Edward Diaz

The promotion of functional urinary bladder regeneration using anti-inflammatory nanofibers

Current attempts at tissue regeneration utilizing synthetic and decellularized biologic-based materials have typically been met in part by innate immune responses in the form of a robust inflammatory reaction at the site of implantation or grafting. This can ultimately lead to tissue fibrosis with direct negative impact on tissue growth, development, and function. In order to temper the innate inflammatory response, anti-inflammatory signals were incorporated through display on self-assembling peptide nanofibers to promote tissue healing and subsequent graft compliance throughout the regenerative process. Utilizing an established urinary bladder augmentation model, the highly pro-inflammatory biologic scaffold (decellularized small intestinal submucosa) was treated with anti-inflammatory peptide amphiphiles (AIF-PAs) or control peptide amphiphiles and used for augmentation. Significant regenerative advantages of the AIF-PAs were observed including potent angiogenic responses, limited tissue collagen accumulation, and the modulation of macrophage and neutrophil responses in regenerated bladder tissue. Upon further characterization, a reduction in the levels of M2 macrophages was observed, but not in M1 macrophages in control groups, while treatment groups exhibited decreased levels of M1 macrophages and stabilized levels of M2 macrophages. Pro-inflammatory cytokine production was decreased while anti-inflammatory cytokines were up-regulated in treatment groups. This resulted in far fewer incidences of tissue granuloma and bladder stone formation. Finally, functional urinary bladder testing revealed greater bladder compliance and similar capacities in groups treated with AIF-PAs. Data demonstrate that AIF-PAs can alleviate galvanic innate immune responses and provide a highly conducive regenerative milieu that may be applicable in a variety of clinical settings.

The Role of Genetically Modified Mesenchymal Stem Cells in Urinary Bladder Regeneration.

Recent studies have demonstrated that mesenchymal stem cells (MSCs) combined with CD34+ hematopoietic/stem progenitor cells (HSPCs) can function as surrogate urinary bladder cells to synergistically promote multi-faceted bladder tissue regeneration. However, the molecular pathways governing these events are unknown. The pleiotropic effects of Wnt5a and Cyr61 are known to affect aspects of hematopoiesis, angiogenesis, and muscle and nerve regeneration. Within this study, the effects of Cyr61 and Wnt5a on bladder tissue regeneration were evaluated by grafting scaffolds containing modified human bone marrow derived MSCs. These cell lines were engineered to independently over-express Wnt5a or Cyr61, or to exhibit reduced expression of Cyr61 within the context of a nude rat bladder augmentation model. At 4 weeks post-surgery, data demonstrated increased vessel number (~250 vs ~109 vessels/mm2) and bladder smooth muscle content (~42% vs ~36%) in Cyr61OX (over-expressing) vs Cyr61KD (knock-down) groups. Muscle content decreased to ~25% at 10 weeks in Cyr61KD groups. Wnt5aOX resulted in high numbers of vessels and muscle content (~206 vessels/mm2 and ~51%, respectively) at 4 weeks. Over-expressing cell constructs resulted in peripheral nerve regeneration while Cyr61KD animals were devoid of peripheral nerve regeneration at 4 weeks. At 10 weeks post-grafting, peripheral nerve regeneration was at a minimal level for both Cyr61OX and Wnt5aOX cell lines. Blood vessel and bladder functionality were evident at both time-points in all animals. Results from this study indicate that MSC-based Cyr61OX and Wnt5aOX cell lines play pivotal roles with regards to increasing the levels of functional vasculature, influencing muscle regeneration, and the regeneration of peripheral nerves in a model of bladder augmentation. Wnt5aOX constructs closely approximated the outcomes previously observed with the co-transplantation of MSCs with CD34+ HSPCs and may be specifically targeted as an alternate means to achieve functional bladder regeneration.

Continuous erector spinae plane block for an open pyeloplasty in an infant

Since its initial description in September 2016 [1], the erector spinae plane (ESP) block has garnered widespread interest amongst regional anesthesiologists. A facial plane block where local anesthetic is injected between the erector spinae muscle (ESM) and the underlying transverse process (TP), this block has been used successfully for chronic pain and perioperative analgesia in adults [1,2]. Experiences with children, however, are limited thus far [3,4]. Until now, only 2 reported cases of continuous ESP block in children exist, both in patients undergoing a thoracotomy [4,5]. After obtaining informed written consent from the parents, we describe the first report of a continuous ESP block in a child undergoing an open urological procedure. An 11 month old, 8.2 kg, male underwent an open pyeloplasty with ureteral stent insertion for left ureteropelvic junction obstruction with a continuous ESP block for intraoperative and post-operative analgesia. Following inhalational induction and endotracheal tube placement, the patient was turned into a left lateral decubitus position and a left ESP block was performed under aseptic conditions. A 38mm 5 to 13 MHz linear transducer was placed in a longitudinal, parasagittal orientation over the tip of the TP of T6. The depth from the skin to the TP was under 1 cm. An 18G 51 mm Sonoplex stimulation cannula with indwelling catheter (E-Cath, Pajunk Medical Systems LP) was inserted in-plane craniocaudally until the tip of T8 TP was contacted. Following hydro-dissection with saline to lift the ESM off the TP (Fig. 1), the stimulation cannula was removed and a 20G inner catheter was introduced within the indwelling catheter, fixed via Luer lock and secured at 5.1 cm at the skin. The catheter was bolused intraoperatively with 0.3 ml/kg, ropivacaine 0.2% every hour and 0.3 ml/kg, ropivacaine 0.5% at the end of surgery. For maintenance of anesthesia, a combination of sevoflurane 0.9% and propofol 100 μg/ kg/min were used. In addition, 15 mg/kg of acetaminophen, 1 μg/kg clonidine and 30mg/kg magnesium sulfate were given intravenously. The patient had Faces, Legs, Activity, Cry, Consolability (FLACC) scores of 0/10 in PACU and 0–4/10 in hospital over the next 36 h. The ESP catheters were infused with ropivacaine 0.2%, 3.5 ml every 90min. The patient received 2 doses of 0.5 mg/kg IV ketorolac on POD 1 and was transitioned to PO ibuprofen 10mg/kg once eating on POD 1. The catheter was removed early on POD 2 and the patient was discharged (Fig. 1). This is the first report of successful use of a continuous ESP block for an open pyeloplasty with ureteral stent insertion in an infant. The continuous infusion not only facilitated maintenance of surgical anesthesia with lower amounts of anesthesia intraoperatively but also allowed for complete avoidance of opioid during the patients entire hospital stay. This is in contrast, to our institutions current practice for this procedure. Typical analgesic management of children includes a ropivacaine 0.2%, 0.75–1.25ml/kg caudal with intraoperative short acting opioid (fentanyl 2–4 μg/kg) and post-operative as needed rescue opioid along with ketorolac and acetaminophen. A continuous ESP block may allow us to avoid the need for a caudal. With the lower risk profile of an ESP compared to central blocks, this may be of added benefit. In addition, with the uncertainty of long term neurological side effects of general anesthesia on infants, utilizing an ESP catheter may allow for adequate surgical anesthesia with minimal additional anesthetic. Finally, with prevalent opioid shortages, the continuous ESP block can provide an opioid free alternative with satisfactory pain control. Future prospective trials comparing ESP block with current standard analgesic techniques are needed to test such hypothesis.

Carbon dioxide laser for detrusor tunnel creation in robot-assisted laparoscopic extravesical ureteral reimplant.

OBJECTIVE Demonstrate and report initial results using a carbon dioxide (CO2) laser for detrusor tunnel creation in robot-assisted laparoscopic extravesical ureteral reimplant (RALUR). METHODS Retrospective chart review was performed for cases of RALUR from 2011 to 2014. Patients undergoing complex reconstruction (ureteral tailoring, dismembered reimplant, concomitant ureteroureterostomy), and those who had incomplete follow-up were excluded. Variables, including use of the CO2 laser, were collected and correlated with outcomes. RESULTS 23 patients representing 40 ureteral units were included for analysis. A CO2 laser was used in 9/23 (39%) patients and 16/40 (40%) ureteral units. Intraoperative mucosotomy was reported in 3/14 (21%) patients for the electrocautery group and 1/9 (11%) patients for the CO2 laser group. Resolution of VUR was observed in 11/14 (79%), and 9/9 (100%) of patients for the electrocautery group and the CO2 laser group, respectively. Two complications were identified in the electrocautery group of patients: ileus (Clavien 2), and transient bilateral ureteral obstruction requiring placement of ureteral stents (Clavien 3B). There were no complications in the CO2 laser group. CONCLUSIONS Creation of the detrusor tunnel with a CO2 laser is safe and effective, and is associated with a lower rate of failure and complication in this cohort.

Identification of the variables associated with pain during transrectal ultrasonography‐guided prostate biopsy in the era of periprostatic nerve block: the role of transrectal probe configuration

Currently, peri‐prostatic nerve block (PPNB) is the most effective method to reduce pain during TRUS biopsy. Although the advance in PPNB allowed a better tolerability of the procedure by most of patients, a minority of men still find the procedure unacceptably painful. We found in this study that the probe design and the needle guide affect pain encountered during different steps of TRUS guided PBx.

Pediatric penile reconstruction using autologous split-thickness skin graft

This video provides a case report of penis entrapment secondary to excessive skin removal during circumcision. It highlights the technical aspects of pediatric penile reconstruction using autologous split-thickness skin graft (STSG). Key points include: 1. Infection prevention is paramount and antibiotic prophylaxis is routine. 2. The usual harvest site for the STSG is the lateral thigh because of its source of glabrous skin and convenient proximity to the penis. The lateral thigh is also outside of the diapered area, which helps lessen postoperative pain and infectious risks. 3. A dermatome is used to harvest the STSG. Skin thickness for penis coverage at this age is usually 10-12/1000 of an inch. 4. Direct contact of the graft and wound bed is essential for graft uptake. Hemostasis of the wound bed is critical to prevent hematoma formation. Elimination of redundant tissue is also important to ensure maximal contact between the graft and underlying wound bed. 5. A pressure dressing or bolster is used to prevent shear, and provide contact between the graft and wound bed for at least the first 5 days. 6. A semi-occlusive dressing, Tegaderm, was used on the donor site and it is believed that it provides a moist environment conducive for epithelial and dermal healing. 7. Lymphedema can result if excess distal penile skin is not excised. It is prudent to limit the amount of mucosal collar or consider direct anastomosis to the glans.

Laparoscopic-assisted vesicocalicostomy for severe pelvi-ureteral stricture disease.

A laparoscopic approach was of benefit in limiting ultimate incision size in this case of vesicocalicostomy in a patient with severe ureteric stricture disease.A 39-year-old female previously treated with shock wave lithotripsy developed extensive ureteral stricture disease. After 2 unsuccessful attempts at retrograde balloon dilatation, she was evaluated at our center for further management. Successful reconstruction was performed with laparoscopic-assisted vesicocalicostomy.

MP19-03 THE ANGIOGENIC SIGNALING MOLECULE CYR61 INDUCES INCREASED NEO-VASCULARIZATION IN REGENERATED BLADDER TISSUE

INTRODUCTION AND OBJECTIVES: Bone marrow mesenchymal stem cells (BMMSCs) are a promising alternative cell source in bladder tissue engineering especially for improving tissue angiogenesis. Obstacles remain concerning stimulation and persistence of angiogenic vessels during bladder regeneration. The pleiotropic effects of CYR61 manifest in the regulation of inflammation, tissue repair, and angiogenesis. Here the effects of CYR61 on bladder tissue regeneration are evaluated by grafting scaffolds seeded with modified human BMMSCs that either overexpress (OX) or have limited expression of CYR61 in a nude rat bladder augmentation model. METHODS: Human BMMSCs were modified to either OX CYR61 or limit CYR61 expression by gene knockdown (KD) utilizing small interfering RNA constructs. Western blot confirmed levels of protein expression. Modified BMMSCs were seeded at 1.5 10 cells/cm onto poly (1,8-octanediol-co-citrate) (POC) scaffolds 7e8 days prior to use. Urodynamics (UDS) were obtained followed by a 50e60% partial cystectomy with bladder augmentation using the cell/scaffold composites in nude rats (n1⁄45 per group). At sacrifice (4 and 10 weeks) animals underwent repeat UDS, capillarioscopy, and harvest of augmented bladders. Vessel characteristics and muscle content were quantified with Trichrome stain. Peripheral nerve regeneration was quantified with neuron specific b III tubulin immunofluorescence staining. RESULTS: At 4 weeks, CYR61 OX, as compared to KD, resulted in significantly increased vessel number (249.9 22.3 vs. 108.8 5.5 vessels/mm, p<0.001) and muscle content (42.3 1.3% vs. 36.1 1.6%, p<0.05). Previously published data from our laboratory has shown far fewer vessels (POC 63.8 5.4, unmanipulated MSCs 83.4 15.8 vessels/mm) and decreased muscle content in 4 week controls (POC 9.3 1.9%, unmanipulated MSCs 38.4 1%). CYR61 KD demonstrated significant loss of muscle content from 36.1 1.6% at 4 weeks down to 25.0 2.7% at 10 weeks (p<0.05). At 4 and 10 weeks, capillariscopy and UDS demonstrated functional bladders and capillaries in all animals. At 4 weeks CYR61 OX resulted in primitive nerve in-growth of 664.1 87.9 mm into regenerated tissue (mean length 39.3 5.9 mm). No nerve elements were noted in CYR61 KDs. CONCLUSIONS: CYR61 is a potent extracellular signaling molecule that increases functional vasculature, preserves muscle content from 4 to 10 weeks, and induces the growth of neural elements at 4 weeks in regenerated bladder tissue.

Catheter-Associated Urinary Tract Infections: If You Hear Hoofbeats…

Editor’s note: Annals has partnered with EM:RAP, enabling our readers without subscriptions to the EM:RAP service to enjoy their commentary on Annals publications. This article did not undergo peer review and may not reflect the view and opinions of the editorial board of Annals of Emergency Medicine. There are no financial relationships or other consideration between Annals and EM:RAP or its authors.