Bladder and erectile dysfunction before and after rectal surgery for cancer.

OBJECTIVE: To establish the incidence of bladder and erectile dysfunction after rectal surgery for cancer. PATIENTS AND METHODS: Twenty patients (16 men and four women, median age 66 years, range 36-78) with carcinoma of the rectum were prospectively studied immediately before and 4 months after operation by clinical assessment, uroflowmetry and video-cystometrography. All patients were catheterized routinely at the time of surgery. Those experiencing voiding difficulties after catheter removal were managed by intermittent self-catheterization or an indwelling urethral catheter. RESULTS: Before surgery, only six patients had completely normal bladder function and 13 of the 16 men were at least partially potent. Eight of the 19 patients who eventually had surgery developed identifiable bladder dysfunction, of whom three had urodynamic evidence of complete bladder denervation. Three men who were potent before became impotent after surgery. CONCLUSIONS: Bladder and erectile dysfunction are recognized complications of radical rectal surgery, although there is significant variation in the reported risk; much of this variability is related to the retrospective nature of most previous studies. This study demonstrates the importance of prospective urodynamic evaluation and confirms that the small but significant risk of permanent bladder dysfunction is likely to be related to pelvic nerve injury at the time of surgery.

The effect of aminolaevulinic acid-induced, protoporphyrin IX-mediated photodynamic therapy on the cremaster muscle microcirculation in vivo.

The effect of photodynamic therapy on normal striated muscle was investigated using 30 adult male rats. Animals were divided into six groups. Three control groups received phosphate-buffered saline by gavage and violet light at 105, 178 and 300 mW cm-2 respectively. Three experimental groups received aminolaevulinic acid (ALA; 200 mg kg-1) and violet light at 105, 178 and 300 mW cm-2 respectively. After exposure of the cremaster muscle animals were allowed to equilibrate and vessel diameters and bloodflow assessed. Following photoactivation measurements were taken every 10 min over a 2 h period. Photoactivation of experimental groups at the two higher power densities resulted in an initial decrease in both arteriolar and venular diameters, and a concomitant decrease in blood flow. The magnitude of these changes and the degree of recovery by the end of the observation period was related to power density. No effects were observed in the control groups. These results suggest that microcirculatory damage may contribute to the mechanism of action of photodynamic therapy with ALA.

Kinetics of endogenous protoporphyrin IX induction by aminolevulinic acid: preliminary studies in the bladder.

Photodynamic therapy (PDT) is an experimental treatment for cancer in which cell damage is achieved by the action of light on a photosensitizing drug. Though an effective treatment for superficial bladder cancer, its use has been limited due to complications relating to laser light dosimetry and the tissue specificity of the photosensitizer hematoporphyrin derivative (HPD). Aminolevulinic acid (ALA), a precursor in the biosynthesis of heme, induces the production of the endogenous photosensitizer protoporphyrin IX (PpIX) in a variety of tissues. We have studied the kinetics of PpIX accumulation in the rat bladder following ALA administration using a fluorimetric porphyrin assay. After oral and intravenous administration of ALA a rapid rise in PpIX content occurs followed by a reduction to control values by 24 hours. No increase in bladder PpIX content was detected after topical administration.