Glomerular filtration rate after left renal vein division and reconstruction during infrarenal aortic aneurysm repair
Received 26 September 2006; accepted 17 November 2006. published online 26 January 2007.
Objectives
The study assessed the effect on postoperative renal function of left renal vein (LRV) division and reconstruction by direct reanastomosis or graft interposition during infrarenal abdominal aortic aneurysm (AAA) repair.
Methods
Between January 2001 and March 2006, 1189 patients underwent elective open repair of infrarenal AAAs. LRV division was performed in 15 (1.3%) and its reconstruction in all but one (LRV group), where the LRV was occluded. Patients’ glomerular filtration rates (GFRs) were retrospectively estimated through postoperative day 4 by using the Cockcroft-Gault equation and compared with the GFRs of 56 controls undergoing AAA repair without LRV division (control group) randomly identified from a prospectively compiled database in a 4:1 ratio. Post hoc 1:1 case-matched analysis was also performed. Statistical analyses were performed as appropriate.
Results
Comparison of demographics and risk factors revealed no statistically significant differences between the two groups with the exception of the following: AAAs were larger in LRV group (71.4 ± 17.1 mm vs 56.0 ± 14.6 mm; P = .003) and preoperative GFR was lower in LRV group (65.3 ± 19.0 mL/min/1.73 m2 vs 82.8 ± 22.3 mL/min/1.73 m2; P = .009). Postoperatively, the trend of GFR with time did not differ between groups (P = .33). The variation of GFR at day 4 after surgery compared with preoperative values was not different either (5.6 ± 12.6 mL/min/1.73 m2 vs 1.0 ± 15.5 mL/min/1.73 m2; P = .67). A further 1:1 case-matched multivariate analysis of variance, matching patients and controls by AAA size and preoperative GFR, showed no difference in trend of GFR with time between groups (P = .15). Operative time was not significantly longer in LRV group (148.4 ± 35.8 minutes vs 131.0 ± 40.3 minutes; P = .07). No differences between groups were found for blood loss (585.7 ± 264.2 mL vs 567.7 ± 222.5 mL; P = .88), perioperative complications (5 vs 8; P = .12), or hospital length of stay (6.2 ± 1.8 days vs 5.5 ± 1.2 days; P = .10). A 6-month follow-up of renal function available in 12 patients of LRV group showed no significant decrease in GFR compared with postoperative values (70.8 ± 24.8 mL/min/1.73 m2 vs 69.1 ± 23.5 mL/min/1.73 m2; P = .86). At duplex scan, the reconstructed LRV could be insonated in nine of these 12 patients and all were patent.
Conclusions
LRV division during AAA repair was associated with larger aneurysms and preoperative subclinical renal function impairment. In these patients, LRV reconstruction was associated with the maintenance of preoperative renal functional status without significantly lengthening of operative time or increasing the complications from surgery.
Vascular Surgery, San Raffaele Scientific Institute, Università Vita-Salute, Milan, Italy.
Correspondence: Massimiliano M. Marrocco-Trischitta, MD, Vascular Surgery, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy.
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