Surgery (Austin & Northern Health) - Research Publications

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    Endoscopy training in Australia during COVID-19: Efficacy and knowledge assessment of gastroenterology and general surgery trainees
    Pu, LZCT ; Cox, DRA ; Be, KH ; Ng, J ; Yeaman, F ; Gilhotra, RA ; Efthymiou, M ; Vaughan, R ; Nestel, D ; Perini, M ; Muralidharan, V ; Chandran, S (WILEY, 2022-12)
    BACKGROUND AND AIM: During COVID-19, restrictions to elective endoscopy were introduced worldwide. A reduction in procedures may impact trainees' endoscopy learning. This study aims to assess Australian advanced gastroenterology and general surgery trainees' self-perceived efficacy and knowledge in endoscopy during the pandemic. METHODS: All Australian gastroenterology and general surgery trainees in their last 2 years of accredited training were invited to participate through email (2020-2021 and 2021-2022 training cycles). The primary outcome was to assess trainees' self-efficacy and knowledge regarding gastrointestinal endoscopy. Secondary outcomes included subgroup analysis between gastroenterology and general surgery trainees. Self-perceived efficacy was assessed with Likert-scale questions on 20 endoscopy procedures and knowledge was assessed through 21 endoscopy-related multiple choice questions. RESULTS: Eighty-one trainees responded to a self-efficacy questionnaire and 77 responded to the knowledge questionnaire. Over 90% of the trainees were confident or extremely confident in diagnostic endoscopy, but only half demonstrated similar efficacy for therapeutic endoscopy. The efficacy for basic endoscopy procedures was higher for gastroenterology trainees (64.0% vs 51.1%, P < 0.001). Last-year trainee achievement of conjoint committee requirements for upper gastrointestinal endoscopy was achieved in 95.8% of gastroenterology trainees versus 22.2% of surgical trainees (P < 0.001). The median score on the knowledge questionnaire was also higher for the gastroenterology subset (90.5% vs 71.4%, P < 0.001). CONCLUSION: During COVID-19, endoscopy trainees' self-efficacy in endoscopic diagnostic procedures was achieved for most trainees. The differences in self-perceived efficacy and knowledge between gastroenterology and surgical trainees may be reflective of the different opportunities for learning between the two groups.
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    Captopril, a Renin-Angiotensin System Inhibitor, Attenuates Tumour Progression in the Regenerating Liver Following Partial Hepatectomy
    Riddiough, GE ; Walsh, KA ; Fifis, T ; Kastrappis, G ; Tran, BM ; Vincan, E ; Muralidharan, V ; Christophi, C ; Gordon, CL ; Perini, MV (MDPI, 2022-05)
    (1) Liver regeneration following partial hepatectomy for colorectal liver metastasis (CRLM) has been linked to tumour recurrence. Inhibition of the renin−angiotensin system (RASi) attenuates CRLM growth in the non-regenerating liver. This study investigates whether RASi exerts an antitumour effect within the regenerating liver following partial hepatectomy for CRLM and examines RASi-induced changes in the tumour immune microenvironment; (2) CRLM in mice was induced via intrasplenic injection of mouse colorectal tumour cells, followed by splenectomy on Day 0. Mice were treated with RASi captopril (250 mg/kg/day), or saline (control) from Day 4 to Day 16 (endpoint) and underwent 70% partial hepatectomy on Day 7. Liver and tumour samples were characterised by flow cytometry and immunofluorescence; (3) captopril treatment reduced tumour burden in mice following partial hepatectomy (p < 0.01). Captopril treatment reduced populations of myeloid-derived suppressor cells (MDSCs) (CD11b+Ly6CHi p < 0.05, CD11b+Ly6CLo p < 0.01) and increased PD-1 expression on infiltrating hepatic tissue-resident memory (TRM)-like CD8+ (p < 0.001) and double-negative (CD4-CD8-; p < 0.001) T cells; (4) RASi reduced CRLM growth in the regenerating liver and altered immune cell composition by reducing populations of immunosuppressive MDSCs and boosting populations of PD-1+ hepatic TRMs. Thus, RASi should be explored as an adjunct therapy for patients undergoing partial hepatectomy for CRLM.
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    SARS-CoV-2 infection and venous thromboembolism after surgery: an international prospective cohort study
    Li, E (WILEY, 2022-01)
    SARS-CoV-2 has been associated with an increased rate of venous thromboembolism in critically ill patients. Since surgical patients are already at higher risk of venous thromboembolism than general populations, this study aimed to determine if patients with peri-operative or prior SARS-CoV-2 were at further increased risk of venous thromboembolism. We conducted a planned sub-study and analysis from an international, multicentre, prospective cohort study of elective and emergency patients undergoing surgery during October 2020. Patients from all surgical specialties were included. The primary outcome measure was venous thromboembolism (pulmonary embolism or deep vein thrombosis) within 30 days of surgery. SARS-CoV-2 diagnosis was defined as peri-operative (7 days before to 30 days after surgery); recent (1-6 weeks before surgery); previous (≥7 weeks before surgery); or none. Information on prophylaxis regimens or pre-operative anti-coagulation for baseline comorbidities was not available. Postoperative venous thromboembolism rate was 0.5% (666/123,591) in patients without SARS-CoV-2; 2.2% (50/2317) in patients with peri-operative SARS-CoV-2; 1.6% (15/953) in patients with recent SARS-CoV-2; and 1.0% (11/1148) in patients with previous SARS-CoV-2. After adjustment for confounding factors, patients with peri-operative (adjusted odds ratio 1.5 (95%CI 1.1-2.0)) and recent SARS-CoV-2 (1.9 (95%CI 1.2-3.3)) remained at higher risk of venous thromboembolism, with a borderline finding in previous SARS-CoV-2 (1.7 (95%CI 0.9-3.0)). Overall, venous thromboembolism was independently associated with 30-day mortality (5.4 (95%CI 4.3-6.7)). In patients with SARS-CoV-2, mortality without venous thromboembolism was 7.4% (319/4342) and with venous thromboembolism was 40.8% (31/76). Patients undergoing surgery with peri-operative or recent SARS-CoV-2 appear to be at increased risk of postoperative venous thromboembolism compared with patients with no history of SARS-CoV-2 infection. Optimal venous thromboembolism prophylaxis and treatment are unknown in this cohort of patients, and these data should be interpreted accordingly.
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    Age 80 years and over is not associated with increased morbidity and mortality following pancreaticoduodenectomy
    Kim, SY ; Fink, MA ; Perini, M ; Houli, N ; Weinberg, L ; Muralidharan, V ; Starkey, G ; Jones, RM ; Christophi, C ; Nikfarjam, M (WILEY, 2018-05)
    BACKGROUND: Pancreaticoduodenectomy (PD) is associated with high morbidity, which is perceived to be increased in the elderly. To our knowledge there have been no Australian series that have compared outcomes of patients over the age of 80 undergoing PD to those who are younger. METHODS: Patients who underwent PD between January 2008 and November 2015 were identified from a prospectively maintained database. RESULTS: A total of 165 patients underwent PD of whom 17 (10.3%) were aged 80 or over. The pre-operative health status, according to American Society of Anesthesiologists class was similar between the groups (P = 0.420). The 90-day mortality rates (5.9% in the elderly and 2% in the younger group; P = 0.355) and the post-operative complication rates (64.7% in the elderly versus 62.8% in the younger group; P = 0.88) were similar. Overall median length of hospital stay was also similar between the groups, but older patients were far more likely to be discharged to a rehabilitation facility than younger patients (47.1 versus 12.8%; P < 0.0001). Older patients with pancreatic adenocarcinoma (n = 10) had significantly lower median survival than the younger group (n = 69) (16.6 versus 22.5 months; P = 0.048). CONCLUSION: No significant differences were seen in the rate of complications following PD in patients aged 80 or over compared to younger patients, although there appears to be a shorter survival in the elderly patients treated for pancreatic cancer. Careful selection of elderly patients and optimal peri-operative care, rather than age should be used to determine whether surgical intervention is indicated in this patient group.
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    Post hepatectomy liver regeneration stimulates tumour progression in the residual liver
    Riddiough, G ; Kastrappis, G ; Paolini, R ; Fifis, T ; Perini, M ; Muralidharan, V ; Christophi, C (Elsevier BV, 2019)
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    Searching for the link; mechanisms underlying liver regeneration and recurrence of colorectal liver metastasis post partial hepatectomy
    Riddiough, GE ; Fifis, T ; Muralidharan, V ; Perini, MV ; Christophi, C (WILEY, 2019-08)
    Despite excellent treatment of primary colorectal cancer, the majority of deaths occur as a result of metastasis to the liver. Recent population studies have estimated that one quarter of patients with colorectal cancer will incur synchronous or metachronous colorectal liver metastasis. However, only one quarter of these patients will be eligible for potentially curative resection. Tumor recurrence occurs in reportedly 60% of patients undergoing hepatic resection, and the majority of intrahepatic recurrence occurs within the first 6 months of surgery. The livers innate ability to restore its homeostatic size, and volume facilitates major hepatic resection that currently offers the only chance of cure to patients with extensive hepatic metastases. Experimental and clinical evidence supports the notion that following partial hepatectomy, liver regeneration (LR) paradoxically drives tumor progression and increases the risk of recurrence. It is becoming increasingly clear that the processes that drive liver organogenesis, regeneration, and tumor progression are inextricably linked. This presents a major hurdle in the management of colorectal liver metastasis and other hepatic malignancies because therapies that reduce the risk of recurrence without hampering LR are sought. The processes and pathways underlying these phenomena are multiple, complex, and cross-communicate. In this review, we will summarize the common mechanisms contributing to both LR and tumor recurrence.
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    Bile duct resection for eosinophilic cholangitis
    Tai, J ; Perini, MV ; Azlanudin, A ; Muralidharan, V ; Christophi, C (WILEY, 2019-11)
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    Emergency presentations of acute biliary pain: changing patterns of management in a tertiary institute
    Cox, DRA ; Fong, J ; Liew, CH ; Goh, SK ; Yeoh, M ; Fink, MA ; Jones, RM ; Mukkadayil, J ; Nikfarjam, M ; Perini, MV ; Rumler, G ; Starkey, G ; Christophi, C ; Muralidharan, V (WILEY, 2018-12)
    BACKGROUND: Acute biliary pain is the most common presentation of gallstone disease. Untreated patients risk recurrent pain, cholecystitis, obstructive jaundice, pancreatitis and multiple hospital presentations. We examine the outcome of implementing a policy to offer laparoscopic cholecystectomy on index presentation to patients with biliary colic in a tertiary hospital in Australia. METHODS: This is a retrospective cohort study of adult patients presenting to the emergency department (ED) with biliary pain during three 12-month periods. Outcomes in Group A, 3 years prior to policy implementation, were compared with groups 2 and 7 years post implementation (Groups B and C). Primary outcomes were representations to ED, admission rate and time to cholecystectomy. RESULTS: A total of 584 patients presented with biliary colic during the three study periods. Of these, 391 underwent cholecystectomy with three Strasberg Type A bile leaks and no bile duct injuries. The policy increased admission rates (A = 15.8%, B = 62.9%, C = 29.5%, P < 0.001) and surgery on index presentation (A = 12.0%, B = 60.7%, C = 27.4%, P < 0.001). There was a decline in time to cholecystectomy (days) (A = 143, B = 15, C = 31, P < 0.001), post-operative length of stay (days) (A = 3.6, B = 3.2, C = 2.0, P < 0.05) and representation rates to ED (A = 42.1%, B = 7.1%, C = 19.9%, P < 0.001). There was a decline in policy adherence in the later cohort. CONCLUSION: Index hospital admission and cholecystectomy for biliary colic decrease patient representations, time to surgery, post-operative stay and complications of gallstone disease. This study demonstrates the impact of the policy with initial improvement, the dangers of policy attrition and the need for continued reinforcement.
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    Sentinel lymph node mapping in liver resection for colorectal liver metastases
    Perini, MV ; Tai, J ; Muralidharan, V ; Christophi, C (WILEY, 2019-07)