Robot-assisted pelvic floor reconstructive surgery: an international Delphi study of expert users.

BACKGROUND: Robotic surgery has gained popularity for the reconstruction of pelvic floor defects. Nonetheless, there is no evidence that robot-assisted reconstructive surgery is either appropriate or superior to standard laparoscopy for the performance of pelvic floor reconstructive procedures or that it is sustainable. The aim of this project was to address the proper role of robotic pelvic floor reconstructive procedures using expert opinion. METHODS: We set up an international, multidisciplinary group of 26 experts to participate in a Delphi process on robotics as applied to pelvic floor reconstructive surgery. The group comprised urogynecologists, urologists, and colorectal surgeons with long-term experience in the performance of pelvic floor reconstructive procedures and with the use of the robot, who were identified primarily based on peer-reviewed publications. Two rounds of the Delphi process were conducted. The first included 63 statements pertaining to surgeons' characteristics, general questions, indications, surgical technique, and future-oriented questions. A second round including 20 statements was used to reassess those statements where borderline agreement was obtained during the first round. The final step consisted of a face-to-face meeting with all participants to present and discuss the results of the analysis. RESULTS: The 26 experts agreed that robotics is a suitable indication for pelvic floor reconstructive surgery because of the significant technical advantages that it confers relative to standard laparoscopy. Experts considered these advantages particularly important for the execution of complex reconstructive procedures, although the benefits can be found also during less challenging cases. The experts considered the robot safe and effective for pelvic floor reconstruction and generally thought that the additional costs are offset by the increased surgical efficacy. CONCLUSION: Robotics is a suitable choice for pelvic reconstruction, but this Delphi initiative calls for more research to objectively assess the specific settings where robotic surgery would provide the most benefit.

Evaluation of the Pubocervical Fascia With 3-Dimensional Endovaginal Ultrasonography and Correlation With Intraoperative Findings During Robotic Sacrocervicopexy.

OBJECTIVES: To evaluate the pubocervical fascia (PF) in patients with pelvic organ prolapse (POP) using 3-dimensonal endovaginal ultrasonography (EVUS) and to correlate the PF appearance with both pelvic examination and intraoperative findings during ultrasonographic robotic-assisted laparoscopic sacrocervicopexy and pubocervical fascia reconstruction (u-RALS-PFR). METHODS: A retrospective analysis was performed in 120 women with symptomatic POP. Preoperative evaluation was done using EVUS. We identified areas of PF weakness based on pelvic examination as hypoechoic and hyperechoic defects (HHD) between the bladder and vagina. Study measurements included distance from the HHD to the pubic symphysis, HHD to the bladder neck, HHD to the posterior bladder wall, and hypoechoic-hyperechoic area. We correlated these metrics with the respective POP-Q stages and findings during u-RALS-PFR. RESULTS: Using the quantitative measures during EVUS, we found a significant association between mean HHD (2.7 cm) and POP-Q stage III, and between HHD and number of plications performed during surgery. The larger the HHD, the more severe the POP-Q stage of the anterior compartment of the vaginal wall; thus, more plications were performed on the PF (7-12 plications) during robotic sacrocervicopexy, and consequently the anterior arm of the Y-mesh was significantly trimmed (6-8 cm). CONCLUSION: HHD obtained by EVUS was associated with severe POP-Q stage III and seemed to correlate with the number of plications during robotic sacrocervicopexy. Performing these plications on the PF significantly decreased the length of the anterior vaginal mesh needed for the procedure. These findings may open new applications for preoperative ultrasonography in evaluation and treatment of patients with apical and anterior POP.

Ultrasonography and robotic-assisted laparoscopic sacrocervicopexy with pubocervical fascia reconstruction: comparison with standard technique.

The objective of this study was to evaluate our technique of ultrasonography and robotic-assisted sacrocervicopexy with pubocervical fascia reconstruction (u-RALS-PFR) versus standard robotic-assisted laparoscopic sacrocervicopexy (s-RALS) in the treatment of patients with symptomatic apical/anterior vaginal prolapse. A retrospective analysis was done using the data in two community hospitals. Thirty women presented with symptomatic vaginal apical prolapse and desired minimally invasive surgery (video): (a) standard robotic-assisted laparoscopic sacrocervicopexy (s-RALS) (n = 15) or (b) ultrasound and robotic-assisted sacrocervicopexy with pubocervical fascia reconstruction (u-RALS-PFR) (n = 15) were eligible to participate. All participants underwent a standardized evaluation, including a structured urogynecologic history and physical examination with pelvic organ prolapse quantitative staging. There was longer operating room time in the u-RALS-PFR group compared with the s-RALS group (average difference 35 min); however, sacral promontory dissection time was less in the u-RALS-PFR (average difference of 15 min). The anterior/posterior vaginal dissection and mesh tensioning time was longer in the u-RALS-PFR, as expected. There was only one surgical and anatomic failure (7%) in the s-RALS group after 6 months of surgery (POP Q = Aa + 1, Ba0, Ap-2, Bp-3, C-7). Our technique of ultrasonography and pubocervical fascia reconstruction during RALS appears to be feasible and safe. It aims to improve anterior and apical support, minimize the use of mesh and improve visualization during surgery. u-RALS-PFR approach will add some additional time during surgery but may provide better outcomes.

Robotic-assisted laparoscopic apical suspension: description of the spiral technique.

This video's objective was to describe our spiral technique and surgical steps of robotic-assisted laparoscopic apical suspension (RALAS) in the treatment of patients with symptomatic apical vaginal prolapse. A 70-year-old Caucasian woman, gravida 3, para 2 had symptomatic pelvic organ prolapse (POP) apical/anterior stage III. At pelvic ultrasound evaluation, the uterus was small and normal appearing of adnexa bilaterally. She failed pessaries and is sexually active. The most relevant complaints were vaginal bulging and pressure. She denied urinary incontinence. During the surgery, we used (1) 3-0, V-Loc™ (Covidien) and we reinforced these absorbable sutures with (2) 2-0, GORE-TEX® Suture (Gore Medical). The Si da Vinci Surgical System was used with 4 arms and 5 trocars configuration, docked on the patient's left side. On the right/left apical support, we used V-Loc and Gore-Tex and these provided the initial 2 points suspension on the uterosacral ligaments (USL). We like to attach the left to the right USL. We then developed the space between the bladder and vagina and proceed with a plication of the pubocervical fascia with V-loc sutures. Two anterior apical support sutures were taken from the vagina to the transversalis fascia on the anterior abdominal wall and then hid behind the bladder peritoneum. The tension of these sutures was maintained with Hem-o-lock (TeleFlex) and LAPRA-TY (Ethicon). With the spiral technique, we secured these sutures through aponeurosis of abdominal muscle inside-outside-inside using a Carter-Thomason (Cooper Surgical) laparoscopic port closure system. This technique may provide a better long-term support for the anterior apical compartment.

Visualization of the neurovascular bundles and major pelvic ganglion with fluorescent tracers after penile injection in the rat.

OBJECTIVE: To evaluate whether fluorescent tracers can consistently label the neurovascular bundles (NVBs) and major pelvic ganglion (MPG) after an intracavernosal penile injection, as the reported incidence of erectile dysfunction (ED) in men after radical prostatectomy (RP) is 55-65% and thus preservation of erectile function, sparing one or both of the NVBs remains one of the most vital factors. MATERIALS AND METHODS: Male Sprague-Dawley rats (3 months old) received penile injections (20 microL; seven rats/group) of either deionized water (DW), Fluoro-Gold (FG), Fast-Blue (FB), Fluoro-Ruby (FR) or green fluorescent pseudorabies virus (GF-PRv). The rats were killed at 2, 3 and 14 days after injection and the NVBs and MPG were harvested and placed directly under fluorescence light. Image analysis was done by computer, coupled to a microscope equipped with a digital camera. Each NVB and MPG were analysed for its staining pattern and consistency. RESULTS: When compared with the FB, FR and GF-PRv rats, the FG-injected rats had better staining of the NVB at 2, 3 and 14 days after injection. Under x200, FG highlighted the axons of the cavernous nerve (CN) and cell bodies (MPG). This indicates that FG injection into the penis induced the strongest CN labelling (positive staining) at 2 and 3 days after injection as compared with FB-, FR- and GF-PRv-injected rats. CONCLUSION: FG injection into the penis has consistent retrograde staining of the NVBs and MPG after 3 days. Therefore, we predict that FG could potentially be used to improve the identification of the NVB in other models. However, further studies need to be carried out before these tracers can be used in humans.

Subarachnoid hemorrhage as complication of phenylephrine injection for the treatment of ischemic priapism in a sickle cell disease patient.

INTRODUCTION: Ischemic priapism (IP) is a urologic condition, which necessitates prompt management. Intracavernosal injection of phenylephrine is a usual treatment modality utilized for the management of these patients. Aim. We present a case of subarachnoid hemorrhage following intracavernosal injection of phenylephrine for IP in a patient with sickle cell disease. METHODS: We analyzed the degree of subarachnoid hemorrhage in our patient after intracavernosal injection of phenylephrine. The patient had an acute rise in blood pressure during corporal irrigation. This was followed by the onset of severe headache. Computed tomography (CT) scan confirmed the diagnosis of a subarachnoid hemorrhage. MAIN OUTCOME MEASURE: Subarachnoid hemorrhage associated with intracavernosal injection of phenylephrine. Result. A 23-year-old African American male with a history of sickle cell disease presented with a painful penile erection. The patient was started on intravenous fluids, oxygen by nasal canula, and analgesic medication. After this, a blood gas was obtained from his left corpora cavernosa. This was followed by normal saline irrigation and injection of phenylephrine. The patient complained of a sudden, severe "terrible headache" immediately following the last injection, and noncontrast CT scan of the head was obtained and a subarachnoid hemorrhage was noted. The patient was admitted for observation and no significant changes were noted. CONCLUSIONS: Intracavernosal injection of phenylephrine for the management of IP can be associated with several possible complications. We present our single case complicated with the formation of a subarachnoid hemorrhage. The patient was treated conservatively and had no long-term neurologic sequelae. Davila HH, Parker J, Webster JC, Lockhart JL, and Carrion RE. Subarachnoid hemorrhage as complication of phenylephrine injection for the treatment of ischemic priapism in a sickle cell disease patient.

Robotic and laparoendoscopic single-site utero-sacral ligament suspension for apical vaginal prolapse: evaluation of our technique and perioperative outcomes.

The objective of this study was to evaluate our technique and steps of robotic and laparoendoscopic single-site utero-sacral ligament suspension in the treatment of patients with symptomatic apical vaginal prolapse. A retrospective analysis was done using the data in 2 community hospital. Eighteen women presented with vaginal apex prolapse and desired minimally invasive surgery (video): (a) Laparoendoscopic single-site utero-sacral ligament suspension (LESS-UTSLS) (n = 13) or (b) robotic-assisted single-site utero-sacral ligament suspension (RASS-UTSLS) (n = 5) were eligible to participate. All participants underwent a standardized evaluation, including a structured urogynecologic history and physical examination with pelvic organ prolapse quantitative stage. Participants also completed validated questionnaire about pain scale. Multiples perioperative values were obtained to evaluate our minimally invasive approach. There were no differences in demographic, pre-operative anatomic, and functional data between groups. Concomitant anti-incontinence surgery with trans-obturator tape among the LESS-UTSLS vs RASS-UTSLS groups was performed in 2 (15 %) compared with 0 (0 %) and vaginal hysterectomy 2 (15 %) compared with supracervical hysterectomy 2 (40 %), respectively. The UTSLS operating time was similar in the RASS group compared with the LESS group (difference 9 min. There were only one POP (8 %) recurrence (stage 3) and one umbilical hernia (8 %) in the LESS-UTSLS group after 12 months of surgery. Two patients (15 %) developed stress urinary incontinence after LESS-UTSLS. We presented our technique and perioperative outcomes. RASS-UTSLS was similar operative times to LESS UTSL (+9 min), no differences in post-operative pain, anatomic support, or complications 6 months. We found that robotic surgical systems may accelerate the learning curve in the single-site surgery. Future investigations are warranted to discern the best applications for robotic single site technology in benign gynecologic surgery.

Robotic-assisted laparoscopic radical nephrectomy using the Da Vinci Si system: how to improve surgeon autonomy. Our step-by-step technique.

Herein, we describe several steps to improve surgeon autonomy during a Left Robotic-Assisted Laparoscopic Radical Nephrectomy (RALRN), using the Da Vinci Si system. Our kidney cancer program is based on 2 community hospitals. We use the Da Vinci Si system. Access is obtained with the following trocars: Two 8 mm robotic, one 8 mm robotic, bariatric length (arm 3), 15 mm for the assistant and 12 mm for the camera. We use curved monopolar scissors in robotic arm 1, Bipolar Maryland in arm 2, Prograsp Forceps in arm 3, and we alternate throughout the surgery with EndoWrist clip appliers and the vessel sealer. Here, we described three steps and the use of 3 robotic instruments to improve surgeon autonomy. Step 1: the lower pole of the kidney was dissected and this was retracted upwards and laterally. This maneuver was performed using the 3rd robotic arm with the Prograsp Forceps. Step 2: the monopolar scissors was replaced (robotic arm 1) with the robotic EndoWrist clip applier, 10 mm Hem-o-Lok. The renal artery and vein were controlled and transected by the main surgeon. Step 3: the superior, posterolateral dissection and all bleeders were carefully coagulated by the surgeon with the EndoWrist one vessel sealer. We have now performed 15 RALRN following these steps. Our results were: blood loss 300 cc, console time 140 min, operating room time 200 min, anesthesia time 180 min, hospital stay 2.5 days, 1 incisional hernia, pathology: (13) RCC clear cell, (1) chromophobe and (1) papillary type 1. Tumor Stage: (5) T1b, (8) T2a, (2) T2b. We provide a concise, step-by-step technique for radical nephrectomy (RN) using the Da Vinci Si robotic system that may provide more autonomy to the surgeon, while maintaining surgical outcome equivalent to standard laparoscopic RN.

Aging-related induction of inducible nitric oxide synthase is vasculo-protective to the arterial media.

OBJECTIVE: Aging associated erectile dysfunction (ED) is primarily caused by the reduction in smooth muscle cells (SMC) and an increase in collagen within the corpora cavernosa, assumed to result from an increase in reactive oxygen species (ROS). This is accompanied by the expression of inducible nitric oxide synthase (iNOS) to produce nitric oxide that scavenges ROS and inhibits collagen deposition. We investigated whether with aging similar processes occur within the arterial media SMC that share some common physiological functions with the cavernosal SMC. METHODS: Aged (22-24 months) male Brown Norway rats received water with or without an inhibitor of iNOS activity (L-N-(iminoethyl)-lysine acetate [L-NIL], 0.1 g/l), for 3 weeks. Young (3 months) untreated rats were used as control (n=5 per group). Tissue sections from the penis, abdominal aorta, femoral and brachial arteries were stained for collagen, SMC, iNOS, ROS plasminogen activator inhibitor (PAI) and apoptosis, and evaluated by quantitative image analysis. ROS were also determined in fresh tissue and whole blood by the GSH/GSSG ratio. RESULTS: It was observed that most aging-induced changes in the media of the arterial tree from the aorta to the resistance arteries in the penis are similar to what occurs in the corpora cavernosa, i.e. a decrease in the SMC/collagen ratio and an increase in ROS and iNOS, and specifically in the case of the resistance arteries, an increase in SMC apoptosis and PAI. iNOS inhibition by L-NIL further increased ROS and decreased the SMC/collagen ratio in the media. CONCLUSIONS: These observations suggest that ED and arteriosclerosis in the aging male may share a common etiology, and that the expression of iNOS by the SMC is an attempt to counteract this fibrosis.

Total or partial prostate sparing cystectomy for invasive bladder cancer: long-term implications on erectile function.

OBJECTIVE: To review the long-term results in patients treated with either total or partial prostate-sparing cystectomy, focusing on erectile function (EF), as en-bloc radical cystectomy (RC) with or without urethrectomy has been the method of choice for managing invasive bladder carcinoma, but has inherent risks of subsequent urinary incontinence and erectile dysfunction, with a marked effect on quality of life, especially in younger patients. PATIENTS AND METHODS: Between 2003 and 2005 we assessed 21 men (mean age 56 years) who had either a prostate apex-sparing cystectomy (PASC, 15) or total prostate-sparing cystectomy (TPSC, six). The mean follow-up was 30 months for PASC and 24 months for TPSC. The evaluation before surgery included standard bladder cancer staging, prostate specific antigen level, a digital rectal examination and a complete medical history, with attention to self-reported EF before surgery and the EF domain of the International Index of EF (IIEF) after surgery. RESULTS: The EF domain score was 20 after PASC and 30 after TPSC; this correlates with mild to moderate ED in the PASC group vs normal erectile function in the TPSC group. After transurethral resection of the bladder tumours (TURBT) 10 of 14 in the PASC group were T1 or T2a, and in the TPSC group, five of six were T2a and one patient was T2b. From the cystectomy specimen, in the PASC group eight were understaged compared with the TURBT specimen (T2b/T4a vs T1/T2a), while in the TPSC group there was understaging two (T3a vs T2a/T2b); this was significantly different (P < 0.05). There was recurrence of urothelial carcinoma in one of 15 and one of six after PASC and TPSC, respectively. CONCLUSION: The EF domain score after PASC was 10 points lower than after TPSC, representing a 30% increase in EF by preserving the entire prostate. We conclude that in patients with invasive bladder cancer, EF can be significantly preserved by prostate-sparing cystectomy. If adequate selection criteria are applied, EF can be preserved without compromising cancer control.

Antisense and short hairpin RNA (shRNA) constructs targeting PIN (Protein Inhibitor of NOS) ameliorate aging-related erectile dysfunction in the rat.

INTRODUCTION: Over-expression of penile neuronal nitric oxide synthase (PnNOS) from a plasmid ameliorates aging-related erectile dysfunction (ED), whereas over-expression of the protein inhibitor of NOS (PIN), that binds to nNOS, increases ED. AIM: To improve this form of gene therapy for ED by comparing the electrical field response of short hairpin RNA (shRNA) for PIN with that of antisense PIN RNA. MAIN OUTCOME MEASURE: Both shRNA and antisense RNA gene therapy vectors increased intracavernosal pressure in aged rats. METHODS: PIN small interfering RNA (siRNA), and plasmid constructs for cytomegalovirus promoter plasmid vector (pCMV-PIN), pCMV-PIN antisense RNA, pSilencer2.1-U6-PIN-shRNA; and pSilencer2.1-U6-randomer-shRNA were prepared and validated by transfection into HEK293 cells, determining the effects on PIN expression by Western blot. Plasmid constructs were then injected, followed by electroporation, into the penile corpora cavernosa of aged (20-month-old) Fisher 344 rats and, 1 month later, the erectile response was measured by intracavernosal pressure increase following electrical field stimulation (EFS) of the cavernosal nerve. PIN was estimated in penile tissue by Western blot and real-time reverse transcriptase-polymerase chain reaction. Cyclic guanosine monophosphate (cGMP) measurements were conducted by competitive enzyme immunoassay (EIA). Immunohistofluorescence detected PIN in corporal tissue sections. RESULTS: In cell culture, PIN siRNA and plasmid-expressed pU6-PIN-shRNA effectively reduced PIN expression from pCMV-PIN. pSilencer2.1-U6-PIN-shRNA corrected the impaired erectile response to EFS in aged rats and raised it above the value for young rats, more efficiently than pCMV-PIN antisense RNA. PIN mRNA expression in the penis was decreased by >70% by the shRNA but remained unaffected by the antisense RNA, whereas PIN protein expression was reduced in both cases, particularly in the dorsal nerve. PIN antisense increased cGMP concentration in treated tissue by twofold. CONCLUSION: pSilencer2.1-U6-PIN-shRNA gene therapy was more effective than the antisense PIN mRNA in ameliorating ED in the aged rat, thereby suggesting that PIN is indeed a physiological inhibitor of nNOS and nitrergic neurotransmission in the penis.

Sexual function after surgery for prostate or bladder cancer.

BACKGROUND: Compromised sexual function is often a side effect for patients following radical surgical procedures for bladder or prostate cancer. METHODS: The authors review the classification and physiology of sexual function and dysfunction. Moreover, they explain the possible pathophysiology directly resulting from surgery, and they discuss several approaches available to address these problems. RESULTS: Options for male sexual dysfunction, primarily erectile dysfunction resulting from radical prostatectomy or surgery for bladder cancer, range from patient education to penile prosthesis implantation. Female sexual dysfunction caused by surgical intervention for bladder cancer includes problems with libido, arousal, orgasm, and dyspareunia. Treatment options for women can include sex therapy, hormonal therapy, and preventive strategies. However, no consensus has been established on the most effective agents and time points to treat male or female sexual dysfunction following radical cystectomies or prostatectomies. The chronic intermittent treatment of erectile dysfunction following radical prostatectomy has been commonly referred to as penile rehabilitation. CONCLUSIONS: Additional research is needed to obtain further data concerning sexual dysfunction in both men and women following radical pelvic surgeries. Modification of surgical techniques, the use of various treatment modalities for sexual dysfunction, and the development of new agents will help to successfully minimize or prevent damage and restore normal sexual function after local surgical therapy for prostate or bladder cancer in the future.

Vardenafil prevents fibrosis and loss of corporal smooth muscle that occurs after bilateral cavernosal nerve resection in the rat.

OBJECTIVES: Impotence, specifically corporal veno-occlusive dysfunction (CVOD), occurs after radical prostatectomy. It results from the effects of cavernosal nerve damage, which causes smooth muscle (SM) loss and an increase in collagen within the corpora. Recent reports have suggested that long-term treatment with phosphodiesterase-5 inhibitors after radical prostatectomy may prevent such changes. We aimed to determine whether bilateral cavernosal nerve resection (BCNX) in the rat leads to CVOD and whether long-term phosphodiesterase-5 inhibition ameliorates these histologic and functional impairments. METHODS: Rats (n = 7 to 11/group) underwent either the sham operation, BCNX, or BCNX plus 30 mg/L vardenafil in the drinking water. Before the rats were killed 45 days later, CVOD was assessed by dynamic infusion cavernosometry. The corpora underwent histochemistry/immunohistochemistry with quantitative image analysis for SM/collagen ratio, collagen III/I ratio, alpha-SM actin, inducible nitric oxide synthase (iNOS), proliferating cell nuclear antigen, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling as a marker of apoptosis. RESULTS: Compared with the sham group, the BCNX rats demonstrated CVOD as measured by the drop rate, a 60% reduction in the SM/collagen ratio, a twofold increase in iNOS expression, and a threefold increase in intracorporeal apoptosis. Compared with the BCNX group, vardenafil increased both iNOS and proliferating cell nuclear antigen expression (SM cell replication), with normalization of the dynamic infusion cavernosometry drop rate and SM/collagen ratio. CONCLUSIONS: Long-term treatment with vardenafil may prevent CVOD after radical prostatectomy by preserving SM content and inhibiting corporal fibrosis possibly by its effect on iNOS.

Peyronie's disease associated with increase in plasminogen activator inhibitor in fibrotic plaque.

OBJECTIVES: To investigate whether tissue expression of plasminogen activator inhibitor type 1 (PAI-1) is increased in the fibrotic plaque of human Peyronie's disease (PD). Increased tissue levels of PAI-1, an inhibitor of both fibrinolysis and collagenolysis, have been found in a variety of fibrotic conditions. Recently, it was reported that PAI-1 expression was also increased in the fibrotic plaque of an animal model of PD induced by the injection of fibrin into the tunica albuginea (TA) of the penis. METHODS: Tissue (n = 10/group) and cells (n = 4/group) obtained from the penile TA plaque of patients with PD or from normal TA were subjected to RNA extraction and real-time reverse transcriptase-polymerase chain reaction. Tissues were also analyzed by immunohistochemistry (n = 8/group) for the detection of PAI-1 expression at the transcription and protein levels. RESULTS: A significant 3.5-fold to 16-fold increase was found in both PAI-1 mRNA and protein levels in the human PD plaque and the respective fibroblast cultures compared with the normal non-PD TA. CONCLUSIONS: The observed increase in PAI-1 in the human PD plaque agrees with what has been observed in the rat and suggests that PAI-1 may be a key pro-fibrotic factor in the development of human PD.

Gene transfer of inducible nitric oxide synthase complementary DNA regresses the fibrotic plaque in an animal model of Peyronie's disease.

The goal of the present study was to investigate the antifibrotic role of inducible nitric oxide synthase (iNOS) in Peyronie's disease (PD) by determining whether a plasmid expressing iNOS (piNOS) injected into a PD-like plaque can induce regression of the plaque. A PD-like plaque was induced with fibrin in the penile tunica albuginea of mice and then injected with a luciferase-expressing plasmid (pLuc), either alone or with piNOS, following luciferase expression in vivo by bioluminescence imaging. Rats were treated with either piNOS, an empty control plasmid (pC), or saline. Other groups were treated with pC or piNOS, in the absence of fibrin. Tissue sections were stained for collagen, transforming growth factor (TGF) beta1, and plasminogen-activator inhibitor (PAI-1) as profibrotic factors; copper-zinc superoxide dismutase (CuZn SOD) as scavenger of reactive oxygen species (ROS); and nitrotyrosine to detect nitric oxide reaction with ROS. Quantitative image analysis was applied. Both iNOS and xanthine oxido-reductase (XOR; oxidative stress) were estimated by Western blot analysis. Luciferase reporter expression was restricted to the penis, peaked at 3 days after injection, but continued for at least 3 wk. In rats receiving piNOS, iNOS expression also peaked at 3 days, but expression decreased at the end of treatment, when a considerable reduction of plaque size occurred. Protein nitrotyrosine, XOR, and CuZn SOD increased, and TGFbeta1 and PAI-1 decreased. The piNOS gene transfer regressed the PD plaque and expression of profibrotic factors, supporting the view that endogenous iNOS induction in PD is defense mechanism by the tissue against fibrosis.