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Biomedical subjects

A K Li

Publications and source records attributed to A K Li.

At least 19 recordsLinked to original sources
PubMed1998

Selective internal radiation therapy for nonresectable hepatocellular carcinoma with intraarterial infusion of 90yttrium microspheres.

PURPOSE: To evaluate the efficacy of intraarterial 90yttrium (90Y) microspheres in nonresectable hepatocellular carcinoma (HCC). METHODS AND MATERIALS: Patients with nonresectable HCC, but without extrahepatic disease, who also had lung shunting < 15% and tumor-to-normal ratio > or =2, as determined by simulation using (99m)technetium macroaggregated albumin, were entered into the study. The radiation dose delivered to the lungs, tumor, and normal liver was estimated by a partition model. 90Y microspheres were infused into the hepatic artery at the time of hepatic angiography or through an implanted arterial portacatheter under fluoroscopy. Repeated treatments were given for residual or recurrent tumor. Response to treatment was monitored by serum alpha-fetoprotein or ferritin levels, together with serial computed tomography. RESULTS: Seventy-one patients, including 20 patients with postoperative recurrence, were initially treated with an activity of 0.8 to 5.0 Giga-Becquerel (GBq) (21.6-135.1 mCi) (median 3.0 GBq or 81.1 mCi) of 90Y microspheres. There was a 50% reduction in tumor volume in 19 (26.7%) patients after the first treatment. However, the overall objective response in terms of changes in alpha-fetoprotein levels was 89% [partial response (PR) 67%, complete response (CR) 22%] among the 46 patients with raised pretreatment levels. The serum ferritin level in the other 25 patients dropped by 34 to 99% after treatment. Treatment was repeated in 15 patients. The maximum number of treatments was 5 and the maximum total activity was 13.0 GBq (351.4 mCi), given in 3 treatments. The estimated radiation doses to the nontumorous liver ranged from 25 to 136 Gy (median 52 Gy) in the first treatment and the highest total radiation dose was estimated to be 324 Gy. For the tumors, the estimated radiation doses ranged from 83 to 748 Gy (median 225 Gy) in the initial treatment and the highest cumulative dose reached was 1580 Gy. The residual tumors were resected in 4 patients. Two of these had complete histological remission, but only occasional viable tumor cells were found in the necrotic centers of the tumors resected from the other 2 patients. The median survival of the 71 patients was 9.4 months (range 1.8 to 46.4 months). Treatment was well tolerated and there was no bone-marrow toxicity, or clinical evidence of radiation hepatitis or pneumonitis. CONCLUSIONS: Selective internal radiation therapy using 90Y microspheres is effective for selected cases of nonresectable HCC and is well tolerated. The objective response rate in terms of drop in tumor marker levels is higher than that based on reduction in tumor volume shown by computed tomography. The nontumorous liver appears more tolerant to internal radiation than external beam radiation. Selective internal radiation treatment may convert nonresectable tumors to resectable ones.

Adult↗
PubMed1998

Laparoscopic-assisted vs. open surgery for colorectal cancer: comparative study of immune effects.

PURPOSE: Our aim was to test the hypothesis that laparoscopic-assisted resection for colorectal cancer has an immunologic advantage over traditional open surgery. METHODS: Sixteen patients with colorectal cancer were randomized to undergo laparoscopic-assisted resection or open surgery. Basic patient data were recorded, and serum interleukin-6 levels, relative proportions of lymphocytes, and human leukocyte antigen-DR expression on monocytes were determined at specific time intervals. RESULTS: Operating time was longer for laparoscopic-assisted resection (P=0.02), but analgesic requirements were less (P=0.04). All patients exhibited the following: interleukin-6 levels increased to a maximum at 4 hours and returned to preoperative levels within 48 hours. This response appeared greater for open resection (mean peak level, 313 vs. 173 pg/ml; P=0.25). Relative granulocytosis (P < 0.001) was seen within 48 hours, which was offset by a decrease in percentage of lymphocytes (P < 0.001). Changes in lymphocyte subfractions were most significant seven days postsurgery: natural killer cells decreased (P=0.003); T cells increased (P=0.008), with elevation in the CD4/CD8 ratio (P=0.003). B cells were largely unchanged at all time periods. Human leukocyte antigen-DR expression on monocytes was significantly less at 48 hours postsurgery (P < 0.001). All changes were reversed within three weeks of surgery. There were no differences when comparing laparoscopic-assisted resection with open surgery. CONCLUSIONS: Both laparoscopic-assisted resection and open surgery affect the immune response. It would appear that laparoscopic-assisted resection does not have an immunologic advantage over open surgery in patients with colorectal cancer.

Adult↗
PubMed1998

Common bile duct stones become smaller after endoscopic biliary stenting.

BACKGROUND AND STUDY AIMS: Endoscopic biliary stenting is often used for large or difficult common bile duct (CBD) stones that cannot be extracted at one session. We compared the sizes of the CBD stones after a period of stenting. PATIENTS AND METHODS: Over a 6-year period, a total of 444 patients with large CBD stones (> 2 cm diameter) or difficult CBD stones were managed in our endoscopy unit, of which 46 were treated by endoscopic stenting. Twenty-eight had second ERCP for stone removal after a median period of 63 days (range 17-1002 days). The largest diameter of the stones and the CBD (after correction of magnification) before and after stenting were compared using the Wilcoxon signed test. RESULTS: Before stenting the largest diameters of CBD stones were 11-46 mm (mean 24.9 mm) and decreased to 5-46 mm (mean 20.1 mm) after stenting. The difference in stone sizes was statistically significant although the CBD diameter pre- and post-stenting was not significantly different. The reduction in stone sizes was not significantly correlated with the duration of stenting. CONCLUSION: CBD stones became smaller after stenting. As the difficulty of stone extraction increases with stone size, a period of stenting may make subsequent removal easier for patients with large or difficult CBD stones.

Aged↗
PubMed1998

The evolution of stigmata of hemorrhage in bleeding peptic ulcers: a sequential endoscopic study.

BACKGROUND AND STUDY AIMS: Stigmata of hemorrhage in bleeding peptic ulcers have prognostic characteristics. In the present study, the evolution of these stigmata was studied prospectively using daily endoscopic examinations. PATIENTS AND METHODS: From January 1989 to October 1989, 778 consecutive patients with bleeding peptic ulcers underwent endoscopy within 24 hours of admission. The bleeding peptic ulcers were assigned by three endoscopists to five categories, those with: a) active bleeding, b) a nonbleeding visible vessel, c) adherent clot, d) dot, or e) a clean base. Actively bleeding ulcers were treated by epinephrine injection. Ulcers with nonbleeding visible vessels, adherent clots, or dots were left untreated. Daily endoscopic examinations were carried out for three subsequent days, or until the ulcer base became clean. RESULTS: On day 0, there were 56 actively bleeding ulcers (7%), 62 ulcers with visible vessels (8%), 104 with adherent clots (13%), 182 with flat dots (23%), and 374 with a white base (48%). On the subsequent three days, 24 of 62 ulcers with visible vessels (39%), 30 of 104 with adherent clots (29%), 24 of 182 with dots (13%), and 19 of 374 with a clean base (5%) on day 0 re-bled endoscopically or clinically, or both. The overall rebleeding risk was 9.9%, 4.9%, and 2.7% on days 1, 2, and 3, respectively. CONCLUSIONS: Stigmata of hemorrhage in bleeding peptic ulcers are predictive of rebleeding. They represent intermediate phases in the evolution of bleeding vessels into clean-based ulcers. The associated rebleeding risk diminishes as the vessel disappears from the ulcer base.

Endoscopy, Gastrointestinal↗
PubMed1998

Planning criteria for multicentre, multilingual telemedicine conferences.

The international telemedicine conference Chinese TeleMed 96 was held in November 1996. This three-way teleconference included delegates in London (where the international telemedicine conference TeleMed 96 was taking place) and medical staff from one Beijing hospital and one Hong Kong medical faculty. In total, over 1000 health-care personnel across eight time-zones participated. The event demonstrated that the quality of teleconferencing technology was suitable for medical teaching, for providing medical consultations to remote locations and for stimulating medical exchanges. In general, planning a telemedicine conference requires a longer lead time, a wider representation of expertise in the organizing committee and more financial resources than conventional conferences. It is recommended that the aim and format of a telemedicine conference be determined at least one year before the target date. Criteria for improving the preparation of such conferences have been identified and a set of guidelines for future conference organizers has been drawn up.

Humans↗
PubMed1998

System approach for a multicenter, multilingual international telemedicine conference.

Chinese Telemed 96, a three way international telemedicine conference was successfully held in November 1996. Over 1,000 physicians, allied health professional and medical students participated in this conference in Beijing, Hong Kong and London. This program demonstrated that the quality of telecommunication technology was suitable for the Chinese University of Hong Kong, Faculty of Medicine to use it in facilitating medical consultations and sharing expertise among widely dispersed colleagues. The consensus of Hong Kong participants was that the audiovideo and telecommunication technology used in this conference were adequate. In order to improve overall quality, however, a better co-ordination of the technical support across sites is required. Other felt that the conference suffers from the shortage of highly trained technical staff required to support the communication system. However, following the total evaluation of this conference, it is concluded that while technical support, site and location are important factors in a good telemedicine conference, a well run telemedicine conference is more dependent on a sound planning process and its execution.

Congresses as Topic↗
PubMed1997

Randomised comparison between adrenaline injection alone and adrenaline injection plus heat probe treatment for actively bleeding ulcers.

OBJECTIVE: To compare endoscopic adrenaline injection alone and adrenaline injection plus heat probe for the treatment of actively bleeding peptic ulcers. DESIGN: Randomised prospective study of patients admitted with actively bleeding peptic ulcers. SETTING: One university hospital. SUBJECTS: 276 patients with actively bleeding ulcers detected by endoscopy within 24 hours of admission: 136 patients were randomised to endoscopic adrenaline injection alone and 140 to adrenaline injection plus heat probe treatment. MAIN OUTCOME MEASURES: Initial endoscopic haemostasis; clinical rebleeding; requirement for operation; requirement for blood transfusion; hospital stay, ulcer healing at four weeks; and mortality in hospital. RESULTS: Initial haemostasis was achieved in 131/134 patients (98%) who received adrenaline injection alone and 135/136 patients (99%) who received additional heat probe treatment (P = 0.33). Outcome as measured by clinical rebleeding (12 v 5), requirement for emergency operation (14 v 8), blood transfusion (2 v 3 units), hospital stay (4 v 4 days), ulcer healing at four weeks (79.1% v 74%), and in hospital mortality (7 v 8) were not significantly different in the two groups. In the subgroup of patients with spurting haemorrhage 8/27 (29.6%; 14.5% to 50.3%) patients from the adrenaline injection alone group and 2/31 (6.5%; 1.1% to 22.9%) patients from the dual treatment group required operative intervention. The relative risk of this was lower in the dual treatment group (0.17; 0.03 to 0.87). Hospital stay was significantly shorter in the dual treatment group than the adrenaline injection alone group (4 v 6 days, P = 0.01). CONCLUSION: The addition of heat probe treatment after endoscopic adrenaline injection confers an advantage in ulcers with spurting haemorrhage.

Adult↗
PubMed1997

Laparoscopic-assisted resection of rectosigmoid carcinoma. Immediate and medium-term results.

BACKGROUND: The technique of laparoscopic-assisted resection of colorectal carcinoma has been established. However, whether such a procedure is beneficial to patients is uncertain. OBJECTIVE: To review the immediate and medium-term results of laparoscopic-assisted resection in patients with rectosigmoid carcinoma. PATIENTS AND INTERVENTIONS: We attempted laparoscopic-assisted sigmoid colectomy or anterior resection in 50 patients with rectosigmoid carcinoma (ie, the study group). The results were compared with those of 50 matched patients who underwent conventional open resection in the immediate prelaparoscopic era (ie, the control group). RESULTS: The median follow-up times for the study and control groups were 32.8 and 39.1 months, respectively. The operating time was significantly longer (P < .001, Student t test), while the analgesic requirement was significantly less (P < .001, Mann-Whitney U test) and the duration of hospitalization was significantly shorter (P = .001, Mann-Whitney U test), in the study group than in the control group. The oncological clearance (ie, the number of lymph nodes removed and the distal resection margin), the complication rate, the disease-free rate, and the survival rate were comparable in the 2 groups. CONCLUSION: The immediate and medium-term results of laparoscopic-assisted resection of rectosigmoid carcinoma are promising.

Aged↗
PubMed1997

Laser-assisted removal of a foreign body impacted in the esophagus.

BACKGROUND AND OBJECTIVE: We reported the use of Holmium-YAG laser in the management of a foreign body impacted in the esophagus. STUDY DESIGN/PATIENTS AND METHODS: Esophagoscopy was performed on a man with a denture impacted in the esophagus. The denture was disimpacted into the stomach and fractured with Holmium-YAG laser before removal. RESULTS: The denture was successfully removed in three pieces without complications. CONCLUSION: Holmium-YAG laser can be used to fragment foreign bodies to aid in their removal.

Adult↗
PubMed1997

Clinical evaluation of the partition model for estimating radiation doses from yttrium-90 microspheres in the treatment of hepatic cancer.

Radiation doses to the tumour and non-tumorous liver compartments from yttrium-90 microspheres in the treatment of hepatic cancer, as estimated by a partition model, have been verified by correlation with the actual doses measured with a beta probe at open surgery. The validity of the doses to the lungs, the tumour and non-tumorous liver compartment as estimated by the partition model was further evaluated in clinical settings. On the basis of the observation that one of three patients who received more than 30 Gy from a single treatment and one of two patients who received more than 50 Gy from multiple treatments developed radiation pneumonitis, it was deduced that an estimated lung dose < 30 Gy from a single treatment and a cumulative lung dose < 50 Gy from multiple treatments were probably the tolerance limits of the lungs. Three of five patients who received lung doses > 30 Gy as estimated by the partition model and were predicted to develop radiation pneumonitis, did so despite the use of partial hepatic embolization to reduce the degree of lung shunting. Furthermore, a higher radiological response rate and prolonged survival were found in the group of patients who received higher tumour doses, as estimated by the partition model, than in the group with lower estimated tumour doses. Thus the radiation doses estimated by the partition model can be used to predict (a) complication rate, (b) response rate and (c) duration of survival in the same manner as the actual radiation doses measured with a beta probe at open surgery. The partition model has made selective internal radiation therapy using 90Y microspheres safe and repeatable without laparotomy.

Adult↗
PubMed1997

Failure of the Hong Kong criteria to predict the severity of acute pancreatitis.

CONCLUSION: The results of the present study demonstrate that the HK criteria do not provide effective prediction of severity. BACKGROUND: Fan et al. (1) have reported previously that a blood urea (BU) > 7.4 mmol/L and/or glucose (BG) > 11 mmol/L at the time of admission to hospital detects a severe attack of acute pancreatitis with a sensitivity of 76% and specificity of 75%. However, a similar study conducted in the West of Scotland did not confirm these findings (sensitivity 33% and specificity 83%). The reason underlying this discrepancy in prediction is unclear, but it may be because of differences in the nature of acute pancreatitis between Asian and Western populations. AIMS: In this study we examined the predictive ability of the Hong Kong (HK) criteria in a patient population similar to that studied by Fan et al. PATIENTS AND METHODS: A consecutive series of 130 patients experienced 135 attacks of acute pancreatitis. One-hundred-and-four (77%) attacks were mild and 31 (23%) severe (including 12 [9.0%] deaths). Eighty-nine (66%) episodes had a biliary etiology. In 19 (14%) of these episodes, the gallstones had a primary ductal origin being associated with recurrent pyogenic cholangitis. RESULTS: Median admission BU concentrations were 5.2 mmol/L (range 3.6-32.1 mmol/L) for the mild group and 7.6 mmol/L (range 3.6-28.8 mmol/L) for the severe group. Corresponding values of BG were 7.1 mmol/L (range 2.1-17.9 mmol/L) and 8.4 mmol/L (range 3.6-28.8 mmol/L), respectively. Differences in admission BU concentrations between patients with mild and severe episodes were significant (p = 0.0001). However, differences in BG concentrations were not (p = 0.16). In the severe group, 14 patients had BU and four patients BG concentrations above the cut-off values. The HK criteria predicted severe acute pancreatitis with a sensitivity of 52% and specificity of 80%. These results compare with values of 79 and 56% for the Ranson criteria and 83 and 60% for the Glasgow score. The best prediction was provided by the APACHE II score 24 h post admission (sensitivity 79%, specificity 82%).

Acute Disease↗
PubMed1997

Laparoscopic ultrasonography during laparoscopic cholecystectomy.

BACKGROUND: This study assessed the effectiveness of laparoscopic ultrasonography in demonstrating biliary anatomy, confirming suspected pathology, and detecting unsuspected pathology. METHODS: Laparoscopic ultrasonography was performed on 48 patients (17 M:31 M) who underwent laparoscopic cholecystectomy. An Aloka 7.5-MHz linear laparoscopic ultrasound transducer was used for scanning. RESULTS: Gallbladder stones were confirmed by laparoscopic ultrasonography in all patients and unsuspected pathology was found in five patients. Two patients were found to have common bile duct stones by laparoscopic ultrasonography and this was confirmed by laparoscopic cholangiography. Laparoscopic ultrasound was found to be helpful during dissection in four patients, particularly in a patient with Mirizzi syndrome. The entire common bile duct was visualized by laparoscopic ultrasonography in 40 patients but was poorly seen in eight patients. The mean time taken for the examination was 9 min (range 4-18 min). CONCLUSION: Laparoscopic ultrasound is useful during laparoscopic cholecystectomy.

Adult↗
PubMed1997

Comparison of two-dimensional vs three-dimensional camera systems in laparoscopic surgery.

BACKGROUND: The lack of depth perception and spatial orientation in video vision are the drawbacks of laparoscopic surgery. The advent of a three-dimensional camera system enables surgeons to regain binocular vision and may be advantageous in complex laparoscopic procedures. METHODS: We prospectively studied two groups of surgeons (with and without experiences in laparoscopic surgery) who performed a designated standardized laparoscopic task using a two-dimensional camera system (Olympus OTV-S4) vs a three-dimensional camera system (Baxter-V. Mueller VS7700) and compared their time performances. RESULTS: The results suggested that only experience in laparoscopic surgery had significant effect on individual's performance. We could not demonstrate any superiority of the 3D system over the 2D system. However, two-thirds of the surgeons commented that the depth perception did improve. CONCLUSIONS: With further refinement of the technology, the 3D system may improve its potential in laparoscopic surgery.

Evaluation Studies as Topic↗