Microwave Tissue Coagulator Research Articles

Microwave focal therapy of prostate cancer: a non-clinical study and exploratory clinical trial.

To examine the safety and efficacy of microwave tissue coagulation (MTC) for prostate cancer and assess its use in lesion-targeted focal therapy in a non-clinical study and a clinical phase II trial. In the non-clinical study using Microtaze® -AFM-712 (Alfresa Pharma Corporation, Osaka, Japan) with an MTC needle, MTC was performed using a transperineal approach to targeted canine prostatic tissue under real-time ultrasonography guidance. Using various MTC output and irradiation time combinations, the targeted and surrounding tissues (rectum, bladder and fat) were examined to confirm the extent of coagulative necrosis or potential cell death, and to compare intra-operative ultrasonography and pathology findings. The exploratory clinical trial was conducted to examine the safety and efficacy of MTC. Five selected patients underwent transperineal MTC to clinically single lesion magnetic resonance imaging (MRI)-visible lesions with Gleason score 3 + 4 or 4 + 4. Prostate-specific antigen (PSA), MRI and Expanded Prostate Cancer Index Composite questionnaire findings were compared before and 6 months after surgery. The region of coagulative necrosis was predictable by monitoring of ultrasonically visible vaporization; thus, by placing the MTC needle at a certain distance, we were able to perform a safe procedure without adverse events affecting the surrounding organs. Based on the non-clinical study, which used various combinations of output and irradiation time, MTC with 30-W output for 60-s irradiation was selected for the prostate. Based on the predictable necrosis, the therapeutic plan (where to place the MTC needle to achieve complete ablation of the target and how many sessions) was strictly determined per patient. There were no serious adverse events in any patient and only temporary urinary symptoms related to MTC therapy were observed. Furthermore, post-treatment satisfaction was very high. All preoperative MRI-visible lesions disappeared, and PSA decreased by 55% 6 months after surgery. Microwave tissue coagulation may be an option for lesion-targeted focal therapy for prostate cancer.

A Case of Post-intubation Granuloma Recurrent After Surgical Resection Treated by Bronchoscopic Microwave Tissue Coagulation

A Case of Post-intubation Granuloma Recurrent After Surgical Resection Treated by Bronchoscopic Microwave Tissue Coagulation

Laparoscopic Non-Ischemic Partial Nephrectomy Using a Microwave Tissue Coagulator : A Single-Institutional Study

We retrospectively investigated the surgical outcomes of renal cell carcinoma (RCC), perioperative complications, and residual renal function in patients receiving laparoscopic non-ischemic partial nephrectomy using a microwave tissue coagulator (MTC). Between January 2002 and December 2015, laparoscopic non-ischemic partial nephrectomy using MTC was performed in 49 patients. The histological diagnosis was RCC in 38 patients, angiomyolipoma in 4, oncocytoma in 2, and others in 5. A histologicallyproven positive surgical margin was observed in 1 (2.0%). Postoperative urine leakage occurred in 1, and it was treated conservatively. The mean follow-up period was 32.0 months. Although there was no patient who died of RCC, local recurrence occurred in 2 patients (4.1%) during the follow-up period. One of these 2 patients had a positive surgical margin. Deterioration of the residual renal function was not observed. Laparoscopic non-ischemic partial nephrectomy using MTC was safe and useful in terms of cancer control and preservation of renal function.

Non-ischemic, Non-renorrhaphy Laparoscopic Partial Nephrectomy Using a Microwave Tissue Coagulator for Small Renal Tumors

Non-ischemic, Non-renorrhaphy Laparoscopic Partial Nephrectomy Using a Microwave Tissue Coagulator for Small Renal Tumors

The Development of Forceps-Type Microwave Tissue Coagulator for Surgical Operation

In this paper, a new type of surgical device for the coagulation and scission of biological tissues, such as blood vessels, using microwave energy is proposed. In addition, the effectiveness of the device for tissue coagulation is evaluated using a numerical analysis and an ex vivo experiment with swine liver tissue. In the numerical analysis, the coagulating capability of the device is evaluated by calculating the temperature distribution inside of the tissue grasped with the device. Microwave energy absorbed by the grasped tissue is used as a heat source for the bioheat transfer equation. In the ex vivo experiment, a prototype of the proposed device is used. The results of these investigations indicate that the proposed device has sufficient coagulating capability of the biological tissue. Moreover, for evaluating the effectiveness of the proposed device in a more realistic condition, an in vivo experiment with the swine tissue has been conducted. In this experiment, venous hemorrhage at the surgical site is stopped using the prototype. As a result, the effectiveness of the proposed device has been confirmed by a surgeon.

Liver resection for hepatocellular carcinoma using a microwave tissue coagulator: Experience of 1118 cases.

To present our extensive experience of hepatectomy for hepatocellular carcinoma using a microwave tissue coagulator to demonstrate the effectiveness of this device. A total of 1118 cases (1990-2013) were reviewed, with an emphasis on intraoperative blood loss, postoperative bile leakage and fluid/abscess formation, and adaptability to anatomical resection and hepatectomy with hilar dissection. The median intraoperative blood loss was 250 mL; postoperative bile leakage and fluid/abscess formation were seen in 3.0% and 3.3% of cases, respectively. Anatomical resection was performed in 275 cases, including 103 cases of hilar dissection that required application of microwave coagulation near the hepatic hilum. There was no clinically relevant biliary tract stricture or any vascular problems due to heat injury. Regarding the influence of cirrhosis on intraoperative blood loss, no significant difference was seen between cirrhotic and non-cirrhotic patients (P = 0.38), although cirrhotic patients tended to have smaller tumors and underwent less invasive operations. This study demonstrated outcomes of an extensive experience of hepatectomy using heat coagulative necrosis by microwave tissue coagulator.

Hand-assisted, conventional and laparoendoscopic single-site surgery for partial nephrectomy without ischemia using a microwave tissue coagulator.

We report our experience of minimally invasive partial nephrectomy without ischemia using a microwave tissue coagulator (MTC) for hand-assisted laparoscopic partial nephrectomy (HALPN), conventional laparoscopic partial nephrectomy (CLPN), and laparoendoscopic single-site surgery for partial nephrectomy (LESSPN). We retrospectively compared the results of these techniques to better define the individual role and the benefits. From July 2005 to September 2012, 28 patients with small and exophytic renal tumors underwent HALPN (n = 12), CLPN (n = 10) and LESSPN (n = 6). In these procedures, the surgeon used an MTC for circumferential coagulation around the tumor. After coagulation, the tumor was resected without renal pedicle clamping. The mean operative time was 259, 194 and 174 min for the HALPN, CLPN and LESSPN groups respectively. Two patients (one in HALPN group and one in LESSPN group) converted to laparotomy due to an inability to maintain hemostasis; however, there were no conversions to ischemic partial nephrectomy or radical nephrectomy. No differences between HALPN, CLPN and LESSPN were noted in terms of estimated blood loss, measured analgesic requirements, outcomes, or complications. We believe that these techniques are feasible and that they minimize the risk of unexpected collateral thermal damage by appropriate MTC needle puncture. When deciding to use HALPN, CLPN or LESSPN, our findings suggest that the choice of surgical approach should depend on the patient's individual circumstance.

Microwave tissue coagulation technique in anatomical liver resection

Anatomical liver resection is currently the preferred treatment for liver cancer. With the recent introduction of medical microwave coagulation for liver metastases, anatomical hepatectomy may be performed more efficiently. The present study retrospectively reviewed the results of microwave tissue coagulation performed during anatomical liver resection for patients with liver disease at the TangDu Hospital (Xi'an, China) between January, 2009 and June, 2012. A total of 128 patients met the inclusion criteria and were divided into two groups for comparison; those treated with the microwave coagulation technique (n=66) and the conventional group (n=62), who were treated with standard partial hepatectomy. There was no reported perioperative mortality. The univariate analysis revealed that the duration of liver dissection, intraoperative blood loss, intraoperative erythrocyte transfusion volume and alanine aminotransferase levels on the 5th postoperative day were significantly different between the microwave and conventional groups (P<0.05). Therefore, microwave tissue coagulation in anatomical liver resection was shown to be efficacious and safe and, provided proficient skills are developed in this technique, microwave tissue coagulation may be an effective alternative to anatomical hepatectomy.

Laparoendoscopic Single-Site Partial Nephrectomy Without Hilar Clamping Using a Microwave Tissue Coagulator

To report our initial experience and evaluate the possibility of nonhilar clamp laparoendoscopic single-site (LESS) partial nephrectomy by using a microwave tissue coagulator. From December 2010 to May 2012, all patients with an exophytic, solitary, enhancing small (≤4.0 cm) renal mass were chosen to receive the study treatment. A multichannel port provided both a retroperitoneal and transperitoneal approach. A rigid, articulating apparatus was used to perform dissection, exposure of tumor, tissue coagulation, and resection without hilar clamping. Pathologic and hematologic data, subjective evaluation of pain, and scar appearance were analyzed. Nonhilar clamp LESS partial nephrectomy by using a microwave tissue coagulator was performed in seven patients (mean operative time, 208 min; mean blood loss, 39 mL; mean renal mass size, 1.7 cm); one procedure with uncontrolled bleeding needed to be converted to conventional laparoscopic partial nephrectomy. No transfusion was necessary. Pathologic investigation demonstrated six renal-cell carcinomas and one oncocytoma. The hemoglobin level decreased by a mean of 1.1 g/dL. Patients did not complain about pain, and they had great satisfaction with the results. The mean duration of hospital stay was 13.8 days. LESS partial nephrectomy without hilar clamping by using a microwave tissue coagulator is possible for renal masses, confers postoperative outcomes comparable to the standard counterpart, and assures patient satisfaction. By use of a microwave tissue coagulator, additional trocars were not necessary, and LESS partial nephrectomy could be accomplished through a single port, which reduced invasion and increased the cosmetic satisfaction of the patients.

Metachronous occurrence of ipsilateral renal cell carcinoma treated with retroperitoneal laparoscopic non-ischemic partial nephrectomy using microwave tissue coagulator after retroperitoneal non-ischemic open partial nephrectomy：A case report

Metachronous occurrence of ipsilateral renal cell carcinoma treated with retroperitoneal laparoscopic non-ischemic partial nephrectomy using microwave tissue coagulator after retroperitoneal non-ischemic open partial nephrectomy：A case report

Clinical T1腎腫瘍に対するソフト凝固を使用した無阻血腎部分切除術の検討：マイクロ波組織凝固との比較

We have performed non-ischemic partial nephrectomy for clinical T1 renal tumors using microwave tissue coagulation (MTC group) or soft coagulation (soft coagulation group). The clinical outcomes were retrospectively compared between the two groups. A total of 36 patients were analyzed in this study (22 in the MTC group and 14 in the soft coagulation group). The anatomical characteristics of the renal tumors were assessed using the R.E.N.A.L Nephrometry Score. Renal function was assessed by the estimated glomerular filtration rate. The preoperative estimated glomerular filtration rate was 72.1 ml/min in the MTC group and 65.6 ml/min in the soft coagulation group (p = 0.05). The R.E.N.A.L Nephrometry Score was not significantly different between the two groups. Clavian grade > or = 2 postoperative complications occurred in one patient (4.5%) in the MTC group and one patient (7.1%) in the soft coagulation group. Postoperative local recurrence and distant metastasis occurred in one patient (8.3%) in the soft coagulation group and no patients in the MTC group, which was not a significant difference between the two groups. The median postoperative decrease in estimated glomerular filtration rate was 11.5% in the MTC group and 3.6% in the soft coagulation group. Postoperative renal preservation tended to be better in the soft coagulation group than in the MTC group, but this difference was not significant. The use of soft coagulation in non-ischemic partial nephrectomy for the treatment of clinical T1 renal tumors is as effective as that of MTC.

Renal cell neoplasm of oncocytosis: a type of unclassified renal cell carcinoma.

A 69-year-old woman was referred to us because a cyst in the lower pole of the left kidney had been pointed out on screening ultrasound. Computed tomography (CT) demonstrated a mural nodule of the wall of the cyst with an enhancement effect, suggesting cystic renal cell carcinoma (cT1aN0M0). The patient underwent retroperitoneoscopic non-ischemic partial nephrectomy using a microwave tissue coagulator. A hematoxylin-eosin-stained specimen showed that the wall of the cystic tumor consisted of the proliferation of large cells with rich eosinophilic granules in the cytoplasm and round-shaped nuclei, which were the characteristics of oncocytoma. This was followed by immunohistochemical studies, because of findings of local cell invasion, mitosis, and necrosis, suggesting malignancy. The results were: CK7, strongly positive; PAX2, negative; colloidal iron stain, negative; c-kit, weakly positive; vimentin, positive; and RCC marker, negative. Thus, although the tumor showed characteristics of oncocytoma and/or chromophobe renal cell carcinoma (pT1a), it could not be classified according to the known categories: it should be designated as renal cell carcinoma (neoplasm) of oncocytosis, a novel category of unclassified renal cell carcinomas. The present case indicated the fact that renal cell carcinomas resembling oncocytoma certainly exist.

THE EFFICACY OF MICROWAVE THERAPY VIA BRONCHOFIBERSCOPE IN THE TREATMENT OF SEVERE TRACHEA STENOSIS

To evaluate the efficacy of microwave therapy via bronchofiberscope for treatment of severe trachea stenosis. Microwave tissue coagulation (MTC) and diathermy (MD) therapy via bronchofiberscope were performed on 37 patients with severe trachea stenosis diseases at least two times. The effective rate immediately after treatment was 100% in all cases. After one month, the rate remained 100% in the patients with benign diseases, but it dropped to 67% in the patients with malignant tumors. We have demonstrated that the microwave thermotherapy via bronchofiberscope is an effective method to treat patients with benign trachea stenosis noninvasively. For cancer patients with trachea soakage and blockage, it can be performed to improve their life quality by alleviating their agonies.

Laparoendoscopic Single-Site Surgery for Partial Nephrectomy Without Ischemia Using a Microwave Tissue Coagulator

Herein, we report our initial experience with laparoendoscopic single-site surgery for partial nephrectomy (LESSPN) using a microwave tissue coagulator (MTC). Two patients with small and exophytic renal tumors underwent LESSPN. A multichannel port was inserted into the peritoneal or retroperitoneal space through a 3-cm skin incision. After tumor exposure, the surgeon introduced a laparoscopic MTC instrument through a 5-mm port and the tumor margin was coagulated circumferentially. After coagulation, the tumor was resected without renal pedicle clamping. These procedures were successfully performed without any conversions to standard laparoscopy or need for placement of additional trocars. The operative times were 183 and 160 minutes, respectively. The estimated blood loss was <150 mL in both cases. The final length of the LESS wound was 3 cm. Using the transumbilical approach, the operative scar receded into the umbilicus and was hardly visible. This novel surgical technique is feasible and enables the bloodless resection of a renal tumor without renal pedicle clamping. Further clinical experience and longer follow-up are needed to define the benefits of this new technique.

Chyluria after partial nephrectomy: A rare but considerable complication

An 82-year-old male patient underwent open left lower-pole partial nephrectomy with a microwave tissue coagulator (Microtaze). Pathological findings showed clear cell renal cell carcinoma, pT1a, Fuhrman grade 2 with negative margins. Then 2 years later, he presented with urinary retention. His urine appeared cloudy and milky only after meals, but appeared normal at other times. He was diagnosed with chyluria after partial nephrectomy. Endoscopic sclerotherapy with silver nitrate was carried out, because his serum albumin decreased to 3.4 g/dL within 3 months. He had an uneventful postoperative course. His chyluria completely disappeared and has not recurred for 11 months. Although chyluria after nephrectomy is very rare, there is a possibility that the frequency of chyluria after partial nephrectomy might increase, because the number of partial nephrectomies continues to increase worldwide. We herein summarize this rare surgical complication and discuss the effectiveness of endoscopic sclerotherapy as a therapeutic tool.

Transumbilical laparoendoscopic single-site partial nephrectomy using a microwave tissue coagulator

Transumbilical single-port laparoscopy has emerged as a method to further enhance cosmetic benefits and reduce morbidity. We present an initial experience with transumbilical laparoendoscopic single-site partial nephrectomy (LESS-PN). A 36-year-old woman visited our hospital for the treatment of a left exophytic renal cell carcinoma, 17 mm in diameter, located at the lower pole. We decided to use transumbilical LESS-PN to treat this case. A multichannel port was placed through the center of the umbilicus, and the tumor was exposed using bent laparoscopic instruments. The tumor was then removed after microwave tissue coagulation. All procedures were performed without renal artery occlusion, and only slight bleeding occurred. Transumbilical LESS-PN using a microwave tissue coagulator was performed with an excellent cosmetic outcome and no complications. To the best of our knowledge, this is the first report of LESS-PN using a microwave tissue coagulator.

腎細胞癌に対するマイクロ波組織凝固装置を用いた後腹膜鏡下腎部分切除術

Recently partial nephrectomy is often indicated for treating small renal cell carcinoma (RCC) and is considered as a standard surgery for stage T1a RCC in terms of the favorable oncological outcomes comparative with radical nephrectomy. Particularly, non-ischemic partial nephrectmy by using a microwave tissue coagulator (MTC) is the most simple and safe nephron-sparing surgery. Besides, partial nephrectomy using an MTC is very suitable for laparoscopic surgery in selected patients.We reviewed our surgical procedures and 24 RCC patients who underwent retroperitoneoscopic partial nephrectomy by using an MTC.

再発膀胱癌に対する軟性膀胱鏡下マイクロ波凝固術の治療効果について

We have performed transurethral microwave tissue coagulation (MTC) for urinary bladder cancer, and especially applied MTC to small tumors of outpatients without anesthesia. In this report, flexible MTC (f-MTC) with a flexible cystoscope was performed. Ten patients of recurrent bladder cancer were treated. The tumor gradings were G1 and G2 in 4 and 6 cases. Six cases had solitary tumor and 4 cases had multiple tumors. In 8 cases, tumors were up to 3 mm in diameter, and 2 cases had tumors over 5 mm. Recurrence occurred in 3 cases. One case was followed by TUR-Bt and 2 cases were followed by f-MTC. This procedure is less painful and it can be performed immediately after cystoscopy. It was useful in the treatment of small bladder cancer.

Cholangioscopic microwave tissue coagulation (MTC) and recanalization of the bile duct with complete obstruction due to pancreatic carcinoma in the far advanced stage

Cholangioscopic microwave tissue coagulation (MTC) and recanalization of the bile duct with complete obstruction due to pancreatic carcinoma in the far advanced stage

Usefulness of percutaneous low output microwave tissue coagulation therapy using needle electrode 1 mm in diameter for solitary liver cancer

Usefulness of percutaneous low output microwave tissue coagulation therapy using needle electrode 1 mm in diameter for solitary liver cancer