Satoshi Makihata

Tracheal transplantation for carinal reconstruction in dogs

BACKGROUND Experimental carinal allotransplantation has been performed with tracheocarinal Y-shaped allografts in dogs. In this study we tried canine carinal reconstruction with cylindrical allografts. MATERIAL AND METHODS Carinal reconstruction was performed with allotransplantation of cylindrical trachea in dogs, and graft healing was evaluated by bronchoscopic observation, mucosal blood flow measurement, and histologic examination. A section of the recipient carina containing five tracheal rings and two main stem bronchi was removed, and a donor trachea seven rings long was inserted between the recipient trachea and the left main stem bronchus; then side-to-end anastomosis was performed between the graft midportion and recipient right main stem bronchus (new carina). The grafts were wrapped with pedicled omentum. Fresh grafts were transplanted into one group of dogs (n=8 ), and grafts cryopreserved for 1 week were transplanted into another group (n=7). RESULTS No anastomotic leakage occurred in any dog. Excellent healing of grafts and graft anastomoses was observed by fiberoptic bronchoscopy in six dogs (75%) in the fresh graft group and in four dogs (57%) in the cryopreserved graft group. The mucosal blood flow in the new carina decreased remarkably and, although it recovered, mucosal blood flow remained under the preoperative level on day 28 after the operation. CONCLUSION Cylindrical tracheal allotransplantation is useful for carinal reconstruction, and the method of side-to-end anastomosis between the donor trachea and recipient bronchus is a feasible and accessible procedure in dogs.

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

OBJECTIVE The 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. METHODS Between 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. RESULTS Lymph 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). CONCLUSIONS Lymph 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.

Cartilaginous injury limits cryopreservation of tracheal isograft

Histological recovery of tracheal grafts after cryopreservation was investigated using a rat heterotopic tracheal transplant model in order to evaluate the clinical applicability of tracheal cryopreservation.

Obliterative airway disease and graft stenting in pig-to-dog tracheal xenotransplantation

OBJECTIVE Obliterative airway disease occurring in concordant tracheal xenografts in rodent models is histologically similar to obliterative bronchiolitis in human lung allografts. We studied whether obliterative airway disease would occur in a large animal-discordant model. METHODS Pig and dog tracheas were cryopreserved for 7 to 14 days, and 18 recipient dogs given splenectomy 7 days before transplantation, then seven tracheal rings were removed and a corresponding five-ring donor tracheal segment was transplanted to the excised site. Grafts were wrapped with pedicled omentum and inmmunosuppression was conducted with tacrolimus or deoxyspergualin. Graft status was observed by bronchoscopy. Dogs were classified into three groups. Group 1 consisted of dog-to-dog allotransplantation animals (control group, n = 5), Group 2 of pig-to-dog xenotransplantation animals (n = 8), and Group 3 of pig-dog xenotransplantation animals who also underwent graft stenting immediately after transplantation (n = 5). RESULTS Grafts healed well in 4 of 5 Group 1 dogs. Tracheal stricture began on day 5 post transplantation and the lumen was obstructed by fibrosis by days 8 to 14 in all Group 2 dogs. All Group 3 dogs remained in good respiratory status until death. CONCLUSION Obliterative airway disease developed quickly in pig-to-dog discordant tracheal xenografts. Graft stenting is a feasible treatment for managing of tracheal obstruction.

A combination of MTAP and BAP1 immunohistochemistry is effective for distinguishing sarcomatoid mesothelioma from fibrous pleuritis

OBJECTIVES Histologic diagnosis of malignant pleural mesothelioma (MPM) is not always straightforward. Loss of BRCA1-associated protein 1 (BAP1) expression as detected by immunohistochemistry (IHC) (BAP1 IHC) and homozygous deletion (HD) of 9p21 as detected by fluorescencein situ hybridization (FISH) (9p21 FISH) are effective for distinguishing malignant mesothelial proliferation from benign proliferation. We have previously reported that immunohistochemical expression of the protein product of the methylthioadenosine phosphorylase (MTAP) gene, which is localized in the 9p21 chromosomal region, is correlated with the deletion status of 9p21 FISH in MPM tissues. In this study, we investigated whether a combination of MTAP and BAP1 IHC could distinguish sarcomatoid MPM from fibrous pleuritis. MATERIALS AND METHODS We examined IHC expressions of MTAP and BAP1 and 9p21 FISH in sarcomatoid/desmoplastic (n = 18) and biphasic MPM (n = 12) and in fibrous pleuritis (n = 17). In biphasic MPM, only sarcomatoid components were evaluated for IHC and FISH. The sensitivity and specificity of each detection assay for discriminating MPM cases from fibrous pleuritis was determined. In addition, we compared the IHC expression of MTAP with the deletion status of 9p21 FISH. RESULTS MTAP IHC and BAP1 IHC showed 80% and 36.7% sensitivity, respectively, and both showed 100% specificity in differentiating MPM from fibrous pleuritis. A combination of MTAP and BAP1 IHC yielded greater sensitivity (90%) than that detected for MTAP IHC alone or BAP1 IHC alone. Moreover, a high degree of concordance was observed between the results of MTAP IHC and HD of 9p21 FISH (κ = 0.63). CONCLUSIONS With an accurate interpretation of results, combined MTAP and BAP1 IHC is a reliable and effective method for distinguishing sarcomatoid MPM from fibrous pleuritis.