Recurrent laryngeal nerve palsy and substernal goiter. An Italian multicenter study.

The aim of this retrospective multicenter study was to verify whether the substernal goiter and the type of surgical access could be risk factors for recurrent laryngeal nerve palsy during total thyroidectomy. Between 1999-2008, 14,993 patients underwent total thyroidectomy. Patients were divided into three groups: group A (control; n=14.200, 94.7%), cervical goiters treated through collar incision; group B (n=743, 5.0%) substernal goiters treated by cervical approach; group C (n=50, 0.3%) in which a manubriotomy was performed. Transient and permanent unilateral palsy occurred significantly more frequently in B+C vs. A (P≤.001) and in B vs. A (P≤.001). Transient bilateral palsy was significantly more frequent in B+C vs. A (P≤.043) and in C vs. A (P≤.016). Permanent bilateral palsy was significantly more frequent in B+C vs. A (P≤.041), and in B vs. A (P≤.037). Extension of the goiter into the mediastinum was associated to increased risk of recurrent nerve palsy during total thyroidectomy.

Review article: in vitro studies of gall-bladder smooth muscle function. Relevance in cholesterol gallstone disease.

The interplay between contraction and relaxation in the gall-bladder muscularis leads to appropriate gall-bladder emptying and refilling during fasting and in the postprandial state in vivo. Several studies in both human and animal models have focused on cellular and molecular events in the gall-bladder wall in health and disease in vitro. Principal methods to study gall-bladder smooth muscle function include receptor binding studies (at the level of plasmamembranes or histological sections), phase contrast microscopy (at the level of isolated smooth muscle cells), and tensiometry (at the level of smooth muscle strips or the whole gall-bladder). At a very early stage, cholesterol gallstone disease is characterized by exposure of the gall-bladder wall to excess of biliary cholesterol and the cytotoxic effect of the bile salt deoxycholate. On a long-term basis, a form of gall-bladder leiomyopathy develops with defects involving the mechanisms of signal transduction at the level of plasmamembranes. The end-stage result is pathological contraction and/or relaxation of smooth musculature, impaired gall-bladder motility and gall-bladder stasis, all key factors in the pathogenesis of biliary cholesterol crystallization and gallstones.