Objective: To assess the safety and efficacy of hyperbaric oxygen (HBO) for treating radiation cystitis a long-term follow-up study was done in patients with prostate cancer, the second most common malignancy in Japan. Patients and Methods: A total of 38 patients at an age of 68 ± 8 years with radiation cystitis following irradiation of prostate cancer were treated with HBO at 2 absolute atmospheric pressures for 90 min daily. The average number of HBO treatment sessions in each patient was 62 ± 12. The follow-up period was 11.6 ± 3.7 years. We evaluated objective and subjective symptoms periodically with special reference to the initiation timing of HBO therapy. Results: High efficacy ratios of objective and subjective findings were obtained at 2 and 4 (79–95%) years, respectively. After 7 years’ follow-up, these ratios decreased slightly (72–83%) but still remained stable thereafter (75–88%) without any serious accident. Comparison of late morbidity scores before and 11.6 years after HBO therapy showed significant improvement (p < 0.0005). Twenty-eight patients (74%) obtained nonrecurrent outcome. They had received 18% lower (p < 0.001) radiation dosage than recurrent patients. The interval between the onset of hematuria and start of HBO treatment in nonrecurrent patients was 30% shorter (p < 0.001) than that of recurrent patients. Conclusions: We elucidated the long-term safety and beneficial effect of HBO therapy of radiation cystitis in patients with prostate cancer. Early application of HBO treatment after the onset of hematuria appears to produce favorable outcome.

The microvascular architecture of the human corpus cavernosum penis was studied by scanning electron microscopy of vascular corrosion casts. The corpus cavernosum was supplied by the penile deep artery. It gave off branches to become either arteries distributed within the corpus cavernosum or those directly supplying the corpus spongiosum urethrae. The former arteries further divided into small arteries which fell into two categories: 1) arteries breaking up into capillaries, and 2) arteries draining directly into the cavernous sinuses. The capillaries were collected into venular networks just beneath the tunica albuginea (the subalbugineal venular plexus), while the cavernous sinuses were collected into venules at the periphery of the corpus cavernosum. These postcavernous venules also received venules from the subalbugineal venular plexus, and left the corpus cavernosum. Thus, two circulatory routes are evident within the corpus cavernosum. These findings suggested that the penile erectile cycle is controlled by hemodynamic changes between these two routes within the corpus cavernosum.

Observations of the tissue oxygen tension alteration were made using an open tip type oxygen electrode polarographic method as an index of blood flow change in the penile skin, corpus cavernosum and thigh skin of 16 males aged 20-26 years (average age: 20.5 years). In another five males aged 18-21 (average age: 19.8 years) the relationship between corpus cavernosum tissue oxygen tension alteration and penile circumference change in the erection process was observed. This relation was obtained in the penile circulation model, and penile hemodynamics were ascertained. In the flaccid penis the corpus cavernosum contains low-oxygen blood and there is a blockade at the vascular tree in the corpus cavernosum. In the tumescence phase the blood flow of the corpus cavernosum increased suddenly by the relief of cavernosum vascular blockade. During the penile tumescence phase the increased inflow and outflow persisted in corpus cavernosum, and in penile skin the blood also increased initially, but gradually decreased as penile circumference increased. After erection was attained it is thought that resistance to inflow occurred by outflow pathway contraction. In the detumescence phase, a decrease of inflow and a concomitant increase of outflow occurred and the reopening of outflow is thought to be necessary for prompt penile detumescence.

The effects of electrical stimulation of hypogastric nerve and sympathetic chain on ‘electroerection’ (penile erection induced by electrical stimulation of the pelvic nerve) were studied in dogs to clarify the physiological roles that these neural inputs may play in producing and/or maintaining penile erection. As an objective parameter of hemodynamics of the penile circulation, the pressure in the corpus cavernosum of the penis was measured. Hypogastric nerve electrostimulation was performed in 24 dogs who had received pelvic nerve stimulation and, therefore, had ‘electroerection’. Ten dogs responded to this procedure with an augmentation of ‘electroerection’, 10 with an attenuation of ‘electroerection’, and 4 with no appreciable changes. 4 out of the 10 animals who exhibited an attenuation response were then given an α₁-adrenergic blocker (prazosin hydrochloride) prior to the electrical stimulation to evaluate the specificity of the effects of the hypogastric nerve stimulation. In 3 of the 4 dogs the attenuation effect was abolished by this treatment and instead an augmentation effect became evident. Sympathetic chain electrostimulation was performed in 6 dogs with ‘electroerection’. When applied to the L_4–5 interganglionic segment, it produced a biphasic response which consisted of an initial increase followed by a decrease of the intracorporeal pressure. In contrast, stimulation of the L_2–3 interganglionic segment produced a monophasic response consisting of only augmentation of the intracorporeal pressure. These data suggested that there might be two groups of fibers in the hypogastric nerve and sympathetic chain which are functioning antagonistically, and that the anti-erectile neural inputs are mediated primarily by the α₁-adrenergic system. To examine the sites of penile vasculature where the innervating hypogastric nerve exerts its effects, electrical pelvic/hypogastric nerve stimulations were performed in dogs in whom the inflow blood circulation to the corpora cavernosa was disrupted by arterial ligation and replaced by a constant saline infusion. It appears that the stimulatory input via the hypogastric nerve caused an increased blood flow into the cavernous space due to vasodilation of the inflow blood vessels, and the inhibitory effect occurred mainly due to relaxation of the draining blood vessels with a resultant increase of the blood outflow from the cavernous space.

Renal metastases of osteogenic sarcoma are unusual clinical occurrence and cases of osteogenic sarcoma treated by nephrectomy for renal metastases have been rarely reported. We report a 19-year-old male who was successfully treated by left nephrectomy for a metastatic tumor of osteogenic sarcoma from the right femur. In 1989 above-knee amputation was performed and the initial relapse with right pulmonary metastasis was treated by right upper lobectomy in 1991. In February 1992 he developed left renal and left pulmonary metastasis, hence left nephrectomy and left upper lobectomy were performed. Metastases of osteogenic sarcoma to the organs other than the lung and bone will increase because of the improvement of diagnostic modalities. Our study suggests that a bone scan is useful for routine follow-up of patients with osteogenic sarcoma and that resection of the metastatic lesion can improve these patients' quality of life.