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Biomedical subjects

S T Fan

Publications and source records attributed to S T Fan.

At least 145 records · Page 8Linked to original sources

Ruptured hepatocellular carcinoma as a complication of transarterial oily chemoembolization.

BACKGROUND: Transarterial oily chemoembolization (TOCE) is frequently employed as a non-operative treatment for hepatocellular carcinoma (HCC). Serious complications of TOCE are well known but ruptured HCC as a fatal complication of TOCE has not been reported previously. METHODS: A retrospective study was performed on all patients who received TOCE for treatment of HCC from January 1989 to October 1996; the complication of ruptured HCC within 2 weeks from the procedure was recorded. RESULTS: During the study period, 391 patients received a total of 1443 sessions of TOCE (mean 3.7 sessions per patient) for the treatment of HCC, with an overall median survival of 10.4 months. Six patients developed ruptured tumour within 2 weeks after TOCE, resulting in an overall incidence of 1.5 per cent per patient or 0.4 per cent per procedure. All except one patient died 1-25 days after tumour rupture. Factors common to these six patients included: (1) male sex; (2) large tumour size (range 8-17 cm in diameter); (3) tumour located in the right lobe of the liver; (4) tumour ruptured after the first session of TOCE; and (5) TOCE performed as primary treatment without previous hepatic resection. CONCLUSION: Ruptured HCC is a serious complication of TOCE although the incidence is low. It occurred predominantly in men after the first session of TOCE for a large irresectable tumour of the right lobe.

Carcinoma, Hepatocellular↗

Prolonged survival in selected patients following surgical resection for pulmonary metastasis from hepatocellular carcinoma.

BACKGROUND: Pulmonary metastasis is the commonest site of extrahepatic spread from hepatocellular carcinoma (HCC). The aim of the present study was to evaluate the efficacy of surgical management in patients with solitary pulmonary metastases from HCC. METHODS: This was a retrospective study of patients with HCC admitted for hepatectomy from July 1972 to June 1995. The records of patients who had a pulmonary resection for histologically proven pulmonary recurrence after curative hepatectomy were selected for analysis. RESULTS: In the study interval, 380 patients with HCC underwent hepatectomy. Some 48 patients (12.6 per cent) developed pulmonary metastases documented pathologically or radiologically. Nine (seven men and two women) were suitable for curative pulmonary resection. The median disease-free survival between hepatectomy and appearance of the lung metastasis was 21 months. The median survival after pulmonary resection was 42 months, and the 1-, 2- and 5-year survival rates were 100, 78 and 67 per cent respectively. CONCLUSION: Pulmonary resection for metastases from HCC resulted in long-term survival in these highly selected patients.

Adult↗

Intra-abdominal follicular dendritic cell tumour: a rare tumour in need of recognition.

AIMS: Neoplasms of follicular dendritic cells are uncommon and the majority of them occur in lymph nodes. Rarely, they may occur inside the abdominal cavity. We describe two examples of intra-abdominal follicular dendritic cell (FDC) tumour. One involved the liver and the other involved the ampulla of Vater. Our aims are to complement the current understanding on this disease and to alert histopathologists and clinicians to this rare entity. MATERIALS AND RESULTS: The clinical and radiological findings of the two cases of intra-abdominal follicular dendritic cell tumours were reviewed. The resected specimens were examined macroscopically and microscopically. Immunohistochemical studies, ultrastructural examination and in situ hybridization for Epstein-Barr virus were also performed. Both tumours could not be accurately diagnosed before pathological examination of the resected specimens. The soft to slightly firm consistency of the tumours resembled that of fixed brain tissue, and was distinctly different from hepatocellular carcinoma or pancreatic carcinoma. The fascicular arrangement of syncytial plump to spindle cells in a background of mixed inflammatory cells was the initial clue to the diagnosis, which was confirmed by the immunoreactivity of the tumour cells to follicular dendritic cell markers (CD21 and CD35), and by the demonstration of focal intercellular desmosome-like junctions between the complex cytoplasmic processes of the tumour cells. The tumour cells in the liver tumour also showed presence of Epstein-Barr virus on in situ hybridization study. CONCLUSIONS: Awareness of the entity and the ability to recognize this tumour by histopathologists are emphasized because the tumour closely mimics a wide variety of other tumours and tumour-like lesions. Similar to the other reported FDC tumours of the liver, our case of hepatic follicular dendritic cell tumour is also positive for Epstein-Barr virus, suggesting that the virus may play a role in its pathogenesis.

Adult↗

Prospective randomized study of early versus delayed laparoscopic cholecystectomy for acute cholecystitis.

OBJECTIVE: A prospective randomized study was undertaken to compare early with delayed laparoscopic cholecystectomy for acute cholecystitis. SUMMARY BACKGROUND DATA: Laparoscopic cholecystectomy for acute cholecystitis is associated with high complication and conversion rates. It is not known whether there is a role for initial conservative treatment followed by interval elective operation. METHOD: During a 26-month period, 99 patients with a clinical diagnosis of acute cholecystitis were randomly assigned to early laparoscopic cholecystectomy within 72 hours of admission (early group, n = 49) or delayed interval surgery after initial medical treatment (delayed group, n = 50). Thirteen patients (four in the early group and nine in the delayed group) were excluded because of refusal of operation (n = 6), misdiagnosis (n = 5), contraindication for surgery (n = 1), or loss to follow-up (n = 1). RESULTS: Eight of 41 patients in the delayed group underwent urgent operation at a median of 63 hours (range, 32 to 140 hours) after admission because of spreading peritonitis (n = 3) and persistent fever (n = 5). Although the delayed group required less frequent modifications in operative technique and a shorter operative time, there was a tendency toward a higher conversion rate (23% vs. 11%; p = 0.174) and complication rate (29% vs. 13%; p = 0.07). For 38 patients with symptoms exceeding 72 hours before admission, the conversion rate remained high after delayed surgery (30% vs. 17%; p = 0.454). In addition, delayed laparoscopic cholecystectomy prolonged the total hospital stay (11 days vs. 6 days; p < 0.001) and recuperation period (19 days vs. 12 days; p < 0.001). CONCLUSIONS: Initial conservative treatment followed by delayed interval surgery cannot reduce the morbidity and conversion rate of laparoscopic cholecystectomy for acute cholecystitis. Early operation within 72 hours of admission has both medical and socioeconomic benefits and is the preferred approach for patients managed by surgeons with adequate experience in laparoscopic cholecystectomy.

Acute Disease↗

Laparoscopy and laparoscopic ultrasonography avoid exploratory laparotomy in patients with hepatocellular carcinoma.

OBJECTIVE: This prospective study evaluates the value of laparoscopy and laparoscopic ultrasonography (USG) in avoiding exploratory laparotomy in patients with hepatocellular carcinoma (HCC). SUMMARY BACKGROUND DATA: Laparotomy and intraoperative USG is the gold standard to determine the resectability of HCC. No palliation can be offered to patients found to have unresectable disease, and the surgical exploration causes morbidity. METHODS: From June 1994 to June 1996, 110 of 370 patients (30%) with HCC were considered candidates for possible hepatic resection. Preoperative liver function was assessed using Child-Pugh grading and indocyanine green retention test. The extent of disease was evaluated with radiologic studies, including percutaneous USG, computerized tomography scan, and hepatic angiogram. Nineteen patients were excluded from the study because of previous upper abdominal surgery (n = 12), ruptured tumors (n = 4), refusal by patients (n = 2), and instrument failure (n = 1). Laparoscopy and laparoscopic USG was performed on 91 patients immediately before a planned laparotomy aiming at hepatic resection. Laparotomy was aborted when definite evidence of unresectable disease was found on laparoscopic examination. RESULTS: The median time required for laparoscopy and laparoscopic USG was 30 minutes (range, 10 to 120 minutes). Fifteen patients had evidence of unresectable disease on laparoscopic examination. Among the remaining 76 patients who underwent laparotomy, 9 had exploration only and 67 underwent hepatic resection. Thus, exploratory laparotomy was avoided in 63% of patients with unresectable disease. The laparoscopic examination failed to confirm unresectable disease more often when the tumor was >10 cm in diameter. The procedure accurately assessed the adequacy of the liver remnant and the presence of intrahepatic metastases, but it was less sensitive in determining the presence of tumor thrombi in major vascular structures and the extent of invasion of adjacent organs. When unresectable disease was detected without the need for a laparotomy, the postoperative recovery was faster, and the nonoperative treatment for the tumor could be initiated earlier. CONCLUSIONS: Laparoscopy with laparoscopic USG avoids unnecessary laparotomy in patients with HCC and should precede a planned laparotomy aiming at hepatic resection.

Adolescent↗

Paediatric liver transplantation: Queen Mary Hospital experience.

OBJECTIVE: To assess the results of paediatric liver transplantation in our institution. METHODS: From September 1993 to November 1996, 10 living-related liver transplants (LRLT) and 3 reduced-size liver transplants (RSLT) were performed on 12 children at our hospital. The medical records of the patients were reviewed. All patients suffered from end-stage liver disease resulting from biliary atresia with failed Kasai's operations. Their ages at initial transplantation ranged from 8 months to 11 years. Excluding the 2 older children aged 7.5 and 11 years, the remaining patients were aged 10.5 months on the average and weighed 6 to 9.5 kg (mean: 6.8 kg) at the time of initial transplantation. RESULTS: All living donors were discharged on postoperative day 4 to 8 and resumed their previous normal activities. All recipients were alive with normal liver function and growing after a follow-up period of 3-40 months (mean: 21 months). The patient survival rate was 100%. One patient with RSLT had hepatitis of undetermined aetiology and underwent retransplant with a graft from her mother. The graft survival rate was 92%. Postoperative complications included: postoperative bleeding (n = 3), hepatic vein stenosis (n = I), biliary-enteric anastomotic stenosis (n = 3), intestinal perforation (n = I) and portal vein thrombosis (n = I). They were all treated promptly. In all patients, the hepatic artery (diameter ranged from 1.5 to 2.5 mm) anastomosis was achieved by microvascular technique. There was no hepatic artery thrombosis in our patients. CONCLUSION: With technical refinements, early detection and prompt treatment of complications, and advances in immunotherapy, excellent results can be achieved in paediatric liver transplantation.

Biliary Atresia↗

In situ gene transfer into rat auxiliary liver transplant.

BACKGROUND: A replication-defective retrovirus BAG vector was tested for in situ delivery of the beta-galactosidase gene to auxiliary liver transplant in a rat model. METHODS: The BAG vector, which was shown to be effective in genetic transduction of cultured NIH/3T3 cells, was produced in a psi2 packaging cell and later amplified in a selected PA317 clone. Hepatocyte replication was induced by one-third hepatectomy of the donor liver, and the procedure was followed by auxiliary partial liver transplantation. Twenty-four hours after hepatic induction or transplantation, viral supernatant at 37 degrees C was perfused into the liver graft via the portal vein during a temporary occlusion of the graft portal vein. RESULTS: All animals survived the transplantation procedures and were killed at specified time intervals. Histochemical staining of the liver graft specimens indicated the expression of beta-galactosidase in the gene transferred group but not in the control animals. As demonstrated by polymerase chain reaction assay, the proviral beta-galactosidase sequence was present in the graft specimens, but absent from all other tissues tested. CONCLUSIONS: In short, the retrovirus BAG vector can be useful for in situ delivery of foreign genes to liver graft in transplantation and other clinical settings, providing a simple, consistent, and reliable alternative in hepatic gene therapy experiments.

3T3 Cells↗

Lipopolysaccharide induction of the tumor necrosis factor-alpha promoter in human monocytic cells. Regulation by Egr-1, c-Jun, and NF-kappaB transcription factors.

Biosynthesis of tumor necrosis factor-alpha (TNF-alpha) is predominantly by cells of the monocytic lineage. This study examined the role of various cis-acting regulatory elements in the lipopolysaccharide (LPS) induction of the human TNF-alpha promoter in cells of monocytic lineage. Functional analysis of monocytic THP-1 cells transfected with plasmids containing various lengths of TNF-alpha promoter localized enhancer elements in a region (-182 to -37 base pairs (bp)) that were required for optimal transcription of the TNF-alpha gene in response to LPS. Two regions were identified: region I (-182 to -162 bp) contained an overlapping Sp1/Egr-1 site, and region II (-119 to -88) contained CRE and NF-kappaB (designated kappaB3) sites. In unstimulated THP-1, CRE-binding protein and, to a lesser extent, c-Jun complexes were found to bind to the CRE site. LPS stimulation increased the binding of c-Jun-containing complexes. In addition, LPS stimulation induced the binding of cognate nuclear factors to the Egr-1 and kappaB3 sites, which were identified as Egr-1 and p50/p65, respectively. The CRE and kappaB3 sites in region II together conferred strong LPS responsiveness to a heterologous promoter, whereas individually they failed to provide transcriptional activation. Furthermore, increasing the spacing between the CRE and the kappaB3 sites completely abolished LPS induction, suggesting a cooperative interaction between c-Jun complexes and p50/p65. These studies indicate that maximal LPS induction of the TNF-alpha promoter is mediated by concerted participation of at least two separate cis-acting regulatory elements.

Activating Transcription Factor 2↗

Extending the limit on the size of adult recipient in living donor liver transplantation using extended right lobe graft.

The feasibility of adult-to-adult living donor liver transplantation (LDLT) is restricted by the adequacy of the graft size. A left lobe graft from a relatively small donor will not meet the metabolic demand of a larger recipient. We report a successful LDLT performed on a 90-kg man using an extended right lobe graft weighing 910 g from his relatively smaller-size brother. The donor-to-recipient body weight ratio was only 0.82. No homologous blood transfusion was required for the donor, and the donor recovered uneventfully except for mild transient hyperbilirubinemia. The graft provided adequate function for the metabolic needs of the recipient despite postoperative septic complications. Both donor and recipient were well with normal liver function at 4 months after operation. LDLT using the extended right lobe liver graft can extend the limit on the size of the adult recipient and may be a viable option even when the donor is relatively small compared with the recipient.

Adult↗

Pancreatic insulinomas. A 15-year experience.

OBJECTIVE: To describe our experience in the management of patients with pancreatic insulinomas, emphasizing the need for preoperative localization and the outcome of surgical treatment. DESIGN: A case series. SETTING: A university hospital in Hong Kong. PATIENTS: From 1981 to 1995, 27 patients with pancreatic insulinomas were surgically treated; the mean follow-up was 25.4 months. MAIN OUTCOME MEASURES: Postoperative morbidity and euglycemia during the follow-up period. RESULTS: The accuracy of tumor localization by ultrasonography, computed tomography, and angiography was 33%, 44%, and 52%, respectively. Venous sampling for an insulin assay regionalized 90% of the tumors. In 24 patients with solitary tumors, most lesions detected or missed by preoperative localization could be either seen (n = 14) or palpated (n = 22). Intraoperative ultrasonography (n = 17) has been routinely performed since 1987; nonpalpable tumors were imaged in 2 of 15 patients with solitary tumors. Eight solitary occult tumors were detected by palpation alone or a combination of palpation and intraoperative ultrasonography. Operative mortality occurred in 1 (3.7%) of the 27 patients, while major morbidity developed in 9 (33%) of the patients. Euglycemia was achieved in 25 patients. Surgery cured all patients with benign insulinomas, whereas the cure rate for patients with malignant neoplasms was only 33%. The type of surgical treatment or correct preoperative localization did not affect the outcome of surgery. CONCLUSIONS: Pancreatic insulinomas can be readily localized intraoperatively despite failed preoperative localization studies. Surgical treatment cured benign adenomas but was associated with notable morbidity.

Adolescent↗

Endoscopic sphincterotomy: 7-year experience.

The present study documents the indications and results of endoscopic sphincterotomy (ES) performed over 7 years in a surgical endoscopy unit. Potential improvement of results over this time period was analyzed. ES was associated with rare but undesirable morbidity and mortality. Specific improvement of results over time has not been reported. ES was attempted in 706 patients (336 men, 370 women) from 1987 to 1994 and was accomplished in 689 patients (97.6%). Complications occurred in 50 patients (7.1%), 13 of whom required emergency operative intervention. The overall 30-day mortality was 4.7% (n = 33), and procedure-related mortality was 0. 7% (n = 5). There was a significant decrease in hospital mortality (p < 0.01) and operative intervention for procedure-related complications (p < 0.001) after 1990. Procedure-related mortality has been reduced from 1.3% to 0.3% since 1990 (p = 0.1). ES in emergency situations or for malignant biliary obstruction did not adversely affect the outcome. It was concluded that ES can be performed safely in most patients. With increasing experience, procedure-related morbidity and mortality can possibly be reduced.

Adult↗

Acute biliary pancreatitis: diagnosis and management.

Acute biliary pancreatitis is a serious complication of biliary calculous disease and is associated with significant morbidity and mortality. The role of endoscopic retrograde cholangiopancreatography (ERCP) in the management of acute biliary pancreatitis has been the focus of discussion in recent years. In addition, the exact role of laparoscopic cholecystectomy (LC) in the management of acute biliary pancreatitis has not yet been fully defined. In this report, we evaluated a protocol of emergency ERCP (within 24 hours) for predicted severe attacks, early ERCP (within 72 hours) for predicted mild attacks, and interval LC for management of acute biliary pancreatitis. Between January 1992 and June 1995 a total of 75 patients with acute biliary pancreatitis were managed according to the protocol. Bedside ultrasonography at admission diagnosed 94% of all 64 patients with gallbladder stones, but the sensitivity of visualizing choledocholithiasis was low (19%). Forty-five (60%) of them were predicted to have a severe attack by either Ranson or glucose/urea criteria. Emergency ERCP and endoscopic sphincterotomy (ES) for identifiable common bile duct (CBD) or ampullary stones were performed on all patients predicted to have a severe attack within 24 hours from presentation. An early endoscopic procedure was performed on all patients predicted to have a mild attack within 72 hours from presentation. ERCP was successful in 95% of all patients, and CBD stones were detected in 52 (69%) of them. ES and stone clearance were successful in all of these 52 patients. The morbidity associated with the endoscopic procedure was 3%, and there were no deaths. All except one patient survived the attack of acute pancreatitis, resulting in an overall mortality of 1%. Interval LC was performed on 46 patients with a conversion rate of 4%. The median postoperative hospital stay after LC was 2 days, and there was no major intraoperative or postoperative morbidity or mortality. Our experience suggests that the policy of emergency ERCP for patients with predicted severe disease, early ERCP for patients with predicted mild disease, and interval LC are associated with favorable outcomes in patients with acute biliary pancreatitis. Acute biliary pancreatitis can be managed safely and effectively by a combined endoscopic and laparoscopic approach.

Acute Disease↗

Nonresectional therapies for hepatocellular carcinoma.

BACKGROUND: Surgical resection is generally accepted as the first choice of treatment for hepatocellular carcinoma (HCC). However, due to its multifocal nature, association with chronic liver disease, and frequent postresectional recurrence, nonresectional therapies are important in the management of a significant proportion of patients with HCC. DATA SOURCES: A literature review was performed on the current status of different nonresectional treatment modalities commonly employed for HCC. They include direct ablation methods, systemic chemotherapy, transcatheter arterial chemoembolization, external and targeting radiotherapy, hormonal therapy, and immunotherapy. Multidisciplinary therapy resulting in preoperative cytoreduction has also been reported with improvement of therapeutic results. CONCLUSION: Nonresectional therapies play an essential role in the treatment of inoperable HCC as they lead to satisfactory survival. Percutaneous ethanol injection and transcatheter arterial chemoembolization are the most frequently employed modalities, and they result in a 3-year survival rate of 55% to 70% and about 20%, respectively. Multidisciplinary therapy appears to be the current trend of management and improved survival is achieved especially when unresectable tumors are converted to resectable ones.

Antineoplastic Agents, Hormonal↗

Early decision for conversion of laparoscopic to open cholecystectomy for treatment of acute cholecystitis.

BACKGROUND: Although recent reports suggest an initial laparoscopic approach to acute cholecystitis, the risk factors and consequences of the failure of an attempt remained unknown. METHODS: A retrospective study of 557 laparoscopic cholecystectomies was undertaken to identify 70 patients (13%) with a clinical diagnosis of acute cholecystitis confirmed by ultrasonography. Patients who required conversion to laparotomy (conversion group) were compared to those with successful laparoscopic cholecystectomy (successful group). RESULTS: Eight of 70 patients (11%) required conversion. The conversion group had significantly more elderly (< or =65 years) patients (88% vs 37%; P = 0.02) and larger gallstones as shown on ultrasonography (25 mm vs 15.5 mm; P = 0.03). Other preoperative factors associated with severe inflammation were not predictive. Conversion was associated with the intraoperative finding of severe adhesions and not with those of empyema of gallbladder or gangrenous cholecystitis. Conversion was made after a median laparoscopic surgery time of 50 minutes. The conversion group required more operation time, more analgesics, a longer recovery time, and a longer hospital stay. In addition, the postoperative complication rate was significantly higher (63% vs 16%; P = 0.009). CONCLUSIONS: Patients who required conversion from laparoscopic to open cholecystectomy for acute cholecystitis are at risk for postoperative complications. In elderly patients with large gallstones, the surgeon should made an early decision to convert if severe adhesions are encountered.

Acute Disease↗

Liver transplantation in children: the experience of Queen Mary Hospital, Hong Kong.

Seven living-related liver transplants (LRLT) and two reduced-size liver transplants (RSLT) were performed on eight children who suffered from end-stage liver disease, having previously undergone one to three abdominal operations. Their ages at initial transplantation ranged from 8 months to 11 years (mean 35 months, median 12 months). Excluding the two older children aged 7 and 11 years, respectively, the rest of the children weighed 6 to 9.5 kg (mean 7.3 kg) at the time of the initial transplantation. Seven left lateral segments (S2 + 3) and two left lobes (S2 + 3 + 4) were used; of these the smallest graft had a graft-to-recipient body weight ratio of 0.9%. The volunteer living donors were four mothers, two fathers and one sister who were selected after medical and psychiatric evaluations, and their suitability was confirmed by hematological, biochemical, and radiological criteria. During a follow-up period of 3 to 30 months, all eight children are alive and well with normal liver function, one of them having undergone a retransplant LRLT because of hepatitis of undetermined etiology following a RSLT 1.5 years earlier. All seven donors had an uneventful postoperative course and were discharged on day 4 to 7 postoperatively. They have all resumed normal day-to-day activities. There were no complications in the donor group. A variety of complications occurred in the recipients, all of which were overcome. Operating microscope was used to perform all the arterial anastomoses using microvascular techniques. This method has proven to be a major factor in preventing arterial thrombosis even with the smallest of arterial anastomosis where a 1.5-mm diameter recipient artery was anastomosed to a 2.5-mm diameter donor hepatic artery.

Activities of Daily Living↗