Variation in spatial distance between the lumbar interlaminar window and intervertebral disc space during flexion-extension.

PURPOSE: Knowledge of interlaminar space is important for undertaking percutaneous endoscopic discectomy via an interlaminar approach (PED-IL). However, dynamic changes in the lumbar interlaminar space and the spatial relationship between the interlaminar space and intervertebral disc space (IDS) are not clear. The aim of this study was to anatomically clarify the changes in interlaminar space height (ILH) and variation in distance between the two spaces during flexion-extension of the lumbar spine in vitro. METHODS: First, we used a validated custom-made loading equipment to obtain neutral, flexion, and extension 3D models of eight lumbar specimens through 3D reconstruction software. Changes in ILH (ILH, IL-yH, IL-zH) and distances between the horizontal plane passing through the lowest edge of the lamina of the superior lumbar vertebrae and the horizontal plane passing through the lowest position of the trailing edge of the same-level IDS (DpLID) at L3/4, L4/5 and L5/S1 were examined on 3D lumbar models. RESULTS: We found that ILH was greater at L4/5 than at L3/4 and L5/S1 in the neutral position, but the difference was not significant. In the flexion position, ILH was significantly more than that in neutral and extension positions at L3/4, L4/5, and L5/S1. There were significantly more DpLID changes from neutral to flexion than that from neutral to extension at all levels (L3/4, L4/5, L5/S1). CONCLUSION: These findings demonstrated level-specific changes in ILH and DpLID during flexion-extension. The data may provide a better understanding of the spatial relationship between lumbar interlaminar space and IDS, and aid the development of segment-specific treatment for PED-IL.

An ex vivo liver training model continuously perfused to simulate bleeding for suture skills involved in laparoscopic liver resection: development and validity.

BACKGROUND: Suture skills are essential to laparoscopic liver resection. The current suture training models are not ideal enough. The aim of this study is to develop and verify a highly simulated-bleeding continuously perfused training model (CPTM) and to evaluate its training efficacy. METHODS: CPTM was constructed using fresh lamb liver whose portal veins were perfused with red-dyed liquid gelatin. Construct validity of CPTMs was tested in 33 participants with three levels of laparoscopic experience (experts, intermediates, and novices) who were demanded to finish one superficial stitch and one deep stitch for suture hemostasis on CPTMs. The CPTMs were also evaluated by the experts. CPTMs were compared with dry box training models (DBTMs) regarding training efficacy among the novices who were assigned to DBTM and CPTM groups to, respectively, complete a 10-day training on CPTMs or DBTMs. Before and after their assignments, their superficial stitches were assessed by completion time, suture accuracy, and suture knot performance while their deep stitches by completion time and bleeding control. RESULTS: CPTM proved to be construct valid by both superficial and deep stitches. Significant differences were found regarding completion time (763, 271, 174 s), suture accuracy (4.4, 1.8, 0.2 mm), and suturing knot performance (12.1, 21.5, 22.0) for superficial stitches (p < 0.001), as well as regarding completion time (807, 423, 277 s) for deep stitches (p < 0.001). Positive comments were given by all experts. CPTMs helped novices to acquire laparoscopic suture skills. Their training efficacy was significantly better than that of DBTMs (p < 0.05). Learning curves of CPTM group plateaued at the sixth round for superficial stitches and at the seventh round for deep stitches. CONCLUSION: CPTM offers trainees a highly simulated-bleeding means to acquire advanced laparoscopic suture skills. The suture skills learned on CPTMs may improve significantly at the seventh round.

Development of a continuously perfused ex vivo kidney training model for laparoscopic partial nephrectomy: validity and efficiency.

BACKGROUND: Suture hemostasis is essential for laparoscopic partial nephrectomy (LPN). This study aimed to develop, validate, and test the efficacy of a continuously perfused training model (CPTM) in LPN with high-level simulated bleeding. MATERIALS AND METHODS: The CPTM was constructed using fresh porcine kidneys with renal arteries continuously perfused with red-dyed liquid gelatin. Twenty-nine participants with expert, intermediate, or novice laparoscopic experience levels were recruited. The expert and intermediate participants evaluated the CPTM, and the novice participants were randomly assigned to one of two groups to complete training on a CPTM or dry box training model (DBTM). Messick's framework criteria were utilized to assess the validity and training efficacy of the model. The data were analyzed using the Mann-Whitney U , Kruskal-Wallis, and Friedman tests. A value of P< 0.05 was considered statistically significant. RESULTS: Positive comments were provided by all experts and intermediates for the Content . The Relationships with other variables demonstrated significant differences among novices, intermediates, and experts in all metrics ( P< 0.05). The Consequences showed that the CPTM helped novices acquire LPN skills. The training efficacy was significantly better than that of the DBTM ( P< 0.05). There were no significant differences between the final performances of the novices and the initial performances of the experts ( P >0.05). Synthesizing all metrics, the LPN skills learned using CPTMs were significantly improved in the 12th round of training. CONCLUSION: The CPTM offered a high-level simulation of bleeding with realistic tissue texture for acquiring LPN skills. Training of no fewer than 12 rounds is recommended for a novice's LPN training on the CPTM.

[LC-MS/MS-based screening of new protein biomarkers for cervical precancerous lesions and cervical cancer].

OBJECTIVE: To screen potential plasma protein biomarkers for the progression of cervical precancerous lesions into cervical carcinoma and analyze their functions. METHODS: Plasma samples obtained from healthy control subjects, patients with low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL), cervical cancer (CC), and patients with CC after treatment were enriched for low-abundance proteins for liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The MS data of the samples were analyzed using Discoverer 2.2 software, and the differential proteins (peptide coverage ≥20%, unique peptides≥2) were screened by comparison of LSIL, HSIL and CC groups against the control group followed by verification using target proteomics technology. Protein function enrichment and coexpression analyses were carried out to explore the role of the differentially expressed proteins as potential biomarkers and their pathological mechanisms. RESULTS: Compared with the control group, both LSIL group and HSIL group showed 9 differential proteins; 5 differentially expressed proteins were identified in CC group. The proteins ORM2 and HPR showed obvious differential expressions in LSIL and HSIL groups compared with the control group, and could serve as potential biomarkers for the progression of cervical carcinoma. The expression of F9 increased consistently with the lesion progression from LSIL to HSIL and CC, suggesting its value as a potential biomarker for the progression of cervical cancer. CFI and AFM protein levels were obviously decreased in treated patients with CC compared with the patients before treatment, indicating their predictive value for the therapeutic efficacy. Protein function enrichment analysis showed that all these differentially expressed proteins were associated with the complement system and the coagulation cascades pathway. CONCLUSIONS: We identified 5 new protein biomarkers (F9, CFI, AFM, HPR, and ORM2) for cervical precancerous lesions and for prognostic evaluation of CC, and combined detection of these biomarkers may help in the evaluation of the development and progression of CC and also in improving the diagnostic sensitivity and specificity of cervical lesions.

[Construction of a three-dimensional digital model of the liver of Wuzhishan mini-pig].

OBJECTIVE: To construct a three-dimensional (3D) liver model of Wuzhishan mini-pig for virtual liver surgeries. METHODS: The biliary tree and hepatic arteries of Wuzhishan mini-pig were perfused with perchloroethylene and ethyl acetate along mixed with lead oxide, and the hepatic vein and portal vein were perfused with a mixture of dental base acrylic resin and lead oxide. The sectional images were acquired using a 64-slice spiral CT, and the 3D models of the portal vein, hepatic vein, biliary tree, hepatic arteries, and liver parenchyma were reconstructed using Mimics software; the resection image of the liver was also designed. The intrahepatic vascular cast was prepared by corroding the soft tissue with hydrochloric acid. RESULTS AND CONCLUSION: The intrahepatic vascular cast obtained fully retained the vascular architecture and displayed the fifth- and sixth-level branches of the hepatic vein and portal vein and the third- and fourth-level branches of the artery and bile duct. The 3D model of liver allowed stereoscopic and accurate display of the third- and fourth-level branches of the hepatic vein and portal vein and the second- and third-level branches of the artery and bile duct. The 3D model showed fewer branches but represented the structural distribution identical to the cast. The 3D model could clearly display the spatial relationship between the vasculature and the soft tissue in virtual resection of the liver tissues, and thus provides a useful model for training of laparoscopic liver resection.