Mitsugu Omasa

Isoflurane inhalation after circulatory arrest protects against warm ischemia reperfusion injury of the lungs

Background. Non-heart-beating donors are expected to ameliorate shortages of donors for organ transplantation. The issue of preventing warm ischemic injury after circulatory arrest must be investigated. In the current study, we investigated whether isoflurane inhalation during warm ischemia could attenuate ischemia reperfusion injury (IRI) of the lung. Methods. An isolated perfused rat lung model was used. The rats were allocated into four groups: the no ischemia group; the ischemia-1 minimum alveolar concentration (MAC) iso group (ventilation with air and 1.38% isoflurane); the Ischemia-3MAC iso group (ventilation with air and 4.2% isoflurane); and the Ischemia-no treatment group (ventilation with only air). Lungs were subjected to 50 min of ischemia at 37°C. Physiological lung functions were measured after reperfusion in experiment one. Mitochondrial control ratio (RCR), cytochrome-c release from mitochondria, and caspase activities just after warm ischemia were measured in experiment two. Results. Pulmonary functions in the Ischemia-1MAC iso group were significantly greater than those in the Ischemia-no treatment group for experiment one. There were no dose-dependent effects between 1MAC and 3MAC isoflurane. In experiment two, RCR in the Ischemia-1MAC iso group was significantly greater than that in the Ischemia-no treatment group. Cytochrome-c release and caspase-9 activity in the Ischemia-1MAC iso group were significantly decreased compared to those in the Ischemia-no treatment group. Conclusions. Isoflurane inhalation attenuates warm IRI with the protection of mitochondria. Our results suggest that isoflurane inhalation after circulatory arrest can be a simple and effective method to protect the lung against warm ischemia.

Postoperative radiotherapy is effective for thymic carcinoma but not for thymoma in stage II and III thymic epithelial tumors: the Japanese Association for Research on the Thymus Database Study.

The efficacy of postoperative radiotherapy (PORT) for thymic epithelial tumors is still controversial. Using the Japanese Association for Research on the Thymus (JART) database, this study was aimed at clarifying the efficacy of PORT for Masaoka stage II and III thymic carcinoma and thymoma.

Mild hypothermia ameliorates lung ischemia reperfusion injury in an ex vivo rat lung model

Background: Ischemia reperfusion (I-R) injury of the lung frequently occurs after cardiopulmonary bypass, pulmonary thromboendarterectomy, lung transplantation, and major pulmonary resection with vascular reconstruction. Mild hypothermia ameliorates ischemia reperfusion injury of the brain and the liver. However, the effect of mild hypothermia on I-R injury of the lung has not been investigated. Methods: The lungs of Lewis rats underwent 80 min of ischemia followed by 60 min of reperfusion in an ex vivo perfusion model. The ambient temperature was maintained at either normothermia (38°C, n = 6) or mild hypothermia (35°C, n = 6) during the ischemia and reperfusion. Results: Pulmonary shunt fraction, peak inspiratory pressure, mean pulmonary arterial pressure during reperfusion, and the wet/dry weight ratio of the lung tissue at the end of reperfusion in the mild hypothermia group were significantly (p < 0.05) lower than those in the normothermia group. Total adenine nucleotide, adenosine triphosphate, adenosine diphosphate, and adenosine monophosphate after reperfusion in the mild hypothermia group were significantly (p < 0.05) higher than those in the normothermia group. Conclusion: Mild hypothermia attenuates I-R injury of the lung with maintained levels of intrapulmonary high-energy phosphate compounds after reperfusion, suggesting its beneficial effect on warm lung I-R in clinical settings.

Application of ET-Kyoto solution in clinical lung transplantation

We have developed a new organ preservation solution called extracellular-type trehalose-containing Kyoto (ET-Kyoto) solution. ET-Kyoto solution has been applied in clinical lung transplantation. The patient was a 49-year-old woman with diffuse panbronchiolitis. She underwent bilateral lobar lung transplantation from living donors. Each lobe was flushed with ET-Kyoto solution. After reperfusion, PaO(2) with inhalation of 100% oxygen was more than 500 Torr. Posttransplantation course was uneventful. Despite the relatively short ischemic time of this case report, ET-Kyoto solution may be feasible and safely applied in clinical lung transplantation.

Virtual-assisted lung mapping: outcome of 100 consecutive cases in a single institute

OBJECTIVES We developed virtual-assisted lung mapping (VAL-MAP), a bronchoscopic multispot dye-marking technique using three dimensional (3D) virtual imaging, for precise thoracoscopic sublobar lung resection with safe surgical margins. We herein review the results of 100 consecutive cases of VAL-MAP in our institute to identify types of tumours or resections that benefit from VAL-MAP. METHODS Markings were bronchoscopically made within 2 days preoperatively using virtual 3D images. Post-VAL-MAP computer tomography (CT) scans localizing the actual markings were reconstructed into 3D images for intraoperative navigation. All data on patients, markings and outcomes were prospectively collected, and the contribution of VAL-MAP to the operation was graded by the surgeon. RESULTS Resections of 156 lung lesions in 100 consecutive patients were planned from July 2012 to March 2014. The lesion diameter was 8.3 ± 4.9 (range, 2-24) mm. The total number of actually conducted markings was 380 (3.83 ± 1.07 markings/patient). Eighty-four lesions were resected by 71 wedge resections using 158 markings (2.1 ± 0.1/resection; range, 1-3). Seventy lesions were resected by 63 segmentectomies using 224 markings (3.6 ± 0.1/resection; range, 2-6). Markings were identifiable on post-VAL-MAP CT mostly as ground-glass opacities (87.7%) and/or bronchial dilatation (56.1%). During the operation, 357 of 380 markings (93.9%) were visible on the pleural surface and significantly associated with marking visibility on CT. Multiple markings that were complementary to one another appeared to have contributed to the high rate of successful resection (99.3%) with satisfactory resection margins. The contribution of VAL-MAP to the operation as graded by surgeons demonstrated that VAL-MAP is most effective during wedge resection or complex segmentectomy for hardly palpable, small tumours, while VAL-MAP still plays an important role in simple segmentectomy or resection of palpable tumours by providing higher confidence levels to surgeons during the operation. Minor pneumothoraces were found on post-VAL-MAP CT images in 4 patients without symptoms or a need for treatment. CONCLUSIONS The present study further demonstrated the efficacy and safety of VAL-MAP. VAL-MAP is likely to benefit a broader range of patients than are conventional marking techniques by assisting with both accurate tumour identification and precise determination of resection lines.

Sirolimus treatment for recurrent lymphangioleiomyomatosis after lung transplantation.

Pulmonary lymphangioleiomyomatosis is a rare disease that generally progresses to respiratory failure. We experienced a patient who had recurring lymphangioleiomyomatosis in the transplanted lungs. A chest computed tomographic scan showed a progressing emphysematous change. The patient had a subclinical extent of pan-circumferential stricture at the distal site of the left bronchial anastomosis. We treated the patient with sirolimus for three years. Chest computed tomography showed no sign of exacerbation during the late 3 years, whereas pulmonary function test revealed a slight increase after the use of sirolimus. Bronchial stricture also disappeared almost completely. This is the first reported case with sirolimus treatment for post-transplant recurrent lymphangioleiomyomatosis.

A Case of Congenital Pulmonary Vein Stenosis in an Adult

A 35-year-old Japanese woman, complaining of dyspnea after her first delivery, was diagnosed as having primary pulmonary hypertension. Continuous intravenous prostacyclin resulted in an improvement in her cardiac function, 6-min walk and New York Heart Association class, before she died of pulmonary hypertension crisis during further evaluation for pulmonary transplantation. Since the autopsy findings revealed that all 4 pulmonary veins were extremely stenotic due to hypoplasia, she was diagnosed as having had congenital pulmonary vein hypoplasia with stenosis.

Thoracoscopic wedge lung resection using virtual-assisted lung mapping

Background Virtual-assisted lung mapping is a novel bronchoscopic preoperative lung marking technique using virtual images to conduct multiple concurrent lung markings with dye. This study analyzed the indications, mapping design, and outcomes of lung wedge resection using virtual-assisted lung mapping. Methods From August 2012 to October 2013, 35 patients with 59 lesions were planned to undergo thoracoscopic lung wedge resection aided by virtual-assisted lung mapping. The data related to virtual-assisted lung mapping were prospectively collected, with the exception of the mapping design which was retrospectively analyzed. Results Suspected primary lung cancer (21 lesions in 18 patients) and metastatic lung tumors (38 lesions in 17 patients) were treated by thoracoscopic lung wedge resection with the aid of virtual-assisted lung mapping; 50 wedge resections were conducted with 107 markings. Virtual-assisted lung mapping was most frequently designed to place 2 (n = 15 wedge resections) or 3 (n = 17) markings to both identify the tumor(s) and secure a sufficient resection margin. In 7 wedge resections, anatomical landmarks and/or imaginary auxiliary lines functioned as complementary parts of the lung map when bronchial anatomy did not allow for markings at ideal spots. The resection outcomes were satisfactory without clinically evident complications. Conclusion Multiple markings of virtual-assisted lung mapping not only enabled tumor identification, but also secured sufficient resection margins. Special techniques using anatomical landmarks and imaginary auxiliary lines were complementary to the lung map when bronchial anatomy did not allow for markings at ideal spots.

Postoperative pulmonary function and complications in living-donor lobectomy

BACKGROUND Successful living-donor lobar lung transplantation largely depends on the donors outcome. Because surgical skills and peri-operative management have evolved over time, this study evaluated the recent outcomes of donor lobectomies. METHODS Between 2008 and 2014, 48 consecutive living-donor lobar lung transplantations with 85 donor lobectomies were performed at Kyoto University. All donors were prospectively followed up regularly until 1 year after surgery. RESULTS Right and left lower lobectomies were performed in 49 and 36 donors, respectively. Pulmonary arterial branches were sacrificed at equal frequency in both lobectomies, whereas pulmonary arterioplasty was only performed in left lower lobectomy (n = 9). All donors were discharged after the lobectomies, and none died during follow-up. Post-operative complications occurred in 24 donors (28%) overall, without a significant difference between donor sides. Intraoperative complications were found in 2 donors. Early and late post-operative complications were noted in 17 and 6 donors, respectively. Pneumothorax, pleuritis, and pleural effusion were the most frequent. Post-operative pulmonary function sequentially recovered more than expected and was not significantly affected by the sacrifice of pulmonary arterial branches during lobectomy. By contrast, pulmonary function at 1 year after donor lobectomy in the donors who had peri-operative complications was significantly lower than that in the donors who did not, although even post-operative pulmonary function in the donors with peri-operative complications still recovered more than expected. CONCLUSIONS Living-donor lobectomies have been safely performed in recent decades with low morbidities and without mortality.

Predictive factors of myasthenic crisis after extended thymectomy for patients with myasthenia gravis

OBJECTIVES Postoperative myasthenic crisis (POMC) is one of the serious complications after extended thymectomy for patients with myasthenia gravis (MG). This study aims to clarify the risk factors of POMC occurrence. METHODS The clinical data of 55 MG patients (25 male, 30 female; median age, 51 years) who underwent extended thymectomy at Kyoto University from 2000 to 2013 were retrospectively reviewed. Surgical outcomes and pre- and perioperative predictive factors of POMC were analysed. RESULTS The preoperative Myasthenia Gravis Foundation of America stage was I, II, III and IV in 24, 22, 8 and 1 patients, respectively. Ten patients (18.2%) developed POMC; 6 required prolonged intubation over 24 h and 4 required reventilatory support. All patients were weaned after 5.6 (2-26) days of ventilator support, and were discharged. Univariate analysis revealed a correlation with a high preoperative anti-acetylcholine receptor antibody titre (P = 0.009), history of myasthenic crisis (MC) (P = 0.0004) and unstable MG after preoperative medical therapy (P = 0.003). Multivariate logistic regression analysis showed history of MC (odds ratio, 11.84; 95% confidential interval, 1.05-372; P = 0.045) and unstable MG (odds ratio, 29.45; 95% confidential interval, 2.00-1063; P = 0.013) independently predicted POMC. The surgical response rate was not significantly different between the two groups (66.7% with POMC, 85.4% without POMC; P = 0.334). CONCLUSIONS POMC occurred more frequently in unstable MG before surgery or in patients with a history of MC. Adequate preoperative medical therapy and perioperative care should be provided to these patients.