Although preservation of parathyroid glands in situ is desirable, routine parathyroid autotransplantation during thyroidectomy virtually eliminates postoperative hypoparathyroidism. Normal parathyroid glands resected or devascularized during thyroidectomy for well-differentiated thyroid carcinoma or benign disease should be transplanted in the sternocleidomastoid muscle. Patients with Multiple Endocrine Neoplasia type 2A should have parathyroid glands resected at the time of thyroidectomy for medullary thyroid carcinoma and transplanted in the nondominant forearm. Postoperative management in most patients after thyroidectomy and parathyroid autotransplantation involves temporary calcium and vitamin D replacement and close biochemical evaluation. This precautionary measure of parathyroid autotransplantation markedly reduces the incidence of permanent postoperative hypoparathyroidism.

Iliac artery-ureteral fistula is a rare entity that is being reported with increasing frequency. Patients with iliac artery-ureteral fistulas can be divided into two distinct groups on the basis of the factors that predispose them to having these fistulas. In group I the fistula is associated with degenerative iliac artery disease or previous arterial reconstructive surgery. Patients in group II have undergone some combination of the following procedures: pelvic extirpative surgery for malignancy, urinary diversion, radiation therapy, and ureteral stenting. The diagnosis of an iliac artery-ureteral fistula can be elusive even with the use of multiple imaging methods. Direct operative repair is technically demanding and is associated with high mortality rates. In recent years, treatment has shifted toward percutaneous embolization of the iliac artery and extraanatomic lower extremity vascular reconstruction for group II patients. In this report, the 24 group II patients with iliac artery-ureteral fistulas who previously have been described are reviewed, and a new endovascular treatment for this entity that uses a stented vein graft is detailed.

Rats and mice are frequently used in studies of the regulation of lipoprotein metabolism. Although the species are closely related, they differ dramatically in the responses of their lipoproteins to estrogen administration. In rats, estrogens produce profound decreases in the levels of all plasma lipoproteins and this is attributed largely to estrogen-induced increases of hepatic low-density lipoprotein receptor (LDL-receptor) activity. Estrogens affect mouse plasma lipoproteins to a much lesser extent. Therefore, one of our aims was to compare the regulation of LDL-receptor gene expression in rats and mice at several potential loci of regulation. To assess the specificity of the estrogen effect, we also compared the responses of apolipoprotein A1 (apoAI), apolipoprotein B (apoB), and /3-actin to the response of the LDL-receptor. In male Sprague Dawley rats given 1 7 8 estradiol or 17a-ethinyl estradiol at supraphysiological doses of 5 pg/g body masdday, plasma total cholesterol and triacylglycerols fell to = 5% and = 50%, and, plasma apoAI and apoB fell to = 12% and ~1 6 % of controls, respectively. By contrast, in male C3H/HeJ mice the above parameters dropped only to ~6 5 % of controls and apoB concentrations rose to ~2 0 0 % of controls. In rats, relative rates of LDL-receptor mRNA transcription (nuclear 'run-off' assay) and total hepatic, nuclear and polysomal LDL-receptor mRNA levels (RNase protection assay) increased by 1.5 -2-fold, while synthesis of LDL-receptor protein on hepatic polysomes (in a wheat-germ translation system) increased 8-fold and LDL-receptor protein mass in hepatic plasma membranes increased 10-fold (by immunoblotting). In mouse liver, too, LDL-receptor mRNA levels increased 1.5-fold and the LDL-receptor mRNA transcription start sites in rat and mouse were found to be the same, but mouse LDL-receptor protein mass did not change, i.e. LDL-receptors of mice were similar to rat with respect to transcriptional regulation, but differed in their post-transcriptional control mechanisms.In rats, estrogen administration increased apoAI inRNA transcription rates 1.6-fold and also apoAI mRNA levels in total liver homogenates, nuclei and polysomes, (2-fold for each) consistent with transcriptional regulation. However, apoAI synthesis on total RNA increased less than apoAI mRNA, indicating that apoAI translational control mechanisms, at least in part, also regulate hepatic rates of apoAI production. ApoB mRNA transcription rates and levels showed small increases following estrogen administration. Hepatic p-actin mRNA transcription and levels did not change. These changes in apoAI and apoB in rats were similar to those previously reported for mice, i.e. estrogen regulates apoAI and apoB gene expression both at the transcriptional and translational levels with rats and mice responding similarly. Thus, in rat liver, estrogen upregulates LDL-receptor production by transcriptional and even more so by translational mechanisms while mouse LDLreceptor remains unchanged. These interspecies differences in t...

Purpose: Deterioration in renal fimction is a common cause of morbidity in patients treated surgically for juxtarenal and suprarenal abdominal aortic aneurysms. We reviewed our experience over the last 8 years with 65 consecutive patients undergoing juxtarenal (n = 31) or suprarenal (n = 34) abdominal aortic aneurysm repair. Methods: The aneurysms were repaired with a transabdominal (n = 8), thoracoabdominal (n = 4), retroperitoneal (n = 22), or thoracoretroperitoneal (n = 31) approach. Proximal aortic damps were placed at the suprarenal, supra-superior mesenteric artery, or supraceliac level. Renal hypothermia with cold heparinized saline solution renal artery perfusion was used to protect renal function in 38 patients with either preoperative renal insufficiency or with anticipated prolonged renal ischemia (> 30 minutes). Concomitant renal artery reconstruction was required in 30 patients. Results: Significant operative morbidity developed in 23 (35.3%) patients. There was one (1.53%) perioperative death (0 to 90 days). Temporary dialysis was necessary in two patients. Preoperative renal insufficiency was a significant risk factor on multivariate analysis for a decline in renal function during the first postoperative week. However, serum creatinine concentration had returned to baseline or improved in all patients but two (3.1%) at the time of discharge. In spite of significantly longer renal ischemia, discharge creatinine levels were, on tmivariate analysis, statistically less than baseline creatinine levels in patients with suprarenal aneurysms, patients requiring renal reconstruction, and patients treated with renal hypothermia. The location of the proximal aortic clamp was not a factor in postoperative morbidity. There was no significant difference between juxtarenal and suprarenal aneurysms with respect to operating room time, transfusion requirements, days intubated, resumption of oral diet, or the length of hospitalization. Conclusions: Careful consideration of the route of exposure, location of the proximal aortic clamp, and the preservation of renal function with renal hypothermia and with the repair of significant renal artery lesions will result in minimal morbidity and mortality in patients requiring surgery for juxtarenal or suprarenal abdominal aortic aneurysms. (J VASC SURG 1993;17:948-59.) Abdominal aortic surgery is a common component of the modern vascular surgery practice. In 1991 approximately 29,656 patients underwent elective abdominal aortic surgery (aneurysmal and occlusive disease) in the United States) Most of these proce-From the 948 dures (92%) were confined to the infrarenal aorta. Once a challenging operation, infrarenal aortic surgery is now commonly performed with mortality rates of less than 5%. 2 In approximately 6% (1719), of patients undergoing elective surgery for abdominal aortic disease in 1991,1 the aortic disease extended proximally to involve the renal or visceral vessel segments of the aorta. Such upper abdominal aortic pathology includes juxtarenal aneurysms that ...

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