Sustained local delivery of high-concentration vancomycin from a hybrid biodegradable, antibiotic-eluting, nanofiber-loaded endovascular prosthesis for treatment of mycotic aortic aneurysms.

BACKGROUND: Endovascular repair for mycotic aortic aneurysm (MAA) is a less invasive alternative to open surgery, although the placement of a stent graft in an infected environment remains controversial. In this study, we developed hybrid biodegradable, vancomycin-eluting, nanofiber-loaded endovascular prostheses and evaluated antibiotic release from the endovascular prostheses both in vitro and in vivo. METHODS: Poly(D,L)-lactide-co-glycolide and vancomycin were dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol. This solution was electrospun into nanofibrous tubes, which were mounted onto commercial vascular stents and endovascular aortic stent grafts. In vitro antibiotic release from the nanofibers was characterized using an elution method and high-performance liquid chromatography. Antibiotic release from the hybrid stent graft was analyzed in a three-dimensional-printed model of a circulating MAA. The in vivo drug release characteristics were examined by implanting the antibiotic-eluting stents in the abdominal aorta of New Zealand white rabbits (n = 15). RESULTS: The in vitro study demonstrated that the biodegradable nanofibers and the nanofiber-loaded stent graft provided sustained release of high concentrations of vancomycin for up to 30 days. The in vivo study showed that the nanofiber-loaded stent exhibited excellent biocompatibility and released high concentrations of vancomycin into the local aortic wall for 8 weeks. CONCLUSIONS: The proposed biodegradable vancomycin-eluting nanofibers significantly contribute to the achievement of local and sustainable delivery of antibiotics to the aneurysm sac and the aortic wall, and these nanofibers may have therapeutic applications for MAAs.

Explantation of infected aortic aneurysm and endograft with ascending aorta to mesenteric bypass for mesenteric ischemia.

A 65-year-old man presented with an infected perivisceral aortic aneurysm after previous treatment of an abdominal aortic aneurysm with an endograft. On presentation, he was septic and had occlusion of the celiac, superior mesenteric, inferior mesenteric, and bilateral renal arteries. He underwent a three-stage procedure: first, axillobifemoral bypass; then resection of the thoracoabdominal aorta; and finally bypass from the ascending aorta to the celiac and superior mesenteric arteries with a rifampin-soaked Gelsoft graft (Vascutek, Renfrewshire, Scotland). The abdominal pain resolved, and the patient remains symptom free 10 months postoperatively. This rare surgical revascularization technique offered a nontraditional solution to a difficult surgical issue.

Neoaortic Xenoprosthetic Grafts for Treatment of Mycotic Aneurysms and Infected Aortic Grafts.

BACKGROUND: There is no international consensus regarding the optimum management of infected aortae (mycotic aneurysms, infected aortic grafts). Neoaortoiliac reconstruction has advantages over extra-anatomical bypass grafting; however, the use of autologous vein is associated with venous hypertension and compartment syndrome, alternatively cadaveric homografts are associated with high rates of perianastomotic hemorrhage, limb occlusion, and pseudoaneurysm. Arterial repair using xenoprosthetic patches is associated with lower infection rates compared to the use of prosthetic material. The aim of this case series and literature review is to report the use of xenoprosthetic bovine biomaterial for neoaortic repair of mycotic aneurysmal disease and infected aortic grafts. METHODS: Patients with evidence of infected aortic grafts or mycotic aneurysms who were suitable for open aortic surgery were included. Following removal of the graft/excision of the aneurysmal sac, a 10 × 16 cm XenoSure Biologic Surgical Patch (LeMaitre, Germany) was rolled into a tube, or bifurcated tube graft, and secured with prolene sutures. Proximal and distal anastomoses were conducted as per standard aortic anastomoses. Patients were continued on long-term antibiotics and surveyed with computerized tomography at 1, 3, 6, and 12 months. RESULTS: Six patients underwent bovine aortic repair between 2013 and 2015: an infected Dacron aortobi-iliac graft causing iliac pseudoaneurysm, an infected Dacron aortic graft from open repair later relined with endovascular stent graft, a mycotic iliac aneurysm, and 3 mycotic aortic aneurysms. All were treated with bovine reconstructed aortic grafts or patches. Patients had a median age of 69.5 years (range 67-75), with perioperative and 30-day mortality of 0%. Median follow-up was 13 months (range 2-23). Postoperative contrast-enhanced computed tomography revealed no evidence of infection at the operative site in all patients. Freedom from reinfection and reintervention was 100%. CONCLUSIONS: Xenoprosthetic (bovine) neoaortic grafts are an alternative method to treat infected aortae with excellent short-term freedom from infection and reintervention. Optimum duration of postoperative antibiotic therapy remains undetermined. Further cases and longer follow-up are required to determine the true efficacy of this technique.

Infected Abdominal Aortic Aneurysms Treated with Extra-anatomic Prosthesis Bypass in the Retroperitoneum.

BACKGROUND: Infected abdominal aortic aneurysms (iAAAs) are rare but life-threatening diseases. The purpose of the present study was to report our experience of extra-anatomic prosthesis bypass in the retroperitoneum as a treatment for iAAAs. METHODS: Data of 8 consecutive patients diagnosed with iAAAs and treated by an extra-anatomic prosthesis bypass in the retroperitoneum were retrospectively collected. Operative details were as follows: one side of the retroperitoneal space was selected to build a track, and a bifurcated expanded polytetrafluoroethylene prosthesis was placed through the track. The proximal end of the prosthesis was sutured with the normal segment of abdominal aorta proximal to the infected aneurysm by end-to-end anostomosis. The 2 distal ends of the prosthesis were, respectively, sutured with the external iliac artery distal to the aneurysm. The anastomoses were then consolidated with the nearby connective tissue. After the closure of the retroperitoneum, the infected aneurysm was incised, and the infected tissue was debrided. Drainage tubes were placed in the aneurysm sac, which was packed with an omentum flap. All patients received perioperative antibiotic therapy for a period of time. All 8 patients were regularly followed up by outpatient observation. RESULTS: Eight patients with iAAAs underwent an extra-anatomic prosthesis bypass in the retroperitoneum and debridement of the infected aneurysm. An emergency operation was performed for 1 patient who underwent concomitant gastrointestinal procedures for aortoduodenal fistula. All 8 patients were definitively diagnosed by one or more sequential computed tomography scans combined with other methods. The blood or tissue cultures of all cases were positive in the perioperative period, with Salmonella (5 cases) being the most common pathogens. Other pathogens included Burkholderia pseudomallei (2 cases) and Escherichia coli (1 case). All patients survived and were discharged in 4-5 weeks after their operations. All patients were free from graft infection during the follow-up period. CONCLUSIONS: The extra-anatomic prosthesis bypass in the retroperitoneum for treating iAAAs was safe and effective. Our experience with the procedure may provide a new approach for the treatment of this disease.

Mycotic Aneurysm following a Dog Bite: The Value of the Clinical History and Molecular Diagnostics.

A 63-year-old Caucasian taxi driver presented with a 3-week history of malaise, night sweats, 7 kg weight loss, generalized arthralgia, and persistent mid-lower abdominal pain. Blood inflammatory markers were raised, and a computed tomography scan demonstrated an irregular degeneration of the infrarenal aorta, with a differential diagnosis including aortic infection. An urgent type IV thoracoabdominal aneurysm repair was performed with a rifampicin-soaked aortic tube graft during an open procedure. No organisms were grown from multiple peripheral blood cultures or culture of the affected aorta. However, subsequent 16S ribosomal polymerase chain reaction analysis of the resected aorta identified Capnocytophaga canimorsus as the causative organism-a commensal that lives in the mouth of dogs and cats. The patient subsequently gave a history of multiple bites from his pet dog over recent months-the likely source of infection. He was treated with 8 weeks of intravenous antibiotics before switching to oral antibiotics for an additional 6 weeks.

Hybrid open-endovascular repair of a contained suprarenal mycotic aneurysm using femoral vein.

Mycotic aneurysms have a high mortality rate, predominantly driven by sepsis. We present a 61-year-old patient who was treated with a hybrid open-endovascular repair using autologous femoral vein as a single channel revascularization. This provided a practical and innovative approach to a high-risk situation.

Q fever (Coxiella burnetii) causing an infected thoracoabdominal aortic aneurysm.

We report a patient, which we believe is the first, with a thoracoabdominal aortic aneurysm, Crawford type IV, caused by Q fever (Coxiella burnetii). Treatment consisted of antibiotic therapy started preoperatively and continued postoperatively and an open repair, including resection of the infected aneurysm, replacement with a rifampin-soaked polyester graft, and an omental wrap covering the grafts. After 13 months of follow-up, the patient had no signs of infection, and results of laboratory findings were normal.

Rothia dentocariosa causing intracranial mycotic aneurysm and ischaemic stroke.

We describe a case of subacute bacterial endocarditis and mycotic brain aneurysm caused by Rothia dentocariosa due to untreated dental caries. R. dentocariosa is a rare cause of endocarditis that has a high incidence of aneurysmal and haemorrhagic complications. All patients with intracranial aneurysms who have signs of systemic infection should be considered to have mycotic aneurysms until proven otherwise. Dental habits should be included in regular medical assessment and dental care should be considered for patients presenting with infectious symptoms.

Mycotic carotid pseudoaneurysm: staged endovascular and surgical repair.

Mycotic carotid pseudoaneurysms are rare and challenging to manage. Traditional surgical approaches are technically demanding and can be associated with a high morbidity and mortality. The use of endovascular stents in infected fields remains controversial, and long-term efficacy has not been fully clarified. We describe a case where a combined staged endovascular and open surgical approach was used to successfully manage a mycotic carotid pseudoaneurysm that developed following dental extraction. A covered endovascular stent was used to temporarily exclude the infected pseudoaneurysm, before proceeding to early definitive surgical management. We suggest that staged endovascular therapy followed by early surgical repair should be considered for this difficult surgical problem.

In situ revascularization with rifampicin-soaked silver polyester graft for aortic infection: Results of a retrospective monocentric series of 18 cases.

OBJECTIVE: To evaluate the short and long-term results of in situ prosthetic graft treatment using rifampicin-soaked silver polyester graft in patients with aortic infection. MATERIAL AND METHOD: All the patients surgically managed in our center for an aortic infection were retrospectively analyzed. The primary endpoint was the intra-hospital mortality, secondary outcomes were limb salvage, persistent or recurrent infection, prosthetic graft patency, and long-term survival. RESULTS: From January 2004 to December 2015, 18 consecutive patients (12 men and 6 women) were operated on for aortic infection. Six mycotic aneurysms and 12 prosthetic infections, including 8 para-entero-prosthetic fistulas, were treated. In 5 cases, surgery was performed in emergency. During the early postoperative period, we performed one major amputation and two aortic infections were persistent. Intra-hospital mortality was 27.7%. The median follow-up among the 13 surviving patients was 26 months. During follow-up, none of the 13 patients presented reinfection or bypass thrombosis. CONCLUSION: This series shows that in situ revascularization with rifampicin-soaked silver polyester graft for aortic infection have results in agreement with the literature in terms of intra-hospital mortality with a low reinfection rate.

Extracranial infected carotid artery aneurysm.

Infected aneurysms of the extracranial carotid arteries are rare. This is a case report of a 63-year-old female who developed an infected internal carotid artery aneurysm due to group B Streptococcus ten days after a dental procedure. She was successfully treated with excision of the aneurysm and common to internal carotid artery bypass with greater saphenous vein.

Pasteurella multocida infection, a rare cause of mycotic abdominal aortic aneurysm.

A 64-year-old man was admitted with abdominal pain 6 weeks after treatment with intravenous flucloxacillin for cellulitis of his right leg. Urgent operation was necessary for a mycotic aneurysm of the abdominal aorta due to infection with Pasteurella multocida, a microorganism residing in the oral cavity of domestic animals that very rarely causes infection of native arteries or grafts. The aorta was repaired with a rifampin-coated tube graft. Despite postoperative duodenal perforation, abdominal Candida infections, wound dehiscence, and renal insufficiency, the patient is alive 1 year postoperatively.

Infected thoracoabdominal aortic aneurysms including the major abdominal branches in 4 cases.

We present four cases of infected thoracoabdominal aortic aneurysm (TAAA), including abdominal branches that underwent surgical repair. The mean age of patients at the time of operation was 61+/-18 (range: 39-83) years. The extent of the aneurysm was Crawford type III in 1 case and type IV in the other 3. They all underwent an emergency or urgent operation, which consisted of a debridement of the infected tissue, in situ four-branched Dacron graft replacement, and iodine gauze packing for 48 h followed by omental wrapping of the graft. To prevent postoperative spinal ischemia, intercostal and lumbar arteries were reimplanted under motor-evoked potential (1.25 pairs per patient). There was one (25%) hospital death, but postoperative graft infection did not occur in these present cases during a mean follow-up period of 15+/-43 (1-96) months. Antibiotics were administered intravenously for 8 weeks after the operation, then continued orally for a lifelong period. Postoperatively, paraplegia occurred in one (25%) patient. Our strategy for infected TAAA including major abdominal branches may prevent postoperative graft infection.

The only case of mycotic aneurysm of the PICA: Clinical-radiological remarks and review of literature.

We present the first and only case, reported in literature, of a 67-years-old man with a mycotic aneurysm (MA) of the left posterior inferior cerebellar artery (PICA), caused by group B Streptococcus, that we surgically treated, performing neck aneurysm clipping, preserving patency of parent vessel. Moreover the peculiarity of this case is represented by the fact that the MA is originated from a tooth abscess, treated about two years before. To date, there have been only 10 cases of association between MA with either tooth pathologies or dental surgical procedures and our case is the only one originating from PICA. Therefore an extensive literature analysis was performed. Hence if we observe a patient with a fusiform aneurysm in posterior intracranial circulation and clinical history of fever and/or persistent neck swelling after dental pathologies, it is mandatory to consider the possibility of a MA, for a correct differential diagnosis. If the diagnosis is confirmed, it is necessary to research the origin of infection and to set the specific antibiotics therapy.

Surgical and Antimicrobial Management of a Thoracic Aortic Aneurysm Due to Q Fever: A Case Report and Brief Review.

Coxiella burnetii, the etiologic agent of Q fever, has been associated with vascular infection and aneurysm formation. We report the case of a 36-year-old woman from Iraq who presented with long-standing malaise as well as vague chest and shoulder discomfort and was found to have a saccular aneurysm of the descending thoracic aorta. Serology assays were positive for chronic C burnetii infection. She was treated with successful aneurysm resection and aortic replacement with a rifampin-impregnated Maquet Hemashield (TM) Dacron interposition graft interposition graft in addition to 18 months of doxycycline and hydroxychloroquine. The patient is without evidence of recurrent infection on follow-up at 3 years. To our knowledge, this is the first case of aortic aneurysm secondary to Q fever reported in the United States. We review the diagnosis, surgical management, antibiotic therapy, and surveillance of a thoracic aortic aneurysm secondary to Q fever.

In situ prosthetic graft replacement for mycotic aneurysm of the aorta.

Mycotic aneurysms as defined in this study include only those naturally occurring aortic aneurysms that result from or are secondarily infected by bacteria arising in a distant site of infection. Of the 2,585 patients treated for aortic aneurysm during the past 8 1/2 years, 22 patients had disease conforming to this definition. The aneurysms were located in the ascending aorta in 2 patients, ascending aorta and arch in 5, arch and descending aorta in 1, descending thoracic aorta in 1, separate descending and abdominal aorta in 1, thoracoabdominal aorta in 5, upper abdominal aorta in 6, and infrarenal abdominal aorta in 1. The primary source of infection was the urinary tract in 2 patients, salmonellosis in 4, pneumonia in 3, sub-acute bacterial endocarditis in 2, ear, nose, and throat in 2, cellulitis of the hand in 1, chronic wounds in 2, dental extraction in 1, lumbar disc space infection in 1, septic thrombophlebitis in 1, and generalized febrile illness in 3. The duration of febrile illness ranged from 2 weeks to 1 year. All patients were treated with antibiotics and operation was performed within 24 hours after admission in 11 patients and within one to eight days after admission in 11. Treatment consisted of in situ graft replacement. Appropriate antibiotics were given intravenously for 4 to 6 weeks in patients with positive cultures and continued orally for the rest of the patients' lives. Of the 22 patients, 19 (86%) were early survivors, and all are still alive 3 months to 8 years postoperatively. Only 1 had a recurrent infection, which involved the intervertebral disc space.

Multiple mycotic arch-thoraco-abdominal aortic aneurysms: a successful case of in situ graft replacement.

Mycotic aortic aneurysms are an uncommon yet still life-threatening pathology. We report on a 67-year-old male who had a persistent fever and back pain. Contrast enhanced computed tomography (CT) showed multiple aortic aneurysms located in the aortic arch, the descending thoracic aorta and the supraceliac abdominal aorta. After 2 months of antibiotic therapy, a staged operation was carried out with 2-week interval, which includes a graft replacement of aortic arch with elephant trunk technique and a graft replacement of thoraco-abdominal aorta with omental transfer. The postoperative course was uneventful. This case seems to be quite rare in terms of multiplicity and location of mycotic aneurysms. Surgical strategy for this pathology is discussed.

Fungal infection in a dissecting aneurysm of the thoracic aorta.

We describe a 54-year-old man who had an ascending aortic prosthetic graft and a porcine aortic valve prosthesis that were infected by Candida albicans. This infection led to the formation of a dissecting false aneurysm of the remaining transverse and entire descending thoracic aorta, and the man was admitted to our hospital for surgical treatment in February of 1991. Staged in situ graft replacement was performed using Borst's "elephant trunk" repair for the proximal aortic reconstruction and an open distal anastomosis technique for the distal repair. Candida albicans in the residual prosthetic graft was identified, and therapy with high-dose liposomal amphotericin B was initiated. The use of liposomal amphotericin B reduces the incidence of adverse effects and allows administration of higher doses than those possible with conventional amphotericin B therapy. Lifelong antifungal therapy is recommended for patients with C. albicans infection of prosthetic aortic grafts.