Discussion

Article Outline

• Copyright

Dr Randolph L. Geary (Winston-Salem, NC). Dr Samson and colleagues are to be congratulated for a provocative presentation and excellent clinical results in a challenging group of patients. This topic is controversial and the literature fairly evenly split with half of the largest case series arguing left renal vein ligation is safe and the other half concluding the vein should be kept in continuity to avoid renal insufficiency, hematuria, or pelvic venous congestion. Our bias at Wake Forest is that mobilizing the vein and dividing its various tributaries provides excellent exposure of the peri-renal aorta in all but a handful of cases. In our last 200 aortic reconstructions, I could find only four cases in which the left renal vein was divided and in two cases the vein was subsequently repaired. This brings me to my first question. In your opinion, how often is dividing the vein simply a convenience rather than a requirement to safely complete the operation? Do you divide the vein in every case requiring supra-renal aortic control or are these 56 cases a subset of the total requiring supra-renal cross-clamping by your group during the period of study? Second, only half of your patients contributed to the 1 year analysis. Of these, only 2 patients had a significant decline in renal function and both were from the subset that demonstrated renal insufficiency before surgery. How many of the patients with renal insufficiency at baseline were actually captured in your 1 year analysis? If only 2, then following the entire population out to 1 year may change your conclusions. Finally, while only 1 patient showed a significant decline in glomerular filtration rate (eGFR) at discharge, a number of patients had transient renal failure in the perioperative period. Do the authors know whether transient renal dysfunction contributed to the length of stay or perhaps an increased number of cardiopulmonary complications? Again, I congratulate the authors on their excellent clinical results and thank them for bringing this controversial topic to our attention.

Dr Samson. Thank you for your questions, I am going to answer the last one first. I do not have the data to show whether their transient increase influenced the length of stay and it is something that we will look at and perhaps include in the manuscript. As far as whether we ligate the renal vein only when it is technically necessary or whether we have a low threshold – originally, in the study, obviously we ligated it only when we felt it was necessary. Now we say, if you don't mind me being somewhat sarcastic, “hey look there is the renal vein, let's go ligate it”, because we really do believe that it gets in the way and prevents operating on a more normal aorta. In our opinion, ligation of the renal vein is the key to safe aortic surgery and all the problems that occur with aortic surgery occur when you try to operate to a diseased aorta. So we now ligate the left renal vein with impunity. The other problem with trying to preserve the renal vein and simply ligating its tributaries is that if you don't get a good view having done that, you are then with your back against the wall because you can no longer ligate the vein. So we would much prefer to just ligate the vein at that time. Finally, all 8 patients with baseline renal failure were captured in the long-term follow-up.