Patient-Reported Outcome Measures Following Hyperbaric Oxygen Therapy for Radiation Cystitis: Early Results From the Multicenter Registry for Hyperbaric Oxygen Therapy

PURPOSE

Our purpose was to determine changes in patient-reported hematuria and urinary symptoms after hyperbaric oxygen (HBO2) treatment for radiation cystitis (RC).

MATERIALS AND METHODS

We analyzed prospectively collected data from the Multicenter Registry for Hyperbaric Oxygen Therapy Consortium accumulated within a week of beginning and ending HBO2. Measures included the modified Radiation Therapy Oncology Group (RTOG) Hematuria Scale, Urinary Distress Inventory Short Form, and EuroQol Five Dimension Five Level instrument. RTOG hematuria and Urinary Distress Inventory Short Form scores were compared using the sign test. Logistic regression was used to evaluate characteristics associated with hematuria improvement.

RESULTS

A total of 470 registry patients had RC. The median age, number of HBO2 sessions, and years after radiation were 73 (IQR 12) years, 39 (IQR 10) sessions, and 5 (IQR 8) years, respectively. Eighty-four percent of patients (393/470) had prostate cancer‒related radiation. EuroQol Five Dimension Five Level scores improved from 0.83 (IQR 0.14) to 0.85 (IQR 0.22; P < .001. Three hundred seventy patients had complete RTOG hematuria scores that improved from 2 (IQR 2) to 0 (IQR 2; P < .001. Two hundred forty-six patients had complete Urinary Distress Inventory Short Form ratings that decreased from 33.3 (IQR 44) to 22.2 (IQR 33; P < .001). Regression analysis of those with visible hematuria before HBO2 showed lower improvement odds associated with higher HBO2 hematuria scores (odds ratio [OR] 0.44, 95% CI 0.26-0.73; P < .01), a smoking history (OR 0.44, 95% CI 0.21-0.92; P = .03), or a nonprostate cancer history (OR 0.32, 95% CI 0.10-0.99; P = .05).

CONCLUSIONS

HBO2 for RC improved reported hematuria, urinary function, and quality of life. Higher baseline hematuria scores, smoking, and nonprostate cancer history were associated with lower odds of hematuria improvement.

Management of pediatric renal trauma: Results from the American Association for Surgery and Trauma Multi-Institutional Pediatric Acute Renal Trauma Study

BACKGROUND

Pediatric renal trauma is rare and lacks sufficient population-specific data to generate evidence-based management guidelines. A nonoperative approach is preferred and has been shown to be safe. However, bleeding risk assessment and management of collecting system injury are not well understood. We introduce the Multi-institutional Pediatric Acute Renal Trauma Study (Mi-PARTS), a retrospective cohort study designed to address these questions. This article describes the demographics and contemporary management of pediatric renal trauma at Level I trauma centers in the United States.

METHODS

Retrospective data were collected at 13 participating Level I trauma centers on pediatric patients presenting with renal trauma between 2010 and 2019. Data were gathered on demographics, injury characteristics, management, and short-term outcomes. Descriptive statistics were used to report on demographics, acute management, and outcomes.

RESULTS

In total, 1,216 cases were included in this study. Of all patients, 67.2% were male, and 93.8% had a blunt injury mechanism. In addition, 29.3% had isolated renal injuries, and 65.6% were high-grade (American Association for the Surgery of Trauma Grades III-V) injuries. The mean Injury Severity Score was 20.5. Most patients were managed nonoperatively (86.4%), and 3.9% had an open surgical intervention, including 2.7% having nephrectomy. Angioembolization was performed in 0.9%. Collecting system intervention was performed in 7.9%. Overall mortality was 3.3% and was only observed in patients with multiple injuries. The rate of avoidable transfer was 28.2%.

CONCLUSION

The management and outcomes of pediatric renal trauma lack data to inform evidence-based guidelines. Nonoperative management of bleeding following renal injury is a well-established practice. Intervention for renal trauma is rare. Our findings reinforce differences from the adult population and highlights opportunities for further investigation. With data made available through Mi-PARTS, we aimed to answer pediatric specific questions, including a pediatric-specific bleeding risk nomogram, and better understanding indications for interventions for collecting system injuries.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level IV.

PROPOSED REVISION OF THE AMERICAN ASSOCIATION FOR SURGERY OF TRAUMA RENAL TRAUMA ORGAN INJURY SCALE: SECONDARY ANALYSIS OF THE MULTI-INSTITUTIONAL GENITOURINARY TRAUMA STUDY

BACKGROUND

This study updates the American Association for Surgery of Trauma (AAST) Organ Injury Scale (OIS) for renal trauma using evidence-based criteria for bleeding control intervention.

METHODS

This was a secondary analysis of a multi-center retrospective study including patients with high grade renal trauma from 7 Level-1 trauma centers from 2013-2018. All eligible patients were assigned new renal trauma grades based on revised criteria. The primary outcome used to measure injury severity was intervention for renal bleeding. Secondary outcomes included intervention for urinary extravasation, units of packed red blood cells (PRBCs) transfused within 24 hours, and mortality. To test the revised grading system, we performed mixed effect logistic regression adjusted for multiple baseline demographic and trauma covariates. We determined the area under the receiver-operator curve (AUC) to assess accuracy of predicting bleeding interventions from the revised grading system and compared this to 2018 AAST organ injury scale.

RESULTS

based on the 2018 OIS grading system, we included 549 patients with AAST Grade III-V injuries and CT scans (III: 52% (n = 284), IV: 45% (n = 249), and V: 3% (n = 16)). Among these patients, 89% experienced blunt injury (n = 491) and 12% (n = 64) underwent intervention for bleeding. After applying the revised grading criteria, 60% (n = 329) of patients were downgraded and 4% (n = 23) were upgraded; 2.8% (n = 7) downgraded from grade V to IV, and 69.5% (n = 173) downgraded from IV to III. The revised renal trauma grading system demonstrated improved predictive ability for bleeding interventions (2018 AUC = 0.805, revised AUC = 0.883; p = 0.001) and number of units of PRBCs transfused. When we removed urinary injury from the revised system, there was no difference in its predictive ability for renal hemorrhage intervention.

CONCLUSIONS

A revised renal trauma grading system better delineates the need for hemostatic interventions than the current AAST OIS renal trauma grading system.

LEVEL OF EVIDENCE

II.

Shattered Kidney After Renal Trauma: Should It Be Classified As an American Association for the Surgery of Trauma Grade V Injury?

OBJECTIVE

To study the prevalence and management of shattered kidney and to evaluate if the new description of "loss of identifiable renal anatomy" in the 2018 American Association for the Surgery of Trauma (AAST) organ injury scale (OIS) would improve the ability to predict bleeding control interventions.

METHODS

We used high-grade renal trauma data from 21 Level-1 trauma centers from 2013 to 2018. Initial CT scans were reviewed to identify shattered kidneys, defined as a kidney having ≥3 parenchymal fragments displaced by blood or fluid on cross-sectional imaging. We further categorized patients with shattered kidney in two models based on loss of identifiable renal parenchymal anatomy and presence or absence of vascular contrast extravasation (VCE). Bleeding interventions were compared between the groups.

RESULTS

From 861 high-grade renal trauma patients, 41 (4.8%) had shattered kidney injury. 25 (61%) underwent a bleeding control intervention including 18 (43.9%) nephrectomies and 11 (26.8%) angioembolizations. 18 (41%) had shattered kidney with "loss of identifiable parenchymal renal anatomy" per 2018 AAST OIS (model-1). 28 (68.3%) had concurrent VCE (model-2). Model-2 had a statistically significant improvement in area under the curve over model-1 in predicting bleeding interventions (0.75 vs 0.72; P = .01).

CONCLUSION

Shattered kidney is associated with high rates of active bleeding, urinary extravasation, and interventions including nephrectomy. The definition of shattered kidney is vague and subjective and our definition might be simpler and more reproducible. Loss of identifiable renal anatomy per the 2018 AAST OIS did not provide better distinction for bleeding control interventions over presence of VCE.

Glans Adipodermal Augmentation for Management of Neophallus Fat Atrophy After Penile Implant Insertion: Surgical Technique and Outcomes

OBJECTIVE

To describe our surgical technique and outcomes of glans augmentation with autologous adipodermal or acellular dermal matrix (ADM) interposition grafts for fat atrophy of the neophallus following penile implant insertion.

METHODS

We retrospectively reviewed the outcomes of glans augmentation in phalloplasty patients presenting with fat atrophy following penile prosthesis insertion. Glans augmentation is performed by making a small posterior coronal incision to preserve the shaft-to-glans dermal blood supply. A plane is made between the glans skin and the capsule of the distal penile implant cylinder. An adipodermal graft or ADM sheet graft is then sized to the glans dissection space and inserted, covering the implant capsule and filling the glans. The graft harvest site and posterior coronal incisions are then closed. The primary postoperative outcome was the recurrence of implant glans skin impingement or erosion.

RESULTS

From October 2017 through January 2023, 15 patients underwent glans augmentation after penile prosthesis insertion. The mean follow-up was 20 months. Adipodermal grafts were placed in 12 (80%) patients and ADM grafts in 3 (20%) patients. Two patients developed complications requiring surgical revision and 3 patients are considering a secondary glans augmentation, for a potential surgical revision rate of 33% (5/15). There were no wound infections, implant infections, or erosions.

CONCLUSION

Glans augmentation with adipodermal or ADM graft interposition between the glans skin and implant capsule improves the neophallus appearance and may help prevent future implant erosion in phalloplasty patients who develop fat atrophy after penile implant insertion.

Grade V renal trauma management: results from the multi-institutional genito-urinary trauma study

PURPOSE

To investigate management trends for American Association for the Surgery of Trauma (AAST) grade V renal trauma with focus on non-operative management.

METHODS

We used prospectively collected data as part of the Multi-institutional Genito-Urinary Trauma Study (MiGUTS). We included patients with grade V renal trauma according to the AAST Injury Scoring Scale 2018 update. All cases submitted by participating centers with radiology images available were independently reviewed to confirm renal trauma grade. Management was classified as expectant, conservative (minimally invasive, endoscopic or percutaneous procedures), or operative (renal-related surgery).

RESULTS

Eighty patients were included, 25 of whom had complete imaging and had independent confirmation of AAST grade V renal trauma. Median age was 35 years (Interquartile range (IQR) 25-50) and 23 (92%) had blunt trauma. Ten patients (40%) were managed operatively with nephrectomy. Conservative management was used in nine patients (36%) of which six received angioembolization and three had a stent or drainage tube placed. Expectant management was followed in six (24%) patients. Transfusion requirements were progressively higher with groups requiring more aggressive treatment, and injury characteristics differed significantly across management groups in terms of hematoma size and laceration size. Vascular contrast extravasation was more likely in operatively managed patients though a statistically significant association was not found.

CONCLUSION

Successful use of nonoperative management for grade V injuries is used for a substantial subset of patients. Lower transfusion requirement and less severe injury radiologic phenotype appear to be important characteristics delineating this group.

Decision making in metoidioplasty and phalloplasty gender-affirming surgery: a mixed methods study

BACKGROUND

Gender-affirming surgical procedures, such as metoidioplasty and phalloplasty for those assigned female at birth, are complex and multistaged and involve risks. Individuals considering these procedures experience greater uncertainty or decisional conflict, compounded by difficulty finding trustworthy information.

AIM

(1) To explore the factors contributing to decisional uncertainty and the needs of individuals considering metoidioplasty and phalloplasty gender-affirming surgery (MaPGAS) and (2) to inform development of a patient-centered decision aid.

METHODS

This cross-sectional study was based on mixed methods. Adult transgender men and nonbinary individuals assigned female at birth at various stages of MaPGAS decision making were recruited from 2 study sites in the United States to participate in semistructured interviews and an online gender health survey, which included measures of gender congruence, decisional conflict, urinary health, and quality of life. Trained qualitative researchers conducted all interviews with questions to explore constructs from the Ottawa decision support framework.

OUTCOMES

Outcomes included goals and priorities for MaPGAS, expectations, knowledge, and decisional needs, as well as variations in decisional conflict by surgical preference, surgical status, and sociodemographic variables.

RESULTS

We interviewed 26 participants and collected survey data from 39 (24 interviewees, 92%) at various stages of MaPGAS decision making. In surveys and interviews, affirmation of gender identity, standing to urinate, sensation, and the ability to "pass" as male emerged as highly important factors for deciding to undergo MaPGAS. A third of survey respondents reported decisional conflict. Triangulation of data from all sources revealed that conflict emerged most when trying to balance the strong desire to resolve gender dysphoria through surgical transition against the risks and unknowns in urinary and sexual function, appearance, and preservation of sensation post-MaPGAS. Insurance coverage, age, access to surgeons, and health concerns further influenced surgery preferences and timing.

CLINICAL IMPLICATIONS

The findings add to the understanding of decisional needs and priorities of those considering MaPGAS while revealing new complexities among knowledge, personal factors, and decisional uncertainty.

STRENGTHS AND LIMITATIONS

This mixed methods study was codeveloped by members of the transgender and nonbinary community and yielded important guidance for providers and individuals considering MaPGAS. The results provide rich qualitative insights for MaPGAS decision making in US contexts. Limitations include low diversity and sample size; both are being addressed in work underway.

CONCLUSIONS

This study increases understanding of the factors important to MaPGAS decision making, and results are being used to guide development of a patient-centered surgical decision aid and informed survey revision for national distribution.

Urethral outcomes in metoidioplasty and phalloplasty gender affirming surgery (MaPGAS) and vaginectomy: a systematic review

Background

There is currently a paucity of data on urethral-related outcomes in metoidioplasty and phalloplasty gender affirming surgery (MaPGAS) with urethral lengthening (UL)and vaginectomy.

Methods

A systematic review was performed utilizing MEDLINE, Web of Science, Cochrane Library, Europe PMC, OSF Preprints, and EMBASE. Methodologic quality was scored using Methodological Index for Non-Randomized Studies (MINORS) criteria. Four independent reviewers performed the article evaluation, data extraction, and methodologic quality assessment. Primary outcomes included standing to urinate/pee (STP), penile length, glanular meatus, urethral stricture, fistula, and flap necrosis. Results were summarized qualitatively with descriptive statistics.

Results

A total of 2,881 articles of which 11 retrospective reviews of 13 cohorts met criteria; 4.3/16 average (avg) MINORS score. Six metoidioplasty cohorts had an average penile length of 6 cm, 74% reported successful STP, and a quarter developed stricture or fistula. Phalloplasty cohorts included radial forearm flap (RF) and Anterolateral Thigh flap (ALT). Of the 4 RF studies nearly a third developed a stricture or fistula and only one study reported 99% STP with a glanular meatus. Three ALT studies reported no length but had 80-90% STP with a glanular meatus and a quarter with stricture or fistula.

Conclusions

Urethral complications in MaPGAS-UL in a cohort with prior vaginectomy are common and variably reported. Patient centered outcome measures as well as clearly defined outcome metrics created in partnership with community members are needed.

The Outcomes of Pelvic Fracture Urethral Injuries Stratified by Urethral Injury Severity: A Prospective Multi-institutional Genitourinary Trauma Study (MiGUTS)

OBJECTIVES

To determine patient outcomes across a range of pelvic fracture urethral injury (PFUI) severity. PFUI is a devastating consequence of a pelvic fracture. No study has stratified PFUI outcomes based on severity of the urethral distraction injury.

METHODS

Adult male patients with blunt-trauma-related PFUI were followed prospectively for a minimum of six months at 27 US medical centers from 2015-2020. Patients underwent retrograde cystourethroscopy and retrograde urethrography to determine injury severity and were categorized into three groups: (1) major urethral distraction, (2) minor urethral distraction, and (3) partial urethral injury. Major distraction vs. minor distraction was determined by the ability to pass a cystoscope retrograde into the bladder. Simple statistics summarized differences between groups. Multi-variable analyses determined odds ratios for obstruction and urethroplasty controlling for urethral injury type, age, and Injury Severity Score.

RESULTS

There were 99 patients included, 72(72%) patients had major, 13(13%) had minor, and 14(14%) had partial urethral injuries. The rate of urethral obstruction differed in patients with major (95.8%), minor (84.6%), and partial injuries (50%) (p< 0.001). Urethroplasty was performed in 90% of major, 66.7% of minor, and 35.7% of partial injuries (p<0.001).

CONCLUSIONS

In PFUI, a spectrum of severity exists that influences outcomes. While major and minor distraction injuries are associated with a higher risk of developing urethral obstruction and need for urethroplasty, up to 50% of partial PFUI will result in obstruction, and as such need to be closely followed.

Patient Risk Factors and Their Association with Patient Reported Urinary Quality of Life following Artificial Urinary Sphincter Placement: A Paired Pre-and Post-operative Analysis

OBJECTIVE

To evaluate the associations between patient risk factors and incontinence related patient-reported outcome measures (PROMs) pre-and-post artificial urinary sphincter (AUS) implantation. We hypothesize patient risk factors, including prior radiation and diabetes will have a negative association with post AUS PROMs.

METHODS

A review of prospectively collected pre-and-post-operative Incontinence Symptom Index [ISI] and Incontinence Impact Questionnaire-7 (IIQ-7)s from multiple institutions in the Trauma and Urologic Reconstruction Network of Surgeons was performed. Changes in pre-and-post AUS ISI and IIQ-7 scores were compared for the entire cohort then stratified by patients with prior AUS, obesity, diabetes, prior radiation, and mixed urinary incontinence.

RESULTS

A total of 145 patients, 67.2 (SD 10.9) years had complete pre-and-post AUS questionnaires (median follow up 186 days, IQR 136-362). Post AUS ISI and IIQ-7 scores improved significantly for the group at large. Prior radiation was associated with less improvement in total IIQ-7 scores, -25.5 (31.9) vs. -39 (33.0), p=0.03. Obesity was associated with a greater reduction in incontinence severity -13.6 (SD 9.1) vs. -9.2 (SD 8.9), P<0.01, urge -5.2(SD 4.2) vs. -2.5(SD 4.5), p <0.01, and total ISI score -29.7(SD19.7) vs. -21.2 (SD 19.9), p=0.02. Prior AUS, diabetes, and mixed incontinence were not associated with post AUS PROMs outcome.

CONCLUSION

Overall, patients reported a significant reduction in incontinence severity, bother, impact, and distress post AUS placement. Prior radiation was associated with less improvement in total IIQ-7 scores. In contrast, obesity demonstrated a greater reduction in ISI severity and urge scores compared to non-obese patients.

International Multicenter Registry for Hyperbaric Oxygen Therapy: Results through June 2021

INTRODUCTION

The International Multicenter Registry for Hyperbaric Oxygen Therapy (International Report Registered Identifier DERR1-10.2196/18857) was established in 2011 to capture outcomes and complications data for both Undersea and Hyperbaric Medical Society (UHMS) approved and selected unapproved hyperbaric oxygen (HBO2) therapy indications.

METHODS

A Research Electronic Data Capture (REDCap) template was designed and distributed to all participating centers for prospective data collection. Centers contributed de-identified demographic, treatment, complications, and outcome data. This report provides summary data on sites and enrollment, as well as pre- and post-treatment data on quality of life (EQ-5D-5L questionnaire), head and neck radiationoutcomes, non-healing wounds (Strauss score), and idiopathic sudden sensorineural hearing loss. Data were analyzed mainly using the Wilcoxon signed-rank test.

RESULTS

Twenty-two centers contributed data for 2,880 patients. The most common UHMS-approved indication was delayed radiation injury, followed by enhancement of wound healing, and carbon monoxide poisoning. One hundred and twenty-five patients were treated for non-UHMS approved indications. Quality of life, head and neck radiation symptoms, Strauss wound scores, and hearing were significantly improved after HBO2. Complication rates were low and comparable to previous reports. The registry also offered the ability to analyze factors that affect outcomes, such as smoking and severity of hearing loss.

DISCUSSION

The registry accrues prospective data on defined outcomes from multiple centers and allows for analysis of factors affecting outcomes. This registry does not have a control group, which is a limitation. Nevertheless, the registry provides a unique, comprehensive dataset on HBO2 outcomes from multiple centers internationally.

A systematic review of decision aids for gender affirming therapy

BACKGROUND

Transgender and gender diverse (TGD) persons considering gender affirming therapy have to make many complex medical decisions, potentially without understanding the associated harms or benefits of hormonal and surgical interventions. Further, clinicians are often unaware of how best to communicate information to persons seeking gender affirming therapy. Patient decision aids have been developed to provide evidence-based information as a way to help people make decisions in collaboration with their clinicians. It is unclear whether such tools exist for persons seeking gender affirming therapy. The objective of our systematic review is to search for and determine the quality of any existing patient decision aids developed for TGD persons considering gender affirming therapy, and the outcomes associated with their use.

METHODS

We adapted a search strategy for databases using two key concepts "decision support intervention/patient decision aid" and "transgender". We also conducted a brief online search of Google and abstracts from relevant conferences to identify any tools not published in the academic literature. Following study selection and data extraction, we used the International Patient Decision Aid Standards instrument (IPDASi) to assess the quality of patient decision aids, and the Standards for UNiversal reporting of patient Decision Aid Evaluations (SUNDAE) checklist to assess the quality of evaluations.

RESULTS

We identified 762 studies; none were identified from Google or conference content. One tool met our inclusion criteria: an online, pre-encounter patient decision aid for transmasculine genital gender-affirming surgery developed in Amsterdam, translated in English and Dutch. The tool met all the IPDASi qualifying criteria, and scored a 17/28 on the certification criteria, and 57/112 on the quality criteria. The efficacy of the patient decision aid has not been evaluated.

CONCLUSIONS

Despite multiple decisions required for gender affirming therapies, only one patient decision aid has been developed for transmasculine genital reconstruction. Further research is required to develop patient decision aids for the multiple decision points along the gender affirming journey.

External validation of a nomogram predicting risk of bleeding control interventions after high-grade renal trauma: The Multi-institutional Genito-Urinary Trauma Study

BACKGROUND

Renal trauma grading has a limited ability to distinguish patients who will need intervention after high-grade renal trauma (HGRT). A nomogram incorporating both clinical and radiologic factors has been previously developed to predict bleeding control interventions after HGRT. We aimed to externally validate this nomogram using multicenter data from level 1 trauma centers.

METHODS

We gathered data from seven level 1 trauma centers. Patients with available initial computed tomography (CT) scans were included. Each CT scan was reviewed by two radiologists blinded to the intervention data. Nomogram variables included trauma mechanism, hypotension/shock, concomitant injuries, vascular contrast extravasation (VCE), pararenal hematoma extension, and hematoma rim distance (HRD). Mixed-effect logistic regression was used to assess the associations between the predictors and bleeding intervention. The prediction accuracy of the nomogram was assessed using the area under the receiver operating characteristic curve and its 95% confidence interval (CI).

RESULTS

Overall, 569 HGRT patients were included for external validation. Injury mechanism was blunt in 89%. Using initial CT scans, 14% had VCE and median HRD was 1.7 (0.9-2.6) cm. Overall, 12% underwent bleeding control interventions including 34 angioembolizations and 24 nephrectomies. In the multivariable analysis, presence of VCE was associated with a threefold increase in the odds of bleeding interventions (odds ratio, 3.06; 95% CI, 1.44-6.50). Every centimeter increase in HRD was associated with 66% increase in odds of bleeding interventions. External validation of the model provided excellent discrimination in predicting bleeding interventions with an area under the curve of 0.88 (95% CI, 0.84-0.92).

CONCLUSION

Our results reinforce the importance of radiologic findings such as VCE and hematoma characteristics in predicting bleeding control interventions after renal trauma. The prediction accuracy of the proposed nomogram remains high using external data. These variables can help to better risk stratify high-grade renal injuries.

LEVEL OF EVIDENCE

Prognostic and epidemiological study, level III.

Infrapubic Insertion of Penile Implants in Transmen After Phalloplasty

OBJECTIVE

To describe the infrapubic approach to penile prosthesis insertion in transmen after phalloplasty.

MATERIALS AND METHODS

After verifying phalloplasty vascular pedicle anatomy and reliable micturition, patients may be considered for implant surgery. Specific modifications of the infrapubic approach to penile prosthesis insertion as well as individualization of commercially available implants are performed intraoperatively to help reduce the risk of postoperative complications.

RESULTS

In our single surgeon series (MLC) using the infrapubic approach with these specific implants after phalloplasty, 17/107 (16%) patients from October 2017 to November 2020 required revision surgery after mean follow-up of 79.8 weeks.

CONCLUSION

Our infrapubic prosthesis insertion after phalloplasty technique with modifications to commercially available implants may help reduce the risk of postoperative complications.

Clinical and Radiographic Factors Associated With Failed Renal Angioembolization: Results From the Multi-institutional Genitourinary Trauma Study (Mi-GUTS)

OBJECTIVE

To find clinical or radiographic factors that are associated with angioembolization failure after high-grade renal trauma.

MATERIAL AND METHODS

Patients were selected from the Multi-institutional Genito-Urinary Trauma Study. Included were patients who initially received renal angioembolization after high-grade renal trauma (AAST grades III-V). This cohort was dichotomized into successful or failed angioembolization. Angioembolization was considered a failure if angioembolization was followed by repeat angiography and/or an exploratory laparotomy.

RESULTS

A total of 67 patients underwent management initially with angioembolization, with failure in 18 (27%) patients. Those with failed angioembolization had a larger proportion ofgrade IV (72% vs 53%) and grade V (22% vs 12%) renal injuries. A total of 53 patients underwent renal angioembolization and had initial radiographic data for review, with failure in 13 cases. The failed renal angioembolization group had larger perirenal hematoma sizes on the initial trauma scan.

CONCLUSION

Angioembolization after high-grade renal trauma failed in 27% of patients. Failed angioembolization was associated with higher injury grade and a larger perirenal hematoma. Likely these characteristics are associated with high-grade renal trauma that may be less amenable to successful treatment after a single renal angioembolization.

The effect of botulinum toxin on ureteral inflammation

PURPOSE

The impact of onabotulinum toxin type A (BoNT-A) on bladder afferent nerve pathways and chemosensory functions is an active area of investigation. There may be a role for BoNT-A in disorders of the ureter; however, no histologic studies have assessed the effects of BoNT-A on ureteral tissue. Our objective was to develop an animal model of ureteral inflammation and determine the impact of ureteral BoNT-A instillation on known mechanisms of inflammation.

METHODS

The safety and feasibility of a novel animal model of ureteral inflammation was assessed. Through open cystotomy, the effect of ureteral BoNT-A instillation on inflammation was determined through H&E, masson's trichrome, Ki-67 stain, and prostaglandin E (PGE) synthase expression, a known marker of pain and inflammation in ureteral tissue. Urothelial microstructure was assessed using electron microscopy and standard histologic techniques.

RESULTS

All experiments were carried to completion, and no systemic signs of botulinum toxicity were seen. BoNT-A exposure was associated with a decrease in PGE synthase expression in a dose-dependent fashion. BoNT-A exposure was not found to impact collagen deposition or cell proliferation. Disruption of tight junctions between urothelial cells was observed under conditions of inflammation.

CONCLUSION

We describe the feasibility of a novel in vivo model of ureteral inflammation and report the first histologic study of the effects of BoNT-A on the ureter. Preliminary findings show that BoNT-A attenuates ureteral PGE synthase expression under conditions of inflammation. The application of BoNT-A may provide anti-inflammatory and analgesic effects in the context of ureteral disorders.

High grade renal trauma management: a survey of practice patterns and the perceived need for a prospective management trial

Background

To evaluate the current practice patterns of practitioners managing high grade renal trauma and determine perceived need for a prospective trial on the management of renal trauma.

Methods

We distributed an electronic survey to members of the American Association for the Surgery of Trauma (AAST) and The Society of Genitourinary Reconstructive Surgeons (GURS). The survey evaluated demographics, interventional radiology (IR) access, and renal trauma management. Descriptive statistics were utilized to analyze participants' responses.

Results

A total of 253 practitioners responded (age 48.4±10.4 years). The majority were acute care/trauma surgeons (ACS/TS) (63.2%), followed by urologists (34.4%) practicing at level 1 trauma centers (80.6%) in 39 US states. Most participants were in practice >10 years (62.8%); and had completed an ACS/TS (53.8%), or trauma/reconstructive urology (25.7%) fellowship. Ninety-five percent (241/253) found value in renal preservation with 74% utilizing IR embolization in the last year. However, there was wide variation in threshold for angiography, low rates of renal repair (24%) or packing (20%) and half reported performing a nephrectomy within the prior year. More than 80% believed there was value in a prospective trial to evaluate a protocol to decrease nephrectomy rates in renal trauma management.

Conclusions

The majority of respondents had access to IR, reported comfort in renorrhaphy, and valued renal preservation. There was variation in thresholds for bleeding intervention, and nephrectomy was still a common management strategy. There is great interest among trauma surgeons and urologists for a prospective trial of renal trauma management aimed at decreasing nephrectomy when possible.

Erectile dysfunction management after failed phosphodiesterase-5-inhibitor trial: a cost-effectiveness analysis

BACKGROUND

To evaluate the cost-effectiveness of alternate erectile dysfunction (ED) management options after failed first line phosphodiesterase-5-inhibitors (PDE5-I).

METHODS

An empiric, repetitive decision tree analysis model was constructed using literature review and expert clinical judgement. This assessed the expected costs and quality adjusted life years (QALYs) of decision alternatives over a 10-year period. The model incorporated interventions including alternate PDE5-Is, intracorporal injections (ICI) with alprostadil or trimix (alprostadil, phentolamine, and papaverine), and inflatable penile prosthesis placement (IPP) and included respective risks of failure, subsequent interventions, and other complications (including priapism risk). Average model QALY estimates obtained from the literature were as follows: ED =0.56, successful alternate PDE5-I =0.70, successful ICI =0.70, and successful IPP =0.78. Cost data were calculated from a high-volume academic center and published manufacturer data.

RESULTS

Over the 10-year period, IPP placement was the most cost-effective management option per preserved QALY (QALY =7.82, cost =$22,009/10 years) as compared to ICI alprostadil (QALY =8.51, cost =$62,890/10 years), ICI trimix (QALY =8.47, cost =$48,617/10 years) and alternate PDE5-I (QALY =7.73, $52,883/10 years).

CONCLUSIONS

Using expert opinion and published utility, cost, and complication data in a decision analysis, we demonstrated that IPP placement is the most cost-effective ED intervention following failed initial PDE5-I over a 10-year period as compared to alternate treatment options. Such cost-effectiveness outcomes may be used in ED management counseling.

Multicenter analysis of posterior urethroplasty complexity and outcomes following pelvic fracture urethral injury

PURPOSE

To analyze outcomes of posterior urethroplasty following pelvic fracture urethral injuries (PFUI) and to determine risk factors for surgical complexity and success.

METHODS

Patients who underwent posterior urethroplasty following PFUI were identified in the Trauma and Urologic Reconstructive Network of Surgeons (TURNS) database. Demographics, injury patterns, management strategies, and prior interventions were evaluated. Risk factors for surgical failure and the impact of ancillary urethral lengthening maneuvers (corporal splitting, pubectomy and supracrural rerouting) were evaluated.

RESULTS

Of the 436 posterior urethroplasties identified, 122 were following PFUI. 83 (68%) patients were acutely managed with suprapubic tubes, while 39 (32%) underwent early endoscopic realignment. 16 (13%) patients underwent pelvic artery embolization in the acute setting. 116 cases (95%) were completed via a perineal approach, while 6 (5%) were performed via an abdominoperineal approach. The need for one or more ancillary maneuvers to gain urethral length occurred in 4 (36%) patients. Of these, 44 (36%) received corporal splitting, 16 (13%) partial or complete pubectomy, and 2 (2%) supracrural rerouting. Younger patients, those with longer distraction defects, and those with a history of angioembolization were more likely to require ancillary maneuvers. 111 patients (91%) did not require repeat intervention during follow-up. Angioembolization (p = 0.03) and longer distraction defects (p = 0.01) were associated with failure.

CONCLUSIONS

Posterior urethroplasty provides excellent success rates for patients following PFUI. Pelvic angioembolization and increased defect length are associated with increased surgical complexity and risk of failure. Surgeons should be prepared to implement ancillary maneuvers when indicated to achieve a tension-free anastomosis.

Clinical significance of cystoscopic urethral stricture recurrence after anterior urethroplasty: a multi-institution analysis from Trauma and Urologic Reconstructive Network of Surgeons (TURNS)

PURPOSE

To assess the functional Queryoutcome of patients with cystoscopic recurrence of stricture post-urethroplasty and to evaluate the role of cystoscopy as initial screening tool to predict future failure.

METHODS

Cases with cystoscopy data after anterior urethroplasty in a multi-institutional database were retrospectively studied. Based on cystoscopic evaluation, performed within 3-months post-urethroplasty, patients were categorized as small-caliber (SC) stricture recurrence: stricture unable to be passed by standard cystoscope, large-caliber (LC) stricture accommodating a cystoscope, and no recurrence. We assessed the cumulative probability of intervention and the quality of life scores in association with cystoscopic recurrence 1-year post-urethroplasty. Patients with history of hypospadias, perineal urethrostomy, urethral fistula, and meatal pathology were excluded.

RESULTS

From a total of 2630 men in our cohort, 1054 patients met the inclusion criteria: normal (n = 740), LC recurrence (n = 178), and SC recurrence (n = 136) based on the first cystoscopic evaluation performed at median 111 days postoperatively. Median follow-up was 350 days (IQR 121-617) after urethroplasty. Cystoscopic recurrence was significantly associated with secondary interventions (2.7%, 6.2%, 33.8% in normal, LC, and SC groups, respectively). Quality of life variables were not statistically significantly different among the three study groups.

CONCLUSIONS

Many patients with cystoscopic recurrence do not need an intervention after initial urethroplasty. Despite good negative predictive value, cystoscopy alone may be a poor screening test for stricture recurrence defined by patient symptoms and need for secondary interventions.

"Allergic-like" reaction risk in patients undergoing non-intravenous contrast urography

INTRODUCTION

Though widely performed, the safety of non-intravenous contrast (NIVC) urography in patients with documented intravenous, iodinated contrast allergic like reactions (ICA) is unclear. The purpose of this study was to determine the risk of "allergic-like" reaction (ALR) events in patients with ICA undergoing NIVC urography.

MATERIALS AND METHODS

Patients undergoing contrast urography at a single institution were identified between 2011-2014. Patient charts were reviewed for documented ICA prior to index surgery, preoperative allergy prophylaxis with steroid or antihistamine, and acute allergic reactions identified by ICD codes within 24 hours of surgery.

RESULTS

A total of 2,650 patients were included, 1,325 female (50%). Of these patients, 113 (4.2%) had an ICA. Overall 33% (37/113) of patient received preoperative allergy prophylaxis with a steroid or antihistamine. A potential ALR related ICD-9 code was identified in one patient (0.8%) with a prior IVC ALR without allergy prophylaxis within 24 hours preoperatively undergoing percutaneous nephrolithotomy (PCNL). This event was found to be an associated with a myocardial infarction and lacked ALR sequelae.

CONCLUSION

Despite commonly voiced concerns, in this large series of over 2,500 patients, including 113 patients with a prior history of ICA undergoing contrast urography, only one patient was found to have a potential ALR event following PCNL. No patients undergoing a retrograde contrast urography with prior, documented ICA had a NIVC ALR event despite a low rate of pretreatment with corticosteroid or antihistamine.

Urethral Trauma Following Pelvic Fracture From Horseback Saddle Horn Injury Versus Other Mechanisms of Pelvic Trauma

OBJECTIVE

To examine the rate of urethral trauma and pubic symphysis diastasis in saddle horn injury, which occurs when horseback riders are bucked into the air and land with their perineum striking the rigid saddle horn, compared to pelvic fracture from other mechanisms.

METHODS

A retrospective review was performed of male patients presenting to our level-1 trauma center with pelvic ring fractures between January 1, 2001 and December 30, 2016. Demographics, injury severity score, mechanism of injury (saddle horn vs other), pubic symphysis diastasis, and lower genitourinary (GU) injuries (bladder and urethra) were identified in the trauma registry. Chart review confirmed accuracy of lower GU trauma.

RESULTS

A total of 1195 males presented with pelvic ring fractures, average age 43 years (SD 19 years). Of these, 87 of 1195 (7%) presented with lower GU injuries. Saddle horn injuries had a higher rate of lower GU injuries, 12/60 (20%) versus 75 of 1135 (7%) [P = .001]. In those with lower GU injuries, 47 of 87 (54%) had urethral injury. The rate of urethral injury was significantly higher in the saddle horn cohort, 10 of 12 (83%) versus 37 of 75 (49%) [P = .03]. Furthermore, rate of pubic symphysis diastasis was higher amongst saddle horn injuries, 12 of 12 (100%) versus other mechanisms 39 of 75 (52%) [P = .001].

CONCLUSION

We found that urethral injury and pubic symphysis diastasis were higher in patients with saddle horn injury compared to other mechanisms of pelvic ring disruption. Clinicians should be aware of these associations when treating pelvic fracture following equestrian injuries.

An American Association for the Surgery of Trauma (AAST) prospective multi-center research protocol: outcomes of urethral realignment versus suprapubic cystostomy after pelvic fracture urethral injury

Background

Pelvic fracture urethral injuries (PFUI) occur in up to 10% of pelvic fractures. It remains controversial whether initial primary urethral realignment (PR) after PFUI decreases the incidence of urethral obstruction and the need for subsequent urethral procedures. We present methodology for a prospective cohort study analyzing the outcomes of PR versus suprapubic cystostomy tube (SPT) after PFUI.

Methods

A prospective cohort trial was designed to compare outcomes between PR (group 1) and SPT placement (group 2). Centers are assigned to a group upon entry into the study. All patients will undergo retrograde attempted catheter placement; if this fails a cystoscopy exam is done to confirm a complete urethral disruption and attempt at gentle retrograde catheter placement. If catheter placement fails, group 1 will undergo urethral realignment and group 2 will undergo SPT. The primary outcome measure will be the rate of urethral obstruction preventing atraumatic passage of a flexible cystoscope. Secondary outcome measures include: subsequent urethral interventions, post-injury complications, urethroplasty complexity, erectile dysfunction (ED) and urinary incontinence rates.

Results

Prior studies demonstrate PR is associated with a 15% to 50% reduction in urethral obstruction. Ninety-six men (48 per treatment group) are required to detect a 15% treatment effect (80% power, 0.05 significance level, 20% loss to follow up/death rate). Busy trauma centers treat complete PFUI approximately 1–6 times per year, thus our goal is to recruit 25 trauma centers and enroll patients for 3 years with a goal of 100 or more total patients with complete urethral disruption.

Conclusions

The proposed prospective multi-institutional cohort study should determine the utility of acute urethral realignment after PFUI.

Validation of Using Claims Data to Measure Safety of Lumbar Fusion Surgery

STUDY DESIGN

Retrospective analysis of patients undergoing elective lumbar fusion operations, comparing rates of repeat spine surgery based on method of ascertainment.

OBJECTIVE

We report the accuracy of a claims-based approach for reporting repeat surgery compared with medical records abstraction as the "gold standard."

SUMMARY OF BACKGROUND DATA

Previous studies have reported the validity of a claims-based algorithm for grouping patients by surgical indication and classifying operative features, but their accuracy in measuring surgical quality indicators has not been widely examined.

METHODS

We identified a subset of patients undergoing elective lumbar fusion operations at a single institution from 1996 to 2011, excluding those with spinal fracture, spinal cord injury, or cancer. From the medical record we abstracted the incidence of repeat spine operation or rehospitalization at 1 year. We cross-classified each event record with its corresponding value derived from claims. The sensitivity and specificity of the claims-based approach were calculated for reoperation within 30, 90, and 365 days, and all-cause hospital readmission within 30 days.

RESULTS

Medical records linked to claims data were obtained for 520 patients undergoing elective lumbar fusion. Reoperation rates based on chart review were 1.0%, 1.3%, 3.6%, compared with 0.8%, 1.7%, and 3.8% based on the final claims methods at 30, 90, and 365 days, respectively. The claims-based algorithm had sensitivities of 80.0%, 100%, and 94.1% and specificities of 100%, 99.6%, 99.2% for repeat surgery within 30, 90, and 365 days, respectively. The sensitivity for all-cause readmission was 50%.

CONCLUSION

Health care quality improvement efforts often rely on administrative data to report surgical safety. We found that claims-based ascertainment of safety at a single institution was very accurate. However, accuracy depended on careful attention to the timing of outcomes, as well as the definitions and coding of repeat surgery, including how orthopedic device removal codes are classified.

LEVEL OF EVIDENCE

3.

What factors are associated with unplanned return following transurethral resection of bladder tumor? An analysis of a large single institution's experience

OBJECTIVE

This study sought to evaluate factors associated with unplanned hospital return (UR) following transurethral resection of bladder tumor (TURBT), the largest source of readmission among ambulatory urological procedures.

MATERIALS AND METHODS

A retrospective review of TURBTs at a single academic institution between April 2011 and August 2014 was performed. Demographics, comorbidities, length of stay, tumor size and multiple other factors were recorded. UR was recorded within 30 days of surgery. Bivariate and multivariable analyses were performed to determine factors associated with UR.

RESULTS

Among 708 patients undergoing TURBT, 23.9% were female with a mean age of 70 years. The rate of UR was 10.9%. The most common cause of UR was gross hematuria, accounting for 70%. On bivariate analysis, Foley catheter placement in the operating room, non-aspirin anticoagulation and index length of stay longer than 24 h were associated with hematuria-related UR (p < 0.05). Preoperative antibiotics, female gender and aspirin therapy were associated with lower rates of hematuria-related UR (p < 0.05), while tumor size, distance of residence to the hospital, and Foley on hospital discharge (rather than from the operating room) had no association (p > 0.05). On multivariable analysis, only Foley placement in the operating room remained associated with higher rates of hematuria-related UR, while preoperative antibiotics, female gender and aspirin therapy remained associated with a lower likelihood of this event.

CONCLUSIONS

UR following TURBT is common and typically results from gross hematuria. Patients with postoperative Foley catheterization in the operating room may require additional counseling or supervision before discharge, and should be considered for discharge with a Foley rather than having a prompt voiding trial.

Unplanned Hospital Return for Infection following Ureteroscopy-Can We Identify Modifiable Risk Factors?

PURPOSE

Genitourinary infection after ureteroscopy with laser lithotripsy is a clinically significant event that may lead to expensive and morbid return to the hospital. We evaluate factors associated with infection after ureteroscopy with laser lithotripsy leading to unplanned hospital return.

MATERIALS AND METHODS

We performed a retrospective chart review evaluating all ureteroscopy with laser lithotripsy performed at a single academic institution from April 2011 to August 2014. Data were extracted including patient demographics, comorbidities, surgical encounter characteristics, preoperative urine culture status, antibiotic type/duration and compliance with the AUA Best Practice Statement for antibiotic prophylaxis. Bivariate and multivariate analyses were performed to determine factors associated with unplanned return to the hospital.

RESULTS

Among 550 patients undergoing ureteroscopy with laser lithotripsy 45% (248) were female with an average age of 56.8 (± 14.8) years. Overall 3.4% (19 patients) had an unplanned return for genitourinary infection, with most (78.9%, 15 of 19) requiring inpatient readmission. Overall compliance with AUA Best Practice Statement for antibiotic prophylaxis was 48.7% (268 of 550). Rates of infection related returns were higher in patients undergoing preoperative stenting (84.2% vs 58.6%, p=0.025), those with an operative time greater than 120 minutes (89.5% vs 32.6% p <0.001) and those for whom there was AUA Best Practice Statement compliance for antibiotic prophylaxis (78.9% vs 47.6%, p=0.007). These factors remained significant on multivariate analysis (p <0.05).

CONCLUSIONS

Preoperative stenting and longer operative time were associated with a greater likelihood of serious genitourinary infection after ureteroscopy with laser lithotripsy. These patients may warrant additional antibiotic prophylaxis but further research is needed to answer this question more definitively. Interestingly the AUA Best Practice Statement compliance for antibiotic prophylaxis was also associated with a higher risk of infection, underscoring the need for locally appropriate prophylaxis strategies and further study of optimal prophylaxis regimens.

Is the sedimentation sign associated with spinal stenosis surgical treatment effect in SPORT?

STUDY DESIGN

Subgroup analysis of the lumbar spinal stenosis (LSS) without degenerative spondylolisthesis diagnostic cohort of the Spine Patient Outcomes Research Trial multicenter randomized clinical trial with a concurrent observational cohort.

OBJECTIVE

To determine if sedimentation sign on magnetic resonance image can help with LSS treatment decisions.

SUMMARY OF BACKGROUND DATA

LSS is one of the most common reasons for surgery in the US elderly, but there is a dearth of reliable diagnostic tools that give a clear indication for surgery. Recent studies have suggested that positive sedimentation sign on magnetic resonance image may be a possible prognostic indicator.

METHODS

All patients with LSS in both the randomized and observational cohorts had imaging-confirmed stenosis, were surgical candidates, and had neurogenic claudication for at least 12 weeks prior to enrollment. Patients were categorized as "mild," "moderate," or "severe" according to stenosis severity. Of the 654 patients with LSS enrolled in Spine Patient Outcomes Research Trial, complete T2-weighted axial and sagittal digitized images of 115 patients were available for retrospective review. An independent orthopedic spine surgeon evaluated these deidentified Digital Imaging and Communications in Medicine files for the sedimentation sign.

RESULTS

Sixty-six percent (76/115) of patients were found to have a positive sedimentation sign. Those with a positive sedimentation sign were more likely to have stenosis at L2-L3 (33% vs. 10% P=0.016) or L3-L4 76% vs. 51%, P=0.012), and to have severe (72% vs. 33%, P<0.0001) central stenosis (93% vs. 67% P<0.001) at 2 or more concurrent levels (57% vs. 18%, P=0.01). In multivariate models, the surgical treatment effect was significantly larger in the positive sedimentation sign group for Oswestry Disability Index (-16 vs. -7; P=0.02).

CONCLUSION

A positive sedimentation sign was associated with a small but significantly greater surgical treatment effect for Oswestry Disability Index in patients with symptomatic LSS, after adjusting for other demographic and imaging features. These findings suggest that positive sedimentation sign may potentially be a useful adjunct to help guide an informed treatment choice regarding surgery for LSS.

LEVEL OF EVIDENCE

2.

The natural history of nonobstructing asymptomatic renal stones managed with active surveillance

PURPOSE

We documented the natural history of asymptomatic nonobstructing renal calculi managed with active surveillance and explored factors predicting stone related events to better inform shared decision making.

MATERIALS AND METHODS

Patients with asymptomatic nonobstructing renal calculi electing active surveillance of their stone(s) were retrospectively reviewed. Stone characteristics, patient characteristics, and stone related events were collected. We evaluated the effects of stone size and location on development of symptoms, spontaneous passage, requirement for surgical intervention, and stone growth.

RESULTS

We identified 160 stones with an average size of 7.0 ± 4.2 mm among 110 patients with average followup of 41 ± 19 months. Forty-five (28% of total) stones caused symptoms during followup. Notably 3 stones (3% of asymptomatic subgroup, 2% of total stones) caused painless silent obstruction necessitating intervention after an average of 37 ± 17 months. The only significant predictor of spontaneous passage or symptom development was location. Upper pole/mid renal stones were more likely than lower pole stones to become symptomatic (40.6% vs 24.3%, p = 0.047) and to pass spontaneously (14.5% vs 2.9%, p = 0.016).

CONCLUSIONS

Among asymptomatic nonobstructing renal calculi managed with active surveillance, most remained asymptomatic through an average followup of more than 3 years. Less than 30% caused renal colic, less than 20% were operated on for pain and 7% spontaneously passed. Lower poles stones were significantly less likely to cause symptoms or pass spontaneously. Despite 3 stones causing silent hydronephrosis suggestive of obstruction, regular followup imaging facilitated interventions that prevented renal loss.

Failing to follow up: predicting patients that will "no-show" for medically advised imaging following endourologic stone surgery

INTRODUCTION

The purpose of this study is to evaluate predictors of poor compliance after treatment of urinary stone disease.

MATERIALS AND METHODS

This study was a retrospective analysis of patients who underwent stent removal following percutaneous nephrolithotomy (PCNL) or ureteroscopy (URS) between 2008-2012. All patients were scheduled for follow up evaluation and renal ultrasound at 4-6 weeks following stent removal. Patients were stratified based on appointment compliance and demographic variables including gender, age, insurance type (Government Assisted Insurance [GAI] or Private Insurance [PI]), initial procedure, season, distance between home and clinic, average monthly gas price at follow up, and median education attainment. Logistic regression was performed to determine independent predictors of missed follow up.

RESULTS

A total of 301 patients were included, 153 women (51% female) with a mean age of 54 ± 14.2 years. Of the cohort, 22.6% (n = 68) did not return for follow up. GAI was the only variable associated with a greater risk of non-compliance on univariate analysis (OR 2.13 [95% CI 1.12-3.86] p = 0.011) and multivariate analysis (OR 3.14.10 [95% CI 1.48-6.7], p < 0.01). Gender, age, procedure, season, distance, gas prices, and education were not significant predictors.

CONCLUSION

In our study, evaluating characteristics associated with missed follow up after stent removal for PCNL and URS, possession of GAI was the only factor associated with non-compliance. Urologists should be aware that persons with GAI may be at increased risk of missed follow up and should use this information to target interventions to improve compliance.

Colosplenic fistula: a highly unusual colonic fistula

Internal fistulization of the colon to other organs, such as the urinary bladder, vagina, or small bowel is a relatively common complication associated with inflammatory diseases such as diverticulitis, Crohn disease, as well as neoplasia such as colorectal cancer or lymphoma. However, fistulization of the colon to the spleen is an exceedingly rare condition described by few in the literature.

Bonding Corneal Tissue: Applications of Photoactivated Diazopyruvoyl Cross-linking Agent

Photoactivated bis-diazopyruvamide-N,N'-bis(3-diazopyruvoyl)-2,2'-(ethylenedioxy)bis-(ethylamine), (DPD)-was previously shown to bond materials containing type I collagen. However, tensile strength of bonded collagenous tissue ( approximately 78% water) was low compared with that of dehydrated collagenous gelatin ( approximately 14% water). Here we investigated the role of water in corneal tissue bond strength and in bonding corneal tissue to glass. Bonding corneal tissue to glass may be of value in surgically anchoring keratoprostheses to corneas to alleviate problems with extrusion. Bovine corneal samples were lyophilized for various times resulting in tissue hydrations of zero (no water content) to approximately 3.7 (normal water content). The lyophilized corneal tissue was bonded to solid gelatin sheets, to other corneal samples and to glass using 0.3M DPD in chloroform. Control runs used chloroform only. Samples were irradiated with 100 or 200 J of 320-500 nm light. Strong bonds formed with all three materials when corneal tissue hydration was </=1. No bonds or extremely weak bonds formed when tissue hydration levels were >1. No bonding occurred with chloroform alone. Formation of strong bonds only occurs with hydration levels </=1 because corneal collagen fibrils are tightly packed and close enough to cross-link with the 1.78 nm long DPD.

Host preferences and temporal trends of the tick Ixodes angustus in north-central Alberta

We examined host preferences and temporal trends of the tick Ixodes angustus on small mammals in north-central Alberta. Small mammals were live-trapped from 1 June to 29 September 1994 and 3 May to 30 June 1995 in mature aspen (Populus tremuloides) forest near Lac La Biche, Alberta. Abundance of female I. angustus was high in early May (0.90 +/- 0.20 [SE]) and peaked again in late June (0.58 +/- 0.16), whereas abundance of immature I. angustus peaked (1.2 +/- 0.35) in mid-July. Red-backed voles (Clethrionomys gapperi) and deer mice (Peromyscus maniculatus) were the most common host species encountered, and tick abundance (number of ticks per animal examined) on these hosts was strongly influenced by species and sex. Clethrionomys gapperi had higher tick abundance (0.73 +/- 0.07) than did P. maniculatus (0.04 +/- 0.01), and ticks were more abundant on large male C. gapperi (0.97 +/- 0.14) than they were on large female C. gapperi (0.36 +/- 0.08; P = 0.0007). Characteristics of each species and sex of host in relation to susceptibility to parasitism are discussed.

Sex-biased mortality in woodrats occurs in the absence of parental intervention

Male-biased mortality in young animals is often viewed as adaptive discrimination against male offspring by parents unable to raise reproductively competitive sons. Unequivocal evidence of the presence or absence of parental discrimination against males is lacking, however, and the adaptive interpretation of male-biased mortality is confounded by an alternative explanation that it reflects differential energetic requirements between the sexes (due to sexual selection for large size in mature males) independent of parental manipulation. To determine whether maternal discrimination against offspring explains postnatal mortality in a sexually dimorphic rodent, we examined patterns of growth and mortality in offspring of food-restricted and food-enriched lactating bushy-tailed woodrats, Neotoma cinerea. We also monitored mothers and their litters daily throughout lactation for evidence of maternal discrimination against offspring. Offspring of food-restricted mothers showed depressed growth, and mortality of offspring born to both food-restricted and food-enriched mothers was male-biased, but in the absence of maternal discrimination. Offspring that died were no less likely to be attached to their mother's teats in the 10 days prior to death than were offspring that successfully weaned. Similarly, offspring of food-restricted mothers were attached as often as were offspring of food-enriched mothers. In a series of behavioural arena trials in the first 10 days after birth, restricted mothers were no less attentive toward their sons than they were to their daughters, nor did mothers treat their offspring that did not survive to weaning differently from those that survived. Our findings provide empirical evidence that postnatal, sex-biased mortality in offspring is not necessarily due to parental intervention, and they call into question the adaptive interpretations of previous examples of sex-biased offspring mortality. Copyright 1998 The Association for the Study of Animal Behaviour Copyright 1998 The Association for the Study of Animal Behaviour.

Pilocarpine-induced movement of the trabecular mesh

From geometrical considerations of the trabecular meshwork, ciliary muscle contraction has been predicted to produce an inward movement of the mesh. Goniophotographs taken under carefully controlled conditions before and after topical administration of pilocarpine showed a change in angle between cornea and mesh that is consistent with the predicted change.

The effect of iloprost on the rabbit eye

Some prostaglandins, topically applied, are known to lower intraocular pressure; a few have been shown to increase facility of outflow. Iloprost (ZK36374), a stable PGI2 analog, was tested in rabbits for effect on intraocular pressure and facility, but was found totally inactive on either.

Mechanism of glaucoma secondary to increased venous pressure

Model experiments and mathematical analysis of intraocular pressure and blood flow show that as venous pressure is increased there is a rapidly increasing tendency for intraocular veins to collapse. Vein collapse slows blood flow markedly. We propose that the visual field loss in glaucoma secondary to elevated venous pressure is associated with intraocular vein collapse and retardation of intraocular blood flow.

Short-term re-epithelialization of the alkali-burned rabbit cornea

Pfister and associates have shown that treatment with citrate solution reduces the incidence of stromal ulceration after alkali burn of the cornea. In the course of study of the effect of inhibitors of plasminogen activation on corneal re-epithelialization following alkali burns, we noted that when citrate was used in the medication, the healing process proceeded rapidly for three days; however, the denuded area became abruptly larger on the fourth day, and then resumed healing on the fifth day.

Perfusion outflow facility in the rabbit eye. Stabilization by EACA

The time-dependent increase in apparent facility of outflow (washout effect) that occurs with prolonged perfusion of the eye has imposed limitations on the study of aqueous humor dynamics. The washout effect in postmortem in situ rabbit eyes, undergoing constant pressure perfusion with a saline perfusate, can be attenuated dramatically by adding to the perfusate the serine protease inhibitor and antifibrinolytic agent epsilon-aminocaproic acid (EACA) at a concentration of 3.8 X 10(-3) molar. Washout curves from 13 pairs of rabbit eyes, plotted as outflow facility versus time, were fitted by linear regression, and their washout slopes calculated. The washout slope of all of the 13 eyes perfused with normal saline + EACA was lower in magnitude (less washout) than the paired control eye in the same animal, perfused with a control perfusate of normal saline + leucine. Wilcoxon signed rank test yielded P less than 0.001. This suggests that a significant component of the washout effect may be mediated by fibrinolytic activity, or by some EACA sensitive component of the aqueous drainage pathway, and that addition of EACA to a saline perfusate may be useful for blunting the washout effect in prolonged perfusion studies.

Proptosis and increase of intraocular pressure in voluntary lid fissure widening

The eyeball proptoses about 0.5 mM and increases in intraocular pressure (IOP) about 2 mmHg with voluntary widening of the lid fissure. The findings probably result from the retraction of the upper lid into the orbit, thus increasing the volume of orbit contents and forcing the eyeball forward. Decrease in IOP with repeated tonometry may result, in part, from decay of the increased pressure induced by lid fissure widening.

Intraocular blood flow from analysis of angiograms

A method of analysing fluorescein angiograms that yields a parameter of intraocular blood flow designated as the fluorescein appearance rate is presented. The appearance rate was decreased in those eyes in which intraocular pressure (Pi) was found to be increased. The appearance rate was also decreased in the two cases of "low tension glaucoma" whose angiograms we have analysed. The decrease in appearance rate with increase of Pi is the result of increasing vascular flow resistance due to constriction of veins at their exit from the eye.

Instantaneous tonometry

Respiration and arterial pulse cause intraocular pressure to cyclically vary around a mean pressure. Both the respiratory and arterial pulse waves approximate sine waves, and we have represented the IOP cycle as the sum of sinusoidal pressure waves. A rapidly acting tonometer may record any portion of the IOP cycle. We have computed the probability that a single pressure measurement will lie within a given interval around mean IOP and the probability that the mean of several such measurements will lie within a given range of mean pressure. The probability that an IOP estimate will lie in a given range of mean IOP decreases as the IOP cycle amplitude increases but increases as the number of tonometric measurements averaged together increases.

The effect of lens depression on the components of outflow resistance

The effect of lens depression on resistance to flow through the inner wall of Schlemm's canal, circumferentially along the canal, and through the collector channels was measured in enucleated eyes. In one series of experiments the anterior chamber was perfused while canal pressure was monitored, thus allowing us to estimate inner wall resistance and a combination of canal plus collector-channel resistance. In a second series of experiments the inner canal wall was blocked with oil while the canal was perfused, allowing us to measure both circumferential flow resistance and collector-channel resistance. Lens depression decreased inner canal wall resistance in five of five eyes and decreased circumferential flow plus collector-channel resistance in one of eight eyes. These results suggest that tensing the trabecular mesh increases canal inner wall porosity and opens the canal when it is partially collapsed.

The conventional outflow resistances

The concept of the conventional aqueous outflow pathway (through the trabecular meshwork and other components of the canal's inner wall, along Schlemm's canal to collector channels, and out of the eye through the collector channels) was modeled on tubes with leaky walls and a network of electrical resistances. Analysis of these models suggested experiments to test the models and to assess the magnitude of the resistance of portions of the pathway. We found that the well-known increase in outflow resistance with increased intraocular pressure was, in large measure, the result of blockage of the collector channels, probably by the canal's inner wall. A model of the trabecular meshwork predicted that tension on the scleral spur and trabecular mesh would cause the meshwork to arch over Schlemm's canal. We depressed the lens to generate such tension, and found that the resistance of the inner wall of the canal decreased. In one eye, lens depression also decreased resistance to flow in the collector channels and the canal of Schlemm and prompted the suggestion that when secretory inhibitors are used in glaucoma, cyclo-tonic agents should be used simultaneously to relieve canal collapse and blockage of collector channels by inner canal wall.