Present status of Sumitomo's space borne cryocoolers

Kanao, Ken-Ichi,Hirabayashi, Masayuki,Tsunematsu, Shoji,Katsyhiro Narasaki 한국우주과학회 2006 한국우주과학회보 Vol.15 No.2

Development of Solar Inverter with FRT and DVS Capabilities

Kanao, Norikazu,Mizuo, Kensuke,Fujii, Kansuke The Korean Institute of Electrical Engineers 2013 The Journal of International Council on Electrical Vol.3 No.3

With increasing penetration of renewable energies, especially, photovoltaic energy, more and more concern about power stability will be required because most distributed generators like solar inverters don't have fault ride-through (FRT) capability and reactive power supply capability which is called as dynamic voltage support (DVS). These capabilities haven't been required for a grid code in Japan. Penetration of large amount of PV into power system would deteriorate power system stability in the future. This paper first presents an effect of a distributed generator with FRT and DVS on voltage stability of power system by a simple simulation. Next this paper describes how to perform those capabilities of solar inverter and notes a relation between FRT/DVS and islanding. Then, we examined the methods in a factory test and manufactured a 20-kW prototype of a solar inverter with FRT/DVS capabilities. Finally we performed a field test in real power system, resulting in a good performance.

Various types of total laparoscopic nerve-sparing radical hysterectomies and their effects on bladder function

Hiroyuki Kanao,Kazuko Fujiwara,Keiko Ebisawa,Tomonori Hada,Yoshiaki Ota,Masaaki Andou 대한부인종양학회 2014 Journal of Gynecologic Oncology Vol.25 No.3

Objective: This study was conducted to ascertain the correlation between preserved pelvic nerve networks and bladder function after laparoscopic nerve-sparing radical hysterectomy. Methods: Between 2009 and 2011, 53 patients underwent total laparoscopic radical hysterectomies. They were categorized into groups A, B, and C based on the status of preserved pelvic nerve networks: complete preservation of the pelvic nerve plexus (group A, 27 cases); partial preservation (group B, 13 cases); and complete sacrifice (group C, 13 cases). To evaluate bladder function, urodynamic studies were conducted preoperatively and postoperatively at 1, 3, 6, and 12 months after surgery. Results: No significant difference in sensory function was found between groups A and B. However, the sensory function of group C was significantly lower than that of the other groups. Group A had significantly better motor function than groups B and C. No significant difference in motor function was found between groups B and C. Results showed that the sensory nerve is distributed predominantly at the dorsal half of the pelvic nerve networks, but the motor nerve is predominantly distributed at the ventral half. Conclusion: Various types of total laparoscopic nerve-sparing radical hysterectomies can be tailored to patients with cervical carcinomas.

Unexpected result of minimally invasive surgery for cervical cancer

Hiroyuki Kanao,Yoichi Aoki,Nobuhiro Takeshima 대한부인종양학회 2018 Journal of Gynecologic Oncology Vol.29 No.4

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Step-by-step demonstration of “sciatic-nerve-preserved beyond- LEER” in a Thiel-embalmed cadaver: a novel salvage surgery for recurrent gynecologic malignancies

Hiroyuki Kanao,Masato Tamate,Motoki Matsuura,Sachiko Nagao,Miseon Nakazawa,Shutaro Habata,Tsuyoshi Saito 대한부인종양학회 2024 Journal of Gynecologic Oncology Vol.35 No.5

Objective: Complete resection is the curative treatment choice for recurrent gynecologicalmalignancies. Laterally extended endopelvic resection (LEER) is an effective surgical salvagetherapy for lateral recurrence. However, when a recurrent tumor occupies the ischial spineand sacrum, LEER is not indicated, and surgical salvage therapy is abandoned. Theoretically,complete resection of such a tumor is possible by additional pelvic bone resection alongwith the standard LEER. Nevertheless, owing to the anatomical complexities of the beyond-LEER procedure, 2 major issues should be solved: sciatic nerve injury and tumor disruptionduring pelvic bone amputation. To overcome these technical challenges, we applied amultidirectional beyond-LEER approach, a novel salvage surgical procedure, with an aim ofdemonstrating its technical feasibility. Methods: We created a simulation model of a laterally recurrent tumor that occupied theright ischial spine and sacrum in a Thiel-embalmed cadaver. Results: Multidirectional approaches, including laparoscopic, perineal, and dorsal phases,were safely applied. We laparoscopically marked the L4-L5-S1 complex and S2 nerve withdifferent colored tapes, and by pulling them out into a dorsal surgical field, the sciatic nervewas safely preserved. The dissection lines of the multidirectional approaches were alignedusing tapes as landmarks, and complete tumor clearance without tumor disruption wasaccomplished. By following the cadaveric training, the first laparoscopic-assisted beyond-LEER procedure was successfully performed in a patient with recurrent ovarian cancer. Conclusion: Using a Thiel-embalmed cadaver, we demonstrated the technical feasibility ofa sciatic nerve-preserved beyond-LEER procedure, which was successfully performed in apatient with recurrent ovarian cancer.

Transvaginal cervical tumor-concealing no-look no-touch technique in minimally invasive radical hysterectomy for early-stage cervical cancer: a novel operation technique

Hiroyuki Kanao,Atsushi Fusegi,Makiko Omi,Ariane C. Youssefzadeh,Hidetaka Nomura,Koji Matsuo 대한부인종양학회 2023 Journal of Gynecologic Oncology Vol.34 No.3

The Laparoscopic Approach to Cervical Cancer (LACC) trial demonstrated that minimally invasive radical hysterectomy was inferior to the open approach [1]; this unexpected result could be attributed to the spillage of cancer cells [2]. Following the LACC trial, laparoscopic radical hysterectomy without an intrauterine manipulator upon completion of a vaginal cuff closure became the new standard treatment method [3]. However, the lack of intrauterine manipulator results in poor visualization and inadequate paracervical tissue resection. This study describes the no-look no-touch technique to address this difficulty. The core procedures in our no-look, no-touch laparoscopic radical hysterectomy are: (Step 1) Creation and closure of a vaginal cuff; (Step 2) Manipulation of the uterus without an intra-uterine manipulator; and (Step 3) Exposure of the paracervical tissues by the suspension technique. The patient eligibility for our procedure is as follows: 1) previously untreated cervical cancer (those who underwent diagnostic conization could be included); 2) clinical stage IA2, IB1, IB2, and IIA1 based on the 2018 International Federation of Gynecology and Obstetrics staging system; 3) histologically confirmed cervical cancer, including squamous cell carcinoma, adenocarcinoma, and adenosquamous carcinoma. The important indication for this procedure is in cases where the tumor is less than 4 cm in diameter. We previously reported that our no-look no-touch technique enables smooth performance of laparoscopic radical hysterectomy without worsening oncologic outcomes [4]. According to a recent systematic review and meta-analysis [5], minimally invasive radical hysterectomy with vaginal cuff closure is a safe treatment option; however, it involves a steep learning curve, which has impeded its increased application. This video will hopefully make minimally invasive radical hysterectomy with protective maneuvers against cancer cell spillage more accessible. Based on our experiences, we propose that our transvaginal cervical tumor-concealing no-look no-touch technique will mitigate the risk of surgical spill of tumor cells during minimally invasive radical hysterectomy. The informed consent for use of this video was taken from the patient.

Reconstruction of the diaphragm with autologous fascia lata during cytoreduction in patients with advanced ovarian cancer

Hiroyuki Kanao,Shiho Tsumura 대한부인종양학회 2023 Journal of Gynecologic Oncology Vol.34 No.4

Cytoreductive surgery for patients with advanced ovarian cancer often requires full-thickness resection of the diaphragm [1]. In most cases, the diaphragm can be closed directly; however, when the defect is wide and simple closure is difficult, reconstruction using a synthetic mesh is usually performed [2]. However, the use of this type of mesh is contraindicated in the presence of concomitant intestinal resections because of the risk of bacterial contamination [3]. Autologous tissue shows a higher resistance to infection than artificial materials [4]; thus, we introduce diaphragm reconstruction using autologous fascia lata during cytoreduction for advanced ovarian cancer. A patient with advanced ovarian cancer underwent right diaphragmatic full-thickness resection with concomitant resection of the rectosigmoid colon, and complete resection was achieved. The defect of the right diaphragm measured 12×8 cm, and direct closure was impossible. A section of the right fascia lata measuring 10×5 cm was harvested and sutured to the diaphragmatic defect with a 2-0 proline continuous suture. The harvesting of the fascia lata required only 20 minutes, with little blood loss. No intraoperative or postoperative complications were experienced, and adjuvant chemotherapy was initiated without any delay. Diaphragm reconstruction with the fascia lata is a safe and simple method, and we propose this reconstruction technique especially for patients with advanced ovarian cancer who undergo concomitant intestinal resections. The informed consent for use of this video was taken from the patient.

Should indications for laterally extended endopelvic resection (LEER) exclude patients with sciatica?

Hiroyuki Kanao,Yoichi Aoki,Atsushi Fusegi,Nobuhiro Takeshima 대한부인종양학회 2020 Journal of Gynecologic Oncology Vol.31 No.5

Objective: Previously, indications for laterally extended endopelvic resection (LEER) haveexcluded patients with sciatica because R0 resection has not been deemed possible [1]. Because laparoscopy optimizes visualization and thus provides for meticulous dissection, wehypothesized that R0 resection can be achieved by means of laparoscopic LEER in patientswith sciatica. This video article aimed to clarify the technical feasibility of laparoscopic LEERperformed for laterally recurrent previously irradiated cervical cancer with concomitant sciatica. Methods: We investigated technical feasibility of laparoscopic LEER performed as a salvagetherapy following abdominal radical hysterectomy and concurrent chemoradiotherapy ina patient suffering laterally recurrent cervical carcinoma with concomitant sciatica. Therecurrent tumor involved the right external and internal iliac artery and vein, ileocecum,rectosigmoid colon, right ureter, right obturator nerve, and right sciatic nerve, with aresulting fistula between the tumor and the rectosigmoid colon, and severe sciatica. Resection of all these structures was essential for achievement of R0 status, and suchresection means concomitant femoral bypass with prosthetic graft interposition andgastrointestinal/urinary tract resection. Results: Laparoscopic LEER with femoral-femoral artery bypass could be conductedwithout any postoperative complications. Pathological R0 resection could be achieved, andlocal recurrence could have been controlled. However, the patient died from liver and lungmetastasis at 1 year after this resection surgery. Conclusion: Laparoscopic LEER for a laterally recurrent previously irradiated cervical cancerwith concomitant sciatica was technically feasible, however, further study involving a greaternumber of patients and longer follow-up period is warranted to determine the stringentindications.

Feasibility and outcome of total laparoscopic radical hysterectomy with no-look no-touch technique for FIGO IB1 cervical cancer

Hiroyuki Kanao,Koji Matsuo,Yoichi Aoki,Terumi Tanigawa,Hidetaka Nomura,Sanshiro Okamoto,Nobuhiro Takeshima 대한부인종양학회 2019 Journal of Gynecologic Oncology Vol.30 No.3

Objectives: Intraoperative tumor manipulation and dissemination may possibly compromise survival of women with early-stage cervical cancer who undergo minimally-invasive radical hysterectomy (RH). The objective of the study was to examine survival related to minimallyinvasive RH with a “no-look no-touch” technique for clinical stage IB1 cervical cancer. Methods: This retrospective study compared patients who underwent total laparoscopic radical hysterectomy (TLRH) with no-look no-touch technique (n=80) to those who underwent an abdominal radical hysterectomy (ARH; n=83) for stage IB1 (≤4 cm) cervical cancer. TLRH with no-look no-touch technique incorporates 4 specific measures to prevent tumor spillage: 1) creation of a vaginal cuff, 2) avoidance of a uterine manipulator, 3) minimal handling of the uterine cervix, and 4) bagging of the specimen. Results: Surgical outcomes of TLRH were significantly superior to ARH for operative time (294 vs. 376 minutes), estimated blood loss (185 vs. 500 mL), and length of hospital stay (14 vs. 18 days) (all, p<0.001). Oncologic outcomes were similar between the 2 groups, including disease-free survival (DFS) (p=0.591) and overall survival (p=0.188). When stratified by tumor size (<2 vs. ≥2 cm), DFS was similar between the 2 groups (p=0.897 and p=0.602, respectively). The loco-regional recurrence rate following TLRH was similar to the rate after ARH (6.3% vs. 9.6%, p=0.566). Multiple-pelvic recurrence was observed in only 1 patient in the TLRH group. Conclusion: Our study suggests that the no-look no-touch technique may be a useful surgical procedure to reduce recurrence risk via preventing intraoperative tumor spillage during TLRH for early-stage cervical cancer.

Laparoscopic resection surgery for malignant transformation of extragonadal endometriosis by the “pincer” approach

Hiroyuki Kanao,Mai Nishimura,Atsushi Murakami 대한부인종양학회 2022 Journal of Gynecologic Oncology Vol.33 No.3

Up to 1% of women with endometriosis develop endometriosis-associated neoplasms [1]. Most endometriosis-associated malignant tumors develop from the ovarian endometriomas, whereas those developing from extragonadal lesions are extremely rare, estimated at 0.2% [2]. Because they are uncommon, a treatment protocol for the malignant transformation of extragonadal endometriosis lesions has not been clearly defined. When the lesion is confined to the site of origin and R0 resection is achieved, the 5-year survival rate is between 82% and 100%; therefore, complete resection should be performed [3]. The patient inthis video had previously undergone hysterectomy, bilateral salpingo-oophorectomy, left nephrectomy, and low-anterior resection of the rectum due to severe endometriosis. Ten years after the surgery, the patient had a 6 cm endometrioid adenocarcinoma developing from the residual endometriosis lesion at the left uterosacral ligament that involved the bladder, left ureter, and rectum. In this case, the tumor was attached to the pelvis due to infiltration of the left sacrospinous ligament. To completely remove the tumor, we used laterally extended endopelvic resection with abdominoperineal resection of the rectum. We used the laparoscopic-perineal-laparoscopic approach (pincer approach) because improved visualization of the left sacrospinous ligament increases the probability of achieving complete resection [4]. Pathological R0 resection was achieved without intraoperative or postoperative complications. Thus, for tumors that are firmly attached to the pelvic floor, the pincer approach can be useful for achieving R0 resection. The informed consent for use of this video was taken from the patient.