Estimation of creatinine clearance in patients with Cushing's syndrome

Postoperative renal impairment and longitudinal change in renal function after adrenalectomy in patients with Cushing's syndrome

OBJECTIVES

To evaluate the renal function after adrenalectomy in patients with Cushing's syndrome in comparison with that in patients with primary aldosteronism.

METHODS

This retrospective study included 35 patients with Cushing's syndrome and 51 patients with primary aldosteronism who underwent unilateral adrenalectomy and were followed up for >6 months. The renal function was analyzed before and after adrenalectomy using the estimated glomerular filtration rate. Postoperative renal impairment was defined as a >25% reduction in the estimated glomerular filtration rate from baseline at 1 month after adrenalectomy. Multivariate logistic regression analyses were carried out to examine whether the differences between Cushing's syndrome and primary aldosteronism increased the risk of postoperative renal impairment. Longitudinal changes were calculated starting 1 month after adrenalectomy using the linear mixed model.

RESULTS

The mean estimated glomerular filtration rate in both groups significantly decreased at 1 month after adrenalectomy from baseline. Postoperative renal impairment was observed in four (11%) and 12 (24%) patients in the Cushing's syndrome and primary aldosteronism groups, respectively. Multivariate analysis showed that preoperative systolic blood pressure was independently associated with postoperative renal impairment, but not with the type of the disease. There was no significant increase or decrease in postoperative estimated glomerular filtration rate observed after the initial decrease after adrenalectomy in either group.

CONCLUSIONS

Patients with Cushing's syndrome show the same persistent renal impairment after adrenalectomy as that reported in patients with primary aldosteronism. Attention should be given to possible masked renal damage in clinical practice for the management of Cushing's syndrome.

Flexible ureteroscopic lithotripsy: first-line therapy for proximal ureteral and renal calculi in the morbidly obese and superobese patient

BACKGROUND AND PURPOSE

The surgical treatment of kidney and proximal ureteral stones in morbidly obese patients (>14 kg/m2) remains difficult because shockwave lithotripsy is precluded by weight limitations and percutaneous nephrolithotomy is associated with difficult access and a high (9%) rate of transfusion. We review our experience with retrograde ureteroscopic lithotripsy in morbidly obese patients with renal and proximal ureteral stones.

PATIENTS AND METHODS

Between December 1992 and April 2000, five women and three men with a mean age of 46.5 years (range 33-68 years) and a mean body mass index of 54 (range 45-65.2) underwent 10 independent ureteroscopic procedures for urolithiasis. The average stone size was 11.1 mm (range 5-25 mm). Lithotripsy was performed with the holmium laser in eight patients (60%) the electrohydraulic lithotripter in four (30%), and the tunable-dye laser in the remaining patient. Stone-free status was defined as no stones visible on a plain film with nephrotomograms or CT scan at 3 months.

RESULTS

The mean operation time was 101 minutes (range 45-160 minutes), and 60% of the procedures were done on an outpatient basis. After the initial procedure, the stone-free rate was 70%. Two patients had fragments <4 mm, and no further therapy was undertaken. There was one complication: transient renal insufficiency (serum creatinine concentration 3.7 mg/dL) secondary to aminoglycoside toxicity. No transfusions were needed.

CONCLUSION

In the morbidly obese patient with symptomatic stones <1.5 cm, ureteroscopic lithotripsy is safe, successful, and efficient.