Outcomes of externalized pyeloureteral versus internal ureteral stent in pediatric robotic-assisted laparoscopic pyeloplasty.

INTRODUCTION: After pyeloplasty, urinary drainage options include internal double-J (DJ) ureteral stents or externalized pyeloureteral (EPU) stents, which can avoid bladder symptoms and additional anesthetic exposure from stent removal. Comparative outcome studies, however, are lacking following primary pediatric robotic-assisted laparoscopic pyeloplasty (RALP). OBJECTIVE: To compare operative success, operative time, hospitalization, and postoperative complications of EPU versus DJ stents following RALP. STUDY DESIGN: Consecutive children undergoing primary RALP from 10/2013 to 9/2015 were retrospectively identified. Data collected included patient demographics, stent type and duration, postoperative complications, and operative success. To control for confounding by indication for EPU stent, propensity score weighting was used to balance baseline covariates. Weighted regression analyses compared between-group differences in study outcomes. RESULTS: At median follow-up of 12.3 months, 44 and 17 patients underwent DJ and EPU stenting, respectively. At baseline, DJ stent patients were older than EPU stent patients (median 7.7 vs 1.2 years, P = 0.01) and were less likely to be on postoperative antibiotic prophylaxis (25 vs 76%, P < 0.001). After weighting, these differences disappeared. All EPU stents were removed in the outpatient clinic; all DJ stents were removed under anesthesia. On weighted regression analyses (Summary Fig.), EPU stents had no different associations than DJ stents with operative success (95 vs 94%, between-group difference 1%, 95% CI -11, 13; P = 0.86), complications, or operative time, but did have 0.6 of a day more hospitalization (95% CI 0.04, 1.2; P = 0.04). DISCUSSION: Patients receiving EPU stents were different at baseline from those receiving DJ stents. After propensity score weighting balanced these covariates, EPU stents were associated with similar operative success, complications, and operative time to DJ stents. Further study is warranted in larger prospective cohorts. CONCLUSION: Use of EPU stents provided a viable alternative, particularly in younger patients, to DJ stenting with comparable success and complications, while avoiding the need for an additional anesthetic.

Tunica vaginalis flap for salvaging testicular torsion: A matched cohort analysis.

INTRODUCTION: In testicular torsion, ischemia time from pain onset impacts testicular salvage. A tunica albuginea fasciotomy to relieve compartment pressure followed by a tunica vaginalis flap (TVF) may enhance salvage. OBJECTIVE: To define the optimal window of ischemia time during which TVF may be most beneficial to avoid orchiectomy. STUDY DESIGN: A retrospective cohort study of males presenting with testicular torsion at a single tertiary-care institution from January, 2003 to March, 2017. Ischemia time was defined as duration of pain from onset to surgery. Because TVF would be an option to orchiectomy, and it was found that ischemia time was longer in testicles that underwent orchiectomy, matching was performed. Cases of torsion treated with TVF were matched 1:1 with cases treated with orchiectomy on age at surgery, and ischemia time. Outcomes included postoperative viability, defined as palpable testicular tissue with normal consistency, and atrophy, defined as palpable decrease in size relative to contralateral testicle. Sensitivity analyses were performed restricting to the subgroups with postoperative ultrasound, >6 months' follow-up, and additionally matching for degrees of twist. RESULTS: A total of 182 patients met eligibility criteria, of whom 49, 36, and 97 underwent orchiectomy, TVF, and septopexy alone, respectively. Median follow-up was 2.7 months; 26% of patients had postoperative ultrasound (61% of TVF group). In the orchiectomy, TVF, and septopexy groups, respectively, median ischemia times were 51, 11, and 8 h, postoperative viability rates were 0, 86, and 95%, and postoperative atrophy rates were 0, 68, and 24%. After matching, 32 patients with TVF were matched to 32 patients who underwent orchiectomy. In the TVF group, postoperative viability occurred in 95% (19/20) vs 67% (8/12) of patients with ischemia times ≤24 and >24 h, respectively. Atrophy occurred in 67% (12/18) vs 83% (10/12) of these same respective patients. Sensitivity analysis by ultrasound and longer follow-up found similar viability results, although atrophy rates were higher. Additional matching for degrees of twist showed lower viability and higher atrophy rates for increasing ischemia times. DISCUSSION: Patients who presented with testicular torsion with ischemia times ≤24 h and who were being considered for orchiectomy may have benefitted most from TVF, albeit at high risk of atrophy. However, for ischemia times >24 h, TVF may still have preserved testicular viability in two-thirds of cases. A limitation was short follow-up. CONCLUSION: A TVF was a valid alternative to orchiectomy for torsed testicles, albeit with high testicular atrophy rates.

Robot-assisted retroperitoneal lymph node dissection (RA-RPLND) in the adolescent population.

BACKGROUND: Robot-assisted retroperitoneal lymph node dissection (RA-RPLND) has built on success and techniques of laparoscopic RPLND, with the added benefits of robotic technology. This paper demonstrates use of the da Vinci Xi® system for RA-RPLND in two adolescent patients. METHODS: Case #1: A 17-year-old male presented with a left testicular mass and elevated alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG). Pathology revealed a mixed non-seminomatous germ cell tumor (60% embryonal, 35% yolk sac, 5% choriocarcinoma, + lymphovascular invasion). Tumor marker normalized post-orchiectomy, and staging imaging was without evidence of metastatic disease. After discussion of options he opted to undergo RA-RPLND. Case #2: A 15-year-old male presented with a right para-testicular mass and negative tumor markers. He underwent inguinal exploration and excision of the paratesticular mass. Final pathology revealed an ectomesenchymoma with a spindle cell rhabdomyosarcoma component. Staging imaging was negative, and after discussion of options he underwent completion orchiectomy and RA-RPLND. RESULTS: The patient in Case #1 underwent a left modified-template nerve-sparing RA-RPLND. Sixteen lymph nodes were negative for tumor. The patient in Case #2 underwent complete bilateral nerve-sparing RA-RPLND. Forty-two lymph nodes were negative for tumor. Estimated blood loss was <50 cc for both cases, and console time averaged 262 min. CONCLUSION: This was a report of two cases of RA-RPLND in the adolescent population. RA-RPLND is technically feasible in this population, and further study of RA-RPLND is needed to determine long-term outcomes, as this technique is becoming more widely adopted.

Is glans penis width a risk factor for complications after hypospadias repair?

INTRODUCTION: Recent studies have suggested that a smaller glans penis size may be associated with a higher likelihood of complications after hypospadias repair. Accurate identification of risk factors other than the well-understood variable of meatal location would allow development of better prognostic models and individualized risk stratification. OBJECTIVE: To test the hypothesis that a smaller width of the glans penis predicts adverse outcomes after hypospadias surgery. METHODS: Prospectively recorded clinical data were reviewed from a single-institution registry of primary hypospadias repairs performed between 2011 and 2014. Follow-up records were examined for occurrence of complications. Urethroplasty complications were defined to include meatal stenosis, dehiscence, urethrocutaneous fistula, urethral stricture, and/or urethral diverticulum. The subset of meatal stenosis and dehiscence were regarded as glanular complications. Regression analyses were performed to determine association between glans width and occurrence of complications. Because pre-operative androgen stimulation is known to increase glans penis size, separate subgroup analyses were included of patients with and without pre-operative use of testosterone cream. RESULTS: A total of 159 patients met criteria for inclusion in the study cohort: 140 patients underwent a single-stage repair, while 19 patients had a two-stage repair. The median glans penis width was 15 mm (range 10-22). Eighty-four patients (53%) received testosterone cream pre-operatively and had a significantly wider glans penis than the 75 patients who did not (median 15.5 vs 14 mm; P < 0.001). Median clinical follow-up was 7 months (IQR 1-12), with a minimum time elapsed since surgery of 10 months at the time of chart review. Twenty-four patients (15%) had one or more urethroplasty complications, including 11 (7%) with glanular complications. Overall, there was no statistically significant association between glans width and urethroplasty complications (P = 0.26) or glanular complications (P = 0.90) (Summary Table). Subgroup analyses of patients with and without pre-operative testosterone also revealed no significant associations between glans width and complications. CONCLUSIONS: Glans penis width was not a risk factor for complications after hypospadias repair. This finding differs from the results of other recent studies and encourages further research into the value of measuring penile parameters in patients undergoing hypospadias repair.

Two-Step Fowler-Stephens orchiopexy for intra-abdominal testes: a 28-year single institution experience.

PURPOSE: Two-Step Fowler-Stephens orchiopexy for high undescended testes allows for mobilization of the testicle to the scrotal position while preserving perfusion by collateral circulation after gonadal vessel ligation. Although used for decades, the long-term efficacy of this procedure has not been reported. We present our 28-year clinical experience with this technique. MATERIALS AND METHODS: We retrospectively studied a cohort of patients who underwent 2-step Fowler-Stephens orchiopexy at our institution between 1982 and 2009. Patients were excluded if either step was performed elsewhere or if followup was less than 6 months. Bivariate and multivariate analyses were performed to determine associations between clinical, surgical and anatomical factors and testicular viability at last followup. RESULTS: A total of 62 patients (79 testes) met inclusion criteria. Median followup was 3.1 years (range 0.6 to 20). Based on the most recent examination/ultrasound, 70.9% of testicles were considered to be normal, with the remainder exhibiting relative (15.2%) or complete (14.9%) atrophy. Of the 10 testes assessed at or after puberty 6 were normal and 4 showed relative atrophy. On bivariate and multivariate analyses only an open second stage approach was associated with normal testicular viability, with 69.9% of normal vs 18.9% of completely atrophic testes being managed by an open approach (p = 0.0084). CONCLUSIONS: Thought to be highly effective in short-term followup, our data suggest that 2-step Fowler-Stephens orchiopexy leads to complete testicular viability in 70.9% of cases. This viability is strongly associated with an open second step.

Heterotopic ossificans in chronic venous insufficiency: a new consideration for clinical, aetiology, anatomy and pathophysiology staging.

OBJECTIVES: Heterotopic ossification is defined as the abnormal formation of true bone within extra-skeletal soft tissues. It may be associated with a variety of clinical conditions, but is most frequently seen with musculoskeletal trauma, neurologic injury or genetic abnormalities. It has also been described in patients with chronic venous insufficiency; however, it often goes underdiagnosed due to chronic ulceration that masks exam findings. To date, few reports of heterotopic ossification due to chronic venous disease exist within the literature with the most recent dating back to the 1970s. METHODS: We present a case study of a man presenting with extensive leg ulceration and a history of chronic venous insufficency. He had a large non-healing venous stasis ulcer of the left lower extremity with extensive heterotopic ossification discovered intraoperatively. RESULTS: The patient was managed with serial wound debridement, innovative woundcare and eventual split thickness skin grafting that achieved limb salvage despite the complexity of his wound. CONCLUSIONS: Our discussion focuses on the epidemiology, pathophysiology, diagnostic work-up and management of heterotopic ossification in the setting of chronic venous insufficiency. We propose that heterotopic ossification be included in any future modifications of the clinical, aetiology, anatomy and pathophysiology system classification as a complication of chronic venous disease.

Osteoblast intracellular localization of Nmp4 proteins.

Nmp4 proteins are transcription factors that contribute to the expression of type I collagen and many of the matrix metalloproteinase genes. Numerous Nmp4 isoforms have been identified. These proteins, all derived from a single gene, have from five to eight Cys(2)His(2) zinc fingers, the arrangement of which directs specific isoforms to nuclear matrix subdomains. Nmp4 isoforms also have an SH3 binding domain, typical of cytoplasmic docking proteins. Although recent evidence indicates that Nmp4 proteins also reside in the osteoblast cytoplasm, whether they localize to specific organelles or structures is not well defined. The intracellular localization of a protein is a determinant of its function and provides insights into its mechanism of action. As a first step toward determining the functional relationship between the cytoplasmic and nuclear Nmp4 compartments, we mapped their location in the osteoblast cytoplasm. Immunocytochemical analysis of osteoblasts demonstrated that Nmp4 antibodies labeled the mitochondria, colocalized with Golgi protein 58K, and lightly stained the cytoplasm. Western analysis using Nmp4 antibodies revealed a complex profile of protein bands in the nuclear, mitochondrial, and cytosolic fractions. Several of these proteins were specific to defined intracellular domains. Consistent with the western analyses, reverse transcription-polymerase chain reaction (RT-PCR) analysis detected previously uncharacterized Nmp4 isoforms. These data necessarily enlarge the known Nmp4 family from nuclear matrix transcription factors to a more widely extended class of intracellular proteins.

Three-dimensional X-ray microscopy with accurate registration of tomographic sections.

X-ray microtomography has been used to study the internal flaws and external shape of a 0.75 X 1 mm copper sulphate crystal at a resolution of 25 microns. The problems of accurate tomographic reconstruction and the subsequent registration of the reconstructed sections to give a complete 3-D image are considered when the position of the axis of rotation of the specimen varies slightly between projections.

Phase measurement x-ray interferometry.

A phase-step procedure is used with an x-ray interferometer to allow the use of standard phase-plot methods of fringe analysis. When used to measure displacement, this method allows more precise and reliable interpolation of fringe spacings than methods previously reported and is more tolerant of experimental uncertainties. Using the silicon (111) lattice planes as diffracting elements (period 0.3135625 nm), displacement measurements with a standard deviation of 0.003 nm can be routinely achieved. The experimental and data analysis methods required to achieve this resolution are reported.

The use of color in image enhancement of x-ray microtomographs.

This paper examines the effectiveness in displaying monochrome images as color images and presents a pseudo-color enhancement technique for enhancing features in x-ray microtomographs of biological and inorganic materials. The technique utilizes the knowledge that the gray levels (intensities) in the image represent the linear absorption coefficients of the elements in the material and assigns pixels with similar gray levels and hence similar absorption coefficients to a color. Since each color in the pseudo-color enhanced image represents a range of gray levels and this corresponds to an element or phase in the material, its microstructure can easily be determined. This paper also discusses the problems associated with the selection of colors and presents a scheme which uses the CIE 1976 L*u*v* uniform color space to select 256 colors for replacing the 256 gray shades used to represent the monochrome image.

X-ray microtomography of biological tissues using laboratory and synchrotron sources.

X-ray microradiography is a well established technique for the study of biological structures in which the projected absorption is measured, usually with photographic film or resist. If scanning X-ray microradiography with a 15-µm beam, 2-D scanning, and photon counting is used, more accurate results can be obtained and real-time experiments undertaken. Addition of a rotation axis allows computerized axial tomography to be done at a resolution of 15 µm. This technique overcomes the inherent difficulty of microradiography that all detail perpendicular to the plane of the specimen is superimposed. This method has been applied to the study of the 3-D mineral distribution in a 0.8×0.8 mm column of human cortical bone with a laboratory X-ray source. Calculation of the wavelength dependence of the linear absorption coefficient for liver and bone shows that, for a choice of wavelength in the range of 3-0.4 Å (4-30 keV), the specimen thickness can be from 100µm-2 cm and 10 µm-3 mm, respectively.Synchrotron X-radiation has the potential for better resolution because of the higher intensity, which allows the use of a narrower beam. There is also the possibility of determining individual element 3-D distributions from measurements on either side of the absorption edges because of the continuous nature of the spectrum and also the possibility of doing this from X-ray fluorescence measurements. To investigate these possibilities, a tomographic apparatus has been built based on the availability of accurately ground, tungsten carbide balls. Metrological assessment shows that the specimen remains within <1 µm of the required position during translation and rotation. Preliminary X-ray tomographic studies with a 4-µm diameter beam have been started at the Daresbury laboratory synchrotron source.