Investigating focal spot position drift in a mobile imaging system equipped with a monobloc-based x-ray generator.

BACKGROUND: Misalignment or double-contouring artifacts can appear in high-resolution 3D cone beam computed tomography (CBCT) images, potentially indicating geometric accuracy issues in the projection data. Such artifacts may go unnoticed in low-resolution images and could be associated with changes in the focal spot (FS) position. PURPOSE: High-resolution 3D-CBCT imaging by a mobile imaging device with a large gantry clearance offers more versatility for clinical workflows in image-guided brachytherapy (IGBT), intraoperative radiation therapy (IORT), and spinal, as well as maxillofacial surgery. However, misalignment or double-contouring artifacts hinder workflow advancements in these domains. This paper introduces intrinsic calibration and geometrical correction methods as extensions to a well-established technique for addressing geometrical deviations resulting from factors such as gravity or mechanical inconsistencies. These extensions cover shifts and drifts of the FS depending on FS size selection, temperature, tube current, and tube potential. The proposed methods effectively mitigate artifacts in high-resolution CBCT images stemming from geometrical inaccuracies in projection data, without requiring additional equipment like a pinhole device. METHODS: Geometrical offsets and drifts of the x-ray tube FS were characterized on a mobile multi-purpose imaging system, the ImagingRing-m. A pinhole-like experiment was simulated by adjusting the movable collimation unit to a small rectangular aperture within the FS size range. The influence of filament selection, that is, FS size, temperature, the relatively low tube currents, as well as tube potential settings have been studied on two different monobloc types sharing the same x-ray tube insert. The Catphan 504 and an Alderson head phantom were used to assess resulting image artifacts. RESULTS: Switching the FS size to one different from what was used for geometrical (gravitation, mechanical variations) calibration induced the most notable position changes of the x-ray FS, resulting in double-contouring artifacts and blurring of high-resolution 3D-CBCT images. Incorporating these shifts into a geometrical correction method effectively minimized these artifacts. Thermal drifts exhibited the second largest geometrical changes, comparable to FS size shifts across the thermal operating conditions of the x-ray system. The proposed thermal drift compensation markedly reduced thermal drift effects. Tube current and potential had little impact within the range of available tube currents, eliminating the need for compensation in current applications. CONCLUSIONS: Augmenting the geometrical calibration pipeline with proposed FS drift compensations yielded significant enhancements in image quality for high-resolution reconstructions. While compensation for thermal effects posed challenges, it proved achievable. The roles of tube current and potential were found to be negligible.

Osteitis pubis following holmium laser enucleation of the prostate.

Osteitis pubis is a rare, inflammatory condition involving the pubic symphysis. While osteitis pubis has been reported following many urological procedures, including those addressing bladder outlet obstruction such as transurethral resection of the prostate, it has never been reported after holmium laser enucleation of the prostate (HoLEP). Here, we detail the clinical course of a patient found to have osteitis pubis following HoLEP. This patient presented several weeks after surgery with non-specific, persistent symptoms of groin pain and difficulty ambulating, alerting our clinicians to consider osteitis pubis which was confirmed on MRI of the pelvis. While the majority of osteitis pubis cases are managed with locally invasive techniques, our patient's symptoms were successfully managed conservatively with Foley catheter placement, oral antibiotics and close follow-up. At 9 months postoperative, the patient has reported complete resolution of symptoms and continues to be followed closely.

Ejaculatory Preserving Holmium Laser Enucleation of the Median Lobe: Preserving Sexual Function While Improving Urinary Outcomes.

OBJECTIVE: To evaluate perioperative outcomes related to sexual and urinary function in patients who underwent a holmium laser enucleation of the prostate (HoLEP) with selective laser enucleation of the median lobe. MATERIALS AND METHODS: We retrospectively reviewed the first 450 HoLEP cases by a single surgeon from April 2019 to March 2022. Fifty-five patients with intravesical-prostatic protrusion or high bladder neck without obstructing lateral lobes underwent selective enucleation of the median lobe of the prostate. Patients were asked to comment on whether they had retrograde ejaculation during their follow-up appointment. Urinary function was assessed using the American Urological Association Symptom Score and subjective evaluation of urinary incontinence. RESULTS: Median age of the cohort was 65 years (range: 44-91). Compared to preoperative, there was significant improvement in mean postoperative American Urological Association Symptom Score (22.5 vs 6.9, P < .001), mean postoperative quality of life scores (4 vs 1.2, P < .001), and mean postoperative post void residual volumes (244.1 vs 69.3 cc, P < .001). No patients reported stress urinary incontinence. Of the 55 patients who underwent selective enucleation of the median lobe, 40 were sexually active. Of those men, 35 reported normal ejaculation, 3 had retrograde ejaculation that was unchanged from pre-op, and 2 had new ejaculatory dysfunction. CONCLUSION: In this case series of selective laser enucleation of the median lobe, urinary function significantly improved in short-term follow-up with preservation of ejaculation in approximately 90% of men.

Reimbursement of surgical procedures for benign prostatic hyperplasia: are we disincentivizing complex care?

PURPOSE OF REVIEW: To provide an overview of how surgical benign prostatic hyperplasia (BPH) procedures are compensated in the United States and the implications of the current reimbursement system on the care of patients. RECENT FINDINGS: The resource-based relative value care system is Medicare's current reimbursement model. There is strong evidence that the current system does not adequately account for complex care. Consequently, for BPH surgical procedures, treatment options best suited for complex patients are not adequately reimbursed which may have implications on healthcare delivery and outcomes. SUMMARY: Inadequate reimbursement for certain BPH procedures may disincentivize the care of complex patients. Procedures such a holmium laser enucleation of the prostate are well suited for complex patients but have a steep learning curve. The incentive to learn and offer such procedures to complex patients may be unfairly influenced by reimbursement levels, which in the end penalizes patients and the treatments available to them.

"En-Bloc" Enucleation With Early Apical Release Compared to Standard Holmium Laser Enucleation of the Prostate: A Retrospective Pilot Study During the Initial Learning Curve of a Single Surgeon.

OBJECTIVE: To compare operative efficiency of Holmium laser enucleation of the prostate (HoLEP) using both the standard multi-incisional approach and en-bloc enucleation with early apical release during the initial learning curve. MATERIALS AND METHODS: We retrospectively reviewed the initial 95 consecutive men who underwent HoLEP between April 2019 and September 2020 by a single surgeon. We compared patient demographics, and pre-, intra-, and post-operative metrics between both groups. Differences between groups were evaluated with Mann-Whitney U and Kruskal-Wallis tests. RESULTS: Forty-nine patients underwent the standard HoLEP approach, and 46 patients underwent the en-bloc approach. Compared to a standard HoLEP, the en-bloc approach was associated with decreased operative time (131.11 minutes vs 153.59 minutes, P = .007) with similar weights of tissue removed. Operative efficiency, as measured by grams of prostate tissue removed per minute, was greater for the en-bloc approach (0.49 g/min vs 0.36 g/min, P = .005). There was no difference in length of stay (0.91 days vs 0.96 days, P = .383), laser efficiency (4.41 kJ/g vs 4.83 kJ/g, P = .200), or number of post-operative complications (10 vs 6, P = .236) between the groups. CONCLUSION: Utilization of the en-bloc technique during the initial learning curve allows for a faster, more efficient operation without any difference in functional outcomes or major complications compared to a standard HoLEP.

Benign Prostatic Hyperplasia: Clinical Manifestations, Imaging, and Patient Selection for Prostate Artery Embolization.

Prostate artery embolization (PAE) has been shown to be safe and effective at treating lower urinary tract symptoms (LUTS), urinary retention, and hematuria caused by benign prostatic hyperplasia (BPH). To distinguish from other causes of these symptoms, a multidisciplinary evaluation by a urologist and interventional radiologist should include a complete history to screen for any nonprostate causes of LUTS. The International Prostate Symptom Score is a useful objective measure to quantify the patient's urinary complaints. A physical exam should be performed to evaluate a patient's candidacy for angiography, and baseline laboratory evaluation should ensure that the patient's coagulation and kidney function are adequate. In certain situations, patients may benefit from cystoscopy and urodynamic evaluation to ensure their symptoms are related to BPH. A review of the patient's imagining can be the most important component of the evaluation of a patient prior to PAE, because a patient's gland size is often a primary driver of what procedural options available are to him. Men with small glands (≤30 mL) can be treated with several of the available minimally invasive transurethral procedures, but larger glands (≥80-120 mL) may be limited to holmium laser enucleation of prostate, thulium laser enucleation of prostate, surgical prostatectomy, or PAE, depending on institutional practice patterns. Secondary considerations include medical comorbidities, the risks for sexual side effects, the risk for bleeding, and the possible adverse events associated with the procedure, which are all low for PAE. Most patients suffering from symptomatic BPH resulting in LUTS, retention, or hematuria will benefit from PAE.

Analysis of adverse outcomes in the post-anesthesia care unit based on anesthesia liability data.

STUDY OBJECTIVE: The aim of this study is to provide a contemporary medicolegal analysis of claims brought against anesthesiologists in the United States for events occurring in the post-anesthesia care unit (PACU). DESIGN: In this retrospective analysis, we analyzed closed claims data from the Controlled Risk Insurance Company (CRICO) Comparative Benchmarking System (CBS) database. SETTING: Claims closed between January 1, 2010 and December 31, 2014 were included for analysis if the alleged damaging event occurred in a PACU and anesthesiology was named as the primary responsible service. PATIENTS: Forty-three claims were included for analysis. Data regarding ASA physical status and comorbidities were obtained, whenever available. Ages ranged from 18 to 94. Patients underwent a variety of surgical procedures. Severity of adverse outcomes ranged from temporary minor impairment to death. INTERVENTIONS: Patients receiving care in the PACU. MEASUREMENTS: Information gathered for this study includes patient demographic data, alleged injury type and severity, operating surgical specialty, contributing factors to the alleged damaging event, and case outcome. Some of these data were drawn directly from coded variables in the CRICO CBS database, and some were gathered by the authors from narrative case summaries. RESULTS: Settlement payments were made in 48.8% of claims. A greater proportion of claims involving death resulted in payment compared to cases involving other types of injury (69% vs 37%, p = 0.04). Respiratory injuries (32.6% of cases), nerve injuries (16.3%), and airway injuries (11.6%) were common. Missed or delayed diagnoses in the PACU were cited as contributing factors in 56.3% of cases resulting in the death of a patient. Of all claims in this series, 48.8% involved orthopedic surgery. CONCLUSIONS: The immediate post-operative period entails significant risk for serious complications, particularly respiratory injury and complications of airway management. Appropriate monitoring of patients by responsible providers in the PACU is crucial to timely diagnosis of potentially severe complications, as missed and delayed diagnoses were a factor in a number of the cases reviewed.

Cerebral cortex dose sparing for glioblastoma patients: IMRT versus robust treatment planning.

BACKGROUND: To date, patients with glioblastoma still have a bad median overall survival rate despite radiation dose-escalation and combined modality treatment. Neurocognitive decline is a crucial adverse event which may be linked to high doses to the cortex. In a planning study, we investigated the impact of dose constraints to the cerebral cortex and its relation to the organs at risk for glioblastoma patients. METHODS: Cortical sparing was implemented into the optimization process for two planning approaches: classical intensity-modulated radiotherapy (IMRT) and robust treatment planning. The plans with and without objectives for cortex sparing where compared based on dose-volume histograms (DVH) data of the main organs at risk. Additionally the cortex volume above a critical threshold of 28.6 Gy was elaborated. Furthermore, IMRT plans were compared with robust treatment plans regarding potential cortex sparing. RESULTS: Cortical dose constraints result in a statistically significant reduced cerebral cortex volume above 28.6 Gy without negative effects to the surrounding organs at risk independently of the optimization technique. For IMRT we found a mean volume reduction of doses beyond the threshold of 19%, and 16% for robust treatment planning, respectively. Robust plans delivered sharper dose gradients around the target volume in an order of 3 - 6%. Aside from that the integration of cortical sparing into the optimization process has the potential to reduce the dose around the target volume (4 - 8%). CONCLUSIONS: We were able to show that dose to the cerebral cortex can be significantly reduced both with robust treatment planning and IMRT while maintaining clinically adequate target coverage and without corrupting any organ at risk. Robust treatment plans delivered more conformal plans compared to IMRT and were superior in regards to cortical sparing.

Efficacy of Tumor-Infiltrating Lymphocytes Combined with IFN-α in Chinese Resected Stage III Malignant Melanoma.

BACKGROUND: This study aims to explore the efficacy of tumor-infiltrating lymphocytes (TIL) along with interferon-α (IFN-α) to treat stage III malignant melanoma (MM) patients in China. METHODS: Between May 2010 and October 2014, 77 patients of stage III MM who underwent surgery were collected in this study. These patients were divided into two groups: patients who received TIL + IFN-α ± RetroNectin-activated cytokine-induced killer cells (R-CIK) in Arm 1 (n = 27) and IFN-α ± R-CIK in Arm 2 (n = 50) as adjuvant therapy. The primary endpoints were disease-free survival (DFS) time and DFS rates measured at time points of 1, 2, and 3 years. The secondary endpoints were overall survival (OS) rates measured at time points of 1, 2, 3, and 5 years as well as OS as evaluated by Kaplan-Meier. RESULTS: Our results indicated that the median DFS and OS in Arm 1 were significantly better than those in Arm 2. The data also demonstrated that DFS rate and OS rates in Arm 1 were significantly better than those in Arm 2 at all measured time points. CONCLUSION: Patients who undergo surgical excision of stage III MM appear to enjoy prolonged DFS and OS when treated with TIL + IFN-α compared to IFN-α alone.

Nine-degrees-of-freedom flexmap for a cone-beam computed tomography imaging device with independently movable source and detector.

PURPOSE: Couch-mounted cone-beam computed tomography (CBCT) imaging devices with independently rotatable x-ray source and flat-panel detector arms for acquisitions of arbitrary regions of interest (ROI) have recently been introduced in image-guided radiotherapy (IGRT). This work analyzes mechanical limitations and gravity-induced effects influencing the geometric accuracy of images acquired with arbitrary angular constellations of source and detector in nonisocentric trajectories, which is considered essential for IGRT. In order to compensate for geometric inaccuracies of this modality, a 9-degrees-of-freedom (9-DOF) flexmap correction approach is presented, focusing especially on the separability of the flexmap parameters of the independently movable components of the device. METHODS: The 9-DOF comprise a 3D translation of the x-ray source focal spot, a 3D translation of the flat-panel's active area center and three Euler-rotations of the detector's row and column vectors. The flexmap parameters are expressed with respect to the angular position of each of the devices arms. Estimation of the parameters is performed, using a CT-based structure set of a table-mounted, cylindrical ball-bearing phantom. Digitally reconstructed radiograph (DRR) patches are derived from the structure set followed by local 2D in-plane registration and subsequent 3D transform estimation by nonlinear regression with outlier detection. RESULTS: Flexmap parameter evaluations for the factory-calibrated system in clockwise and counter-clockwise rotation direction have shown only minor differences for the overall set of flexmap parameters. High short-term reproducibility of the flexmap parameters has been confirmed by experiments over 10 acquisitions for both directions, resulting in standard deviation values of ≤0.183 mm for translational components and ≤0.0219 deg for rotational components, respectively. A comparison of isocentric and nonisocentric flexmap evaluations showed that the mean differences of the parameter curves reside within their standard deviations, confirming the ability of the proposed calibration method to handle both types of trajectories equally well. Reconstructions of 0.1 mm and 0.25 mm steel wires showed similar results for the isocentric and nonisocentric cases. The full-width at half maximum (FWHM) measure indicates an average improvement of the calibrated reconstruction of 85% over the uncalibrated reconstruction. The contrast of the point spread function (PSF) improved by 310% on average over all experiments. Moreover, a reduced amount of artifacts visible in nonisocentric reconstructions of a head phantom and a line-pair phantom has been achieved by separate application of the 9-DOF flexmap on the geometry described by the independently moving source arm and detector arm. CONCLUSIONS: Using a 9-DOF flexmap approach for correcting the geometry of projections acquired with a device capable of independent movements of the source and panel arms has been shown to be essential for IGRT use cases such as CBCT reconstruction and 2D/3D registration tasks. The proposed pipeline is able to create flexmap curves which are easy to interpret, useful for mechanical description of the device and repetitive quality assurance as well as system-level preventive maintenance. Application of the flexmap has shown improvements of image quality for planar imaging and volumetric imaging which is crucial for patient alignment accuracy.

Technical Note: Procedure for the calibration and validation of kilo-voltage cone-beam CT models.

PURPOSE: The aim of this work is to propose a general and simple procedure for the calibration and validation of kilo-voltage cone-beam CT (kV CBCT) models against experimental data. METHODS: The calibration and validation of the CT model is a two-step procedure: the source model then the detector model. The source is described by the direction dependent photon energy spectrum at each voltage while the detector is described by the pixel intensity value as a function of the direction and the energy of incident photons. The measurements for the source consist of a series of dose measurements in air performed at each voltage with varying filter thicknesses and materials in front of the x-ray tube. The measurements for the detector are acquisitions of projection images using the same filters and several tube voltages. The proposed procedure has been applied to calibrate and assess the accuracy of simple models of the source and the detector of three commercial kV CBCT units. If the CBCT system models had been calibrated differently, the current procedure would have been exclusively used to validate the models. Several high-purity attenuation filters of aluminum, copper, and silver combined with a dosimeter which is sensitive to the range of voltages of interest were used. A sensitivity analysis of the model has also been conducted for each parameter of the source and the detector models. RESULTS: Average deviations between experimental and theoretical dose values are below 1.5% after calibration for the three x-ray sources. The predicted energy deposited in the detector agrees with experimental data within 4% for all imaging systems. CONCLUSIONS: The authors developed and applied an experimental procedure to calibrate and validate any model of the source and the detector of a CBCT unit. The present protocol has been successfully applied to three x-ray imaging systems. The minimum requirements in terms of material and equipment would make its implementation suitable in most clinical environments.

Efficacy of RetroNectin-activated cytokine-induced killer cell therapy in the treatment of advanced hepatocelluar carcinoma.

The present study aimed to investigate the efficacy of RetroNectin-activated cytokine-induced killer cell (R-CIK) therapy in advanced hepatocellular carcinoma patients as compared with conventional chemotherapy, a comparison that has not yet been thoroughly studied. From January 2010 to October 2013, 74 patients with an initial diagnosis of advanced hepatocelluar carcinoma were enrolled in the study. Patients were assigned to one of two treatment arms: patients in arm 1 (n=37) received R-CIK treatment as the first line therapy, whereas those in arm 2 (n=37) received chemotherapy as the first line treatment. The primary end point measured in this study was median overall survival (mOS). Median progression-free survival time (mPFS) and 1- and 2-year survival rates were recorded as secondary end points. Kaplan-Meier analysis was performed on all mOS and mPFS data, and treatment hazard ratios were established using the Cox proportional hazards model. The 1-year survival rate in treatment arm 1 was 42.47% vs. 24.89% in arm 2 (95% CI, 24.91-59.01% vs. 12.10-40.02%, P=0.066); the 2-year survival rates were 21.24 and 5.53% (95% CI, 4.60-45.86 vs. 0.46-21.06%, P=0.106) in arms 1 and 2, respectively; the mPFS in arm 1 was 4.37 vs. 3.90 (x2=0.182, P=0.670) in arm 2; and the mOS in arm 1 was 14.03 months vs. 9.46 months(x2=4.406, P=0.036) in arm 2. Calculations of univariate analyses of arm 1, R-CIK cycles ≥6, KPS >70, AFP ≤400 ng/ml, and findings of no vascular invasion and no extra-hepatic metastasis were potential predictive factors (P<0.05). Calculations from multivariate analyses similarly identified these factors as potentially having predictive value (P<0.05). The main adverse effects of R-CIK therapy included fever and headache pain. R-CIK treatment may prolong mOS in advanced hepatocellular carcinoma patients compared with conventional chemotherapy. Patients who underwent ≥6 cycles of R-CIK, had KPS scores >70, AFP ≤400 ng/ml, displayed no evidence of vascular invasion, and no extra-hepatic metastasis appeared to have longer survival times compared with other cohorts in the present study.

Efficacy of cytokine-induced killer cells in the treatment of elderly patients with metastatic pancreatic adenocarcinoma.

Currently, metastatic pancreatic cancer is associated with disappointing survival outcomes. This is largely due to a rapid progression of the disease and a precipitous deterioration in the health of affected individuals, especially elderly patients who are often unable to tolerate chemotherapy. The aim of this study was to evaluate the efficacy and safety of adoptive immunotherapy using cytokine-induced killer cells (CIK) as a first-line treatment for metastatic pancreatic cancer. Between December 2010 and June 2012 eight patients were enrolled in this study. All participants were elderly, suffering from metastatic pancreatic cancer, and unable to tolerate chemotherapy. All patients in this study received R-CIK therapy only as a first-line treatment. In the eight patients, 1 had complete response (CR), 5 had stable disease (SD) and 2 had progression disease (PD). Therefore, the overall response rate (ORR) was 12.5% (1/8) and the disease control rate (DCR) was 75.0% (6/8 patients). The 1-year survival rate was 37.5%, and the median overall survival time (mOS) was 13.04 months (95% CI: 5.9-20.2). The results indicated that no significant positive or negative predictive factors were identified by univariate analysis. The main adverse effect of R-CIK was fever and the side effect rate was 25.0% (2/8). Adoptive immunotherapy using R-CIK cells showed comparable OS to survival data seen in previous trials assessing conventional chemotherapies in elderly patients and the adverse effect is less pronounced.

Cost-utility analyses in spine care: a qualitative and systematic review.

STUDY DESIGN: Systematic review. OBJECTIVE: A systematic review was performed to identify US-based cost-utility analyses (CUA) studies in spine care and to critically evaluate the quality of the available literature. SUMMARY OF BACKGROUND DATA: There has been a recent trend in the United States toward increased publication of economic analyses in spine care. The cost-effectiveness of spine interventions and the quality of published literature is not well understood. METHODS: A MEDLINE search was conducted to identify cost analyses in spine care. Articles were excluded on the basis of the following criteria: nonspine care, nonoperative, non-US based, nonclinical, and not CUA. Of the 424 screened articles, 20 met inclusion criteria. Quality of studies was assessed using the Quality of Health Economic Studies instrument. RESULTS: Evidence for the cost-effectiveness of operative spinal intervention is varied. The majority of available studies report favorable cost-effectiveness ratios, however, a few studies suggest that certain operative interventions are not cost-effective. Average Quality of Health Economic Studies score of all included studies was 75.1 (60-93). The quality of evidence is variable and there are a number of weaknesses in the available literature, most significant of which is that few studies adopt a long-term time horizon or have sufficient follow-up (N = 3/20). High Quality of Health Economic Studies scoring studies were more likely to have sensitivity analysis (P = 0.016), societal cost perspective (P = 0.014), and a funding disclosure (P = 0.03). CONCLUSION: There is a small but rapidly growing body of US-based CUA in spine care. The quality of CUA evidence is variable but there are significant opportunities to strengthen future CUA studies in spine. This study highlights the need for more attention to CUA research and the quality of these studies in spine care.

Optimization of the stopping-power-ratio to Hounsfield-value calibration curve in proton and heavy ion therapy.

For CT-based dose calculation in ion therapy a link between the attenuation coefficients of photons and the stopping-power of particles has to be provided. There are two commonly known approaches to establish such a calibration curve, the stoichiometric calibration and direct measurements with tissue substitutes or animal samples. Both methods were investigated and compared. As input for the stoichiometric calibration the data from ICRP-report 23 were compared to newly available data from ICRP-report 110. By employing the newer data no relevant difference could be observed. The differences between the two acquisition methods (direct measurement and stoichiometric calibration) were systematically analyzed and quantified. The most relevant change was caused by the exchange of carbon and oxygen content in the substitutes in comparison to the data of the ICRP-reports and results in a general overshoot of the Bragg peak. The consequence of the differences between the calibration curves was investigated with treatment planning studies and iso-range surfaces. Range differences up to 6mm in treatment plans of the head were observed. Additionally two improvements are suggested which increase the accuracy of the calibration curve.

Paratesticular leiomyosarcoma: case report and review.

Paratesticular leiomyosarcoma is a rare entity. Greater than 95% of tumors arising within the scrotal sac are testicular in origin. Of the paratesticular tumors, rhabdomyosarcoma accounts for nearly half of malignant masses. Paratesticular leiomyosarcoma is infrequently encountered, resulting in a relative paucity of literature regarding this tumor type. Here we present a case report of a leiomyosarcoma arising from the spermatic cord in a 71-year-old man and review the literature regarding paratesticular leiomyosarcoma presentation, diagnosis and treatment.

A randomized prospective trial of primary versus AlloDerm closure of buccal mucosal graft harvest site for substitution urethroplasty.

OBJECTIVES: To present a prospective, randomized trial comparing primary and AlloDerm closure of the oral harvest site. The use of buccal mucosa grafts for substitution urethroplasty is an established and durable technique. The optimal management of the buccal mucosa grafts harvest site for the intraoral defect has yet to be determined. METHODS: Between February 2003 and September 2006, a total of 20 men undergoing buccal mucosal urethroplasty were randomly assigned to either primary (n = 10) or AlloDerm closure (n = 10) of the oral harvest site. All patients were clinically examined postoperatively and each completed a 10-point analog pain score and descriptive questionnaire postoperatively, at 3 weeks, and at 3, 6, and 12 months. RESULTS: A 100% of patients completed the study at 12 months follow-up. Oral pain dissipated acutely after 3 weeks. No significant differences in either neurosensory or mouth tightness symptoms were noted, except increased incidence of cheek swelling at 3 weeks in the AlloDerm group. CONCLUSIONS: AlloDerm proved to be an effective means of closing the harvest site, but offered no significant advantages when compared with primary closure. AlloDerm closure was associated with increased morbidity in mouth tightness symptoms, cheek swelling, and discomfort while chewing food; only increased incidence of cheek swelling at 3 weeks was found to be significant. Despite its excellent molecular properties and nonimmunogenic nature, the role of AlloDerm graft use in closing the buccal mucosal harvest site appears to be an unnecessary step. Primary closure was extremely well tolerated in both short- and long-term follow-up, with minimal sequelae at 12 months.

Preliminary report on use of AlloDerm for closure of intraoral defects after buccal mucosal harvest.

The ideal method for managing the intraoral defect after harvesting buccal mucosa for urethral reconstruction has not been clearly established. We describe a novel technique using AlloDerm to cover the harvest site, providing a simple means for a potentially less painful tension-free closure.

Angiotensin receptor blockade decreases fibrosis and fibroblast expression in a rat model of unilateral ureteral obstruction.

PURPOSE: Unilateral ureteral obstruction is characterized by histopathological changes including interstitial fibrosis, fibroblast specific protein expression, tubular atrophy and apoptosis, and macrophage infiltration. Angiotensin II has been implicated in some of these changes. We examined the effect of angiotensin blockade on markers of renal injury, including fibroblast specific protein expression, fibrosis, apoptosis and macrophage infiltration. We used losartan, an angiotensin II antagonist, in a unilateral ureteral obstruction model and studied animals 3 weeks after unilateral ureteral obstruction, a time at which renal damage is well established. MATERIALS AND METHODS: Rats underwent unilateral ureteral obstruction and were given either drinking water or losartan for 21 days. Kidneys were harvested and examined for fibrosis (trichrome and the Sircol assay for collagen), apoptosis (TUNEL), and fibroblast specific protein expression and macrophage infiltration (immunohistochemistry). RESULTS: Unilateral ureteral obstruction was found to induce fibrosis, apoptosis, fibroblast expression and macrophage in the obstructed kidney. Losartan significantly decreased apoptosis and macrophage infiltration in the obstructed kidney. It also decreased fibrosis, as measured by either trichrome staining assessed by a pathologist, the Sircol assay for collagen or fibroblast specific protein expression. However, approximately 50% of the changes were not affected by the current treatment, suggesting that other factors contribute to renal damage in unilateral ureteral obstruction. CONCLUSIONS: We observed the direct contribution of angiotensin II to both apoptotic and cellular transition processes (epithelial mesenchymal transition) and fibrosis in unilateral ureteral obstruction. Because these processes are active not only in unilateral ureteral obstruction, but also in other renal diseases, the value of angiotensin II blockade as an important part of the antifibrotic armamentarium has been confirmed.