempt to drain both liver lobes.

Biliary Tract Neoplasms↗