Mycotic Abdominal Aortic Aneurysms - A Tertiary Centre Experience and Formulation of a Management Protocol.

BACKGROUND: Mycotic abdominal aorta aneurysm (MAAA) is a rare and life-threatening condition. Because of its rarity, there is a lack of adequately powered studies and consensus on its treatment and follow up. This study aimed to review the outcomes following surgical intervention for MAAA in a single tertiary centre and to formulate a management protocol based on available evidence and expert opinion. MATERIALS AND METHODS: Data were collected by retrospective review of case records of all patients who underwent repair of MAAA in a single tertiary referral centre from 2001 to 2018. Demographic, clinical and outcome data were analysed and compared with previously published series in the literature. A management protocol was formulated based on available literature which was then reviewed and modified as per expert opinion from multidisciplinary discussions. RESULTS: Seventeen patients underwent repair of MAAA during the study period including 4 Open repairs, 4 surgeon modified fenestrated endovascular aortic aneurysm repairs (SM FEVAR) and 9 endovascular aortic aneurysm repairs (EVAR). One-year overall survival was 94.1%, 3-year survival was 81.8% and 5-year survival was 75.0%. The infection-free survival at 1, 3, and 5 years was 87.5%, 81.8% and 62.5%, respectively. The overall survival and infection-free survival curves for Open repair, EVAR and SM FEVAR when compared using Log Rank (Mantel-Cox) test and did not show any statistically significant difference. CONCLUSIONS: Management of MAAA with selective use of open or endovascular repair, in combination with appropriate long-term antibiotic therapy, can achieve acceptable outcomes. The proposed protocol can aid as a guiding document for the management of MAAA but needs taking into consideration individual patient variability and local expertise.

Operative and 1-Year Outcomes of the Custom-Made Fenestrated Anaconda Aortic Stent Graft-A UK Multicenter Study.

BACKGROUND: Early and 1-year outcomes are presented for fenestrated endovascular aneurysm repair (FEVAR) of complex aortic aneurysmal disease with the custom-made Anaconda fenestrated stent graft in 101 patients. METHODS: Retrospective site-reported data from the first 101 elective cases (2010-2014) from 4 UK centers were studied to evaluate patient demographics, aneurysm morphology, clinical success, and 1-year outcomes in patients undergoing fenestrated aneurysm repair with the custom-made Anaconda device. RESULTS: 101 fenestrated grafts (median age 76, 85% male) were implanted with a total of 255 fenestrations (196 renal arteries, 48 superior mesenteric artery, and 11 celiac arteries) with 3% mortality, 98.4% target vessel patency (TVP) at 30 day follow-up. Although 15 type I or III endoleaks were demonstrated at completion angiography, all 10 type Ia endoleaks resolved spontaneously. Survival by Kaplan-Meier analysis was 97% and 91% at 1 month and 1 year, respectively; with 75.8% showing reduction in abdominal aortic aneurysm diameter and only 1 patient with sac expansion. Freedom from loss of TVP was 97.6%. CONCLUSIONS: Custom-made fenestrated Anaconda devices demonstrate low procedural mortality and a high rate of technical and clinical success at 30 days and 1 year.

Are we cross-matching too much blood for elective open abdominal aortic aneurysm repair?

OBJECTIVES: This study aims to identify current blood transfusion requirements in elective open abdominal aortic aneurysm repair and to compare this to an existing maximum surgical blood order schedule. METHODS: We retrospectively identified patients who underwent elective open abdominal aortic aneurysm repair over a 40-month period in our institution. Pre-operative number of units cross-matched and the number of units actually transfused were identified. The cross-match to transfusion ratio was then calculated. RESULTS: Blood transfusion at any time post-operatively was required in 23 (48.9%) cases. Patients needing an intra-operative blood transfusion had a median of 2 units. Of the pre-operative cross-matched units (123), only 43 were used, giving a cross-match to transfusion ratio of 2.86. CONCLUSION: Our current maximum surgical blood order schedule is poorly followed and a cross-match to transfusion ratio of 2.86 indicates we are cross-matching too many units for elective open abdominal aortic aneurysm repair. A carefully considered individualised management of blood products, with the requirement of at least a valid group and save sample, may be more appropriate.

Arteriovenous fistula formations: key to vascular surgical training.

PURPOSE: To highlight missed training opportunities in daycase surgery for trainees to acquire competency in vascular anastomosis by performing arteriovenous fistula (AVF) formations. METHODS: Operative Room Management Information System records were reviewed for AVF procedures in daycase and general theatres at a UK Foundation Trust between 2007 and 2012. Data collected included procedure, procedure time (PT), patient length of stay (LOS), readmissions within 30 days of procedure and lead and assistant surgeons involved. RESULTS: Of 199 daycase AVF procedures reviewed, 59.3% (n=118) were brachiocephalic formations and 34.2% (n=68) radiocephalic formations. Trainees attended 41.2% of daycase AVF procedures and were lead surgeon in 7.3% of these. Mean PT was 64 minutes for consultants compared with 56 minutes for trainees, with no significant difference (p=0.297). Median patient LOS was less than 24 hours for both groups. Six daycase AVF procedures resulted in patient readmission within 30 days; five of these were operated on by consultants and one by a staff grade. During the same period, 258 AVF procedures were performed in general theatres. Trainees attended 64.3% of AVF formations performed in general theatres and were lead surgeon in 5.8% of these. CONCLUSIONS: Trainees attended and led few daycase AVF formations despite no significant difference in PT, patient LOS or readmission rate between consultant-led and trainee-led cases. Trainees attended more AVF formations performed in general theatres than daycase. However, trainees led a greater proportion of daycase AVF formations, possibly due to a less complex case mix that is more suitable for training.

Rupture of the Left External Iliac Artery and Right Groin Pseudoaneurysm Formation following Angioplasty in a Patient with Neurofibromatosis Type 1 and Undiagnosed Bilateral Phaeochromocytoma.

Neurofibromatosis type 1 (NF1) is a genetic condition, which affects 1 in every 3000 births. Patients with NF1 are at increased risk of a variety of vascular abnormalities. This report presents the case of a 60-year-old male with NF1 who suffered a left external iliac rupture and a right pseudoaneurysm following angioplasty. In addition, these were further complicated by previously undiagnosed, bilateral phaeochromocytomas. The inherent weakness in vessel wall architecture found in NF1 coupled with the hypertension evident during and after the procedure contributed to haemorrhage and pseudoaneurysm formation. Caution must be taken in such patients when considering vascular intervention.

Endovascular management of delayed complete graft thrombosis after endovascular aneurysm repair.

Graft thrombosis rates after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms vary widely in published series. When thrombosis does occur, it usually involves a single limb and occurs within 3 months of stent-graft insertion. If the entire endoprosthesis is thrombosed, treatment may be challenging because femoro-femoral crossover graft insertion is not an option and a greater volume of thrombus is present, thus making thrombolysis more difficult. We present two cases of delayed thrombosis after EVAR involving the entire stent-graft. These were successfully treated by a combined surgical and endovascular technique, and patency has been maintained in both cases to date.

Endovascular repair of a primary iliac-cecal fistula presenting with gastrointestinal hemorrhage.

We report a case of an arterio-enteric fistula between an external iliac artery aneurysm and otherwise healthy cecum, presenting with torrential hemorrhage per rectum in an 85-year-old patient. Whilst fistulization to the aorta and common iliac arteries has been reported, to our knowledge no previous cases of primary fistulization between an external iliac aneurysm and normal cecum have been. Successful endovascular exclusion of the aneurysm was undertaken with a Wallgraft covered stent and the patient remains well at 1 year.

Autologous thrombin: a new embolization treatment for traumatic intrasplenic pseudoaneurysm.

PURPOSE: To report the use of autologous thrombin for transcatheter embolization of a traumatic parenchymal splenic pseudoaneurysm. CASE REPORT: A 15-year-old boy presented with a splenic parenchymal laceration after blunt abdominal trauma. The patient was managed conservatively but developed an intrasplenic pseudoaneurysm (grade III AAST scale) with subcapsular contrast extravasation after 3 weeks. Autologous thrombin was isolated from the patient's blood and subsequently delivered to the lesion by transcatheter superselective injection into the aneurysm neck. The patient was asymptomatic after the procedure. Nine months' follow-up demonstrated a normal spleen with completely homogenous parenchyma. CONCLUSIONS: Autologous thrombin injection to induce thrombosis of intrasplenic pseudoaneurysm represents a new treatment option for traumatic abdominal organ injuries. Intrasac thrombosis can be safely induced to successfully restore the splenic parenchymal integrity without introduction of foreign material and associated risks of adverse reactions or infection that might accompany the use of commercial thrombin preparations.

Autologous thrombin for treatment of pseudoaneurysms.

Femoral pseudoaneurysms arise in up to 2% of patients after femoral cannulation for cardiac catheterisation. We used autologous thrombin for percutaneous obliteration of pseudoaneurysms occurring after catheterisation. We prepared autologous thrombin isolates from blood of ten patients with femoral pseudoaneurysms, and injected this solution into the pseudoaneurysms with duplex imaging guidance. We then assayed thrombin activity. All pseudoaneurysms were successfully thrombosed without substantial complications, although three patients needed a repeat procedure within 24 h. We have shown that autologous thrombin-induced thrombosis of pseudoaneurysms is reliable, simple, safe, and cheaper than commercial bovine or human thrombin, and avoids risks of anaphylaxis and contamination with prions.