Statistical controversies in clinical research: comparison of primary outcomes in protocols, public clinical-trial registries and publications: the example of oncology trials.

Background: Protocols are often unavailable to peer-reviewers and readers. To detect outcome reporting bias (ORB), readers usually have to resort to publicly available descriptions of study design such as public clinical trial registries. We compared primary outcomes in protocols, ClinicalTrials.gov and publications of oncology trials and evaluated the use of ClinicalTrials.gov as compared with protocols in detecting discrepancies between planned and published outcomes. Method: We searched for phase III oncology trials registered in ClinicalTrials.gov and published in the Journal of Clinical Oncology and New England Journal of Medicine between January 2014 and June 2015. We extracted primary outcomes reported in the protocol, ClinicalTrials.gov and the publication. First, we assessed the quality of primary outcome descriptions by using a published framework. Second, we evaluated modifications of primary outcomes between each source. Finally, we evaluated the agreement, specificity and sensitivity of detecting modifications between planned and published outcomes by using protocols or ClinicalTrials.gov. Results: We included 65 trials, with 81 primary outcomes common among the 3 sources. The proportion of primary outcomes reporting all items from the framework was 73%, 22%, and 75% for protocols, ClinicalTrials.gov and publications, respectively. Eight (12%) trials presented a discrepancy between primary outcomes reported in the protocol and in the publication. Twelve (18.5%) trials presented a discrepancy between primary outcomes registered at ClinicalTrials.gov and in publications. We found a moderate agreement in detecting discrepant reporting of outcomes by using protocols or ClinicalTrials.gov [κ = 0.53, 95% confidence interval (0.25-0.81)]. Using ClinicalTrials.gov to detect discrepant reporting of outcomes showed high specificity (89.5%) but lacked sensitivity (75%) as compared with use of protocols. Conclusion: In oncology trials, primary outcome descriptions in ClinicalTrials.gov are often of low quality and may not reflect what is in the protocol, thus limiting the detection of modifications between planned and published outcomes.

Tuberculosis and tumour necrosis factor-alpha inhibitor therapy: a report of three cases in patients with psoriasis. Comprehensive screening and therapeutic guidelines for clinicians.

Tumour necrosis factor (TNF)-alpha inhibitors, long used in rheumatology and gastroenterology, have made a significant impact on the therapy of psoriasis and psoriatic arthritis. TNF-alpha is an important cytokine in normal physiological processes such as the immune response to granulomatous infection. Inhibition of this process by TNF-alpha inhibitors has been reported to increase the susceptibility of patients to granulomatous infections such as Mycobacterium tuberculosis. Despite the numerous reported cases in the literature and appropriate warnings on the labels for the three currently approved TNF-alpha inhibitors, current guidelines do not address case-specific issues across the full spectrum of tuberculosis. The probability of developing active tuberculosis has been reported to be as much as seven times higher when recommendations are not followed. We report three cases of tuberculosis induced by TNF-alpha inhibitors despite a rigorous screening policy in our tertiary care psoriasis centre, and suggest tuberculosis-specific guidelines for clinicians using these agents based on a review of the literature.

Bleomycin upregulates gene expression of angiotensin-converting enzyme via mitogen-activated protein kinase and early growth response 1 transcription factor.

Pulmonary fibrosis is a progressive disorder characterized by the loss of alveolar architecture through epithelial and endothelial cell apoptosis and fibroblast proliferation. Recent studies showed that angiotensin-converting enzyme (ACE) activity is increased in fibrotic tissues, and ACE inhibitors administered in vivo ameliorate fibrosis, suggesting that ACE may play a critical role. However, the regulation of ACE expression is not well understood. In the present study, we demonstrate that bleomycin, a chemotherapeutic agent which induces pulmonary fibrosis in animals and humans, increases gene expression of ACE. Treatment of primary bovine pulmonary artery endothelial cells with 0.1 to 1.0 microg/ml bleomycin increased ACE enzymatic activity and ACE mRNA, as monitored by hippuryl-L-histidyl-L-leucine assay and competitive quantitative reverse transcriptase polymerase chain reaction (RT-PCR), respectively. Luciferase reporter constructs showed that upregulation of ACE transcription by bleomycin is mediated through element(s) in the 97-bp ACE promoter. Bleomycin activated p42/p44 mitogen-activated protein kinase (MAPK) and induced nuclear translocation and activation of the early growth response (Egr)-1 transcription factor, a factor previously shown to positively regulate ACE expression. The MAPK kinase1/2 (MEK1/2) inhibitor U0126 blocked MAPK and Egr-1 activation by bleomycin, suggesting that Egr-1 activation is MAPK dependent. These data provide the first evidence that bleomycin activates ACE gene expression through the MAPK pathway and Egr-1.

Acute and chronic interstitial cryotherapy of the adrenal gland as a treatment modality.

BACKGROUND AND OBJECTIVES: Adrenalectomy is indicated for patients with large adrenal lesions or functional tumors. Cryoablation is currently used as a surgical alternative for the treatment of prostate, lung, brain, pharynx, and liver tumors. The purpose of this study was to determine if cryosurgery could be delivered to small areas in the adrenal gland in a controllable and reproducible manner, so that tissue could heal in a nonpathological way. MATERIALS AND METHODS: Fourteen female mongrel dogs underwent acute (N = 8) or chronic (4 weeks) (N = 6) cryoablation using the Cryounit. In the acute study, using an open transabdominal approach, a 2-mm cryoprobe was placed interstitially into the adrenal tissue, while 0.032-inch thermocouples were cannulated into the ipsilateral adrenal artery and vein. Adrenal parenchymal temperature changes were measured using thermocouples placed at 0.4- and 0.8-cm intervals from the cryoprobe. In the chronic study, cryoablation was achieved by transperitoneal laparoscopic access using standard laparoscopic technique. RESULTS: Interstitial cryoprobe temperatures decreased from 33.1 +/- 1.9 degrees C to -148 +/- 1.2 degrees C following 15 minutes of freezing in the acute study. Cryoablation of adrenal tissue achieved temperatures of -41.8 +/- 5.7 degrees C and -21.8 +/- 1 degrees C at distances of 0.4 and 0.8 cm from the cryoprobe, respectively. There were no significant changes in adrenal artery or vein temperatures during cryoablation. Histologically, there was a clear demarcation between viable and nonviable tissue, the latter being characterized by areas of multifocal hemorrhage and pyknosis. After 4 weeks of healing, there was a well-defined line between necrotic and viable tissue. CONCLUSION: Cryoablation of the adrenal gland can be obtained in an effective, controllable, and reproducible manner. This controllable energy form may provide new modality for tissue destruction where adrenal gland preservation is necessary and can be delivered by the laparoscopic approach. Understanding the effect of adrenal cryoablation may allow us to treat selected patients with small tumors in whom organ preservation is necessary.

Functional, social and psychosexual adjustment after vaginal reconstruction.

PURPOSE: We assessed the long-term functional, social and psychosexual outcome in children who underwent vaginal reconstruction. MATERIALS AND METHODS: We interviewed and assessed the psychological development of 16 women 17 to 28 years old (mean age 22) who underwent vaginal reconstruction only or in combination with other urogenital reconstructive procedures at ages 11 months to 18 years (mean 8.8). Psychological measures included the Beck Depression Inventory, Draw-a-Person test and Linkowski acceptance of disability scale as well as a standard questionnaire evaluating the sexual adjustment, social adjustment and ability for self-support of these women. RESULTS: Mean Beck Depression Inventory was 8.5 with less than 9 defined as minimal depression. Mean acceptance of disability score was 83.9 (range 54 to 94), indicating that patients were well adjusted with respect to the disability. Functionally 10 women were satisfied with the appearance of the vagina, 4 were neutral and 2 were dissatisfied. A total of 12 patients had no doubts about their female identity but 2 had occasional, 1 had significant and 1 had chronic doubts. Of the 16 patients 12 have completed high school, 3 are still in high school and 1 has withdrawn from high school. Of the 12 women who have completed high school 9 are currently in college and 3 have completed college. Socially all 16 participants rated family relationships as good and 13 were at least satisfied with their social life. Of the 16 women 12 have had a sexual encounter, including 1 who did not achieve orgasm. Six women are involved in long-term relationships, of whom 1 is married. In regard to the future all patients believe that they will be independent and financially stable with a fulfilling career. CONCLUSIONS: While women who have undergone vaginal reconstruction may be at risk for avoiding interpersonal relationships and sexual intimacy, we did not note this finding in our series. The majority of these patients were well adjusted to their physical condition, and had a high level of education and a stable family life.

Demographics, family histories, and psychological characteristics of prostate carcinoma screening participants.

BACKGROUND: The goals of this study were to 1) understand the reasons that men seek prostate carcinoma screening, in light of the ongoing medical controversy surrounding screening; and 2) assess the level of psychological distress and perceived risk among men seeking screening, and whether or not these variables were dependent on a man's family history of prostate carcinoma. METHODS: The subjects were 126 men (40% had a family history of prostate carcinoma) who participated in a free prostate carcinoma detection program. Questionnaires, which were completed prior to prostate carcinoma screening, included demographic and medical information, reasons for screening participation, general and cancer-related psychological distress, and perceived risk for prostate carcinoma. RESULTS: Among both family history groups, self-referral was the most common reason for attending the screening, compared with receiving a recommendation from a health professional or from a friend or family member. Men with a positive family history were not more distressed than those without a family history; but as the authors predicted, men with a positive family history of prostate carcinoma did report higher levels of perceived risk relative to those without a family history. In addition, an interaction revealed that psychological distress was greater among men with a family history only among those who also reported elevated perceived risk. CONCLUSIONS: Similar to other prostate carcinoma screening programs, men in the current sample largely elected to attend the screening on their own. Furthermore, although perceived risk was higher among men with a family history compared with those without a family history, psychological distress was greater among men with a family history only among those who also reported elevated perceived risk. Thus, among men with a family history of the disease, perceived risk may be a marker of elevated psychological distress. Screening programs should assess family history and perceived risk because of the potential psychological implications for screening participants.

Acute and chronic interstitial cryotherapy of the adrenal as a treatment modality.

Adrenalectomy is indicated for patients with large adrenal lesions or functional tumors. Cryoablation is currently used as a surgical alternative for the treatment of prostate, lung, brain, pharynx, and liver tumors. The purpose of this study was to determine if cryosurgery could be delivered to small areas in the adrenal gland in a controllable and reproducible manner such that tissue could heal in a nonpathologic way. A total of 14 female mongrel dogs underwent acute (n = 8) or chronic (4 weeks, n = 6) cryoablation using the Cryounit. In the acute study using an open transabdominal approach a 2-mm cryoprobe was placed interstitially into the adrenal tissue, whereas 0.032-inch thermocouples were cannulated into the ipsilateral adrenal artery and vein. Adrenal parenchymal temperature changes were measured using 0.032-inch thermocouples placed at 0.4- and 0.8-cm intervals from the cryoprobe. In the chronic study, cryoablation was achieved by transperitoneal laparoscopic access using a standard laparoscopic technique. Interstitial cryoprobe temperatures decreased from 33.1 +/- 1.9 degrees C to -148 +/- 1.2 degrees C following 15 min of freezing in the acute study. Cryoablation of adrenal tissue achieved temperatures of -41.8 +/- 5.7 degrees C and -21.8 +/- 1 degrees C at distances of 0.4 and 0.8 cm from the cryoprobe, respectively. There was no significant change in adrenazl artery or vein temperatures during cryoablation. Histologically there is a clear demarcation between viable and nonviable tissue characterized by areas of multifocal hemorrhage and pyknosis. After 4 weeks of healing a well-defined line of necrotic and viable tissue is visible. Cryoablation of the adrenal can be delivered in an effective, controllable, and reproducible manner. This controllable energy form may provide a new treatment modality for tissue destruction where adrenal gland preservation is necessary and can be performed by the laparoscopic approach. Understanding the effect of adrenal cryoablation may allow us to treat selected patients with small tumors where organ preservation is necessary.

Thick loop transurethral resection of the prostate.

OBJECTIVES: To evaluate the safety and efficacy of the new resection loops for transurethral resection of the prostate (TURP). These loops, which are both thicker and have a modified shape, allow simultaneous resection, increased tissue vaporization, and improved hemostasis. METHODS: Two open studies have been performed with the thick resection loop. In one series, 91 patients underwent TURP with the Vapor Cut (G. Vallancien, Paris), and in another series, 65 patients underwent Wedge (Microvasive, Natick, Mass., USA) resection (A. Perlmutter, New York). RESULTS: At 1 year follow-up, patients who underwent thick loop resection enjoyed the same clinical benefit of thin loop TURP without additional morbidity. Peak urinary flow rate improved to 18.4 and 16.3 cm3/s at 1 year with the Vapor Cut and Wedge, respectively. IPSS fell to 7.2 (Vapor Cut) and 6.2 (Wedge). Postoperative bleeding, meatal stenosis, and urethral stricture were noted, but no impotence or incontinence was observed. CONCLUSIONS: Thick loop resection offers the advantage of improved surgical vision during resection, thus allowing a more accurate and safer resection. This can be performed with only minor modifications of the standard TURP technique.

Interstitial laser prostatectomy.

In an attempt to minimize the need for hospitalization and the associated perioperative and postoperative morbidity, alternatives to transurethral resection of the prostate (the standard treatment modality for benign prostatic hyperplasia) have been sought. Various types of laser prostatectomy have been proposed. Interstitial laser coagulation is performed by placing laser-diffusing fibers directly in the hyperplastic prostatic adenoma. The goal is to achieve coagulation necrosis within the adenoma, which causes the prostatic lobes to regress and thereby relieves the bladder outlet obstruction. Either the transurethral cystoscopic approach or the perineal approach can be used for laser application. Numerous published studies have shown that this laser procedure safely and effectively decreases symptoms of prostatism, increases the urinary flow rate, and reduces the volume of the prostate. Because of substantial tissue edema after treatment, catheter drainage may be necessary for 7 to 21 days. Although retrograde ejaculation has occurred occasionally (affecting from 0 to 11.9% of patients in reported studies) and uncomplicated urinary tract infections are common after interstitial laser coagulation, no cases of impotence or sustained incontinence have been described. Because interstitial laser coagulation is not associated with blood loss or intravascular fluid shifts and, if necessary, can be performed with a combination of local anesthesia and intravenous sedation, even high-risk patients are candidates for this procedure.

The "Wedge" resection device for electrosurgical transurethral prostatectomy.

The "Wedge" (Microvasive, Natick MA) is a new electroresection device for transurethral prostatectomy (TURP) using the standard resectoscope. The design, which is broader than the standard loop and thickens from front to back, results in better hemostasis when used at 275 to 300 W because of its ability to cut and coagulate tissue simultaneously. In the canine model, histologic examination demonstrated a 2-mm zone of coagulation around the chips and in the resection bed; this response was not observed in the specimens resected by the standard tungsten loop. No adjacent tissue damage was found with either the Wedge or the loop, and the temperatures recorded at the capsule rose only 4 degrees C regardless of the device used. In the 65 patients treated, the average hematocrit drop on postoperative Day 1 was 3.0%, and serum sodium was unchanged. One year postoperatively, the peak flow rate had increased by 101%, and the AUA Symptom Score was 6.1. The only surgical complication was urethral strictures (3%) necessitating incision. Most striking was the increased case of resection attributable to improved intraoperative vision. The data suggest that Wedge TURP is as safe and efficacious as standard loop TURP. The surgical field is markedly improved and clear because of intraoperative hemostasis. A TURP can be performed with a view toward minimizing patient morbidity and increasing surgical ease.

Urinary tract infections and pregnancy in women who underwent antireflux surgery in childhood.

PURPOSE: For several decades ureteroneocystostomy has been performed in children to correct primary vesicoureteral reflux. A purported indication for antireflux surgery is to prevent significant upper urinary tract infection during pregnancy. We performed a long-term followup of women who underwent antireflux surgery during childhood to determine outcome in regard to urinary tract infection history and pregnancy. MATERIALS AND METHODS: We identified 227 women of childbearing age who underwent ureteral reimplantation for primary vesicoureteral reflux from 1964 through 1981. Of the 122 women contacted 41 had been pregnant (77 total pregnancies). Cystitis or asymptomatic bacteriuria and pyelonephritis developed during 18 and 5 pregnancies, respectively. The 77 pregnancies resulted in 57 term births, 7 voluntary pregnancy interruptions and 13 spontaneous abortions. RESULTS: Patients who previously underwent successful antireflux surgery continued to have a significant number of urinary tract infections through the intervening years. Despite a higher than expected incidence of pyelonephritis, they had relatively little hypertension and renal insufficiency. During pregnancy the incidence of pyelonephritis was only slightly higher than that of the general population. However, severe complications of pregnancy, such as preeclampsia, premature birth and acute renal failure, occurred more frequently in women with a history of renal scarring or hypertension (7 of 12) than in those with a history of recurrent infection alone (3 of 10). CONCLUSIONS: When renal scarring is present, reflux should be corrected before pregnancy to minimize maternal and fetal morbidity. When scarring is not present, the literature suggests that women with a history of reflux are at increased risk for pyelonephritis during pregnancy whether or not ureterocystostomy was performed. Pregnant women with a history of reflux may benefit from prophylactic antibiotics and women with reflux nephropathy should be followed throughout life.

Microwave thermotherapy for benign prostatic hyperplasia with the Dornier Urowave: results of a randomized, double-blind, multicenter, sham-controlled trial.

OBJECTIVES: To study the efficacy and safety of a new transurethral microwave thermotherapy device (the Urowave) in the treatment of men with clinical benign prostatic hyperplasia (BPH) in a randomized, double-blind, sham-controlled trial. METHODS: A total of 220 patients (mean age 66.2 years) with clinical BPH, an American Urological Association symptom index (AUA SI) of 13 points or more, and a peak flow rate of 12 mL/s or less were enrolled and randomized 2:1 for active versus sham treatment. All treatments were conducted as an outpatient procedure under local anesthesia, with oral sedation and analgesia only. Patients were followed up at 1 week and 1, 3, and 6 months after treatment. RESULTS: The treatments were well tolerated, and no patient received general or spinal anesthesia. The AUA SI dropped from 23.6 to 12.7 points at 6 months (P < 0.05) in the active group and from 23.9 to 18.0 points in the sham-treated group (P < 0.05, between-group difference). Statistically significant improvements were also noted for peak flow rate (7.7 to 10.7 mL/s at 6 months for active treatment, 8.1 to 9.8 mL/s for sham treatment, P < 0.05, between-group difference) and for average flow rate. A decrease in AUA SI of more than 30% was achieved in 72% versus 38% of patients (active versus sham treatment, respectively) and more than 50% in 50% versus 19% of patients. In general, active Urowave-treated patients perceived "a lot" of improvement, whereas sham-treated patients perceived "a little" to "some" improvement. More of the actively treated patients had dysuria and urgency after treatment, and ejaculatory dysfunction (e.g., hematospermia) was more common in actively treated patients as well. Secondary urinary retention after removal of the catheter occurred in 8 patients (5.4%). CONCLUSIONS: The Dornier Urowave transurethral microwave thermotherapy device for treatment of clinical BPH is effective in decreasing symptoms and bother and improving quality of life and flow rate and is superior to sham treatment. Patients perceive a great deal of improvement, independent of their baseline symptom severity. Adverse events are in general transient and mild in nature. Extended follow-up is necessary to document long-term durability of improvements.

Mechanism of microwave thermotherapy.

Possible mechanisms by which transurethral microwave thermotherapy creates an improvement in vodiing parameters are reviewed. The therapy creates coagulation necrosis in the hyperplastic adenoma, and thus has the potential to create volume reduction, change in the periurethral tissue, and changes in efferent neuromuscular elements and sensory neural elements. Evidence is presented that suggests that several of these mechanisms are likely important, and there is not a singular mechanism of action.

Long-term intravesical oxybutynin chloride therapy in children with myelodysplasia.

PURPOSE: We evaluated the clinical use of long-term intravesical oxybutynin chloride in the treatment of neurogenic bladder dysfunction in children with myelodysplasia who could not tolerate oral anticholinergics. MATERIALS AND METHODS: We retrospectively reviewed the records of all patients recommended for intravesical oxybutynin chloride therapy. A total of 12 girls and 18 boys 1 to 17 years old was recruited for study. Oxybutynin chloride (5 mg.) was instilled 2 times daily and pretreatment cystograms were compared to followup urodynamic studies. Duration of therapy was 2 to 26 months (mean 13, median 12). RESULTS: Mean total capacity plus or minus standard deviation increased from 209 +/- 103 to 282 +/- 148 ml. (p < 0.01), mean safe capacity increased from 157 +/- 105 to 234 +/- 147 ml. (p < 0.01) and mean age adjusted safe capacity increased from 76 +/- 36 to 115 +/- 62%. Of the 29 patients who were incontinent 3 (10%) achieved continence and 19 (65%) reported a decreased use of sanitary pads. None of the patients had systemic side effects related to intravesical treatment. CONCLUSIONS: We believe that intravesical oxybutynin chloride is a viable treatment option for patients with myelodysplasia in whom oral therapy fails.

Is there a best alternative to treating the obstructed upper pole?

PURPOSE: We addressed whether salvage of upper pole renal units in comparison to partial nephrectomy affects differential renal function in patients with a duplicated obstructed upper pole. MATERIALS AND METHODS: We retrospectively reviewed the records of all children who underwent surgery for a unilateral obstructed duplicated kidney at our institution from 1988 to 1995. Patients were evaluated with respect to postoperative complications, reoperation rate and percent change in differential renal function of the obstructed duplicated kidney, as determined by nuclear renography. RESULTS: We identified 46 patients with a unilateral obstructed upper pole of a duplicated kidney who were divided into 2 groups. Group 1 (12 patients) underwent an upper pole salvage procedure, that is ureteropyelostomy or ureteroureterostomy, and group 2 (31 patients) underwent partial nephrectomy. Three reoperations (25%) were performed in group 1 and 1 (4%) was done in group 2. Postoperative symptomatic urinary tract infections were diagnosed in 3 group 1 patients (25%) and in 2 (8%) in group 2. Average change in ipsilateral renal function in the 8 patients who underwent upper pole salvage procedures was 2.25 +/- 2.34% (range -6 to 12). In the 8 patients who underwent upper pole nephrectomy and who also had postoperative renal scans average change in function was -1.25 +/- 4.51% (range -23 to +16). CONCLUSIONS: There was no statistically significant loss of relative renal function in patients treated with partial nephrectomy and no significant gain in relative renal function in those treated with an upper pole salvage procedure. The reoperation rate was higher in the upper pole salvage than in the partial nephrectomy group (25 versus 4%). While not statistically significant, we believe that this rate is clinically important. We think that partial nephrectomy should remain the preferred treatment for most patients with obstructed duplicated kidneys.

Renal cell carcinoma in children: the Detroit experience.

PURPOSE: We analyzed the presentation, treatment and survival of 6 children with renal cell carcinoma. MATERIALS AND METHODS: We retrospectively reviewed the pathological and hospital records of 6 children diagnosed with renal cell carcinoma at Children's Hospital of Michigan (5) and Henry Ford Hospital (1) from 1980 to 1995. RESULTS: The most common presenting complaints were flank pain (50%) and a palpable abdominal mass (50%), while gross hematuria was present in only 1 patient (16%). No patient had the classic triad of flank pain, hematuria and palpable mass. Only 1 patient had localized disease (stage II), while 5 of the 6 presented with stage III or IV disease. While followup is limited, all patients with stage III disease are without evidence of recurrence at a mean 38.5 months and 1 of 2 with stage IV disease is without evidence of disease at 22 months. CONCLUSIONS: Although renal cell carcinoma in childhood often presents at an advanced stage, the prognosis for those with isolated regional lymph node involvement appears to be encouraging.

Priapism associated with sickle cell hemoglobinopathy in children: long-term effects on potency.

PURPOSE: Children with sickle cell priapism have traditionally been treated conservatively with surgery done as a last resort. Only sparse subjective data are available on the long-term assessment of potency in these patients. MATERIALS AND METHODS: We retrospectively reviewed the charts of all pediatric patients with sickle cell priapism who presented to Children's Hospital of Michigan between 1972 and 1992, and subsequently assessed erectile capabilities subjectively by questionnaire and objectively by RigiScan. RESULTS: Of the 15 patients interviewed 5 had undergone shunt procedures. The return of potency tended to vary inversely with patient age at onset and duration of priapism. CONCLUSIONS: Shunts performed within 48 hours, especially in postpubertal children, seemed more likely to preserve potency.

Alteration of laser-tissue interaction with the 805 nm diode laser using indocyanine green in the canine prostate.

BACKGROUND AND OBJECTIVE: Research interests in laser prostatectomy continue to evaluate a variety of wavelengths and treatment parameters in an effort to optimize treatment. Recently, a semiconductor diode laser with a wavelength of 805 nm has become available for clinical use; however, free-beam noncontact applications were limited by the low power output (25 W). In this study in the canine prostate, the possible potentiating effects of intravenously administered indocyanine green (ICG) were evaluated with the 805 nm diode laser. STUDY DESIGN/MATERIALS AND METHODS: A total of 16 fixed position, free-beam lasings were performed at 25 W for 60 sec in four dogs with eight lasings before and eight lasings after ICG administration. Endoscopic observations and measurements of lesion volumes were used to evaluate the laser-tissue interactions. RESULTS: Prior to ICG administration, we observed that side fire irradiation produced primarily small coagulative lesions. Following ICG administration, however, immediate and more noticeable tissue vaporization occurred, although total lesion size was not increased. Pathologic review demonstrated less coagulation and hyperemia, but a larger vaporized cavity in the ICG treated tissue. CONCLUSION: These findings suggest intravenous ICG alters laser-tissue interaction with the 805 nm diode laser in the canine prostate. The use of the 805 nm diode laser with enhancing chromophores deserves further investigation.