Olfactory changes after endoscopic endonasal transsphenoidal approach for skull base tumors.

OBJECTIVES/HYPOTHESIS: The increased number of endoscopic endonasal transsphenoidal approaches (EETSA) has been associated with sinonasal complications such as olfactory dysfunction. Current studies have compared preoperative and postoperative olfactory function according to surgical type and age. STUDY DESIGN: Retrospective review of medical records at a tertiary referral center. METHODS: Patients were divided into two groups according to surgical type and into four groups according to age. The two surgical groups were defined based on the bilateral nasoseptal flap technique (group A: right conventional nasoseptal flap and left modified nasoseptal rescure flap; group B: bilateral modified nasoseptal rescue flap). The four age groups were ≤ 30, 31-45, 46-60, and ≥ 61 years. Patients underwent preoperative olfactory function evaluation using a visual analogue scale (VAS), the Connecticut Chemosensory Clinical Research Center Test (CCCRC), and the Cross-Cultural Smell Identification Test (CCSIT). Repeat testing was performed 6-months postoperatively. RESULTS: A total of 226 patients who underwent binostril four-hand EETSA were included in this study. In both groups A and B, the olfactory function was significantly decreased according to CCCRC and CCSIT scores (P < 0.05). The VAS scores were significantly decreased in both groups (P < 0.05). The symptom scores and olfactory test results were significantly changed in >30-year-old patients who had undergone EETSA. CONCLUSION: EETSA might contribute to olfactory dysfunction independent of surgery type. In addition, age may affect the restoration of olfaction after EETSA. Patients who plan to undergo EETSA must be informed that their olfaction may be impaired. LEVEL OF EVIDENCE: 4.

Chronic treatment with tempol does not significantly ameliorate renal tissue hypoxia or disease progression in a rodent model of polycystic kidney disease.

In the present study, we tested whether polycystic kidney disease (PKD) is associated with renal tissue hypoxia and oxidative stress, which, in turn, contribute to the progression of cystic disease and hypertension. Lewis polycystic kidney (LPK) rats and Lewis control (Lewis) rats were treated with tempol (1 mmol/L in drinking water) from 3 to 13 weeks of age or remained untreated. The LPK rats developed polyuria, uraemia and proteinuria. At 13 weeks of age, LPK rats had greater mean arterial pressure (1.5-fold), kidney weight (sixfold) and plasma creatinine (3.5-fold) than Lewis rats. Kidneys from LPK rats were cystic and fibrotic. Renal hypoxia was evidenced by staining for pimonidazole adducts and hypoxia-inducible factor (HIF)-1α in cells lining renal cysts and upregulation of HIF-1α and its downstream targets vascular endothelial growth factor (VEGF), glucose transporter-1 (Glut-1) and heme oxygenase 1 (HO-1). However, total HO activity did not differ greatly between kidney tissue from LPK compared with Lewis rats. Renal oxidative and/or nitrosative stress was evidenced by ninefold greater immunofluorescence for 3-nitrotyrosine in kidney tissue from LPK compared with Lewis rats and a > 10-fold upregulation of mRNA for p47phox and gp91phox. Total renal superoxide dismutase (SOD) activity was sevenfold less and expression of SOD1 mRNA was 70% less in kidney tissue from LPK compared with Lewis rats. In LPK rats, tempol treatment reduced immunofluorescence for 3-nitrotyrosine and HIF1A mRNA while upregulating VEGF and p47phox mRNA expression, but otherwise had little impact on disease progression, renal tissue hypoxia or hypertension. Our findings do not support the hypothesis that oxidative stress drives hypoxia and disease progression in PKD.