Microwave Scissors-Based Sutureless Laparoscopic Partial Nephrectomy Versus Conventional Open Partial Nephrectomy in a Porcine Model: Usefulness and Complications.

BACKGROUND: This study aimed to compare the benefits and safety of microwave scissors-based sutureless laparoscopic partial nephrectomy (MSLPN) with those of conventional open partial nephrectomy (cOPN). METHODS: Each kidney in nine pigs underwent MSLPN using microwave scissors (MWS) via transperitoneal laparoscopy or cOPN via retroperitoneal open laparotomy. The kidney's lower and upper poles were resected under temporary hilar-clamping. The renal calyces exposed during renal resections were sealed and transected using MWS in MSLPN and were sutured in cOPN. For MWS, the generator's power output was 60 W. Data on procedure time (PT), ischemic time (IT), blood loss (BL), normal nephron loss (NNL), and extravasation during retrograde pyelogram were compared between the two techniques. RESULTS: The authors successfully performed 22 MSLPNs and 10 cOPNs. Compared with cOPN, MSLPN was associated with significantly lower PT (median, 9.2 vs 13.0 min; p = 0.026), IT (median, 5.9 vs 9.0 min; p < 0.001), BL (median, 14.4 vs 38.3 mL; p = 0.043), and NNL (median, 7.6 vs 9.4 mm; p = 0.004). However, the extravasation rate was higher in the MSLPN group than in the cOPN group (54.5 % [n = 12] vs 30.0 % [n = 3]), albeit without a significant difference (p = 0.265). Pelvic stenosis occurred in one MSLPN procedure that involved deep lower pole resection near the kidney hilum. CONCLUSIONS: The study data show that MSLPN can improve intraoperative outcomes while reducing technical demands for selected patients with non-hilar-localized renal tumors. However, renal calyces, if violated, should be additionally sutured to prevent urine leakage.

A Prospective Multicenter Observational Study of Venous Thromboembolism after Gastric Cancer Surgery (SHISA-1601).

INTRODUCTION: This study aimed to clarify the frequency and risk factors of intercurrent venous thromboembolism (VTE) in patients undergoing major curative gastric cancer surgery. METHODS: This prospective, multicenter, observational study included patients with gastric cancer who underwent radical gastrectomy at 5 hospitals between June 2016 and May 2018. Patients who were preoperatively administered anticoagulants were excluded. RESULTS: A total of 126 patients were eligible to participate. VTE occurred within 9 days postoperatively in 5 cases (4.0%; 2 symptomatic and 3 asymptomatic). Postoperative day (POD) 1 plasma D-dimer and soluble fibrin (SF) levels were significantly higher in the VTE group than in the non-VTE group. Receiver-operating characteristic curve (ROC) analysis indicated a statistically significant ability of POD 1 D-dimer and SF levels to predict postoperative VTE development after gastrectomy; this finding was reflected by an area under the curve (AUC) of 0.97 (95% CI 0.92-1.0) and 0.87 (95% CI 0.74-1.0), respectively. Cutoff values of D-dimer (24.6 µg/mL) and SF (64.1 µg/mL) were determined. Intraoperative blood transfusion (odds ratio [OR] 7.86), POD 1 D-dimer ≥24.6 µg/mL (OR 17.35), and POD 1 SF ≥64.1 µg/mL (OR 19.5) were independent predictive factors for postoperative VTE (p < 0.05). CONCLUSION: VTE occurred in 4.0% patients (1.6% symptomatic and 2.4% asymptomatic) after gastric cancer surgery; however, with an early diagnosis and anticoagulant therapy, no patients experienced progression. Careful observation of patients with a high risk for VTE, including intraoperative blood transfusion and high POD 1 D-dimer or SF levels, would contribute to the early detection of VTE.

The invention of microwave surgical scissors for seamless coagulation and cutting.

PURPOSE: We developed a microwave energy-based scissors device (MWCX) that is capable of performing cutting and coagulation using 2.45 GHz microwave energy. This paper aims to present the concept of the device and assess the basic functions including the hemostasis, cutting, and sealing abilities. METHODS: Seven beagle dogs were used in our experiments. In six dogs, we measured the coagulation time (CT), lateral thermal injury (LTI), bursting pressure (BP). The dogs were then subjected to re-laparotomy 1 week later to allow us to investigate the results. In one dog, the same factors and the quantities of smoke and mist emitted were compared to those observed when using a Harmonic Focus (HF) device. RESULTS: At 60 W, the MWCX could cut and seal small (5 s, diameter 1-2 mm) and medium-sized (10 s, 3-4 mm) vessels with complete hemostasis. The liver (length 2 cm) was cut for 30 s. Harvested vessels were sealed for 10 s (artery, 17 times; vein, six times). The mean BP was 887. 8 ± 41.5 mmHg in the medium arteries and 457.2 ± 118.0 mmHg in veins, with a mean diameter of 4.5 ± 1.3 mm. In a comparative study, the MWCX showed similar results to the HF with regard to the CT, BP and LTI, and emitted less smoke and mist. CONCLUSION: The MWCX showed similar levels of functionality and safety to HF, as well as the advantages offered by the use of microwave energy. Microwave devices might be used in the majority of applications for which traditional energy devices are used.

Minimally invasive surgery using the open magnetic resonance imaging system combined with video-assisted thoracoscopic surgery for synchronous hepatic and pulmonary metastases from colorectal cancer: report of four cases.

Simultaneous resection of hepatic and pulmonary metastases (HPM) from colorectal cancer (CRC) has been reported to be effective, but it is also considered invasive. We report the preliminary results of performing minimally invasive surgery using the open magnetic resonance (MR) imaging system to resect synchronous HPM from CRC in four patients. All four patients were referred for thoracoscopy-assisted interventional MR-guided microwave coagulation therapy (T-IVMR-MCT) combined with video-assisted thoracoscopic surgery (VATS). The median diameters of the HPM were 18.2 and 23.2 mm, respectively. The median duration of VATS and T-IVMR-MCT was 82.5 and 139 min, respectively. All patients were discharged without any major postoperative complications. One patient was still free of disease at 24 months and the others died of disease progression 13, 36, and 47 months without evidence of recurrence in the treated area. Thus, simultaneous VATS + T-IVMR-MCT appears to be an effective option as a minimally invasive treatment for synchronous HPM from CRC.

Initial experiences with MR Image-guided laparoscopic microwave coagulation therapy for hepatic tumors.

PURPOSE: Percutaneous thermal ablation is used for treating hepatic tumors. Recent advances in laparoscopy and imaging modalities have led to the development of a novel image-guided minimally invasive loco-regional treatment. The aim of this trial was to apply laparoscopic assistance to magnetic resonance (MR) image-guided thermoablation instead of ultrasonography, because of its various advantages. METHODS: Patients with hepatic tumors and liver cirrhosis underwent magnetic resonance (MR) image-guided laparoscopic microwave coagulation therapy using a borescope and endoscopic forceps. Six cases of laparoscopic microwave coagulation treatment using MR image guidance were successfully performed between January 2000 and December 2008. Tumors were detected, punctured, and ablated in an open-configured MR scanner. A total of nine hepatocellular carcinoma nodules were preoperatively identified in S3, S5 and S6 (mean diameter = 20.8 ± 5.4 mm). RESULTS: MR-guided microwave coagulation was laparoscopically achieved in all patients without any significant complications that required invasive treatment. The mean length of the operation was 275.3 ± 60.5 min, and the mean postsurgical hospital stay was 10.0 ± 2.3 days. Postoperative confirmation scanning was performed without moving the patients. CONCLUSION: MR-guided laparoscopic microwave coagulation therapy is an effective treatment for hepatic tumors adjacent to other organs, as it allows for more accurate detection of lesions and for tumors to be treated safely while avoiding adjacent organs. It is less invasive than conventional procedures, because the MR real-time guidance enabled continuous monitoring throughout the procedure.

Resectable carcinoma developing in the remnant pancreas 7 years and 10 months after distal pancreatectomy for invasive ductal carcinoma of the pancreas: report of a case.

BACKGROUND: Pancreatic ductal adenocarcinoma, which represents 90% of pancreatic cancers, is one of the most lethal and aggressive malignancies. Operative resection remains the only treatment providing prolonged survival, however, recurrence of pancreatic ductal adenocarcinoma occurs in up to 80% of patients with pancreatic cancer within 2 years of a potential curative resection. There are few reports of pancreatic carcinoma recurrence (primary second cancer) in the remnant pancreas after pancreatectomy. CASE PRESENTATION: A 52-year-old woman underwent a distal pancreatectomy for pancreatic cancer in September 2004. Adjuvant chemotherapy was started after surgery and continued for 4 years. In March 2012, marked elevation of DUPAN-II was observed, followed by an irregular stenotic finding in the main duct. We performed an en bloc resection of the remnant pancreas in July 2012. Histologically, the tumor contained a second primary pancreatic carcinoma with lymph node metastasis. At follow-up 20 months after the second operation, the patient was alive without recurrence. Fourteen cases of resectable cancer developing in the remnant pancreas after a pancreatectomy for cancer have been reported; a minority of these was identified as second primary tumors. Therefore, our patient's primary second cancer is a rare event. CONCLUSION: The patient is considered to have shown a rare, unique pancreatic cancer recurrence. Persistent elevation of a tumor marker and extensive imaging led to proper diagnosis and treatment.

Draft genome sequence of emm103/ST1363 Streptococcus pyogenes strain AB1, isolated from the blood of a woman with peritonitis and toxic shock syndrome.

We report the draft genome sequence of Streptococcus pyogenes strain AB1 isolated from the blood of a woman with peritonitis-toxic shock syndrome. The genome measured 1.855 Mbp, with a G + C content of 38.3%. Sequences unmapped to the reference genome sequence of M1 SF370 (GenBank accession number AE004092.2) were characterized.

Successful treatment of streptococcal toxic shock syndrome complicated by primary peritonitis and bilateral empyema in a healthy young woman: Identification of uncommon clone emm103 and novel sequence type 1363.

Streptococcal toxic shock syndrome (STSS) has a dramatic clinical course and high mortality rate. Here, we report a case of STSS complicated by primary peritonitis and bilateral empyema. A previously healthy young woman was diagnosed with STSS complicated by primary peritonitis and bilateral empyema. Blood culture results on admission were negative. Sever shock, respiratory failure, systemic inflammation, thrombocytopenia, renal failure, ascites, and pleural effusion occurred, mimicking thrombocytopenia, anasarca, fever, reticulin fibrosis/renal failure and organomegaly (TAFRO) syndrome. Retesting blood cultures identified Streptococcus pyogenes. Gram staining of ascites and pleural fluid indicated gram-positive cocci in chains. Antibiotics, immunoglobulins, and surgical intervention led to recovery without complications. Ex-post genotypic analyses showed uncommon emm103.0 (cluster E3) of emm long sequence (784 base) and novel sequence type 1363. STSS diagnosis can be difficult as it mimics other systemic inflammatory diseases. Therefore, it is crucial for clinicians to perform microbiological examinations from infection foci, even if the initial culture is negative.

Magnetic resonance and ultrasound image-guided navigation system using a needle manipulator.

PURPOSE: Image guidance is crucial for percutaneous tumor ablations, enabling accurate needle-like applicator placement into target tumors while avoiding tissues that are sensitive to injury and/or correcting needle deflection. Although ultrasound (US) is widely used for image guidance, magnetic resonance (MR) is preferable due to its superior soft tissue contrast. The objective of this study was to develop and evaluate an MR and US multi-modal image-guided navigation system with a needle manipulator to enable US-guided applicator placement during MR imaging (MRI)-guided percutaneous tumor ablation. METHODS: The MRI-compatible needle manipulator with US probe was installed adjacent to a 3 Tesla MRI scanner patient table. Coordinate systems for the MR image, patient table, manipulator, and US probe were all registered using an optical tracking sensor. The patient was initially scanned in the MRI scanner bore for planning and then moved outside the bore for treatment. Needle insertion was guided by real-time US imaging fused with the reformatted static MR image to enhance soft tissue contrast. Feasibility, targeting accuracy, and MR compatibility of the system were evaluated using a bovine liver and agar phantoms. RESULTS: Targeting error for 50 needle insertions was 1.6 ± 0.6 mm (mean ± standard deviation). The experiment confirmed that fused MR and US images provided real-time needle localization against static MR images with soft tissue contrast. CONCLUSIONS: The proposed MR and US multi-modal image-guided navigation system using a needle manipulator enabled accurate needle insertion by taking advantage of static MR and real-time US images simultaneously. Real-time visualization helped determine needle depth, tissue monitoring surrounding the needle path, target organ shifts, and needle deviation from the path.

Correlation between high field MR images and histopathological findings of rat transplanted cancer immediately after partial microwave coagulation.

PURPOSE: To investigate the immediate effects of microwave coagulation on rat tumors in various magnetic resonance (MR) images at high magnetic field strength using histopathological examinations as reference. MATERIALS AND METHODS: Tumors implanted in rat femurs were partially thermocoagulated by microwave. Immediately after, T1- and T2-weighted images, diffusion-weighted images (DWIs), and contrast-enhanced T1 weighted images (CE-T1WIs) were acquired with a 7-tesla MR scanner. After measurements, tumors were examined histopathologically with hematoxylin-eosin (HE) staining and histochemically for acid phosphatase activity. RESULTS: Without contrast, boundaries of coagulated areas were unclear on MR images, including apparent diffusion coefficient (ADC) maps. CE-T1WIs clearly showed immediate contrast enhancement of untreated areas of tumor, and the area of enhancement gradually enlarged in 5 min. Quantitative analyses were conducted by classifying tumor areas by contrast enhancement results. Signal intensities of the areas in the MR images showed no significant differences, but at the periphery, ADC values were significantly higher in areas with delayed enhancement than those with immediate enhancement. Compared with histopathological findings, with microwave thermocoagulation, increased ADC value seemed to derive from collection of extracellular fluid in the outer zone, where acid phosphatase activity was attenuated. CONCLUSION: ADC values in the areas with delayed enhancement of CE-T1WIs were higher than those in non-affected areas, but MR images could not show areas of coagulation within tumors. Clear detection of the boundaries of coagulated areas required contrast enhancement, even at magnetic field strength of 7T.

Exogenous C-type natriuretic peptide restores normal growth and prevents early growth plate closure in its deficient rats.

Signaling by C-type natriuretic peptide (CNP) and its receptor, natriuretic peptide receptor-B, is a pivotal stimulator of endochondral bone growth. We recently developed CNP knockout (KO) rats that exhibit impaired skeletal growth with early growth plate closure. In the current study, we further characterized the phenotype and growth plate morphology in CNP-KO rats, and the effects of exogenous CNP in rats. We used CNP-53, an endogenous form of CNP consisting of 53 amino acids, and administered it for four weeks by continuous subcutaneous infusion at 0.15 or 0.5 mg/kg/day to four-week old CNP-KO and littermate wild type (WT) rats. We demonstrated that CNP-KO rats were useful as a reproducible animal model for skeletal dysplasia, due to their impairment in endochondral bone growth. There was no significant difference in plasma bone-turnover markers between the CNP-KO and WT rats. At eight weeks of age, growth plate closure was observed in the distal end of the tibia and the calcaneus of CNP-KO rats. Continuous subcutaneous infusion of CNP-53 significantly, and in a dose-dependent manner, stimulated skeletal growth in CNP-KO and WT rats, with CNP-KO rats being more sensitive to the treatment. CNP-53 also normalized the length of long bones and the growth plate thickness, and prevented growth plate closure in the CNP-KO rats. Using organ culture experiment of fetal rat tibia, gene set enrichment analysis indicated that CNP might have a negative influence on mitogen activated protein kinase signaling cascades in chondrocyte. Our results indicated that CNP-KO rats might be a valuable animal model for investigating growth plate physiology and the mechanism of growth plate closure, and that CNP-53, or its analog, may have the potential to promote growth and to prevent early growth plate closure in the short stature.

Fluorine-19 fast recovery fast spin echo imaging for mapping 5-fluorouracil.

We investigated the effects of fast recovery (FR) to increase the sensitivity of fluorine-19 ((19)F) fast spin echo (FSE) in mapping 5-fluorouracil (5-FU) and its metabolites. We added an additional 90 degrees pulse (which flips back longitudinal magnetization at the end of the sequence) to the chemical shift selective (19)F FSE pulse sequence. In 5-FU solution, FR remarkably improved the signal-to-noise (S/N) ratio of (19)F 5-FU images, having higher effects with shorter repetition time and smaller echo train numbers. In animal studies, FR produced a conspicuous increase in (19)F signals in the urinary bladder. FR effects for (19)F signals in the liver were smaller than those in other organs but still substantial. Utilization of FR in (19)F FSE images promises more sensitive observation of (19)F metabolite maps of 5-FU and other (19)F-containing compounds that have relatively long relaxation times.

Thermal tissue change induced by a microwave surgical instrument in a rat hepatectomy model.

BACKGROUND: Microwaves exhibit great potential in tissue heating, which causes effective coagulation. Using this energy, we have developed the microwave coagulation surgical instrument (MWCX) for clinical application. Here, we characterized the impact of MWCX on tissues including heating property, tissue change, and spread of thermal injury. METHODS: Hepatectomy was performed with MWCX using a rat model. The resections were completed using various energy levels and powers. Tissue temperature during radiation was recorded. Tissue change and lateral thermal injury (LTI) was assessed immediately, 7 days, 3 months, and 6 months after resection. RESULTS: All cutting and hemostasis procedures were successfully accomplished. Major histologic findings consisted of deformation or destruction of hepatocytes, tissue edema, and peripheral hemorrhage. At various energy levels, 200 to 1000 J, the tissue was heated up to approximately 80°C to 140°C causing 2.7- to 6.5-mm LTI on the 7th day. LTI was then decreased gradually in the following term. At certain energy levels, the application of neither 20 W nor 40 W induced significant difference in both heating and LTI. CONCLUSIONS: MWCX achieved effective tissue coagulation with relevant tissue injury, and it should be a good candidate for clinical application.

Lymphoepithelial cyst with sebaceous glands of the pancreas: a case report.

BACKGROUND: Lymphoepithelial cyst (LEC) of the pancreas is a rare benign tumor. LEC with sebaceous glands of the pancreas is extremely rare, and its histogenesis remains unclear. CASE PRESENTATION: We present a 66-year-old man with an incidental finding of a cystic lesion at the neck of the pancreas. Pancreatic juice cytology results and elevated serum carbohydrate antigen 19-9 and Dupan-2 levels indicated that the cyst was a potential adenocarcinoma. Therefore, a pancreaticoduodenectomy was performed. Macroscopically, the tumor was a unilocular cyst with a thin transparent wall, filled with soft yellow material. Pathological findings showed that the cyst was lined with squamous epithelium, accompanied by dense lymphoid tissue with scattered germinal centers. There were no hair follicles, but sebaceous glands were present in the lymphoid tissue just beneath the squamous epithelium. Therefore, the histopathological diagnosis was an LEC with sebaceous glands of the pancreas. Furthermore, the squamous epithelium surrounding the cyst was pathologically continuous with the tubular structure, indicating that the tubular structure transitioned into the squamous epithelium. CONCLUSIONS: We report an extremely rare case of LEC with sebaceous glands of the pancreas. Moreover, the pathological findings, which showed that the tubular structure transitioned into the squamous epithelium, suggested that this was squamous metaplasia. In order to investigate the histogenesis of LEC of the pancreas, the pathological findings must be evaluated.

Utility of a microwave surgical instrument in sealing lymphatic vessels.

BACKGROUND: This study assessed the ability of a novel microwave coagulation surgical instrument (MWCX) to seal lymphatic vessels when compared with LigaSure (Valleylab, Boulder, CO), the Harmonic Scalpel (HS; Ethicon Endo-Surgery, Cincinnati, OH), and electric cautery. METHODS: The burst pressure of pig inguinal lymphatic vessels was assessed after the sealing of vessels with each surgical instrument. The rate of lymphorrhea from pig mesenteric lymphatic vessels was also investigated using indocyanine green and visualized with the Photodynamic Eye system (Hamamatsu Hotoniks, Hamamatsu, Japan). RESULTS: Burst pressures were higher with MWCX (average, 300 mm Hg), LigaSure (average, 290 mm Hg), and HS (average, 253 mm Hg) when compared with electric cautery (average, 152.3 mm Hg; vs MWCX: P = .002, vs LigaSure: P = .002, vs HS: P = .004). The rate of lymphorrhea was significantly lower with LigaSure (13.3%), HS (18.8%), and MWCX (13.3%) when compared with electric cautery (77.3%; vs LigaSure: P < .001, vs HS: P < .001, vs MWCX: P < .001). CONCLUSIONS: MWCX was equivalent to LigaSure and HS in terms of the ability to seal lymphatic vessels.

Preliminary clinical experiences of a motorized manipulator for magnetic resonance image-guided microwave coagulation therapy of liver tumors.

BACKGROUND: In magnetic resonance (MR) image-guided microwave thermocoagulation of liver tumors, the choice of the optimal puncture route is an important and time-consuming process. To assist this process, we have developed a motorized MR-compatible manipulator. METHODS: The manipulator consists of a passive end effecter with 2 degrees-of-freedom (DOF) rotation and active base stages with 3 ultrasonic motors. It automatically chases the preset target point with synergetic remote-center-of-motion (RCM) control. A mechanical torque limiter and an electrical shutdown switch were added for patient safety. RESULTS: The manipulator was used for this procedure in 15 cases and successfully utilized to treat liver tumors in various locations. Thoracoscopic assistance was combined with the manipulator in 6 cases. No complications were experienced. CONCLUSIONS: The manipulator was found to be very effective for assisting MR-guided microwave coagulation of liver tumors.

An easy-to-use microwave hyperthermia system combined with spatially resolved MR temperature maps: phantom and animal studies.

BACKGROUND: Hyperthermia has been used in multimodal cancer treatments, and in randomized, controlled studies, hyperthermia is an effective cancer therapy. For clinical accuracy and safety, however, temperature monitoring during treatment is essential. We aimed to develop a convenient microwave hyperthermia system combined with spatially resolved real-time temperature monitoring to improve its efficacy and safety. MATERIALS AND METHODS: Using an MR-compatible irradiation-type microwave applicator, agar phantoms, thigh muscles of rabbit, and subcutaneous VX2 tumors of rabbit were heated in combination with noninvasive MR temperature maps. For MR temperature calculation, a proton resonance frequency method was used. After determination of temperature coefficients and evaluation of the precision in MR thermometry, distribution of microwave heating over time was examined for each substance. RESULTS: The temperature coefficients of phantoms, rabbit muscles, and VX2 tumors were -0.00977, -0.00976, and -0.01027 ppm/ degrees C, respectively. The 95% limits of agreement of MR and fluoroptic thermometry in the three subjects were +0.318/-0.339 degrees C, +0.693/-0.661 degrees C, and +0.564/-0.526 degrees C, respectively. Concerning VX2 tumor, the average tumor temperature was 42.60 +/- 0.14 degrees C and the surface of skin was 43.27 +/- 0.45 degrees C in the 60-min experimental period. CONCLUSIONS: With this easy-to-use microwave hyperthermia system, effective hyperthermia was accomplished in phantoms and living animals in combination with MR temperature maps.