A geometrical model of L4-L5 lumbar segment was constructed using a three-dimensional graphics software. Four conditions of the degenerated discs, i.e. light degeneration, moderate degeneration, severe degeneration and complete excision degeneration, were simulated with loading situations using finite element method under the condition of appropriate computational accuracy. By applying a vertical load of 378.93 N on L4 vertebral plate, stress nephograms on joint isthmus under four different working conditions were obtained. The results showed that the contacted area of facet joint was influenced by the degree of intervertebral disc degeneration level, which influenced the mises stress on joint isthmus. It was proved that joint isthmus was the important pressure-proof structure of the back of lumbar vertebra, and the stress values and distribution were related to structural stiffness of the back of lumbar vertebra as well as the contact area of facet joint. The conclusion could be the theoretical reference for the analysis of spinal biomechanics and artificial disc replacement as well.
ObjectiveTo explore the effectiveness of thoracic endovascular aortic repair (TEVAR) for blunt thoracic aortic injury (BTAI) with hostile stent-graft proximal landing zone. MethodsA retrospective analysis was made on the clinical data of 13 patients with BTAI with hostile stent-graft proximal landing zone treated by TEVAR between December 2007 and December 2014. There were 10 males and 3 females with the mean age of 44 years (range, 24-64 years). The imaging examination indicated Stanford type B aortic dissection in 7 cases, pseudoaneurysm in 3 cases, aneurysm in 1 case, and penetrating ulcer in 2 cases. According to the partition method of thoracic aortic lesion by Mitchell, 8 cases underwent stent-graft with left subclavian artery (LSA) coverage, 3 underwent chimney stents for LSA, and 2 for left common carotid artery (LCCA). In 2 cases receiving chimney TEVAR involving LCCA, one underwent steel coils at the proximal segment of LSA to avoid type II endoleak and the other underwent in situ fenestration for endovascular reconstruction of LSA. ResultsAll TEVAR procedures were successfully performed. The mean operation time was 1.8 hours (range, 1-3 hours); the mean intraoperative blood loss was 120 mL (range, 30-200 mL); and the mean hospitalization time was 15 days (range, 7-37 days). No perioperative death and paraplegia occurred. The patients were followed up 3-30 months (mean, 18 months). Type I endoleak occurred in 1 case during operation and spontaneously healed within 6 months. Hematoma at brachial puncture site with median nerve compression symptoms occurred in 1 case at 3 weeks after operation; ultrasound examination showed brachial artery pseudoaneurysm and thrombosis, and satisfactory recovery was obtained after pseudoaneurysmectomy. No obvious chest pain, shortness of breath, left upper limbs weakness, numbness, and dizziness symptoms were observed. Imaging examination revealed that stentgraft and branched stent remained in stable condition. Meanwhile the blood flow was unobstructed. No lesions expanded and ruptured. No new death, bacterial infection, or other serious complications occurred. ConclusionAccording to Mitchell method, individualized plan may be the key to a promising result. More patients and further follow-up need to be included, studied, and observed.
ObjectiveTo investigate the adequate surgical procedures for well-differentiated thyroid cancer (WDTC) located in the isthmus.MethodsNineteen patients with WDTC located in the isthmus were identified with WDTC and managed by surgery in Department of General Surgery in Xuanwu Hospital of Capital University from Jun. 2013 to May. 2018.ResultsAmong the nineteen cases, fifteen patients had a solitary malignant nodule confined to the isthmus, four patients had malignant nodules located separately in the isthmus and unilateral lobe. One patient received extended isthmusectomy as well as relaryngeal and pretracheal lymphectomy; six patients received isthmusectomy with unilateral lobectomy and central compartment lymph node dissection of unilateral lobe; four patients received isthmusectomy with unilateral lobectomy and subtotal thyroidectomy on the other lobe as well as central compartment lymph node dissection of unilateral lobe; seven patients received total thyroidectomy or isthmusectomy with unilateral lobectomy and nearly total thyroidectomy on the other lobe, as well as central compartment lymph node dissection of both sides; one patient received total thyroidectomy and central compartment lymph node dissection of both sides, as well as lateral thyroid lymph node dissection of both sides. The median operative time was 126 minutes (67–313 minutes), the median intraoperative blood loss was 30 mL (10–85 mL), and the median hospital stay was 6 days (4–11 days). Hypocalcemia occurred in 12 patients. There were no complications of recurrent laryngeal nerve palsy or laryngeal nerve palsy occurred. All the nineteen patients were well followed. During the follow up period (14–69 months with median of 26 months), there were no complications of permanent hypoparathyroidism occurred, as well as the 5-year disease-specific survival rate and survival rate were both 100%.ConclusionsFor patients with well-differentiated thyroid cancer located in the isthmus with different diameters and sentinel node status, individualized surgical procedures should be adopted.
Objective To analyze the clinical and pathological factors related to the metastasis of contralateral central lymph nodes (Cont-CLNs) in unilateral near isthmus papillary thyroid carcinoma (PTC), and to establish a prediction model of lymph node metastasis, so as to provide reference for the scope of lymph node dissection. Methods A total of 381 unilateral PTC patients from February 2012 to June 2022 were collected in our hospital, and according to the location of the cancer, they were divided into the isthmus group (n=152) and the unilateral glandular lobe group (n=229) , and the correlation analysis was performed on whether there was Cont-CLNs metastasis. One hundred and fifty-two patients in the unilateral isthmus PTC group were further divided into metastatic and non metastatic groups based on whether Cont-CLNs metastasis occurred. Univariate analysis was used to analyze the relationship between gender, age, distribution of glandular lobe, tumor size, tumor location, pathological subtype, capsule invasion, thyroid stimulating hormone (TSH) level, combine Hashimoto’s thyroiditis (HT), ipsilateral central lymph nodes（Ipsi-CLNs) metastasis and Cont-CLNs metastasis. According to the univariate analysis results of this study and the possible high-risk factors of contralateral central lymph node metastasis of unilateral thyroid papillary carcinoma in other literatures, they were included in logistic multivariate analysis to obtain independent risk factors and establish a prediction model. Results The incidence of Cont-CLNs metastasis in unilateral isthmus PTC patients was higher than that in nilateral glandular lobe group (24.3% vs. 14.4%, χ²=6.009, P=0.014). Univariate analysis showed that Cont-CLNs metastasis in patients with unilateral near isthmus PTC was correlated with age (P=0.02), tumor size (P＜0.01), capsule invasion (P＜0.01) and Ipsi-CLNs metastasis (P＜0.01), but not with gender, distribution of glandular lobe, tumor location, pathological subtype, TSH level and whether to merge HT (P＞0.05). Further logistic multivariate analysis suggested that capsule invasion and Ipsi-CLNs metastasis were independent risk factors for Cont-CLNs metastasis in patients with unilateral near isthmus PTC. Moreover, the above logistic multifactor prediction model is proved to be effective by the test of goodness of fit by Hosmer and Lemeshow. Conclusions Capsule invasion and Ipsi CLNs metastasis are high risk factors for Cont-CLNS metastasis in patients with unilateral near isthmus PTC. It is suggested that such patients should be cleaned up with prophylactic Cont-CLNs while cleaning up Ipsi-CLNs.