Advances in cancer DNA methylation analysis with methPLIER: use of non-negative matrix factorization and knowledge-based constraints to enhance biological interpretability.

DNA methylation is an epigenetic modification that results in dynamic changes during ontogenesis and cell differentiation. DNA methylation patterns regulate gene expression and have been widely researched. While tools for DNA methylation analysis have been developed, most of them have focused on intergroup comparative analysis within a dataset; therefore, it is difficult to conduct cross-dataset studies, such as rare disease studies or cross-institutional studies. This study describes a novel method for DNA methylation analysis, namely, methPLIER, which enables interdataset comparative analyses. methPLIER combines Pathway Level Information Extractor (PLIER), which is a non-negative matrix factorization (NMF) method, with regularization by a knowledge matrix and transfer learning. methPLIER can be used to perform intersample and interdataset comparative analysis based on latent feature matrices, which are obtained via matrix factorization of large-scale data, and factor-loading matrices, which are obtained through matrix factorization of the data to be analyzed. We used methPLIER to analyze a lung cancer dataset and confirmed that the data decomposition reflected sample characteristics for recurrence-free survival. Moreover, methPLIER can analyze data obtained via different preprocessing methods, thereby reducing distributional bias among datasets due to preprocessing. Furthermore, methPLIER can be employed for comparative analyses of methylation data obtained from different platforms, thereby reducing bias in data distribution due to platform differences. methPLIER is expected to facilitate cross-sectional DNA methylation data analysis and enhance DNA methylation data resources.

External focus instruction using a paper balloon: impact on trunk and lower extremity muscle activity in isometric single-leg stance for healthy males.

Introduction: Core stability is crucial for preventing and rehabilitating lumbar spine injuries. An external focus instruction using a paper balloon is an effective way to activate the trunk muscles. However, the degree of trunk and lower extremity muscle activation during single leg stance with external focus instruction using a paper balloon is unknown. This study aimed to investigate the core muscle involving activity in the trunk and lower extremities on both the support and non-support sides with or without using external focus instruction using a paper balloon during isometric single-leg stance. Methods: Thirteen healthy males aged 20-28 years volunteered to take part in this study and performed a single leg stance task with and without an external focus instruction, pressing their non-supporting foot onto a paper balloon without crushing it. The participant's muscle electrical activity was recorded during the single leg task using surface EMG and intramuscular EMG for six trunk muscles (transversus abdominis, internal oblique, external oblique, rectus abdominis, multifidus, and lumbar erector spinae) and five lower extremity muscles (gluteus maximus, gluteus medius, adductor longus, rectus femoris, and biceps femoris). Results: Compared to the normal single leg stance, the external focus instruction task using a paper balloon showed significantly increased transversus abdominis (p < 0.001, p < 0.001), internal oblique (p = 0.001, p < 0.001), external oblique (p = 0.002, p = 0.001), rectus abdominal (p < 0.001, p < 0.001), lumbar multifidus (p = 0.001, p < 0.001), lumbar erector spinae (p < 0.001, p = 0.001), adductor longus (p < 0.001, p < 0.001), rectus femoris (p < 0.001, p < 0.001), and biceps femoris (p < 0.010, p < 0.001) muscle activity on the support and non-support sides. Conclusion: In conclusion, external focus instruction using a paper balloon significantly activates the trunk and lower extremities muscles on both the support and non-support sides. This finding provides insights for designing programs to improve coordination and balance. The benefits extend to diverse individuals, encompassing athletes, tactical professionals, and the general population, mitigating the risk of injury or falls linked to inadequate lower limb balance.

Clinicopathological predictors of postoperative long-term myasthenic status in resected thymoma with myasthenia gravis.

PURPOSE: Surgical patients with thymoma and myasthenia gravis (MG) must have their MG status and oncological outcomes critically monitored. We aimed to identify clinicopathological predictors of the postoperative MG status. METHODS: We conducted a retrospective review of 40 consecutive surgical patients with MG-related thymomas between 2002 and 2020. The quantitative myasthenia gravis score (QMGS) and Myasthenia Gravis Foundation of America post-intervention status (MGFA-PIS) were used to evaluate postoperative MG status. RESULTS: All patients underwent extended total thymectomy. The most common WHO type was type B2 (32%), while 65% of patients had type B1-B3 and 35% had type A-AB thymomas. Eleven patients (28%) achieved controlled MG status in MGFA-PIS 6 months after surgery. This controlled status was observed more frequently in type A-AB than in B1-B3 (57% vs. 12%, p = 0.007). In a multivariate analysis, WHO type (A-AB or B1-B3) was an independent predictor of worsening episodes of MG based on the QMGS (Type B1-B3, hazard ratio: 3.23, 95% confidence interval: 1.12-9.25). At the last follow-up, 23 patients (58%) achieved controlled MG status. The 5-year overall survival rate of all patients was 93.7%. CONCLUSION: The WHO type of thymoma is an informative predictor of postoperative MG status in patients with MG-related thymoma.

Nuss procedure for the treatment of pectus excavatum with dyspnea following oropharyngeal cancer surgery: a case report.

Pectus excavatum (PE) causes cardiopulmonary dysfunction depending on the degree and form of the depression. The patient was a 74-year-old woman with a history of PE. Fourteen years ago, a total glossolaryngectomy was performed for oropharyngeal cancer. Two years later, the patient gradually experienced difficulty in breathing. Computed tomography (CT) revealed severe PE and right main bronchial stenosis. We performed a Nuss procedure for PE repair to surgically release the stenosis of the right main bronchus. Postoperative chest CT showed improvement in the sternal depression and right main bronchial stenosis. Furthermore, shortness of breath was relieved postoperatively. Oropharyngeal cancer surgery may cause tracheal support disruption, leading to leftward shift and severe stenosis of the right main bronchus due to sternum depression. This is an important report regarding respiratory distress caused by a combination of PE and post-oropharyngeal cancer surgery.

Combined Ravitch and Nuss procedure for patients with severe pectus excavatum: technique and initial results.

The Nuss procedure for pectus excavatum (PE) is both less invasive and very simple compared to the Ravitch procedure. However, it may be difficult to perform the Nuss procedure in cases of severe PE. Therefore, we developed a Combined Ravitch and Nuss (CRN) procedure and examined its effectiveness in patients with severe PE. Nine patients with severe PE underwent the CRN procedure. Data on patient characteristics and perioperative results were collected retrospectively. The median Haller index (HI) was 15.4 (range, 6.3-29.3). No significant intraoperative adverse events were noted. Postoperatively, marked improvements in HI were seen in all cases (3.29, range, 2.72-4.96). Two surgical site infections on the shallow layer and one wound seroma occurred. No recurrences were observed during the observation period. Our novel CRN procedure is useful for achieving adequate and sustainable sternal elevation with less invasiveness for patients with severe PE.

Combined Ravitch and Nuss procedure for pectus excavatum with dyspnea following scoliosis repair.

Pectus excavatum (PE) is often associated with scoliosis and can elicit cardiovascular disturbances under rare conditions. Here we report a patient who was treated with a combined Ravitch and Nuss procedure for PE with dyspnea following scoliosis repair to improve her symptoms. The patient was a 49-year-old woman with a history of PE and scoliosis. Right inferior pulmonary vein stenosis was caused by posterior spinal fusion for scoliosis prior to the PE repair. We could safely correct the chest wall deformity and treat dyspnea by performing a modified Ravitch repair in combination with the Nuss procedure.

Effectiveness of an educational approach between adolescents and adults with patellofemoral pain syndrome: a scoping review with meta-analysis.

[Purpose] This study aimed to compare the effectiveness of an educational approach between adolescents and adults with patellofemoral pain syndrome. [Participants and Methods] The PROSPERO protocol number is CRD42022362680. Four databases (PubMed, CINAHL, Scopus, Cochrane) were searched. Randomized control trials on the effectiveness of the educational approach for patellofemoral pain syndrome were compared between adolescents and adults. Two investigators independently screened eligible studies. Two randomized control trials proceeded through meta-analysis with a visual analogue scale in the mid-term (from 18 weeks to 6 months). [Results] The meta-analysis results indicated that no significant difference was observed between education and combined education with exercise. A tendency to improve in the intervention of combined education with exercise for adolescents was noted, whereas no effect of education for adults was observed. [Conclusion] Treatment strategies combining education with exercise for patellofemoral pain syndrome may differ between adolescents and adults.

[Clinicopathological Features and Imaging Characteristics of Pulmonary Mucosa-associated Lymphoid Tissue Lymphoma].

BACKGROUND: Pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma is a rare disease. We report seven cases of pulmonary MALT lymphoma. CASES: Chest computed tomography (CT) revealed various morphological features, including a solitary mass, a solid nodule, and ground-glass opacity. Multiple nodules were observed in one patient. However, the tumor margins were ill-defined in all seven cases, and air bronchograms were identified in five cases. The solitary mass was found to extend along the pulmonary lymphatic vessels. Six patients underwent R0 resection, while one underwent an open lung biopsy. Histopathological findings in all seven cases showed lymphoepithelial lesions. Regarding their immunohistological findings, all patients were diagnosed with pulmonary MALT lymphoma. Two patients received postoperative chemotherapy with rituximab. The progression-free survival time was 52 (range, 22-122) months. Postoperative course was uneventful in all patients. CONCLUSION: MALT lymphoma is characterized by an ill-defined margin, air bronchogram, and tumor extension along the pulmonary lymphatic vessels, all of which aid in diagnosis. MALT lymphoma is a low-grade lymphoma, and the prognosis is favorable. Therefore, follow-up examination without treatment can be one of the therapeutic options if patients are diagnosed with pulmonary MALT lymphoma.

Relationship between Isokinetic Trunk Muscle Strength and Return to Sports Competition after Conservative Therapy in Fresh Cases of Lumbar Spondylolysis: A Retrospective Observational Study.

This study aimed to clarify the relationship between isokinetic trunk muscle strength and return to sporting activities in fresh cases of lumbar spondylolysis treated with conservative therapy. Patients included a total of ten men (age: 13.5 ± 1.7) who were instructed by their attending physicians to stop exercising and who met the eligibility criteria. Isokinetic trunk muscle strength was measured immediately after exercising for the first time (First) and one month (1M). Flexion and extension and maximum torque/body weight ratio were significantly lower First compared to 1M at all angular velocities (p < 0.05). Maximum torque generation time was significantly lower for First at 120°/s and 180°/s than at 1M (p < 0.05). Correlations with the number of days to return to sports competition were detected at 60°/s for maximum torque generation time (p < 0.05, r = 0.65). Following conservative treatment for lumbar spondylolysis, it was considered necessary to focus on trunk flexion and extension muscle strength and contraction speed of trunk flexors at the beginning of the exercise period. It was suggested that trunk extension muscle strength in the extension range might be one of the critical factors for returning to sports.

Entry phase in men's backward dive pike: association between the shoulder joint and trunk angles.

BACKGROUND: A high prevalence of lower back pain has been observed in competitive divers. Hyperextension of the lumbar vertebrae during water entry is considered the main mechanism behind the incidence of lower back pain in divers. Therefore, this study aimed to investigate the influence of the shoulder angle on the entry alignment. METHODS: Posture angles of 13 male drivers (age: 16.8±2.9 years) who were invited to the national training camp in 2012 by Japan Swimming were recorded at the time of water entry via 201B using a high-speed camera. RESULTS: A negative correlation was observed between shoulder joint flexion and trunk extension angles on water entry. In addition, the trunk angle was significantly different between groups. For the lower back pain group, 210.4±5.7°, and in the non-lower back pain group, 199.9±9.0°, angles were observed with a larger extension of the trunk on water entry in the lower back pain group. CONCLUSIONS: The alignment on water entry was associated with the occurrence of lower back pain. Which suggested that enough shoulder flexibility can prevent the incidence of lower back pain.

Feasibility and safety of percutaneous cryoablation under local anesthesia for the treatment of malignant lung tumors: a retrospective cohort study.

Background: In our institution, computed tomography (CT)-guided percutaneous cryoablation has been performed in patients with malignant lung tumors under local anesthesia. This study aimed to examine the feasibility and safety of percutaneous cryoablation for the treatment of malignant lung tumors. Methods: From July 2002 to December 2016, 227 patients (56 with primary lung cancer and 171 with metastatic lung tumor) underwent percutaneous cryoablation for the treatment of malignant lung tumors using a cryosurgical unit at our institution. Demographic factors, duration of post-treatment hospitalization, and adverse event and mortality rates were retrospectively investigated in 366 treatment sessions targeting 609 lesions. Results: The median diameter of the targeted tumor was 1.3 cm. All the cryoablation procedures were completed under local anesthesia, and the median duration of post-treatment hospitalization was two days. Adverse events (grade 2 or higher) were observed in 79 sessions (21.6%), with pneumothorax being the most common. In five sessions (1.4%), patients had grade 3 adverse events. There was no 30-day mortality; however, there were two 60-day mortality (0.5%) due to acute exacerbation of interstitial pneumonia. In multivariate analysis, independent predictors of adverse events were comorbid interstitial pneumonia [odds ratio (OR) =2.20; 95% confidence interval (CI): 1.04-4.64] and no history of pulmonary resection on the treated side (OR =3.04; 95% CI: 1.65-5.62). Conclusions: Cryoablation is a feasible and safe treatment for malignant lung tumors with acceptable adverse event rates. However, the mortality risk in patients with comorbid interstitial pneumonia should be fully recognized.

The Influence of Anticipation of Movement Starting Time on Feedforward Activation of Trunk Muscles during Rapid Shoulder Joint Movements.

This study aimed to clarify the differences in the onset of trunk muscle activity with and without anticipation of the movement starting time during rapid shoulder movements. Ten healthy men in a relaxed upright position performed rapid 135° flexion, 135° abduction, and 45° extension of the shoulder on the dominant hand side with and without anticipation of the movement starting time. They moved their shoulder joints following a 3-s countdown and a light stimulus in the anticipation and non-anticipation conditions, respectively. Electromyography of the anterior and posterior quadratus lumborum, transversus abdominis, internal oblique, external oblique, rectus abdominis, lumbar multifidus, lumbar erector spinae on the non-dominant hand side, and the middle deltoid on the dominant hand side were measured. The onset of activity of each trunk muscle relative to the onset of the middle deltoid was calculated. Two-way analysis of variance (eight trunk muscles × two anticipation conditions) was used to compare the onset of electromyographic activity of the trunk muscles in each direction of the shoulder movement. There were significant interactions between the muscles and anticipation conditions during shoulder abduction and extension. The onset of activity in the anterior and posterior quadratus lumborum, transversus abdominis, and internal oblique occurred earlier with anticipation of the movement starting time than without anticipation during shoulder abduction and extension. The anticipation of movement starting time may contribute to a reliable center of mass control within the support base and improve lumbar spine stability by hastening the onset of activity of the deep trunk muscles.

Comparison of abdominal muscle activity with various verbal instructions and onset activity analysis during draw-in maneuver.

Draw-in is a promising intervention for regaining isolated control of the transverse abdominis (TrA). Exercises to stimulate isolated contractions are needed; however, the appropriate methods are unclear. The objectives of this study were to examine how the muscle activity and muscle activity ratio of abdominal muscles change with various verbal instructions and to determine the onset of the abdominal muscles during draw-in. The participants were 21 healthy men. TrA electromyography was performed using fine-wire electrodes, and the internal oblique (IO), external oblique (EO), and rectus abdominis (RA) were determined using surface electrodes. The participants performed seven abdominal exercises according to verbal instructions and isolated voluntary contraction of the TrA for more than 5 sec. The TrA showed higher activity in bracing. IO and EO activities were highest in bracing, whereas RA showed the highest activity in maximum bracing. TrA/IO and TrA/EO were not significantly different between conditions. The results of the onset activity analysis of the abdominal muscles during the draw-in maneuver showed that the TrA was significantly earlier than the other muscles. The activity ratios of TrA to IO and EO were highly individualized and did not differ according to the verbal instruction. Maximum draw-in showed more significant IO activity, and bracing showed co-contraction of the superficial and deep abdominal muscles. During draw-in, the TrA initiated the earliest activity among the abdominal muscles and then isolated activity for 1.1 sec.

Double stapling method for closure of intraoperative alveolar air leakage adjacent to the staple line: a randomized experimental study on ex vivo porcine lungs.

Background: Alveolar air leakage from a pleural defect around the staple line is one of the complications after wedge resection of the lung. An intraoperative closure of the pleural defect by suturing can cause additional pleural rupture due to tension of the pleura adjacent to staple lines. Therefore, we have introduced a novel closure method for pleural defect adjacent to the staple line, named the double stapling method. This study compared the efficacy of two closure methods; the double stapling method and conventional suturing method with pledgets using ex vivo porcine lungs. Methods: The double stapling method involves closing the pleural defect by suturing the two parallel staple lines at both sides of the pleural defect. This method was developed to distribute the pleural tension around the needle holes of suturing. As a model of pleural defect adjacent to the staple line after wedge resection, wedge resection of the caudal lobe of left porcine lungs was performed, and a superficial square pleural defect (10 mm × 10 mm) adjacent to the staple line was made by scalpel. The defect was closed using the following two methods: (I) suturing with pledgets (n=10); and (II) double stapling method (n=10). The lobe was inflated in water at an airway pressure of 20, 25, and 30 cmH2O; closure success or failure was judged by the absence or presence of air leakage. Results: The closure success was confirmed in 2 (20%) out of 10 cases in the suturing with pledgets group and 9 (90%) out of 10 in the double stapling method group (P=0.007). In 4 out of 10 cases in the suturing with pledgets group, new pleural clefts longer than 3 mm were created around the needle holes of suturing. Conclusions: Ex vivo experiments have suggested the superiority of the double stapling method for the intraoperative closure of alveolar air leakage adjacent to the staple line after wedge resection, compared to conventional suturing with the pledget method.

Separate evaluation of unilateral lung function using upright/supine CT in a patient with diaphragmatic paralysis.

Background: Unilateral diaphragmatic paralysis is a condition in which the unilateral diaphragm is paralyzed and elevated. Orthopnea due to lung compression by an elevated diaphragm in the supine position is common in patients with unilateral diaphragmatic paralysis. Although its symptom is posture-dependent, the effect of posture on lung function in unilateral diaphragmatic paralysis has not been studied. Computed tomography (CT) can be used to assess lung volume. However, conventional CT cannot be performed in the upright position. A pulmonary function test can be performed in both upright and supine positions. However, it cannot evaluate the function of each lung separately. Case presentation: We report a case of a 79-year-old man with unilateral diaphragmatic paralysis. He presented with difficulty in inspiration, specifically in the supine position, and underwent both conventional supine CT and newly developed upright CT to assess the effect of posture on the function of each lung. The difference between expiratory and inspiratory lung volumes on CT in the supine position was less than that in the upright position by 46% and 4% on affected and healthy sides, respectively. We previously reported that the difference between expiratory and inspiratory lung volumes on CT correlated with inspiratory capacity on the pulmonary function test. A 46% decline in inspiratory capacity on the affected side in the supine position likely caused orthopnea in this patient. Conclusions: Supine/upright CT is helpful to assess the influence of posture on unilateral lung function in patients with unilateral diaphragmatic paralysis.

Prognostic Impact of the Histologic Lepidic Component in Pathologic Stage IA Adenocarcinoma.

INTRODUCTION: Because several articles have reported a prognostic association with the radiologic features of ground-glass opacity, we explored whether the histologic presence of a lepidic component had similar significance. METHODS: We retrospectively evaluated 380 consecutive surgically resected lung adenocarcinomas (ADCs) of pathologic (p)stage IA. The tumors were classified into lepidic-positive and lepidic-negative ADCs. Clinicopathologic characteristics, radiographic ground-glass opacity status, and disease-free survival were compared between lepidic-positive and lepidic-negative ADCs and between part-solid and solid nodules on computed tomography images. RESULTS: Of the 380 cases, 176 (46.3%) were lepidic-positive ADCs. Of the overall patients with pT1, lepidic-positive ADCs were found to have significantly better recurrence-free survival (5 y, 95.4% versus 87.0%, p = 0.005), but this significance was not reproduced in pT1 subcategories (pT1a, pT1b, and pT1c). Furthermore, the presence of the lepidic component was not an independent prognostic factor in the multivariate analysis (hazard ratio = 0.46 [95% confidence interval: 0.19-1.14], p = 0.09). We also analyzed the extent of the lepidic component with 10% incremental valuables. Although we found that a 10% or greater extent of lepidic component made the recurrence-free survival difference the largest, a clear prognostic impact was not obtained with this cutoff point. CONCLUSIONS: Although lepidic-positive ADCs tended to have a favorable outcome, the lepidic component was not a clear independent prognostic factor in pstage I ADC.

Immediate changes in chest mobility and trunk muscle activity during pelvic tilt following different trunk muscle exercises.

BACKGROUND: Given the characteristics of the superficial trunk muscles that cross the chest and pelvis, their excessive contraction might limit chest mobility. OBJECTIVE: To examine the immediate effects of two types of trunk muscle exercises on chest mobility and trunk muscle activities. METHODS: Fourteen healthy men (age: 21.1 ± 1.0 years, height: 172.7 ± 5.6 cm, weight: 61.0 ± 7.1 kg, body mass index: 20.4 ± 1.7 kg/m2; mean ± SD) randomly performed trunk side flexion and draw-in exercises using a cross-over design. The chest kinematic data and trunk muscle activities were measured before and after each intervention during the following tasks: maximum inspiration/expiration and maximum pelvic anterior/posterior tilt while standing. Two-way repeated measures analysis of variance was used for statistical analysis (P< 0.05). RESULTS: After the side flexion, upper and lower chest mobility significantly decreased, and superficial trunk muscle activity significantly increased during the maximum pelvic anterior tilt (P< 0.05). Additionally, after the draw-in, upper chest mobility significantly increased during the maximum pelvic anterior tilt (P< 0.05). CONCLUSIONS: Increased activity of the superficial abdominal muscles might limit chest mobility during maximum pelvic anterior tilt. Conversely, the facilitation of deep trunk muscles might increase upper chest mobility during the maximum pelvic anterior tilt.

Predictive factors and economic impact of prolonged air leak after pulmonary resection.

OBJECTIVE: Prolonged air leak (PAL) is one of the most common complications after pulmonary resection for lung cancer. This study aimed to identify the factors that predict PAL, and to evaluate the impact of PAL on the development of additional complications and cost of hospitalization. METHODS: A total of 2278 patients who underwent pulmonary resection other than pneumonectomy for lung cancer from 2014 to 2018 were retrospectively enrolled in this study. PAL was defined as air leak that continued more than 5 days after the operation. Multivariate analyses were conducted to identify significant predictors of PAL, using clinical information. Development of complications other than PAL, and cost of hospitalization care were also analyzed. RESULTS: PAL was observed in 91 (4.0%) cases. Multivariate logistic regression analysis revealed that the presence of intrathoracic adhesion (odds ratio [OR] 4.476, p < 0.001), smoking history > 20 pack-year (OR 2.441, p = 0.005), male sex (OR 2.269, p = 0.013), and lobectomy or bilobectomy (OR 1.935, p = 0.025) were significant risk factors for PAL. The presence of PAL was related to the development of additional complications (p < 0.001). The cost of hospitalization care in patients with PAL was about 1.3 times higher than that in patients without PAL (p < 0.001). CONCLUSIONS: PAL is related to additional complications and higher cost of hospitalization care. Surgeons should pay careful attention to minimize the incidence of PAL in patients with risk factors including intrathoracic adhesion, history of heavy smoking, male sex, and lobectomy or bilobectomy.

Assessment of Resectability of Mediastinal Germ Cell Tumor Using Preoperative Computed Tomography.

BACKGROUND AND OBJECTIVES: Mediastinal germ cell tumor (MGCT) is a relatively rare tumor. Complete resection after chemotherapy is a standard treatment against this disease. However, the risk factors of incomplete resection are unclear. Therefore, we analyzed survival rates and risk factors for incomplete resection based on preoperative imaging. METHODS: We retrospectively reviewed the medical records of patients (n = 56) with MGCT operated at National Cancer Center Hospital, and analyzed preoperative computed tomography (CT) data in terms of relationship of the tumor and vessels, and investigated survival rate and risk factors for incomplete resection. RESULTS: A total of 56 patients underwent resection of MGCT. The 5-y progression-free survival (PFS) and overall survival (OS) were 79% and 83%. In multivariate analysis, complete resection was the only significant prognostic factor for better PFS (hazard ratio (HR) = 9.083, P= 0.00021) and OS (HR = 5.519, P= 0.0445). The preoperative CT finding of arteries (including the aorta, right brachiocephalic artery, left common carotid artery, and left subclavian artery) surrounded by the tumor was a predictor of incomplete resection (odds ratio = 10.089, P= 0.049). CONCLUSIONS: Complete resection is essential for improving the survival of MGCT, and the risk stratification using preoperative CT imaging brings important information to achieve the complete resection.