Pararenal aortic aneurysms: the future of open repair

Open Repair of Pararenal Aortic Aneurysms: Operative Management, Early Results, and Risk Factor Analysis

Surgical treatment of pararenal aortic aneurysms, if compared to open surgical repair of infrarenal aneurysms, is technically more demanding and characterized by problems related to organ ischemia. To better define challenges, risks, and results, we analyzed our experience with the treatment of pararenal aortic aneurysms. Between January 1993 and March 2005, 119 consecutive patients underwent surgery for pararenal aneurysms at our institution. A prospective analysis of results was performed. According to their localization, we treated 85 juxtarenal aneurysms and 34 suprarenal aneurysms. One hundred and three patients underwent primary repair of an atherosclerotic aneurysm, four patients underwent surgical repair of an anastomotic pseudoaneurysm, and eight patients underwent correction of an aneurysm of the pararenal aorta proximal to a previous infrarenal anastomosis. Four patients underwent emergency operation for a ruptured aneurysm. In the juxtarenal aneurysm group, the 30-day mortality rate was 4.7% (4/85) including three patients with ruptured aneurysm. In the suprarenal aneurysm group, the 30-day mortality rate was 2.9% (1/34). Preoperative renal insufficiency was present in 16 patients, respectively in 7 patients with juxtarenal aneurysms and in 9 patients with suprarenal ones. In 22 patients, we registered a transient increase in creatinine levels with return to baseline levels by discharge. Four patients required long-term dialysis. In three patients, a short period of dialysis was required. Clamping time longer than 30 min was associated with a higher risk of transient postoperative deterioration of renal function (p = 0.0073). Preoperative renal insufficiency was associated with a higher risk of persistent postoperative deterioration of renal function (p < 0.0001). Morbidity and mortality of elective surgery for pararenal aneurysms is acceptable. One of the main risks of this surgery is renal morbidity. Preoperative renal insufficiency and long periods of renal ischemia are associated with a higher risk of postoperative deterioration of renal function that is often, but not always, reversible. Nowadays, pararenal aneurysm repair is a safe procedure, especially if performed electively.

Factors affecting outcomes of open surgical repair of pararenal aortic aneurysms: A 10-year experience

PURPOSE

Few large series document surgical outcomes for patients with pararenal abdominal aortic aneurysms (PAAAs), defined as aneurysms including the juxtarenal aorta or renal artery origins that require suprarenal aortic clamping. No standard endovascular alternatives presently exist; however, future endovascular branch graft repairs ultimately must be compared with the gold standard of open repair. To this end, we present a 10-year experience.

METHODS

Between 1993 and 2003, 3058 AAAs were repaired. Perioperative variables, morbidity, and mortality were retrospectively assessed. Renal insufficiency was defined as a rise in the concentration of serum creatinine by > or = 0.5 mg/dL. Factors predicting complications were identified by multivariate analyses. Morbidity and 30-day mortality were evaluated with multiple logistic regression analysis.

RESULTS

Of a total of 3058 AAA repairs performed, 247 were PAAAs (8%). Mean renal ischemia time was 23 minutes (range, 5 to 60 minutes). Cardiac complications occurred in 32 patients (13%), pulmonary complications in 38 (16%), and renal insufficiency in 54 (22%). Multivariate analysis associated myocardial infarction with advanced age (P = .01) and abnormal preoperative serum creatinine (>1.5 mg/dL) (P = .08). Pulmonary complications were associated with advanced age (P = .03), renal artery bypass (P = .02), increased mesenteric ischemic time (P = .01), suprarenal aneurysm repair (P < .0008), and left renal vein division (P = .01). Renal insufficiency was associated with increased mesenteric ischemic time (P = .001), supravisceral clamping (P = .04), left renal vein division (P = .04), and renal artery bypass (P = .0002), but not renal artery reimplantation or endarterectomy. New dialysis was required in 3.7% (9/242). Abnormal preoperative serum creatinine (>1.5 mg/dL) was predictive of the need for postoperative dialysis (10% vs 2%; P = .04). Patients with normal preoperative renal function had improved recovery (93% vs 36%; P = .0002). The 30-day surgical mortality was 2.5% (6/247) but was not predicted by any factors, and in-hospital mortality was 2.8% (7/247). Median intensive care and hospital stays were 3 and 9 days, respectively, and longer stays were associated with age at surgery (P = .007 and P = .0002, respectively) and any postoperative complication.

CONCLUSIONS

PAAA repair can be performed with low mortality. Renal insufficiency is the most frequent complication, but avoiding renal artery bypass, prolonged mesenteric ischemia time, or left renal vein transection may improve results.