The level of accordance between preoperative and postoperative diagnosis in patients undergoing adrenalectomy - a study of 230 consecutive cases.

Introduction: Patients are qualified for an adrenalectomy due to endocrine or oncologic reasons. Final histopathological diagnoses include a wide spectrum of more than a dozen entities. The aim of this study was to compare preoperative and postoperative diagnoses of patients undergoing adrenalectomy to determine the level of diagnostic accuracy, as well as sex and age of patients. Material and methods: A group of 214 patients (230 specimens in total) operated on in a single center was studied and their demographic and pathological data were investigated. Results: The majority of diagnoses were characterized by both high positive predictive value and sensitivity, excluding pheochromocytoma (60.0% and 67.7%, respectively) and adrenal cyst (100% and 37.5%, respectively). Patients operated on due to Cushing's syndrome were statistically significantly more often females (p = 0.009), while those with metastases (diagnosed both pre- and postoperatively) were more often males (both p = 0.001). Patients qualified due to non-functioning tumors were older than those with Cushing's or Conn's syndrome (p = 0.044 and p = 0.002, respectively). Conclusions: The lowest diagnostic accuracy is observed in cases of pheochromocytoma and adrenal cyst. Meticulous preparation of the patient for hormonal tests, including discontinuation of certain medications, is essential for obtaining accurate results. The diagnosis of Cushing's syndrome is more prevalent in females, while metastasis syndrome is more prevalent in males. Adrenocortical carcinoma may initially be diagnosed as a non-functioning tumor (1.6% of such cases) or a recurrence of a previously resected tumor, which should always raise a suspicion of a malignant neoplasm.

Current Knowledge on the Use of Neuromonitoring in Thyroid Surgery.

Thyroid surgery rates have tripled over the past three decades, making it one of the most frequently performed procedures within general surgery. Thyroid surgery is associated with the possibility of serious postoperative complications which have a significant impact on the patient's quality of life. Recurrent laryngeal nerve (RLN) palsy and external branch of the superior laryngeal nerve (EBSLN) palsy are, next to hypoparathyroidism and postoperative bleeding, some of the most common complications. The introduction of neuromonitoring into thyroid surgery, which enabled both the confirmation of anatomical integrity and the assessment of laryngeal nerve function, was a milestone that began a new era in thyroid surgery. The International Neural Monitoring Study Group has produced a standardization of the technique of RLN and EBSLN monitoring during thyroid and parathyroid surgery, which in turn increased the prevalence of neural monitoring during thyroidectomy. The current status of IONM and the benefits of its use have been presented in this publication.

The Incidence Trend and Management of Thyroid Cancer-What Has Changed in the Past Years: Own Experience and Literature Review.

Because of ambiguous and widely debated observations concerning the incidence, trend, and management of TC, we performed this analysis. We drew attention to some events, such as "cancer screening activity", introduction of noninvasive follicular neoplasm with papillary-like nuclear features (NIFTP) to TC types, possibility of papillary thyroid microcarcinoma (PTMC) active surveillance (AS), occurrence of personalized medicine in TC management, and, finally, COVID-19 pandemic time. Because of the opinion that all changes have been made mostly by PTC, we compared it to the remaining types of TC in terms of incidence, clinical and pathological characteristics, and treatment. We analyzed patients treated in a single surgical center in eastern Europe (Poland). The prevalence of TC significantly increased from 5.15% in 2008 to 13.84% in 2015, and then significantly decreased to 1.33% in 2022 when the COVID-19 pandemic lasted (p < 0.0001). A similar trend was observed for PTC, when the incidence significantly increased to 13.99% in 2015 and then decreased to 1.38% in 2022 (p < 0.0001). At that time, the NIFTP category was introduced, and observation of PTMC began. The prevalence of FTC and MTC also increased until 2015 and then decreased. Significant differences in age, types of surgery, necessity of reoperation, and pTNM between PTCs and other types of TCs were observed. The average age was significantly lower in PTC patients than in patients with the remaining types of TC (p < 0.0001). Four milestones, including NIFTP introduction, the possibility of PTMC AS, personalized cancer medicine, and the COVID-19 pandemic, may have influenced the general statistics of TC.

Proving the Superiority of Intraoperative Recurrent Laryngeal Nerve Monitoring over Visualization Alone during Thyroidectomy.

Vocal fold paralysis after thyroid surgery is still a dangerous complication that significantly reduces patients' quality of life. Since the intraoperative neuromonitoring (IONM) technique has been introduced and standardized, the most frequently asked question is whether its use has significantly reduced the rate of RLN injury during thyroid surgery compared to visual identification alone (VA). The aim of this study was to attempt to prove the superiority of IONM over VA of the RLN during thyroid surgery in the prevention of vocal fold paralysis, taking into account risk factors for complications. The medical records of 711 patients (1265 recurrent laryngeal nerves at risk of injury) were analyzed retrospectively: in 257 patients/469 RLNs at risk, thyroid surgery was performed with IONM; in 454 patients/796 RLNs at risk, surgery was performed with VA. The statistical analysis showed that in the group of patients with IONM only one risk factor-the surgeon's experience-proved statistically significant (OR = 3.27; p = 0.0478) regarding the overall risk of vocal fold palsy. In the group of patients where only visualization was used, 5 of the 12 factors analyzed were statistically significant: retrosternal goiter (OR = 2.23; p = 0.041); total thyroid volume (OR = 2.30; p = 0.0284); clinical diagnosis (OR = 2.5; p = 0.0669); gender (OR = 3.08; p = 0.0054) and risk stratification (OR = 3.30; p = 0.0041). In addition, the cumulative risk, taking into account the simultaneous influence of all 12 factors, was slightly higher in the group of patients in whom only VA was used during the procedure: OR = 1.78. This value was also considerably more statistically significant (p < 0.0001) than that obtained in the group of patients in whom IONM was used: OR = 1.73; p = 0.004. Conclusions: Risk factors for complications in thyroid surgery are not significant for any increase in the rate of vocal fold paralysis as long as surgery is performed with IONM, in contrast to thyroid surgery performed only with VA, thus proving the superiority of IONM over VA for safety.

Analysis of Risk Factors for Phonation Disorders after Thyroid Surgery.

Phonation disorders after thyroidectomy are among the most common complications and occur as a result of recurrent laryngeal nerve (RLN) injury. The multivariate analysis of risk factors for phonation disorders after thyroidectomy was assessed. A group of 830 patients with 1500 RLNs at risk of injury during thyroidectomy were analyzed retrospectively. The impact of the method of RLN identification, age, sex, BMI, kind of thyroid surgery, pathology, surgeon's experience and thyroid volume on vocal cord paralysis was analyzed. We found that the retrosternal goiter and the volume above 100 mL were the most important risk factors for both transient and permanent paralysis. Thyroid cancer had a statistically significant impact on the increase in permanent paralysis, while this indication had practically no impact on transient paralysis. Among patients over 65 years with obesity, the probability of transient complications approximately doubled, with no effect on the permanent paralysis. Men were approximately 1.7 times more likely to develop any type of phonation disorder. Secondary operations more than doubled the risk of transient and permanent vocal cord paralysis. Thyroidectomy with only visual RLN identification was associated with a risk of both transient and permanent vocal cord paralysis almost two times higher, compared to neuromonitoring.

Assessment of Preoperative TSH Serum Level and Thyroid Cancer Occurrence in Patients with AUS/FLUS Thyroid Nodule Diagnosis.

Thyroid-stimulating hormone (TSH) is a growth factor associated with the initiation and progression of well-differentiated thyroid cancer (WDTC). Atypia of undetermined significance and follicular lesion of undetermined significance (AUS/FLUS) are the most uncertain cytological diagnoses of thyroid nodules. The aim of the study was to determine the association of histopathological diagnosis with preoperative serum TSH levels in patients with AUS/FLUS thyroid nodule diagnosis. Among 5028 individuals with thyroid nodules, 342 (6.8%) with AUS/FLUS diagnoses were analyzed. The frequency of all histopathology diagnoses was assessed for associations with preoperative serum TSH levels. The median TSH concentration was significantly higher in patients with AUS/FLUS diagnosis and histopathology of WDTC than in patients with the same cytology result and histopathology of a benign tumor (p < 0.0001). The diagnostic potential of serum TSH level was determined to evaluate risk of malignancy in patients with thyroid nodules classified into the Bethesda III category. ROC analysis showed the TSH concentration at a cutoff point of 2.5 mIU/L to be an acceptable prognostic factor for WDTC. For this optimal cutoff point, the AUC was 0.877, the sensitivity was 0.830, and the specificity was 0.902. Preoperative serum TSH levels in patients with AUS/FLUS thyroid tumor diagnosis should be taken into consideration in the decision-making process and clinical management.

Risk factors of papillary thyroid microcarcinoma that predispose patients to local recurrence.

BACKGROUND: Currently, less aggressive treatment or even active surveillance of papillary thyroid microcarcinoma (PTMC) is widely accepted and recommended as a therapeutic management option. However, there are some concerns about these approaches. We investigated whether there are any demographic, clinical and ultrasound characteristics of PTMC patients that are easy to obtain and clinically available before surgery to help clinicians make proper therapeutic decisions. METHODS: We performed a retrospective chart review of 5,021 patients with thyroid tumors surgically treated in one center in 2008-2018. Finally, 182 (3.62%) PTMC patients were selected (158 (86.8%) females and 24 (13.2%) males, mean age 48.8±15.4 years). We analyzed the disease-free survival (DFS) time of the PTMC patients according to demographic and histopathological parameters. Univariate and multivariate logistic regression analyses were used to assess the relationships of demographic, clinical and ultrasound characteristics with aggressive histopathological features. RESULTS: Age ≥55 years, hypoechogenicity, microcalcifications, irregular tumor shape, smooth margins and high vascularity significantly increased the risk for minimal extrathyroidal extension (minETE), lymph node metastasis (LNM), and capsular and vascular invasion (p<0.0001). Multivariate logistic regression analysis demonstrated a statistically significant risk of LNM (OR = 5.98, 95% CI: 2.32-15.38, p = 0.0002) and trends toward significantly higher rates of minETE and capsular and vascular invasion (OR = 2.24, 95% CI: 0.97-5.19, p = 0.056) in patients ≥55 years than in their younger counterparts. The DFS time was significantly shorter in patients ≥55 years (p = 0.015), patients with minETE and capsular and vascular invasion (p = 0.001 for all), patients with tumor size >5 mm (p = 0.021), and patients with LNM (p = 0.002). CONCLUSIONS: The absence of microcalcifications, irregular tumor shape, blunt margins, hypoechogenicity and high vascularity in PTMC patients below 55 years and with tumor diameters below 5 mm may allow clinicians to select individuals with a low risk of local recurrence so that they can receive less aggressive management.

Thyroid cancer surgery - in what direction are we going? A mini-review.

The prevalence of thyroid cancer, especially in women, is increasing dramatically. Therefore, patients often undergo thyroidectomy upon diagnosis. However, the cosmetic outcome after surgery is of particular concern for many patients. Thus, minimally invasive procedures for treating thyroid disease have been established in recent decades. Total endoscopic and robotic procedures have been slowly and successively introduced while meeting all oncological criteria. Our analysis of the advantages and disadvantages of scarless surgical procedures suggests that the cosmetic aspects of these surgeries will continue to become more important. This review assesses the recent findings regarding the roles of endoscopic and robotic procedures in thyroid cancer surgery.

Distribution of the Highest Plantar Pressure Regions in Patients with Diabetes and Its Association with Peripheral Neuropathy, Gender, Age, and BMI: One Centre Study.

The abnormal plantar pressure distribution and value play a key role in the formation of plantar calluses and diabetic foot ulcer. The prevalence of the highest pressure different distribution and its association with various factors among patients with diabetes is not well known. The study purpose was to evaluate the prevalence of different regions for the highest pressure on the sole and its association with selected factors among patients with diabetes. Medical records of nonulcer patients were retrospectively analysed. The relationship between pressure patterns on the sole obtained during a pedobarographic test as a semiquantitative assessment with colourful print analysis and neuropathy, gender, age, and BMI was searched. The most common location of the highest pressure was the central part of the forefoot. No association was found between the different highest pressure regions and age, sensory neuropathy, calluses, and foot deformities. The highest pressure on the lateral part of the foot and midfoot was observed more often in females and in patients with a BMI ≥ 35. The prevalence of the highest pressure on the forefoot was more common in patients with a BMI < 35. Conclusions. The most frequent regions of the highest pressure on the sole in patients with diabetes were the central part of the forefoot (2-3 metatarsal heads) with no simple relationship to the assessed variables other than BMI < 35. Female gender and higher BMI seem to be responsible for shifting the place of the highest pressure to other places of the foot.

Patients with III and IV category of the Bethesda System under levothyroxine non-suppressive therapy have a lower rate of thyroid malignancy.

Thyroid nodules (TNs) assigned to the Bethesda System categories III and IV include numerous clinical characteristics, which increase or decrease the risk of malignancy. However, there are very few data regarding the influence of TSH non-suppressive thyroid hormone therapy (NSTHT) on the risk of malignancy in patients in the aforementioned categories. We assessed the number of patients with thyroid nodules assigned to categories III and IV who take TSH NSTHT and if thyroid hormone therapy is associated with a rate of malignancy. We retrospectively analyzed the medical records of 4,716 individuals and selected 532 (11.28%) patients with Bethesda System category III and IV thyroid nodules. All participants underwent surgery, and histopathological verification was obtained in all cases. In all, 33.1% of individuals with category III and IV thyroid nodules took TSH NSTHT. In patients with category III nodules, application of NSTHT was associated with a lower rate of thyroid cancer (TC), though this observation was not significant (OR = 0.55, p = 0.381). In patients with category IV nodules, we demonstrated a significantly lower rate of TC when NSTHT was applied (OR = 0.44, p = 0.005). In conclusion, the prevalence of patients with Bethesda System category III and IV thyroid nodules who take NSTHT is high. TSH NSTHT significantly decreases a rate of malignancy in category IV, but not category III patients.

Acromegaly associated with GIST, non-small cell lung carcinoma, clear cell renal carcinoma, multiple myeloma, medulla oblongata tumour, adrenal adenoma, and follicular thyroid nodules.

Acromegaly is associated with increased growth hormone (GH) and insulin-like growth factor-I (IGF-I) secretion which may support tumour development and growth. A 68-year-old woman was diagnosed with acromegaly due to typical clinical and hormonal characteristics. While contrast-enhanced MRI at diagnosis did not reveal a pituitary adenoma, a 5-mm lesion was identified on repeat scanning 13 months later. Abdominal and chest CT showed tumours of the stomach, right adrenal gland, and right lung. The CT also showed a hypodense lesion in the liver and heterogeneous echostructure of the thyroid gland with left lobe solid-cystic tumour. Somatostatin receptor scintigraphy revealed increased tracer accumulation in the right thyroid lobe. No tracer accumulation was noted at the location of the other tumours. The resected stomach, adrenal, chest, and thyroid lesions did not show GH secretion. The patient refused pituitary surgery, and her acromegaly is currently well-controlled with somatostatin analogue therapy. A CT scan 19 months later revealed a contrast-enhancing left kidney tumour that was a G1-grade clear cell carcinoma. Four years after the acromegaly diagnosis multiple myeloma were diagnosed with secondary renal amyloidosis. Genetic screening for a paraganglioma gene panel, AIP, MEN1, and CDKN1B mutations were negative. A next-generation cancer panel containing 94 cancer genes did not identify any possible unifying gene abnormality in her germline DNA. Coexistence of acromegaly and numerous other tumours suggests a common aetiology of these disorders. However, no genetic abnormality could be identified with the tests that have been performed.

Thyroid incidentaloma as a "PAIN" phenomenon- does it always require surgery?

A thyroid nodule discovered during imaging study performed due to unrelated thyroid disease is known as a thyroid incidentaloma, while positron emission tomography (PET) associated incidental neoplasm of thyroid is known as a "PAIN" phenomenon.To evaluate which patients with "PAIN" phenomenon should undergo surgery in regards to cytology results.Retrospective review of 4716 patients consecutively admitted and surgically treated in tertiary surgical center. 49 (1.04%) patients with "PAIN" phenomenon were identified. All of them had ultrasound-guided fine needle aspiration biopsy (UG-FNAB) performed and cytological results were evaluated according to The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). Patients were divided into 2 subgroups according to histopathological diagnosis: group 1 (n = 25) with benign tumor and group 2 (n = 24) with thyroid cancer.Cytology results were the significant predictors of cancer occurrence in patients with "PAIN" phenomenon (P < .0001). Logistic regression analysis confirmed that category III or higher of TBSRTC in patients with "PAIN" phenomenon significantly increased the risk of cancer (OR = 168.7, P < .0001).Patients with "PAIN" phenomenon and cytology assigned to category III or higher of the Bethesda system should undergo surgery due to significant risk of thyroid malignancy.

Perioperative complications of adrenalectomy - 12 years of experience from a single center/teaching hospital and literature review.

INTRODUCTION: The perioperative complication rate of adrenalectomy varies between 1.7% and 30.7% in the medical literature. This study presents outcomes of adrenalectomy in our center and tries to point out risk factors for perioperative problems. MATERIAL AND METHODS: We retrospectively analyzed all patients who underwent adrenalectomy in our department from January 2004 to June 2015. Patient's sex, indication for procedure, tumor laterality, surgical approach and surgeon's case volume were taken into consideration as possible risk factors for complications. RESULTS: There were 177 adrenalectomies performed on 170 patients. We reported 18 (10.2%) perioperative complications, 12 (6.8%) surgical and 6 (3.4%) medical. Laparotomy was a significant risk factor for medical (p < 0.01) and overall problems (p = 0.02). Operations more expansive than just adrenalectomy were associated with higher risk of medical complications (p = 0.01). Procedures performed by surgeons with higher volume were associated with smaller risk of medical complications (p < 0.01). Right and left adrenalectomies seem to be related to different kinds of risk - bleeding on the right, injury of surrounding structures on the left (p = 0.05). Patient's sex, indication for procedure, bilateral procedure and side of operation were not statistically significant risk factors for complications. CONCLUSIONS: Adrenal glands are surrounded by various anatomic structures (colon, pancreas, spleen, diaphragm) that may be injured during adrenalectomy. Complications following a laparoscopic procedure may arise from the use of monopolar coagulation and the patient's position on the operating table. High insufflation pressure during retroperitoneoscopic procedures may cause subcutaneous emphysema.

Voice quality preservation in thyroid surgery with neuromonitoring.

PURPOSE: Voice problems are common after thyroidectomy. The aim of this study was to assess the voice related quality of life after thyroidectomy with neuromonitoring. The sociodemographic and treatment factors influencing the quality of voice after the operation were investigated. METHODS: A total of 40 patients after thyroidectomy with neuromonitoring were enrolled into the study. The voice outcome was analyzed pre and postoperatively by two validated self-assessment questionnaires: Voice Handicap Index and Voice-Related Quality of Life survey. RESULTS: All external branches of the superior laryngeal nerve were identified during the operation. There were no recurrent laryngeal nerve palsies. The mean total VHIs before and after thyroid operation were 1.2 [SD 2.564] and 2.8 [SD 6.944], respectively (p = 0.5). Preoperatively, the mean overall score for the V-RQOL was 99.6; postoperatively 98.7 (p = 0.05). A strong correlation between the V-score of the V-RQOL and O-score of the VHI before and after thyroidectomy was observed (both p < 0.001). There was no correlation between V-RQOL or VHI and sex, the kind of thyroid operations, diagnosis, thyroid function, the mean volume of the goitre, the presence of retrosternal position and the extent of thyroid operations (p > 0.05). A small correlation between the mean age of the patients and postoperative O-Score of the VHI (p = 0.007650) and between the mean age and postoperative V-Score for the V-RQOL (p = 0.00648) was observed. CONCLUSIONS: The use of neuromonitoring in thyroid surgery is beneficial for patients to improve voice quality. The identification and preservation of EBSLNs is crucial to eliminate altered voice after thyroidectomy.

Evaluating the introduction of intraoperative neuromonitoring of the recurrent laryngeal nerve in thyroid and parathyroid surgery.

INTRODUCTION: Paresis of the recurrent laryngeal nerve (RLN) is a complication of thyroid surgery. Neuromonitoring as is gaining acceptance among surgeons. The aim of the study was to assess the number of technical problems in the initial phase of intraoperative neuromonitoring (IONM) use and the specificity, sensitivity, positive predictive value and negative predictive value of neuromonitoring. The number of cases of postoperative paresis (transient and permanent) was assessed. MATERIAL AND METHODS: The prospective analysis included 101 thyroid operations with IONM (190 RLNs at risk of injury) in the period from January to April, 2012. Demographic data, rate of RLN identification, sensitivity, specificity and predictive value of the method, the duration of the procedure and the percentage of RLN paresis were considered. RESULTS: The RLN was identified in 92% of the cases. Technical problems were observed in 12.98%, of which 61% were due to incorrect positioning of the endotracheal tube electrodes in relation to the vocal cords. The sensitivity, specificity, negative and positive predictive value and the accuracy of the method were respectively 71%, 98%, 62.5%, 98.9% and 97%. Early nerve injury occurred in 3.7% of the cases; 2.6% were temporary paresis and 1.1% permanent. CONCLUSIONS: During the initial stages of implementing IONM we experienced technical problems that required correction in every tenth patient. The positive predictive value was relatively low; nevertheless, good results in terms of the rate of accurate identification of the RLN as well as the low rate of RLN paresis support the use of this method.

A functional assessment of anatomical variants of the recurrent laryngeal nerve during thyroidectomies using neuromonitoring.

PURPOSE: The aim of the study was to assess the usefulness of intraoperative neuromonitoring (IONM) in identifying anatomical variants of the recurrent laryngeal nerve (RLN) during thyroidectomies, with emphasis on the nerve's relationship to the inferior thyroid artery (ITA), Zuckerkandl's tubercle, nonrecurrent laryngeal nerves (NRLNs), and extralaryngeal bifurcation. METHODS: A total of 128 subjects undergoing surgery for thyroid disorders were enrolled in the study, and the course and anatomical variants of RLN were assessed with IONM application. RESULTS: The standard relationship between RLN and ITA was that the artery and nerve intersect (100%). The right RLN was below the ITA in 76.67% of the patients, and the left RNL was below it in 75.81%. There were no statistically significant differences in the relationship between RLN and ITA on the two sides; and gender did not significantly influence the relationship between the RLN and ITA on either side. In one patient a nonrecurrent inferior laryngeal nerve was present on the right side (0.83%). RLN bifurcation was observed in 33.33% of the patients on the right and in 19.35% on the left side; the difference between sides was statistically significant (p < 0.05). Posterior tubercle (Zuckerkandl's tubercle) was observed on the right in 83% of the subjects and on the left in 69%. The age, thyroid volume and body mass index (BMI) did not influence the size of the tumor. CONCLUSIONS: The utilization of IONM of the RLN in thyroid surgery adds a new dimension to the standard of visual nerve identification allowing for functional nerve testing at the most vulnerable area of the dissection: at the level of Berry's ligament, posterior tubercle (Zuckerkandl's tubercle) and crossing of the RLN with the inferior thyroid artery.

Thyroid reoperation using intraoperative neuromonitoring.

PURPOSE: Thyroid reoperations are at a high risk of recurrent laryngeal nerve (RLN) injury. The aim of the study was to investigate whether the use of intraoperative neuromonitoring (IONM) can aid in the RLN identification and minimize the risk of its injury, in comparison with visual RLN identification. METHODS: This was a retrospective cohort study of patients who underwent thyroid reoperations with and without the use of IONM. Primary endpoint was the RLN identification rate; secondary: the prevalence of RLN injury, the frequency of total thyroidectomies, and the course of the RLN. RESULTS: The study involved 61 patients undergoing thyroid reoperation among whom 24 were operated on with visual RLN identification only, while 37 procedures used IONM. In the non-monitored reoperations, 44.4% of the RLN were visually identified, as opposed to 91.6% in the IONM group (p < 0.001). Transient paresis occurred in three nerves with visualization (6.6%), and in one in IONM group 1.6% (p = 0.185). Permanent paresis occurred in the group with visualization (6.6%), as opposed to none with neuromonitoring. The extent of resection in both groups was significantly different (p = 0.043). Total, near-total thyroidectomies, Dunhill operations and subtotal thyroidectomies were performed in 71, 17, 4, and 8% in the visualization group, and in 94, 0, 3, and 3%, respectively, in the IONM group. A non-anatomical RLN course was observed in 80% of the reoperations with IONM. CONCLUSIONS: Thyroid reoperation should be performed using IONM, because it allows for a significantly improved RLN identification rate and a significantly more radical resection.

Experience with intraoperative neuromonitoring of the recurrent laryngeal nerve improves surgical skills and outcomes of non-monitored thyroidectomy.

PURPOSE: Intraoperative neuromonitoring (IONM) can serve as a tool to increase skills in recurrent laryngeal nerve (RLN) identification and complete removal of thyroid tissue. The aim of this study was to validate this hypothesis. METHODS: This prospective study involved 632 patients (1161 RLNs at risk) who underwent thyroid surgery in 2011-2014. Although IONM was not used until 2012, this prospective study started on 1 January 2011. The three participating surgeons knew about the study before that date and that the rate of RLN identification would be carefully measured in total and near-total surgery. Solely, visual identification of the RLN was used throughout 2011. IONM was introduced as a training tool in 2012-2014 for the first 3 months of each year. In the remaining months, thyroid operations were performed without IONM. Outcomes of non-monitored thyroid operations were compared before (01-12/2011) vs. after (04-12/2012-2014) 3 months of exposure to IONM yearly (01-03/2012-2014). The rate of RLN identification was assessed in total and near-total thyroidectomies and in totally resected lobes in Dunhill's operation. The prevalence of RLN injury and the utilization of total thyroidectomy were evaluated. RESULTS: In 2011, the rate of successful RLN visual identification in total and near-total thyroidectomies and in totally resected lobes in Dunhill's operation was 45.71 %. After the introduction of IONM in 2012-2014, in the procedures performed without IONM, the rate was 86.66, 90.81, and 91.3 %. The prevalence of RLN injury in 2011 was 6.8 %, while in the years following the introduction of IONM, it was 3.61, 2.65, and 1.45 %. Utilization of total thyroidectomy increased from 47.9 % in 2011 to 100 % in 2014. CONCLUSIONS: Experience with IONM led to an increase in RLN identification (p < 0.0001), a decrease of RLN injury (p < 0.05), and an increase in the safe utilization of total thyroidectomy (p < 0.0001) in non-monitored thyroid operations. IONM is a valuable tool for surgical training.

The learning curve for intraoperative neuromonitoring of the recurrent laryngeal nerve in thyroid surgery.

PURPOSE: Intraoperative neuromonitoring (IONM) of the recurrent laryngeal nerve (RLN) is often used in thyroid surgery. However, this procedure is complex and requires a learning period to master the technique. The aim of the study was to evaluate the learning curve for IONM. METHODS: A 3-year period (2012-2014) of working with IONM (NIM3.0, Medtronic) was prospectively analyzed with a special emphasis on comparing the initial implementation phase in 2012 (101 patients, 190 RLNs at risk) with subsequent years of IONM use in 2013 (70 patients, 124 RLNs at risk) and 2014 (65 patients, 120 RLNs at risk). RESULTS: The rate of successful IONM-assisted RLN identification increased gradually over the 3-year study period (92.11 % in 2012 vs. 95.16 % in 2013 vs. 99.16 % in 2014; p = 0.022), with a corresponding decrease in the rate of technical problems (12.87, 4.3, and 4.6 %, respectively; p = 0.039). The rate of RLN injuries tended to decrease over time: 3.68, 1.55, and 0.83 %, respectively (p = 0.220). Between 2012 and 2014, increases in the sensitivity (71.4 vs. 100 %), specificity (98 vs. 99 %), positive predictive value (62.5 vs. 75 %), negative predictive value (98 vs. 100 %), and overall accuracy of IONM (97.4 vs. 99.6 %) were observed (p = 0.049). Increasing experience with IONM resulted in more frequent utilization of total thyroidectomy (92 % in 2012 vs. 100 % in 2013-2014; p = 0.004). CONCLUSIONS: There was a sharp decrease in the number of technical problems involving equipment setup from 2012 to 2014.