|Year : 2011 | Volume
| Issue : 1 | Page : 147-148
Reconstruction of ureteral defect lesion with vein graft and a biodegradable endoluminal stent: An innovative therapeutic approach
Rohit Kathpalia, Vengetesh K Sengottayan, Apul Goel
Department of Urology, CSM Medical University, Lucknow, Uttar Pradesh, India
|Date of Web Publication||29-Mar-2011|
Department of Urology, CSM Medical University, Lucknow, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Kathpalia R, Sengottayan VK, Goel A. Reconstruction of ureteral defect lesion with vein graft and a biodegradable endoluminal stent: An innovative therapeutic approach. Indian J Urol 2011;27:147-8
|How to cite this URL:|
Kathpalia R, Sengottayan VK, Goel A. Reconstruction of ureteral defect lesion with vein graft and a biodegradable endoluminal stent: An innovative therapeutic approach. Indian J Urol [serial online] 2011 [cited 2020 Apr 4];27:147-8. Available from: http://www.indianjurol.com/text.asp?2011/27/1/147/78401
Wolters HH, Heistermann HP, Stöppeler S, Hierlemann H, Spiegel HU, Palmes D. A new technique for ureteral defect lesion reconstruction using an autologous vein graft and a biodegradable endoluminal stent. J Urol 2010;184:1197-203.
| Summary|| |
Management of proximal ureteral defects has been a challenge. Unlike distal ureter, natural substitutes like bladder are not available for the proximal defects. Wolters et al. studied the feasibility of a substitute to replace the ureter using a venous graft.  An experimental study was performed that included 42 pigs weighing between 20 and 25 kg. These pigs were then randomized and divided into three experimental groups. In all animals, a segment of the external jugular vein (EJV) was resected and harvested in heparinized isotonic saline solution at room temperature, to replace part of the ureter. In group 1 (n=14), a 3-cm segment of proximal ureter was resected and replaced by the resected EJV, the venous interponate (VI), which was sutured continuously end to end using 6-0 PDS suture. In group 2 (n=14), the same procedure was done with the venous interponate stented (VIS). The stent was endoluminal and made of biodegradable poly-l-lactic acid (PLLA). In group 3 (n=14), only median laparotomy and ureteral mobilization was done that served as the control group.
Renal function, ultrasound, and histologic examination of kidney and ureter were done at the time of surgery and 7 days and 6 months after surgery. Serum urea and creatinine were significantly increased in group 1 at both 7 days and 6 months in comparison to group 2 (creatinine 2.9 ± 0.6 vs 2.1 ± 0.2 mg/dl, P = 0.002 and urea 33.1 ± 7.3 vs 13.7 ± 2.2 mg/dl, P <0.001). Ultrasound at day 7 showed ipsilateral renal pelvic congestion in 4 of group 1 pigs and hydronephrosis in all at 6 months. Ureteral interponate strictures at day 7 and severe morphological changes in kidney at 6 months were noted in group 1, while group 2 showed no such changes. At day 7, in group 1 a severe inflammatory reaction and necrosis were visible in interponate, while in group 2 macroscopically regular urothelium was noted. At 6 months in group 1, a scarred ureteral stricture was visible; in contrast, group 2 showed regular urothelium.
The authors concluded that combining an autologous vein graft with a biodegradable endoluminal stent represents an innovative therapeutic approach to ureteral defect lesions and is an attractive alternative to small bowel interposition allowing preservation of the natural antireflux mechanism.
| Comments|| |
Ureteral defects are severe complications caused by iatrogenic lesions or trauma. Distal ureteral injuries can be managed easily by ureteroneocystostomy with or without psoas hitch or Boari flap while repair of proximal defects usually requires complex treatment procedures like ureteral replacement using bowel or kidney auto-transplantation that are fraught with complications.
The authors inspired by the promising results of reconstructing defects of the bile duct using a temporarily stented venous interponate  used this new technique to reconstruct proximal ureteral defects. PLLA is a polymer of l-lactic acid and is known for its good long-term biocompatibility.  Biodegradable stents made up of PLLA thus allow reorganization of the capillary structure by neoangiogenesis and served as the basis of neourothelialization growing out from the edges of the ureteral defect. At 4 months in the group with the PLLA stent, the venous interponate was already covered with urothelium, probably by ingrowth from the native ureteral stumps. , At that time, the stent material was completely degraded and the neoureter showed a thickened wall diameter, accompanied by an inflammatory reaction. At 6 months, the neoureter almost completely resembled native ureter with CK7-positive columnar urothelium and newly formed capillaries in the ureteral wall.
For treating proximal ureteral defects, this method is an attractive alternative; however, further long-term study is needed to confirm that no late ureteral strictures develop. Due to the simple technique and availability of suitable vein (long saphenous) in humans, this new procedure shows potential for clinical application in patients with long proximal ureteral defects.
| References|| |
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