Infectious aortitis with mycotic pseudoaneurysm

Case contributed by Dr Michael P Hartung

Presentation

Abdominal pain, fever, leukocytosis.

Patient Data

Age: 65
Gender: Male

Heavy atherosclerosis of the abdominal aorta, mesenteric, and iliac vessels. Hazy stranding and mildly prominent lymph nodes about the abdominal aorta at the level of and slightly inferior to the renal arteries. No definite periaortic gas is identified. No aortoenteric fistula. 

Posterior projecting  small pseudoaneurysm at the level of the right renal artery, with the defect in the wall measuring 6-7 mm and the extraluminal collection measuring 2.1 x 0.8 x 1.2 cm.  Focal ectasia measuring 2.6 cm in the mid segment of the infrarenal abdominal aorta
without aneurysm. 

Severe narrowing and heavy plaque at the origin of the right renal artery. Ill-defined rounded area of low attenuation along the anterior interpolar cortex which could represent small area of inflammation, infarction, or mass.

Colonic dilation with large amount of stool.

PREOPERATIVE DIAGNOSIS
Severe infection of the mid abdominal visceral aorta involving the superior mesentery, renal arteries. Extensive lymphadenopathy of the prerenal segment.

Operation

  1. Laparotomy.
  2. Repair of abdominal aorta with a cadaveric thoracic aorta.
  3. Left renal artery bypass.
  4. Splenectomy.
  5. Right axillary femoral bypass graft.

Procedure/Description
Under endotracheal anesthesia after the usual preparation and draping, an incision was made in the right infraclavicular fossa as well as the right groin. The common femoral artery was dissected and encircled with vessel loops. The dissection was carried also in the upper part and the axillary artery was dissected and encircled with vessel loops. The plan was to do a temporary bypass to perfuse the lower extremity while there is a supraceliac clamp. So I placed an 8 mm PTFE graft and just gave him 3000 units of Heparin and clamped the axillary artery proximally and distally to the axillary anastomosis with 5-0 Prolene on venous and the femoral anastomosis also with 5-0 Prolene. Adequate hemostasis was secured. This was functioning quite adequately.

Abdominal cavity was entered through midline incision after appropriate prep and drape in the usual sterile fashion and the abdominal cavity had some degree of free fluid, large gelatinous material. The colon was significantly dilated. Retraction of the bowel using a pericolic incision on the left was done. The transverse colon from inflammatory process had strict adherence to the spleen and was inseparable and ended up doing a splenectomy while mobilizing the colon. Splenic pedicle was ligated doubly with 0 silk. The left colon was mobilized to the right and this mass of lymphatic structures, adenopathy and inflammatory tissue was then encountered over the aorta between the inferior mesenteric artery and the superior mesenteric artery. This was opened and extensive oozing and bleeding also occurred. Nonetheless, using electrocoagulation we mobilized as much as possible adequately. Incision was carried all the way up to the supraceliac aorta where the cruciate was divided. Supraceliac aorta then encircled and clamped in the usual fashion. Distally, the clamp was applied to the aorta just above the inferior mesentery since it had good perfusion given the supraceliac clamp. Following that, the renal artery which had been controlled with vessel loop on the left side was occluded and instilled after opening the aorta with renal perfusion solution. The right renal artery was never visualized nor was there any orifice visible in this destructed area, aorta adjacent to the superior mesenteric artery. The aorta had to be transected above the superior mesenteric artery, which had to be transected because of the necrotic aorta. Proximal anastomosis was done to the cadaveric thoracic graft that had been appropriately sought and prepared and anastomosis was completed with 3-0 Prolene and suture line hemostasis was adequate. We then decided that we will just do the distal anastomosis prior to doing SFA, mesenteric and renal artery anastomosis so it would lay better and facilitate the anastomosis and make it easier. So we did the lower anastomosis with 3-0 Prolene and had extensive difficulty with bleeding. Nonetheless, the bowel was still adequately perfused at this stage, so proceeded with the renal artery bypass which we used femoral artery from a cadaver and did a proximal anastomosis to the graft and additional anastomosis to the renal artery with 5-0 Prolene and flow was detected within the renal artery. We tried removing the inferior mesenteric artery, but the patient had extensive oozing from every area of dissection that had been carried out. It appeared he was in a state of coagulopathy and his base deficit was up to 16. He was doing quite poorly and multiple attempts were made and ultimately the oozing could not be controlled adequately. We had redone the lower anastomosis twice, but there was no specific anastomotic bleeding, most of the bleeding appeared to be more venous than arterial. We packed the area thoroughly and then closed his abdomen and disconnected the axillary femoral bypass graft and ligated it. We did not disconnect it from the artery though.

At this stage, I concluded that this patient was not salvageable and his coagulopathy was consuming him in addition to the uncontrollable bleeding from every orifice that we sutured appeared futile, so after closing the abdomen we discussed with the family and he was transferred to the intensive care so the family could visit him. He had a blood pressure at the time of transfer although low.

Case Discussion

Laboratory values:

  • WBC 23.8 
  • Lactate 13.2
  • Blood cultures positive for MRSA 

Infectious aortitis with small pseudoaneurysm. The periaortic stranding, adenopathy, and history of fever with leukocytosis should lead to very high suspicion for this diagnosis. The pseudoaneurysm is likely mycotic in origin.

A detailed operative note is provided for review. Attempt at cadaveric repair was unsuccessful due to irreversible coagulopathy, eventually resulting in the patient's demise.

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Case information

rID: 59830
Published: 9th Jun 2018
Last edited: 9th Jun 2018
System: Vascular
Inclusion in quiz mode: Included

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