Patient Factors Influencing Prescription of Antithrombotic Medication After Lower Limb Endovascular Intervention.

OBJECTIVE: There is significant practice variation in the use of antithrombotic therapy after endovascular intervention for lower limb peripheral arterial disease, with differences in medication choice and duration. Prescriber decision making is complex, and patient factors have been shown to substantially contribute to prescribing variation. To determine the influence of patient factors on antithrombotic prescribing, a discrete choice experiment was distributed to vascular surgeons and trainees across Australia and Aotearoa New Zealand. METHODS: After pilot testing, the discrete choice experiment questionnaire was distributed to 300 vascular surgeons and trainee members of the Australian and New Zealand Society for Vascular Surgery. Multinomial logistic regression models were used to analyse patient factors that had the most influence on decisions to prescribe a second antithrombotic agent, and the preferred choice of antithrombotic (clopidogrel 75 mg daily or rivaroxaban 2.5 mg twice daily) in addition to aspirin 100 mg daily. The odds ratio (OR) with 95% confidence interval (CI) reported preference strength. RESULTS: A total of 44 questionnaires were completed between September and October 2023, reaching the 15% targeted response rate. Prescribing a second antithrombotic was more likely after femoropopliteal stenting compared with angioplasty (OR 1.89, 95% CI 1.20 - 2.13), and in chronic limb threatening ischaemia compared with intermittent claudication (OR 1.58, 95% CI 1.20 - 2.13). Most respondents preferred clopidogrel over rivaroxaban (62%), with over a third of respondents exclusively prescribing clopidogrel. Patients with stents (OR 1.77, 95% CI 1.32 - 2.37) or moderate bleeding risk (OR 1.38, 95% CI 0.97 - 1.84) were more likely to receive clopidogrel than rivaroxaban. CONCLUSION: This study demonstrates that vascular surgeons primarily prioritise antithrombotic prescribing decisions by procedure type. Clopidogrel is more likely to be prescribed than rivaroxaban as a second agent in combination with aspirin, especially after stenting. Knowing these clinician preferences can target implementation strategies towards supporting decision making in subgroups of patients according to individual risk profiles.

Prescriber decision-making on antithrombotic therapy after endovascular intervention for peripheral artery disease: a protocol for a discrete choice experiment.

INTRODUCTION: Peripheral artery disease (PAD) is a major risk factor for cardiovascular morbidity and mortality, despite surgical and endovascular treatments. Emerging evidence supports the use of immediate antithrombotic medications after endovascular intervention for PAD, however, there is a lack of consensus regarding choice and duration of antithrombotic therapy. Prescriber decision-making is a complex process, with prior studies demonstrating patient factors can influence variability in antithrombotic therapy for PAD. However, it remains unclear the relative contribution of these factors. This paper describes a planned study that aims to (1) determine the influence of patient factors on clinician preference for antithrombotic therapy following endovascular intervention and (2) compare differences in prescribing preferences between consultant vascular surgeons and trainees. METHODS AND ANALYSIS: This cross-sectional survey will evaluate antithrombotic prescribing choices using a discrete choice experiment (DCE) that has been developed and piloted for this study. A list of attributes and levels was generated using a mixed-methods approach. This included an extensive literature review and semistructured interviews with prescribing clinicians. Following final selection of included attributes, specialised software was used to construct a D-efficient design for the DCE questionnaire. The electronic questionnaire will be administered to vascular trainees and consultant surgeons across Australia. These data will be analysed using multinomial logistic regression, treating the decision to prescribe antithrombotic therapy as a function of both the attributes of the two alternatives, as well as characteristics of the respondent. Latent class analysis will be used to explore heterogeneity of responses. ETHICS AND DISSEMINATION: Ethics approval was obtained from the University of Sydney Human Ethics committee (2023/474). The results of this study will be published in peer-reviewed journals and presented at national vascular surgical conferences. These results will be used to improve understanding how clinicians make prescribing decisions and to inform future strategy to enhance guideline-directed prescribing.

Clinical algorithm for the management of advanced pelvic tumours involving the aortoiliac axis.

Pelvic exenteration offers potentially curative treatment for locally advanced and recurrent pelvic tumours. Laterally infiltrating tumours involving the pelvic sidewall have historically been considered unresectable. Highly specialised exenteration units have accumulated experience with en bloc resection of part or all of the iliac vascular system for tumours with major vessel involvement. These approaches involve complex vascular dissection and reconstructive techniques requiring collaboration with the vascular surgery unit. Adding to the complexity is the paucity of evidence on oncovascular techniques in the pelvis given its developing nature. An algorithm for the workup to determine resectability and the vascular reconstruction approach for advanced pelvic tumours involving the aortoiliac axis is suggested based on current literature and personal experience from the authors' unit.

The evolution of oncovascular pelvic surgery: A historical perspective.

Pelvic exenteration surgery has evolved dramatically in recent decades and now represents the standard of care for many patients with advanced pelvic malignancy. Most recently the use of complex vascular resection and reconstructive techniques have been applied in advanced pelvic oncology surgery at specialist units and these oncovascular techniques are considered one of the frontiers in this field. This article summaries the historical evolution of oncovascular surgery in the pelvis and sets the scene for where this treatment is going. The role of vascular resection and reconstruction in curative treatment of advanced pelvic malignancy is an evolving area that is redefining the boundaries of what was historically thought possible.

Oncovascular surgery for advanced pelvic malignancy.

BACKGROUND: The number of units with experience in extended radical resections for advanced pelvic tumours has grown substantially in recent years. The use of complex vascular resections and reconstructive techniques in these units is expected to increase with experience. This review aimed to provide a cutting-edge overview of this evolving surgical approach to complex pelvic tumours with vascular involvement. METHODS: This was a narrative review of published data on major vascular resection and reconstruction for advanced pelvic tumours, including preoperative evaluation, techniques used, and outcomes. Advice for treatment decisions is provided, and based on current literature and the personal experience of the authors. Current controversies and future directions are discussed. RESULTS: Major vascular resection and reconstruction during surgery for advanced pelvic tumours is associated with prolonged operating time (510-678 min) and significant blood loss (median 2-5 l). R0 resection can be achieved in 58-82 per cent at contemporary specialist units. The risk of major complications is similar to that of extended pelvic resection without vascular involvement (30-40 per cent) and perioperative mortality is acceptable (0-4 per cent). Long-term survival is achievable in approximately 50 per cent of patients. CONCLUSION: En bloc resection of the common or external iliac vessels during exenterative pelvic surgery is a feasible strategy for patients with advanced tumours which infiltrate major pelvic vascular structures. Oncological, morbidity, and survival outcomes appear comparable to more central pelvic tumours. These encouraging outcomes, combined with an increasing interest in extended pelvic resections globally, will likely lead to more exenteration units developing oncovascular experience.

En bloc resection of the common or external iliac vessels during exenterative pelvic surgery is a feasible strategy for patients with advanced tumours. The risk of major complications is similar to that of extended pelvic resection without vascular involvement (30­40 per cent), and the risk of mortality or limb loss is very low in contemporary practice (0­4 per cent and 0 per cent, respectively). Oncological and survival outcomes appear comparable to more central pelvic tumours. The choice of interposition grafts remains contentious. Where the common or external iliac vein is chronically stenosed or occluded, ligation without reconstruction can be safely performed and avoids the risk of thrombosis and pulmonary embolism. Comparative long-term data on pre-emptive extra anatomical reconstruction versus intraoperative anatomical reconstruction is required.

Desmoid fibromatosis involving the ureter: A rare presentation with intraoperative challenges.

Following failed retrograde and antegrade ureteric stenting, a 35-year-old male patient underwent an elective boari flap for marked proximal hydroureteronephrosis due to a periureteric mass in the right iliac fossa. Intraoperative vascular surgical assistance was required for control of arterial bleeding due to friable vessel wall. Histopathology demonstrated desmoid fibromatosis.

Variation in treatment and outcomes for patients with chronic limb-threatening ischaemia in New South Wales, Australia.

BACKGROUND: Chronic limb-threatening ischaemia (CLTI) carries significant amputation and mortality risks. Australian population-based outcomes for CLTI are inadequately known. This study aimed to distinguish factors associated with outcomes in the first 2 years after CLTI surgery. METHODS: By linking routinely collected health administrative and mortality data from New South Wales, this population-based cohort study identified patients with ischaemic rest pain, gangrene or ulceration undergoing vascular surgery in public hospitals between 2010 and 2012. The primary outcome was 2-year amputation-free survival (AFS), and secondary outcomes included readmission and reoperation rates. Multivariable regression analysis identified prognostic factors adjusted for patient, hospital and geographic factors. RESULTS: Primary CLTI surgery was performed on 4898 patients. Almost half the cohort had minor amputations without concurrent revascularization (2398, 49%), and the remaining patients had open (652, 13%) or endovascular (1848, 38%) surgery. At 2-years, the AFS rate was 72%. Significant disparity was seen between age groups, with the 2-year AFS 71% in patients aged 75 years or older, compared to 95% in patients aged less than 75 years (P < 0.001). Place of residence or hospital training status did not significantly influence AFS or readmission, but non-training hospitals had higher rates of reoperation. CONCLUSION: This population-based cohort study demonstrated variable outcomes for patients with CLTI, particularly with respect to older age, admission acuity and comorbidity. Results may guide service improvements however further research is needed into how population-wide health initiatives can address age-related disparities in CLTI.

An unusual case of upper limb ischemia in a marathon runner.

Acute limb ischemia in young adults warrants thorough investigation to determine the underlying cause. Here, we present a case of acute upper limb ischemia in a marathon runner secondary to paradoxical embolism. The patient had associated deep venous thrombosis of the lower limb with multiple pulmonary emboli and patent foramen ovale. This case report emphasizes the under-recognition of intense endurance exercise as a risk factor for venous thromboembolism and highlights the potentially debilitating embolic sequelae of venous thromboembolism in patients with patent foramen ovale.

Paget-Schroetter syndrome: A contemporary review of the controversies in management.

AIM: To assess the current evidence, controversies and technologies behind the various approaches and steps in the management of Paget-Schroetter syndrome. MATERIALS AND METHODS: We performed a narrative review based on a literature search in Embase, Medline, Pubmed and Google Scholar through keyword searching related to upper extremity deep vein thrombosis, Paget-Schroetter syndrome and venous thoracic outlet syndrome. RESULTS: There is a paucity of high-quality evidence assessing the efficacy of contemporary approaches for the management of acute upper extremity deep vein thrombosis which, though promising, is largely limited to single institution case studies and small series. As a result, a formal systematic review could not be performed. CONCLUSIONS: Paget-Schroetter syndrome is a rare condition, whose management approaches are largely guided by the accumulated expertise and clinical experience of vascular specialists. In the absence of randomized controlled trials, current practice has been guided by retrospective reviews and experience. Modern approaches and protocols appear to remain distinct between health care facilities, but have common features including early clot lysis, surgical decompression with first rib resection, followed by adjunctive open or endovascular procedures. Further high-quality level 1 evidence and research are required in order to standardize treatment for this condition.

Rare case of a proximal descending thoracic aorta mycotic aneurysm following intravesical BCG injections for the treatment of bladder cancer.

A 79-year-old man presented with an enlarging thoracic aneurysm on the background of superficial bladder cancer treated with intravesical bacillus Calmette-Guérin (BCG) injections. Following the injections, he developed deranged liver function tests and hepatomegaly. Liver biopsy revealed granulomatous hepatitis compatible with disseminated mycobacterial infection (BCG-osis) and was treated with anti-tuberculosis agents for 12 months. A surveillance CT scan performed as a follow-up for his bladder cancer in 2018 revealed a saccular thoracic aneurysm at the ligamentum arteriosum, which was metabolically active on positron emission tomography (PET) scan. Given the timeframe from intravesical instillation of BCG and the metabolic activity on PET scan, the lesion was consistent with a mycotic aneurysm secondary to disseminated mycobacterial infection. Following multidisciplinary team discussion, a thoracic endovascular aneurysm repair was performed. The stent grafts were placed distal to the left subclavian artery with good angiographic results and no immediate postoperative complications. He was initiated on long-term antibiotics to cover potential bacterial pathogens including mycobacterium.

Functional magnetic resonance angiography in the diagnosis of iliac artery endofibrosis in an endurance runner.

A 45-year-old woman was presented with a 2-year history of left lower limb claudication symptoms occurring only during long-distance running. Multimodal imaging with exercise duplex ultrasonography and magnetic resonance angiogram confirmed the presence of flow-limiting stenoses in the left external iliac artery consistent with a diagnosis of left external iliac artery endofibrosis. She successfully underwent a left external iliac endarterectomy with vein patch repair and returned to full physical activity soon after. A year following full recovery from her original operation, she presented with similar symptoms on the right side and was managed in a similar manner. This report illustrates an unusual case of bilateral iliac artery endofibrosis occurring in an older endurance runner. We also present a novel diagnostic modality of pre-exercise and postexercise magnetic resonance angiography for iliac endofibrosis.

Early outcomes using dedicated venous stents in the upper limb of patients with venous thoracic outlet syndrome: A single centre experience.

INTRODUCTION: Surgical management of Venous Thoracic Outlet Syndrome (vTOS) is based upon resection of the first rib. The optimal method to treat any residual venous scarring however remains unclear. The purpose of this study was to evaluate a single quaternary centre's early and mid-term outcomes following endovascular reconstruction of the axillo-subclavian vein using dedicated venous stents in patients with VTOS. METHODOLOGY: A retrospective analysis of patients at Royal Prince Alfred Hospital, who underwent upper limb deep venous stenting as an adjunct in the treatment of vTOS was performed. All patients between 2012 and 2017 were included. Stent patency was assessed with duplex ultrasonography. All re-interventions and their indications were recorded. RESULTS: A total of 24 limbs in 21 patients (13 female, median age 44 yrs) were treated with dedicated venous stents between 2012 and 2017. All patients had resection of their first rib using a transaxillary approach. Nine patients initially presented with an acute DVT and underwent thrombolysis. In three of these patients a venous stent was placed before rib resection following completion of lysis. In the remainder, the median time for stent placement following surgery was 64 days. Median follow-up from stent insertion was 50 months. Primary, primary-assisted and secondary patency at 24 months was 55%, 95% and 100% respectively with one patient lost during follow-up. There were no major complications. A total of 14 re-interventions were performed on these patients. Three patients reported residual symptoms following stenting including heaviness (n = 1), bluish discolouration (n = 1) and prominent veins on the chest (n = 1) with the remainder asymptomatic. CONCLUSION: In this single centre study, endovascular reconstruction using dedicated venous stents appears to be an effective and safe method to reconstruct a damaged subclavian vein following rib resection in patients with vTOS.

Extramammary Paget's disease of the perianal region: a 20-year experience.

BACKGROUND: To evaluate the results obtained from cases of perianal Paget's disease (PPD) and to provide a current perspective in the diagnostic evaluation and surgical management of this condition. METHODS: A retrospective review of a single quaternary referral centre's experience with PPD from January 1994 to December 2013 was performed. Medical records were reviewed to collect data on demographics, preoperative investigations, complications, pathology and recurrence. A review of existing literature was also performed. RESULTS: Five patients (four females, one male) with histologically confirmed PPD were identified. The median age of presentation was 72 (range 61 to 78). Three patients were recurrences following previous excisions and first presentations in two patients. Only one patient had an underlying diagnosis of cancer. The median time to diagnosis was 24 months. Four patients underwent wide local excision with skin graft and/or local flap reconstruction and one patient required an abdominoperineal excision for recurrence. Four patients had involved lateral margins despite wide local excision but follow-up to date has only revealed one local recurrence. A review of available literature suggests that synchronous cancers can occur in up to 33% of patients and that a further 10% may be associated with metachronous cancers. Surveillance recommendations seem anecdotal and do not appear to be supported by available literature. CONCLUSION: PPD is a management challenge. Association with synchronous and metachronous carcinomas may not be as strong as initially thought. Surgery is the mainstay treatment with the need to balance between minimizing disease recurrence and functional sequelae from excessive tissue loss.

Late rupture of abdominal aortic aneurysm after endovascular repair.

OBJECTIVE: The purpose of this study was to compare findings at presentation and surgical outcomes in patients in whom abdominal aortic aneurysms (AAAs) ruptured after endovascular repair and in patients in whom AAAs ruptured before any treatment during a defined period at a single center. METHODS: This is a retrospective analysis of consecutive patients who presented to Royal Prince Alfred Hospital with ruptured AAA from September 2003 to September 2014. Medical records of each patient were reviewed to retrieve demographics, findings at presentation, and surgical outcome. Comparison of the outcomes between those occurring after endovascular repair (group 1) and those occurring without previous endovascular treatment (group 2) was made using the data collected and combining the results obtained by a previous study that analyzed the same findings between 1992 and 2003 from the same center to provide a total 22-year experience (1992-2014) at a single quaternary referral center. RESULTS: From May 1992 to September 2014, there were 1921 elective repairs of intact infrarenal AAAs, with 1288 endovascular and 633 open repairs. During 22 years, 40 of the 1288 patients (3.1%) who underwent endovascular repair for AAA had rupture. The proportion of patients with hypotension at presentation in group 1 (13/40) was significantly less than in group 2 (108/138; P < .01). The difference in perioperative 30-day mortality rate in group 1 (8/40 [20%]) compared with group 2 (68/138 [49%]) was significant (P < .01). CONCLUSIONS: This study confirmed that endovascular AAA repair does not prevent rupture in all patients. The data suggest that rupture, when it does occur, may not be accompanied by such major hemodynamic changes and higher mortality rate as with rupture of an untreated AAA. Strict surveillance and follow-up are required, especially in patients with relatively large initial AAA diameter or presence of endoleak and graft migration, to reduce the rate of ruptures after endovascular repair. Complete prevention will remain challenging because rupture may occur without any predisposing abnormalities. With the advent of new-generation devices, continuous larger long-term studies are required to document reduction in rupture rates after endovascular aneurysm repair.

A randomized trial assessing the impact of three different glycoprotein IIb/IIIa antagonists on glycoprotein IIb/IIIa platelet receptor inhibition and clinical endpoints in patients with acute coronary syndromes.

AIMS: To compare three glycoprotein IIb/IIIa receptor antagonists (GPIs) in terms of platelet inhibition and major adverse cardiac events (MACEs), and assess the rate of bleeding and MACEs between GPIs and coadministered P2Y12 agents. METHODS: Eighty-three acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) with planned GPI use were randomized to receive high-dose bolus tirofiban, double-bolus eptifibatide, or abciximab followed by a 12-hour infusion. Glycoprotein IIb/IIIa platelet receptor inhibition was measured at baseline and at 10 minutes, 1 hour, and 24 hours postbolus dose. Major adverse cardiac events and bleeding complications at 30 days were documented. The incidence of MACEs and bleeding in patients receiving ticagrelor or prasugrel were compared to those given clopidogrel. RESULTS: There were no statistically significant differences in platelet inhibition between GPIs at 10 minutes (P=.085) and 1 hour (P=.337). At 24 hours, abciximab achieved statistically significantly higher median [interquartile range] platelet inhibition (75 [65-88]%) compared to tirofiban (28 [3-56]%; P<.0001) and eptifibatide (44 [31-63]%; P=.007). There were no differences in bleeding or MACEs depending on GPI or P2Y12 inhibitor administered. CONCLUSIONS: Glycoprotein receptor inhibitors achieve similar levels of platelet inhibition at 10 minutes and 1 hour; however, abciximab maintains this benefit 24 hours after bolus dose. We did not witness an increased rate of bleeding in patients given new potent P2Y12 inhibitors and a GPI in the modern era.

Pseudoaneurysm of the thoracic aorta following botulinum toxin injection to the esophagus.

Aortic pseudoaneurysms are uncommon and are usually secondary to penetrating trauma. We describe the presentation and management of an elderly woman who suffered a pseudoaneurysm of the descending thoracic aorta several days after receiving botulinum toxin injection to the esophagus. Urgent thoracic endovascular aortic repair was performed, and long-term antibiotic therapy was commenced. Despite a slow initial clinical recovery, she returned to an independent lifestyle, with radiographic resolution of the pseudoaneurysm seen at follow-up. This case illustrates that endovascular aortic repair is a suitable and safe treatment option for this unusual presentation.

Assessment of age in ulcerative colitis patients with ileal pouch creation - an evaluation of outcomes.

INTRODUCTION: The aim of the study was to determine if age at the creation of an ileal pouchanal anastomosis (IPAA) has an impact on the outcomes in patients with ulcerative colitis (UC). MATERIALS AND METHODS: A retrospective review of all patients who underwent IPAA for UC from 1999 to 2011 was performed. Long-term functional outcome was assessed using both the Cleveland Clinic and St Mark's incontinence scores. RESULTS: Eighty-nine patients, with a median age of 46 (range, 16 to 71) years, formed the study group. The median duration of disease prior to their pouch surgery was 7 (0.5 to 39) years. There were 57 (64%) patients who were aged ≤50 years old and 32 (36%) who were >50 years old. Fifty-seven (64%) patients developed perioperative complications of which 51 (89.5%) were minor. High ileostomy output (n = 21, 23.6%) and urinary symptoms (n = 13, 14.6%) were the most commonly encountered complications. The older patients were more likely to have an ASA score ≥3 and a longer length of stay. Although there was a higher incidence of complications in the older group of patients, the difference was not statistically significant. There were no significant differences in the incidence of severe complications. Forty-nine (55%) patients completed our questionnaire on the evaluation of their functional outcomes. There were no significant differences in the Cleveland Clinic and St Mark's incontinence scores between the older (n = 19, 38.8%) and younger (n = 30, 61.2%) patients. There were also no significant differences in the frequency of bowel movements during the day or overnight after sleep between the 2 groups. CONCLUSION: IPAA procedure for patients with UC can be safely performed. Long-term functional outcome is not significantly influenced by the age at which the IPAA was created.

High on treatment platelet reactivity and stent thrombosis.

BACKGROUND: Stent thrombosis (ST) remains a major adverse outcome of percutaneous coronary intervention (PCI). We examined potential associations between high on treatment platelet reactivity and the risk of ST and assessed the effects of increased antiplatelet dosage on platelet inhibition. METHODS: Differences in clinical characteristics and the effect of aspirin and clopidogrel on platelet reactivity were determined after angiographically proven ST in 16 patients and in 40 patients without ST. Platelet reactivity was determined using the VerifyNow assays (Accumetrics Inc., San Diego, CA). Patients found with high on treatment platelet reactivity (P2Y12 Reaction Units ≥ 235 and/or Aspirin Reaction Units ≥ 550) returned following two weeks of double dose antiplatelet therapy for further analyses. RESULTS: High post aspirin and/or clopidogrel platelet reactivity was significantly more common in patients with ST versus controls (75% vs. 2.5%, p = < 0.001). Overall, ST patients were younger (52.8 ± 10.5 vs. 59 ± 9.6 years; p = 0.039), had more pre-existing coronary artery disease (75% vs. 42%; p = 0.028) and smaller reference vessel diameters (2.9 ± 0.36 vs. 3.2 ± 0.54 mm; p = 0.047) when compared to controls. After double dose therapy, antiplatelet reactivity improved significantly in ten out of 12 subjects on clopidogrel (83.3%) and the two patients on aspirin who initially had high on treatment platelet reactivity. CONCLUSION: This study demonstrates that high on treatment platelet reactivity with aspirin and/or clopidogrel is common amongst patients who develop stent thrombosis. Additionally this resistance can be improved with doubling the prior dose of antiplatelet therapy.