Simultaneous aortic and renal artery reconstruction: Evolution of an eighteen-year experience

AbstractPurpose: We reviewed an 18-year experience with combined abdominal aortic and renal artery reconstruction (AOR) with a particular focus on patients' clinical risk profile and surgical results in contemporary practice as compared with earlier experience.Methods: One hundred seventy patients underwent AOR during the interval January 1, 1976 to June 30, 1994. To examine parameters representative of current practice, the cohort was divided into group I patients (n = 110) treated before 1990 and group II (n = 60) treated between 1990 and 1994. Median follow-up duration for the entire cohort was 8.4 ± 0.6 years. Renal artery reconstruction patency and patient survival rates were calculated by life-table methods. Logistic and Cox regression analysis were used to determine predictors of perioperative and long-term morbidity/mortality rates.Results: Although demographic features changed little over the review period, the detection (56% vs 73%, p = 0.03) and treatment with percutaneous transluminal coronary angioplasty/coronary artery bypass grafting (11% vs 40%, p = 0.0001) of associated coronary artery disease were more frequent in group II versus group I patients. Alternatively, renal insufficiency was more frequent in group I patients. The operative mortality rate for the entire cohort was 6.5% (group I = 9% vs group II = 2%, p = 0.06). Changing trends of surgical techniques over the review period included (group I vs II, respectively) increased use of bilateral simultaneous renal artery repair (12% vs 25%, p < 0.005) and transaortic endarterectomy as the renal artery reconstruction technique (3% vs 25%, p < 0.0001). Favorable response in blood pressure control was noted in 68% of group II patients. The cumulative 5-year survival rate for all patients was 75% with an initial serum creatinine of 2.0 mg/dl or greater being the only negative predictor of late survival after regression analysis.Conclusion: The current operative mortality rate for AOR is in the range anticipated for aortic surgery alone, and this appears to be related to improved detection and treatment of associated coronary artery disease and intervention before major deterioration in renal function. These findings coupled with currently available natural history data relative to renovascular disease justify an aggressive approach with AOR when significant renal artery stenosis is detected during evaluation of aortic disease. (J VASC SURG 1995;21:916-25.

Renal artery reconstruction for the preservation of renal function

AbstractPurpose: We reviewed a 13-year experience with an emphasis on long-term survival and renal function response when renal artery reconstruction (RAR) was performed primarily for the preservation or restoration of renal function in patients who had atherosclerotic renovascular disease.Methods: From January 1, 1980, to June 30, 1993, 139 patients underwent RAR for renal function salvage and were retrospectively reviewed. Inclusion criteria were either preoperative serum creatinine level >2.0 mg/dl (67% of patients) or RAR to the entire functioning renal mass irrespective of baseline renal function. Patient survival was calculated by life-table methods. Cox regression analysis was used to determine relative risk (RR) estimates for the late outcomes of continued deterioration of renal function and late survival after RAR. A logistic regression model was used to evaluate variables associated with perioperative complications.Results: Clinical characteristics of the cohort were notable for advanced cardiac (history of congestive heart failure, 27%; angina, 22%; previous myocardial infarction, 19%) and renal disease (serum creatinine level <2.0 mg/dl, 33%; 2.0 mg/dl to 3.0 mg/dl, 40%, >3.0 mg/dl, 27%). Cardiac disease was the principle cause of early (6 of 11 operative deaths) and late death. Operative management consisted of aortorenal bypass in 47%, extraanatomic bypass in 45%, and endarterectomy in 8%; 45% of patients required combined aortic and RAR. The operative mortality rate was 8%; significant perioperative renal dysfunction occurred in 10%. Major operative morbidity was associated with increasing azotemia (RR = 2.1; p = 0.001; 95% confidence interval [CI], 1.3 to 4.7 for each 1.0 mg/dl increase in baseline creatinine level). Of those patients who had a baseline creatinine level ≥2.0 mg/dl, 54% had ≥20% reduction in creatinine level after RAR. Late follow-up data were available for 87% of operative survivors at a mean duration of 4 years (range, 6 weeks to 12.6 years). Actuarial survival at 5 years was 52% ± 5%. Continued deterioration in renal function occurred in 24% of patients who survived operation, and eventual dialysis was required in 15%. Deterioration of renal function after RAR was associated with increasing levels of preoperative creatinine (RR = 1.6; 95% CI, 1.2 to 1.8; p = 0.001 for each 1.0 mg/dl increment in baseline creatinine level), and inversely related to early postoperative improvement in creatinine level (RR = 0.41; 95% CI, 0.2 to 0.9; p = 0.04).Conclusions: Intervention before major deterioration in renal function and an aggressive posture toward the frequently associated coronary artery disease are necessary to improve long-term results when RAR is performed for renal function salvage. (J Vasc Surg 1996;24:371-82.

Infusion of the Branched Chain Amino Acids in Postoperative Patients: Anticatabolic Properties

Postinjury metabolism is characterized by breakdown of muscle protein as substrate for energy production and gluconeogenesis and by the resultant loss of lean body mass and weight loss. The branched chain amino acids (BCAAs) which are principally oxidized by the skeletal muscle have been implicated in recent in vitro and in vivo studies as having special anticatabolic and regulating effects in skeletal muscle. We studied the anticatabolic effects of the BCAAs in 35 patients undergoing operative injury of moderate severity. In a prospective randomized and blinded manner patients were infused for five days starting immediately after surgery with either 5% dextrose or 5% dextrose with an amino acid solution containing 22, 35 or 100% BCAAs. All patients survived and there were no major postoperative complications. Mean hospital stay was 17 days for patients receiving amino acids and 19 days for patients receiving 5% dextrose only (p = ns). All three groups receiving amino acid solutions were in nitrogen equilibrium or in a slight positive nitrogen balance, while the group receiving 5% dextrose only was in a mean negative nitrogen balance of 6.6 ± 0.6 gN/day. The differences between the three groups receiving amino acids were slight and not significant. Weight loss was 2 ± 0.7 kg in the 5% dextrose group, 1 ± 0.7 kg in the 22% BCAAs group, 0.5 ± 0.5 kg in the 35% BCAAs group and the 100% BCAAs group gained 0.4 ± 1.8 kg. Blood chemistries in the different groups and during the study period remained within normal limits except for ammonia levels rising significantly in the 5% dextrose group and SGOT levels rising in the 22% and 35% BCAA groups. With mild variations the plasma amino acid patterns in all groups were similar to the normal pattern, even in the 100% BCAAs group receiving an unbalanced amino acid solution, suggesting the complete cessation of amino acid efflux from muscle, the muscle depending solely on the exogenous supply of BCAAs to satisfy its metabolic requirements. The results suggest that early nutritional suppport in the postoperative period will result in nitrogen equilibrium and that the infusion of the three BCAAs only in the postoperative state is as effective in preventing muscle catabolism as other more balanced amino acid solutions. In the postinjury state balanced amino acid solutions rich in BCAA may prove beneficial

Initial experience with endovascular aneurysm repair: Comparison of early results with outcome of conventional open repair

AbstractPurpose: To determine the safety, effectiveness, and problems encountered with endovascular repair of abdominal aortic aneurysm (AAA). Initial experience with endoluminal stent grafts was examined and compared with outcome for a matched concurrent control group undergoing conventional operative repair of AAA. Methods: Over a 3-year period, 30 patients underwent attempts at endovascular repair of infrarenal AAA. Of the 28 (93%) successfully implanted endografts, 8 were tube endografts, 8 bifurcated grafts, and 12 aortouniiliac grafts combined with femorofemoral bypass. Most of the procedures were performed in the past year because the availability of bifurcated and aortoiliac endografts markedly expanded the percentage of patients with AAA who might be treated with endoluminal methods. The follow-up period ranged from 1 to 44 months, with a mean value of 11 months. Results: Endovascular procedures demonstrated significant advantages with respect to reduced blood loss (408 versus 1287 ml), use of an intensive care unit (0.1 versus 1.75 days), length of hospitalization (3.9 versus 10.3 days), and quicker recovery (11 versus 47 days). Although the total number of postoperative complications was identical for the two groups, the nature of the complications differed considerably. Local and vascular complications characteristic of endovascular repair could frequently be corrected at the time of the procedure and tended to be less severe than systemic or remote complications, which predominated among the open surgical repair group. On an intent-to-treat basis, 23 (77%) of the 30 AAAs were successfully managed with endoluminal repair. The seven (23%) failures were attributable to two immediate conversions caused by access problems, three persistent endoleaks, one late conversion caused by AAA expansion, and one late rupture. Conclusions: Although less definitive than those for conventional operations, these early results suggest that endovascular AAA repair offers considerable benefits for appropriate patients. The results justify continued application of this method of AAA repair, particularly in the treatment of older persons at high risk. (J Vasc Surg 1998;27:992-1005.