Renal artery reconstruction for the preservation of renal function

PURPOSE

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 > or = 2.0 mg/dl, 54% had > or = 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.

Management of the renal allograft recipient: immunosuppressive protocols for long-term success

To determine the benefits of long-term cyclosporine (CsA) immunosuppression, renal allograft recipients were randomly assigned to a protocol of either: CsA+azathioprine (Aza)+prednisone (TD), or to a protocol in which CsA was discontinued from the regimen of Aza+prednisone (CsA D/C). With a mean follow-up of nearly 7 years since transplantation, 30/47 (64%) CsA D/C and 27/45 (60%) TD had functioning allografts. Although long-term survivals were similar, hazards of the CsA D/C protocol were evident (40% rate of acute rejection following CsA D/C). Conversely, continued CsA in the TD protocol provided the opportunity for prednisone reduction, or even complete prednisone withdrawal in selected patients. A TD protocol which can provide equivalent long-term success, and eventually lower or omit prednisone, is preferable to a protocol of CsA D/C.

Long-term, low-dose cyclosporine treatment of renal allograft recipients. A randomized trial

Ninety-two adult renal allograft recipients, receiving baseline immunosuppression with CsA and prednisone, were assigned randomly to one of the following regimens. CsA was discontinued (D/C group) in 47 recipients who were then maintained on Aza and prednisone; or Aza was added to continued low-dose CsA and prednisone (triple drug [TD] group) in 45 patients. Entry into the study required an absence of rejection and a stable creatinine for at least four months prior to randomization. The mean month of randomization was 8.34 +/- 2.9 for the D/C group, and 7.2 +/- 3.2 for the TD group. Following randomization, a significantly greater rate of rejection (P less than .01) was observed in the D/C group (40%) than in the TD group (13%). With a mean follow-up of 30 months, 41/47 of D/C allografts (87.2%) and 39/45 TD allografts (86.6%) were functioning. Nevertheless, rejection had a persistent adverse effect on allograft function, in both the D/C and TD groups, up to 36 months following randomization. Parameters such as donor-type and rejection prior to randomization did not identify recipients at risk for rejection following randomization. Therefore, although the CsA withdrawal regimen might be ideal, the opportunity to select appropriate candidates remained elusive. In contrast, the safety of the TD regimen became apparent. Neither significant nephrotoxicity nor hypertension was observed, and the opportunity for less daily prednisone was evident. Despite its additional cost, the TD regimen utilizing indefinite low-dose CsA, is preferred.

The selective use of antilymphocyte serum for cyclosporine treated patients with renal allograft dysfunction

Eighty-seven adult renal allograft recipients were initially treated with cyclosporine-prednisone immunosuppression. Thirty patients experienced no episode of rejection. Antilymphocyte antibody therapy (ALS) was administered to 21 of the 68 recipients of cadaveric donor allografts for either primary allograft dysfunction or acute rejection, and to 6 of 19 recipients of haploidentical, living-related allografts because of steroid-resistant rejection. The cumulative allograft and patient survival for the entire series (follow-up 9-36 months) was 84% and 95%, respectively. This improvement in the rate of successful transplantation can be attributed to the selective addition of ALS therapy to recipients with specific instances of renal allograft dysfunction. In this report, the indications for the use of ALS preparations following prophylactic CsA immunosuppression are reviewed. Experience with the protocols of the ALS administration is also discussed. In selected cases, the administration of either ATG or OKT3 can significantly benefit CsA recipients who experience either primary allograft nonfunction or an epidose of acute rejection.

Immunological monitoring of diabetic and nondiabetic recipients of renal allografts

Peripheral blood T-lymphocyte populations were monitored sequentially in diabetic recipients of renal allografts. Unfractionated buffy coat preparations were reacted with the murine monoclonal antibodies, OKT3 (all circulating T-cells), OKT4 (helper/inducer/regulatory T-cells), and OKT8 (cytotoxic/suppressor cells). Levels of peripheral blood lymphocyte subpopulations of diabetic patients monitored prior to transplantation revealed no significant abnormalities. Following transplantation, but prior to any therapy for acute rejection, the mean percentage of OKT3, 4, and 8 reactive cells in diabetic recipients closely resembled those observed in nondiabetic recipients. After treatment for acute rejection, a marked decrease in the mean OKT4/OKT8 ratio from normal (1.90 +/- 0.7) was observed in both diabetic (1.04 +/- 0.5), and nondiabetic (1.35 +/- 0.5) allograft recipients. Eleven of thirteen diabetic recipients with long-term functioning allografts were found to have a depressed OKT4/OKT8 ratio (mean 1.03 +/- 0.6). T-cell subset monitoring of diabetics with end-stage renal failure failed to reveal any significant differences from nondiabetic, uremic patients. The high incidence (75%) of allograft rejection noted in these diabetic allograft recipients similarly suggests normal immunocompetence. Following successful completion of rejection therapy, however, reduction in the ratio of OKT4 to OKT8 reactive cells suggests that an alteration in immune responsiveness has occurred. Immunological monitoring of these long-term diabetic recipients with functioning allografts suggests that the observation of a consistently depressed OKT4/OKT8 ratio may (1) be useful in predicting continued allograft function and (2) prompt the more rapid reduction of steroid medication to maintenance dosage since this pattern may be indicative of subclinical viral infection.