The clinicopathological features of thrombosis with thrombocytopenia syndrome following ChAdOx1-S (AZD1222) vaccination and case outcomes in Australia: a population-based study.

Background: Thrombosis with thrombocytopenia syndrome (TTS) associated with viral vector COVID-19 vaccines, including ChAdOx1-S (AstraZeneca AZD1222) vaccine, can result in significant morbidity and mortality. We report the clinicopathological features of TTS following ChAdOx1-S vaccination and summarise the case outcomes in Australia. Methods: In this cohort study, patients diagnosed with TTS in Australia between 23 March and 31 December 2021 were identified according to predefined criteria. Cases were included if they met the Therapeutic Goods Administration (TGA) probable and confirmed case definitions and were reclassified using Centres for Disease Control and Prevention (CDC) definition for analysis. Data were collected on patient baseline characteristics, clinicopathological features, risk factors, treatment and outcomes. Findings: A total of 170 TTS cases were identified, with most occurring after the first dose (87%) of ChAdOx1-S. The median time to symptom onset after vaccination and symptom onset to admission was 11 and 2 days respectively. The median age of cases was 66 years (interquartile range 55-74). All except two patients received therapeutic anticoagulation and 66% received intravenous immunoglobulin. Overall, 85.3% of cases were discharged home after a median hospitalisation of 6 days, 9.4% required ongoing rehabilitation and 5.3% died. Eight deaths were related to TTS, with another dying from an unrelated condition while receiving treatment for TTS. Deaths occurred more commonly in those classified as Tier 1 according to the CDC definition and were associated with more severe thrombocytopenia and disease-related haemorrhage. Interpretation: TTS, while rare, can be severe and have catastrophic outcomes in some individuals. In Australia, the mortality rate was low compared to that reported in other high-income countries. Almost all received therapeutic anticoagulation with no bleeding complications and were successfully discharged. This emphasises the importance of community education and an established pathway for early recognition, diagnosis and treatment of TTS. Funding: Australian Commonwealth Department of Health and Aged Care. H.A Tran, N. Wood, J. Buttery, N.W. Crawford, S.D. Chunilal, V.M. Chen are supported by Medical Research Future Funds (MRFF) grant ID 2015305.

Large size and haemorrhage are not contraindications to laparoscopic resection of hepatocellular adenoma.

BACKGROUND: Hepatocellular adenoma (HCA) is a hepatocyte derived neoplastic lesion with an increasing incidence and a strong association with oestrogen therapy. Laparoscopic resection has proven safe for small, non-ruptured lesions whilst its use for large adenomas (≥10 cm) and cases of haemorrhage requires further investigation. METHODS: All patients undergoing liver resection for HCA at the Royal Brisbane Hospital between January 2003 and April 2018 were analysed. Ethics approval was obtained. RESULTS: Thirty-three laparoscopic and three open resections were performed in 35 patients, all female, with a median age of 35 years (range 14-75). Nine laparoscopic resections were performed for large adenomas (≥10 cm) and 17 laparoscopic resections were performed for adenomas of intermediate size (5-9.9 cm). Only one conversion to open surgery was required for an intermediate sized tumour. Haemorrhage, either intratumoural, intraparenchymal or free intraperitoneal was the indication for resection in six of the 33 laparoscopic cases. Median operative time was 143 and 266 min for laparoscopically resected intermediate and large lesions, respectively. The median length of stay was 5 days (range 4-9) and no major complications were observed in the laparoscopic group. ß-catenin mutation was seen in four of nine large adenomas whereas the inflammatory subtype constituted 11 of 17 intermediate sized lesions. CONCLUSION: Laparoscopic surgery has been demonstrated to be safe for the resection of HCA in this group of patients. Importantly, haemorrhage and/or large size were not barriers to laparoscopic resection.

Subclassification of hepatocellular adenomas: practical considerations in the implementation of the Bordeaux criteria.

Hepatocellular adenomas are benign liver lesions with a risk of rupture and malignant transformation. Various molecular subgroups have been identified which appear to have characteristic morphological and immunohistochemical features. We examined the morphology and immunohistochemical profile of a series of 121 HCA from 97 patients to identify the HCA subtypes present and determine the number at risk for malignant transformation according to the World Health Organization (WHO) criteria for hepatocellular adenomas. There were 34 HNF1α inactivated HCA (28%), 61 inflammatory HCA (50%), 15 ß-catenin activated HCA (12%) and 11 unclassified adenomas (9%). This proportion of cases was similar to that seen in other series utilising molecular classification. The morphological features of the adenomas were suggestive but not definite indicators of the subtypes present. Morphological features that showed overlap between the subtypes included steatosis within the lesion, a ductular reaction and focal atypia, so that immunohistochemical typing was required for accurate classification. In conclusion, immunohistochemistry is a clinically useful surrogate for identifying underlying molecular changes in the HCA subtypes.

Emergency appendicectomy in Australia: findings from a multicentre, prospective study.

BACKGROUND: Emergency appendicectomy is the most common emergency surgical procedure performed in Australia. Despite this frequency, there is a relative paucity of contemporary, broad-based, local data that examine how emergency appendicectomies are currently performed and what are the outcomes from these operations. METHODS: A multicentre, prospective, observational study was performed. Patients were recruited by local investigators for a period of 2 months with 30-day follow-up. Patients were eligible for study inclusion if they underwent an emergency appendicectomy for suspected acute appendicitis. The primary outcome of the study was the negative appendicectomy rate (NAR), with secondary outcomes including 30-day complication rates, method of operation and conversion rates. RESULTS: A total of 1189 patients were recruited across 27 centres. The NAR across all centres was 19.0%. 98.2% of appendicectomies were performed with a laparoscopic-first approach. The rate of conversion from laparoscopy to open operation was 2.4%. 9.4% of patients were recorded as having one or more of the following complications: readmission (6.6%), surgical site infection (1.9%), intra-abdominal abscess (2.7%) or further intervention (1.5%). Patients who had an open operation had higher rates of readmission and surgical site infection. CONCLUSION: The NAR found in this study is within the traditional measures of acceptance; however, this rate is high when measured against modern international benchmarks.

Intercostal and transthoracic trocars enable easier laparoscopic resection of dome liver lesions.

BACKGROUND: Dome liver lesions (those in segments VII or VIII) pose a challenge to standard laparoscopic resection. The use of additional intercostal and transthoracic trocars (ITTs) potentially facilitates resection over standard subcostal laparoscopic (SSL) techniques. METHODS: A retrospective review of a prospectively collected liver resection database was performed, selecting all minor resections of segments VII and VIII using the ITT and SSL approaches. The techniques of intercostal transdiaphragmatic access are described and the surgical outcomes of the two groups compared. RESULTS: A total of 19 patients were analysed. The ITT group included 8 patients and the SSL group included 11. The groups were comparable in median lesion size (20 mm in the ITT group and 26 mm in the SSL group). Blood loss, operative times, morbidity and conversion rates were similar. There was no lung injury or postoperative clinical pneumothorax in any patient undergoing transdiaphragmatic access. Median hospital stay was significantly shorter in the ITT group (2 days) than in the SSL group (6 days) (P = 0.032). CONCLUSIONS: The ITT approach is safe, effective and complementary to standard laparoscopic techniques for the resection of small tumours in segments VII and VIII.