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Dive into the research topics where Kazuhiro Iwase is active.

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Featured researches published by Kazuhiro Iwase.


Surgical Laparoscopy Endoscopy & Percutaneous Techniques | 2002

Splenic artery embolization using contour emboli before laparoscopic or laparoscopically assisted splenectomy.

Kazuhiro Iwase; Jun Higaki; Hyung-Eun Yoon; Shoki Mikata; Minoru Miyazaki; Akiko Nishitani; Shinichi Hori; Wataru Kamiike

The present study assessed preoperative splenic artery embolization using spherical embolic material, super absorbent polymer microspheres (SAP-MS), before laparoscopic or laparoscopically assisted splenectomy. Distal splenic artery embolization using 250 to 400 &mgr;m SAP-MS was performed in nine cases with ITP and in seven cases with the other diseases with splenomegaly. Laparoscopic or laparoscopically assisted splenectomies, including a hand-assisted procedure and the procedure involving left upper minilaparotomy, were done 2 to 4 hours after embolization. Conversion to traditional laparotomy was not required in any of the 16 cases, while conversion to 12-cm laparotomy was required in one case with massive splenomegaly. Mean operating time was 161 minutes, and mean intraoperative blood loss was 290 mL. No major postoperative complications were identified, and only one patient reported postembolic pain before surgery. Preoperative splenic artery embolization using painless embolic material, SAP-MS, would be effective for easy and safe laparoscopic or laparoscopically assisted splenectomy.


Surgical Endoscopy and Other Interventional Techniques | 1997

Laparoscopic cholecystectomy and time-course changes in renal function: The effect of the retraction method on renal function

Y. Miki; Kazuhiro Iwase; Wataru Kamiike; Eiji Taniguchi; K. Sakaguchi; J. Sumimura; Hiroshi Matsuda; I. Nagai

AbstractBackground: Recently, the retraction method has been used to reduce intraabdominal pressure (IAP) during laparoscopic surgery. The purpose of this study was to determine the serial changes in renal function during laparoscopic cholecystectomy (LC) using the retraction method. Methods: Urine output, effective renal plasma flow (ERPF), and glomerular filtration rate (GFR) were measured serially in seven patients who underwent LC with 12 mmHg pneumoperitoneum (High-IAP group) and five who underwent LC using the retraction method with 4 mmHg pneumoperitoneum (Low-IAP group). Results: Urine output, ERPF, and GFR were decreased during pneumoperitoneum in the High-IAP group, whereas no significant changes in any of these parameters were observed in the Low-IAP group. Conclusions: Our findings demonstrate that reduction of IAP to 4 mmHg using the retraction method prevents the transient renal dysfunction caused by prolonged 12 mmHg pneumoperitoneum during LC, suggesting that the retraction method reduces the risk of perioperative renal dysfunction during laparoscopic surgery.


Surgical Laparoscopy Endoscopy & Percutaneous Techniques | 1999

Laparoscopically assisted splenectomy following preoperative splenic artery embolization using contour emboli for myelofibrosis with massive splenomegaly.

Kazuhiro Iwase; Jun Higaki; Shoki Mikata; Yasushi Tanaka; Masato Yoshikawa; Shinichi Hori; Keigo Osuga; Satoru Kosugi; Toshiharu Tamaki; Wataru Kamiike

Laparoscopically assisted splenectomy with an 8- to 10-cm left upper paramedian laparotomy was performed following preoperative splenic artery embolization using painless contour emboli (super absorbent polymer microsphere) with early successful results in two men (46 and 37 years old) with myelofibrosis accompanied by massive splenomegaly. Dissection around the lower part of the spleen and the hilum initially was performed intracorporeally with the usual laparoscopic view under 12 mm Hg pneumoperitoneum. The alternating changes of viewpoints between the direct view through an 8- to 10-cm incision and the usual laparoscopic view with or without application of a retraction method were effective for safe hilar devascularization. Preoperative splenic artery embolization at the distal site was effective for safe dissection around the enlarged spleen. The patients did not complain of pain before operation. Preoperative painless embolization and laparoscopically assisted splenectomy with small laparotomy promotes the feasibility and safety of minimally invasive splenectomy for myelofibrosis with massive splenomegaly.


Surgery Today | 1993

The solitary cutaneous metastasis of asymptomatic colon cancer to an operative scar

Kazuhiro Iwase; Hiroaki Takenaka; Sennya Oshima; Kazushi Kurozumi; Yoshiharu Nishimura; Katsuhide Yoshidome; Tomoyuki Tanaka

Although umbilical or cutaneous metastases from asymptomatic internal malignancies are occasionally documented, the literature contains no report of a solitary cutaneous metastasis to an old operative scar from an asymptomatic internal malignancy. A rare case of colonic cancer presenting as a solitary subcutaneous metastasis to a lower abdominal scar resulting from an open prostatectomy is described in this communication. It was impossible to distinguish this subcutaneous metastasis from a pyogenic granuloma caused by residual sutures without histological evidence. Thus, a granuloma that persists despite repeated treatment may be a possible sign of asymptomatic internal malignancy.


Digestive Diseases and Sciences | 1992

Determination of tumor marker levels in cystic fluid of benign liver cysts

Kazuhiro Iwase; Hiroaki Takenaka; Senya Oshima; Akihiko Yagura; Yoshiharu Nishimura; Katsuhide Yoshidome; Tomoyuki Tanaka

The levels of tumor markers in cystic fluid and serum were measured in six patients with benign biliary cyst of the liver. AFP in the cystic fluid was lower than the upper normal limit for serum in all cases, and CEA in the cystic fluid was higher than the upper normal limit for serum in one of the six cases. CA19-9, DU-PAN 2, and SPAN 1 in cystic fluid were much higher than the upper normal limit for serum in all cases (more than 100-fold for CA19-9, twofold for DU-PAN 2, and ninefold for SPAN 1). CA19-9, DU-PAN 2, and SPAN 1 in cystic fluid were significantly higher than the levels in the corresponding serum. Positive immunohistochemical staining against CA19-9, DU-PAN 2, and SPAN 1 was observed in the cytoplasm of the epithelial cells of the cyst wall. These results suggested that the high concentrations of CA19-9, DU-PAN 2, and SPAN 1 in the cystic fluid were due to secretion from the epithelial cells in the benign biliary cysts.


Surgery Today | 2009

Carcinosarcoma of the gallbladder producing α-fetoprotein and manifesting as leukocytosis with elevated serum granulocyte colony-stimulating factor: Report of a case

Kazunori Shimada; Kazuhiro Iwase; Toyokazu Aono; Sumio Nakai; Shin-ichi Takeda; Makoto Fujii; Masaru Koma; Kazuhiro Nishikawa; Chu Matsuda; Masashi Hirota; Hiroaki Fushimi; Yasuhiro Tanaka

A 69-year-old man was referred to our hospital for investigation of leukocytosis and a persistent fever of 38°C, but we could find no evidence of a specific infection. The leukocyte count was 18 000/mm3, and the serum granulocyte colony-stimulating factor (G-CSF) and α-fetoprotein (AFP) levels were both elevated, at 66.3 pg/ml and 1,495 ng/ml, respectively. Computed tomography (CT) showed a gallbladder tumor and we performed extended cholecystectomy. Postoperatively, the fever subsided and the leukocyte count, serum G-CSF and AFP level normalized. Histologically, the tumor was a carcinosarcoma of the gallbladder. Immunohistochemical staining of the tumor cells was positive for AFP, but negative for G-CSF. This is the first report of a carcinosarcoma of the gallbladder producing AFP. The laboratory findings and clinical course strongly suggested that the tumor produced not only AFP, but also G-CSF.


Surgery Today | 1999

Running closure of clean and contaminated abdominal wounds using a synthetic monofilament absorbable looped suture.

Kazuhiro Iwase; Jun Higaki; Yasushi Tanaka; Haruhiko Kondoh; Masato Yoshikawa; Wataru Kamiike

The effectiveness of using an absorbable suture material for continuous closure of abdominal wounds, especially contaminated wounds, has not yet been determined. Thus, the present study was conducted to investigate the wound complications that developed following continuous closure of clean and contaminated abdominal wounds using polydioxanone (PDS), compared with those that developed following interrupted closure using braided silk. Running closure using PDS was performed in 152 patients (PDS group), while 280 patients who underwent interrupted closure using braided silk served as controls (SILK group). The occurrence rates of wound dehiscence, early wound infection, and incisional hernia did not differ significantly between the two groups; however, the incidence of late suture sinus formation in the PDS group (1.3%) was significantly lower than that in the SILK group (7.1%). Moreover, late suture sinus formation following PDS suturing healed within 1 week after percutaneous drainage alone without removal of suture strings, whereas late suture sinus following braided silk suturing took an average of 16 days to heal and required removal of the infected suture strings in all 20 patients. These findings indicate the potential usefulness of PDS as a suture material to achieve running closure of clean or contaminated abdominal wounds.


Surgical Laparoscopy Endoscopy & Percutaneous Techniques | 2003

Laparoscopic resection of intra-abdominal esophageal duplication cyst.

Keiwa Kin; Kazuhiro Iwase; Jun Higaki; Hyung-Eun Yoon; Shoki Mikata; Minoru Miyazaki; Masami Imakita; Wataru Kamiike

&NA; Esophageal duplication cysts are frequently encountered in the mediastinum and rarely in the abdomen. A case of laparoscopic resection of an intra‐abdominal esophageal duplication cyst is reported. An incidental 4.5 × 4.0 × 3.5‐cm, wellcircumscribed, homogenous mass anterior to the intra‐abdominal esophagus was detected on staging CT examinations for breast cancer in a 51‐year‐old woman. Laparoscopic resection of the lesion was performed after completion of breast‐conserving surgery and whole breast irradiation. The defect of the muscular layer of the esophagus caused by the complete removal of the lesion required repair with muscular sutures. It was helpful to inspect the integrity of the esophageal wall repair by examining the exterior wall of the esophagus laparoscopically while insufflating air into the esophageal lumen through a fiberoptic esophagoscope. A laparoscopic approach utilizing intraoperative esophagoscopy is easy and safe for removal of intra‐abdominal esophageal duplication cysts.


Surgical Endoscopy and Other Interventional Techniques | 1997

Thoracoscopic enucleation of a large leiomyoma located on the left side of the esophageal wall

Eiji Taniguchi; Wataru Kamiike; Kazuhiro Iwase; Toshirou Nishida; Akinori Akashi; Shuichi Ohashi; Hiroshi Matsuda

AbstractThoracoscopic enucleation through the right thorax was successfully performed for a large leiomyoma located on the left wall of the upper-middle esophagus. Using intraoperative esophagoscopy, the exact location of the tumor was identified by trans-illumination. Two sling tapes passed around the esophagus made the procedure as easy as that for tumor located on the right wall of the esophagus. We considered that the thoracoscopic approach through the right thorax can be applied to various types of esophageal leiomyoma, even a large one located on the left side of the esophagus.


Gastric Cancer | 2002

Reduced thiamine (vitamin B1) levels following gastrectomy for gastric cancer

Kazuhiro Iwase; Jun Higaki; Hyung-Eun Yoon; Shoki Mikata; Minoru Miyazaki; Wataru Kamiike

Abstract.Abstract.Background: Vitamin B1 deficiency is well known as a possible complication following gastric restrictive surgery for morbid obesity; however, reduced vitamin B1 levels in patients who have undergone gastrectomy for gastric cancer have not been discussed previously.Methods: Serum vitamin B1 levels were determined after the return to normal daily activity in 54 patients with distal gastrectomy for gastric cancer, 32 patients with total gastrectomy for gastric cancer, and 30 patients with radical surgery for colorectal cancer. Changes from serum vitamin B1 levels before operation to those after return to normal daily activity, without nutritional support, were investigated in 25 patients with gastrectomy for gastric cancer and 26 patients with radical surgery for colorectal cancer.Results: Decreased serum vitamin B1 levels, below the normal range, were recognized in 7 of the 54 distally gastrectomized patients and in 5 of the 32 totally gastrectomized patients, whereas no such decrease was recognized in any patient after colorectal surgery. Decreased serum vitamin B1 level was recognized within 6 months after the operation in 6 of the 7 distally gastrectomized patients showing a decreased vitamin B1 level and in 3 of the 5 totally gastrectomized patients showing a decreased vitamin B1 level. Postoperative serum vitamin B1 levels were significantly lower than those before operation in patients with gastrectomies, whereas there was no significant difference in serum vitamin B1 levels before and after the surgeries in patients with surgery for colorectal cancer.Conclusion: Vitamin B1 levels may be reduced in gastrectomized patients, especially within 6 months after operation, even after their return to normal daily activity without nutritional support.

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Tomoyuki Tanaka

Jikei University School of Medicine

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