To explore the safety and efficacy for radiofrequency ablation of paroxysmal supraventricular tachycardia (PSVT) guided by Carto Univu three-dimensional mapping system.
 Methods: A total of 99 patients with PSVT underwent radiofrequency catheter ablation (RFCA) were assigned to a Carto Univu group (51 patients) and a two-dimensional X-ray group (48 patients) according to the mapping method. The operation time, X-ray exposure time, X-ray exposure dose, dose area product (DAP), operation success rate and complication rate were compared between the two groups.
 Results: The Carto Univu group and the two-dimensional X-ray group were not significant difference in the operation time, the X-ray exposure time of placing catheter, the X-ray DAP of placing catheter, the number of discharge, the discharge power, and the total discharge time (P>0.05). The mapping and ablation time, total exposure time, mapping and ablation DAP and total DAP in the Carto Univu group were significantly lower than those in the two-dimensional X-ray group (P<0.01). In the right accessory pathway cases, the mapping and ablation DAP and the total DAP in the Carto Univu group decreased compared with X-ray group (P<0.05), but it decreased more profound (P<0.01) in the left accessory pathway cases and the dual atrioventricular nodal pathways cases. Seven cases in the Carto Univu group achieved "zero X-ray", including 5 cases of the dual atrioventricular nodal pathways and 2 cases of the left accessory pathway. The immediate success rate for the two groups was 100%. After 3-12 months of follow-up, there was no recurrence in the Carto Univu group but 3 suspected recurrences in the two-dimensional X-ray group. In addition, no complications occurred in the two groups. 
 Conclusion: Carto Univu electroanatomic mapping system can guide PSVT safely and effectively during radiofrequency ablation and reduce radiation exposure to both doctors and patients. It is especially suitable for dual atrioventricular nodal pathways, which may even achieve "zero X-ray". Perhaps Carto Univu will be the first choice for RFCA of dual atrioventricular nodal pathways.
Catheter Ablation ; instrumentation ; methods ; Humans ; Imaging, Three-Dimensional ; instrumentation ; methods ; Operative Time ; Radiation Exposure ; prevention & control ; statistics & numerical data ; Radiography ; statistics & numerical data ; Recurrence ; Tachycardia, Supraventricular ; diagnostic imaging ; surgery ; Treatment Outcome

OBJECTIVETo explore the therapeutic effect of radiofrequency ablation for tongue venous malformation( VM).

METHODSFrom July 2013 to July 2014, 30 cases with tongue VM (local or diffuse) were retrospectively analyzed. 23 cases underwent radiofrequency ablation treatment. The radiofrequency electrode tip(0. 5 mm in diameter) was inserted into the lesion 1 mm below the bottom with 25 W in power and 15-30 s of pulse. The treatment was repeated when the electrode tip was removed back every 1 mm. Multi-point treatment was performed.

RESULTS15 cases with unilateral VM were completely healed after one-stage radiofrequency ablation. 8 cases with bilateral VM received two-stage radiofrequency ablation with a 3-6 months of interval. Among the 8 cases, completely healing was achieved in 5 cases, partial VM residue happened in 3 cases due to its diffuse lesion and reservation of tongue function. 23 cases were followed up for 3 month to 1.5 years. Good cosmetic and functional results was achieved in 20 cases with no relapse. Partial VM residue was left in 3 cases.

CONCLUSIONSRadiofrequency ablation can effectively treat tongue VM with minimal morbidity and good cosmetic appearance. It also avoids the disadvantages of surgery.

Catheter Ablation ; instrumentation ; methods ; Electrodes ; Humans ; Retrospective Studies ; Tongue ; blood supply ; Treatment Outcome ; Vascular Malformations ; surgery ; Veins ; abnormalities

OBJECTIVE: To determine the in vivo efficiency of monopolar radiofrequency ablation (RFA) using a dual-switching (DS) system and a separable clustered (SC) electrode to create coagulation in swine liver. MATERIALS AND METHODS: Thirty-three ablation zones were created in nine pigs using a DS system and an SC electrode in the switching monopolar mode. The pigs were divided into two groups for two experiments: 1) preliminary experiments (n = 3) to identify the optimal inter-electrode distances (IEDs) for dual-switching monopolar (DSM)-RFA, and 2) main experiments (n = 6) to compare the in vivo efficiency of DSM-RFA with that of a single-switching monopolar (SSM)-RFA. RF energy was alternatively applied to one of the three electrodes (SSM-RFA) or concurrently applied to a pair of electrodes (DSM-RFA) for 12 minutes in in vivo porcine livers. The delivered RFA energy and the shapes and dimensions of the coagulation areas were compared between the two groups. RESULTS: No pig died during RFA. The ideal IEDs for creating round or oval coagulation area using the DSM-RFA were 2.0 and 2.5 cm. DSM-RFA allowed more efficient RF energy delivery than SSM-RFA at the given time (23.0 +/- 4.0 kcal vs. 16.92 +/- 2.0 kcal, respectively; p = 0.0005). DSM-RFA created a significantly larger coagulation volume than SSM-RFA (40.4 +/- 16.4 cm3 vs. 20.8 +/- 10.7 cm3; p < 0.001). Both groups showed similar circularity of the ablation zones (p = 0.29). CONCLUSION: Dual-switching monopolar-radiofrequency ablation using an SC electrode is feasible and can create larger ablation zones than SSM-RFA as it allows more RF energy delivery at a given time.
Animals ; Catheter Ablation/*instrumentation/*methods ; *Electrodes ; Feasibility Studies ; Liver/*surgery ; Male ; Sus scrofa ; Time Factors

OBJECTIVE: To compare the in-vitro efficiency of dual-switching monopolar (DSM) radiofrequency ablation (RFA) using a separable clustered electrode (Octopus(R) electrodes) with consecutive monopolar (CM) and switching monopolar (SM) RFA techniques to create an ablative zone in the explanted bovine liver. MATERIALS AND METHODS: For DSM-RFA, we used a prototype, three-channel, dual generator RFA Unit and Octopus(R) electrodes with three, 17 gauge internally cooled electrodes. The RFA Unit allowed simultaneous radiofrequency (RF) energy delivery to two electrodes of the Octopus(R) electrodes as well as automatic switching among the three electrode pairs according to the impedance changes. RF energy was sequentially applied to one of the three electrodes for 24 minutes (group A; CM mode, n = 10) or alternatively applied for 12 minutes (group B; SM mode, n = 10) or concurrently applied to a pair of electrodes for 12 minutes (group C; DSM mode, n = 10) in explanted bovine livers. Changes in the impedance and current during RFA as well as the dimensions of the thermal ablative zones were compared among the three groups. RESULTS: The mean, delivered RF energy amounts in groups A, B, and C were 63.15 +/- 8.6 kJ, 72.13 +/- 5.4 kJ, and 106.08 +/- 13.4 kJ, respectively (p < 0.001). The DSM mode created a significantly larger ablation volume than did the other modes, i.e., 68.1 +/- 10.2 cm3 (group A), 92.0 +/- 19.9 cm3 (group B), and 115.1 +/- 14.0 cm3 (group C) (p < 0.001). The circularity in groups A, B, and C were 0.84 +/- 0.06, 0.87 +/- 0.04 and 0.90 +/- 0.03, respectively (p = 0.03). CONCLUSION: DSM-RFA using Octopus(R) electrodes can help create large ablative zones within a relatively short time.
Analysis of Variance ; Animals ; Catheter Ablation/*instrumentation/methods ; Cattle ; Electric Impedance ; Electrodes ; Equipment Design ; Liver/*surgery

OBJECTIVETo compare the therapeutic effect of traditional and modified apocrine gland removal surgery with the combination of high radiofrequency knife for axillary osmidrosis.

METHODS105 cases (210 sides) were randomly divided into traditional group A (38 cases, 76 sides) and modified group B (67 cases, 134 sides). The wound healing and complications were recorded. The clinical effect was followed up for 6-12 months after operation.

RESULTSNo flap necrosis happened in both groups. The cure rate was 82.89% (63/76)) and 92.54% (124/134) in group A and B, respectively, which was significantly different (P < 0.05). The effective rate of hair removal in group A and B was 42. 1%, 59. 7% (P < 0. 05). There is no markedly difference between the two groups in postoperative hematoma( P >0.05). The recurrence rate in group A and B was 9.21% and 1.49% respectively, with a statistically difference between them (P < 0.05).

CONCLUSIONSModified apocrine gland removal surgery with the combination of high radiofrequency knife can expose the apocrine gland better and the gland, as well as hair, can be removed in the most. The residue hair and recurrency of osmidrosis are very lower.

Adolescent ; Adult ; Apocrine Glands ; surgery ; Catheter Ablation ; instrumentation ; methods ; Female ; Humans ; Hyperhidrosis ; surgery ; Male ; Middle Aged ; Treatment Outcome ; Young Adult

OBJECTIVE: To determine in vivo efficacy of radiofrequency ablation (RFA) in porcine liver by using 15-gauge Octopus(R) (15-G Octopus(R)) electrodes to create a large coagulation. MATERIALS AND METHODS: A total of 18 coagulations were created by using a 180-W generator and 15-G Octopus(R) electrodes during laparotomy, performed in 14 pigs. Coagulation necrosis was created in the pig livers by the use of one of three RFA protocols: 1) group A, monopolar RFA using a 15-G Octopus(R) electrode with a 5-mm inter-electrode distance (n = 4); 2) group B, monopolar RFA using a 15-G Octopus(R) electrode with a 10-mm inter-electrode distance (n = 6); and 3) group C, switching monopolar RFA using two 15-G Octopus(R) electrodes (n = 8). The energy efficiency, shape, maximum and minimum diameters (Dmx and Dmi), and the volume of the coagulation volume were measured in each group. The Summary statistics were obtained and Mann-Whitney test was were performed. RESULTS: The mean ablated volume of each group was 49.23 cm3 in A, 64.11 cm3 in B, and 72.35 cm3 in C. The mean Dmx and Dmi values were 5.68 cm and 4.58 cm in A and 5.97 cm and 4.97 cm in B, respectively. In group C, the mean diameters of Dmx and Dmi were 6.80 cm and 5.11 cm, respectively. The mean ratios of Dmi/Dmx were 1.25, 1.20, and 1.35 in groups A, B, and C, respectively. There was one animal death during the RFA procedure, the cause of which could not be subsequently determined. However, there were no other significant, procedure-related complications during the seven-hour-delayed CT scans. CONCLUSION: RFA procedures using 15-G Octopus(R) electrodes are useful and safe for creating a large ablation in a single electrode model as well as in the multiple electrodes model.
Animals ; Catheter Ablation/*methods ; Electrocoagulation/*instrumentation ; *Electrodes ; Liver/radiography/*surgery ; Statistics, Nonparametric ; Swine ; Tomography, X-Ray Computed

OBJECTIVE: To prospectively evaluate the safety and short-term therapeutic efficacy of switching monopolar radiofrequency ablation (RFA) with multiple electrodes to treat medium-sized (3.1-5.0 cm), hepatocellular carcinomas (HCC). MATERIALS AND METHODS: In this prospective study, 30 patients with single medium-sized HCCs (mean, 3.5 cm; range, 3.1-4.4 cm) were enrolled. The patients were treated under ultrasonographic guidance by percutaneous switching monopolar RFA with a multichannel RF generator and two or three internally cooled electrodes. Contrast-enhanced CT scans were obtained immediately after RFA, and the diameters and volume of the ablation zones were then measured. Follow-up CT scans were performed at the first month after ablation and every three months thereafter. Technical effectiveness, local progression and remote recurrence of HCCs were determined. RESULTS: There were no major immediate or periprocedural complications. However, there was one bile duct stricture during the follow-up period. Technical effectiveness was achieved in 29 of 30 patients (97%). The total ablation time of the procedures was 25.4 +/- 8.9 minutes. The mean ablation volume was 73.8 +/- 56.4 cm3 and the minimum diameter was 4.1 +/- 7.3 cm. During the follow-up period (mean, 12.5 months), local tumor progression occurred in three of 29 patients (10%) with technical effectiveness, while new HCCs were detected in six of 29 patients (21%). CONCLUSION: Switching monopolar RFA with multiple electrodes in order to achieve a sufficient ablation volume is safe and efficient. This method also showed relatively successful therapeutic effectiveness on short-term follow up for the treatment of medium-sized HCCs.
Adult ; Aged ; Carcinoma, Hepatocellular/radiography/*surgery ; Catheter Ablation/instrumentation/*methods ; Contrast Media/diagnostic use ; Disease Progression ; Electrodes ; Female ; Humans ; Iohexol/analogs & derivatives/diagnostic use ; Kaplan-Meier Estimate ; Liver Neoplasms/radiography/*surgery ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; Prospective Studies ; Tomography, X-Ray Computed/*methods ; Ultrasonography, Interventional

Radiofrequecy ablation is the most widely used local ablative therapy for both primary and metastatic liver tumours. However, it has limited application in the treatment of large tumours (tumours >3cm) and multicentric tumours. In recent years, many strategies have been developed to extend the application of radiofrequency ablation to large tumours. A promising approach is to take advantage of the rapid advancement in imaging and robotic technologies to construct an integrated surgical navigation and medical robotic system. This paper presents a review of existing surgical navigation methods and medical robots. We also introduce our current developed model - Transcutaneous Robot-assisted Ablation-device Insertion Navigation System (TRAINS). The clinical viability of this prototyped integrated navigation and robotic system for large and multicentric tumors is demonstrated using animal experiments.
Catheter Ablation ; instrumentation ; methods ; Humans ; Imaging, Three-Dimensional ; Liver ; Liver Neoplasms ; pathology ; surgery ; therapy ; Robotics ; Surgery, Computer-Assisted ; instrumentation ; methods ; Surgical Procedures, Operative ; methods

OBJECTIVETo investigate the feasibility and safety of ultrasound-guided transrectal microwave ablation in reducing the prostate volume.

METHODSUltrasound-guided transrectal microwave ablation of both sides of the prostate was conducted on experimental dogs with the output volume of 30W for 120 seconds. The dogs were sacrificed on the very day of the ablation, and the prostate and its surrounding tissues were excised for observation of the thermal lesions and pathological examination.

RESULTSA total of 12 thermal lesions were achieved on the two sides of the prostate. The ultrasonogram manifested dense echo and increasing extent in the ablated area, and then an irregular heterogeneous echogenic area and clearly differentiated margin. Pathological examination of the gross specimen showed a little stagnant blood under the rectal mucous, the urethra and bladder not injured, and the thermal lesions elliptical, clearly margined and with the mean size of (0.94 +/- 0.30) cm3.

CONCLUSIONUltrasound-guided transrectal microwave ablation of the prostate can effectively cause coagulative necrosis of the local tissue without inflicting thermal injury upon the surrounding tissues. Conventional grayscale ultrasound can give a real-time'display of the extent of thermal lesion and the whole process of the ablation.

Animals ; Catheter Ablation ; instrumentation ; methods ; Dogs ; Feasibility Studies ; Male ; Microwaves ; Prostate ; diagnostic imaging ; Rectum ; diagnostic imaging ; Ultrasonography

OBJECTIVETo analyze the transmural lesions of different parts of the pig heart atrium received different times of ablation applied with Atricure bipolar radiofrequency system.

METHODSSix fresh (ex vivo time<20 min) pig hearts with atrium preserved intact were used as the experimental objects and experimental groups were divided according to the ablation position. The Atricure bipolar radiofrequency system was applied in the ablation of the parts of the atrium, such as posterior wall of left atrium, anterior wall of left atrium, anterior wall of right atrium and posterior wall of left atrium close to mitral posterior ring. Ablate the position of the atrium lengthened about 2.0 cm with the same thickness with an interval of 0.5 cm for 4 times respectively, also recording the time of every ablation. For each part and each time of ablation, the ablated atrial tissue was preserved with 4% formaldehyde and 5% glutaraldehyde, and was sent for observation under light microscope and transmission electron microscope. The ablation time and lesion were analyzed statistically.

RESULTSIn the same position of the atrium, ablation time decreased with the times of the ablation, in different position of the atrium with same time of ablation, time showed a positive proportion with the thickness of the atrium.

CONCLUSIONSAtricure bipolar radiofrequency system is very safe and efficient, also convenient for manipulation. With regard to the relatively thinner part of the atrium, such as posterior wall and anterior wall of left atrium, at least two times of ablation can ensure transmural lesion of the atrial tissue, but to the position of the atrium such as anterior wall of right atrium and posterior wall of left atrium close to mitral posterior ring, 3 to 4 times of ablation can ensure transmural lesion of the atrial tissue.

Animals ; Catheter Ablation ; instrumentation ; methods ; Heart Atria ; pathology ; In Vitro Techniques ; Swine ; Time Factors