Background: Autologous tissues such as buccal mucosa (BM) are widely used for reconstruction of urethral strictures; however, limitations such as donor site morbidity and scarce tissue supply require the development of alternative biomaterials for urethral repair. The goals of this study were to determine the safety and efficacy of bi-layer silk fibroin (BLSF) matrices for urethral stricture repair and compare histological and functional outcomes to the standard approach, BM urethroplasty under good laboratory practices.Material and methods: A total of 13 rabbits exhibiting urethral stricture formation following electrocoagulation injury were treated with onlay urethroplasty with either acellular BLSF (N = 7) or autologous BM (N = 6) grafts for 3 months. Uninjured control rabbits were maintained in parallel (N = 4).Results and conclusion: Animals receiving BLSF implants were demonstrated to be functionally equivalent to BM grafts in their ability to restored strictured calibers, support micturition and promote tissue regeneration with minimal inflammation.

OBJECTIVE:To evaluate the relationship between renal pelvis pressure and infection after ureteroscopy, using a live swine model. MATERIALS AND METHODS:In anaesthetised pigs, a 1-h ureteroscopy was performed using a pressure-sensing guidewire, with renal pelvis pressure maintained at either 37 mmHg or 75 mmHg for the entire procedure and infusion with saline alone or with a standardised concentration of uropathogenic Escherichia coli strain CFT073 (1.5 × 107 colony-forming units [CFU]/mL). Venous blood sampling was performed during and after the procedure. Vital signs, inflammatory biomarkers, and renal tissue and blood cultures were assessed. RESULTS:In 21 pig kidneys, study groups were: 37 mmHg with saline irrigation (n = 3); 75 mmHg with saline irrigation (n = 4); 37 mmHg with saline irrigation with 1.5 × 107 CFU/mL E. coli (n = 7); and 75 mmHg with saline irrigation with 1.5 × 107 CFU/mL E. coli (n = 7). Statistically significant changes in inflammatory biomarkers were most pronounced in the group with 75 mmHg saline irrigation + E. coli and were significantly elevated compared with the control group and the group receiving E. coli irrigation at 37 mmHg. Positive blood cultures were noted in 5/7 animals treated with E. coli at 75 mmHg; no others developed bacteraemia. CONCLUSION:In this swine model of ureteroscopy, irrigation with saline + E. coli at a renal pelvis pressure of 75 mmHg resulted in bacteraemia and inflammatory biomarker elevations significantly greater than both E. coli irrigation with renal pelvis pressure maintained at 37 mmHg and the control.

BJU InternationalEarly View Research Letter A novel technique for measurement of fluid absorption during ureteroscopy Juliana Villanueva-Congote, Juliana Villanueva-Congote Department of Urology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USASearch for more papers by this authorDavid Hinojosa-Gonzalez, David Hinojosa-Gonzalez Department of Urology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USASearch for more papers by this authorMichal Segall, Michal Segall Department of Urology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USASearch for more papers by this authorJennifer Saunders, Jennifer Saunders Boston Scientific Corporation, Marlborough, Massachusetts, USASearch for more papers by this authorJay Budrewicz, Jay Budrewicz CBSET, Lexington, Massachusetts, USASearch for more papers by this authorBrian H. Eisner, Corresponding Author Brian H. Eisner [email protected] orcid.org/0000-0002-8891-4100 Department of Urology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA Correspondence: Brian H. Eisner, Department of Urology, GRB 1102, Massachusetts General Hospital, Harvard Medical School, Boston, 55 Fruit Street, Massachusetts, 02114, USA. e-mail: [email protected]Search for more papers by this author Juliana Villanueva-Congote, Juliana Villanueva-Congote Department of Urology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USASearch for more papers by this authorDavid Hinojosa-Gonzalez, David Hinojosa-Gonzalez Department of Urology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USASearch for more papers by this authorMichal Segall, Michal Segall Department of Urology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USASearch for more papers by this authorJennifer Saunders, Jennifer Saunders Boston Scientific Corporation, Marlborough, Massachusetts, USASearch for more papers by this authorJay Budrewicz, Jay Budrewicz CBSET, Lexington, Massachusetts, USASearch for more papers by this authorBrian H. Eisner, Corresponding Author Brian H. Eisner [email protected] orcid.org/0000-0002-8891-4100 Department of Urology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA Correspondence: Brian H. Eisner, Department of Urology, GRB 1102, Massachusetts General Hospital, Harvard Medical School, Boston, 55 Fruit Street, Massachusetts, 02114, USA. e-mail: [email protected]Search for more papers by this author First published: 07 June 2024 https://doi.org/10.1111/bju.16410Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. REFERENCES 1Hinman F. Urology: the clinical significance of pyelovenous backflow. Cal West Med 1928; 29: 111 CASPubMedGoogle Scholar 2Bhojani N, Koo KC, Bensaadi K, Halawani A, Wong VKF, Chew BH. Retrospective first-in-human use of the LithoVue™ elite ureteroscope to measure intrarenal pressure. BJU Int 2023; 132: 678–685 10.1111/bju.16173 CASPubMedWeb of Science®Google Scholar 3Hjertberg H, Jorfeldt L, Schelin S. Use of ethanol as marker substance to increase patient safety during transurethral prostatic resection. Urology 1991; 38: 423–428 10.1016/0090-4295(91)80230-5 CASPubMedWeb of Science®Google Scholar 4Hill AJ, Basourakos SP, Lewicki P et al. Incidence of kidney stones in the United States: the continuous National Health and Nutrition Examination Survey. 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ObjectiveTo compare a RADA16-based self-assembling peptide hydrogel versus an inorganic powder-based spray device for controlling postoperative bleeding in upper and lower GI mucosal lesions in pigs.MethodsMultiple mucosal lesions were endoscopically-created in the stomachs and lower colons of six Yorkshire swine on Day 0. Three animals’ wounds were treated with 2.5% RADA16 solution (PuraStat®), two animals were treated with an aerosolized mineral powder (Hemospray®), and one animal was an untreated control. Primary outcomes were test article applications required to control initial bleeding, time-to-hemostasis, and rebleeding incidence. Secondary outcomes included animal recovery, and clinical pathology at weekly endoscopic evaluations and the 4-week study terminus.ResultsNumber of material administrations required and time-to-hemostasis was comparable between PuraStat and Hemospray groups. Rebleeding rates were comparable between treatments. Two of 12 (17%) Hemospray and none of 18 (0%) PuraStat stomach sites experienced rebleeding during the final 4 min of the 10-min observation period. No delayed bleeding was observed during weekly endoscopic follow-ups. Hematology and serology values remained normal in all animals. Histology showed expected healing responses at all PuraStat- and Hemospray-treated defects, with less inflammation than untreated sites. Histomorphological observations were comparable between different groups for both the stomach and colon for test and control materials, with lower inflammation scores than untreated sites. Performance and usability responses were generally good with both systems, although the Ability to Treat Intended Site score was significantly better with PuraStat in upper GI lesions.ConclusionsPuraStat and Hemospray were effective topical hemostats for mild-to-moderate bleeding in upper and lower GI wounds. Rebleeding was observed in two of 12 Hemospray-treated sites and none of 18 PuraStat-treated sites. PuraStat and Hemospray were associated with better wound healing than untreated controls. The ability to treat upper GI lesions was easier with the PuraStat versus Hemospray system.

ObjectiveTo evaluate the relationship between renal pelvis pressure and fluid absorption during ureteroscopy (URS) in a live porcine model.Materials and MethodsFlexible URS (fURS) was performed in anaesthetised female Yorkshire pigs. Prior to performing fURS, a 0.3556‐mm (0.014″) pressure‐sensing guidewire (Comet™, Boston Scientific) was placed to monitor renal pelvis pressure. A simulated fURS procedure was then performed for 1 h. Infusion of irrigation fluid (5% ethanol in saline) at target renal pelvis pressures (37–150 mmHg) was maintained for 1 h using a pressure bag and real‐time feedback from the pressure‐sensing guidewire. Venous blood was sampled every 10 min. The volume of irrigation fluid absorbed was estimated with established equations.ResultsA URS procedure was performed in vivo in 18 porcine kidneys and the volume of irrigation fluid absorbed during the 1 h URS was calculated. The mean (SD) volume of irrigation fluid absorbed after 1 h of simulated URS was 7.6 (5.7), 10.8 (7.1), 26.0 (15.8), and 56.8 (22.3) mL at renal pelvis pressures of 37, 55, 75, and 150 mmHg, respectively. Compared with URS with renal pelvis pressure of 37 mmHg, the volume of fluid absorption was significantly greater at renal pelvis pressures of 75 and 150 mmHg (P = 0.026 and P = 0.047, respectively). In addition, compared with URS with renal pelvis pressure of 37 mmHg, the rate of absorption was significantly greater at renal pelvis pressures of 75 and 150 mmHg (both P < 0.001).ConclusionIn this study of an in vivo porcine model of URS, increasing renal pelvis pressures during URS were associated with increases in irrigation fluid absorption and increases in the rate of fluid absorption.

OBJECTIVES:A prior publication introduced the Strome-Blitzer balloon's ability to obtain circumferential esophageal cytologic sampling. This GLP study was requisite for FDA approval to determine if equivalent cell capture and cellularity was observed with the balloon compared to surface sampling brushes and to determine the balloon's usability for naive otolaryngologists.METHODS:Three naïve users tested the Hobbs brush and Strome-Blitzer balloon on 4 Yorkshire swine. Four anatomical sites were sampled, beginning distally and ending proximally. In 2 animals, the balloon was used first distally and in the remaining 2, 4 new Hobbs brushes were used distally first. Moving proximally, the balloon and brushes were sequentially alternated. In follow-the-leader fashion, the balloon was introduced trans-orally followed by an endoscope to the desired site. The balloon was inflated exposing the abrasive strips to contact the esophageal mucosa. Moving the balloon 1 to 2 cm superiorly and inferiorly effected circumferential cell capture. The balloon was collapsed and removed, preserving the cellularity. The Hobbs brush was passed through the scope's channel. Four brushes, 1 per quadrant, obtained the samples at an anatomical site. The balloon was rated as pass/fail on the following: delivery, kinking, usability, and malfunction. A blinded veterinary pathologist evaluated the cytology.RESULTS:There was no device malfunction, mucosal trauma, or difficulty with device use. Balloon cytologic samples were comparable in cellularity and quality to the brush.CONCLUSION:A single balloon sampling was comparable to 4 brushes in capturing diagnostically relevant cellular volumes and architecture. Naïve users easily performed the procedures after reading the guidelines.LEVEL OF EVIDENCE:3.

Coronary bifurcations have complex flow patterns including secondary flow zones and helical flow, which directly affect pathophysiological mechanisms such as the development of atherosclerosis. The objective of this study was to generate insights into the effects of curvature, bifurcation angle and the presence of stents on flow patterns and resulting haemodynamics in coronary left main bifurcations. The blood flow and associated metrics were modelled in both idealised and patient-specific bifurcations with varying curvature and bifurcation angles with and without stents, resulting in a total of 128 geometries considered. The results showed that larger curvature of bifurcating vessels has a significant influence on secondary flow, especially with distance to the bifurcation region, causing a skew, spin and asymmetry of Dean vortices, an increase in helical flow intensity with symmetry loss, and a decrease in adversely low time-average wall shear stress (TAWSS). Generally, asymmetric flow patterns coincided with adversely low TAWSS regions. In identical stented geometries, the presence of the stents induced local recirculation immediately adjacent to the stent struts, thus generating adversely low TAWSS in these areas, with some effect on the overall secondary flow. Overall, the effect of stents outweighed the effect of curvature and BA. This new knowledge contributes to a better understanding of the joint effects of curvature, bifurcation angle, and stents on flow patterns and haemodynamics in coronary bifurcations.

PURPOSE:To determine the number of runs with blades up (BU) using the JetStream Navitus to achieving optimal debulking in a porcine model of femoropopliteal artery in-stent restenosis (ISR).METHODS:In this porcine model, 8 limbs were implanted with overlapping nitinol self-expanding stents. ISR was treated initially with 2 blades-down (BD) runs followed by 4 BU runs (BU1 to BU4). Quantitative vascular angiography (QVA) was performed at baseline, after 2 BD runs, and after each BU run. Plaque surface area and percent stenosis within the treated stented segment were measured. Intravascular ultrasound (IVUS) was used to measure minimum lumen area (MLA) and determine IVUS-derived plaque surface area.RESULTS:QVA showed that plaque surface area was significantly reduced between baseline (83.9%±14.8%) and 2 BD (67.7%±17.0%, p=0.005) and BU1 (55.4%±9.0%, p=0.005) runs, and between BU1 and BU2 runs (50.7%±9.7%, p<0.05). Percent stenosis behaved similarly with no further reduction after BU2. There were no further reductions in plaque surface area or percent stenosis with BU 3 and 4 runs (p=0.10). Similarly, IVUS (24 lesions) confirmed optimal results with BU2 runs and no additional gain in MLA or reduction in plaque surface area with BU3 and 4. IVUS confirmed no orbital cutting with JetStream Navitus. There were no stent strut discontinuities on high-resolution radiographs following atherectomy.CONCLUSION:JetStream Navitus achieved optimal tissue debulking after 2 BD and 2 BU runs with no further statistical gain in debulking after the BU2 run. Operators treating ISR with JetStream Navitus may be advised to limit their debulking to 2 BD and 2 BU runs to achieve optimal debulking.

The JetStream Navitus (JS) atherectomy device (Boston Scientific) is a rotational cutter with aspiration capability to treat infrainguinal arterial obstructive disease. Intravascular ultrasound (IVUS) assessment of the number of blades up (BU) runs needed to achieve optimal tissue debulking in in-

The JetStream Navitus (JS) atherectomy device is a rotational cutter with aspiration capability designed to treat infrainguinal arterial obstructive disease. JS XC can be operated with blades down (BD) (2.1 or 2.4 mm perimeter) or blades up (BU) (3.0 or 3.4 mm perimeter) to treat femoropopliteal