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T K Tsang

Publications and source records attributed to T K Tsang.

At least 19 recordsLinked to original sources
PubMed1999

Silicone-covered metal stents: an in vitro evaluation for biofilm formation and patency.

Self-expanding metal stents are being used more commonly to prevent biliary tract obstruction. Silicone-covered self-expanding metal stents (Wallstent, Schneider, Inc.) have been developed to prevent tumor ingrowth. Biofilm formation and occlusion material in silicone-covered self-expanding metal stents compared to standard polyethylene stents were examined in an in vitro model. Matched pairs of polyethylene and silicone-covered metal stents were perfused with infected bile for 8, 12, and 16 weeks at a rate of 0.5 cc/min at 37 degrees C. Two reservoirs fitted with silicone-covered metal stents had ampicillin/sulbactam added and were perfused for 16 weeks. The stents were then analyzed by scanning electron microscopy and light microscopy for biofilm formation and presence of occlusion material. The two ampicillin/sulbactam-treated stents showed no biofilm formation. Biofilm was seen on all of the remaining stents. There was a difference in occlusion thickness between the 8- and 16-week polyethylene stents, and no difference between the biofilm thickness at 8, 12, or 16 weeks in the silicone-covered metal stents. Silicone-covered self-expanding metal stents will likely extend patency rates in malignant obstructive jaundice by providing a larger lumen for bile flow and allowing cyclical antibiotics to prevent bacterial biofilm formation.

Ampicillin↗
PubMed1998

Use of single percutaneous endoscopic gastrostomy in management of gastric volvulus in three patients.

Gastric volvulus is a rare condition that occurs when the stomach twists either in an organoaxial or mesenteroaxial direction. In patients with recurrent episodes of volvulus, standard therapy is surgical correction. Many patients, however, are not candidates for surgical therapy because of comorbid conditions or advanced age. Our aim was to determine if the insertion of a single percutaneous gastrostomy tube placement would assist in management of gastric volvulus in patients not able to undergo surgical therapy. The alpha-loop maneuver was used to reduce gastric volvulus in three elderly patients. A percutaneous endoscopic gastrostomy tube was then inserted to prevent recurrent volvulus. Single percutaneous gastrostomy tube placement was successful in managing volvulus in these three patients. Single percutaneous endoscopic gastrostomy tube placement is a useful treatment alternative to surgery in patients requiring therapy of gastric volvulus.

Aged↗
PubMed1997

Inhibition of biliary endoprostheses occlusion by ampicillin-sulbactam in an in vitro model.

An important first step in stent occlusion is the formation of a bacterial biofilm. This is followed by deposition of granules similar to that found in brown pigment stones. Previous in vitro models for studying occlusion have used synthetic biles without bilirubin or pooled human bile, which is limited in supply. Our aim was to develop a new in vitro model of stent occlusion with porcine gallbladder bile and then, with the model, assess whether ampicillin-sulbactam can prevent biofilm formation and thus occlusion. Sterile porcine gallbladder bile was contaminated with Escherichia coli then divided into eight reservoirs, four of which then received ampicillin-sulbactam. The bile was then circulated through 10F polyethylene stents. Bile was changed weekly for 8 weeks. In the stents that were untreated, biofilm and sludge were seen in all four, whereas the four ampicillin-sulbactam-treated stents had no biofilm when viewed by electron microscopy. Furthermore, the levels of calcium, cholesterol, and bilirubin in the reservoirs decreased significantly in the untreated bile as compared with the treated bile (p < 0.05). In this in vitro model, the losses of calcium, cholesterol, and bilirubin are likely caused by deposition of granules into the biofilm matrix. Ampicillin-sulbactam can prevent biofilm formation if used continuously.

Ampicillin↗
PubMed1997

Use of oral GoLytely solution in relief of refractory fecal impaction.

Constipation and fecal impaction are common disorders with multiple treatment options. We describe the use of GoLytely oral solution in 10 patients admitted to a community hospital and referred to a single gastroenterologist for fecal impaction refractory to conventional medical treatment. Seven women and three men received enemas, bisacodyl suppositories, and digital fragmentation either solely or in combination prior to the administration of GoLytely oral solution. The patients had no clinical and radiological evidence of bowel obstruction. All had underlying cardiovascular problems. Their mean age was 78.1 years (range 49-100 years). GoLytely oral solution (Braintree Laboratories, Inc.) was administered at a rate of 100 ml/hr per orem to three patients, via nasogastric tube in six patients, and via gastrostomy tube in one patient. All 10 patients were able to regularly pass feces and show radiographical colorectal clearing within 6.0 to 57.25 hr (mean 23.60 hr). No significant complications were observed. Eight patients were discharged from the hospital within 24 hr of termination of treatment while two patients remained for unrelated medical conditions. GoLytely oral solution effectively relieved fecal impaction in 10 patients refractory to conventional medical treatment.

Administration, Oral↗
PubMed1997

Effect of temperature on stability of eight components of porcine gallbladder bile.

Our aim was to evaluate the stability of eight components of porcine bile (pH, total and ionized calcium, total and unconjugated bilirubin, phospholipid, cholesterol, and bile salts) over a 17-day period at three temperatures: -15, 4, and 37 degrees C. The pH and concentrations of total and ionized calcium, phospholipid, cholesterol, and bile salts were stable over 17 days. Total bilirubin was stable at -15 degrees C, but declined over 17 days by approximately 25% at 4 degrees C and 70% at 37 degrees C (P < 0.003). A rapid increase in the unconjugated bilirubin was seen within two days at all temperatures to between 7.5 and 12 times the levels at day 0 (P < 0.009). Thereafter unconjugated bilirubin at -15 and 4 degrees C continued to increase at a much slower rate. By contrast, unconjugated bilirubin at 37 degrees C declined beginning on day 4 and fell to 1.33 times levels at day 0 by day 17 (P < 0.002). We conclude that bile can be stored at -15 degrees C for 17 days with stability of most components, but unconjugated bilirubin will rise. The loss in total bilirubin is significant at 37 degrees C.

Animals↗
PubMed1997

Volvulus of the small bowel: an uncommon complication after laparoscopic cholecystectomy.

We report here two patients with volvulus of the small bowel after laparoscopic cholecystectomy (LC). There has been only one case report of a similar condition after LC in the English literature; the patient had malrotation of the midgut. Both patients we are reporting had previous pelvic surgery resulting in intraabdominal adhesions. Volvulus had occurred along an axis between the mesenteric attachment and the adhesion to the parietal peritoneum of the involved loop of small bowel. The creation of pneumoperitoneum could conceivably allow rotation to occur. One patient presented with signs of peritonitis from a gangrenous segment of small bowel. The other presented with continued abdominal pain after surgery. Definitive diagnosis was made only at laparotomy. Previous surgery is considered a relative contraindication to LC, although the incidence of morbidity and conversion to open procedure appear not to be influenced by previous surgery. Surgeons should be aware of volvulus as a complication after LC in patients who had previous abdominal surgery.

Adult↗
PubMed1993

Hepatic dysfunction after repeated isoflurane administration.

Isoflurane, a halogenated volatile anesthetic, has not been associated with a distinct hepatic injury syndrome, as has halothane. Previous cases of suspected isoflurane-induced hepatotoxicity have been reported but questioned. We report the case of a patient without previous liver disease who developed repeated episodes of hepatitis after repeated exposures to isoflurane. Although no biopsy study was conducted, the temporal relationships illustrated in this case strengthen the argument for isoflurane-induced hepatotoxicity.

Chemical and Drug Induced Liver Injury↗
PubMed1990

Percutaneous-endoscopic biliary stenting in patients with occluded surgical bypass.

PURPOSE: The purpose of this investigation was to test the feasibility of using a recently developed technique of placing internalized biliary stents into patients who have had reobstruction after initial surgical bypass. PATIENTS AND METHODS: Seven men and three women, 46 to 85 years of age (eight with pancreatic carcinoma, one with metastatic colon, and one with metastatic ovarian carcinoma), all had reobstruction after initial surgical bypass palliation. Subsequent attempts to place stents via endoscope failed in five patients; a pair of 7-Fr stents placed in one patient failed to drain well. Endoscopic stenting in four patients was not even attempted because of severely distorted anatomy. Nine of the 10 patients then had successful internal stent placement by a combined percutaneous-transhepatic and peroral-endoscopically guided technique. RESULTS: One of these nine placeable stents failed to drain well and the patient died 8 days later with massive tumor. Seven showed a significant decrease in bilirubin levels and improved quality of life. Two of these had sepsis that responded to antibiotics. Life span ranged between 11 days and 10 months, with one patient still alive; no deaths were directly due to stents. CONCLUSION: A combined transhepatic-peroral technique of placing internalized biliary stents can be expected to result in repalliation in a majority of patients with reobstruction after earlier surgical bypass and in whom subsequent attempts at endoscopic placement of stents have failed or in whom tumor growth prevents undertaking the endoscopic approach.

Aged↗