Severe structural damage of the seemingly non-diseased infrarenal aortic aneurysm neck.
OBJECTIVE
The success of open and endovascular repair of abdominal aortic aneurysms (AAA) is hampered by postoperative dilatation of the anatomical neck of the AAA, which is used for graft attachment. The purpose of this study was to determine whether the macroscopically non-diseased infrarenal aortic neck of AAA is histologically and biochemically altered at the time of operative repair.


METHODS
We harvested full-thickness aortic wall samples as longitudinal stripes spanning from AAA neck to aneurysmal sac in 22 consecutive patients undergoing open surgical AAA repair. Control tissue was obtained from five organ donors and five deceased subjects undergoing autopsy without evidence of aneurysmal disease. We assessed aortic media thickness, number of intact elastic lamellar units, media destruction, and neovascularization grade and performed immunohistochemistry for matrix metalloproteinase (MMP)-9 and phosphorylated c-Jun N-terminal kinase (p-JNK). MMP-9 and p-JNK protein expressions were quantified using Western Blots.


RESULTS
The median thickness of the aortic media was 1150 mum in control tissue (range, 1000-1300), 510 mum in aortic necks (250-900), and 200 mum in aortic sacs (50-500, P from nonparametric test for trend <.001). The number of intact elastic lamellar units was 33 in controls (range, 33-55), 12 in aortic necks (0-31) and three in aortic sacs (0-10, P < .001). The expression of MMP-9 and p-JNK as assessed by Western Blots (P = .007 and .061, respectively) and zymography (P for trend <.001) were up regulated in both the AAA neck and sac compared with controls. Except for p-JNK expression, differences between tissues were similar after the adjustment for age, gender, and type of sampling.


CONCLUSIONS
The seemingly non-diseased infrarenal AAA neck in patients with AAA undergoing surgical repair shows histological signs of destruction and upregulation of potential drug targets.
Diehm
Nicolas
N
Division of Clinical and Interventional Angiology, Swiss Cardiovascular Center, University Hospital Bern, Bern, Switzerland.
Di Santo
Stefano
S
Schaffner
Thomas
T
Schmidli
Juerg
J
Völzmann
Jan
J
Jüni
Peter
P
Baumgartner
Iris
I
Kalka
Christoph
C
D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000473:pathology* / Q000601:surgery*; D015415:Biomarkers / Q000032:analysis; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D007813:Laparotomy / Q000379:methods; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis; D012016:Reference Values; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D046509:Tissue Culture Techniques; D017539:Tunica Intima / Q000473:pathology; D014656:Vascular Surgical Procedures / Q000009:adverse effects / Q000379:methods*
D015415:Biomarkers; D048031:JNK Mitogen-Activated Protein Kinases; D020780:Matrix Metalloproteinase 9