The value of plasma metanephrine measurements during adrenal vein sampling.

Objective: The assessment of primary aldosteronism incorporates adrenal vein sampling (AVS) to lateralize aldosterone excess. Current adrenal vein sampling protocols rely on concurrent cortisol measurements to assess successful cannulation and lateralization and may be inaccurate in the setting of autonomous cortisol secretion. We aimed to compare the measurement of plasma cortisol and metanephrine concentrations to assess cannulation and lateralization during AVS. Design: This is a diagnostic accuracy study in a tertiary referral endocrinology department. Methods: Forty-one consecutive patients with confirmed primary aldosteronism undergoing AVS (49 procedures) were included. None had cortisol autonomy. The use of plasma metanephrine-based ratios were compared with standard cortisol-based ratios to assess cannulation and lateralization during ACTH-stimulated AVS. Results: There was strong agreement between a cortisol selectivity index (SI) ≥5.0 and an adrenal vein (AV) to peripheral vein (PV) plasma metanephrine ratio (AVmet-PVmet) of ≥12.0 to indicate successful cannulation of the AV (n = 117, sensitivity 98%, specificity 89%, positive predictive value (PPV) 95%, negative predictive value (NPV) 94%). There was strong agreement between the standard cortisol-based SI and an AV plasma metanephrine-to-normetanephrine ratio (AVmet-AVnormet) of ≥2.0 to indicate successful cannulation (n = 117, sensitivity 93%, specificity 86%, PPV 94%, NPV 84%). There was strong agreement between the cortisol- or metanephrine-derived lateralization index (LI) > 4.0 for determining lateralization (n = 26, sensitivity 100%, specificity 94.1%, PPV 91.6%, NPV 100%). Conclusions: Ratios incorporating plasma metanephrines provide comparable outcomes to standard cortisol-based measurements for interpretation of AVS. Further studies are required to assess the use of metanephrine-derived ratios in the context of confirmed cortisol autonomy. Significance statement: Primary aldosteronism is a common cause of secondary hypertension, and adrenal vein sampling remains the gold standard test to assess lateralization. Cortisol-derived ratios to assess cannulation and lateralization may be affected by concurrent cortisol dysfunction, which is not uncommon in the context of primary aldosteronism. Our study showed comparable outcomes when using accepted cortisol-derived or metanephrine-derived ratios to determine cannulation and lateralization during adrenal vein sampling. Further research is required to validate these findings and to assess the use of metanephrine-derived ratios in the context of confirmed concurrent cortisol dysfunction.

Post-procedure surveillance in liver biopsy: how long is long enough?

AIM: To assess the incidence of complications following liver biopsy and the impact of pre-procedural pethidine on complications and analgesia administration. METHOD: A retrospective audit of percutaneous liver biopsies undertaken at Dunedin Public Hospital (2001-2006). Patients' medical files were consulted for demographics, biopsy indication, complications, frequency, and timing of analgesia. RESULTS: 447 biopsies were analysed. Primary indications included: hepatitis C (38.8%), abnormal liver function tests (18.3%), methotrexate therapy (12.5%), and malignancy (10.3%). 303 (68%) biopsies resulted in no complications. Major complications were not experienced. Minor complications included: pain (32.2%), hypotension (1.3%), nausea/vomiting (0.9%), and alcohol withdrawal (0.2%). More females (47%) than males (31%) reported complications. Post-procedural analgesia was administered in 31% of biopsies; only 9% required analgesia more than 2 hours after biopsy. Patients who had pre-procedural pethidine experienced similar rates of complications as patients not receiving pre-procedural pethidine, but received less post-procedural opiate analgesia. CONCLUSION: No major complications occurred, whilst the rate of minor complications was comparable with previous studies. Pain was the most common complication, although use of analgesia after 2 hours of observation was low. Our findings suggest that post-procedural observation may safely be reduced to two hours but it is currently unknown if early mobilisation following discharge will lead to complications.

Effects of epicatechin gallate on wound healing and scar formation in a full thickness incisional wound healing model in rats.

Catechins are naturally occurring polyphenolic compounds with putative anti-inflammatory, antioxidant and free radical scavenging effects in vitro. However, their potential effects in vivo have not been established. Therefore we have investigated the effects of the catechin epicatechin gallate (ECG), on scar formation in a full thickness incisional model of wound healing in rats. ECG showed a significant improvement in the quality of scar formation both in terms of maturity and orientation of the collagen fibers. An increase in inducible nitric oxide synthase and cyclooxygenase-2 and a decrease in arginase-I activity and protein levels were observed at earlier time points. In addition, an increase in the number of new blood vessels was observed in the ECG-treated group. This correlated with the protein levels of vascular endothelial growth factor, the most potent angiogenic protein known. This study has therefore demonstrated, for the first time, that catechins, namely ECG, can significantly improve the quality of wound healing and scar formation. These effects may in part be due to an acceleration of the angiogenic response and an up-regulation of the enzymes nitric oxide synthase and cyclooxygenase.