[Educational Impact of Using Three-dimentional Models for Preoperative Simulation of Segmentectomy for Medical Students].

BACKGROUND: Lung segment anatomy is complex and difficult for medical students to comprehend, so education is a challenging issue. Three-dimensional (3D) models may be a more effective teaching tool for medical students. We evaluated the usefulness of 3D models in education for segmentectomy. METHODS: Sixty-six students who participated in clinical training for thoracic surgery from November 2020 to March 2022 were included in the study. Computed tomography (CT) images, 3D-CT images, and 3D models were used to investigate students' level of understanding for each lung segment. Levels of understanding were assessed using a questionnaire administered using the interview method. The results of the questionnaire were tabulated and analyzed using the Kruskal-Wallis test. RESULTS: The response rate was 100%. Comprehension scores for all questions were highest for 3D models, followed by 3D-CT and CT. These results suggest that use of a 3D entity model may have a high educational effect. CONCLUSION: Although it is unclear whether students' comprehension was directly related to their understanding of correct anatomy, our results suggest that 3D models may be an effective way for medical students to understand lung segmentectomy.

Salivary metabolites as potential predictive biomarkers for lung surgery complications: a retrospective cross-sectional study.

PURPOSE: Saliva is often used as a tool for identifying systemic diseases because of the noninvasive nature of its collection. Moreover, salivary metabolites can be potential predictive factors for postoperative survival. We conducted the present study to establish whether salivary metabolites can function as predictive biomarkers for lung surgery complications. METHODS: Unstimulated salivary samples were collected from 412 patients before lung surgery. Salivary metabolites were analyzed comprehensively by capillary electrophoresis mass spectrometry. Clinical data with the discriminatory ability of biomarkers were assessed to predict lung surgery complications using multivariate logistic regression analysis. The primary endpoint was the risk factors for postoperative complications of Clavien-Dindo grade ≥ III. RESULTS: Postoperative complications of Clavien-Dindo grade ≥ III developed in 36 patients (8.7%). There was no postoperative 30-day mortality. Male sex (odds ratio [OR], 3.852; 95% confidence interval CI 1.455-10.199; p = 0.007) and salivary gamma-butyrobetaine (OR, 0.809; 95% CI 0.694-0.943; p = 0.007) were identified as significant risk factors for postoperative complications of Clavien-Dindo grade ≥ III. CONCLUSION: Salivary metabolites are potential noninvasive biomarkers for predicting postoperative complications of lung surgery.

Learning Curve for Thoracoscopic Individual Basilar Segmentectomy: 18-Year Experience.

BACKGROUND: Thoracoscopic anatomical individual basilar segmentectomy remains challenging owing to the deep intraparenchymal location of the hilar structures and anatomical variations. We analyzed and reported the experience and progress of thoracoscopic anatomical individual basilar segmentectomy at our university hospital. METHODS: We retrospectively examined the patients who underwent anatomical basilar segmentectomy at our institution from January 2004 to December 2021. We divided our analysis period into two parts: the first period (2004-2012) was the introductory period of video-assisted thoracoscopic surgery (VATS) segmentectomy, and the second period (2013-2021) was the maturity period of VATS segmentectomy. The learning curve of the leading surgeon in the second period was also evaluated based on the operative time and cumulative sum value of the operative time. RESULTS: Overall, 127 cases were evaluated, among whom 33 and 94 cases were assessed during the introductory and maturity periods of thoracoscopic segmentectomy, respectively. Age (P = 0.003) and Charlson comorbidity index (P = 0.002) were higher in the second period than in the first period. Use of a uniport (P = 0.006) was higher, and postoperative hospitalization duration (P = < 0.001) and operative time (P = 0.024) were shorter in the second period than in the first period. A learning curve obtained during the maturity period showed: The inflection point for the learning curve of thoracoscopic basilar segmentectomy was reached after 42 cases. CONCLUSIONS: We have demonstrated a single institution's progress and learning curve for difficult segmentectomies. This may be helpful to institutions considering performing this surgery.

[Right Brachial Artery Thromboembolism After Left Upper Lobectomy].

A 71-year-old man underwent a computed tomography( CT) scan to check for prostate cancer metastasis. It revealed a lung tumor in the left upper lobe, and he was referred to our division. Under clinical diagnosis of primary lung cancer, left upper lobectomy was performed. Dense adhesion due to the history of tuberculosis was observed. On the first postoperative day, he complained of sudden numbness in his right arm during rehabilitation. The emergent contrast-enhanced CT revealed the right brachial arterial thromboembolism. We performed an embolectomy, and further analysis of the postoperative enhanced CT revealed a longer left upper pulmonary vein stump than usual. We thought it to be the cause of the thrombus formation and started anticoagulation therapy. The postoperative course was uneventful, without recurrence of thromboembolism.

Revaluation of a selected segmental insufflation technique in total thoracoscopic lung segmentectomy.

We report selected insufflation technique using direct bronchial insufflation to visualize the intersegmental plane during total thoracoscopic segmentectomy. Following the transection of the bronchus using a stapler, a small incision was created in the dissected target bronchus, and direct air insufflation was performed at the small incision site. The target segment was inflated, while the preserved segments appeared to collapse, and a demarcating line was visualized between the inflated and deflated lung parenchyma. This technique quickly identifies the anatomic intersegmental plane without warranting special equipment such as jet ventilation or indocyanine green (ICG). Furthermore, this method saves time in creating inflation-deflation lines.

Combined basilar subsegmentectomy for intralobar sequestration via uniportal VATS: a case report.

BACKGROUND: Combined basilar subsegmentectomy via uniportal video-assisted thoracoscopic surgery is an extremely complex surgery. Moreover, no the existing reports describe the procedure and technique. Here, we present the technique of combined basilar subsegmentectomy that was successfully performed via uniportal video-assisted thoracoscopic surgery to treat intralobar pulmonary sequestration in an adult patient. CASE PRESENTATION: A 57-year-old man underwent surgery for oropharyngeal carcinoma. Preoperative computed tomography showed several cystic lesions in the right lower lobe. Subsequent enhanced computed tomography revealed an anomalous artery branching from the abdominal aorta and a normal pulmonary vein. The patient with diagnosed with Pryce type III intralobar pulmonary sequestration and underwent right S7 posterior + 10bc combined basilar segmentectomy via uniportal video-assisted thoracoscopic surgery. The postoperative course was uneventful, and the patient was discharged 4 days after surgery. At the 8-month follow-up, computed tomography showed no abnormalities. CONCLUSIONS: We successfully performed combined basilar subsegmentectomy via uniportal video-assisted thoracoscopic surgery. This surgical approach is useful for the treatment of intralobar pulmonary sequestration occurring at the basal segment of the lung.

The preoperative assessment of thoracic wall adhesions using four-dimensional computed tomography.

OBJECTIVE: Pleural adhesions are challenging during lung cancer surgery and may be associated with a long surgery time and excessive blood loss due to pleural adhesiolysis. We used preoperative four-dimensional computed tomography to quantitatively assess parietal pleural adhesions and determine its diagnostic accuracy. METHODS: A total of 216 patients with lung cancer underwent four-dimensional computed tomography during the study period. Pleural adhesions were subsequently confirmed by surgery in 85 of these patients, whereas 126 patients had no adhesions. The movements of the tumor or target vessels (α) was tracked. Receiver-operating characteristic curve analysis was used to identify the relationship between adhesions and (α). RESULTS: The movement of (α) was smaller in patients with adhesions than in those without adhesions. The greater the adhesion, the shorter the movement distance (p < 0.001). Receiver-operating characteristic curve analysis demonstrated an area under the curve for the moving (α) point at 0.71 (95% confidence interval: 0.62-0.80) in the upper lung field and at 0.75 (95% confidence interval: 0.64-0.85) in the lower field. To identify adhesions, a cut off of 11.3 mm (sensitivity = 43.6%, specificity = 93.2%) in the upper lung field and a cut off of 41.2 mm (sensitivity = 71.4%, specificity = 66.0%) in the lower lung field were established. CONCLUSIONS: Four-dimensional computed tomography is a novel and helpful modality for predicting the presence of parietal pleural adhesions. To obtain robust evidence, further accumulation of cases and re-examination of the analysis methods are needed.

Residual middle lobectomy after right upper or lower lobectomy: indications and outcome.

OBJECTIVES: Residual middle lobectomy after upper lobectomy and lower lobectomy differs in their indications and perioperative outcomes. Therefore, we aimed to evaluate the indications and perioperative outcomes of residual middle lobectomy after upper and lower lobectomy. METHODS: The data of 14 patients who underwent residual middle lobectomy after upper or lower lobectomy between January 1997 and December 2021 were extracted and analyzed. RESULTS: Overall, six patients underwent residual middle lobectomy after upper lobectomy. The indication was second primary lung cancer in five patients and local recurrence in the hilar lymph node between the middle and lower lobar bronchi in one patient. However, one patient was treated with the R2 operation. The remaining eight patients underwent residual middle lobectomy after lower lobectomy. The indication was second primary lung cancer and bronchopleural fistula or stenosis in two and six patients, respectively. No postoperative 90-day mortality was observed. CONCLUSIONS: Residual middle lobectomy for second lung cancer after upper lobectomy is difficult because of severe hilar adhesions. Simultaneous resection of hilar structures or pulmonary artery and parenchyma might be an option. Residual middle lobectomy could be a treatment option for bronchopleural fistula or stenosis after lower lobectomy.

Thoracoscopic Lateral Basal Segmentectomy Based on Dissection Along the Intersegmental Veins.

In the conventional method of lateral basal (S9) segmentectomy, the intersegmental plane is first divided between the superior segment and the anterior segment, then the S9 segment is removed from the other basilar segments. We show here our modified method of thoracoscopic S9 segmentectomy based on dissection along the intersegmental veins. Our technique is unique in that we do not divide the intersegmental plane between the superior segment and the anterior segment. The merits are that it avoids additional parenchymal splitting from the superior segment and that it may be used when an incomplete interlobar fissure is present.

Cannula removal with hemostasis secured by thoracoscopic support for accidental central vein puncture: a case report.

Central venous catheterization is a commonly used procedure for disease management. However, the procedure is not without risks of severe morbidity. We herein report hemostasis for accidental venous puncture using thoracoscopy. A 44-year-old man with short bowel syndrome and chronic renal failure required central venous catheterization for nutritional management and hemodialysis. Right internal jugular vein puncture was performed under ultrasonographic guidance, and the guidewire was inserted into the right atrium under fluoroscopic guidance. However, the operator inadvertently perforated the vein, and the thoracic cavity was entered while inserting the introducer. The patient's vital signs were stable; therefore, we performed emergency surgery after computed tomography and achieved hemostasis through thoracoscopic surgery. Sufficient caution should be exercised while inserting central venous catheters through a thrombosed internal jugular vein. In some instances of catheter-induced vessel injury, combined surface and thoracoscopic hemostasis may be a reliable and minimally invasive management option.

Thoracoscopic "cut-through" segmentectomy for small-sized lung cancer in a deep central location.

The use of segmentectomy and subsegmentectomy for the management of lung lesions is well established. However, the use of subsegmentectomy for deep seated lesions in the upper lobe is difficult because of sufficient surgical margins. Here, we present a patient whose lung lesion was in a deep central area and at the borders of three segments in the upper lobe of the right lung. We used combined subsegmentectomy (S1b + S3a) video-assisted thoracoscopic surgery for this small-sized lung cancer in a deep central location.

Intracellular Protein Photoactivation Using Sterically Bulky Caging.

Methods for intracellular protein photoactivation have been studied to elucidate the spatial and temporal roles of proteins of interest. In this study, an intracellular protein photoactivation method was developed using sterically bulky caging. The protein of interest was modified with biotin via a photocleavable linker, and then conjugated with streptavidin to sterically block the protein surface for inactivation. The caged protein was transduced into cells and reactivated by light-induced degradation of the conjugates. A cytotoxic protein, saporin, was caged and photoactivated both in vitro and in living cells with this method. This method achieved control of the cytotoxic activity in an off-on manner, introducing cell death selectively at the designed location using light. This simple and versatile photoactivation method is a promising tool for studying spatio-temporal cellular events that are related to intracellular proteins of interest.

Roles and outcomes of thoracoscopic anatomic lung subsegmentectomy for lung cancer.

OBJECTIVES: We performed sublobar resections, including thoracoscopic segmentectomy and subsegmentectomy for small lung cancers, and analysed the results of indications and outcomes of thoracoscopic subsegmentectomy. METHODS: Between March 2005 and May 2020, 357 consecutive patients underwent thoracoscopic anatomic sublobar resections for lung cancer, including 68 patients undergoing subsegmentectomy. These patients were compared with 289 patients who underwent segmentectomy during the same period. RESULTS: Subsegmentectomies included mono-/bi-/tri-subsegmentectomies for 34/23/11 of 68 patients, respectively. The median tumour size was 13.5 mm, significantly smaller than tumours in patients who underwent a segmentectomy (P < 0.001). Tumours obtained by mono-subsegmentectomy (11.0 mm) were significantly smaller than bi-/tri-subsegmentectomy (P = 0.028). The proportion of ground-glass opacity-dominant tumours obtained by subsegmentectomy (85.3%) was higher than that obtained by segmentectomy. The proportion of intentional cases satisfying the criteria for sublobar resection was higher than that of segmentectomy cases. Although tumour locations in 40 patients were not identified during surgery, tumours were correctly resected in 39 patients without tumour markers. The median operative time and blood loss were 167 min and 13 ml, significantly shorter and less, respectively, in subsegmentectomy than in segmentectomy patients (P = 0.005, P = 0.006). Duration of drainage and hospitalization were 1 and 5 days, respectively, for subsegmentectomy patients; complications occurred in 6 (8.8%). Outcomes were similar to those of the segmentectomy patients. Although 4 subsegmentectomy patients died of other diseases, none showed cancer recurrence during a mean follow-up of 50 months. CONCLUSIONS: Thoracoscopic subsegmentectomy can be used for patients with ground-glass opacity-dominant lung cancers <1.5 cm if adequate margins can be secured.

Endobronchial Malignant Peripheral Nerve Sheath Tumor in a Pediatric Patient.

A 13-year-old girl presented to the emergency department with exertional dyspnea. She had no notable medical history. A chest radiograph revealed left pulmonary atelectasis. Bronchoscopy showed an endobronchial tumor obstructing the left main bronchus, protruding into the trachea. Endobronchial polypectomy was performed under general anesthesia. The specimen was found to be a malignant peripheral nerve sheath tumor. The tumor had a local recurrence, however it probably went into spontaneous regression. She is alive 25 years after the initial surgery. This is the first reported case of an endobronchial malignant peripheral nerve sheath tumor in a pediatric patient.

Thoracoscopic Completion Bilobectomy for Bronchial Stenosis.

A 66-year-old man with primary lung cancer underwent 4-port thoracoscopic right lower lobectomy. One month postoperatively, he was diagnosed with obstructive pneumonia and bronchial stenosis of the middle lobe. Due to recurrent obstructive pneumonia, the covered self-expanding stent was placed in the middle lobar bronchus. One month later, the stent was obstructed. Six months after the initial surgery, thoracoscopic completion bilobectomy was performed; the postoperative course was uneventful. Seven years after the initial surgery, he had no recurrence. This lobectomy approach is an option for bronchial stenosis.

Outcome of thoracoscopic anatomical sublobar resection under 3-dimensional computed tomography simulation.

BACKGROUND: Previous studies have reported the feasibility and efficacy of thoracoscopic anatomical sublobar resection under three-dimensional computed tomography (3DCT) simulation; however, its long-term outcomes have not been clearly established in primary lung cancer. This study aimed to evaluate the long-term outcomes of this technique. METHODS: We retrospectively reviewed data from 112 consecutive patients with selected clinical stage IA non-small cell lung cancer (NSCLC) who underwent thoracoscopic anatomical sublobar resection from 2004 to 2014. This procedure was planned using preoperative 3DCT simulation to ensure sufficient surgical margins and enabled tailor-made surgery for each patient. Patients who had predominantly ground glass opacity lung cancers underwent anatomical sublobar resection as a curative-intent resection. Other patients who were high-risk candidates for lobectomy underwent anatomical sublobar resection as a compromised limited resection. RESULTS: Of the 112 cases, 82 had a curative-intent resection, while 30 had a compromised limited resection. Recurrence occurred in only 2 cases (1.8%), both of which were in the compromised limited group. A second primary lung cancer was observed in 5 cases (4.5%). Of the 5 patients, 4 underwent surgery for a second cancer and had no recurrence. The 5-year overall survival, lung cancer-specific overall survival, and recurrence-free survival rates were 92.5%, 100%, and 98.2%, respectively, for all cases; 97.6%, 100%, and 100%, respectively, in the curative-intent group; and 75.8%, 100% and 92.6%, respectively, in the compromised limited group. CONCLUSIONS: Thoracoscopic anatomical sublobar resection under 3DCT simulation may be an acceptable alternative treatment in selected patients with NSCLC. TRIAL AND CLINICAL REGISTRY: Clinical registration number: IRB No. 2020-98 (Dated: 2020.6.30).

Video-Assisted Thoracoscopic Segmentectomy for Deep and Peripheral Small Lung Cancer.

BACKGROUND: We aimed to retrospectively compare the long-term prognosis and recurrence after segmentectomy between nonsmall cell lung cancer (NSCLC) patients with deep and peripheral lesions. METHODS: Data were extracted for 85 lobectomy-tolerable NSCLC patients with tumors measuring ≤2 cm, who underwent video-assisted thoracoscopic segmentectomy with curative intent during January 2006 to December 2014. Tumor location was determined by the surgeon using thin-slice (1 mm) and three-dimensional computed tomography. Overall and recurrence-free survival was compared between patients with peripheral and deep lesions using univariate and multivariate Cox proportional hazard models. The indications for segmentectomy included NSCLC measuring ≤2 cm and consolidation/tumor ratio ≤20%, solid NSCLC ≤1 cm, and indeterminate nodule ≤1.5 cm. RESULTS: No recurrence of peripheral and deep lesions was noted. The 5-year overall survival was 96.4% for all patients, and 100 and 95.3% for patients with deep and peripheral lesions, respectively. There was no significant difference between the overall survival rates associated with the deep and peripheral lesions (95% confidence interval [CI], 89.5-98.8, nonsignificant, 86.4-98.4, respectively; p = 0.189). In a multivariate analysis, the American Society of Anesthesiologists score (hazard ratio [HR], 13.30; 95% CI, 1.31-210.36; p = 0.028) and histology (HR, 0.03; 95% CI, 0.00-0.32; p = 0.037) were independent prognostic factors for overall survival; tumor location was not a prognostic factor. CONCLUSIONS: When video-assisted thoracoscopic segmentectomy with curative intent was performed with sufficient surgical margins, the location of small NSCLC did not affect recurrence risk and prognosis. Video-assisted thoracoscopic segmentectomy for small NSCLC is acceptable, regardless of the tumor location.

Differential diagnosis of lung cancer and benign lung lesion using salivary metabolites: A preliminary study.

BACKGROUND: Saliva is often used as a biomarker for the diagnosis of some oral and systematic diseases, owing to the non-invasive attribute of the fluid. In this study, we aimed to identify salivary biomarkers for distinguishing lung cancer (LC) from benign lung lesion (BLL). MATERIALS AND METHODS: Unstimulated saliva samples were collected from 41 patients with LC and 21 with BLL. Salivary metabolites were comprehensively analyzed using capillary electrophoresis mass spectrometry. To differentiate between patients with LCs and BLLs, the discriminatory ability of each biomarker was assessed. Furthermore, a multiple logistic regression (MLR) model was developed for evaluating discriminatory ability of each salivary metabolite. RESULTS: The profiles of 10 salivary metabolites were remarkably different between the LC and BLL samples. Among them, the concentration of salivary tryptophan was significantly lower in the samples from patients with LC than in those from patients with BLL, and the area under the curve (AUC) for discriminating patients with LC from those with BLL was 0.663 (95% confidence interval [CI] = 0.516-0.810, p = 0.036). Furthermore, from the MLR model developed using these metabolites, diethanolamine, cytosine, lysine, and tyrosine, were selected using the back-selection regression method. The MLR model based on these four metabolites had a high discriminatory ability for patients with LC and those with BLL (AUC = 0.729, 95% CI = 0.598-0.861, p = 0.003). CONCLUSION: The four salivary metabolites can serve as potential non-invasive biomarkers for distinguishing LC from BLL.