Reconstruction of ureteral defects with a tubular skin graft secondarily prefabricated utilizing omentum as a carrier: an experimental study

Robot-assisted ureteral reconstruction using a tubularized peritoneal flap: a novel technique in a chronic porcine model

OBJECTIVE

To evaluate the feasibility and functional outcomes in porcine models of a novel robotic surgical technique for the treatment of complex ureteral injuries and strictures.

MATERIALS AND METHODS

Six pigs underwent robotic ureteral reconstruction using a long tabularized peritoneal flap and followed for 6-9 weeks after the surgery. Ureteral flap vascularity, intra-renal pressure, patency of the conduct, endoscopic aspect of the flap, renal function and histopathology were evaluated.

RESULTS

All animals successfully underwent ureteral reconstruction using a tubularized peritoneal flap. Median operative time was 223 min (162-360). Flap tubularization suture took 31 min (19-47), and proximal anastomosis took 20 min (15-38). Bladder mobilization with psoas hitch and distal anastomosis took 9 min (7-12) and 23 min (13-46), respectively. On follow-up, significant shrinkage of the ureteral flap in both length and width was observed. Antegrade pyelograms confirmed dilation and tortuosity of the proximal ureter, dilation of the renal pelvis, and major and minor calyxes without any definitive strictures. Microscopically, focal urothelial lining was seen in the neoureter. Creatinine level was significantly higher at the end of the follow-up period (p = 0.003).

CONCLUSIONS

Robot-assisted ureteral reconstruction using a tubularized peritoneum flap is technically feasible and reproducible. The flap sustained abundant vascular supply after different intervals of follow-up and the peritoneal mesenchymal cells differentiated into urothelium and myofibroblasts. Further studies are needed to address the issue of functional obstruction to improve long-term renal function outcomes.

Microvascular endothelial cells sustain preadipocyte viability under hypoxic conditions

Obesity, soft tissue wound healing, adipose tissue engineering, lipomas, and other physiological and pathophysiological conditions necessitate a clear understanding of the interactions between adipocytes and endothelial cells. Adipogenesis and angiogenesis are intimately integrated, despite not being in direct apposition with one another. However, underlying mechanisms have not been elucidated. In this study, the interactions of preadipocytes (PAs) and microvascular endothelial cells are investigated under varying defined O2 conditions, using a coculture system. Results clearly demonstrate that endothelial cells release a soluble factor that sustains PAs viability under hypoxic conditions. Vascular endothelial cell growth factor is not the potential soluble factor (data not shown).