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Nardi et al. Postoperative malperfusion in aortic dissection

patient AAAD survival outcomes have been shown to this evidence. Nonetheless, many surgeons still limit
relate closely to the length of time between diagnoses the extent of surgery to the ascending aorta, even
and surgeries. [18,19] Given the high mortality of patients though limited repair has a higher probability of re-
with mesenteric malperfusion (40-100%), initial intervention on the remaining aortic segments at a
management with an interventional procedure treating later date. The primary aim of performing AAAD is
the condition should be considered. [20,21] In fact, as an emergent, life-saving procedure. If a center is
previous data suggested that mesenteric malperfusion only able to perform a limited repair technique, but still
was associated with the highest mortality rates when saves the life of the patient, then the primary intention
compared to malperfusions occurring in any other of the procedure has been achieved. [24,25]
organ systems. The surgical strategy presented here,
consisting of immediate aortic dissection treatment, In this study, no independent predictors of renal
showed that incidence of preoperative malperfusion and mesenteric PM were identified. However, using
was reduced roughly in half; from 56% preoperatively univariate analyses, having a LVEF value less than
to 25% in the immediate postoperative period. 40% was statistically relevant (P < 0.0001). Additionally,
having entry tears distal to ascending aortic segments
Univariate analyses of preoperative variables that required extensive repairs and longer surgical
determined that three risk factors predicted the times was also recognized as a significant risk factor
occurrence of a PM in any organ system. These risk (P < 0.05).
factors were: having a LVEF less than 40%, having renal
impairment that required continuous hemofiltration, This study had several limitations. First, it was a
and having an entry tear distal to the ascending retrospective analysis of an experience at a single
aorta or the proximal aortic arch. However, the only institution. Second, preoperative treatments to address
variable that maintained significance in the multivariate organ malperfusions were not performed. Third, the
model was having a preoperative LVEF of less than possible effects of revascularization strategies for the
40%. Reduced ejection fraction likely associated with treatment of PM were not explored. Revascularization
concomitant ischemic coronary disease, which could techniques may improve long-term outcomes.
have increased the risk of a postoperative low cardiac
function and subsequent PM. Juxtaposition of intimal In conclusion, PM is a severe condition that is
tears distal to the ascending aorta or the proximal frequently associated with adverse immediate and
arch were non-significant factors in the multivariate long-term outcomes in surgical AAAD patients. At this
analyses. However, these factors contributed risk to institution, the incidence of PM after AAAD surgery was
progression of aortic disease and PM. Patients with a noteworthy, occurring in roughly 10% of patients. AAAD
primary entry tear in the descending aorta were at the surgical procedures effectively reduced preoperative
highest risk of PM. These patients probably required malperfusions in about half of cases. In fact, repairs
additional extensive repairs compared to patients with to the ascending aorta and proximal arch, as well as
primary entry tears in the ascending aorta. Some of removal of primary tears, significantly increased the
these high-risk patients may benefit from a “frozen true lumen flow and allowed treatment of a majority
elephant trunk” procedure to address the entire of malperfusion syndromes, including those in the
pathology. [22] cerebral, mesenteric, and renal systems. Postoperative
malperfusion, especially involving the kidneys, was
Analysis of preoperative variables contributing risk associated with high in-hospital mortality and reduced
for each type of PM revealed that only one variable long-term survival. There was no evidence that the
independently predicted cerebral PM: preoperative types of surgical techniques undertaken, the sites of
cerebral malperfusion (OR: 2.5, 95% CI: 1.0-6.1, P < cannulation, or the use of more complex interventions
0.05). Shortening the length of time between onset of (requiring circulatory arrest during cardiopulmonary
cerebral symptoms and dissected aortic surgery was bypass) were risk factors contributing to PM.
critical for improved outcomes in this subset of patients.
Estrera et al. [23] reported improved outcomes in AAAD Authors’ contributions
patients who underwent cardiac surgeries within 10 h Study design: P. Nardi, C. Olevano, C. Bassano, E.
of neurological symptom onsets. Bovio, G. Ruvolo
Development of methodology: P. Nardi, C. Bassano
With regard to arterial cannulation sites, some authors Collection of data: C. Olevano, E. Bovio, L. Cecchetti
have suggested that cannulation of the axillary artery Analysis and/or interpretation of data: P. Nardi, C.
will ensure better brain protection during surgery. Olevano, C. Bassano, E. Bovio
However, the experience reported here did not confirm Writing (not revising) all or sections of the manuscript:
82 Vessel Plus ¦ Volume 1 ¦ June 27, 2017