Nutcracker Syndrome: laparoscopic external stenting of the renal vein (″the shield technique″)

External Stenting (Exostenting) to Correct Vascular Torsion and Angulation

Organ transplantation can be associated with vascular torsions and angulations of both recipient and donor vessels. Such kinks and/or torsions of vessels can compromise the vascular integrity, obstruct inflow and/or outflow, and result in loss of the organ and/or body parts. On many occasions, mild angulations and torsions can be successfully addressed by repositioning the organ. In cases where the abnormal findings persist, maneuvers such as placing a fat pad to create a smoother curve, or even opening the peritoneum (in the case of kidney transplants) to allow for a better positioning of the organ, are associated with successful outcomes. When such torsions/angulations persist despite these approaches, further innovative tactics are required. In the current report, we propose a technique that involves longitudinally opening of a synthetic graft that is rigid enough to maintain its shape, such as a ringed polytetrafluoroethylene graft, and placing it as an external stent around the angulated/torsioned vessel. This maneuver will correct the underlying vascular compromise without having to perform any further invasive interventions, such as reimplanting the organ or resecting part of the involved vessel. Although primarily illustrated for application by describing an instance in which exostenting was applied during kidney transplantation, our approach could be applied to any vessel under many circumstances where angulations/twists are encountered. In this report, we describe the use of an external stent, also called exostenting, to correct a severe torsion/angulation of the external iliac artery in a kidney transplant recipient where all other measures were unsuccessful.

'Full prosthetic jacket': external stenting of the renal vein

Introduction: We present a case of positional compression of the left renal vein (LRV) after right nephrectomy and caval reconstruction, treated by external stenting using a reinforced vascular prosthesis.Case report: A 69-year-old female patient presented because of swelling of the left leg. A renal cell carcinoma (RCC) was visualized on computed tomography (CT) scan in the right kidney, with a thrombus occluding the inferior caval vein (ICV) and the right renal vein (RRV). A right nephrectomy was performed, with ligation of the already occluded ICV. Venotomy allowed thrombectomy of the ICV above the level of the renal veins. Venous return from the left kidney was secured by reconstruction of the confluence of the LRV and the ICV. Postoperatively, urinary output declined, leading to anuria and elevated levels of serum creatinine. With surgical exposition of the LRV, a flow of 387 mL/min was measured. After removal of exposition, flow in the LRV dropped to 51 mL/min. The positional compression was treated with a reinforced vascular PolyTetraFluoroEthylene (PTFE) prosthesis placed around the LRV.Discussion: Besides some reports on external stenting of the renal vein in the treatment of nutcracker syndrome (NS), this is the first report describing this technique outside this clinical entity.