title: Kinks of the transplant renal artery without accompanying intraarterial pressure gradient do not require correction: five-year outcome study.
abstract: Significant transplant renal artery stenosis (TRAS) results in an intraarterial pressure gradient and increasing graft dysfunction correctable by endovascular therapy. Kinks of the transplant artery cause velocity gradients on Doppler ultrasound, but some will have no intraarterial pressure gradient across the kink. It is not known whether these nonflow limiting kinks progress further to threaten graft function and should undergo endovascular correction. This is a longitudinal study of conservatively managed arterial kinks to define their natural history. Fourteen patients who had undergone angiography over a 5-year period for suspected TRAS had kinks of the renal artery. True intraarterial pressures were measured in all cases by slow withdrawal of an end-hole catheter after intraarterial injection of a vasodilator. Those with a significant pressure change (> or =10% change in peak systolic pressure across the area of suspicion) underwent endovascular treatment. The rest were managed conservatively, with maximal antihypertensive therapy. Outcome of all 14 cases was determined by follow-up of creatinine levels, blood pressure (BP) control and graft outcome over a 3-5-year period (median 4 years). Of the 14 patients with kinks, 10 were male and 4 female; age range 23-67 years (mean 47 years). Eleven had received cadaveric transplants and 3 were allografts; 12 had end-to-side and 2 end-to-end anastomosis, 11/14 cases had an intraarterial pressure ratio of <10% and at median 4 years follow-up on conservative treatment, the serum creatinine of these 11 patients did not differ significantly from those who underwent successful endovascular treatment (mean 118 micromol/l versus 149 micromol/l; p = 0.30, Mann Whitney test). Mean blood pressure was 137/82 mmHg, with a range of 124-155/56-95 mmHg. Only one patient has required an unexplainable increase in antihypertensive medication. Grafts (2/11) were lost and both had chronic rejection on histology. There were no unexplained graft failures. Kinks of the renal transplant artery with normal intraarterial pressures do not appear to progress and threaten renal graft function. Satisfactory graft outcome was seen on 5-year follow-up with conservative therapy alone.
authors.affiliation: Department of Nephrology and Radiology, St. George's Hospital, Blackshaw Road, London, SW17 0QT, United Kingdom.
authors.forename: Gim Chuah
authors.initials: GC
authors.lastname: Chua
authors.forename: Sue
authors.initials: S
authors.lastname: Snowden
authors.forename: Uday
authors.initials: U
authors.lastname: Patel
mesh_terms: D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001794:Blood Pressure / Q000502:physiology*; D003404:Creatinine / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016030:Kidney Transplantation / Q000009:adverse effects / Q000000981:diagnostic imaging; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012077:Renal Artery / Q000000981:diagnostic imaging*; D012078:Renal Artery Obstruction / Q000175:diagnosis* / Q000209:etiology; D012189:Retrospective Studies; D016896:Treatment Outcome; D014463:Ultrasonography
chemical_list: D000959:Antihypertensive Agents; D003404:Creatinine