**11. Clinical cases**

We present here a report of 3 cases of MAAs treated in our center, with a description of the procedural techniques and outcomes.

#### **11.1 Clinical case description**

The first patient (JGR) was a 72-year-old male with a medical background of smoking, who was evaluated for fever and general malaise. Physical examination revealed an expansive abdominal pulsatile mass, with pain on palpation. Laboratory testing showed elevation of elevated WBC (22 × 103 /μL), and inflammatory markers (CRP, ESR, and procalcitonin). CT angiogram revealed an infected infrarenal AAA, measuring 9.2 cm in diameter, with periaortic edema and gas (**Figure 2**). After cardiac, pulmonary, and renal evaluation, the patient was treated with an aorto-aortic silver-coated Dacron bypass graft. Blood cultures were positive for Staphylococcus aureus. After an uneventful recovery, he was discharged from hospital 10 days after surgery on long-term antibiotics.

**57**

**Figure 3.**

**Figure 2.**

*aneurysm.*

*Mycotic Aortic Aneurysms*

*DOI: http://dx.doi.org/10.5772/intechopen.86328*

The second patient (ABM) was a 66-year-old male with a medical history of chronic obstructive pulmonary disease (COPD), hypertension, and smoking. He was initially evaluated in the emergency department for hematochezia, fever, and abdominal pain. Physical examination showed a distended abdomen with an abdominal pulsatile mass. Laboratory testing showed markedly elevated inflammatory markers, including CRP and ESR. The patient presented sudden rectal bleeding and hypotension. Emergent CT angiography scan demonstrated a MAA at the level of the infrarenal aorta, with an associated primary aorto-enteric fistula (AEF) **Figure 3**. He was taken to the operating room and had an urgent open aortic and small bowel repair. An aorto-aortic straight bypass graft, using a silver-coated-Dacron graft, was performed. Repair of the fistula into the jejunum was carried out with resection of the perforated bowel, and end-to-end anastomosis of a non-affected segment of jejunum. A Jackson-Pratt drain was left for 6 postoperative days. Blood cultures and aortic tissue sample were both positive for *Salmonella* sp. The patient was kept in the intensive care unit (ICU) for 5 days. After evaluation by the infectious disease team, he was discharged home on long-term antibiotics 16 days after the surgery. He had a follow-up at 1, 6, and 12 months. His last CT scan showed no signs of aortic infection, without elevation of inflammatory markers on laboratory testing.

His latest physical examination revealed no vascular abnormalities.

The third patient (RMS) was a 74-year-old male who was admitted with persistent back pain and fever. CT scan revealed a juxtarenal infected aortic aneurysm

*Patient 1. Chest computed tomography (CT) scan presenting a 9-cm MAA in the infrarenal aorta. MAA compressing (white arrow) the duodenum (A). Sagittal, frontal, and sagittal planes (B).* MAA*: mycotic aortic* 

*Patient 2. Abdomen angiography CT scan showing an infrarenal MAA. Multilobular mass seen in axial (A) and sagittal (B) planes. Presence of an aortoenteric fistula (AEF) at the site (yellow arrow) of this MAA (C).*

#### *Mycotic Aortic Aneurysms DOI: http://dx.doi.org/10.5772/intechopen.86328*

*Aortic Aneurysm and Aortic Dissection*

**10. Prosthetic aortic infection**

Procedures are usually performed under epidural or general anesthesia, with open exposure of one or both common femoral arteries. In those undergoing TEVAR, cerebrospinal fluid (CSF) drainage should be considered in those patients with expected long thoracic segment coverage. Coverage of the left subclavian artery (LSA) is usually avoided unless completely necessary. Some authors have described aneurysm sac drainage after EVAR. The procedure is usually performed in a prone position. A 21-G needle is inserted into the aneurysm sac. Following dilation, a 14–16 Fr drainage catheter is used to aspirate and send the contents for microbiological analysis. Pryluck et al. consider that it might aid to decrease the infectious content of the aneurysm sac and effectively prevent late reinfection [44].

Although this chapter tries to focus on primary MAAs, infected aneurysms or pseudoaneurysms can also occur following prosthetic replacement of the aorta. The incidence of prosthetic aortic graft infection has been described in 0.5–2%

Plastic surgery-reassembling procedures have also been described for coverage of arterial tissue after reconstruction, especially after infections involving the ascending aorta, aortic arch, and descending thoracic aorta. These procedures involve musculocutaneous pedicled flaps using various different muscles (including rectus abdominis, pectoralis major, latissimus dorsi, and vastus lateralis muscles) [46]. The application of these vascularized muscle and omental flaps by plastic surgeons, in conjunction with cardiothoracic and vascular surgeons, might be an important alternative for an adequate management of these prosthetic aortic infections. Omental flaps have been previously described as the most common applied type of autologous flap for coverage of ascending aorta, aortic arch, and descending thoracic aortic graft infections. Other options for wound closure in cases of infected prosthetic aortic grafts with associated wound infection include different types of vacuum-assisted closure (VAC) devices [46].

We present here a report of 3 cases of MAAs treated in our center, with a

The first patient (JGR) was a 72-year-old male with a medical background of smoking, who was evaluated for fever and general malaise. Physical examination revealed an expansive abdominal pulsatile mass, with pain on palpation. Laboratory

ers (CRP, ESR, and procalcitonin). CT angiogram revealed an infected infrarenal AAA, measuring 9.2 cm in diameter, with periaortic edema and gas (**Figure 2**). After cardiac, pulmonary, and renal evaluation, the patient was treated with an aorto-aortic silver-coated Dacron bypass graft. Blood cultures were positive for Staphylococcus aureus. After an uneventful recovery, he was discharged from

/μL), and inflammatory mark-

description of the procedural techniques and outcomes.

testing showed elevation of elevated WBC (22 × 103

hospital 10 days after surgery on long-term antibiotics.

of cases, including both early and delayed-onset complications [45]. All these prosthetic graft infections are associated with high morbidity and mortality rates. As previously described in the chapter, different surgical techniques have been described for repair of infected MAAs and aortic graft infection. Removal of all

infected tissue and infected grafts are essential for a successful result.

**56**

**11. Clinical cases**

**11.1 Clinical case description**

The second patient (ABM) was a 66-year-old male with a medical history of chronic obstructive pulmonary disease (COPD), hypertension, and smoking. He was initially evaluated in the emergency department for hematochezia, fever, and abdominal pain. Physical examination showed a distended abdomen with an abdominal pulsatile mass. Laboratory testing showed markedly elevated inflammatory markers, including CRP and ESR. The patient presented sudden rectal bleeding and hypotension. Emergent CT angiography scan demonstrated a MAA at the level of the infrarenal aorta, with an associated primary aorto-enteric fistula (AEF) **Figure 3**.

He was taken to the operating room and had an urgent open aortic and small bowel repair. An aorto-aortic straight bypass graft, using a silver-coated-Dacron graft, was performed. Repair of the fistula into the jejunum was carried out with resection of the perforated bowel, and end-to-end anastomosis of a non-affected segment of jejunum. A Jackson-Pratt drain was left for 6 postoperative days. Blood cultures and aortic tissue sample were both positive for *Salmonella* sp. The patient was kept in the intensive care unit (ICU) for 5 days. After evaluation by the infectious disease team, he was discharged home on long-term antibiotics 16 days after the surgery.

He had a follow-up at 1, 6, and 12 months. His last CT scan showed no signs of aortic infection, without elevation of inflammatory markers on laboratory testing. His latest physical examination revealed no vascular abnormalities.

The third patient (RMS) was a 74-year-old male who was admitted with persistent back pain and fever. CT scan revealed a juxtarenal infected aortic aneurysm

#### **Figure 2.**

*Patient 1. Chest computed tomography (CT) scan presenting a 9-cm MAA in the infrarenal aorta. MAA compressing (white arrow) the duodenum (A). Sagittal, frontal, and sagittal planes (B).* MAA*: mycotic aortic aneurysm.*

#### **Figure 3.**

*Patient 2. Abdomen angiography CT scan showing an infrarenal MAA. Multilobular mass seen in axial (A) and sagittal (B) planes. Presence of an aortoenteric fistula (AEF) at the site (yellow arrow) of this MAA (C).*

with gas within the aneurysmal sac, measuring 9 cm in diameter (**Figure 4**). Further preoperative MRI-imaging revealed spondylodiscitis at the level of the lumbar vertebra L3-L4 (**Figure 4**).

The patient was taken to the operating room and underwent an aorto-aortic straight rifampicin-bonded Dacron bypass-graft. Subsequent aortic wall tissue and blood cultures were found to be both positive for *Staphylococcus aureus*. Intravenous antibiotics were continued throughout the admission period and for 3 months after. After evaluation of the vertebral osteomyelitis by the orthopedic and microbiologist teams, he was discharged from the hospital 14 days after surgery on long-term intravenous (initially) and oral antibiotics.

Since 2011, we have performed in our center a novel hybrid repair in 2 cases of mycotic aortic aneurysms (MAAs), one of them a primary juxtarenal MAA, and the other one a suspected inflammatory infrarenal aortic aneurysm. This hybrid repair consisted in a two-stage procedure, performed within at least one-month difference, or once inflammatory markers and radiologic imaging studies had normalized.

The first stage of the procedure consisted in performing an open repair of the MAA, with interposition of a cryopreserved arterial allograft. This was done in 2 patients who presented with abdominal pain and a pulsatile mass on physical examination, with a CT angiogram that showed a contained ruptured aortic aneurysm in both cases. An aorto-aortic bypass graft using a cryopreserved arterial allograft was performed in both cases (**Figure 5**).

#### **Figure 4.**

*Patient 3. CT scan revealing a juxtarenal MAA with gas within the aneurysmal sac (B), measuring 9 cm in diameter (A). Magnetic resonance imaging (MRI) showing vertebral osteomyelitis (spondylodiscitis) in a sagittal plane, with bone erosion (red arrow) at the level of vertebral bodies L3-L4 (C).*

#### **Figure 5.** *Intraoperative images showing the surgical preparation of the arterial aortic cryopreserved allografts (A and B).*

**59**

*Mycotic Aortic Aneurysms*

repair of MAAs [23, 41].

vascular surgeon to confront.

**12. Discussion**

*DOI: http://dx.doi.org/10.5772/intechopen.86328*

In the second stage, an endoprosthesis (Zenith® stent graft, Cook Medical Inc., Bloomington, Indiana, USA) was implanted just below the renal arteries, in the infrarenal aorta, 1 month after the procedure in the first patient. In the second case, an aortic endoprosthesis (Zenith Flex® stent graft, Cook Medical Inc., Bloomington, Indiana, USA) was deployed in the infrarenal aorta, sealing the inside

We believe that this alternative option might decrease the risk of rupture of the cryopreserved allograft anastomosis, which is a devastating complication of open

Treatment of aortic infection is still one of the most challenging situations for a

Open extra-anatomic bypass revascularization combined with extensive debridement of all infected aortic and peri-aortic tissues, with excision of the infected aorta and oversewing of the non-infected aortic stump has been consid-

Open surgical options include the use of antibiotic-soaked Dacron grafts, cryopreserved aortic allografts, and biological bovine pericardial materials. The use of the superficial femoral vein (SFV)and femoral or popliteal vein segments have also been used as an alternative to in situ reconstructions in aortic infections [26, 32]. Revascularizations using vein grafts have the advantage of a potential lower risk of infection/reinfection. SFV as an autologous material has shown excellent performance in terms of long-term infectious complications. The main disadvantage is that vein harvesting is time-consuming. Another possible disadvantage of using the SFV is its diameter discrepancy with the aorta, and the possible limitation of vein length. These vein reconstructions are also functional and durable on follow-up over time [47–49]. Some groups have presented lower rates of recurrent infection and lower morbidity and mortality rates associated with rifampicin-soaked Dacron grafts

Cryopreserved arterial allografts have the advantage of a higher resistance to infection, with low rates of reinfection. Techniques in cryopreservation have improved in the last decade, possibly contributing to better outcomes of revascular-

MAAs of the ascending aorta and aortic arch, without a past medical history of previous cardiac or cardiovascular surgery, are very rare. Macedo et al. reported an incidence of 2.6% of MAAs of the ascending aorta after a review of their more than 25-year experience with aortic mycotic aneurysms [51]. Descriptions of mycotic ascending aortic aneurysms or pseudoaneurysms in the literature are very scarce. MAAs of the thoracoabdominal aorta are also less common than those of the infrarenal aorta. Previous series have presented an incidence of primary infection of the thoracic and thoracoabdominal aorta affecting 0.7–4.5% of aortic aneurysms altogether [35]. Mycotic saccular, fusiform, and pseudoaneurysms of the ascending and descending thoracic aorta have been described in the literature. Repair of these aneurysms may be performed with different techniques, including cryopreserved arterial homografts, prosthetic antibiotic-soaked grafts, visceral debranching and endovascular stent-graft repairs, bovine pericardium patch grafts, and Dacron

The largest series of mycotic aortic aneurysms was presented by Heinola et al. in 2018. This international multicenter study included 187 patients. In their series, 51

of the cryopreserved allograft, 6 months after the initial procedure.

ered the standard treatment for aortic infection [22, 26, 31].

compared to those with untreated grafts [35, 45].

grafts with biological tissue coverage [35, 45, 52].

ization using these allografts [35, 41, 50].

#### *Mycotic Aortic Aneurysms DOI: http://dx.doi.org/10.5772/intechopen.86328*

In the second stage, an endoprosthesis (Zenith® stent graft, Cook Medical Inc., Bloomington, Indiana, USA) was implanted just below the renal arteries, in the infrarenal aorta, 1 month after the procedure in the first patient. In the second case, an aortic endoprosthesis (Zenith Flex® stent graft, Cook Medical Inc., Bloomington, Indiana, USA) was deployed in the infrarenal aorta, sealing the inside of the cryopreserved allograft, 6 months after the initial procedure.

We believe that this alternative option might decrease the risk of rupture of the cryopreserved allograft anastomosis, which is a devastating complication of open repair of MAAs [23, 41].
