Kan Okabayashi

Video-assisted thoracoscopic esophagectomy for esophageal cancer

AbstractBackground: The Ivor-Lewis procedure is a radical, invasive, and effective procedure for the resection of most esophageal cancers. To minimize invasiveness, we performed thoracoscopic and video-assisted esophagectomy and mediastinal dissection for esophageal cancer.n Methods: From November 1995 to June 1997, 23 patients with intrathoracic esophageal cancer, excluding T4 cancers, underwent thoracoscopic and video-assisted esophagectomy. Bilateral cervical dissections were performed as well as preparation of the gastric tube and transhiatal dissection of the lower esophagus. The cervical esophagus was cut using a stapler knife, and esophageal reconstruction was performed through the retrosternal route or anterior chest wall. Next, thoracoscopic mediastinal dissection and esophagectomy were performed.n Results: The mean volume of blood loss was 163 ± 122 ml; mean thoracoscopic surgery duration, 111 ± 24 min; mean postoperative day for patients to start eating, 8 ± 3 days; and mean hospital stay, 26 ± 8 days. No patient developed systemic inflammatory response syndrome postoperatively. Tracheal injury occurred and was repaired during the thoracoscopic approach in one patient. No patients died within 30 days after surgery. Postoperative complications included transient recurrent nerve palsy in five patients, pulmonary secretion retention requiring tracheotomy in two, and chylothorax in one. Five patients died of cancer recurrence within 1 year of surgery.n Conclusions: Our surgical experience with thoracoscopic and video-assisted esophagectomy indicate that it is a feasible and useful procedure.

The number of lymph node metastases influences survival in esophageal cancer

Background and Objectives: Lymph node involvement adversely affects the survival of patients with esophageal cancer. We retrospectively investigated whether the number of involved lymph nodes and the degree of lymph node dissection affect survival.

Reconstruction of trachea and carina with immediate or cryopreserved allografts in dogs

BACKGROUNDnGrafting is required when primary reconstruction of a tracheocarinal defect is not feasible. To determine the viability of and the nature of the healing process occurring in the cryopreserved graft, we performed tracheocarinal transplantation in dogs.nnnMETHODSnWe performed 32 tracheocarinal reconstructions in dogs using autotransplanted, immediately transplanted, or cryopreserved allografts. The viability of each graft was evaluated serially by fiberoptic macroexamination and by measurement of the tracheal mucosal blood flow using a hydrogen clearance method. In group A (n = 8), the tracheal carina was removed and reimplanted immediately. In group B (n = 8), the tracheocarina was allotransplanted immediately after harvest. In group C (n = 8), allotransplantations were performed using grafts cryopreserved for 1 to 3 weeks by freeze-drying. In group D (n = 8), we attempted to achieve immunosuppression-free transplantation with the cryopreserved allografts.nnnRESULTSnSufficient viability and good healing (6/8, 75%) occurred in the dogs with cryopreserved tracheocarinal allotransplants. Three of 8 dogs (38%) with cryopreserved allotransplants survived for 25 to 57 days without immunosuppression.nnnCONCLUSIONSnThe cryopreservation of tracheocarinal allografts for 3 weeks without the use of a preservative solution was shown to be feasible. Cryopreservation prolonged the survival of nonimmunosuppressed allotransplants in dogs.

Stenting for airway obstruction in the carinal region.

BACKGROUNDnRecent progress on airway stents has provided sufficient airway patency for patients with airway obstruction; however, when the stenosis exists in the carinal zone, establishing an excellent airway condition is still troublesome because of the anatomic structure.nnnMETHODSnWe treated 15 patients with severe tracheobronchial stenosis involving a carinal bifurcation region, using several types of stenting devices (long T-tube, T-Y tube, wire reinforced Y tracheostomal tube, Freitag Dynamic stent [Karl Storz, Tuttlingen, Germany], and covered metallic stent). All patients had advanced inoperable tumors (lung cancer, n = 6; esophageal cancer, n = 3; thyroid cancer, n = 3; mediastinal tumor, n = 3).nnnRESULTSnAll but 2 patients had immediate relief of respiratory symptoms. One patient died of respiratory failure caused by pulmonary lymphatic spread 3 days after Dynamic stent insertion. In 1 patient with severe left main bronchial stenosis due to lung cancer, effective palliation was not achieved by insertion of a covered metallic stent because of its insufficient expansion against the stenosis. Mean survival after successful stenting was 4.3 months (range, 1 to 15 months). There were no complications directly attributable to the stents.nnnCONCLUSIONSnAs evidenced by the clinical effectiveness, airway stenting for inoperable tumor is valuable in such patients. Choosing a stent that will fully cover the lesion and allow sufficient tolerance against compression is important to successful stenting. Benefits such as ease of phonation and stent maintenance should also be considered.

Free Radical-Mediated Tissue Injury in Acute Lung Allograft Rejection and the Effect of Superoxide Dismutase

BACKGROUNDnThe role of monocytes and neutrophils is crucial during acute allograft rejection. They have the capacity to generate toxic reactive oxygen intermediates in response to specific agonists that may act as tissue destructive molecules. We examined the possibility of reactive intermediate-mediated tissue injury in acute lung allograft rejection, as well as the effect of superoxide dismutase.nnnMETHODSnAllogenic (Brown Norway to F344) or syngenic (F344 to F344) rat left-lung transplantation was performed. Generation of reactive oxygen intermediates in peripheral blood was evaluated by the method of luminol-dependent chemiluminescence. Cell membrane phospholipid peroxidation in the graft was measured as malondialdehyde concentration. The third group of animals having allografts received bovine erythrocyte superoxide dismutase (5,000 U/kg intravenously every 12 hours after transplantation).nnnRESULTSnRelative chemiluminescence response in the allograft recipient to normal F344 was elevated on postoperative day 1 (257%), then decreased slightly on day 3 (156%) and was elevated again on day 7 (560%) as the process of rejection progressed. Allograft tissue malondialdehyde levels (248.37 +/- 112.35 nM/whole lung, n = 6; p < 0.05 by Students t test) were higher than isograft levels (139.29 +/- 35.93 nM/whole lung, n = 6) on day 7. Superoxide dismutase treatment significantly ameliorated the histologic degree of rejection on day 7.nnnCONCLUSIONSnThese results demonstrate the tissue destructive activity of reactive oxygen intermediates during lung allograft rejection. To scavenge free radicals may be a useful therapeutic modality in the management of acute lung allograft rejection.

Adenosquamous carcinoma of the lung: surgical results as compared with squamous cell and adenocarcinoma cases

OBJECTIVESnAn adenosquamous carcinoma (ASC) of the lung is a relatively rare tumor. In this multi-institutional cohort study, we tested the hypothesis that an ASC exhibits more aggressive clinical behavior as compared to adenocarcinoma (AC) and squamous cell carcinoma (SC).nnnMETHODSnThis retrospective cohort study used a prospective database produced by the Japan National Hospital Organization Study Group for Lung Cancer over a 7-year period (operations from 1997 to 2003, follow-up data until March 2010). During that period, 4668 cases underwent an operation for various types of primary malignant lung tumors. When a sample from a tumor comprised at least 20% each of SC and AC, the case was classified as ASC. Pathologic staging was done according to the seventh edition of the International Union against Cancer (UICC) Tumor Node Matastasis (TNM) classification of malignant tumors.nnnRESULTSnWe identified 114 patients with ASC (2.4%), 2993 with AC (64.2%), and 1369 with SC (29.3%). Kaplan-Meier survival curves for all stage cases, p-stage IA, IB, and IIIA tumors indicated that ASC cases had the least favorable survival. The 5-year survival rates for all stage cases were 23.3% for ASC, 58.0% for AC (p < 0.0001), and 40.8% for SC (p < 0.0001). The 5-year survival rates for p-stage IA were 42.0% for ASC, 81.8% for AC (p = 0.0005), and 63.4% for SC not significant (NS), while those for p-stage IB were 19.3%, 65.3% (p = 0.0024), and 46.8% (NS), respectively, and those for p-stage IIIA were 17.8%, 24.8% (p = 0.0154), and 18.8% (NS), respectively. There was a tendency for greater survival differences between ASC and AC in earlier tumor stages. A step-wise multivariable model demonstrated that sex, age, performance status, histology, tumor size, p-stage, operative method, and neoadjuvant/adjuvant therapy were independent prognostic factors.nnnCONCLUSIONnASC of the lung is more aggressive than AC and SC. The decreased survival of patients with ASC as compared with either of those single histology tumors suggests the need for a clinical trial of adjuvant chemotherapy that includes early-stage patients.

Postoperative chylothorax following partial resection of mediastinal lymphangioma : report of a case

We report herein the rare case of a 20-year-old man in whom a mediastinal lymphangioma was incidentally detected by a chest roentgenogram taken during a routine health examination. Both computed tomography and magnetic resonance imaging confirmed a mass measuring 3×7 cm in diameter in the left anterior mediastinum. A thoracoscopic exploration was done, which confirmed a diagnosis of mediastinal lymphangioma, and 3 days later a sternotomy was performed. However, the tumor could not be completely extirpated due to partial invasion. Following the thoracoscopic procedure, a chylous discharge developed which was difficult to treat conservatively and he continued to drain 700–1,000 ml of chyle daily 2 weeks following the tumor extirpation. Therefore, a right thoracotomy with ligation of the thoracic duct was performed which resolved the chylothorax. The patient remains well without any regrowth of the regional tumor 9 months after his operation.

A model to assist training in thoracoscopic surgery

VATS is a relatively new technology that has become the standard for therapy and diagnosis of lung disease. However, there are few detailed descriptions of VATS education and training in the available literature. We have thus made a thoracoscopic trainer that is very helpful and practical for refining thoracoscopic skills. The mechanism of this trainer is based on circulating vessels in a lung, which were covered with a plastic replica of the human body. A thoracoscope and minimally invasive instruments are able to access the lung from the trocar in a replica that is life sized. The trainer consists of three disposable components: artificial pulmonary vessels, the lung, and parts connecting to the heart pump. The model was tested in a seminar of minimally invasive lung surgery, and compared to the Wet-Lab. The model was shown to reproduce the human anatomical situation in a video assisted thoracic lobectomy. Due to its perfect simulation, quality, simple handling, and economic benefits, this trainer serves to enhance the training of thoracic surgeons, simultaneously decreasing the number of animal experiments. It is recommended for all surgeons, students, and medical assistant trainees embarking on thoracoscopic work.

Lymph node metastasis and prognosis in small peripheral non-small-cell lung cancers.

OBJECTIVEnThe lymph node dissection and curative resection for small peripheral non-small-cell lung cancers, it is essential to know the incidence and distribution of lymph node metastasis to confirm the pathological stage.nnnMETHODSnBetween January 1984 and August 1996, lobectomy with systemic mediastinal dissection (standard lobectomy) was conducted in 49 patients with small peripheral non-small-cell lung cancers (2.0 cm or less in diameter), and limited resection was conducted in 15 with cardiopulmonary insufficiency.nnnRESULTSnLymph node metastasis was confirmed histologically in 14 patients undergoing standard lobectomy (28.6%). The incidence of lymph node metastasis was high in tumors with pleural (p2) or subpleural (p1) involvement (63.6%) (7/14). The 5-year survival between standard lobectomy and limited resection patients (83% vs. 71%) was not statistically significant. In patients undergoing standard lobectomy, survival in those with node-negative disease was better than in those with node-positive disease (94% vs. 44%, p < 0.01).nnnCONCLUSIONSnLymph node involvement, especially in tumors with pleural involvement, is not uncommon, even when tumors are 2.0 cm or less in diameter. Systemic hilar and mediastinal dissection is therefore required for disease staging and treatment.

Evaluation of the Malignant Grade of Thymic Epithelial Tumors According to the Epithelial Subclassification

Abstract: We investigated the clinicopathological correlations among 49 surgically resected thymic epithelial tumors (TET), which were subclassified according to the six subtypes established by the Marino, Kirchner, and Müller-Hermelink system, which were renamed as follows: spindle cell type (medullary thymoma), mixed spindle and polygonal cell type (mixed medullary and cortical thymoma), small polygonal cell type (predominantly cortical thymoma), large polygonal cell type (cortical thymoma), atypical type (well differentiated thymic carcinoma), and cytologically malignant type (high-grade thymic carcinoma). The related categories were grouped for statistical analysis as follows: group 1, spindle cell type and mixed type; group 2, small polygonal cell type and large polygonal cell type; group 3, atypical type; group 4, cytologically malignant type. The association of each group with the presence of myasthenia gravis, tumor stage, and the length of survival was studied. Myasthenia gravis was significantly present in patients with small polygonal type, large polygonal type, and atypical type tumors (groups 2 and 3) ( P = 0.003). The tumors in group 1 showed the lowest tumor stage while those of group 4 had the most advanced tumor stage ( P = 0.002). The patients in group 4 had the worst prognosis, followed by those in group 3, 2, and 1, in that order. The differences among these groups were statistically significant ( P = 0.0003). From our results, we determined that TET can be separated into an extremely low-grade malignancy group (group 1), a low-grade malignancy group (group 2), an intermediate malignancy group (group 3), and a high-grade malignancy group (group 4).