Evaluation of Bi-Layer Silk Fibroin Grafts for Tubular Ureteroplasty in a Porcine Defect Model

Ureteral reconstruction with autologous tissue grafts is often limited by tissue availability and donor site morbidity. This study investigates the performance of acellular, bi-layer silk fibroin (BLSF) scaffolds in a porcine model of ureteroplasty. Tubular ureteroplasty with BLSF grafts in combination with transient stenting for 8 weeks was performed in adult female, Yucatan, mini-swine (N = 5). Animals were maintained for 12 weeks post-op with imaging of neoconduits using ultrasonography and retrograde ureteropyelography carried out at 2 and 4 weeks intervals. End-point analyses of ureteral neotissues and unoperated controls included histological, immunohistochemical (IHC), histomorphometric evaluations as well as ex vivo functional assessments of contraction/relaxation. All animals survived until scheduled euthanasia and displayed mild hydronephrosis (Grades 1-2) in reconstructed collecting systems during the 8 weeks stenting period with one animal presenting with a persistent subcutaneous fistula at 2 weeks post-op. By 12 weeks of scaffold implantation, unstented neoconduits led to severe hydronephrosis (Grade 4) and stricture formation in the interior of graft sites in 80% of swine. Bulk scaffold extrusion into the distal ureter was also apparent in 60% of swine contributing to ureteral obstruction. However, histological and IHC analyses revealed the formation of innervated, vascularized neotissues with a-smooth muscle actin+ and SM22α+ smooth muscle bundles as well as uroplakin 3A+ and pan-cytokeratin + urothelium. Ex vivo contractility and relaxation responses of neotissues were similar to unoperated control segments. BLSF biomaterials represent emerging platforms for tubular ureteroplasty, however further optimization is needed to improve in vivo degradation kinetics and mitigate stricture formation.

Laparoscopic ureteral reconstruction in a kidney transplant: successful clinical cases

Treatment of ureteral strictures in the long-term post-transplant period is a complex surgical procedure. We present successful clinical cases of developed laparoscopic ureteral stricture reconstruction methods at three levels (in the pelvis, along the ureter, in the anastomosis area). These methods have shown their clinical efficacy: they are less traumatic, there are no adverse events in the early and long-term postoperative periods, and there is accelerated rehabilitation of recipients after surgery.

LAPAROSCOPIC TRANSPERITONEAL URETEROURETEROSTOMY COMBINED WITH RETROGRADE FLEXIBLE URETEROSCOPY ASSISTANCE FOR URETERAL STRICTURE- CASE SERIES OF SEVEN PATIENTS

Most strictures of the ureters are detected and usually occur in the part of the ureter when the calculus has been trapped for a long time, after ESWL or as a complication of transureteral lithotripsy after the introduction of the holmium laser. The treatment of these strictures variesand depends on many parameters, the most important being the type of stricture, severity, length and location. In many cases, endoscopic treatment with stenting is the first choice of treatment performed retro or antegrade. In case of failure or contraindication for endoscopic treatment, ureteral reconstruction can be performed by open, laparoscopic or robotic techniques. Laparoscopic ureteroureterostomy is a preferred minimally invasive technique for the treatment of benign ureteral strictures.

Surgical management in retroperitoneal fibrosis: beyond ureterolysis

Background Retroperitoneal fibrosis can be associated with bilateral dense and extensive periureteral adhesions. When ureterolysis could not be successfully performed due to disease extent and severity, elaborate ureteral reconstructive procedures will be required. Case presentation A young male with retroperitoneal fibrosis presented with bilateral hydroureteronephrosis. The ureteral involvement was extensive and adhesions were dense. He was managed by laparoscopic boari flap ureteroneocystostomy on one renal unit and laparoscopic nephrectomy with renal autotransplantation on the other renal unit. Conclusions Ureterolysis is not feasible in all cases of retroperitoneal fibrosis. Extensive bilateral ureteral reconstruction without using intestinal segments is feasible. Minimally invasive surgical reconstructive procedures can be successfully employed in such scenarios also.

Etiology and Ureteral Reconstruction Strategy for Iatrogenic Ureteral Injuries: A Retrospective Single-Center Experience

Objective: To analyze the etiology, characteristics, and ureteral reconstruction strategies of iatrogenic ureteric injuries in a high-volume center. Methods: Between September 2010 and August 2019, we retrospectively collected patients who underwent ureteral reconstruction due to iatrogenic ureteric injuries. Patient profiles, laboratory data, imaging studies, perioperative data, and complications were recorded. Results: Sixty-eight patients were enrolled in this study. The upper, middle, and lower thirds of the ureter were affected in 30, 2, and 36 cases, respectively. Of the 68 ureteric injuries, 69.1% occurred during urological procedures, followed by gynecological procedures, general surgery, radiotherapy, and orthopedic surgery. The majority of urological injuries (41, 87.2%) occurred due to stone removal. There was a significant difference in the age, sex, and location of ureteric injuries between the urological and nonurological groups. The median follow-up time was 17.9 months. The overall symptom remission rate was 91.2% and ranged from 87.5 to 100% for different reconstructive surgeries. Conclusions: Urological procedures were the most common cause of iatrogenic ureteric injury; thus, extra care should be taken. Timely detection and appropriate treatment of the ureteric injuries are necessary. Treatment strategies should be depended on the location and length of injury.