Renal and peri-renal abscesses in children: proposed physio-pathologic mechanisms and treatment algorithm.

Renal and perinephric abscess in children are uncommon. Three basic pathophysiologic mechanisms are involved, namely, hematogenous spread, ascending infection and contamination by proximity to an infected area. Six pediatric patients diagnosed with renal abscess were treated at our institution from 1990-2000. Five patients were females; ages ranged from 3-17 years (mean 11.8 years). Diagnosis, as expected, was not readily apparent at presentation. Computerized tomography and renal sonograms were the most useful imaging modalities. Gram-negative bacteria were commonly isolated; only one patient grew Staphylococcus aureus. All patients received broad-spectrum intravenous antibiotics. Additional treatments consisted of percutaneous drainage (4 patients), exploratory laparotomy (1 patient, for presumed Wilm's tumor) and nephrectomy (2 patients). A new classification of the etiologic mechanisms of this condition is proposed along with a simple and practical treatment algorithm.

Acute renal failure due to rhabdomyolysis associated with radical perineal prostatectomy.

We report a case of acute renal failure due rhabdomyolysis as a result of the exaggerated lithotomy position during radical perineal prostatectomy. The pathogenesis, diagnosis, management, and preventive measures of acute renal failure associated with rhabdomyolysis are also reviewed.

Spontaneous rupture of adrenal myelolipoma: spiral CT appearance.

We report the helical computed tomographic findings of a symptomatic giant (11 cm) adrenal myelolipoma with spontaneous extracapsular hemorrhage. Narrow collimation (3 mm) imaging and three-dimensional reconstructions were useful to fully characterize the components and location of the lesion. A literature search showed a striking male and right-sided predominance for spontaneously hemorrhagic myelolipomas.

Laser ablation of urethral hair.

BACKGROUND AND OBJECTIVE: Two separate cases involving laser ablation of hair follicles in the neourethra are described. STUDY DESIGN/MATERIALS AND METHODS: Urethral hair developed secondarily to free-flap urethroplasty for congenital urethral defects. In both cases, cystoscopic depilation with electrocautery fulguration was attempted on multiple occasions. RESULTS: No improvement was seen; therefore, laser ablation was employed. Both patients remain free of regrowth at greater than one year of follow-up.

Delta-aminolevulinic acid-mediated photosensitization of prostate cell lines: implication for photodynamic therapy of prostate cancer.

BACKGROUND: Delta-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) is currently being investigated for the treatment of prostate diseases. In this study, we evaluate 1) the in vitro production of protoporphyrin IX (PPIX) (the active photosensitizing agent of ALA-mediated PDT) by two different prostate cancer cell lines (LNCaP and PC-3) and a benign, modified, prostatic cell line (TP-2), and 2) the extent of PDT-induced cell injury, as determined by electron microscopy (EM) and cell survival. METHODS: The cell lines were assigned into four treatment groups: group 1, control, no ALA and no light irradiation; group 2, dark control, ALA only; group 3, light control, radiation only; and group 4, PDT, ALA followed by irradiation (630 nm, 3 joules/cm2). The experiments were performed in triplicate. ALA concentration was 50 microg/ml of media in all instances. RESULTS: Following incubation with ALA, PPIX production was significantly increased in the three cell lines studied, and more notably in the PC-3 cell line. Compared to controls, EM and cell survival studies demonstrated significant mitochondrial damage and decreased survival, respectively, in the cells treated with PDT. This was also more evident in the PC-3 cell line. CONCLUSIONS: Our results demonstrate that prostate cells differ in their response to ALA-mediated PDT. This response appears to depend on the intracellular production of PPIX and the cell type, i.e., on the functional and structural characteristics of the cell mitochondria. In addition, our results suggest that PDT might be effective at killing prostate cancer cells.

Palliation of pain associated with metastatic bone cancer using samarium-153 lexidronam: a double-blind placebo-controlled clinical trial.

PURPOSE: To evaluate the effectiveness and safety of samarium-153 (153Sm) lexidronam (EDTMP) in a double-blind, placebo-controlled study. PATIENTS AND METHODS: Patients with painful bone metastases secondary to a variety of primary malignancies were randomized to receive 153Sm-EDTMP 0.5 or 1.0 mCi/kg, or placebo. Treatment was unblinded for patients who did not respond by week 4, with those who had received placebo eligible to receive 1.0 mCi/kg of active drug in an open-label manner. Patient and physician evaluations were used to assess pain relief, as was concurrent change in opioid analgesia. RESULTS: One hundred eighteen patients were enrolled onto the study. Patients who received 1.0 mCi/kg of active drug had significant reductions in pain during each of the first 4 weeks in both patient-rated and physician-rated evaluations. Pain relief was observed in 62% to 72% of those who received the 1.O-mCi/kg dose during the first 4 weeks, with marked or complete relief noted in 31% by week 4. Persistence of pain relief was seen through week 16 in 43% of patients who received 1.0 mCi/kg, of active drug. A significant correlation (P = .01) was observed between reductions in opioid analgesic use and pain scores only for those patients who received 1.0 mCi/kg 153Sm-EDTMP. Bone marrow suppression was mild, reversible, and not associated with grade 4 toxicity. CONCLUSION: A single dose of 1.0 mCi/kg of 153Sm-EDTMP provided relief from pain associated with bone metastases. Pain relief was observed within 1 week of administration and persisted until at least week 16 in the majority of patients who responded.

Value of prostatic cancer screening in patients treated for benign prostatic hyperplasia with medical or minimally invasive modalities.

OBJECTIVE: To assess the likelihood of overlooking the diagnosis of prostate cancer (PCA), using current screening methods, in patients treated for benign prostatic hyperplasia (BPH) with medical or minimally invasive treatment modalities, which do not produce tissue specimens for histologic review. To appraise this, we examined the impact of the preoperative use of prostatic specific antigen (PSA) in combination with transrectal ultrasound (TRUS) and systematic sextant prostate needle biopsy (PNbx) on the subsequent incidence of stage A PCA in patients undergoing transurethral resection of the prostate (TURP). METHODS/RESULTS: After excluding all patients found to have PCA during pretreatment screening, 485 patients who underwent TURP for presumed BPH from 1976 to 1994, were reviewed. From 1976 to 1989, PSA was not used for pretreatment screening, and stage A PCA was diagnosed in 11.4% of 317 patients. In 1990 and 1991, pretreatment screening included PNbx obtained under ultrasound guidance for PSA > or = 15.0 ng/ml. Stage A PCA was diagnosed in 14.2% of 63 patients. From 1992 to 1994, pretreatment screening included systematic sextant PNbx performed for PSA > 4.0 ng/ml, and stage A PCA was diagnosed in 2.8% of 105 patients. The difference in incidence of stage A PCA between the first two groups and group three was significant (p = 0.021); so is the difference in incidence of stage A2 (p = 0.037). For stage A1, the difference did not reach statistical significance (p = 0.089). CONCLUSION: Our findings suggest that systematic sextant PNbx for PSA > 4.0 ng/ml significantly reduces the risk of overlooking prostate cancer in patients undergoing treatment of BPH with modalities that do not provide tissue specimens.

Increased incidence of non-transitional cell carcinoma of the bladder in women of the Texas Gulf Coast region.

The objective of our study was to verify a suspected increased incidence of non-transitional cell carcinoma (TCC) of the bladder in female patients treated at our institution. The study included 169 patients, 83% of whom resided in the Texas Gulf Coast region. Tumors were considered TCC or non-TCC on the basis of their predominant histologic pattern. The incidence of non-TCC among men (8.1%) was comparable with data from American tumor registries and European studies. In contrast, our female patients exhibited a marked increased incidence of non-TCC (42.3%), which is approximately five times higher than that in other series. All male and female patients with non-TCC had invasive disease. History of urinary tract infections was strongly associated with non-TCC. Our results suggest that our sample of the female population in the Texas Gulf Coast region has a significantly high incidence of non-TCC. This unusual trend merits further investigation.

Mechanism of healing of the human prostatic urethra following thermal injury.

OBJECTIVES: To characterize histopathologically the healing response of the prostatic urethra after laser thermal coagulation and standard transurethral resection of the prostate (TURP). METHODS: The study included 31 patients who underwent radical prostatectomy because of malignancy. Twenty-two (first group) had laser radiation either at the time of surgery (18 patients) or from 1 to 12 weeks prior to prostatectomy (4 patients). Nine patients (second group) had TURP from 6 to 96 weeks prior to prostatectomy. RESULTS: Coagulation necrosis followed by sloughing was observed during the first 10 weeks after laser radiation. After the first 10 weeks, the healing response was otherwise stereotypical and comparable for both groups of patients. Re-epithelialization was prominent and resulted from migration of proliferating epithelial cells from the remaining acinar and ductal epithelium. Squamous metaplasia was conspicuous and present indefinitely. Development of inflammatory reaction followed by granulation tissue and well-organized fibroblastic stroma were sequentially recognized, but less prominent. Complete re-epithelialization and wound sealing was not observed before the first 12 weeks of healing. CONCLUSIONS: Our study suggests that laser thermal coagulation and TURP are partial-thickness injuries. Because of the abundant germinal epithelium in the remaining prostatic glands and ducts, the healing response of the prostatic urethra is relatively unimpeded and free of contractures, analogous to second-degree skin burns.

Accumulation of porphyrins in plasma and tissues of dogs after delta-aminolevulinic acid administration: implications for photodynamic therapy.

Protoporphyrin accumulates in tissues after administration of delta-aminolevulinic acid, and can be used as a photosensitizer for photodynamic therapy. To determine the distribution of porphyrins in a large animal model after administration of this porphyrin precursor, delta-aminolevulinic acid was administered to anesthetized dogs (100 mg/kg body weight intravenously) and porphyrin concentrations were measured in tissues (liver, pancreas, prostate, bladder, muscle and skin), plasma and urine for 6-10 h. Porphyrins increased markedly (up to 50-fold) in plasma within 1 h, were still markedly increased at 8 h, and consisted mostly of coproporphyrin III and protoporphyrin. Tissue porphyrin concentrations increased more slowly, were highest in liver, pancreas and prostate 7-10 h after delta-aminolevulinic acid administration, and were predominantly protoporphyrin. Maximum porphyrin concentrations in liver were 3- and 4-fold higher than in pancreas and prostate, respectively. Urinary delta-aminolevulinic acid excretion increased and was greatest 2-4 h after dosing; urinary porphobilinogen and porphyrins increased more gradually and remained increased up to at least 8 h. Coproporphyrin III was the predominant porphyrin in urine at all times, but hepta-, hexa- and pentacarboxyl porphyrins increased proportionally after administration of delta-aminolevulinic acid. These results indicate that porphyrins accumulate in plasma as well as tissues and urine after administration of delta-aminolevulinic acid, and may contribute to tumor necrosis during photodynamic therapy.

Optical characterization and coagulation performance of side-emitting fiber delivery systems for laser therapy of benign prostatic hyperplasia: a comparative study.

OBJECTIVES: Currently, various side-emitting optical fibers with different tip geometry are used transurethrally to deliver laser radiation for treatment of benign prostatic hyperplasia (BPH). Since fiber tip design could profoundly affect the size and profile of the emitted laser beam, and consequently the tissue response and the extent of tissue coagulation, we evaluted commercially available fibers in regard to their optical characteristics and their ability to coagulate tissue in a controlled experimental setting. METHODS: Thirteen fibers manufactured by different companies and clinically used at the present time were tested using a surgical neodymium: yttrium-aluminum-garnet laser. The profile of the laser beam delivered via each fiber was imaged on a CCD camera at various distances and evaluated by means of a laser beam analyzer. Beam divergence angle was then calculated for each tip. Tissue coagulation effects were assessed by irradiating samples of beef muscle immersed in water at 37 degrees C. The fiber tip was kept 2.5 mm away from the tissue and irrigation was maintained at flow rate of 350 to 400 cc/min during irradation. Laser powers of 20, 40, and 60 W were used for 180, 90, and 60 seconds, respectively, delivering a total energy of 3600 J. RESULTS: The results of the optical evaluation divided the fibers into two major groups: broad beam with large divergence angle and narrow beam with small divergence angle. Statistical analysis of the data (using analysis of variance) showed that volumes of coagulated tissue were significantly larger for broad beam fibers than for narrow beam fibers (1.15 +/- 0.32 versus 0.89 +/- 0.34 cm 3; P < 0.05). Also, significantly larger volumes were obtained for 20 W when compared with 60 W (1.08 +/- 0.43 versus 0.88 +/- 0.27 cm 3; P < 0.05). CONCLUSIONS: The laser power density delivered by individual fibers to the prostate tissue may vary significantly, thus greatly affecting the extent of tissue coagulation. Therefore, irradiation parameters must be optimized for each fiber type.

Healing response of the canine prostate to Nd:YAG laser radiation.

The objective of the study was to characterize the healing response of the canine prostate to laser thermal injury. The study included 20 canine prostates that underwent transurethral laser radiation. The prostates were retrieved 1 hr after laser radiation in 7 dogs (acute group), and from 3 days to 9 weeks in 13 dogs (chronic group). Two distinct features were observed. First, reepithelialization of the prostate urethra resulted from mobilization of proliferating epithelial cells from acinar and ductal prostatic epithelium into the cavity surface, and not from the edges of the wound at the bladder neck. Squamous cell metaplasia was a prominent feature of reepithelialization. Second, the healing process in the canine prostate was relatively unimpeded. The large glandular component provided abundant germinal epithelial growth, and the absence of stromal elements allowed for complete sloughing of necrotic tissue without residual eschars. Further, the lesions in the chronic group had a tendency to be larger than those in the acute group, suggesting that extended delayed necrosis may occur at deep prostatic tissue layers.

Laser irradiation for the treatment of benign prostatic hyperplasia.

Benign prostatic hyperplasia (BPH) is one of the most common medical problems encountered in the United States. For many years, transurethral resection of the prostate (TURP) has been the mainstay of treatment for symptomatic BPH. In recent times, newer modalities of treatment in the form of drugs (a- blockers, LHRH-agonist, anti-androgens, 5 a-reductase inhibitors), microwave hyperthermia, prostatic stents, balloon urethroplasty, laser prostatectomy, and most recently High Intensity Focal Ultrasound (HIFU) and Trans Urethral Needle Ablation (TUNA) are challenging TURP as the gold standard therapy for BPH. Today, laser prostatectomy holds a special place in therapy of BPH, as it is easy to perform, safe to apply with a vastly improved patient compliance, and is the first choice in certain special circumstances, e.g., patients on anticoagulants. In this chapter we discuss the present status of laser prostatectomy for BPH.

Histopathologic effects of laser radiation on the human prostate.

High levels of applied laser irradiation to the prostate will carbonize or vaporize tissue, and may cause explosive expansion of superheated tissue water. Lower levels, used most often to relieve obstruction caused by benign prostatic hypertrophy, will cause coagulation necrosis. This effect is apparent within 1 h of application. In contrast to the canine, in which laser-coagulated prostate sloughs in 2 to 3 weeks leaving a smooth cavity, in the human necrotic tissue is sloughed irregularly over a period ranging up to 12 weeks. This difference is attributed to the dominantly glandular nature of the canine prostate, and the dense fibromuscular composition of the human prostate stroma. Sloughing is accomplished by surface liquefaction, cavitation of the necrotic coagulum, and to a lesser degree, formation of granulation tissue at the margins. As often occurs at the margin of spontaneous infarcts in the prostate, squamous metaplasia may be prominent at the margins of laser-induced coagulation necrosis.

Development of human papillomavirus type 16 associated squamous cell carcinoma of the scrotum in a patient with Darier's disease treated with systemic isotretinoin.

In contrast to squamous cell carcinoma of the penis, scrotal carcinoma has historically been associated with exposure to environmental or industrial carcinogens and has only rarely been correlated with human papillomavirus. We report on a patient with squamous cell carcinoma of the scrotum in which human papillomavirus type 16 was integrated into the tumor cell genome, suggesting a causal role of human papillomavirus in the development of squamous cell carcinoma of the scrotum. Other unique features of our case include the presence of Darier's disease, an uncommon genodermatosis, and treatment with oral retinoids, which have prophylactic value in the prevention of cutaneous malignancies.

Histopathological evaluation of laser thermocoagulation in the human prostate: optimization of laser irradiation for benign prostatic hyperplasia.

We have previously shown in a canine prostate model that a noncontact low power neodymium:YAG laser regimen of 15 watts for 180 seconds yields a larger volume of coagulation necrosis than the currently recommended high power regimen of 50 watts for 60 seconds. These 2 regimens have not yet been compared in humans. The objective of this study was to evaluate histopathologically the thermocoagulation effect of these 2 laser regimens in the human prostate and the effect of the spatial distribution of the laser lesions on the extent of coagulation necrosis. The study was conducted in 10 patients undergoing radical prostatectomy or cystoprostatectomy. The laser treatment was given transurethrally 1 hour before removal of the specimen. There were no fractures of the prostate. The coagulation necrosis did not reach the peripheral zone and it was minimal in areas rich in fibromuscular tissue, such as the bladder neck. At times, nodular benign prostatic hyperplasia was unaffected. A 4-quadrant treatment in the same plane often yielded small nonconfluent lesions. Confluent lesions in the same plane yielded approximately 30% greater depth of coagulation necrosis, which was achieved when 3 or 4 lesions were created on each side of the prostate (per single transverse plane). Likewise, coagulation necrosis observed with 15 watts for 180 seconds was approximately 40% greater than that noted with the 50 watts for 60 seconds regimen. Our findings suggest that noncontact laser prostatectomy is a safe procedure that can be improved by modifying the laser regimen and the spatial distribution of lesions.