Ryuichi Waseda

Electrothermal bipolar vessel sealing device LigaSureV for pulmonary artery ligation--burst pressure and clinical experiences in complete video-assisted thoracoscopic major lung resection for lung cancer.

Intraoperative bleeding is one of the main severe complications in complete video-assisted thoracoscopic surgery (c-VATS). We investigated whether one sealing device, the LigaSureV (LSV) vessel sealing system (Valleylab, Tyco Healthcare, Boulder, CO, USA) was experimentally and clinically safe and effective for c-VATS. The burst pressures (BP) of each pulmonary artery (PA) in resected lungs were measured and were compared between a thin PA group (<5 mm) and a thick PA group (> or =5 mm). To investigate the influences of the sealing situations to the adequacy of sealing, BPs were measured after dry or wet conditioned PA (soaked with 0.9% saline) were sealed and cut by the LSV. Clinically, a total of 203 PA were divided with the LSV in c-VATS. The BP of the thin PA with small diameters (<5 mm) were higher than the thick PA (607 mmHg vs. 447 mmHg; P<0.05). The sealing effect was higher when the thick PA was sealed in a dry state than in a wet state (447 mmHg vs. 399 mmHg; P<0.05). However, average BP was physiologically high enough to inhibit a burst even for thick PA sealed in a wet state. There was single case of delayed bleeding sealed PA resulted from seal contact with a sucton device. These studies demonstrated the safety and efficacy of the LSV to sealed PA in c-VATS.

Usefulness of fluorine-18 fluorodeoxyglucose-positron emission tomography in management strategy for thymic epithelial tumors

BACKGROUND This study investigated the usefulness of fluorine-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) during the treatment of thymic epithelial tumors in combination with Ki-67 evaluation based on surgical cases in our department. METHODS Between November 2003 and May 2011, 39 patients with thymic epithelial tumor underwent preoperative FDG-PET. The maximum standardized uptake value (SUVmax) of each category within Masaoka stage, World Health Organization classification, tumor diameter, myasthenia gravis, and Ki-67 label index were compared. To examine risk factors for relapse, SUVmax, age, sex, and surgical radicality were investigated in addition to those items. RESULTS The mean SUVmax was 4.5 (range, 1.2 to 14.6) and was significantly higher for Masaoka stage IV than for I and II (all p < 0.008) and for World Health Organization classified thymic cancer compared with all other types (all p < 0.0001). Mean SUVmax revealed significantly higher values for large tumors than for small tumors (p = 0.02). Mean SUVmax was significantly higher for high Ki-67-positive samples (p = 0.0004), indicating a strong correlation between SUVmax and the Ki-67 label index (ρ = 0.77, p = 0.0001). SUVmax accurately reflected therapeutic efficacy in patients with induction therapy. Univariate analysis revealed Masaoka stages III and IV and pathologically incomplete resection as risk factors for relapse. On multivariate analysis, independent risk factors for relapse comprised only Masaoka stages III and IV. CONCLUSIONS FDG-PET SUVmax does reflect proliferation and invasiveness of thymic epithelial tumors and can provide an index for diagnosis and treatment, although it is not a risk factor for relapse. FDG-PET is also useful for evaluating induction therapy efficacy and detecting relapse.

Pattern and predictors of false positive lymph node involvement on positron emission tomography in patients with non-small cell lung cancer.

Objectives The aim of this study was to elucidate the optimal parameters for diagnosing false positive (FP) lymph nodes (LNs) in patients with non-small cell lung cancer.Methods We reviewed 292 patients with non-small cell lung cancer (NSCLC). Fluorodeoxyglucose positron emission tomography (FDG-PET) imaging was performed at 1 hour (early) post-FDG injection and repeated 2 hours (delayed) after injection. We analyzed the relationship between the pathology of LNs and the results of PET, and the percent change in the standardized uptake value (%ΔSUV) between the two time-points.Results Eighteen of 46 cases (39.1%) in the FP group showed higher SUVs for their LNs compared with those for primary tumor, whereas 13.2% in the true positive group (p = 0.032) had higher SUVs for their LNs. Thirty-four of 36 cases in the true positive group had %ΔSUV ranging from 0% to 61.5% compared with only 13 of 33 in the FP group. Twenty out of 22 cases (90.9%) where %ΔSUV was over 61.5% or under 0% were considered as FP.Conclusions Patients with higher SUVs for LNs than for primary tumors and patients with extremely high or low %ΔSUVs tended to have FP LNs.

A novel fluorescence technique for identification of the pulmonary segments by using the photodynamic diagnosis endoscope system: An experimental study in ex vivo porcine lung

OBJECTIVE Photodynamic diagnosis is a technique that has been proposed to enhance tumor detection and resection. We modified this technique to identify pulmonary segments and examine the feasibility of this technique in ex vivo porcine lungs. METHODS The photodynamic diagnosis endoscope system consisted of the D-Light system as the excitation light source and a TRICAM camera as the fluorescence sensing endoscope (Karl Storz GmbH & Co, Tuttlingen, Germany). Vitamin B2 was used as the fluorescence substance. Two kinds of segmentectomy were performed in right porcine lung. After identification of the segmental bronchus, the fluorescent substance was injected transbronchially. The fluorescent segment was observed using the photodynamic diagnosis endoscope system, and the identified intersegmental plane was cut using scissors. The operative data collected were the success rate of accurately identifying the pulmonary segments. The duration and light intensity of fluorescence of the target segment were recorded to provide an objective measurement of success. The same parameters were also measured for the adjacent segment. RESULTS Overall, 20 segmentectomies were performed, 10 of each kind--cranial segmentectomy and L2 segmentectomy. In all procedures, it was possible to identify the target segment by its yellow-green fluorescence. No unexpected injuries of the major segmental bronchi and vessels nor incorrect recognition of target segments occurred. The success rate of accurately identifying pulmonary segments was 100%. The duration and light intensity of this fluorescence technique was enough to perform pulmonary segmentectomy. CONCLUSIONS This florescence technique using vitamin B2 and the photodynamic diagnosis endoscope system is useful to identify the target pulmonary segment easily and clearly in ex vivo porcine lung.

Myasthenia gravis complicated with lung cancer and middle mediastinal thymoma.

Myasthenia gravis complicated by lung cancer is rare, and the association between myasthenia gravis and lung cancer is unclear. Thymoma located in the middle mediastinum is very rare. We describe a case of myasthenia gravis complicated with lung cancer and middle mediastinal thymoma in a 69-year-old woman.

Robotic intragastric surgery: A new surgical approach for the gastric lesion

BackgroundIntragastric surgery is accepted as a minimally invasive procedure for mucosal or submucosal lesions. Robotic surgery promises to extend the capabilities of the minimally invasive surgeon and many surgical specialties are applying this new technology. However, there is no report of robotic intragastric surgery. We describe the use of the da Vinci® Surgical System for intraluminal mucosal resection of the stomach.MethodsWe developed our porcine intragastric surgery model using the Tuebingen MIS Trainer. We set a tentative lesion on the posterior wall near the esophagocardiac junction (ECJ) of the stomach and performed mucosal resection of the lesion using the da Vinci Surgical System. We also performed closure of the defect after mucosal resection and subsequent closure of the intentional gastric perforation.ResultsUsing our porcine intragastric surgery model, we successfully performed mucosal resection of the tentative lesion. We also smoothly completed closure of the defect and closure of the perforation without any complications. The mean size of the mucosa was 6 cm and the mean duration of the procedure was only 12 min.ConclusionsThe safety and efficacy of robotic intragastric surgery was preliminarily established in this study. However, further studies are needed to prove its practical feasibility in humans using the da Vinci Surgical System to make it an effective operation.

Total port-access lobectomy via a subcostal trans-diaphragmatic approach for lung cancer †

Video-assisted thoracic surgery has been recognized as an acceptable technique for the treatment of early-stage lung cancer, with the potential advantage of lower postoperative pain than that experienced after open thoracotomy. However, the procedure cannot completely alleviate postoperative pain and paraesthesia and causes some degree of intercostal nerve damage. To minimize postoperative pain in video-assisted thoracic surgery, several new approaches have recently been reported. We describe the case of a 51-year old woman who successfully underwent total port-access, video-assisted thoracoscopic lobectomy for Stage IA lung cancer via the subcostal trans-diaphragmatic approach. Our results demonstrate the feasibility and safety of this procedure, which offers the advantages of minimizing intercostal nerve damage and facilitating better handling of staplers.

Radiologic and Nuclear Medicine Predictors of Tumor Invasiveness in Patients With Clinical Stage IA Lung Adenocarcinoma

BackgroundThe aim of this study was to analyze parameters to predict tumor invasiveness according to high-resolution computed tomography and positron emission tomography in patients with clinical stage IA lung adenocarcinoma.MethodsA total of 122 patients with clinical stage IA lung adenocarcinoma were enrolled in the study. Receiver operating characteristic (ROC) curves were constructed for three factors—the degree of solid tumor component (solid%), maximum standard uptake value (SUVmax) and tumor size—and cutoff values were determined to reveal the highest sensitivity and specificity to diagnose tumor invasiveness. We created an algorithm for detecting tumor invasiveness (model 1). The data for the three factors were combined and their ROC curves constructed (model 2). A prospective study was conducted to validate the utility of these models.ResultsMultivariate analysis identified solid%, SUVmax, and tumor size as potentially important predictors of tumor invasiveness. In the ROC curve analysis, solid% (area under the curve was 0.882) had the largest area under the curve, followed by the SUV (0.867) and tumor size (0.747). The combination assay using all three factors had the highest sensitivity and specificity for prediction (0.902). Models 1 and 2 were applied to the prospectively enrolled cases, and their utility was reviewed. Both models showed 100% sensitivity, with model 2 showing a slightly higher diagnostic value than model 1.ConclusionsThe solid portion ratio was a more powerful clinical predictor for lymphovascular invasion than the SUVmax. Our novel scoring model for tumor invasiveness can be employed for preoperative assessment of tumor invasiveness.