SummaryBackground An elevation of fractionated plasma or urinary metanephrine (MN) or nor-metanephrine (NMN), collectively called metanephrines (MN and NMN), >4-fold above the upper limit of normal (ULN) is usually considered to be diagnostic for pheochromocytoma (PHEO). There are a greater number of false positive results when the elevations are more modest. Aim To identify biochemical and radiological features in PHEOs with modest elevations (<4-fold above ULN) of metanephrines. Methodology We retrospectively reviewed the charts of 112 patients with PHEO (10% extra-adrenal) and 208 patients with a non-PHEO adrenal mass operated from 1997-2011, who had metanephrines measured pre-operatively. We divided PHEO into group 1 (n = 90) with metanephrines ≥4-fold ULN and group 2 (n = 22) with metanephrines <4-fold ULN. The non-PHEO group was designated as group 3. Results The median (range) tumour size in group 1 and group 2 was 4Á8 cm (1Á7-22) and 3Á0 cm (1Á7-5) respectively (P < 0Á001). All patients with PHEO in group 2 had a tumour <5 cm in size. The MN fraction was elevated in about 65% of groups 1 and 2; only 2 (1%) patients in group 3 had an elevated urinary MN fraction, and none were associated with an elevated plasma MN fraction. All PHEOs had a pre-contrast attenuation ≥17 Hounsfield Units (HU). Conclusions Modest elevations (<4-fold ULN) of the NMN fraction in an adrenal mass >5 cm are almost always falsely positive. Elevations in plasma and urinary MN fraction are less likely to be false positive. The CT pre-contrast attenuation of PHEOs is >10 HU.
We delineate the current role of extra-anatomical revascularization techniques in the treatment of patients with atherosclerotic renal artery stenosis. There are 2 components to this study. In part 1 all abdominal aortograms performed between 1989 and 1993 were reviewed to document the presence of significant abdominal aortic and visceral arterial atherosclerosis in patients with atherosclerotic renal artery stenosis. A total of 254 patients with atherosclerotic renal artery stenosis was identified. Among 44 patients with severe unilateral disease the incidence of significant abdominal aortic atherosclerosis was 75%. The incidence of significant (greater than 50%) stenosis of the celiac, right common iliac and left common iliac arteries was 52%, 32% and 27%, respectively. In 129 patients with severe atherosclerotic renal artery stenosis bilaterally or in a solitary kidney the incidence of significant abdominal aortic atherosclerosis was 81%, and the incidence of significant (greater than 50%) stenosis of the celiac, right common iliac and left common iliac arteries was 59%, 57% and 59%, respectively. These data indicate that hepatorenal, splenorenal and iliorenal bypass cannot be performed in many patients with atherosclerotic renal artery stenosis due to significant disease involving the donor vessels for these operations. In part 2, all patients undergoing surgical renal revascularization with an extra-anatomical bypass operation between 1980 and 1992 were reviewed. A total of 175 operations was done in 171 patients, including hepatorenal bypass in 59, splenorenal bypass in 54, iliorenal bypass in 37, thoracic aortorenal bypass in 23, renal autotransplantation in 1 and superior mesentero-renal bypass in 1. There were 5 operative deaths (2.9%) and 7 cases of postoperative graft thrombosis (4%). All patients with poorly controlled hypertension were cured or improved postoperatively. Among patients with ischemic nephropathy, postoperative renal function improved in 35%, remained stable in 47% and deteriorated in 18%. Extra-anatomical techniques remain an important component of the surgical armamentarium for atherosclerotic renal artery stenosis. Thoracic aortorenal bypass is a useful new approach in patients with significant celiac and iliac occlusive disease.
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