Soo J. Rhee

Does transrenal fixation of aortic endografts impair renal function

OBJECTIVES Transrenal fixation (TFX) of aortic endografts is thought to increase the risk for renal infarction and impaired renal function. We studied the late effects of TFX on renal function and perfusion. METHODS Of 189 patients with commercial aortic endografts, which we inserted between 1995 and 2002, we reviewed data for 130 patients (112 men, 18 women) with available creatinine (Cr) concentration and contrast enhanced computed tomography (CT) scans preoperatively and 1 to 97 months after the procedure. Of the 130 patients, 69 patients had TFX and 61 patients had infrarenal fixation (IFX). Both groups were physiologically comparable. Average age was 76 +/- 8 years for patients with TFX and 75 +/- 8 years for patients with IFX. Presence of renal infarct or renal artery occlusion was determined by nephrograms on serial contrast-enhanced CT scans. RESULTS Mean follow-up was 17 +/- 16 months (range, 1-54 months) for TFX and 21 +/- 21 months (range, 1-97 months) for IFX. Mean serum Cr concentration increased significantly during long-term follow-up in both groups (TFX, 1.3 +/- 0.5 mg/dL to 1.5 +/- 0.8 mg/dL, P <.01; IFX, 1.3 +/- 0.7 mg/dL to 1.4 +/- 0.8 mg/dL, P <.03). Creatinine clearance (CrCl) similarly decreased over long-term follow-up in both groups (TFX, 53.3 +/- 17.7 mL/min/1.73 m(2) to 47.9 +/- 16.2 mL/min/1.73 m(2), P <.01; IFX, 58.1 +/- 22.7 mL/min/1.73 m(2) to 53.1 +/- 23.4 mL/min/1.73 m(2), P <.02). There were no significant differences in the increase in Cr concentration (P =.19) or decrease in CrCl (P =.68) between TFX and IFX groups. Small renal infarcts were noted in four patients (5.8%) in the TFX group and one patient (1.6%) in the IFX group. No increase in Cr concentration or decrease in CrCl was noted in any patient with a renal infarct. Postoperative renal dysfunction developed in 7 of 69 patients (10.1%) in the TFX group and 7 of 61 patients (11.5%) in the IFX group. There were no statistically significant differences between groups with respect to number of patients with new renal infarcts (P =.37) or postoperative renal dysfunction (P =.81). CONCLUSION There is a slight increase in serum Cr concentration and decrease in CrCl after aortic endografting. However, there was no significant difference in these changes between patients with TFX and IFX. Although TFX may produce a higher incidence of small renal infarcts, these do not impair renal function. Thus our midterm results suggest that TFX can be performed safely, with no greater change in renal function than observed after IFX.

Fate of collateral vessels following subintimal angioplasty

Purpose: To evaluate the fate of collateral vessels adjacent to and within the target lesion following subintimal angioplasty (SIA). Methods: Pre and postprocedural angiograms were reviewed for 29 patients undergoing SIA of the lower extremity arteries over a 3-year period. The number of patent collateral vessels ≤5 cm proximal to the occlusion (proximal segment) and ≤5 cm distal to the occlusion (distal segment) were recorded pre and postprocedurally and compared. In addition, the number of collateral vessels that were re-opened within the recanalized segment following SIA was counted. Results: The mean number of patent collaterals in the proximal segment was 1.9 (range 0–4) preprocedurally and 1.4 (range 0–4) postprocedurally (p<0.002). The mean number of patent collaterals in the distal segment was 1.9 (range 0–4) pre-procedurally and 1.0 (range 0–4) postprocedurally (p<0.0001). Previously absent collaterals within the recanalized segment were observed in 4 (14%) of 29 patients post-SIA. The mean number of collateral vessels within all 3 segments (proximal, treated, and distal) was 3.9 collaterals preprocedurally and 2.9 collaterals postprocedurally Conclusions: Some collateral vessels are sacrificed during SIA, but the majority are preserved. In addition, SIA has the potential to open new collaterals within the occluded segment. These collaterals may play an important role should restenosis develop within the target segment.

Patency Rates of Femorofemoral Bypasses Associated with Endovascular Aneurysm Repair Surpass Those Performed for Occlusive Disease

PURPOSE To evaluate the patency rates of femorofemoral grafts performed in conjunction with aortomonoiliac or aortomonofemoral (AMI/F) endografts. METHODS Over the past 8 years, 110 patients (98 men; mean age 77+/-7 years, range 57-90) underwent aortoiliac aneurysm repair with an AMI/F endograft. Follow-up data in these patients were prospectively collected for a mean 2.3 years (range 1-68 months). RESULTS There were 2 early (<7 days) AMI/F endograft thromboses with secondary femorofemoral graft occlusion. In both patients, patency of all grafts was restored by thrombectomy plus stenting of the endograft. Three late (4, 5, and 10 months) AMI/F endograft thromboses led to femorofemoral graft failure; 2 were successfully treated, but the third patient refused further intervention. No femorofemoral bypass failed in the absence of AMI/F endograft thrombosis. There were no femorofemoral graft infections. Four-year life-table primary and secondary patency rates were 95% and 99%, respectively. CONCLUSIONS Femorofemoral bypasses with AMI/F endografts for aneurysmal disease are durable procedures and have better patency than femorofemoral grafts used to treat occlusive disease. Femorofemoral bypass patency rates alone are not a disadvantage of aortomonoiliac endografts.

Repetitive bypass and revisions with extensions for limb salvage after multiple previous failures

The optimal treatment of patients facing imminent amputation after multiple (≥2) failed prior ipsilateral bypasses is unclear. We analyzed a group of patients undergoing multiple lower extremity bypasses for limb salvage to assess the utility of attempting multiple revascularizations. From 1990 to 2005, 105 revascularization procedures were performed in 55 limbs of 54 patients with imminent limb-threatening lower extremity ischemia after failure of ≥2 prior infrainguinal bypasses in the same leg. Fifty-five operations were the third procedure (Group A) and 50 operations were the fourth or more (Group B). We compared primary/secondary patency and limb salvage rates by Society for Vascular Surgery criteria. Limb salvage rates did not differ between patients undergoing a third bypass and those undergoing four or more bypasses at one year (62 versus 65%, NS) or at three years (58 versus 61%, NS). Secondary patency was not different between groups (76 versus 76%, P = NS) at one and three years (71 versus 70%, NS). Primary patency also did not differ between the two groups, at one year (24 versus 35%, NS), or at three years (11 versus 15%, NS). No differences were observed in morbidity and mortality rates between the groups. In conclusion, the likelihood of success of repetitive limb revascularization was unrelated to the number of previous failures. The expected incremental failure rate with each successive bypass was not found. These results, coupled with the three-year limb salvage rate of over 50% in patients who otherwise would have required amputation, lend support to aggressive use of limb revascularization in selected patients even after two or more failed bypasses.

Importance of Phasicity in Detection of Proximal Iliac Vein Thrombosis with Venous Duplex Examination

Superficial venous reflux is commonly the cause of symptomatic venous disease, but proximal venous obstruction may also play a role. A duplex ultrasound evaluating bilateral common femoral veins can detect differences in phasicity, which may be due to pelvic venous obstruction. We report a case of a patient with recurrent symptomatic varicose veins after treatment of superficial venous reflux. Based the duplex ultrasound results of damped respiratory phasicity, the patient was diagnosed with deep venous obstruction which was confirmed on MRV.