IONM and minimally invasive videoassisted thyroidectomy.

BACKGROUND: We know that benefits of MIVAT are related to a better cosmetic result and lower post-operative pain in comparison to CT. The incidence of nerve cold palsy is related to a correct identification of the recurrent laringeal nerve (RLN) as standard procedure in thyroid surgery. From September 2014 we have introduced the use of intraoperative neural monitoring(I-IONM) in all thyroidectomies in the Unit of General Surgery of University Hospital of Parma, including in MIVAT. PATIENTS AND METHODS: We have considered all patients treated from September 2014 to September 2017 for thyroid diseases using MIVAT and IONM. Intermittent neuromonitoring with NIM-3.0 equipment (Medtronic, Jacksonville, FL, USA) was used during all operations. We have recorded all data about age, sex, diagnosis, surgical time, i-IONM signal, postoperative pain, postoperative hypocalcemia after 24 hours, haematoma and vocal cord palsy. The mean hospital stay was collected from surgical procedure to hospital discharge. We have considered vocal dysfunctions that persist six months after surgery as permanent. RESULTS: From September 2014 to September 2017 we treated consecutively with both MIVAT and i-IONM 100 patients. Considering the extent of surgery, 26 pts underwent to hemithyroidectomy and 74 pts to total thyroidectomy. The mean surgical time was 61.8 minutes. In 7 cases the patients were affected by preoperative clinical dysphonia. Using I-IONM during thyroidectomy, we recorded in 5 cases (5%) a loss of signal; in two cases (2%) we experienced a temporary postoperative vocal cord palsy. DISCUSSION: In our experience the use of IONM has improved the safety during thyroidectomy because precision that can be achieved by endoscopic procedures is further improved by complementary use of IONM. The costs associated to a potential reduction of medical litigation have not been investigated.

IONM and thyroidectomy in benign thyroid disease. Analysis of adverse events.

OBJECTIVES: The aim of this study is to identify statistically significant differences in the onset of postoperative complications in patients undergoing thyroid surgery for benign pathology, following the systematic introduction of intraoperative neuromonitoring (IONM) of the laryngeal nerves. MATERIALS AND METHODS: In this study we have retrospectively analysed data of 604 consecutive patients underwent to thyroidectomy in the Unit of General Surgery - University Hospital of Parma between January 2011 and December 2017. All patients were divided in two groups: the first group of patients was operated without the use of IONM (Group A) the second group was operated after the introduction of the systematic use of IONM (Group B). We have compared the incidence of adverse events in these two groups, analysing the impact of IONM on the onset of the most frequent complications after thyroid surgery. We have considered the impact of other variables in both groups, such as thyroiditis, hyperfunction and gland sinking in mediastinum. RESULTS: No statistically significant differences in the incidence between Group A (patients operated without the use of IONM) and Group B (patients operated with the use of IONM) were detected, though a decreasing trend after the introduction of IONM was observed. No statistically significant differences were reported even analysing the influence of other patient's variables such as thyroiditis, hyperfunction and glandular sinking in mediastinum. CONCLUSION: Even if the number of patients considered is not sufficient to value statistically significant differences, the decreasing trend of the incidence of postoperative complications after introduction of IONM encourage us. The surgeon expertise is still the most relevant variable influencing the decreasing of postoperative complications, underlining the importance of the centralization of this kind of surgery in the high volume centres.

Modulation of auxin-binding proteins in cell suspensions : I. Differential responses of carrot embryo cultures.

This paper shows that the level of 2,4-dichlorophenoxyacetic acid (2,4-D) in the medium determines the level of auxin-binding proteins in the membranes of carrot, Daucus carota, cells grown in suspension. This induction takes slightly more than 2 hours to complete and can be elicited by natural as well as synthetic auxins. The auxin binding sites thus generated, which are pronase-sensitive, bind 2,4-D, indoleacetic acid, and naphthalene-acetic acid (NAA) equally well. However both alpha- and beta-NAA bind, whereas only alpha-NAA is effective in the inductive process. Cells committed to embryogeny (proembryogenic masses) do not respond to auxin, i.e. their level of auxin-binding proteins remains very low, and they do not seem to synthesize the hormone, as indicated by inhibitor studies. Sensitivity to, and production of, auxin, begins when the embryo becomes polarized, i.e. at postglobular stage.

Modulation of auxin-binding proteins in cell suspensions : II. Isolation and initial characterization of carrot cell variants impaired in somatic embryogenesis.

Cultured cell lines from carrot (Daucus carota L.) with little or no embryogenic potential were examined for the auxin-binding capacity of their membranes. The lines belonged to different classes: (a) wild-type lines kept in culture for different periods (the longer the period, the lower being their embryogenic potential); (b) variants, isolated after mutagenesis, showing normal growth but a lack of embryogenic response; (c) auxin-resistant lines, isolated as colonies on solid media containing 45 µM 2,4-D; (d) a previously described tumorous line (E9) isolated because of its resistance to hypomethylating drugs. All of these lines showed alterations in auxin-induced, auxin-binding capacity (modulation), i.e. in the non-embryogenic lines the addition of auxin increased the auxinbinding capacity to a very small degree, or removal of the hormone did not produce the proper decrease in that capacity, or both defects could be simultaneously present. Both types of defects were shown to be correctable: after treatments designed to increase the amplitude of modulation, embryogenic capacity was restored in a number of lines.

A carrot cell variant temperature sensitive for somatic embryogenesis reveals a defect in the glycosylation of extracellular proteins.

The temperature-sensitive carrot cell variant ts11c, arrested in somatic embryogenesis after the globular stage, was characterized. The sensitivity to a shift from 24 degrees C (permissive temperature) to 32 degrees C (non-permissive temperature) is greatest at the globular stage of embryogenesis, while cells proliferating in unorganized fashion and plantlets are not affected. Embryogenesis in ts11c is also arrested at the permissive temperature by replacement of conditioned culture medium with fresh medium. The timing of sensitivity of ts11c to medium replacement coincides with the sensitivity to temperature shift. Both sensitivities are recessive in somatic hybrids between ts11c and wild-type cells. Extracellular glycoproteins synthesized by ts11c at the non-permissive temperature contain much less fucose than those synthesized by the wild type. The glycoproteins synthesized by the variant under non-permissive conditions do not accumulate at the periphery of the embryo, as their wild-type counterparts do, but instead show a diffuse distribution throughout the embryo. The defect in ts11c can be fully complemented by the addition of extracellular wild-type proteins. A revertant of ts11c was isolated that simultaneously reacquired temperature insensitivity and normal glycosylation ability. Collectively, these observations indicate that ts11c is not able to perform proper glycosylation at the non-permissive temperature and suggest that the activity of certain extracellular proteins, essential for the transition of globular to heart stage somatic embryos, depends on the correct modification of their oligosaccharide side-chains.