Results 1 to 4 of 4

Thread: Coselli, et al. (2004). Bypass during aortic aneurysm repair and paraplegia.

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1

    Coselli, et al. (2004). Bypass during aortic aneurysm repair and paraplegia.

    • Coselli JS, LeMaire SA, Conklin LD and Adams GJ (2004). Left heart bypass during descending thoracic aortic aneurysm repair does not reduce the incidence of paraplegia. Ann Thorac Surg. 77: 1298-303. The Michael E. DeBakey Department of Surgery, Division of Cardiothoracic Surgery, Baylor College of Medicine and The Methodist DeBakey Heart Center, Houston, Texas, USA. BACKGROUND: The preferred technique for spinal cord protection during surgical repair of descending thoracic aortic aneurysms (DTAAs) remains controversial. The purpose of this retrospective analysis was to determine if the use of left heart bypass (LHB) reduced the incidence of paraplegia in patients who underwent DTAA repair. METHODS: Over a 15-year period 387 consecutive patients underwent surgical repair of DTAAs using either the "clamp-and-sew" technique (341 patients, 88.1%) or distal aortic perfusion via a LHB circuit (46 patients, 11.9%). Data regarding patient characteristics, operative variables, and outcomes were retrieved from a prospectively maintained database. The impact of LHB on the frequency of paraplegia was determined using univariate and propensity score analyses. RESULTS: There were 17 operative deaths (4.4%) including 11 patients (2.8%) who died within 30 days. Paraplegia occurred in 10 patients (2.6%). On univariate analysis increasing age (p = 0.03), increasing aortic clamp time (p < 0.001), increasing red blood cell transfusion requirements [p = 0.01), and acute dissection [p = 0.03) were associated with increased incidence of paraplegia. Patients who received LHB had a similar incidence of paraplegia [2/46, 4%) compared with those treated without LHB [8/341, 2.3%; p = 0.3). Both matching and stratification propensity score analyses confirmed that LHB was not associated with reduced risk of paraplegia. CONCLUSIONS: On retrospective analysis the use of LHB during DTAA repair did not reduce the incidence of spinal cord injury. The "clamp-and-sew" technique remains an appropriate approach to DTAA repair.

  2. #2
    After some thought, I conclude that I disagree with the recommendation of this study for the folowing reasons:

    1. The authors found a remarkably low incidence of paraplegia (4%) in both the bypassed and non-bypassed aortic repair cases. In many previous studies of non-bypassed aortic repair, incidences of paraplegia were as high as 40%. So, clearly, the likelihood of paraplegia is higher in some centers and probably for some forms of aortic aneurisms. I suspect that these patients may not have as serious aneurisms and the aneurisms did not involve the part of the aorta that provided blood flow to the T6-8 segment of the spinal cord.

    2. This was not a randomized study. Only 46 of 341 patients received left heart bypass, presumably because the surgeons judged that these patients required the bypass. Of those patients that were judged to need bypasses, their statistics were the same as those that did not need bypasses. Thus, the bypass seem to have achieved what it should have done... i.e. reduce the incidence of paraplegia to acceptably low levels (4%), the same as those patients that were judged not to need bypasses.

    I think that a more reasonable conclusion from this study would be that bypasses are safe and should be based on clinical judgement of the severity of the aorta aneurysm and whether or not the patient required bypass. If this were a randomized study, I would be agree with the conclusion but it is not a randomized study and therefore is subject to the confounding variable of why the surgeons chose to bypass some patients and not others for bypass.

    Wise.

  3. #3
    Dr Young, have you seen any studies on the incidence of spinal cord hypoxia or infarct when the newer abdominal aneurysm stents are used? This is the hot topic where I work. To date we have not had a SCI patient due to surgery with this method, while we have had several with traditional cut and sew procedures.

    (KLD)

  4. #4
    KLD, there are many studies of this subject in the early 1990's. In the 1980's, when I was doing much of the evoked potential monitoring at NYU Medical Center of patients, we found that an aortic cross-clamp of longer than 30 minutes was associated with a high incidence of paraplegia. If the surgery can be done with a cross-clamp time of less than 30 minutes, I don't think that many patients had this problem. Please note, however, that those people who required a cross-clamp time of longer than 30 minutes tended to have more extensive aneurysms that extended longer distances in the aorta and required aortic grafts. Because this is not a randomized study, those patients who did not get bypasses may have had smaller aneurysms, thereby explaining the lower incidence of paraplegia.

    No, I have not seen any studies regarding the new abdomenal aortic stents.

    Wise.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •