Masayuki Shinchi

A pilot study of photoacoustic imaging system for improved real-time visualization of neurovascular bundle during radical prostatectomy

Photoacoustic imaging, a noninvasive imaging based on optical excitation and ultrasonic detection, enables one to visualize the distribution of hemoglobin and acquire a map of microvessels without using contrast agents. We examined whether it helps visualize periprostatic microvessels and improves visualization of the neurovascular bundle.

Pilot Study of Prostate Cancer Angiogenesis Imaging Using a Photoacoustic Imaging System

OBJECTIVES To investigate a link between the appearance of photoacoustic imaging (PAI) and microvasculature in prostate cancer and to assess the feasibility of PAI for angiogenesis imaging in prostate cancer. METHODS We have developed a PAI system equipped with a transrectal ultrasound (TRUS)-type probe. Three patients who underwent PAI just before prostate biopsy and subsequently underwent radical prostatectomy were included. The PAI appearance was retrospectively reviewed, and in each patient, 4 representative areas were selected: 1 with high PAI signal intensity, 1 with low PAI signal intensity, 1 peripheral to the index tumor, and 1 inside the index tumor. The correlation of PAI intensity with 3 microvascular parameters-microvascular density, total vascular area (TVA), and total vascular length (TVL)-assessed by CD34-immunostaining in resected specimens was analyzed. RESULTS In all 3 patients the PAI intensity, TVA, and TVL in areas with high-intensity PAI signals were significantly higher than those in areas with low-intensity PAI signals, suggesting that PAI appearance describes the distribution of microvasculature in prostatic tissue correctly. All index tumors showed a ring-like PAI appearance consisting of a peripheral area of high signal intensity completely or partially surrounding an area with low signal intensity. The PAI intensity, TVA, and TVL in the periphery of the index tumors were significantly higher than those inside of the index tumors. CONCLUSION The intensity of PAI signals might reflect the microvascularity in normal prostatic tissues and index tumors. PAI could be a novel modality for imaging prostate cancer angiogenesis.

Do Transurethral Treatments Increase the Complexity of Urethral Strictures

Purpose: We examined the impact on urethral stricture complexity at urethroplasty of previous transurethral treatments such as dilation, urethrotomy and stenting, which are most commonly performed when treating male urethral stricture. Materials and Methods: We retrospectively reviewed the records of 45 males who had undergone transurethral treatments before urethroplasty. We compared urethrography findings at initial diagnosis with those at urethroplasty. Males with failed hypospadias repair, lichen sclerosis or a history of prior urethroplasty were excluded from analysis. We considered stricture complexity increased if the number and/or length of strictures on urethrography at urethroplasty was greater than that at initial diagnosis or false passage was newly identified. Results: Of the patients 39 (87%), 32 (71%) and 13 (29%) had undergone urethral dilation, urethrotomy and urethral stenting, respectively, and 39 (87%) had undergone repeat or multiple kinds of transurethral treatments. Stricture complexity was increased in 22 men (49%) while 7 (16%) required urethroplasty more complex than that anticipated from urethrography findings at initial diagnosis. Increased stricture complexity was significantly associated with a history of urethrotomy (p = 0.03), urethral stenting (p = 0.0002) and repeat transurethral treatments (p = 0.01). Multivariate analysis revealed that urethral stenting (p = 0.01) and repeat transurethral treatments (p = 0.01) were independent predictors of increased stricture complexity. Conclusions: Repeat transurethral treatments increase stricture complexity and are potentially counterproductive. Even a single application of temporary urethral stenting carries a high risk of complicating the stricture and requiring complex urethroplasty.

Primary Realignment for Pelvic Fracture Urethral Injury Is Associated With Prolonged Time to Urethroplasty and Increased Stenosis Complexity

OBJECTIVE To compare the clinical courses of patients with pelvic fracture urethral injury (PFUI) according to initial management strategy. METHODS We reviewed the clinical courses of 63 patients with PFUI who were initially treated elsewhere and underwent delayed anastomotic urethroplasty by a single surgeon between 2008 and 2015. Patients were grouped according to their initial treatment: by suprapubic tube placement alone (49 patients, SPT group) or primary realignment (14 patients, PR group). Time to urethroplasty was defined as the period between injury and delayed urethroplasty. Clinical data regarding the status of urethral stenosis, urethroplasty procedure, and treatment outcome were analyzed. RESULTS The mean time to urethroplasty in the PR group was about 3 times than that in the SPT group (133 months vs 47 months, P = .035). Fifty percent of the PR group (7 of 14) had a history of repeated urethrotomy or dilation before referral, a percentage significantly higher than that of the SPT group (20.4%, 10 of 49, P = .027). The percentage of patients having a false passage and iatrogenic scar was significantly higher in the PR group (42.9% vs 16.3%, P = .035), but there was no significant between-group difference in urethral stenosis length, operative time, operative blood loss, or the percentage of patients requiring inferior pubectomy or urethral rerouting. CONCLUSION PR does not facilitate delayed urethroplasty, and patients who undergo PR are at high risk of having a more complicated stenosis and longer time to urethroplasty, presumably because of repeated transurethral procedures.

Pubourethral Stump Angle Measured on Preoperative Magnetic Resonance Imaging Predicts Urethroplasty Type for Pelvic Fracture Urethral Injury Repair

OBJECTIVE To examine whether the type of delayed urethroplasty required for pelvic fracture urethral injury, which is not easily predicted from conventional urethrography findings, can be predicted from preoperative magnetic resonance imaging (MRI) results. PATIENTS AND METHODS Records of 74 male patients with pelvic fracture urethral injury who underwent MRI of the pelvis at least 3 months after injury and, subsequently, delayed anastomotic urethroplasty were retrospectively analyzed. Pubourethral stump length (PUL) was defined as the distance between the distal end of the proximal urethral stump and the lower border of the inferior pubic ramus. Pubourethral stump angle (PUA) was defined as the angle between the long axis of the pubis and the line between the distal end of the proximal urethral stump and the lower border of the inferior pubic ramus. Both PUL and PUA were measured in sagittal T2-weighted MRI. RESULTS Delayed urethroplasty was performed by a simple perineal approach in the 28 patients requiring only bulbar urethral mobilization with or without corporal splitting and by elaborate approach in the 46 additionally requiring inferior pubectomy or an abdominoperineal approach with urethral rerouting. The overall success rate defined as no recurrent stricture on urethroscopy was 94.6%. Disruption at the prostate apex, greater urethral gap length, longer PUL, and lower PUA were in univariate analysis significantly associated with an elaborate approach. In multivariate analysis, only low PUA was an independent predictor of the need for an elaborate approach. CONCLUSION PUA measured on MRI is useful for predicting the type of reconstruction needed for urethral repair.

PD29-10 PREDICTION OF THE TYPE OF URETHROPLASTY FOR PELVIC FRACTURE URETHRAL INJURY BY PUBO-URETHRAL STUMP ANGLE MEASURED ON PREOPERATIVE MRI

procedure, notably, if corporeal splitting and/or inferior pubectomy (CS/ IP) are required. Consequently, a long learning curve is surely needed. Herein, we used retrograde urethrogram (RGU) to envisage the intraoperative difficulty during AU for PFUI. We hypothesized that as deep as the urethra goes into the pelvis, the more complexity is anticipated. METHODS: A retrospective review for patients underwent AU for PFUI at a tertiary referral center was conducted between January 2010 and March 2016. The standard position for RGU is semi-lateral with only one obturator foramen is visualized. To address how deep the urethra goes into the pelvis, an imaginary line is drawn from the pubis symphysis down to a point midway between the tips of pubic rami, representing theoretically the midsagittal plane of the perineal membrane. Zones where the proximal end of the anterior urethra is present, are (A) anterior to the line, (B) on the line, and (C) across the line posteriorly (Fig.). The complexity of the procedure was defined as the need of any auxiliary maneuver beyond distal urethral mobilization (CS/ IP) to achieve adequate anastomosis. Predictors were tested only in patients with successful AU. Further analysis was performed to detect the association between this hypothesis and the outcome defined by the need for instrumentation after AU. RESULTS: 129 patients were analyzed. 39 (30%) patients required auxiliary procedures beyond mobilization of the distal urethra and 36 (27.9%) reported failure. Among patients with successful AU, zone C was the only factor significantly associated with complex AU [13 (44.8%) vs 12 (18.8%)]. Furthermore, zone C [Odds ratio (OR): 4.9, p1⁄40.006], as well as combined pelvic fracture (OR: 4.6, p1⁄40.009), were the only independent predictors of treatment failure. CONCLUSIONS: We defined a simple method to predict intraoperative complexity and treatment failure after AU for PFUI. This is might be of help for preoperative counseling and intraoperative planning by selecting cases for training and reserving particular ones for high volumesurgeons.

PD60-03 PRE- AND POST-TREATMENT URETHROGRAMS SHOW THAT TRANSURETHRAL TREATMENTS INCREASE THE COMPLEXITY OF URETHRAL STRICTURES

INTRODUCTION AND OBJECTIVES: Urethroplasty is usually a definitive treatment for recurrent urethral stricture. However, patients often wait a significant period of time for urethroplasty, especially in a universal healthcare system, and may incur further risk of complications due to urethral stricture. The purpose of this study is to examine the incidence and predictors of complications due to urethral stricture in patients awaiting urethroplasty. METHODS: A retrospective review of patients undergoing urethroplasty fromSept2009-2013 ina single centerwasperformed.Patients treated outside of the regional health authority were excluded to minimize unidentified complications and interventions. The primary outcome was complication due to urethral stricture, defined as any unplanned intervention with the health care system during the period between decision to perform surgery and urethroplasty date. These complications included urinary tract infection (UTI), urolithiasis, acute urinary retention, genitourinary pain related to stricture, and catheter-related issues. RESULTS: 276 patients met study criteria. Mean stricture length was 4.5 cm, and most strictures were bulbar (67.4%) or penile (15.2%) in location. Idiopathic (47.8%), traumatic (15.9%), and iatrogenic (10.9%) were the most common stricture etiologies. Overall, 44 (15.9%) patients presented with a complication with a mean time to complication of 65.9 days. The mean surgical wait time was 164 days. Complications included urinary tract infection (56.8%), acute urinary retention (20.5%), genitourinary pain requiring intervention (5.8%), and catheter related events (15.9%). Univariate analysis for factors predicting complications yielded catheter dependency (clean-intermittent catheterization or suprapubic catheter)(p<0.001) and number of prior endoscopic treatments (p1⁄40.005) as significant, with prior urethroplasty (p1⁄40.06) trending towards significance. Multivariate Cox regression analysis found catheter-status (p<0.001;H.R. 2.3, 95%CI:1.5-3.4) andprior urethroplasty (p1⁄40.013;H.R. 1.7, 95% CI: 1.1-2.5) to be significantly associated with complications. CONCLUSIONS: Our study is the first to examine and quantify the morbidity of urethroplasty wait times. Approximately 16% of patients presented with a complication while awaiting urethroplasty at a mean of 66 days after the decision for surgery. Urethroplasty wait time should be less than 66 days and patients whom are catheter dependent or failed prior urethroplasty should be prioritized, as they are more likely to develop complications.

Possibility of transrectal photoacoustic imaging-guided biopsy for detection of prostate cancer

A transrectral ultrasonography (TRUS) guided prostate biopsy is mandatory for histological diagnosis in patients with an elevated serum prostate-specific antigen (PSA), but its diagnostic accuracy is not satisfactory; therefore, a considerable number of patients are forced to have an unnecessary repeated biopsy. Photoacoustic (PA) imaging has the ability to visualize the distribution of hemoglobin clearly. Thus, there is the potential to acquire different maps of small vessel networks between cancerous and normal tissue. We developed an original TRUS-type PA probe consisting of a microconvex array transducer with an optical illumination system providing coregistered PA and ultrasound images. The purpose of this study is to demonstrate the clinical possibility of a transrectral PA image. The prostate biopsy cores obtained by transrectal systemic biopsies under TRUS guidance were stained with HE staining and anti-CD34 antibodies as a marker of the endothelium of the blood vessel in order to find a pattern in the map of a small vessel network, which allows for imaging-based identification of prostate cancer. We analyzed the association of PA signal patterns, the cancer location by a magnetic resonance imaging (MRI) study, and the pathological diagnosis with CD34 stains as a prospective intervention study. In order to demonstrate the TRUS-merged-with-PA imaging guided targeted biopsy combined with a standard biopsy for capturing the clinically significant tumors, we developed a puncture needle guide attachment for the original TRUS-type PA probe.