Low-latency gravitational wave alert products and their performance at the time of the fourth LIGO-Virgo-KAGRA observing run

Multimessenger searches for binary neutron star (BNS) and neutron star-black hole (NSBH) mergers are currently one of the most exciting areas of astronomy. The search for joint electromagnetic and neutrino counterparts to gravitational wave (GW)s has resumed with ALIGO's, AdVirgo's and KAGRA's fourth observing run (O4). To support this effort, public semiautomated data products are sent in near real-time and include localization and source properties to guide complementary observations. In preparation for O4, we have conducted a study using a simulated population of compact binaries and a mock data challenge (MDC) in the form of a real-time replay to optimize and profile the software infrastructure and scientific deliverables. End-toend performance was tested, including data ingestion, running online search pipelines, performing annotations, and issuing alerts to the astrophysics community. We present an overview of the low-latency infrastructure and the performance of the data products that are now being released during O4 based on the MDC. We report the expected median latency for the preliminary alert of full bandwidth searches (29.5 s) and show consistency and accuracy of released data products using the MDC. We report the expected median latency for triggers from early warning searches (-3.1 s), which are new in O4 and target neutron star mergers during inspiral phase. This paper provides a performance overview for LIGO-Virgo-KAGRA (LVK) low-latency alert infrastructure and data products using theMDCand serves as a useful reference for the interpretation of O4 detections.

Effects of dietary supplementation of microencapsulated Enterococcus fecalis and the extract of Camellia oleifera seed on laying performance, egg quality, serum biochemical parameters, and cecal microflora diversity in laying hens

The aim of this study was to investigate the effects of microencapsulted Enterococcus faecalis (MEF) and the extract of Camellia oleifera seed (ECOS) on laying performance, serum biochemical parameters, and cecal microflora diversity in laying hens. A total of 180 Hy-Line Brown laying hens, 26-wk-old, were randomly allocated to 6 treatments with 10 replicates and 3 hens per replicate. Dietary treatments were as follows: (A) control group, basal diet; (B) basal diet + 100 mg MEF/kg diet (1 × 1010 cfu/g MEF); (C) basal diet + 300 mg ECOS/kg diet; (D) basal diet + 100 mg MEF/kg diet + 300 mg ECOS/kg diet; (E) basal diet + 500 mg ECOS/kg diet; (F) basal diet + 100 mg MEF/kg diet + 500 mg ECOS/kg diet. The results showed that diets supplemented with MEF and ECOS had no significant effects on laying rate, average egg size, average daily feed intake, feed conversion ratio, eggshell thickness, albumen height, and yolk color (P > 0.05), but had significant effects on egg shape index, eggshell strength, and Haugh unit (P < 0.05) during whole feeding phases. Compared to the control group, the serum IgA and IgG levels of birds in Group F significantly increased (P < 0.05). The serum total cholesterol, low-density lipoprotein cholesterol, total triglyceride, and blood urea nitrogen levels of birds in Group D and Group F significantly reduced (P < 0.05), and the high-density lipoprotein cholesterol level of birds in Group D and Group F significantly increased (P < 0.05). At the phylum level, Firmicutes decreased (P < 0.05) and Bacteroidetes increased (P < 0.05) in the birds of Group D. Ruminococcus and Bacteroides were significantly affected by dietary treatments (P < 0.05), and Bacteroides in the birds of Group D significantly increased at the genus level. Therefore, diet supplemented with MEF and ECOS can significantly improve serum biochemical parameters and increase cecal microflora diversity.

Effects of microencapsulated Enterococcus fecalis CG1.0007 on growth performance, antioxidation activity, and intestinal microbiota in broiler chickens

We performed a series of trials to assess the effect of dietary supplementation with microencapsulated Enterococcus fecalis CG1.0007 on growth performance, antioxidation activity, and intestinal microbiota in Arbor Acres broiler chickens ("broilers"). A total of 150 1-d-old broilers were assigned randomly to 5 feeding treatments (a control group fed the basal diet, 3 groups fed the basal diet plus various concentrations of microencapsulated CG1.0007, and 1 group fed the basal diet plus an antibiotic). Changes in important genera of intestinal bacteria were studied using 16S rRNA gene-based PCR-denaturing gradient gel electrophoresis (DGGE) profiling and real-time quantitative PCR analysis of fecal samples. During the course of the 42-d experimental period, ADG of the birds fed the high and intermediate concentrations of microcapsules were significantly greater (9.90 and 9.50%, respectively) and the ratios of feed to gain fed were significantly lower (4.40 and 4.00%, respectively) compared with the control group. The total antioxidant capacity and the content of malondialdehyde and superoxide dismutase in the microcapsule-treated groups showed significant changes in terms of antioxidation. The numbers of Lactobacillus and Bifidobacterium were significantly greater in the microcapsule-treated groups than in the control group. Cluster analysis indicated that the DGGE bacterial profiles were related to the feeding treatments and revealing the diversity and richness of the intestinal microbiota associated with supplementation of microcapsules. In summary, our results indicate that dietary addition of microencapsulated E. fecalis CG1.0007 enhanced the growth performance of the broilers and improved their health.

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.

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.

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.

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.

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.

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.

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.

Laparoscopic resection of splenic artery aneurysm

A new, lateral approach was used for the laparoscopic resection of splenic artery aneurysm. This approach was found to be convenient and straightforward.

Ectopic gallbladder revisited, laparoscopically: a case report

A case of the rare congenital anomaly ectopic gallbladder is presented. A 16-year-old girl suffered attacks of epigastric pain unrelated to eating. On abdominal ultrasonography, the gallbladder could not be found in its usual position. Endoscopic retrograde cholangiography demonstrated the gallbladder on the left side of the common duct and the cystic duct arising from the right hepatic duct. Laparoscopic cholecystectomy was done without complication. This appears to be the first reported case of laparoscopic removal of an ectopic gallbladder. The importance of preoperative cholangiography is emphasized for accurate diagnosis and preoperative location of the gallbladder.

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%).

Gastrointestinal autonomic nerve tumour presenting as small bowel volvulus: a rare disease with a rare presentation

A 78-year-old Chinese woman presented with recurrent postprandial abdominal pain. Computerised tomography revealed a small bowel tumour causing volvulus of a segment of the small bowel. Laparotomy confirmed an extraluminal ileal tumour with partial volvulus of the involved small bowel segment. Small bowel resection was done. Histological and ultrastructural studies confirmed a gastrointestinal autonomic nerve tumour. We review the medical literature on this rare tumour.

Laparoscopy-assisted sigmoid colectomy for volvulus

We report on five male patients with sigmoid volvulus treated by laparoscopy-assisted sigmoid colectomy. Intraoperative colonic irrigation was used in two patients prior to resection and primary anastomosis. An intracorporeal technique of bowel anastomosis was used that allowed smaller skin incisions as compared with the extracorporeal technique. All five patients recovered uneventfully, and most were discharged within 1 week after the operation. There was no recurrence at the conclusion of the follow-up. Laparoscopy-assisted sigmoid colectomy may prove to be the procedure of choice in patients with sigmoid volvulus.

Laser therapy for multiple biliary papillomatosis via choledochoscopy

BACKGROUND

Multiple biliary papillomatosis is a rare tumour of the biliary tract but is capable of multicentric malignant transformation. The complete removal of these tumours is difficult because it involves a field change of the biliary tract.

METHODS

Exploration with choledochoscopy is a prerequisite for thorough assessment of the extent of involvement. Incorporation of laser ablation via a laser-delivering fibre with choledochoscopy permits complete removal of the tumour.

RESULTS

Repeated laser therapy via choledochoscopy through the T-tube tract enables complete ablation of the tumour which changes the outlook of the prognosis. This is confirmed on subsequent cholangiography.

CONCLUSIONS

Laser therapy via choledochoscopy is a satisfactory mode of treatment for multiple biliary papillomatosis. It enables complete and precise ablation of the tumour which certainly changes the prognosis of this condition.

Abdominal mass and haematuria

Images

Arteriovenous shunts in patients with hepatic tumors

The study aimed to investigate the influence of tumor type, tumor size, tumor vascularity and treatment on arteriovenous shunts between the liver and lungs in patients with hepatic cancer.

METHODS

Our previous assessment of the degrees of lung shunting using intra-arterial 99mTc-macroaggregated albumin in 125 patients with hepatocellular carcinoma (HCC) was extended to include 377 patients with HCC and 25 patients with colorectal liver metastases. Patients were given 111 MBq (3 mCi) of 99mTc-macroaggregated albumin during hepatic angiography. The lungs and the liver were localized as regions of interest on the digitized gamma scintigraphic image. The total counts taken over the lungs divided by the total counts taken over both the lungs and the liver gave the percentage of lung shunting. Tumor size was measured by computerized tomography or ultrasound scan. Tumor vascularity was assessed based on the degree of neovascularization. Linear regression and Wilcoxon rank test were used for statistical analysis.

RESULTS

Patients with HCC had a higher median (7.6%) and a wider range (< 1-75.4%) of percentages of lung shunting when compared with those with colorectal liver metastases (median, 4.7%; range, < 1-23.9%). The lung shunting correlated with the tumor size in the 377 patients with HCC (r = 0.359; p < 0.0001). Excluding one outlier, we found a similar correlation in 24 patients with colorectal metastases (r = 0.686; p < 0.0001). In HCC, the mean lung shunting increased with increasing tumor size, up to 15 cm, and then remained almost unchanged, up to a size of > 20 cm. The mean lung shunting also increased with increasing vascularity grades, as assessed by hepatic angiography. The difference between any two vascularity grades was statistically significant (p = 0.0001-0.0148). Similar analysis by subgroups in colorectal liver metastases was impossible because of the small number of patients. Lung shunting decreased in HCC patients after the tumors were treated, but it might increase or decrease when the disease recurs.

CONCLUSION

The lung shunting was influenced by the type, size and vascularity of the hepatic tumor. The change in lung shunting with the status of the tumor after treatment further suggests a neoplastic nature of the blood vessels involved in the arteriovenous shunt.

Tumour-to-normal uptake ratio of 90Y microspheres in hepatic cancer assessed with 99Tcm macroaggregated albumin

The selective delivery of a high dose of radiation to malignant hepatic tumours by infusion of non-biodegradable yttrium-90 (90Y) microspheres via the hepatic artery while sparing the non-tumorous liver parenchyma depends on the tumour-to-normal uptake ratio (T/N) of the therapeutic radiopharmaceutical. Using intrahepatic arterial technetium-99m macroaggregated albumin (99Tcm-MAA), the effect of tumour type, tumour vascularity assessed by hepatic angiography (HAG), tumour size and the degree of extrahepatic shunting on the T/N was investigated in 377 patients with hepatocellular carcinoma (HCC) and 25 patients with colorectal liver metastases. HCC was shown to have a wider range of T/N (0.2-26.5) compared with liver metastases (2.3-7.2). HCC with vascularity grade 1 on HAG had significantly lower T/N but there was no significant difference in HCC with higher vascularity grades. This confirmed that vascularity on HAG does not predict T/N. Overall there was no correlation between T/N and tumour size. Large tumours (> 20 cm) had a significantly lower T/N, probably due to necrosis in the tumour centres. A decrease in mean T/N with increasing percentages of lung shunting was observed in HCC. Determination of T/N by simulation with 99Tcm-MAA is recommended before internal radiation therapy with 90Y microspheres.

Stigmata of hemorrhage in bleeding peptic ulcers: an interobserver agreement study among international experts

BACKGROUND

Stigmata of hemorrhage predict rebleeding and outcome of patients with bleeding peptic ulcers. There are variabilities in reported incidences of stigmata and their respective rebleeding risks. We sought to study the interobserver agreement among experts.

METHODS

Between June 1994 and July 1994, 100 consecutive patients with bleeding peptic ulcers underwent videoendoscopy within 24 hours of their admissions. An edited videotape of these ulcers was compiled and sent to an international panel of 14 experts. They independently rated these ulcers exclusively into one of the six categories: spurting, oozing, nonbleeding visible vessel, adherent clot, flat pigmented spot, or clean based. Agreement between any two experts was expressed by a kappa estimate (kappa). Agreements over individual stigmata and a composite kappa estimate (kappa(w)) signifying overall agreement were also computed.

RESULTS

Out of the possible 91 pairwise kappa estimates among 14 experts, 35 (38.5%) were less than or equal to 0.40, indicating poor agreement. None of the kappa estimates was greater than 0.75. Composite kappa estimates for individual stigmata were as follows: spurting kappa = 0.664, oozing kappa = 0.420, nonbleeding visible vessel kappa = 0.342, adherent clot kappa = 0.426, flat pigmented spot kappa = 0.393, and clean-based ulcer kappa = 0.371. The weighted kappa estimate was 0.426.

CONCLUSION

Agreement between experts was poor in more than a third of occasions. Although the overall interobserver agreement was fair (0.4 < kappa < 0.75), agreements for nonbleeding visible vessels, flat pigmented spots, and clean-based ulcers were poor.

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.

Anal and perianal tuberculosis: a report of three cases in 10 years

From the computerized pathology record, three cases of anal and perianal tuberculosis were encountered in the Prince of Wales Hospital, Hong Kong during the last 10 years. The clinical history, examination findings and relevant investigations were reviewed retrospectively. Comparison was made with previous literature. Emphasis was put on the diversity of clinical presentations including acute perianal abscess, chronic anal ulcer and fistula in ano. It is concluded that a high index of suspicion is important to ensure an early diagnosis.

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.

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.

Use of a cotton tape tie in laparoscopic colorectal surgery

In this short article we describe the use of a cotton tape tie in laparoscopic colorectal surgery. This technique is useful in: (i) retraction and manipulation of the bowel; (ii) exteriorization of a bulky specimen; and (iii) occlusion of the rectal lumen to permit effective cytocidal rectal lavage.

Obturator hernia revisited: a review of 12 cases in 7 years

Twelve patients with obturator hernia seen over a 7-year period were reviewed retrospectively. All were elderly females presenting with small bowel obstruction. The median body weight was 35 kg. A significant proportion of patients (33%) came from homes for elderly people and were either bed-ridden or wheel chair-bound. All 12 patients were classified as high-risk-patients in pre-operative assessment. Only one patient (8.8%) had a history of previous abdominal operation. Clinical signs such as Howship-Romberg sign and palpable groin mass were absent in these patients. Contrast radiography was performed in three patients and was not helpful in the diagnosis. A correct pre-operative diagnosis was suspected in only one case. The medium treatment delay was 1.5 days and the gut resection rate was 75%. The overall mortality rate was high (25%). A high index of clinical suspicion is important in the diagnosis and obturator hernia should be suspected whenever an elderly thin female with no previous abdominal surgery developed small bowel obstruction. Early laparotomy is recommended in such patients.

A logical approach to hepatocellular carcinoma presenting with jaundice

OBJECTIVE

This prospective cohort study on patients with hepatocellular carcinoma (HCC) presenting with jaundice emphasized the importance of differentiating patients with hepatic insufficiency from patients with obstructive jaundice caused by tumor.

SUMMARY BACKGROUND DATA

There are little data in the medical literature on the management of patients with HCC presenting with jaundice. Experience has accumulated mainly from case reports and retrospective studies.

METHODS

Data were collected prospectively on 2095 patients with HCC seen over a 12-year period. All patients were investigated with blood tests, abdominal ultrasound, and chest radiography. Endoscopic retrograde cholangiopancreatography-percutaneous transhepatic cholangiography, computed tomography and hepatic angiography were carried out in selected patients.

RESULTS

Of the 530 patients who had clinically detectable jaundice, 481 had jaundice due to hepatic insufficiency and 49 patients had obstructive jaundice. Patients with hepatic insufficiency had extremely poor prognosis, and 90% of them died within 10 weeks of first presentation. "Curative" resection, however, was possible in 9 of 49 patients with obstructive jaundice, and histologic analysis showed resectional margin involvement by tumor in 1 patient. In addition, 35 patients were treated with biliary stents to relieve the obstructive jaundice. Supportive treatment only was given to five patients who were considered too terminally ill. The overall survival of patients with HCC with obstructive jaundice was similar to those patients who presented with no clinical detectable jaundice and was much better than those with jaundice due to hepatic insufficiency (log-rank test, p < 0.001).

CONCLUSIONS

The prognosis of patients with HCC who presented with jaundice due to hepatic insufficiency was dismal. It is important to identify the patients who had obstructive jaundice because with proper treatment, good palliation and occasional cure are possible.

Evaluation of artificial skin (Integra) in a rodent model

The biocompatibility of artificial skin (Integra) has been investigated in clean surgical wounds of 20 guinea-pigs. A rectangular 3 x 3 cm full-thickness skin defect with excision carried down to the panniculus carnosus was prepared on the dorsal area of the guinea-pig. A thin layer of silver sulfadiazine cream was applied and artificial skin was placed to cover the wound. At day 14, the uppermost silicone layer was removed. Good take of the artificial skin was observed in 18 of 20 animals. Microscopy showed good vascular ingrowth in 14 of the 18 animals. The remaining four animals showed necrotic tissue, absence of vascularization and haemorrhage in the wound bed. Two of the 20 wounds showed purulent discharge. In this animal model, clinical 'take' of the neodermis was achieved in 18/20 animals (90 per cent), while vascular ingrowth was observed in only 14/20 animals (70 per cent). These results suggested that artificial skin in clean surgical wound is readily biologically incorporated into surrounding viable tissue.

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.

Hepatocellular carcinoma

Hepatocellular carcinoma is the most common cancer in males. Surgery is the only curative treatment, but is applicable in only 10-15% of patients. Systemic chemotherapy, transarterial embolization or chemo-embolization can only palliate. In the future, selective internal radiation may have a role in downstaging inoperable hepatoma to operable tumour.

Spontaneous internal herniation through the foramen of Winslow: a case report

A 41-year-old woman, who presented with acute onset of generalized peritonitis, was found to have a segment of strangulated small bowel incarcerated in the lesser peritoneal sac through the foramen of Winslow. The strangulated small bowel was reduced and resected. The predisposing factors for this condition as mentioned in the literature were not present in this case. In particular, the herniation was associated with a small foramen of Winslow and the presentation was one of rapidly developing peritonitis.

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.

Is there a role for preoperative infusion or intraoperative cholangiography?

Background: There has been a resurgence of interest in recent years in preoperative infusion cholangiography (PIC). The role of routine PIC compared to routine intraoperative cholangiography (IOC) has not been clearly defined.

Study design: In our department between 1985 and 1991, 1,042 of 1,576 consecutive patients with biliary calculous disease had elective cholecystectomy: 694 patients were prospectively scheduled for PIC, and 348 patients were randomly allocated to IOC. The patients in the PIC and IOC groups were similar with regard to age, history of biliopancreatic complications, and laboratory findings. The cost of PIC in Sweden is nearly five times greater than the cost of IOC.

Results: Satisfactory opacification of the biliary system was obtained in 90.1 and 96.8 percent of patients who underwent PIC and IOC, respectively. Preoperative infusion cholangiography required support by IOC in 19.5 percent of patients. There were no statistically significant differences between the PIC and IOC groups with regard to the incidence (7 percent in both groups) of or positive predictive value (68 and 80 percent, respectively) for bile duct stones, rate of retained stones (6 and 20 percent, respectively), intraoperative (5.6 and 6.3 percent, respectively) or postoperative (13.3 and 15.9 percent, respectively) morbidity, or incidence of bile duct anomalies (0.9 and 0.3 percent, respectively). Median operative time was longer in .patients with (95 minutes) compared to those without (75 minutes) IOC (p<0.001). More postoperative complications occurred after bile duct exploration (26 of 75 patients) compared to cholecystectomy alone (114 of 917 patients, p<0.001). The 30-day mortality was zero. Minor bile duct injuries occurred in two patients (0.2 percent) at cholecystectomy, (one with and one without bile duct exploration). In no patient was the cholangiographic finding of a biliary anomaly crucial for the safe execution of cholecystectomy.

Conclusions: In our study, PIC and IOC were comparable, but routine use of either method did not promote the safety of cholecystectomy and thus their routine use is not warranted. The shorter operative time and preoperative identification of common bile duct (CBD) stones provided by PIC might favor this examination when applied selectively in patients with increased risk of having CBD stones. However, this potential advantage is offset by the need for PIC to be supported by IOC in approximately 20 percent of patients. Also, the cost of PIC is greater than the cost of IOC.

Pitfalls in the management of preauricular sinuses

A total of 159 operations for the excision of a preauricular sinus carried out in 117 patients over an 8-year period were reviewed. Previous excision, the use of a probe to delineate the sinus and operating under local anaesthesia all increased the chance of recurrence. The condition recurred more often in patients who developed post-operative wound sepsis than in those who healed primarily. Means of decreasing the recurrence rate include: (1) meticulous dissection of the sinus by an experienced head and neck surgeon under general anaesthesia; (2) the use of an extended preauricular incision; (3) clearance down to the temporalis fascia to ensure complete removal of all epithelial components; (4) avoidance of sinus rupture; and (5) closure of wound dead space.

High prevalence of Helicobacter pylori infection in duodenal ulcer perforations not caused by non-steroidal anti-inflammatory drugs

There has been controversy regarding the relationship between Helicobacter pylori and perforated peptic ulcer, which is known to have a high recurrence rate if only simple patch repair is performed. The aim of this study was to evaluate the association between H. pylori infection and intake of non-steroidal anti-inflammatory drugs (NSAIDs) in patients with perforated duodenal ulcers. Of the 73 patients recruited over a 16-month period, 51 (70 per cent) had evidence of H. pylori infection by intraoperative gastroscopy and antral biopsies. The infection rate rose to 80 per cent if NSAID users were excluded. The H. pylori-infected group was significantly younger (mean 47.6 versus 62.5 years), with a male preponderance (49 of 51 versus 14 of 22 patients), and had significantly less NSAID consumption (three of 51 versus ten of 22) and more prolonged dyspepsia (40 of 51 versus ten of 22), compared with H. pylori-negative patients. H. pylori infection probably plays an important role in the causation of non-NSAID-induced duodenal ulcer perforation. Whether eradication of the bacteria can alleviate the strong ulcer diathesis in this subgroup of patients is unknown.

Hepatic haemangioendothelioma presenting with early heart failure in a newborn: treatment with hepatic artery embolization and interferon

We report our management of a newborn presenting in utero with congestive heart failure secondary to a giant hepatic haemangioendothelioma. Control of heart failure was achieved by transcatheter hepatic artery embolization, and rapid regression of the tumor was observed after a course of alpha 1 interferon. The combination of hepatic artery embolization and interferon may be a useful approach in the management of this rare, potentially fatal condition.

Mesh hernioplasty using a stapler

BACKGROUND

The recent development of laparoscopic hernioplasty has evoked extensive re-examination of the safety and effectiveness of using synthetic mesh materials in hernia surgery. We have investigated the efficacy of anterior stapling mesh repair in the treatment of inguinal hernia.

METHODS

From July 1993 to June 1994, a modified open mesh hernioplasty using staples for anchorage has been performed in 127 patients.

RESULTS

The mean age of patients was 61.4 +/- 13.0 years. Over 90% of them were operated on under local anaesthesia. The operation time ranged from 30 to 95 min with a median of 39 min. Only sixteen patients (12.6%) required postoperative parenteral analgesics and the median time for resuming daily activities was 7 days. Apart from two patients with reactionary haemorrhage, there was no other significant complication observed. Only one recurrence was encountered over the 26-month median follow-up period.

CONCLUSIONS

We conclude that the modified mesh hernia repair with a stapling device is a feasible, inexpensive and safe procedure that is well tolerated under local anaesthesia by most patients.

A prospective study on the use of water-soluble contrast follow-through radiology in the management of small bowel obstruction

BACKGROUND

The purpose of this prospective study was to determine the value of water-soluble contrast follow-through radiology in predicting the outcome in patients with small bowel obstruction.

METHODS

Patients with clinical and radiological evidence of small bowel obstruction were selected according to pre-set criteria. A water-soluble contrast follow-through examination using 76% urografin was carried out within 24 h of hospital admission. The result was interpreted as 'significant obstruction' if the contrast failed to reach the caecum in 4 h or if there was a clear cut-off in the gastrointestinal tract. The result was interpreted as 'insignificant obstruction' if the contrast reached the caecum within 4 h. The surgeon was blinded to the result of the contrast examination in the patient management, and the decision to operate was based entirely on conventional clinical grounds.

RESULTS

Fifty-one patients in an 18 month period underwent the contrast examinations. Thirty-four patients (67%) had previous abdominal operations. The results showed that significantly more patients who had 'significant obstruction' on contrast radiology required surgery to relieve the intestinal obstruction (17/19) than those who had "insignificant obstruction' (1/32; Fisher's exact test, P < 0.0001). This difference was found to be significant in both patient subgroups: patients with or without previous abdominal operation. There was no major morbidity or mortality related to the contrast radiology procedure.

CONCLUSIONS

Urografin follow-through examination is a safe procedure; using 4 h as the cut-off it is highly predictive of the outcome in small bowel obstruction in patients with or without previous abdominal operation.

Endoscopic drainage aborts endotoxaemia in acute cholangitis

Forty patients with acute calculous cholangitis had successful endoscopic drainage. Bile from nasobiliary drains and venous blood was collected at 0, 12, 24, 36 and 48 h after endoscopy. Endotoxin levels were measured by the chromogenic Limulus Amoebocyte Lysate assay. There was a significant reduction in both bile and serum endotoxin levels after endoscopic drainage (P < 0.001). Endotoxaemia occurred when bile endotoxin reached 10(3) EU/ml and rose exponentially beyond this threshold. Significant association was demonstrated between both bile and serum endotoxins to the clinical features of cholangitis (P < 0.05). No correlation was evident between serum endotoxin and the parameters of white cell count, serum bilirubin and alkaline phosphatase (r = 0.53, 0.00 and 0.00 respectively). Endoscopic drainage is effective in lowering bile and serum endotoxin levels and clinical signs and symptoms reliably predict endotoxaemia.

A randomized study comparing laparoscopic versus open repair of perforated peptic ulcer using suture or sutureless technique

OBJECTIVE

This study compares laparoscopic versus open repair and suture versus sutureless repair of perforated duodenal and juxtapyloric ulcers.

BACKGROUND DATA

The place of laparoscopic repair of perforated peptic ulcer followed by peritoneal toilet of the peritoneal cavity has been established. Whether repair of the perforated peptic ulcer by the laparoscopic approach is better than conventional open repair and whether sutured repair is better than sutureless repair are both undetermined.

METHODS

One hundred three patients were randomly allocated to laparoscopic suture repair, laparoscopic sutureless repair, open suture repair, and open sutureless repair.

RESULTS

Laparoscopic repair of perforated peptic ulcer (groups 1 and 2) took significantly longer than open repair (groups 3 and 4; 94.3 +/ 40.3 vs. 53.7 +/ 42.6 minutes: Student's test, p < 0.001), but the amount of analgesic required after laparoscopic repair was significantly less than in open surgery (median 1 dose vs. 3 doses) (Mann-Whitney U test, p = 0.03). There was no significant difference in the four groups of patients in terms of duration of nasogastric aspiration, duration of intravenous drip, total hospital stay, time to resume normal diet, visual analogue scale score for pain in the first 24 hours after surgery, morbidity, reoperation, and mortality rates.

CONCLUSIONS

Laparoscopic repair of perforated peptic ulcer is a viable option. Sutureless repair is as safe as suture repair and it takes less time to perform.