Role of Copeptin in Predicting Postoperative Hyponatremia and Hypernatremia in Patients Undergoing Endoscopic Pituitary Adenoma Surgery.

BACKGROUND AND OBJECTIVES: Arginine vasopressin (AVP) is an important hormone responsible for maintaining sodium homeostasis after pituitary surgery. The measurement of AVP levels is difficult because of its short half-life (t1/2). Copeptin is a preprohormone of AVP, and it is a more stable peptide, which can be used as surrogate marker for AVP. This study aims to assess the role of copeptin as a predictor of postoperative hyponatremia and hypernatremia in patients undergoing endoscopic pituitary adenoma surgery. METHODS: This prospective study included 50 patients who underwent endoscopic pituitary adenoma surgery. Serum copeptin levels of these patients were assessed (1) preoperatively (C1), (2) at extubation (C2), and (3) postoperative day 4 (C3). Perioperative data regarding fluid and sodium balance were collected from patients. Statistical analysis was done using the above data. RESULTS: The copeptin values were assessed against the sodium disturbances. 100% of patients who developed transient diabetes insipidus had a relative decrease in C2 from C1 (P - .0002). 88% of patients who developed early hyponatremia had a relative increase in C2 as compared with C1 (P < .01). 75% of patients who developed delayed hyponatremia had a relative increase in C3 as compared with C1 (P = .003). CONCLUSION: A relative increase or decrease in early change in copeptin (C2-C1) can predict development of early hyponatremia or transient central diabetes insipidus, respectively. A relative increase in delayed change in copeptin (C3-C1) can predict development of delayed hyponatremia.

CMR gives clue to "ragged red fibers" in the heart in a patient with mitochondrial myopathy.

Mitochondrial myopathy may manifest either as isolated myopathy or as a neuromuscular multisystemic disease and is caused by genetic defects in the mitochondrial genome resulting in respiratory chain disorders. MELAS, which is characterised by mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes due to gene mutations in the mitochondrial DNA (adenine-to-guanine transition at nucleotide pair 3243, m.3243A>G), constitutes such a mitochondrial multisystemic disease. Although hypertrophied or dilated cardiomyopathy is quite common in MELAS, there have been no cardiovascular magnetic resonance (CMR)-based studies in these patients so far. This case report represents the first case in which comprehensive CMR and endomyocardial biopsy (EMB) data were obtained in the same patient with mitochondrial myopathy. Late gadolinium enhancement (LGE) imaging demonstrated a unique pattern of myocardial damage and histological work-up revealed the presence of "ragged red fibers" (conglomerates of mitochondria) in the heart tissue verifying the diagnosis of a mitochondrial cardiomyopathy as part of the underlying mitochondrial disease MELAS.

Feeding arteries of the spinal cord at CT angiography before and after thoracic aortic endografting.

PURPOSE: To study the visualization of spinal cord feeding arteries in patients with complex thoracic aortic pathology undergoing endovascular aortic repair (EVAR) using an optimized protocol for multislice computed tomographic angiography (MSCTA). METHODS: Eighteen consecutive patients (13 men; mean age 63 years, range 45-79) with aortic type B dissections (n=5), chronic expanding aortic dissections (n=5), thoracic aortic aneurysms (n=6), or penetrating aortic ulcers (n=2) underwent 16-slice CTA before and after (mean interval 9 days) EVAR. Pulse rate and neurological status were documented. Quantitative density measurements were taken at regions of interest (ROI) in the ascending thoracic aorta and at the level of the diaphragm. Two experienced radiologists qualitatively assessed the posterior intercostal arteries (PIA; fully visible, partially visible, non-visible), dorsal branches (DB; visible/non-visible), and artery of Adamkiewicz (AKA; visible/non-visible) on multiplanar reformations and maximum intensity projection reconstructions. RESULTS: MSCTA was performed successfully in 17/18 patients before and after EVAR (1 patient was excluded after EVAR owing to rising creatinine levels). Before EVAR, MSCTA revealed 197/203 PIAs within the stented area, of which 179 were fully and 18 partially visible. No significant (p=0.37) difference was noted for overall PIA detection within the stented area on post-EVAR MSCTA (185/203 PIA), although only 124 were fully and 61 partially visible. Similar results were obtained for DB visualization. The AKA were seen in 10/17 patients pre EVAR and 9/17 post EVAR. In 2 patients, the AKA was localized within the stented aortic segment. ROI analysis revealed contrast densities of 427+/-89 HU and 398+/-84 HU on pre- and post-EVAR MSCTA, respectively. No neurological events were observed. CONCLUSION: The majority of posterior intercostal arteries and dorsal branches remain open after EVAR due to retrograde perfusion. High-resolution MSCTA permits accurate pre- and post-EVAR visualization of spinal cord feeding arteries in patients with thoracic aortic pathology.