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Featured researches published by Gen Kawa.


European Urology | 2009

Laparoscopic Radical Nephroureterectomy: A Multicenter Analysis in Japan

Osamu Kamihira; Ryohei Hattori; Akito Yamaguchi; Gen Kawa; Osamu Ogawa; Tomonori Habuchi; Akihiro Kawauchi; Jiro Uozumi; Shigeaki Yokoi; Masao Tsujihata; Yoshihiro Hasui; Keiko Miyakoda; Harue Tada; Yoshinari Ono; Seiji Naito

BACKGROUND Laparoscopic nephroureterectomy (LNUx) is prevalent in Japan and throughout the world, but long-term outcome data remain limited. OBJECTIVE To understand the present state of LNUx in Japan, we conducted a multicenter analysis of clinical outcome and long-term cancer control for patients who underwent the procedure. DESIGN, SETTING, AND PARTICIPANTS Between January 1995 and December 2005, 1003 patients with urothelial cancer in the upper urinary tract were treated with LNUx at 51 institutions in Japan, and patient data were collected retrospectively. MEASUREMENTS Patient profiles were gathered and analyzed for survival, intravesical recurrence, and risk factors influencing them. RESULTS AND LIMITATIONS Median operative time was 320 min. Median bleeding volume was 232 ml. Complications occurred in 93 cases (9.3%) intraoperatively and in 107 cases (10.7%) postoperatively. Overall survival rate was 70% at 5 yr. Grade 3, pT3 or pT4, multifocal tumor, lymph-node metastasis, and previous or coexistent bladder tumor were independent risk factors for overall survival. Intravesical recurrence rate was 43% at 5 yr. Intravesical recurrence occurred more frequently in males, in patients with multifocal tumors, in patients with previous or coexistent bladder tumors, and in patients who underwent the hand-assisted approach. CONCLUSIONS Our report represents the largest multicenter analysis of LNUx reported to date. Male sex and the use of the hand-assisted approach were shown for the first time to be risk factors for recurrence-free survival and intravesical recurrence. To further analyze the effectiveness of LNUx, a long-term outcome comparison with risk stratification must be made between LNUx and open nephroureterectomy.


World Journal of Surgical Oncology | 2012

Two cases of gastrointestinal perforation after radiotherapy in patients receiving tyrosine kinase inhibitor for advanced renal cell carcinoma

Takaaki Inoue; Hidefumi Kinoshita; Yoshihiro Komai; Takashi Kawabata; Gen Kawa; Yoshiko Uemura

We report two cases of gastrointestinal perforation (GIP) after radiotherapy in patients receiving tyrosine kinase inhibitor (TKI) for advanced renal cell carcinoma (RCC). Case 1 was a 61-year-old woman with lung metastases after a radical nephrectomy for a right RCC (cT3aN0M0) treated with interferon-alpha (OIF, 5 MIU, three times per week). She developed lytic metastases of the left femur and the left acetabulum. She was treated with palliative radiotherapy to the metastatic portion (3 Gy × 10 fractions), and 400 mg sorafenib twice per day plus continuing interferon alpha. She experienced sudden left lower abdominal pain after four weeks of treatment, and was diagnosed with a perforation of the sigmoid colon with fecal peritonitis. Case 2 was a 48-year-old man with lung, lymph node, and bone metastases after a radical nephrectomy for a right RCC (cT2N0M0), and was treated with 400 mg sorafenib twice per day. He developed lytic bone metastases of the lumbar vertebrae, which was treated with palliative radiotherapy to L2-4 (3 Gy × 10 fractions). He experienced sudden abdominal pain after two months of radiation treatment, and was diagnosed with a perforation of the sigmoid colon with fecal peritonitis. These cases underwent radiotherapy, and therefore this may be related to the radiosensitivity of TKI.


Biomedicine & Pharmacotherapy | 2002

Section 3. Adrenal: Laparoscopic adrenalectomy for pheochromocytoma: a literature review

Takashi Murota; Naoki Oguchi; Gen Kawa; Kouei Muguruma

Laparoscopic adrenalectomy has become the standard treatment for benign adrenal tumors, providing minimal invasiveness and early recovery. In the case of pheochromocytomas, special attention should be paid perioperatively to prevent excessive hypertension or hypotension. The protocol should include sufficient preoperative medication with alpha 1 blockers, early ligation of the adrenal vein, and minimal handling of the tumor itself. A literature review of 227 laparoscopic adrenalectomies for pheochromocytomas revealed that the perioperative data, including the operative time, blood loss, and hemodynamic status, were similar or slightly better in the laparoscopic procedures as compared to the open procedures, although the convalescence period was significantly shorter in the laparoscopic surgery. The majority of surgeons prefer the transperitoneal approach for pheochromocytomas, although some authors use the retroperitoneal approach successfully. A comparison of the perioperative data from laparoscopic surgeries for pheochromocytomas versus those for other adrenal tumors showed that the former had slightly higher demands to complete the procedure safely. In the treatment of familial pheochromocytoma due to multiple endocrine neoplasia type 2 or von Hippel-Lindau disease, a cortical-sparing adrenalectomy can be safely performed laparoscopically. In conclusion, laparoscopic adrenalectomy is the standard for small pheochromocytomas, with a high success rate when the procedure is performed by experienced surgeons.Abstract Laparoscopic adrenalectomy has become the standard treatment for benign adrenal tumors, providing minimal invasiveness and early recovery. In the case of pheochromocytomas, special attention should be paid perioperatively to prevent excessive hypertension or hypotension. The protocol should include sufficient preoperative medication with alpha 1 blockers, early ligation of the adrenal vein, and minimal handling of the tumor itself. A literature review of 227 laparoscopic adrenalectomies for pheochromocytomas revealed that the perioperative data, including the operative time, blood loss, and hemodynamic status, were similar or slightly better in the laparoscopic procedures as compared to the open procedures, although the convalescence period was significantly shorter in the laparoscopic surgery. The majority of surgeons prefer the transperitoneal approach for pheochromocytomas, although some authors use the retroperitoneal approach successfully. A comparison of the perioperative data from laparoscopic surgeries for pheochromocytomas versus those for other adrenal tumors showed that the former had slightly higher demands to complete the procedure safely. In the treatment of familial pheochromocytoma due to multiple endocrine neoplasia type 2 or von Hippel–Lindau disease, a cortical-sparing adrenalectomy can be safely performed laparoscopically. In conclusion, laparoscopic adrenalectomy is the standard for small pheochromocytomas, with a high success rate when the procedure is performed by experienced surgeons.


International Journal of Urology | 1999

LEIOMYOSARCOMA OF THE SPERMATIC CORD

Jun Watanabe; Takahito Soma; Gen Kawa; Hida S; Mototsugu Koisi

Abstract Background : A rare case of leiomyosarcoma from the spermatic cord is described. A 72‐year‐old man complained of a hard, golf‐ball sized mass in the right inguinal canal.


International Journal of Urology | 2010

Rectal injury during laparoscopic radical prostatectomy: detection and management.

Tomoko Masuda; Hidefumi Kinoshita; Sachiyo Nishida; Gen Kawa; Mutsushi Kawakita

Among 294 patients who underwent laparoscopic radical prostatectomy (LRP), five (1.7%) developed complications such as rectal injury (RI) and rectourethral fistula (RUF). In four patients, the RI was immediately repaired by placing two layers of uninterrupted sutures without fecal diversion. The RI in two of these four patients were diagnosed using a transrectally inserted Hegar uterine dilator (26 mm). The remaining patients, who presented with RUF as the primary manifestation, were conservatively managed, and the fistulas closed spontaneously. Most of the RI detected during the operation were managed with primary fistula closure without fecal diversion. In some cases of postoperative RUF, spontaneous closure may occur while the patient is waiting for surgical repair.


Asian Journal of Endoscopic Surgery | 2012

Laparoendoscopic single-site surgery for urachal remnants.

T Iida; Gen Kawa; N Takizawa; T Kawabata; Yoshihiro Komai; Hidefumi Kinoshita

Urachal remnants are relatively rare but may potentially cause various symptoms and an increased risk for developing adenocarcinoma. Open or laparoscopic surgery is usually used for their resection. Laparoendoscopic single‐site surgery has been recently applied in several surgical procedures. This report describes two cases of vesicourachal diverticulum treated by resection using laparoendoscopic single‐site surgery.


International Journal of Urology | 2006

Retroperitoneoscopic pyeloplasty : Using reconstructive methods based on intraoperative findings

Gen Kawa; Motohiro Tatsumi; Yoshihito Hiura; Koei Muguruma; Hidefumi Kinoshita

Aim: Reconstructive laparoscopic procedures have been recognized as a less invasive treatment than conventional open procedures. However, although the laparoscopic pyeloplasty has also been accepted as useful, few findings have been reported relevant to the retroperitoneal approach. To elucidate its effectiveness and safety, laparoscopic surgery via the retroperitoneal approach was examined in our institution. Furthermore, the importance of laparoscopic observation for ureteropelvic junction and urine passage ureteropelvic junction without indwelling ureteral stent.


International Journal of Urology | 2010

Uninterrupted suturing of renal parenchyma in laparoscopic partial nephrectomy decreases renal ischemic time and intraoperative blood loss

Gen Kawa; Hidefumi Kinoshita; Yoshihiro Komai; Takaaki Inoue; Junko Masuda

We examined factors affecting renal ischemic time and intraoperative blood loss in laparoscopic partial nephrectomy and attempted to determine which method of suture for parenchymal closure is effective in this operation. Fifty‐seven patients who underwent laparoscopic partial nephrectomy were studied. Some variables and methods of suture for parenchymal closure were tested for independent effects on ischemic time and bleeding volume. Mean renal ischemic time and estimated blood loss were 38 min and 175 mL, respectively. Method of suture for parenchymal closure was the only factor independently associated with intraoperative blood loss less than 100 mL. Furthermore, uninterrupted suture for parenchymal closure was a significant factor associated with renal ischemic time less than 30 min. Renal ischemic time or intraoperative blood loss can be decreased by using uninterrupted suture for parenchymal defect.


The Journal of Sexual Medicine | 2012

Recovery of Erectile Function after Nerve-Sparing Laparoscopic Radical Prostatectomy in Japanese Patients Undergoing Both Subjective and Objective Assessments

Hisanori Taniguchi; Gen Kawa; Hidefumi Kinoshita

INTRODUCTION The sexual potency rate following a radical prostatectomy can vary. In Japanese patients, sexual activity after nerve-sparing prostatectomy seems especially unfavorable. Most studies have assessed potency status subjectively using questionnaires. AIMS The aim of this study is to evaluate the recovery of potency in Japanese patients after nerve-sparing laparoscopic prostatectomy (nsLRP) both subjectively and objectively. METHODS Twenty-seven patients operated on with nsLRP (bilateral sparing in four patients, unilateral in 23 patients) were enrolled. The mean age of the patients was 60.1 years. Seventeen of 27 patients used type 5 phosphodiesterase inhibitors on demand at least 3 months after surgery. MAIN OUTCOME MEASURES Subjective erectile function was examined by the international index of erectile function (IIEF)-15 and by the erection hardness score (EHS) questionnaires before and at 3, 6, and 12 months after surgery. Objective erectile function, with measurement of rigidity and tumescence of the penis, was evaluated by RigiScan-Plus as the erectile response to audio-visual stimulation. RESULTS IIEF erectile function domain, IIEF-total, and EHS scores decreased significantly after surgery; they were almost half of pretreatment levels at 12 months after surgery. On the other hand, penile rigidity and tumescence measured by RigiScan also decreased significantly 3 months after surgery. However, these values gradually improved, and head nearly recovered at 12 months after surgery. At 12 months after surgery, recovery rates of penile rigidity and tumescence from baseline were rigidity 92.6% at tip and 96.3% at base, with tumescence of 87% at tip and 76% at base. CONCLUSIONS Discrepancies were found between results of subjective and objective assessments of erectile function. From an objective viewpoint, the recovery of erectile function in Japanese patients after nsLRP was not bad.


The Aging Male | 2011

Symptomatic change in Japanese hypogonadal patients several years after androgen replacement therapy

Hisanori Taniguchi; Gen Kawa; Hidefumi Kinoshita

Objective. There are few reports on the prognosis of patients receiving androgen replacement therapy (ART). In this study, we evaluated the subsequent symptoms of Japanese hypogonadal patients who had received ART, within several years previously by mail-in survey. Methods. Thirty-three aged men with symptoms of hypogonadism and testosterone deficiency who had received ART for 6 months responded to this survey. The survey consisted of questions associated with present physical and mental status and desire to resume ART. The Aging male’s symptoms (AMS) scale, IIEF-5 and SF-36 were also evaluated at pre-initiation, termination of ART and the time of the survey. Results. The mean duration from the last treatment was 55 months. Compared with the treatment period, more than half of patients (57.5%) answered that their present condition was better. Scores on the AMS scale, IIEF and SF-36 were all improved significantly in the early stages of treatment and not worsened a long period of time after ART was discontinued. Conclusions. For symptomatic Japanese hypogonadal patients, subjective effects of treatment were observed during the early treatment period and remained unchanged after discontinuation of ART. A short treatment period may thus be adequate in Japanese hypogonadal patients as regards symptomatic changes.

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Kenji Yoshida

Kansai Medical University

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Masaaki Yanishi

Kansai Medical University

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Motohiko Sugi

Kansai Medical University

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Takashi Murota

Kansai Medical University

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Takashi Yoshida

Kansai Medical University

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Takao Mishima

Kansai Medical University

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Yoshihiro Komai

Kansai Medical University

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