Inter-prefectural and urban-rural regional disparities in lung cancer surgery: a Japanese nationwide population-based cohort study from 2017 to 2019.

PURPOSE: To investigate regional disparities in lung cancer surgery in Japan. METHODS: The annual incidence of lung cancer, lung cancer surgery, and the number of board-certified thoracic surgeons in Japan during 2014-2019 were investigated using a national open database. Lung cancer surgeries were categorized by procedure (wedge resection, segmentectomy, lobectomy, pneumonectomy) and approach (open, thoracoscopic). Disparities in 47 prefectures and urban-rural disparities during 2017-2019 were evaluated using the Gini coefficient and an unpaired t-test. Correlation was assessed using Pearson's correlation method. RESULTS: The national annual average incidences of lung cancer and lung cancer surgery were 121,106 and 50,959, respectively, in 2014-2019. The use of the thoracoscopic approach increased over time in all procedures, except pneumonectomies. The Gini coefficients of lung cancer, thoracoscopic surgery, and board-certified thoracic surgeons indicated low inequality across prefectures; however, those of open surgery indicated high inequality. Open surgery was more common in urban areas than in rural areas. The number of thoracoscopic surgeries and board-certified thoracic surgeons by prefecture were moderately correlated. CONCLUSION: The thoracoscopic approach is becoming more common in lung cancer surgery, with little inter-prefectural regional disparity in the incidence of lung cancer, thoracoscopic surgeries, or the number of board-certified thoracic surgeons.

Intermediate-term oncologic outcomes after video-assisted thoracoscopic thymectomy for early-stage thymoma.

OBJECTIVE: To evaluate the impact on patient survival of video-assisted thoracoscopic surgery (VATS) thymectomy for the treatment of early-stage thymoma, by comparing the intermediate-term oncologic outcomes with outcomes after open thymectomy. METHODS: Eighty-two patients who underwent complete resection of a Masaoka stage I or II thymoma between November 1998 and December 2011 were reviewed. RESULTS: The patients included 32 men and 50 women (median age, 57 years; range, 20-90 years), of whom 44 had stage I thymoma and 38 had stage II thymoma. Seventy-one patients underwent VATS, of whom 4 (5.6%) underwent conversion to open thymectomy; the remaining 11 patients underwent planned open thymectomy. Thirty-six patients underwent total thymectomy and 46 underwent partial thymectomy. Operative mortality was nil. The tumor stage, tumor size, and proportion of patients who underwent total thymectomy were not significantly different between the open and VATS thymectomy groups. The median follow-up period was 49 months (VATS, 48 months; open, 52 months). There was a significant difference between the 2 groups for the estimated 5-year overall survival (VATS, 97.0%; open, 79.5%; P=.041) but not in the estimated 5-year recurrence-free survival. CONCLUSIONS: Our findings indicate that the intermediate-term oncologic outcomes after VATS thymectomy for early-stage thymoma are as favorable as outcomes after open thymectomy. Further follow-up is still required to evaluate the long-term outcomes after VATS thymectomy.

[An autopsied case of giant small cell carcinoma of the pancreas].

A 58-year-old man who complained of an abdominal tumor was admitted to our hospital. Abdominal CT scan showed that a 15-cm tumor occupied the entire right upper abdomen and that there were ascites and liver metastases. A liver biopsy was performed. The liver biopsy showed a small cell carcinoma pattern, but no definitive origin of the tumor was determined. Considering the extensive peritoneal invasion and multiple liver metastases, he received 2 / courses of cisplatin/etoposide chemotherapy, but his tumor became larger with concomitant abdominal pain and nausea. The patient suddenly died due to multiple organ failure caused by tumor necrosis. The autopsy revealed a pathological diagnosis of primary small cell carcinoma of the pancreas.

Pheochromocytoma of the posterior mediastinum undiagnosed until the onset of intraoperative hypertension.

An asymptomatic 42-year-old man was diagnosed with a posterior mediastinal mass, most likely a nonfunctioning, benign, neurogenic tumor for which thoracoscopic surgery was initially indicated. However, the systemic blood pressure rapidly increased to a critical level immediately after starting the surgical manipulation of the tumor, which was suggestive of a hyperfunctioning pheochromocytoma. The tumor was removed after controlling the blood pressure and was histologically diagnosed as a pheochromocytoma. The patient had an uneventful course, and the tumor was proven to be sporadic through further postoperative investigations. The possibility of extraadrenal pheochromocytoma should be considered in the preoperative diagnosis of an intrathoracic paraaortic tumor, even in an asymptomatic patient.

Alternative choices of total and partial thymectomy in video-assisted resection of noninvasive thymomas.

BACKGROUND: The purpose of this report is to discuss the appropriate choice of procedures for video-assisted resection of thymoma according to factors such as the presence of myasthenia gravis or location of the tumor. METHODS: We evaluated the short-term results of thoracoscopic surgery for 30 consecutive cases of noninvasive thymoma. Unilateral thoracoscopic partial (or subtotal) thymectomy (UTPT) was employed in patients with nonmyasthenic thymoma localized to the unilateral mediastinum, and extended (or total) thymectomy by an infrasternal mediastinal approach (ETIS) in myasthenic cases or those in which total thymectomy was considered inevitable. RESULTS: UTPT was performed on 11 nonmyasthenic patients, and ETIS on 19 (13 myasthenics and six nonmyasthenics). Three patients in the ETIS group underwent conversion to sternotomy because of pericardial dissemination, pleural adhesion, and vascular injury, respectively. The mean surgical duration was 163 min and 224 min and mean blood loss was 123 g versus 149 g for UTPT and ETIS, respectively. Post-thymomectomy myasthenia occurred in a patient after UTPT who made an excellent recovery to remission after the re-UTPT. There has not been any recurrence detected for 48 months of mean postoperative follow-up. CONCLUSIONS: Our trial regarding the choice of total or partial thymectomy in thoracoscopic surgery for thymomas yielded acceptable results that warrant further investigations into long-term survival and recurrence after longer-term observation of patients undergoing these procedures.

[Endoscopic surgery with the sternum-lifting method].

Fourteen years have passed since video-assisted thoracic thymectomy (VATS-T) began to be used to treat diseases of the thymus. Indications for VATS-T have been expanded by ensuring sufficient space for easy endoscope manipulation using the sternum-lifting method. A variety of VATS-T techniques are available, including the cervical approach, bilateral VATS, infrasternal approach, and others. Although these techniques have the common feature of not involving sternotomy, they differ from each other in terms of the extent of thymectomy. In Japan, bilateral VATS (involving neck incision combined with sternum lifting) or the infrasternal approach (based on the full-directional technique) is often used for extended or maximal thymectomy in myasthenia gravis patients. In a short-term prospective study, VATS-T was shown to be more beneficial than sternotomy in myasthenia gravis patients and those with noninvasive thymoma. With the overall trend toward increased performance of minimally invasive surgery, VATS-T has been more widely adopted as a surgical approach for patients with diseases of the thymus. However, as the number of patients treated with VATS-T has increased, problems specific to endoscopic surgery have become an increasing concern. Whether VATS-T can be considered truly beneficial for patients will depend on the success or failure in solving these problems and the results of long-term prospective studies on the prognosis of patients after treatment with this procedure.

Wide resection of the upper right hemithorax combined with amputation of the right arm for a recurrent desmoid tumor.

A 66-year-old woman had a recurrent desmoid tumor in the right thoracic apex. The tumor infiltrated the brachial plexus and eventually rendered the upper right extremity functionless. The tumor was removed by aggressive wide resection of the right upper hemithorax with simultaneous amputation of the functionless right arm. Reconstruction of the chest wall was accomplished, utilizing the soft tissues of the remnant arm as a pedicled flap to cover the full-thickness defect. Aggressive wide resection of the chest wall with limb amputation is technically challenging but unavoidable in some cases of recurrent desmoid tumor.

[Minimally invasive surgery for mediastinal disease patients performed with special skills such as hand-assistance].

From 1997 to 2005, we performed endoscopic surgery on the thymus in 163 patients with myasthenia gravis or thymoma. The outcomes in these patients were analyzed, with the following conclusions obtained. Endoscopic extended thymectomy is acceptable as a standard operative procedure for myasthenia gravis patients. Endoscopic surgery on the thymus is indicated for stage II or less advanced cases of thymoma according to Masaoka classification. When hand-assisted thoracoscopic surgery (HATS) is used for surgery on the thymus, median sternotomy is not required. If applied only to cases in which it is truly indicated, endoscopic surgery on the thymus can be expected to shorten operative time compared with conventional operative procedures requiring median sternotomy and to serve as minimally invasive surgery in the true sense of the term.

[Clinical calibration dosimetry in JSMP-01: measurements using Farmer-type cylindrical ion chambers.].

The Japan Society of Medical Physics (JSMP) Task Group published Standard dosimetry of absorbed dose in external beam radiotherapy (Standard dosimetry 01) as a new high-energy photon and electron dosimetry protocol in 2002. In this study, we present Standard dosimetry 01 as the JSMP-01 protocol for the convenience of users. This protocol is based on using an ion chamber having a (60)Co absorbed dose to water calibration coefficient, N(D,w), which is calculated from a (60)Co exposure calibration coefficient, N(c). We present dose comparisons between a reference chamber and various Farmer-type cylindrical chambers with different wall materials. The absorbed dose to water was compared at the calibration depths of 5 cm for a (60)Co beam, 10 cm for photons, and d(c) = 0.6 R(50) - 0.1 (cm) for electrons according to JSMP-01. The JARP chamber in the Kyushu Regional Center which meets third-order standards in Japan was used as the reference chamber. The absorbed dose to water for the Farmer-type chambers determined according to JSMP-01 agreed with that for the JARP chamber within 1% for photon and electron beams. The doses obtained by JSMP-01 and the Japan Association of Radiological Physics protocol (JARP-86) were also compared for photon and electron beams. For the Farmer-type chambers with photon beams, JSMP-01 results were up to 1.5% higher than JARP-86 results. For electron beams JSMP-01 results were higher than JARP-86 results by 1.3-2.8%.

[Clinical calibration dosimetry in JSMP-01: measurements using plane-parallel ion chambers.].

The Japan Society of Medical Physics (JSMP) Task Group published Standard dosimetry of absorbed dose in external beam radiotherapy (Standard dosimetry 01) as a new high-energy photon and electron dosimetry protocol in 2002. In this study, we present Standard dosimetry 01 as the JSMP-01 protocol for the convenience of users. This protocol is based on using an ion chamber having a (60)Co absorbed dose to water calibration coefficient, N(D,w), which is calculated from a (60)Co exposure calibration coefficient, N(c). We present dose comparisons between a reference chamber and various plane-parallel chambers. The absorbed dose to water was compared at the calibration depth of 5 cm for a (60)Co beam and d(c) = 0.6R(50) - 0.1 (cm) for electron beams according to JSMP-01. The absorbed dose to water calibration coefficients, [N(D,w)](Co) and [N(D,w)](18E), for the plane-parallel chambers were also determined by (60)Co and electron beam cross-calibrations using a reference chamber. The dose for the plane-parallel chambers derived from [N(D,w)](Co) and [N(D,w)](18E) was compared to that for the reference chamber using electron beams. The JARP chamber in the Kyushu Regional Center which meets third-order standards in Japan was used as the reference chamber. The doses for the plane-parallel chambers determined according to JSMP-01 agreed with that for the JARP chamber within 1% and 2% for (60)Co and electron beams, respectively. For electron beams, the doses for the plane-parallel chambers calculated from [N(D,w)](Co) and [N(D,w)](18E) were within 1.5% and 1.0% compared to those for the JARP chamber, respectively, except for the Exradin A10 chamber.

Metastatic somatostatinoma of the chest wall.

A 72-year-old male was diagnosed as having a thoracic tumor in the left chest wall five years after resection of primary pancreatic somatostatinoma. The tumor was suggestive of metastasis to the chest wall or to the left lung from the previously resected somatostatinoma based on the abnormally elevated serum somatostatin level. Percutaneous biopsy confirmed that the lesion was an islet cell tumor and thoracotomy demonstrated metastasis to the left third rib without involvement of the left lung. Our case represents a rare documentation of somatostatinoma metastatic to the chest wall for which complete resection was performed.

A novel procedure using a tissue expander for management of persistent alveolar fistula after lobectomy.

We treated a patient with postlobectomy persistent alveolar fistula using a tissue expander, which is a prosthesis widely used in plastic surgery. The patient had thoracic empyema develop after right bilobectomy for lung cancer, and consequently underwent drainage of empyema followed by muscle flap closure for alveolar fistula. A residual space remained, and air leak persisted. However, implanting and expanding a tissue expander enabled us to tightly fix the flap on the raw pulmonary surface, which eventually solved the air leak. The tissue expander greatly contributed to muscle flap closure for a persistent alveolar-pleural fistula with a large remaining thoracic space.

[Anesthetic management for video-assisted extended thymectomy of patients with myasthenia gravis].

BACKGROUND: Thymectomy is one of therapeutic modalities for patients with myasthenia gravis. Since 1998, we have performed video-assisted extended thymectomy, which is much less invasive than traditional method. However, its optimal perioperative management has not been established. METHODS: From April 1998 to December 2003, 40 patients with myasthenia gravis underwent video-assisted extended thymectomy in our hospital. Anesthesia was maintained with propofol, sevoflurane and epidural anesthesia. No muscle relaxant was used. Operations were performed in supine position and required differential lung ventilation of both sides in turn for manipulation. A central venous catheter was inserted in the femoral vein to prepare for unexpected bleeding or other hemodynamic changes. RESULTS: Seven patients presented hypoxemia under differential lung ventilation and needed bilateral lung ventilation or addition of CPAP to nondependent lung. Unexpected bleeding from the left innominate vein occurred in two patients and required median sternotomy. Severe hypotension caused by compression of the heart during operation was observed in twenty-one patients. Extubation in the operating room was successful in all patients except one with severe bulbar paralysis before preoperative period. CONCLUSIONS: It is important to examine both surgical techniques of video-assisted surgery and physiological features of myasthenia gravis for anesthetic management of video-assisted extended thymectomy.

Resection and reconstruction of the airway in patients with advanced thyroid cancer.

The prognosis of patients with differentiated thyroid cancer is relatively fair, with a 10-year survival rate above 80%. One of the important prognostic factors is cancer invasion to the airway. For the last 25 years we have been performing combined resection of the trachea and larynx and have reported a relatively good 10-year survival (67.7%) and improved quality of life (QOL). However, operative complications associated with the procedure, especially insufficiency of the anastomosis and bleeding from large vessels, are life-threatening. Of 40 patients who underwent resection of the trachea, insufficiency of the anastomosis occurred in 4 and subsequent massive bleeding from carotid artery due to neck infection in 2. Tracheal resection should be carried out carefully by avoiding insufficiency. We have concluded that combined resection is a good treatment choice for survival and good QOL when performed for local control in patients with differentiated thyroid cancer.

Solitary fibrous tumor of the pleura presenting as an aneurysm-like lesion with the strongly contrasted tumor stain by angiography.

We treated a patient with solitary fibrous tumor of the pleura (SFT) whose angiograms demonstrated its feeders and strongly contrasted tumor stain. Although no one has clearly identified the specific features of SFT on angiograms, SFT can be suspected in the clinical setting if a localized chest wall tumor presents with the feeders and strongly contrasted tumor stain shown by angiography.

Thymidylate synthase and dihydropyrimidine dehydrogenase mRNA levels in tumor tissues and the efficacy of 5-fluorouracil in patients with non-small-cell lung cancer.

We examined 116 stage I-IIIA non-small-cell lung cancer (NSCLC) patients for intra-tumoral expression of thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) using TaqMan reverse transcription polymerase chain reaction (RT-PCR) assay to clarify the correlation between gene expression and the efficacy of 5-fluorouracil (5-FU) in patients with NSCLC. Patients who were administered 5-FU alone after surgery comprised the 5-FU group (n = 30), and those who underwent only surgery comprised the control group (n = 86). When dichotomized at the mean TS and DPD mRNA level, patients with low-DPD tumors who were administered 5-FU had a significantly better prognosis than those who did not receive adjuvant treatment (p = 0.041). In addition, in the 5-FU group, 10 patients with both low-TS and low-DPD tumors have not had any relapse, whereas 8 of the 20 patients with either high-TS or high-DPD tumors developed distant metastasis after surgery. Based on these results, the quantitation of TS and DPD mRNA levels may predict the efficacy of 5-FU after surgery for patient with NSCLC.

Advantage of earlier thoracoscopic clipping of thoracic duct for post-operation chylothorax following thoracic aneurysm surgery.

We report that an earlier thoracoscopic clipping of the thoracic duct was advantageous in a case of post-operation chylothorax that occurred following thoracic aneurysm surgery. A 61-year-old man developed chylothorax on postoperative day 2 following graft replacement of the descending thoracic aorta using a left-sided thoracotomy. Since a replaced graft infection is lethal, earlier thoracoscopic clipping of the thoracic duct through the right side chest wall was indicated. The patient underwent thoracoscopic clipping on postoperative day 7 and was successfully treated. The duration of drainage was 2 days and oral intake was started on the seventh day. From our results, we recommend a thoracoscopic procedure through the opposite (right) side chest wall in the early stage of chylothorax development following thoracic aneurysm surgery.

New prognostic indicator for non-small-cell lung cancer, quantitation of thymidylate synthase by real-time reverse transcription polymerase chain reaction.

Thymidylate synthase (TS) is an enzyme that catalyzes an important DNA biosynthesis process. The gene expression of TS has not been reported in non-small-cell lung cancer (NSCLC) patients. To clarify the correlation between TS mRNA levels and clinicopathological features of NSCLC, we examined 70 Stage I and II NSCLC patients for intra-tumoral expression of TS using TaqMan reverse transcription polymerase chain reaction (RT-PCR) assay and immunohistochemistry methods. We also investigated the TS promoter 28 bp polymorphism in 48 cancer tissues using PCR amplification of genomic DNA. Lung cancer tissue showed higher TS mRNA levels than normal lung tissue (Mann-Whitney U-tests; p = 0.0020). Further, TS mRNA expression was correlated with immunohistochemical TS expression (p = 0.029). We obtained 2 different DNA fragments, which indicated triple-repeat (3R) and double-repeat (2R) type alleles. Cancer tissues with the 3R/3R genotype showed significantly higher TS mRNA levels as compared to those with other genotypes (p = 0.0019). The TS genotype was also correlated with immunohistochemical TS expression (chi(2) test; p = 0.0079). The disease-free survival of the low TS mRNA level group was significantly better than those with high TS mRNA levels (log-rank test; p = 0.010), however, there were no significant differences found by immunohistochemical evaluation (p = 0.34) or TS genotype analysis (p = 0.11). A multivariate analysis revealed that high TS mRNA levels independently contributed to disease-free survival. The quantitation of TS mRNA levels is clinically more sensitive and useful for determining the prognosis of Stage I and II NSCLC patients than an immunohistochemical evaluation.

[A case of fibrosing mediastinitis manifesting recurrent nerve palsy].

A 68 year-old man was referred and admitted to our hospital because of hoarseness due to recurrent nerve palsy and an anterior mediastinal tumor detected on chest CT. Chest CT showed a low-density tumor surrounding the aorta and branching arteries. Chest MRI revealed a low-intensity tumor in both T1- and T2-weighted images. The tumor was adjacent to the heart and aorta in the upper anterior mediastinum. A biopsy was performed under minimally invasive video-assisted thoracic surgery (VATS) and a diagnosis of fibrosing mediastinitis was made histopathologically. Oral prednisolone treatment markedly reduced the tumor and improved not only abnormal laboratory data such as C-reactive protein, but also the hoarseness. We report herein that steroid monotherapy was successful in treating a case of fibrosing mediastinitis manifesting recurrent nerve palsy.

Swan-Ganz catheter-induced pseudoaneurysm of the pulmonary artery.

Pseudoaneurysm of the pulmonary artery (PA) induced by Swan-Ganz catheter injury is an important complication with high mortality. We report a case of PA pseudoaneurysm treated by PA repair. A 52-year-old woman developing infiltrate in the right lung field in chest radiography after a second mitral valve replacement was diagnosed with PA pseudoaneurysm confirmed by contrast-enhanced computed tomography and pulmonary angiography. The cause was considered Swan-Ganz catheter injury. The patient was carefully observed because there was no evidence of bronchial hemorrhage. The perforation was closed and the cavity plicated under extracorporeal circulation to avoid delayed rupture of the pseudoaneurysm when she underwent a third mitral valve replacement.