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Makoto Hashizume

Publications and source records attributed to Makoto Hashizume.

At least 19 recordsLinked to original sources
PubMed2006

Robotic surgery setup simulation with the integration of inverse-kinematics computation and medical imaging.

At present, there are representative robot operation systems such as da Vinci and ZEUS which have realized minimally invasive surgery by the use of dexterous manipulators. In the operating room, medical staff must prepare and set up an environment in which the robot has optimal freedom of motion and its functions can be fully demonstrated for every case. The range of motion in which the robot can reach and be maneuvered is restricted by the fixed point of the trocar site. We have developed a preoperative planning system with the function of volume rendering of medical images and automatic positioning by applying an inverse-kinematics computation of surgical robot. The motion of a surgical robot can be simulated in advance with the intuitive interface and kinematics computation program running in the background of the system. If robotic surgery planning with volume rendering of DICOM images is possible, the discussion of a surgical plan can be directly made just after the diagnosis considering the patient-specific structure. This kind of setup platform would be essential for the future introduction of surgical robotics into an operating room.

Algorithms↗
PubMed2006

Asymmetry of mediolateral laxity of the normal knee.

BACKGROUND: Understanding the normal kinematics of the joints is important for reconstructive surgery. However, only a few extensive studies have been done on medial and lateral laxity of the normal knee. METHODS: Radiographs of 50 normal knees were obtained under varus and valgus stress in both extension and flexion and the relative angle of the articular surface was measured. RESULTS: In extension, the mean angle was 4.9 degrees in varus stress and 2.4 degrees in valgus stress. In flexion, the mean angle was 4.8 degrees in varus stress and 1.7 degrees in valgus stress. Lateral laxity was significantly greater than medial laxity in both extension and flexion. CONCLUSIONS: Lateral laxity may be necessary for the medial pivot movement of the normal knee. There is some disagreement regarding the importance of pursuing the perfect rectangular gaps during total knee arthroplasty (TKA). The methods for measuring the tension of soft tissues during the operation are not accurate and do not always reflect the postoperative tensions of dynamic phases, such as walking and standing. Slight lateral laxity can be accepted with TKA, and further studies are necessary to determine whether prosthesis lift-off occurs in the replaced knee with slight lateral laxity similar to that in the normal knee.

Adult↗
PubMed2006

Arthroscopic resection of the discoid lateral meniscus: long-term follow-up for 16 years.

PURPOSE: Although the clinical outcome of arthroscopic resection for a torn discoid lateral meniscus is known to be successful in the short term, long-term successful results are necessary. We reviewed the clinical results of arthroscopic meniscectomy for a torn discoid lateral meniscus in 29 knees, with an average follow-up of 16 years. METHODS: Subjective symptoms were evaluated with the use of a questionnaire developed by the International Knee Documentation Committee (IKDC). The trends of IKDC scores and patient age at the time of surgery were statistically evaluated through a stepwise piecewise linear regression analysis. Radiographic examination was performed in 15 knees. RESULTS: The average IKDC score was 87 points. Statistical analysis conducted with the use of a regression model of scores revealed that the regression line declined from 90 to 72 points at ages between 25 and 30 years at the time of surgery. Radiographic examination revealed that patients with degenerative changes at the lateral joint compartment, such as joint space narrowing and subchondral sclerosis, were of greater average age at the time of surgery than did patients who did not develop these changes. CONCLUSIONS: Results suggest that clinical outcomes associated with this method are successful for longer than 10 years for patients younger than 25 years of age; however, older patients may develop problems caused by degenerative changes that may result from increased stress on the affected joint compartment. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Adolescent↗
PubMed2006

Consensus on extra-hepatic portal vein obstruction.

The Asian Pacific Association for the Study of the Liver (APASL) had set up a working party on portal hypertension in 2002 with a mandate to develop consensus on various aspects of portal hypertension. The first of these consensuses has been developed on extra-hepatic portal vein obstruction (EHPVO). It was discussed and prepared by the experts in this field from the Asian region and was presented at the annual meeting of the APASL, at Bali in August 2005. This article summarizes all the consensus statements approved by the APASL on various aspects of EHPVO.

Anticoagulants↗
PubMed2006

Geriatric patients presenting to the emergency department of a Japanese university hospital.

To evaluate the trend of elderly patients visiting the emergency department of a Japanese University Hospital, out patient-based records were reviewed of the emergency department of Kyushu University Hospital from 2000 to 2004. A total number of 7610 emergency patients visited the department during the five year period. The median (25%, 75%) of age was 32 (22, 56). Patients aged 65 years and over accounted for 16% of all attendances. All the patients were classified into 6 groups according to the diagnosis, (1) Respiratory, (2) Circulatory, (3) Central nervous system, (4) Abdominal, (5) Trauma, and (6) Others. The median age in each group was (1) 27 (15, 49), (2) 66 (53, 76), (3) 51 (27, 67), (4) 33 (22, 56), and (5) 26 (20, 46), respectively. There was a statistically significant difference observed, reciprocally except between (1) and (5) (P < 0.05). The patients showed statistically significant difference in the annual transition of the disease (P < 0.0001). In the elderly, the annual transition of the disease showed statistically significant decreases in Circulatory (P = 0.0015) and in Central nervous (P < 0.0001), and an increase in Abdominal (P < 0.0001), respectively. Death rate at the outpatient clinic in the elderly showed much higher than in the younger (P < 0.0001). Admission rate was also much higher in the elderly than in the younger (P < 0.0001). Elderly emergency patients have both internal and external intrinsic factors. They have to be treated carefully since their condition easily deteriorates. Provisions for the problems surrounding the elderly should be made as a nationwide effort.

Age Factors↗
PubMed2005

Selective cyclooxygenase (COX) inhibition causes damage to portal hypertensive gastric mucosa: roles of nitric oxide and NF-kappaB.

Portal hypertension (PHT) is associated with increased susceptibility of the gastric mucosa to injury by a variety of factors, including nonsteroidal anti-inflammatory drugs (NSAIDs) that nonselectively inhibit both isoforms of cyclooxygenase (COX-1 and -2). PHT gastric mucosa also has excessive nitric oxide (NO) production that contributes to the general increased susceptibility to injury. Using a rat model of PHT, we studied whether selective COX inhibition, which does not damage normal (normotensive) gastric mucosa, is sufficient to cause PHT gastric damage and, if so, whether and how excessive NO is involved. Indomethacin, a nonselective NSAID, caused 2.4-fold more gastric injury to PHT vs. normotensive sham-operated (SO) control rats. Neither NS-398 nor celecoxib, selective COX-2 inhibitors, caused gastric damage in either SO or PHT rats. SC-560, a selective COX-1 inhibitor, did not cause gastric damage in SO rats but dose-dependently caused gastric damage in PHT rats. There was a compensatory increase in COX-2 expression and activity in SC-560-treated SO rats but not SC-560-treated PHT rats. Partial inhibition of NO production restored gastric COX-2 expression and activity levels in SC-560-treated PHT rats to those of SC-560-treated SO rats, by a mechanism consistent with induction of NF-kappaB, and significantly reduced gastric damage. These studies indicate that, in contrast to normotensive gastric mucosa, inhibition of COX-1 alone is sufficient to cause PHT gastric damage as a result of excessive NO that prevents the induction of NF-kappaB and the compensatory increase in COX-2.

Animals↗
PubMed2005

Prognostic value of thymidine phosphorylase activity in liver tissue adjacent to hepatocellular carcinoma.

BACKGROUND: Measurement of thymidine phosphorylase (TP) activity in normal liver tissue adjacent to hepatocellular carcinoma (HCC) may predict multicentric recurrence a long time after an operation. The authors investigated this activity in 92 patients with HCC who had a single HCC equal to or less than 5 cm. METHODS: Fresh samples (tumors with adjacent normal tissues) were collected from 92 patients with HCC who underwent curative hepatic resection. The levels of TP activity in nonfixed, fresh, and frozen HCC specimens with adjacent noncancerous liver tissue were biochemically measured by using an enzyme-linked immunosorbent assay method. RESULTS: Patients who had a high TP level in normal liver tissue had significantly earlier recurrence (median disease-free survival, 819 days; 95% confidence interval [95% CI], 478-1044 days) compared with patients who had a low TP level (median disease-free survival, 1376 days; lower limit of 95% CI, 921 days; P = 0.0171). Multivariate analysis showed that patients who had a low TP level in adjacent liver tissue had a 0.387-fold higher risk of postoperative recurrence compared with patients who had a high TP level (P = 0.0067). CONCLUSION: TP activity in normal liver tissue adjacent to HCC is related to tumor occurrence and may predict postoperative tumor recurrence.

Aged↗
PubMed2005

Surgical robot setup simulation with consistent kinematics and haptics for abdominal surgery.

Preoperative simulation and planning of surgical robot setup should accompany advanced robotic surgery if their advantages are to be further pursued. Feedback from the planning system will plays an essential role in computer-aided robotic surgery in addition to preoperative detailed geometric information from patient CT/MRI images. Surgical robot setup simulation systems for appropriate trocar site placement have been developed especially for abdominal surgery. The motion of the surgical robot can be simulated and rehearsed with kinematic constraints at the trocar site, and the inverse-kinematics of the robot. Results from simulation using clinical patient data verify the effectiveness of the proposed system.

Biomechanical Phenomena↗
PubMed2005

Tele-surgical simulation system for training in the use of da Vinci surgery.

Laparoscopic surgery including robotic surgery allows the surgeon to be able to conduct minimally invasive surgery. A surgeon is required to master difficult skills for this surgery to compensate for the narrow field of view, limitation of work space, and the lack of depth sensation. To counteract these drawbacks, we have been developing a training simulation system that can allow surgeons to practice and master surgical procedures. In addition, our system aims to distribute a simulation program, to provide a means of collaboration between remote hospitals, and to be able to provide a means for guidance from an expert surgeon. In this paper, we would like to show the surgery simulation for da Vinci surgery, in particular a cholecystectomy. The integral parts of this system are a soft tissue model which is created by the sphere-filled method enabling real-time deformations based on a patient's data, force feedback devices known as a PHANToM and the Internet connection. By using this system a surgeon can perform surgical maneuvers such as pushing, grasping, and detachment in real-time manipulation. Moreover, using the broadband communication, we can perform the tele-surgical simulation for training.

Computer Simulation↗
PubMed2005

A laparoscopic radical prostatectomy assisted by the "ZEUS" robotic system: an initial case report.

A 68-year-old man with prostate cancer, T1cN0M0, was treated with laparoscopic radical prostatectomy (LRP) assisted by the ZEUS robotic system. The ZEUS system was utilized only for vesico-urethral anastomosis, one of the most difficult procedures to perform during LRP. We could complete the vesico-urethral anastomosis using the ZEUS system for 100 min without any intraoperative complications. The urethral catheter was removed 7 days after operation. To our knowledge, this is the initial case of robot-assisted radical prostatectomy using the ZEUS system.

Aged↗
PubMed2005

[Robot-assisted surgery].

Computer-enhanced surgical systems are becoming common worldwide. Currently, 331 da Vinci surgical systems have been installed. Robotic surgery was successfully performed on more than 20,000 patients in 2004. Intuitive Surgical has received FDA clearance for laparoscopic and thoracoscopic procedures, including hysterectomy or prostatectomy, as well as cardiac revascularization. The Japanese "Future Project" team has developed a prototype of a smaller surgical robotic system and successfully performed telesurgery on animals between Tokyo and Fujinomiya on August 8, 2002, and between Fukuoka and Seoul on March 2, 2005. Robotic surgery will lead to dramatic progress in medicine with the development of surgical navigation systems, simulation systems, and telementoring systems.

General Surgery↗
PubMed2004

Essential role of PDGFRalpha-p70S6K signaling in mesenchymal cells during therapeutic and tumor angiogenesis in vivo: role of PDGFRalpha during angiogenesis.

Discovery of the common and ubiquitous molecular targets for the disruption of angiogenesis, that are independent of the characteristics of malignant tumors, is desired to develop the more effective antitumor drugs. In this study, we propose that the platelet-derived growth factor receptor-alpha (PDGFRalpha)-p70S6K signal transduction pathway in mesenchymal cells, which is required for functional angiogenesis induced by fibroblast growth factor-2, is the potent candidate. Using murine limb ischemia as a tumor-free assay system, we demonstrated that p70S6K inhibitor rapamycin (RAPA) targets mesenchymal cells to shut down the sustained expression of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF), via silencing of the PDGFRalpha-p70S6K pathway. Irrespective of the varied expression profiles of angiogenic factors in each tumor tested, RAPA constantly led the tumors to dormancy and severe ischemia in the time course, even associated with upregulated expression of VEGF from tumors. Because RAPA showed only a minimal effect to hypoxia-related expression of VEGF in culture, these results suggest that RAPA targets the host-vasculature rather than tumor itself in vivo. Thus, our current study indicates that the PDGFRalpha-p70S6K pathway is an essential regulator for FGF-2-mediated therapeutic neovascularization, as well as for the host-derived vasculature but not tumors during tumor angiogenesis, via controlling continuity of expression of multiple angiogenic growth factors.

Animals↗
PubMed2004

Robotic surgery and cancer: the present state, problems and future vision.

In the 1990s, laparoscopic surgery entirely changed the traditional style of surgical operations. Laparoscopic cholecystectomy has spread rapidly and is now established as the standard treatment. However, besides cholecystectomy, endoscopic procedures are still not applied so widely to a variety of surgical operations. This is because laparoscopic techniques, such as suturing or ligation, make it difficult for surgeons to perform other kinds of operations and thus greatly increase their mental and physical stress. It is necessary to introduce various advanced technologies such as: surgical robots, three dimensional (3D) images, computer graphics (CG), computer simulation technology and others. Surgical robots, including the AESOP, da Vinci and ZEUS systems, provide surgeons with technologically advanced vision and hand skills. As a result, such systems are expected to revolutionize the field of surgery. However, there have so far been few studies which discuss the indications of robotic surgery for tumors/cancer. Therefore, herein we review various studies published in English to focus on the application of robotic surgery to tumors/cancer. We point out that there are several problems to be solved for robot surgery: i) price of surgical robots, ii) training systems for surgeon, iii) coverage by medical insurance, iv) downsizing and v) navigation system. In conclusion, we believe that, in the near future as robotic technology continues to develop, almost all kinds of endoscopic surgery will be performed by this technology. It will replace traditional surgery not only in the treatment of benign diseases but also in malignant illnesses.

Cardiovascular Diseases↗
PubMed2004

Propranolol alone may not be acceptable to prevent first esophageal variceal bleeding in Japanese cirrhotic patients: randomized controlled trial.

BACKGROUND AND AIM: In Japan, endoscopic injection sclerotherapy (EIS) is widely used to prevent first esophageal variceal bleeding, in contrast to pharmacological therapy which is the main treatment used in the rest of the world. The present study investigated if propranolol alone is acceptable to prevent first esophageal variceal bleeding in Japanese cirrhotic patients. This was compared with EIS. METHODS: Twenty-five Japanese cirrhotic patients with endoscopically proven, likely to bleed esophageal varices were randomly assigned for propranolol administration (12 patients; group A) and EIS (13 patients; group B) to prevent first esophageal variceal bleeding. Complications, non-recurrence rate, bleeding rate and probability of survival were compared between the two groups. RESULTS: One patient in group A had severe bradycardia with loss of consciousness that seriously worsened his quality of life. The cumulative non-recurrence rate of group A was significantly lower compared with that of group B (P < 0.05). In group A, 2 of the 12 patients requested to discontinue taking propranolol and were excluded from the trial. The EIS treatment (group B) showed excellent results. No patient in group A or group B bled from esophageal varices throughout this study. The two groups showed no statistically significant differences in probability of survival. CONCLUSIONS: Propranolol alone may not be acceptable to prevent first esophageal variceal bleeding in Japanese cirrhotic patients.

Adrenergic beta-Antagonists↗
PubMed2004

Development of a camera model and calibration procedure for oblique-viewing endoscopes.

Oblique-viewing endoscopes (oblique scopes) are widely used in medical practice. They are essential for certain procedures such as laparoscopy, arthroscopy and sinus endoscopy. In an oblique scope the viewing directions are changeable by rotating the scope cylinder. Although a camera calibration method is necessary to apply augmented reality technologies to oblique endoscopic procedures, no method for oblique scope calibration has yet been developed. In the present paper, we formulate a camera model and a calibration procedure for oblique scopes. In the calibration procedure, Tsai's calibration is performed at zero rotation of the scope cylinder, then the variation of the external camera parameters corresponding to the rotation of the scope cylinder is modeled and estimated as a function of the rotation angle. Accurate estimation of the rotational axis is included in the procedure. The accuracy of this estimation was demonstrated to have a significant effect on overall calibration accuracy in the experimental evaluation, especially with large rotation angles. The projection error in the image plane was approximately two pixels. The proposed method was shown to be clinically applicable.

Algorithms↗
PubMed2004

[Present and future developments of the virtual surgery and tele-virtual surgery system].

One of the applications available now in the medical field is the virtual surgery system. This system allows surgeons a safe place to master surgical techniques and to plan surgical procedures before the operation. To provide the system for use in a clinical situation, a soft tissue model and a force feedback device suited for the surgery is required. In this paper, we would like to introduce our virtual surgery system, which possesses a soft tissue model that can show accurate, real-time deformation and is equipped with a force feedback device that allows the user to experience the tactile sensations. In addition, we will introduce our tele-virtual surgery simulation system for training in the procedures used in robotic surgery.

Computer Graphics↗