Preventing sheep carotid artery spasm for vascular graft surgery and computed tomography angiography.

The development of small-diameter vascular grafts requires testing in large animal models before advancing to clinical trials. Vascular graft interposition implantation in sheep carotid arteries (CAs) is the most widely used model, but ovine CAs are prone to severe spasm following surgical manipulation, potentially impairing graft performance assessment. There is a paucity in the literature on reducing sheep CA spasm using effective vasodilator therapeutic protocols. In this study, four healthy Merino cross White Suffolk wethers (1-2 years, 52.1 ± 0.8 kg) underwent CT angiography and CA graft surgery. CT angiography using iodinated contrast agent was performed with innominate artery access via the CA or ascending aortic arch access via the femoral artery. Sheep were randomly allocated to then underwent right CA sham surgery or left CA vascular graft implantation. A variety of vasodilators, including papaverine, sodium nitroprusside, verapamil and their combination, were tested for preventing or treating CA spasms intraoperatively. Blood flow was reassessed immediately after CA surgery using CT angiography. The results showed that innominate artery access via the CA for CT angiography in sheep induced pre-surgical CA spasm with reduced arterial flow. Conversely, ascending aortic arch access via the femoral artery for CT angiography did not cause CA spasm and maintained arterial flow. During CA graft surgery, surgical trauma induced CA spasm, which was prevented by localised intraarterial administration of vasodilators papaverine hydrochloride and verapamil prior to significant surgical manipulation.

Synchronous Carotid Endarterectomy and Anaortic Off-Pump Coronary Artery Bypass Surgery.

BACKGROUND: There is ongoing debate regarding the optimal strategy and timing for the surgical management of patients with severe concomitant carotid and coronary artery disease. Anaortic off-pump coronary artery bypass (anOPCAB), which avoids aortic manipulation and cardiopulmonary bypass, has been shown to reduce the risk of perioperative stroke. We present the outcomes of a series of synchronous carotid endarterectomy (CEA) and anOPCAB. METHODS: A retrospective review was performed. The primary endpoint was stroke at 30 days post-operation. Secondary endpoints included transient ischaemic attack, myocardial infarction and mortality 30 days post-operation. RESULTS: From 2009 to 2016, 1,041 patients underwent anOPCAB with a 30-day stroke rate of 0.4%. The majority of patients had preoperative carotid-subclavian duplex ultrasound screening and 39 were identified with significant concomitant carotid disease who underwent synchronous CEA-anOPCAB. The mean age was 71±7.5 years. Nine patients (23.1%) had previous neurological events. Thirty (30) patients (76.9%) underwent an urgent operation. For CEA, a conventional longitudinal carotid endarterectomy with patch angioplasty was performed in all patients. For anOPCAB, total arterial revascularisation rate was performed in 84.6% and the mean number of distal anastomoses was 2.9±0.7. In the 30-day postoperative period, there was one stroke (2.63%), two deaths (5.26%), two transient ischaemic attacks (TIAs) (5.26%) and no myocardial infarction. Two patients experienced acute kidney injury (5.26%), one of which required haemodialysis (2.63%). Mean length of stay was 11.37±7.9 days. CONCLUSION: Synchronous CEA and anOPCAB is a safe and effective option for patients' severe concomitant disease. Preoperative carotid-subclavian ultrasound screening allows identification of these patients.

Indications for and outcomes of major lower limb amputations at a tertiary-referral centre in Australia.

OBJECTIVES: Major amputations are classically associated with significant morbidity and mortality. With the increasing prevalence of risk factors for amputation, namely, diabetes and peripheral arterial disease, we sought to identify the major indications for lower limb amputation in an Australian cohort. A secondary aim was to assess the outcomes, namely, mortality, of amputees over the previous decade. METHODS: This study assessed all patients undergoing major lower limb amputations between 2012 and 2020. Variables analysed included comorbidities, indication for amputation, in-hospital complications and mortality, duration of hospital stay, and out-patient mortality. RESULTS: 317 amputations were performed on 269 patients. 55% of amputations were below knee, 45% above knee, with one through-knee amputation. Indications included ischaemia (55.2%), infection (30.6%), malignancy (6.9%), trauma (4.4%), and chronic pain or instability (2.5%). In-patient mortality rate was 7.6%, with mortality rates of 21.5% at one year, and 70.1% at 10 years. Post-operative complications occurred in 43% of amputations. Rural, regional, and remote (RRR) patients did not suffer disproportionately from major amputations, however, were more likely to require amputations for ischaemia. Patients undergoing amputation for infective causes demonstrated lower mid-term mortality rates compared to those undergoing amputations for ischaemia (56.1 vs 60.4% at 5 years, p = 0.007). CONCLUSION: Major amputations continue to be associated with significant morbidity and mortality, both in the short and long term. Patients undergoing amputations for ischaemic causes demonstrate poorer outcomes than their infective counterparts, with outcomes being even worse in RRR populations. Prevention of amputations via intense management of comorbidities would benefit both patients and the healthcare system.

Aortic graft explants - A single institution analysis of incidence and outcomes.

OBJECTIVES: Explantation of both endovascular endovascular aneurysm repair and open aortic grafts is a procedure associated with high peri-operative risk, and the current study sought to determine the outcomes and trends over time in these patients. METHODS: This study examined data from all patients undergoing explant of an aortic graft (both open and endovascular) between January 2004 and December 2020 at a single centre. Variables analysed included comorbidities, duration to and indication for explantation, type of revascularization, in-hospital complications and mortality, duration of hospital and ICU stay, and out-patient mortality. RESULTS: Of 688 open and 1352 EVARs performed, 46 patients underwent 48 explants. Five were open grafts and 43 were endografts, equating to an explant rate of 0.73% of open and 3.18% EVARs. Average time to explant was 70 months, with patients presenting electively having a significantly longer duration to representation than those presenting emergently (51 vs 44 months, p=0.003). Indication for explant was endoleak in 70%, infection in 23%, and occlusion in 6%. Of the endoleaks, 61% of were Type 1, 22% Type II, 11% Type IV, and 6% Type V. On representation, 17 patients (35%) were symptomatic. Overall mortality rate was 8.3%, with a trend for higher mortality in emergent than elective presentations (11.8 vs 6.5%, p=0.55). There was no change in explant rate over time. CONCLUSIONS: Elective aortic graft explantation is associated with low mortality, despite its complexity and patient comorbidities. Patients presenting with symptoms suffered higher mortality and a longer post-operative course, suggesting that aortic graft explantation should be considered sooner rather than later, rather than persisting with repeated endovascular management.

The failing endograft-A systematic review of aortic graft explants and associated outcomes.

OBJECTIVE: The prominent use of endovascular stent grafts in the management of abdominal aortic aneurysms is associated with increased descriptions of late complications such as graft infection and endoleaks, which can confer significant morbidity and mortality. Failed endovascular management of late complications often requires open conversion and graft explantation. This systematic review sought to highlight the peri- and post-operative course of patients undergoing aortic graft explants to inform readers of the associated morbidity and mortality of patients undergoing this procedure. METHODS: The review was conducted in accordance with PRISMA guidelines. A search of the PubMed, Google Scholar and Ovid MEDLINE databases from January 1995 to April 2021 was performed with a combination of MeSH terms pertaining to endovascular aneurysm repair and open conversion. Articles were screened and included based on pre-determined selection criteria. RESULTS: A total of 818 studies were identified, with 41 meeting inclusion criteria. These studies examined a total of 1324 patients, 84.3% of whom were male with a mean age of 74 years at explantation. Mean time to graft explantation was 36 months, with a mean aneurysm size of 66 mm. The majority of aortic explants were performed for persistent endoleaks (68%), and 10% for infection. There was high morbidity with the procedure, with high rates of post-operative complications (mean, 37%) and 30-day mortality (11%). The most common complications included renal (15%), respiratory (12%) and cardiac (9%). Most explanted grafts were first-generation endografts. Morbidity and mortality rates were reduced in patients undergoing elective explants compared to emergent procedures (3.3% compared to 43.4%). CONCLUSION: Aortic graft explant remains a highly co-morbid procedure, with high rates of peri- and post-operative complications and mortality. The number of explant procedures reported over the past 25 years has increased, reflecting the prominent use of EVAR in the management of AAAs. Whilst remaining a highly co-morbid procedure, patients undergoing elective explants had markedly reduced rates of mortality and morbidity compared to emergent explants. Thus, clinical focus should be on identifying patients who require graft explantation early to perform these procedures in an elective setting.

Patient and Geographical Disparities in Functional Outcomes After Major Lower Limb Amputation in Australia.

BACKGROUND: Major lower limb amputations are associated with considerable disability, low quality of life, and poor rates of returning to work, all of which are often attributed to the poor level of functional mobility that amputees experience postoperatively. This study aimed to quantify ambulatory outcomes after major lower limb amputation and identify potential prognostic factors for patients most likely to achieve ambulation and prosthesis use, with the hypothesis that variation in outcomes correlates to age, level of amputation, and place of residence at the time of amputation. METHODS: This retrospective cohort study identified functional outcomes for patients who had lower limb amputations between 2012 and 2020. Patients were identified from the 10th revision of the International Classification of Diseases Australian Modification (ICD-10-AM)-coded state-wide government-maintained hospital administrative data by procedure codes for lower limb amputation. The primary outcomes were ambulation at the time of discharge from acute hospital stay, discharge destination, and prosthesis use. Variables for adjustment included patient age, comorbidity, level of amputation, and place of residence. RESULTS: Three-hundred and seventeen amputations were performed in 269 patients. Most procedures were transtibial amputations (56.4%) and for ischemic/infective indications (84%). Thirty-seven percent of patients were ambulating independently at the time of discharge and 55.9% demonstrated independent mobility with prosthesis at follow-up. Ambulation at the time of discharge predicted patients who were more likely to return home rather than residential or hospital care (odds ratio [OR] 1.8 95%; confidence interval [CI] 1.0-3.2). Patients with transtibial amputation were more likely to achieve prosthesis use than transfemoral (OR 4.4, 95% CI 2.1-9.5), after adjusting for age, comorbidity, and geographical factors. Mobility and prosthesis use was lowest in patients who were older, had transfemoral amputations, and resided in regional or rural areas. CONCLUSIONS: The significant outcome disparities identified in this cohort study highlight the need for targeted quality interventions aimed at improving functional outcomes for patients undergoing major amputation for peripheral artery disease.

Has EVAR changed the outcomes of ruptured abdominal aortic aneurysms? A decades worth of experience in an Australian Teaching Hospital.

BACKGROUND: Ruptured abdominal aortic aneurysms (rAAA) are associated with significant mortality, and equipoise remains as to whether patients managed with endovascular stent grafts (rEVAR) demonstrate better outcomes when compared to traditional open repair (OR). This study sought to examine the outcomes of patients presenting with rAAA to our institution and assess the perioperative outcomes and outpatient mortality of patients over the past decade. METHODS: A retrospective analysis was conducted. Patients treated for rAAA between 2010 and 2019 were identified from a search of the hospital database for ACHI and ICD-10 codes for repair of AAA. Demographic, operative and post-operative variables were collected from electronic medical records of identified patients. RESULTS: Eighty patients were identified, 51 of whom presented with a rAAA. The majority of repairs were rEVARs (59%). Median age was 76 years. Median length of admission to ICU was 3 days, and median length of hospital admission was 10 days. Overall in-patient mortality was 26%, with rates of 39% at 3 years and 47% at 5 years. No significant difference in outpatient mortality was found in patients undergoing rEVAR compared to OR, with rates of 61% at 5 years compared to 65% at 5 years, respectively (p = 0.8). CONCLUSION: Perioperative outcomes of our cohort of patients undergoing endovascular repair compared to open repair for ruptured and symptomatic AAAs are comparable over the past decade. Given equipoise remains between repair methods, further observational studies are required to quantify benefits of OR and endovascular repairs for ruptured and symptomatic AAAs.

Complete Erosion of an Aortobifemoral Bypass Graft Limb into Duodenum.

A 67-year-old male with a history of aortobifemoral bypass graft (ABF) for critical limb ischemia 10 months prior at a regional hospital was transferred to our center with 1 week history of rigors and 3 months of a chronic discharging left groin sinus. Two months prior he had a right-sided ureteric stent inserted for ureteric obstruction. Routine bloods revealed an acute-on-chronic renal injury and subsequent noncontrast computed tomography (CT) demonstrated left-sided hydroureter and hydronephrosis suggestive of extrinsic compression by the left bypass graft limb. A new left-sided ureteric stent was inserted and the right exchanged with no gross signs of infection. His impaired renal function precluded intravenous contrast and so a CT with oral contrast showed circumferential oral contrast and gas surrounding the right limb of his ABF. Urgent gastroscopy revealed periprosthetic erosion with the ABF limb traversing the distal third part of the duodenum. He underwent bilateral axillofemoral bypass grafts, laparotomy with explantation of the ABF, and primary duodenojejunostomy. Bilateral ureters were compressed by overlying graft limbs. Bilateral groins were infected with frank pus on exploration and were associated with impending anastomotic disruption of his previous ABF distal anastomoses. His postoperative course was complicated by colonic ischemia with perforation leading to irreversible multiorgan failure. This patient was remarkably well on presentation with life-threatening pathology. He had no abdominal symptoms or gastrointestinal bleeding. This case demonstrates the diagnostic and management difficulties of periprosthetic erosions and the consequences of graft tunneling superficial to ureters.

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.

Open versus Endovascular Repair of Arch and Descending Thoracic Aneurysms: A Retrospective Comparison.

BACKGROUND: Thoracic aortic aneurysms (TAAs) contribute significant mortality if left untreated, but surgical repair has historically carried substantial risks. METHODS: We sought to observe trends and outcomes of open and endovascular thoracic endovascular aneurysm repair thoracic aortic repairs, so conducted a retrospective review of all patients who presented for management of TAAs from 2003 to 2013 at 2 hospitals in Sydney, Australia. RESULTS: A total of 179 patients presented with TAAs over the study period, including 5 ruptures. Fifty-two were treated nonoperatively, with 127 surgically repaired. Operative duration was significantly shorter in endovascular than open repair of arch (193 ± 108 vs. 396 ± 98 min, P = 0.0001) and descending aneurysms (242 ± 116 vs. 422.5 ± 161 min, P = 0.003). There were no differences in mortality or complication rates (including paraplegia), duration of hospital or intensive care unit stay, or transfusion requirements between endovascular and open TAA repairs. CONCLUSIONS: Apart from reduced surgical duration, this study revealed no benefits of endovascular over open TAA repair. Overall morbidity and mortality were low, even in elderly patients.

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.

Outcomes After En Bloc Iliac Vessel Excision and Reconstruction During Pelvic Exenteration.

BACKGROUND: Advanced pelvic cancers involving the lateral pelvic compartment, and particularly the iliac vasculature, are difficult to manage. Common or external iliac vessel involvement has traditionally been considered a contraindication for curative surgery. OBJECTIVE: The purpose of this study was to investigate pathological and surgical outcomes, particularly postoperative morbidity of pelvic exenteration with en bloc major iliac vascular excision and reconstruction. DESIGN: This study was a case series. SETTINGS: The study was conducted at a quaternary referral center for pelvic exenteration in Sydney. PATIENTS: Patients included those undergoing en bloc iliac vessel excision as part of their pelvic exenteration for a locally advanced pelvic malignancy. MAIN OUTCOME MEASURES: Over the study period, 336 patients underwent pelvic exenteration. Twenty-one patients (6.3%) underwent en bloc vascular excision of 29 vessels for tumor involvement. Twenty-four vessels required reconstruction. The primary outcomes were postoperative complications and pathologic outcomes. Survival rates were estimated using the Kaplan-Meier technique. RESULTS: Operating time for patients who underwent vascular excision and reconstruction was longer, but this did not reach significance (631 vs 531 minutes; p = 0.052). Mean blood loss was significantly higher in the vascular excision and reconstruction group (6.8 vs 3.4 L; p < 0.001). Patients who required en bloc vascular excision were less likely to have R0 margins compared with patients who did not (38% vs 78%; p < 0.001). There was no intraoperative or 30-day mortality. Overall graft patency and limb loss at 1 year were 96% and 0%. A total of 52% of patients had at least 1 vascular related complication. Median overall and disease-free survival times were 34 and 26 months. LIMITATIONS: This study is limited by a relatively small number of heterogeneous patients. CONCLUSIONS: En bloc vascular resection and reconstruction for contiguous tumor involvement is feasible and safe in selected patients. Advanced pelvic tumors involving iliac vessels should not be precluded from curative surgery in specialized institutions.

Surgical teaching program for our senior medical students: room for improvement.

BACKGROUND: To ensure the quality of surgical teaching within our graduate entry medical program, a distinctive surgical teaching program has been developed at Sydney Medical School-Central. Spanning 2 years, the program includes lectures, small group surgical clinical tutorials, and formal student surgical grand rounds presentations, plus clinical placements and attendance in operating theaters. We sought to evaluate the effectiveness of the program. METHODS: In 2013, at the completion of year 4, all graduating students (n=54) were asked to complete an open and closed-ended questionnaire regarding their experience of the surgical program. RESULTS: A total of 44/54 (81%) students completed the questionnaire. Students reported a high level of engagement with their experience in clinical tutorials, and a moderate level of engagement in surgical lectures. Students found the clinical attachment to be the least useful method of teaching, with the surgical grand rounds presentation also eliciting a poor response from students. CONCLUSION: While both large group lectures and small group learner-centered teaching methods were highly valued by students, changes are needed to enhance clinical attachments for students in surgical wards. The benefits of students being made to feel part of a team during their surgical clinical attachments, along with adequate inpatient contact and formative feedback, should not be underestimated.

Severe diverticulitis after heart, lung, and heart-lung transplantation.

BACKGROUND: In this study, we reviewed our experience with severe diverticulitis in patients who have undergone heart and/or lung transplantation to assess whether transplant recipients are at increased risk of having severe diverticulitis compared with the general population. METHODS: We reviewed the records of patients who underwent heart and/or lung transplantation from 1984 to 2000, inclusive, and identified patients with severe diverticulitis that required surgery or that resulted in death. We compared this incidence with the incidence of such complications in the general population, served by the same institution during a 2-year period, 1999 to 2000. RESULTS: A total of 953 patients underwent transplantation in the study period. The mean follow-up was 57 months, a total follow-up of 4528 patient-years. Nine patients (mean age, 54 years) had severe diverticulitis that required surgical intervention (8 patients) or that resulted in death (1 patient died without surgical intervention). During 1999 to 2000, 16 patients (mean age, 66 years) from the general population were treated for severe diverticulitis that required surgical intervention, 3 of whom died. From census and area health data, we found that the study institution serves approximately 90000 people older than 40 years, with a total follow-up of 180000 patient-years. The incidence rate ratio for severe diverticulitis when comparing the transplant with the non-transplant groups was 22.2 (95% confidence interval; 9.9-50.0; p < 0.001). CONCLUSIONS: Patients with severe diverticulitis who have undergone heart and/or lung transplantation can be treated surgically with a small mortality rate. Transplant recipients probably are at substantially increased risk of experiencing severe diverticulitis.