John Fletcher | The University of Sydney (original) (raw)

Papers by John Fletcher

Frontiers in Immunology, 2021

Dyslipidemia promotes development of the atherosclerotic plaques that characterise cardiovascular... more Dyslipidemia promotes development of the atherosclerotic plaques that characterise cardiovascular disease. Plaque progression requires the influx of monocytes into the vessel wall, but whether dyslipidemia is associated with an increased potential of monocytes to extravasate is largely unknown. Here (using flow cytometry) we examined recruitment marker expression on monocytes from generally healthy individuals who differed in lipid profile. Comparisons were made between monocyte subsets, participants and relative to participants’ lipid levels. Monocyte subsets differed significantly in their expression of recruitment markers, with highest expression being on either the classical or non-classical subsets. However, these inter-subset differences were largely overshadowed by considerable inter-participant differences with some participants having higher levels of recruitment markers on all three monocyte subsets. Furthermore, when the expression of one recruitment marker was high, so t...

Endovascular aneurysm repair (EVAR) was first performed at Westmead in 1994 with the EndoVascular... more Endovascular aneurysm repair (EVAR) was first performed at Westmead in 1994 with the EndoVascular Technology (EVT) "Ancure"  device. The advantage of this endograft was its unibody design with secure hook attachment system but it was considered more complex to use than other systems and required a large delivery sheath (27FG). We had 59 successful Ancure  implants up until 2000 when the device became unavailable and this cohort of patients has been carefully followed for a mean of 78 months. Early intervention for graft limb occlusion was needed in 15.3% and abdominal conversion was required in 5.1% (one within one month, one at three years and one at 9 years). There have been 25 late deaths (42.4%), none from AAA rupture. Endoleak rate was 15.3% with six patients requiring intervention (two open and four endovascular). Initial aneurysm diameter was significantly greater in patients with endoleak (p=0.03); an initial reduction of sac diameter occurred in both endoleak and non-endoleak patients but this reduction was not maintained in endoleak patients. Colour Doppler was an effective means of followup. Overall, the Ancure  device has been durable with no subsequent interventions needed in 85% of patients after the first three months following implantation, but late events out to nine years emphasise the need for indefinite follow-up. Since 2000 the Cook Zenith  device has been our stent-graft of choice. With 75% of abdominal aortic aneurysms now managed by EVAR, the decreasing proportion of open vascular surgery has major implications for vascular surgical training.

International angiology : a journal of the International Union of Angiology, 2008

Development of antithrombotic compounds has traditionally been performed in patients undergoing t... more Development of antithrombotic compounds has traditionally been performed in patients undergoing total hip and knee replacement surgery. A high number of asymptomatic deep-vein thromboses are radiologically detectable, and bleeding and other adverse events (AE) are easy to observe. However, standardization of study procedures and endpoints in early proof-of-concept studies and late pure clinical endpoint studies has been lacking. This has made comparison between studies difficult, economic analyses speculative and potential benefits of applying the drug regimen in non-selected patients uncertain. In this paper, the International Surgical Thrombosis Forum proposes a strategy for the clinical investigation of new pharmacological agents for the prophylaxis of postoperative thrombotic events. First, dose titration safety studies of short duration, in highly selected patients using objective venographic endpoints are recommended. Bleeding should be divided into the quantified volume of su...

Archives of Internal Medicine, 1992

Preventing pulmonary embolization by interrupting vena caval flow has been attempted since 1893. ... more Preventing pulmonary embolization by interrupting vena caval flow has been attempted since 1893. Inferior vena cava (IVC) filters have been available for 20 years, and currently there are five filters commercially available in the United States (Greenfield filter, Titanium Greenfield filter, Simon-Nitinol filter, Bird's Nest filter, and LGM or Vena Tech filter) and two other filters under development (Amplatz filter and Günther filter). Although these devices are widely used, their clinical utility and safety have not been completely evaluated. Controlled clinical trials to determine the clinical role for IVC filters have not been attempted, but numerous case series describing the outcomes of the seven current filters have been published. We have systematically reviewed these studies to clarify what is known about the indications, safety, and effectiveness of IVC filters. Using the MEDLINE database, all English-language publications since 1970 that included follow-up clinical information after filter insertion were reviewed and eight methodologic guidelines were employed to assess the scientific quality of the clinical information. Twenty-four case series were reviewed: 16 concerned the Greenfield filter (1632 patients), and eight dealt with newer designs (925 patients). Commonly noted methodologic problems included failure to report the initial extent of thromboembolic disease, incomplete description of the patient assembly process, and incomplete and potentially biased outcome assessment. Recurrent clinical pulmonary embolism was rare after filter placement, and only eight deaths from pulmonary embolism were reported. Filter complications were common but rarely life threatening; four (0.16%) deaths from filter complications were noted among the reviewed studies. Thrombotic complications following filter placement included insertion-site deep vein thrombosis and IVC obstruction. These events were rare, but they occurred with all filter types. Inferior vena cava filters appear to be effective in preventing recurrent pulmonary embolism. Despite the large published experience with IVC filters, many questions remain about their indications, safety, and effectiveness. Anticoagulant therapy, if not contraindicated, should be used in conjunction with filters. While there is no ideal filter, some situations call for specific filters. Filter selection and insertion require experience, modern angiographic technique, and collaboration between clinicians caring for patients and the interventional radiologists or surgeons inserting the device.

Introduction A prospective cohort study was conducted to assess the incidence of venous thromboem... more Introduction A prospective cohort study was conducted to assess the incidence of venous thromboembolism (VTE) in 300 patients undergoing elective spinal surgery. Although this subject has been extensively studied in patients undergoing joint replacement surgery, the true incidence of VTE related to spinal surgery remains unknown. We also sought to assess the efficacy of various forms of VTE prophylaxis, another area which has not been adequately studied. Methods Bilateral lower extremity venous duplex scans were performed pre-operatively, within one week postoperatively and at 4 to 6 weeks post-operatively. Information was collected regarding age, gender, body mass index, type and duration of surgical procedure, intra-operative blood loss and blood transfusion, pre- and post-operative mobility and other risk factors for VTE. All patients received vigorous mechanical prophylaxis with 56% of patients receiving pharmacological prophylaxis (unfractionated or low molecular weight heparin...

Journal of vascular surgery, Jan 28, 2016

The Covered vs Balloon Expandable Stent Trial (COBEST) is the first multicenter trial to investig... more The Covered vs Balloon Expandable Stent Trial (COBEST) is the first multicenter trial to investigate the patency of covered stents (CSs) and bare-metal stents (BMSs) in the treatment of aortoiliac arterial disease. The short-term results demonstrated that CSs were superior to BMSs in maintaining patency for TransAtlantic Inter-Society Consensus (TASC) C and D lesions at 18 months and were equivalent to BMSs for TASC B lesions. The current study was conducted to determine if the initial patency advantage of CSs over BMSs was sustained at the 5-year follow-up. A retrospective post hoc analysis of COBEST was performed. Originally, 125 patients with 168 iliac arteries were prospectively enrolled and randomly assigned to receive a CS or BMS. In this study, 77 of the 125 patients (61.6%; 119 limbs) were assessed at 60 months for the primary and secondary end points, with particular attention paid to the outcomes stratified according to TASC lesion severity. The primary end point was the r...

Medicine …, 2011

Symptomatic venous thromboembolism (VTE) is a leading cause of death after admission to hospital... more Symptomatic venous thromboembolism (VTE) is a leading cause of death after admission to hospital. Recognition of when to act before and after patients are admitted to hospital with VTE will help prevent mortality and morbidity. ... Symptomatic venous thromboembolism ...

The Medical journal of Australia

International Journal of Molecular Sciences, 2021

Monocytes play a key role in cardiovascular disease (CVD) as their influx into the vessel wall is... more Monocytes play a key role in cardiovascular disease (CVD) as their influx into the vessel wall is necessary for the development of an atherosclerotic plaque. Monocytes are, however, heterogeneous differentiating from classical monocytes through the intermediate subset to the nonclassical subset. While it is recognized that the percentage of intermediate and nonclassical monocytes are higher in individuals with CVD, accompanying changes in inflammatory markers suggest a functional impact on disease development that goes beyond the increased proportion of these ‘inflammatory’ monocyte subsets. Furthermore, emerging evidence indicates that changes in monocyte proportion and function arise in dyslipidemia, with lipid lowering medication having some effect on reversing these changes. This review explores the nature and number of monocyte subsets in CVD addressing what they are, when they arise, the effect of lipid lowering treatment, and the possible implications for plaque development. ...

Medical Journal of Australia, 1982

The sequelae of gastrectomy are well-known. This paper describes a complicated clinical course wh... more The sequelae of gastrectomy are well-known. This paper describes a complicated clinical course which occurred eight years after partial gastrectomy. Initial features included marked weight loss, anaemia, multiple lung and liver abscesses, and cholestatic jaundice. Acalculous cholecystitis with a mucocele of the gallbladder developed later. We emphasise the value of total parenteral nutrition in supporting such critically ill patients.

Journal of Quality In Clinical Practice, 1999

A planned surgical admission is a major event for a patient and, when cancelled, not only causes ... more A planned surgical admission is a major event for a patient and, when cancelled, not only causes great distress to the patient and relatives but is also a frustrating waste of resources if a fully staffed operating theatre lies idle. At Westmead Hospital, a bed management team was established with the appointment of a Clinical Nurse Consultant as Bed Manager to coordinate admissions in conjunction with all staff involved in the processing of surgical patients. Despite a reduced number of available surgical beds, throughput was maintained with a significantly reduced number of cancelled booked cases, which decreased to zero and have remained so since the end of 1995. It has been found that it is possible to achieve a situation where all booked surgical patients can be admitted as planned while still providing for emergency patients. This requires a coordinated approach with an emphasis on teamwork led by a dedicated Bed Manager working with medical and nursing staff on surgical wards together with the bookings office, pre-admission clinic, operating theatre and anaesthetics department.

International angiology : a journal of the International Union of Angiology, 1997

The incidence of deep vein thrombosis (DVT) has been well documented in general and orthopaedic s... more The incidence of deep vein thrombosis (DVT) has been well documented in general and orthopaedic surgery but there have been few reports of the incidence of DVT following vascular surgery. Our aim was to perform a prospective study of the incidence of DVT in patients managed on the Vascular Unit at our institution. One hundred and forty two consecutive patients presenting for repair of abdominal aortic aneurysm, reconstruction of lower extremity arterial occlusive disease or amputation were studied. Venous duplex ultrasound examination was performed preoperatively and between day seven to 10 postoperatively. All patients received standard DVT prophylaxis of 5,000 units of unfractionated heparin subcutaneously three times daily and intraoperative sequential compression devices. Fourteen patients (9.8%) were found to have postoperative DVT with one patient (0.7%) having a documented pulmonary embolism. The incidence of DVT following reconstructive surgery was 9.1% and 14.3% following a...

Annals of the Royal College of Surgeons of England, 1984

Carotid endarterectomy was performed 28 times in 27 patients. All but one patient had symptomatic... more Carotid endarterectomy was performed 28 times in 27 patients. All but one patient had symptomatic carotid artery disease, 59% had bilateral disease and 59% had associated intracranial disease. Barbiturate therapy was used as a means of cerebral protection during carotid artery cross-clamping. Neurological deficit occurred in two patients, being permanent in one patient (3.5%); both patients had bilateral carotid and intracranial disease and both had carotid stump pressures greater than 55 mmHg. No morbidity could be attributed to barbiturate usage.

Annals of the Royal College of Surgeons of England, 1988

Two hundred and twenty-six central venous catheters were placed in 195 consecutive patients requi... more Two hundred and twenty-six central venous catheters were placed in 195 consecutive patients requiring central venous catheterisation for total parenteral nutrition (TPN). Of these 226 catheters, 198 were placed percutaneously into the subclavian vein by the infraclavicular route. In 99 consecutive subclavian catheter insertions, a 12G needle with introducing sheath was used to puncture the vein (Group 1). The Seldinger method of catheterisation was used in another 99 consecutive subclavian catheter insertions (Group 2), the vein being punctured with a 19G needle. Pneumothorax occurred on three occasions (3.0%) in Group 1 but did not occur in Group 2. However, there were two episodes of pleural extravasation in Group 2 (2.0%) which may have been due to guide wire perforation of a central vein; this complication did not occur in Group 1. Although the Seldinger technique of insertion should reduce the incidence of pneumothorax, care should be taken in passage of the guide wire.

Surgery, 1986

The nitrogen balance in 28 patients undergoing aortic grafting for aneurysm or occlusive disease ... more The nitrogen balance in 28 patients undergoing aortic grafting for aneurysm or occlusive disease was studied. Patients were randomized to receive after surgery either standard intravenous fluids (group 1), parenteral nutrition (group 2), or early postoperative enteral feeding (group 3). The mean daily negative nitrogen balance was 11.22 gm in group 1, 4.20 gm in group 2, and 4.14 gm in group 3. The difference between group 1 and groups 2 and 3 was highly significant (p less than 0.001), but there was no significant difference between groups 2 and 3. It is concluded that early postoperative enteral feeding can be as effective as parenteral nutrition in reducing the negative nitrogen balance induced by major surgery.

Insall & Scott Surgery of the Knee, 2012

Cardiovascular Surgery, 1997

Femoropopiiteal I C~~~&.&WZS: Postoperative outcome of arterial reconstruction in octogenarians w... more Femoropopiiteal I C~~~&.&WZS: Postoperative outcome of arterial reconstruction in octogenarians with limb threatening &hernia and the diabetic patients with gangrenous foot was extremely poor, and criteria of surgical indication remain controversial. However, the results of reconstructive arterial surgery including tibia1 arterial bypass were acceptably good with regard to mortality and limb salvage rates in patients without these medical conditions.

Journal of Parenteral and Enteral Nutrition, 1987

Serum transferrin and prealbumin levels were determined at intervals of 3 to 4 days in 16 patient... more Serum transferrin and prealbumin levels were determined at intervals of 3 to 4 days in 16 patients requiring nutritional support. Caloric and nitrogen intake were measured and nitrogen balance calculated. There were 117 intervals available for analysis. A mean decrease in transferrin of 12.95 mg/dl was associated with a mean decrease in nitrogen balance of 0.92 g/day, whereas a mean increase in transferrin of 21.04 mg/dl was associated with a mean increase in nitrogen balance of 1.49 g/day; the correlation between changes in transferrin with changes in nitrogen balance was statistically significant (p = 0.02). Upward and downward changes in prealbumin were also associated with corresponding changes in nitrogen balance, but the changes were not statistically significant. Decreases in transferrin and prealbumin were also associated with a lower caloric intake. Operation caused a significant decrease in prealbumin (p = 0.003) and nitrogen balance (p = 0.05); a decrease in transferrin also occurred, but was not statistically significant. There was a highly significant correlation between serum transferrin and prealbumin (p = 0.001) and also between the interval changes in transferrin and prealbumin (p less than 0.001). In conclusion, transferrin was found to correlate closely with prealbumin. Changes in transferrin were more significantly related to changes in nitrogen balance, and from the results of this study, measurement of serum transferrin can be recommended as a useful parameter in following the nutritional status of patients receiving nutritional support.