Regional variations and sex-related differences of stiffness in human tracheal ligaments.

PURPOSE: There have been numerous studies focused on the stiffness of tracheal cartilage. However, no research has been conducted specifically on the annular ligament, nor have any regional differences in the annular ligament been identified. The purpose of this study was to investigate the stiffness of the ligaments present between the thyroid, cricoid and tracheal cartilages. METHODS: The ligaments were identified in the cervical region of living subjects with ultrasonography. The stiffness of the ligaments was measured from the body surface using a digital palpation device (MyotonPRO). Since it is impossible to measure the entire trachea in a living subject, an additional measurement was performed on human cadavers. RESULTS: Both in vivo and cadaveric investigations found that the stiffness of annular ligaments decreased gradually from the superior to inferior parts. There was no difference in the stiffness between males and females in the superior part of the trachea. However, the stiffness of the middle and inferior parts was predominantly higher in females than in males. Furthermore, males showed significant differences in stiffness between the superior and middle parts, while females showed no significant differences. CONCLUSION: These results reveal that there are regional and sex-related differences in the stiffness of human tracheal ligaments.

Dual Image Navigation to Secure Surgical Margins in Thoracoscopic Segmentectomy.

PURPOSE: Video-assisted thoracoscopic surgery (VATS) segmentectomy is being increasingly used for the management of non-small cell lung cancer. For non-palpable lesions, surgeons frequently find difficulty in ensuring a sufficient surgical resection margin. OBJECTIVE: The purpose of this study was to evaluate the role of intraoperative dual image navigation in combination with the infrared thoracoscopy with intravenous injection of indocyanine green (IRT-ICG) method and intraoperative computed tomography (CT) in detecting oncological margins. METHODS: This study involved 34 consecutive patients who underwent both IRT-ICG and intraoperative CT-assisted thoracoscopic segmentectomy between October 2017 and July 2021. The intersegmental line on the visceral pleura was visualized using the IRT-ICG method. The intersegmental line was marked by clipping, and an intraoperative CT scan was performed under bilateral lung ventilation. Intraoperative CT or three-dimensional CT reconstruction images were used by surgeons to confirm the correct anatomic segmental border and to secure a sufficient resection margin. RESULTS: A well-defined intersegmental line was observed in 91.2% of patients. In eight cases, the surgeon needed to make some modifications to the resection line to secure a sufficient surgical margin. The mean surgical margin assessed on gross examination by the pathologist was 23.4 ± 9.0 mm. Complete resection was achieved in all patients using this approach. CONCLUSIONS: Intraoperative dual image navigation combined with the IRT-ICG method and intraoperative CT scan enables surgeons to perform definitive VATS segmentectomy for non-palpable lesions.

[Mixed Squamous Cell and Glandular Papilloma in the Peripheral Lung:Report of a Case].

Pulmonary papillary tumors are usually occur in the upper respiratory tract, and solitary papilloma in the peripheral lung are extremely rare. Lung papillomas sometimes show the elevation of tumor marker or F18-fluorodeoxyglucose (FDG) uptake, and are difficult to distinguish from lung carcinoma. Here we report a case of mixed squamous cell and glandular papilloma in the peripheral lung. An 85-years-old man without smoking history had been presented with an 8-mm nodule in right lower lobe in chest computed tomographic (CT) 2 years before. Since the diameter of the nodule increased to 12 mm, and positron emission tomography (PET) revealed an abnormally increased FDG uptake in the mass (SUVmax 4.61). StageIA2 lung cancer (cT1bN0M0) was suspected and wedge resection of the lung to make a definitive diagnosis and for treatment was performed. The definite pathological diagnosis was mixed squamous cell and glandular papilloma.

Regeneration of emphysematous lungs using gelatin sheets that release basic fibroblast growth factor.

PURPOSE: Basic fibroblast growth factor (bFGF) induces regeneration and neovascularization of the lungs. We conducted this study to demonstrate the regeneration of emphysematous lungs achieved by gelatin sheets that slowly release bFGF into the visceral pleura in a canine model. METHODS: Porcine pancreatic elastase was used to induce bilateral lower lobe pulmonary emphysema in dogs. Slow-release bFGF gelatin sheets were attached to the visceral pleura of the left lower lobe via thoracotomy. The subjects were divided into two groups: one treated with gelatin sheets containing slow-release bFGF (bFGF+ group, n = 5), and the other, treated with only gelatin sheets (bFGF- group, n = 5). The subjects were euthanized after 28 days and histologic lung assessment was performed. The results were evaluated in terms of the mean linear intercept (MLI) and microvessel count. RESULTS: The MLI was significantly shorter in the bFGF+ group than in the bFGF- group; (110.0 ± 24.38 vs. 208.9 ± 33.08 µm; P = 0.0006). The microvessel count was not significantly different between the bFGF+ and bFGF- groups (12.20 ± 3.007 vs. 5.35 ± 2.3425; P = 0.075); however, it was significantly higher in the bFGF-attached lungs than in the emphysema group (12.20 ± 3.007 vs. 4.57 ± 0.8896; P = 0.012). CONCLUSIONS: Attaching gelatin sheets with slow-release bFGF to the visceral pleura induced lung regeneration and vascularization in a canine pulmonary emphysema model.

Safe pneumonectomy for locally advanced lung cancer after induction therapy.

PURPOSE: To assess the safety and long-term outcomes of pneumonectomy after IT (IT-Pn) versus upfront pneumonectomy without IT (U-Pn) for locally advanced non-small-cell lung cancer (NSCLC). METHODS: We reviewed the clinical records of 69 patients who underwent pneumonectomy as U-Pn (n = 30) or IT-Pn (n = 39) between 2000 and 2019 at our institution, RESULTS: U-Pn included patients with pathological N0 (n = 13), N1 (n = 11) and N2 (n = 6). Among the patients treated with IT-Pn, 18 had pathological N0 (including 7 with complete responses), 5 had N1, 14 had N2, and 2 had N3. It was suggested that 22 cases could be down-staged after IT. The 5-year overall survival (OS) was 28.1% in the U-Pn group and 43.1% in the IT-Pn group (p = 0.275), being 40.2% for IT-Pn with p-N2,3, but not reached for U-Pn with N2 (p = 0.307). The 90-day mortality was 6.7% for the U-Pn group and 5.1% for the IT-Pn group (p = 0.646). Major complications occurred in 25 patients (64.1%) treated with IT-Pn and 18 patients treated with U-Pn (60.0%; p = 0.602). CONCLUSIONS: Pneumonectomy for NSCLC can be performed safely after IT with favorable results. For patients with N2 disease, induction therapy followed by surgery may warrant further study.

[Surgical Approach for Treatment of Postoperative Bronchopleural Fistula and Pyothorax].

A bronchopleural fistula is a serious condition that can develop into pyothorax. The incidence of bronchopleural fistula depends on the surgical procedure. Bronchopleural fistulas are classified into early and late types based on the time of development following surgical intervention. Early-stage fistulas show poor prognosis and require prompt treatment. It is important to confirm the status of infection in the thoracic cavity to devise an optimal treatment plan. Bronchopleural fistula closure is challenging and may be unsuccessful in patients with uncontrolled infection. Immediate open window thoracostomy should be performed in patients with empyema. The window is closed after effective clearance of thoracic cavity infection. Prompt and systematic treatment improves prognosis.

[Anomalous V2 Preoperatively Identified by Three-dimensional Computed Tomography in a Patient with Primary Lung Cancer of Right Upper Lobe].

A 61-year-old woman was found to have multiple ground-glass nodules( GGNs) in both lungs by chest computed tomography (CT) scan. The lesion of the right S2 contained a partial solid component and was suspected to be minimally invasive adenocarcinoma. Three-dimensional CT showed two anomalous V2s descending dorsally to the intermediate bronchus and draining into the inferior pulmonary vein. Thoracoscopic segmentectomy of the right S2 was performed safely. The pathological diagnosis was adenocarcinoma in situ. Since aberrant pulmonary vessels increases the surgical risk during video-assisted thoracoscopic anatomical lung resection, preoperative three-dimensional CT is useful in performing safe surgical procedure.

[Empyema Secondary to Percutaneous Liver Drainage via Thoracic Cavity for Hepatic Abscess].

Percutaneous liver drainage is associated with few complications. We report a case of empyema secondary to passage of a drain through the chest cavity in a patient treated with percutaneous liver drainage for hepatic abscess. A 72-year-old man was diagnosed with a liver abscess and underwent percutaneous liver drainage via the 7th intercostal space. He developed fever 7 days after the drainage procedure and was diagnosed with empyema on chest computed tomography and underwent video-assisted thoracoscopic curettage. Intraoperatively, we observed the liver drainage tube penetrated the thoracic cavity and the diaphragm, and he was diagnosed with iatrogenic empyema. The patient's postoperative course was uneventful, and the chest drain was removed on the 3rd postoperative day. Percutaneous liver drainage is associated with the risk of penetration of the thoracic cavity and the diaphragm.

[Thoracoscopic Diaphragmatic Stitching for the Catamenial Pneumothorax].

A 46-year-old woman experienced an initial episode of right-sided spontaneous pneumothorax at the time of menstruation. The findings of thoracoscopic examination suggested catamenial pneumothorax. Thoracoscopic surgery revealed multiple blueberry spots on the diaphragm. Considering the patient to be premenopausal within several years and expecting postoperative hormonal therapy, we stitched all lesions without resection for detailed histopathological diagnosis. The patient is well 5 months postoperatively.

Role of surgery in multi-modality treatment for carcinomatous pleuritis in patients with non-small cell lung cancer.

OBJECTIVE: To evaluate the role of surgery in the treatment of the patients with non-small cell lung cancer with pleural dissemination. METHODS: The clinical records of 25 patients (mean age 69 years) diagnosed with carcinomatous pleuritis during a thoracotomy by pathological examination and followed by surgery between 1994 and 2012 were reviewed. The treatment modality, including surgery, the clinicopathologic characteristics and 5-year survival were analyzed. RESULTS: There were 16 adenocarcinomas, 6 squamous cell carcinomas and 3 large cell carcinomas. Surgery included resection of the main tumor by partial resection in 10 cases, segmentectomy in 2 cases, lobar resection in 12 cases and bilobectomy in 1 case. Intrathoracic irrigation was performed in 20 cases. The pathological N status was N0/N1/N2/Nx: 10/6/7/2. Fifteen patients received adjuvant therapy. The overall 5-year survival rate was 22.2 %. The 5-year survival rates of the N0, N1 and N2 groups were 36.0, 16.7 and 14.3 %, respectively (p = 0.0068). Nine patients lived more than 3 years including 5 in N0, 3 in N1 and 1 in N2. CONCLUSIONS: Surgery should not be excluded from the multi-modality treatment of patients with carcinomatous pleuritis because there are some patients who could benefit from surgery especially if they are in N0 status.

Segmentectomy Provides Comparable Outcomes to Lobectomy for Stage IA Non-small Cell Lung Cancer with Spread through Air Spaces.

This study aimed to compare the recurrence-free survival (RFS) and overall survival (OS) among wedge resection (non-anatomical resection), segmentectomy and lobectomy for pathological stage IA non-small cell lung cancer (NSCLC) with spread through air spaces (STAS). Patients underwent surgical treatment for pathological stage IA NSCLC between January 1, 2005, and March 31, 2016, at our hospital. Surgical procedures were classified as lobectomy, segmentectomy, and wedge resection. Among the 555 analyzed cases, STAS was observed in 148 patients (26.7%). STAS was correlated with worse RFS (P < 0.001) and OS (P < 0.001) and was an independent poor prognostic factor for RFS (hazard ratio: 2.37, P < 0.001) and OS (hazard ratio: 2.02, P < 0.001) in the multivariate analysis. In patients with STAS, the RFS and OS in the segmentectomy group were comparable to those in the lobectomy group. However, the RFS and OS in the wedge resection group were significantly lower than those in the lobectomy group (RFS, P < 0.001; OS, P = 0.001). Wedge resection was an independent prognostic factor for poor RFS (hazard ratio [HR] = 3.87; 95% confidence interval [CI] = 1.84 - 8.12, P < 0.001), and poor OS (hazard ratio [HR] = 3.39; 95% confidence interval [CI] = 1.33 - 8.76, P = 0.011) in the multivariate analysis. Segmentectomy is an adequate operation for patients with stage IA NSCLC with or without STAS. However, wedge resection is associated with a higher risk of recurrence in this patient population.

[Predictor of intrathoracic lymph node metastasis in peripheral non-small cell lung cancers 20 mm or less in greatest dimension].

PURPOSES: To assess the independent predictor of lymph node metastasis( LNM) in peripheral smallsized non-small cell lung cancers (NSCLCs), we conducted a clinicopathologic analysis of patients with small-sized NSCLCs with and without intrathoracic LNM. METHODS: We retrospectively studied 213 patients who had undergone surgical resection of NSCLCs 20 mm or less in diameter. Categories of patient characteristics were divided into 2 groups based on clinicopathologic features, and the incidence of LNM was compared. Univariate and multivariate analyses of factors affecting overall survival( OS) were also conducted. RESULTS: In pN1-2 group (n=19), the incidence of elevated (>5 ng/dl) of preoperative carcinoembryonic antigen (CEA) and larger tumor size (>10 mm) was significantly higher than that in pN0 group (n=194) [p=0.0004, 0.0025]. Preoperatively, 73.7% patients were diagnosed as having lower stage in N-staging. Multivariate analysis identified only pN staging as an independent prognostic factor (p=0.002). CONCLUSIONS: It is likely that preoperative CEA and tumor size are useful in selecting patients with micro-N1-2 disease among those with small-sized NSCLCs. Our results indicate that limited resection should be avoided in patients with elevated CEA or tumors more than 10 mm in size, even if preoperative radiographic findings suggest no intrathoracic LNM.

A New Method to Identify Air Leaks After Pulmonary Resection Using Indocyanine Green Aerosol.

BACKGROUND: This study investigated whether air leak sites resulting from pulmonary resection could be identified by the administration of aerosolized indocyanine green into the airway. METHODS: Sixty-one patients who underwent lung resection surgery (54 video-assisted thoracoscopic surgeries and 7 thoracotomies) during 2019 to 2021 were enrolled. An additional sealing test including indocyanine green administration and observation with a near-infrared camera was performed after the conventional sealing test. The results of the indocyanine sealing test were compared with those of the conventional sealing test and evaluated. The observation period set for evaluating adverse events was 1 month. RESULTS: The conventional sealing test detected 38 air leak points, of which 20 were caused by stapler-related pleural defects. The indocyanine green sealing test identified 55 indocyanine green fluorescent sites. Among these, 37 sites were matched with air leak points identified in the conventional sealing test, and 18 new sites were identified in the indocyanine green test. Reexamination of newly identified indocyanine green fluorescent sites with the conventional sealing test showed 13 air leak sites additionally. The detection rate of the conventional sealing test was 75% and that of the indocyanine green sealing test was 98% (P = .001). No complications attributable to the aerosolized indocyanine green were encountered. CONCLUSIONS: The indocyanine green sealing test could identify air leak points overlooked by the conventional method. This procedure may be suitable in video-assisted surgery to improve surgical field visibility, and it allows prolonged observation of the lung in a collapsed state.

Perpendicular implantation of porcine trachea extracellular matrix for enhanced xenogeneic scaffold surface epithelialization in a canine model.

Objective: The availability of clinically applied medical materials in thoracic surgery remains insufficient, especially materials for treating tracheal defects. Herein, the potential of porcine extracellular matrix (P-ECM) as a new airway reconstruction material was explored by xenotransplanting it into a canine trachea. Methods: P-ECM was first transplanted into the buttocks of Narc Beagle dogs (n = 3) and its overall immuno-induced effects were evaluated. Subsequently, nine dogs underwent surgery to create a tracheal defect that was 1 × 2 cm. In group A, the P-ECM was implanted parallel to the tracheal axis (n = 3), whereas in group B the P-ECM was implanted perpendicular to the tracheal axis (n = 6). The grafts were periodically observed by bronchoscopy and evaluated postoperatively at 1 and 3 months through macroscopic and microscopic examinations. Immunosuppressants were not administered. Statistical evaluation was performed for Bronchoscopic stenosis rate, graft epithelialization rate, shrinkage rate and ECM live-implantation rate. Results: No sign of P-ECM rejection was observed after its implantation in the buttocks. Bronchoscopic findings showed no improvement concerning stenosis in group A until 3 months after surgery; epithelialization of the graft site was not evident, and the ECM site appeared scarred and faded. In contrast, stenosis gradually improved in group B, with continuous epithelium within the host tissues and P-ECM. Histologically, the graft site contracted longitudinally and no epithelialization was observed in group A, whereas full epithelialization was observed on the P-ECM in group B. No sign of cartilage regeneration was confirmed in both groups. No statistically significant differences were found in bronchoscopic stenosis rate, shrinkage rate and ECM live-implantation rate, but graft epithelialization rate showed a statistically significant difference (G-A; sporadic (25%) 3, vs. G-B; full covered (100%) 3; p = 0.047). Conclusions: P-ECM can support full re-epithelialization without chondrocyte regeneration, with perpendicular implantation facilitating epithelialization of the ECM. Our results showed that our decellularized tracheal matrix holds clinical potential as a biological xenogeneic material for airway defect repair.

[Prognosis of surgically treated large cell neuroendocrine carcinoma].

Large cell neuroendocrine carcinoma (LCNEC) is a relatively rare tumor in malignant lung neoplasms. The prognosis of LCNEC is poor and there is no consensus on the treatment for LCNEC. We report our retrospective assessment of 11 patients of LCNEC from 1999 to 2008. Three of 11 patients had malignant exudate at thoracotomy. Seven patients received limited resection. There was a recurrence even after complete surgical resection in its early stage. Four patients received platinum-based chemotherapy for adjuvant therapy or recurrence. The response to platinum-based chemotherapy was relatively good and may be comparable to that of small cell lung cancer. The overall 5-year survival rate was 30.3%. Pulmonary LCNEC represents an aggressive tumor and multimodal treatment is required.

Constant-rate intravenous infusion of indocyanine green leading to high fluorescence intensity in infrared thoracoscopic segmentectomy.

OBJECTIVES: The purpose of this study was to determine whether or not fluorescence could be increased by administering indocyanine green at a constant rate, thus stabilizing its blood concentration. METHODS: In 20 consecutive patients undergoing segmentectomy, the dominant pulmonary arteries were ligated, blocking blood in the target segment. Fluorescence intensity was then observed using different indocyanine green administration methods under infrared thoracoscopy. Intravenous administration of indocyanine green, via a syringe pump at a rate of 12.5 mg/min, was defined as the constant rate group. The bolus group was defined by a 5-mg indocyanine green rapid intravenous injection. The fluorescence intensity was compared at the time of maximum fluorescence and 2 minutes after fluorescence initiation. RESULTS: At maximum staining, the fluorescence intensity of the normal blood flow area was brighter in the constant rate group (median, 184.2; interquartile range, 170.2-200.1) compared with the bolus group (median, 122.3; interquartile range, 87.3-144.7; P = .0003). The fluorescence of the normal blood flow was retained even after 2 minutes. There was no difference in the fluorescence intensity of the ischemic segments. CONCLUSIONS: The constant rate method showed brighter and better fluorescence than the bolus injection, without an increase in the dose. The contrast between adjacent segments was clear, facilitating the differentiation of the areas.

Prognostic value of carcinoembryonic antigen and CYFRA21-1 in patients with pathological stage I non-small cell lung cancer.

BACKGROUND: The aim of this retrospective study was to assess the prognostic value of serum tumor markers (carcinoembryonic antigen (CEA) and CYFRA21-1) in patients with pathologic (p-) stage I non-small cell lung cancer (NSCLC) undergoing complete resection. METHODS: Two hundred and seventy-five patients (163 males, 112 females, mean age 67.1 years) with p-stage I NSCLC who underwent complete resection at our institution between April 1999 and October 2004 were examined. Patients who had received preoperative chemotherapy or radiotherapy were excluded, as were patients who had multiple malignancies including multiple lung cancer. The serum levels of tumor markers were measured using commercially available immunoassays within 1 month before surgical resection. Serum levels of CEA and CYFRA21-1 higher than 5.0 and 2.8 ng/ml, respectively, were considered as positive according to the manufacture's instructions. RESULTS: The histological classification was adenocarcinoma in 193 patients, squamous cell carcinoma in 71, large cell carcinoma in 5, and other histological type in 6. One hundred and fifty-seven patients had T1 disease and 118 patients had T2 disease. The positive ratio of CEA and CYFRA21-1 was 25.7% and 13.7%, respectively, and in relation to histological type was 27.8% and 7.8% in adenocarcinoma, and 20.6% and 28.4% in squamous cell carcinoma. The overall 5-year survival rate was 79.3%. With a median follow-up of 35.5 month for surviving patients, those with initial CYFRA21-1 serum levels higher than 2.8 ng/ml had a significantly worse prognosis (p=0.0041). Patients with an elevated preoperative CEA level exceeding 5.0 ng/ml had a shorter disease-free survival period (p=0.0003). In patients with adenocarcinoma, a CEA level above 5.0 ng/ml was associated with shorter survival and early recurrence, whereas CYFRA21-1 showed no such association. In patients with squamous cell carcinoma, elevated preoperative CEA was not related to survival and recurrence. In these patients, preoperative CYFRA21-1 level exceeding 2.8 ng/ml was associated with a poorer outcome, whereas preoperative CYFRA21-1 level was not associated with cancer recurrence. CONCLUSION: The patients with p-stage I adenocarcinoma whose preoperative CEA level was high might be considered as good candidates for adjuvant chemotherapy. The prognostic value of CYFRA21-1 could not be confirmed for stage I NSCLC, and preoperative CYFRA21-1 level was not useful in selecting the candidates for adjuvant chemotherapy.

Intra-thoracic fibrous tissue induction by polylactic acid and epsilon-caprolactone copolymer cubes, with or without slow release of basic fibroblast growth factor.

OBJECTIVE: We investigated whether implantation of polylactic acid and epsilon-caprolactone copolymer (PLAC) cubes with or without basic fibroblast growth factor (b-FGF) released slowly from gelatin microspheres was able to induce fibrous tissue in the dead space remaining after pneumonectomy in the thoracic cavity. METHODS: Left pneumonectomy was performed in Japanese white rabbits. In the control group (n=6), the left thoracic cavity was closed without any treatment. In the FGF group (n=6), gelatin microspheres that released 100 microg of b-FGF were implanted into the left thoracic cavity. In the PLAC group (n=6), PLAC cubes were implanted into the left thoracic cavity. In the PLAC/FGF group (n=6), both PLAC cubes and gelatin microspheres releasing 100 microg of b-FGF were implanted into the left thoracic cavity. RESULTS: In the control and FGF groups, herniation of the heart, mediastinal shift, and overinflation of the right lung were observed. No granular tissue formation was observed. In the PLAC and PLAC/FGF groups, a dense area of newly formed soft tissue was observed, and only a mild mediastinal shift was observed during the 3-month follow-up period. Pathological examination revealed induction of fibrous and granular tissue in the left thoracic cavity. The foreign-body reaction induced by PLAC was very mild. CONCLUSIONS: Implantation of PLAC cubes with or without gelatin microspheres releasing 100 microg of b-FGF is able to induce fibrous tissue in the post-pneumonectomy dead space.

Elastofibroma developing at the subscapular port site after thoracoscopic surgery: first case report.

In recent years, the number of cancer patients who undergo endoscopic surgery has been increasing, and port-site recurrence is becoming a more common complication. A 66-year-old woman underwent thoracoscopic left lower lobectomy with lymph node dissection for pT1aN0M0 adenocarcinoma of the lung. Six years after surgery, CT revealed a subscapular tumor measuring 3 cm at the site of the surgical port wound. Although port-site cancer recurrence was suspected, needle biopsy revealed that the tumor was an elastofibroma. During 6 months of follow-up, MRI revealed no further change, and it was concluded that development of the tumor at the subscapular port site had been merely coincidental.