Computer-aided demarcation of early gastric cancer: a pilot comparative study with endoscopists.

BACKGROUND: Precise area diagnosis of early gastric cancer (EGC) is critical for reliable endoscopic resection. Computer-aided diagnosis (CAD) shows strong potential for detecting EGC and reducing cancer-care disparities caused by differences in endoscopists' skills. To be used in clinical practice, CAD should enable both the detection and the demarcation of lesions. This study proposes a scheme for the detection and delineation of EGC under white-light endoscopy and validates its performance using 1-year consecutive cases. METHODS: Only 300 endoscopic images randomly selected from 68 consecutive cases were used for training a convolutional neural network. All cases were treated with endoscopic submucosal dissection, enabling the accumulation of a training dataset in which the extent of lesions was precisely determined. For validation, 462 cancer images and 396 normal images from 137 consecutive cases were used. From the validation results, 38 randomly selected images were compared with those delineated by six endoscopists. RESULTS: Successful detections of EGC in 387 cancer images (83.8%) and the absence of lesions in 307 normal images (77.5%) were achieved. Positive and negative predictive values were 81.3% and 80.4%, respectively. Successful detection was achieved in 130 cases (94.9%). We achieved precise demarcation of EGC with a mean intersection over union of 66.5%, showing the extent of lesions with a smooth boundary; the results were comparable to those achieved by specialists. CONCLUSIONS: Our scheme, validated using 1-year consecutive cases, shows potential for demarcating EGC. Its performance matched that of specialists; it might therefore be suitable for clinical use in the future.

Coronary Artery Bypass Grafting through Thoracoabdominal Spiral Incision in a Patient with Tracheotomy and Severe Obesity / 日本心臓血管外科学会雑誌

A 60-year-old man with type 2 diabetes mellitus and severe obesity (height 170 cm, weight 160 kg, BMI 55) was admitted to our hospital because of acute inferior wall myocardial infarction due to acute thromboembolism of the right coronary artery (RCA). Because of three-vessel coronary diseases, we planned coronary artery bypass grafting after the medical therapy. The patient was intubated, then suffered congestive heart failure and pneumonia, and had a tracheotomy because of obesity hypoventilation syndrome. When his general condition improved after 14 months of medical therapy, we performed the operation. At that time, his weight had decreased to 107.5 kg, and BMI decreased to 37.2. We decided that tracheotomy was necessary to avoid respiratory complications. We chose a thoracoabdominal spiral incision for 2 reasons. Firstly we needed to avoid wound contamination by the tracheotomy stoma. Secondly we decided that the left internal thoracic artery (LITA) and the right gastroepiploic artery (RGEA) were sufficient for bypass grafts to the left anterior descending artery (LAD), the diagonal branches (D1), the posterolateral artery (PL) and the posterior descending artery (PD). Before the operation, epidural anesthesia was performed for postoperative analgesia to prevent respiratory dysfunction. In the right semi-lateral position at 30°, a 4th intercostal space thoracotomy was performed, and the LITA was harvested. The skin incision was extended to the midline of the abdomen and the RGEA was harvested. The end of the LITA was anastomosed with the free RGEA as I composite and the composite was anastomosed to the LAD, the D1, the 14 PL and the 4 PL without cardiopulmonary bypass. Without any perioperative blood transfusion, the patient was discharged with no perioperative complication, including mediastinitis. With this incision, we achieved secure prevention of wound contamination by the tracheotomy stoma, harvesting of a sufficient length of the LITA and RGEA and good visualization of the anastomotic sites with less cardiac displacement than median sternotomy.

Strategies, Risks, and Outcomes in Cardiac and Aortic Reoperations / 日本心臓血管外科学会雑誌

Cardiovascular reoperations involve high-risk because of adhesions. We examined the strategies and clinical outcomes of the reoperations in our institute. From January 2003 to December 2008, 52 patients underwent reoperations, accounting for 4.5% of all adult patients. The duration from the previous surgery was 10.1±9.3 years. Reoperations were performed due to infection (<i>n</i>=10), after valve surgery (<i>n</i>=16), after coronary surgery (<i>n</i>=9), due to Marfan syndrome (<i>n</i>=3), after aortic surgery (<i>n</i>=7), after congenital surgery (<i>n</i>=4), and for other reasons. In the reoperations, the same surgical site was exposed in 65%, the femoral vessels were exposed before re-sternotomy in 77%, the inflow was on the ascending aorta in 35%, and cardiopulmonary bypass was initiated before re-sternotomy in 37%. Systemic cooling was needed in 4 patients and some maneuvers for patent internal thoracic artery grafts in 6 patients. The operation time of 9.6±2.5 h and the cardiopulmonary bypass time of 295±111 min, respectively. We experienced intraoperative injuries in 16 patients (31%). Platelet transfusion was needed in 90% and a second CPB in 15%. Postoperative complications included hemorrhage (14%), infection (13%), stroke (4%), respiratory failure (44%), and renal failure (1%). The hospital mortality was 7.7% (4/52) due to uncontrolled infection, liver failure, pulmonary hemorrhage, and left ventricular rapture. The 2-year survival rate was 83.1% with the mean follow-up of 24±18 months. In conclusion, although the risk of injuries at re-sternotomy was not high, limited surgical field due to adhesions resulted in fatal injuries and in the cardiac reoperations we experienced. We need to improve our strategies for further reduction in mortality and morbidities in reoperations.

Left Subclavian Artery Arising from Kommerell's Diverticulum of a Left High Aortic Arch / 日本心臓血管外科学会雑誌

A 39-year-old woman was referred for assessment of abnormality of on a CT scan with a vascular anomaly of the aortic arch. This patient was completely asymptomatic with no concomitant pathologies and no reported prior trauma. Laboratory data for syphilitic or other microbial infections were negative. The diagnosis was confirmed by angiographic computed tomographic scan with 3-dimensional reconstruction. This technique documented the presence of the aneurysm and the left subclavian artery arising from the unique form of aneurysm. Early surgery was preferred because of the young age of the patient and the morphology and the size of the aneurysm (50 mm). Surgery was performed by a left postero-lateral thoracotomy through the forth intercostal space. Femoro-femoral partial cardiopulmonary bypass was used for distal perfusion. An aortic clamp was placed just distal to the left carotid artery, and a second clamp was placed in the descending thoracic aorta. The aortic isthmus was replaced with a 20-mm Dacron graft, and the left subclavian artery was reimplanted to the prosthesis with an 8-mm Dacron graft interposition. This aneurysm was the result of abnormal organogenesis of a primitive aortic arch and the remnant of the dorsal aorta, in other words, Kommerell's diverticulum. Microscopic examination demonstrated severe medial layer atrophy. In the light of the high risk of rupture, which was proved to be present by the very thin aneurysm wall at the time of surgery, we suggest early surgical treatment of idiopathic isthmus aneurysms in young patients regardless of aneurysm diameter.

Successful Surgical Repair of Impending Rupture of a Pseudoaneurysm of the Brachiocephalic Artery with Prior Reconstruction of the Carotid Artery / 日本心臓血管外科学会雑誌

We report the successful repair of impending rupture of a pseudoaneurysm of the brachiocephalic artery (BCA) in a 70-year-old man. He had undergone a mediastinal tumor resection through a median sternotomy in 1995. Pathological examination revealed non-Hodgkin's lymphoma. Two years later, he underwent radiation therapy of 65 Gray for metastasis to the supraclavicular lymph nodes. On January 18, 2000, plastic surgeons planned to perform a pectoralis major musculocutaneous flap to repair a radiation skin ulcer. During the operation, the BCA was lacerated, possibly in an area of radiation tissue damage. We performed a prosthetic graft (10-mm Gelseal^TM) replacement of the BCA. The right subclavian artery had to be ligated. Postoperative digital subtraction angiography (DSA) showed excellent reconstruction of the artery. Magnetic resonance angiography of the brain showed a deficit in the anterior communicating artery and stenosis of the posterior communicating artery, which indicated that the reconstruction procedure was reasonable. Seven months later, on August 18, 2000, the patient was transferred to our hospital because of swelling of the right neck and oozing from the previous cutaneous wound. CT scan and DSA demonstrated the presence of a pseudoaneurysm of the proximal anastomosis site, which required emergency surgery. Before this third sternotomy, a saphenous vein graft was interposed between both external carotid arteries. Removal of the prosthetic graft and resection of the pseudoaneurysm were performed under mild hypothermia and cardiopulmonary bypass with left common carotid arterial perfusion. Then, the wound was closed completely using a left pectoralis major musculocutaneous flap. The postoperative course was uneventful and DSA showed good patency of the graft and intracranial arteries. The patient was discharged without neurological complications. We conclude that prior reconstruction of the carotid artery is a safe and effective procedure for patients with aneurysmal changes in the BCA, especially in the case of re-operation.

A Successful Surgically Treated Case of Patent Ductus Arteriosus Associated with Noonan's Syndrome / 日本心臓血管外科学会雑誌

A 37-year-old woman with Noonan's syndrome underwent surgery for patent ductus arteriosus (PDA) and ventricular septal defect (VSD) with cardiomyopathy. Preoperative examination showed a small left-to-right shunt ratio (L→R) and mild pulmonary hypertension. However she had severe heart failure and repeated upper respiratory infections. The cardiomyopathy of this patient was the dilated type rather than the hypertrophic obstructive type which is usually seen in Noonan's syndrome. Postoperative cardiac functions did not improve significantly. This report discussed the operative technique, indications, and cardiac function aspects associated with Noonan's syndrome.