M.B. Siroky

Most cases of erectile dysfunction (ED) are associated with oxidative stress risk factors such as diabetes mellitus, smoking, hypercholesterolaemia and hypertension. Our goal was to search for markers of oxidative stress in arteriogenic ED and examine the protective role of dietary antioxidants. Atherosclerosis-induced ED was developed in rabbits by balloon de-endothelialization of the iliac arteries. Ballooned and age-matched control animals were assigned into subgroups receiving pomegranate extract antioxidants in drinking water or tap water as placebo. After 8 weeks, penile blood flow and erectile activity were recorded. Erectile tissue relaxation, oxidative products, oxidative stress-responsive genes and structure were examined using organ bath, enzyme immunoassay, quantitative real-time polymerase chain reaction and transmission electron microscopy, respectively. Arterial ballooning caused diffused atherosclerosis, decreased intracavernosal blood flow and led to ED. Impairment of endothelium-dependent relaxation, diffused fibrosis, increased oxidative products, upregulation of superoxide dismutase (SOD) and aldose reductase (AR) gene expression, mitochondrial and endothelial structural damage and increased caveolae were evident in erectile tissues from atherosclerotic animals receiving placebo. Upregulation of antioxidant enzymes SOD and AR failed to protect ischaemic erectile tissue from oxidative injury. Pomegranate extract significantly improved intracavernosal blood flow, erectile activity, smooth muscle relaxation and fibrosis of the atherosclerotic group in comparison with the atherosclerotic group receiving placebo, but did not normalize them to the age-matched control levels. Pomegranate extract appeared more effective in diminishing oxidative products, preventing SOD and AR gene upregulation, and protecting mitochondrial, endothelial and caveolae structural integrity of the atherosclerotic group. Our data suggest the presence of oxidative stress in ED and a more efficient action of antioxidants on molecular and ultrastructural alterations than on distinct functional deficit and structural damage in the ischaemic penis.

We measured the maximum urinary flow rate monthly for 1 year by uroflowmetry in 1,645 patients in a double-blind, placebo-controlled study of finasteride therapy for benign prostatic hyperplasia. Patients were randomized to receive placebo (555) or finasteride (1,090). A total of 23,857 flow measurements was obtained. Because of the presence of artifacts on many uroflow curves, we read the maximum urinary flow rate values manually and compared them to the values provided electronically by the uroflowmeter. On average, the manually read values were 1.5 ml. per second lower than the machine read values. Artifacts causing a difference of 2 ml. per second or more between the 2 methods were found in 20% and of more than 3 ml. per second in 9% of the tracings. The difference between treatment groups in mean maximum urinary flow rate change at the end of the study was the same with both reading methods. However, confidence intervals were 15 to 25% larger for the machine read compared to the manually read values. This larger variability in machine read maximum urinary flow rate has a marked negative impact on the power of statistical tests to assess any given difference in maximum urinary flow rate between treatment groups. Furthermore, it increases sample size requirements by 50% to achieve any given statistical power. We conclude that maximum urinary flow rate artifacts contribute significantly to the variability of maximum urinary flow rate measurement by uroflowmetry. Manual reading of the maximum urinary flow rate eliminates an important fraction of such variability.

Acquired cystic kidney disease has become increasingly recognised as a significant risk in patients with end-stage renal disease, especially in those maintained on chronic haemodialysis and peritoneal dialysis. A review of the literature indicates that nearly 50% of patients on dialysis for more than 3 years develop renal cystic changes. The major complications of this condition are neoplasia and spontaneous renal haemorrhage. The risk of developing renal carcinoma has been estimated to be more than 30 times higher in dialysis patients with cystic changes than in the general population. Our experience with 5 patients is reported, including 3 with renal tumours and 1 with metastatic disease. Careful surveillance of dialysis patients using yearly ultrasonography and computed tomography is recommended. The evolving indications for radical nephrectomy in this disease are discussed.

The proper assessment of erectile dysfunction can be objectively accomplished only by examining the vascular, hormonal, neurologic, and psychologic components. The vascular surgeon today requires the ability to participate in multidisciplinary approach to diagnosis and needs an understanding of pelvic hemodynamics to design aortoiliac reconstructions that optimize pelvic blood flow. We perform a history and physical examination carefully designed to evaluate erectile ability and detail vascular involvement. Outpatient serum samples are obtained for hormonal analysis. In the noninvasive vascular laboratory, we measure the penile blood pressure using a 2.5 cm cuff and a 10 MHz Doppler probe. We feel strongly that measuring the right and left cavernosal artery pressures directly and determining the penile/brachial index (PBI) most accurately reflects penile flow. A PBI less than 0.6 is diagnostic of vasculogenic impotence, and a PBI greater than 0.75 is normal. We perform our pelvic steal test by exercising the thigh and buttock muscle groups, and comparing the PBI before and after exercise. A decrease of 0.1 or more represents a positive steal test. Measurement of nocturnal penile tumescence is valuable in cases where history, physical examination, and noninvasive vascular laboratory evaluations do not correspond. A neurologic evaluation may include cystometrography or sacral latency testing when indicated. Psychological screening is performed in all patients. We screened 54 vascular clinic patients and found 81% to be symptomatic of erectile dysfunction. In this group, 79% had a PBI less than 0.75, and 38% had a positive pelvic steal test. Illustrative cases are presented herein and the implications in aortoiliac surgery are discussed.