Standardized Duplex Ultrasound-Based Protocol for Early Diagnosis of Transplant Renal Artery Stenosis: Results of a Single-Institution Retrospective Cohort Study

Table 3

Flow-chart detailing the study design. TRAS = transplant renal artery stenosis.

Patients undergoing kidney transplantation from July 1991 at Careggi University Hospital; ()
Patients eligible for the standardized ECD- based follow-up protocol for early detection of TRAS (started on January 1998); (, 85%)	Patients undergoing KT from 1991 to 1998 excluded due to lack of standardized follow- up protocols for diagnosis of TRAS; (, 15%)
Patients enrolled in the standardized follow-up protocol with complete clinical data available; (, 77%)	Patient excluded due to the following; (i) Any medical or surgical complications in the postoperative period; (ii) Unavailable clinical data; (iii) Lack of follow-up data; (, 23%)
Patients enrolled in the study undergoing regular follow-up at our Institution; (Study population); (, 97%)	Patients with ECD diagnosis of transplant renal artery kinking (TRAK) excluded from the study; (, 3%)
Patients with clinical or ECD suspicion of TRAS undergoing diagnostic angiography; (, 10%)	Patients continuing the Protocol Strategies according to the specific risk categories; (Table 2); (, 90%)
Patients diagnosed with TRAS; (, 95%)	Patients with no evidence of TRAS, of which 1 TRAK, continuing the regular follow-up protocol; (, 5%)
Patients with TRAS < 50% continuing regular follow-up protocol; (; 2%)
Patients with TRAS of 50–70% with a peak systolic pressure gradient across the stenosis of <20 mmHg undergoing PTA only; (; 5%)
Patients with TRAS > 70% with a peak systolic pressure gradient across the stenosis of >20 mmHg undergoing PTA + Stenting; (; 93%)
Patients undergoing diagnostic angiography for suspicion of TRAS during follow-up; (, 14%)
Patients with re-TRAS treated with re-PTA + stenting; ()	Patients with no evidence of TRAS continuing the regular follow-up protocol; ()