Surgery (Austin & Northern Health) - Research Publications
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ItemAge 80 years and over is not associated with increased morbidity and mortality following pancreaticoduodenectomy(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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ItemEmergency presentations of acute biliary pain: changing patterns of management in a tertiary institute(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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ItemInduction of Th1Immune responses following laser ablation in a murine model of colorectal liver metastases(BIOMED CENTRAL LTD, 2011-05-29)BACKGROUND: Preliminary experimental studies have suggested that the in situ destruction of tumor tissue by local laser ablation (LA) may also stimulate host immunity against cancer. We investigated local and systemic induction of immune responses after laser ablation in the setting of residual tumor. METHODS: A murine colorectal cancer (CRC) liver metastasis model was used. Selected tumors of liver CRC bearing mice and livers of mice without tumor induction were treated with LA. Liver and tumor tissues from the ablation sites and from distant sites were collected at various time points following LA and changes in CD3+ T cells and Kupffer cells (F4/80 marker) infiltration and the expression of interferon gamma (IFNγ) were investigated by immunohistochemistry and ELISpot. Base line levels of CD3+ T cells and Kupffer cells were established in untreated mice. RESULTS: The presence of tumor induced significant accumulation of CD3+ T cells and Kupffer cells at the tumor-host interface, within the tumor vascular lakes and increased their baseline concentration within the liver parenchyma. LA of the liver induced accumulation of CD3+ T-cells and Kupffer cells at the site of injury and systemic induction of immune responses as discerned by the presence of IFNγ secreting splenocytes. LA of liver tumors induced significant increase of CD3+ T-cells at site of injury, within normal liver parenchyma, and the tumor-host interface of both ablated and distant tumors. In contrast Kupffer cells only accumulated in ablated tumors and the liver parenchyma but not in distant tumors. IFNγ expression increased significantly in ablated tumors and showed an increasing trend in distant tumors. CONCLUSION: Laser ablation in addition to local tumor destruction induces local and systemic Th1 type immune responses which may play a significant role in inhibiting tumor recurrence from residual micrometastases or circulating tumor cells.
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ItemTreatment with the vascular disruptive agent OXi4503 induces an immediate and widespread epithelial to mesenchymal transition in the surviving tumor(WILEY-BLACKWELL, 2013-10)Epithelial to mesenchymal transition (EMT) is considered an important mechanism in tumor resistance to drug treatments; however, in vivo observation of this process has been limited. In this study we demonstrated an immediate and widespread EMT involving all surviving tumor cells following treatment of a mouse model of colorectal liver metastases with the vascular disruptive agent OXi4503. EMT was characterized by significant downregulation of E-cadherin, relocation and nuclear accumulation of β-catenin as well as significant upregulation of ZEB1 and vimentin. Concomitantly, significant temporal upregulation in hypoxia and the pro-angiogenic growth factors hypoxia-inducible factor 1-alpha, hepatocyte growth factor, vascular endothelial growth factor and transforming growth factor-beta were seen within the surviving tumor. The process of EMT was transient and by 5 days after treatment tumor cell reversion to epithelial morphology was evident. This reversal, termed mesenchymal to epithelial transition (MET) is a process implicated in the development of new metastases but has not been observed in vivo histologically. Similar EMT changes were observed in response to other antitumor treatments including chemotherapy, thermal ablation, and antiangiogenic treatments in our mouse colorectal metastasis model and in a murine orthotopic breast cancer model after OXi4503 treatment. These results suggest that EMT may be an early mechanism adopted by tumors in response to injury and hypoxic stress, such that inhibition of EMT in combination with other therapies could play a significant role in future cancer therapy.
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ItemAssessment of Liver Remnant Using ICG Clearance Intraoperatively during Vascular Exclusion: Early Experience with the ALIIVE Technique.(Hindawi Limited, 2015)Background. The most significant risk following major hepatectomy is postoperative liver insufficiency. Current preoperative assessment of the future liver remnant relies upon assumptions which may not be valid in the setting of advanced resection strategies. This paper reports the feasibility of the ALIIVE technique which assesses the liver remnant with ICG clearance intraoperatively during vascular exclusion. Methods. 10 patients undergoing planned major liver resection (hemihepatectomy or greater) were recruited. Routine preoperative assessment included CT and standardized volumetry. ICG clearance was measured noninvasively using a finger spectrophotometer at various time points including following parenchymal transection during inflow and outflow occlusion before vascular division, the ALIIVE step. Results. There were one case of mortality and three cases of posthepatectomy liver failure. The patient who died had the lowest ALIIVE ICG clearance (7.1%/min versus 14.4 ± 4.9). Routine preoperative CT and standardized volumetry did not predict outcome. Discussion/Conclusion. The novel ALIIVE technique is feasible and assesses actual future liver remnant function before the point of no return during major hepatectomy. This technique may be useful as a check step to offer a margin of safety to prevent posthepatectomy liver failure and death. Further confirmatory studies are required to determine a safety cutoff level.
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ItemImpact of a goal directed fluid therapy algorithm on postoperative morbidity in patients undergoing open right hepatectomy: a single centre retrospective observational study(BMC, 2019-07-31)BACKGROUND: Right hepatectomy is a complex procedure that carries inherent risks of perioperative morbidity. To evaluate outcome differences between a low central venous pressure fluid intervention strategy and a goal directed fluid therapy (GDFT) cardiac output algorithm we performed a retrospective observational study. We hypothesized that a GDFT protocol would result in less intraoperative fluid administration, reduced complications and a shorter length of hospital stay. METHODS: Patients undergoing hepatectomy using an established enhanced recovery after surgery (ERAS) programme between 2010 and 2017 were extracted from a prospectively managed electronic hospital database. Inclusion criteria included adult patients, undergoing open right (segments V-VIII) or extended right (segments IV-VIII) hepatectomy. PRIMARY OUTCOME: amount of intraoperative fluid administration used between the two groups. SECONDARY OUTCOMES: type and amount of vasoactive medications used, the development of predefined postoperative complications, hospital length of stay, and 30-day mortality. Complications were defined by the European Perioperative Clinical Outcome definitions and graded according to Clavien-Dindo classification. The association between GDFT and the amount of fluid and vasoactive medication used was investigated using logistic and linear regression models. RESULTS: Fifty-eight consecutive patients were identified. 26 patients received GDFT and 32 received Usual care. There were no significant differences in baseline patient characteristics. Less intraoperative fluid was used in the GDFT group: median (IQR) 2000 ml (1175 to 2700) vs. 2750 ml (2000 to 4000) in the Usual care group; p = 0.03. There were no significant differences in the use of vasoactive medications. Postoperative complications were similar: 9 patients (35%) in the GDFT group vs. 18 patients (56%) in the Usual care group; p = 0.10, OR: 0.41; (95%CI: 0.14 to 1.20). Median (IQR) length of stay for patients in the GDFT group was 7 days (6:8) vs. 9 days (7:13) in the Usual care group; incident rate ratio 0.72 (95%CI: 0.56 to 0.93); p = 0.012. There was no difference in perioperative mortality. CONCLUSIONS: In patients undergoing open right hepatectomy with an established ERAS programme, use of GDFT was associated with less intraoperative fluid administration and reduced hospital length of stay when compared to Usual care. There were no significant differences in postoperative complications or mortality. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry: no 12619000558123 on 10/4/19.
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ItemBiliary stenting versus surgical bypass for palliation of periampullary malignancy(SPRINGER INDIA, 2013-03)BACKGROUND: Patients with periampullary cancers may not be suitable for curative resection due to locally advanced disease, metastases, or poor health. Biliary stenting and surgical bypass are utilized for symptom control, but the true benefit of one technique over the other is not clear. METHODS: A retrospective analysis of case records was undertaken of patients with periampullary (pancreatic head/uncinate process, distal bile duct, and ampulla of Vater and surrounding duodenum) malignancy treated between June 2004 and June 2010 in a tertiary center by palliative biliary stenting or palliative surgical bypass. RESULTS: Of the 69 patients included in the analysis, combined biliary and gastric bypass was performed on 28, while 41 underwent biliary stent (metallic, n = 39) insertion. Patients undergoing stenting were significantly older and less likely to be offered chemotherapy than those from the surgical bypass group. Overall, there were significantly more complications in the stent insertion group (85 %) than the surgical bypass group (36 %) (p = 0.003). The stent group required significantly more subsequent procedures than the surgical bypass group. Metal stent obstruction occurred in 16 of 39 (41 %) patients, with a median stent patency of 224 days. The overall median survival of patients in this study was 7 months with no significant difference between the groups (p = 0.992). The presence of metastases at presentation was the only independent factor associated with decreased survival. CONCLUSION: There was no survival difference between stenting vs. surgical bypass for palliation of periampullary cancer. There was, however, a high rate of stent occlusion and need for repeat procedures in patients treated by metal stenting, suggesting that stenting may be best suited to patients predicted as having the shortest survival.
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ItemPressurized Pulse Irrigation with Saline Reduces Surgical-site Infections following Major Hepatobiliary and Pancreatic Surgery: Randomized Controlled Trial(SPRINGER, 2014-02)BACKGROUND: Surgical site infections (SSI) are a significant cause of postoperative morbidity. Pressurized pulse irrigation of subcutaneous tissues may lower infection rates by aiding in the debridement of necrotic tissue and reducing bacterial counts compared to simply pouring saline into the wound. METHODS: A total of 128 patients undergoing laparotomy extending beyond 2 h were randomized to treatment of wounds by pressurized pulse lavage irrigation (<15 psi) with 2 L normal saline (pulse irrigation group), or to standard irrigation with 2 L normal saline poured into the wound, immediately prior to skin closure (standard group). Only elective cases were included, and all cases were performed within a specialized hepatobiliary and pancreatic surgery unit. RESULTS: There were 62 patients managed by standard irrigation and 68 were managed by pulse irrigation. The groups were comparable in most aspects. Overall there were 16 (13 %) SSI. Significantly fewer SSI occurred in the pulse irrigation group [4 (6 %) vs. 12 (19 %); p = 0.032]. On multivariate analysis, the use of pulse irrigation was the only factor associated with a reduction in SSI with an odds ratio (OR) of 0.3 [95 % confidence interval (95 % CI) 0.1-0.8; p = 0.031]. In contrast, hospital length of stay of greater than 14 days was associated with increased infections with an OR of 7.6 (95 % CI 2.4-24.9; p = 0.001). CONCLUSIONS: Pulse irrigation of laparotomy wounds in operations exceeding 2 h duration reduced SSI after major hepatobiliary pancreatic surgery. (Australian New Zealand Clinical Trials Registry, ACTRN12612000170820).
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ItemRestrictive intraoperative fluid optimisation algorithm improves outcomes in patients undergoing pancreaticoduodenectomy: A prospective multicentre randomized controlled trial(PUBLIC LIBRARY SCIENCE, 2017-09-07)We aimed to evaluate perioperative outcomes in patients undergoing pancreaticoduodenectomy with or without a cardiac output goal directed therapy (GDT) algorithm. We conducted a multicentre randomised controlled trial in four high volume hepatobiliary-pancreatic surgery centres. We evaluated whether the additional impact of a intraoperative fluid optimisation algorithm would influence the amount of fluid delivered, reduce fluid related complications, and improve length of hospital stay. Fifty-two consecutive adult patients were recruited. The median (IQR) duration of surgery was 8.6 hours (7.1:9.6) in the GDT group vs. 7.8 hours (6.8:9.0) in the usual care group (p = 0.2). Intraoperative fluid balance was 1005mL (475:1873) in the GDT group vs. 3300mL (2474:3874) in the usual care group (p<0.0001). Total volume of fluid administered intraoperatively was also lower in the GDT group: 2050mL (1313:2700) vs. 4088mL (3400:4525), p<0.0001 and vasoactive medications were used more frequently. There were no significant differences in proportions of patients experiencing overall complications (p = 0.179); however, fewer complications occurred in the GDT group: 44 vs. 92 (Incidence Rate Ratio: 0.41; 95%CI 0.24 to 0.69, p = 0.001). Median (IQR) length of hospital stay was 9.5 days (IQR: 7.0, 14.3) in the GDT vs. 12.5 days in the usual care group (IQR: 9.0, 22.3) for an Incidence Rate Ratio 0.64 (95% CI 0.48 to 0.85, p = 0.002). In conclusion, using a surgery-specific, patient-specific goal directed restrictive fluid therapy algorithm in this cohort of patients, can justify using enough fluid without causing oedema, yet as little fluid as possible without causing hypovolaemia i.e. "precision" fluid therapy. Our findings support the use of a perioperative haemodynamic optimization plan that prioritizes preservation of cardiac output and organ perfusion pressure by judicious use of fluid therapy, rational use of vasoactive drugs and timely application of inotropic drugs. They also suggest the need for further larger studies to confirm its findings.
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ItemSpatial morphological and molecular differences within solid tumors may contribute to the failure of vascular disruptive agent treatments(BIOMED CENTRAL LTD, 2012-11-15)BACKGROUND: Treatment of solid tumors with vascular disrupting agent OXi4503 results in over 90% tumor destruction. However, a thin rim of viable cells persists in the tumor periphery following treatment, contributing to subsequent recurrence. This study investigates inherent differences in the microenvironment of the tumor periphery that contribute to treatment resistance. METHODS: Using a murine colorectal liver metastases model, spatial morphological and molecular differences within the periphery and the center of the tumor that may account for differences in resistance to OXi4503 treatment were investigated. H&E staining and immunostaining were used to examine vessel maturity and stability, hypoxia and HIF1α levels, accumulation of immune cells, expression of proangiogenic factors/receptors (VEGF, TGF-β, b-FGF, and AT1R) and expression of EMT markers (ZEB1, vimentin, E-cadherin and β-catenin) in the periphery and center of established tumors. The effects of OXi4503 on tumor vessels and cell kinetics were also investigated. RESULTS: Significant differences were found between tumor periphery and central regions, including association of the periphery with mature vessels, higher accumulation of immune cells, increased growth factor expression, minimal levels of hypoxia and increased evidence of EMT. OXi4503 treatment resulted in collapse of vessels in the tumor center; however vasculature in the periphery remained patent. Similarly, tumor apoptosis and proliferation were differentially modulated between centre and periphery after treatment. CONCLUSIONS: The molecular and morphological differences between tumor periphery and center may account for the observed differential resistance to OXi4503 treatment and could provide targets for drug development to totally eliminate metastases.