[Endovascular treatment of stenosis of the renal artery in transplanted kidney]

Diabetes insipidus-like state complicating percutaneous transluminal renal stenting for transplant renal artery stenosis

BACKGROUND

To report the incidence, etiology, and treatments of diabetes insipidus-like state that complicate percutaneous transluminal renal stenting (PTRS) for transplant renal artery stenosis (TRAS).

METHODS

Data from 7 patients on whom PTRS for TRAS was performed between October 2008 and March 2012 were reviewed retrospectively. The parameters investigated included blood flow velocity, blood pressure, and creatinine levels before and after the intervention.

RESULTS

The procedural success rate was 100%. Three cases developed a diabetes insipidus-like state in the immediate postprocedural period. Urine output returned to normal within 2 weeks after treatment. The median blood flow velocity was significantly reduced from 4.51 m/sec (4.31-4.61 m/sec) at the time of TRAS diagnosis to 1.33 m/sec (1.31-1.51 m/sec) at the most recent follow-up of the group with a diabetes insipidus-like state. The ratio of median blood flow velocity before and after stenting in the group with a diabetes insipidus-like state was significantly higher than that in the group without a diabetes insipidus-like state (3.39 vs. 1.93).

CONCLUSIONS

Diabetes insipidus-like state that complicates PTRS for TRAS is not an uncommon event, but appears to be underreported in the medical literature. A high ratio of pre- and poststenting median blood flow velocity may be a predictor for a postprocedural diabetes insipidus-like state. The most probable cause may be the marked increase in renal arterial flow. Early recognition of the condition is essential to avoid dehydration and electrolyte imbalance.

Endovascular treatment of external iliac vein stenosis caused by graft compression after kidney transplantation

A 57-year old patient presented with approximately 80% stenosis of the left external iliac vein due to compression by the renal graft after kidney transplantation. The initial clinical manifestation of this vascular complication was progressive edema of the left lower limb, starting in the foot during the immediate postoperative period and reaching the thigh. Renal function also deteriorated during the first four months after transplantation. Venous Doppler ultrasound findings were suggestive of a diagnosis of extrinsic compression by the kidney graft and so phlebography was ordered, confirming stenosis of the left external iliac vein. The patient was initially treated with balloon angioplasty, but there was still residual stenosis so a stent was inserted, eliminating the stenosis. The edema reduced over time and the patient's renal function improved. While vascular complications are rare, and potentially severe, events, success rates are good if treatment is started early.