Ultrasound-guided Microwave Ablation Research Articles

Recurrence patterns following laparscopic ultrasound-guided microwave ablation for colorectal liver metastases

Recurrence patterns following laparscopic ultrasound-guided microwave ablation for colorectal liver metastases

Preprocedural Platelet-to-Lymphocyte and Platelet-to-Neutrophile Ratios as the Predictors of Local Recurrence Following Ultrasound-Guided Microwave Ablation for Colorectal Cancer Liver Metastases

Preprocedural Platelet-to-Lymphocyte and Platelet-to-Neutrophile Ratios as the Predictors of Local Recurrence Following Ultrasound-Guided Microwave Ablation for Colorectal Cancer Liver Metastases

Microwave Ablation Compared With Laser Ablation for Treating Benign Thyroid Nodules in a Propensity-Score Matching Study.

Objective: The efficacy and safety of percutaneous ultrasound-guided microwave and laser ablation (MWA and LA, respectively), for treating benign thyroid nodules (BTNs), were retrospectively compared.Methods: Patients (n = 318) underwent ablation of 328 BTNs. Confounding bias was reduced by propensity-score matching, and finally the MWA and LA groups each comprised 160 nodules. At baseline (before ablation), 3, 6, and 12 months, and every 6 months thereafter, the following were recorded: nodule volume reduction rate (VRR), neck symptom scores, cosmetic scores, complications, and side effects.Results: The baseline characteristics of the MWA and LA groups were comparable. The volumes of all nodules were less at all follow-ups relative to the baseline, as were the symptom and cosmetic scores at postoperative 6 months and thereafter (P < 0.01). At each follow-up, the overall VRRs of the MWA and LA groups were comparable. However, for nodules ≥13 mL, the VRR associated with LA at ≥6 months was significantly greater than that of MWA. The average ablation time for MWA was less than that of LA (P < 0.01). The overall incidences of major complications, minor complications, and side effects were 1.6, 2.2, and 18.4%, respectively, and there were no significant differences between the MWA and LA groups.Conclusion: Percutaneous ultrasound-guided MWA and LA are both safe and effective for the treatment of BTNs. Each can significantly reduce the nodule volume and improve the neck symptoms and appearance of patients, with a low incidence of adverse side effects. The efficiency of MWA is higher than that of LA. For nodules ≥13 mL, MWA may be preferred, but at 6 months and subsequent follow-ups the reduction in volume was greater in patients receiving LA.

Ultrasound-Guided Microwave Ablation of Unresectable Hepatocellular Carcinoma: Short Term Response and Predictors of Success

Abstract Background: Microwave ablation (MWA) refers to all electromagnetic methods of inducing tumor destruction. Aim of Study: The aim of this study was to evaluate the outcome of ultrasound-guided microwave ablation of unre-sectable hepatocellular carcinoma using cold shaft antenna. Material and Methods: A total of 65 patients with Hepa-tocellular carcinboma (HCC) were referred to interventional Radiology Department for ablation of presumed non resectable tumor. The study group included 49 (75.4%) male and 16 (24.6%) female, with an average age (±SD) of 55±7.2 years (range, 48-72 years). Conventional gray scale ultrasound and triphasic computed tomography were performed for all patients before ablation. The microwave system used was HS AMICA (apparatus for microwave ablation, hospital service, Rome, Italy), with electronically controlled microwave generator. A 14 Gauage cooled shaft electrode named AMICA-probe was used to deliver microwave power to the liver tissue. The patients were then followed-up with contrast enhanced com-puted tomography (CT) and serum a-fetoprotein levels. Results: Among the 65 patients, complete ablation was achieved in 60 patients after initial treatment (92.3%). Initial complete ablation rates in patients with nodules 5cm were 100%, 92.1%, and 85.7% respectively. The probability of achieving a complete ablation was signif-icantly greater in patients with tumor size of <5cm. Conclusion: Sonographically guided MWA is an effective ablative method that can be applied in unresectable HCC of various sizes and different locations with reasonable safety.

Ultrasound-guided microwave ablation in the individualized treatment of hepatocellular carcinoma adjacent to danger areas

Objectives To investigate the efficiency and safety of ultrasound-guided microwave ablation (MWA) for hepatocellular carcinoma (HCC) adjacent to danger areas. Methods The 106 patients with HCC treated by ultrasound-guided MWA were retrospectively included in our study. There were 149 lesions in total, including 8 lesions adjacent to gallbladder, 33 lesions adjacent to grade Ⅰ-Ⅱ bile duct, 39 lesions adjacent to diaphragm, 28 lesions adjacent to gastrointestinal tract and 41 lesions adjacent to hepatic capsule. The mean diameter of the tumors was (2.04±0.92)cm. Individualized treament strategies for different sites of the tumors were conducted. The early complete ablation rate of the tumors was assessed by enhanced computed tomography (CT) or magnetic resonance imaging (MRI) one month later and followed up regularly. Results The total inactivation rate was 89.9%. The early complete ablation rates of adjacent gallbladder, adjacent grade Ⅰ-Ⅱ bile duct, adjacent diaphragm, adjacent gastrointestinal tract and adjacent hepatic capsule were 100%, 84.8%, 89.7%, 92.9%, 90.2% respectively. The local progression rates were 0, 15.2%, 10.3%, 7.1%, 9.8%, respectively. The 1-, 2- and 3-year survival rates were 91.6%, 85.8% and 74.5%. Total cases were ablated 149 times. Serious complications accounted for 6.6%, including diaphragm injury, needle implantation, abdominal hemorrhage, severe infection, bile tumors. Conclusions Our study presented a novel individualized treament strategies using MWA in HCC patients. The individualized scheme effectively boosted the complete ablation rate of tumors and significantly improve the clinical outcome of HCC patients. Key words: Ultrasonography; Microwaves; Ablation techniques; Liver neoplasms

One-lung ventilation to treat hepatic dome lesion \u2013 a further step towards minimally invasive surgery: a case report

BackgroundAlthough liver resection is still the best treatment for primary or metastatic hepatic lesions, a conventional surgical approach may be challenging in patients with a history of previous abdominal surgery. We present a case of a 58-year-old white man with paracaval, subdiaphragmatic, recurrent hepatocellular carcinoma; he had a history of multiple abdominal surgeries.MethodsIn select patients, percutaneous ultrasound-guided thermal ablation is a valid non-surgical alternative due to its safety, efficacy, and good tolerability. Hepatic lesions located in the posterosuperior segments, however, can be difficult to reach via a percutaneous approach.ResultFor these cases, one-lung left-sided ventilation may be particularly helpful in blocking the right hemidiaphragm and improving the acoustic window to the liver.ConclusionWe present a case of paracaval, subdiaphragmatic, recurrent hepatocellular carcinoma in which the tumor was only reachable after one-lung left-sided ventilation that was successfully treated by percutaneous ultrasound-guided microwave ablation.

US-guided microwave ablation for primary hyperparathyroidism: a safety and efficacy study.

To evaluate the safety and efficacy of microwave ablation (MWA) with the assistance of continuous cool saline injection (CCSI) in patients with primary hyperparathyroidism (PHPT). Between November 1, 2014, and February 29, 2016, 22 patients with PHPT were enrolled and treated with ultrasound-guided MWA assisted by CCSI. The levels of parathyroid hormone (PTH) and serum calcium were recorded before and after the MWA. Patients were divided into two groups (normalized and unnormalized groups) according to treatment efficacy. Fisher's exact test and the Mann-Whitney test were used to compare data between the two groups. Timing differences in serum PTH and calcium levels were analyzed with repeated measures analysis of variance. Normalized outcomes for both PTH and calcium levels were achieved in 19 of 22 (86.36%) patients with PHPT. In the normalized group, PTH levels remained normal for 12months after MWA. PTH levels in the unnormalized group were outside the reference range at six of seven follow-ups within 12months following MWA. By contrast, serum calcium levels gradually decreased in all patients in both groups. The mean serum PTH and mean calcium levels at 6months after therapy were significantly lower than those before MWA (both p < 0.05). A transient voice change developed in eight patients. One patient experienced hypocalcaemia, which was corrected by oral calcium supplementation within 2months. US-guided MWA assisted by CCSI is safe and effective for destroying parathyroid gland tissue and may serve as a therapeutic alternative for patients with PHPT. • Microwave ablation is a new option for patients with hypercalcemic or normocalcemic primary hyperparathyroidism. • Microwave ablation can decrease PTH and calcium levels with sustained efficacy in most patients. • Treatment is safe and causes only transient side effects.

Local recurrence rates following laparoscopic ultrasound-guided microwave ablation for hepatic metastases of colorectal adenocarcinoma

Background: For patients with oligometastatic colorectal adenocarcinoma (CRC) isolated to the liver, local therapy including hepatic resection and local ablative procedures are recommended, though patients with tumors larger than 3cm have been shown to have higher local recurrence rates with ablation. Historically, radiofrequency ablation (RFA) was the predominant ablative modality chosen, but more recently, microwave ablation (MWA) has begun to supplant RFA due to a number of advantages. This study primarily aims to evaluate the local recurrence rate of this modality in our institution. Methods: A retrospective review was conducted of patients who underwent laparoscopic MWA from 2007 to 2018 at Carolinas Medical Center, a major regional quaternary care facility with hepatopancreatobiliary surgical subspecialty care within the Atrium Health System. Patients were identified from medical records containing the International Classification of Disease (ICD)-9 and 10 codes for colorectal adenocarcinoma and the current procedural terminology (CPT) code for laparoscopic ablation of liver tumors (47370), which was exclusively performed using MWA under ultrasound guidance at our facility during this time period. Retrospective chart review was used to identify demographic, perioperative, and postoperative clinical outcomes data. Patients were divided into two groups: patients with all tumors ≤3 cm and patients with at least one tumor >3 cm. Data were then analyzed using STATA. Results: A total of 167 patients with 328 tumors underwent MWA from 2007–2018 with an average follow up of 17.7 months (range: 0-80mos). 142 patients with a combined 279 tumors were included in the ≤3 cm group, while 25 patients with a combined 49 tumors were included in the >3cm group. Patients in the ≤3 cm group were significantly younger than those with larger tumors (median age 58 vs. 69, p = 0.002). There were no other significant demographic differences between the two groups. The majority of patients had only 1 tumor ablated (range: 1 to 14). There was no difference between the two groups in median number of tumors ablated. Median operative time was 115 minutes in the ≤3 cm group and 104 minutes in the >3 cm group (p = 0.702). Incomplete ablation, defined as residual tumor at the time of initial reimaging following MWA, was lower for the ≤3cm group, but this did not reach statistical significance (2.9% vs. 8.0%, p = 0.220). Most notably, there was a significant discrepancy between the two groups in local recurrence rates. Expressed as number of recurrences over number of tumors ablated for each group, significantly fewer tumors in the ≤3 cm group recurred locally (11.8% vs. 30.3%, p = 0.008). This represents local recurrence in 24 (17.9%) patients in the ≤3 cm group, and in 10 (40.0%) patients in the >3 cm group, p = 0.013. Conclusion: Numerous studies have demonstrated the safety and efficacy of local thermal ablative techniques, predominantly RFA, for oligometastatic CRC to the liver. Several recent studies have demonstrated promising results for MWA as well. Data from our retrospective series suggests that local recurrence rates in patients with tumors ≤3 cm who underwent MWA are comparable to those reported in the literature for patients undergoing hepatic resection, while those with larger tumors have notably higher local recurrence rates. While at least one multicenter randomized controlled trial to compare surgical resection with thermal ablation is ongoing, our institutional experience indicates that MWA is an effective treatment modality in patients with CRC metastases ≤3 cm.

An experimental study on endoscopic ultrasound-guided microwave ablation for porcine liver and pancreas

Objective To evaluate the feasibility and safety of endoscopic ultrasound-guided microwave ablation (EUS-MWA) for porcine liver and pancreas by assessing physiological state and pathological changes. Methods EUS-MWA was performed on liver and pancreas of 8 healthy pigs after general anesthesia. The needle size was 1.9 mm in diameter, and the power of ablation was 65 W, 10 min on liver and 60 W, 5 min on pancreas. The levels of blood amylase and hepatic transaminase were examined before and after the operation. All pigs underwent CT scan on the right postoperative day to assess the extent of ablation and complications. Two pigs were killed 6 hours after operation and 2 others were killed 24 hours after operation to assess structural damage around the puncture path. The remaining 4 pigs were raised to 2 weeks after operation to observe diet, activities and mental state. The ablated areas of liver and pancreas underwent pathological analysis after dissection, and non-ablation regions were treated as the control. Results All 8 pigs underwent EUS-MWA and their vital signs were stable during the operation. Except for the difficulty in locating the pancreas in one case, other surgical procedures were smooth and 18 ablations were performed totally (10 in liver and 8 in pancreas). CT scans showed quasi-circular low density lesions in the liver and pancreas, and the maximum diameter of the ablation area in liver and pancreas was 2.8±0.3 cm, 1.8±0.2 cm respectively. There was no free intraperitoneal gas, ascites or pleural effusion. The level of blood amylase increased at 6 hours after operation and the peak value occurred within 12-24 hours. The level of hepatic transaminase had a mild elevation. The rearing group showed transient food refusal and activity reduction after the operation, but all returned to normal within 1-2 days. No fever, vomiting or other abnormalities occurred. Puncture path burn, adjacent organ damage and bleeding was not observed except for one case of gastric wall burns during pancreas ablation. Pathology showed massive coagulative necrosis and peripheral bleeding area in the liver ablation center, and diffuse focal necrosis in the tissue of the pancreatic ablation area. Conclusion EUS-MWA is safe and feasible for porcine liver and pancreas, which can be used for the treatment of human liver and pancreatic diseases in the future. Key words: Ultrasonography; Microwaves; Endoscopes; Animal experimentation

Ultrasound-Guided Microwave Ablation for the Management of Inguinal Neuralgia: A Preliminary Study with 1-Year Follow-up

PurposeTo evaluate the feasibility and efficacy of ultrasound-guided microwave ablation for the treatment of inguinal neuralgia. Materials and MethodsA retrospective review of 12 consecutive ultrasound-guided microwave ablation procedures was performed of 10 consecutive patients (8 men, 2 women; mean age, 41 years [range, 15–64 years]), between August 2012 and August 2016. Inclusion criteria for inguinal neuralgia included clinical diagnosis of chronic inguinal pain (average, 17.3 months [range, 6–46 months]) refractory to conservative treatment and a positive nerve block. Pain response—reduction of pain level and duration and percent pain reduction using a 10-point visual analog scale (VAS) at baseline and up to 12 months after the procedure—was measured. Nine patients had pain after the inguinal hernia repair, and 1 patient had pain from the femoral artery bypass procedure. The microwave ablation procedure targeted the ilioinguinal nerve in 7 cases, the genitofemoral nerve in 4 cases, and the iliohypogastric nerve in 1 case. ResultsAverage baseline VAS pain score was 6.1 (standard deviation, 2.5). Improved pain levels immediately after the procedure and at 1, 6, and 12 months were statistically significant (P = .0037, .0037, .0038, .0058, respectively). Also, 91.7% (11/12) of the procedures resulted in immediate pain relief and at 1 month and 6 months. At 12 months, 83.3% (10/12) of patients had an average of 69% ± 31% pain reduction. Percent maximal pain reduction was 93% ± 14% (60%–100%), and the average duration of clinically significant pain reduction was 10.5 months (range, 0–12 months.). No complications or adverse outcomes occurred. ConclusionsUltrasound-guided microwave ablation is an effective technique for the treatment of inguinal neuralgia after herniorrhaphy.

Treatment of primary hepatic carcinoma through ultrasound-guided microwave ablation.

To study the clinical effect of ultrasound-guided microwave ablation on primary hepatic carcinoma. The subjects comprised 94 patients with primary hepatic carcinoma who were admitted to our hospital between August 2014 and November 2016. They were divided into two groups in accordance with a random-number table. The control (n = 47) and study (n = 47) groups received conventional surgical excision and ultrasound-guided microwave ablation, respectively. The operation duration, clinical effect, complication occurrence rates, and hepatic functions of the two groups were compared. The control group exhibited longer duration of operation and length of stay but significantly lower quantities of intraoperative bleeding and blood transfusion (P < 0.05) than the study group. The study group demonstrated significantly higher (P < 0.05) effective rate of treatment but significantly lower (P < 0.05) occurrence rate of complications than the control group. The study group exhibited significantly higher (P < 0.05) albumin and total bilirubin levels but significantly lower alanine aminotransferase and aspartate transaminase levels than the control group. No difference was observed in prothrombin time between the two groups (P > 0.05). Ultrasound-guided microwave ablation treatment offers the advantages of minor injury and low complication occurrence rates. Moreover, it is associated with faster postoperative recovery and improved hepatic function. Thus, it is worthy as a clinical option and must be promoted and applied.

US-guided microwave ablation for secondary hyperparathyroidism in patients after renal transplantation: a pilot study

Objective: To assess the safety and efficacy of ultrasound-guided microwave ablation (MWA) in the treatment of patients who develop secondary hyperparathyroidism (SHPT) after renal transplantation (RT).Methods: In total, nine patients, each with symptomatic SHPT caused by RT and at least one enlarged parathyroid gland, underwent MWA via hydrodissection. Intact parathyroid hormone (i-PTH), serum calcium, serum phosphorus, creatinine and blood urea nitrogen concentrations, before and after MWA, were assessed and compared.Results: Complete ablation was achieved in all patients for a total of 14 ablated parathyroid glands. The mean follow-up time was 17.2 ± 1.7 months post-operation. The mean maximum diameter of the parathyroid glands was 1.3 ± 0.4 cm (range: 0.4–2.0 cm). The ablation power implemented was 30 W and the mean time for each parathyroid gland to achieve complete ablation was 287.5 ± 83.4 s. The mean i-PTH, serum calcium and phosphorus concentrations at one day post-MWA (69.6 pg/mL, 2.23 ± 0.29 mmol/L, 1.2 2 ± 0.48 mmol/L, respectively) were significantly lower than those before MWA (780.0 pg/mL, 2.62 ± 0.32 mmol/L, 1.39 ± 0.61 mmol/L, respectively; p < .01), whereas the creatinine and blood urea nitrogen concentrations before and after MWA did not differ significantly from each other (p > .05). No significant differences were found between the biomarker concentrations observed at one day post-MWA and at the follow-ups (p > .05). No major operation-related complications occurred.Conclusion: Ultrasound-guided MWA is a safe and effective technique for destroying parathyroid gland tissue in patients who develop SHPT after RT and its clinical effects are long-lasting.

Comparison of ultrasound-guided percutaneous microwave ablation and parathyroidectomy for primary hyperparathyroidism

Purpose: To compare the clinical efficacy of ultrasound-guided percutaneous microwave ablation (MWA) and parathyroidectomy for primary hyperparathyroidism.Methods: In an observational retrospective study, we compared the outcomes in patients with primary hyperparathyroidism who underwent ultrasound-guided MWA with the outcomes in those who underwent surgical resection (SR). The primary outcome was cure rate. Secondary outcomes were the rate of complications, and the difference of the treatment parameters of two treatment methods. Propensity-score matching was used to assemble a cohort of patients with similar baseline characteristics.Results: Among 108 patients who met inclusion criteria, 28 patients who underwent ultrasound-guided MWA (MWA group) and 28 who underwent SR (SR group) had similar propensity scores and were included in the analyses. There was no significant difference in the cure rate between MWA group and SR group (82.1% vs. 89.3%, p = .705). Patients who underwent MWA had significantly less estimated blood loss and shorter surgical time than those who underwent SR (p < .001). The incidence of side effects and complications was comparable between MWA group and SR group (21.4% vs. 25%, p = .752).Conclusions: MWA and SR provided comparable short-term results in terms of cure rate and complications in treatment of primary hyperparathyroidism. Ultrasound-guided percutaneous MWA is a promising and minimally invasive method for primary hyperparathyroidism.

A novel software platform for volumetric assessment of ablation completeness

Purpose: To retrospectively evaluate the accuracy of a novel software platform for assessing completeness of percutaneous thermal ablations.Materials & methods: Ninety hepatocellular carcinomas (HCCs) in 50 patients receiving percutaneous ultrasound-guided microwave ablation (MWA) that resulted in apparent technical success at 24-h post-ablation computed tomography (CT) and with ≥1-year imaging follow-up were randomly selected from a 320 HCC ablation database (2010–2016). Using a novel volumetric registration software, pre-ablation CT volumes of the HCCs without and with the addition of a 5 mm safety margin, and corresponding post-ablation necrosis volumes were segmented, co-registered and overlapped. These were compared to visual side-by-side inspection of axial images.Results: At 1-year follow-up, CT showed absence of local tumor progression (LTP) in 69/90 (76.7%) cases and LTP in 21/90 (23.3%). For HCCs classified by the software as “incomplete tumor treatments”, LTP developed in 13/17 (76.5%) and all 13 (100%) of these LTPs occurred exactly where residual non-ablated tumor was identified by retrospective software analysis. HCCs classified as “complete ablation with <100% 5 mm ablative margins” had LTP in 8/49 (16.3%), while none of 24 HCCs with “complete ablation including 100% 5 mm ablative margins” had LTP. Differences in LTP between both partially ablated HCCs vs completely ablated HCCs, and ablated HCCs with <100% vs with 100% 5 mm margins were statistically significant (p < .0001 and p = .036, respectively). Thus, 13/21 (61.9%) incomplete tumor treatments could have been detected immediately, were the software available at the time of ablation.Conclusions: A novel software platform for volumetric assessment of ablation completeness may increase the detection of incompletely ablated tumors, thereby holding the potential to avoid subsequent recurrences.

Percutaneous Microwave Ablation of Metastatic Lymph Nodes from Papillary Thyroid Carcinoma: Preliminary Results.

Our purpose is to assess the effectiveness and safety of ultrasound-guided percutaneous microwave ablation (MWA) for lymph node metastases (LNMs) from papillary thyroid carcinomas (PTC). In total, 14 patients with recurrent PTC were enrolled in this retrospective study. The vascularity within the ablation zone was evaluated by contrast-enhanced ultrasonography (CEUS) after MWA. Patients were followed up with measurement of the size and volume of tumor, serum thyroglobulin, and clinical evaluation at 7days, 1, 3, 6months, and every 6months thereafter. Twenty-one LNMs were confirmed by biopsy and successfully treated by MWA in a single session. No incomplete ablation was detected by CEUS after treatment. The average largest diameter and volume of the tumors were reduced from 10.1 ± 4.7mm (range, 3.1-20.0mm) and 291.9 ± 255.6mm3 (range, 11.6-766.6mm3) to 0.9 ± 1.6mm (range, 0-4.1mm; p < 0.05) and 4.0 ± 9.0mm3 (range, 0-31.6mm3; p < 0.05) at the final follow-up. Neither progression of treated tumors nor newly suspicious LNMs could be detected after treatment. The overall complication rate was 7.1% (1/14). Ultrasound-guided MWA can effectively control LNMs from PTC, but it is less safe for tumors in the central compartment. MWA may become an alternative therapy in selected PTC patients, who were ineligible or refused to undergo repeated neck explorations.

Cyto-inactivation instantly induced by microwave ablation on thyroid nodules

Objective: To explore the effect of microwave ablation on thyroid nodules cell activity by the reaction of key enzyme of cell activation. Methods: From November 2017 to February 2018, 104 patients with 120 thyroid nodules underwent ultrasound-guided microwave ablation at Super-minimally Invasive Medicals, Shanghai International Medical Center, aged 14-55 years, 42 males and 62 females.Twice core needle biopsy were performed before and after thermal ablation.The specimen were using hematoxylin and eosin (HE) staining and enzyme histochemical staining with include succinate dehydrogenase (SDH) and nicotinamide adeninedinucleotide phosphate diaphorase (NADPH-d), respectively, and observe under microscope. Results: Enzyme histochemical staining showed that the positive rate of SDH and NADPH-d in the marginal region and transitional region were 100% before ablation, and were 0% immediately after ablation.The positive rate of SDH and NADPH-d histochemical staining in the same area before and immediately after ablation was statistically significant (P<0.05). Shortly after microwave ablation, the tissue structure and cell morphology showed no obvious alteration in HE stained sections, but in sections with enzyme histochemical staining, the activity of SDH and NADPH-d in ablated tissue disappeared.The accuracy rate of pathologic diagnosis was 100% after ablation. Conclusions: SDH and NADPH-d enzyme activity may be better in evaluating the short-term efficacy of microwave ablation of thyroid nodules than HE staining.

The Study of Partial Microenvironment Pre- and Post-microwave Ablation in Rabbit Peripheral Pulmonary VX2 Tumors

Purpose: The aim of this study was to investigate the changes of CD3 and CD20 in the microenvironment of rabbit peripheral lung cancer before and after microwave ablation (MA). Methods: Twenty-four rabbits with lung VX2 tumor were randomly divided into four groups (n = 6 in each group). Ultrasound-guided MA was gone using 40 W powers as the treatment mode for about 60s. The animals were sacrificed by injecting anesthetic into the ear vein before and after MA. The thoracic ribs were cut off and the lung lobes were removed completely with tumor and then washed with saline. Part of the organization placed into 4% formaldehyde for pathological examination; part placed into 2.5% glutaraldehyde for the electron microscopy. Result: The histological features of ablation lesions showed as morphological abnormalities of tumor cells, cell and nuclear elongated by heat; the cells of alveolar wall degeneration and necrosis. The alveolar wall ruptured and alveolar structure disappeared. Blood cells and inflammatory cells appeared in the alveolar interstitial and a large number of serous exudated. The positive cell numbers of CD3 and CD20 cells at 2 weeks after MA were significantly different from those before MA and at 3 days and 1 week after MA (P< 0.01). There was no significant difference in the positive cells of CD3 and CD20 before and 3 days and 1 week after MA. Conclusion: The number of immune cells in tumor adjacent tissue increased significantly after MA and the level of local anti-tumor immune cells was also increased. Keywords: Histological features, microwave ablation, peripheral lung cancer, formaldehyde, electron microscopy, thoracic ribs.

Application of intraoperative ultrasonography in robot-assisted laparoscopic hepatectomy

Objective To explore the application and significance of intraoperative laparoscopic ultrasound(IOUS) in robot-assisted laparoscopic hepatectomy. Methods From February 2015 to February 2017, 135 patients undergoing liver resection with robotic approach were enrolled in the study. All data about demographic, surgical procedure and postoperative course were collected prospectively and analyzed. IOUS was routinely performed in these patients. To assist the localization and resection of liver tumor, a four steps IOUS protocol in robotic liver surgery was proposed, including exploration, verification, guidance, and confirmation. If necessary, intraoperative laparoscopic ultrasound guided microwave ablation of liver tumor to complete the treatment. Results A total of 11 additional lesions in 11 patients were detected in 135 patients, 7 patients accepted strategic surgical modification: 4 cases were enlarged resection, and 3 cases were treated with microwave ablation. There were only 17 patients lost blood more than 1 000 ml in all patients. No patient suffered from any single or multiple organ dysfunctions, and there was no mortality observed. Conclusions IOUS is indispensable to understand lesions and vessels, confirm the complete resection of the tumor in robot-assisted laparoscopic hepatectomy. It is also a necessary tool for the microwave ablation of liver tumor. Key words: Ultrasonography; Laparoscopes; Hepatectomy

Therapeutic effect of transcatheter arterial chemoembolization combined with ultrasound-guided microwave ablation for treatment of liver cancer in special sites

Objective: To investigate the efficacy and clinical value of transcatheter arterial chemoembolization (TACE) combined with ultrasound-guided microwave ablation for the treatment of liver cancer in special sites. Methods: The patients with liver cancer in special sites (the liver cancer was adjacent to the gallbladder, dome of diaphragm, gastrointestinal tract, heart, great vessels, and portal vein, with the shortest distance from the tumor to the organ/lumen < 0.5 cm ) were enrolled as treatment group, and the patients with primary liver cancer in normal sites treated in our hospital during the same period were randomly enrolled as control group. They underwent TACE combined with ultrasound-guided microwave ablation. The 6-month, 12-month, 18-month and 24-month survival rates of the patients in two groups were analyzed. Results: The clinical data of 40 patients with liver cancer in special sites, including 9, 7, 5, 11, 3, 3, and 2 patients with liver cancer adjacent to the gallbladder, dome of diaphragm, gastrointestinal tract, portal vein, hepatic vein, inferior vena cava, and heart, respectively, and another 40 patients in control group were collected in the study. The negative rate of alpha-fetoprotein (AFP) was 83.3% in the treatment group and 82.8% in the control group. The 6-month, 12-month, 18-month, and 24-month survival rates were 100.0%, 95.0%, 90.0%, and 80.0%, respectively, in the treatment group, and 100.0%, 97.5%, 92.5%, and 85.0%, respectively, in the control group. Conclusion: TACE combined with ultrasound-guided microwave ablation is as effective for liver cancer in special sites as for those in normal sites, with high safety, and is feasible in clinical application.

Ultrasound-guided microwave ablation in the treatment of benign thyroid nodules in 435 patients.

The objective of the present study was to investigate the effectiveness and safety of ultrasound-guided microwave ablation in the treatment of benign thyroid nodules. A total of 474 benign thyroid nodules in 435 patients who underwent ultrasound-guided microwave ablation from September 2012 to August 2015 were included. Nodule volume and thyroid function were measured before treatment and at 1, 3, 6, and 12 months and subsequently after every 6 months. The nodule volume reduction rate and changes of thyroid function were evaluated. The volume of all thyroid nodules significantly decreased after ultrasound-guided microwave ablation. The average volume was 13.07 ± 0.95 ml before treatment, and 1.14 ± 0.26 ml at 12-months follow-up. The mean volume reduction rate was 90% and the final volume reduction rate was 94%. The volume reduction rate of mainly cystic nodules was significantly higher than that of simple solid and mainly solid nodules (all P < 0.05). The pretreatment volume of nodules was positively correlated with the final volume reduction rate at final follow-up ( P = 0.004). No serious complications were observed after treatment. In conclusion, ultrasound-guided microwave ablation is an effective and safe technique for treatment of benign thyroid nodules, and has the potential for clinical applications. Impact statement Ultrasound-guided MWA is an effective and safe technique for the treatment of benign thyroid nodules. It can significantly reduce the nodule volume, improve the patients' clinical symptoms, has less complication, guarantees quick recovery, meets patients' aesthetic needs, and shows less interference on the physiological and psychological aspects of the body. MWA should be a good complement to traditional open surgery and has potentials in clinical applications.