Risk Factors for Calcium-Phosphate Disorders after Thyroid Surgery.

INTRODUCTION: Iatrogenic hypoparathyroidism following thyroidectomy is one of the most common complications significantly reducing patients' quality of life. OBJECTIVES: This study aimed to analyze the risk factors for calcium-phosphate disorders following thyroidectomy. PATIENTS AND METHODS: The study group consisted of 211 patients who underwent thyroidectomy for different conditions in 2018-2020. Demographic, clinical and surgical risk factors were analyzed against hypoparathyroidism and hypocalcemia. RESULTS: Hypoparathyroidism occurred in 15.63% of patients, and hypocalcemia occurred in 45% of those operated on. There was statistical significance between hypoparathyroidism and the extent of thyroid surgery: thyroidectomy vs. lobectomy (p = 0.02, OR = 4.5) and surgeon experience (p = 0.016, OR = 6.9). Low preoperative PTH levels were associated with a higher incidence of hypoparathyroidism (p = 0.055, OR = 0.9). There was a statistically significant correlation between the occurrence of hypocalcemia and preoperative vitamin D deficiency (p = 0.04, OR = 3.5). Low calcium levels before surgery were associated with a higher incidence of hypocalcemia (p = 0.051, OR = 0.5). Meta-analyses of selected risk factors confirmed that the most significant factor in the incidence of hypocalcemia was a decrease in PTH levels (p < 0.001). CONCLUSIONS: The extent of thyroid surgery and the experience of the surgeon are the most significant risk factors for hypoparathyroidism. Hypocalcemia is much more common than hypoparathyroidism. Among the risk factors for hypocalcemia, in addition to the decrease in parathormone levels due to iatrogenic parathyroid damage, we should mention vitamin D deficiency in the preoperative period.

Application and efficacy of transcutaneous electrical acupoint stimulation (TEAS) in clinical practice: A systematic review.

Transcutaneous electrical acupoint stimulation (TEAS) is an emerging therapeutic approach that combines the effects of transcutaneous electrical nerve stimulation (TENS) with acupuncture point stimulation. Due to its noninvasive nature, it possesses relative advantages over traditional acupuncture and needle-based electrostimulation. Despite the large number of randomized clinical trials (RCTs) describing the effectiveness of TEAS in different applications, its role and mechanism are still not fully understood. The aim of this study was to systematically compare and summarize the latest studies examining a variety of TEAS applications in clinical practice. Databases, including Medline (PubMed), Cochrane Library and Google Scholar were searched without any time restrictions (as of March 2021). The analysis was performed according to the Cochrane Collaboration criteria. Out of 637 studies, only 22 RCTs were selected. Nine studies evaluated the impact of TEAS on nausea and vomiting (NV), showing beneficial effects compared to standard therapy. Eight RCTs examined the effectiveness of TEAS in pain management, reporting pain alleviation described using the visual analog scale (VAS) and lowering of total opioid doses. Improvement of postoperative recovery, in vitro fertilization and pregnancy outcomes, as well as display of cardioprotective properties were found to positively correlate with TEAS. As a noninvasive modality with advantages over classical acupuncture and needle-based electrostimulation, TEAS may be a valuable tool in clinical practice, particularly for pain and NV management. However, considering the methodological quality of the RCTs, rigorous large-scale clinical trials are required to evaluate the clinical utility of this method.

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.

The Use of Artificial Intelligence in the Diagnosis and Classification of Thyroid Nodules: An Update.

The incidence of thyroid nodules diagnosed is increasing every year, leading to a greater risk of unnecessary procedures being performed or wrong diagnoses being made. In our paper, we present the latest knowledge on the use of artificial intelligence in diagnosing and classifying thyroid nodules. We particularly focus on the usefulness of artificial intelligence in ultrasonography for the diagnosis and characterization of pathology, as these are the two most developed fields. In our search of the latest innovations, we reviewed only the latest publications of specific types published from 2018 to 2022. We analyzed 930 papers in total, from which we selected 33 that were the most relevant to the topic of our work. In conclusion, there is great scope for the use of artificial intelligence in future thyroid nodule classification and diagnosis. In addition to the most typical uses of artificial intelligence in cancer differentiation, we identified several other novel applications of artificial intelligence during our review.

Transcutaneous electrical acupoint stimulation to reduce opioid consumption in patients undergoing inguinal hernia repair: protocol for a randomized controlled trial.

BACKGROUND: The purpose of this study is to evaluate the efficacy and safety of transcutaneous electrical acupoint stimulation (TEAS) in the postoperative treatment of patients undergoing inguinal hernia repair compared with sham and no treatment group. METHODS: This study is a protocol for a three-armed, single-blinded, placebo-controlled randomized controlled trial. Ninety participants scheduled for inguinal hernia repair will be randomly assigned to the TEAS group (n = 30), sham group (n = 30), and control group (n = 30). The TEAS group will receive treatment using four portable coin-sized electro-stimulators at both local and distal acupuncture points. The sham group will receive sham treatment with mock electrostimulation. The treatment groups will receive mixed frequency stimulation (alternating at 2 and 100 Hz every 3 s) in continuous mode for 30 min at intervals of 2 h for 24 h postoperatively. The control group will receive postoperative pain control using patient-controlled analgesia (PCA) device. The primary outcome is the total morphine dose received in the postoperative period (mg) using PCA 24 h after surgery. The number of PCA demands (i.e., times the button will be pressed) and delivered bolus doses, score on the Visual Analogue Scale, opioid-related side effects, the requirement for supplemental medications, score on the Hospital Anxiety and Depression Scale (HADS), and blood levels of stress hormones cortisol and prolactin. DISCUSSION: The results of this trial will determine whether TEAS with intensified stimulation protocol is a safe and effective option for reducing analgesic consumption and postoperative pain. TRIAL REGISTRATION: ISRCTN76428396. Registered on 05 October 2020. https://www.isrctn.com/ISRCTN76428396.

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.

Update on the Diagnosis and Management of Medullary Thyroid Cancer: What Has Changed in Recent Years?

Medullary thyroid carcinoma (MTC) is a neoplasm originating from parafollicular C cells. MTC is a rare disease, but its prognosis is less favorable than that of well-differentiated thyroid cancers. To improve the prognosis of patients with MTC, early diagnosis and prompt therapeutic management are crucial. In the following paper, recent advances in laboratory and imaging diagnostics and also pharmacological and surgical therapies of MTC are discussed. Currently, a thriving direction of development for laboratory diagnostics is immunohistochemistry. The primary imaging modality in the diagnosis of MTC is the ultrasound, but opportunities for development are seen primarily in nuclear medicine techniques. Surgical management is the primary method of treating MTCs. There are numerous publications concerning the stratification of particular lymph node compartments for removal. With the introduction of more effective methods of intraoperative parathyroid identification, the complication rate of surgical treatment may be reduced. The currently used pharmacotherapy is characterized by high toxicity. Moreover, the main limitation of current pharmacotherapy is the development of drug resistance. Currently, there is ongoing research on the use of tyrosine kinase inhibitors (TKIs), highly specific RET inhibitors, radiotherapy and immunotherapy. These new therapies may improve the prognosis of patients with MTCs.

Advances in the Diagnosis and Therapeutic Management of Gastroenteropancreatic Neuroendocrine Neoplasms (GEP-NENs).

Neuroendocrine neoplasms (NENs) are an increasingly common cause of neoplastic diseases. One of the largest groups of NENs are neoplasms localized to the gastroenteropancreatic system, which are known as gastroenteropancreatic NENs (GEP-NENs). Because of nonspecific clinical symptoms, GEP-NEN patient diagnosis and, consequently, their treatment, might be difficult and delayed. This situation has forced researchers all over the world to continue progress in the diagnosis and treatment of patients with GEP-NENs. Our review is designed to present the latest reports on the laboratory diagnostic techniques, imaging tests and surgical and nonsurgical treatment strategies used for patients with these rare neoplasms. We paid particular attention to the nuclear approach, the use of which has been applied to GEP-NEN patient diagnosis, and to nonsurgical and radionuclide treatment strategies. Recent publications were reviewed in search of reports on new strategies for effective disease management. Attention was also paid to those studies still in progress, but with successful results. A total of 248 papers were analyzed, from which 141 papers most relevant to the aim of the study were selected. Using these papers, we highlight the progress in the development of diagnostic and treatment strategies for patients with GEP-NENs.

Atypia and Follicular Lesions of Undetermined Significance in Subsequent Biopsy Result: What Clinicians Need to Know.

Atypia and follicular lesions of undetermined significance (AUS/FLUS) is the most controversial category of The Bethesda System. The risk of malignancy (ROM) in this group is estimated as 5-15%, however, the occurrence of two or more subsequent biopsy results with AUS/FLUS diagnosis makes these clinical situations more complex. We evaluated the ROM and prognostic value of aggressive ultrasound (US) features in 342 patients with thyroid nodules (TNs) with subsequent biopsy results of AUS/FLUS. We assessed US features and compared them with the final histopathological diagnosis. Overall, 121 (35.4%) individuals after first AUS/FLUS diagnosis underwent surgery and 221 (64.6%) patients had repeated biopsies. The ROM after first, second, and third biopsies with subsequent AUS/FLUS diagnosis were 7.4%, 18.5%, and 38.4% respectively. We demonstrated significantly higher rates of occurrence of aggressive US features in patients with malignancy (p < 0.0001). The age <55 years old was also a significant risk factor for TC (p = 0.044). Significant associations were found between aggressive US features and malignancy in patients after first diagnosis of AUS/FLUS (p < 0.05). The juxtaposition of US features with the number of biopsy repetitions of TN with consecutive AUS/FLUS diagnoses may simplify the decision-making process in surgical management. Two or three consecutive biopsy results with AUS/FLUS diagnosis increases the ROM.

The Correlation of Age with Prognosis of Atypia of Undetermined Significance and Follicular Lesion of Undetermined Significance in Thyroid Nodules.

PURPOSE: Although some prognostic variables and risk factors for thyroid cancer (TC) are age-related, the association between age and the risk of TC in patients with thyroid nodules (TNs) assigned to atypia of undetermined significance (AUS) and follicular lesion of undetermined significance (FLUS) is poorly estimated. The aim of this study was to assess the histopathology of AUS/FLUS and the risk of TC according to the age of the patients at the time of AUS/FLUS diagnosis. PATIENTS AND METHODS: Among 5021 individuals treated for TNs at one institution from 2008 to 2018, 161 (3.2%) patients with 161 TNs assigned to the AUS/FLUS category (1 nodule per patient) were selected and stratified by age at initial diagnosis: <55 years, 55-75 years and >75 years. Logistic regression analysis was used to estimate the association of age with the risk of TC diagnosis. RESULTS: Ninety-one (56.52%) patients <55 years old, 58 (36.02%) patients 55-75 years old, and 12 (7.45%) individuals >75 years old were identified. There were 130 (80.7%) females and 31 (19.3%) males with a mean age of 50.6 ± 16.12 years. Among the evaluated TNs, 142 (88.2%) were ultimately diagnosed as benign, and 19 (11.8%) were diagnosed as malignant. Younger age in patients was significantly related to malignancy outcome (p=0.024 for age <55 years). Patients aged 55-75 years had a significantly lower risk of TC than the other age categories (p=0.040). The risks of high vascularity and fast tumor growth were significantly higher in the youngest category than in the other categories (age <55 years old: p=0.045 and p=0.002, respectively). CONCLUSION: Although patients with TNs classified as AUS/FLUS by ultrasound-guided fine needle aspiration biopsy (UG-FNAB) are not typically qualified for surgery, it is worth noting that younger patients with an AUS/FLUS diagnosis might be at a higher risk of TC.

Obesity and Overweight Are Associated with Minimal Extrathyroidal Extension, Multifocality and Bilaterality of Papillary Thyroid Cancer.

Epidemiological studies have shown a strong association between high body mass index (BMI) and papillary thyroid cancer (PTC). We assessed the clinical and histopathological features of PTC in patients with a higher BMI and compared them to analogous parameters in PTC patients with a normal BMI. We retrospectively analyzed 5021 medical records of patients admitted and surgically treated for thyroid tumors in one center between 2008 and 2018. Finally, we extracted data from 523 adult patients with PTC and stratified patients into two groups according to BMI: Group 1 with BMI < 25 kg/m2 and Group 2 with BMI ≥ 25 kg/m2. Data stratification was performed to estimate the association of overweight and obesity with clinical and histopathological features of PTC in both univariable and multivariable binary logistic regression analyses. Overall, compared to patients with a normal BMI, overweight and obese patients had a greater risk of minimal extrathyroidal extension (minimal ETE), multifocality and bilaterality of PTC (p < 0.001 for all). Analysis did not show that BMI was significantly associated with the more advanced tumor-node-metastasis (TNM) stage (p = 0.894). Obesity and overweight were significantly associated with higher aggressiveness of PTC. When considering various management options for PTC patients, these findings regarding overweight and obesity should be taken into consideration during the decision-making process.

Recommendation for cholecystectomy protocol based on intraoperative ultrasound - a single-centre retrospective case-control study.

INTRODUCTION: There is a strong need to make laparoscopic cholecystectomy as safe as possible, but sometimes complications in the form of bile duct and/or vascular injury occur. The safe plane of dissection can be precisely identified with intraoperative ultrasound, ensuring reduction of the complication rate to a minimum. AIM: To evaluate the advantages of the cholecystectomy protocol based on the use of intraoperative ultrasound during laparoscopic and open cholecystectomy. MATERIAL AND METHODS: The study group consisted of 700 patients with symptomatic cholecystolithiasis, which was divided into two subgroups: with the critical view of safety only (312 patients) and with the critical view of safety + laparoscopic/open cholecystectomy ultrasound (388 patients). Laparoscopic cholecystectomy and conversion in patients from the second subgroup were performed under the control of intraoperative ultrasound. RESULTS: We did not observe any biliary complications, and the visualization of the common bile duct, the proper hepatic artery and the portal vein was obtained in every patient from the critical view of safety + laparoscopic/open cholecystectomy ultrasound group. The mean time of the operation was significantly shorter and the conversion, biliary injury and intraoperative bleeding rates were significantly lower in this group of patients. CONCLUSIONS: Intraoperative ultrasound is a very efficient and safe method of guidance, and its use should be standard along with the critical view of safety during cholecystectomy.

Laparoscopic Ultrasound and Safe Navigation Around the Shrunken Gallbladder.

Background: The contracted gallbladder may predispose to a higher rate of biliary or vasculobiliary injury (VBI). It is usually associated with unclear anatomy due to chronic inflammation and fibrosis in the hepatoduodenal ligament region. Laparoscopic ultrasound (LUS) can very effectively delineate anatomical conditions during cholecystectomy. Our study aimed to compare the visual and ultrasonographic navigation around the shrunken gallbladder. Materials and Methods: The study group consisted of 612 patients qualified for laparoscopic cholecystectomy. The shrunken gallbladder was diagnosed intraoperatively in 13 patients (2.1%). In 6 patients, the only intraoperative navigation method was a visual evaluation of anatomical conditions, and in 7 patients, the method was LUS. Results: The operating time and the length of hospital stay after surgery were significantly lower, the number of conversions was insignificantly lower, and the number of successful visualization of anatomical conditions was significantly higher in the LUS group. We did not observe any bile duct and VBI in patients with the shrunken gallbladder. Conclusions: The combination of the fundus-first and subtotal cholecystectomy with LUS navigation might be an effective proposal when coming across the shrunken gallbladder.

DNA methylation in adipocytes from visceral and subcutaneous adipose tissue influences insulin-signaling gene expression in obese individuals.

OBJECTIVE: Both obesity and insulin resistance are characterized by severe long-term changes in the expression of many genes of importance in the regulation of metabolism. Because these changes occur throughout life, as a result of external factors, the disorders of gene expression could be epigenetically regulated. MATERIALS/METHODS: We analyzed the relationship between obesity and insulin resistance in enrolled patients by means of evaluation of the expression rate of numerous genes involved in the regulation of adipocyte metabolism and energy homeostasis in subcutaneous and visceral adipose tissue depots. We also investigated global and site-specific DNA methylation as one of the main regulators of gene expression. Visceral and subcutaneous adipose tissue biopsies were collected from 45 patients during abdominal surgery in an age range of 40-60 years. RESULTS: We demonstrated hypermethylation of PPARG, INSR, SLC2A4, and ADIPOQ promoters in obese patients with insulin resistance. Moreover, the methylation rate showed a negative correlation with the expression of the investigated genes. More, we showed a correlation between the expression of PPARG and the expression of numerous genes important for proper insulin action. Given the impact of PPARγ on the regulation of the cell insulin sensitivity through modulation of insulin pathway genes expression, hypermethylation in the PPARG promoter region may constitute one of the epigenetic pathways in the development of insulin resistance in obesity. CONCLUSIONS: Our research shows that epigenetic regulation through excessive methylation may constitute a link between obesity and subsequent insulin resistance.

Transcutaneous Electrical Acupoint Stimulation Reduces Postoperative Analgesic Requirement in Patients Undergoing Inguinal Hernia Repair: A Randomized, Placebo-Controlled Study.

Given the rising rate of opioid-related adverse drug events during postsurgical pain management, a nonpharmacologic therapy that could decrease analgesic medication requirements would be of immense value. We designed a prospective, placebo-and-randomized controlled trial to assess the clinical effect of transcutaneous acupoint electrical stimulation (TEAS) on the postoperative patient-controlled analgesia (PCA) requirement for morphine, as well as side effects and recovery profile after inguinal hernia repair. Seventy-one subjects undergoing inguinal hernia repair with a standardized anesthetic technique were randomly assigned to one of three analgesic treatment regimens: PCA + TEAS (n = 24); PCA + sham-TEAS (no electrical stimulation) (n = 24), and PCA only (n = 23). The postoperative PCA requirement, pain scores, opioid-related side effects, and blood cortisol levels were recorded. TEAS treatment resulted in a twofold decrease in the analgesic requirement and decreased pain level reported by the patients. In addition, a significant reduction of cortisol level was reported in the TEAS group at 24 h postoperatively compared to the sham and control groups. We conclude that TEAS is a safe and effective option for reducing analgesic consumption and postoperative pain following inguinal hernia repair.

Recommendation for Photographic Documentation of Safe Laparoscopic Cholecystectomy.

BACKGROUND: Bile duct injury and vasculobiliary injury are possible complications during laparoscopic cholecystectomy which can lead to increased morbidity, mortality, costs of hospitalization and litigation. Proper documentation of the critical view of safety and safe plane of dissection may play a crucial role for archivization, teaching and medicolegal purposes. METHODS: The study group consisted of 100 patients with symptomatic cholecystolithiasis qualified for laparoscopic cholecystectomy. The critical view of safety was documented on two photographs and safe plain of dissection obtained with laparoscopic ultrasound was documented on one photograph as well as the whole procedure was recorded. The photographs were printed in the operating theatre and videos were stored on an external hard drive. RESULTS: The mean time to obtain and analyse photographs was significantly shorter than video, and the size of the stored data was significantly smaller for photographs than videos. The cost of one documentation procedure was significantly lower for video than photographs. Critical view of safety was obtained in 91 patients, and laparoscopic ultrasound was successful in 99 patients. The conversion rate was 2%, and fundus-first cholecystectomies were performed in 6% of patients. We did not observe any biliary and vascular complications. CONCLUSIONS: Photographic documentation of the critical view of safety and safe plane of dissection should be an inherent part of laparoscopic cholecystectomy. Our proposal of documentation prepared in the operating theatre and stored in the patient's documentation is an example of an easy, fast and cheap method of data archivization.

The evaluation of B-SAFE and ultrasonographic landmarks in safe orientation during laparoscopic cholecystectomy.

INTRODUCTION: Even though the prevalence of bile duct injury (BDI) is nowadays lower than before and close to the era of open cholecystectomy, there is a strong need to make it even lower. B-SAFE is a group of five visual landmarks that may be used before dissection in the hepatocystic triangle for better orientation around the gallbladder. Another method is laparoscopic ultrasound (LUS), which enables confirmation of structures in the hepatoduodenal ligament and delineation of the safe plane of dissection. AIM: To evaluate the use of B-SAFE and ultrasonographic landmarks during laparoscopic cholecystectomy in navigation around the gallbladder. MATERIAL AND METHODS: The study group consisted of 158 patients with symptomatic cholecystolithiasis. The methods of intraoperative orientation around the gallbladder attempted in every patient during laparoscopic cholecystectomy included B-SAFE and ultrasonographic landmarks. RESULTS: The identification rate of ultrasonographic landmarks - the upper border of "Mickey Mouse" sign (MMS) (the equivalent of the Rouviere's sulcus), the bile duct, and the hepatic artery - was significantly higher in patients with body mass index ≥ 30 kg/m2 and fibrosis and chronic inflammation in the gallbladder neck than B-SAFE. LUS was also significantly more successful in the identification of the bile duct in the whole study group than B-SAFE. There were no significant differences according to the identification of the duodenum. The conversion rate was 2.6%, and we did not observe any BDI. CONCLUSIONS: Visual landmarks defined in B-SAFE are not as reliable as ultrasonographic landmarks; thus, LUS should be taken into consideration in the first place as a method of navigation around the gallbladder.