Microwave Thermoablation Research Articles

52769 Microwave Thermoablation of Eccrine Glands to Treat Residual Limb Hyperhidrosis

52769 Microwave Thermoablation of Eccrine Glands to Treat Residual Limb Hyperhidrosis

Microwave Thermal Ablation of Thyroid Nodules with the MONTREAL Technique: Preliminary Clinical Results.

Ultrasound-guided percutaneous Microwave Thermoablation (MWA) is an increasingly popular minimally invasive therapy for the treatment of benign thyroid nodules due to its remarkable heating velocity and resilience to heat sinking. We present a cohort of 26 patients (17 F, 9M, mean age 56.2yy) with 20 goiters (mean volume 34.9cc, min 6.5cc-max 84cc) and 6 autonomously functioning nodules (AFTNs, mean volume 11.6cc, min 3.5cc-max 24cc) treated with MWA, using the moving shot technique and a novel energy delivery algorithm (MONTREAL), based on intra-operative real-time reflectivity measurements: each moving shot was automatically terminated when reflectivity was observed to ramp up. 17G or 18G internally cooled 2.45 GHz applicators were used (AMICA-PROBE, HS HOSPITAL SERVICE SpA), operated at 15-30W. On average, each treatment deposited 9.9±5.5kJ during 696±325s, through 26.7±14.4 moving shots: the mean moving shot duration was 28.1±9.0s, yielding a mean ablation time per unit nodule volume of 34.3±19.1s/cc. No mild nor severe complications were recorded. Post-MWA ultrasound follow-up showed a mean volume reduction ratio of 59.1±10.2% [min 44% - max 80%] at 3 months and of 70.1±8.5% [min 53% - max 91%] at 6 months, with slightly better outcomes in the AFTNs sub-group (volume reduction of 65.3±10.2%/76.0±4.0% at 3/6 months and, in all cases, normal TSH values at 3 months upon pharmacological therapy suspension). MWA treatments of benign nodules with the MONTREAL technique appeared to be safe, fast, and effective. Further research is warranted to confirm these preliminary results.

Transperineal microwave thermoablation for benign prostatic hyperplasia-related lower urinary tract symptoms in an elderly patient.

Transperineal prostate microwave thermoablation (TPMT) has been established as a safe means of treating benign prostatic hyperplasia (BPH); however, its effectiveness in addressing BPH-related lower urinary tract symptoms (LUTS) remains unexplored. This case study aims to evaluate the efficacy of TPMT in LUTS attributed to BPH. An 84-year-old man with LUTS due to BPH-induced bladder outlet obstruction, unresponsive to previous medical treatments, and failed prostate artery embolization, underwent TPMT. Three coaxial needles were positioned at the midline, right, and left sides of the hypertrophic transitional zone of the prostate. Microwave energy, with parameters determined using liver data and targeted ablation area, was applied at 2,450 MHz in continuous mode. The tissue temperature was monitored using bilateral thermocouple sensors. The patient exhibited no changes in defecation rhythm, abdominal discomfort, or anorectal pain. Temporary postoperative hematuria was promptly resolved through saline irrigation within 6 hours, and hematological evaluations showed normal results. Significant clinical improvements were observed (e.g., prostate volume, prostate-specific antigen levels) accompanied by an increase in peak flow rate. Thus, TPMT appears to be a promising intervention for bladder outlet stenosis and LUTS induced by BPH.

Emprint Microwave Thermoablation System: Bridging Thermal Ablation Efficacy between Human Patients and Porcine Models through Mathematical Correlation.

To investigate the in vivo ablation characteristics of a microwave ablation antenna in the livers of humans with tumors, a retrospective analysis of the ablation zones was conducted after applying Emprint microwave ablation systems for treatment. Percutaneous microwave ablations performed between January 2022 and September 2022 were included in this study. Subsequently, immediate post-ablation echography images were subjected to retrospective evaluation to state the long ablated diameter, short ablated diameter, and volume. The calculated ablation lengths and volume indices were then compared between in vivo and ex vivo results obtained from laboratory experiments conducted on porcine liver. The ex vivo data showed a good correlation between energy delivered and both increasing ablated dimensions (both p < 0.001) and volume (p < 0.001). The in vivo data showed a good correlation for dimensions (p = 0.037 and p = 0.019) and a worse correlation for volume (p = 0.142). When comparing ex vivo and in vivo data for higher energies, the ablated volumes grew much more rapidly in ex vivo cases compared to in vivo ones. Finally, a set of correlations to scale ex vivo results with in vivo ones is presented. This phenomenon was likely due to the absence of perfusion, which acts as a cooling system.

Percutaneous treatment of chest wall chondroid hamartomas: the experience of a single center

BackgroundThoracic mesenchymal hamartomas are rare benign lesions. Rarely symptomatic, they may compress pulmonary parenchyma, leading to respiratory distress. Although spontaneous regression has been documented, the more common outcome is progressive growth. The treatment of choice is en bloc excision of the involved portion of the chest wall, frequently leading to significant deformity.ObjectiveThe aim of our study was to describe percutaneous techniques to treat these lesions.Materials and methodsWe collected data of children with thoracic mesenchymal hamartomas who were treated at our institution from 2005 to 2020 using various percutaneous techniques. Techniques included radiofrequency thermoablation, microwave thermoablation (microwave thermoablation) and cryoablation.ResultsFive children were treated for chest wall hamartomas; one child showed bilateral localization of the mass. Two children underwent microwave thermoablation, one radiofrequency thermoablation and two cryoablation; one child treated with cryoablation also had radiofrequency thermoablation because mass volume increased after the cryoablation procedure. The median reduction of tumor volume was 69.6% (24.0–96.5%). One child treated with microwave thermoablation showed volumetric increase of the mass and underwent surgical removal of the tumor. No major complication was reported.ConclusionPercutaneous ablation is technically feasible for expert radiologists and might represent a valid and less invasive treatment for chest wall chondroid hamartoma, avoiding skeletal deformities.

Our experience with vein and hemorrhoid surgery 14 months after introducing microwave thermoablation

Our experience with vein and hemorrhoid surgery 14 months after introducing microwave thermoablation

Introduction of the microwave thermoablation (MWA) method to hemorrhoid surgery

Abstract:In addition to the traditional surgical options for hemorrhoid disease, newer treatment methods are evolving along the principle of reducing the burden on patients and providing similar or better healing. Thermo-based systems achieve the desired effect with less physical destruction. In this paper, we discuss the results of hemorrhoid surgery performed with laser and microwave devices.Patients and methods:We compare the results of 26 operations done with laser fibers and 14 operations using microwave rigid antennas.Results:In both groups, the average complaint-free period developed within 2 weeks, no significant difference was found between the two methods.Discussion:As we are always looking for new methods and surgical solutions, an option we are testing now indicates that thermal treatment can provide a quick and complete cure without the need for complicated safety requirements of laser interventions.

Long-term Effectiveness of Microwave Thermoablation in Persons With Residual Limb Hyperhidrosis: A Case Series.

Excessive sweating or focal hyperhidrosis (HH) of the residual limb in persons with amputations is thought to be a significant contributor to residual limb dermatoses, prosthesis dysfunction, and decreased quality of life. Treatment algorithms used for HH in persons without amputation do not effectively translate to residual limb HH, and research in this area is sparse. We discuss the long-term outcomes of three patients treated with microwave thermoablation (MT) on their residual limbs who had previously been unsuccessfully managed with topical antiperspirants and botulinum toxin injections. On average, there was a decrease of two points in the Hyperhidrosis Severity Scale score among the three patients 4-6 years after treatment. Although the reported side effects of post-procedure edema and prolonged time out of a prosthesis are challenging, MT of the residual limb appears to be a promising treatment modality for persons with amputation. Further investigations for standardized treatment guidelines are required to improve management of residual limb HH with MT.

Microwave Thermoablation of Colorectal Liver Metastases Close to Large Hepatic Vessels Under Pringle Maneuver Minimizes the "Heat Sink Effect".

Liver resection and thermoablation are the mainstay of the surgical management of colorectal liver metastases (CRLM). The main limitation of thermoablation is the "heat-sink" effect for nodules next to large vessels. Herein, we report the preliminary results of microwave ablation (MWA) with associated Pringle maneuver to overcome this flaw. From November 2017, we performed intraoperative MWA with Pringle maneuver for nodules ≤3cm with immediate proximity to large vessels (distance≤5mm, diameter≥3mm). We collected characteristics of nodules, surgical procedures and postoperative morbidity. Diameter of the ablation area, especially the ablative minimal margin, was calculated for each nodule. Recurrence was also evaluated. Nineteen patients underwent MWA with Pringle maneuver for 23 nodules. Nineteen (83%) ablated nodules were located in segments VI, VII and VIII, and one nodule was in segment I. Median size of nodules was 15mm (10-21). No deaths occurred. Six patients (38%) experienced complications, among them only one was subsequent to the thermal ablation. Ablative minimal margin was ≥5mm for 19 (83%) nodules. Margin was not sufficient for four nodules, among them only 2/23 cases (8.7%) of in situ recurrence occurred after 12months of median follow-up. In this preliminary study, MWA with Pringle maneuver was associated with a low related morbidity rate and favorable oncological outcome, especially when the radiological minimal margin was sufficient.

P1.05-062 Is Lung Microwave Thermoablation a Valid Alternative to Surgery in High Risk Patients? A Propensity Match Analysis

Surgery is considered the best treatment in Stage I non-small cell lung cancer. Local non–surgical therapies (radiotherapy, thermoablation) are becoming valid alternative to surgery in high risk patients (poor cardiac or pulmonary function, elderly patients). Patients submitted in our Department to Microwave thermoablation (MW) were compared with a cohort of patient submitted to lung lobectomy in the same period of time, abstracted from our database with a propensity match method. The study was retrospective on data recorded prospectively. Primary endpoint was overall survival. From June 2009 to October 2014 in our Department, 36 patients underwent MW for Stage I non-small cell lung cancer (NSCLC) or lung metastasis. From our database were abstracted 41 patients with a propensity match method, submitted to lung lobectomy. Two groups were comparable by age, diagnosis, stage and gender. MW group resulted elder than Surgery group (75,5 vs 72,2 years; p<0,001). Lesion diameter was greater in MW group (20,9 vs 26,5 cm; p<0,001). Overall survival, analyzed by actuarial survival curve, was comparable (Logrank test p=0,2). In our experience, in a propensity match evaluation, lung MW thermoablation resulted non inferior than lung lobectomy in terms of overall survival. Even though surgery is still considered the first choice in patients affected by Stage I NSCLC or lung metastasis, lung MW thermoablation is confirmed as a valid alternative treatment in high risk patients. Randomized prospective studies are mandatory.

Thermoablation therapy in the treatment of benign lesions

Depending on their size and location, some benign tumors can cause prolonged discomfort and even rupture and fatal bleeding in severe cases. Hitherto the therapeutic strategies for such lesions were observation, surgery and in selected cases transarterial embolization. Our aim was to present the possibilities of thermoablation for treating lesions. Here we present interventions of four patients in Semmelweis University Department of Transplantation and Surgery. A thyroid adenoma and a kidney angiomyolipoma were treated with radiofrequency ablation. Two patients with a liver haemangioma were treated with microwave thermoablation technique. Complications were not observed in any of the cases. In most cases, the size of the treated lesions decreased. The mean decrease in volume was 32.7%. The contrast enhancement of the lesions also decreased, the mean reduction in contrast enhancing volume was 75.3%. Thermoablational procedures for the benign tumors presented above are safe. The therapy shows excellent cosmetic results, a shorter hospital stay and quicker recovery. Orv. Hetil., 2016, 157(51), 2040-2047.

Efficacy of Ablation Therapy for Secondary Hyperparathyroidism by Ultrasound Guided Percutaneous Thermoablation

The objective of this study was to explore the value of ultrasound-guided percutaneous microwave thermoablation to treat secondary hyperparathyroidism (SHPT). One hundred and thirty-eight parathyroid glands from 56 patients with SHPT were ablated in this study. All the parathyroid glands were evaluated by real-time contrast-enhanced ultrasound before, during and after ablation. Changes in serum parathyroid hormone (sPTH) levels were measured before treatment and at 1 h, 1 wk, 1 mo and 6 mo after thermoablation treatment. All 56 cases had a 1-mo follow-up, and 34 cases had a 6-mo follow-up. The sPTH level of the 54 cases 1 mo after ablation was significantly lower than that before (p < 0.05). In the 34 cases that had a 6-mo follow-up, the sPTH levels were also significantly lower at 6 mo after ablation than before (p < 0.05). Bone pain in patients improved post-operatively (p < 0.05), but itchiness and insomnia did not improve (p > 0.05). Ultrasound-guided percutaneous microwave thermoablation is a feasible and effective non-surgical alternative treatment for SHPT patients.

Robot-assisted microwave thermoablation of liver tumors: a single-center experience.

To evaluate and compare the needle placement accuracy, patient dose, procedural time, complication rate and ablation success of microwave thermoablation using a novel robotic guidance approach and a manual approach. We performed a retrospective single-center evaluation of 64 microwave thermoablations of liver tumors in 46 patients (10 female, 36 male, mean age 66 years) between June 2014 and February 2015. Thirty ablations were carried out with manual guidance, while 34 ablations were performed using robotic guidance. A 6-week follow-up (ultrasound, computed tomography and MRI) was performed on all patients. The total procedure time and dose-length product were significantly reduced under robotic guidance (18.3 vs. 21.7 min, [Formula: see text]; 2216 vs. 2881 mGy[Formula: see text]cm, [Formula: see text]). The position of the percutaneous needle was more accurate using robotic guidance (needle deviation 1.6 vs. 3.3 mm, [Formula: see text]). There was no significant difference between both groups regarding the complication rate and the ablation success. Robotic assistance for liver tumor ablation reduces patient dose and allows for fast positioning of the microwave applicator with high accuracy. The complication rate and ablation success of percutaneous microwave thermoablation of malignant liver tumors using either CT fluoroscopy or robotic guidance for needle positioning showed no significant differences in the 6-week follow-up.

Therapy of thyroid nodules by ultrasound-guided microwave thermoablation

Therapy of thyroid nodules by ultrasound-guided microwave thermoablation

Image-guided microwave thermoablation of hepatic tumours using novel robotic guidance: an early experience.

To evaluate and compare novel robotic guidance and manual approaches based on procedural accuracy, procedural time, procedural performance, image quality as well as patient dose during image-guided microwave thermoablation. The study was prospectively performed between June 2013 and December 2013 using 70 patients. Forty randomly selected patients (group1) were treated with manual guidance and 30 patients (group2) were treated using a novel robotic guidance. Parameters evaluated were procedural accuracy, total procedural time, procedural performance, quantitative/qualitative image quality and patient dose. Two-sided Student's t test and Wilcoxon rank-sum test were used to test the significance of the data and p values less than 0.05 were considered statistically significant. Accuracy parameters were significantly higher in group2 (all p < 0.05). Total procedural time showed a mean time difference of 3min (group2 > group1; p = 0.0008). Volume CT dose index and dose-length product were significantly lower for group2 compared to group1 (all p < 0.05) for CT fluoroscopy imaging. Total procedural performance score was higher for group2 compared to group1 (p = 0.0001). Image quality parameters were insignificant between examined groups. The novel robotic guided approach improved the accuracy of targeting the target tumour, reduced patient dose and increased procedural performance (which influences the procedural safety) during ablation. • Few reports are available in the literature regarding robotic-assisted liver microwave ablation. • The robotic guided approach improved accuracy of localizing the target tumour. • Radiation dose on patients was reduced with the robotic guidance. • Numbers of insertions and readjustments were reduced, lowering chances of complications.

National Trends in Surgical Therapy for Benign Prostatic Hyperplasia in the United States (2000-2008)

To report an update of the change in usage trends for different surgical treatments of benign prostatic hyperplasia (BPH) among the United States Medicare population data from 2000-2008. The rate of usage of thermotherapy and laser therapy in the surgical treatment of BPH has been changing over the past decade in conjunction with a steady decrease of transurethral resection of the prostate (TURP). Using the 100% Medicare carrier file for the years 2000-2008, we calculated counts and population-adjusted rates of BPH surgery. Rates of TURP, thermotherapy, and laser-using modalities were calculated and compared in relation to age, race, clinical setting, and reimbursement. After years of a steady rise, the total rate of all BPH procedures peaked in 2005 at 1078/100,000 and then declined by 15.4% to 912/100,000 in 2008. TURP rates continued to decline from 670 in 2000 to 351/100,000 in 2008. Rates of microwave thermoablation peaked in 2006 at 266/100,000 and then declined 26% in 2008. Laser vaporization almost completely replaced laser coagulation and in 2008 was the most commonly performed procedure second to TURP, with the majority performed as outpatient procedures (70%) and an increasing percentage in the office (12%). Men between ages 70 and 75 had the highest rate of procedures. Reimbursement rates correlate using some but not all procedures. Racial disparities reported previously appear to have resolved. Surgical treatment of BPH continues to change rapidly. TURP continues to decline and laser vaporization is the fastest growing modality. There is a big shift toward outpatient/office procedures. Reimbursement rates do not appear to have a consistent effect on usage.

Laparoscopic Microwave Ablation and Enucleation of Small Renal Masses: Preliminary Experience

Advancements in imaging and laparoscopy have led to the expansion of minimally invasive techniques in the ablation of small renal masses (SRMs). We report the results of a study aimed at assessing the efficacy of thermoablative microwave (MW) effects on SRMs and the haemostatic as well as necrotic MW effects on the parenchyma surrounding the neoplasm.From November 2008 to October 2010, 10 patients with SRMs underwent laparoscopy-guided Tru-Cut biopsy, MW tumour ablation, and enucleation. Mean age was 66 yr (range: 46–84 yr). Mean renal tumour diameter was 2.75cm (range: 1.3–4.2cm). MW antennas were applied one to three times depending on tumour volume, location, and shape. After MW thermoablation, laparoscopic enucleation was performed to evaluate the histopathologic and haemostatic effects of MW.The mean MW antenna application time was 14.1min (range: 4–30min). Enucleation did not require renal pedicle clamping in any of the cases because no significant bleeding took place. Preablation pathology revealed clear cell renal carcinoma of Fuhrman grade I–II in all cases. Postablation pathology showed extensive coagulative necrosis without skipped tumour areas. No intra- or postoperative complications were reported.Histopathologic effects on SRMs provide consistent proof of principle for future studies.

In vivo microwave‐induced porcine kidney thermoablation: results and perspectives from a pilot study of a new probe

To test the in vivo effects (toxicity, completeness of necrosis, dimensions of the lesion) of microwave thermoablation on porcine kidneys, using the Amica Probe v3 (Hospital Service SpA, Aprilia, Italy), in a refrigerated 17-G microwave applicator, that can be used to induce a spherical necrotic area. Six pigs were used; each kidney was treated, with no kidney pedicle clamping, by microwave thermoablation at least in three different zones with different exposure times and power, during open surgery. Twelve kidneys had 32 microwave thermoablations overall. The kidneys were then surgically removed, and necrotic lesions measured and evaluated microscopically. The sphericity index (SI) was also calculated to evaluate lesion reproducibility. Areas of renal tissue that were missed were then microscopically evaluated by NADH in vivo staining. In all, 32 thermoablations were applied; the mean (sd) lesion diameter ranged from 1.2 (0.3) to 4.2 (0.1) cm and changed in relation to both power and time of exposure. The 50-W power particularly induced necrotic renal lesions ranging from 1.9 (0.2) to 4.2 (0.1) cm as a function of the time of exposure and the optimal SI (1.04). Pathological evaluation showed no skipped areas in the context of the lesion, or healthy kidney tissue damage close to necrotic lesions. Thermoablation with the Amica probe is safe and showed excellent in vivo effects in this porcine model. Increasing the exposure time at 50 W power could be a useful percutaneous minimally invasive treatment for small solid masses (<4.2 cm), avoiding the risk of missing tumour areas or kidney parenchymal damage from microwave treatment.

IN VIVO MICROWAVE-INDUCED PORCINE KIDNEY THERMOABLATION: RESULTS AND PERSPECTIVES FROM PILOT STUDY OF A NEW PROBE?

OBJECTIVE To test the in vivo effects (toxicity, completeness of necrosis, dimensions of the lesion) of microwave thermoablation on porcine kidneys, using the Amica Probe v3 (Hospital Service SpA, Aprilia, Italy), in a refrigerated 17-G microwave applicator, that can be used to induce a spherical necrotic area. PATIENTS AND METHODS Six pigs were used; each kidney was treated, with no kidney pedicle clamping, by microwave thermoablation at least in three different zones with different exposure times and power, during open surgery. Twelve kidneys had 32 microwave thermoablations overall. The kidneys were then surgically removed, and necrotic lesions measured and evaluated microscopically. The sphericity index (SI) was also calculated to evaluate lesion reproducibility. Areas of renal tissue that were missed were then microscopically evaluated by NADH in vivo staining. RESULTS In all, 32 thermoablations were applied; the mean (sd) lesion diameter ranged from 1.2 (0.3) to 4.2 (0.1) cm and changed in relation to both power and time of exposure. The 50-W power particularly induced necrotic renal lesions ranging from 1.9 (0.2) to 4.2 (0.1) cm as a function of the time of exposure and the optimal SI (1.04). Pathological evaluation showed no skipped areas in the context of the lesion, or healthy kidney tissue damage close to necrotic lesions. CONCLUSIONS Thermoablation with the Amica probe is safe and showed excellent in vivo effects in this porcine model. Increasing the exposure time at 50 W power could be a useful percutaneous minimally invasive treatment for small solid masses (<4.2 cm), avoiding the risk of missing tumour areas or kidney parenchymal damage from microwave treatment.

Transperineal Microwave Thermoablation in Patients with Obstructive Benign Prostatic Hyperplasia: A Phase I Clinical Study with a New Mini-Choked Microwave Applicator

To evaluate the tolerability and safety of a newly designed probe for trans-perineal microwave thermoablation (TPMT) of the prostate in patients with benign prostatic hyperplasia (BPH), and the in vivo microwave effects on prostatic tissue. Nine patients with obstructive BPH who were candidates for open prostatectomy were selected for this study. Under local anesthesia and transrectal ultrasound monitoring, all patients underwent a single standardized application of TPMT. The visual analog scale (VAS) and Short Form-36 health survey (SF-36) questionnaire were administered to each patient prior to, during, and 1 month after TPMT in order to evaluate pain and quality of life. Then the International Index of Erectile Function (IIEF-5) and International Prostate Symptom Score (IPSS) questionnaires were administered to each patient at baseline and 1 month after prostatectomy in order to evaluate sexual and urinary function, respectively. Then all patients were divided into three groups and underwent open prostatectomy 7, 15, and 30 days after TPMT, respectively. The prostatic adenomas were then evaluated by a pathologist. No adverse events from TPMT treatment were noted. In particular, no patients reported local, pelvic, or abdominal pain during the procedure or subsequent alterations of defecation rhythm, ano-rectal/intestinal problems, or hematuria. No differences in quality of life or in sexual function were reported. The diameters of the lesions obtained with TPMT treatment ranged from 16 to 18.1 mm in all patients. Quasi-spheroid lesions with a well-defined area of complete coagulative necrosis were documented in all removed adenomas 7, 15, and 30 days after TMPT. The AMICA-PROBE is a safe, well-tolerated, and repeatable method to treat BPH with microwave thermotherapy. The spheroid lesions obtained demonstrated the maximal control over the radial and longitudinal coagulative effects of the therapy. Phase II studies are needed to further evaluate the efficacy of this new probe.