Fumitsugu Kojima

Long-term survival after video-assisted thoracic surgery lobectomy for primary lung cancer.

BACKGROUND Despite its feasibility and safety, use of video-assisted thoracic surgery (VATS) lobectomy for malignancies has spread slowly during the past decade because no definitive conclusions have been reached regarding the oncologic validity of this approach for malignancies. Thus, the purpose of this study was to analyze the indications and long-term results of VATS major pulmonary resections for primary lung cancers. METHODS Of 502 patients who had surgical resections for primary lung cancers at the National Hospital Organization Himeji Medical Center from May 2000 to December 2003, the cases of the 325 patients who were originally scheduled for VATS major pulmonary resections (pneumonectomy, bilobectomy, lobectomy, and segmentectomy) were retrospectively reviewed. At this hospital, after an initial learning-curve period, indications for VATS were extended to all cases for which this approach was thought possible. For better analysis of long-term survival rates, patients whose follow-up periods were more than 5 years after surgery were analyzed. RESULTS Of the 325 scheduled VATS resections, 21 procedures (6.4%) were eventually converted to open thoracotomies. In-hospital death occurred in 1 patient (0.3%). The average follow-up period for all censored cases was 66 months. Overall and disease-free 5-year survival rates were 85% and 83% for stage Ia (192 cases), 69% and 64% for stage Ib (50 cases), 48% and 37% for stage II (27 cases), and 29% and 19% for stage III (50 cases), respectively (p < 0.0001). Patients who were operated on using the VATS approach increased year by year, especially after 2002, when indications for using this method were extended (ratio of VATS to total cases, approximately 50% in the first 2 years and more than 80% in the latter 2 years). Long-term survival rates during the entire study period were comparable, especially in early stage lung cancer cases. CONCLUSIONS Use of VATS major pulmonary resection for primary lung cancer is feasible, with long-term patient survival comparable to that of conventional thoracotomy. Thus, it is possible that this approach might become the standard in experienced surgical centers, especially for early stage lung cancer cases. Further investigation at multiple centers is required.

Meta-Analysis of Therapeutic Procedures for Acquired Subglottic Stenosis in Adults

BACKGROUND Treatment for adult subglottic stenosis is technically demanding and no therapeutic algorithm exists. We performed the present meta-analysis of treatment for this condition in an attempt to compare efficacy on the basis of type of procedure. METHODS We identified 24 eligible retrospective studies reporting the therapeutic results for inclusion criteria. Meta-analysis was performed by combining the results of the reported success rates; success is defined as a condition requiring no further treatment. The relative risk was used as a summary statistic. RESULTS Pooled success rates of laryngotracheal resection and anastomosis (12 articles) and laryngoplasty with or without grafting (7 articles) were 95% and 76%, respectively, using a random-effects model. Success rates of endoscopic dilatation and laser resection (6 articles) varied between 40% and 82%. Meta-regression analysis showed a significant difference in the success rates between laryngotracheal reconstruction and laryngoplasty and between laryngotracheal reconstruction and an endoscopic procedure. When the indication for endoscopic management was a lesion size less than 1 cm, the results were significantly better. CONCLUSIONS The success rate of laryngotracheal reconstruction is significantly higher than that of laryngoplasty or endoscopic intervention; however, endoscopic intervention is worth trying for lesions smaller than 1 cm without framework destruction.

Sleeve lung resection for lung cancer: Analysis according to the type of procedure

OBJECTIVE Although sleeve lobectomy for lung cancer is widely accepted as an alternative to pneumonectomy, its use remains controversial. This study aimed to evaluate the surgical results after sleeve lung resection and to compare the outcomes of different procedural approaches. METHODS The medical records of 201 patients who underwent sleeve lung resection for lung cancer were retrospectively reviewed. Three groups were compared: a standard group (lobectomy or bilobectomy; n = 173), limited group (segmentectomy; n = 8), and extended group (lobectomy or bilobectomy plus segmentectomy; n = 20). RESULTS Three patients died postoperatively (1.4%). Anastomotic complications occurred in 7 patients (3.4%; fistula in 4 patients, stenosis in 3 patients), 6 of whom were successfully treated surgically or conservatively. Five-year overall and disease-free survivals were 57.8% and 50.3%, respectively. Sites of recurrence included anastomotic sites (n = 5), ipsilateral thorax (n = 11), mediastinum (n = 10), and distant sites (n = 43). Multivariate analysis showed that the influence of nodal status on both overall and disease-free survival was significant. All patients in the limited group but 1 who underwent lobectomy for recurrence in another lobe are alive without recurrence. Three patients in the extended group experienced distant metastasis, but none experienced local recurrences. Multivariate analysis showed extended group-to-standard group hazard ratios of 0.53 (95% confidence interval, 0.23-1.23) for overall survival and 0.48 (95 confidence interval, 0.22-1.05) for disease-free survival. CONCLUSION Sleeve lung resection can achieve local tumor control and long-term survival with low mortality and few anastomotic complications. Nodal status significantly affects long-term survival. Limited and extended resections are also feasible with local and long-term results comparable to those of standard sleeve lobectomy.

Thoracoscopic surgery support system using passive RFID marker

This paper proposes a RFID based thoracoscopic surgery support system, which is capable of marking a tumor inside organ tissue. The marker composed of small RFID-tags is implanted in the vicinity of tumor found in the endoscopy test. In the thoracoscopic surgery operation for removing the tumor, an RFID detector determines the accurate position of the implanted RFID-tag markers by measuring the strength of the signal emitted from the target tag. Due to limitation in the size of RFID-tag, the proposed system employs a passive RFID. To activate the passive tag implanted in the organ tissue, this paper designs a saddle-shape efficient power supply antenna. A sensitive and frequency-selective receiver is then designed for detecting the weak signal from the tag. The feasibility test confirms that the proposed method is capable of determining the accurate location of RFID tags implanted in the patients organ tissue.

A meta-analysis of debulking surgery versus surgical biopsy for unresectable thymoma

Observational studies on long-term outcomes following debulking surgery or surgical biopsy for unresectable thymoma showed various results. This meta-analysis was designed to determine the effect of debulking surgery against surgical biopsy on overall survival in patients with unresectable thymoma. The PubMed database was queried for studies published in the English language on unresectable thymoma and overall survival. We compared overall survival following surgery in patients undergoing debulking surgery and patients undergoing surgical biopsy for unresectable thymoma. Meta-analysis was performed using the Mantel-Haenszel method, and potential publication bias was evaluated with a funnel plot of precision. No randomized trials on this topic were identified. Thirteen retrospective observational studies containing a sum of 314 patients with information on the number of deaths and person-years were suitable for analysis. Information on Masaoka stages, World Health Organization histology and indications for debulking surgery versus surgical biopsy was lacking in most studies. Diversity of neoadjuvant and adjuvant treatments was noted among the eligible studies. One hundred and seventy-two (54.8%) patients underwent debulking surgery and 142 (45.2%) underwent surgical biopsy. The pooled hazard ratio was 0.451 (95% confidence interval: 0.336-0.605, P < 0.001), favouring patients undergoing debulking surgery compared with patients undergoing surgical biopsy. The funnel plot of precision demonstrated no important publication bias. Our results suggest that debulking surgery for unresectable thymoma may be associated with improved overall survival and be considered for patients with unresectable thymoma.

Development of a composite and vascularized tracheal scaffold in the omentum for in situ tissue engineering: a canine model

OBJECTIVES We herein report on development of a composite (synthetic and biological) tracheal scaffold with vascularized autologous connective tissue in the omentum, followed by in situ tissue engineering of the composite scaffold with the pedicled omentum. In this preliminary report, we focus on development and evaluation of the vascularized autologous connective tissue in the omentum. METHODS In animal experiment 1, a polypropylene framework as a synthetic component was placed in the omental sac for 3 weeks and another was placed in the pouch of Douglas as a control in five beagle dogs. In animal experiment 2, a polypropylene framework placed in the omental sac for 3 weeks was compared with a polypropylene framework coated with porcine atelocollagen, which was also placed in the omental sac in another five dogs, to investigate whether the coating of porcine atelocollagen contributes to development of more vascularized connective tissue. Macroscopic, radiological and histological evaluations were performed for developed autologous connective tissue on the frameworks, with a focus on its thickness and capillary vessels. RESULTS In animal experiment 1, the polypropylene framework in the omentum developed a composite tracheal scaffold with homogeneous and significantly thicker (2.6 ± 0.5 vs 1.2 ± 0.4 mm, P <0.0001) connective tissue in which more capillary vessels per 10-power field of view (3.5 ± 2.2 vs 0 ± 0, P = 0.015) were identified, compared with the control in the pouch of Douglas. In animal experiment 2, the omentum developed significantly thicker connective tissue on the polypropylene framework coated with porcine atelocollagen (3.6 ± 0.7 vs 2.2 ± 0.4 mm, P <0.0001) in which not significantly more capillary vessels were identified (3.5 ± 2.2 vs 5.0 ± 2.7, P = 0.12), compared with the framework that was not coated. CONCLUSIONS Placement of the polypropylene framework in the omental sac resulted in development of homogeneous and vascularized autologous connective tissue on the polypropylene framework for a composite tracheal scaffold. The framework coated with porcine atelocollagen did not show an additional benefit in inducing vascularization. This preliminary report will be followed by the long-term evaluations of in situ tissue engineering of the composite tracheal scaffold.

A synthetic bioabsorbable sheet may prevent postoperative intrapleural adhesions following thoracotomy: a canine model

OBJECTIVES Intrapleural adhesions following thoracotomy may be associated with prolonged operating time or a higher complication rate at reoperation. The aim of this experimental study was to investigate the anti-adhesion property of a bioabsorbable sheet following thoracotomy in a canine model. METHODS Ten adult beagle dogs underwent bilateral muscle-sparing thoracotomies with single ribs resected under general anaesthesia. A bioabsorbable sheet composed of poly-L-lactide copolymer (45 wt%) and ε-caprolactone (45 wt%) layered with polyglycolic acid (10 wt%) was sutured intrapleurally on the parietal pleura to cover the defect on the left, but not placed on the right side as a control. All the dogs were followed up with chest computed tomography until being sacrificed (6 months at the maximum). Thoracoscopic evaluations were performed at 1, 3 and 6 months for intrapleural adhesions at the thoracotomy site and absorption of the bioabsorbable sheet. The incidences of intrapleural adhesions were compared between the experimental side and the control side by the χ(2) test. Histological (macroscopic and microscopic) analyses of regenerated chest wall tissue were also performed at 1, 3 and 6 months. RESULTS All the dogs survived uneventfully until being sacrificed without any postoperative complications or significant radiological findings. The bioabsorbable sheet prevented intrapleural adhesions in all subjects. There were statistically significant differences in the incidence of intrapleural adhesions between the experimental side and the control side at the thoracotomy incision (0 vs 80%, P = 0.0014) at 1 month, (0 vs 66.7%, P = 0.014) at 3 months and (0 vs 75%, P = 0.028) at 6 months. The bioabsorbable sheet was found residual at 1, 3 and 6 months in all subjects. Histological analyses confirmed regenerated chest wall layers with significantly more capillary vessels at 1 month (P = 0.015), but not at 3 and 6 months (P = 0.84 and 0.41, respectively), in the regenerated mucosal and submucosal layers on the experimental side. CONCLUSIONS Our findings suggest that the bioabsorbable sheet may prevent intrapleural adhesions with parietal pleurae regenerated with more vascularization at 1 month following thoracotomy. No adverse findings were noted with the sheet.

A rigid and bioabsorbable material for anterior chest wall reconstruction in a canine model

OBJECTIVES The optimal material for anterior chest wall reconstruction following chest wall resection remains controversial. The aim of this experimental study was to evaluate short-term, morphological and histological outcomes of anterior chest wall reconstruction with a rigid and bioabsorbable material in a canine model. METHODS Twenty adult beagle dogs underwent anterior chest wall resection. In the experimental group (n = 10), the anterior chest wall was reconstructed with a rigid and bioabsorbable material composed of poly-L-lactide acid matrix (60 wt%) and uncalcined and unsintered hydroxyapatite particles (40 wt%), whereas in the control group it was (n = 10) reconstructed with dual polypropylene mesh sheets. Short-term complication rates were compared with a χ(2) test. Postoperative sternal deviations were evaluated with sternal alignment angles using computed tomography and multiplanar reconstruction and were compared with Mann-Whitney U-test immediately after reconstruction, and at 1, 3, 6, 9 and 12 months postoperatively. Histological findings of the regenerated chest wall tissue were obtained after staining with haematoxylin and eosin and Elastica van Gieson (EVG) and compared at 3, 6, 9 and 12 months. RESULTS There was not a significant difference in the short-term postoperative complication rate (P = 0.53) and the complication rate was 20% (wound infection, n = 1 and lethal mediastinitis, n = 1) in the control group and 10% (wound infection, n = 1) in the experimental group. The postoperative sternal deviation was significantly less remarkable at 1 month (123.3 ± 32.2° vs 159.4 ± 19.7°, P = 0.027), 3 months (109.8 ± 34.7° vs 150.9 ± 34.2°, P = 0.039) and 12 months (61 ± 15.6° vs 170.3 ± 6.6°, P = 0.046) in the experimental group than in the control group, whereas no significant difference was noted immediately after reconstruction (165.7 ± 6.4° vs 168.4 ± 9.1°, P = 0.50). Histological findings showed dense connective tissue in the regenerated chest wall in both groups and showed chondroblasts in the regenerated chest wall tissue at 3 and 6 months only in the experimental group. CONCLUSIONS Our results suggest that anterior chest wall reconstruction with a rigid and bioabsorbable material is feasible and may be a valuable alternative to reconstruction with a non-rigid and non-absorbable material.

Collagen fleece failed to prevent intrapleural adhesions in a canine model: failure of murine models to translate into a large animal model

Intrapleural and anti-adhesive materials were investigated in murine models, but not in a large animal model before clinical application. Our results failed to show any anti-adhesion effect of collagen fleece and suggested the thoracic physiology in murine models would not translate into a large animal model.

Effect of virtual-assisted lung mapping in acquisition of surgical margins in sublobar lung resection

Objective Virtual‐assisted lung mapping is a preoperative bronchoscopic multi‐spot dye‐marking technique. This study aimed to examine the efficacy of virtual‐assisted lung mapping for obtaining sufficient surgical margins in sublobar lung resection. Methods The multicenter, prospective, single‐arm study was conducted from September 2016 to July 2017 in 19 registered centers. Patients who required sublobar lung resection and careful determination of resection margins underwent virtual‐assisted lung mapping followed by thoracoscopic surgery. Successful resection was defined as resection of the lesion with margins greater than the lesion diameter or 2 cm using the preoperatively planned resection without additional resection. We defined the primary goal of the study as achieving successful resection in 95% of lesions. Results The resection of 203 lesions (average diameter, 9.6 ± 5.3 mm) was intended in 153 patients. The lesions included pure and mixed ground‐glass nodules (75 [35.9%] and 36 [17.2%], respectively), solid nodules (91 [43.5%]), and others (7 [3.3%]). Surgical procedures included wedge resection (131, 71.2%), segmentectomy (51, 27.7%), and others (2, 1.1%). Successful resection was achieved in 178 lesions (87.8% [95% confidence interval, 82.4‐91.9%]), and virtual‐assisted lung mapping markings successfully aided in the identification of 190 lesions (93.6% [95% confidence interval, 89.3‐96.5%]). Multivariable analysis showed that the most significant factor affecting resection success was the depth of the necessary resection margin (P = .0072). Conclusions This study showed that virtual‐assisted lung mapping has reasonable efficacy, although the successful resection rate did not reach the primary goal. The depth of the required margin was the most significant factor leading to resection failure. Graphical abstract Figure. No Caption available.