Myeloid sarcoma of the periprostatic tissue and prostate: Case report and review of literature

Myeloid sarcoma (MS) is a rare extramedullary tumor composed of immature cells of myeloid lineage that destroy the original tissue architecture in which it is found. It is most commonly identified in patients with acute myelogenous leukemia, and less often in myelodysplastic syndromes (MDSs) and other myeloproliferative disorders. It is most commonly reported in the periosteum, bone, skin, and lymph nodes but has been reported in many other sites of the body. Herein, we describe a case of MS involving the periprostatic tissue and review of literature of MS of the prostate. Our patient was initially diagnosed with MDS and was in remission following successful treatment. Six months later, the patient was diagnosed with prostate adenocarcinoma, and MS of the periprostatic tissue was incidentally discovered in the postprostatectomy pathology specimen. An extensive review of literature from 1997 to 2014 revealed a total of eight cases of MS involving the prostate. Of the eight cases of MS of the prostate, four were primary MS (absence of a history of leukemia) and four were secondary MS. Three received local radiation to the prostate with relief of obstructive symptoms, and one of them had a repeat prostate biopsy negative for leukemic cells. Despite being a rare entity, MS should be considered as a differential diagnosis of soft tissue masses, especially in patients with a history of hematological malignancies.

Breast metastases from a malignant peripheral nerve sheath tumor of the kidney: An unusual presentation

Malignant peripheral nerve sheath tumors (MPNSTs) are extremely rare soft tissue sarcomas of ectomesenchymal origin. They are commonly seen in association with neurofibromatosis type 1 (NF-1), but can also occur without a history of NF (isolated MPNST). MPNSTs are most commonly located on the extremities (brachial and sacral plexus), head and neck, and trunk regions and are rarely reported in genitourinary organs. These tumors are aggressive, with a high recurrence rate and distant metastases. MPNST involving the kidney is extremely rare, and review of the literature using PubMed from 2001 to 2014 revealed eight cases of MPNST involving the kidney (seven, primarily involving the kidney and one metastatic MPNST of the kidney). Herein, we describe a case of breast metastases from an MPNST of the kidney without a history of NF-1. The patient was initially diagnosed with a spindle cell neoplasm of the kidney with peripheral nerve sheath differentiation. Eventually, the patient developed a right breast mass that was diagnosed as metastatic MPNST. The patient refused any kind of treatment and died 6 months later in hospice care.

Antibiotic pretreatment of hydrogel ureteral stent

PURPOSE

To compare bacterial adhesion to hydrogel-coated and uncoated ureteral stents. The antimicrobial activity of coated and uncoated stents treated with commonly used antibiotic solutions also was evaluated.

MATERIALS AND METHODS

Hydrogel coated and uncoated stent segments were dipped in different antibiotic solutions (ciprofloxacin, gentamicin, and cefazolin). Normal saline was used as the control. The segments were incubated in separate broths of Escherichia coli and Enterococcus faecalis to reach the log phase. They were sonicated to free the bacteria, and colony-forming units were determined after 48 hours. To evaluate antibacterial activity, hydrogel-coated and uncoated stent segments were dipped in the above-mentioned antibiotic solutions. Normal saline was used as the control. Segments were incubated in separate Mueller-Hinton agar plates inoculated with E. coli or Enterococcus faecalis, and the zones of inhibition were determined at 24 hours. The duration of antibacterial activity for each bacterium-antibiotic combination also was studied.

RESULTS

Hydrogel coating did not significantly reduce bacterial adhesion. Zones of inhibition around stent pieces dipped in antibiotic solutions differed with the organism and the antibiotic. Cefazolin produced a significantly larger zone of inhibition with hydrogel-coated stent, but the duration of antibacterial activity was similar to that of uncoated stent. Hydrophilic coating significantly increased the duration of antibacterial activity of ciprofloxacin and gentamicin.

CONCLUSION

Hydrogel coating on the surface of ureteral stents does not prevent or reduce bacterial adhesion. However, after antibiotic treatment, stents exhibit antibacterial activity in the local environment at greater intensity and for a longer time, depending on the bacterium-antibiotic combination.

Multiple retained needles: an unusual complication of intracavernous self-injection

Intracavernous self-injection of pharmacologic agents is an effective method of treatment of erectile dysfunction. Intracorporeal needle breakage is a rare complication of intracavernosal self-injection. We report an unusual case of multiple retained needles in a 44-year-old man who presented with penile edema after intracavernous self-injection complicated by needle breakage. The patient was treated with nonoperative therapy and observed on a course of antibiotics to which he responded favorably. He continued to have good erectile function. We also present a review of the reported data and recommend a treatment strategy for the management of retained intracorporeal needles.

Antibiotic Soaked Hydrophilic Coated Bioflex: A New Strategy in the Prevention of Penile Prosthesis Infection

OBJECTIVES

To find conditions that reduce the susceptibility of penile prostheses to infection, we studied the effect of coating the surface of polyurethane (Bioflex) with a hydrophilic material with and without antibiotics in decreasing bacterial colony counts both in vitro and in experiments in rats.

MATERIALS AND METHODS

The in vitro experiment was performed using seven strips each of polyvinylpyrrolidone (PVP)-coated and uncoated polyurethane. These strips were dipped in saline for 5 minutes followed by incubation in a suspension of Staphylococcus epidermidis (SE) for a period of 10 minutes. Colony counts were determined after sonication of strips. For the in vitro experiments, 60 rats were used. Thirty animals each had uncoated or coated polyurethane implanted subcutaneously. In each group, strips were implanted after dipping them in either saline (N = 15) or an antibiotic solution (N = 15) consisting of 1 g/L vancomycin and 160 mg/L gentamicin. A bacterial suspension containing SE was then directly introduced into the subcutaneous pockets of all the animals prior to closure. After 7 days, strips were explanted along with 0.5 x 0.5 cm of surrounding tissue, and sonicated. Colony counts were performed on each sonicate. The data were analysed using Student's t-test. A P-value less than or equal to 0.05 was considered to be statistically significant.

RESULTS

The in vitro study demonstrated a statistically significant (41%) reduction in the colony count of SE within the coated polyurethane strips compared to the uncoated Bioflex strips (150 +/- 44.7 CFU vs. 253 +/- 45.0 CFU, respectively, P-value < 0.05). Animal studies showed that bacterial CFU was highest in the uncoated Bioflex strip (29 +/- 24.5 CFU), followed by uncoated Bioflex with antibiotic treatment (24 +/- 28.1 CFU), coated Bioflex (17 +/- 25.2 CFU) and coated Bioflex with antibiotic treatment (13 +/- 16.1 CFU). Antibiotic treatment of coated Bioflex caused a significant reduction in the bacterial CFU compared to uncoated Bioflex (13 +/- 16.1 vs. 29 +/- 24.5 CFU, respectively, P = 0.04). This represents a 55% reduction in the bacterial count. While the reduction in the bacterial count in the coated Bioflex strip was not statistically different from that in the uncoated strip, a trend towards significance was noted with a 41% reduction (P > 0.05) in bacterial count in the coated Bioflex group compared to uncoated Bioflex.

CONCLUSIONS

In conclusion, in vitro studies demonstrate a significant (41%) reduction in the colony count of SE in PVP-coated polyurethane compared to uncoated polyurethane. In vivo study in rats showed that antibiotic treatment of PVP-coated Bioflex resulted in a statistically significant reduction (55%) in colony count of SE compared to uncoated Bioflex.

FATE OF THE RETAINED RESERVOIR AFTER REPLACEMENT OF 3-PIECE PENILE PROSTHESIS

PURPOSE

We evaluated patients who underwent surgery for implant malfunction to determine whether retaining the reservoir was associated with an increased risk of erosion or infection. We also reviewed the literature to study possible risk factors for reservoir erosion.

MATERIALS AND METHODS

We reviewed the records of 85 patients who underwent 98 procedures for replacement of a malfunctioning 3-piece penile implant. Of these patients 13 underwent 2 replacement procedures. At the time of primary surgery the reservoir was placed in either the retropubic space or extraperitoneally in the lower lateral abdomen if the patient had undergone prior pelvic surgery. During surgery for replacement of the malfunctioning implant the cylinders and pump were removed, and the reservoir of the original 3-piece device was retained. During followup patients were assessed for implant function and the development of any complication such as infection and/or reservoir erosion into the bladder or bowel.

RESULTS

Infection developed in 1 patient and implant malfunction occurred in 13 but no patient had erosion of the retained reservoir. All 85 patients had a functioning implant at a mean followup of 50 months (range 12 to 148). Review of the literature suggests that prior pelvic surgery and infection are major risk factors for reservoir erosion.

CONCLUSIONS

Retaining the reservoir during replacement of malfunctioning 3-piece implants is not associated with a significant risk of erosion and routine removal is not necessary. Prior pelvic surgery and infection appear to be risk factors for reservoir erosion.

URETHROPLASTY IN PATIENTS OLDER THAN 65 YEARS: INDICATIONS, RESULTS, OUTCOMES AND SUGGESTED TREATMENT MODIFICATIONS

PURPOSE

Despite an aging population, the results of urethroplasty in elderly patients have not been extensively reported. We performed a multi-institutional review of urethroplasty results in 70 elderly males to determine outcomes.

MATERIALS AND METHODS

We reviewed all urethroplasties performed on males older than 64 years with at least 6 months of followup at 4 medical centers. Stricture type varied and included anastomotic urethroplasty (44%), penile fasciocutaneous onlay flap (31%), Johanson urethroplasty (stage 1, 6%, stages 1 and 2, 4%), buccal mucosa grafts (7%), foreskin grafts (6%) and meatoplasty (1%).

RESULTS

Stricture recurred in 11 (16%) patients, but was managed with a single direct visual internal urethrotomy or dilation in 5 of 11 patients, yielding a final success rate of 91%. Recurrent strictures were more common after fasciocutaneous flaps (7 of 22 cases, 32%) than end-to-end urethroplasty (2 of 31 cases, 6%, p <0.05). Compared to patients younger than 65 years there were more treatment failures, but this was not statistically significant. Perioperative complications were uncommon. Moderate bladder outlet obstructive symptoms developed in 3 patients due to benign prostatic hyperplasia. Notably 6 patients treated previously for post-radiation strictures did well without complications.

CONCLUSIONS

Older men tolerate urethroplasty and these data indicate that therapy should not be withheld solely on the basis of age. The potential for impaired flap blood supply in this population is suggested but has not been proven. Benign prostatic hyperplasia must be considered in those patients who have decreased stream after stricture repair.

New perineal bone-anchored male sling: lessons learned

OBJECTIVES

To identify factors affecting outcome after the male sling procedure for stress urinary incontinence.

METHODS

A total of 46 incontinent men, with a mean age of 67 years, underwent perineal bone-anchored male sling placement. Three titanium bone screws with preattached pairs of No. 1 polypropylene sutures were placed directly into the medial aspect of each inferior ramus of the pubic bone. To compress the urethra, three different types of materials were used: absorbable biomaterial, silicone-coated polypropylene mesh, or a composite graft. Patient characteristics, incontinence etiology and severity before surgery, prior collagen injections, and type of material used were assessed, and the association with the outcome of the male sling procedure was determined.

RESULTS

The procedure was successful in 35 (76%) of 46 patients at a mean follow-up of 18 months (range 6 to 30). Nineteen patients were totally dry and 16 had improved 50% or more compared with before surgery. Failure occurred in 11 patients (24%). Patients who received a composite graft or mesh alone had a better outcome compared with the absorbable sling group (97% and 75% versus 0%, respectively, P = 0.001). The severity of pretreatment incontinence also had a negative impact on the outcome.

CONCLUSIONS

Patients with mild-to-moderate incontinence and the use of a composite graft had the best outcomes after the perineal bone-anchored male sling.

Tissue ingrowth in penile implants and its effect on repeat penile surgery

Penile implant malfunction is usually treated by removal of the original malfunctioning implant followed by replacement with a new device. During replacement, the original implant can be explanted without any difficulty, as it is not adherent to the surrounding tissue. Herein, we describe two cases of tissue ingrowth into the implant that produced difficulty during explantation and suggest ways in which this condition can be managed.

Comparison of satisfaction rates and erectile function in patients treated with sildenafil, intracavernous prostaglandin E1 and penile implant surgery for erectile dysfunction in urology practice

PURPOSE

We compared erectile function status and satisfaction rates in patients who received treatment for erectile dysfunction (ED) with sildenafil, intracavernous prostaglandin E1 (ICI) and penile implant surgery (IPP).

MATERIALS AND METHODS

A total of 138 consecutive patients who received treatment for ED between April 2000 and April 2001 were considered candidates for study. Mean followup was 19.54 months. Of the patients 27 were not available for followup and 26 were not on any form of treatment. Of the patients receiving treatment for ED 85 were administered the Erectile Dysfunction Inventory for Treatment Satisfaction (EDITS) questionnaire and the Erectile Function Domain (EFD) of the International Index of Erectile Function questionnaire. Three treatment groups were identified, including 31 patients on sildenafil citrate, 22 on ICI and 32 who underwent IPP. Mean total EDITS, EDITS Index and EFD scores in the 3 groups were considered for statistical evaluation.

RESULTS

There was no statistical difference in the total EDITS (25.59 versus 27.06, p = 0.48), EDITS Index (58.16 versus 61.15, p = 0.49) or EFD (22.91 versus 20.26, p = 0.12) score between the groups on ICI and sildenafil citrate, respectively. Total EDITS, EDITS Index and EFD scores were significantly higher in patients who underwent IPP than those on sildenafil citrate (36.09 versus 27.06, p <0.001, 82.03 versus 61.51, p <0.001 and 27.88 versus 20.26, p <0.001, respectively). Total EDITS, EDITS Index and EFD scores were significantly higher in patients who underwent IPP than those on ICI (36.09 versus 25.59, 82.03 versus 58.16 and 27.88 versus 22.91, respectively, all p <0.001).

CONCLUSIONS

At a mean followup of 19.54 months patients who underwent penile implant surgery had significantly better erectile function and treatment satisfaction than those receiving sildenafil citrate and intracavernous prostaglandin E1.

Cigarette smoking induces apoptosis in rat testis

In a previous studywe demonstrated the deleterious effect of cigarette smoke on spermatogenesis in the testis of peripubertal Sprague-Dawley rats. In this study we investigated the development of apoptosis as a possible contributing factor to the pathogenic mechanism underlying these effects. Peripubertal rats were exposed to cigarette smoke with the Walton Horizontal Smoking Machine. Similarly, age-matched control rats were exposed to room air with the smoking machine. Rats from both groups were sacrificed after 45 days of treatment and the testes were removed. Testes were stained utilizing the terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) staining technique. DNA fragmentation was further evaluated using gelectrophoresis. There was a significant increase in the incidence of apoptosis in the treated group compared to the control group as demonstrated by the larger amount of tubules containing > or = 3apoptotic bodies in the smoke-exposed group, that is, 36% versus 14% in the control group (p < 0.05). Agarose gel electrophoresis demonstrated the DNA ladder in the treated group but not in the control animals. In conclusion, chronic cigarette smoke induces apoptosis in the rat testis. Apoptosis may be one of the pathogenic mechanisms responsible for defective spermatogenesis in the rat following chronic cigarette smoking.

Chronic cigarette smoking induces an oxidantantioxidant imbalance in the testis

OBJECTIVES

We have previously demonstrated the harmful effect of chronic inhalation of cigarette smoke on the testis in Sprague-Dawley rats. The aim of the present study was to investigate the role of free oxygen radicals and reactive oxygen species in inducing testicular damage in Sprague-Dawley rats following exposure to cigarette smoke.

MATERIALS AND METHODS

Sprague-Dawley rats, 25 days old, were exposed daily to cigarette smoke by the Walton smoking machine for a period of 15, 30, and 45 days. Age-matched Sprague-Dawley rats were exposed to room air with the smoking machine and served as controls. Rats were sacrificed from each group at 15, 30, and 45 days and the testes were removed. The testicular tissue levels of glutathione and lipid peroxidation product malonaldehyde (MDA) were measured colorimetrically using the Bioxytech GSH-400 and LPO-586 kits, respectively. The activity of glutathione peroxidase was assessed colorimetrically using the Bioxytech GPx-340 kit. Statistical analysis was performed using ANOVA followed by the t test.

RESULTS

There was a 47.8% increase in the MDA in the treated rat testis compared with the control rat after 45 days of exposure to cigarette smoke or air, respectively (p < 0.05). This was associated with a parallel significant decrease in the level of glutathione and glutathione peroxidase activity in the treated rat testis, 38.2% and 29.1%, respectively, after 45 days of cigarette smoke exposure (p < 0.05). No significant difference was noted in the levels of glutathione, glutathione peroxidase, and lipid peroxidation end products after 15 and 30 days of treatment.

CONCLUSIONS

Chronic cigarette smoke inhalation is associated with an increase in the level of oxidants and a simultaneous decrease in the level of antioxidants in the rat testis. This abnormality of the oxidant-antioxidant balance may be one of the mechanisms leading to testicular tissue damage and abnormal spermatogenesis in the rat testis following chronic inhalation of cigarette smoke.

Morphometric analysis of rat testis following chronic exposure to cigarette smoke

PURPOSE

To assess the effect of chronic exposure to cigarette smoke on spermatogenesis in Sprague-Dawley rats.

MATERIALS AND METHODS

Twenty 5-day-old Sprague-Dawley rats were exposed daily to cigarette smoke by the Walton smoking machine for a period of 15, 30, and 45 days. Age-matched Sprague-Dawley rats exposed to room air with the smoking machine served as controls. Rats were sacrificed from each group at 15, 30, and 45 days and the testes were removed. Fifty seminiferous tubules were assessed in each group. Morphometric and histopathologic analyses of the testes were carried out. The following parameters were studied: (1) Number of germ cells (step 7 spermatids), (2) seminiferous tubule diameter, (3) height of germinal epithelium, (4) presence of degenerating or sloughed cells, (5) failure of release of spermatids into the tubular lumen, and (6) degeneration of Leydig cells. Statistical analysis was performed using ANOVA followed by the t test.

RESULTS

There was a significant decrease in the germ cell count (step 7 spermatids) in the rats exposed to cigarette smoke for 30 days (93.19 versus 98.15 step 7 spermatids in the control animals (p < 0.001). This decrease persisted in the rats exposed to cigarette smoke for 45 days (82.47 versus 103.01 step 7 spermatids in control animals, p < 0.001). The mean seminiferous tubule diameter was significantly reduced only in the rats exposed to cigarette smoke for 45 days (0.283 microm versus 0.299 microm in the control animals, p < 0.001). There was no significant difference in the height of the germinal epithelium, and no degenerating cells were noted in either group.

CONCLUSIONS

Cigarette smoke adversely affects spermatogenesis in pubertal Sprague-Dawley rats.

Lipid peroxidation and antioxidant activities in rat testis after chronic cocaine administration

OBJECTIVES

Our recent study has shown that cocaine has adverse action on spermatogenesis and fertility in male rats. Adverse effects of cocaine on the testes may be mediated by oxidative damage and subsequent lipid peroxidation. Glutathione is a cellular antioxidant and is found in high concentrations in the rat testes. In this study, the effects of chronic cocaine administration on the activities of glutathione peroxidase, the level of testicular reduced glutathione, and lipid peroxidation were investigated.

METHODS

Thirty-day-old male Sprague-Dawley rats were given cocaine hydrochloride (15 mg/kg body weight) subcutaneously daily for 90 days. Control animals received equal volumes of normal saline daily for 90 days. Testes were removed at 15, 30, 60, and 90 days after cocaine injection. Tissues were washed and homogenized in ice-cold metaphosphoric acid solution or Tris-HCI buffer. Reduced glutathione, glutathione peroxidase, and malonaldehyde levels were determined by colorimetric assay. Statistical analysis was performed using analysis of variance.

RESULTS

Testicular reduced glutathione and glutathione peroxidase were significantly decreased in the treatment testes 15, 30, 60, and 90 days after chronic cocaine injection compared with controls (P <0.05). The testicular malonaldehyde level was 20.8% (P <0.05), 22.1% (P <0.05), 31.2% (P <0.05), and 24.7% (P <0.05) above the control value on days 15, 30, 60, and 90, respectively.

CONCLUSIONS

Our findings demonstrate that chronic administration of cocaine to male rats induces a depletion of reduced glutathione and glutathione peroxidase. Adverse effects of cocaine on the testes are at least in part due to impairment of the function of the antioxidant defense and further enhancement of lipid peroxidation.

Penile implant success in patients with corporal fibrosis using multiple incisions and minimal scar tissue excision

OBJECTIVES

To establish the efficacy of "minimal scar tissue excision" in the treatment of penile fibrosis.

METHODS

Thirty-four patients with extensive penile fibrosis who underwent placement of penile implant from October 1989 to April 1998 were evaluated by a chart review of the patient's follow-up data. Function of the implant was evaluated at follow-up visits. The follow-up ranged from 4 to 84 months (mean 23.7, median 22). All patients had undergone minimal scar tissue excision of the fibrous tissue in the penis.

RESULTS

All patients underwent successful introduction of the penile implant, and in no patient was the procedure abandoned because of technical difficulty. Intraoperatively, 1 patient developed a tear in the crus. It was not recognized during the initial operation but was repaired at a subsequent date by Gore-Tex grafting. The Uniflate prosthesis of another patient failed 2 years after the initial surgery and was replaced with the Mentor alpha-1 implant. None of the patients developed infection. All the patients had a functioning implant at the time of last review.

CONCLUSIONS

Minimal scar tissue excision is a safe and effective method in the management of extensive penile fibrosis.

Cocaine induced apoptosis in rat testes

PURPOSE

Exposure of rats to chronic cocaine results in disruption of spermatogenesis including reduction of germ cells. However, the cellular mechanism responsible for the testicular damage in testes is still unknown. We have studied the role of apoptosis in cocaine induced testicular damage.

MATERIALS AND METHODS

Thirty-day-old male Sprague-Dawley rats were given cocaine hydrochloride (15 mg./kg. body weight) subcutaneously daily for 90 days. Control animals received equal volumes of normal saline daily for 90 days. Testes were removed at 15, 30, 60, and 90 days of cocaine administration. In situ detection of germ cells with DNA strand breaks in paraffin-embedded testicular section (5 microm.) was achieved by the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP in situ nick end-labeling (TUNEL) method. DNA fragmentation was also determined by gel electrophoresis.

RESULTS

Apoptotic cells were found in the spermatocytes and spermatogonia of germinal epithelium. Less than 7% of seminiferous tubule cross sections showed a high level of apoptosis (> or =3 apoptotic cells per tubule) in control animals compared with experimental group where 25% of the tubules showed a high level of apoptosis (p<0.05). The number of apoptotic cells was significantly increased by 15 days, peaked at 30 days and persisted up to 90 days of cocaine exposure when compared with controls (p<0.05). DNA isolated from the cocaine treated testes displayed a clear ladder pattern whereas the DNA from controls did not.

CONCLUSIONS

The experimental results presented here suggest that cocaine exposure leads to significant apoptosis in rat testes and the mechanism of cocaine induced testicular injury may be related to the induction of apoptosis.

Assessment of psychosexual adjustment after insertion of inflatable penile prosthesis

OBJECTIVES

To evaluate the psychosexual benefit obtained from multicomponent penile implant surgery in patients with erectile dysfunction.

METHODS

A psychosexual questionnaire was given to 35 patients undergoing penile prosthesis implantation before surgery and at 3 months, 6 months, and 1 year after surgery. The questionnaire consisted of 13 questions scored on a scale from 1 through 5. Results of the questionnaire were statistically analyzed for differences among the preoperative, 3-month postoperative, 6-month postoperative, and 1-year postoperative period.

RESULTS

The general linear model evaluation showed a significant difference for each overall combination of the following pairs: preoperative versus 3 months postoperative (P=0.0005) and 3 months postoperative versus 6 months postoperative (P=0.002). There was no overall difference between psychosexual total score at 6 months after surgery and 1 year after prosthesis implantation (P=0.85). The patients perceived improvement in their erectile ability and libido. Concern about obtaining and maintaining an erection during intercourse was significantly alleviated. There was an increase in the frequency of sexual activity and an improvement in satisfaction with sex life. A decrease in feelings of sadness, depression, anxiety, anger, frustration, and embarrassment related to sexual activity was also noted.

CONCLUSIONS

The current study demonstrates significant improvement in the psychosexual well being of multicomponent penile implant recipients, with attainment of a high level of patient satisfaction up to 1 year after surgery.

Antibacterial activity of antibiotic coated silicone grafts

PURPOSE

Postoperative infection remains one of the most serious complications of implantation of penile prostheses. Attempts to reduce the rate of infection by spraying the prosthesis with an antibiotic solution prior to implantation, along with perioperative antibiotics, have failed to eradicate infection. No published studies have evaluated the effect of antibiotic coating of penile prostheses. In this study, we evaluate the antibacterial effect of antibiotic-coated silicone strips as a surrogate for the penile prosthesis.

MATERIALS AND METHODS

Strips coated with several different antibiotics were dipped in bacterial solutions containing Staphylococcus epidermidis or S. aureus and implanted subcutaneously in adult Sprague-Dawley rats. After a week, the strips were removed, and the number of bacteria on the strips and in the surrounding tissue were determined. The in vitro antibiotic activity of the antibiotic-coated strips against the same organisms was also determined.

RESULTS

In the group of rats that received silicone strips contaminated in vitro with S. epidermidis, six of nine control rats yielded strips and tissues containing heavy bacterial growth. None of six strips coated with rifampin/minocycline yielded bacterial growth, nor did any of the seven strips coated with vancomycin. One of seven rats that received amikacin-coated strips had infection of the strip. The tissue results were similar to the strip results. In the group using S. aureus as the contaminating bacterium, the strips and tissues from eight of nine control rats yielded bacteria. None of the six rifampin/minocycline-coated strips yielded bacteria, while two of seven vancomycin-treated strips and two of six amikacin-coated strips were infected with S. aureus. The difference in bacterial growth between controls and antibiotic-coated strips reached a level of statistical significance for the rifampin/minocycline and vancomycin groups and was highly significant for the rifampin/minocycline groups.

CONCLUSION

The experimental results presented here suggest that coating silicone graft material with antibiotics, particularly rifampin/minocycline, can reduce the incidence of graft colonization in contaminated wounds in rats, even in the absence of systemic antibiotics. These graft materials may prove useful in preventing the infection of penile prostheses.