Bipolar Radiofrequency Probe Research Articles

Use of monopolar and bipolar radiofrequency probes for treatment of cutaneous leiomyoma

Abstract Cutaneous leiomyomas are tumors of smooth muscle origin which appear as erythematous papules and nodules that are mostly painful to touch. Although surgical excision is the gold standard treatment, other destructive methods such as electrodessication, cryotherapy or carbon-dioxide laser may also be done for cure. Our patient presented with painful cutaneous leiyomyomas which resolved well with radiofrequency ablation done with two different techniques using monopolar and bipolar radiofrequency probes. There was no recurrence at 8 months follow-up.

Arthroscopic removal of osteochondral fragments located within the condylar fossa of the third metacarpus/metatarsus in Thoroughbred yearlings.

To describe an arthroscopic technique for the removal of osteochondral fragments located within the condylar fossa of the third metacarpal/tarsal bone. Retrospective study. Thoroughbred yearlings (n=11). Osteochondral fragments located within the condylar fossa of the third metacarpal/tarsal bone identified during presale radiographic examination were removed via arthroscopy, assisted with ultrasonography in select cases. Complete fragment removal was confirmed by intraoperative radiography. Fragments were successfully removed using rongeurs following dissection of soft tissue attachments using a bipolar radiofrequency probe. No postoperative complications occurred. An ipsilateral arthroscopic and instrument portal coupled with ultrasound assistance and a radiofrequency probe allowed for successful removal of fragments located within the condylar fossa of the third metacarpal/tarsal bone. The technique allowed for the removal of the unstable osteochondral fragment and associated physical debris. The described surgical technique enables the removal of osteochondral fragments located within the condylar fossa of the third metacarpal/tarsal bone with minimal disruption to the surrounding soft tissues.

Bipolar Radiofrequency Ablation Does Not Result in Full-Thickness Articular Cartilage Penetration: An Ex Vivo Bovine Investigation

PurposeTo evaluate the depth of penetration of manufacturer-recommended bipolar radiofrequency (BRF) output in healthy hyaline cartilage.MethodsTwo matched knees from a bovine specimen were harvested for immediate testing. BRF probes were used to treat the articular cartilage in a hydrated noncontact technique employing a 1-mm spacer on patellar, condylar, and trochlear surfaces. Two manufacturer-recommended ablate power settings were evaluated to analyze the effect of varying power outputs on the depth of penetration. Surfaces were randomized and treated with BRF ablate setting 3 (AB-3), 4 (AB-4), or left untreated as a control (12 grids each). Slices were extracted from treatment zones and subjected to fluorescein diacetate and propidium iodide viability stains and analyzed with confocal light microscopy. A general linear model was used to determine whether variables such as ablation setting, cartilage location, and side significantly influenced depth of penetration (DoP) and cartilage thickness (Minitab 19, Chicago, IL). When significance was noted (P < .05), a post hoc-Tukey test was used to investigate specific differences.ResultsAB-3 had a 50.9% lower mean DoP than AB-4 (P = .006). The mean DoP was 237.9 ± 140.6 μm for AB-3 and 484.1 ± 267.0 μm for AB-4. Median DoP values were 243.2 ± 149.5 μm for AB-3, 51.2% lower than the 498.4 ± 286.0 μm for AB-4. The mean maximum DoP for AB-3 was 302.4 ± 167.8 μm, 50.6% lower than AB-4 value of 611.6 ± 299.1 μm. Analysis of the cartilage thickness confirmed there was no difference in overall cartilage thickness used for AB-3 versus AB-4 testing (P = .953).ConclusionsThe RF probe ablate power setting AB-3 demonstrated significantly less articular cartilage depth of penetration than the AB-4 setting in a healthy bovine model.Clinical RelevanceDebridement of chondral lesions with plasma BRF is of clinical interest. The presented study adds basic science information for those considering performing this technique.

Transforaminal Endoscopic Lumbar Discectomy and Foraminotomy with Modified Radiofrequency Nerve Stimulator and Continuous Electromyography Under General Anesthesia

Transforaminal endoscopic lumbar approaches involve working in Kambin's triangle. These procedures are performed on awake patients or under general anesthesia with continuous electromyography. Potential morbidity of this approach includes injury to exiting and traversing nerve roots, as substantial dissection or cauterization of overlying tissues is required for visualization. We developed a novel connection system that accepts input from a bipolar radiofrequency probe to allow direct nerve stimulation in conjunction with electromyography. This study included 30 consecutive patients undergoing transforaminal endoscopic lumbar approaches for discectomies (73.3%), foraminal stenosis (23.3%), or lateral recess stenosis (3.3%). Demographic, operative, and outcomes data were collected. Average age of patients was 61.4 years, and the L4-5 segment was most commonly treated (65.6%). Electrophysiologic mapping of the exiting nerve root was attempted in 28 patients with an average stimulation threshold of 8.6 ± 0.9 mA. Mapping of the traversing nerve root was attempted in 12 patients with an average stimulation threshold of 6.0 ± 0.8 mA. There were no instances of new postoperative sensorimotor deficits or dysesthesia. These findings persisted through mean and median follow-up of 294 days and 165 days, respectively. No patient required subsequent lumbar surgery. Our modified instrumentation and technique allow for accurate identification of the exiting and traversing nerve roots with minimal changes to the workflow of transforaminal endoscopic lumbar approaches. Modification of a bipolar radiofrequency device connection arrangement is simple, inexpensive, and reusable. In this study, no patients developed injury or pain related to nerve root dysfunction.

Transforaminal endoscopic system technique for discogenic low back pain: A prospective Cohort study

ObjectiveTo investigate the clinical outcomes of transforaminal endoscopic system(TESSYS) for discogenic low back pain(DLBP). Methods62 consecutive patients with one-level DLBP applying to the including criteria underwent TESSYS from January 2010 to December 2013. These patients included 38 males and 24 females with a mean age of 42.7 ± 5.4 years (range, 18–73 yr) and a mean follow-up of 26.8 ± 4.2 months (range, 12–48 months). The visual analog scale (VAS) were used for back pain, the Oswestry Disability Index (ODI) for lumbar function, and the modified MacNab criteria for clinical global outcomes. Results24 patients showed only inflammatory granuloma on annulus tear tissues(Group A), 16 patients showed no annulus tear but adhesion and inflammatory granuloma among the intracanal annulus fibrous(AF), posterior longitudinal ligament(PLL) and the abdomen side of the dura sac(Group B) and 22 patients showed both(Group C). Concordant pain could be triggered by touching the inflammation with the bipolar radiofrequency probe. The success rate (excellent and good) of group C was much higher than A and B(P < 0.05). The whole success rate was 75.8%. Of the 4 patients with poor result, 2 refused further surgical treatment and showed either no improvement or worsening. The remaining 2 patients had spinal fusion surgery and achieved better results. VAS and ODI had significantly improved after surgery (P < 0.01). No unexpected complications were seen. ConclusionTEEYS is an effective method in treating DLBP and the complete management of the inflammatory granuloma was the key point in achieving better results.

Mechanical Effects of Heat Exposure From a Bipolar Radiofrequency Probe on Suture Under Simulated Arthroscopic Conditions

To determine conditions for the safe use of radiofrequency (RF) tissue ablation probes that avoid damaging suture material. Four sutures made of 3 different materials commonly used in arthroscopic procedures were analyzed in a saline bath related to effects of RF-produced heat by proximity, duration, and intensity settings measuring burn-through time and ultimate load to failure. The parameters tested were electrode-to-suture distance, power setting, and the presence of tendon tissue or metallic anchor eyelets. Outcome variables were the burn-through time and the ultimate failure load of differently treated suture samples. Mean burn-through time for suture in direct contact with the RF probe ranged from 57.2 to 14.7seconds for ultra-high-molecular-weight polyethylene (UHMWPE) sutures, 1.1seconds for polydioxanone suture, and 0.8seconds for polyethylene terephthalate suture. One of the UHMWPE sutures was capable of withstanding 3seconds of direct contact with the RF probe without any compromise in tensile strength. No suture material tested had any mechanical change as long as the RF probe was kept 1mm from the suture. Heat from RF tissue ablation probes can cause undetected damage. High-strength UHMWPE sutures were less sensitive to an RF treatment than polyester sutures. The use of different test substrates did not significantly influence the burn through time. Heat from RF probes can damage some suture material if direct contact is made even briefly. The use of RF devices may be safe for the suture when a distance between probe and suture of >1mm is maintained. Suture made from UHMWPE may tolerate up to 3seconds of RF probe contact and not sustain significant damage. Surgeons must use great care when using RF devices in the vicinity of suture placement.

Working conditions of bipolar radiofrequency on human articular cartilage repair following thermal injury during arthroscopy

Background The thermal injury during bipolar radiofrequercy results in chondrocyte death that limits cartilage repair. The purpose was to determine the effects of various factors of bipolar radiofrequency on human articular cartilage after thermal injury, offering suitable working conditions for bipolar radiofrequency during arthroscopy. Methods Osteochondral explants from 28 patients undergoing total knee arthroplasty (TKA) in Department of Orthopaedic, Peking University Reople's Hospital from October 2013 to May 2014, were harvested and treated using bipolar radiofrequency in a light contact mode under the following conditions: various power setting of levels 2, 4 and 6; different durations of 2 seconds, 5 seconds and 10 seconds; irrigation with fluids of different temperatures of 4°C, 22°C, and 37°C; two different bipolar radiofrequency probes ArthroCare TriStar 50 and Paragon T2. The percentage of cell death and depth of cell death were quantified with laser confocal microscopy. The content of proteoglycan elution at different temperatures was determined by spectrophotometer at 530 nm. Results Chondrocyte mortality during the treatment time of 2 seconds and power setting of level 2 was significantly lower than that with long duration or in higher level groups (time: P=0.001; power: P=0.001). The percentage of cell death after thermal injury was gradually reduced by increasing the temperature of the irrigation solutions (P=0.003), the depth of dead chondrocytes in the 37°C solution group was significantly less than those in the 4°C and 22°C groups (P=0.001). The proteoglycan elution was also gradually reduced by increasing the temperature (P=0.004). Compared with the ArthroCare TriStar 50 group, the percentage of cell death in the Paragon T2 group was significantly decreased (P=0.046). Conclusions Thermal chondroplasty with bipolar radiofrequency resulted in defined margins of chondrocyte death under controlled conditions. The least cartilage damage during thermal chondroplasty could be achieved with lower power, shorter duration, suitable temperature of irrigation solutions and chondroprotective probes. The recommendations for the use of bipolar radiofrequency to minimize cartilage damage could be achieved with a power setting of level 2, treatment duration of 2 seconds, suitable fluid temperature (closer to body temperature of 37°C) and chondroprotective Paragon T2 probes.

Treatment of painful extraspinal bone metastases with percutaneous bipolar radiofrequency under local anesthesia: feasibility and efficacy in twenty-eight cases.

To retrospectively assess the feasibility and efficacy of bipolar radiofrequency ablation (RFA) of extraspinal osseous neoplasms performed under local anesthesia. Twenty-eight patients (21 males, 7 females; mean age, 61.2 years) underwent RFA under local anesthesia between 2005 and 2012. All included patients suffered from painful osseous metastases refractory to previous medication; all presented with end-stage neoplasms. RFA was performed under computed tomography (CT) guidance with bipolar radiofrequency probes. All procedures were performed under local anesthesia (lidocaine-ropivacaine) and nitrous oxide ventilation. Intravenous injection of paracetamol was performed throughout the procedure with or without intravenous injection of nalbuphin. Tolerance of procedure was recorded. Pain efficacy was evaluated on visual anologue scale (VAS) scores at day 7, 1 month, and at 6 months after the procedure. Technical success rate was 100%. The procedure was considered not painful in 4 cases and tolerable in 20 cases. Average procedural time was 23.1 minutes. Mean VAS score prior to RFA was 8.1/10. Significant decrease of pain was noted at day 7 (3.3/10, p<0.001, n=27), 1 month (3.8/10, p<0.001, n=27), and 6 months (4.5/10, p<0.001, n=13). No complications were noted. Bipolar RFA of osseous metastases is a safe and effective treatment for refractory bone metastases. Its feasibility under local anesthesia should broaden the indications.

Biliary drainage combined with intraductal radiofrequency ablation for treatment of malignant biliary obstruction

Objective To evaluate the safety and clinical effectiveness of biliary drainage combined with endoscopic intraductal radiofrequency ablation(RFA) for treatment of malignant biliary obstruction. MethodsEighteen patients with malignant biliary obstruction,who were unsuitable for surgical resection,were prospectively selected for this study.During endoscopic retrograde cholangiopancreatography(ERCP),when biliary cannulation was successfully done,a bipolar radiofrequency probe was introduced into the bile duct via a guide wire.RFA was done under fluoroscopy,which was followed by stent placement.The patients were closely observed and followed up after procedure. ResultsAll patients received successful RFA and biliary drainage.Twelve patients were implanted with plastic stents and 6 with metal stents;3 patients were also implanted with pancreatic stents.Four patients developed mild complications(2 cholangitis and 2 pancreatitis),which were controlled by conservative therapy.Jaundice was promptly controlled in 61%(11/18) patients.The patients were followed up for a median of 10.9 months(range 2.0-15.4 months).The stent patency rates of 3 months,6 months and 12 months were 87%(13/15),64%(9/14) and 25%(2/8),respectively.The 6 month-and 12 month-survival rates were 67%(8/12) and 50%(4/8),respectively. ConclusionBiliary drainage combined with endoscopic intraductal RFA is technically feasible and safe for treatment of malignant biliary obstruction.

Bipolar Radiofrequency Ablation: Development of a New Expandable Device

To test the performance of an expandable bipolar probe as a simple technical solution for extending the coagulation volume. On the basis of a commercially available monopolar radiofrequency (RF) probe (LeVeen), an expandable bipolar RF probe was developed by integrating a second electrode into the probe shaft. The influence of length on the second electrode, and the distance between both electrodes and generator output was investigated by performing ten ablations for each condition on a freshly excised bovine liver. Macroscopically quantified coagulation volumes, lesion shape characteristics, and procedure durations were recorded. Results of the prototype featuring the optimal configuration were compared to the original LeVeen probe and commonly used bipolar RF probe (CelonLabPower). Extension of the shaft electrode length, increasing distance between the shaft electrode and the tip electrode, and reduction of generator output resulted in increasing coagulation volumes. The coagulation volumes the prototype generated were significantly smaller and more elliptically shaped than the monopolar probe (9.4 ± 1.5 cm(3) vs. 12.1 ± 1.6 cm(3)), but were larger than the commercially available bipolar RF probe (vs. 7.3 ± 0.5). The procedure duration of the prototype was comparable to the monopolar probe (467 ± 31 s vs. 464 ± 17 s) and shorter than the bipolar probe (vs. 2009 ± 444 s). In comparison to the commercially available bipolar system, the developed prototype exhibited favorable results. The first benchmark testing of the developed bipolar prototype had promising results. However, further optimization of the applicator design and ablation protocol is needed to enlarge the achievable coagulation volume.

Safety and Efficacy of Endoscopic Radiofrequency Ablation in Non-Resectable Cholangiocarcinoma: A Case Series

Purpose: Surgery remains the only curative treatment for cholangiocarcinomas. Less than 20% of tumors are resectable at the time of diagnosis. Median survival without surgery is about 3 months. Multiple studies have shown that photodynamic therapy plus biliary stenting improve jaundice, prolong survival and enhance quality of life. Endoscopic radiofrequency ablation (RFA) followed by self-expandable metal stenting has been shown to be safe and effective in small trials. Methods: Three patients with non-resectable hilar cholangiocarcinoma underwent ERCP and focal ablation therapy using an endoscopic bipolar radiofrequency probe, ENDOHPB (EMcizion Ltd, UK) at either 7 or 10 W for 90 seconds. Following the RFA, two patients had a non-covered self-expandable metal stent placed and the third had two bilateral plastic stents. All had a repeat ERCP following treatment. Results: Mean age was 68; two were females. There were no procedure-related complications. There was a significant reduction in total bilirubin (Table 1). At a mean of 89 days after initial treatment patients had repeat ERCP. Because of severe stricture, patient #3 received 10 W rather than 7 W at initial treatment and bilateral plastic stents were placed after ablation, in anticipation of possible retreatment at follow-up. At the time of repeat ERCP, the cholangiogram showed marked improvement of the malignant stricture diameter from <3 mm to 6 mm. A 12 mm extraction balloon was pulled through the stricture with minimal resistance. Further ablation was therefore withheld. Plastic stents were then replaced by an uncovered metal stent.Table: No Caption available.Conclusion: Endobiliary RFA is safe, well tolerated and may prove to be an effective palliative intervention that helps maintain biliary patency in patients with unresectable cholangiocarcinoma. It is possible that 10 W for 90 seconds may be as safe but more effective compared 7 W treatments for the same duration. Large randomized studies are needed to evaluate the safety and efficacy of this intervention.

Mo1321 Safety of an Endoscopic Bipolar Radiofrequency Probe in the Management of Malignant Biliary Strictures: A Single Center Experience

Anatomy: Roux-Y hepaticojejunostomy: liver transplant (live donor, N 8; cadaveric, N 3), cholecystectomy injury revision (N 9), other (N 7). Technical Success: 94% in OA-ERCP vs. 73% in PTBD (p 0.27). Median months to resolve AS: 2 (0-9.5) in OA-ERCP vs. 7.5 (3-34) in PTBD (p 0.03). Number of subsequent procedures in OA-ERCP vs. PTBD group were 28 (median 1, range 0-10) vs. 104 (median 5, range 2-43)(p 0.002). OA-ERCP group had 42 (median 2, range 1-11) total interventions: dilation and/or cautery (N 22), dilation/ cautery/stent (N 3), subsequent PTBD (N 18). PTBD group had 111 (median 6, range 3-44) total interventions: int/ext drain placement(N 11), balloon dilation/ drain exchange(N 27), drain exchanges only (N 60), drain removals (N 11), and subsequent ERCP to traverse AS (N 2). Complications: OA-ERCP perforation (N 2; non-operative) and bleeding (N 1); PTC cholangitis(N 2), fistula (N 1), and bacteremia/sepsis (N 2)(19% vs. 46%, p 0.21). Median postprocedural hospitalization days in OA-ERCP 0 (0-1) vs. 2 (1-51)in PTBD (p 0.0002). Follow-up for median 11 months (1-42) in 25/27 (92.6%) patients. Clinical improvement in OA-ERCP vs. PTBD group was 86% vs 60%, respectively (p 0.19). None of the ERCP and 9.1% in PTBD group required surgical intervention (p 0.48). Conclusions: 1)OA-ERCP is associated with fewer procedures and post-procedural hospitalization days to achieve success rates similar to PTBD. 2) Clinical improvement is seen in the majority of patients with documented anastomotic strictures treated by OA-ERCP or PTBD. 3) In expert hands, OA-ERCP for treating AS may be the preferred choice due to the need for fewer procedures and a shorter duration of treatment to achieve AS resolution.

Efficacy of a cooled bipolar epicardial radiofrequency ablation probe for creating transmural myocardial lesions

Creation of transmural myocardial lesions with epicardial surgical devices to treat atrial fibrillation is difficult. A new cooled bipolar radiofrequency ablation probe was used to create transmural myocardial lesions under controlled conditions. The Coolrail (AtriCure, Inc, West Chester, Ohio) is a handheld probe with 2 parallel 30-mm long radiofrequency conductors. Conductors are cooled by water irrigation. Lesions were delivered to epicardial surface of isolated bovine myocardium sliced 3- to 8-mm thick, with blood flow beneath tissue at 0 or 0.4 m/s. Contact pressure between probe and tissue was either 450 g or 900 g. Tissue temperatures were measured. Tissue was sectioned every 5 mm along lesion long axis to determine lesion dimensions. For 80 experiments with 450-g contact pressure, epicardial lesion length was 31.3 mm (interquartile range, 30.1-32.8 mm); endocardial lesion length was 14.1 mm (interquartile range, 0.0-22.6 mm). Average lesion depth was 4.2 +/- 0.74 mm. Temperature at probe interface was 81 degrees C +/- 21 degrees C; that at blood pool interface was 53 degrees C +/- 12 degrees C. Lesions were always transmural when tissue thickness was 4.0 mm or less. Endocardial blood flow did not influence lesion depth. With 900-g contact pressure, increased depth was always transmural at 4.8-mm tissue thickness or less. This irrigated bipolar radiofrequency probe consistently produced transmural lesions in tissue 4 mm or thinner under controlled conditions in vitro. Lesion depth was increased by greater pressure on probe and not affected by blood flow. Endocardial lesions were smaller than epicardial dimensions.

Endoscopic Radiofrequency Ablation in Colorectal Cancer

There are a number of alternative approaches to palliate cancers of the rectosigmoid, which may not be well tolerated or produce effective symptom relief. Therefore, there is a continuing need to develop alternative techniques for palliation. This paper reports our initial assessment of a new bipolar radiofrequency probe (Endoblate). Twelve patients with rectosigmoid tumors were treated with Endoblate during transanal endoscopic microsurgery. In ten patients, this was followed by surgical resection and two patients were treated with Endoblate alone. This study was designed to assess the technical utility of the device, immediate complications, and histologic effect. There were no technical problems. In the patients who had resection of the tumor immediately after ablation (n = 10), there were no local complications evident at surgery. Histology of the resected specimens showed that, on average, 82 (range, 60-99) percent of the tumor mass was destroyed in the ablation zone. In the remaining two patients, Endoblate alone was used successfully to stop bleeding from the tumor. These preliminary results illustrate the evolution and endoscopic application of bipolar radiofrequency technology. Endoblate showed potential as a useful and safe tool for the palliation of lower gastrointestinal malignancy.

Habib Laparoscopic Bipolar Radiofrequency Device: A Novel Way of Creating an Avascular Resection Margin in Laparoscopic Partial Nephrectomy

Hemostasis during the laparoscopic partial nephrectomy (LPN) is a challenge. Usually, the renal hilum is clamped to minimize blood loss. However, prolonged ischemia leads to irreversible damage. Therefore, new technology is needed to minimize blood loss while performing LPN without hilar clamping. The Habib 4x Laparoscopic device (Angio Dynamics, Queensbury, NY) is a four-pronged bipolar radiofrequency probe that is proven to reduce blood loss in laparoscopic liver resections without hilar clamping. The aim of this pilot study was to evaluate this new technology in LPN. Three patients, with exophytic renal lesions (1.1-4 cm), underwent LPN without hilar clamping, using the Habib Laparoscopic device to create an avascular resection margin. Mean operative time was 150.3 minutes, mean estimated blood loss was 100 cc, and none of the patients required transfusions. There was no significant difference between the mean pre- and postoperative serum creatinine levels (P > 0.05). All 3 resected masses were renal-cell carcinomas. Intraoperative frozen sections demonstrated negative margins in all cases. However, in the second case, with a renal lesion of 4 cm, the permanent section analysis on margins was read as focally positive. There were no complications. On follow-up imaging of up to 12 months, there were no recurrences. The Habib 4x Laparoscopic device permits the resection of exophytic renal lesions without the need for hilar clamping. However, a cautery artifact can cause difficulty in interpreting the frozen-section analysis of resection margins. Therefore, its use should be restricted to lesions of less than 2 cm.

Partial Scapholunate Ligament Injuries Treated With Arthroscopic Debridement and Thermal Shrinkage

To present the early results of arthroscopic debridement and thermal shrinkage using radiofrequency probes for partial (Geissler grades I and II) scapholunate (SL) interosseous ligament injuries of the wrist. Sixteen patients with a mean age of 34 years (range, 18-54 y) presenting with chronic dorsoradial wrist pain unresponsive to initial conservative treatment for a mean period of 12 weeks were included in this study. No patient showed radiologic signs of static dissociation (SL interval, <3.5 mm; mean SL angle, 49 degrees ) before surgery. Diagnostic arthroscopy showed a partial SL tear in 14 patients and redundancy of the ligament in 2. Partial SL tears involved the membranous (proximal) and volar part of the ligament. All lesions were debrided and treated with thermal shrinkage using a bipolar radiofrequency probe. The mean follow-up period was 19 months (range, 9-34 mo). Fourteen patients experienced substantial pain relief whereas in 2 the pain remained unchanged. Eight patients were completely pain free. The mean flexion-extension arc was 142 degrees and the mean grip strength was 78% that of the unaffected side. No patient showed radiologic signs of arthritis or static or dynamic instability after surgery (SL interval remained <3.5 mm; mean SL angle, 53 degrees ). Based on the modified Mayo wrist score there were 8 excellent, 6 good, 1 fair, and 1 poor result. Partial SL ligament tears can be a source of radial-sided wrist pain. Scapholunate ligament debridement and thermal shrinkage effectively provided pain relief for most of the patients treated. Stability was maintained radiographically. No complications were noted from the use of radiofrequency probes. These reasonably favorable short-term results should be viewed cautiously. A longer follow-up study is necessary to determine the ultimate efficacy of this procedure.

The Role of Flexible Radiofrequency Energy Probes in Hip Arthroscopy

Summary: Radiofrequency energy has been a controversial practice in orthopaedic surgery for the past few decades. Both monopolar and bipolar radiofrequency probes have been used to shrink and ablate soft tissues. In hip arthroscopy, a new family of Eflex long, flexible monopolar probes has been designed to access all areas of the hip joint. Debridement of a torn acetabular labrum, thermal capsulorraphy, thermal chondroplasty, ablation of chondral flaps, synovectomy, and shrinkage of hypertrophic ligamentum teres are possible with the monopolar probes. Short-term to midterm clinical results of these procedures are promising; however, long-term outcomes studies are necessary to further evaluate the effectiveness of radiofrequency use in hip arthroscopy.

Thermal probes: What’s available in 2004

Thermal energy has had a wide array of applications over the course of modern medicine. In the past decade, orthopedic surgeons have used both monopolar and bipolar radiofrequency probes to deliver thermal energy for the treatment of various orthopedic maladies. There are several systems available to orthopedic surgeons, each with a manufacturer-suggested indication and use. This article provides a synopsis of each manufacturer's system in table format and briefly reviews the advantages and disadvantages of each.

Chondrocyte viability and metabolic activity after treatment of bovine articular cartilage with bipolar radiofrequency: An in vitro study

Purpose: Some controversy exists regarding the effects of radiofrequency (RF) probes on articular cartilage. To further elucidate these effects, we examined the chondrocyte viability and metabolic activity after treatment of fresh bovine articular cartilage with bipolar RF probes. Type of Study: In vitro assessment. Methods: Three fresh bovine knees served as a baseline control for chondrocyte viability, yielding 6 samples (1 from each medial femoral condyle and 1 from each lateral femoral condyle). After the baseline expected chondrocyte viability was determined, 3 additional bovine knees served as the experimental specimens for the study. Under sterile conditions, 2 different bipolar RF probes were used to treat the articular surface in a light contact mode, moving at a linear rate of 3 to 4 mm/s to provide tissue debridement. Full-thickness articular cartilage was then harvested from each of the treatment areas. Six samples per probe were then assessed for chondrocyte viability using fluorescent double-staining followed by confocal microscopy; 6 samples per probe were assessed for metabolic activity using an 35SO 4 incorporation assay; and 12 additional untreated samples were obtained to serve as controls for viability (n = 6) and metabolic activity (n = 6). Results: The depth of chondrocyte death (mean ± standard deviation) was 109.4 ± 22.1 μm after treatment with the ACD-50 probe, and was 172.3 ± 34.3 μm after treatment with the 2.5-mm/90° probe. The 35SO 4 uptake (mean ± standard deviation) was 2584 ± 1388 cpm/mg dry cartilage for the ACD-50 probe and 1995 ± 852 cpm/mg of dry cartilage for the 2.5-mm/90° probe. The 35SO 4 uptake for the control was 2647 ± 1380 cpm/mg dry cartilage. Conclusions: The 2 probes tested created a well-controlled debridement with smooth edges and a defined margin of chondrocyte death that extended approximately 100 to 200 μm deep to the treatment area. There does not appear to be a significant effect on the metabolic activity of the chondrocytes adjacent to the treatment zone, but with the small sample size we lacked sufficient statistical power to definitively determine these effects. Clinical Relevance: The 2 bipolar radiofrequency probes tested created a well-controlled debridement in normal articular cartilage with smooth edges and a defined margin of chondrocyte death that extended approximately 100 to 200 μm into the treatment area.

Ultrasound-guided radiofrequency submucosal tongue-base excision for sleep apnoea: a preliminary report.

Surgery for sleep apnoea is challenging, particularly in patients with macroglossia. This has led us to develop a new procedure for reduction of the tongue base with low morbidity. Two types of bipolar radiofrequency probe were used via a percutaneous approach under an aseptic technique and general anaesthesia on 15 consecutive patients with retropalatal and retrolingual collapse. The lingual neurovascular bundles and probe were simultaneously identified with intraoperative real-time ultrasound to prevent neurovascular damage, and five patients had additional tongue mucosal suture advancement. All patients had previous or concurrent palatal surgery. The increase in cephalometric (retrolingual) posterior airspace (PAS) was 4 mm with a Spinevac wand and mucosal suture advancement, which is comparable to current-staged monopolar radiofrequency protocols requiring treatment for up to 6 months. Overall, 40% polysomnographic success was achieved, but it was 80% when additional phase 1 procedures were used. Morbidity was minimal with careful adherence to the perioperative care protocol.