Biomedical subjects

Felipe Rafael Zaldivar-Ramirez

Publications and source records attributed to Felipe Rafael Zaldivar-Ramirez.

3 recordsLinked to original sources

PubMed2005

Importance of the intraoperative identification of the external branch of the superior laryngeal nerve during thyroidectomy: electromyographic evaluation.

OBJECTIVE: To establish the frequency and degree of postthyroidectomy injury of the external branch of the superior laryngeal nerve (EBSLN) by means of electromyography and to assess whether intraoperative identification of the nerve and the presence of malignancy influence morbidity. PATIENTS AND METHODS: Prospective, randomized, blind study. Comparison of 100 superior thyroid poles subjected to surgery because of benign and malignant disease, divided in three groups: G1, thyroidectomies, without searching for the EBSLN; G2, thyroidectomies, searching for the EBSLN; G3, Control, lobes, contralateral to the lobectomy, not surgically manipulated. The electromyographic function of the EBSLN was assessed in all cases, classifying the degree of injury and clinically assessing its function. Central tendency measures were used, as well as X (2) and multiple variance analysis. RESULTS: In G1, with 50 dissections of the superior pole, 25 injuries were found in 15 patients (10 bilateral and 5 unilateral). In G2, EBSLN injury was found after 13 explorations of the superior pole in 8 patients (5 bilateral and 3 unilateral). G3 patients did not present EBSLN injury. X (2) among groups and degree of injury revealed that intraoperative identification of the EBSLN decreases its injury. No evidence were found that injury frequency is increased by the presence of thyroid malignancy, extracapsular infiltration, or size of tumor. Clinical manifestations of hoarseness were present in 14% of G1 patients and 8% of G2 patients. DISCUSSION: The rate of EBSLN injury increased when not exploring and/or identifying it expressly. The presence of cancer, extracapsular extension, or size of the thyroid tumor exerted no influence on the frequency of injury; localization of the nerve was the only factor affecting injury. Hoarseness correlated with the degree of injury. CONCLUSION: EBSLN must be localized expressly to decrease the risk of injury.

Adolescent↗

PubMed2004

Combined use of fine-needle aspiration biopsy, MIBI scans and frozen section biopsy offers the best diagnostic accuracy in the assessment of the hypofunctioning solitary thyroid nodule.

PURPOSE: The probability of malignancy is increased in hypofunctioning solitary thyroid nodules (HFNs). Fine-needle aspiration biopsy (FNA), (99m)Tc-methoxyisobutylisonitrile (MIBI) and frozen section biopsy (FS) have limited independent diagnostic accuracy for the differential diagnosis of HFNs. The goal of this study was to assess the accuracy of the three independent diagnostic methods in distinguishing between benign and malignant disease. METHODS: A total of 130 patients with an HFN on the (99m)Tc-pertechnetate scan were included in this study. FNA, MIBI scans, FS, thyroidectomy and histological analysis of surgical specimens for final diagnosis were performed in all patients. RESULTS: Of the 130 patients, 80 (61.54%) had benign lesions and 50 (38.46%), malignant lesions. FNA was diagnostic in 78/130 (60%) patients and non-diagnostic in 52/130 (40%) patients. None of the patients with a negative MIBI scan had a final histological diagnosis of malignancy, and MIBI scans were negative in 38.46% of patients with non-diagnostic FNA results. FS was diagnostic in 104/130 (80%) patients and non-diagnostic in 26/130 (20%) patients. Sensitivity, specificity, positive and negative predictive values and positive and negative likelihood ratios were 81.3%, 97.8%, 96%, 88%, 36.95 and 0.19 respectively for FNA; 100%, 61.3%, 61.7%, 100%, 2.58 and 0 respectively for MIBI; and 80.5%, 100%, 100%, 89%, 0 and 0.2 respectively for FS. Use of both MIBI scans and FS in patients with non-diagnostic FNA rendered a specificity and sensitivity of 100%. CONCLUSION: MIBI scans exclude malignancy in a significant proportion of patients with non-diagnostic FNAs (38% in this study). Cystic nodules with a positive MIBI scan should be further investigated even when the FNA result indicates a benign lesion. Combined use of FNA, MIBI and FS offers the best diagnostic accuracy.

Adaptor Proteins, Signal Transducing↗

PubMed2002

Causes for early reintervention after thyroidectomy.

BACKGROUND: The purpose of our study was to ascertain the causes for early reintervention after thyroidectomy performed by a surgical team using a systematized surgical technique. MATERIAL/METHODS: We analyzed 1131 patients, 939 (83.1%) women and 192 (16.9%) men, average age 38.7 years (range 12 to 79). Of these patients, there were 675 hemithyroidectomies with isthmusectomy (59.74%), 189 subtotal thyroidectomies (16.71%), and 267 total thyroidectomies, alone or with regional lymphatic dissection at levels VI and VII (23.55%). Statistical analysis was performed by main tendency measures and chi square (chi-squared) for comparison of two independent samples; the dependent variable was the rate of early reintervention, while the independent variables included causes, time of presentation, hormonal functional state and extent of surgery. RESULTS: Early reintervention was necessary in 11 cases (0.97%). 9 were due to hematoma (0.79%) resolved with drainage and hemostasis, and two (0.18%) due to acute respiratory failure (ARF) caused by laryngeal edema, resolved by tracheostomy. Analysis based on diagnosis, extent of surgery and functional state failed to reveal statistically significant differences. The maximum time presentation of complications was 6 hours. CONCLUSIONS: The most intense postoperative monitoring is necessary during the first six hours. The low frequency of early reintervention and the appearance of complications in less than 8 hours enable thyroid surgery to be performed on a short-stay basis with adequate safety margins.

Adolescent↗